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1. Field of the Invention
The present invention relates to a projection TV set apparatus, more particularly to a projection lens assembly of a projection TV set apparatus which can prevent a reduction in focusing performance of projection lenses caused by a rise in temperature during operation.
2. Description of the Related Art
Rear projection type projection television set apparatuses have larger screens than regular television sets and enable large-sized displays. In such rear projection type projection TV set apparatuses, projection cathode-ray tubes (CRT) produce red (R), green (G), and blue (B) images which they project to a screen. The viewer sees the picture on the opposite side of the screen from the side where the images are projected.
In front of the projection CRTs, lens assemblies are provided which focus the images produced from the projection CRTs to form the picture on the screen. Each lens assembly consists of a mirror sleeve and at least one lens fitted inside the mirror sleeve. In general, there are a combination of plastic lenses and glass lenses in the mirror sleeve of the lens assembly. The mirror sleeve is typically comprised of a metal or plastic.
The coefficients of thermal expansion of plastics, metals, and glass fall into the following relationship: Ep>Em>Eg, where Ep is the coefficient of plastics, Em is the coefficient of metals, and Eg is the coefficient of glass.
The projection CRTs become high in temperature during operation and therefore usually are cooled at the front.
The fronts of the projection CRTs can become as high as 90.degree. C. in temperature, however. Accordingly, the lens assemblies also become heated and problems arise as a result of the differences in the coefficients of thermal expansion of the components of the assemblies.
For example, if the mirror sleeve is made of a metal, a plastic lens will be subjected to pressure from the mirror sleeve due to its having a larger coefficient of thermal expansion than the mirror sleeve. The lens face will deform in shape and the focusing performance will therefore drop. A glass lens, further, has a smaller coefficient of thermal expansion than the mirror sleeve and therefore a gap will be caused at the fitting portion between the mirror sleeve and the glass lens. As a result, the plastic lens and glass lens will become off-centered from each other. In this case as well, the focusing performance will drop.
Note that even if the mirror sleeve is made of plastic, a similar problem will arise with the glass lens.
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Typically, a computer system is provided with a preconfigured operating system (OS), which is then customized or configured for a specific user. The configuration of the OS generally involves assigning configuration parameters, such as a computer name, host name, host IP address, host gateway, host subnet, etc., to the computer system, and can be performed by a reseller or dealer, on site via an automated process, or on site by the specific user.
If performed by the reseller or dealer, the computer system's final destination must be known prior to the configuration process. For large computer system rollouts, the dealer will typically store a large quantity of computer systems and customize them as they are deployed to various destinations. If these computer systems are not shipped immediately to their respective destinations, but warehoused instead, the dealer must be able to identify a particular computer system, e.g., by serial number, for a particular destination at shipping time. Physically identifying the particular computer system among thousands of warehoused computer systems can be a daunting task. If the computer system is shipped to an incorrect destination, the configuration parameters embedded in the computer system's OS will not correspond to the destination, and the computer system will not operate correctly.
At the user's site, the system configuration can be deployed via an automated process, e.g., by transmitting the customized OS over a network link. Nevertheless, this process requires network bandwidth and if the customized OS is large, e.g., 10–15 gigabytes, the transmission can take hours. Alternatively, the OS can be customized manually by the user, which introduces data entry errors. Nevertheless, for complex program images, it may be necessary to incur the expense of hiring a skilled configuration expert to handle the customization.
Accordingly, there exists a need for a method and system for customizing a computer system. The method and system should allow the computer system to be configured quickly at the dealer or on site, and should have little or no impact on network bandwidth. The present invention addresses such a need.
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Before the advent of machine-based language translations (hereafter, “machine translations”), translation between two languages was only possible via intervention or interpretation by a person educated in both languages. In contrast, typical machine translators generally operate based on statistical/stochastic analysis of context and grammar, usually without need of human intervention/interpretation.
Typical machine translation is often error prone, particularly where the text to be translated has a minimal context. Text having minimal context is often found in conversations, which employ brief sentence construction. Additionally, machine translations often have trouble with abbreviations, acronyms, diminutives, colloquial words/phrases, proper nouns, and common nouns, which are also commonly found in conversational text.
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A signal port of a computing component can have a capacitance that degrades a signal (e.g., a digital signal, an analog signal) communicated via the signal port. The signal port can include, for example, an input/output (I/O) port. For example, an input port of a computing component can have an input capacitance that degrades a relatively high speed signal (e.g., a signal greater than 1 Gigahertz (GHz) communicated via the input port. The capacitance can be due, at least in part, to a size (e.g., a surface area) of a metal contact (e.g., a bump metal) associated with the input port. Thus, a need exists for systems, methods, and apparatus to address the shortfalls of present technology and to provide other new and innovative features to reduce input capacitance.
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Integrated circuits having a logic circuit and reception means are known and are now used to an increasing extent in the form of so-called RFID (Radio Frequency Identification) transponders for identification purposes in the service sector or in the fields of logistics, trade or manufacturing. However, also systems utilizing lower frequencies (below 800 MHz) are used.
A transponder normally includes a semiconductor chip for storing data, which may be programmable and rewritable, and an antenna being adapted for the relevant frequency band (e.g. US-UHF: 902-928 MHz, Europe: 863-868 MHz, ISM: 2.4-2.483 GHz). A common RFID system comprises RFID transponders, reading devices having a system antenna providing a bi-directional (data) communication between the transponders and the reading devices.
In general, there is a distinction between active transponders and passive transponders. Active transponders are provided with an energy supply of their own while passive transponders receive the power necessary for operation from the high frequency signals, which are also used for communication.
US 2004/0131897 A1 discloses an RF transponder which combines the features of active and passive transponders. The transponder of US 2004/0131897 A1 comprises an electronic circuit, an RF antenna and a battery, wherein the electronic circuit is connected to the battery and thus receives energy from the battery upon reception of RF energy by the antenna which closes a switch between the electronic circuit and the battery and enables an electric connection between the battery and the electronic circuit.
The known transponder systems are limited in their purpose since the transponders only provide a functionality of identification and data communication between the transponders and the reading devices.
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High resolution liquid crystal displays (LCD), used in conjunction with overhead projectors, have become popular devices with which to project text, graphics and images from personal computers to a large audience. Most LCD projection panels are designed to operate with overhead projectors that are characterized as "transmissive," that is to say, light rays emanating from a projector lamp in the base of the projector, under the LCD, pass through the LCD once before being projected onto a screen. In reflective overhead projectors, however, the lamp is in the "head" of the projector, over the LCD, and the light rays pass down through the LCD and are then reflected back up through the LCD before being projected onto a screen. Reflective overhead projectors are advantageous because they can be condensed into a smaller volume, and thus can be made highly portable. For example, some reflective overhead projectors can fit into a briefcase-like carrying case. When LCD projection panels that have been designed for use with transmissive overhead projectors are used with reflective overhead projectors, the result is usually a very dark, double image.
One reflective overhead projection system includes an LCD having polarizers on both sides. This sandwich is separated by an air gap from a fresnel lens and a reflector. This system has three drawbacks. First, the projected image is a double image because the plane of the image is separated quite some distance from the plane of the reflection. Second, the system suffers from low light transmission--less than 10% for a super twisted nematic LCD. Third, the projected image suffers from glare from the specular reflection of the projector light from the top of the polarizer surface, which obscures the desired image.
Another reflective LCD overhead projection system is shown in Japanese Kokai 2-193,183 published on Jul. 30, 1990. That system uses an LCD pressed against a polarizing plate separated by an air gap from a minor fresnel lens. Light rays from a projector lamp first pass through the LCD, the polarizing plate, and then the air gap. The light rays are then reflected by the minor fresnel lens, and pass back through the polarizing plate and exit the LCD. While this system eliminates the double image problem, the double pass of the light rays through the polarizing plate and the absorption attendant each pass limits the overall brightness achievable with this system, as does absorption by the metallized surface of the fresnel lens.
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1. Field of the Invention
The present invention relates to a magnetic thin-film memory device, particularly to a random access memory provided with a memory cell having a magnetic tunneling junction (MTJ).
2. Description of the Background Art
An MRAM (Magnetic Random Access Memory) device is watched as a memory device capable of storing data in a nonvolatile manner at a low power consumption. The MRAM device is a memory device for storing data in a nonvolatile manner by using a plurality of magnetic thin films formed on a semiconductor integrated circuit and capable of random-accessing each magnetic thin film.
Particularly, it is recently announced that performances of an MRAM device is remarkably advanced by using a magnetic thin film utilizing a magnetic tunnel junction (MTJ) as a memory cell. An MRAM device provided with a memory cell having a magnetic tunnel junction is disclosed in technical documents, such as xe2x80x9cA 10 ns Read and Write Non-Volatile Memory Array Using a Magnetic Tunnel Junction and FET Switch in each Cellxe2x80x9d, ISSCC Digest of Technical Papers, TA7.2, February 2000 and xe2x80x9cNonvolatile RAM based on Magnetic Tunnel Junction Elementsxe2x80x9d, ISSCC Digest of Technical Papers, TA7.3, February 2000.
FIG. 42 is a schematic diagram showing a configuration of a memory cell having a magnetic tunnel junction, hereafter also merely referred to as MTJ memory cell).
Referring to FIG. 42, an MTJ memory cell is provided with a magnetic tunnel junction portion MTJ whose resistance values are changed in accordance with the level of storage data and an access transistor ATR. The access transistor ATR is constituted of a field-effect transistor and connected between the magnetic tunnel junction portion MTJ and a ground voltage Vss.
A write word line WWL for designating data write, a read word line RWL for designating data read, and a bit line BL serving as a data line for transferring an electrical signal corresponding to the level of storage data under data read and data write are arranged on an MTJ memory cell.
FIG. 43 is a conceptual diagram for explaining the operation for reading data from an MTJ memory.
Referring to FIG. 43, a magnetic tunnel junction portion MTJ has a magnetic layer having a constant-directional fixed magnetic field (hereafter also simply referred to as a fixed magnetic layer) FL and a magnetic layer having a free magnetic field (hereafter also simply referred to as a free magnetic layer) VL. A tunnel barrier TB constituted of an insulating film is set between the fixed magnetic layer FL and the free magnetic layer VL. A magnetic field having a direction same as or different from the direction of the fixed magnetic layer FL is written in the free magnetic layer VL in a nonvolatile manner in accordance with the level of storage data.
Under data read, the access transistor ATR is turned on in accordance with activation of the read word line RWL. Thereby, a sense current Is supplied from a not-illustrated control circuit is circulated as a constant current through a current path from the bit line BL to the magnetic tunnel junction portion MTJ, access transistor ATR, and ground voltage Vss.
Resistance values of the magnetic tunnel junction portion MTJ are changed in accordance with the magnetic-field-directional relative relation between the fixed magnetic layer FL and the free magnetic layer VL. Specifically, when the magnetic-field direction of the fixed magnetic layer FL is the same as a magnetic-field direction written in the free magnetic layer VL, the resistance value of the magnetic tunnel junction portion MTJ decreases compared to the case in which the both magnetic-field directions are different from each other.
Therefore, under data read, a voltage drop caused at the magnetic tunnel junction portion MTJ by the sense current Is differs in accordance with a magnetic direction stored in the free magnetic layer VL. Thereby, by starting the supply of the sense current Is after once precharging the bit line BL to a high voltage, it is possible to read the level of the data stored in an MTJ memory cell by monitoring a change of voltage levels of the bit line BL.
FIG. 44 is a conceptual diagram for explaining the operation for writing data in an MTJ memory cell.
Referring to FIG. 44, under data write, a read word line RWL is inactivated and an access transistor ATR is turned off. Under the above state, a data write current for writing a magnetic field in a free magnetic layer VL is supplied to a write word line WWL and a bit line BL. The magnetic-field direction of the free magnetic layer VL is decided by a combination of directions of data write currents flowing through the write word line WWL and bit line BL.
FIG. 45 is a conceptual diagram for explaining the relation between directions of a data write current and a magnetic field under data write.
Referring to FIG. 45, a magnetic field Hx shown by a horizontal axis shows the direction of a magnetic field H (WWL) generated by a data write current flowing through a write word line WWL. A magnetic field Hy shown by a vertical axis shows the direction of a magnetic field H (BL) generated by a data write current flowing through a bit line BL.
A magnetic-field direction stored in a free magnetic layer VL is newly written only when the sum of the magnetic fields H (WWL) and H (BL) reaches the region outside of the asteroid curve shown in FIG. 25. That is, when a magnetic field corresponding to the region inside of the asteroid curve is applied, a magnetic-field direction to be stored in the free magnetic layer VL is not updated.
Therefore, to update the data stored in a magnetic tunnel junction portion MTJ through the write operation, it is necessary to supply current to both the write word line WWL and bit line BL. A magnetic-field direction once stored in the magnetic tunnel junction portion MTJ, that is, storage data is held in a nonvolatile manner until new data is written.
Also under the data read operation, the sense current Is flows through the bit line BL. However, because the sense current Is is set so as to be smaller than the above data write current by 1 digit or 2 digits, the data stored in an MTJ memory cell is not easily erroneously rewritten due to the sense current Is under data read.
The above technical documents disclose an art for integrating the above MTJ memory cell on a semiconductor substrate to constitute an MRAM device serving as a random access memory.
FIG. 46 is a conceptual diagram showing MTJ memory cells integrated and arranged in a matrix.
Referring to FIG. 46, it is possible to realize a highly-integrated MRAM device by arranging the MTJ memory cells on a semiconductor substrate as a row. FIG. 46 shows a case in which the MTJ memory cells are arranged in n rowsxc3x97m columns (n, m: natural number).
As already described, it is necessary to arrange bit line BL, write word line WWL, and read word line RWL on each MTJ memory cell. Therefore, it is necessary to arrange n write word lines WWL1 to WWLn, n read word lines RWL1 to RWLn, and m bit lines BL1 to BLn on nxc3x97m MTJ memory cells arranged in a matrix.
Thus, it is general to set an independent word line to an MTJ memory cell correspondingly to the read operation and write operation respectively.
FIG. 47 is a structural drawing of an MTJ memory cell formed on a semiconductor substrate.
Referring to FIG. 47, an access transistor ATR is constituted in a p-type region PAR on a semiconductor substrate SUB. The access transistor ATR has source/drain regions 110 and 120 and a gate 130. The source/drain region 110 is connected with a ground voltage Vss through a metallic wiring formed on a first metallic-wiling layer M1. A metallic wiring formed on a second metallic-wiring layer M2 is used for a write word line WWL. Moreover, a bit line BL is provided for a third metallic-wiring layer M3.
A magnetic tunnel junction portion MTJ is set between the second metallic-wiring layer M2 on which a write word line WWL will be formed and the third metallic-wiring layer M3 on which a bit line BL will be formed. The source/drain region 120 of the access transistor ATR is electrically connected with the magnetic tunnel junction portion MTJ through a metallic film 150 formed on a contact hole, the first and second metallic-wiring layers M1 and M2, and a barrier metal 140. The barrier metal 140 serves as a cushion set to electrically connect a magnetic tunnel junction portion MTJ with a metallic wiring.
As already described, in the case of an MTJ memory cell, a read word line RWL is formed as a wiring independent of a write word line WWL. Moreover, it is necessary to supply a data write current for generating a magnetic field having an intensity equal to or larger than a predetermined value under data write to the write word line WWL and bit line BL.
On the other hand, the read word line RWL is formed to control the gate voltage of the access transistor ATR but it is unnecessary to positively supply current to the line RWL. Therefore, to improve an integration degree, a read word line RWL has been constituted of a polysilicon layer or polycide structure on the same wiring layer as the gate 130 without newly forming an independent metallic wiring layer.
By using the above configuration, it is possible to control the number of metallic wiring layers and integrate and arrange MTJ cells on a semiconductor substrate. However, because a read word line RWL is constituted of a polysilicon layer or the like, it has a comparatively large resistance value. Thereby, problems occur that a signal propagation delay increases in the read word line RWL under data read and acceleration of data read operation is impeded.
Moreover, a configuration is known which uses a PN-junction diode as an access device instead of an access transistor as the structure of an MTJ memory cell which can be further integrated compared with the MTJ memory cell shown in FIG. 42.
FIG. 48 is a schematic illustration showing the configuration of an MTJ memory cell using a diode. Referring to FIG. 48, the MTJ memory cell MCDD using the diode is provided with a magnetic tunnel junction portion MTJ and an access diode DM. The access diode DM is connected between the magnetic tunnel junction portion MTJ and a word line WL by assuming the direction from the junction MTJ toward the word line WL as the forward direction. A bit line BL is set so as to intersect with the word line WL and connected with the magnetic tunnel junction portion MTJ.
Data is written in the MTJ memory cell MCDD by supplying a data-write current to the word line WL and bit line BL. The direction of the data-write current is set in accordance with the level of write data similarly to the case of a memory using an access transistor.
A word line WL corresponding to a selected memory cell is set to a low-voltage (e.g. ground voltage Vss) state when data is read. In this case, by precharging a bit line BL to a high-voltage (e.g. power-supply voltage Vcc) state, it is possible to supply a sense current Is to the magnetic tunnel junction portion MTJ because the access diode DM is turned on. However, because a word line WL corresponding to an unselected memory cell is set to a high-voltage state, a corresponding access diode DM is kept turned off and the sense current Is does not circulate.
Thus, also in the case of an MJT memory cell using an access diode, it is possible to execute data read and data write.
FIG. 49 is a structural drawing when setting the MTJ memory cell shown in FIG. 48 on a semiconductor substrate.
Referring to FIG. 49, an access diode DM is formed with an N-type region NWL on a main semiconductor substrate SUB and a P-type region PAR formed on the N-type region NWL. FIG. 49 shows an N well as a case of forming an N-type region.
The N-type region NWL corresponding to the cathode of an access diode DM is connected with a word line WL set to a metallic wiring layer M1. The P-type region PAR corresponding to the anode of the access diode DM is electrically connected with a magnetic tunnel junction portion MTJ through a barrier metal 140 and a metallic film 150. A bit line BL is set to a metallic-wiring layer M2 and connected with the magnetic tunnel junction portion MTJ. Thus, by using an access diode instead of an access transistor, it is possible to constitute an MTJ memory cell advantageous for high integration.
However, because a data-write current circulates through the word line WL and bit line BL under data write, a voltage drop due to the data-write current occurs in these wirings, respectively. Because the voltage drop occurs, the PN junction of the access diode DM may be turned on at a part of the MTJ memory cell in which data will not be written depending on a voltage distribution on the word line WL and bit line BL. As a result, erroneous data write may be executed because an unexpected current circulates through the MTJ memory cell.
Thus, a conventional MTJ memory cell MCDD using an access diode is advantageous for high integration but it has a problem that the data write operation becomes unstable.
The present invention is made to solve the above problem and its object is to accelerate and stabilize the data read operation of an MRAM device having an MTJ memory cell.
It is an object of the present invention to accelerate the data read operation of an MRAM having an MTJ memory cell.
In short, the present invention is regarding to a magnetic thin-film memory device comprising a memory array, a plurality of write word lines, a plurality of read word lines, a word-line-current control circuit, a plurality of data lines, and a read/write control circuit.
The memory array has a plurality of magnetic memory cells arranged in a matrix. Each of the magnetic memory cells includes a storing section whose resistance values are changed in accordance with the level of storage data to be written when a data-write magnetic field to be applied by first and second data-write currents is larger than a predetermined magnetic field and a memory-cell selection gate connected in series with the storing section. The magnetic memory cells are provided correspondingly to rows of a plurality of write-word-line magnetic memory cells and respectively constituted of a wiring having a first resistivity. Each of a plurality of write word lines is selectively activated in accordance with a row selection result under data write and data read. The word-line-current control circuit forms and cuts off the current path of the first data write current for at least activated one of the write word lines under data write and data read. A plurality of the data lines are provided corresponding to columns of the magnetic memory cells. Upon data writing and data reading, the read/write control circuit respectively supplies the second data write current and data read current to at least that one of the data lines, which corresponds to the selected column, under data write and data read. A plurality of the read word lines are provided corresponding to rows of the magnetic memory cells and are respectively constituted of a wiring having a second resistivity higher than the first resistivity. Each read word line is selectively activated together with corresponding one of the write word lines under data read and at least activated one of the read word lines turns ON a corresponding memory-cell selection gate.
Therefore, main advantage of the present invention lies in the fact that it is possible to reduce the signal propagation delay of a read word line and accelerate the data read operation by controlling a read word line having a large resistance value together with a write word line having a small resistance value.
Moreover, because row selection under data read is executed in accordance with the hierarchical control of a main read word line having a small resistance value and a read word line divided for each region, it is possible to independently control the read word line and write word line and accelerate the data read operation.
According to another aspect of the present invention, a magnetic thin-film memory device comprises a memory array, a plurality of write word lines, a plurality of data lines, a read/write control circuit, a plurality of main read word lines, a plurality of read word lines, and a plurality of read-word-line drivers. The memory array has a plurality of magnetic memory cells arranged in a matrix. The memory array is divided into a plurality of regions along the column direction. Each of the magnetic memory cells includes a storing section whose resistance values are changed in accordance with the level of storage data written by a data-write magnetic field generated by first and second data-write currents and a memory-cell selection gate connected in series with the storing section. A plurality of write word lines correspond to rows of magnetic memory cells in common to a plurality of regions and are respectively constituted of a wiring having a first resistivity. The write word lines are selectively activated in accordance with a row selection result in order to supply a first data-write current under data write. A plurality of the data lines are provided corresponding to columns of the magnetic memory cells. Upon data writing and data reading, the read/write control circuit respectively supplies the second data-write current and data read current to at least that one of the data lines, which corresponds to the selected column, under data write and data read, respectively. A plurality of the main read word lines are provided in common to a plurality of regions and respectively constituted of a wiring having a second resistivity. The read word lines correspond to rows of the magnetic memory cells each of the plurality of regions and are respectively constituted of a wiring having a third resistivity higher than the first and second resistivities. Each of the read word lines corresponds to any one of the main read word lines. The read-word-line drivers correspond to the read word lines. Each of the read-word-line drivers activates corresponding one of the read word lines in accordance with the activation of corresponding one of the main read word lines. At least activated one of the read word lines turns ON a corresponding memory-cell selection gate.
Therefore, because a word line having a small resistance value can be used for both data read and data write, it is possible to reduce the number of wirings and accelerate the data read operation.
Still another aspect of the present invention is a magnetic thin-film memory device comprising a memory array, a plurality of data lines, a read/write control circuit, a plurality of word lines, and a word-line-current control circuit.
The memory array has a plurality of magnetic memory cells arranged in a matrix. Each of the magnetic memory cells includes a storing section whose resistance values are changed in accordance with the level of storage data written by a data-write magnetic field according to first and second data-write currents and an access transistor connected in series with the storing section. The data lines correspond to columns of the magnetic memory cells. Upon data writing and data reading, the read/write control circuit respectively supplies first data-write current and data-read current to at least that one of the data lines, which corresponds to the selected column under data write and data read. The word lines correspond to rows of the magnetic memory cells and are respectively activated in accordance with a row selection result. At least activated one of the word lines turns ON a corresponding access transistor. The word-line-current circuit forms a current path of the second data-write current on at least activated one of the word lines. The word-line-current control circuit cuts off the current path of each of the word lines under data read.
Therefore, because a word line can be used for both data read and data write, it is possible to reduce the number of wirings and accelerate the data read operation.
According to another aspect of the present invention, a magnetic thin-film memory device includes a memory array, a plurality of write word lines, a word-line driving circuit, a plurality of data lines, a read/write control circuit, and a plurality of read word lines. The memory array has a plurality of magnetic memory cells arranged in a matrix. Each of the magnetic memory cells includes a storing section in which resistance values are changed in accordance with the level of storage data written when a data-write magnetic field applied by first and second data-write currents is larger than a predetermined magnetic field and a memory-cell selection gate for passing a data read current through the storage section during data read. The write word lines are provided respectively corresponding to rows of magnetic memory cells to constitute a write-word-line pair every two lines. Two write word lines constituting each word-line pair are electrically connected at least at one ends of the memory array. The word-line driving circuit is provided at the other end of the memory array to set two write word lines constituting a write-word-line pair corresponding to a selected row to first and second voltages one each in order to supply a first data-write current under data write. The data lines are set respectively so as to correspond to columns of magnetic memory cells. The read/write control circuit respectively supplies a second data-write current and a second data read current to at least that one of the data lines, which corresponds to the selected column, under data write and data read. The read word lines are respectively set so as to correspond to rows of magnetic memory cells and each of the lines turns ON a corresponding memory-cell-selection gage in accordance with a row selection result under data read.
Therefore, a data-write current is circulated by forming a reciprocating-current path by a write-word-line pair corresponding to a selected memory cell row. As a result, it is possible to execute row selection by selecting write-word-line pair half the number of write word lines. Therefore, it is possible to simplify the configuration of the word-line driving circuit. Moreover, because magnetic fields generated around a magnetic memory cell by data-write currents circulating through two write word lines constituting one same write-word-line pair corresponding to a selected memory cell row work so as to be cancelled each other, it is possible to reduce magnetic-field noises around the memory cell.
Still another aspect of the present invention, a magnetic thin-film memory device is including a memory array, a plurality of write word lines, a word-line-current control circuit, a word-line driving circuit, a plurality of data lines, a read/write control circuit, and a plurality of read word lines. The memory array has a plurality of magnetic memory cells arranged in a matrix. Each of the magnetic memory cells includes a storage section in which resistance values are changed in accordance with the level of storage data written when a data-write magnetic field applied by first and second data-write currents is larger than a predetermined magnetic field and a memory-cell selection gate for passing a data read current through the storage section under data read. Each magnetic memory cell is set correspondingly to a row of a plurality of write-word magnetic memory cells and shared by every two rows. The word-line-current control circuit forms and cuts off the path of the first data-write current to at least activated one of the write word lines under data write and data read. The word-line driving circuit activates a write word line corresponding to a selected row under both data read and data write, respectively. The data lines are set respectively so as to correspond to a column of magnetic memory cells. The read/write control circuit respectively supplies a second data-write current and a second data read current to at least that one of data lines which corresponds to the selected column under data read and data write. The read word lines are set respectively so as to correspond to a row of magnetic memory cells and each of the lines turns ON the corresponding memory-cell selection gate in accordance with a row selection result. Each read word line is selectively activated together with a corresponding write word line in accordance with a row selection result under data read.
Therefore, it is possible to secure a sectional area by securing the wiring pitch of the write word line WWL with sharing a write word line WWL. As a result, it is possible to control occurrence of electromigration and improve the operational reliability by reducing the current density of a write word line. Furthermore it is possible to accelerate the data read operation by reducing the signal propagation delay of a read word line.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
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The invention relates to a light grid for the detection of objects in a monitoring region having a transmitter unit comprising a plurality of light transmitters and a receiver unit comprising a plurality of light receivers in which respective pairs of light transmitters and light receivers associated with one another and bounding the monitoring region can be activated in succession in time in dependence on a synchronization signal transmitted between the transmitter unit and the receiver unit. The invention further relates to a method for the operation of such a light grid.
Light grids of this kind are used, for example, in highly automated production systems in which work pieces are automatically fed, machined and taken away again. These production systems are provided as a rule with fully automatic machining centers (e.g. robot devices) and transport devices. Since the feeding, machining and taking away regions at the same time represent possible danger regions, for example for operators, it is necessary with such systems to provide protection against non-permitted intrusion. Such protection can be achieved by means of light grids of the kind initially mentioned.
Since synchronous operation between the light transmitter and the light receiver is required for the operation of a light grid, it is usual in light grids in accordance with the state of the art to emit a synchronization signal coupled to a first monitoring signal, for example from the first light transmitter of the transmitter unit, in the direction of the first light receiver of the receiver unit in order to activate it. Subsequent to this synchronization procedure, all further pairs of light transmitters and light receivers associated with one another are then activated in succession according to a given timetable in order to thus realize the desired monitoring function. The disadvantage of this procedure is that whenever the synchronization signal is interrupted, for example by a work piece moving into the monitoring region, no synchronization can take place between the transmitter unit and the receiver unit and thus the operation of the light grid is interrupted. It is therefore customary practice to deactivate light grids for, for example, the time of the moving in and out of an object, whereby disadvantageously no protection against non-permitted intrusion exists in this time.
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In water desalinisation equipment using the principle of evaporation to remove salt and other minerals, it is customary to have an evaporator in which conditions are so adjusted that steam or vapour is formed which is then taken to a heat exchanger whereby the steam is condensed to provide the distilled water.
In such systems it is customary to feed brine into the evaporator from a constant level supply and to then so adjust conditions between the evaporator and the heat exchanger that the necessary transfer of the vapour will take place, such a method including for instance the use of a pump which moves the vapour to the heat exchanger.
Among these systems embodying this general principle are those in which refrigeration equipment is used to evaporate water at ambient or raised temperature, the evaporator of the refrigeration system being connected to the condenser through pump means, the condenser ensuring that the steam or vapour is brought back to its liquid phase to form the distillate.
It has also been proposed by us in such a system to use what we term a "blow-down" pump which draws off excess water from the evaporator when the salinity of that water reaches a certain value, this then ensuring that the products left behind in the evaporation process are washed out of the system so that the process can be a continuous one.
One of the problems encountered in apparatus of this type is to be able to maintain correct movement of the vapour or steam, and also to maintain the necessary pressure differentials in the system because obviously in the evaporator a lowered pressure must exist to ensure ready boiling of the liquid while in the condenser it may be preferable to have a higher pressure to ensure ready condensation of the vapour.
As the pumps must be of a nature such that they can draw the necessary vacuum in the condenser, problems exist in achieving good seals in such pumps, and according to one of our earlier Patent Applications a system of water seals was used so that relatively inexpensive gear pumps could be used for the drawing of the vacuum.
The object of the present invention is to provide an improved pumping system for use in evaporative distillation plants of the general type outlined whereby the necessary seals can be readily obtained and in which in the ultimate form it is unnecessary to use expensive condensers and evaporators.
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Embodiments of the present invention are generally directed to file synchronization, and more particularly, to real-time synchronization of multiple files.
Generally, as more and more people work remotely, multiple parties need to refer to a common document for visual reference, for example, during a remote meeting or teleconference. Synchronizing the shared information between a presenter and participants becomes a common issue due to frequent updates to the contents of shared material or presentation materials (e.g., changing slides based on the presenter's view). For example, as a presenter progresses through slides or photos from a master terminal, each remote user must update their display accordingly and without direct visual reference to the master terminal.
In some cases, the participants of a remote meeting have their own copies of documents and the presenter has its own copy. It follows that with multiple copies of a single file, there may be discrepancies and/or it may become difficult to synchronize displayed information for each file copy. In other cases, the files used by participants are in different formats, but the display of the files needs to be synchronized. For example, syncing the display of a slide and associated audio content.
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Phenomenon of surface plasmon of metals has been widely used nowadays. Researchers find if a special metallic nanostructure is disposed on an interface between dielectric materials, it can generate an interaction between electromagnetic waves and the metallic nanostructure and result in many novel optical characteristic. The optical characteristic can be controlled via modifying the structure, size, relative position, periodical arrangement of the metallic nanostructures and types of the dielectric materials around the metallic nanostructures. Therefore, special nanostructures can be fabricated via controlling the parameters of the metallic nanostructures to generate desired surface plasmon resonances, which can be applied in many photoelectronic products, photoelectronic measurements and academic researches. In the current stage, the surface plasmon waves have been applied to many fields, such as Raman spectrom measurement, thin film thickness measurement, optics constant measurement, solar cells, optical sensors, and biological sensors.
Particularly, surface plasma can also be applied to increasing the light luminous efficiency of light emitting diode (LED). It was found that the surface plasma effect produced at the interface between the metallic nanostructure and the dielectric material can magnify the action of the electromagnetic field and generate near-field effect, thus enhancing the luminous efficiency of the nearby quantum dots or quantum wells and promoting the light luminous efficiency and brightness of solid-state LED.
Besides, light generated by recombination of electrons and holes in quantum wells is omnidirectional. Thus, only the light emitted towards a direction away from the substrate is applicable unless there is a light guiding mechanism, and the light emitted towards the direction needs to penetrate heterogeneous layers to reach the air. During penetration, optical reaction produced inside the heterogeneous layers will cause a portion of the emitted light to be constrained inside the heterogeneous layers and converted into another form of energy. As a result, the emitted light is decreased layer by layer. If a surface plasmon structure is disposed on the interface between the heterogeneous layer and the air, the energy lost in the optical reaction can be easily absorbed and coupled. The surface plasmon structure can convert the momentum loss into photons and radiate the photons. The above-mentioned phenomenon is the so-called Localized Surface Plasmon Resonance (LSPR).
A Taiwan patent No. I395348 discloses a “Semiconductor Light Emitting Element”, which is an LED element having high light-emitting efficiency by using the technique of surface Plasmon. It discloses a metallic surface and a plurality of through-holes which are formed on the metallic surface and have a specified shape. Those through-holes are arranged in specified positions to form a metallic surface grating, which can excite generation of the surface plasma waves for achieving better light emitting efficiency.
Moreover, A Taiwan patent No. I363440 discloses “Light Emitting Element, Light Emitting Diode and Method for Fabricating the Same”. Briefly, an LED structure of this patent includes a surface plasmon coupling unit to generate surface plasmon waves and increase the luminous efficiency of LED.
The abovementioned conventional methods for fabricating specific nanostructures to generate surface plasma waves normally use technologies such as vapor deposition, sputtering coating, photo masks, pattern development and etching to form a plurality of metallic nanostructure regions, and then perform annealing process to transform the metallic nanostructure regions into spherical structures by the effect of surface tension. Therefore, the abovementioned conventional methods are complicated and expensive.
Besides, surface plasmon may be categorized into Surface Plasmon Polaritons (SPP) and Localized Surface Plasmon (LSP). The SSP exists on the interface between a metallic material and a dielectric material, wherein the LSP exists in a metallic nanostructure by a resonance mode. So far, the conventional technology is unable to apply the SSP and the LSP techniques in an identical systematic structure. The conventional technology is either unable to provide a cheaper process to generate the SSP and the LSP simultaneously.
In the conventional technology, surface plasmon can only exist in an interface between a metallic material and a dielectric material, which considerably constrains the design of surface plasmon generation structures. Therefore, the conventional technology still has room to improve.
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1. Field of the Invention
The inventions relate generally to medical connectors. In particular, certain embodiments of the inventions relate to medical connectors for use with standard luer connectors. In certain embodiments, the medical connectors generate a positive flow of fluid away from a medical implement as the implement is removed from an end or port of the medical connector.
2. Description of the Related Art
Medical connectors are often used to selectively open and close fluid pathways for use in treating patients. In some connectors, a small amount of retrograde fluid flow occurs when the connector is closed, drawing fluid away from the patient and toward the connector. This retrograde flow can lead to clotting or obstructions in the fluid line, effectively shortening the time period during which a particular injection point is useable. In many applications, it is advantageous to minimize or eliminate such retrograde flow or to produce a positive flow of fluid toward the patient as the valve closes.
U.S. Pat. No. 6,599,273 (incorporated herein in its entirety) includes a general description of some examples of medical connectors in which retrograde fluid flow may occur. U.S. Pat. Nos. 6,245,048, 6,428,520, 6,695,817, and U.S. Patent Application Publication No. 2006-0161115A1 (incorporated herein in their entireties) include general descriptions of some examples of medical valves in which a positive flow of fluid is produced away from the medical connector and toward the patient as the connector closes. There are many different types of medical connectors, and the foregoing patents are cited merely to illustrate some ways in which fluid can be transferred through connectors. The methods, structures, and principles disclosed herein can be used in or adapted to function with the connectors (and components thereof) disclosed in the foregoing patents as well as in many different types of medical connectors known or used in this field.
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When riding a snowboard, each of the user's boots is secured to the snowboard, e.g., with an apparatus called a “binding.” The bindings keep the user and board from separating during the ride down the slope. Bindings are also commonly configured to transfer forces from the user to the snowboard, allowing the user to control the snowboard during the ride.
One common type of binding for use with a snowboard, which may be referred to as a “strap-in” binding, may be designed to receive a boot, such as, for example, the type of boot that may be referred to in the art as a “soft boot.” A strap-in binding commonly incorporates one or more adjustable straps, which, when tightened, push the user's boot against the relatively rigid interior surfaces of the binding. The pressure of the straps and the interior surfaces hold the boot in the binding while the snowboard is in use and help the user to control the snowboard.
Another common type of snowboard binding may be referred to in the art as a “step-in” binding. A step-in binding may incorporate a relatively flat base that includes a mechanism that connects to hinges, fixtures, and/or other mechanisms on the bottom of the user's boot. A boot for use with a step-in binding is typically more rigid and sturdy than one typically used with a strap-in binding, and the rigid structures of the boot may transmit forces exerted by the user to the board, helping the user to control it. The construction that makes a boot suitable for use with a step-in binding may also make the boot heavier than a soft boot, however, as may the hardware built into the boot that is needed to secure the boot to the snowboard.
Inconveniences attend use of either of the strap-in binding and the step-in binding. For example, securing a boot inside a strap-in binding commonly requires that the user's hands be available to tighten the straps. A common consequence is that a snowboard user cannot ride directly off of a ski lift and onto a slope, as skiers may do, because the user typically must first get off of the ski lift and then secure at least one boot to the appropriate binding.
Step-in bindings, as mentioned above, commonly entail using boots that may be heavier and stiffer than the soft boots that may typically be used with a strap-in binding. The weight and rigidity may make such boots less comfortable to wear than soft boots, and experienced snowboard users may feel that the weight and rigidity compromise the user's control of the snowboard during a ride.
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1. Technical Field
The present invention relates to a method for data processing in general, and in particular to a method for performing address mapping for a system memory. Still more particularly, the present invention relates to a method for performing address mapping to access information stored in a system memory within a computer system.
2. Description of the Prior Art
In a typical data processing system, information is typically loaded in a system memory at wherever free space is available. Thus, a virtual address of a block of information usually do not reflect where the physical address (or actual address) in the system memory in which the information is actually stored.
The physical address space is considered as a contiguous space. Each physical address corresponds to a storage location in a memory bank within a system memory. A line is the part of a memory bank that consists of a number of storage locations that can be addressed as a whole by a line-number or bank-internal address. A block consists of one line or multiple lines. The physical addresses, that are assigned to storage locations contained within one block, are only different from each other by several least significant address bits called a block offset. The most significant address bits of a physical address constitute a block address, and they are identical for the same block. If a block includes one line, and a line consists of one storage location, then the block address equals the physical address.
Accordingly, a virtual address can be translated into a physical address by a translation process graphically illustrated in FIG. 1. As shown, a virtual address includes a page number 11 and a page offset 12. Page offset 12 represents a certain point within a page. Page number 11 and page offset 12 are then translated into a block address 13 and a block offset 14. Block offset 14 represents a certain point within a block. Usually, the least significant bits of page offset 12 are used as block offset 14, and the remaining bits of page offset 12 are used as the least significant bits for block address 13. The most significant bits of block address 13 are obtained by translating page number 11 via a page table 15. Page table 15 is updated each time new information is loaded into a memory. In a data processing system having only one memory bank 16, FIG. 1 represents the entire process of addressing a predetermined block i within memory bank 16.
A system memory typically have more than one memory bank. If blocks of data having consecutive block addresses are mapped on lines within the same memory bank, then a problem occurs if they have to be accessed in the same sequence. This is because after an access has been made to one line of a memory bank, the memory bank usually needs a short period of time to xe2x80x9crecoverxe2x80x9d before another access can be made. Hence, consecutive block address accesses would require more time than is desirable.
One solution to the above-mentioned problem is to interleave data in different memory banks that can be separately accessed. Thus, if storage locations with consecutive block addresses are distributed over separate memory banks, the blocks can be accessed one memory bank immediately after the other without any wait time. The simplest way to do this is to use one portion of the block address as the memory bank number and the rest of the block address as line-number (or bank-internal address), as graphically shown in FIG. 2. With this method, the distribution of consecutive block. addresses over a system memory 20 is bank-wise, and the overall access time is much improved in many cases.
However, this known method requires that the number of memory banks within system memory 20 to be a power of two, and that the interleaving be uniform (i.e., sequential), which is not optimal in various applications. Generally speaking, sequential accesses to a memory, such as system memory 20, are not randomly distributed but follow a certain pattern, depending on the type of applications. Thus, even if data is stored in an interleaved manner in several memory banks, such as system memory 20 shown in FIG. 2, sequential accesses for consecutive block addresses may occur at the same memory bank.
Ideally, memory accesses should be distributed uniformly over all memory banks in order to achieve best performance. To that end, various interleaving schemes, such as prime degree interleaving, pseudo-random interleaving, irreducible interleaving, etc., have been developed over the years for handling the memory distribution problem, specifically related to scientific applications. However, with these prior art interleaving schemes, address mapping often involves complex calculations that also lead to relatively large memory latencies. Consequently, it would be desirable to provide an improved method for performing address mapping to access information stored in a memory.
In accordance with a preferred embodiment of the present invention, a memory is organized in multiple of memory banks, and each memory bank is identified by a respective bank number. A block address portion of a physical address is translated to a corresponding bank number and an associated internal bank address. The bank number is formed by concatenating an output from a first lookup table and an output from a second lookup table. The output from the first lookup table is obtained by a first and a second segments of the block address portion, while the output from the second lookup table is obtained by a third and a fourth segments of the block address portion. Data stored in a specific location within the memory banks can be accessed by the bank number and the associated internal bank address.
All objects, features, and advantages of the present invention will become apparent in the following detailed written description.
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The present invention relates to lens system for projecting television images. Specifically, a multiple element lens system is employed using a single aspheric element for projecting images which lie on a curved image surface.
Projection lenses and projection cathode ray tube systems for magnifying and projecting television images to distant screens are known. In the projection television art, efforts have been made to provide simplified, and hence low cost, projection lenses for magnifying and projecting color television images.
It is recognized, specifically in U.S. Pat. Nos. 4,249,205 and 4,595,263, that curved images provide certain advantages when designing a projection lens. Specifically, the number of optical elements are simplified because of the relaxed requirements for correction of images which lie on a curved image surface.
Each of the above-referenced patents describes a projection lens system wherein curved television images are generated from cathode ray tubes having spherical or aspherical surfaces. Light from more than one curved image surfaces is combined with a dichroic mirror assembly, coupled either through an immersion medium or by air to a single aperture for projection.
The curved image surfaces can be magnified using a projection lens system which has one or more aspheric elements for preserving image resolution, providing a highly corrected image. The aspheric surfaces permit preservation of high resolution, while allowing higher lens speed. The production of these aspheric surfaces has typically been done by imposing the aspheric surface on spherical substrates (in most circumstancs, glass has been used for the substrate). Considerable tedious and expensive efforts are required to ashperize the spherical surfaces, enhancing the cost of the finished lens system. In U.S. Pat. No. 4,595,263, several aspheric surfaces are employed for providing correction to the curved image generated from the spherical CRT surface.
Thus, it is clear that one way to reduce the costs of such projection lens systems is to reduce the number of required aspheric surfaces, and to produce the elements at a lower cost.
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This section introduces aspects that may help facilitate a better understanding of the disclosure. Accordingly, these statements are to be read in this light and are not to be understood as admissions about what is or is not prior art.
Metals in general, and in particular rare earth elements (REE's), are critical components of many high-valued products, such as petroleum refining catalysts, phosphors in color television and flat panel displays (cell phones, portable DVDs, and laptops), permanent magnets, and rechargeable batteries for hybrid and electric vehicles. Rare earth elements consists of 15 lanthanides (Ln's), scandium and yttrium. Currently, the REE's used in the U.S. are primarily imported from China, which produces more than 90% of the REE's used globally. Since China has reduced the export quota almost by half since 2010, it is highly desirable to develop efficient and cost-effective processes to produce and recover REE's domestically.
As an example, a typical production process for the rare earth elements can include the following steps: (1) physical separations (gravity concentration, flotation, magnetic, or electrostatic separation) which are used to separate rare earth minerals from sands and rocks in the ore; (2) dissolution of rare earth minerals in acidic or caustic solutions; (3) separation of each REE element from the mixture solutions; (4) precipitation of each REE element using oxalic acid to obtain solid REE oxalate, which is then decomposed under heat to form REE oxide of a single element. Among these steps, Step (3) is most challenging and costly because many of the REE's are present in the solution, and they have very similar chemical properties, ionic sizes, and charges.
The current large-scale production of REE's is mainly based on solvent extraction. Almost 20 sequential or parallel extraction steps using organic solvents (naphthenic acid or phosphorous-based extractants) and strong acids (hydrochoric acid or sulfuric acid) are needed to separate the REE's into eight or ten major fractions. Such a method requires large amounts of organic extractants and highly acidic or caustic aqueous solutions, which generates a lot of environmentally-hazardous wastes.
An alternative method to separate REE's is ligand-assisted displacement chromatography using an ion exchanger. In this method, the REE's are loaded onto a strong-acid cation exchange resin, and then displaced by sodium or ammonium ions in the presence of a ligand. In order to increase the purity and yield, a large column (0.45 L), a large amount of ligand solution (>130 column volumes), and a long displacement time (>3 weeks) are required to separate a small amount of REE's (<2 g), resulting in low productivity and poor ligand efficiency. Worse still, after each run, the column needs to be regenerated by a concentrated solution of acid or transition metal salt, which increases the operation cost significantly. As a result, this method is estimated to have a production cost of 40/kg, which is not economical for large-scale productions.
Another method to achieve REE's separation is extraction chromatography, in which a chelating agent is immobilized onto a resin to increase the selectivity of the sorbent for the REE's. The resins were developed by Argonne National Laboratory in the 1970's, and have been tested in analytical chromatography. Column test data showed that two small columns (with 0.3 g resin) can be used in tandem to capture and purify six REE's using two pH elution steps. However, the resin supply is limited at present, and the resin life is not well evaluated. Most importantly, the resin cost is over 16,000/kg, which is highly uneconomical for large-scale REE's separation.
There is therefore an unmet need for an efficient, cost effective method and system for achieving rare earth metal ion separation.
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Polymeric documents of value offer several benefits over their paper counterparts. In particular, polymeric banknotes can offer greatly increased durability and resistance to counterfeiting through the incorporation of security features. A requirement for polymeric banknotes is that certain physical properties are similar to the more commonly used paper banknotes. Those properties relate to tactile feel, strength, tear resistance, handling, folding, and crumple resistance.
In the past, laminates have been used for banknotes having biaxially oriented polymeric film and a non-printed window incorporate security features. However, there are several the shortcomings of banknotes based on some of the laminates. Laminate constructions primarily based on polyolefin film offer improved physical properties. Other alternatives include banknotes that incorporate outer layers of paper laminated to a polymeric core as a way to obtain paper-like properties.
Polymeric banknotes offer unique opportunities to incorporate security features that are designed to discourage counterfeiting. Many efforts relating to banknotes describe the possibility of a transparent window somewhere on the banknote, which offers a quick visual check for authenticity and is difficult to reproduce with copying techniques. Further refinements of the window include an optically variable device, such as a Moire pattern or diffraction grating, which is visible in the window. In most cases, the security feature must be added as a separate component with an additional process step.
Polymeric laminates having a large number of layers and exhibiting optically unique properties have been considered as a basis for “plastic” currency. Multilayered optical films with unique optical properties that can be used as security features on certain documents of value have been considered. Polymeric multilayer optical films have previously been made with PEN, PET, and CoPEN polymers (See for example, U.S. Pat. No. 5,882,774).
Researchers, however fail to address the physical properties required for that application. (See additional references U.S. Pat. Nos. 4,162,343, 4,937,134, 5,089,318, and U.S. Pat. No. 6,045,894.)
There would be great value in a multilayered film with optical properties that combines the physical properties required for polymeric banknotes with an inherent security feature that would be difficult to counterfeit.
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Pacemaker leads represent the electrical link between the pulse generator and the heart tissue, which is to be excited and/or sensed. These pacemaker leads include single or multiconductors that are connected to an electrode in an electrode assembly at an intermediate portion or distal end of a pacing lead. A connector is included at the proximal end to form the electrical connection with the pacemaker.
To implant the lead within the patient, the lead is often fed intravenously toward the heart. The lead may be implanted within or travel through complex or tortuous vasculature. Once positioned at a desirable location, the lead is fixated to the patient at a location, for example, by actively fixating the lead to the heart. To actively fixate a lead, an element, such as a helical tip at the distal end of the lead, is rotated out of the lead and in to the patient. The helical tip is electrically connected with one or more conductors wound in a coaxial or co-radial configuration. However, co-radial construction does not permit active fixation.
Accordingly, there is a need for a lead with a non-stationary to stationary electrical interconnect.
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1. Field of the Invention
The present invention relates to a perpendicular magnetic recording head which performs a recording action by applying a recording magnetic field perpendicularly to a recording medium plane.
2. Related Background Art
As is well-known, a perpendicular magnetic recording head includes a main magnetic pole layer and a return yoke layer which are laminated with a predetermined distance therebetween on a surface opposing a recording medium and are magnetically coupled to each other on the deeper side of the medium-opposing surface in the height direction, a magnetic gap layer interposed between the main magnetic pole layer and return yoke layer on the medium-opposing surface, and a coil layer inducing a recording magnetic field between the main magnetic pole layer and return yoke layer upon energization. The recording magnetic field induced between the main magnetic pole layer and return yoke layer perpendicularly enters a hard magnetic film of the recording medium from the front end face of the main magnetic pole layer and returns to the front end face of the main magnetic pole layer through a soft magnetic film of the recording medium. This performs magnetic recording at a part opposing the front end face of the main magnetic pole layer.
A so-called shielded pole structure has recently been proposed, in which the distance (gap distance) between the main magnetic pole layer and return yoke layer on the surface opposing the recording medium is set narrow, i.e., to about 50 nm, in order to suppress the divergence of magnetic fluxes directed from the main magnetic pole layer to the return yoke layer and realize magnetic recording with less bleeding. On the other hand, the size in the track width direction of the front end face of the main magnetic pole layer, i.e., recording track width size, has been becoming narrower as hard disk drives have been attaining higher recording densities.
In a perpendicular magnetic recording head having a narrowed track, how to suppress side fringing at the time of skewing where the head is driven in a state tilted with respect to a recording medium has become a problem.
As a method of suppressing side fringing at the time of skewing, it has been known to provide a magnetic shield layer for absorbing magnetic fluxes leaking from sides of the main magnetic pole layer in the vicinity of the main magnetic pole layer as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-190518), for example. Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-100520) and Patent Document 3 (Japanese Patent Application Laid-Open No. 2006-216098) also show such techniques.
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Radio frequency identification (RFID) devices are becoming increasingly popular for a variety of industrial, retail, transportation, and other applications. RFID technology provides a positive identity for any object, person, or the like, bearing an RFID transponder through the use of a passive, radio frequency signal. In a typical application, an RFID transponder comprises an antenna and an integrated circuit. When a separate RFID reading device broadcasts a radio frequency signal, the signal interacts with the RFID transponder antenna. The transponder antenna converts part of the received RF signal energy into an electrical current. This electrical current powers the integrated circuit. The integrated circuit then modulates its impedance to create a return RF signal. This return RF signal is then detected by the antenna in the RFID reading device. This modulated, RF return signal carries encoded data about the transponder based on the data previously stored in the integrated circuit. For example, the serial number of the transponder may be returned to the RFID reading device via this modulated RF signal. Finally, the RFID reading device decodes the signal returned from the transponder to complete the identification.
RFID transponders are being integrated into a growing number of applications. Employee identity badges, animal identity devices, retail pricing and inventory devices, retail security devices, manufacturing product and material tracking devices, vehicle identification devices, and the like, are just a few examples of the expanding area of applications for RFID technology. RFID transponders are ideally suited for integration with a wide variety of products and in a wide variety of situations. RFID transponders may be purely passive devices where all of the energy for operating the integrated circuit is derived from the broadcast RF signal. Alternatively, active RFID systems may incorporate an on-board battery to provide power to the identity chip and/or power for the transponder's return RF signal. In fixed systems, such as motor vehicle transponders used for automated toll collection, the additional cost of the on-board battery is easily justified by the improved performance of the device. Conversely, in cost sensitive applications such as retail pricing and security tags, the RFID transponder device must be as inexpensive as possible and is therefore, typically, a passive device.
The on-board antenna is a key enabling technology for RFID transponder devices. The broadcast RF energy may be in the form of a magnetic field, an electric field, or a mixed field as in typical radio signal broadcast. The transponder antenna is designed with a shape and a size based on the characteristics of the broadcast RF energy such as the field type and the signal frequency. Moreover, the design of RFID tags typically requires matching the antenna impedance and load impedance, usually by a matching circuit, for maximizing the RF power from the reader's interrogation or command signal received at the tag antenna to be delivered to the RFIC with minimum loss, and thereby achieve optimum tag sensitivity. Theoretically, maximum power delivery is achieved by conjugate impedance matching, which demands that the impedance from the antenna be, as closely as possible, the mathematical conjugate of the RFID input impedance. This represents an ideal impedance match.
In many applications, it is desirable to reduce the overall size or “footprint” of a particular RFID device. The reduced size may be required for inclusion on or in retail goods having small dimensions. Alternatively, it may simply be desirable to make the RFID device as inconspicuous as possible. While technology exists to drastically reduce the size of an IC component of an RFID device, similar miniaturization of the antenna of an RFID device can result in a significant reduction in performance. As stated above, a particular IC and antenna of an RFID device ideally have matched impedance characteristics. By reducing the overall size of the RFID device, and thus the antenna, it may prove difficult to adequately provide the impedance characteristics for efficient function of the device. As such, the RFID may suffer from inefficient power transfer to the IC, a reduced operating range with respect to an interrogator, and a weak return signal in response.
In addition, an antenna connected to a RFID tag is generally designed for operation on a specific or narrow range of substrates to which it may be attached. Other substrates may cause the radiation efficiency of the antenna to deteriorate from the designed optimal mounting substrates. Thus, the antenna, and consequently the RFID device, will no longer function as intended. This loss of antenna efficiency may be due to a number of variable packaging factors. For example, each substrate has its own dielectric and conductive characteristics that typically affect the impedance matching between the wireless communication device and its antenna. Impedance matching ensures the most efficient energy transfer between an antenna and the wireless communication device, as discussed above, and placement of an RFID device in proximity to a surface having dielectric and conductive properties outside of a particular range may reduce the performance of the RFID device. These adverse effects to the performance of an RFID device may also be experienced upon the inclusion or integration of an electronic article surveillance (“EAS”) tag or device. Such EAS devices often include a magneto-acoustic mechanism having one or more metallic components that may subsequently interfere with or reduce the performance characteristics of a particular RFID device.
In view of the above, it would be desirable to provide an RFID device having a reduced footprint while providing for efficient operation on a variety of surfaces and/or in combination with an EAS tag.
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In 1964, Levin and Bang discovered the phenomenon in which horseshoe crab (limulus) amebocyte lysate (hereinafter sometimes abbreviated as LAL) is immediately coagulated (gelled) by a Gram-negative bacterial endotoxin [J. Levin and F. B. Bang: Bull. Johns Hopkins Hospital, 115, 265-274 (1964)]. Since then, LAL has been widely utilized as the so-called Limulus Test reagent in a method of specific detection of endotoxins. Today, three genera, four species of horseshoe crab survive throughout the world and Limulus polyphemus, Tachypleus tridentatus, Tachypleus gigas and Carcinoscorpius rotundicauda are known. "Limulus Test" reagents comprising the amebocyte lysate of L. Polyphemus occurring in the United States and T. tridentatus occurring in Japan and China have been commercialized. [See, for example, Progress in Clinical and Biological Research: volume 93; "Endotoxins and their Detection with the Limulus Amebocyte Lysate Test", edited by Stanly W. Watson, Jack Levin and Thomas J. Novitsky, published in 1982 by Alan R. Lisps Inc., pages 7-24, entitled: The Limulus Test and Bacterial Endotoxins: Some Perspectives by J. Levin.]
LAL was first considered to react specifically only with endotoxins. Recent studies have shown that LAL has been found to react with (1.fwdarw.3)-.beta.-D-glucan as well as endotoxin. The coagulation system of LAL, like the mammalian blood coagulation system, consists of two or more cascade reactions of coagulation factors, and include not only an endotoxin-mediated pathway (factor C pathway), but also a pathway to be triggered by (1.fwdarw.3)-.beta.-D-glucan (factor G pathway) [T. Morita et al., FEBS LETTERS, 129, 318-321 (1981), and S. Iwanaga et al., J. Protein Chem., 5, 255-268 (1986)]. Accordingly, work has been done in order to render the Limulus test as endotoxin-specific as possible. For example, T. Obayashi et al., Clin. Chim. Acta, 149, 55-65 (1985) proposed a method of determining an endotoxin by using a reagent obtained by removing factor G from LAL by separation and reconstitution of the coagulation factors. An endotoxin specific assay kit in accordance with this method is sold under the tradename "Endospecy.RTM." by Seikagaku Kogyo Co., Ltd.
The above-proposed assay method has a very strong demand as an endotoxin-specific assay. However, this method involves certain disadvantages to be described.
(1) To separate and remove factor G from limulus amebocyte lysate composed of a plurality of coagulation factors, it is necessary to perform the operation of separating the individual factors in the absence of an endotoxin or (1.fwdarw.3)-.beta.-D-glucan. Accordingly, the endotoxin or (1.fwdarw.3)-.beta.-D-glucan must be removed completely in advance from tools, devices and chemicals used in the separating operation for fractionation.
(2) As the separating operation proceeds, the amebocyte lysate becomes diluted, and it must occasionally be concentrated.
(3) Every time a separating operation is carried out, the factors decrease in activity or a loss of the fractions occurs.
(4) The coagulogen (clottable protein precursor) is separated and removed together with factor G.
Because of these disadvantages, the above proposed assay method can be applied only to a chromogenic method, and cannot be applied to methods utilizing the gellation phenomenon such as a gellation method, turbidimetry and turbidimetric kinetic assay. In the course of studying a pathway to be triggered by (1.fwdarw.3)-.beta.-D-glucan (factor G pathway) in the LAL coagulation mechanism, the present inventors unexpectedly found that among (1.fwdarw.3)-.beta.-D-glucans heretofore considered to be involved only in the activation of factor G, one containing a structural portion consisting of a specific number of continuously bound (1.fwdarw.3)-.beta.-D-glucoside structural units, quite contrary, shows a factor G inhibiting action. This finding has led to accomplishment of the present invention.
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Stem cells are special cells that have the ability to develop into many different types of tissue: bone, muscle, nerve, etc. In theory, they could be grown into replacements for almost any part of the human body. Stem cells are typically found in the embryo and umbilical cord of an organism, and in reservoirs within the human body. Researchers hope that stem cells will provide a solution to cure diseases caused by cell failure, and for repairing tissues that do not repair themselves. Heart damage, spinal cord injuries, Parkinson's disease, leukemia, and diabetes are among diseases named in relation to stem cell research. Hence, researchers are of the opinion, if these stem cells are controlled, they could cure a variety of debilitating diseases in the years to come. Stem cells are separated into three (3) distinct categories viz. Totipotent, Pluripotent, and Multipotent. Stem cells are best described in relation to normal human development. Thus, a fertilized egg is totipotent. It produces an entire organism. After several cycles of cell division, these totipotent cells begin to specialize, becoming pluripotent. As the embryo begins to develop, these pluripotent cells become multipotent, specifically producing blood, skin, nerve, or other types of body cells. While stem cells are extraordinarily important in early human development, multipotent stem cells are also found in children and adults. For example, one of the best understood stem cells are the blood stem cells. Blood stem cells reside in the bone marrow of every child and adult, and in fact, they can be found in very small numbers circulating in the blood stream. Blood stem cells perform the critical role of continually replenishing the supply of blood cells—red blood cells, white blood cells, and platelets throughout the life span.
Stem cells are the building blocks of blood and immune systems. They form the white cells that fight infection, the red cells that carry oxygen and platelets that promote clotting. Stem cells are normally found in bone marrow where they continue to generate new blood cells throughout the life span of an individual. The presence of these stem cells in the bone marrow, has made marrow transplantation an important therapeutic modality in the treatment of variety of malignant and non-malignant diseases. This is because of the realization that permanent clinical benefit from transfused blood cells can come from transplantation of multipotent haematopoietic stem cells. Besides bone marrow, Mobilized Peripheral Blood (MPB), and Umbilical Cord Blood (UCB) have also been used successfully for transplantation. In recent years although significant advances have been made in bone marrow transplantation (BMT), the basic problem of finding a suitable matching donor still remains. This is because a group of antigens expressed by the leukocytes called the human leukocyte antigens (HLA) need to match between the donor and the recipient. Further bone marrow harvesting is a painful and invasive procedure and many donors are unwilling to donate marrow. Therefore, the search for alternate sources of stem cells has led to the development of stem cell transplant protocols from different tissues like liver (Kochupillai 1991), mobilized peripheral blood (Benboubker 1995), and cord blood (Mayani 1998). Of these, cord blood has significant advantages over the others. Increasingly, experts say cord blood transplants have distinct advantages over more traditional bone marrow transplants in stimulating the growth of healthy white blood cells. Stem cells can be collected from the bone marrow. However, the collection procedure is invasive, time-consuming, requires an anaesthetic and is painful for the donor. Also, cord blood is easily available, involves a non invasive collection procedure and is better tolerated in transplants across the HLA barrier.
Like bone marrow, umbilical cord blood is rich in stem cells. Umbilical Cord Blood is the blood that remains in the placenta and umbilical cord following birth. Until recently the placenta and umbilical cord were discarded after delivery as medical waste, but now research has shown that cord blood is a rich source of blood (haematopoetic) stem cells, which can be collected, processed and frozen for potential future use. An experimental procedure to use umbilical cord blood instead of bone marrow to treat immune diseases is gaining attention from doctors and patients.
In the face of extraordinary advances in the prevention, diagnosis, and treatment of human diseases, devastating illnesses such as heart disease, diabetes, cancer, and diseases of the nervous system, such as Parkinson's Disease and Alzheimer's Disease, continue to deprive people of health, independence, and well-being. Research in human developmental biology has led to the discovery of human stem cells (precursor cells that can give rise to multiple tissue types), including embryonic stem (ES) cells, embryonic germ (EG) cells, fetal stem cells, and adult stem cells. Recently, techniques have been developed for the in vitro culture of stem cells, providing unprecedented opportunities for studying and understanding human embryology. As a result, scientists can now carry out experiments aimed at determining the mechanisms underlying the conversion of a single, undifferentiated cell, the fertilized egg, into the different cells comprising the organs and tissues of the human body. Although it is impossible to predict the outcomes, scientists and the public will gain immense new knowledge in the biology of human development that will likely hold remarkable potential for therapies and cures.
Human Mesenchymal Stem Cells are adult stem cells that are present in bone marrow stroma. They are a heterogeneous population which have been well characterized in their ability to proliferate in culture and differentiate into multiple mesechymal lineages under controlled conditions.
Until the present, Human Mesenchymal Stem Cells are being cultured in animal serum such as Fetal Bovine Serum (FBS), Human adult blood serum or a complex mixture of growth factors derived by mixing purified factors which are either isolated from FBS or Human Adult blood serum or a mixture of growth factors derived from recombinant methods.
However, these conventional culture media are associated with shortcomings and risks.
Stem cells from adult/fetal as well as other sources are being widely used to regenerate tissues in patients after they have degenerated. For this purpose, these cells have to be grown in the tissue culture for varying periods of time using defined media, the principle constituent of which is animal serum such as Fetal Bovine Serum (FBS).
FBS is the most widely used serum in the culturing of cells, tissues and organs in vitro, in industry, medicine, and science. FBS has been shown to be essential for adhesion, proliferation and differentiation of the cells. However, animal serum such as FBS can be infected with several pathogens such as prions. Several known and unknown viruses may be present in the serum. Therefore cells/tissue cultured in the presence of FBS get infected and transmit these pathogens to the patient on transplantation. As stated FBS may have known and unknown pathogens which may get transmitted to the human transplant subject, if these cells are grown in FBS. The pathogens present in FBS are difficult to screen for likely causative agents of diseases in humans. Hence, using such cells in a human can be life threatening as there is every chance of a pathogen getting transmitted along with these cells.
Human adult blood serum also supports growth of several cells, however, it cannot substitute for FBS. Moreover, it is difficult to harvest large amounts of serum from Human adult blood. Hence, it is not widely used for culturing of cells, tissues and organs in vitro.
Several investigators have tried to use a combination of complex mixture of growth factors which are known to influence growth and differentiation of stem cells. However, the success is limited and it has been shown conclusively that at least 2% v/v of the tissue culture media should be made up of FBS for optimal growth of the cells.
There is a dire need to find an adequate substitute for conventional culture media for growing Human Mesenchymal Stem Cells. Looking to the need of the hour, the present inventors have resolved the above issue of concern and have come out with a solution which will be of utmost importance in the field of regenerative medicine. The inventors have come out with a unique component for culturing Human Mesenchymal Stem Cells. The present invention is advantageous over the prior art as it obviates the problems associated with the conventional culture media for growing Human Mesenchymal Stem Cells.
The present invention has solved the problem by culturing human stem cells in umbilical cord blood serum. Cord blood being a natural substance, is found to be rich in growth factors. Taking this factor in mind, the inventors of the present invention, have investigated a method of growing Human Mesenchymal Stem Cells in cord blood serum.
Use of umbilical cord blood in haematopoietic reconstitution has been around since 1970. However, no work has been done in using umbilical cord blood as a source for growing Human Mesenchymal Stem Cells. The inventors of the present invention have been successful in discovering this novel source for growing Human Mesenchymal Stem Cells.
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The invention relates to a pusher centrifuge with a centrifuge drum, a pusher bottom, a filler pipe for the material to be centrifuged connected to the centrifuge housing and extending coaxially into the centrifuge drum, and a distribution cone positioned downstream of the filler pipe and concentric thereto having its end with the greater diameter facing the pusher bottom at a distance so as to leave an annular gap.
In pusher centrifuges of this type there is a need to accelerate the material to be centrifuged, for increasing the throughput while at the same time gently treating sensitive solid particles and reducing wear at the centrifuge, especially wear of the slotted screen in the supply area, to the angular velocity of the solid particle cake within the centrifuge drum.
In an attempt to solve this problem, in a pusher centrifuge known from German Patent DE 28 48 156 C2 the material to be centrifuged is unsatisfactorily preaccelerated through a guiding wall, extending perpendicularly to the centrifuge axis, to an angular velocity of the filter cake formed so that a spontaneous dewatering, required for forming a push-resistance solid particle cake within the supply area, cannot be ensured. This results in a reduction of the mass throughput within the pusher centrifuge. From German Patent 43 08 749 a pusher centrifuge is furthermore known in which the material to be centrifuged is accelerated to a high velocity by a pump wheel-like insert between the pusher bottom and the guide disk. However, the constructively resulting high radial acceleration component, which is even further enhanced by the number of the pump wheel vanes, results in great wear of the slotted screen coating within the supply area.
The object of the invention is therefore to provide a pusher centrifuge with which solid materials can be separated from liquids with optimal mass throughput and with reduced wear of the slotted screen coating within the supply area.
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In general, ink jet printing machines or printers include at least one printhead that ejects drops or jets of liquid ink onto a recording or image forming media. A phase change ink jet printer employs phase change inks that are in the solid phase at ambient temperature, but transition to a liquid phase at an elevated temperature. The molten ink can then be ejected onto a printing media by a printhead directly onto an image receiving substrate, or indirectly onto an intermediate imaging member before the image is transferred to an image receiving substrate. Once the ejected ink is on the image receiving substrate, the ink droplets quickly solidify to form an image.
In both the direct and offset printing architecture, images may be formed on a continuous media web. In a web printer, a continuous supply of media, typically provided in a media roll, is conveyed by a plurality of rollers that are arranged to guide the media web through a print zone where a plurality of printheads are positioned to deposit ink onto the web to form images. Beyond the print zone, the media web is gripped and pulled by mechanical structures so a portion of the media web continuously moves through the print zone. Tension bars or rollers may be placed in the feed path of the moving web to remove slack from the web so it remains taut without breaking.
In continuous-web direct to paper printing, a fixing assembly is used after the ink is jetted onto the web to fix the ink to the web. The fixing assembly used depends on the type of ink. For example, when using melted phase change ink to form images, the fixing assembly may include a spreader configured to apply pressure to the ink and web to spread the ink on the web. The function of the spreader is to transform a pattern of ink droplets deposited onto a web and smear them out to make a more uniform and continuous layer. The spreader uses pressure and/or heat to reduce the height of the ink droplets and fill the spaces between adjacent drops. When UV curable inks are used, the fixing assembly may include one or more curing lamps to cure the UV ink onto the web.
Sometimes the ink deposited onto the web may bleed into the web before the ink is fixed to the web. For example, a liquid or molten uncured ink may bleed into the fibers of a paper substrate and become at least partially visible from the backside of the substrate. This problem is known in the art as showthrough or bleed-through, and is generally known to exist for any type of liquid ink deposited on a porous substrate. This issue is more pronounced in inks of low viscosity, such as ink jet inks, while higher viscosity inks are less susceptible to this problem. Specifically, showthrough is a measure of how colorized an ink makes the backside of the substrate.
In previously known systems, bleed-through detection on a temperature sensitive printing system (i.e. ink jet) was only able to be detected visually, after the image had been printed. In addition, the ability to correct or remediate the factors that may be causing image bleed-through the use of a real-time detection mechanisms while actively printing has been limited or non-existent. For example, if bleed-through was visually detected for a given media type, the print process critical parameters would be manually adjusted prior to printing the customer job and would not be adjusted during the printing of the job. Depending on the familiarity of the printer operator with the print process, the adjustment may or may not ultimately alleviate the bleed-through condition.
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There is interest in many field of application to move from a pure Hydraulic Actuation System (HAS) to an Electro Mechanical Actuation System (EMAS). Examples are present both in aeronautics, where the concept of a “More Electric Aircraft” is becoming more and more important, and in ground/undersea vehicles. In the aeronautic field this trend is justified by the potential reduction of weight compared to a HAS and by the versatility offered by the electric approach. However, EMAS do not reach the same power density levels of hydraulic systems. The energy efficiency of EMAS can also be limited by the screw mechanism, i.e. self-locking screw, when the application requires position hold (like in aircraft seats). Moreover, EMAS suffer of a common issue that is the jamming, in addition to wear in the incorporated gears as well as in the screw mechanism, which can lead to backslash. In EMAS, a gearbox is necessary in order to lower the actuating torque thus permitting the use of small electric motors. This gearbox can negatively affect the overall volume and weight of the system. Furthermore, the high reduction ratio can have detrimental effect on the dynamic behavior of the system since, the inertia will be over-perceived from the motor. For these reasons, in particular for the jamming issue, for flight controls so far the EMAs are used only for backup purpose; also, they should be equipped in such a way to be easily decoupled by the other actuator during jamming.
The EHA solution can be seen as a more convenient way to transit to the “More Electric Aircraft”. The use of compact EHAs can permit to combine the power to weight advantage of hydraulic systems with the ease of control and wiring advantages of the electric systems. This concept has been well received in the aerospace field, and several solutions for EHA are currently available in the market.
The pump is an element in any hydraulic system, as concerns energy efficiency, noise emissions, life and reliability. In EHA systems, the pump design can be fixed displacement, being the flow controlled by the electric motor speed with a design suitable for miniaturization and permitting higher shaft speed. From this regard, external gear pumps offer high potential, considering manufacture cost and simplicity.
Various embodiments of the inventions described herein present novel and unobvious ways to improve electro-hydraulic actuation systems, and also positive displacement pumps.
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The present invention relates to an in-cylinder injection type internal combustion engine.
Recently, an in-cylinder injection type internal combustion engine for improving an engine output and a fuel economy has been practiced. In the internal combustion engine of this kind, as disclosed in Unexamined Published Japanese Patent Application 8-312404, for example, fuel is injected in a suction stroke while making an air/fuel ratio feedback control performing the stoichiometric air/fuel ratio as a target value in a medium/high load region that demands an engine output. In a low load region, on the other hand, the fuel is injected in the compression stroke while making an open loop control at a super-lean air/fuel ratio (e.g., 25 or higher) which is far leaner than the stoichiometric air/fuel ratio.
In other words, the compression stroke injection in the in-cylinder injection type internal combustion engine effects the laminar combustion at the super-lean air/fuel ratio aiming mainly at improving the fuel economy. As a result, the compression stroke injection of the in-cylinder injection type internal combustion engine is executed exclusively in the lean air/fuel ratio region.
However, the internal combustion engine of this kind is troubled by various problems: that the drive is performed at a far leaner air/fuel ratio than that of the existing internal combustion engine for injecting the fuel into the intake passage so that the exhaust gas temperature drops to inactivate the once active catalyst; and that the fuel injection timing varies between the suction stroke and the compression stroke in dependence upon the drive state so that the torque fluctuates.
We have made experiments by changing the target air/fuel ratio of the compression stroke injection to the outside the super-lean air/fuel ratio region so as to find effective means for solving those problems, and have found that the engine characteristics at the time when the compression stroke injection was effected in the air/fuel ratio region in the vicinity of the stoichiometric air/fuel ratio were drastically different from those at the suction stroke injection time.
An object of the invention is to provide an in-cylinder internal combustion engine which is enabled to solve the problems inherent to the in-cylinder internal combustion engine by exploiting the engine characteristic changes at the time when the air/fuel ratio region of the compression stroke injection is extended.
According to a first aspect of the invention, there is provided an in-cylinder injection type internal combustion engine which has: a first operation mode for performing a suction stroke injection while making an air/fuel ratio feedback control performing a stoichiometric air/fuel ratio as a first target air/fuel ratio; and a second operation mode for performing a compression stroke injection while making an air/fuel ratio feedback control performing a predetermined air/fuel ratio in the vicinity of the stoichiometric air/fuel ratio as a second target air/fuel ratio, and selectively switching each drive mode under a predetermined condition.
According to this in-cylinder injection type internal combustion engine, the suction stroke injection at the stoichiometric air/fuel ratio or the compression stroke injection in the vicinity of the stoichiometric air/fuel ratio is selectively performed so that the exhaust gas characteristics or the output characteristics are improved by exploiting the changes of the engine characteristics accompanied with the switching of the injection modes.
In the embodiment of the invention, it is preferable that the operation mode switching means switches the operation mode to the first operation mode when the internal combustion engine is in the medium/high load drive state and switches the operation mode to the second operation mode when the internal combustion engine is in the drive state demanding a temperature rise of the catalyst of an exhaust purifying catalyst. It is preferable that the second target air/fuel ratio in the air/fuel ratio feedback control in the second operation mode is set at a slightly leaner air/fuel ratio than the stoichiometric air/fuel ratio.
According to our aforementioned experiments, the emissions of the reduced components such as carbon monoxide (CO) or the excess oxygen (O2) at the time of performing the compression stroke injection in the vicinity of the stoichiometric air/fuel ratio are more than those at the suction stroke injection at the stoichiometric air/fuel ratio. With the compression stroke injection in the vicinity of stoichiometric air/fuel ratio, more specifically, a rich air/fuel ratio region is established locally in the combustion chamber so that the incomplete combustion occurs to produce much CO while leaving much O2 in the remaining combustion chamber regions. As a result, the emissions of CO and O2 at the compression stroke injection time in the vicinity of the stoichiometric air/fuel ratio are more than those at the suction stroke injection time at the stoichiometric air/fuel ratio. When the CO and O2 exhausted from the combustion chamber reach the catalyst, moreover, the CO and O2 cause oxidations under the action of the catalyst so that the catalyst temperature is raised by the result heat of reaction. In the medium load drive region, therefore, the necessary engine output can be generated, and the catalyst temperature can be raised in response to its demand. By the compression stroke injection at the lean air/fuel ratio, the rich misfire or the poor fuel economy is prevented, and the emission of smoke is suppressed to improve the exhaust characteristics.
In the embodiment of the invention, air/fuel ratio detecting means is preferably constructed of oxygen concentration detecting means. By using this oxygen concentration detecting means, the sensor system relating to the air/fuel ratio feedback control is made simple and inexpensive, and the control itself is simplified.
On the other hand, the output of the oxygen concentration detecting means is ordinarily turned at the stoichiometric air/fuel ratio between a first output value and a second output value. In the air/fuel ratio feedback control, moreover, an air/fuel ratio correction value is generally variably adjusted in response to that output turn. Therefore, the oxygen concentration detecting means has an output turning point (or first output turning point) at which the output is turned between the first output value and the second output value.
According to our experiments, when the emissions of the reduced components and the excess oxygen are augmented by the compression stroke injection in the vicinity of the stoichiometric air/fuel ratio, the output turning point of the oxygen concentration detecting means shifts from the stoichiometric air/fuel ratio in dependence upon the construction of the oxygen concentration detecting means. When an oxygen sensor used is prepared by coating the inner and outer surfaces of a cylindrical zirconia element with porous platinum electrodes having catalytic actions, for example, the sensor output turning point (or second output turning point) during the execution of the compression stroke injection in the vicinity of the stoichiometric air/fuel ratio shifts to the leaner side by an air/fuel ratio of about 0.3 to 1.0 from the first output turning point corresponding to the stoichiometric air/fuel ratio. By making the feedback control at the oxygen sensor output turning point shifted to the leaner side in the second mode, therefore, the reduced components and the excess oxygen can be optimized to efficiently raise the temperature of the catalyst disposed in an exhaust passage, for example.
In the aforementioned embodiment of the invention, preferably, the air/fuel ratio correction value to be made variable according to the output of the oxygen concentration detecting means in the air/fuel ratio feedback control is corrected to increase or decrease when the operation mode is switched.
According to the air/fuel ratio feedback control for making the air/fuel ratio correction value variable in response to the turn of the oxygen sensor output, the sensor output turning point is shifted to the leaner side, as has been described hereinbefore. Just after the operation mode switching between the first operation mode and the second operation mode, therefore, the shift of the output turning point of the oxygen sensor output is delayed to delay the optimization of the air/fuel ratio correction value (as should be referred to FIG. 8). Thus, a convergence into a new target air/fuel ratio accompanied with the operation mode switching may take a long time to deteriorate the stability in the air/fuel ratio control.
Therefore, the air/fuel ratio control is stabilized by correcting to increase/decrease the air/fuel ratio correction value at the operation mode switching time to forcibly bring the practical air/fuel ratio just after the operation mode switching close to a new target air/fuel ratio so that the time period required for the air/fuel ratio to converge into the new target air/fuel ratio may be shortened to stabilize the air/fuel ratio control. In other words, the air/fuel ratio feedback control, based on the new target air/fuel ratio, is started early, even when the fuel injection timing changes according to the switching between the suction stroke injection and the compression stroke injection.
In the aforementioned embodiment of the invention, more preferably, the air/fuel ratio correction value in the first operation mode is subtracted and corrected (refer to FIG. 6) at the time of switching the operation mode from the first operation mode to the second operation mode. When the second operation mode is switched to the first operation mode, on the other hand, the air/fuel ratio correction value in the second operation mode is added and corrected. This subtraction/addition correction may be a fixed value or may be determined according to the engine running state (e.g., the engine speed and the volumetric efficiency) from a preset map. According to this preferred mode of embodiment, the air/fuel ratio correction at the operation mode switching time is optimized.
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1. Field of the Invention
The present invention relates to an optical device in which optical rotatory dispersion hardly occurs so that the optical device can be used for forming a vertically aligned liquid-crystal display apparatus wide in viewing angle and excellent in display quality.
2. Description of the Related Art
In a TN type liquid-crystal cell containing liquid-crystal molecules aligned in a direction horizontal to cell substrates with positive dielectric anisotropy, there was a tendency that the quality of black display was deteriorated by light leakage owing to birefringence of liquid-crystal molecules near to the cell substrates. Heretofore, in consideration of the tendency, there was known a liquid-crystal display apparatus including a vertically aligned (VA) liquid-crystal cell containing liquid-crystal cell molecules aligned substantially vertically to cell substrates with positive or negative dielectric anisotropy, polarizers disposed on opposite surfaces of the liquid-crystal cell, and one or two phase retarders exhibiting index anisotropy of nx=ny>nz and interposed between the liquid-crystal cell and either or each of the polarizers. An optical device made of cholestric liquid crystal has been proposed as the phase retarder (Unexamined Japanese Patent Publications No. Sho. 62-210423 and No. Hei. 3-67219).
The phase retarder is provided for compensating for birefringence produced in an oblique viewing azimuth displaced from a frontal direction to prevent light leakage to thereby obtain good black display even in such an oblique viewing direction. That is, the VA liquid-crystal cell transmits light on the basis of substantially vertical alignment of liquid-crystal molecules of the liquid-crystal cell almost without any change of the plane of polarization. Hence, arrangement of the polarizers in the form of crossed-Nicol on opposite surfaces of the cell can achieve light blockade in a frontal direction perpendicular to the liquid-crystal cell when the liquid-crystal cell is inactive, that is, when the liquid-crystal cell is not supplied with any external voltage. Hence, there is a tendency that good black display is formed in the frontal direction but birefringence occurs in an oblique viewing direction. The phase retarder is provided for compensating for such birefringence. In the background-art cholesteric liquid-crystal type phase retarder, there was however a problem that display quality is deteriorated because of variations in the compensating effect.
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The present disclosure relates to subject matter contained in Japanese Patent Application P2000-205173 filed on Jul. 6, 2000, which is expressly incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a backlighted liquid crystal display (LCD) assembly mounted on a circuit substrate.
2. Description of the Related Art
LCD""s are widely used in applications where space and weight are limiting factors. One of such applications is information indicators used in compact electronic cameras, which provide visual information about various settings and conditions of a camera to, the camera user. Other compact, portable, electronic devices, such as mobile computers and cellular phones, may also often have an information display using an LCD. Because LCD""s are not self-illuminating, some sort of backlighting is desirable in order for LCD""s to be viewed even when electronic cameras or other portable electronic devices are used under night or other low light level conditions.
Light-emitting panels, such as electroluminescent (EL) panels, have been used for providing backlighting of LCD""s because an EL panel can be formed as very thin panel so that it allows backlighted LCD""s to have a highly reduced thickness. More specifically, a typical backlighted LCD assembly that is designed to be mounted on a circuit substrate includes an LCD screen panel formed as a thin, flat panel and an EL panel also formed as a thin, flat panel and disposed behind the LCD screen panel. The EL panel is disposed behind the LCD screen panel in order to provide backlighting of the LCD screen, and both of the panels are mounted on and electrically connected to the circuit substrate.
Generally, the space available for installation of a backlighted LCD assembly in an electronic camera or other portable electronic device is so limited that the assembly should be designed to have as reduced a thickness as possible. However, it has been often difficult to achieve a backlighted LCD with a sufficiently reduced thickness, primarily due to the required electrical connections between the circuit substrate and the LCD screen panel and between the circuit substrate and the EL panel. These electrical connections tend to increase the total thickness of the assembly. Further, these electrical connections may often lead to relatively high manufacturing costs of the assembly.
In view of the foregoing, it is an object of the present invention to provide a backlighted liquid crystal display assembly mounted on a circuit substrate, which includes a liquid crystal display (LCD) screen panel formed as a thin, flat panel and a light-emitting panel also formed as a thin, flat panel and providing backlighting of the LCD screen panel, wherein the required electrical connections between the circuit substrate and the LCD screen panel and between the circuit substrate and the light-emitting panel are improved in order to minimize the thickness of the assembly and/or reduce the manufacturing costs of the assembly.
In accordance with the present invention, there is provided a backlighted liquid crystal display assembly mounted on a circuit substrate. The circuit substrate has a mounting surface having contact pads formed thereon for electrical connection with the assembly. The assembly comprises: a liquid crystal display (LCD) screen panel formed as a thin, flat panel and having contact pads for external electrical connection; a light-emitting panel for providing backlighting of the LCD screen panel, the light-emitting panel being formed as a thin, flat panel and having contact pads for external electrical connection; at least one electrical-interconnection rubber member having a plurality of conductive areas formed of a conductive rubber material and at least one insulating area formed of an insulating rubber material and separating the plurality of conductive areas from each other; and a retainer structure which retains the LCD screen panel, the light-emitting panel and the at least one electrical-interconnection rubber member to the mounting surface of the circuit substrate while keeping them in a predefined positional relationship such that (i) the electrical-interconnection rubber member has a first portion disposed and compressed between the LCD screen panel and the mounting surface of the circuit substrate and a second portion disposed and compressed between the LCD screen panel and the light-emitting panel and (ii) the conductive areas of the electrical-interconnection rubber member are in contact with and provide electrical interconnection among the contact pads of the circuit substrate, the contact pads of the LCD screen panel and the contact pads of the light-emitting panel.
The LCD screen panel may have interconnection conductive traces formed thereon, each of which has opposite ends terminating at corresponding ones of the contact pads of the LCD screen panel. In such a case, the light-emitting panel and the circuit substrate may be electrically interconnected through the at least one electrical-interconnection rubber member and the interconnection conductive traces.
The LCD screen panel may have front and back surfaces, with the contact pads of the LCD screen panel being formed on the back surface of the LCD screen panel. The light-emitting panel may have front and back surfaces, with the contact pads of the light-emitting panel being formed on the front surface of the light-emitting panel. Further, the LCD screen panel and the light-emitting panel may be retained by the retainer structure such that (i) the back surface of the LCD screen panel and the front surface of the light-emitting panel are opposed to each other, (ii) the first portion of the electrical-interconnection rubber member is disposed and compressed between the back surface of the LCD screen panel and the mounting surface of the circuit substrate and (iii) the second portion of the electrical-interconnection rubber member is disposed and compressed between the back surface of the LCD screen panel and the front surface of the light-emitting panel.
The light-emitting panel may be retained to the mounting surface of the circuit substrate, with the back surface of the light-emitting panel being pressed against the mounting surface by resilient force of the at least one electrical-interconnection rubber member being compressed.
The LCD screen panel may be generally rectangular in shape and have a first pair of opposite side edges and a second pair of opposite side edges, with the contact pads of the LCD screen panel being arranged in a pair of rows extending along the first pair of opposite side edges, respectively. The at least one electrical-interconnection rubber member may comprise first and second bar-like electrical-interconnection rubber members extending along the first pair of opposite side edges, respectively, of the LCD screen panel. Further, the first bar-like electrical-interconnection rubber member may have a first portion disposed and compressed between the LCD screen panel and the mounting surface of the circuit substrate and a second portion disposed and compressed between the LCD screen panel and the light-emitting panel.
The light-emitting panel may be generally rectangular in shape and have a first pair of opposite side edges, a second pair of opposite side edges and a tab portion projecting from one of the first pair of opposite side edges, with the contact pads of the light-emitting panel being located on the tab portion. In such a case, the second portion of the first bar-like electrically-interconnection rubber member may be disposed and compressed between the LCD screen panel and the tab portion of the light-emitting panel.
The retainer structure may comprise a generally rectangular frame for receiving therein and locating the LCD screen panel, the light-emitting panel and the first and second bar-like electrical-interconnection rubber members relative to the frame.
In addition, the retainer structure may comprise a retainer cap for (i) retaining the rectangular frame at its desired positions on the mounting surface of the circuit substrate and (ii) engaging the front surface of the LCD screen panel along the side edges thereof to press the LCD screen panel against the bar-like electrical-interconnection rubber members so as to compress the latter.
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In a known fashion, the friction existing between the movable valve body and the valve element of the valve that is integral with the housing, as soon as the valve is to be actuated, must be reduced to the relatively low value of sliding friction to ensure reliable response of the valve and especially to avoid the development of stick-slip effects, especially during the small strokes that correspond to only a fraction of the maximum control stroke. The time intervals within which certain functional positions and/or opening cross sections of flow paths in the valve are reached are kept as short as possible in this manner.
An exciting winding associated with one of the functional positions of the solenoid valve is energized, and a ripple is imposed on its exciting current that results in a pulsating rise and fall of the magnetic forces that "pull" the armature against the action of a return spring into its required position. This required position, which corresponds to a desired throughput cross section of the valve in this functional position, must result from the equilibrium of the magnetic positioning force generated by the excitation of the winding and by the restoring force of the respective acting valve spring, which increases with deflection of the armature. In order to achieve short switching times for solenoid valves controlled in this manner, powerful return springs must be used and high exciting currents must be generated to energize the exciting windings, powerful return springs to permit a rapid return of the armature to its basic position when the excitation is shut off, and high exciting currents in order to displace the armature sufficiently rapidly against the action of the powerful return springs. To accelerate the switching processes, as proposed in British 885,121, it is also possible, when shutting off the excitation of one exciting winding briefly, to excite the winding that produces magnetic forces in the opposite direction, but this would entail considerable control-engineering expense and/or considerable expense for additional control windings.
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Heretofore, as a method for producing cyclohexyl alkyl ketones, there is known a method of obtaining them from a Grignard reagent synthesized from bromocyclohexenes, and a fatty acid chloride (see Non-Patent Document 1). Also known is a method of obtaining them by synthesizing cyclohexanecarbonitrile followed by similarly reacting it with ethylbromomagnesium (see Non-Patent Document 2). However, the above-mentioned prior-art technique has some problems in that the process is long and the disposal of wastes such as metal salts and others is difficult. In addition, in case where an aromatic ketone is hydrogenated with pressurized hydrogen according to the prior-art technique (see Non-Patent Document 3), the process involves a drawback in that not cyclohexyl alkyl ketones but aliphatic alcohols or alkylcylohexanes are synthesized as a result of reduction of the carbonyl group. Further, Patent Document 1 describes a method of producing a cyclohexyl alkyl ketone in which the cyclohexyl group has an alkyl substituent, as a result of hydrogenation of a phenyl alkyl ketone in which the phenyl group has an alkyl substituent; however, the yield in this method is about 30% and is low.
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Control of the vertical position of the arc in a horizontally-operated HID lamp is desirable in a number of lighting applications, particularly automotive HID headlamps. The reasons are several-fold, and depend on the application. In horizontal HID lamps, the arc is bowed upwards by buoyancy induced gas convection in the arc tube. Straightening the arc can improve lamp life and color by both eliminating overheating of the top of the arc tube and increasing the temperature of the fill chemicals which reside at the bottom of the arc tube. In addition, a straightened arc provides a light source which is more compatible with optical collection and projection systems. It may also be desirable to move the light beam which is projected from the optical system by deflecting the arc in a controlled manner.
Several techniques have already been used to straighten arcs of horizontally operated lamps. These include the use of narrow-bore arc tubes to constrain the arc; excitation of acoustic resonances in the gas in the arc tube; rotating the gas in the arc tube about the arc axis either by flowing the gas, or rotating the entire arc tube; and applying a downward force on the gas by applying a horizontally oriented magnetic field which is perpendicular to the arc axis.
The force on the arc by a magnetic field is the vector cross product of the arc current and the magnetic field. If the arc axis and the magnetic field are perpendicular, and both lie in the horizontal plane, the force is vertical. The direction and magnitude of the force depends on the product of the magnitude and direction of the magnetic field and the arc current. To maintain a downward force on an alternating current arc, therefore, the magnetic field must be an alternating current synchronized with the arc current. This approach has been demonstrated and has been proposed as a product for automotive headlamps. The problem with this approach is that the equipment required to produce an alternating current magnetic field of sufficient magnitude is large, cumbersome, energy-consuming, and heat producing. Positioning the magnetic pole-pieces without negatively-impacting the design of the optical fixture is a challenge. Early attempts to achieve magnetic deflection with alternating current failed. The electromagnets were too slow. It was believed, that it was not possible to create fast and alternating magnetic fields to follow the signal of the alternating current ballast. Recently this has been overcome as shown in U.S. patent application Ser. No. 09/099,379.
By contrast, a direct current arc is easily straightened or deflected by a constant magnetic field of a modest level which is easily achieved even at a significant distance from a permanent magnet. However, direct current is not desirable in HID lamps because the current flow in one direction causes migration of the chemicals toward the cathode and results in separation of the various color components of the arc. Additionally, the anode and cathode electrodes must be designed differently, and the entire arc tube constructed asymmetrically to account for the unequal heat loads, and sealing difficulties.
To be practical, the whole magnetically deflected arc lamp system must be simple and reliable. The lamp, the ballast and the magnetic system must each be inexpensive to manufacture, efficient to operate and reliable. A simple alternating current lamp would be useful, but this has required the synchronized magnets described. A simple permanent magnet or electromagnet would be useful, but this has required the less desirable direct current lamps. The combination has not been possible. The present Applicant has now found a solution.
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1. Field of the Invention
The present invention relates to improvements in methods and apparatus of the type commonly used to automatically and rapidly sort minute particles, e.g. biological cells, entrained in a moving liquid on the basis of certain predetermined particle characteristics. More particularly, it relates to a particle-sorting method and apparatus in which particles of interest are selectively extracted from their entraining liquid by using a hydraulic impulse to selectively eject such particles of interest from the entraining liquid.
2. The Related Prior Art
Flow cytometry is commonly used to differentiate various types of cells and other “formed bodies” comprising a biological fluid, e.g., whole blood. Conventional flow cytometers commonly comprise an optically-transparent flow cell, usually made of quartz, having a central channel through which a stream of cells to be individually identified is made to flow. Movement of the cell stream through the flow cell channel is hydrodynamically entrained to the central longitudinal axis of the flow cell channel by a cell-free sheath liquid that concentrically surrounds the cell stream and flows along with the cell stream as it passes through the flow cell channel. As each cell passes through a cell-interrogation zone of the flow cell channel, it is irradiated with a focused beam of radiation (as commonly provided by a laser source). Upon impinging upon each cell, the laser beam is scattered in a pattern characteristic of the morphology, density, refractive index and size of the cell. Further, the spectral characteristics of the laser beam may act to excite certain fluorochromes associated with selected cells, as may be the case when a cell's DNA has been previously stained with such fluorochromes, or when a fluorochrome molecule has been previously conjugated with a selected type of cell, either directly or via an intermediate bead or the like. Photodetectors strategically positioned about the optical flow cell serve to convert the light-scattered by each cell and the fluorescence emitted by the excited fluorochromes to electrical signals which, when suitably processed, serve to identify the irradiated cell. In addition to the light scatter and fluorescence measurements made on each cell, some flow cytometers further characterize each cell by measuring certain physical and/or electrical properties of each cell as it passes through the flow cell. Using the well-known Coulter Principle, a DC and/or an RF current is caused to pass through a constricted aperture in the flow cell channel simultaneously with the movement of cells therethrough. The volume of each cell affects the level of DC current through the flow cell aperture, and the cell's electrical conductivity affects the RF current through such aperture. See, for example, the flow cytometer disclosed in the commonly assigned U.S. Pat. No. 6,228,652, issued in the names of Carlos M. Rodriguez et al.
A conventional light scatter and fluorescence-sensing flow cytometer of the type noted above is disclosed in U.S. Pat. No. 3,710,933 issued to Mack J. Fulwyler et al. To this standard flow cytometer, Fulwyler et al. have added a cell-sorting component that operates to selectively remove and collect certain cells of interest (e.g., abnormal cells) from the effluent of cells that have already passed through the optical flow cell and have been identified as to cell type. More specifically, the cell-sorting component comprises a piezoelectric device that acts to vibrate the flow cell so as to effect the production a stream of droplets from the cell-entraining sheath liquid exiting from the flow cell. Ideally, each droplet contains but a single cell that has been characterized as to cell type by the light-scatter and fluorescence measurements just made on such cell. Each droplet in the droplet stream is then electrostatically charged as it passes between a pair of electrically charged plates, and each charged droplet is selectively deflected (or not deflected) towards a collection container as it passes between a pair of electrostatically charged deflection plates, such plates being charged to a droplet-deflecting polarity only at a time to deflect droplets (and cells) of interest. The instantaneous polarity of the deflection plates is determined by a cell-characterization processor that processes the cell-measurement signals from the optical flow cell.
In cell-sorting flow cytometers of the above type, the continuous production of suitably sized droplets can be problematic. Not only is it technically difficult to continuously produce droplets that contain only a single cell, but also the required size of the droplets is so small (aerosol in size) that it is difficult to control their precise movement as they exit from the flow cell. Typically, when it is suspected that a droplet contains more than one cell, the droplet is allowed to proceed to a waste container in order to avoid potential contamination of the collected cells of interest with other cells.
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Sense amplifiers are used as sensing elements to detect the cell status in a memory array field, e.g. in a flash memory. There is an increasing demand for performance improvements such as latency reduction and power reduction.
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Use of syringes for injections is commonplace in hospital environments as well as in clinics and even homes for example, by diabetics and the like. As used herein, the term "syringe" broadly refers to a medical instrument used to inject fluids into the body or draw fluids from the body. In general, syringes include a plastic barrel in communication with a metal needle provided for insertion into a vein, muscle or the like. Liquid material to be injected into the body can be provided in the plastic barrel and dispensed through the needle which is in fluid communication therewith. Alternatively, body fluids can be withdrawn through the needle and collected in the plastic barrel. Because of the intimate nature of the uses to which syringes are put, it is important that they be provided initially in a sterile condition. However, syringes are no longer sterile after use. Accordingly, disposal of used syringes has become a major health problem.
There has always been and continues to be a danger that a person will stab themselves with the needle of a used syringe. This danger is heightened in this day of infectious and deadly diseases such as AIDS, hepatitis and the like since it is not possible to know if the person who used the syringe had such a disease. Consequently, all used syringes have become suspect objects of fear and are subject to strict disposal standards.
Hospitals, clinics and doctor's offices are generally required to separate the needle from the plastic barrel of the syringe and to dispose of each in separate and secure approved containers for disposal of infectious waste. In addition, infectious waste can only be removed for destruction by licensed carters, who must be hired by the hospital, clinic or doctor's office.
Numerous syringe disposal systems wherein the syringe is somehow broken or severed are known. One such system is disclosed in U.S. Pat. No. 4,565,311 issued to Pugliese et al. on Jan. 21, 1986. The device disclosed in Pugliese is a machine having knives, which are mounted so as to be capable of engaging a syringe positioned in the machine and severing the syringe in multiple locations. After severing, the parts of the syringe fall into a container and the container is disposed of as a unit.
U.S. Pat. No. 4,375,849 issued to Hanifl on Mar. 8, 1983 discloses a needle removal and disposal device including a container with a cap. The cap includes means for disengaging the needles from the syringes. The disengaged needles are stored within the container. The device does not provide means for disposing of the plastic portion of the syringe.
U.S. Pat. No. 4,452,358 issued to Simpson on June 5, 1984 shows a medical appliance disposal container having at least one opening for insertion of medical appliances. At least one of the openings includes a needle destruction means whereby needles can be destroyed while attached to a syringe and the destroyed needle-syringe assembly can be inserted into the disposal container through the opening. The disposal container is designed for use throughout a health care facility and is useful for reducing the risk of spillage if the container is upset.
U.S. Pat. No. 4,488,643 issued to Pepper on Dec. 18, 1984 discloses a disposal system for syringe and needle combinations. The system includes a container that has a lid with a flexible resilient one-way valve. The valve permits the needle and/or syringe to be inserted, but prevents reemergence of the needle and/or syringe out of the container. The lid further includes a passive bending structure which bends the needle to render it unusable prior to insertion into the container.
U.S. Pat. No. 4,553,687 issued to Harkins et al on Nov. 19, 1985 discloses yet another needle breaking and storage device. The device includes a closed compartment with an aperture in one wall for receiving a hypodermic needle and permitting it to be severed and to fall into a storage receptacle. Various ways of retaining the severed needle tips in the receptacle are disclosed including a magnet and a viscous liquid which partially coats the severed tips. The device further includes a second aperture dimensioned to similarly allow the severance of the tip of the hypodermic syringe and a separate receptacle for storage of the severed syringe tips.
A different type of syringe disposal unit is shown in U.S. Pat. No. 4,662,516 issued to Baker, Sr. et al. on May 5, 1987. The Baker apparatus includes a series of wall units, each of which include a pivoted, lockable panel and an upper opening for supporting the top surface of a thermoplastic liner contained in a basket. Medical debris is collected in the thermo-plastic liner which is periodically removed and heated in an autoclave to melt the liner around the debris. The liner is melted at a temperature of less than about 250.degree. F. while pressure is maintained on the bag and liner. This temperature is not sufficient to melt the plastic of the syringes within the liner and accordingly, the liner and syringes are only sterile as long as the liner is not punctured. It is certainly not sufficiently sterile to meet requirements of the Federal Environmental Protection Agency (E.P.A.), the Food and Drug Administration (F.D.A.), and a significant number of Health and Sanitation Departments, namely including New York. All of the prior art syringe disposal systems are disadvantageous in that the syringe material is not rendered sterile and special disposal of the material as infectious waste is necessary.
It is, therefore, an object of the invention to provide an apparatus that processes used syringes for sterile disposal.
Another object of the invention is to provide an apparatus for processing used syringes for disposal which melts the plastic portion of the syringe so that the melted plastic can encapsulate the needle to form a melted mass and renders the melted mass sterile.
A further object of the invention is to provide a process for rendering used syringes sterile for disposal purposes.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
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The invention generally relates to polishing pads with a window, systems containing such polishing pads, and processes for making and using such polishing pads.
The process of fabricating modern semiconductor integrated circuits (IC) often involves forming various material layers and structures over previously formed layers and structures. However, the underlying features can leave the top surface topography of an in-process substrate highly irregular, with bumps, areas of unequal elevation, troughs, trenches, and/or other surface irregularities. These irregularities can cause problems in the photolithographic process. Consequently, it can be desirable to effect some type of planarization of the substrate.
One method for achieving semiconductor substrate planarization or topography removal is chemical mechanical polishing (CMP). A conventional chemical mechanical polishing (CMP) process involves pressing a substrate against a rotating polishing pad in the presence of a slurry, such as an abrasive slurry.
In general, it is desirable to detect when the desired surface planarity or layer thickness has been reached and/or when an underlying layer has been exposed in order to determine whether to stop polishing. Several techniques have been developed for the in situ detection of endpoints during the CMP process. For example, an optical monitoring system for in situ measuring of uniformity of a layer on a substrate during polishing of the layer has been employed. The optical monitoring system can include a light source that directs a light beam toward the substrate during polishing, a detector that measures light reflected from the substrate, and a computer that analyzes a signal from the detector and calculates whether the endpoint has been detected. In some CMP systems, the light beam is directed toward the substrate through a window in the polishing pad. A layer of slurry is typically present between the substrate and an upper surface of the window.
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The present disclosure relates to a method of exposing an extreme ultraviolet (EUV) photoresist, and an apparatus for implementing the same.
Extreme ultraviolet lithography is a lithography technology using an extreme ultraviolet (EUV) wavelength radiation for exposure. As used herein, EUV refers to a range of electromagnetic radiation having a wavelength from 10 nm to 50 nm. When an EUV photon is absorbed in a photoresist, at least one photoelectron, secondary electrons, and thermal electrons are generated by ionization. The photoelectrons are generated as a direct result of a photon-matter interaction between the EUV photon and the matter in the photoresist layer. The secondary electrons are caused by collision of the photoelectron with additional electrons as the photoelectron travels through the photoresist material. The thermal electrons are derived from the photoelectrons or the secondary electrons due to their energy loss or due to collisions that transfer energy less than about 2.5 eV.
EUV photoresist exposure (on a semiconductor wafer) is typically accomplished by generating photoelectrons within a photoresist layer. Upon generation, the photoelectrons do not have controlled directionality. As a result, feature edges defined by an EUV exposure are variable and dependent upon the path of the secondary electrons, their inelastic collisions, the resultant thermalization that ultimately drives the decomposition of the photoacid generator (PAG) within the photoresist, and the resist polymer/molecular distribution and homogeneity for reaction sites.
Thermalized electrons are estimated to have a mean free path of about 2 nm to 5 nm. Currently, the imaged feature edge roughness, as well as resolution of the minimum feature size, is insufficient for EUV lithography to be able to achieve the required performance for utilization in semiconductor manufacturing. To date, high volume semiconductor wafer exposure tooling has not had to address photoelectron directionality, as the resist exposure has been a photon induced reaction.
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1. Field
Example embodiments relate to a transflective display apparatus.
2. Description of the Related Art
Mobile devices, for example, mobile phones, personal digital assistants (PDAs), portable multimedia players (PMPs), and digital multimedia broadcasting (DMB) devices, have become widely used. These mobile devices have caused changes in lifestyles in view of their amount of use, application fields, and diverse contents. Mobile device displays have expanded to allow the display of web documents and video from a relatively simple information type display, for example, the display of sound and text.
In addition to displays of mobile devices, public information displays (PIDs) are leading a main outdoor billboard market owing to an emerging tendency toward video outdoor billboards instead of text based outdoor billboards. Outdoor visibility is a performance index for PIDs.
Transmittive display apparatuses or self-emission type display apparatuses with illumination of high luminance may be used to display a clear image in the bright outdoors. However, these display type apparatuses consume a relatively large amount of energy. Research into reflective type display apparatuses for displaying an image by using a peripheral light without additional energy consumption has been conducted, but the reflective type display apparatuses are inferior to the transmittive display apparatuses or self-emission type display apparatuses in terms of brightness and/or image quality.
A transflective display apparatus may use an external light and light of an embedded light source as image forming light. The external light is used to form an image in the bright outdoors, an inside light is used to form the image in a dark place, and both the external light and inside light are used to form the image in an environment of intermediate luminance, thereby forming an image having high visibility in any environment and reducing the amount of energy consumed by the embedded light source.
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With the spread of mobile communication through mobile phones, services have recently been provided based on a wireless communication system with high-speed capability, e.g., W-CDMA or CDMA-2000 technology. Direct sequence spread spectrum is used in such a mobile communication system to improve a communication rate and a call quality. A pseudo noise (PN) code, which is pseudo-random binary data, is used as a spreading code for the direct sequence spread spectrum. A PN code generator having a small circuit scale and high-speed capability is desired.
FIG. 14 is a circuit diagram illustrating a conventional PN code generator 80, and FIG. 15 is a diagram depicting an operation of the conventional PN code generator 80.
As illustrated in FIG. 14, the conventional PN code generator 80 is configured of a shift register consisting of fifteen registers FF1 through FF15 connected in series, and a single exclusive-OR gate XR. A feedback output of the last stage register FF15 is input through the exclusive-OR gate XR to the first stage register FF1. An output of the first stage register FF1 is input to the exclusive-OR gate XR.
Referring to FIG. 15, suppose that the initial contents of the individual registers FF1 through FF15 are D1 through D15, respectively. If a clock pulse is applied to each of the registers FF1 through FF15, the contents thereof are shifted by one bit into the next register FF and, further, the contents of the first stage register FF1 becomes contents obtained as a result of the exclusive-OR operation of the contents of the first stage register FF1 itself and the contents of the last stage register FF15. This is performed in response to the application of each clock pulse.
There is proposed a circuit for generating parallel pseudo-random data (Japanese Laid-open Patent Publication Nos. 9-321585 and 2002-342072).
In the case of the PN code generator 80 as illustrated in FIG. 14, one-bit data is produced every clock cycle. Accordingly, time corresponding to two clock cycles is necessary to produce two-bit data, and likewise, time corresponding to “n” clock cycles is necessary to produce n-bit data.
In order to produce n-bit data, e.g., 8-bit data, at high speed, it is necessary to appropriately increase the clock rate, which unfortunately makes the circuit configuration complicated.
The devices disclosed in Japanese Laid-open Patent Publication Nos. 9-321585 and 2002-342072 are capable of outputting multi-bit data in parallel; however the circuit configuration thereof is complex.
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Reference is made to my own prior U.S. Pat. No. 3,287,866 upon an improved foundation and wall drainage system including a drainage tile positioned adjacent the inner wall of the footer of the outer block wall-footer construction in a conventional basement wall. The basement wall has drain openings provided in the inner wall of the block wall whereby water seeping into the block wall center openings can flow out to a gravel bed and down to a drain tile embedded in the gravel bed and positioned adjacent the footer. However, these drain tile and gravel bed in the prior units can get blocked with silt, or dirt. Normally gravel is placed around the drain tile to allow entry of the water into the drain tile. However, the chemicals in the water will stick to the gravel and, in time, not let the water pass through the pipe. These chemicals can be iron or lime in the water or chemicals on the surface of the rock. That is, the system has worked well but the material used for filling around the footer and foundation wall may become tightly packed and sand and gravel may pack into any original open areas adjacent the footer-drain tile area and tend to slow down or prevent good drainage through the system.
I also refer to my copending patent application, Ser. No. 535,157 relating to an improved wall and foundation drainage construction and utilizing a drainage member secured to or positioned on an upper inner surface of the footer and connecting to drainage openings provided in a bottom block of the wall and extending out to gravel means associated with the drain tile and an improved action can be obtained from a construction of that type which aids in the flow of water to the drain tile means provided.
Yet another type of a construction is shown in U.S. Pat. No. 3,283,460 wherein a protector strip of generally L-shape in vertical section is positioned on the inner corner of a wall and foundation unit to aid in sealing the connection therebetween, but to permit drainage from the wall thereunder down to an associated drain tile unit. A drain tile, is positioned on a basement floor and is operatively connected to the wall-foundation unit at the lower inner surface thereof, as shown in U.S. Pat. No. 3,304,672 but this type of a drainage tile means is unsightly and is exposed to damage by not being covered in the wall-foundation unit. Further, relative to the piping system of this patent which is placed upon the floor, this system will not work for various reasons. The cement used will come loose in time, as there is no cement which will permanently adhere where water is constantly present. In addition, since the unit is placed upon the floor, there is always that half of the block under the floor which will never drain, resulting in the constant presence of corrosive water and musty odors.
In poured concrete basements, water will penetrate between the footer and the wall due to the pressure existing on the outside of the wall and footer. This new inside drainage system allows water to move freely into the pipe.
The general object of the present invention is to provide a new and improved block wall and foundation drainage construction apparatus wherein an open drainage area is provided immediately adjacent an inner wall of the footer of the wall-foundation unit.
Another object of the invention is to provide an improved drainage tile in a foundation drainage assembly wherein the drainage tile can be molded from plastic or other extrudable material and wherein drain apertures can be provided in a lower portion thereof and a reinforcing or support flange can be provided thereon on an upper portion of the drainage tile.
Another object of the invention is to provide a drainage tile which can be molded in a plurality of pieces and be readily assembled into an open centered drainage unit, and to have an upper shelf provided on the drainage tile and position it at and above an open area provided adjacent the footer and which support shelf connects to the block wall above drainage openings provided therein.
Other objects of the invention are to provide a novel and improved hollow centered drainage means, to support a cover plate or support shelf of a drain tile assembly in a unique manner in a basement drainage system; to utilize conventional members in making up a block wall-footer unit and to form an efficient, long lived drainage means for a basement which is competitive in price and which will provided long service life.
In general the present invention relates
a foundation wall and drainage tile system which comprises PA1 a footer, an inner wall of the footer having an open area extending therealong, PA1 a wall formed of hollow building blocks with openings in their upper and lower surfaces and arranged vertically on the footer, the lower most row of the building blocks having space and portions in the inner wall surfaces thereof communicating with the interior of the hollow building blocks to form drainage openings adjacent to the open area provided, and PA1 a basement floor is present and is above the drainage openings, and a drain means including a hollow center portion having a plurality of drain slots formed in a lower area thereof is positioned in the open area provided adjacent the footer, and PA1 a plate means bridging over said open area and supported on the drain means and a part of the blocks above the drainage openings whereby the plate means can support a marginal portion of the basement floor thereon.
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Digital communication receivers typically must sample an incoming waveform and then reliably detect the sampled data. Typically, a receiver includes a Clock and Data Recovery (CDR) system to recover the clock and data from an incoming data stream. The CDR system generates a clock signal having the same frequency and varying phase as the incoming signal, which is then used to sample the received signal and detect the transmitted data.
CDR systems often employ well-known multiple stage proportional-integral (PI) digital loop filters, typically having multiple integrators in series. In a second order filter, for example, the first integrator includes a proportional register (PREG), and the second integrator includes an integral register (IREG), in a known manner. The CDR system recovers or locks to an initially unknown phase offset and frequency offset present in the incoming signal The integral state of the loop is directly related to the frequency offset The integral register is typically initialized to a value of zero (0) and the integral register value will eventually converge to a value that is proportional to the frequency of offset.
When a CDR is in a locked state, the sampling latches see a time stationary NRZ signal As a result, the Decision Feedback Equalization (DFE) eye opening can be calculated by comparing (for example, using an exclusive-or operation (XOR)) the decision latch output with the output of a vertical roaming latch, constrained with N-previous bits. See, fox example, U.S. patent application Ser. No. 11/540,946, filed Sep. 29, 2006, entitled “Method And Apparatus For Determining Latch Position For Decision-Feedback Equalization Using Single-Sided Eye,” for a discussion of DFE eyes. If the CDR loses the locked state, however, the NRZ signal is not time stationary. The CDR will start to diverge from the sampling clocks. When a CDR is out of lock, the CDR loop may build up the wrong values for the integral and proportional registers (IREG and PREG) Conventional techniques have used integral register (IREG) or proportional register (PREG) variability as an indication of CDR loss detection. Such conventional techniques, however, may confuse integral or proportional register variability with actual parts-pet-million (ppm) deviation
A need exists for methods and apparatus for detecting a loss of lock condition in a clock and data recovery system. A further need exists for methods and apparatus that take corrective action to restore a locked condition in a clock and data recovery system.
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Hydroforming is a cost-effective method of shaping ductile metals such as aluminum, brass, low alloy steels, and stainless steel into lightweight, structurally stiff and strong pieces. Hydroforming is widely used in the automotive industry for making complex shapes that are made possible by the hydroforming process to produce stronger, lighter, and more rigid unibody structures for vehicles, as well as in the shaping of aluminum tubes for bicycle frames. Hydroforming is a specialized type of die forming that uses a high pressure hydraulic fluid to press room temperature working material into a die. In order to hydroform aluminum into a vehicle's frame rail, a hollow tube of aluminum is placed inside a negative mold that has the shape of the desired result. High pressure hydraulic pumps inject fluid at very high pressure inside the aluminum, which causes the aluminum to expand until it matches the mold. The hydroformed aluminum is then removed from the mold. Hydroforming allows complex shapes with concavities to be formed, which would be difficult or impossible with standard solid die stamping. Hydroformed parts can often be made with a higher stiffness-to-weight ratio and at a lower per unit cost than traditional stamped or stamped and welded parts. Virtually all metals capable of cold forming can be hydroformed, including aluminum, brass, carbon and stainless steel, copper, and high strength alloys.
The design of the front end architecture of a vehicle is often influenced by assembly requirements for engine installation, and the vehicle's cooling system module. Furthermore, installation clearances for the front bumper often require splitting the lower bar radiator support away from the bolster, which may require a roll form stamping of the lower bar to meet structural requirements.
Thus, there exists a need for front end load bearing bolsters with improved structural performance and lower component weight, while also minimizing material, tooling, and production costs.
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1. Field of the Invention
The present invention relates to pattern recognition and more particularly to a novel system which is useful in identifying shapes of various objects and patterns.
2. Description of Prior Art
According to a typical prior-art system of pattern recognition, the contour of an object under observation is first analyzed by the spatial analysis, followed by replacement of the analyzed contour line by infinitesimal line segments. Line functions of the line segments are then computed by the method of least squares, thereby to determine the edge lines.
Finding functions for infinitesimal line segments of a contour line, which is an essential part of the prior-art system, invariably involves very complicated time-consuming processes, requiring a sophisticated apparatus. Furthermore, any complicated shapes which are impossible to express in terms of line functions cannot be identified by a system of the type just discussed.
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As is well known to those skilled in the art, it is desired to provide lubricating oil systems which minimize the friction between moving parts of a machine. Constant attempts are being made to find new techniques and compositions which may permit improved operation.
It is an object of this invention to provide novel compositions and a process for preparing these compositions. Other objects will be apparent to those skilled in the art.
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1. Field of the Invention
The present invention relates to a high-voltage electronic part, in particular, to a high-voltage block for supplying voltage to a focusing electrode of a CRT, and if necessary for supplying voltage to a screen electrode of a CRT.
2. Description of the Prior Art
For supplying voltage to a focusing electrode of a CRT, a high-voltage electronic part such as a high-voltage block is used. With such a high-voltage electronic part, a voltage-dividing resistor is used for division of the voltage from a flyback transformer. The voltage-dividing resistor is stored in a case. In this case, there are also stored a coupling capacitor, which is used for overlapping dynamic focusing voltage on output divided by the voltage-dividing resistor, and a smoothing capacitor for smoothing output from the voltage dividing resistor for focusing.
However, since the voltage supplied with such a high-voltage electronic part is high, an adequate distance is required between the voltage-dividing resistor and the capacitor when the insulation and the influence of the induced ripples are taken into consideration. Therefore, it is difficult to miniaturize the high-voltage electronic part. Furthermore, since the high-voltage electronic part can not be miniaturized, influence induced by heat is large, and there are problems about its reliability e.g. risk of deformation thereof.
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This invention relates to stabilized earth structures, and particularly to stabilization of embankments.
In my prior U.S. Pat. Nos. 3,421,326 and 3,686,873, I have described structures which stabilize an earth mass. These prior patents disclose elongated reinforcing elements which have a substantially uniform cross section throughout their length, and which are sufficiently pliable or flexible to allow for slight displacement in a vertical direction to accommodate for uneven placement of the earth during construction of the structure. The earth adjacent the elements engages the surfaces of the reinforcing element with sufficient pressure to prevent longitudinal displacement of the reinforcement elements in the mass, although the reinforcing elements are subjected to substantial tensile forces.
Attempts have been made to increase frictional forces between the earth and the reinforcement members. For example, it has been proposed to use aluminum for the reinforcement members with its surface roughened by grooves, but this provides only a slight increase in the coefficient of friction.
A further difficulty with prior earth stabilization structures is that the metallic components are subjected to corrosion, particularly at joints. Over long periods of time, it is possible that corrosion would cause failure of one or more of the metallic components. In the past, this has been taken care of by providing metal components which have a greater cross sectional area than is necessary to support the forces anticipated. The obvious disadvantage of this technique is that additional metal is required, thereby increasing the cost.
Accordingly, it is an object of this invention to provide an improved earth stabilization structure wherein the frictional engagement between reinforcement elements and the earth mass is enhanced.
A further object of the invention is to provide an earth stabilization structure wherein metallic joints are protected from the effects of corrosion.
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1. Field of the Invention
The present invention pertains to the field of automated typesetting and more particularly relates to a method and apparatus for composing typographical artwork on color sensitive photographic medium.
2. State of the Prior Art
Ornamental fonts, that is, artistically rendered lettering, is presently used in a variety of print and visual media. For example, advertising copy, titles and headings in magazines, television station logos, motion picture titles and credits are just a few of the many uses for ornamental fonts. A wide variety of font designs exist, each design giving rise to an entire alphabet based on a common motif or appearance. The font may have a three dimensional appearance, including beveled edges and drop shadows. The letters may be rendered so as to impart the appearance of metallic reflections, of a chromed surface, color, light and shadow effects and an almost infinite number of combinations and variations, limited only by the artist's creativity and skill. Each character is individually rendered by an artist by elaborate and time consuming processes, onto a sheet of transparency film to create the desired composition. This procedure is tedious and makes such artistic typographical work very expensive as well as time consuming.
Where the typographical composition is to be of a monochrome nature, it is possible to use more economical photographic methods for preparing the typographical layout. The individual type characters may be stored, as for example, on photographic film and projected one by one onto a single sheet of photosensitive material. The letters are positioned on the photographic sheet so as to compose the desired layout. The composition is carried out visually by an operator who selects the individual characters and projects their images onto the desired location on the photographic sheet so as to compose the layout. This kind of photocomposition is possible for monochrome material because the photographic emulsion is relatively insensitive to selected wave lengths of radiation. Thus, it is possible to visually create a composition under red light, known as a "safe light," without exposing the monochrome photographic sheet. The images of the characters may be projected through a safe light filter onto the photographic material, such that their position and appearance are visible to the operator, but without exposing the photosensitive emulsion.
It is presently accepted in the industry that photocomposition of colored typographical artwork is not possible because color sensitive photographic material is sensitive to all wave lengths of visible radiation and such composition, therefore, cannot be carried out under a safe light by the aforementioned visual method. As a result, it is presently necessary to resort to the aforedescribed cut and paste methods of composing the typographic layouts.
There are, however, known optical and photographic devices which, due to their inherent flexibility and ability to be programmed to operate in various desired modes, could be adapted to operate in the manner disclosed herein. These devices include motion control animation cameras which are operated by servo-mechanisms under computer control. These devices are normally used to take multiple image photographs of objects placed on a movable table under a servo controlled camera. Such an animation stand with rotoscope capabilities could be adapted to perform the method disclosed herein by using the camera to project images onto the movable table and properly programming the computer. However no such use of these animation stands has heretofore been attempted, and such application is unknown in the industry. The scope of the present invention, therefore, extends to the use of existing animation stands and similar equipment which may be programmed to perform the novel process disclosed by this specification.
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There is an increased emphasis today on the development of computing tools which incorporate digital video capabilities. For example, a common computing application is the use of a teleconferencing workstation in which digital video information is transmitted across ordinary telephone lines. Conventional teleconferencing systems consist of a camera which captures an image and outputs a digital stream of data. This data is then compressed by an ordinary processor and encoded for subsequent transmission across phone lines. At the other end of the phone lines, another processing device performs the decoding process, which is simply the inverse of the encoding algorithm. Eventually, the original digital video information is retrieved and stored at the destination computing resource. Typically, a central processing unit of a microprocessor is utilized to perform both the encoding and decoding functions in present teleconferencing systems.
One problem with these prior art approaches is that system performance is usually constrained by the memory traffic along the various data pathways. For instance, digital information output from the camera is typically transmitted to the central processing unit along a system bus, which also communicates with a main memory. Data transmission between the CPU, camera, memory, and network across the system bus is slowed by the frequent memory traffic associated with normal video processing. In certain circumstances, adding a cache memory can actually increase the memory traffic since the cache must frequently access the main memory (e.g., during writebacks, updates, etc.).
Another problem with such systems is that the video camera, frame grabber board and the compression hardware are separate components. This means that each of these components must be interfaced and maintained separately, as described above.
By way of example, video information is usually transmitted from by the camera at data rates in excess of 10 megabytes per second (MB/sec). In teleconferencing applications, this video data eventually gets sent to the outside world via a network. In the meantime, however, the network is also sending encoded images back to the central processing unit to be decoded. The decoding process requires that the information first be written to memory, and then be operated on by the central processing unit. This tends to increase the memory traffic along the system bus.
As will be seen, the present invention offers a system providing video compression/encoding for communications across a network which alleviates much of the memory traffic along the system bus. The novel features of the invention allow for a dramatic decrease in the memory bandwidth requirements of the system, as well as providing increased video processing and computational abilities.
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1. Field of the Invention
The present invention relates generally to mobile communication devices which operate in wireless communication networks, and more particularly to methods and apparatus for limiting communication capabilities at the mobile device based on predetermined conditions detected at the mobile device.
2. Description of the Related Art
Modern-day mobile communication devices which operate in wireless communication networks provide end users with the ability to place and receive two-way voice calls, send and receive text messages and e-mail messages, and send and receive other information such as Internet data. Such communication devices utilize a radio frequency (RF) transceiver for transmitting and receiving such information.
Unfortunately, adverse conditions (such as adverse temperature conditions) may compromise the performance or utility of the mobile device. For example, when a mobile device is communicating information with use of its RF transceiver, the RF transceiver heats up and its temperature rises. If the temperature of the RF transceiver is outside certain specification parameters, the RF transceiver undesirably emits spurious signals at unacceptable levels. These spurious signals may be outside certain standards, such as those established by the Federal Communications Commission (FCC) or Industry Canada, for example, and/or cause interference with other communications in the network. In addition, if the temperature of a rechargeable battery of the mobile device is outside certain specification parameters for too long, the battery may experience permanent damage and require replacement or could even explode.
Under such adverse conditions, the mobile station could power down its circuitry and inhibit all communications, but the end user would be left with no ability to communicate information. This would be undesirable in at least some circumstances, such as in emergency situations. What are needed are methods and apparatus which overcome the deficiencies of current practices.
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This invention relates to devices useful in supporting and displaying decorative lighting, and more particularly, to a device adapted to support a decorative light, such as a Christmas light. One aspect of the invention relates to a plastic or metal bracket that will support a decorative light and can be installed without screws, nails or other hardware which may pierce or otherwise impair gutters or roofs. Another aspect of invention relates to a mounting bracket or a device for decorative lighting and is in itself supported by frictional engagement with a support structure such as gutters or roof shingles and provides mechanism by which the decorative light may be positioned at different angles with respect to a roof or gutter or other support surface. Another aspect of the invention is a bulb holder for use with the mounting bracket which accommodates bulbs of various sizes.
The use of decorative lighting for both commercial purposes and for residential purposes is well known. A major portion of exterior decorative lighting is seasonal in nature, such lighting being installed primarily during holiday periods and then removed after the holiday period has passed. Decorative lights are typically purchased as "strings" in which a large number of individual sockets are wired together, and bulbs, frequently colored, are inserted into each socket. Plugs are provided at one or both ends for connection to other light strings or to an electrical power source. Typically, at the Christmas season, there are bulbs which are of various sizes, for instance, mini bulbs, C-7 bulbs and C-9 bulbs. The C-9 bulbs are larger than the C-7 bulbs which are larger than the mini bulbs.
The present invention is directed to deficiencies that have been encountered with devices previously used to install and display exterior decorative lighting including the necessity of using a variety of bulb holders to accommodate bulbs of various sizes. In the past, exterior decorative lights have sometimes been installed by stapling light strings onto the eaves of fascia of a building. Stapling often leaves unattractive holes in the support surface when the decorative lighting and staples are removed. Moreover, the use of staples or the like also runs the risk of damaging the exterior coating on the power cords thereby possibly rendering the strings unsafe. Threaded hooks have also been used to support light strings in the past, but the hooks themselves are difficult to install, and did not secure the bulb sockets in a preferred orientation. One light bracket which does not mutilate or otherwise impair roofs, gutters or facia is disclosed Gary U.S. Pat. No. 4,851,977 issued Jul. 25, 1989. The device there disclosed installs between shingles on a roof and works for its intended purpose but lacks the versatility of the subject invention. Another device particularly adapted for gutters is illustrated in Adams U.S. Pat. No. 5,141,192, issued Aug. 25, 1992.
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Recent progress in sensor technology has allowed low-Earth-orbit (LEO) satellites to shrink significantly in size, disrupting a legacy industry where traditional satellites cost $500 million to $1 billion to build and launch. Major investments are being made to address the new opportunities this provides for data collection, and many companies are launching nanosatellites and/or microsatellites into LEO to capture this opportunity. The rapidly expanding satellite infrastructure is generating vast amounts of data, reaching nearly 20 PB/year in 2014, with no signs that the trend will level off. To bring the data down from LEO requires an average communication rate of 5 Gb/s, continuously, and that demand will continue to grow.
Typically, most satellites download data via space-to-ground radio-frequency (RF) links, communicating directly with fixed ground stations as the satellites fly within range. The current ground station infrastructure has several key limitations that present significant challenges as the satellite industry continues to grow. Satellite-to-ground communications are “line-of-sight,” meaning that ground stations can receive data directly only from satellites that are above the local horizon. The duration of a satellite pass over a ground station depends on the altitude of the satellite and the distance between the ground station and the ground track of the satellite. With satellites in LEO, the maximum pass duration is typically less than ten minutes.
The frequency of passes is strongly dependent on the satellite orbit parameters and the location of the ground station. For example, a satellite in equatorial orbit will pass over an equatorial ground station on each orbit. With a typical orbital period of 90 minutes, that means 16 passes per day. Similarly, a satellite in a polar orbit will pass over a ground station located at the North Pole once per orbit. On the other hand, the satellite in polar orbit will pass over the equatorial ground station between two and four times per day depending on the alignment of the ground track with the location of the ground station. However, the satellite in equatorial orbit will never pass over the polar ground station. Most LEO satellites are in orbits at some inclination between equatorial and polar, and most ground stations are located at latitudes well south of the North Pole. As such, the pass frequency for any given satellite over any given ground location will typically be three to five times per day for ground stations that are not at high latitude (above about 60 degrees) and not at latitudes higher than the orbital inclination of the satellite.
The consequence of limitations on pass duration and frequency is that a satellite in LEO will be within communication range of a given ground station for no more than 10 percent of a day, and typically for less than 2 percent of a day. These constraints on pass duration and pass frequency are driven by orbital dynamics and can be overcome by increasing the number of ground stations or locating the ground stations at very high latitudes. Avoiding downlink constraints requires a large number of geographically-diverse ground stations that are inherently underutilized.
One method of compensating for the limitations on ground contact time is to increase the data transmission rate during available contact time. High data rates in the RF require some combination of high transmitter power and high-gain antennas on the satellite and the ground station. High power transmitters and high-gain antennas on the space segment are constrained by power and mass limitations on the satellite. High-gain antennas on the ground are not mass limited, but tend to be very large (e.g., 10 meters or more in diameter) and require significant capital investment.
As data produced in LEO increases substantially with more satellites launched, downlink infrastructure must grow to meet demand. However, a more fundamental limitation to downlink rates will be encountered in the future, simply due to the overuse of available RF bandwidth in the space environment. Further, adding new RF ground terminals will not help, because the stations will interfere with one another. Similarly, RF bandwidth is constrained on the space side, i.e., when two satellites are relatively close to one another, their RF signals can interfere.
For new satellite companies leveraging advances in satellite costs, capital investment for an extended ground station network is particularly burdensome because the size and cost of the ground network does not scale with the size of the satellites. Ground station costs have not scaled at the same rate as satellite costs, requiring significant further investment to match growth in satellite capacity.
Laser communication has the potential to provide data rates adequate to handle all the data generated on orbit for the foreseeable future. However, current laser communication technology requires placing expensive laser transmitters on each satellite, and further placing operational constraints on the satellite (e.g., pointing, jitter, etc.) that are often beyond the capability of budget satellites. Thus, there is a need for a laser communication system that can support a broad range of satellites at a moderate cost and without putting undue burden on the satellites.
There have been proposals for a distributed constellation of satellites in Earth orbit, called network satellites, that would enhance the utility of client satellites in Earth orbit by providing a high-bandwidth data link to ground. Client satellites include any satellite in Earth orbit that collects data at a high rate, where high can mean that satellite operations are constrained by availability of communications bandwidth, or that satellite operations require one or more dedicated ground stations. The network satellites receive data from the client satellites, and subsequently, transfer the client data to the ground using optical communication. The proposed system also includes several widely-distributed optical ground stations for receiving data from the network satellites.
In the proposed system, the network satellites were envisioned to have high-gain RF receivers that receive data from client satellites. In addition, the network satellites were envisioned to have laser communication transmitters to send data to the ground. Another form of the network satellites had both laser transmitters and optical receivers (telescopes) to receive data transmitted by other laser systems.
In both types of network satellites, simultaneous operation of both the receive mode and the transmit mode would not be possible because the pointing requirements of the receiver (whether optical or RF) would be incompatible with the pointing requirements of the transmitter. In the current state of the art, this problem is solved using a two-axis gimbal system that allows the laser to point in the required direction and with its required degree of precision, while the rest of the satellite would point as necessary to receive the incoming signal. However, these two-axis gimbal systems tend to be both expensive, and too large for most small satellites.
Thus, an alternative communications relay satellite system may be beneficial.
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1. Field of the Invention
The present invention relates to a paper sheet processing apparatus, which is applied as a paper money processing apparatus, for example, for classifying and stacking paper money in stacking boxes according to the kinds of money and whether the condition of money is normal or damaged.
2. Description of the Related Art
A paper money processing apparatus of this kind is functionally divided into a sorting machine, a money counting machine and a normal/damaged classifying machine. The sorting machine has a setting unit to set paper money (hereinafter called a note), a take-in device to take in and feed the paper money set in the setting unit, and a judgment unit to judge the kind, front/back, direction and true/false of a note. The machine classifies and stacks a specified number of notes in a stacking box based on the result of the judgment.
A note failed to judge by the judgment unit, or judged impossible to handle in the machine is classified into a rejection box.
The money counting machine has a data add-up function added to the money sorting machine, and counts the input money data for each transaction batch, adds up the transaction amount of a day, and totalizes the input money for each customer. When receipt of money for each transaction is confirmed, a large number of notes are often continuously stacked in a stacking box in many cases. The stacking number of notes is set to 100-2000 for one stacking box, for examples.
The normal/damaged classifying machine judges whether a note taken in from a take-in device is normal or damaged in a judgment unit, and classifies the note into normal or damaged based on the result of judgment, and stacks the note. A note is judged damaged, if a degree of stain or damage exceeds a preset level. A damaged note is bad in the quality and condition, having adherence of tape, bent corner, peeled-off end, tear, wrinkle, and tired, for example. The damaged note classifying performance of the normal/damaged classifying machine depends much upon the quality and condition of a note.
The stacking box is provided with a backup, a width guide and a position adjusting guide. The width of a note led into the stacking box is guided by the width guide, stacked on a backup, and adjusted the longish side by the position adjusting guide. An impeller is provided in the note input side of the stacking box, to guide notes one by one to the stacking box.
However, in the prior art, the backup descends a certain distance whenever a predetermined number of notes are stacked on the backup, and the height of stacked notes is varied depending on the quality and conditions of a note.
When the height of stacked notes increases, a space to receive a subsequent note is not ensured, causing a jam or a stack error. Contrarily, when the height of stacked notes decreases, the distance to drop a note becomes long, the position of a note becomes unstable, and a note is stacked in being stood or inclined.
Particularly, when the apparatus is used as a money counting machine, the stack height is uneven and the stacking performance becomes unstable when the backup descent distance is controlled to a certain level, because a number of notes are stacked and the quality and condition of each note are different in each batch of receipts from a different customer.
In the prior art, the position of the width guide in a stacking box is uniformly controlled according to the sizes of note, and if the position of the width guide is set to a note size +0˜1 mm, for example, and the quality and condition of a note are bad, the corner and edge of a note is caught by the width guide, causing a stack error.
In the prior art, the position adjusting operation of the position adjusting guide is controlled according to the size of each kind of note (speed, amplitude, number of position adjustment, and position adjusting timing for each note), and the edge of note is not aligned as expected and the stacking performance may become bad. For example, a tired note is merely bent and the stacking position is not adjusted as expected, even if the position is adjusted at a high speed and large amplitude. A note having a bent corner or peeled-off end is not normally positioned even if the note position is adjusted in the stacked state, because the bent corner or peeled-off end is caught by the upper and lower notes.
In the prior art, an impeller is provided in a fixed condition, and when a note fed to a stacking box is displaced to the sliding direction against to the center of the feeding, the position and center of gravity of a note against the impeller are displaced, the balance becomes bad, and the note drops or projects from the impeller, giving a bad influence to the stacking performance. A note asymmetrical to the center, for example, a note having a peeled-off edge or a largely bent corner, or a broken note is displaced from the impeller or the center of gravity is displaced, and the balance becomes bad and drops or projects from the impeller, giving a bad influence to the stacking performance.
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The use of and development of communications has grown nearly exponentially in recent years. The growth is fueled by larger networks with more reliable protocols and better communications hardware available to service providers and consumers. Communications and media features for vehicles have also recently experienced many advances.
In particular, digital video entertainment systems and satellite radio provide many users options not available only a few years ago. Entertainment systems are valuable to drivers and passengers alike, but are particularly useful for entertaining children. The existing media services for vehicles may include high monthly service costs or may be limited to on-hand media content.
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Particulates or particulate matter entrained in exhaust (burned gas of diesel oil) from a diesel engine is mainly constituted by carbonic soot and a soluble organic fraction (SOF) of high-boiling hydrocarbon and contains a trace of sulfate (misty sulfuric acid fraction).
In order to suppress the particulates from being diffused into atmosphere, conventionally a filter for capturing particulates is incorporated in an engine exhaust system.
An example of the particulate filter comprises a honeycomb core made of ceramics such as cordierite and having a number of passages compartmentalized by porous thin walls, exhaust from an engine flowing through the passages.
In the above-mentioned particulate filter, alternate ones of the parallel passages have plugged one ends so as to guide the exhaust to unplugged one ends of the gas passages adjacent thereto; the passages through which the exhaust flows have the plugged other ends so as to connect unplugged other ends of the gas passages adjacent thereto to a muffler.
Thus, the particulates entrained in the exhaust are captured by the porous thin walls and only the exhaust passing through the walls is discharged to the atmosphere.
The particulates attached to the thin walls will spontaneously ignite to be oxidized when an engine operating status is shifted to a region with increased exhaust temperature.
However, for example, in a shuttle-bus running mainly on city roads with generally lower running speeds, there is few chance to continue an engine operational status capable of obtaining exhaust temperature suited for oxidation treatment of the particulates. As a result, a captured particulate amount will exceed an oxidized amount, leading to clogging of the porous thin walls.
Thus, recently, a plasma assisted exhaust emission control device (gas treatment reactor vessel) has been proposed which can oxidize particulates even if exhaust temperature is low (See, for example, Reference 1).
In this exhaust emission control device, inner and outer electrodes in the form of drilled stainless cylinders are coaxially arranged in a chamber. A gap between the electrodes is charged with dielectrics in the form of pellets so as to allow the exhaust to pass. The exhaust from the engine is guided to a gap between the chamber and the outer electrode.
Thus, the particulates entrained in the exhaust supplied from between the chamber and the outer electrode to the pellet charged layer are attached to the pellets and only the exhaust passing through the pellet charged layer is discharged to the atmosphere.
Moreover, higher voltage is applied across the electrodes to generate discharge plasma and excite the exhaust, so that unburned hydrocarbon, oxygen and nitrogen monoxide are activated into oxygen-containing hydrocarbon, ozone and nitrogen dioxide, respectively.
Thus, even with lower exhaust temperature, the particulates attached to the pellets will spontaneously ignite to be oxidized. [Reference 1] JP 2002-501813A
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In the power steering systems of automobiles, solid particles developed through wear of the system parts are present in the fluid causing contamination, increased friction and raised fluid temperatures. These particles also increase deterioration of the hoses and seals. Therefore, it is desirable to refine the power steering fluid by filtering such particles. Presently, there are known filters which employ a paper filtering element together with a relief valve made of a combination spring, valve disc and seat arrangement. Such known filter devices are generally complex, involving the spring and valve seat arrangement, and therefore are expensive to manufacture. Also, such known filter devices are often not reliable due to the spring arrangement employed. There are other known types of filter devices being used in automobiles which are less expensive than the above-noted power steering filter devices but which are not suitable for the same purpose of filtering the fine particles existent in power steering systems and, consequently, such known filters also do not provide adequate and reliable relief valve means in the filter. Examples of such filters devices are the floating oil screens used in the oil sumps of engines as described in U.S. Pat. No. 2,192,432 to Gulick, U.S. Pat. No. 2,508,952 to Kline and U.S. Pat. No. 3,662,887 to Uhlhorn, Jr. Such patents disclose devices mounted or floating in the oil sump of an internal combustion engine to prevent sludge and the like from entering the oil pump. When the screen becomes badly clogged with foreign matter, the suction pull on the screen will open a valve formed by a portion of the screening element and a wall portion to allow oil flow without screening. In such known oil sludge filter devices, the wire screen element is intended for filtering out relatively large particles and sludge and is inappropriate for filtering fine particles, even if the screened mesh openings were made smaller. The screen material is highly flexible and subject to random deformation and, therefore, the screen valve may easily open under unintended variable and minor conditions not due to clogging, such as slight variations in suction pressure and very small build ups of heavy sludge against the very flexible screen causing a suction sufficient to move the screen valve into an open position. Also, the non-rigid nature of the screen material affords it no spring force to return it to its original closed position once the minor suction fluctuation is reduced to normal. This absence of rigidity, or memory, could result in the screen valve opening and remaining open even after the minor suction fluctuation is removed. This random deformation and uncontrolled shifting of the position of the screen element in such oil sludge filters results in a relief valve which cannot be designed for opening under predetermined, controlled conditions of filter clogging. Also, the valve seal formed by an element of the screen with the wall is generally a loose-acting seal made under slight pressures of the screen element on a wall. Thus, such a loose and uncontrolled sealing means as used in these oil sludge filter devices is not suitable for the requirements in filtering the fine particles in a power steering system.
In U.S. patent application No. 588,540 filed on March l2, 1984 by William Hayes and James Dohrenwend, now U.S. Pat. No. 4,517,083, the co-inventor William Hayes being the inventor of the present application and said application being assigned to the same assignee herein, there is described a filter device for use in the return line of a power steering system for filtering the fine metal particles in the power steering fluid. The Hayes et al filter device includes a filter disc made of a soft material and located in intimate contact with one side of a perforated support plate. The above described filter device by Hayes et al provides an effective filter for the fine particles present in a power steering system as well as a relief valve and seal therefor. Since the filter device is connected in the fluid line of a power steering system, the inlet tube and outlet tube are identified or marked to aid the installation person in connecting the power steering hoses to the appropriate inlet and outlet tubes.
However, in some installations, it is possible that the filter device is installed backwards due to the failure by the installation person to follow the instructions. This occurs when the input flow from the power steering gear is mistakenly connected to the outlet tube of the filter device. This backwards flow of fluid through the filter device might cause the soft felt filter disc to be forced against the inlet tube opening in a manner which, in time, may block such opening and prevent the passage of fluid out of the filter device. Therefore, it would be desirable to provide in such power steering filter device a means for preventing the blockage of fluid flow due to the incorrect, backward connection of the filter device in the power steering system.
Also, in filter devices used in some systems, such as the power steering system, the filter material may comprise a relatively large area, compared with the much smaller fluid inlet which directs the fluid under pressure towards the filter material. Therefore, it is desirable to have the fluid exiting from the inlet tube be dispersed so that there is no concentration of fluid, and particles, against the one small area of the filter material located directly opposite to the inlet tube.
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This section introduces aspects that may help facilitate a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art.
Some wavelength selective switches devices are relatively expensive and large due to the requirement of free-space optics and several optical components assembled in a large sealed enclosure.
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1. Field of the Invention
The present invention relates to a ceramic capacitor that is formed on a substrate, and a method of manufacturing same.
2. Related Background Art
In the past, a stacked ceramic capacitor has been known as one of ceramic capacitors. Such a stacked ceramic capacitor 1 has a structure as shown in FIG. 23, and is configured in accordance with a stacked member 6 in which some ceramic dielectric layers 2 and some internal electrode layers 4 are alternately stacked in a up-down direction, and a pair of electrodes 8A, 8B that are formed so as to sandwich this stacked member 6 laterally. Furthermore, regarding the internal electrode layers 4 of this capacitor 1, any two adjacent internal electrode layers 4 are connected to different electrodes 8A, 8B as shown FIG. 23B in detail.
As a method of manufacturing the stacked ceramic capacitor described above, a sheet method and a print method are known. Both of these manufacturing methods manufacture a stacked ceramic capacitor by the method comprises steps of, forming a stacked member in which layers consisting of a ceramic dielectric powder that configure dielectric layers and layers consisting of an electrode paste (a conductive paste) that configure internal electrode layers are alternately stacked in a plurality of layers, and providing external electrodes subsequent to baking this stacked member.
In forming these dielectric layers, a ceramic compact (a so-called green sheet), which is manufactured by mixing together a ceramic dielectric powder, an organic binder and an organic solvent to create a slurried dielectric paste, making this dielectric paste into a sheet shape using a doctor blade method or the like, and suitably drying the green sheet, is utilized. On the other hand, the electrode paste utilized in forming the internal electrode layers is made into a paste by dispersing nickel or another such metallic powder into an organic binder and an organic solvent.
Then, the stacked ceramic capacitor is manufactured normally by the method comprises steps of, screen printing the electrode paste onto the surface of the green sheet, drying off the organic solvent included in the electrode paste, overlapping the plurality of compacts and pressing that, chipping and baking the stacked member produced by the overlapped compacts. The plurality of internal electrode layers is exposed at the lateral face of the chipped stacked member, and the external electrode is formed on the lateral face of the stacked member so as to electrically connect these internal electrode layers.
According to the progress toward smaller, thinner, more lightweight electronic devices in recent years, the stacked ceramic capacitor mentioned above is needed to be further smaller, moreover, the ceramic dielectric layers and internal electrode layers of these capacitors are required to be as thin as possible (made low profile), and stacked as many of these layers as possible (multi-layered) from the standpoint of higher capacity.
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The present invention relates generally to a label for a container, package or the like which has a removable portion having a temperature sensitive indicia thereon.
In the past, various attempts have been made to provide consumers with convenient methods of determining the temperature within a package or container. These applications have included the permanent attachment of the thermally sensitive element to the particular package or container. As such, the thermally sensitive element is not reusable or transferable.
U.S. Pat. No. 5,786,578 to Christy et al. describes a label having a thermochromatic ink temperature indicator which is attached to a microwaveable container. The label indicates temperatures which are xe2x80x9cOKxe2x80x9d or xe2x80x9cTOO HOT,xe2x80x9d depending on the temperature of the contents of the container.
U.S. Pat. No. 5,918,981 to Ribi describes several uses for thermochromatic inks. One embodiment is for a label which places the letter xe2x80x9cUNxe2x80x9d in thermochromatic ink before the word xe2x80x9cSAFExe2x80x9d in standard ink. If the temperature of the label rises above a set point, the letters xe2x80x9cUNxe2x80x9d become visible, signifying that the contents of the package to which the label is attached have become unacceptably hot. In another embodiment applies a stripe of thermochromatic ink to a container as a temperature indicator.
U.S. Pat. No. 3,864,976 to Parker describes an overwrap for a container. The overwrap is described as a thin plastic film onto which thermally sensitive ink has been printed.
U.S. Pat. No. 5,482,373 to Hutchinson describes the application of a thermometer to the side of a drink bottle, such as a soda can as shown in FIG. 1 or a beer bottle as shown in FIG. 3. The thermometer is shown as a label which can be purchased separately from the container whose temperature is to be monitored. The temperature sensitive element of the thermometer is described as a thermochromatic ink.
U.S. Pat. No. 2,308,087 to Lappala describes a temperature sensing label. The label is made of a clear film onto which temperature sensitive paint is applied. The clear film is then folded over onto itself to entrap the paint. Lappala describes applying the paint to form words which will then appear at a set temperature.
U.S. Pat. No. 4,878,588 to Ephraim shows a temperature indicator built into the side of a baby bottle. The temperature indicator consists of several cells of temperature sensitive liquid crystals, whose visual properties change at set temperatures.
The present invention contemplates a label for use on a package, container or the like having a thermally sensitive label or label portion which may be removed from the main body of the label to be applied to another container.
In one embodiment of the present invention, the label includes at least two plies, an outer ply and an inner ply. The interior surface of the outer ply and the outer surface of the second ply are permanently adhered to one another over a major portion thereof. A temperature sensing element is provided a one location on the outer ply. In the area of this portion of the label, the outer ply and the second ply are releaseably adhered to one another. The temperature sensing element is preferably created by a thermochromatic ink printed on the inside surface of the outer ply. A pressure sensitive reusable adhesive is provided to the interior surface of the outer ply over the thermochromatic ink.
The temperature sensing element may be defined by a series of perforations within the outer ply. This portion is removable from the inner ply of the label and the remaining portions of the outer ply. The temperature sensing element, thus, may be removed from the package or container and secured to a second container for temperature sensing. Depending on the strength and type of adhesive, the removable temperature sensing element may be repeatedly applied to various packages for sensing of the temperature of the packages or the goods therein.
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Referring to FIG. 1A, the prior art U.S. Pat. No. 4,298,243 shows an electrical connector for connecting two kinds of electrical conducting terminals. There is only one conducting element 6A located inside the insulating housing 8A. The conducting element 6A connects a flat-type conducting terminal to a conducting core. Wherein the conducting core is directly inserted into the cylindrical crimp ferrule 14A at the end of the conducting element 6A. An external clamping force is then exerted to deform the cylindrical crimp ferrule 14A to fasten the conducting core; therefore, the connecting force between the conducting core and the conducting element 6A is weak. Meanwhile, the conducting element 6A sticks out and inserts into the insulating housing 8A by an inverting hook 12A; consequently, it is inconvenient for the overall assembly of the connector.
Referring to FIGS. 1B and 1C, another example of the prior art shown in U.S. Pat. No. 5,203,726 is an electrical terminal connector capable of connecting two kinds of terminals. Besides the metallic terminal 14B (FIG. 1B), a crimp portion 16C (FIG. 1C) is introduced to connect the conducting core for increasing the connecting force of the conducting core and the metallic terminal 14B. When assembling the connector, the front part 44C of crimp portion 16C surrounds the crimping end 30B of the metallic terminal 14B from a breach 50B and props up the ramp 40B tightly. The stress concentration also occurs near the intersection of the breach 50B and the ramp 40B to reduce the combining strength of the metallic terminal and the crimp portion 16C.
Referring to FIG. 1D, another example of the prior art shown in U.S. Pat. No. 6,997,746 shows a conducting element 50D connecting to two electrical terminals. In order to connect the conducting core without any additional cylindrical crimp ferrule, the structure of the conducting element 50D is very complicated and not easy to fabricate.
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Typical end closures for beer and beverage containers have an opening panel and an attached leverage tab for pushing the opening panel into the container to open the end. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum or steel. End closures for such containers are also typically constructed from a cutedge of thin plate of aluminum, formed into a blank end, and manufactured into a finished end by a process often referred to as end conversion. These ends are formed in the process of first forming a cutedge of thin metal, forming a blank end from the cutedge, and converting the blank into an end closure which may be seamed onto a container.
These types of container ends have been used for many years, with almost all such ends in use today being the “ecology” or “stay-on-tab” (“SOT”) ends in which the tab remains attached to the end after a tear panel, including large-opening ends (“LOE”), is opened. The tear panel being a portion of the can end defined by a primary score line or length. The tear panel may be opened, that is the score may be severed, and the tear panel displaced at an angular orientation relative to the remaining portion of the can end. The tear panel remains hingedly connected to the remaining portion of the can end by a hinge segment, leaving an opening through which the user draws the contents of the container. In an LOE, the opening is typically at least 0.5 square inches in area, but in more recently developed ends, LOE-type openings have had areas less than 0.5 square inches.
It is also well known to provide a secondary score line of lesser depth than the primary score line. This score line, commonly referred to as an “antifracture score” is provided to reduce residual stresses associated with the primary score line so as to prevent or minimize the occurrence of microcracks in, or premature fracture along, the primary score line.
Opening of the tear panel is operated by the tab which is attached to the can end by a rivet. The tab is attached to the can end such that a nose of the tab extends over a proximal portion of the tear panel. A lift end of the tab is located opposite the tab nose and provides access for a user to lift the lift end, such as with the user's finger, to force the nose against the proximal portion of the tear panel.
When the tab nose is forced against the tear panel, the score initially ruptures at a vent region of the score. This initial rupture of the score is primarily caused by the lifting force on the tab resulting in lifting of a central region of the can end, immediately adjacent the rivet. As the tab is lifted further, the score rupture propagates along the length of the score, eventually stopping at the hinge segment.
To improve openability of the can end, manufacturers first designed tear panels with circumferential emboss beads to stiffen the tear panel. However, tear panels having an emboss bead have a tendency to dome or bulge when the beverage container is pressurized. Thus, the tear panel must be pushed back through the pour open upon opening. This required an increased amount of pressure to snap the tear panel through the pour opening. When beverage can manufacturers began producing can ends with larger pour openings, and consequently larger tear panels, this increase in required opening force became an issue or problem. These LOEs have a greater tendency to bulge due to their much greater surface area.
The circumferential emboss bead generally gave way to a down panel on the center portion of the tear panel to further improve openability. The down panel was developed to lower the magnitude of the force required to open the tear panel, especially on LOEs. The down panel generally does not bulge. This keeps the score flat. When the score is flat, the pour panel does not have to pass back though the pour opening as the can end is opened. The down panel produced a concave effect upon initial opening. This allowed score on LOE's to shear easier or with less force.
However, prior to pressurization, LOEs have a tendency to exhibit an upward dome. This causes a nose portion of the tab to ride a little high. When the LOEs are stacked, this high riding tab nose causes sponginess in the can end stacking. This sponginess can lead to miscounts of ends in a sleeve of stacked ends or can lead to longer sleeves than if the sponginess did not occur. For example, 4 to 5 inch differences in bag or sleeve length from one sleeve to the next can be experienced based on the sponginess of the stack.
Additionally, the contact between the tab and the product side of the adjacent, or next stacked, can end may encourage manufacturers to produce tabs with less height and less perfectly formed curved edges. Such tabs may have less height, but also has less strength for opening the can end.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior can ends of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.
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Several types of effector cells have surface receptors that bind the Fc portion of immunoglobulin (IgG). When such cells (monocytes, granulocytes, K cells, etc.) encounter target cells that have been opsonized with IgG antibodies, they form conjugates with the target cells. Subsequently, the effector cells either lyse or phagocytose the target cells, depending upon the effector cell type, the target cell type and the specific Fc receptor type involved.
Two distinct classes of IgG Fc receptors (FcR) have been identified on human monocytes and on the human monocytic cell line U937. Looney, R. J., et al., (1986) J. Immunol. 136:1641-1647. One is a 72 kDa sialoglycoprotein (p72) with high affinity (Ka=10.sup.8 -10.sup.9 M-1) for monomeric human IgG1 and IgG3 and for murine subclasses IgG2a and IgG3. Alexander, M. D., et al. (1978) Immunol. 35:115-123; Anderson, C. L. and Abraham, G. N. (1980) J. Immunol. 125:2735-2741; Lubeck, M. D. et al. (1985) J. Immuno. 135: 1299-1304. The other receptor is a 40 kDa molecule (p40) which shows relatively low affinity for monomeric IgG. Looney, et al., supra; Jones, D. H., et al. (1985) J. Immunol. 135:33483353. P40 has been defined by its ability both to form rosettes with erythrocytes coated with murine IgG1 and to bind aggregated murine IgG2b at low ionic strength. In addition, a monoclonal antibody (IV3) has been prepared which binds to the 40 kDa receptor and inhibits ligand binding. See Looney, R. J., et al., supra. This receptor is present not only on mononuclear phagocytes but on human platelets, neutrophils and eosinophils. Rosenfeld, S. I., et al. (1985) J. Clin. Invest. 76:2317-2322.
These two Fc receptors on human monocytes have been shown to mediate anti-T3-induced human T cell mitogenesis by distinct subclasses of murine IgG. The 72 kDa FcR mediates murine IgG2a anti-T3-induced stimulation whereas the 40 kDa FcR mediates murine IgG1 anti-T3-induced T cell mitogenesis. See Looney et al., supra. Based upon their distinctive affinities for murine IgG subclasses, p72 and p40 are thought to be the human homologues of murine macrophage FcRI and FcRII specific for murine IgG2a and IgG2b/1, respectively. Although not present on monocytes or U937 cells, a third class of IgG FcRs has been described on human neutrophils and null cells.
It has been demonstrated that target cell conjugation and lysis can also be induced by covalently cross-linked heteroantibody made up of both anti-Fc receptor antibody and antibody directed against a target cell epitope. When effector cells bind such heteroaggregates to their Fc receptor, they can specifically bind and lyse target cells which have not been opsonized, but which express the appropriate target antigen. Segal et al. have recently reported cytolysis of tumor cells by mouse monocytes with an attached heteroantibody which joins the Fc receptor of the monocyte on one end with tumor cell epitopes on the other end. The targeting of effector cells with conventional heteroantibodies, however, is likely to be only marginally effective in vivo because the binding of antibody to Fc receptors can be blocked by physiological concentrations of IgG.
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1. Technical Field
The present invention relates to monitoring apparatus, method, and program, particularly to monitoring apparatus, method, and program, which can properly monitor management of shop visit and illegal action of a player.
2. Background Art
Recently, there are proposed technologies of capturing a face image of the player in an amusement shop to monitor the management of shop visit and the illegal action.
For one of the proposed technologies, the following is proposed. For register of a suspicious person, using a face image in the amusement shop, based on illegal action information detected in an amusement machine, the face image of a person playing a game with the amusement machine is registered as the face image of the suspicious person (see Patent Document 1).
There is also proposed a technology of managing a visit and leaving history by capturing the face image of the player who visits the shop with cameras placed in an entrance and an exit (for example, see Patent Document 2).
Patent Document 1: Japanese Unexamined Patent Publication No. 2001-178958
Patent Document 2: Japanese Unexamined Patent Publication No. 2007-020653
However, in the technology of Patent Document 1, in the case where the illegal action cannot be detected in the amusement machine, there is a likelihood of not being able to register the face image of the player as the suspicious person.
In the technology of Patent Document 2, due to natural light or disturbance light, such as headlights of a vehicle, sometimes the face image of the player cannot be well captured at a doorway of the store when the player visits the amusement shop. In such cases where a determination that the player who visits the store does not exist or a determination that the player who visits the store does not leave the store is made, there is a likelihood that the player who visits the store cannot be correctly managed or monitored.
Many cameras are placed in the doorway as means for preventing a failure to capture the face image. Although the failure to capture the face image can be avoided to some extent, there is a likelihood that the management becomes complicated because the number of cameras that capture the image of the doorway is increased to capture the same person plural times.
In view of the foregoing, an object of at least one embodiment of the present invention is to be able to properly manage the visit of the player and monitor the illegal action of the suspicious person such that the registered face image can properly be managed while the face image of the person to be registered is correctly registered.
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The object of the present invention is a process for the purification of 2,6-diisopropyl phenol.
2,6-diisopropyl phenol, i.e. propofol, is a pharmaceutically important compound which is used in anesthesia. The agent is especially well suited for use in surgical procedures of short duration because of its short halflife. The purity requirements of the agent for intravascular administration are very high, and the aim is a purity which is at least 99.9%.
Propofol is commercially available product. It is made from phenol and propene by Friedel-Crafts-alkylation, whereby in the reaction, besides the desired propofol I ##STR1## small amounts of other isomers and phenol derivatives are formed, the major contaminants being (II) 2,4- and (III) 2,5-diisopropyl phenol, (IV) 2,4,6-triisopropyl phenol, and (V) 1-isopropoxy-2,4-diisopropylbenzene.
The compounds formed in the reaction have previously been separated by fractional distillation, but this is very difficult due to the small differences in the boiling points of the compounds to be separated. Thus, after fractional distillation the product still contains up to 0.5% by weight, but normally not less than 0.3% by weight of the said contaminants, as determined mass spectrometrically. Of the above mentioned impurities, the compound 2,4-diisopropyl phenol (II) constitutes the major part, such as up to 3/4, e.g. from about 1/4 to about 3/4 of the total contaminants.
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1. Field of the Invention
This invention pertains to a modem which may be operated in a half-duplex mode to exchange digital data over two-wire circuits without the need of a preamble prior to each data transmission. Therefore as soon as the modem stops transmitting it is instantaneously ready to receive data.
2. Description of the Prior Art
Conventional half-duplex modems are used to operate two-wire leased or dial telephone circuits. Two-wire circuits require transmission in only one direction at a time unless costly, non-ideal band splitting or echo cancellation techniques are employed. These non-ideal techniques induce impairments which necessarily limit the highest possible transmission rate.
Half-duplex modems which transmit data in only one direction at a time are not limited by these impairments. They can transmit at a higher data rate. At the highest possible data rate, complex receivers are required. These receivers have many adaptive functions, including gain control, carrier recovery, timing recovery, frequency offset compensation, adaptive automatic equalizers, and data randomizers. All of these functions require time to initialize which significantly delays the start of transmission.
Before transmitting data, a terminal first sends a Request-to-Send, RTS, signal to its modem. Data transmission is not allowed, however, until the modem returns a Clear-to-Send (CTS) signal. The period between RTS and CTS is defined here as the CTS delay. During this time, special sequences are transmitted which allow the remote receiver to train all of its adaptive functions. These adaptive functions are reset prior to each transmission. As the modem's data rate increases, the CTS delay increases. For example, for a 2400 bps modem, the delay is 8 ms, for a 4800 bps modem the delay is 50 ms, and for a 9600 bps modem the delay is 253 ms.
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An example of a microphone array including a plurality of microphones arranged in array is disclosed in Patent Literature 1. According to Patent Literature 1, first and second microphones are disposed with a predetermined distance D therebetween in a microphone array. A third microphone is disposed between the first and second microphones, being spaced by a distance D/2 from the first and second microphones. A fourth microphone is disposed at a location between the third and first microphones, being spaced by a distance D/4 from the first and third microphones. A fifth microphone is disposed at a location between the third and fourth microphones, being spaced from the third and fourth microphones by a distance D/8. A sixth microphone is disposed at a location between the fifth and third microphones, being spaced from the third and fifth microphones by a distance D/16. A seventh microphone is disposed at a location between the sixth and third microphones, being spaced from the third and sixth microphones by a distance D/32. A eighth microphone is disposed at a location between the seventh and third microphones, being spaced from the third and seventh microphones by a distance D/64.
Audio signals from these microphones, which form microphone units, are processed by beam forming. More specifically, the first through third microphones form a first microphone unit; first, fourth and third microphones form a second microphone unit; the third through fifth microphones form a third microphone unit; and the third, fifth and sixth microphones form a fourth microphone unit. The third, sixth and seventh microphones form a fifth microphone unit; and the third, seventh and eighth microphones form a sixth microphone unit. The audio signals from the first and second microphones in the first microphone unit are multiplied by a factor 0.5, and the audio signal from the third microphone is multiplied by a factor 1. The audio signals from the first through third microphones multiplied by the respective factors are combined by combining means into a composite signal. Similarly, in each of the second through sixth microphone units, the audio signals are processed in such a manner that the audio signals from the microphones located at the opposite ends of that microphone unit are multiplied by a factor of 0.5 with the audio signal from the microphone at the center of that microphone unit being multiplied by a factor 1, whereby a composite signal is formed. The thus produced composite signals are combined to thereby provide the microphone system with sharp directivity over a wide frequency range. Further, the audio signal from each of the microphones is provided with a delay in a delay circuit, and the delayed audio signals are supplied to a beam forming section. With this arrangement, influence of differences in distance between a speaker and the respective microphones is removed by providing a delay equal to the delay of the last arriving audio signal for the audio signals from the other microphones.
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1. Field of the Invention
This invention relates to photographic objective lenses and in particular to such lenses that comprise three air spaced elements.
2. Description of the Prior Art
Triplet lenses for use in photographic apparatus are well known and have been used for many years. Moreover, high relative aperture lenses have also been in use for many years in the photographic industry. However, with the advent of available light photography, the use of high relative aperture lenses has spread to photographic apparatus designed to be mass produced for the amateur market. The price of such lenses then becomes of great concern and the relatively complex, well corrected, high relative aperture lenses known in the art are too costly.
The introduction of plastic elements in triplet lensens has been generally adopted in order to decrease the cost of such lenses. However, the introduction of plastic elements has usually resulted in accentuation of certain design problems. For instance, variation in the back focus length due to thermally induced contraction and expansion of the optics may be increased.
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1. Field of the Invention
This invention relates to a method for growing a Group III atomic layer, more particularly to a method for growing a Group III atomic monolayer that is exactly one atom thick on a prescribed portion of a substrate, thereby opening the way to atomically controlled fabrication of the quantum wires, quantum boxes and other semiconductor quantum nanostructures which are viewed as basic structures for next-generation, high-performance optical devices and electronic devices.
2. Description of the Prior Art
The ever-increasing discreteness of energy levels and intensification of density of states resulting from increasingly smaller semiconductor microstructures point to the theoretical possibility of the appearance of various new quantum phenomena in small dimension semiconductor nanostructures. For example, it has been predicted that ultra-high speed field effect transistors will be realized by markedly suppressing the various electron scattering processes in quantum wires and that the oscillation threshold current temperature and its dependence of semiconductor lasers will be reduced by utilizing quantum wires and quantum boxes as the active layers. Researchers around the world are in fact actively exploring small-dimension semiconductor quantum nanostructures because they believe them to be indispensable to the building of the next generation of large-capacity, ultra-high speed information and communication systems.
To enable these and other quantum phenomena, the low-dimension quantum nanostructure should preferably satisfy the following conditions:
(1) Small Quantum Structure Size:
Pronounced quantum mechanical phenomena arise in small-sized semiconductor quantum nanostructures only when the energy difference between the first and second quantum energy levels of the structures is much larger than the electron thermal energy kT (k: Boltzmann constant, T: absolute temperature). In the case of AlGaAs/GaAs, for example, a structure with dimensions not exceeding 15 nm is required to satisfy this condition at room temperature.
(2) High Density
When quantum wires are used as conducting channels, for example, the amount of electric current passing through a single quantum wire is limited due to the single electron mode nature of quantum wires. Therefore, to obtain enough current to drive the following stage, circuit, it is necessary to increase the wire density and use multiple paths in parallel. Similarly, in the case of configuring a semiconductor laser using a quantum nanostructure as the active layer, it becomes necessary to increase the quantum nanostructure density in order to enhance the light confinement coefficient.
(3) High Uniformity
In all quantum nanostructure, quantum effects can be attributed to intensified density of states. However, maintaining the state intensification requires quantum nanostructures of consistent size. To ensure adequate quantum effects, the quantum nanostructure size fluctuation generally has to be held to under around 10%.
(4) High Quality
Securement of a high degree of electron migration and high light emission efficiency requires a high-quality quantum nanostructure without defects.
Various methods for satisfying these conditions have been proposed regarding the fabrication of quantum wires, quantum boxes and sundry other semiconductor quantum nanostructures. These include, for example, the method of directly processing two-dimensional structures using electron beam lithography and etching techniques, the method of selective growth on a non-planar substrate by metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) etc., as well as self-organization growth methods and the like. Among these, MOCVD selective growth is viewed as a particularly promising technology for its ability to fabricate defect-free quantum nanostructures by enabling their formation in the course of crystal growth.
Since this method requires a growth temperature of higher than around 700.degree. C. to achieve high selectivity, however, it is still inadequate on a number of points regarding the size, uniformity and crystal purity of the quantum nanostructures obtained.
Previously, before the accomplishment of this invention, the inventors proposed a method for fabrication of AlGaAs/GaAs quantum wires by use of flow rate modulation epitaxy (FME) FEM is basically a method in which Group III materials and Group V materials are supplied alternately. Taking Ga and As as examples of Group III and V atoms, each growth cycle consists of four gas supply periods as shown in FIG. 2: a Ga supply period t1, an H.sub.2 purge period t2, an As supply period t3 and an H.sub.2 purge period t4. (Ga can be supplied using triethylgallium (TEGa) and As using AsH.sub.3, for example.) This cycle is repeated a prescribed number of times. As indicated by bias flow Ro, a small amount of As (an amount not causing crystal growth) is supplied continuously even during the Ga supply period t1 and the H.sub.2 purge periods t2 and t4. Owing to the extremely low arsenic partial pressure during the Ga supply period, the surface migration of Ga atoms is promoted, particularly at tow temperatures. The supply of the small amount of AsH.sub.3 also suppresses desorption of As atoms from the substrate surface during the periods t1, t2 and t4 and prevents invasion of impurities. Crystal of extremely high quality can therefore be grown.
However, FME fundamentally lacks a self-limiting mechanism when it is applied to a flat substrate with uniform physical properties. Therefore, if atoms in an amount greater than that which causes growth of a single atomic layer (an atomic monolayer) are supplied (i.e., when the thickness of the film to be grown during each growth cycle is set greater than an atomic monolayer), the excess atoms form droplets on the surface. This degrades the crystal quality. Conventionally, therefore, it has been important to hold the growth rate to less than one atomic monolayer, generally to less than 0.7-0.9 atomic layer. In light of this conventional practice, the quantum wire fabrication proposed earlier by the inventors limits the growth rate to not more than 0.9 atomic layer per growth cycle. When this method was used to grow AlGaAs/GaAs quantum wires in V-grooves formed in a substrate, fairly good results were obtained as regards reducing the lateral width and improving the crystal quality of the fabricated quantum wires.
Thus, thanks to the application of FME, quantum nanostructures can be viewed as having reached a practically utilizable level in terms of size and crystal quality. Nevertheless, their density and uniformity still fall far short of practical requirements and stand as a major obstacle to the realization of high performance devices. Moreover, since there is a tradeoff between density and uniformity in quantum nanostructures, improvement in both aspects has been extremely difficult with conventional technologies. For example, while sufficiently high density can be achieved by use of advanced technologies such as electron beam lithograph, structures that are uniform on the atomic level are extremely difficult to achieve by etching in accordance with the exposed pattern. Since the conventional etching and lithograph are not atomically controlled processes. The size fluctuation is therefore considerable. Generally, when the substrate pattern size falls below around 1 .mu.m and becomes smaller than the material migration length on the substrate surface, the effect of the substrate size fluctuation on the crystal growth process becomes pronounced, in the end causing large fluctuation in the size of the quantum nanostructures.
A need is thus felt for a crystal growth method capable of fabricating practicable quantum nanostructures--a method that is substantially unaffected by substrate pattern fluctuation and capable of atomic layer level control. This invention was accomplished to meet this need, which is not satisfied by any technology proposed heretofore. The object of this invention is therefore to provide a new method suitable for forming quantum nanostructures including at least a Group III atomic layer which is little affected by substrate pattern density, tolerates size fluctuation to a high degree, and enables Group III atomic layers to be formed properly only as monolayers.
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The formation of slimes by microorganisms is a problem that is encountered in many aqueous systems. For example, the problem is not only found in natural waters such as lagoons, lakes, ponds, etc., and confined waters as in pools, but also in such industrial systems as cooling water systems, air washer systems and pulp and paper mill systems. All possess conditions which are conducive to the growth and reproduction of slime-forming microorganisms. In both once-through and recirculating cooling systems, for example, which employ large quantities of water as a cooling medium, the formation of slime by microorganisms is an extensive and constant problem.
Airborne organisms are readily entrained in the water from cooling towers and find this warm medium an ideal environment for growth and multiplication. Aerobic and heliotropic organisms fluorish on the tower proper while other organisms colonize and grow in such areas as the tower sump and the piping and passages of the cooling system. The slime formation not only aids in the deterioration of the tower structure in the case of wooden towers, but also promotes corrosion when it deposits on metal surfaces. Slime carried through the cooling system plugs and fouls lines, valves, strainers, etc., and deposits on heat exchange surfaces. In the latter case, the impedance of heat transfer can greatly reduce the efficiency of the cooling system.
In pulp and paper mill systems, slime formed by microorganisms is commonly encountered and causes fouling, plugging, or corrosion of the system. The slime also becomes entrained in the paper produced to cause breakouts on the paper machines, which results in work stoppages and the loss of production time. The slime is also responsible for unsightly blemishes in the final product, which result in rejects and wasted output.
The previously discussed problems have resulted in the extensive utilization of biocides in cooling water and pulp and paper mill systems. Materials which have enjoyed widespread use in such applications include chlorine, chlorinated phenols, organobromines, and various organo-sulfur compounds. All of these compounds are generally useful for this purpose but each is attended by a variety of impediments. For example, chlorination is limited both by its specific toxicity for slime-forming organisms at economic levels and by the tendency of chlorine to react, which results in the expenditure of the chlorine before its full biocidal function is achieved. Other biocides are attended by odor problems and hazards in respect to storage, use or handling which limit their utility. To date, no one compound or type of compound has achieved a clearly established predominance in respect to the applications discussed. Likewise, lagoons, ponds, lakes, and even pools, either used for pleasure purposes or used for industrial purposes for the disposal and storage of industrial wastes, become, during the warm weather, beseiged by slime due to microorganisms growth and reproduction. In the case of the recreational areas the problem of infection is obvious. In the case of industrial storage or disposal of industrial materials, the microoganisms cause additional problems which must be eliminated prior to the material's use or disposal of the waste.
Naturally, economy is a major consideration in respect to all of these biocides. Such economic considerations attach to both the cost of the biocide and the expense of its application. The cost performance index of any biocide is derived from the basic cost of the material, its effectiveness per unit of weight, the duration of its biocidal or biostatic effect in the system treated, and the ease and frequency of its addition to the system treated. To date, none of the commercially available biocides has exhibited a prolonged biocidal effect. Instead, their effectiveness is rapidly reduced as the result of exposure to physical conditions such as temperature, association with ingredients contained by the system toward which they exhibit an affinity or substantivity, etc., with a resultant restriction or elimination of their biocidal effectiveness, or by dilution.
As a consequence, the use of such biocides involves their continuous or frequent addition to systems to be treated and their addition to multiple points or zones in the systems to be treated. Accordingly, the cost of the biocide and the labor cost of such means of applying it are considerable. In other instances, the difficulty of access to the zone in which slime formation is experienced precludes the effective use of a biocide. For example, if in a particular system there is no access to an area at which slime formation occurs the biocide can only be applied at a point which is upstream in the flow system. However, the physical or chemical conditions, e.g., chemical reactivity, thermal degradation, etc., which exist between the point at which the biocide may be added to the system and the point at which its biocidal effect is desired render the effective use of a biocide impossible.
Similarly, in a system experiencing relatively slow flow, such as a paper mill, if a biocide is added at the beginning of the system, its biocidal effect may be completely dissipated before it has reached all of the points at which this effect is desired or required. As a consequence, the biocide must be added at multiple points, and even then a diminishing biocidal effect will be experienced between one point of addition to the system and the next point downstream at which the biocides may be added. In addition to the increased cost of utilizing and maintaining multiple feed points, gross ineconomies in respect to the cost of the biocide are experienced. Specifically, at each point of addition, an excess of the biocide is added to the system in order to compensate for that portion of the biocide which will be expended in reacting with other constituents present in the system or experience physical changes which impair its biocidal activity.
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Microprocessor-based controls are used with automotive vehicle engines to perform various functions. One of the functions that has heretofore been proposed for such controls is programmed starting. Programmed starting comprises an algorithm that is executed by the microprocessor when the driver starts the engine, principally to prevent the driver from operating the engine throttle in a way that might adversely affect the starting process. The control is configured to conduct the engine starting procedure in a predetermined manner defined by the algorithm so that the starting procedure is unaffected by the driver's actions during that time. Basically, the control preempts the driver's actions. Once the starting procedure has been successfully completed, full control of the throttle reverts to the driver.
Another function that has heretofore been proposed for microprocessor-based engine controls is programmed vehicle launching. As applied to an automotive vehicle which has a manual transmission, programmed vehicle launching comprises placing both the clutch function and the throttle function under the control of the microprocessor during launch. The microprocessor executes an algorithm that has been predetermined to produce a satisfactory launch.
The incorporation of a programmed launch function in a vehicle comprises not only the development of an algorithm for automating both throttle operation and clutch operation, but also suitable clutch and throttle actuators for performing respective clutch and throttle operations to the exclusion of the clutch and accelerator pedals that are used by the driver. For this reason, the system must of necessity be somewhat complex, and complexity invariably adds to the cost. Moreover, it is a difficult task to write an algorithm that will operate a clutch and throttle satisfactorily for the many different types of launch situations that a driver may encounter. Yet the manner in which a clutch and throttle are operated during launch has a very significant influence on clutch life and performance.
The problem of accelerated clutch wear and tear is typified by the experiences of fleet operators. Different drivers may launch a truck in different ways. Some may be especially careful in conducting a launch; others, less so. One significant cause of accelerated clutch wear and tear is repeated clutch engagements at too high an engine speed. The particular type of clutch may also be a factor in determining the best engine speed for launch.
Because improper clutching can accelerate wear and tear on the clutch, and other powertrain components too, it continues to be a desirable objective to have some sort of algorithm-controlled launch.
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This invention relates to mass-mail handling equipment and more particularly to a device for turning envelopes from a flat, horizontal position to a vertical position on one of its edges.
Mass-mailing equipment has become very diverse in its functions. For instance, inserting equipment transports envelopes along an inserting track while various types of inserts are automatically inserted into the envelopes. The envelopes are normally transported to another piece of equipment that automatically seals the envelopes, weighs them and affixes postage. Still additional equipment can automatically read the zip codes or zip code indicia on the envelopes and indicate zip code breaks in the envelope groups for zip code pre-sorting. This allows the user to take advantage of lower postal rates. Other mass-mailing equipment may include remittance processing equipment and zip code sorting equipment.
Customers utilizing mass-mailing equipment may have differing needs and requirements. Therefore, mass-mailing equipment is generally designed for one specific function. Each piece can then be connected by conveyor or other transport means to additional mail processing equipment so a customized system can be assembled. One problem with this approach is that adjacent mail processing equipment may require the envelopes to be oriented in a position which is different than the discharge of the proceeding piece of equipment. This necessitates transition conveyors or re-orientation devices.
For example, most inserting equipment in use today moves the envelopes along a track with their faces (the addresses) face down and the flaps extended with the back of the flaps up during the insertion mode. The envelopes, as they leave the inserting machine, may have the flaps moistened and sealed before exiting the inserter. If the envelope is then going to have postage applied, it must be turned over 180 degrees so that the postage can be affixed to the face of the envelope. One such device suitable for turning the envelopes over is disclosed in U.S. Pat. No. 4,226,324, entitled "Article Turnover Assembly" and assigned to the applicant of the present invention. A problem with the device illustrated in the '324 patent is that it turns the envelopes over 180 degrees and it is not adaptable to turn the envelopes over only 90 degrees. This same problem is found in other prior art devices.
An object of the inventive device is to provide an apparatus that can turn envelopes 90 degrees at high speeds without the envelopes being dropped from the turning device or jamming within the device.
It is a further object to turn the articles while they are being transported along the path of travel of the envelopes.
A further object of this invention is to provide a turning device which requires a relatively short travel distance from its entrance to its exit while the envelopes are being turned.
Still another object is to provide an envelope turning device which does not require adjustments to accommodate various thicknesses of envelopes.
It is also an object of the invention to provide a turning device which maintains the articles in proper registration and alignment for further processing in a mass-mailing system.
The present article turning device transports flat articles such as envelopes or documents from its entrance location which is properly aligned to receive envelopes from mail processing equipment such as an envelope inserter. The entrance location has a nip formed by upper and lower spherical rollers. The spherical rollers are offset with respect to each other to begin turning the envelope as soon as it enters the nip. At an exit location is a pair of exit rollers which have their axes rotated 90 degrees with respect to the axes of the entrance rollers. Two flexible endless belts are wrapped around the entrance and exit rollers. The flexible endless belts transport and turn the envelopes between them as the belts are moved from the entrance location to the exit location. The belts are twisted 90 degrees between the entrance and exit rollers, and each belt has at least one span which is contiguous to a corresponding span of the other belt.
There is a motor or other suitable driving means for driving at least one of the rollers so that the belts and rollers move together. There also are a pair of idler rollers with one of the idler rollers contacting each of the endless belts to assist in maintaining the belts in proper position around the entrance and exit rollers. The entrance and exit rollers are spherically configured or crowned to keep the endless flexible belts positioned on the rollers.
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The present invention relates in general to memory management systems and in particular to an address translation system with caching of variable-range translation clusters.
Most modern computer systems generally implement some form of virtual memory, in which processes reference system memory locations using a “virtual” address rather than an address of a specific location in the memory. When a process makes a memory request using a virtual address, the system uses a page table to translate the virtual address to a specific location and accesses that location. The page table is typically implemented in a block of memory that includes an entry for each page (e.g., 4 kilobytes) of the virtual address space; the entry stores a physical address of a corresponding page of a physical address space. Page tables can also be structured hierarchically, so that only a portion of the page table needs to be resident in system memory at all times; the portion held in system memory can be used to locate other portions that may have been swapped out.
Virtual memory has a number of common uses. For example, general-purpose computer systems generally cannot guarantee that a process will receive memory resources in any particular arrangement or at any particular location. Virtual addressing enables processes to treat the memory as if it were arranged in a convenient manner, regardless of how it is actually arranged. As another example, systems that support parallel execution of multiple processes can provide a different virtual memory space for each process. This helps to avoid address conflicts between processes. Virtual addressing can also be used to map storage other than system memory, thereby enabling the system to swap data in and out of the system memory, address data in storage devices other than memory storage (e.g., image files resident on a system disk), and so on.
Within graphics processing subsystems, use of virtual memory has been relatively uncommon. Typically, a graphics processing subsystem is implemented on a plug-in printed circuit card that connects to a system bus, such as a PCI (Peripheral Component Interconnect) or AGP (Accelerated Graphics Port) bus. The card usually includes a graphics processing unit (GPU) that implements graphics functionality (e.g., rasterization, texture blending, etc.) and dedicated graphics memory. This memory is generally managed by the GPU or by a graphics driver program executing on the system central processing unit. The GPU can address graphics memory using either physical addresses or offset values that can be converted to physical addresses by the addition of a constant base address. The GPU (or graphics driver program) can also control the arrangement of physical memory allocations. For instance, a pixel buffer that is to be scanned out to a display device can be arranged to occupy a contiguous block of the graphics memory address space. Elements of graphics processing subsystems, including scanout control logic (or display drivers), graphics driver programs, GPUs, and the like are generally designed to use physical addressing and to rely on particular arrangements and allocations of memory.
As the amount of data (e.g., texture data) needed for graphics processing increases, graphics processing subsystems are beginning to rely on system memory for at least some storage of data (and in some instances command lists, etc.). Such subsystems generally use virtual addressing for system memory, with the required address translation being performed by a component external to the graphics processing subsystem. For instance, the AGP bus includes a Graphics Address Relocation Table (GART) implemented in the host-side chipset. Emerging high-speed bus technologies, such as PCI Express (PCI-E), do not provide GART or any other address translation functionality. As a result, graphics cards configured for such protocols will need to implement their own address translation systems if they are to access system memory.
An alternative to the graphics card is an integrated graphics processor (IGP). An IGP is a graphics processor that is integrated with one or more other system bus components, such as a conventional “north bridge” chip that manages the bus connecting the CPU and the system memory. IGPs are appealing as an inexpensive alternative to graphics cards. Unlike conventional graphics cards, an IGP system usually does not include much (or in some cases any) dedicated graphics memory; instead the IGP relies on system memory, which the IGP can generally access at high speed. The IGP, however, generally does not control the physical arrangement or address mapping of the system memory allocated to it. For example, it is not guaranteed that the pixel buffer will occupy a single contiguous block in the physical address space. Thus, designers of IGPs are faced with the choice of redesigning the co-processor and the associated driver programs to use physical addresses provided by the system or relying on virtual addressing.
Given the level of complexity and sophistication of modern graphics processing, redesigning around (unpredictable) physical addresses is a daunting task, which makes a virtual addressing solution desirable. Unfortunately, in many computer systems, virtual addressing can introduce a significant degree of memory overhead, making this option too slow or resource intensive for graphics processing components such as display systems. For example, a typical display system provides a screen's worth of pixel data (e.g., 1280×1024 pixels at four bytes per pixel, for a total of over 5 MB per screen) from the pixel buffer to a display device at a constant screen refresh rate of about 70 Hz. Virtual address translation for this much data would introduce an additional latency that is potentially long and may be highly variable. Such long or variable delays in receiving pixel data from memory could result in incorrect (or black) pixels, or other undesirable artifacts. In addition, if address translation for scanout or other purposes requires a large number of page table accesses, performance of other system components may be adversely affected (e.g., due to congestion on the bus or in the system memory). Conventional address caching and translation lookaside buffer techniques do not alleviate the problem because it is difficult and expensive to provide an on-chip cache large enough to hold all the page addresses needed for scanout.
Another solution is to maintain a complete page table on the graphics chip, thereby allowing faster access times and/or less variability in latency. This solution, however, becomes impractical for large page table sizes. Still another solution divides the virtual address space into “large” and “small” sections, depending on whether the section is mapped to blocks of contiguous physical addresses that exceed a “large size” threshold of e.g., 32 or 64 KB. Pointers to the physical address blocks for “large” sections are stored on chip, while for “small” sections, a lookup in the complete page table is required to complete the translation. In some cases, the result of the most recent page table lookup for each of some number of translation clients can be stored and re-used until the client requests a virtual address on a different page. Such systems can reduce the number of page table accesses in some situations, but the ability to store only one result per client and the inability to share results can still lead to a large number of page table accesses.
Thus, an improved virtual memory system that reduces the number of page table accesses required to translate a group of virtual addresses would be desirable.
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1. Field of the Invention
The present invention relates to a decorative sheet for construction, a decorative concrete product for construction using the decorative sheet, and processes for preparing them. In particular, it relates to a decorative sheet for construction which enables a decorative layer with a backing layer having a natural stone-like pattern or the like to be transferred to an interior or exterior surface of a construction such as a wall, a gatepost, a fence, a passage, a poolside, a pavement, a curb of a road or of a plot in a park, or a surface of other various types of constructions; a decorative concrete product with such a decorative layer with a backing layer transferred thereto by the use of the decorative sheet; and a processes for preparing them.
2. Related Art Statement
To decorate interior and exterior surfaces of constructions and/or to impart improved water resistance thereto, various surface finishes are generally given to inner and outer walls, and floors of constructions and the like.
For example, in application of inner and outer walls and a floor in a construction site, there has heretofore been conducted such a procedure by a skilled artisan that a mixture of a concrete or mortar with an aggregate is prepared in situ and applied, and thereafter, the surface of the resultant is subjected to so-called scrubbed finish by partially scrubbing it off with water or so-called scraped finish by partially scraping it off with a wire brush, or coated with a coating, or tiled. Alternatively, in a case of a construction of large scale, surface-decorated large-sized interior or exterior concrete products such as precast concrete panels or precast concrete blocks are preliminarily manufactured in a factory, and transported into a construction site and constructed there into inner or outer walls and the like.
By the various types of surface finish, aesthetic appearance and solid-looking are imparted to constructions and/or practically desired durability, water resistance and the like are effectively attained. In such various types of finish, in particular scrubbed finish, scraped finish and the like, however, technical skills of skilled artisans are required, and yet it is difficult to attain appearance with just intended pattern and/or color. Further, such finishing operations are likely, from the nature thereof, to be prevented from being carried out in rainy days, i.e., these finishing operations have great problem of susceptibility to weather.
To solve these disadvantages inherent in such finishing operations on constructions, a number of attempts have been proposed.
Japanese Unexamined Utility Model Publication No.64438/1986 discloses a decorative sheet for construction which comprises a resin sheet, an adhesive layer formed on one side of the resin sheet, and aggregates such as sand, gravel or the like deposited over the adhesive layer. According to the reference, concrete is applied onto a construction body, and while the concrete is yet unhardened, the decorative sheet for construction is uniformly pressed against the concrete in such a manner that the side of the decorative sheet on which aggregates such as sand or gravel are deposited is in contact with the concrete, and after completion of hardening of the concrete, the resin sheet is peeled off to thereby transfer the decorative layer comprising an adhesive and aggregates such as sand or gravel onto the surface of the construction.
However, when such a decorative sheet for construction is used, since the aggregates are likely to be insufficiently bonded to each other via the adhesive, detachment of the aggregates tends to occur after the removal of the resin sheet. Accordingly, durability is liable to be poor. In the reference, there is also disclosed an embodiment aiming at improving durability, in which after the deposition of the aggregates such as sand or gravel over the adhesive, a coating film is formed thereon by spraying a resin, glue or the like to strengthen the bonding between the aggregates. It is, however, confirmed that because of poor penetration of the resin or glue into fine voids between the aggregates, such a coating film formed only therefrom cannot sufficiently strengthen the bonding between the aggregates. Further, adhesion between the concrete and the resin or glue is likely to be poor, and hence there occurs a phenomenon that the decorative layer transferred is peeled from the concrete at the time of the removal of the resin sheet. In addition, when a paper sheet is used instead of the resin sheet, the paper sheet is liable to be broken during its removal to partially remain unreleased. Accordingly, smooth release of the paper sheet is hardly expected.
Japanese Unexamined Patent Publication No.277408/1986 discloses a method which comprises forming an adhesive layer on one side of a paper sheet, depositing aggregates such as sand or gravel on the adhesive layer, pressing the resulting sheet against concrete applied as a body of a construction while the concrete is still unhardened in such a manner that the surface on which the aggregates such as sand or gravel are deposited is in contact with the concrete, and removing the paper sheet after completion of hardening of the concrete to fixedly transfer the aggregates such as sand or gravel to the surface of the concrete. Also in this method, the aggregates are incompletely bonded by the adhesive and accordingly liable to detach, thereby leading to poor durability. Further, as specific methods for removing the paper sheet, washing off with water, burning off, abrasion and the like are mentioned. For example, however, water running from upper potion to the lower portion in the method of washing off with water, and use of fire device in the method of burning off make cumbersome limitations in construction, thereby inevitably leading to poor constructional efficiency and increased cost.
To solve the above-mentioned problems, the present inventors have made intensive and extensive studies, and as a result, they have developed a decorative sheet for construction which comprises a resin film, preferably a polypropylene film; a layer formed thereon as a decorative face layer including inorganic aggregates and an additive; and a backing layer formed on the decorative face layer, and they have already filed a patent application relating thereto (Japanese Unexamined Patent Publication No.299833/1990). In this decorative sheet for construction, the backing layer is formed on the resin layer as a decorative face layer including inorganic aggregates to cause to penetrate into fine voids between the inorganic aggregates, thereby further strengthening the bonding between the aggregates.
However, it has disadvantageously often occurred that during transportation of the decorative sheet for construction to a construction site to carry out the application, the polypropylene film and a portion of the decorative face layer unexpectedly separate from each other. Further, it has been found that since an unexpanded one is used as the polypropylene film, the surface thereof is likely to be damaged when a member having an acute tip abuts upon the surface. It has further been found that in the case where a polystyrene film is used instead of the polypropylene film, although separation during transportation does not occur, if removal of the surface polystyrene film is conducted without close attention after application at a predetermined position and transfer of the decorative face layer to a placed concrete, the film is broken and hardly removed in part.
Further, it has been confirmed that in producing a decorative concrete product such as a decorative concrete panel, if the surface film is made of a polypropylene or polystyrene, the surface film may undergo deformation due to contraction by generated heat, thereby disadvantageously causing a partially incomplete transfer of the decorative face layer.
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1. Field of the Invention
This invention lies in the field of magnetic tape decks for writing and reading of digital data on and from magnetic tapes. More particularly, it concerns the design of an automatic tape reel latch, which permits quick and easy positioning of the tape reel over the latch, and by pneumatic pressure, provides a strong force applying friction to the reel, in order to drive it at high accelerations.
2. Description of the Prior Art
In the prior art there are a number of different designs of tape reel latches, on which tape reels can be mounted for rotation by a drive shaft of a tape deck. Most of these are of a strictly mechanical design in which a manually operated cam means forces outwardly a plurality of circumferentially spaced friction pads to grip the inner surface of the tape reel and to drive it in synchronism with the rotation of the reel latch and shaft. These mechanical latches have limited range of the cams which can be provided for mechanical control, and because as the friction pads wear, there is no way to adjust, and the friction pressure is reduced. Thus, these prior art latches have not been entirely satisfactory. In the present system, a reel latch which is operated by pneumatic pressure has a greater range of cam action and applies a selected frictional force, which locks the reel to the hub, and to the drive shaft.
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This invention generally addresses a communications system in which a plurality of spatially separated devices utilize RF communications and more specifically addresses a method for selecting the best antenna pattern from among several choices of antenna patterns. This invention is especially suited for, but not limited to, an environment in which multipath signals and fading problems are significant such as in an RF communication system located inside a building. It also addresses antenna selection techniques which take the presence of people into account.
It is generally known that directive antenna patterns can be utilized to enhance RF communications between remote RF transceiver. It is also generally known that various means exist for controlling an antenna radiation pattern such as by rotating a highly directional antenna, controlling the phasing of different antenna elements to electronically steer the primary beam or radiation pattern, and the selection of different directional antennas targeted at different locations.
Methods for selecting an optimal antenna pattern vary greatly depending upon the environment. In microwave line of sight communication applications, the antenna pattern selection is simple: just orient highly directional antennas pointing at each other. Physically separated antennas may be utilized by an RF transceiver to enhance communications that are not line of sight. In such diversity applications each antenna may be monitored with the antenna having the optimal signal being selected for use or all of the antennas may be combined utilizing the proper phasing to generate an enhanced single signal.
A number of factors make the problem of antenna pattern selection difficult. The reception of multipath signals, i.e. receiving the same signal at different times with different signal strengths from different geographic locations, greatly complicates antenna selection. The constant fading of signals also adds to the problem. These factors are present inside a building in which RF transceivers communicate using the 1-100 GHz(gigahertz) frequency range. The relatively close distances between the antennae and reflectors, such as walls, floors, ceilings and other metal objects large relative to the wavelength, result in strong multipath signals. Continuous fading results from environmental changes such as the movement of people or objects. It is generally desirable to minimize a person's exposure to RF radiation. These exists a need for an antenna pattern selection method which optimizes communications in such an environment.
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For many years agricultural balers have been used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. Usually, a mower-conditioner cuts and conditions the crop material for windrow drying in the sun. When the cut crop material is properly dried, a baler, for example a round baler, travels along the windrows to pick up the crop material and form it into cylindrically-shaped round bales.
More specifically, a pick-up assembly of the baler gathers the cut and windrowed crop material from the ground then conveys the cut crop material into a bale-forming chamber (or bale chamber) within the baler. A drive mechanism operates to activate the pick-up assembly, augers, and a rotor of the feed mechanism. A conventional bale chamber may include a pair of opposing sidewalls with a series of belts, chains, and/or rolls that rotate and compress the crop material into a cylindrical shaped bale. Square balers operate on similar principles but form “slices” which when stacked together form a rectangular or “square” bale.
Current round balers today rely on belt tension to regulate the bale density. However, as belt tension increases, the durability of the belt and rolls decreases. Thus, further increasing belt tension does not serve as a good option to increase bale density. Relatedly, it is also desirable to improve current square balers today to form high density bales.
High density bales are desirable because they would allow people to reduce the numbers of the bales to work with. The present invention is directed to these and other important ends.
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It is known to react polyepoxides with ketimine-blocked amines which include a single secondary amino hydrogen atom. The reaction products can be reacted with an acid to quaternize the tertiary amine groups in the reaction product, and the quaternized reaction product can be dispersed in water. The water reacts with the ketimine groups to release ketone into the water medium and this provides primary amine groups. The resulting amine-functional resin is electrodepositable from aqueous medium at the cathode of a unidirectional electrical system, and it can be cured with a curing agent which is introduced into the water medium for this purpose. The curing agents primarily selected in the prior art have been blocked polyisocyanates. When electrodeposited coatings containing the amine-functional resin and the blocked polyisocyanate are baked, the blocking agent is removed and the amine resin cures. All of the foregoing is illustrated in U.S. Pat. No. 4,031,050.
It would be desirable to replace the blocked polyisocyanate curing agent with an aminoplast resin because these are less costly, but the amine functionality (which is largely constituted by primary amine groups) creates a strongly alkaline environment which inhibits cure with an aminoplast resin.
Another point of importance is the fact that the ketimine-blocked secondary amines which are used in the prior process are derived from diethylene triamine, and it is desired to be able to use ethylene diamine, which is less costly.
Also, and in our prior application Ser. No. 477,432 filed Mar. 21, 1983 entitled Oxazolidine-Blocked Amine Polymers, we reacted a monoalkanol amine, such as monoethanol amine, with an unhindered ketone or aldehyde, and water was removed to generate an oxazolidine which contains a single reactive secondary amino hydrogen atom. This product was then adducted through its secondary amino hydrogen atom with a polyepoxide resin, sufficient oxazolidine being preferably used to consume all of the epoxy groups in the polyepoxide. Upon protonation of at least about 50% of the amine groups in the adduct (which could be nonvolatile when electrocoating was intended) and dispersion in water, hydrolysis of the oxazolidine occurs to generate a secondary amine group. The ketone or aldehyde which formed the oxazolidine was released into the water.
It is desired to employ reaction products possessing a relatively high amine functionality to enable a good cure to be had with blocked polyisocyanates which have lower functionality than typical aminoplast resins, like hexamethoxymethyl melamine. Also, primary amine groups are more reactive and can be used when polyisocyanates are relied upon, and such primary amine groups are not produced in our prior application. It is also desirable to increase the molecular weight of the polyepoxide in some instances by chain extension, and this is also not available in our prior application or in the normal practice of said U.S. Pat. No. 4,031,050.
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In recent years, small unmanned vehicles have been used to supplement or supplant many current operator functions on seafaring vessels and aircraft. They are used to reduce platform size, manpower, and budgets, and to minimize the number of personnel exposed to hostile action.
These unmanned vehicles include both underwater vehicles (UUVs) and aerial vehicles (UAVs). UUVs and UAVs often operate in conjunction with a host vehicle, which is usually either a larger ship or aircraft. UUVs and UAVs are typically deployed from their larger host vehicle via a straightforward and uncomplicated operation. On the other hand, depending upon mission specifics, recovery of a UUV or UAV by the larger host vehicle is anything but simple.
One problem that confounds recovery is that the maximum sustained speed for many small unmanned vehicles is often less than the minimum controllable speed for the larger recovery vehicle. That is true for both seafaring and aerial hosts.
A larger vessel could deploy a cable to catch a UUV. But the cable would be hard to control and, in view of the greater speed of the larger vessel, the shock of being snared could damage the UUV. Likewise, a net could be used by a host aircraft to snare a UAV, but the shock occasioned by the rapid deceleration of the captured UAV can damage it.
Another way to recover a UUV or UAV is to permit it to go dead in the water. This would require that a UAV ditch in the water. UAVs are often fragile and a water landing, especially in rough seas, could damage it. In the case of a UUV, the UUV would simply stop moving. If the UUV's host is a remote multi-mission vehicle (RMMV), this will be problematic, because although quite stable at speed, the RMMV is unstable (and vulnerable) when stationary.
As a consequence, there is a need for a method by which a relatively faster moving vehicle (e.g., host aircraft, host ship, etc.) can recover a relatively slower moving vehicle (e.g., UAV, UUV, etc.).
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This invention relates to a method of fabrication used for semiconductor integrated circuit devices, and more specifically to a method whereby a selective salicide process forms salicide on exposed logic FET""s, while blocking salicide formation on memory FET""s.
In the fabrication of semiconductor integrated circuits the salicide process is well documented for MOSFET and CMOS device formation. Methods are presented which differ in the number of masking steps and processing steps from the present invention.
U.S. Pat. No. 5,672,527 to Lee teaches a method for fabricating an electrostatic discharge protection circuit. The invention describes a process that features only one photo mask to form ESD protection circuit without the salicide and a LDD, lightly doped drain structure.
U.S. Pat. No. 5,719,079 to Yoo et al describes a salicide process for an embedded logic device. A method forming a local interconnect in an SRAM simultaneously with the formation of a salicide in logic devices is described.
U.S. Pat. No. 5,668,024 to Tsia et al is a method to form CMOS devices with a dual sidewall insulator spacers to reduce salicide bridging, as well as, using these regions for pocket implantation regions. The pocket implantation regions are used to reduce punch-through leakage.
U.S. Pat. No. 5,510,648 to Davies et al shows a process for forming salicide with a gate and insulating sidewall spacers of oxide, nitride. The patent teaches that the insulated gate device formed is well suited for the design of low voltage circuits due to the small variations of threshold voltage.
U.S. Pat. No. 4,912,061 to Nasr teaches a method of fabricating CMOS devices using salicide process using a disposable silicon nitride spacer, metal silicide and a single implant step for source, drain and gate. Dual sidewall spacers of oxide/nitride are described with the nitride spacer being removed subsequently.
It is a general object of the present invention to provide an improved method of forming an integrated circuit in which a selective salicide process forms salicide on exposed logic FET""s, while blocking salicide forming on memory FET""s. Thus, yielding logic FET""s with robust salicide structures which exhibit highly conductive lines and contacts, while blocking salicide formation on the sensitive memory FET""s which operate at low voltage and have low leakage, shallow junctions. A conformal layer of thick silicon nitride in conjunction with a salicide blockout mask forms robust selective salicide structures. These structures show low leakage and lack the usual problems associated with conventional salicide processing, such as, silicide bridging, xe2x80x9cribbonsxe2x80x9d or xe2x80x9cstringersxe2x80x9d.
In accordance with the present invention, the above and other objectives are realized in the first embodiment of the present invention by using a method of fabricating robust selective, salicide structures using a second thick conformal layer of dielectric which is refractory and can be selectively etched compared with the etch rate of silicon oxide. This thick conformal layer of refractory dielectric forms a salicide mask, whereby logic FET""s receive the salicide process and memory FET""s are protected by the salicide mask. Hence, a selective salicide process is described in the present invention.
The following process information is provided as a background to the present invention. Prior to said second thick conformal layer of refractory dielectric, conventional processing is provided. For example, a first conformal silicon nitride layer is deposited on oxidized polysilicon gate structures. Anisotropically etch of the silicon nitride layer forms sidewall spacers on the sidewalls of said oxidized polysilicon gate structures. Exposed source and drain regions are then ion implanted forming lightly doped source/drain regions underneath the sidewall structures. Rapid thermal annealing activates the ion implanted dopants while limiting diffusion. The said silicon nitride spacers are etched off leaving oxidized polysilicon gate structures with implanted source and drain regions. Both logic and memory FET""s are processed simultaneously at this stage of the process.
In the first embodiment of the present invention, the second thick conformal layer of refractory dielectric material is any material which meets the general requirements for the process. One of the key requirements is that it must have a high etch selectivity to that of silicon dioxide. In the second embodiment the material is listed as thick silicon nitride. This second conformal material protects the memory FET""s from salicidation.
In the second embodiment of the present invention, the above and other objectives are realized by using the method of selective salicide formation by depositing a second conformal thick layer of silicon nitride, in the thickness range of approximately 500 Angstroms to approximately 1500 Angstroms. Said second thick layer of silicon nitride is patterned by photolithography by applying a salicide blockout mask to the memory FET""s. Anisotropic silicon nitride RIE (Reactive Ion Etch) etching forms robust silicon nitride sidewall spacer structures on the sidewalls of the oxidized silicon nitride gate structures. Greater integrity of the sidewall spacer is achieved with the said thick silicon nitride process.
The blockout photolithography mask is subsequently removed by stripping the resist. Salicide formation process is applied by depositing metals, such as, Ti, Ta, Mo, W, Co, Ni, Pd, Pt onto the substrate. Low electrical resistance, good adhesion and low mechanical stress are some of the more desirable properties in choosing which metal to deposit and by what method to deposit the silicide metal. Silicide formation occurs by diffusion of silicon atoms through the polysilicon to the surface where the reaction with the metal occurs. In some instances, a two step RTA, Rapid Thermal Anneal, in an inert atmosphere converts the silicide from C49 crystal structure to the preferred C54 low electrical resistance structure. Salicide formation occurs in the exposed polysilicon areas and at the top of the source/drain areas, hence it is a self-aligned process. Deleterious bridging, which is silicide formation between the polysilicon and closely spaced source/drain regions is prevented by the robust silicon nitride sidewall structures.
The thick silicon nitride, the silicide protection layer and nitride sidewall spacers are subsequently removed by selectively etching the nitride while leaving the oxide layers and salicide layers intact. This is one of the key aspects of the present invention.
The salicide formation takes place on all the exposed silicon surfaces, that is, at the top of the polysilicon gate and in the diffusion regions. However, the silicon nitride spacers that see exposure to the selective salicide processing metal do not react to form silicide.
The silicon oxide loss or recess in the field isolation region is significantly greater for conventional processing. The reason for this is due to fact that the prior art or traditional process etches silicon oxide to form the salicide mask (self-aligned silicide mask). Therefore, the field silicon oxide, is also etched in the traditional process etch. This non-selective etch results in a recess in the field oxide region. These effects expose the silicon at the edge of the active source/drain regions and cause deleterious silicide formation to occur. This results in leakage around the source/drain. The present invention describes a process whereby thick dielectric silicon nitride can be the refractory material that forms the salicide mask and it can be selectively etched compared with silicon oxide. The selectively etch process minimizes the leakage problem.
In addition, after the salicide process is complete, said thick silicon nitride layer can be anisotropically etched to form sidewall spacers on the memory devices.
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1. Field of the Invention
This invention relates to aqueous binders which can be formulated into coating compositions for any substrates, especially rigid substrates, yielding soft-feel coatings thereon.
2. Descirpition of the Prior Art
In the coating of hard substrates, such as plastics, there is frequently a desire for the coating to achieve a soft feel, where the coated surface, although feeling soft to the touch (like skin or leather), is unimpaired in terms of its mechanical and chemical resistance in comparison to the conventional coatings.
The so-called soft feel coating materials achieve this objective. The substrates coated with them have Kxc3x6nig pendulum hardnesses of less than 20 seconds for coating films approximately 50 xcexcm in thickness. The surfaces are scratch resistant (scratch test with the fingernail) where scratching leaves a trace, it can be removed again simply by wiping with the fingertip. Without sticking or being tacky, the coated surfaces are slip resistant; for example, a glass or metal block does not slip on a surface coated with a soft feel coating material but instead tips when the angle of inclination is gradually increased. If a coating film is detached from a glass surface coated with it, and its extension is measured, a reversible extension of up to 500% is found on measurement at room temperature with a stretching rate of 0.6 cm/s.
Binders for these soft feel coating materials preferably have segments of polymers having a low glass transition temperature; the crosslinking density must still be high enough for there to be very little or no reduction at all in the mechanical and chemical resistance properties but low enough to allow the effect of the low glass transition temperature to be manifested macroscopically as well.
Two-component, or two-pack binders have been disclosed for soft feel coating materials that are based on hydroxyl-containing polyester-urethanes, which are to be cured preferably with isocyanates but also, for example, with acid anhydrides or amino resins.
It has proven impossible to date to provide practicable one-component, or one-pack binders for soft feel coating materials. Although crosslinking with amino resins may be effected at elevated temperature in the manner of a one-component system, the soft surface of the soft feel coating is adversely affected by the high temperatures required. Especially when coating plastics, the crosslinking temperature is limited by the softening temperature of the polymer substrate.
The known, polyisocyanate-based systems which cure at room temperature share the typical problems of isocyanate-cured systems: the limited pot life and limited acceptability from the standpoint of occupational hygiene. A further important disadvantage of isocyanate curing agents in conjunction with soft feel coating materials is the xe2x80x9caftercuringxe2x80x9d which is observed. The polyfunctional isocyanates used for the crosslinking are usually employed in excess. They are able to react with water, or even with the atmospheric moisture, and do so with decarboxylation and formation of the corresponding amines, which in turn form ureas with isocyanates that have not yet reacted. This reaction occurs during the drying of the coating material and adversely affects the feel of the coating film, which is still soft directly following application and initial crosslinking.
There was therefore a need to develop a binder for soft feel coating materials which durably retains this soft feel. A further object was to provide a one-component binder which cures even at moderate temperatures (above 70xc2x0 C., in particular from about 80 to about 150xc2x0 C.) and yet imposes very little restriction on the pot life.
This object has been achieved by the provision of a reactive combination comprising a hydroxyl-containing polyester-urethane and a melamine resin.
The invention accordingly provides a water dilutable binder for soft feel coating materials, comprising an aqueous dispersion of a hydroxyl-containing polyester-urethane A, obtainable by reacting a polyester A1 with hydroxyl groups as functional groups, said polyester A1 having been synthesised from linear, branched or cyclic aliphatic or aromatic difunctional or polyfunctional carboxylic acids A11 and aliphatic linear or branched difunctional or polyfunctional alcohols A12 as reactants, with a polyfunctional isocyanate A2, a compound A3 having at least one hydroxyl, mercapto or amino group which is reactive toward isocyanates and having at least one acid group which reacts only to a minor extent if at all with isocyanates, and also, optionally, with a drying or, preferably, nondrying oil A4, an aqueous solution or dispersion of a triazine resin B which for each molecule derived from a triazine has between 2. and 6 groups selected from methylene groups, methylene ether groups, methylol groups and alkoxymethyl groups, wherein the glass transition temperature of the polyester-urethane A is between xe2x88x9270 and xe2x88x9220xc2x0 C., preferably from xe2x88x9260 to xe2x88x9225xc2x0 C., and in particular from xe2x88x9250 to xe2x88x9230xc2x0 C., and wherein the hydroxyl number of the polyester-urethane A is from 10 to 120 mg/g, preferably from about 20 to about 100, and in particular from 25 to 95 mg/g.
The term xe2x80x9cminor extentxe2x80x9d as used herein means that, under otherwise identical reaction conditions, the reaction rate of the isocyanate-reactive hydroxyl, mercapto or amino groups is at least 5 times as great as that of the acid groups with respect to the same compound containing isocyanate groups.
The polyester A1 is prepared preferably in two stages in a known manner by condensing the entirety of the carboxylic acid component A11 with at least a portion A121 of the polyol component A12, the average functionality of A121 in the first stage being between 1.8 and 2.3, preferably from 1.9 to 2.1.
As component A11, it is preferred to use dicarboxylic acids having 4 to 40 carbon atoms, particular preference being given to succinic acid, adipic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, and a mixture of branched aliphatic dicarboxylic acids obtainable by dimerising unsaturated fatty acids. Up to 10%, preferably up to 5%, of the mass of A11 may comprise one or more higher carboxylic acids having three or more carboxylic acid groups per molecule, such as tricarboxylic and tetracarboxylic acids.
As component A121, it is preferred to use difunctional alcohols having 2 to 20 carbon atoms. Glycol, 1,2- and 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and cyclohexanedimethanol are especially suitable, as are the ether alcohols, diethylene glycol, triethylene glycol and higher oxyethylene diol oligomers up to a degree of polymerisation of approximately 10. It is also possible to use oligomeric propylene glycols; the mass fraction of the ether alcohols in component A121 is preferably up to 30% of the mass of component A121. In the context of the invention it is also possible to use alcohols having a functionality of three or more, and monofunctional alcohols, in each case individually or together, as constituents of component A121. In that case, the amount of these alcohols of higher or lower functionality must be chosen such that the average functionality satisfies the above condition.
Following the condensation of the preferably difunctional reactants of the first stage, the resulting polyester, which typically has an acid number of less than 10 mg/g, preferably less than 5 mg/g, is transesterified with a trifunctional or higher polyfunctional aliphatic alcohol or with a mixture of two or more aliphatic linear or branched alcohols having an average functionality of from 2.2 to 4.5, preferably from 2.5 to 4.0, and in particular from 2.8 to 3.8, referred to collectively below as A122. The component A122 preferably comprises trifunctional alcohols such as glycerol, trimethylolpropane and trimethylolethane, tetrafunctional alcohols such as pentaerythritol, ditrimethylolethane and ditrimethylolpropane, which in accordance with the invention are used preferably in a mixture with difunctional alcohols as defined under A121,and also alcohols of higher functionality such as mannitol, sorbitol and dipentaerythritol. Following the transesterification step, the resultant branched polyester A1 should have a hydroxyl number of from about 50 to about 150 mg/g, preferably from 70 to 130, and in particular from 80 to 120 mg/g, and an acid number of less than 8, in particular less than 5 mg/g.
The polyfunctional isocyanates A2 are aliphatic or aromatic compounds having (on average, where mixtures of two or more compounds are used) two or more than two isocyanate groups per molecule. Suitable aromatic diisocyanates include tolylene diisocyanate (technical-grade mixture of the 2,4- and the 2,6-isomers) and diphenylmethane diisocyanate. Preference is given to linear, branched and cyclic aliphatic isocyanates, especially difunctional isocyanates, having 2 to 15 carbon atoms in the (cyclo)aliphatic radical. Among the aromatic isocyanates, it is also possible to use, preferably, those which carry isocyanate groups on a carbon atom having an aliphatic character; one example thereof is tetramethylxylylene diisocyanate. Other preferred isocyanates are 1,6-diisocyanatohexane, 1,6-diisocyanato-3,3,5- and -3,5,5-trimethylhexane, 1,4-diisocyanatocyclohexane, isophorone diisocyanate, 2,2-bis(4-isocyanatocyclohexyl)propane, and also the uret diones, allophanates and biurets derived therefrom.
The compounds A3 have at least one, preferably two or more, especially two, groups which undergo addition reaction with isocyanates to form urethanes, ureas or thiocarbamates, i.e., hydroxyl, amino, or mercapto groups. As a further functional group they carry an acid group which even under the chosen reaction conditions undergoes little or no reaction with the isocyanate. The acid groups are selected from organically bonded carboxylic, sulfonic and phosphonic acid groups. Preferably, the acid group is sterically shielded by adjacent substituents. Particular preference is given to bishydroxymethylalkanoic acids such as dimethylolpropionic acid, dimethylolbutyric acid, and dimethylolacetic acid.
The oils A4 are the known esters of fatty acids and glycerol, such as linseed oil, and safflower oil; preference is given to nondrying oils, including in particular those in which at least some, preferably more than 5%, of the mass of the fatty acids is also hydroxy-functional. Particular preference is given to castor oil.
Preferably, the polyester-urethane A has an acid number of from about 10 to about 60, with particular preference from about 12 to about 50, and in particular from about 15 to about 40 mg/g, and the acid groups of the polyester-urethane are neutralised to the extent of from 20 to 100%, with particular preference from 30 to 90%, and in particular from 40 to 80%.
The hydroxyl number is defined in accordance with DIN 53 240 as the ratio of that mass mKOH of potassium hydroxide having exactly the same number of hydroxyl groups as a sample under analysis to the mass mB of this sample (mass of the solid in the sample in the case of solutions or dispersions); its customary unit is xe2x80x9cmg/gxe2x80x9d.
The acid number is defined in accordance with DIN 53 402 as the ratio of that mass mKOH of potassium hydroxide required to neutralise a sample under analysis to the mass mB of this sample (mass of the solid in the sample in the case of solutions or dispersions); its customary unit is xe2x80x9cmg/gxe2x80x9d.
The resins used as component B are partially or fully etherified triazine resins, derived from melamine, acetoguanamine, caprinoguanamine, and benzoguanamine or their mixtures. For heat-sensitive substrates it is preferred to use melamine resins in which the number of methylol groups in relation to the number of groups which have been etherified or condensed further to methylene, methylene ether or alkoxymethyl groups is sufficient for the reactivity.
Methylol or N-methylol groups are groups of the type greater than Nxe2x80x94CH2OH, methylene groups are groups of the type greater than Nxe2x80x94CH2xe2x80x94N less than , methylene ether groups are groups of the type greater than Nxe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94N less than , and alkoxymethyl groups are groups of the type greater than Nxe2x80x94CH2xe2x80x94Oxe2x80x94R, where R is usually an alkyl radical selected from methyl, ethyl, n- and iso-propyl and also n-, iso-, sec- and tert-butyl groups, preference being given to methyl and the n- and iso-butyl groups.
Where plastics, textiles, leather or wood are to be coated with the soft feel coating materials of the invention, it is preferred to use those triazine resins which contain predominantly N-methylol groups. Such resins undergo crosslinking reaction with the polyester-urethane even at relatively low temperatures above about 80xc2x0 C. In the case of the coating of metals or glass, it is also possible to use the slower-reacting etherified melamine resins, with or without the addition of customary acidic catalysts.
Predominantly as used herein means that, in this case, the number of N-methylol groups is higher than the number of any other substituent group, such as methylene, alkoxymethyl, or methylene ether groups, in an amino functionality of the triazine resin.
The amounts of components A and B are advantageously chosen so that the ratio of the number of hydroxyl groups in A to the number of reactive groups in B is from 0.7:1 to 1.5:1, preferably from 0.8:1 to 1.4:1, and with particular preference from 0.9:1 to 1.3:1.
The system of the invention cures, surprisingly, from as low as about 80xc2x0 C., preferably from about 90xc2x0 C. Relative to the known systems curable with polyfunctional isocyanates, the systems of the invention have the following advantages:
At approximately equal curing temperature (above 80xc2x0 C.), the systems of the invention are dust-dry after just a short period (about 0.5 hour) of drying in air; this dust-dry coat may immediately be recoated without the occurrence of the xe2x80x9cpoppingxe2x80x9d known with isocyanate-curing systems. In contrast to the isocyanates, the melamine resins in conjunction with the polyester-urethanes are not used in excess; instead, a stoichiometric amount (one methylene, methylol or alkoxymethyl group per hydroxyl group of the polyester-urethane resin) of the melamine resin is sufficient for curing.
At coat thicknesses of as little as above about 30 xcexcm, a soft feel may be obtained with the system of the invention; in the case of the known isocyanate-curing systems, coat thicknesses of at least 50 xcexcm are required. In contrast to the known isocyanate-curing systems, the soft feel coating materials of the invention do not exhibit the phenomenon of aftercuring; the soft feel does not gradually disappear but instead is retained for a long period.
The binders of the invention are outstandingly suitable for the formulation of coating materials which give the substrates coated with them the above-described soft feel. They are used in particular to coat metals, plastics, glass, ceramic, textiles, leather, and wood.
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1. Field of Invention
This invention relates to a motor control system, and more particularly, to a DC motor speed control system having a simple current limiting circuit for limiting excess current to a DC motor from a DC power source.
2. Description of the Prior Art
In a conventional speed control system for a DC motor, wherein drive current to the DC motor is controlled by chopping signals, a current limiting circuit is provided in order to prevent the motor and DC power source from buring when excess current (or sometimes called overcurrent) flows continuously.
In such a prior current limiting circuit; however, disadvantageously, if a large load is momentarily applied to a DC motor during starting or driving, the current limiting circuit is caused to operate, and consequently, current above a predetermined value will not flow in the motor and torque of the motor cannot be increased during that time.
Moreover, in the conventional current limiting circuit, overcurrent to a motor is detected during conduction of a power control element, such as a power transistor. Since the overcurrent may vary near a predetermined limit value, a high frequency switching signal, in synchronization with the frequency of the current variation, is applied to the power transistor, by the current limiting circuit. However, the power transistor cannot respond accurately to the high frequency signal. Thus, overcurrent may flow in the motor continuously. As a result, current limitation is not reliably effected by the prior current limiting circuit and the motor and power transistor may be burned, or in certain circumstances, the power source transformer may also be burned.
Thus, the prior art DC motor control systems leave something to be desired, and improvement is greatly desired.
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There is significant interest in lithium sulfur (i.e., “Li—S”) batteries as potential portable power sources for their applicability in different areas. These areas include emerging areas, such as electrically powered automobiles and portable electronic devices, and traditional areas, such as car ignition batteries. Li—S batteries offer great promise in terms of cost, safety and capacity, especially compared with lithium ion battery technologies not based on sulfur. For example, elemental sulfur is often used as a source of electroactive sulfur in a Li—S cell of a Li—S battery. The theoretical charge capacity associated with electroactive sulfur in a Li—S cell based on elemental sulfur is about 1,672 mAh/g S. In comparison, a theoretical charge capacity in a lithium ion battery based on a metal oxide is often less than 250 mAh/g metal oxide. For example, the theoretical charge capacity in a lithium ion battery based on the metal oxide species LiFePO4 is 176 mAh/g.
A Li—S battery includes one or more electrochemical voltaic Li—S cells which derive electrical energy from chemical reactions occurring in the cells. A cell includes at least one positive electrode. When a new positive electrode is initially incorporated into a Li—S cell, the electrode includes an amount of sulfur compound incorporated within its structure. The sulfur compound includes potentially electroactive sulfur which can be utilized in operating the cell. A negative electrode in a Li—S cell commonly includes lithium metal. In general, the cell includes a cell solution with one or more solvents and electrolytes. The cell also includes one or more porous separators for separating and electrically isolating the positive electrode from the negative electrode, but permitting diffusion to occur between them in the cell solution. Generally, the positive electrode is coupled to at least one negative electrode in the same cell. The coupling is commonly through a conductive metallic circuit.
Li—S cell configurations also include, but are not limited to, those having a negative electrode which initially does not include lithium metal, but includes another material. Examples of these materials are graphite, silicon-alloy and other metal alloys. Other Li—S cell configurations include those with a positive electrode incorporating a lithiated sulfur compound, such as lithium sulfide (i.e., Li2S).
The sulfur chemistry in a Li—S cell involves a related series of sulfur compounds. During a discharge phase in a Li—S cell, lithium is oxidized to form lithium ions. At the same time larger or longer chain sulfur compounds in the cell, such as S8 and Li2S8, are electrochemically reduced and converted to smaller or shorter chain sulfur compounds. In general, the reactions occurring during discharge may be represented by the following theoretical discharging sequence of the electrochemical reduction of elemental sulfur to form lithium polysulfides and lithium sulfide:S8→Li2S8→Li2S6→Li2S4→Li2S3→Li2S2→Li2S
During a charge phase in a Li—S cell, a reverse process occurs. The lithium ions are drawn out of the cell solution. These ions may be plated out of the solution and back to a metallic lithium negative electrode. The reactions may be represented, generally, by the following theoretical charging sequence representing the electrooxidation of the various sulfides to elemental sulfur:Li2S→Li2S2→Li2S3→Li2S4→Li2S6→Li2S8→S8
A common limitation of previously-developed Li—S cells and batteries is capacity degradation or capacity “fade”. Capacity fade is associated with coulombic efficiency, the fraction or percentage of the electrical charge stored by charging that is recoverable during discharge. It is generally believed that capacity fade and coulombic efficiency are due, in part, to sulfur loss through the formation of certain soluble sulfur compounds which “shuttle” between electrodes in a Li—S cell and react to deposit on the surface of a negative electrode. It is believed that these deposited sulfides can obstruct and otherwise foul the surface of the negative electrode and may also result in sulfur loss from the total electroactive sulfur in the cell. The formation of anode-deposited sulfur compounds involves complex chemistry which is not completely understood.
In addition, low coulombic efficiency is another common limitation of Li—S cells and batteries. A low coulombic efficiency can be accompanied by a high self-discharge rate. It is believed that low coulombic efficiency is also a consequence, in part, of the formation of the soluble sulfur compounds which shuttle between electrodes during charge and discharge processes in a Li—S cell.
Some previously-developed Li—S cells and batteries have utilized high loadings of sulfur compound in their positive electrodes in attempting to address the drawbacks associated with capacity degradation and anode-deposited sulfur compounds. However, simply utilizing a higher loading of sulfur compound presents other difficulties, including a lack of adequate containment for the entire amount of sulfur compound in the high loading. Furthermore, positive electrodes formed using these compositions tend to crack or break. Another difficulty may be due, in part, to the insulating effect of the higher loading of sulfur compound. The insulating effect may contribute to difficulties in realizing the full capacity associated with all the potentially electroactive sulfur in the high loading of sulfur compound in a positive electrode of these previously-developed Li—S cell and batteries.
Conventionally, the lack of adequate containment for a high loading of sulfur compound has been addressed by utilizing higher amounts of binder in compositions incorporated into these positive electrodes. However, a positive electrode incorporating a high binder amount tends to have a lower sulfur utilization which, in turn, lowers the effective maximum discharge capacity of the Li—S cells with these electrodes.
Li—S cells and batteries are desirable based on the high theoretical capacities and high theoretical energy densities of the electroactive sulfur in their positive electrodes. However, attaining the full theoretical capacities and energy densities remains elusive. Furthermore, as mentioned above, the sulfide shuttling phenomena present in Li—S cells (i.e., the movement of polysulfides between the electrodes) can result in relatively low coulombic efficiencies for these electrochemical cells; and this is typically accompanied by undesirably high self-discharge rates. In addition, the concomitant limitations associated with capacity degradation, anode-deposited sulfur compounds and the poor conductivities intrinsic to sulfur compound itself, all of which are associated with previously-developed Li—S cells and batteries, limits the application and commercial acceptance of Li—S batteries as power sources.
Given the foregoing, what is needed are Li—S cells and batteries without the above-identified limitations of previously-developed Li—S cells and batteries.
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1. Field of the Invention
The present invention relates to a video phone system. More particularly, the present invention relates to a method for providing a guide broadcasting in the same way as that for a voice call without a change of hardware in a mobile communication system supporting a video phone. Embodiment of the present invention relates to embodiments for providing a guide broadcasting before a call is set up, after a call is set up, and when a call forwarding is performed in providing a video phone service in a mobile communication system.
2. Description of the Related Art
Generally, 3G mobile communication systems using Code Division Multiple Access (CDMA) technology, such as Universal Mobile Telecommunication Service (UMTS) systems, CDMA 2000 1x systems and 1x Evolution Data and Voice (EV-DV) systems, provide consistent services capable of transmitting packet-based texts, digitized voices, and video and multimedia data at a high speed of more than 2 Mbps regardless of the user's global position.
Further, 3G mobile communication systems can distinguish voice calls, which are realtime and have narrow bandwidths, from data calls, which are sensitive to errors and have very wide bandwidths, and provide communication services in speech modes when the voice calls are required. Also, 3G mobile communication systems can provide communication services in data modes when the data calls are required. The voice call is connected through an existing Public Switched Telephone Network (PSTN) called a circuit switched network and the data call is connected through a packet data network, such as the Internet, called a packet switched network.
A video phone service simultaneously transmits voice data and video data, displays the appearance of a listener on a screen during communications, so that a speaker can talk to the listener while seeing the appearance of the listener. As compared with a speech communication service, the video phone service as described above can provide the speaker with greater satisfaction because it enables the speaker to talk to the listener while seeing the appearance of the listener.
Meanwhile, an existing circuit-based mobile phone service provides a guide broadcasting and various tones, which report ‘Voice Mailing Service (VMS) forwarding’, ‘no response’, and ‘busy’ for voice calls. However, since the video phone service is basically provided in a data mode, it is unable to be linked to the guide broadcasting typically provided through voice service. Accordingly, it is necessary to provide a technology capable of providing a guide broadcasting for a video phone in the same level as that for the existing voice call.
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1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for testing an electrical component.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today′s computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago. Computer systems today are often capable of including one or more modular components, components which may be removed and replaced with ease. Such components are typically formed with a printed circuit board (‘PCB’) with many traces etched on the PBC. The manufacturer of such a PCB typically manufactures the PCB, according to some manufacturing tolerances, such as trace width tolerances, tolerances for the material composition of the traces and PCB substrate, tolerances for the position and angles of the etched traces, and other manufacturing tolerances, any of which may affect electrical characteristics of the trace, the PCB, electrical components soldered to the traces, and a computer system in which such a component is installed. Because two electrical components may be manufactured within such manufacturing tolerances, the electrical operating characteristics of two electrical components of the same type may actually vary. Such variations may introduce a small or large amount of variation of electrical characteristics in a larger electrical system in which the component is installed. In fact, in a multi-component system, with each component manufactured within manufacturing tolerances, such variations may compound, causing a large deviation from expected system operation. Current techniques for testing electrical components, however, often do not test for variation within these manufacturing tolerances. Specifically, variation in impedance between traces of PCBs of same-type components, is often ignored. In fact, the only current way to test an electrical component taking into account possible variations in manufacturing tolerances, is to test a batch of different PCBs of the same-type of component. Such a test, however, does not guarantee that the entire range of manufacturing tolerances is taken into account, but instead typically represents only a small number tolerance variations.
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Call handling of either emergency or non-emergency related situations is a process of interacting with a caller to exchange information. The caller may have contacted a particular agency or service provider to gain assistance. A call handling system is the system used by a call handler to communicate with the caller. For example, a caller may dial 911 seeking emergency assistance. Another example is where a caller dials an information service to obtain driving directions or addresses. In either situation, the call may be handled by a call handler using a call handling system.
A particular caller may contact a particular agency or service provider to forward information. For example, a caller may dial 911 to report an emergency situation that the caller has witnessed, such as a crime, an automobile accident or a building fire. An example of a non-emergency situation would be where the caller calls to report local driving or weather conditions or a crime tip line. Whether the caller is calling to gain assistance or report information, a call handler, who may be specially trained in quickly and efficiently exchanging information with a caller, may handle the call.
A critical application of call handling is in the provision of emergency services. In an emergency situation, the call handler may need to quickly extract information from the caller in order to assist the caller. Such is typically the case in emergency medical situations where the call handler must ascertain the type and extent of injury in order to give relevant instructions. Generally, in an emergency situation, a caller will dial 911 and be connected to a local Public Safety Answering Point (PSAP). The PSAP is generally staffed with a group of specially trained call handlers. Typically, the call handlers will respond to callers according to protocols, often dispatching emergency service providers. Call handling is often employed with Computer Aided Dispatch (CAD) systems that dispatch response units, such as police, fire and/or medical units, based on received information. For example, call handling of prior art CAD systems typically involves call handlers who receive calls describing certain events. The call handlers subsequently convey this information to a dispatch unit by manually inputting information into the CAD system, which then recommends the appropriate dispatch unit(s) for response to the event.
Typically, a call handler working in a PSAP will receive textual information, displayed on a computer terminal, regarding the probable location of a caller. If the caller is calling from a landline, systems at the PSAP may access an automatic location information (ALI) database to determine the location of the caller. Accordingly, errors in the ALI database may result in incorrect determinations of caller location. Therefore, the call handler may need to verify the location of the caller. If the caller is calling from a mobile wireless device (e.g., cell phone), location information, if available at all, may not be determinable in the same manner as for landlines. Location information of a caller using a mobile wireless device presented to a call handler may be derived from triangulating signals transmitted by the cell phone. The accuracy of such a location may be dependent on the number of cell towers and signal strength. Global Positioning System (GPS) location data may also be available if the caller is using a cell phone with GPS capabilities. However, GPS systems may be unreliable, for example, if the caller is indoors. Accordingly, in the case of mobile wireless devices, the call handler may need to provide and/or verify the location of the caller.
Generally, the location of the caller is only one part of the information that is exchanged between the caller and the call handler in an emergency situation. For example, at the scene of a major traffic accident, the caller may need to communicate the number of people injured, the number of vehicles involved, location and condition of the vehicles, current conditions (e.g., fog, ice, etc.), and many other aspects of the situation. In current emergency call handling systems, all of this information is communicated verbally between the caller and the call handler and the call handler may forward this information, either verbally or textually, to at least one emergency services provider.
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In a long term evolution system (Long Term Evolution, LTE), as an emerging mobile long term evolution technology, many new technologies are adopted, and four uplink channels, namely, a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH), a physical uplink control channel (Physical Uplink Control Channel, PUCCH), a physical random access channel (Physical Random Access Channel, PRACH), and a sounding reference signal (Sounding Reference Signal, SRS) are defined. The PRACH is used for random access of a user equipment (User Equipment, UE), and the sounding reference signal is used for measuring uplink channel information.
A signal sent by a UE on a PRACH channel is called a preamble sequence (Preamble Sequence), and the PRACH occupies resources of 6 consecutive resource blocks (Resource Block, RB) in a frequency domain. The preamble sequence is a Zadoff-Chu (ZC) sequence, with a length of 839 points.
A ZC sequence is a classic sequence that satisfies a constant amplitude zero autocorrelation (constant amplitude zero autocorrelation, CAZAC) sequence feature, with a mathematic definition as follows:
when N is an even number,
x u ( n ) = ⅇ - j u π n 2 N 0 ≤ n < N ;and
when N is an odd number,
x u ( n ) = ⅇ - j u π n ( n + 1 ) N 0 ≤ n < N .
In the foregoing formulas, ZC sequences with different values of u are called different physical root sequences. A value range of u is (1, 838).
The ZC sequence has good autocorrelation and cross correlation, and these features of ZC are an important basis for coherent demodulation detection of the PRACH.
The ZC sequence has a good autocorrelation feature: Except that an initial point is N, other points are all Os:
R u ( l ) = ∑ k = 0 N - 1 x u ( k ) · x u * ( k + l ) = { N , l = 0 0 , l = others
Result amplitudes of cross correlation between ZC sequences are almost all equal to Sqrt(N):
R u ( l ) = ∑ k = 0 N - 1 x u ( k ) · x v * ( k + l ) ≈ N
A sounding reference signal also comes from a change of a ZC sequence. A sounding reference signal sequence traverses a whole sounding reference signal cell frequency band in a certain time period, and the sounding reference signal cell frequency band is configured by a higher layer, and is related to a bandwidth. In this way, a conflict inevitably occurs between a frequency domain position of the PRACH and a frequency domain position of the sounding reference signal sequence.
When coherent demodulation is performed on a PRACH sequence, a difference between a length of the sounding reference signal sequence and a length of the PRACH sequence results in that the sounding reference signal sequence may seriously damage the cross correlation of the ZC sequence during the coherent demodulation. As a result, whether a peak value after the PRACH sequence is correlated is an autocorrelation value of the PRACH sequence or a cross correlation value introduced due to the sounding reference signal sequence cannot be identified.
In an actual LTE network, a time-frequency domain position of a sounding reference signal of a neighboring cell or a local cell may overlap with a time-frequency domain position of a PRACH of the local cell. The sounding reference signal sequence and a PRACH preamble sequence both belong to ZC sequences, and the two are different in length, so that as described above, reflected cross correlation is not good. When there is no access from a user, the sounding reference signal of the neighboring cell or the sounding reference signal of the local cell incurs interference to PRACH detection of the local cell, and a serious false alarm may be generated in the PRACH detection.
For this case, the present invention provides a method and an apparatus for demodulating a physical random access channel signal, so as to restrain the interference from the sounding reference signal and reduce false alarms in the PRACH detection.
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The present invention relates to a silicon oxide film formed on the surfaces of a plastic substrate. More specifically, the invention relates to a silicon oxide film which has excellent gas shut-off property and is useful in a field of packing materials.
As packing containers, there have heretofore been used metal cans, glass bottles and a variety of plastic containers. Among them, plastic containers have such advantages that they are light in weight and are excellent in shock resistance to some extent accompanied, however, by such problems as permitting the contents to be degenerated and flavor to be decreased due to oxygen that permeates through the container walls.
In metal cans and glass bottles, in particular, no oxygen permeates through the container wall, and what causes a problem is only the oxygen remaining in the containers. In the case of plastic containers, on the other hand, oxygen permeates through the container walls to a degree that is no longer negligible arousing a problem from the standpoint of preserving the contents.
In order to prevent this, there has been proposed a plastic container having a container wall of a multi-layer structure at least one of the layers being formed of an oxygen-blocking resin such as an ethylene/vinyl alcohol copolymer.
However, a multi-layer plastic container requires a technology such as co-extrusion or co-injection of a plurality of resins, a cumbersome formation operation as compared to forming a single-layer resin container, accompanied by a problem of low productivity.
It has also been known already to improve the gas shut-off property by forming a film by vapor deposition on a plastic material of a single layer, and to form a silicon oxide film (SiOx) as well as to form a hard carbon film (DLC).
Japanese Unexamined Utility Model Publication (Kokai) No. 50563/1974 and Japanese Unexamined Patent Publication (Kokai) No. 58171/1974 are teaching silicon oxide films by coating a plastic film based on a physical vaporization method (PVD).
Further, Japanese Unexamined Patent Publication (Kokai) No. 345383/1993 teaches a silicon oxide film formed by the chemical vaporization method (CVD).
Japanese Patent No. 2526766 filed by the present applicant discloses a gas-blocking laminated plastic material comprising a plastic member, a first layer of a polymer formed thereon and containing not less than 15% of silicon, not less than 20% of carbon and the remainder of oxygen, and a second layer of a silicon oxide film formed on the first layer.
However, the conventional silicon oxide film must have a considerably large thickness to impart the required gas shut-off property. Besides, the coated film lacks adhesion to the plastic substrate, softness and flexibility. When, for example, the plastic substrate coated with the above film is drawn, the film is subject to be broken. The productivity is poor, either.
In particular, the silicon oxide film formed by the physical vaporization method (PVD) has inferior oxygen gas shut-off property as compared on the basis of the same film thickness. To achieve the gas shut-off property of the same level, therefore, the film must be formed maintaining a considerably large thickness.
It is therefore an object of the present invention to provide a silicon oxide film having particularly excellent gas shut-off property (gas barrier property), capable of excellently shutting off gases with a small film thickness as compared to the conventional films, the film that is deposited exhibiting excellent adhesion to the plastic substrate, softness and flexibility, lending itself well for being excellently produced.
According to the present invention, there is provided a silicon oxide film formed on the surfaces of a plastic substrate, wherein methyl groups and methylene groups are contained in the silicon oxide film in a portion near the interface to the plastic substrate.
The fact that the methyl groups and the methylenes group are existing in the silicon oxide film of the invention in a portion close to the interface to the plastic substrate, can be confirmed by, for example, depositing an Al film on the surface of the silicon oxide film formed on the surface of the plastic substrate, eluting the plastic substrate by using an organic solvent such as hexafluoroisopropanol or the like, and measuring a first infrared absorption spectrum of the surface of the remaining silicon oxide film. That is, in the first infrared absorption spectrum, an infrared absorption peak due to the methyl group and an infrared absorption peak due to the methylene group appear in a region of wave numbers of from 2800 to 3000 cmxe2x88x921. These peaks make it possible to confirm the presence of the methyl groups and methylene groups. Further, the first infrared absorption spectrum contains an infrared absorption peak due to SiO in a region of wave numbers of from 1000 to 1300 cmxe2x88x921 and, particularly, near 1200 cmxe2x88x921.
By using a secondary ion mass analyzer (SIMS), further, distributions of SiCH2 ions and SiCH3 ions in the film from the outer surface of the silicon oxide film toward the surface of the substrate are measured to make sure the positions where the SiCH2 ions and SiCH3 ions due to an organosilicon compound polymer are present, from which it is obvious that they are not existing on the outer surface of the film but are existing near the interface to the plastic substrate.
That is, in the silicon oxide film of the present invention, the organic groups (methyl groups and methylene groups) are existing near the interface to the plastic substrate accounting for excellent adhesion to the plastic substrate and flexibility. Even when the plastic substrate is intensely drawn, therefore, the film is effectively prevented from being broken.
In the present invention, further, the silicon oxide film has a two-layer structure comprising a first layer positioned on the side of the interface to the plastic substrate and a second layer on the first layer (i.e., layer positioned on the front surface side of the film). The methyl groups and the methylene groups are more distributed in the first layer than in the second layer. It is desired that the methyl groups and the methylene groups are not substantially contained in the second layer.
In the second infrared absorption spectrum of the silicon oxide film of the invention, for example, it is desired that an absorption peak exists in a region of wave numbers of from 1215 to 1250 cmxe2x88x921. The second infrared absorption spectrum is measured by the multiplex reflection differential spectral method from the film surface (surface of the second layer). The above first infrared absorption spectrum chiefly represents infrared absorption characteristics of the first layer positioned near the interface to the plastic substrate while the second infrared absorption spectrum chiefly represents infrared absorption characteristics of the second layer.
That is, owing to the above-mentioned two-layer structure, the silicon oxide film of the present invention exhibits excellent gas shut-off property.
In the second infrared absorption spectrum of the silicon oxide film, further, it is desired that the absorbency ratio defined by the following formula (1),
Ri=A1/A2xc3x97100xe2x80x83xe2x80x83(1)
wherein A1 is an area of an absorbency of wave numbers over a range of from 1215 to 1250 cmxe2x88x921, and
A2 is an area of an absorbency of wave numbers over a range of from 985 to 1250 cmxe2x88x921, is not smaller than 1%.
In the second infrared absorption spectrum of the silicon oxide film of the present invention, further, it is desired that the infrared absorbency ratio of SiOH/SiO is not larger than 0.25.
It is desired that the silicon oxide film of the present invention has a silicon distribution coefficient represented by a ratio of the silicon content and the film thickness (silicon content/thickness) of 0.3 g/cm3, has an oxygen permeation coefficient of not larger than 0.5xc3x9710xe2x88x9216 ccxc2x7cm/cm2/sec/cmHg (30xc2x0 C.) and, further, has a 10-point average surface roughness (Rz) of smaller than 25 nm and a center line average roughness (Ra) of smaller than 10 nm.
The silicon oxide film of the present invention having the above properties can be produced by a plasma CVD method and, usually, has a thickness of as very small as from 2 to 500 nm yet exhibiting excellent gas shut-off property.
According to the present invention, further, there is provided a gas-blocking plastic material having an inner layer and an outer layer of a thermoplastic resin, and an oxygen-absorbing layer between the inner layer and the outer layer, wherein the above silicon oxide film is formed on the surface of the inner layer and/or on the surface of the outer layer.
That is, upon forming the silicon oxide film on the inner surface and/or on the outer surface of the plastic substrate having the oxygen-absorbing layer as described above, there are imparted oxygen shut-off effect due to the oxygen-absorbing layer as well as gas shut-off property due to the silicon oxide film, making it possible to strikingly improve the gas shut-off property.
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The invention relates to a motor drive and control apparatus for a camera, and more particularly, to such apparatus which drives a driven member such as a taking lens or a photographic film used in an automatic focus adjusting unit or automatic film winding unit, respectively, through a given stroke toward a target position where it is stopped.
An automatic focus adjusting unit in which a taking lens is controlled to move to a target in-focus position has been proposed by the present applicant in Japanese Patent Application No. 302,692/1986, where a motor is controlled by comparing a deceleration curve against an actual speed of movement of a taking lens and in which a limited acceleration technique is employed as the taking lens approaches an in-focus position, by limiting an on time of the motor to a fixed time interval in order to prevent an overshooting which may result from the continued on condition of the motor. However, the limited acceleration takes place over a fixed time interval independently of the speed of movement of the taking lens which represents a driven member or the load, and hence it is inevitable that there occurs an over- or under-acceleration. In addition, the program used merely counts the length of time during which the motor is turned on, and hence it is impossible to sense a signal from a detector which detects a speed of movement, causing a likelihood that the speed of movement may be errorneously detected.
An automatic film winding unit in which a drive motor is stopped at a given winding step position is disclosed in Japanese Laid-Open Patent Application No. 24,123/1983. In this disclosure, a pulse which is developed in response to a movement of a film through a given stroke is utilized after the motor has entered a constant speed rotation to derive a speed of movement of a film which represents a driven member, and a brake is applied on the basis of an expected overrun which is derived from a previously stored table representing a relationship between the speed of movement of the film and the magnitude of overrun. However, because the application of the brake is based on the expected overrun, any variation in the load being wound up or drive voltage which might occur during the braking operation may cause a deviation between the expected and the actual overrun, resulting in a failure to stop the film winding operation at a target position. In addition, the relationship between the speed of movement of the film and the overrun may vary from product to product, involving the likelihood that a certain product may fail to stop the film at a target position.
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A database table may be arranged such that it includes multiple columns that store different types of content. Requests to the database table may then be received to read information from and/or write information into those columns. For example, different columns might store text information, numerical values, and/or other types of data. In some cases, portions of a database table will store “Large Object” (LOB) data content, such as in unlimited character string content (CLOB) and/or unlimited binary string content (BLOB) columns.
To efficiently access such LOB content, requests associated with “locators” and/or “streaming” may be provided in connection with a database server. A locator may be associated with a pointer to table column content and can accelerate access operations. However, these types of locators may require a considerable consumption of resources by the database server. In addition, streaming (e.g., as provided in JAVA documentation) may let data be accessed (including reading and writing) in a piecewise and/or sequential fashion.
An Open Structured Query Language (OpenSQL) environment may be associated with a set of Advanced Business Application Programming (ABAP) statements that perform operations on a central database, and the results of the operations (and any error messages) may be independent of the particular database system being used. In this way, OpenSQL may provide a uniform syntax and semantics that can be used in connection with multiple database implementations and/or vendors. Note, however, that OpenSQL does not provide a common syntax definition for locators and/or streaming requests.
Approaches that may improve access to LOB content in database tables could, therefore, be desirable. Moreover, it may advantageous to provide such access in an efficient and convenient manner—even when a number of different database server implementations can be associated with a system.
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When a user watches a video shown on a page of a browser through a device, other contents such as comments of the video and relevant information of the video usually needs to be browsed at the same time, hence an up-down slide operation on content of the page usually needs to be implemented. The up-down slide operation changes a visible region of the page, causing that a video playback region in the page is removed out of the visible region of the page (that is, the visible region of the page no longer includes a complete video playback region). The browser can not continue providing a normal video playback for the user, when the video playback region in the page is removed out of the visible region of the page, thus causing that the user's watching the video is interrupted. In addition, when the user watches a video on a page (such as page A) through a device, if content on another page (such as page B) needs to be browsed, browsing another page (such as page B) may also cause that the browser can not continue providing the normal video playback (namely, a video playback on page A) for the user, thus causing that the user's watching the video is interrupted.
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Radio pagers having selectable silent or tone alerting are known in the art. Typically, a vibrator motor alerts the wearer of the pager in the silent mode. Conventional vibrator motors comprise a cylindrical housing wherein a rotating shaft having a longitudinal axis of significant length to which an external but unbalanced counter weight is attached. "Significant length" means that the rotating shaft is equal to or greater than the diameter of the motor. This previously known type of vibrator motor is relatively large and severely restricts the commercially desired reduction in size of pagers.
Previously known tone alerting systems, i.e., transducer, piezo, or speaker, were conventionally located apart from the vibrator motor. This also restricted the reduction in size of the pager by requiring two separate housing systems for the vibrating motor and the tone alerting system.
Thus, what is needed is a radio pager having a unitary housing exhibiting substantial space saving characteristics by incorporating both a low profile vibrator motor for silent alerting and an tone generator for audio alerting.
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The present invention relates to a plasma processing apparatus for processing an object to be processed (process object) by using plasma.
In processing a process object especially an insulating film by utilizing plasma, a parallel-planar plasma processing apparatus, for example, has hitherto been used in which different two radio frequencies (RF""s) are applied to opposing electrodes (prior art 1). A plasma processing apparatus having a permanent magnet disposed in ring-form arrangement on the back of a RF electrode is disclosed in, for example, JP-A-8-288096 (prior art 2). A plasma processing apparatus, in which a planar antenna member is so disposed as to oppose an electrode carrying an object to be processed, the antenna member being supplied with a xcexc wave and a slit opening is formed in a front surface of the planar antenna, is described in, for example, JP-A-9-63793 (prior art 3). An etching apparatus using a high frequency in UHF band, in which an earth structure on the top of an antenna is concave, is disclosed in, for example, JP-A-11-354502 (prior art 4). Further, a parallel-planar UHF plasma apparatus in which a high frequency in UHF band is supplied to a disk-shaped antenna by a coaxial cable and the antenna diameter is set to a predetermined value n/2xc2x7xcex (n: integer) is disclosed in, for example, JP-A-10-134995 (prior art 5).
Prior art 1 lacks plasma distribution control means and hence, when the kind of gas and the pressure are changed, distribution of radical compositions and that of reaction products change, making it sometimes difficult to make the processing distribution uniform. In addition, plasma is difficult to increase in density and the processing speed (etching rate) is slow.
In prior art 2, the permanent magnet is used and as a result, a magnetic field is formed locally at a site nearly limited to the size of the permanent magnet. When the trapping effect due to the magnetic field is desired to be increased, the intensity of the magnetic field increases near the magnet and the plasma density becomes high at that portion. Further, a bias is applied to the RF electrode to draw ions and as a result, sputtering takes place locally, raising a problem that local wear of the electrode is caused to increase foreign matters and decrease the reliability of the apparatus. For the magnetic field formed at that portion, compatibility between local improvement and distribution controllability is difficult to achieve.
In prior art 3, the slit is formed in the antenna and the length of the slit is set to about xc2xd to {fraction (1/10)} of xcex (xcex:a wavelength of xcexc wave in the tube) to adjust the distribution but it is difficult to adjust the radiation of xcex wave and the electric field distribution.
Prior art 4 pertains to the earth structure on the top of an antenna for avoidance of concentration of electric field. Even if the earth structure is made to be concave, difficulties still remain in making the electric field distribution per se uniform and adjustment of the distribution is difficult to achieve when gas, pressure or power is changed.
In prior art 5, since the antenna center corresponds to the maximum amplitude of electric field and the antenna edge corresponds to the node of electric field, the electric field distribution directly below the antenna always becomes convex. Consequently, it is difficult to make plasma uniform.
Accordingly, an object of the present invention is provide, in a method of generating plasma by using a high frequency in VHF or UHF band and a magnetic field, a plasma processing apparatus which can realize the generation of plasma of high density and high uniformity in a wide parameter region.
To accomplish the above object, according to one aspect of the invention, a plasma processing apparatus comprises a vacuum vessel, a processing chamber arranged in the vacuum vessel and supplied with gas, a support electrode arranged in the processing chamber to support an object to be processed, high frequency admitting means including a disk-shaped antenna for supplying a high frequency in UHF or VHF band to the processing chamber and an emitting port arranged laterally of the antenna and formed of an insulating member, and magnetic field forming means for forming a magnetic field in the processing chamber, wherein in the high frequency admitting means, the ratio between the radius of the antenna and the effective length of the emitting port is 0.4 or more and 1.5 or less. The effective length d* of emitting port referred to herein is given by d*=(f/f0) d/∈rxc2xd where the real size of the emitting port is d, the specific inductivity of the insulating member constituting the emitting port is ∈r, the frequency used is f and the reference frequency f0 is 450 MHz.
Where the high frequency has a wavelength of xcex0 in vacuum, the radius of the antenna is preferably xcex0/4 or less. Preferably, a surface of the antenna opposing the processing chamber is made of Si, SiC or C. Preferably, part of the emitting port is closed with a metal plate to restrict the size of the emitting port approximately to a wafer diameter to be processed. Further, the antenna is formed with a slit opening (openings), a planar member made of Si, SiC or C is arranged on the surface of antenna adjoining plasma and the high frequency is supplied to the processing chamber through the planar member.
Other objects, features and advantages of the present invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
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The problem which our invention addresses is the efficient conversion of thermal energy to electrical energy. Thermophotovoltaic systems for conversion of thermal to electrical energy are well known. These are characterized by moderately inefficient conversion of thermal energy to light energy under optimal conditions, a low band gap photovoltaic device to convert the broadest range of light energy, and a need for cooling the photovoltaic device to prevent the low efficiency conversion of light to electrical energy from even further degradation resulting from a decrease in open circuit voltage associated with increasing temperatures. These characteristics, and the associated problems of prior art thermophotovoltaic (TPV) systems, are best illustrated by a brief examination of existing TPV systems.
A typical power input, or incident radiation, to photovoltaic devices in TPV systems is broad band radiation composed of wavelengths generally in the 1-2 micron range, corresponding to energies in the 0.6 to 1.2 electron volts range. In order for the photovoltaic device to capture as much energy in the broad band radiation as is possible, the band gap must match the lower energies of the radiation, that is, devices with a band gap on the order of no more than about 0.6 electron volts are desirable. This band gap ensures that all energy in the light spectrum is captured, but photon capture is not equally productive for all photons. Thus, that portion of the incident radiation having an energy close to the band gap of the photovoltaic device will effectively promote valence electrons into the conduction band; this leads to very efficient conversion of photons to current carriers. However, light energy substantially in excess of the band gap will promote valence electrons to energy states above the conduction band. These electrons undergo vibrational and rotational decay until they, too, achieve the energy of the conduction band, when as current carriers the electrons can effect conversion to electrical energy in an external circuit. But note that such electrons have lost much energy via vibrational and rotational decay, an energy loss manifested as thermal energy captured by the photovoltaic device itself which leads to a substantial increase in the device's operating temperature. Thus it is clear that the efficiency of energy conversion by a TPV device inherently decreases with an increase in the amount of thermal energy produced by incident radiation with an energy substantially in excess of the band gap.
But both the band gap and the open circuit voltage of the photovoltaic device decrease with increasing temperature. A consequence of decreasing the band gap is that still more of the total incident radiation will be converted to thermal energy because more photons will have energy in excess of that needed to move a valence electron into the conduction band. A consequence of decreasing the open circuit voltage, V.sub.oc, is a lower efficiency of power conversion. This arises because in general the fill factor of a photovoltaic device, i.e., the highest value of the product of current times voltage divided by the product I.sub.sc V.sub.oc, where I.sub.sc is the short circuit current, decreases as the open circuit voltage decreases. Thus, for photovoltaic devices with a band gap of 0.6 eV and a V.sub.oc .about.0.4 volts there is a necessity to cool the photovoltaic device for the sake of maintaining power conversion efficiency.
Where TPV conversion is desired in space, the cooling of photovoltaic devices occurs only via radiation and requires rather large, bulky radiative fins, which in turn exacts weight and volume penalties on the space vehicle. When devices operate at higher temperatures, the size of the radiator drops dramatically following a T.sup.4 power law. Thus, to recapitulate concisely, there is a cascade of undesirable effects arising from broad band radiation having photons with "excess" energy (energy greater than the band gap) which is converted, in large part, to thermal energy, lowering V.sub.oc and thereby decreasing the efficiency of power conversion.
Since many of the undesirable characteristics of present TPV systems arises from a broad radiation energy band impinging on the photovoltaic device, it follows that a narrow radiation energy band could confer important benefits. It also ought to be clear that a higher V.sub.oc when used in prior art TPV devices would maximize conversion efficiency of light to electrical energy. It also follows that if the energy spectrum of the radiation source would closely match the band gap of the photovoltaic device at operating temperatures, there would be minimal energy loss--and consequently maximal energy conversion efficiency--via vibrational and rotational decay from electronic states above the conduction band. Since photovoltaic devices can be made with band gaps over the wide range of 0.3-3 eV, the problem is "merely" one of converting broad band light radiation arising from thermal excitation into a narrow band energy spectrum matching the band gap of a photovoltaic device in the 0.3-3 electron volt range where the device has an open circuit voltage at least as high as the prior art devices. And since the efficiency of power conversion increases with increasing V.sub.oc, it follows that photovoltaic devices with a band gap greater than 0.6 eV are the more desirable devices.
We have achieved this goal by using selective infrared emitters as a means of converting thermal radiation incident on the emitters into narrow band infrared radiation with a peak energy on the order of about 1.2 electron volts. Using photovoltaic devices with a band gap in the 0.75-1.4 eV range, virtually all of the photons from selective infrared emitters can be effectively used to place electrons just into the conduction band of the photovoltaic device. Furthermore, since our higher band gap devices have both a higher open circuit voltage and an inherently higher fill factor, higher conversion efficiencies of light to electrical energy are also achieved. We also shall demonstrate that the photovoltaic device can be operated at temperatures in the 100-300.degree. C. range with additional benefits.
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Swedish patent specifications 7706927-6, 7908805-0 and 8105501-4 disclose systems in which the type of heat exchanger intended for use in practicing the present invention is used. These systems are completely open. For the heat exchanger included in such a system to function it is required that the heat exchanger be sunk to a certain proper level in the liquid, consisting of the polluted water or sea/lake water, which surrounds the cylindrical panels in the presence of variable flow. If this is not possible, overflow pipes or water traps must be used to keep the liquid level in the heat exchanger at the proper level. This involves a large disadvantage, since placing and erection of the heat exchanger are thus decided within certain limits, in turn resulting in that large difficulties in the use of available space can occur in fitting the heat exchanger into the system.
By means of the present invention it is possible to place the heat exchanger in such a location that it is suitable in the system, e.g. without regard to the liquid level in an open system.
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Physical systems can be modeled mathematically to simulate their behavior under certain conditions. There are a wide variety of means to model these systems, ranging from the very simplistic to the extremely complicated. One of the more sophisticated means to model physical systems is through the use of finite element analysis. As the name implies, finite element analysis involves the representation of individual, finite elements of the physical system in a mathematical model and the solution of this model in the presence of a predetermined set of boundary conditions. Another comparable means to model physical systems is through the use of finite difference analysis. Finite difference analysis involves the modeling of individual points within a modeled space and computing the differences between these points. Finite difference analysis is often used for simulating the dynamic behavior of fluids.
Traditional finite difference techniques and finite element techniques using streamlined, upwinding methods are typically used to simulate the production of oil in a reservoir. While each of these techniques has its own advantages, it also has its own disadvantages. Generally speaking, the finite difference techniques produce physically realistic results, but they are not very accurate. The finite element techniques, on the other hand, are more accurate, but they produce results which are not physically realistic.
As a result of their respective disadvantages, both the finite difference techniques and finite element techniques which are conventionally used normally require a great deal of computer resources. In the case of finite difference techniques, reasonable accuracy can be achieved, but this requires many more nodes then would be necessary in a finite element model. This increases the amount of memory and CPU time which are needed to compute an accurate solution. In the case of finite element techniques, comparable accuracy can be achieved with fewer nodes, but the solutions may not be realistic. For example, concentrations may be more than 100 percent, or permeabilities may be negative. Consequently, there may be problems for which the solution does not converge, or for which the solution may converge very slowly. These techniques are therefore less reliable and may require a large number of iterations before acceptable accuracy is achieved.
Because each of these standard techniques has its own drawbacks, and because these drawbacks increase in the amount of computer resources which are necessary to generate acceptable solutions, it would be desirable to provide a method for modeling systems such as oil reservoirs which reliably produces accurate, realistic solutions for these systems.
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In mammals, micturition (urination) is a complex process that requires the integrated actions of the bladder, its internal and external sphincters, the musculature of the pelvic floor, and neurological control over these muscles at three levels (in the bladder wall or sphincter itself, in the autonomic centers of the spinal cord, and in the central nervous system at the level of the pontine micturition center (PMC) in the brainstem (pons) under the control of cerebral cortex) (De Groat, Neurobiology of Incontinence, (Ciba Foundation Symposium 151: 27, 1990). Micturition results from contraction of the detrusor muscle, which consists of interlacing smooth muscle fibers under parasympathetic autonomic control from the sacral spinal cord. A simple voiding reflex is formed by sensory nerves for pain, temperature, and distension that run from the bladder to the sacral cord. However, sensory tracts from the bladder also reach the PMC, resulting in the generation of nerve impulses that normally suppress the sacral spinal reflex arc controlling bladder emptying. Thus, normal micturition is initiated by voluntary suppression of cortical inhibition of the reflex arc and by relaxation of the muscles of the pelvic floor and the external sphincter. Finally, the detrusor muscle contracts and voiding occurs.
Abnormalities of lower urinary tract function, e.g., dysuria, incontinence, and enuresis, are common in the general population. Dysuria includes urinary frequency, nocturia, and urgency, and may be caused by cystitis, prostatitis or benign prostatic hypertrophy (BPH) (which affects about 70% of elderly males), or by neurological disorders. Incontinence syndromes include stress incontinence, urgency incontinence, and overflow incontinence. Enuresis refers to the involuntary passage of urine at night or during sleep.
Prior to the work of the present inventors, treatment of neuromuscular dysfunction of the lower urinary tract has involved administration of compounds that act directly on the bladder muscles, such as flavoxate, a spasmolytic drug (Ruffman, J. Int. Med. Res. 16:317, 1988) also active on the PMC (Guarneri et al., Drugs of Today 30:91, 1994), or anticholinergic compounds such as oxybutynin (Andersson, Drugs 35:477, 1988). The use of .alpha..sub.1 -adrenergic receptor antagonists for the treatment of BPH is also common but is based on a different mechanism of action. (Lepor, Urology, 42:483, 1993).
However, treatments that involve direct inhibition of the pelvic musculature (including the detrusor muscle) may have unwanted side effects such as incomplete voiding or accommodation paralysis, tachycardia and dry mouth (Andersson, Drugs 35:477, 1988). Thus, it would be advantageous if compounds were available that act via the peripheral or central nervous system to, for example, affect the sacral spinal reflex arc and/or the PMC inhibition pathways in a manner that restores normal functioning of the micturition mechanism.
1-(N-phenyl-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)piperazin e (compound A) ##STR1## is described in GB 2 263110 A and is reported to be a 5-HT.sub.1A receptor antagonist. It is also disclosed that it can be used for the treatment of central nervous system disorders, for example as an anxiolytic agent in the treatment of anxiety.
The compounds of the present invention, described below, are structurally different from compound A because of the novel substituents present on the aniline ring at the 2 position. Other differences between the compounds of the present invention and those disclosed in GB 2 263110 A are the substitutions on the aromatic ring at position 4 of the piperazine ring. These structural variations are neither disclosed nor suggested by GB 2 263110 A, particularly with regard to compounds that can be used to improve urinary tract function.
These structural variations result in compounds that are more potent than compound A in pharmacological tests predictive of activity on the lower urinary tract, in particular for activity against urinary incontinence.
Other compounds which have been found by the present inventors to be useful in the methods of the present invention, e.g., treatment of disorders of the urinary tract, are disclosed in U.S. Pat. No. 4,205,173; EP 711,757; U.S. Pat. Des. No. 2,405,441; Chem. Pharm. Bull. 33:1823-1835 (1985), and J. Med. Chem. 7:721-725 (1964), all of which are incorporated by reference.
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“Clarification” is the settling or removal of suspended solids from a liquid, for example in municipal water treatment, the treatment of sugar cane juice, or the manufacture of pulp and paper. Existing clarifier designs have the general disadvantage that large, turbulent eddies are created as liquid flows into the tanks. The turbulence results in inefficient use of the settling area, reduced quality of the liquid overflow, and generally imposes longer residence times than would otherwise be needed. A longer residence time is inherently less efficient and more expensive, especially where perishable or degradable products are involved. For example, in the clarifying sugar juice, a longer residence time can result in partial product deterioration.
Clarification of sugar cane juice is an important part of the milling process. A standard design employs a cylindrical tank with a sloped base, with or without a raking mechanism to remove sludge. Clarified liquid is removed through overflow launders, typically positioned on the periphery of the tank. Alternatively, in a rectangular device, the feed inlet is located on the side opposite from the overflow launder. Some clarifiers include a central well for dispersing flocculants. In most conventional clarifiers, liquid travels horizontally outwards and vertically upward, following a path from the central feed well to overflow outlets or launders (the so-called Dorr design), or from the periphery to a central outlet (the so-called Graver design). The horizontal flow reduces efficiency and throughput: It creates a large-scale, circular motion inside the clarifier, which decreases performance and separation efficiency. A separation that takes only a few minutes on a small scale can take from 30 minutes to several hours in a mill due to the effects of turbulence on settling time.
Both computer modeling and experimental visualization have demonstrated that most existing clarifier designs are inefficient, and are subject to large-scale turbulence. These inefficiencies lead to increased production costs, lower quality output, or both.
Some prior clarifier designs have employed multiple plates to increase settling area and to reduce eddies, but these designs have typically been too expensive and complex for widespread commercial use.
In other prior designs the inlet flow enters the clarifier either through distribution trays or feed launders that provide a large surface area to slow fluid flow. Even so, large-scale eddies can still be created in these devices due to the large mass of flow entering the clarifier. Other design alternatives have not been widely accepted in the sugar industry.
Some recent clarifier designs are more efficient, with reduced residence times. However, these newer designs are more expensive; their installation would require most mills to purchase new equipment or to pay for costly re-engineering. Also the hydrodynamic conditions in the new designs, while somewhat improved, are not much different from those in conventional designs. They typically produce lateral flows that can create large eddies that interfere with settling.
A “lamella” type clarifier uses a stack of parallel, inclined plates within a rectangular vessel to shorten sedimentation pathways. Significant additional surface area is provided for settling, and the travel distance for liquid is reduced. Significant issues for a lamella clarifier include the removal of solids and cleaning of the lamellae. The cost for a lamella clarifier can be significant, especially if it is constructed from a non-polymeric material. (Polymers can be difficult to use with high temperature sugar solutions.)
U.S. Pat. No. 2,488,851 discloses a sugar juice clarifier with a plurality of superposed settling trays.
U.S. Pat. No. 2,470,076 discloses a so-called “Dorr” clarifier, similar to those that are commonly used in sugar mills today.
U.S. Pat. No. 2,611,685 discloses a reaction vessel for contacting vapors with fluidized, finely divided particles. A series of truncated, concentric cones is arranged in the bottom of the vessel to achieve even fluid distribution across the diameter of the reactor.
U.S. Pat. No. 4,609,010 discloses a fluid distribution system that employs a series of perforations in a fluid inlet distributor.
U.S. Pat. No. 5,192,465 discloses a distributor assembly comprising a distributor plate adapted for horizontal positioning and securement to a process column liquid distributor for the symmetrical discharge of liquid therefrom. The distributor plate comprises a member having side walls formed therearound and a plurality of apertures formed therein. The distributor plate is constructed for collecting liquid discharged from the liquid distributor, spreading the liquid thereacross and affording low velocity equal discharge of liquid therefrom into a packing bed therebeneath.
U.S. Pat. No. 3,556,736 discloses an apparatus for contacting two fluids in a fluid-solids contact zone.
U.S. Pat. No. 4,479,875 discloses an inlet distributor for liquid-liquid separators, in which fluid passes through a packing means to provide a pressure drop.
U.S. Pat. No. 4,780,206 discloses a turbulence control system comprising a first baffle, fixedly connected across the interior of an intra-channel clarifier having side walls between the side walls near the point of entry of wastewater into the clarifier, the first baffle covering a desired portion of the cross-sectional flow area within the clarifier; and a second baffle, fixedly connected across the interior of the clarifier between the side walls downstream of the first baffle and covering a desired portion of the cross-sectional flow area left uncovered by the first baffle. The turbulence control system may also comprise at least one accumulation baffle, connected between the side walls and near the bottom of the clarifier, the accumulation baffle extending upward to a desired height within the clarifier, but not so high as to produce a flow velocity that would impede settlement of sludge within the clarifier.
U.S. Pat. No. 5,378,378 discloses the use of helical inlet flow to reduce the energy of liquid and solids flowing in a basin toward a clarifier.
U.S. Pat. No. 5,354,460 discloses a step-down nozzle for the even distribution of fluids at the interface between phases in a column or cell accommodating a plug flow operation structured with an internal flow channel of recursive configuration.
Scott, R. P. (1988). Modification to and experiences with RAPIDORR clarifiers including saccharate liming at Amatikulu. Proc S Afr Sug Technol. Assoc. 62: 32-35 discloses a Dorr-type clarifier, which introduces feed through a hollow rotating pipe in the center of the clarifier. This device distributes the feed into several compartments within the clarifier, in each of which the flow is deflected by a baffle.
Steindl, R. J., Fitzmaurice, A. L. and Alman, C. W. (1998). Recent developments in clarifier design. Aust. Soc. Sugar Cane Technol., 20: 477-483 discloses the use of a single-point feed system to produce a constant velocity in the feed launder, and a uniform distribution of feed around the circumference of the feed well.
U.S. Pat. No. 5,938,333 discloses a fractal design to provide “geometric” control over flow to reduce turbulence.
U.S. Pat. No. 5,944,995 discloses a clarifier in which the feed well diameter increases from top to bottom in a conical shape to decrease the fluid velocity. It also incorporates baffles for added velocity reduction. The base of the feed well includes a downwardly and inwardly angled rim to further reduce velocity.
U.S. Pat. No. 6,800,209 discloses a device that incorporates equally-spaced ports around the circumference. Each port includes baffles that direct the feed stream tangentially, in opposite directions. Energy is dissipated when fluids from adjacent ports collide.
Prior work by the inventors has been presented as: V. Kochergin, C. Gaudet, M. Robert, S. Bergeron—Experience with new design of juice clarifier, ASSCT LA division, Lafayette, La. Feb. 2-3, 2010; and largely cumulative is the following presentation: V. Kochergin, and C. Gaudet, New Approach to Fluid Distribution in the Industrial Clarifiers—40th Joint Annual meeting of ASSCT Florida and Louisiana Divisions, Panama City Beach, Jun. 16-18, 2010. See also V. Kochergin, “A Juice Clarifier with Turbulence Reduction Devices,” Proceedings of South African Sugar Technologists' Association 83rd Annual Congress, Aug. 25-27, 2010, Durban, South Africa.
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The wide adoption of mobile devices along with ubiquitous cellular data coverage has resulted in an explosive growth of mobile applications that expect always-accessible wireless networking. This explosion has placed demands on network performance including demands for fast and reliable communication paths and for reduction of interference in the network. On the user side, instances of slow communication links and/or communication failures have been blamed for user dissatisfaction. On the network side, the slow communication links and communication failures can develop due to interference that has not been adequately mitigated in the communications network.
The above-described background is merely intended to provide an overview of information regarding the effects of interference within a wireless communications network, and is not intended to be exhaustive. Additional context may become apparent upon review of one or more of the various non-limiting embodiments of the following detailed description.
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1. Field of the Invention
The present invention relates to a method of bonding a semiconductor chip that bonds bumps and pads of a semiconductor chip and a substrate by bringing bumps or pads of the semiconductor chip into contact with pads or bumps of the substrate and applying ultrasonic vibration to the semiconductor chip, and also to a bonding apparatus that uses this method of bonding.
2. Related Art
In recent years, when manufacturing semiconductor apparatuses such as semiconductor packages, flip-chip bonding to mount a semiconductor chip on a circuit board has been carried out using a method that brings bumps on the semiconductor chip into contact with pads on the circuit board and applies ultrasonic vibration to the semiconductor chip to bond the bumps on the semiconductor chip and the pads on the circuit board.
It should be noted that there are also cases where bumps are provided on the circuit board and pads are provided on the semiconductor chip.
According to this method of bonding, the bumps and pads are strongly rubbed against each other by the ultrasonic vibration, which causes an alloying reaction to take place between the metal forming the bumps and the metal forming the pads and so results in the bumps and pads being bonded together.
It should be noted that as the combination of materials for the pads and bumps, it is normal to use gold (Au) as the bumps and aluminum (Al) as the pads.
In many cases, the bumps (gold bumps) of the semiconductor chip are formed as so-called “stud bumps”. Stud bumps are formed by first bonding wires to the terminals of the semiconductor chip on which the bumps are to be formed and then breaking off the wires close to the base parts.
In particular, when such stud bumps are bonded to pads using ultrasonic vibration, since the stud bumps are formed in non-uniform and pointed shapes, the stress produced between the bumps and pads tends to be uneven. For this reason, the alloying reaction between the bumps and pads also becomes uneven and so-called “Kirkendall voids” are produced between the bumps and pads, which worsen the bonding and in turn can easily cause a semiconductor apparatus to be defective.
To avoid this problem, before the bumps and pads are bonded together, a technique that levels the bumps to make the shapes of the bumps more even has been conventionally used.
A conventional method of leveling is disclosed in Patent Document 1. A leveling tool with a flat contact surface that contacts all of the stud bumps of a semiconductor chip is placed in contact with the stud bumps and pressed to flatten the tips of the stud bumps, thereby making the shapes of the bumps even (see Patent Document 1, Paragraphs 0009 and 0051, and FIGS. 4, 16, and 18 to 20).
Patent Document 1
Japanese Laid-Open Patent Publication No. 2002-299362 (Paragraphs 0009 and 0051, and FIGS. 4, 16, and 18 to 20)
However, the leveling carried out in a conventional method of bonding a semiconductor chip requires a process that presses a leveling tool onto the bumps of the semiconductor chip, resulting in the problem of the cost and time required when carrying out this process.
Also, although it is desirable to form the bumps in a smooth shape by leveling, if a flat contact surface of a leveling tool is pressed onto the bumps, sharp corners will be formed at the edges of end surfaces of the flattened bumps, so that when the bumps and pads are ultrasonically bonded together, stress will be concentrated at such edges, resulting in insufficient stress in the central parts and, in some cases, problems relating to poor bonding, such as the creation of Kirkendall voids in the central parts of the end surfaces of the bumps.
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The present invention relates to a combustion engine and, more particularly, to an airflow control system for an internal combustion engine having series turbochargers.
An internal combustion engine may include one or more turbochargers for compressing a fluid, which is supplied to one or more combustion chambers within corresponding combustion cylinders. Each turbocharger typically includes a turbine driven by exhaust gases of the engine and a compressor driven by the turbine. The compressor receives the fluid to be compressed and supplies the compressed fluid to the combustion chambers. The fluid compressed by the compressor may be in the form of combustion air or an air/fuel mixture.
An internal combustion engine having series turbochargers may include a wastegate valve for achieving target boost at different altitudes by bleeding exhaust gases. As disclosed in U.S. Pat. No. 5,974,801 (issued to Houtz on Nov. 2, 1999), the engine speed, boost pressure, rack position, and barometric pressure may be monitored. The wastegate valve may then be actuated based on one or more of the monitored parameters.
When boost pressure optimization is a primary objective, a wastegate valve must be made of materials capable of withstanding the high pressures and high temperatures associated with high boost. Such materials can greatly increase the cost of wastegate valve. Further, when boost pressure optimization is a primary objective, fuel consumption is typically a secondary concern.
The present invention is directed to overcoming one or more of the problems as set forth above.
According to one exemplary aspect of the invention, an airflow system for an internal combustion engine having an intake manifold and an exhaust manifold is provided. The airflow system may include a first turbocharger including a first turbine coupled with a first compressor. The first turbine may be configured to receive exhaust flow from the exhaust manifold, and the first compressor may be configured to supply compressed air to the intake manifold. A second turbocharger arranged in series with the first turbocharger may include a second turbine coupled with a second compressor. The system may include a wastegate valve fluidly coupled with the exhaust manifold and movable between a first position and a second position. The first position allows fluid flow exhausted by the engine to bypass at least one of the first turbine and the second turbine, and the second position restricts fluid flow exhausted by the engine from bypassing the first turbine and the second turbine. The system may include a controller configured to restrict supply of pressurized air to the wastegate valve such that the wastegate is in the second position at times when at least one of (i) a monitored load of the engine is less than or equal to a predetermined load for a monitored speed of the engine, (ii) a monitored speed of the engine is less than or equal to a predetermined speed for a monitored load of the engine, and (iii) a monitored temperature of compressed air leaving the first compressor is less than or equal to a predetermined temperature.
According to another exemplary aspect of the invention, an internal combustion engine includes an intake manifold, an exhaust manifold, and first and second turbochargers arranged in series. The first turbocharger may include a first turbine coupled with a first compressor, wherein the first turbine is configured to receive exhaust flow from the exhaust manifold, and the first compressor is configured to supply compressed air to the intake manifold. The second turbocharger may include a second turbine coupled with a second compressor. A wastegate valve may be fluidly coupled with the exhaust manifold and movable between a first position and a second position. The first position allows fluid flow exhausted by the engine to bypass at least one of the first turbine and the second turbine, and the second position restricts fluid flow exhausted by the engine from bypassing the first turbine and the second turbine. A control valve may be operable to control supply of pressurized air to the wastegate valve. A controller may be electrically coupled to the control valve and configured to operate the control valve to restrict the supply of pressurized air to the wastegate valve such that the wastegate is in the second position at times when at least one of (i) a monitored load of the engine is less than or equal to a predetermined load for a monitored speed of the engine, (ii) a monitored speed of the engine is less than or equal to a predetermined speed for a monitored load of the engine, and (iii) a monitored temperature of compressed air leaving the first compressor is less than or equal to a predetermined temperature.
According to yet another exemplary aspect of the invention, a method of controlling airflow to an internal combustion engine having an air intake manifold and an exhaust manifold is provided. The method may include imparting rotational movement to a first turbine and a first compressor of a first turbocharger with exhaust air flowing from the exhaust manifold of the engine, and imparting rotational movement to a second turbine and a second compressor of a second turbocharger with exhaust air flowing from an exhaust duct of the first turbocharger. Air drawn from atmosphere may be compressed with the second compressor, and air received from the second compressor may be compressed with the first compressor. The method may include supplying compressed air from the first compressor to the air intake manifold, fluidly coupling a wastegate valve with the exhaust manifold, and monitoring at least one of engine load, engine speed, and temperature of the compressed air leaving the first compressor. The wastegate valve may be movable between a first position and a second position. The first position allows fluid flow exhausted by the engine to bypass at least one of the first turbine and the second turbine, and the second position restricts fluid flow exhausted by the engine from bypassing the first turbine and the second turbine. The method may also include selectively controlling the supply of compressed air to the wastegate valve such that the wastegate is in the second position at times when at least one of (i) the monitored load of the engine is less than or equal to a predetermined load for the monitored speed of the engine, (ii) the monitored speed of the engine is less than or equal to a predetermined speed for the monitored load of the engine, and (iii) the monitored temperature of the compressed air leaving the first compressor is less than or equal to a predetermined temperature.
According to still another aspect of the invention, a method of controlling airflow to an internal combustion engine is provided. The method may include compressing a stream of air in a first turbocharger, compressing a stream of air in a second turbocharger, and sensing an engine parameter indicative of performance. The method may also include comparing the sensed engine parameter with a predetermined engine parameter and controlling a supply of compressed air to a compressed air cavity of a wastegate on at least one of the first turbocharger and the second turbocharger in response to the comparison.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.
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The present invention is directed to an improvement in the characteristics of a phase-locked loop oscillator circuit.
A typical phase-locked loop oscillator circuit includes a voltage controlled oscillator, a phase detector, and a loop filter. The voltage controlled oscillator provides an output signal having a frequency that is precisely controlled by referencing its phase to that of a reference frequency. The phase detector detects the phase error between a signal derived from the voltage controlled oscillator frequency and a signal derived from the reference frequency. The output of the phase detector is applied to the input of the loop filter, whose characteristics determine the characteristics of the phase-locked loop. The output of the loop filter is applied to a frequency modulation input of the voltage controlled oscillator. This closes a feedback loop which causes the voltage controlled oscillator frequency to track the reference frequency. When the phase of the signal derived from the voltage controlled oscillator frequency is tracking the phase of the signal derived from the reference frequency, it is said that the loop is in lock.
Before the loop comes into lock, the two signals applied to the phase detector are not the same frequency. Since the phase difference between them is constantly changing. The phase difference repeats itself once for every 360.degree. of phase change, hence the output of the phase detector becomes an a-c waveform which oscillates once for every 360.degree. of phase change. Some phase detector types in use will produce a d-c component of the proper polarity at its output when the loop is out of lock, but the output still has a-c components in addition. Any a-c components at the output which are not completely suppressed by the loop filter will frequency modulate the voltage controlled oscillator. In many applications this extraneous modulation is undesirable and hence an out of lock condition is detrimental to the operation of the system of which the phase-locked loop is a part. The design of the loop filter is usually a compromise from among many different desirable characteristics of a phase-locked loop. A loop filter design which will suppress all a-c voltages from the phase detector output is often to slow in responding to frequency variations between the two signals. Also a loop filter which provides fast lock-up characteristics, without the present invention, often cannot suppress all a-c voltages from the output of the phase detector.
When the voltage controlled oscillator arrives at the correct lock-up frequency, the frequency of the two signals applied to the phase detector will become identical. However, the phase error between them at that moment could be any value. Hence the phase-locked loop will momentarily shift the frequency of the voltage controlled oscillator to bring the phase error to zero, thereby producing additional extraneous modulation when lock-up is reached.
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Electronic switches which are suitable for radio frequency (RF) applications and which can be switched between several states of operation by the application of one or more bias voltages to one or more control terminals have widespread applications in such RF devices and components.
For example, modem cellular wireless telephony handsets are generally capable of operating on several different frequency bands and usually require an RF switch to alternately connect a single antenna to the various TX and RX circuit sections of the handset. The RF switch of a cellular handset is often grouped together with RF filters and other RF components in what is commonly referred to as an antenna switching module (ASM) or front end module (FEM). Various applications of RF switches in antenna switching modules are illustrated by Fukamachi et al in US patent application US20040266378A1. It can be seen that for these applications SP2T, SP3T and SP4T RF switches are required. Many other applications for RF switches exist, and the type of switch required is usually governed by parameters specific to the particular application.
An SP2T RF switch includes a common RF port, a first RF input/output port, and a second RF input/output port, the switch has an operation frequency range defined by a lower frequency limit fL and an upper frequency limit fU. An SP2T RF switch furthermore includes two circuit branches where each circuit branch comprises a first end and a second end. The first end of one circuit branch is connected to the first input/output port of the switch and the first end of the other circuit branch is connected to the second input/output port of the switch. The second ends of both circuit branches are connected to the common port of the switch. There are two states of operation of an SP2T RF switch: a first state of operation and a second state of operation. In the first state of operation, a low insertion loss path for RF signals within the operating frequency range of the switch exists between the first input/output port and the common port via one of the circuit branches, and simultaneously there is high isolation between the common port of the switch and the second input/output port for RF signals within the same frequency range; in the second state of operation, a low insertion loss path exists between the second input/output port and the common port via the other circuit branch for RF signals within the operating frequency range of the switch, and simultaneously there is high isolation between the common port of the switch and the first input/output port for RF signals within the same frequency range. Common embodiments of an SP2T RF can furthermore be switched between the first state of operation and the second state of operation actively by the application of a particular combination of control voltages to a number of control terminals of the switch.
A number of prior art embodiments of SP2T RF switches are described below; each prior art embodiment includes a first circuit branch and a second circuit branch where each circuit branch further includes one or more series or parallel active devices, where each active device has two states: an on state where the active devices presents a low impedance path to an RF signal, and an off state where the active devices presents a high impedance path to an RF signal, and where the state of the active device is controlled by the application of a bias voltage to the active device.
In U.S. Pat. No. 3,475,700, Ertel describes several transmit/receive SP2T RF switches which can alternately connect a TX port 14 or an RX port 16 to a common antenna 12. The switch depicted by Ertel in FIG. 1 of U.S. Pat. No. 3,475,700 comprises two series connected PIN diodes 18, 20, each of which can be switched between respective on-states and off-states by the application of a pair of control voltages to control terminals 27, 28. For example, if a negative voltage is applied to control terminal 27, and control terminal 28 is maintained at zero volts, then PIN diode 18 will be in the on-state, and PIN diode 20 will be in the off-state. Thus, TX signals entering the switch at port 14, will be able to pass through the on-state PIN diode 18 directly to the antenna 12, the TX signal will be simultaneously blocked from the RX port 16 by the off-state PIN diode 20. Conversely, if control terminal 27 is maintained at zero volts, and if a negative voltage is applied to control terminal 28, then RX signals entering the switch at the common antenna 12, will be fed directly to the RX port 16, and will be isolated from the TX port 14.
Another embodiment of an SP2T RF switch is depicted by Ertel in FIG. 6 of U.S. Pat. No. 3,475,700; this comprises two parallel connected PIN diodes 166,178, which are switched between respective on-states and off-states by the application of suitable control voltages to control terminals 170, 176, 182. The operation of the SP2T RF switch depicted by Ertel in FIG. 6 of U.S. Pat. No. 3,475,700 is broadly similar to the SP2T RF switch of FIG. 1 of U.S. Pat. No. 3,475,700, except that in the embodiment shown in FIG. 6, the electrical lengths of the pair of microstrip transmission lines between junctions 164 and 158, and between junctions 177 and 158 are both one quarter of a wavelength of the centre frequency of the operating band of the switch. In this way, when one or the other of PIN diodes 166, 178 are in the on-state, the impedance presented at junction 158 by the on-state PIN diode becomes infinitely large, thereby isolating the branch of the circuit including the switched on diode from the antenna 12.
As mentioned above, in each state of operation of an SP2T RF switch, there is a low loss path between the common port of the switch and one of the input/output ports, and simultaneously there is high isolation between the common port of the switch and the other of the input/output ports for RF signals within the operating frequency range of the switch. The principal disadvantage of the various SP2T RF switch embodiments described in U.S. Pat. No. 3,475,700 by Ertel is that the level of isolation offered by each embodiment is limited by the impedance of a single PIN diode in the off-state (FIG. 1) or in the on-state (FIG. 6). Ideally the off-state impedance of a PIN diode is infinite, and the on-state impedance of a PIN diode is zero, this would give rise to infinite isolation for each embodiment, however typical commercially available PIN diodes have an off-state impedance of one or two thousand Ohms, and an on state impedance of one or two Ohms, so that conventional PIN diodes will provide approximately 25 dB of isolation if deployed in the circuits shown in FIG. 1 or FIG. 6 of U.S. Pat. No. 3,475,700.
The isolation of an SP2T PIN diode RF switch can be improved to approximately 40dB if 4 PIN diodes are employed in the switch circuit, two in each circuit branch of the switch. One such SP2T RF switch is described by Kato et al in U.S. Pat. No. 5,519,364. The switch depicted by Kato et al in FIG. 1 of U.S. Pat. No. 5,519,364 is a high isolation SP2T RF switch comprising a pair of shunt PIN diodes in each circuit branch. Another type of SP2T switch architecture is described by Iwata et al, in U.S. Pat. No. 4,220,874. Iwata et al describe a number of embodiments of SP1IT and SP2T RF switches which employ a shunt PIN diode and a series PIN diode in each circuit branch. The SP2T RF switch depicted by Iwata et al in FIG. 4 of U.S. Pat. No. 4,220,874 comprises a pair of shunt PIN diodes D2, D4 and a pair of series PIN diodes D1, D3. The biasing of diodes D1, D2, D3 and D4 is achieved by application of a positive voltage (denoted by V1 in U.S. Pat. No. 4,220,874) or zero volts (denoted by V2 in U.S. Pat. No. 4,220,874) to control terminals S1 and S2 of the switch. The use of two PIN diodes per circuit branch as illustrated in U.S. Pat. No. 5,519,364 and U.S. Pat. No. 4,220,874 offers a substantial increase in the isolation of the switch. FIG. 1 shows a prior art SP2T RF switch according to the embodiment depicted by Iwata et al in FIG. 4 of U.S. Pat. No. 4,220,874.
The SP2T RF switch of FIG. 1 comprises 3 ports: a common port P1, a first input/output port P2, and a second input/output port P3. The switch includes two circuit branches B1, B2, where input/output port P2 is connected to the one end of circuit branch B1, and where input/output port P3 is connected to one end of circuit branch B2, and where the other ends of both circuit branches B1 and B2 are connected to the common port P1. A pair of control voltages applied to control terminals V1 and V2 can set the switch in a first state of operation or a second state of operation according to the logic table given below.
TABLE 1Logic table for prior art SP2T PIN diode switch of FIG. 1.Switch StateV1V2Circuit branch B1Circuit branch B2First State0 V5 VLow Loss betweenHigh Isolationof OperationP1 and P2between P1 and P3Second State5 V0 VHigh IsolationLow Loss betweenof Operationbetween P1 and P2P1 and P3
The switch of FIG. 1 includes PIN diodes D1, D2, D3, D4, where D1 and D2 are the respective shunt and series PIN diodes of circuit branch B1 and where D3 and D4 are the respective shunt and series PIN diodes of circuit branch B2
The switch further includes DC blocking capacitors C1, C2, C3, C4, C5, C6 which are selected so they have a very low impedance for RF signals within the operating frequency range of the switch. DC biasing components C7 and L3 provide a noise free DC voltage at node M, and DC biasing components C8 and L4 provide a noise free DC voltage at node N. DC biasing component L1 provides a path to ground, via R1, for a DC current arising from a nonzero voltage at node G, and similarly DC biasing component L2 provides a path to ground, via R2, for a DC current arising from a nonzero voltage at node H. Resistor R1 is selected to regulate the current which can flow from node G to ground when a DC voltage is present at node G, and resistor R2 is selected to regulate the current which can flow from node H to ground when a DC voltage is present at node H.
In the first state of operation of the RF switch of FIG. 1, diodes D2 and D3 are forward biased, and diodes D1 and D4 are reverse biased. An RF signal entering circuit branch B1 of the switch at port P2, will be substantially unaffected by reverse biased shunt PIN diode D1 connected to node G, will pass through the forward biased series PIN diode D2, will be isolated from circuit branch B2 by reverse biased series PIN diode D4, and hence will pass without significant attenuation to port P1 of the SP2T RF switch of FIG. 1.
Any small percentage of the RF signal which can pass through reverse biased series PIN diode D4 (due to the finite impedance of the reversed biased PIN diode D4), will have a low resistance path to ground at node H via forward biased shunt PIN diode D3 and capacitor C6 (recall that the value of C6 is chosen to be sufficiently large so that it has a low impedance for RF signals within the operating frequency range of the switch). Hence, the RF signal which enters the switch at P2 will be highly isolated from port P3 of the switch.
Consequently, in the first state of operation of the SP2T RF switch of FIG. 1, an RF signal entering the switch at port P2, will pass without significant attenuation to common port P1 of the switch and will be highly isolated from port P3 of the switch. Similarly, an RF signal entering the switch at common port P1, will pass without significant attenuation to port P2 of the switch, and will be highly isolated from port P3 of the switch.
In the second state of operation of the RF switch of FIG. 1, diodes D1 and D4 are forward biased, and diodes D2 and D3 are reverse biased. An RF signal entering circuit branch B2 of the switch at port P3, will be unaffected by reverse biased shunt PIN diode D3 connected to node H, will pass through the forward biased series PIN diode D4, will be isolated from circuit branch B1 by reverse biased series PIN diode D2, and hence will pass without significant attenuation to port P1.
Any small percentage of the RF signal which can pass through reverse biased series PIN diode D2, will have a low resistance path to ground at node G via forward biased shunt PIN diode D1 and capacitor C5. Hence, the RF signal which enters the switch at P3 will be highly isolated from port P2 of the switch.
Consequently, in the second state of operation of the SP2T RF switch of FIG. 1, an RF signal entering the switch at port P3, will pass without significant attenuation to common port P1 of the switch and will be highly isolated from port P2 of the switch. Similarly, an RF signal entering the switch at common port P1, will pass without significant attenuation to port P3 of the switch, and will be highly isolated from port P2 of the switch.
The SP2T RF switch depicted in FIG. 1 above operates very well within the frequency range of current worldwide cellular systems. However, at very high operating frequencies, such as the frequency band allocated for RF based automotive collision avoidance systems (centered at 24.125 GHz), a number of problems are encountered with the practical implementation of the SP2T RF switch depicted in FIG. 1.
As noted above, in the first state of operation of the SP2T RF switch of FIG. 1, an RF signal entering the switch at port P2 is unaffected by the path of the circuit from node G to ground via reverse biased PIN diode D1 and capacitor C5 because of the high impedance presented by the reverse biased PIN diode D1 connected to node G. This high impedance can be represented by a reflection co-efficient of +1 at node G due to the circuit path containing PIN diode D1 and capacitor C5.
In the second state of operation of the SP2T RF switch of FIG. 1, the high isolation of port P2 from signals entering the switch at port P3 or port P1 is achieved by the combination of the high impedance of reversed biased series PIN diode D2, and the low impedance path to ground at node G through forward biased shunt PIN diode D1 and via capacitor C5. The low impedance path to ground at node G via PIN diode D1 and capacitor C5 can be represented by a reflection co-efficient of −1.
In practical implementations, diode D1 and capacitor C5 will be soldered to a PCB and the PCB will include a first metal track which connects node G to the cathode of PIN diode D1 and a second metal track which connects the anode of diode D1 to capacitor C5.
These metal tracks will have a finite length, and the effect of these metal tracks will be to rotate the phase of the reflection co-efficient at node G due to the path containing PIN diode D1 and capacitor C5 so that it will no longer have the ideal value of +1 in the first state of operation of the RF switch of FIG. 1, or −1 in the second state of operation. The phase rotation caused by the finite lengths of metal tracks which connect node G, PIN diode D1 and capacitor C5 will introduce a substantial loss due to the reverse biased PIN diode D1 in the first state of operation of the SP2T RF switch of FIG. 1 and will substantially reduce the isolation offered by the forward biased PIN diode D3 in the second state of operation of the SP2T RF switch of FIG. 1.
At operating frequencies of 24 GHz, a metal track length of only 1 mm or 2 mm will have a significant effect on the phase of the reflection co-efficient at node G, thereby substantially increasing the loss between ports P1 and P2 and substantially reducing the isolation between ports P1 and P3 in the first operation state of the SP2T RF switch of FIG. 1.
A similar analysis reveals that the effect of the finite lengths of metal tracks required to connect node H, PIN diode D3 and capacitor C6 substantially increases the loss between ports P1 and P3, and substantially reduces the isolation between ports P1 and P2 in the second operation state of the SP2T RF switch of FIG. 1.
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{
"pile_set_name": "USPTO Backgrounds"
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