In the memory cell matrix of a semiconductor integrated circuit device having a non-volatile semiconductor memory cell portion and a logic portion, a second-layered Al wires are formed on the first-layered Al wires, with an interlayer insulating film interposed therebetween. The pattern of the second-layered Al wires is the same as that of the first-layered Al wires. This structure reduces the labor for designing mask data, and increases the coating ratio of a resist to an Al layer while minimizing a reduction in the transmittance of ultraviolet ray. As a result, the amount of a reaction compound supplied from the resist into the Al layer for forming the second-layered Al wires increases, which prevents the second-layered Al wires from being undercut. Thus, the second and subsequent-layered Al wires of the logic portion can be effectively prevented from being thinned.

1. Field of the Invention
This invention relates to a semiconductor device in which a non-volatile semiconductor memory cell portion and a logic portion comprising two or more-layered metal layers are formed on a single semiconductor substrate, and more particularly to a semiconductor integrated circuit having an erasable and programmable read only memory (EPROM) as the non-volatile semiconductor memory cell.
2. Description of the Related Art
In the prior art, a semiconductor integrated circuit device employing an EPROM is used as a semiconductor device having a semiconductor substrate, and a non-volatile semiconductor memory cell portion and a logic portion formed on the substrate.
In a semiconductor integrated circuit device of this kind, the logic portion has been developed to have multi-layered aluminum (Al) wirings in accordance with the high-integration/advanced-function tendency of the device. On the other hand, the memory cell portion (EPROM) comprises of a single Al layer in many cases, since the degree of integration is little increased by multi-layered wiring employed therein. Thus, a logic portion with two or more-layered Al wires, a memory cell portion with a single Al wire, and an I/O portion which surrounds the logic portion and the memory cell portion are formed on a single semiconductor substrate.
Further, the capacity of the EPROM has recently been increased, and the memory cell portion has been occupying more than half of the area of the semiconductor integrated circuit device.
The structure of the memory cell having a single Al wire layer will now be explained in more detail.
FIG. 1 is a cross sectional view of the memory cell portion.
As is shown in FIG. 1, the memory cell portion comprises field oxide films 101 selectively formed on a semiconductor substrate 100, floating gates 103 each formed between a corresponding adjacent pair of the field oxide films 101 with an insulating film 102 interposed therebetween, a word line 104 of polysilicon formed on the above elements with an insulating film therebetween, single-layered Al wires 106a and 106b on the word line 104 with an interlayer insulating film 105 therebetween, and a passivation film 107 protecting the surface of the device.
The Al wire 106a is a bit line connected to a drain diffusion layer (not shown) via a drain contact, and the Al wire 106b is a source line connected to a source diffusion layer (not shown) via a source contact.
In a semiconductor integrated circuit device having the memory cell portion with the single-layered Al wires 106a and 106b and a logic portion comprising two or more-layered Al layers, the second and subsequent-layered Al layers of the logic portion are liable to become thinner than its first Al layer for the following reasons.
In general, Al wires are formed by selectively etching an Al layer. This etching is influenced by the coating ratio of a photoresist pattern used as a mask to the Al layer. The lower the coating ratio of the photoresist pattern (i.e., the mask pattern), the greater the Al wire is etched due to undercut. This is because if the coating ratio is low, only a small amount of a carbon compound is supplied from the resist pattern into the Al layer during the RIE (Reactive Ion Etching), with the result that lateral-directional etching or isotripic etching of the Al layer is performed.
Since the memory cell portion does not have second and subsequent-layered Al wire layers, the coating ratios of the resist patterns to the Al layers to be selectively etched are very low at the time of selectively etching the Al layers to form Al wires of second and subsequent-layered layers of the logic portion. Accordingly, the amount of a carbon compound to be supplied from the resist pattern into the Al layers are greatly reduced, and it is highly possible that the Al layers are thinned.
In general, to prevent a metal layer, such as the Al layer, from being thinned, a dummy mask pattern, which is used only to increase the coating ratio, is formed on that portion of the metal layer, at which the coating ratio of a resist pattern to the metal layer is low, in order to increase the coating ratio. Alternatively, a simple line/space pattern is manually provided on the metal layer so as to increase the coating ratio.
However, these dummy patterns for increasing the coating ratios may well reduce the transmittance of ultraviolet ray and hence cause erase-fail of data in a semiconductor integrated circuit device with an EPROM. Thus, the dummy patterns cannot be formed on the memory cell portion.
As described above, it is very difficult to form, on the memory cell portion, a pattern which can maximize the coating ratios of the resists to the second and subsequent-layered metal layers of the logic portion, and at the same time can minimize a reduction in the transmittance of ultraviolet ray. Therefore, the conventional approach to increase the coating ratios cannot be employed to prevent the second and subsequent-layered Al layers of the logic portion from becoming thin.

Semiconductor device having a memory cell portion and a logic portion


An orthopedic fixation device includes a fixation ring, a universal pad, a threaded fixation element, and a fastening nut. The universal pad contains a circular hole and is provided at one end with a protruding arcuate surface and at another end with a recessed arcuate surface concentric with the protruding arcuate surface. The fastening nut is provided with a protruding or recessed arcuate surface located at one side facing the universal pad. The threaded fixation element has an arresting portion which is provided with a protruding or recessed arcuate surface located at one side facing the universal pad. The protruding and recessed arcuate surfaces of the fastening nut and the threaded fixation element are engageable with the universal pad.

The threaded fixation element, such as a threaded rod or bone nail, and the fluted fixation element, such as a fixation plate or lateral fixation block, of the conventional bone fixing device are generally defective in design in that they do not meet to form exactly an angle of 90 degrees, and that the nut cannot be fastened securely with the threaded fixation element. With a view to overcoming such shortcomings as described above, the U.S. Pat. Nos. 4,611,581 and 4,696,290 disclosed respectively a bone fixing plate which is provided with scallops intended to enhance the effect of fastening the threaded fixation element with the fluted fixation element of the conventional bone fixing device. However, the bone fixing plates disclosed in the above-mentioned U.S. patents fail to provide an effective remedial measure. As a result, an improved system was disclosed by Hiromi Matsuzaki, et al. in SPINE, VOLUME 15, NUMBER 11 (1990), pp. 1159-1164. The improved system comprises a fluted fixation element which is provided respectively on both faces of the slot or the through hole thereof with a recessed arcuate surface capable of cooperating with a protruding arcuate surface of an arresting portion of the fixation element having the threaded portion and the arcuate protruding surface of the fixation nut. In view of the fact that the centers of the circles of these two arcuate recessed surfaces are fixed, the fixation element is located on a line connecting these two centers of circles when the fixation nut is tightened. In other words, when the fixation nut is tightened, the fixation element having the threaded portion and the fixation element having the slot form an angle which is fixed and cannot be changed. However, the angle can be adjusted slightly if the fixation nut is not tightened. It must be noted here that the fixation nut must be tightened so as to enable the fixation device to work effectively. Furthermore, the disclosure of the U.S. Pat. No. 4,854,311 comprises a washer which has a specific angle and is located between the threaded fixation element and the fluted fixation element. However, an addition of the washer can often complicates the surgical process.

Universal pad fixation device for orthopedic surgery


An information retrieval system comprises a storage section that stores location information about information selected by a user as a document location information database, an analyzer section that analyzes frequency of utilization of each location information in the document location information database, a retrieval information accumulating section that accumulates information in a predetermined accumulation range on an accumulation base point corresponding to location information having the frequency of utilization equal to or more than a threshold value, as a retrieval information database, and a retrieval section that retrieves required information from a retrieval information database based on a retrieval condition designated by the user.

These days the Internet is used very widely. Further, the amount of document information, for example the number of documents described with HTML (Hyper Text Markup Language), existing on the Internet has increased greatly. For retrieving desired document information from such a large amount of document information, an information retrieval system having a retrieval engine which employs keyword retrieval system is generally used. This type of information retrieval system sets one of the document information as an accumulation base point, accumulates document information linked with the document information of the accumulation base point one after another, and provides them as a database of retrieval information. When actual retrieving is performed, the system retrieves a plurality of (or a single) document information from the retrieval information database by way of the keyword system, and then the retrieved document information becomes the retrieving result.
However, a conventional information retrieval system uniformly accumulates document information started from the document information of the accumulation base point one after another, based on a definite accumulation condition (a number of links, a number of documents, a size of a document or the like). Therefore, it is difficult to obtain retrieval information associated with the retrieval result, which satisfies a large number of users, by the conventional information retrieval system. As a result, the conventional information retrieval system has a drawback of a low accuracy in retrieval, thus it is longed to provide a technique such as means and method that can solve the drawback efficiently.
Internet uses the URL (Uniform Resource Locator) as a standard to specify a means for accessing (a communication protocol) document information stored up on a server and a name of the document information. Document information means information (contents) described in HTML, for example. For instance, to specify a file of a document information stored on a server, the URL are described as [protocol name://server name/file name]. In other words, the URL is information that specifies a location where the document information exists on the Internet. Accordingly, the URL will be hereinafter referred to as a document location information.
Document information may often contain document location information of the other document information to be linked. When such a link condition between document information extends to a plurality of links, it is capable of accumulating a plurality of document information from document information as an accumulation base point, one after another. The above described conventional information retrieval system accumulates document information linked for a predetermined numbers of links (accumulation range) started from the document information of the accumulation base point one after another, based on a definite accumulation condition (a number of links or the like), and provide them as a database of retrieval information. The number of links as accumulation range is decided by a retrieval service company using the information retrieval system, without reflecting a requirement of a user.
The information retrieval system set a keyword designated by a user as a key, retrieves a plurality of (or a single) document information that contains the keyword from the database of retrieval information and obtains a retrieval result. The user browses the desired document information based on the retrieval result.
As described above, while accumulating document information on the Internet, the conventional information retrieval system accumulates document information in an accumulation range, which is uniformly determined by the retrieval service company, from the accumulation base point and performs a retrieval process based on the accumulation result.
However, the conventional information retrieval system has a drawback in that the document information out of the accumulation range, even if the requirement of the user is high, is omitted from the retrieval result as well as the accumulation result. Further, the conventional information retrieval system associates with the document information and accumulates uniformly a plurality of document information in an accumulation range in spite of utility, even if the document information corresponding to the accumulation base point is not utilized much by the user. Therefore, the conventional information retrieval system has also a drawback of containing a large amount of the useless document information in retrieval result and degrading an accuracy of retrieving. That is to say, the retrieving efficiency of the conventional information retrieval system is bad.

Information retrieval system and a computer product


A method is disclosed for controlling the delivery of vapor from a bubbler containing a supply of liquid through which a carrier gas is bubbled and from which bubbler vapor is delivered in a vapor stream entrained with the carrier gas. The method comprises the steps of sensing the ratio of vapor to carrier gas in the vapor stream and applying heat to the liquid within the bubbler at rates relative to the sensed ratios of vapor to carrier gas being delivered from the bubbler in a vapor stream to hold the ratio constant.. A vapor delivery control system is also disclosed which comprises a vaporizer, a heater thermally coupled with the vaporizer, and means for maintaining a supply of liquid in the vaporizer. The system further includes means for introducing a carrier gas into the vaporizer, means for conducting the carrier gas and vapors of the liquid entrained with the carrier gas from the vaporizer, means for sensing the ratio of vapor to carrier gas being conducted from the vaporizer, and means for controlling the heater responsive to the ratio of vapor to carrier gas sensed by the sensing means to hold the ratio constant.

With the advent of optical waveguides for use in the communications industry much emphasis has recently been placed on vapor deposition as a materials forming technique. In constructing preforms from which optical fibers may be drawn, vapors of materials such as SiCl.sub.4, GeCl.sub.4 and POCl.sub.3 must be precisely delivered at controlled mass flow rates to the preform construction site where they are reacted and deposited on or in a support. This can be done by passing carrier gases such as H.sub.2, He, N.sub.2, O.sub.2, or Ar through a supply of the material in liquid form to the deposition site as a mixture with the vapors entrained with the carrier gas. In preforming this operation a vaporizer is ordinarily use of the type known as a bubbler which has a carrier gas intake conduit that terminates with an outlet orifice located below the surface of the liquid materials and an outlet conduit extending from the space above the surface of the liquid within the bubbler to the deposition site.
To construct an optical waveguide preform properly the mass flow rate of the vapor must be carefully programmed and accurately controlled. Heretofore control has been achieved with vaporizer controllers such as the Source Vaporizer Controllers sold by the Tylan Corporation of Torrance, California. Controllers of this type employ a carrier gas mass flow rate sensor and a vapor to carrier gas ratio sensor.
The carrier gas flow rate sensor operates on the theory that the heat added to a known mass of gas is proportional to its temperature rise at relatively constant pressure. It employs two resistance heating elements which are part of a bridge circuit, positioned in series with each other on the outside of a sensor tube. Gas is passed through the tube which creates a bridge imbalance, the signal from which is proportional to the mass flow rate. The vapor to carrier gas ratio sensor also operates as a function of heat transfer. This sensor employs one electrical resistance element located in the carrier gas intake stream and another in the vapor and carrier gas stream, hereinafter termed "vapor stream". Again the sensors are elements of a bridge circuit which indicates an imbalance as soon as the properties of the gas and vapor stream differ. This difference is proportional to the ratio of source to carrier gas.
With these controllers the electrical signals from the carrier gas flow rate and vapor to carrier gas ratio bridge circuits are electronically multiplied and the product compared with a preselected set point for vapor mass flow rate. An error signal is then fed through an amplifier to an electrically controlled valve located in line with the carrier gas intake conduit. When an insufficient mass flow is detected the valve in the carrier gas intake conduit is opened further to increase the flow of carrier gas into the vaporizer which, in theory, serves to pick up more vapor and increase the mass flow rate. Conversely, if too great of mass flow rate is detected the valve is closed somewhat. A more detail description of such vaporizer controllers and their components may be had by reference to U.S. Pat. Nos. 3,938,384 and 3,939,858.
Though the just described system and method for controlling vapor delivery has been found to be the best available, it nevertheless is quite inaccurate with deviations from optimum set points ranging as great at 30% over both long and short terms. This is attributable at least in part to the fact that this method assumes a steady state condition of vapor pressure. In actuality however the system is not in a steady state since vapor pressure depends on numerous criteria such as carrier gas retention time within the liquid, the depth at which the bubbles are released within the liquid, total pressure, carrier gas temperature, localized temperature inhomogentities surrounding the bubbles as they travel toward the liquid surface, and heat flow into the bubbler from its environment. These effects all become more important as flow rates increase and the liquid levels in the bubbler decreases since retention by carrier gases also decreases as localized cooling takes place.
It is thus seen that control of the flow rate of carrier gas into a vaporizer is only a relatively crude method of controlling mass flow rate of vapor from the vaporizer because of the dynamics of such systems. Some investigators have sought to overcome this problem by placing an array of temperature sensors in the liquid housed within the bubbler and controlling heat into the bubbler responsive to sensed temperatures. This approach however has also failed to produce as high a degree of accuracy which again is belived to be attributable at least in part to the dynamics of the system.

Vapor delivery control system and method


A cover for a container is provided with primary and secondary detent means, the primary detent means being mounted on a tamper-evident tear strip and being removable with the tear strip as opening of the cover is desired. Secondary detent means is provided on detent tabs which remain operatively associated with the cover. The limited engagement of the detent tabs with the retaining means of the cover results in facile removal of the cover from operative engagement with the container and the reinstallation and the corresponding and facile reinstallation of the cover upon the container.

Covers having tamper indicating means are well known in the art and have become more widely utilized because of numerous incidents of tampering with the contents of conventional containers, particularly in the drug and comestible fields. Such tamper indicating means can be provided in the form of container seals, tear strips, or the like.
Conventional tear strips are usually provided on covers fabricated from synthetic plastics such as linear polyethylene and are so located on the container that they prevent the opening of the cover until the tear strip is severed from the cover to permit it to be exposed for easy opening.
Conventional tear strips are usually provided in injection molded covers by the provision of a finger grip and a score line which defines the portion of the cover which will be removed by the tear strip action. The score line is provided on the interior of the cover during the injection molding process.
After the tear strip has been removed, sufficient access to the remaining portion of the cover can be had to remove the cover from operative relationship with the retaining means of the cover.
However, after the tear strip has been removed, some covers tend to be difficult to release from the associated container since the relationship between the retaining means of the container and the detent means of the cover tends to cause binding between retaining means and detent means. The cover of the invention eliminates this problem by removing the primary detent means and making the cover "user friendly."

Container cover having primary and secondary detent means


A field effect transistor memory cell having a selectable threshold voltage is formed in a semiconductor layer (18). An n-channel electrically-erasable, electrically-programmable read-only memory cell (12) is formed and includes a source (14) and a drain (16) separated by a channel (20), a tunneling window (22) adjacent drain (16), a floating gate (24) and a control gate (26) capacitively coupled to channel (20). N-channel memory cell (12) is operable to charge and discharge floating gate (24) by Fowler-Nordheim tunneling upon the application of voltages to control gate (26) and drain (16). A p-channel field effect transistor (30) is formed and includes a source (34) in a drain (36) spaced by a channel (38). Floating gate (24) is insulatively disposed adjacent channel (38) such that the conductance of channel (38) is controlled by floating gate (24). A threshold control circuit (76) is provided for biasing channel (38) of p-channel field effect transistor (30) in relationship to control gate (26). A monitoring circuit (90) controls the application of voltage to control gate (26) in response to conduction between source (34) and drain (36) of p-channel field effect transistor (30).

The most widely used electrically-erasable, electrically-programmable, read-only cell is an n-channel field effect transistor with an additional floating gate structure disposed between the channel and the control gate. By charging the floating gate with electrons, a logic "zero" can be programmed into the cell, while allowing the floating gate to remain uncharged programs a logic "one." This is due to the fact that the charge on the floating gate controls the conductance of the underlying channel area, thereby determining whether a current will be sensed between the source and the drain when reading voltages are applied therebetween.
As in the case of the conventional field effect transistor, the channel of a EEPROM cell with an uncharged floating gate (a non-programmed cell) has a threshold voltage V.sub.t. This threshold voltage V.sub.t is primarily a function of the material used to form the channel and can be controlled within limits by the implantation of dopants in the channel during the fabrication of the cell. During the read operation, the control gate must be brought to a potential in excess of the threshold voltage V.sub.t, as determined by the capacitive coupling between the control gate and the floating gate and floating gate and the channel, in order for current to flow between the source and the drain when a voltage potential is created between them. By charging the floating gate with electrons, however, the threshold voltage V.sub.t can be raised.
One means of effecting the charging of the floating gate is through Fowler-Nordheim tunneling. In the n-channel EEPROM, when the control gate is brought to a sufficiently high potential in relationship to the drain, electrons can be made to tunnel through a thin oxide tunneling region adjacent the drain to the floating gate, thereby charging it. By raising the threshold voltage by charging the floating gate, a logic "zero" is programmed into the cell due to the fact that the normal reading voltage applied to the control gate will not exceed the potential necessary to allow the current flow in the channel as raised by the charged floating gate, and therefore no current can be sensed when proper source and drain reading voltages are applied.
In principle, it is possible to set the threshold voltage of a EEPROM to any value by varying the amount of charge residing on the floating gate. This may be done, for instance, by varying the pulse height, duration and/or the number of pulses used in creating the voltage potential between the control gate and the drain. In practice, however, this is not an easy task. First, the threshold voltage has a logarithmic dependency on pulse duration. Further, this process is very slow, requiring unacceptable expenditures of time to program the cell to extreme values. Additionally, variations from cell to cell, especially due to differences in the tunnel oxides used for Fowler-Nordheim tunneling, create consistency problems during array operation. Finally, trapping of materials in the oxide will change the current-voltage (I-V) characteristics of the tunnel diode over time, which may require frequent calibration cycles to determine the write/erase characteristics of the EEPROM cell.
A self-limiting erase scheme for an EEPROM cell is disclosed in U.S. Pat. No. 4,797,856. This device will allow the floating gate of an EEPROM cell to be erased to a predetermined value, thus controlling the threshold voltage of the cell. This device has a major disadvantage if it is ever desired to set the threshold voltage of an unprogrammed cell. In this case, the floating gate would have to be completely charged, and then erased back to a point where the charge remaining on the floating gate set the threshold voltage of the cell to the desired value.
Thus, a need has arisen for an electrically-erasable read only memory cell in which the threshold voltage of the channel can be set either during the write cycle or the erase cycle. Such a device would be self-controlling, and would minimize the need for precise controlling of the voltage application during the write and erase cycles. Further, this device should be capable of fabrication into an integrated circuit form using conventional techniques Finally, the device should be compatible with the peripheral devices currently used with EEPROM cells.

Electrically-erasable, electrically-programmable read-only memory cell with a selectable threshold voltage and methods for its use


An analog/digital converter (ADC) includes an analog stage with at least one first sigma-delta modulator and includes a digital stage with at least one second sigma-delta modulator. The analog stage is configured for outputting a digital signal to the digital stage that is indicative of a noise contribution of the at least one first sigma-delta modulator. The analog stage and the digital stage may be arranged in a multi-stage noise shaping architecture (MASH) architecture.

Sigma-delta modulators are used in various technical fields. Analog/digital conversion (A/D conversion) by means of sigma-delta modulators is useful, e.g., in applications such as wireless or wire-connected communication systems, microcontrollers, sensors, audio/video conversion, etc. Such A/D converters (ADCs) provide a wide dynamic range in the conversion of input signals with a low to medium bandwidth. Based on their concept, the A/D conversion by means of sigma-delta modulators (sigma-delta conversion) provides for a high resolution and high linearity.
The principle of sigma/delta conversion is to measure, integrate and compensate for errors in the evaluation. The basic principles of sigma/delta conversion are known, e.g. from NORSWORTHY S. R., SCHREITER R., TEMES G. C. "Delta-Sigma Data Converters: Theory and Simulation", IEEE Press, 2001.
Depending on the application, it may be worthwhile to reduce a noise contribution of the sigma-delta modulation, e.g. due to quantization noise. In this way, an ADC with a higher signal-to-noise ratio (SNR) can be obtained. For this purpose, higher-order sigma-delta modulators are used e.g., according to reference implementations. Higher-order sigma-delta modulators according to reference implementations have a number of analog amplification structures arranged in series or in parallel. Such an amplification structure can be designed, e.g., as integrator.
However, such techniques can have certain disadvantages and restrictions. E.g., higher-order sigma-delta modulators can have instabilities. This may reduce the accuracy and/or the maximum usable dynamic range of the A/D conversion.

Hybrid digital/analog noise shaping in the sigma-delta conversion


A pipeline identification and calibration apparatus coupled to a pipe communicates with an in-line inspection tool to help a user to determine an extent of damage suffered by the pipe is provided. The apparatus includes a communication sheet coupled to the pipe and having a pipe calibration area and a pipe identification area, the pipe calibration area having a plurality of etchings, voids or magnetic inserts having variable dimensions and spacing between adjacent members of either the etchings, voids or the magnetic inserts. The user compares data generated by the in-line inspection tool to the etchings, voids or magnetic inserts on the pipe calibration area of the communication sheet to determine the extent of damage to the pipe.

The embodiments herein relate generally to pipelines for transporting fluids.
Metallic pipelines are used to gather, transport, and deliver fluids for many purposes. In-Line Inspection (ILI) often employs Magnetic Flux Leakage (MFL) technologies in order to identify and map pipeline anomalies. These ILI and MFL technologies continue to advance and have been the preferred pipeline assessment tool for many years.
Several pipeline identification and positioning systems are disclosed in U.S. Patent Application Publication 20010029989, which includes a plurality of marker coupons disposed throughout the pipe to provide identification information. However, this is disadvantageous because the coupons are spread throughout the pipe instead of being organized together at a single location. This is inefficient and increases the time necessary for the user to gather all of the information from the coupons. In addition, the existence of coupons located throughout many different locations on the pipeline may interfere with the in-line inspection tool's ability to accurately read the pipe.
As such, there is a need in the industry for a pipeline identification and calibration apparatus that overcomes the limitations of the prior art. Specifically, there is a need for a device which would be affixed to the inside or outside of any pipe or pipeline element that will communicate to ILI-MFL devices, and provide a multi-dimensional calibration basis to ILI-MFL devices, while also providing a sacrificial or protective medium to help diminish internal corrosion.

Pipeline identification and calibration apparatus


A valve includes a body having upstream and downstream ports to measure upstream and downstream pressures and configured on a common axis, and a ball arranged in the body to rotate re the common axis between open and closed positions to allow for fluid flow and no fluid flow. The ball has a calibrated member having a calibrated orifice to allow fluid flow and has a flow coefficient and upstream and downstream pressure taps located upstream and downstream of the calibrated orifice and in fluidic communication with the upstream and downstream ports to measure upstream and downstream pressures when in the open position and angled re the common axis, so a direct flow measurement of fluid flow is determined based on a measured pressure differential between upstream and downstream pressure taps re the flow coefficient of the calibrated orifice when in the open position.

1. Field of the Invention
The present invention relates to a technique for providing a direct flow measurement; and more particularly, the present invention relates to a valve configured for providing a direct flow measurement.
2. Brief Description of Related Art
Presently, most systems where a fluid flows require an isolation valve to shut-off flow and a separate flow measurement device to verify the system flow rate. These additional components in the system take up extra space and increase the head loss. Additionally, significant amounts of extra pipe length may be required depending on the type of flow measurement device being used.

Valve having rotatable valve ball with calibrated orifice and coaxial upstream/downstream ports and angled taps to measure upstream/downstream pressures for flow measurement


One aspect of the invention includes an optical amplifier operable to amplify a plurality of optical wavelength signals at least in part through Raman amplification. The amplifier includes an input operable to receive a plurality of wavelength signals and an output operable to communicate an amplified version of at least some of the plurality of wavelength signals. The amplifier further includes a pump assembly operable to generate one or more pump signals and a gain medium operable to receive the plurality of wavelength signals and the one or more pump signals and to facilitate amplification of at least some of the plurality of wavelength signals. The amplifier has associated with it a noise figure having a shape varying as a function of wavelength. At least one of the one or more pump signals is operable to have its power varied to selectively control the shape of the noise figure.

The present invention relates generally to the field of communication systems, and more particularly to a system and method operable to facilitate controlling the shape of a noise figure generated in an optical amplifier.
Optical amplifiers generate noise through a variety of phenomena, such as when signals being amplified interact with one another and when signals being amplified interact with pump signals associated with the amplifier. Different levels of noise can be created at different wavelengths along the spectrum of wavelengths being amplified. This leads to a spectrum of noise created across the wavelengths of the amplified signals.
Although optimization techniques can be developed to counter the effects of noise generated by a particular source, the effectiveness of these techniques can deteriorate where the shape of the noise figure changes over time. Existing optimization techniques are generally not equipped to respond to phenomena that tend to change the shape of the noise figure of the amplifier.
The present invention recognizes a need for a method and apparatus operable to facilitate control of a noise figure generated in an optical amplifier. In accordance with the present invention, a system and method for controlling a noise figure reduces or eliminates at least some of the shortcomings associated with previous communication systems.
In one aspect of the invention, an optical amplifier operable to amplify a plurality of optical wavelength signals at least in part through Raman amplification comprises an input operable to receive a plurality of wavelength signals and an output operable to communicate an amplified version of at least some of the plurality of wavelength signals. The amplifier further comprises a pump assembly operable to generate one or more pump signals and a gain medium operable to receive the plurality of wavelength signals and the one or more pump signals and to facilitate amplification of at least some of the plurality of wavelength signals. The amplifier has associated with it a noise figure having a shape varying as a function of wavelength. At least one of the one or more pump signals is operable to have its power varied to selectively control the shape of the noise figure.
In another aspect of the invention, a multi-stage amplifier comprises a first amplifier stage comprising a Raman amplification stage operable to amplify a plurality of wavelength signals through interaction with one or more pump signals and a second amplifier stage operable to further amplify at least some of the plurality of wavelength signals. The power of at least one of the one or more pump signals in the first stage is operable to be varied in response to a change in power of the plurality of wavelength signals, the variation in pump power selectively controlling the shape of a noise figure of the amplifier during operation of the amplifier.
In yet another aspect of the invention, an optical amplifier operable to amplify a plurality of optical wavelength signals at least in part through Raman amplification comprises an input operable to receive a plurality of wavelength signals and a pump assembly operable to generate one or more pump signals operable to interact with one or more of the wavelength signals over a gain medium to cause Raman amplification of the one or more wavelength signals. The amplifier also comprises control circuitry operable to generate a control signal based at least in part on a signal proportional to the total power of the plurality of wavelength signals. The amplifier is operable to vary the power of at least one of the one or more pump signals in response to the control signal, the variation of the power of the at least one pump signal selectively controlling the shape of a noise figure associated with wavelength signals being amplified.
In still another aspect of the invention, a method of amplifying a plurality of wavelength signals comprises amplifying a plurality of wavelength signals and adding wavelength signals to or dropping wavelength signals from the plurality of wavelength signals. The method further comprises selectively controlling the shape of the noise figure as wavelength signals are added or dropped from the plurality of wavelength signals.
In another aspect of the invention, a method of amplifying optical signals comprises introducing to a gain medium one or more pump signals and a multiple wavelength signal comprising a plurality of wavelength signals and detecting a change in power of the multiple wavelength signal. The method also comprises adjusting a power of at least one of the one or more pump signals in response to the change in power of the multiple wavelength signal to result in selectively controlling the shape of a noise figure associated with the multiple wavelength signal.
In another aspect of the invention, an optical communication system operable to facilitate communication of multiple signal wavelengths comprises one or more transmitters operable to generate alone or collectively a plurality of signal wavelengths and a multiplexer operable to combine the plurality of signal wavelengths into a single multiple wavelength signal for transmission over a transmission medium. The system further comprises a plurality of optical amplifiers operable to receive the plurality of signal wavelengths. At least one of the optical amplifiers comprises a gain medium operable to amplify the multiple wavelength signal through interaction with one or more pump signals, the amplification occurring prior to, during, or after the multiple wavelength signal""s transmission over the transmission medium. The power of at least one of the one or more pump signals is operable to be varied in response to a change in power of the plurality of wavelength signals, the variation in pump power selectively controlling the shape of a noise figure of the amplifier during operation of the amplifier.
Depending on the specific features implemented, particular embodiments of the present invention may exhibit some, none, or all of the following technical advantages. For example, various embodiments of the invention facilitate enhanced amplifier operation by controlling the shape of a noise figure associated with all or a portion of a spectrum of amplified signals.
One aspect recognizes that it would be desirable to maintain the shape of the noise figure in an optical communication system despite changes to the system, such as variations in signal power due to, for example, wavelength signals being added to or dropped from a multiple wavelength signal. This would allow, for example, existing optimization algorithms to continue to be utilized. In addition, in some cases, the peak increase in the noise figure can be lessened by approximately maintaining the shape of the noise figure when system conditions change. Moreover, selectively controlling the shape of the noise figure can reduce or eliminate the need to monitor and adjust individual wavelength signal powers when other wavelength signal powers change.
In at least some embodiments, the shape of a noise figure of an optical amplifier can be effectively modified or maintained by altering the powers of one or more pump wavelengths, in particular pump signals at longer wavelengths. In particular embodiments, all or a majority of the shaping of the noise figure can be accomplished in a first stage of a multiple stage amplifier.
Another aspect recognizes that control signals operable to affect the shape of the noise figure can be generated based at least in part on the total power of the signals being amplified. Although the invention could equally apply to approaches using more complex spectrum analyzing techniques to ascertain a control signal, using total power to determine a control signal provides a simple and cost effective mechanism for controlling noise figure shape. In addition, the relationship between total signal power and adjustments in amplifier pump power to control noise figure shape allows for use of look-up tables or simple algorithms to determine a control signal.
Other technical advantages are readily apparent to one of skill in the art from the attached figures, description, and claims.

System and method for controlling noise figure


It is provided a method for viewing an image that is wider or higher than the display screen, wherein, the image is evenly divided into two portions by using a line passing through centers of larger edges of the image compared to the display screen. The method comprises, at the side of shutter glasses, the steps of receiving a message indicating display of a first portion of the two portions; turning dark of the shutter glasses and turning refraction direction of the shutter glasses towards a first position; turning transparent of the shutter glasses; receiving a message indicating display of a second portion of the two portions; turning dark of the shutter glasses and turning refraction direction of the shutter glasses towards a second position; and turning transparent of the shutter glasses.

Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina.
The vision of a human is not as simple as light registering on a medium, since the brain has to make sense of the visual data eyes provide and construct a coherent picture of reality. This is visual perception. The visual perception is the ability to interpret the surrounding environment by processing information that is contained in visible light, and for human, the information contained in visible light is visual data provided by eyes. The resulting perception is also known as eyesight, sight, or vision (and the terms can be attached with following adjectives: visual, optical, or ocular, e.g. optical vision).
Persistence of vision is widely used. And below list some usages.
In traditional TV, images are displayed in closely-timed sequence one after another. Viewers don't notice the fractional skips between images because that persistence of vision fills in the momentary gap to make the motion seem seamless.
In 3D system including a 3D display and shutter glasses, left and right images (or called views) are displayed sequentially and synchronized with the left eye glass and right eye glass, i.e. when left image is displayed, the left eye glass is set transparent by setting the shutter for left eye glass on and the right eye is set dark by setting the shutter for the right eye glass off. And the similar applies when the right image is displayed. When the display frequency (i.e. switching frequency of the shutter glasses) is high enough, e.g. 120 Hz or 240 Hz for both eyes, viewer can perceive 3D depth without feeling the flicker between left and right images.
Persistence of vision displays (POV display) composes an image by displaying one spatial portion of the image at a time in rapid succession (for example, one column of pixels every few milliseconds). A 2 dimensional POV display is often accomplished by means of rapidly moving a single row of LEDs along a linear or circular path. The effect is that the image is perceived as a whole by the viewer as long as the entire path is completed during the visual persistence time of the human eye. A further effect is often to give the illusion of the image floating in mid-air. A 3 dimensional POV display is often constructed using a 2D grid of LEDs which is swept or rotated through a volume. POV display devices can be used in combination with long camera exposures to produce light writing.
The present invention provides a method to display an image larger than the size of the display to the viewer.

Method and apparatus for viewing an image


A method and apparatus for producing a verification of digital circuits is provided. In an exemplary embodiment, a set of Boolean and Integer constraints are derived, and a set of Boolean and Integer stimuli are generated that meet the constraints. These stimuli are then used to verify a digital design, and a verification report is generated. In other example embodiments, a computing apparatus and computer software product are provided. The computer software product containing a set of executable instructions that, when executed, configure the computing apparatus to produce a verification report by the provided methods.

Integrated circuits (ICs) have become the backbone of modern consumer electronics. The increased demand for functionality of consumer electronics has forced the complexity of IC's to skyrocket. In a number of applications, ICs must be highly functional, low cost and have low power consumption. These demands create increased complexity on the design, verification, and manufacture of ICs.
A typical IC design may involve the creation of electronic components, such as transistors and resistors, and the interconnections of these components onto a substrate, such as silicon. Functional verification of a digital design involves the verification that the design conforms to the specification. Functional verification may involve the validation that a design meets the desired functionality. Part of the process of verification includes the creation of Register Transfer Level (RTL) digital designs that describe in detail the functionality of the device or block at every cycle of the clock. Creation and verification RTL design may be one of the more difficult portions of the design process. In many instances, this verification is a very difficult and time intensive task. Simulation tools are typically used to assist in verification. In most designs, simulation-based functional verification is performed on multiple machines in parallel. During the verification process, "coverage" data is produced that indicates which portions of the functionality and/or code have been tested.
Many contemporary verification flows in industry have adopted a combination of formal property checking and constrained random testing. At their core, both approaches require efficient constraint solving, but formal verification typically seeks out a single solution. In constrained random testing the generation of the stimulus set requires repeated generation of solutions with a good distribution (e.g., uniform) over the solution space. A number of approaches to constrained problem solutions and to stimulus generation for constrained random testing have been used in the art. The efficiencies of these approaches typically fail in either their ability to provide good uniform distribution of stimulus over the solution set, or in their run-time and memory efficiency. Further, some approached perform well for small problems but their performance degrades substantially with the size of the problem.
Therefore there exists a need for a system, and methods for improved stimulus generation for verification of digital design descriptions. One that can produce an appropriate distribution of stimulus in an efficient manner and that scales well to large problems.

System, methods and apparatus for generation of simulation stimulus


This invention relates to a high-frequency oscillator constituted by a signal generator for generating a high-frequency signal and a signal output circuit for outputting the generated high-frequency signal. The signal output circuit comprises a capacitor having one terminal to which the high-frequency signal output from the signal generator is applied, and a microstrip line having one terminal, which is connected to the other terminal of the capacitor, and the other terminal set at a reference potential. This signal output circuit can be miniaturized compared with those constituted only by microstrip lines such as conventional signal output circuits. By properly setting the capacitance of the capacitor and the size of the microstrip line, a filter function can also be imparted to the circuit.

1. Field of the Invention
The present invention relates to a high-frequency oscillator for use in, e.g., a receiving circuit of a satellite communication system.
2. Related Background Art
As a conventional example of a high-frequency oscillator of this type, there is the one described in a paper titled "AN EASY-TO-USE FET DRO DESIGN PROCEDURE SUITED TO MOST CAD PROGRAMS", 1989 IEEE MTT-S Digest, PP. 1,033-1,036. The arrangement of this high-frequency oscillator is diagrammed in FIG. 1.
A DRO (an oscillator using a dielectric resonator; Dielectric Resonator Oscillator) shown in FIG. 1 employs a MESFET (Schottky barrier field-effect transistor) Q1 as an amplifying element. A voltage Vd is applied to the drain of the FET Q1 through microstrip lines 1 to 4, and a voltage Vs is applied to its source through microstrip lines 5 to 8. A dielectric resonator is electromagnetically coupled to microstrip lines 9 and 10 on the gate, and this coupling circuit is expressed as a parallel circuit of L, C, and R. A high-frequency signal which appears at the drain of the MESFET Q1 is output through microstrip lines 11 to 14. The lines 13 and 14 constitute a capacitor, and a load resistor R.sub.L is connected to the line 14.
As described above, the signal output circuit in this conventional high-frequency oscillator has the microstrip lines 11 to 14 as its constituting elements. Accordingly, an area on a semiconductor substrate physically occupied by these lines 11 to 14 is increased to result in a large size of the oscillator as a whole. In addition, the signal output circuit having the above conventional arrangement has only a function of obtaining impedance matching. Therefore, it is impossible to allow the circuit to have, for example, a filter function of inhibiting transmission of signals having specific signal frequency components.

High frequency oscillator having capacitor and microstrip line output filter


A cost-effective method for fabricating MIM capacitors (120). After metal (106) deposition, the metal oxide (108) is formed using an oxidation chemistry that includes CO2 and H2. The CO2/H2 gas ratio is controlled for selective oxidation. Thus, the metal (106) is effectively protected from oxidation due to the existence of both H2 and CO2 as strong reduction reagent.

As semiconductor devices continue to scale to smaller and smaller dimensions, capacitors used in integrated circuits, such as those used in DRAM storage cells, need higher capacitance/unit area. One proposed way to accomplish this is to switch from the conventional polysilicon-insulator-polysilicon capacitors to metal-insulator-metal (MIM) capacitors, such as the one shown in FIG. 1. In the MIM capacitor 10, metals used as the top 12 and/or bottom 14 electrodes are those with low oxygen affinity such as W, Ni, Co, Ir, Ru, and Pt. The insulator 16 is a metal oxide using metals that have a high oxygen affinity. Exemplary metal oxides include Ta2O5, Nb2O5, Al2O3, Y2O3, HfO2, TiO2, BaO, SrO and the so-called BST (BaxSr1-xTiO3, 0<.times.<1). These metal oxides have dielectric constant values ranging from 10 to 1000 (depending on material, microstructure, crystalline phase, and crystal orientation).
Currently, Ta2O5 and BST are considered the most promising capacitor materials for 256 Mbit and 1 Gbit DRAMs. Ta2O5 and BST can be deposited through reactions of metal-organic precursors and oxygen and annealed in the O2 or UV-O3 ambient. Unfortunately, due to their low oxidation resistance, W, Ni and Co are easily oxidized in the O2 ambient at the high temperatures required. When trying to deposit Ta2O5 on W, the W oxidizes to form WO3-y which can vaporize and result in a nonuniform dielectric. Moreover, Ta2O5-y can be produced instead of Ta2O5. Ta2O5-y is not stociometric and results in reduced capacitance due to leakage. Although Ir, Ru, and Pt have very high oxidation resistance, they are very expensive and difficult to etch.
One prior art method of selective oxidation for poly-metal gate formation was proposed by Kobayashi et al (Proc. of 15.sup.th Conf. Solid State Devices and Material p. 217 (1983)). In this method, a wet hydrogen oxidation procedure was developed to allow the silicon to oxidize while leaving the tungsten unaffected in a post gate-etch oxidation. The method is based on thermodynamic calculations which show that at, for example, 1000.degree. C. and a P(H2O)/P(H2) ratio (partial pressure ratio of H2O and H2) of 1.0e-05, the equilibrium: EQU Si+2 H2O.rarw..fwdarw.SiO2+2H2
prefers the right side of the reaction, i.e., oxidation of Si and EQU W+3H2O.rarw..fwdarw.WO3+3H3
prefers the left side of the reaction, i.e., reduction of WO3 to W. Therefore, under appropriate conditions, it is possible to oxidize silicon again such that the oxidation rate of W will be prevented.
Unfortunately, it is difficult to generate a uniform steam of pure H2O without heavy metal contaminants because it is hard to completely remove heavy metal from the clean and deionized water used in steam generators for semiconductor device manufacturing. It is also dangerous to generate and control a proper H2/H2O gas ratio using a burning process of mixed oxygen and hydrogen under an excessive hydrogen environment.
The above process has been proposed for light thermal oxidation. In the area of non-selective CVD-SiO2, several CO2-H2 gas chemistries have been proposed. One such gas chemistry is SiH4-CO2-H2 and another is SiH2Cl2-CO2-H2. A CO2-H2 gas chemistry has also been used to produce H2O for H2O addition reactions such as 2AlCl3+3H2O.fwdarw.Al2O3+6HCl. In addition, CO gas has been used in metallurgy as a strong reduction reagent of metal oxides for metal production.

Selective oxidation methods for metal oxide deposition on metals in capacitor fabrication


An organic light emitting display device includes a substrate including a plurality of pixel regions each including a light emitting region and a transparent region, a gate electrode in the light emitting region, a first insulating interlayer covering the gate electrode and extending from the light emitting region to the transparent region, a drain electrode on the first insulating interlayer and constituting a transistor in conjunction with the gate electrode, a planarization layer covering the transistor and exposing a top surface of the first insulating interlayer in the transparent region, and a first electrode on the planarization layer.

1. Field
Aspects of embodiments of the present invention relate to an organic light emitting display device and a method of manufacturing the organic light emitting display device.
2. Description of the Related Art
A transparent organic light emitting display device includes a transparent region that allows light to pass through the display device and enables objects to be seen from behind the display device, such as when the display device operates in an "OFF" state. For example, in the "OFF" state, the organic light emitting display device may display an image in a pixel region adjacent to the transparent region using light generated from an organic light emitting layer thereof. As such, it may be desired for the organic light emitting display device to have enhanced characteristics while ensuring desired transmittance.

Method of manufacturing an organic light emitting display device


A bend stiffener 4 comprising a plurality of beams 5a-g arranged to be disposed around a tubular member 2. A support is provided for connecting the bend stiffener 4 to the tubular member 2. A first rigid rod 6a connects a first beam 5b of the plurality of beams to a second beam 5c of the plurality of beams. The first rigid rod 6a is connected at a surface of the first beam 5b such that it does not lie on the same axis as a second rigid rod 7a connected at an opposite surface of the first beam 5a. A stiffness of any of the plurality of beams and connectors between beams and rods provides bend stiffening to the tubular member 2.

Risers and umbilicals are typically used in offshore hydrocarbon production to transport fluids (such as produced hydrocarbons or hydraulic fluids) between a well head at the sea bed and a surface vessel, for example a rig or a drill ship. Motion of the surface vessel caused by wind, waves, ocean currents and so on, leads to bending of the risers and umbilicals. This places periodic mechanical stresses on the risers and/or umbilicals, which can lead to mechanical failure.
The weakest point of each riser or umbilical is the point immediately adjacent to the connection to the surface vessel. This is the region subject to the highest mechanical stress, and therefore the region most likely to fail.
In order to strengthen the riser at this point, it is known to attach a bend stiffener 1 to the riser (the word riser is used herein to describe any pipe or umbilical extending from the surface vessel towards the well head or other subsea installation), as illustrated in FIG. 1. The bend stiffener 1 is disposed around a riser 2 that is connected at a riser connection point 3 to a surface vessel. This point is known as the "hang-off".
Existing bend stiffeners in use tend to be polyurethane stiffeners moulded into a truncated conical shape. Other types of material that have similar elastic properties to polyurethane may be used.
Conical bend stiffeners have an insulating effect around the riser, as they do not allow free movement of water. If the riser is carrying hot fluids, such as high temperature hydrocarbons, this insulating effect can give rise to high temperatures between the bend stiffener and the riser. Similarly, if an umbilical contains a high voltage power cable, this can give rise to heat. If the heat cannot dissipate away from the riser in the hang-off region, if may damage the riser or the bend stiffener. Heat is known to degrade polyurethane, so over time the bend stiffener and any polymeric outer sheath on the riser will become more prone to mechanical failure. This leads to a reduction in the lifetime of the outer sheath and the bend stiffener.


An integrated, externally-mounted Automated Dependent Surveillance-Broadcast (ADS-B) device comprising in one embodiment a 1030 MHz transmitter, a 1030 MHz antenna, a 1090 MHz receiver, a 1090 MHz antenna, a GNSS receiver, at least one GNSS antenna, a 978 MHz transmitter, and a 978 MHz antenna, wherein these components are integrated into a single enclosure, and wherein the GNSS antenna is placed at least partially into a projection extending out from the main enclosure body, such that the GNSS antenna has improved visibility to GNSS signals originating from altitudes above the current altitude of aircraft when the ADS-B device is mounted on the bottom of an aircraft.

1. Field of the Invention
The present invention relates generally to the field of aviation, and specifically to an Automated Dependent Surveillance-Broadcast (ADS-B) navigation device that can be mounted on the exterior or an aircraft.
2. Description of the Related Art
The Federal Aviation Administration (FAA), the national aviation authority in the United States with the authority to regulate and oversee all aspects of American civil aviation, has mandated the use of ADS-B Out by Jan. 1, 2020. ADS-B is the implementation of the FAA's Next Generation Air Transportation System, or "NextGen", a system designed to replace the aging and limited radar-based system currently used by air traffic controllers to track aircraft in controlled airspace.
ADS-B is an aircraft and satellite-based transmission system. It can be broken down into two main functions: ADS-B Out and ADS-B In.
An aircraft with ADS-B Out will transmit its position (derived from a certified GPS source) and its velocity to other aircraft, and Air Traffic Control (ATC) ground stations using an ADS-B modified Mode S transponder or a Universal Access Transceiver (UAT).
An aircraft with ADS-B In can receive information from other aircraft transmitting ADS-B information, and can also receive traffic and weather information, which will be broadcast for free.
The FAA ADS-B mandate currently requires only ADS-B Out be implemented in operation aircraft by Jan. 1, 2020. ADS-B In is currently considered optional for aircraft, and it not included in the 2020 FAA mandate. Many countries outside the United States already have an existing, in-force mandate for ADS-B equipped aircraft, or have a deadline for implementation well before 2020.
The installation of an ADS-B system on an aircraft is typically best done by a qualified avionics shop and is not easily done by an A&P (Aircraft and Powerplant) mechanic or other personnel. Given the number of aircraft currently in operation, and based on the number of avionics shops that are available to do the work, it may not be possible for all aircraft which need ADS-B Out installations on time to meet the mandated deadline of Jan. 1, 2020. There are a large number of A&P mechanics in the country, relative to the number of avionics shops, but it is more involved to have an A&P mechanic install a complex avionics system. An A&P mechanic, however, readily installs antennas on the outside of the aircraft and performs other aircraft maintenance tasks.
What is needed in the art is an ADS-B system that has been designed such that it can be mounted easily by an A&P mechanic or other available personnel, and which reduces the cost and complexity from existing ADS-B systems.

Integrated, externally-mounted ADS-B device


The present invention relates to circuitry and an associated method for detecting a synchronization signal in a multi-media data transmission system. Preferably, the circuitry (10) includes process controller (40), memory (44), and a comparator (46). The process controller (40) controls the receipt of bit groups of data (52) and the storage of the bit groups of data (50) in the memory (44). The memory (44) operably couples to the process controller (40), receives the data, and stores the data in a predetermined order based upon the process controller (40). The comparator (46) couples to the process controller (40) and the memory (44) and compares the corresponding index locations of the bit groups (52) to a synchronization pattern (58). When the synchronization pattern (58) matches the predetermined set of bit groups (52), the comparator (46) generates the synchronization detection signal (60). The synchronization detection signal (60) then allows further equipment within the receiver to selectively operate on the data blocks received.

This invention relates generally to the transmission and receipt of digitized information, and more particularly relates to an apparatus and method for determining a synchronization signal within an accumulation of received data.
The transmission and receipt of digital data across a communication link has been known in the art for years. In a typical communication system, a transmitter transmits data over a transmission path to a remotely located receiver. The receiver receives the data and passes the data along so that it may be used. As one skilled in the art will readily appreciate, many types of transmitting and receiving equipment may be employed depending upon particular data transmission and receipt requirements.
In modern digital communication systems, data transmission requirements are great. Thus, digital signals are transmitted and received at high frequencies. Thus, equipment at both the transmitting and receiving location must be capable of handling data at the high data transmission rates. In some applications, a single data link is insufficient to obtain large enough data transmission rates. Thus, multiple data links are often employed to obtain the required data transmission rate. As one skilled in the art will readily appreciate, the transmission and receipt of digital data at high frequencies and the associated processing requirements for separating and combining signals requires substantial resources of great complexities.
To somewhat simplify the data transmission and receipt process, standardized protocols have been established. Digital data typically is organized into blocks of digital data, each data block comprising a plurality of bit groups, with the data blocks encoded at the transmitting location and transmitted across the data link. However, data is typically transmitted as a bit stream and it is difficult to relate a particular bit to a corresponding data location. Thus, the transmitter and receiver have been designed to segregate the bit stream into the bit groups. Upon receipt, the bit groups are stored at the receiving location in a sequential manner and represent a sequential bit group in a block of data.
However, when data transmissions are initiated or otherwise interrupted, the receiver does not know which received bit group is the first bit group of a data block and which bit group is the last bit group of the data block. Thus, a synchronization signal is encoded into each data block so that the receiver may determine which bit group is the first bit group in the data block and which bit group represents the last bit group in the data block. Once a synchronization signal is determined, the receiver synchronizes to each subsequently received data block and handles the bit groups accordingly.
In a standard communication protocol, the synchronization signal encoded in a plurality of last bits in various bit groups. For example, in the case of the H.221 communication protocol, each bit group is one byte of data and each data block contains 80 bytes. The synchronization signal is encoded in the eighth bit position of sequentially received bytes of the data block. Thus, by viewing the eighth bit position of a sequentially received number of bytes, the synchronization signal may be determined, and the starting byte and ending byte of each data block may also be determined. Further, because data blocks are transmitted and received sequentially, once a particular starting byte has been determined, the receiver has xe2x80x9clockedxe2x80x9d onto the particular received signal and recognizes each subsequent data block as it is received.
Each data block in a video teleconference may contain audio data, video data, user data, data relating to the control of the other data, time stamp information, and attributes of the equipment at the receiving and transmitting locations. After data is received by the receiver and it is ordered properly, further processing is performed by the receiver so that it can generate the audio, video, and control signals.
In the case of a receiving-transmitting pair that uses a plurality of transmission paths, data blocks may be skewed in time such that they must be reassembled upon receipt. For example, in a system employing five transmission paths with each path sharing a portion of the data transmission workload, data transmitted over respective paths is often skewed in time. In systems employing a plurality of transmissions, once the synchronization signal is determined on each transmission path, the time skewing of the signals may be determined and the timing of the receipt of signals may be determined. Once the synchronization signals are determined for the various transmission paths, the differing blocks of data may more easily be related to one another over time. Time stamps contained in the blocks may be accessed if required and an expeditious reconstruction of the total signal may be accomplished with reduced processing.
One prior art solution for determining the synchronous signal involved using a large shift register having a width of 167 bits. This particular prior art device looked at an ending bit of each byte received by the receiver, shifted the bit into the shift register, and did the same for the remaining 166 ending bits. Decoding circuitry associated with the shift register viewed the 1st through 7th bits, 81st bit, and 161st through 167th bits, and compared the bits with a known synchronization pattern. When a match occurred, the synchronization signal was found and a signal was transmitted from the device to indicate which byte represented the start of the data block. While the particular prior art device accurately determined the synchronous signal, it required significant hardware. Further, in some systems, bits of a transmitted bit group may be transposed due to operation of repeaters along the transmission line. Thus, after transposition, the synchronization signal may reside in an unexpected bit location. The described prior art device could not detect the presence of the synchronization signal in an unexpected bit location. Thus, in some systems the prior art device could not function to determine the synchronization signal.
Another prior art device looked at a single bit of each byte received from the data transmission path and used the bit as an input to a state machine. The state machine, if it received the proper input for seven sequential bits, entered a delay cycle and waited for an 81st bit to compare and check to determine if the bit compared correctly to the expected value. If so, the prior art device issued a synchronization block signal to further components in the system. While this system was inexpensive, it could easily miss the synchronous signal due to falsing, in which case, it would miss a true synchronization signal and would have to wait until the next data block to reinitiate its operation. Further, this prior art device also could not detect the synchronization signal in a bit location other than the expected bit location.
Thus, there exists a need in the art for a highly reliable synchronization signal detect circuit that is efficient in detecting valid blocks, while minimizing the hardware required.

Apparatus and method for determining a synchronization signal


A magnetic head and disk tester which has linear encoders (40 and 42) installed on lateral sides of a carriage (30) which carries a magnetic head (34), movable in a radial direction along a hard disk. Positions of the magnetic head with respect to the hard disk are measured by means of the linear encoders which are arranged on both lateral sides of the carriage. Outputs of the encoders are supplied to an arithmetic unit (45) which calculates the arithmetic mean of the encoder's outputs and transmits the resulting signal via a feedback line (47) to a piezoelectric translator (37). The translator is the final drive element in the carriage-drive system and is used for fine positioning of the carriage. Thus, if during positioning of the magnetic head the latter is installed in an erroneous position, e.g., because of yawing which may result from asymmetrical friction on both sides of the carriage, the feedback-positioning system composed of the encoders, the arithmetic unit, and the piezoelectric translator calculates the error and shifts the carriage in a direction opposite to the error to the correct position.

1. Field of the Invention
The present invention relates to magnetic-head and magnetic-disk testers, particularly to improved testers of read-write heads and magnetic disks and to a method for compensating positioning errors which occur during the operation of such testers.
2. Description of Prior Art
Prior to assembling computer disk drives, their main components, i.e., magnetic read-write heads and magnetic disks, are usually checked on magnetic-head and disk testers.
An example of a prior-art head and disk tester is shown in FIG. 1, a schematic perspective view of the tester. Such tester is described in earlier U.S. Patent application Ser. No. 840,527 filed Feb. 25, 1992 now U.S. Pat. No. 5,254,946, granted Oct. 19, 1993. The tester comprises two parallel bottom rails 10 and 12 which are rigidly attached to a tester housing 13, e.g., by bolts (not shown) and support and guide top rails 14 and 16, respectively. Top rails 14 and 16 are rigidly attached to an outer ring 18 which rotatingly supports an inner ring 20. The latter carries a magnetic-head holder 21 with a magnetic head 22. Thus, magnetic head 22 can move back and forth in the directions indicated by an arrow A and can be rotated by means of inner ring 20 around an axis B, which passes through head 22. A spindle 24 rotates around a fixed axis and supports and rotates a magnetic disk 26 to be tested.
For positioning the head at a predetermined location of disk 26 and at a predetermined angle to the disk's track (not shown), top rails 14 and 16 are guided over bottom rails 10 and 12 and shift magnetic head 22 radially with respect to magnetic disk 26. Inner ring 20 is then rotated, thus placing magnetic head 22 in the required position and at a predetermined angle to the track.
The testing requires that magnetic head 22 and disk 26 be accurately positioned in a predetermined relationship with respect to each other. Among parameters to be measured, an important one is track profile. Track profile is a characteristic which is obtained by measuring a read-back signal parameter, such as amplitude, pulse shape, etc., which depends on the transverse shift of the magnetic head with respect to the center line of the track.
Outer ring 18, together with top rails 14 and 16, form a carriage 28 which is shown in FIG. 1. Carriage 28 is moved along bottom rails 10 and 12 from a reversible stepper motor via a lead screw (not shown).
The system shown in FIG. 1 is an open-loop system, i.e., it does not employ feedback. Typically, the width of the track is about 10 .mu.m or less. The open-loop system of this type produces a positioning uncertainty of about 1 .mu.m. However, with the advent of a new generation of hard disks with tracks narrower than 10 .mu.m, the uncertainty of 1 .mu.m becomes unacceptable for measurement purposes.
One method of improving positioning accuracy is to employ a closed-loop system, measuring the displacement of head 22 and actively correcting any positioning error. It is, however, very difficult to measure the displacement of head 22 directly by means of a measurement instrument. This is because the space adjacent to the head is occupied by spindle 24, magnetic disk 26, and means for removably mounting head 22 on carriage 28. Therefore there is not enough room for locating the measurement instrument such as a linear encoder.
An attempt has been made to solve this problem by providing a tester with a closed-loop system which incorporates a measuring instrument located in a different place than the center of the carriage, e.g., on the side of the carriage. An example of such a device is an experimental disk/head tester which was constructed by Guzik Technical Enterprises of San Jose, California in July 1992. A schematic three-dimensional view of this tester is shown in FIG. 2.
The tester of FIG. 2 is essentially the same as the one of FIG. 1, with the exception that a linear encoder 11 is installed in close proximity to one side of carriage 28a, e.g., near bottom rail 12a. Encoder 11 consists of two parts: a stationary part or a reader head 11a which is attached, e.g., to housing 13a by screws 15 and 17, and a movable part, i.e., encoder scale 11b which is rigidly attached to carriage 28a, e.g., to top rail 16a by screws 19 and 23.
When during testing carriage 28a moves together with magnetic head 22a relatively to magnetic disk 26a, encoder 11 is used for determining a position of magnetic head 22a. Encoder 11 does not measure the position of magnetic head 22a: it is assumed that the displacement of a measurement point on the side of the carriage 28a, where the encoder is located, is approximately equal to that of the center of magnetic head. However, this is not true, if yawing occurs during the movement of the carriage.
More specifically, in the case of yawing, magnetic head 22a is displaced with respect to the measurement point by being rotated around this point with a radius equivalent to the distance from magnetic head 22a to the measurement point. With the radius of 10 cm and a yawing angle, which may be as high as 5 .mu.radians, the displacement of magnetic head 22a with respect to the measurement point due to yawing, i.e., the position measurement error, may be as high as 0.5 .mu.m.
Therefore, the closed loop compensation system (not shown) of the tester of FIG. 2, which uses an output signal of encoder 11 as a feedback signal to compensate for the head-position error, cannot achieve an accuracy better than 0.5 .mu.m.

Method and apparatus for compensating positioning error in magnetic-head and magnetic-disk tester


A method is disclosed for detecting the presence of a target nucleotide sequence in a polynucleotide. The method comprises hybridizing a first nucleotide sequence and a second nucleotide sequence to non-contiguous portions of a target nucleotide sequence, covalently attaching the first and second sequences when they are hybridized to the target sequence, and determining the presence of covalently attached first and second sequences. The presence of the covalently attached first and second sequences is related to the presence of the target nucleotide sequence. The invention may be applied to target nucleotide sequences in DNA or RNA. Specific target nucleotide sequences of interest will frequently be characteristic of particular microorganisms, viruses, viroids, or genetic characteristics, including genetic abnormalities.

1. Field of the Invention
This invention relates to methods for detecting the presence of target nucleotide sequences.
Nucleic acid hybridization has been employed for investigating the identity of nucleic acids. Hybridization is based on complementary base pairing. When at least partially complementary single stranded nucleic acids are incubated in solution under suitable conditions of temperature, pH and ionic strength, complementary base sequences pair to form double stranded stable hybrid molecules. The ability of single stranded deoxyribonucleic acid (ssDNA) or ribonucleic acid (RNA) to form a hydrogen bonded structure with its complementary nucleic acid sequence has been employed as an analytical tool in recombinant DNA research. The availability of radioactive nucleoside triphosphates of high specific activity and the synthetic methods of incorporating these nucleotides into nucleic acid probes such as the .sup.32 P labelling of DNA with T.sub.4 polynucleotide kinase and other well known methods has made it possible to identify, isolate, and characterize various nucleic acid sequences of biological interest. Nucleic acid hybridization has great potential in diagnosing disease states mediated by alteration in or additions to nucleic acid composition of the host. These alterations in nucleic acid composition will include genetic or environmental change in DNA by insertions, deletions, rearrangements, point mutations, or acquiring foreign DNA by means of infection by bacteria, molds, fungi, and viruses. Nucleic acid hybridization has, until now, been employed primarily in academic and industrial molecular biology laboratories. The application of nucleic acid hybridization as a diagnostic tool in clinical medicine is limited because of the frequently very low concentration of disease related DNA or RNA present in a patient's body fluid and the unavailability of a sufficiently sensitive rapid method of DNA hybridization analysis.
Current methods for detecting DNA probes generally involve immobilization of the target nucleic acid on a solid support such as nitrocellulose paper, cellulose paper, diazotized paper, or a nylon membrane. After the target nucleic acid is fixed on the support, the support is contacted with a suitably labelled probe nucleic acid for about two to forty-eight hours. After the above time period, the solid support is washed several times at a carefully controlled temperature to remove unbound and nonspecifically bound probe without removing specifically bound probe. The support is then dried and the hybridized material is detected by autoradiography or by colorimetric methods. When very low concentrations must be detected, the ratio of specific to non-specifically bound probe can be very low and repeated washing under highly stringent conditions is frequently required. Under these conditions the sensitivity of the assay is often compromised because of substantial loss of specifically bound probe and failure to achieve a high enough specific to non-specific binding ratio to permit easy detection. When very low concentrations must be detected, the current methods are slow and labor intensive and non-isotopic labels that are less readily detected than radiolabels are frequently not suitable.
The use of .sup.32 P nucleotide as a nucleic acid probe label is not desirable for several reasons. First, .sup.32 P has a relatively short half life of 14.2 days. Consequently, the complementary probe DNA must be prepared just prior to the hybridization procedure to achieve maximum sensitivity. Secondly, the high decay energy of .sup.32 P creates handling and disposal problems and undesirable hazards. It would therefore be advantageous in most cases to utilize a label which is less hazardous and prolongs the shelf life of the probe. High specific activity tritium labelled probes present one alternative. While tritium has not generally been found useful in previous hybridization methods which requires extended exposure times for detection by autoradiography, a solution method which detects labelled probe by liquid scintillation counting would be highly sensitive and desirable. Another less energetic isotope than .sup.32 P but with a long half life is carbon-14.
The development of non-radioactive labeling of nucleic acid probes presents another alternative. A sensitive non-radioactive DNA labelling system is described by Langer, et al., Proc. Nat. Acad. Sci., USA, 78, 6633 (1981). The system is based on the incorporation of a biotinylated deoxyuridine triphosphate into the DNA probe by the nick translation procedure. The resultant biotinylated DNA probe is stable and behaves as does a non-biotinylated DNA probe. Detection of the biotinylated DNA has been applied to the detection of specific DNA and RNA sequences in fixed cells or in tissues following in situ hybridizations and also in hybridizations of DNA fragments separated by gel electrophoresis and transferred onto nitrocellulose filters. The detection of the hybridized biotinylated probe is accomplished by either fluorescent antibody or enzyme amplification techniques. These techniques are further described by Gardner, BioTechniques, 1, 38 (1983) and Lewin, Science, 221, 1167 (1983).
Other non-radioactive methods which have been described involve conjugating a fluorescent molecule such as tetramethylrhodamine or fluorescein isothiocyanate, to the 3'-terminus of single stranded RNA. These fluorescent RNA probes have been applied to cytochemical hybridizations. Bauman, et al., J. Histochem. Cytochem, 29, 227-238 (1981).
A method for increasing sensitivity to permit the use of a simple, rapid, (nonisotopic), homogeneous or heterogeneous method for detecting nucleic acid sequences is necessary.
2. Description of the Prior Art
Langer, et al., Proc. Natl. Acad. Sci. USA, (1981) 78, 6633-6637 discloses the enzymatic synthesis of biotin labelled polynucleotides and the use of these materials as novel nucleic acid affinity probes. The detection of viral genomes in cultured cells and paraffin imbedded tissue sections using biotin labelled hybridization probes is discussed by Brigati, et al., Virology, (1983) 126, 32-50. U.S. Pat. No. 4,486,539 discloses the detection of microbial nucleic acids by a one step sandwich hybridization test. Sensitive tests for malignancies based on DNA detection is described in U.S. Pat. No. 4,490,472. U.S. Pat. No. 4,480,040 discloses the sensitive and rapid diagnosis of plant viroid diseases and viruses employing radioactively labelled DNA that is complementary to the viroid or to the nucleic acid of the virus being diagnosed. European Patent Application 83106112.2 (Priority U.S. Patent Application Ser. No. 391,440 filed Jun. 23, 1982) teaches modified labelled nucleotides and polynucleotides and methods of preparing, utilizing, and detecting the same. Methods and compositions for the detection and determination of cellular DNA are disclosed in U.S. Pat. No. 4,423,153.
Detection and isolation of homologous, repeated and amplified nucleic acid sequences is disclosed in U.S. Pat. No. 4,675,283. A single stranded self-hydridizing nucleic acid probe capable of repeatedly hybridizing to itself or other nucleic acids to form an amplified entity is described in U.S. patent application Ser. No. 888,058, filed Jul. 22, 1986. U.S. Pat. Nos. 4,683,195 and 4,683,202 disclose a homogeneous polynucleotide displacement assay with digestion of the displaced RNA single strand polynucleotide from the reagent complex and amplifying nucleic acid sequences with treatment of separate complementary strands of the nucleic acid with two oligonucleotide primers. European Patent Application No. 0200362 describes a process for amplifying, detecting or cloning nucleic acid sequences and useful in disease diagnosis and in preparation of transformation vectors. A method for simple analysis of relative nucleic acid levels in multiple small samples by cytoplasmic dot hybridization is described in U.S. Pat. No. 4,677,054. A hybridization method of detecting nucleic acid sequences with a probe containing a thionucleotide is described in U.S. Pat. No. 4,647,529.
A simple and efficient enzymatic method for covalent attachment of DNA to cellulose and its application for hydridization-restriction analysis and for in vitro synthesis of DNA probes is described in Nucleic Acids Research (1986) 14:9171-9191. Cleavage of single stranded oligonucleotides by Eco RI restriction endonuclease is described in Nucleic Acid Research (1987) 15:709-716.
A nucleic acid hybridization assay employing probes cross-linkable to target sequences is described in U.S. Pat. No. 4,599,303. The method involves the preparation of a specific single stranded ribonucleic acid or deoxyribonucleic acid molecule into which a bifunctional cross-linking molecule has been covalently incorporated. The incorporation is such that the cross-linking molecule retains the capacity to undergo a second reaction with the nucleic acid of the bacterial, viral, or mammalian chromosome, which is the target for the probe such as to form a covalent cross link. Following cross-linking, the uncrossed link probe is separated from covalently cross-linked probe-target complex using one of several procedures which differentiate between single stranded probe and double stranded covalently linked probe-target complex.
Detection of target sequences in nucleic acids by hybridization using diagnostic and contiguous probes for diagnosis of genetic abnormality diseases, especially in an automated procedure, is described in European Patent Application No. 0 185 494A2. In the method a sample is hybridized with a probe complementary to a diagnostic portion of the target sequence (the diagnostic probe) and with a probe complementary to a nucleotide sequence contiguous with the diagnostic portion (the contiguous probe) under conditions wherein the diagnostic probe remains bound substantially only to the sample nucleic acid containing the target sequence. The diagnostic probe and contiguous probe are then covalently attached to yield a target probe that is complementary to the target sequence and the probes which are not attached are removed. In a preferred mode, one of the probes is labeled so that the presence or absence of the target sequence can then be tested by melting the sample nucleic acid target probe duplex, eluting the dissociated target probe, and testing for the label.
The above method suffers at least one disadvantage in that contiguous sequences are required. To carry out the method, one must identify the diagnostic sequence and the contiguous sequence and create diagnostic and contiguous probes complementary to the above sequences. If the diagnostic and contiguous sequences are not identified precisely, then the diagnostic and contiguous probes may not hybridize sufficiently and the assay specificity and sensitivity is lost or substantially decreased.

Method for detection of specific nucleic acid sequences


The adjustable, dynamic target system has an impact resistant target silhouette mounted to the upper end of a shaft journal for rotation about a horizontally supported axle. The lower end of the shaft carries the counter weight that can be adjustable positioned along the lower end of the shaft to produce varying dynamic affects according to the impact force of projectile and the skill of the marksman.

The present invention relates to an adjustable dynamic target system for use with firearms which provides a target that moves when struck and which can be adjusted to provide a selectable dynamic response to firearms with varying caliber and power for shooters with diverse levels of skill.
With the increasing use of body armor, such as bullet proof vests, by criminals and military forces, the head and neck areas remain as practically the only unprotected vital body areas where a gunshot will inflict a disabling wound on an assailant or enemy combatant during a deadly confrontation. For this reason, law enforcement and military agencies have in recent years placed increased emphasis on training their personnel to aim at these vital areas when faced with a life threatening situation.
In the past, firearms training for law enforcement and military personnel has relied upon conventional targeting systems where a target outline of the upper or trunk portion of the human body provides a central aiming point or bullseye in the middle of the chest area. The expertise of an individual marksman was determined by actually inspecting bullet holes made in the target based on their proximity to the central aiming point. In some specialized training environments, dynamic targets were used where a panel in the shape of a human silhouette was hinge mounted at the bottom with a releasable latch mechanism to provide a "knock down" type action when the target was hit, which caused the latch to release allowing the upright target to swing down to a horizontal position. After each hit, the target had to be returned to and latched in its upright position either manually or by expensive automatic reset systems.
With such "knock down" type target systems, the bullet would have to strike in an impact area at some minimum distance from the hinge to create enough torque to overcome the restraining force of the latch mechanism. However, this minimum distance between the impact point and hinge varied depending on the force of the projectile which meant that, with smaller caliber, less powerful firearms, bullets would have to strike higher on the target to overcome a given latch restraining force. Although the restraining force of the latching mechanism might be varied to suit projectiles of different calibers and power, that was for the most part impractical because, given a particular latch setting, frequent adjustments were needed to compensate for wear on the abutting contact surfaces of the mechanism.

Adjustable dynamic target system for firearms


The disclosure provides an array substrate, a display panel and a display device, for increasing a viewing angle of the display device. The array substrate includes a plurality of data lines and a plurality of gate lines arranged to cross each other, and a column of pixel units between adjacent data lines, at least one pixel unit each includes at least two sub-pixel electrodes, a voltage compensation unit for charging at least one sub-pixel electrode of the pixel unit and a voltage division unit for reducing a voltage on at least one of other sub-pixel electrodes of the pixel unit. The voltage compensation unit and the voltage division unit are adjusted such that voltages on sub-pixel electrodes are not all the same, thereby deflection angles of liquid crystal molecules located within regions corresponding to the sub-pixel electrode are different from each other, enabling wide viewing-angle display of the display device.

Technical Field
Embodiments of the present disclosure generally relate to the field of display technologies, and particularly, to an array substrate and a method of manufacturing the same, a display panel and a display device.
Description of the Related Art
Liquid crystal display has become dominant in flat panel display recently due to its characteristics such as small volume, low power consumption, no radiation and the like. The size of the liquid crystal display has become larger and larger, thus there is higher requirement for a range of viewing angle of the liquid crystal display.
In a conventional liquid crystal display, liquid crystal molecules are generally driven to deflect by a vertical electric field between a pixel electrode and a common electrode line, thus when viewing from a side of the liquid crystal display, there are low contrast and color distortion, that is, there is a problem related to a narrow viewing angle. In order to solve the above problem, there has proposed a liquid crystal display comprising an array substrate, which comprises a plurality of data lines and a plurality of gate lines, adjacent data lines define a column of pixel units, each pixel unit comprises two sub-pixel electrodes and a storage capacitor, and one of the sub-pixel electrodes is discharged through the storage capacitor, such that voltages on the two sub-pixel electrodes are different from each other, and thus such that deflection angles of the liquid crystal molecules located within regions corresponding to the two sub-pixel electrodes are different from each other, thereby improving the viewing angle of the liquid crystal display.
However, since the charges on both two sub-pixel electrodes will be consumed, a voltage difference between the two sub-pixel electrodes may decrease when the charges on the two sub-pixel electrodes are consumed by different amounts, so that a difference between deflection angles of the liquid crystal molecules located within regions corresponding to the two sub-pixel electrodes will be smaller, thereby the improvement of the viewing angle of the liquid crystal display is not significant; in other words, there is still a problem of narrower viewing angle in existing display devices.

Array substrate and method of manufacturing the same, display panel and display device