According to some embodiments, a capacitor includes a storage conductive pattern, a storage electrode having a complementary member enclosing a storage conductive pattern so as to complement an etch loss of the storage electrode, a dielectric layer disposed on the storage electrode, and a plate electrode disposed on the dielectric layer. Because the complementary member compensates for the etch loss of the storage electrode during several etching processes, the deterioration of the structural stability of the storage electrode may be prevented. Additionally, because the complementary member is formed on an upper portion of the storage electrode, the storage electrode may have a sufficient thickness to enhance the electrical characteristics of the capacitor that includes the storage electrode.

1. Field of the Invention
This disclosure relates to a semiconductor device and a method of manufacturing the semiconductor device. More particularly, the disclosure relates to a semiconductor device including a capacitor that has a storage electrode having greatly improved electrical characteristics and structural stability, and a method of manufacturing a semiconductor device having such a capacitor.
2. Description of the Related Art
In general, semiconductor memory devices such as dynamic random access memory (DRAM) devices can store data or information therein. The data or information may be stored in the semiconductor memory devices, and the data or information may also be read from the semiconductor memory devices. A typical single unit memory cell of the semiconductor memory device includes one capacitor and one transistor. The capacitor of the semiconductor memory device typically includes a storage electrode, a dielectric layer, and a plate electrode. To improve a storage capacitance of the semiconductor memory device, a capacitor with a high capacitance value is required.
As semiconductor memory devices become highly integrated, the area of the unit memory cell of the semiconductor memory device is decreased. To ensure a sufficient storage capacitance of the semiconductor memory device, the capacitor may have various shapes such as a box, a cylinder, etc. However, as a design rule for the semiconductor memory device decreases, the aspect ratio of the capacitor increases because the capacitor must be formed in a correspondingly limited unit area. The aspect ratio is defined as the ratio between a height of the capacitor and a width of the capacitor. As a result, adjacent capacitors having a high aspect ratio may lean against each other so that the adjacent capacitors are electrically connected with each other, thereby causing a two-bit short between the adjacent capacitors.
To overcome the above problem, cylindrical capacitors having a stepped sidewall and methods for fabricating the same are disclosed in U.S. Pat. No. 5,610,741 issued to Hwang et al.
FIGS. 1 to 4 are cross-sectional diagrams illustrating a conventional method for forming cylindrical capacitors having stepped inner side faces.
Referring to FIG. 1, storage node contact holes (not shown) that expose contact regions are formed through an insulating interlayer 1 positioned on a semiconductor substrate.
Storage node contact plugs are formed in the storage node contact holes, respectively. A nitride etching stop layer 6 is then formed on upper faces of the storage node contact holes and on an upper face of the insulating interlayer 1.
A lower mold layer 9 and an upper mold layer 12 are successively formed on an upper face of the etching stop layer 6. Here, the lower mold layer 9 includes a material that has an etch rate greater than that of a material included in the upper mold layer 12 with respect to an etching solution including hydrogen fluoride (HF). For example, the lower mold layer 9 may be formed using boro-phosphor silicate glass (BPSG) or phosphor silicate glass (PSG), etc., and the upper mold layer 12 may be formed using undoped silicate glass (USG) or tetra ethyl ortho silicate (TEOS), etc.
The upper mold layer 12, the lower mold layer 9, and the etching stop layer 6 are successively patterned to form preliminary storage node holes 15 that expose the storage node contact plugs 3. Here, upper portions of the preliminary storage node holes 15 have diameters greater than those of lower portions of the preliminary storage node holes 15.
Referring to FIG. 2, exposed inner side faces of the lower mold layer 9 in the preliminary storage node holes 15 are isotropically etched to thereby form storage node holes 18. Lower portions of the storage node holes 18 have diameters greater than those of the preliminary storage node holes 15. As a result, the storage node holes 18 have stepped inner side faces.
Referring to FIG. 3, a conductive layer 21 and a hemi-spherical grain (HGS) silicon layer 24 that covers the mold layer and inner faces of the storage node holes 18 are successively formed. A sacrificial layer 27 is then formed to thereby fill the storage node contact holes 18.
Referring to FIG. 4, the sacrificial layer 18, the HGS silicon layer 24, and the conductive layer 21 are removed until the upper face of the upper mold layer 12 is exposed to thereby form a conductive layer pattern 30 and a HSG silicon layer pattern 33 in the storage node contact holes 18. Sequentially, the upper mold layer 12 and the lower mold layer 9 are successively removed to thereby form storage electrodes 36 that include the conductive layer pattern 30 and the HGS silicon layer pattern 33. Here, the storage electrodes 36 have stepped inner side faces.
Upper portions of the storage electrodes 36 may be thinner during several etching processes for forming the storage electrodes 36 of capacitors. Lower portions of the storage electrodes 36 may be etched once or twice, whereas the upper portions of the storage electrodes 36 may be etched at least three times. As a result, the upper portions of the storage electrodes 36 may have thicknesses that are much less than those of the lower portions of the storage electrodes 36. Because the thicknesses of the upper portions of the storage electrodes 36 are relatively thin compared to the lower portions of the storage electrodes, the electrical characteristics of the upper portions of the storage electrodes 36 may deteriorate. In addition, because the storage electrodes 36 having the thin upper portions are structurally unstable, the upper portions of the storage electrodes 36 may become bowed or deformed. Thus, the structural stability of capacitors that include the storage electrodes 36 may deteriorate. To overcome the bowing, stacked capacitors are disclosed in Japanese Laid Open Patent Publication No. 2003-224210.
FIGS. 5 to 8 are cross-sectional diagrams illustrating a method for forming stacked capacitors according to Japanese Laid Open Patent Publication No. 2003-224210.
Referring to FIG. 5, an insulating interlayer 45 is formed on the semiconductor 42 including underlying structures such as bit lines (not shown) and contact regions (not shown). Contact holes (not shown) are formed to expose the contact regions.
Contact plugs 48 are formed in the contact holes. A first etching stop layer 51, a first insulation layer 54, a second etching stop layer 57, and an antireflective 63 are successively formed on an upper face of the contact plugs 48 and on an upper face of the insulation inter layer 45.
A photoresist pattern 66 is formed on the antireflective coating 63. The antireflective coating 63, the second insulation layer 60, the second etching stop layer 57, the first insulation layer 54, and the first etching stop layer 51 are successively etched to form openings 69 that expose upper faces of the contact plugs 48.
Referring to FIG. 6, the photoresist pattern 66 and the antireflective coating 63 are removed. A first conductive layer 72 is then formed on an upper face of the conductive layer 60 and on inner faces of the openings 69.
A third insulation layer is formed on an upper face of the first conductive layer 72 to thereby fill the openings 69. The third insulation layer is partially etched to thereby form a third insulation layer pattern 75 in the openings 69.
Referring FIG. 7, the first conductive layer 72 is partially etched. The third insulation layer pattern 75 and the second insulation layer 60 are then removed to thereby form storage electrodes 78.
Referring to FIG. 8, a dielectric layer 81 and a plate electrode 84 are successively formed, and cover a partially exposed upper face of the second etching stop layer 57 and partially exposed faces of the storage electrodes 78. As a result, stacked capacitors 87 are formed.
Because the first insulation layer 54 and the first etching stop layer 51 are disposed between the stacked capacitors 87, the storage electrodes 78 are not fully used. As a result, the capacitances of the stacked capacitors 87 may be reduced. That is, because outer side faces of lower portions of the storage electrodes 87 are not covered with the dielectric layer 81 and the plate electrode 84, the lower portions of the storage electrodes 87 may not contribute to the capacitances of the capacitor.
In addition, because the storage electrodes 78 are formed by several etching processes, upper portions of the electrodes 78 may be thinner. As a result, the upper portions of the storage electrodes 78 may still become bowed or deformed.
Embodiments of the invention address these and other disadvantages of the conventional art described above.

Semiconductor device having a capacitor with a stepped cylindrical structure and method of manufacturing same


The present invention relates to a cross dipole including a plurality of dipole elements respectively corresponding to a plurality of frequency bands and reconfiguring the plurality of frequency bands. A cross dipole module includes a circuit for controlling a signal of the cross dipole according the cross dipole and an external control signal. An array antenna includes a plurality of cross dipole modules arranged in one dimension or two dimensions. A multiple input multiple output antenna includes a plurality of array antennas for independently operating and an indoor supporting system for respectively applying a control signal to the plurality of array antennas, and reconfigures a distance between the neighboring array antennas.

(a) Field of the Invention
The present invention relates to a cross dipole, a cross dipole module, an array antenna, and a multiple input multiple output antenna.
This work was supported by the IT R&D program of MIC/IITA [2007-F-041-01, Intelligent Antenna Technology Development].
(b) Description of the Related Art
Needs for wireless communication services including wireless broadband (Wibro), world interoperability for microwave access (WiMAX), and wireless LAN (WLAN) have been increased. Since wideband is used for the wireless communication services, a multiple input multiple output (MIMO) method is combined to the wireless communication services to increase a data rate.
Generally, in a base station antenna for the wireless communication service, cross dipoles are arranged in one dimension or two dimensions, and a power combining circuit is used to combine power.
In addition, for the wireless communication service to which the MIMO method is used, it is required to independently drive a plurality of antennas to perform multiple input or multiple output. According to the MIMO method, as correlation between signals input or output through the plurality of antennas is decreased, the data rate increases. In this case, as a distance between the neighboring antennas increases, the correlation between the signals input or output through the antennas decreases. However, when the distance between the neighboring antennas is increased, the size of the antenna is problematically increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Cross dipole, cross dipole module, array antenna, and multiple input multiple output antenna

Electronics and Telecommunications Research Institute


A plasma display device and driving method. A plurality of subfields from one frame are divided into a first subfield group and a second subfield group. A first subfield and a second subfield having adjacent weights in the first subfield group each include a reset period for resetting the discharge cells, a first address period for selecting discharge cells in the first line group, a first sustain period for performing a sustain discharge, a second address period for selecting discharge cells in the second line group and a second sustain period for performing a sustain discharge.

(a) Field of the Invention
The embodiments of the present invention relate to a plasma display device and a driving method thereof. Specifically, embodiments of the present invention relate to a plasma display device for reducing flicker and a driving method thereof.
(b) Description of the Related Art
Flat panel displays such as liquid crystal display devices (LCDs), field emission displays (FEDs) and plasma display devices are actively being developed. Plasma display devices in flat panel displays have better brightness, luminescent efficiency and wider viewing angles in comparison to other types of flat panel displays. Therefore, plasma displays have been focused on as substitutes for the conventional cathode ray tubes (CRTs) in large display devices such as display devices that are greater than 40 inches in size.
A direct current (DC) plasma display device has electrodes that are exposed to a discharge space without insulation, thereby causing a current to directly flow through the discharge space during the application of a voltage to the electrodes. Therefore, a problem with such a DC plasma display device (PDP) is that it requires a resistance for limiting the current. On the other hand, an alternating current (AC) plasma display device has electrodes that are covered with a dielectric layer, which forms a natural capacitance component that restricts the current and protects the electrodes from the impact of ions during discharge. As a result, the AC plasma display device has an advantage over the DC plasma display device because it has a longer lifetime.
As shown in FIG. 1, the above-noted plasma display device divides one frame of an input video signal data into a plurality of subfields and combines the subfields to express grayscale levels. Each subfield has a reset period, an address period and a sustain period. The reset period is for initializing the status of each discharge cell so as to facilitate an addressing operation on the discharge cell. The address period is for applying an address voltage to cells to be turned-on (i.e., addressed cells) to accumulate wall charges in these cells. Cells that do not have the address voltage applied to them are not selected to be turned-on cells. The sustain period is for applying a sustain discharge pulse or set of pulses to perform a discharge for displaying images via the turned-on cells selected during the address period.
FIG. 1 illustrates one frame that is divided into eight subfields to express 256 different grayscale levels. Each subfield (SF1-SF8) includes reset periods (not shown), address periods (A1-A8) and sustain periods (S1-S8). The sustain periods (S1-S8) have emission periods with durations of 1T, 2T, 4T, . . . , 128T where T is a unit of time. The emission periods have different individual durations with the combined ratio of 1:2:4:8:16:32:64:128.
For example, a grayscale level of 3 is expressed by discharging a discharge cell during a first subfield (SF1) having an emission period with a duration of 1T and a second subfield (SF2) having an emission period with a duration of 2T so as to have a total emission period with a duration of 3T. In this way, a combination of different subfields, each having different emission periods, produces pictures having 256 different grayscale levels.
Expression of grayscale levels by the plasma display device generates flicker that is detectable by human vision. The flicker is more easily detected when the screen size becomes larger or its refresh frequency is low. A plasma display device generates a large amount of flicker when generating phase alternation line (PAL) images when the two above-noted conditions are present. In this case, the flicker can only be reduced by controlling (i.e. increasing) the frequency, because the screen size cannot be modified.
As shown in FIG. 2, subfields of one frame are divided into two groups, G1 and G2, each with the same arrangement of subfield weights except that the least significant bit (LSB) subfield in each group differs. This scheme reduces flicker that is generated by a large screen plasma display device that uses 50 Hz video signals. This scheme is more efficient in reducing flicker than the conventional arrangements of subfields such as the minimum increment arrangement or the minimum decrement arrangement. However, the scheme shown in FIG. 2 may generate flicker at specific grayscale levels because it cannot divide the amount of emitted light into two equal smaller amounts.

Plasma display device and driving method thereof


A cap display for displaying a cap having a bill affixed to a fully opened crown. The cap display having transparent inner and outer shells which are shaped and sized such that the inner shell is smaller than the outer shell and such that the cap can be interposed between them with the cap's crown fully opened. Inner and outer crown portions of the shells generally conform to corresponding inner and outer crown surfaces of the crown of the cap. A shell securing mechanism for releasably securing together the inner and outer shells may be in the form of latching mechanisms disposed on an inner base on the inner shell and an outer base on the outer shell. The shells may include inner and outer risers between the inner and outer bases and the inner and outer bill portions so that a sign may be placed between the risers at front ends of the bill portions. The bases may further include corresponding base rims extending downward from peripheries of the bill and crown portions of the shells and a hook for hooking the cap display may also be incorporated, such as in the form of a tab attached to the outer shell and an aperture in the tab.

1. Field of the Invention
This invention relates to an apparatus for protectively storing and displaying sports and other types of caps such as baseball caps characterized by a crown and a bill. More particularly, the present invention is directed to an apparatus for holding these caps open and in a clear transparent display to protect and preserve the caps.
2. Description of Related Art
Sports caps such as baseball, golf, and racing caps and the like are collected by many people who wish to safekeep and display the caps in a manner that fully displays and protects the caps. Many companies give similar caps to customers to advertise and promote their products and people may also wish to display these caps. Such caps, hereinafter referred to as caps, are characterized by a front bill attached to a crown, wherein the crown is often, but not always, creased so as to allow a back half of the crown to be folded into itself. Protective holders have been developed to house a cap so that the form of the cap is retained during carriage and storage and some modicum of protection for the cap is provided. A form retaining holder or case for storing a visored cap is disclosed in U.S. Pat. No. 5,012,531 provides an upper shell and a lower shell, both shell portions sized and adapted to accommodate a visored type cap, such as used in the game of baseball, when the back portion of the cap is folded forwardly into the interior of the front portion of the cap. This holder interposes a cap having its crown half folded in on itself between upper and lower shells. The upper and lower shells are connected by a fastener and by a lip on the lower surface of the visor portion of the upper shell wherein the lip is adapted to engage the visor of lower shell therein. Though protection is afforded the cap, it is not displayed to its fullest extent, so that the outside and the inside of the crown is fully viewable. Since the crown of the cap is folded undesirable fold lines may develop which may decrease the monetary as well as the aesthetic value of the cap. Furthermore, there is no way to place this holder flat with respect to the bottom rim of the crown for the purpose of displaying the cap. Therefore, it is highly desirable to have a clear protective cap holder that fully displays and holds the form of the crown. Towards this end, the present invention was developed.


An electric powered skateboard having an electric motor which directly drives one of the wheels of the skateboard. The board is preferably controlled by a remote controller which smoothly accelerates the motor and also smoothly brakes the motor electrically. Preferably the direct drive is through a toothed belt and preferably a high torque/low RPM electric motor is used.

The field of the invention is powered skateboards and the invention relates more particularly to electric powered skateboards.
Skateboards are a popular way for young persons to travel. Although there are some gasoline powered skateboards in use, the overwhelming use of skateboards is simply foot power. Electric powered skateboards have been very limited in range and have been hard to control. One such skateboard is shown in U.S. Pat. No. 5,020,621 where a remote controlled unit is used to turn on and off the electric motor which is connected to one of the rear wheels by an O-ring belt. The board has a brake which presses against the rear wheels and may be also controlled by a Bowden cable from the cable connected remote control device. A remote controlled electric skateboard is shown in U.S. Pat. No. 5,330,026 which utilizes an electric motor between two of the wheels of the skateboard. An electric motor is connected to the wheels by sun and planet gear units. An on/off power to the motor is provided by a remote control device. A one-way bearing allows the board to coast when the motor is turned off.
U.S. Pat. No. 5,487,441 shows a motorized skateboard which is controlled by a foot switch. It may be either driven by a drive wheel in the center or the rear wheels may be driven by a drive shaft and gear arrangement. Once again, the motor is provided with an on and off controller.
There are numerous difficulties with these approaches. Because an electric powered skateboard includes both a motor and batteries, it becomes a relatively heavy unit and means must be provided to stop the unit so that it does not constitute a safety hazard to bystanders if the user loses control. While the device of U.S. Pat. No. 5,020,621 has a Bowden cable controlled brake, the use of a cable interferes with the freedom of movement on the board. In the event the user falls off of the board it is very likely that the cable will be pulled out of the unit by the inertia of the board. A motor which is merely turned on causes a substantial battery drain as it starts and also tends to provide a somewhat abrupt start. The result are boards which are limited in range and very difficult to control.

Remote control electric powered skateboard


A method for assembling at least two parts, connected by main and secondary definitive connections arranged in predetermined positions, includes: secondary definitive connections each housed in secondary definitive holes passing through the parts to be assembled, made independently of one another before the parts are assembled, main definitive connections each housed in main definitive holes passing through the parts to be assembled, made during the same operation while the parts are held in place by the secondary definitive connections.

FIG. 4 shows an assembly 10 of two parts 12.1, 12.2 connected by a plurality of definitive connections 14 each housed in first and second coaxial definitive holes 16.1, 16.2 passing through the first and second parts 12.1, 12.2, respectively.
Each definitive connection 14 has a diameter D0 substantially equal to (fitting clearance aside) the diameter of the first and second definitive holes 16.1, 16.2.
In accordance with known practice as shown in FIGS. 1 to 5, before the definitive connections 14 are put in place, the first and second parts 12.1, 12.2 are held in place in an assembly position by means of the temporary connections 18, also referred to as pins, as shown in FIG. 2.
For each of these temporary connections 18, the first and second parts 12.1, 12.2 comprise pre-holes 20.1, 20.2 the diameters d0 of which are smaller than the diameter of a definitive connection 14. As shown in FIG. 1, these pre-holes 20.1, 20.2 are made independently of one another before the first and second parts 12.1, 12.2 are assembled. These pre-holes 20.1 and 20.2 are positioned at certain positions of the definitive connections 14.
The number and the distribution of the temporary connections 18 are determined in such a way that the first and second parts 12.1, 12.2 do not become deformed and remain pressed closely against one another while the definitive connections 14 are being put in place. As shown in FIG. 5, the number of temporary connections 18 represents between 10 and 30% of the total number of definitive connections 14.
After the temporary connections 18 have been put in place, the definitive connections 14 are put in place starting with those closest to the temporary connections 18 and moving gradually further away.
For each definitive connection 14, the definitive holes 16.1, 16.2 are made during the same drilling operation. Thus, the definitive holes 16.1, 16.2 of each definitive connection 14 are perfectly coaxial and have the same diameter. After the drilling step, the definitive connection 14 is put in place in the definitive holes 16.1, 16.2, as shown in FIG. 3. The steps of drilling and putting in place are performed successively for each of the definitive connections 14.
When all of the definitive connections 14 have been put in place between the temporary connections 18, the latter are removed. The pre-holes 20.1, 20.2 are then drilled out to the diameter D0 of the definitive holes 16.1, 16.2 and then the final definitive connections 14 are put in place.
The steps of putting in place and removing the temporary connections 18, and of drilling the pre-holes 16.1, 16.2 out to the diameter of the definitive holes 16.1, 16.2, are relatively time-consuming, which tends to increase the cost of assembly.

Method for assembling at least two parts by means of main and secondary definitive connections and assembly obtained using this method


A method for automated computerized audio visual dubbing of a movie comprises (i) generating a three-dimensional head model of an actor in a movie, the head model being representative of specific facial features of the actor, and (ii) generating a three-dimensional head model of a dubber making target sounds for the actor, the dubber head model being representative of specific facial features of the dubber, as the target sounds are made. The method also comprises modifying at least a portion of the specific facial features of the actor head model according to the dubber head model such that the actor appears to be producing target sounds made by the dubber.

Movies are often played to an audience that is not familiar with the original language, and thus cannot understand the sound track of such movies. Two well known common approaches exist to solve this problem. In one approach sub-titles in typed text of the described language are added to the pictures, and the viewers are expected to hear the text in a foreign language and simultaneously to read its translation on the picture itself. Such reading distracts the viewers from the pictures and from the movie in general. Another approach is dubbing, where the original sound-track with the original text is being replaced by another sound-track with the desired language. In this case there is a disturbing mis-match between the sound-track and the movements of the mouth.
There have been some earlier attempts to overcome these disadvantages, none of which have been commercialized because of inherent principal difficulties which made the practical execution unrealistic. Thus, in U.S. Pat. No. 4,600,281 a method is described which performs the measurements of the shape of the mouth manually by a ruler or with a cursor, and corrects the mouth shape by moving pixels within each frame. As will be seen in the description of the invention, the method according to the present invention is inherently different and much superior in the following points: In the present invention the tracking of the shape of the mouth is done automatically and not manually. In the present invention changing the shape of the mouth is done by using a three-dimensional head model, for example like those described by P. Ekman and W. V. Friesen, (Manual for the Facial Action Unit System, Consulting Psychologist Press, Palo Alto 1977). In the present invention the mouth area of the actor is replaced using the mouth area of a reference similarity frame. In the present invention mouth status parameters of the dubber are substituted for mouth status parameters of the actor.
The U.S. Pat. No. 4,260,229 relates to a method of graphically creating lip images. This U.S. patent is totally different from the present invention: In the U.S. patent, speech sounds are analyzed and digitally encoded. In the present invention no sound analysis is done; nor is any required at all.
To make for better viewing of the audio visually dubbed movie, the present invention provides a computerized method wherein, in addition to replacing the sound track to the target text, the mouth movements of the actor are being automatically changed to match the target text. The new mouth movements are linguistly accurate and visually natural looking according to all of the observable parameters of the actor's face.

Method and system for the automatic computerized audio visual dubbing of movies

Yissum Research Development Company of the Hebrew University of Jerusalem


Methods for reducing wear in pumping components during fracturing operations. A coated proppant is used that causes less wear on the pumping components as the proppant is pumped into the wellbore. The proppant coating consists of a substrate having a coating thereupon which eliminates sharp edges on the substrate and functions as a lubricant to materially reduce mechanical erosion of the pumping components. The proppant substrate may consist of any of a number of materials, including sand, ceramic, resin coated sand, or resin coated ceramic particle. The coating preferably comprises one or more layers of one or more of the following materials (or the coating having low friction coefficients is part of a mixture of the coating): antimony trioxide, bismuth, boric acid, calcium barium fluoride, copper, graphite, indium, fluoropolymers (FTFE), lead oxide, lead sulfide, molybdenum disulfide, niobium dielenide, polytetrafluoroethylene, silver, tin, or tungsten disulfideor zinc oxide. The coating material may be applied to the substrate in a number of ways known in the art.

1. Field of the Invention
The invention relates generally to devices and methods for decreasing erosion damage to pumping components during downhole fracturing operations and for extending the life of the equipment used. In particular aspects, the invention relates to the composition of proppants used in fracturing operations.
2. Description of the Related Art
Fracturing operations are used to improve the flow of hydrocarbons from a subterranean formation and into a wellbore. Fracturing involves pumping of a fracturing fluid into the wellbore under extremely high pressure in order to induce fracturing in the formation rock immediately surrounding the wellbore. Fracturing increases the porosity in the formation and allows freer transmission of hydrocarbons through the formation and into the wellbore. Proppants are often included in the fracturing fluid. Proppants are generally particulate matter that is carried in a fracturing fluid. The proppant particles will reside within the small cracks and crevices of the formation that are created by the fracturing fluid, effectively permitting freer flow of fluids to continue after the fracturing agent is no longer pumped down the wellbore under pressure.
Currently, attempts are being made to increase the lengths of the zones that can be fractured and packed with proppant (i.e., increased zone lengths of about 300-400 feet are being considered). This increase in length dictates raising the treatment pump rate and proppant volume to be able to treat these lengthened zones. Unfortunately, increasing pump rate and proppant volume has significant deleterious effects upon the pumping components, including fluid conveying tubing, surface lines, chokes, manifolds, work strings, valves, and the downhole gravel pack liner assembly. Conventional proppants are extremely erosive and create tremendous wear upon pumping equipment during use. Erosion is usually a function of flow velocity and the amount of abrasive material being flowed. The erosion rate increases in direct correspondence with an increase in proppant volume (i.e., doubling the amount of proppant doubles the erosion rate). However, doubling the pump rate will increase the amount of erosion by a factor of four. As a result, operations that require both increased proppant amounts and increased flow rates are particularly problematic.
The components that tend to suffer the most severe damage during pumping of proppants are portions of the cross-over tool, including the cross-over port, cross-over housing, and lower extension. The casing and other elements on the gravel pack liner assembly where changes in interior casing diameter will also demonstrate significant wear.
To date, the conventional wisdom has been that measures taken to reduce erosion damage caused by the proppant might also tend to reduce the effectiveness of the proppant in the formation. For this reason, the inventors believe that they have not been used in conventional hydraulic fracturing operations or fracture packing operations wherein they are run through a cross-over tool. Instead, resin-coated proppants have been used primarily in hydraulic fracture stimulation treatments.
Resin-coated proppants are known materials. A coating method is described, for example, in U.S. Pat. No. 4,494,318 issued to Smillie. Further, such resin-coated proppants are available commercially from suppliers such as Santrol and Borden Chemical. However, conventional resin-coated proppants are not coated with the goal of reducing erosion and, as a result, do not perform this function optimally. Most conventional coatings are designed to provide improved strength to the proppant substrate, thereby, increasing the strength of the proppant particle within the formation fracture. Alternatively, coatings are engineered to permit the individual proppant particles to bond together to help control proppant flowback, which might occur as production fluid is flowed into the wellbore at an increased rate. An example of this type of proppant is described in U.S. Pat. No. 5,604,184 issued to Ellis et al.
The present invention addresses the problems of the prior art.

Use of coated proppant to minimize abrasive erosion in high rate fracturing operations


A combined adjustable pet ball-throwing rod includes a rod body. A front ball socket is fixed to a first end of the rod body. The front ball socket has a hollow connecting tube. A rear ball socket is detachable and slidably sleeved on the connecting tube. The front ball socket and the rear ball socket form an elastic ball socket. The connecting tube is provided with a retaining portion, the first end of the rod body is provided with a buckling portion, and the buckling portion is buckled in the retaining portion. The quantity of the retaining portions is two, and the two retaining portions are respectively located on two opposite side walls of the connecting tube. The quantity of the buckling portions is two, and one buckling portion is buckled in one retaining portion.

A pet ball-throwing rod is typically a pet toy including a rod body and a hemispherical socket arranged at the end of the rod body. In use, a toy ball is placed into the hemispherical socket, the dog owner grasps the rod body and throws the toy ball. Due to the acceleration given by the rod body, the toy ball is launched in the direction of the throw. Then, pets like a dog will pursue and fetch the ball, retrieve the ball, and bring it back to the owner, which can enhance the responsiveness and cooperativeness during use.
However, pet ball-throwing rods in the prior art have the following deficiencies. 1. The ball socket on one ball-throwing rod has a non-adjustable size and thus can only fit into the toy ball in a specific size, which has poor compatibility. 2. Ball sockets are mostly plastic and retain the toy balls by elastic deformation, however, the ball sockets are likely to become loose after long-term use and fail to retain the toy balls of equal size for continuous use.

Combined adjustable pet ball-throwing rod


A valve actuation mechanism includes rockers moved by a camshaft, each rocker being adapted to exert a valve opening force on at least a portion of a valve opening actuator of each cylinder, via an activation piston, housed in a bore of the rocker and movable with respect to the rocker under action of a fluid pressure raise in a chamber fluidly linked to the bore, from a first position to a second position, in which a cam follower of the rocker reads at least one auxiliary cam sector of a cam of the camshaft so as to perform an engine operating function. Each rocker includes a reset valve adapted to reduce fluid pressure in the chamber. The valve actuation mechanism includes, for each rocker, a reset cam profile adapted to open the reset valve when the activation piston has to be moved from its second position to its first position, and each reset valve includes a cam follower adapted to drive the reset valve as a function of the movement of the reset profile.

The invention concerns a valve actuation mechanism for an internal combustion engine on an automotive vehicle. The invention also concerns an automotive vehicle, such as a truck, equipped with such a valve actuation mechanism.
Automotive vehicles, such as trucks, often rely on an engine brake function to slow down in order, for example, to reduce wear of the friction brake pads and to prevent overheating of the friction brakes, particularly on downward slopes. It is known to perform engine brake by acting on the amount of gas present in the cylinders of the engine in two distinct phases. In a first phase, when the pistons are near a bottom dead center, one injects exhaust gases into the chambers of the cylinders so as to slow down the pistons when they move towards their high level. This is done by slightly opening at least a valve connected to an exhaust manifold, while exhaust gases are prevented to be expelled from the exhaust pipe and thereby at a certain pressure above atmospheric pressure. In the second phase, the gases which are compressed by the piston are expelled from the chamber of the cylinder when the piston is at or near its top dead center position in order to prevent an acceleration of the piston under effect of volcanic expansion of compressed gas. This is done by slightly opening a valve so as to expel gases from the cylinder. In most cases, the valve (or valves) which is (are) opened for the engine brake function is (are) a main exhaust valve. An engine brake system is described in document WO 9009514.
To perform these engine brake valves movements, also called engine brake valves lifts, the engine comprises, for each cylinder, a rocker acting, on the valves to open and close them. The rocker is acted upon by a rotating cam which has at least one lift sector to cause the lifting (opening) of the valve. If the valve is also an exhaust or an intake valve, the corresponding cam will comprise a main valve lift sector and one or several auxiliary valve lift sectors (also called main valve lift bump and auxiliary valve lift bump) When engine brake is needed, a cam follower surface of the rocker is moved in close contact with a cam of a camshaft moving the rocker so that the brake movements of the valve are obtained, when the cam follower interacts with the auxiliary valve lift sectors. In normal operating conditions of the engine, the valves should not perform these movements and the roller of the rocker is kept slightly remote from the cam so that the cam follower does not interact with the auxiliary valve lift sectors. The distance or clearance between the roller and the cam ensures that only the larger main lift sector on the cam, dedicated to the main exhaust event, causes an opening of the exhaust valve, but not one or several smaller auxiliary lift sectors dedicated to the engine brake function. This clearance is suppressed when engine brake is needed, by moving an activation piston of the rocker to make a close contact between the roller and the cam, so that engine brake dedicated lift sectors on the cam also cause an opening of the valve. An engine brake system having such valve actuation mechanism is described in WO-91/08381
In the case of a system where two valves are to be actuated, the piston can be in contact with the valves through a valve bridge.
When the engine brake valve opening(s) have been performed, a reset function is preferably to be performed. In other words, the activation piston needs to be moved towards its initial position in order to ensure that the valves are closed early enough before fuel admission, in order to prevent negative airflow by valve overlapping.
Engine brake systems generally comprise a control valve to direct pressurized control fluid pressure in a chamber adjacent to the piston to move the activation piston from its initial position to its engine brake actuation position. The control valve controls whether or not the engine brake function is activated. This control valve lets pressurized control fluid flow, at a pressure of for example 2 to 5 bars, towards each rocker as long as the engine brake function is needed. which typically lasts several seconds or tens of seconds during which the engine and the cam shaft may perform several hundreds or thousands of complete revolutions. In some systems, a check valve is provided to prevent any fluid flow out of the chamber. In some known systems, such as the one described in WO-91/08381, the check valve can nevertheless be forced to an open position, allowing the control fluid to escape the chamber when the engine brake is not needed. This is achieved when no control pressure is sent to the control valve. In known systems, there is only one control valve for several cylinders, so that it is not possible to use the control valve to empty the chamber to allow retraction of the piston, if such retraction is needed for a period of time inferior to one revolution of the camshaft.
It is known from U.S. Pat. No. 5,890,469 to use a rotating by-pass valve, housed inside the rocker and which opens or closes a fluid circuit in which a pressure raise provokes the outward movement of the piston. This by-pass valve is opened when the piston must be pushed back. The by-pass valve is rotated by a gear fixed to the rotation axis of the rocker. The solution of U.S. Pat. No. 5,890,469 is not entirely satisfying because, when a single valve engine brake technology is used, the reset valve opens the fluid circuit but at a time when no force is exerted on the piston to push it back in its normal position so that it tends to stay in a second position. At the time the valve springs exert a force on the piston, the fluid circuit is not opened, tending to prevent the piston from moving back to its first position.
It is desirable to provide a valve actuation mechanism in which, when a specific operation of the engine must he activated, the piston can be reset to its first position by using the by-pass valve especially with a single valve brake technology.
To this end, an aspect of the invention concerns a valve actuation mechanism for an internal combustion engine on an automotive vehicle, comprising rockers moved by a camshaft, each rocker being adapted to exert a valve opening force on at least a portion of a valve opening actuator of each cylinder, via an activation piston of the rocker, movable with respect to the rocker under action of a fluid pressure raise in a chamber, from a first position, to a second position, in which a cam follower of the rocker reads at least one auxiliary valve lift sector of a cam of the camshaft so as to perform an engine operating function, each rocker comprising a reset valve, adapted to release fluid pressure in the chamber. The valve actuation mechanism is characterized in that it comprises, for each rocker, a reset cam profile adapted to open the reset valve when the brake activation piston has to be moved from its second position to its first position, and in that each reset valve comprises a cam follower, adapted to drive the reset valve as a function of the movement of the reset profile.
Thanks to an aspect of the invention, the movement of the reset valve is not only dependant on the movements of the rocker and can be controlled by the movements of the reset cam or of the cam follower. This permits to open the reset valve exactly when needed and independently for each rocker. The fluid circuit is opened and the pressure reduced at the moment when the force of the springs which maintain the valves in their closed position is exerted on the activation piston. This permits to reduce the valve overlapping between the intake and the exhaust valves.
According to further aspects of the invention which are advantageous but not compulsory, such a valve actuation mechanism may incorporate one or several of the following features:                The reset profile is made on a reset cam of a camshaft of the valve actuation mechanism, and whereas the cam follower of the reset valve cooperates with the reset cam.        The reset cam is integral with or mounted on the camshaft which moves the rocker on which the reset cam is mounted.        The reset profile is made on the cam follower of the reset valve, and whereas the reset profile cooperates with the cam which is read by the cam follower of the rocker.        The cam follower of the reset valve comprises a lever arm.        The reset valve is rotatable around a longitudinal axis, and whereas the lever arm is fast in rotation with the reset valve.        The lever are is mounted on a shaft of the reset valve, said shaft protruding outside the rocker along a rotation axis of the reset valve.        Each rocker comprises a check valve movable between a first position, in which the check valve allows passage of fluid between the chamber and a fluid circuit feeding the chamber, and a second position, in which the check valve blocks passage of fluid between the chamber and the fluid circuit and whereas each reset valve is adapted to bypass the check valve and links the chamber and the fluid circuit feeding the chamber.        The reset valve comprises two parallel through holes and two parallel grooves linking the through holes with each other, and whereas the through holes communicate with the duct which bypasses the check valve when the reset valve is in its opened position.        The reset valve comprises a peripheral surface adapted to obturate the duct which bypasses the check valve when the reset valve is in its closed position.        The reset valve has a cylindrical form with a circular section.        The valve mechanism is an exhaust valve actuation mechanism.        The activation piston activates an exhaust gas recirculation function when it is in its second position.        The activation piston activates an engine brake function when it is in its second position.        The engine brake function is realized by opening two exhaust valves and whereas the valve opening force is exerted by the activation piston on the whole valve opening actuator.        The engine brake function is realized by opening one of two exhaust valves, whereas the portion of the valve opening actuator on which the valve opening force is exerted is a slider block, on which said valve is mounted and which is movable, with respect to the valve opening actuator, along the opening axis of said valve, and whereas each rocker comprises a finger adapted to exert, under rotation of the rocker, a valve opening force on the remaining portion of the valve opening actuator, on which the second valve is mounted.        The valve actuation mechanism is an intake valve actuation mechanism.
The invention also concerns an automotive vehicle, such as a truck, comprising a valve actuation mechanism as mentioned here above.

Valve actuation mechanism and automotive vehicle comprising such a valve actuation mechanism


A mobile power washer includes a heater module that is displaceable from an operative position, beneath a vented panel, to an access position enabling easy servicing or replacement of the module. The module includes a heater and a heat exchanger for heating water drawn from tanks for delivery at high pressure through a spray gun attached to a hose. A buffer tank is provided for retaining water heated by the heater for mixing with cold water from the tanks prior to further heating in the heat exchanger and delivery from the spray gun.

This invention relates to a mobile power washer for supplying pressurized hot water.
It is known to provide a high pressure power washer mounted on a trailer. A typical trailer mounted power washer may be powered by a petrol or diesel engine and be capable of delivering water supplied from a water tank through a hand held gun at a pressure of between 120 and 250 bar, and at a flow rate of between 12 and 18 liters per minute. Generally, the water supplied is untreated and therefore at ambient temperature, for example between 2° C. and 10° C.
However, hot water is sometimes required. For example, hot water is used on building sites for defrosting metal reinforcements prior to concreting and for cleaning tasks. Hot water is also required by the military, for example, for showering of soldiers in remote locations and for decontamination. There is therefore a need to provide a high pressure power washer capable of delivering hot water.
One known method of providing hot water on location is to fill the water tank of an existing trailer mounted power washer with hot water. However, this is generally inconvenient, because there may be no adequate source of hot water available, and the hot water, once in the tank of the power washer, may cool before use, particularly if the hot water source is some distance from the location where the hot water is required. Furthermore, the seals in existing washers are typically designed for use with cold water, and so may not be able to cope with hot water, for example, in excess of 50° C., and leaks may occur.
Alternatively, it is known to provide a machine providing high pressure hot water by passing a high pressure cold flow directly through a heated coil. However, machines of this type are typically large and heavy and are not particularly suitable for trailer mounting. They also require regular servicing and have a relatively short life expectancy.
WO2008/068490 discloses a trailer mounted power washer including an oil fired heater which heats a working fluid. Washing water passes through a heat exchanger where it is heated by the working fluid as the water passes from a tank to a pump and a delivery device such as a spray gun. When delivery of water is stopped, water flows through a bypass loop which incorporates a cooler to avoid friction induced overheating of the recirculating flow. A disadvantage of the power washer of WO2008/068490 is that there is a significant loss of heat from the bypass loop which cannot be recovered when delivery of water starts again.


In the present invention, even if a mobile terminal is close to a base station, the position of the mobile terminal is measured accurately. The disclosed method for calculating the position of a mobile terminal comprises: measuring the differences between the propagation distances of the signals on the channels between a plurality of base stations and the mobile terminal; determining if the mobile terminal is close to a base station; calculating the position of the mobile terminal by a common formula if it is determined that the mobile terminal is not in close proximity to any of the base stations; calculating the position of the mobile terminal in close proximity to a base station if it is determined that the mobile terminal is in close proximity to one of the base stations; and outputting the position of the mobile terminal calculated through either of the routines for calculating the mobile terminal position.

1. Field of the Invention
The present invention relates to a mobile terminal position calculation method, positioning system, and position calculation apparatus for measuring the position of a mobile terminal, using radio signals.
2. Description of Related Art
In a cellular telephony system, a method of calculating the present position of a mobile terminal, using signals transmitted from base stations to the mobile terminal has been proposed. For example, such a method is described in Patent Document Cited 1, JP-A No. 181242/1995.
In the method of measuring the present position of a mobile terminal, described in Patent Document Cited 1 (FIGS. 14 and 15), first, in an action of measuring differences between propagation distances 110, measurements are taken of differences between propagation distances of signals from the mobile terminal to multiple base stations. Concretely, a mobile-terminal 104 receives signals transmitted from cellular telephony base stations 101, 102, and 103. At this time, the mobile terminal 104 records the times at which the respective signals from the base stations have arrived at the mobile terminal. By calculating differences between the signal arrival times, time differences of signal propagation on the channels from the base stations to the mobile terminal T1−T2 and T3−T2 are calculated. Finally, the thus calculated propagation time differences are multiplied by light velocity and, thereby, differences between the propagation distances of the signals from the base stations to the mobile terminal D1−D2=c (T1−T2) and D3−D2=c(T3−T2) are calculated.
Next, in an action of calculating MT position by trilateration 111, the position of the mobile terminal is calculated, using the principle of trilateration. Concretely, a relation (equation) given in mathematical expression 1 between propagation distance differences D1−D2 and D3−D2 measured in the action of measuring differences between propagation distances 110 and the position of the mobile terminal (X, Y) is solved to obtain unknown values (X, Y) of the mobile terminal position. In mathematical expression 1, c represents light velocity and DN (N=1, 2, 3) represents distance from the mobile terminal to base station N.c(T1−T2)=D1−D2 c(T3−T2)=D3−D2 DN={(X−XN)2+(Y−YN)2}1/2(N=1, 2, 3)  [Mathematical expression 1]
Finally, in an action of outputting MT position 112, the mobile terminal position obtained by solving the equation of mathematical expression 1 is output as the result of position calculation.
Also, a method of calculating the present position of a mobile terminal, using signals transmitted from the mobile terminal and received by a plurality of base stations has been offered; for example, such a method using signals transmitted on a wireless LAN, disclosed in JP-B No. 260772/2002 corresponding to U.S. application Ser. No. 10/463,608, a prior application made by one of the present inventors.
In the foregoing method of prior art, as shown in FIGS. 14 and 15, firstly, the position of a mobile terminal cannot be obtained according to conditions of measurement. For example, if |c(T1−T2)|>D12 (where D12 is distance between base station 1 and base station 2) due to the influence of measurement errors of propagation time differences, the condition of forming a triangle among the mobile terminal, base station 1, and base station 2 is not satisfied and the equation of mathematical expression 1 does not give a real root. Especially, when the mobile terminal is in close proximity to a base station, the above condition |c(T1−T2)|>D12 is met by even a small degree of measurement errors and, therefore, the probability that the equation of mathematical expression 1 does not give a real root increases. In such cases, the position of the mobile terminal cannot be obtained by the method of prior art.
In general, the equation of mathematical expression 1 gives a plurality of position solutions. If the mobile terminal is in the proximity of a base station, there is the plurality of position solutions to the equation of mathematical expression 1 near the base station. Consequently, it is impossible to select a proper solution from the plurality of position solutions of the mobile terminal. Thus, in this case also, the position of the mobile terminal cannot be obtained.
As mentioned above, when the mobile terminal is positioned in the proximity of a base station, its position cannot be obtained, and an area where a position information service is offered is narrowed and convenience is lowered.
Secondly, a rise in the cost of the position information service may be induced. Because the equation of mathematical expression 1 is difficult to solve analytically, a method of obtaining a solution by repetitive arithmetic operations is generally taken. This method involves large amounts of arithmetic operations and it may be necessary to repeat arithmetic operations hundreds of thousand of times according to conditions, and a high load is applied to an arithmetic unit which executes position calculation. When making use of applications which tolerate position measurement errors within a few hundred meters, for example, weather forecasts and information services about road traffic congestion and the like, the arithmetic unit must have performance enough to cope with excessive loads and this causes a rise in the cost of mobile terminals and the cost of the position information service.

Method for calculating the position of a mobile terminal, positioning system, and position calculation apparatus


A device and method for endovascular radiation therapy that prevents unwanted damage to blood vessels during treatment is described. The device is adapted to prevent the emission end of an energy delivery device from coming into contact with the wall of a blood vessel. The device is also adapted to sense the inputted radiation power and prevent irradiation above a preselected power or energy level. Both features serve to prevent radiation, having an overly high intensity or power density, from impacting the vessel wall and causing a puncture.

1. Field of the Invention
Present invention relates to a device and method for treating venous disorders in general, and more particularly, an endovascular radiation therapy device with catheter to prevent damages in vascular wall.
2. Invention Disclosure Statement
Endovascular laser therapy is an effective and minimally invasive way to close diseased or abnormal blood vessels, and can be an effective alternative to more invasive treatments such as vein stripping, or chemical treatments. It can be effectively applied to treat various vascular abnormalities and diseases such as varicose veins.
Generally, endovascular laser therapy is accomplished by inserting a flexible optical fiber into a blood vessel and advancing it until the distal end (emission end) of the fiber is located near the area of the blood vessel that is to be closed. Typically, an introducer catheter/sheath is first inserted and advanced to a position near the desired location to be irradiated. This allows the optical fiber to be advanced into position while avoiding possible damage to the blood vessel or fiber during advancement.
Before irradiation, the optical fiber is positioned so that the distal end of the fiber is located in the introducer sheath at some short distance from the distal end of the sheath. The sheath is then partially withdrawn or the fiber is advanced to expose the fiber's distal end within the blood vessel. A radiation source such as a laser is then activated, and radiation is transmitted to the distal end of the fiber and is applied to the vessel wall. Generally, in order to close a desired length of the blood vessel, the optical fiber and sheath are slowly withdrawn while radiation is applied to the blood vessel.
Present methods and equipment for vein closing attempt to bring the vein walls into contact with the fiber optic device used. For example, in U.S. Pat. No. 6,398,777 by Navarro, a method for treating blood vessels using endovascular techniques to deliver laser energy is disclosed. Laser energy of 532 and 1064 nm is delivered into the vein using fiber optics and angiocatheter. Vein closing is achieved by contact of fiber with blood vessel wall. Such contact can result in vessel wall perforation.
Other state of the art treatments may allow for accidental contact between the fiber's distal end and the vessel wall. This can pose the risk of perforations if certain energy levels are exceeded or other unfortunate circumstances arise. Perforations result in bleeding into the surrounding tissue, causing post-treatment bruising and its associated discomfort.
There are numerous attempts to avoid contact with the vessel wall and regulate irradiation during intravascular laser treatments.
A balloon would be a prior art way to do this, but balloons are complex, prone to complication, and affect the amount of radiation incident on vessel wall. Also, a balloon may interfere with vein closure.
U.S. Pat. No. 5,167,686 by Wong discloses a catheter for delivering ablative radiant energy to a blood vessel to remove obstructive biological material. Radiation is applied in such a way that the energy density of the emitted beam drops sharply so that material beyond the working zone is not removed. This helps to avoid the risk of puncturing the blood vessel, as material is removed in limited layers. A fiber optic waveguide is extended through the lumen of the catheter, terminates in the catheter and is secured with an optical system located at the distal end of the catheter. The optical system both protects the optic fiber and shapes the beam to achieve the limited ablation desired.
U.S. Application No. 2007179486A1 by Welch et al. discloses a laser fiber optic for endovascular laser therapy; having a heat resistant insulated tip shield, covering the distal end of optic fiber. The insulative tip shield has echogenic qualities to increase ultrasound reflectivity. The distal tip of the optical fiber of ½ to 2 cm is not covered by protective shield. The chance of exposed tip getting carbonized when in contact with blood cells can cause thermal destruction to tissue, reduced output and also can damage the fiber tip.
U.S. Pat. Nos. 7,273,478 and 7,559,329 by Appling disclose an endovascular treatment device for use with an optical fiber, featuring a spacer to position the distal end of the fiber away from the inner wall of the blood vessel to evenly distribute radiation to avoid perforation or uneven closure. The spacer is initially in an "undeployed state" during insertion, and a "deployed state" where it positions the optical fiber for irradiation. The spacer may include a plurality of ribs which radially expand to position the fiber. The spacer may be incorporated into a catheter or attached to the optical fiber.
US Application 2008/0021527 A1 by Hennings et al. provides an apparatus and method for treatment of varicose veins. The improved method used reduces the amount of heat, induces coagulum at the fiber tip and prevents heat damage. This invention uses infrared radiation in the range of 1.2-2.7 μm to irradiate endothelial cells and collagen of the vein wall thus permanently occluding the vessel. A non-hemoglobin absorbing wavelength e.g. 1320 nm with higher energy per pulse is used to avoid formation on coagulum at the fiber tip. It also proposes the use of a silica clad fiber and a spacer to prevent coagulum at the fiber tip. Disadvantages to this invention include the need of movable means to center the fiber, which may cause improper position if the spacer does not deploy properly. Also, because the spacer is in contact with the vessel wall, it may become damaged or deformed while the fiber and spacer are withdrawn during irradiation.
It is an object of the present invention to provide a simplified device for endovascular radiation treatments that avoids puncturing the vessel wall by preventing contact between the emission means of an optical fiber and the vessel wall. The present invention addresses this need.

Contact free and perforation safe endoluminal laser treatment device and method


Provided are terminal-free connectors for flexible interconnect circuits. A connector for connecting to a flexible interconnect circuit comprises a base comprising a housing chamber defined by at least a first side wall and a second side wall that are oppositely positioned about the base. A circuit clamp is coupled to the base via a first hinge, and is configured to move between a released position and a clamped position. A cover piece is coupled to the base via a second hinge, and is configured to move between an open position and a closed position. The circuit clamp is configured to secure the flexible interconnect circuit between the base and the circuit clamp in the clamped position. One or more protrusions on the circuit clamp are each configured to interface with a socket within the first or second side wall to secure the circuit clamp in the clamped position.

Electrical power and control signals are typically transmitted to individual components of a vehicle or any other machinery or system using multiple wires bundled together in a harness. In a conventional harness, each wire may have a round cross-sectional profile and may be individually surrounded by an insulating sleeve. The cross-sectional size of each wire is selected based on the material and current transmitted by this wire. Furthermore, resistive heating and thermal dissipation is a concern during electrical power transmission requiring even larger cross-sectional sizes of wires in a conventional harness. Additionally, traditional connectors for joining the interconnect circuits with the individual components may be rather bulky, heavy, and expensive to manufacture. Yet, automotive, aerospace and other industries strive for smaller, lighter, and less expensive components.
What is needed are terminal-free connectors and circuits comprising terminal-free connectors that are lighter and cheaper to manufacture, and which may be configured for flexible interconnect circuits that do not include traditional round cross-sectional profiles.

Terminal-free connectors and circuits comprising terminal-free connectors


A spreading code generating device for a Code Division Multiple Access (CDMA) communication system. The device comprises a PN (Pseudorandom Noise) code sequence generator for generating PNi and PNq sequences; an orthogonal code generator for generating first and second orthogonal codes which perform Differential Phase Shift Keying (DPSK) state transitions at intervals of at least two chips; and a spreading code generator for generating spreading codes Ci and Cq by mixing the PNi and PNq code sequences with the first and second orthogonal codes such that a present phase of the spreading codes Ci and Cq alternately makes Quadrature Phase Shift Keying (QPSK) and DPSK state transitions with respect to a previous phase of the spreading codes Ci and Cq.

This application claims priority to an application entitled xe2x80x9cDevice and Method for Generating Spreading Code and Spreading Channel Signals Using Spreading Code in CDMA Communication Systemxe2x80x9d filed in the Korean Industrial Property Office on Sept. 29, 1998 and assigned Ser. No. 98-40507, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to a spread spectrum device and method for a CDMA communication system, and in particular, to a device and method for generating spreading sequences.
2. Description of the Related Art
Code Division Multiple Access (CDMA) mobile communication systems have developed from an existing mobile communication standard which mainly provides voice service into the IMT-2000 standard which can provide not only voice service but also high speed data transmission service. For example, the IMT-2000 standard can provide high quality voice, moving picture, and Internet search services. In CDMA communication systems, communication links between a base station and a mobile station include a forward link for transmitting from the base station to the mobile station and a reverse link for transmitting from the mobile station to the base station.
In CDMA communication systems, the reverse link typically employs a PN (Pseudorandom Noise) code complex spreading scheme as the spread spectrum method. However, the PN code complex spreading scheme has a problem when the power amplifier has an increase in the peak-to-average power ratio (PAR) because of user data. In the reverse link, an increase in the peak-to-average ratio of transmission power causes xe2x80x98re-growth,xe2x80x99 described below, which affects the design and performance of the power amplifier in the mobile stations. The characteristic curve of the power amplifier in the mobile station has a linear area and a non-linear area. When the transmission power of the mobile station increases, the signal of the mobile station will enter the non-linear area, interfering with the frequency areas of other users, which is called the xe2x80x9cre-growthxe2x80x9d phenomenon. In order not to interfere with the frequency areas of the other users, the cell area should be reduced in size and mobile stations in a cell area should transmit to the corresponding base station at a lower transmission power. Therefore, there is a need for a spreading method which decreases PAR while minimizing the degradation of bit error rate (BER) performance which affects the overall system performance.
A description of the PN complex spreading scheme will be made herein below with reference to a transmitter in a conventional CDMA communication system.
FIG. 1 illustrates a channel transmitter, including a spread spectrum device, for a CDMA communication system. As illustrated, the channel transmitter includes an orthogonal spreader 101, a complex multiplier 102, a PN sequence generator 103 and a lowpass filtering and modulation part 104.
Referring to FIG. 1, the transmission data of each channel is applied to the orthogonal spreader 101 after channel coding, repetition and interleaving through corresponding channel coders (not shown). The orthogonal spreader 101 then multiplies the input channel data by a unique orthogonal code assigned to the corresponding channel to orthogonally spread the input channel data. Walsh codes are typically used for the orthogonal codes. The PN sequence generator 103 generates spreading sequences for spreading the transmission signals of the respective channels. PN sequences are typically used for the spreading sequences. The complex multiplier 102 complex multiplies the signals output from the orthogonal spreader 101 by the spreading sequences output from the PN sequence generator 103 to generate complex spread signals. The lowpass filtering and modulation part 104 baseband filters the complex spread signals output from the complex multiplier 102 and then converts the baseband filtered signals to RF (Radio Frequency) signals.
FIG. 2 is a detailed diagram illustrating the channel transmitter of FIG. 1 for the reverse link.
Referring to FIG. 2, the transmission data of each channel undergoes channel coding, repeating, channel interleaving and binary mapping in such a manner that a signal xe2x80x9c0xe2x80x9d is mapped to xe2x80x9c+1xe2x80x9d and a signal xe2x80x9c1xe2x80x9d to xe2x80x9cxe2x88x921xe2x80x9d, prior to being input to the corresponding channel. The data of the respective channels is multiplied by unique orthogonal codes in multipliers 111, 121, 131 and 141. In FIG. 2, channel transmitters include a pilot channel transmitter, a control channel transmitter, a supplemental channel transmitter and a fundamental channel transmitter. As stated above, Walsh codes are typically used for the orthogonal codes that spread the respective channels. The orthogonally spread data of the control channel, the supplemental channel and the fundamental channel is multiplied by gains appropriate for each channel by the first to third gain controllers 122, 132 and 142. The channel data is added by binary adders 112 and 133 and then applied to the complex multiplier 102. Herein, the outputs of the binary adders 112 and 133 will be referred to as xe2x80x9cchannelized dataxe2x80x9d.
The complex multiplier 102 multiplies the outputs of the adders 112 and 133 by spreading codes to perform spreading. As stated above, the PN codes output from the PN sequence generator 103 are used for the spreading codes. The PN codes input to the complex multiplier 102 have a rate equal to a chip rate and may have a value comprised of xe2x80x9c+1xe2x80x9d and xe2x80x9cxe2x88x921xe2x80x9d. Herein, unless otherwise stated, the PN codes are assumed to have a value of xe2x80x9c+1xe2x80x9d and xe2x80x9cxe2x88x921xe2x80x9d.
With regard to the complex multiplier 102, channelized data output from the adder 112 is applied to multipliers 113 and 143, and channelized data output from the adder 133 is applied to multipliers 123 and 134. Further, a spreading code PNi output from the PN sequence generator 103 is applied to the multipliers 113 and 123 and a spreading code PNq output from the PN sequence generator 103 is applied to the multipliers 134 and 143. In addition, outputs of the multipliers 113 and 134 are subtracted from each other by an adder 114 and then applied to a first lowpass filter 115; and outputs of the multipliers 123 and 143 are added to each other by an adder 135 and then applied to a second lowpass filter 136.
A real signal out of the outputs from the binary adder 114 is input to the first lowpass filter 115 and an imaginary signal is input to the second lowpass filter 136. Output signals of the lowpass filters 115 and 136 are gain controlled by fourth and fifth gain controllers 116 and 137, respectively, then modulated, added together, and transmitted through a transmission channel. The lowpass filtering and modulation part 104 lowpass filters and modulates the output data of the binary adders 114 and 135, and then outputs the modulated data from a binary adder 118.
Several methods have been proposed for reducing the PAR of the signals output from the first and second lowpass filters 115 and 136, and those methods are based on how the PN sequence generator 103 generates the spreading codes PNi and PNq. In general, the peak-to-average power ratio PAR depends on both zero-crossings, which occur when the signs of PNi and PNq are simultaneously changed, and hold-phase-state, which occurs when the signs of both PNi and PNq are not changed. More specifically, zero-crossings (ZC) happen when, for example, an initial state in the first quadrant transitions to the third quadrant, causing a phase shift of xcfx80. Further, a hold-phase-state, or xe2x80x9chold,xe2x80x9d happens when, for example, an initial state in the first quadrant remains in the first quadrant, causing no phase shift.
As stated above, in conventional QPSK (Quadrature Phase Shift Keying) spreading, a phase of the generated spreading codes can transition from the first quadrant to any of the second, third and fourth quadrants according to the value of the PN codes. Accordingly, when the conventional spreading code generation method is used, the PAR performance may deteriorate due to the zero-crossing phenomenon and the hold-phase-state phenomenon. Therefore, in a CDMA communication system, during spreading, the PAR is increased depending on the PNi and PNq.
It is, therefore, an object of the present invention to provide a device and method for generating a spreading sequence which can decrease the peak-to-average power ratio without degrading BER performance in a CDMA communication system.
It is another object of the present invention to provide a device and method for repeatedly generating a QPSK and xcfx80/2-DPSK (Differential Phase Shift Keying) phase-shifted PN sequence as a spreading sequence in a CDMA communication system.
It is further another object of the present invention to provide a device and method for generating a QPSK, xcfx80/2-DPSK, and zero-crossing or hold phase-shifted PN sequence as a spreading sequence in a CDMA communication system.
It is still another object of the present invention to provide a device and method for generating a spreading sequence which alternately performs a DPSK phase shift and a QPSK phase shift by mixing a PN sequence with a specific orthogonal code in a CDMA communication system.
It is yet another object of the present invention to provide a device and method for generating a DPSK and QPSK phase-shifted spreading sequence by mixing a generated PN sequence with a previous spreading sequence, and generating a spreading sequence which alternately performs a DPSK phase shift and a QPSK phase shift by selecting a generated spreading sequence, in a CDMA communication system.
It is yet another object of the present invention to provide a device and method for generating a spreading sequence which repeats the pattern of a QPSK phase shift, a DPSK phase shift, a zero-crossing or hold (ZCH), and a DPSK phase shift by mixing a PN sequence with a specific orthogonal code in a CDMA communication system.
It is yet another object of the present invention to provide a device and method for generating a QPSK phase shift, a DPSK phase shift, a 180xc2x0 or 0xc2x0 phase-shift (ZCH) spreading sequence by mixing a generated PN sequence with a previous spreading sequence, and generating a spreading sequence which repeatedly performs QPSK, DPSK, zero-crossing or hold, and DPSK phase shifts by selecting the generated spreading sequence, in a CDMA communication system.
It is yet another object of the present invention to provide a device and method for alternately generating a QPSK and xcfx80/2-DPSK phase-shifted PN sequence as a spreading sequence, and spreading/despreading a channel signal using the generated spreading sequence, in a CDMA communication system.
It is yet another object of the present invention to provide a device and method for generating a QPSK, xcfx80/2-DPSK, zero-crossing or hold phase-shifted PN sequence as a spreading code, and spreading/despreading a channel signal using the generated spreading sequence, in a CDMA communication system.
To achieve the above and other objects, a spreading code generating device is provided for a CDMA communication system. The device is comprised of a PN sequence generator for generating PNi and PNq sequences; an orthogonal code generator for generating first and second orthogonal codes which perform DPSK state transitions at intervals of at least two chips; and a spreading code generator for generating spreading codes Ci and Cq by mixing the PNi and PNq sequences with the first and second orthogonal codes such that the present phase of the spreading codes Ci and Cq alternately generates QPSK and DPSK state transitions with respect to the phase of the previous spreading codes Ci and Cq.

Device and method for generating spreading code and spreading channel signals using spreading code in a CDMA communication system


An improvement in the process of transporting biological materials into living cells by bombarding the cells with microprojectile particles coated with biological material. In the improved process prior to coating of the particles such as tungsten beads for example, with biological material such as DNA, the particles are first pretreated with a strong inorganic acid such as nitric acid.

This invention relates to an improved process for transferring biological materials such as nucleic acid into the cytoplasm of living cells. With the rapid advancement of recombinant DNA technology, there is a wide-ranging need for biologists to transfer biologic substances from one cell to another, and to transfer synthetic biological material into living cells to exert their activity therein. Such materials can include biological stains, proteins (antibodies or enzymes), and, most commonly, nucleic acids genetic material (either RNA or DNA). Most of the techniques used are painstakingly slow and use methods which transport materials into, at most, only a few cells at a time. More recently, there has been developed a particle bombardment process which utilizes a particle gun, as described in Sanford, et al., 1987, "Delivery of Substances Into Cells and Tissues Using A Particle Bombardment Process," Journal of Particle Science and Technology 5:27-37, the disclosures of which are hereby incorporated herein by reference.
An earlier invention of one of the joint inventors, Dwight Tomes, relates to an improved particle gun which uses a gun having a rifled barrel. The disclosure of particle gun bombardment and the method of transport of biological materials such as DNA into living cells as described in Tomes, IMPROVED PARTICLE GUN, filed May 12, 1989, Ser. No. 07/351,075, now abandoned, is incorporated herein by reference.
The effectiveness of particle transport is, of course, measured by the ability of living cells into which the transported particles have been inserted to pick up and express the biological material. This, of course, depends upon a wide variety of conditions. The less the expression, the less successful the transport. Correspondingly, the more successful the expression of the living cells i.e. the extent that they pick up and express the transported biological material, the better the nucleic acid insertion experiments.
In the particle gun technique the biological material (DNA for example) is mixed with the carrier. The carrier generally is comprised of a substantially inert metal in the form of small beads which function as microprojectiles. Generally, the microprojectiles have a diameter within the range of about 1 micron to about 4 microns. These beads can be made from tungsten, palladium, platinum or gold or an alloy thereof. Tungsten is preferred for reasons of economics. However, tungsten generally does not give as good or as successful transport and expression as does gold unless used with the parent pre-treatment process. Beads can generally range from about 1 micron to about 1.5 microns in diameter.
In the most preferred process, the beads are mixed with a small amount of biological material such as DNA or RNA. This is mixed with calcium chloride and a certain amount of polyamine is added.
Generally the ranges of each of these ingredients should be as follows:
Twenty-five .mu.l of tungsten particles at a concentration of 15-400 mg in 2 ml sterile water are placed in a sterile 10 ml centrifuge tube and agitated to suspend the beads. The preferred amount of beads is 375 mg/2 ml. Twenty-five .mu.l of the suspended tungsten beads are placed in an Eppendorf tube and DNA is added at a concentration of 1 .mu.g/.mu.l with the amount varying between 1 .mu.land 20 .mu.l, the preferred amount being 10 .mu.l. A calcium chloride solution of 25 .mu.l and having a concentration between 1.0-4.0M, preferably 2.5M is mixed with the DNA/bead mixture.
While addition of spermidine to the biological material/microprojectile combination has been previously employed, it has now been more broadly discovered that addition of a variety of polyamines to mixtures of tungsten beads and DNA or RNA in preparing microprojectiles significantly improve rates of transformation. While not intending to be limited by theory, it is believed that the polyamine improves delivery of biological material to the cells in this process by improving adherence of the materials to the microprojectile beads. Suitable polyamines have been found to include, for example, spermine, spermidine, caldine, thermine, and the like. The preferred polyamine, spermine, has been found to be superior to the previously disclosed spermidine additive. Accordingly, at this point a polyamine, preferably spermine, in an amount of 10 .mu.l and a concentration between 0.05M and 0.5M, preferably at 0.1M is added followed by finger vortexing. This mixture is allowed to stand for 10 minutes prior to centrifugation for one to two minutes at 9,000 rpm. Centrifugation may be used but is not required. The microprojectile mixture forms a pellet at the bottom of the Eppendorf tube. Before use, supernatant is withdrawn from the tube to provide a final volume of 30 .mu.l.
The DNA/bead mixture is sonicated briefly to suspend the microprojectiles prior to use. The suspended microprojectiles carrying the biological material are transferred to the forward end of the macroprojectile by micropipette in aliquots of 1-5 .mu.l, with 1.5 .mu.l preferred.
Among the difficulties which have been encountered in the past in using microprojectiles is that large masses of DNA would clump onto the particles which make it harder to separate and also make it more likely that the particles will kill the cells during bombardment.
As can be seen, there is therefore a continuing need to develop microprojectile bombardment processes for improved transformation of biological materials into living cells by a process which will not kill the cells during bombardment, by a process which can utilize inexpensive tungsten beads, and by a process can use such lesser expensive beads and still achieve a highly successful transformation and expression. This invention has as its primary objective the fulfillment of this need.

Pretreatment of microprojectiles prior to using in a particle gun


An automatic temperature controlled shower head assembly includes a housing having an inlet port and a plurality of outlet ports to permit water to flow therethrough; a valve device operatively associated with the input port controls the volume of water flowing through the assembly depending upon the position of a temperature responsive drive mechanism mounted within the housing in operative relationship to the valve device. The drive mechanism detects temperature changes of the flowing water and acts in response to these temperature changes, within a predetermined range, wherein the valve device is moved to automatically vary the volume of water flowing from the outlet ports depending upon the temperature of the water.

1. Field of the invention
The present invention relates to shower heads, and more particularly, to a shower head valve that automatically reduces the flow of water when the water temperature flowing therethrough exceeds a certain predetermined temperature range.
2. Discussion of the Relevant Art
The prior art abounds with devices that attempt to protect individuals from being scalded when taking a shower both at home and at motels, hotels, etc. Turning the shower "ON" with the hot water valve in the open position may cause a person using the shower to be scalded before the water can be turned "OFF" or cold water added. The present invention automatically prevents this from happening and also conserves energy. The instant invention prevents a young child, for example, from inadvertently turning "ON" the shower at full hot and being injured thereby. This is prevented, since the shower head valve assembly will automatically close down the water flow within in a certain temperature range until the safe temperature is reached for full water flow.
Another feature of the present invention is that when a sudden drop in the cold water pressure occurs, resulting in a reduction of cold water volume, the ratio of cold water to hot water changes and the water temperature becomes extremely hot very quickly. The present invention overcomes this problem by reducing the water flow so that the user may take steps to preventing himself from being scalded. If the cold water thereafter returns to normal the valve assembly will gradually open and let the water flow return to its previously selected setting.
One device that attempts to overcome this problem is disclosed in U.S. Pat. No. 5,368,227 issued to McGinnis on Nov. 29, 1994. However, the device disclosed therein provides an auxiliary path for the water flow, should it become excessively hot, which could still harm the user thereof.
The patent to Kolt issued as U.S. Pat. No. 4,402,455 on Sep. 6, 1983 appeared to solve the problem but was subject to water temperature variations with changes in water pressure beyond a narrow range.
Therefore, it is an object of the present invention to provide an automatic temperature controlled shower head assembly that limits the temperature of the water flowing therethrough.
It is another object of the present invention to provide an automatic temperature controlled shower head assembly that opens and closes without the use of any electrical energy.
It is yet another object of the present invention to provide an automatic temperature controlled shower head assembly that is safe for children to use.
The foregoing and other objects and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawing, which forms a part hereof, and which is shown by way of illustration with specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and structural changes may be made without departing from the spirit and scope of the instant invention.

Automatic temperature controlled shower head assembly


The metallic sheet for shadow mask comprises a Fe-Ni alloy sheet having mainly of Fe and Ni; degrees of planes on a surface of the alloy sheet, the degree of {331} plane being 14% or less, the degree of {210} plane 10% or less and the degree of {211} plane 10% or less; and a ratio of degrees of planes which is {210}/[{331}+{211}] being 0.2 to 1.. Another thin metallic sheet for shadow mask comprises a Fe-Ni alloy sheet having mainly of Fe and Ni; degrees of planes on a surface of the alloy sheet, that of {111} plane being 5% or less, that of {100} plane 50 to 93%, that of {110} 24% or less, that of {311} plane 1 to 10%, that of {331} 1 to 14%, that of {210} plane 1 to 10% and that of {211} plane 1 to 10%; a ratio of degrees of planes which is [{100}+{311}+{210}]/[{110}+{111}+{331}+{211}] being 0.8 to 20.

1. Field of the Invention
The present invention relates to a thin metallic sheet for a shadow mask having high etching performance and particularly to a shadow mask thin metallic sheet made of Fe-Ni alloy suitable for a color cathode ray tube.
2. Description of the Related Art
Recent up-grading trend of color television toward high definition TV has employed Fe-Ni Invar alloy containing 34-38 wt. % of Ni as the alloy for the shadow mask to suppress color-phase shift. INVAR alloy is a low-expansion alloy containing 36% nickel, 0.35% manganese and the balance iron with carbon. The Fe-Ni Invar alloy which contains 34-38 wt. % of Ni is hereinafter referred to as "conventional Fe-Ni alloy". Compared with low carbon steel which has long been used as a shadow mask material, the conventional Fe-Ni alloy has considerably lower thermal expansion coefficient. Accordingly, a shadow mask made of conventional Fe-Ni alloy raises no problem on color-phase shift coming from the thermal expansion of shadow mask even when an electron beam heats the shadow mask.
Common practice of making a shadow mask from a thin alloy sheet includes the following steps. The alloy sheet is photo-etched to form the passage-holes for the electron beam on the thin alloy sheet for shadow mask. The passage-hole for electron beam is hereinafter referred to as "hole". The thin alloy sheet for shadow mask perforated by etching is hereinafter referred to as "flat mask". (2) The flat mask is subjected to annealing. (3) The annealed flat mask is pressed into a curved shape of cathode ray tube. (4) The pressformed flat mask is assembled to a shadow mask which is then subjected to blackening treatment. However, the Invar alloy of conventional Fe-Ni is inferior to the shadow mask material of low carbon steel in terms of etching performance to prepare many micropores.
Conventional Fe-Ni INVAR alloy is considerably weak in corrosion resistance to etching liquid and has large crystal grain size. Compared with mild steel. The result is that light penetrating through the micropores formed by the etching process results in a blurred periphery of the pierced holes of the flat mask. Also, the brightness of light penetrated through the flat mask of conventional Fe-Ni Invar alloy is inferior to that of mild steel. Such a degraded brightness of flat mask is a serious disadvantage in the recently emphasized demand for bright screens. To cope with the problem on etching performance, the prior art 1 and the prior art 2 have been presented.
The prior art 1 is introduced in JP-B-H2-9655 (the term "JP-B-" referred to herein signifies "examined Japanese patent publication"). The patent describes that precise and uniform etching is performed by aggregating {100} plane by 35% or more onto the surface of thin Invar alloy sheet. The flat mask prepared by the method, however, still has hazy photo-irregularity and weak brightness of flat mask, which are left as quality issues.
The prior art 2 is described in JP-A-S62-2437825 (the term "JP-A-" referred to herein signifies "unexamined Japanese patent publication"). In the patent, an aggregated {100} plane onto the rolled plane of Fe-Ni Invar alloy gives the surface roughness Ra in a range of 0.2 to 07 .mu.m and Sm at 100 .mu.m or below, and gives the crystal grain size number of No. 8.0 or above. The etching speed is improved and also the production of blurred periphery of pierced hole is reduced. Still, the flat mask prepared by this method is weak in brightness, which is left as an issue. The finest grain size number described in the patent is No. 10.0 which corresponds to 11 .mu.m of grain size. The grain size (B), (.mu.m), is calculated from the grain size number (A) by the following equation. EQU (A)=16.6439-6,6439.times.log{(B)/1.125}


An apparatus for outputting data of a semiconductor memory apparatus, which is capable of varying the slew rate and the data output timing, includes a bias generator that generates a bias having a level corresponding to a set value, a slew rate controller that controls a pull-up slew rate or a pull-down slew rate of input data on the basis of the bias generated by the bias generator, and a data outputting unit that outputs data on the basis of the slew rate controlled by the slew rate controller. Therefore, it is possible to satisfy various operational conditions without changing the structure of the circuit and to correspond rapidly and appropriately with a change of the system, which enables the applied range of the products to be extended.

1. Technical Field
The present invention relates to a semiconductor memory apparatus, and in particular, to an apparatus and a method for outputting data of a semiconductor memory apparatus.
2. Related Art
FIG. 1 shows an apparatus for outputting data of a semiconductor memory apparatus according to the related art. Referring to FIG. 1, the data outputting apparatus comprises a predriver 10 and a main driver 20. The predriver 10 includes a pull-up circuit 11 that controls a slew rate due to pulling-up of input data and a pull-down circuit 12 that controls a slew rate due to pulling-down of input data, and the main driver 20 includes transistors P1 and N1 connected between a power terminal and a ground terminal.
The pull-up circuit 11 and the pull-down circuit 12 have the same structure. In detail, as shown in FIG. 2, the pull-up circuit 11 and the pull-down circuit 12 have an inverter structure in which transistors P2 and N2 are connected between a power terminal and a ground terminal, and a resistor R10 is connected to an output terminal.
The operation of the above-mentioned related art will be described.
When data is input to the predriver 10, an up-signal and a down signal each having a predetermined gradient are output by the pull-up circuit 11 and the pull-down circuit 12 of the predriver 10.
In this state, when the data is shifted from a high level to a low level, an off-delay of the transistor P1 of the main driver 20 is controlled by raising the level of the up-signal, and an on-delay of the transistor N1 of the main driver 20 is controlled by lowering the level of the down-signal of the transistor N1.
In contrast, when the data is shifted from a low level to a high level, an on-delay of the transistor P1 of the main driver 20 is controlled by lowering the level of the up-signal, and an off-delay of the transistor N1 of the main driver 20 is controlled by raising the level of the down signal.
The pull-up slew rate and the pull-down slew rate are controlled as described above.
However, according to the related art, a rising delay and a falling delay of the up signal and the down signal, which are the main parameters for controlling the slew rate are determined by the resistor R10 and turn on-resistances of the transistors P2 and N2.
Therefore, the data outputting apparatus of a semiconductor memory apparatus has the following problems.
It is not applicable for a system that requires a high speed operation because the slew rate is fixed by the resistor and the turn on-resistance of the transistors such that the slew rate cannot be varied.
Further, the applicable range is excessively limited due to the fixed slew rate and the fixed data output timing.

Apparatus and method for outputting data of semiconductor memory apparatus