A photoelectric conversion apparatus is constructed in such an arrangement that a light-source substrate, in which a light source is arranged, and a photosensor are directly mounted on a frame bearing the strength of the main body of an information processing apparatus, the above light-source substrate may be unified with an electric circuit substrate of the information processing apparatus, and the electric circuit substrate has the photosensor and the light source, whereby the size and weight of the apparatus can be further decreased, the freedom of design and engineering design can be improved, and simplification of assembling and improvement in reliability can be achieved.

1. Field of the Invention
The present invention relates to photoelectric conversion apparatus and information processing apparatus, and more particularly to photoelectric conversion apparatus suitably applicable to input portions in facsimile devices, image readers, scanners, copiers, electronic blackboards, etc., which are information processing apparatus for reading image information while relatively moving the original or the like subjected to image reading in close contact on a primary line sensor, and the information processing apparatus therewith.
2. Related Background Art
Recently, in order to further decrease the size or further enhance the performance as to information processing apparatuses such as facsimile devices, image readers, etc., elongate line sensors that can be used in a 1:1 optical system have been developed as photoelectric conversion apparatuses for information processing apparatuses. In order to further decrease the size and the cost, photoelectric conversion apparatus and information processing apparatus have been developed for directly detecting reflected light from the original by a sensor without using a 1:1 fiber lens array but through a transparent spacer of glass or the like.
FIG. 1 is a diagrammatic, perspective view of a conventional photoelectric conversion apparatus, and FIG. 2 is a diagrammatic cross section thereof when the photoelectric conversion apparatus is cut along 2--2 in FIG. 1. In FIG. 1 and FIG. 2, reference numeral 1 designates a photosensor, 101 a sensor substrate, 102 photoelectric conversion elements, 103 a wiring part, 104 a mount plate, and 105 a transparent protection layer.
As shown in FIG. 1 and FIG. 2, a plurality of photoelectric conversion elements 102 are arranged in line on the sensor substrate 101, and the transparent protection layer 105 comprised of a thin glass plate or the like is provided on the photoelectric conversion elements 102 in order to protect the photoelectric conversion elements 102 and to act as a spacer between the photoelectric conversion elements 102 and the original Output signals from the photoelectric conversion elements 102 are arranged as capable of being output to the outside through the wiring part 103. These sensor substrate 101, photoelectric conversion elements 102, wiring part 103, and transparent protection layer 105 are incorporated with the mount plate 104, thus composing the photoelectric conversion apparatus 1. The mount plate 104 is made of an easily-moldable material such as a resin, and is molded except for an optically transparent portion of the member.
The structure of a photoelectric conversion element used in such a photoelectric conversion apparatus is next explained briefly referring to FIG. 3.
FIG. 3 is a diagrammatic cross section for illustrating an example of the photoelectric conversion element. In FIG. 3, reference numeral 170 is a substrate, 171 a light-shielding layer, for example, of aluminum or chromium, 172 an insulator layer, for example, of silicon nitride, 173 a semiconductor layer, for example, of i-type amorphous silicon, 174 an ohmic contact layer, for example, of n.sup.+ -type non-single-crystal silicon, 175 an electrode layer, for example, of aluminum, 176 a passivation layer, for example, of silicon nitride or polyimide, and 177 an adhesive layer, for example, of an epoxy resin.
As shown in FIG. 3, the sensor substrate 101 has a photoelectric conversion element having the light-shielding layer 171 provided on the substrate 170 in correspondence to a photoelectric conversion portion so as to prevent illumination light from the substrate side from entering the photoelectric conversion portion, the insulator layer 172 provided on the light-shielding layer 171, the semiconductor layer 173 provided on the insulator layer, and the electrode layer 175 provided through the ohmic contact layer 174 above the semiconductor layer with a space for an incident area of light, and the passivation layer 176 provided on the photoelectric conversion element; and the transparent protection layer 105 is provided through the adhesive layer 177 above the sensor substrate 101.
Light L emitted from a light source (not shown) passes through the sensor substrate 101, adhesive layer 177, and transparent protection layer 105 to reach the original P, and reflected light from the original P is incident to the space formed in the electrode layer 175 to be photoelectrically converted according to the incidence of light.
FIG. 4 is a diagrammatic, sectional, structural drawing for illustrating an example of a facsimile device with a communication function as an example of the information processing apparatus having the above photoelectric conversion apparatus.
In FIG. 4, reference numeral 180 denotes the facsimile device, 181 a feed roller, 182 a separator pawl, 183 a conveying roller, 184 a system control substrate, 185 a platen roller, 186 a recording head, 187 a power supply section, 188 the photoelectric conversion apparatus, 189 an operation panel, P the original, and W a recording medium.
As shown in FIG. 4, the facsimile device 180 supplies the original P to an image reading section by the feed roller 181 when the original P is inserted thereinto. In the original reading section the photoelectric conversion apparatus 188 is disposed and the original P is conveyed as urged against the reading portion by the conveying roller 183 opposed to the photoelectric conversion apparatus 188. This urging is effected by an urging device such as a spring, not shown. As urging the conveying roller 183 and/or the photoelectric conversion apparatus 188 against each other, the original P conveyed to between the conveying roller 183 and the photoelectric conversion apparatus 188 is further conveyed in a discharge direction. The separator pawl 182 is used for separating and feeding the originals P set in a pile one by one.
Further, the facsimile device 180 has the recording head 186 for recording an image received or information read by the above photoelectric conversion apparatus 188 in a recording medium W, and the platen roller 185 for conveying the recording medium W for recording information by the recording head 186.
The power supply 187 is a power-supply portion for driving the facsimile device 180, the system controller 184 is provided for controlling an image reading means including the photoelectric conversion apparatus 188 and the recording means including the recording head 186, and the operation panel 189 is a so-called control portion of the facsimile device 180.
The photoelectric conversion apparatus 188 is mounted, as shown, to a frame 4 (a main body frame in the drawing) provided in the facsimile device 180. This frame is normally provided in order to attain mainly the strength of the apparatus main body.
FIG. 5 is a diagrammatic, structural drawing for illustrating a mounting portion of the photoelectric conversion apparatus 188 and surroundings thereof.
In FIG. 5, reference numeral 191 represents a light source such as light-emitting diodes, 192 a sensor frame, 193 a light-source substrate, and 194 a connector. For using the light-emitting diodes as a light source 191, a plurality of light-emitting diodes are arranged at intervals on the light-source substrate 193. The photosensor 1 and light-source substrate 193 are mounted to the sensor frame 192 so as to be incorporated therewith, thereby composing the photoelectric conversion apparatus 188. The connector 194 is provided for supplying the power for driving the photoelectric conversion elements or the light-emitting diodes and/or for outputting electric signals carrying information output from the photoelectric conversion elements.
The photoelectric conversion apparatus 188 is mounted by unrepresented means in a recess formed in the frame 4.
FIG. 6 is a diagrammatic, perspective assembly drawing for illustrating the mounting portion of the photoelectric conversion apparatus 188 and surroundings thereof
In FIG. 6, reference numeral 195 stands for a flexible board for outputting signals from the photosensor 1, 196 a flexible board for outputting the signals from the photoelectric conversion apparatus 188 to the outside, and 197 an electric connection portion in FIG. 7 to be connected with the flexible board.
As shown in FIG. 6, the photoelectric conversion apparatus 188 is arranged so as to be dropped into the recess formed in the frame 4, and the flexible board 196 is connected to the electric connection portion on the apparatus body side, thereby electrically being connected with the apparatus body. The conveying roller 183 is disposed above the reading portion of the photoelectric conversion apparatus 188, as described above. The signal line from the photosensor 1 is first electrically connected through the flexible board 195 to the light-source substrate 193 and then electrically connected through a signal processing circuit provided in the light-source substrate 193 and through the flexible board 196 to a processing circuit on the apparatus body side.
FIG. 7 is a diagrammatic, structural drawing for illustrating an example of the connection relation between the photoelectric conversion apparatus 188 and the system control substrate 184 in the facsimile device 180.
As shown in FIG. 7, the flexible board 196 from the photoelectric conversion apparatus 188 is electrically connected with the connector 197 formed in the system control substrate 184.
However, with attempt to achieve further reductions of cost, size, and weight for the information processing apparatus constructed in the above structure, there was virtually no room for further reductions of cost, size, and weight, because the photoelectric conversion apparatus is constructed in a unit structure using the sensor frame. Another problem was that the limits of further reductions of size and weight would impose restrictions on freedom of engineering design of the apparatus main body or freedom of design thereof.

Photoelectric conversion apparatus and information processing apparatus


A spring clip for urging an electrical component onto a heat sink housing within an electronics component module is described. The spring clip comprises an elongated planar body, retention device for securing the body of the spring clip to the heat sink housing, the retention device depending downward from the body. The spring clip also includes urging device for contacting and urging the electrical component into a heat conducting relationship with the heat sink housing. The urging device includes a first elongate member depending downward from the body to a u-shaped junction. A second elongate member, extending upward from the u-shaped member and terminating at a contact surface, maintains the electrical component in a heat conducting relationship with the heat sink housing.

Typically, the assembly of an electronics module involves mounting various electrical components to a printed circuit board. Electrical components, such as transistors, generate significant amounts of heat requiring special provisions to dissipate the generated heat. The electrical component should be in thermally conductive contact with a heat sink to obtain maximum heat transfer from the electrical component to the heat sink. This conductive heat transfer is directly proportional to the contact pressure between the component and the heat sink.
Various spring devices have been designed for urging an electrical component into contact with a heat sink. U.S. Pat. Nos. 5,225,965 and 5,170,324 illustrate a spring clip for urging an electrical component into a heat conductive relationship with a vertical heat sink. These spring clips exhibit a common deficiency: they are retained in position by clamping over the top of the vertical heat sink. This configuration prevents the use of a heat sink as an outside wall of a sealed electronics module. Furthermore, due to the method of retention, the effective spring force applied to the electrical component is dependent upon the tolerances of the retaining clamp.
For a compact electronics module it would be desirable to provide a spring clip for urging an electrical component against a heat sink which also serves as an exterior housing for a sealed electronics module. Still further, it would be desirable to provide a spring clip that is capable of exerting a force on the electrical component independent of precision tolerancing, thereby eliminating high costs of precision tolerancing.


Stretcher for a transmission belt comprising a fixed part suitable for being rigidly connected to a support structure and provided with a pin defining a first axis, a movable part comprising a hub rotating on the pin about the first axis, a pulley carried by the movable part and rotating with respect thereto about a second axis distinct from the first axis and parallel thereto, and a spiral spring interposed between the fixed part and the movable part and suitable for loading in use the movable part in the direction tending to keep the pulley in engagement with the relative belt. The spring has an internal end secured to the pin, and an external end secured to the hub, and is interposed between two bushes which support the hub on the fixed part and are provided with respective flanges cooperating axially with the spring.

The invention relates to a stretcher for a transmission belt and particularly but not exclusively for a belt for transmitting motion from the drive shaft of an internal combustion engine to auxiliary elements driven by the said engine.
Stretchers are known which comprise a fixed part suitable for being rigidly connected to a support structure integral with the engine block, a movable part hinged to the fixed part about a first axis, a pulley carried by the movable part and rotating with respect thereto about a second axis distinct from the first axis and parallel thereto, and a spring interposed between the fixed part and the movable part, which loads the movable part in the direction tending to keep the pulley in engagement with the relative belt.
Variations in belt tension due to the selective actuation of the various accessories and to wear are therefore compensated by consequent variations in the deformation of the spring and corresponding movements of the axis of rotation of the pulley.
According to a known embodiment, the fixed part comprises a pin defining the first axis, and the movable part comprises a hub rotating on the pin with the interposition of a bush, also having the function of damping by friction the oscillations of the movable part under the pulsating load transmitted by the belt to the pulley, and thus to the said movable part. The spring, a spiral one, is wound round the hub and has an internal end secured to the said hub and an external end secured to a flange of the fixed part.
The known stretchers of the type briefly described have a number of disadvantages.
Because the pulley is supported in projecting manner by the movable part, the pull of the belt causes a tilting moment on the said movable part (i.e. tending to rotate the latter about an axis transverse to its own axis of rotation). The tilting moment is balanced by the restraining reaction of the fixed part through the bush; this tends, however, to stress the bush in anomalous manner, creating non-uniform wear in it.
Obviously, the effects of the tilting moment could be reduced by increasing the dimensions of the pin and the bush whilst retaining the same configuration; this would, however, involve an undesirable increase in the size of the hub and hence also of the fixed part.


The present invention provides to a wearable smart device having electrical wiring comprising a stretchable conductive composition having excellent in durability such as repeated bending properties and repeated twisting properties, a material for realizing the wearable smart device, and a method for producing the wearable start device.

Recently, a wearable electronic device intended to use an electronic device having input/output function, calculation function, and communication function in a state of being very close to or in close contact with a body has been developed. As such a wearable electronic device, devices with an accessory-type shape such as a wristwatch, eyeglasses, and earphones, and a wearable smart device of textile-integrated device where electronic functions are incorporated into a garment are known. Moreover, a touch body-type or a skin patch-type wearable smart device being in close contact with a human body, and an implant-type wearable smart device expected to be embedded in a human body are being further developed.
An electrical wiring for supplying power or transmitting signals is necessary for an electronic device. In particular, for a textile-integrated wearable electronic device or a skin patch-type wearable device, the electrical wiring is also required to have stretchability in accordance with a stretchable garment or substrate. Usually, an electrical wiring made of a metal wire or metal foil inherently has no practical stretchability, and hence a technique for providing stretching capabilities in a pseudo manner by arranging a metal wire or metal foil in a wave shape or in a repeated horseshoes shape is employed.
In the case of the metal wire, it is possible to form a wiring by regarding the metal wire as an embroidery yarn and sewing it into a garment. However, it is clear that such a method is not suitable for mass production.
A method of forming a wiring by etching metal foil is common as a method for producing a printed wiring board. A method is known in which the metal foil is attached to a stretchable resin sheet, and a wave-shaped wire is formed in the same manner as in the printed wiring board to make a stretchable wiring in a pseudo manner (refer to Non-Patent Document 1). In this method, stretchability is given in a pseudo manner by twist deformation of the wave-shaped wiring portion. However, the metal foil varies also in the thickness direction due to the twist deformation, and thus if it is used as a part of a garment, the garment has highly uncomfortable wearing feeling, which is not preferable. In addition, when the metal foil undergoes excessive deformation due to washing or the like, permanent plastic deformation occurs in the metal foil, and the wiring may also have the problem of the durability.
As a method to realize a stretchable conductor wiring, a method using a special conductive paste has been proposed. In such a method, conductive particles such as silver particles, carbon particles, and carbon nanotubes, elastomer such as urethane resin with stretchability, natural rubber, or synthetic rubber, and a solvent etc. are kneaded to form a paste, and using the resulting paste, a wiring is printed and drawn on a garment directly or in combination with a stretchable film substrate or the like.
A conductive composition including metal-based conductive particles and a stretchable binder resin can macroscopically realize a stretchable conductor. From a microscopic viewpoint, in the conductive composition obtained from the above-mentioned paste, the resin binder portion is deformed upon receiving an external force, and the conductivity is maintained within a range in which the electrical chain of the conductive particles is not broken. The resistivity observed macroscopically is higher than that of metal wires or metal foil. However, since the composition itself has stretchability, the wiring is not required to have a shape like a wave-shaped wiring, and flexibility in the width and the thickness of the wiring increases. Therefore, on a practical level, it is possible to realize a wiring with a low resistance compared with a metal wire.
Patent Document 1 discloses a technique in which silver particles and silicone rubber are combined, and the conductive film on the silicone rubber substrate is further covered with silicone rubber to suppress degradation of conductivity during elongation. Patent Document 2 discloses a combination of silver particles and a polyurethane emulsion and that a conductive film with high conductivity and a high elongation ratio can be obtained. Furthermore, many examples have also been proposed in which improvement of characteristics is attempted by combining conductive particles having a high aspect ratio such as carbon nanotubes, silver particles, and the like.
Furthermore, Patent Document 3 discloses a technique for directly forming an electrical wiring in a garment using a printing method.

Abstract: An electrical wiring including a fine line having an electrical line interval of 1 mm or less, preferably the line width of less than 1 mm, is formed by printing a paste for forming a stretchable conductor containing metal-based conductive particles and a non-crosslinked elastomer, and further dried and cured at a low temperature condition of 120° C. for 30 minutes. As a result, the wearable smart device having electrical wiring constituted by fine lines without sagging of the edge is obtained.


The present invention provides an FFT/IFFT processor for use with N data values. In one embodiment, the FFT/IFFT processor includes an even-odd data mapper configured to provide a mapping of the N data values into N/2 mapped complex data values if the N data values are real. Additionally, the FFT/IFFT processor also includes a separator-combiner, coupled to the even-odd data mapper, configured to compute either an FFT based on the mapping or an IFFT based on the N data values if the N data values are complex.

Communication systems extensively employ digital signal processing techniques to accomplish increasingly more sophisticated and complex computational algorithms. Expanding applications are being fueled by new technologies and increasing demand for products and services. The Discrete Fourier Transform (DFT) is employed in many of these applications to provide a needed transformation between sampled time-domain signals (that are usually digitized) and their frequency-domain equivalents. The DFT may be calculated in three different ways. A set of simultaneous equations can be employed, but this technique is too inefficient to be of practical use. Correlation techniques can also be used, but computational requirements make this technique cumbersome or expensive to implement on a broad scale.
The Fast Fourier Transform (FFT) is an ingenious algorithm first discovered by Karl Friedrich Gauss, the great German mathematician of a century ago, and rediscovered and applied by J. W. Cooley and J. W. Tukey in 1965. The FFT is typically hundreds of times faster than the other DFT methods mentioned above and is therefore the algorithm of choice for a broad spectrum of applications employing the DFT. For example, the FFT is a critical element of a digital communication system that employs Orthogonal Frequency Division Multiplexing (OFDM) or Discrete Multitone (DMT) techniques.
The FFT is based on a "divide and conquer" model that decomposes a DFT into N points, which actually correspond to N separate DFTs consisting of a single point. The whole transform is then obtained from these simpler transforms. For example, an N-point DFT computation can be divided into two N/2-point DFT computations that can be further divided into two N/4-point DFT computations, and so on until complete. Actually, the division occurs after a reorganization of the points, such that each point corresponds to a two-point DFT in each position when using a method based on radix-2. After this division and DFT computation, a merging process is performed in which the simpler DFT transforms are reassembled into the complete DFT transform. Of course, the Inverse Fast Fourier Transform (IFFT) also advantageously appropriates these techniques to provide transformation between frequency domain data and time domain data.
An input of N real data values may be processed by an N point FFT to provide an output of N complex data values. Conversely, an input of N complex data values may be processed by an N point IFFT to provide an output of N real data values. A basic computational element that is advantageously employed to further enhance the benefits of FFT/IFFT processing is called a butterfly structure. The butterfly structure accepts two complex input numbers and performs one complex multiplication, one complex addition and one complex subtraction to produce two complex output numbers. However, as N increases in magnitude, the number of complex multiplications required increases nonlinearily thereby placing additional burdens on processing and storage requirements.
Accordingly, what is needed in the art is a more effective way to provide N point FFT/IFFT computations employing real data.

FFT/IFFT processing system employing a real-complex mapping architecture


Methods, systems, and apparatuses are provided for resolution-independent dither sample insertion for audio transmissions. Audio transmitters transmit audio data streams to audio receivers. Data inactivity in the data stream triggers the audio receivers to enter power-saving/sleep modes in which synchronization with the audio transmitters is lost thus requiring time consuming resynchronization. Inactivity such as silence or zero-value data is detected in a data stream. Upon detection, a dither sample is inserted into the data stream and transmitted to the audio receiver to prevent the loss of synchronization. The dither sample may have a negative value and be formatted for resolution-independence with respect to the audio receiver.

1. Technical Field
The subject matter described herein relates to systems, apparatuses, and methods for inserting dither samples that are independent of data resolution into audio signals and transmissions.
2. Background Art
Data transmission on audio channels occurs between audio transmitters and audio receivers. Audio transmitters, such as set-top boxes (e.g., cable/satellite set-top boxes), provide audio signals to audio receivers, such as televisions and/or other home theater devices. In order to save power, audio receivers typically enter a power saving mode when no data (i.e., silence or an inactive data stream) is transmitted the audio transmitters. The audio receivers resume a normal mode of operation when data resumes in the received data stream (i.e., sound or an active data stream). However, audio receivers may become unsynchronized with audio transmitters during the power saving mode. For instance, during a power saving mode, audio receivers may stop tracking the clock signal provided with the audio data from the audio transmitter. When an audio receiver fails to track the clock, synchronization with an audio transmitter may be lost, and when the audio receiver comes out of its power saving mode, the transmitter clock must be re-acquired by the audio receiver to recapture synchronization. The process of re-acquiring synchronization often results in unpleasing noise such as pops, clicks, and/or static at the audio receiver. Additionally, re-acquiring synchronization requires additional delay and consumption of processor cycles.
In the current state of the art, a dither sample is provided to an audio receiver from an audio transmitter during periods in which only silence is transmitted to the audio receiver. In prior solutions, a dither sample usually is a data value that is the smallest possible positive data value that may be transmitted to an audio receiver so that resulting audio that is broadcast based on the dither sample is of a low amplitude. Typically, data is transmitted from audio transmitters in a 1's complement or 2's complement format, and therefore, dither samples typically have a value of '1' (usually in hexadecimal representation) regardless of the bit resolution of the transmission. For example, a 16-bit resolution dither sample with value '1' is 0001h, and a 24-bit resolution dither sample with value '1' is 000001h. However, when the audio transmitter has a higher bit resolution than the audio receiver, such a dither sample may not be received by the audio receiver. For instance, a 24-bit audio transmitter may provide audio data to a 20-bit or 16-bit audio receiver. In these cases, the audio transmitter provides 24-bit dither samples of 000001h, but because of their lower bit resolutions, 20-bit and 16-bit audio receivers truncate the dither samples (one or more right-most bits are lost). In a 20-bit resolution audio receiver, a 24-bit dither sample of 000001h is received as 00000h, and in a 16-bit resolution audio receiver, a 24-bit dither sample of 000001h is received as 0000h. Consequently, the dither sample is not received in these cases, and the 20-bit and 16-bit audio receivers effectively receive silence (no data or inactive data streams) and go into power saving modes where synchronization is lost.
Similarly, a 24-bit audio receiver may receive audio data from a 20-bit or 16-bit audio transmitter. A dither value of '0001h' (16-bit) or a dither value of '00001h' (20-bit) will be received as higher amplitude values by the 24-bit audio receiver: '000100h' and '000010h' respectively.

Resolution-independent dither sample insertion for audio transmissions


In a device for moving a slide from a slide tray via a slide chute (3) into a slide gate, an integral component (1) is provided which includes the slide chute (3), a support means for a motor-driven cam (15) and support means for a slide lifter (22), slide pressure means (24, 26) and a tray release lever (16) adapted to arrest a slide tray as well as supporting guide means (6, 6a) for the tray release lever (16) and guides (8d, 8e) adapted to receive the lens mount.

DE-OS 2 345 333 discloses a device by means of which slides can be transported in the vertical direction out of a tray into their projection position and back into said tray. A vertical plate provided with a gate in the area of the projection raypath mounts a motor-driven cam for actuating both a slide changing means hinged to said plate and a carriage which is arranged on said plate and shiftable in the horizontal direction for aligning the slide in the slide gate.
This known device is disadvantageous in that the insertion of the plate complete with slide gate and slide changing means causes manufacturing problems and requires considerable adjustment work in order to arrange the plate exactly at right angles with the optical axis of the projection raypath in the projector housing.
In known slide projectors the lens mount and the holding means for the insertion of the slide positioning means are usually integrally formed. In the case of one of such slide projectors (DE-GM 1 732 715) the lens mount, the holding means for the slide positioning means and a support for the condenser lens system are designed as an integral assembly unit.

Device for moving a slide into a slide gate and for receiving a lens mount


A hydraulically actuated medical instrument includes an elongated shaft having proximal and distal ends, a hydraulically actuated end effector at the distal end of the shaft and a fluid flow path extending through the shaft to the end effector. The shaft may be capable of an angled configuration where at least a portion of the shaft is manually movable to a direction in which it extends at an angle to another portion of the shaft. The end effector is not limited to a linear configuration and at least a portion of an elongated end effector extends at an angle relative to another portion of the end effector as is needed or desirable for the particular procedure to be performed.

The present invention relates in general to medical instruments suitable for endoscopic or laproscopic applications, and capable of passing through a trocar or similar device. More specifically, the present invention relates to a novel hydraulically actuated medical instrument suitable for stapling or other desired endoscopic or laproscopic applications.
Surgical instruments, such as staplers, graspers, scissors, coagulators and the like, suitable for endoscopic or laproscopic applications in which the device is inserted through a cannula or trocar, are well known. As described in more detail below, the present invention, in its most preferred embodiment, is directed to an endoscopic stapler particularly suited for minimally invasive surgery, such as for isolating the left a trial appendage on human hearts. Such procedures are described in U.S. Pat. No. 5,306,234, and U.S. patent application Ser. No. 09/315,601, filed on May 20, 1999 to Aaron V. Kaplan, both of which are incorporated by reference herein.
Also, endoscopic medical instruments are often of complicated construction, especially when the instrument is articulated to allow the handle and/or end effector to pivot or rotate. Typically, a mechanical linkage extends between the handle and end effector to allow operator actuation of the end effector. When the instrument is of the type that permits articulation, the mechanical linkage must accommodate the articulation. This often results in a design that is relatively complicated, that is costly to manufacture and/or that may still experience limitations regarding the degree or direction of articulation.
The mechanical linkage also may limit the shape, or configuration of the shaft and/or the ability of the shaft to be flexible so as to navigate a path within the body cavity during the medical procedure.
Other complications of a mechanical linkage may also arise relative to the shape and configuration of the end effector. The mechanical linkage must interface with the end effector so as to permit relative movement of the jaws in addition to driving of the staples. This can result in a complex attachment between the end effector and mechanical linkage that is expensive to make and difficult to assemble.


The present invention relates to the resolution by preferential crystallization of potassium salts of racemic omeprazole which is a solvate of ethanol and/or of ethylene glycol, which consists in converting the omeprazole to the potassium salt in the form of a solvate or of a mixture of these solvates in the presence of an excess of inorganic base which is a source of potassium, the said potassium salts existing in the form of conglomerates, and in then resolving the said conglomerates, independently or simultaneously, by preferential crystallization in order to separate the two (S) and (R) enantiomers of these potassium salts of omeprazole.

More particularly, the invention relates to the preparation of the pure enantiomer (S)-(−)-omeprazole (esomeprazole), with the chemical name 5-methoxy-2-[(S)-[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulphinyl]-1H-benzimidazole, and of its pharmaceutically acceptable alkali metal salts.
Very specifically, the present invention relates to the resolution of the potassium salts of racemic omeprazole by preferential crystallization and in particular by the AS3PC (Auto-Seeded Programmed Polythermic Preferential Crystallization) method.
Racemic omeprazole is represented by the following general formula (I):

The invention relates both to the omeprazole of above formula (I) and to its tautomeric form, and likewise as regards its salts and enantiomers below.
The pure enantiomer (S)-omeprazole (esomeprazole) is represented by the following general formula (II):

This pure enantiomer is sold as a drug in the form of the (S)-omeprazole magnesium salt trihydrate under the Nexium® name, represented by the following general formula (III):

It may be remembered that the magnesium salt of the (S) enantiomer of omeprazole is the first proton pump inhibitor (PPI) developed and sold in the pure enantiomer form. Racemic omeprazole and esomeprazole are employed to treat gastric and/or duodenal ulcers. They can be used in the prevention and treatment of gastrointestinal disorders, gastro-oesophageal reflux, digestive tract hemorrhage and dyspepsia. Furthermore, (S)-omeprazole can be of use in the treatment of psoriasis and in the treatment of infections with the bacterium Helicobacter pylori and related pathologies.
Omeprazole and its enantiomers belong to the chemical class of the prazoles comprising a benzimidazole or imidazopyridine ring system. Mention may be made, among the many prazoles sold or in the course of clinical development, of: ilaprazole, lansoprazole, leminoprazole, pantoprazole and rabeprazole/pariprazole in their racemic and/or pure enantiomer form.
These prazoles, and more particularly their corresponding alkali metal or alkaline earth metal salts, are used as inhibitors of gastric acid secretion and as such in the treatments.
They are chiral sulphoxides, the sulphur atom of which, bonded on the one hand to an oxygen atom and on the other hand to heteroaromatic ring A and methylene-heteroaromatic ring B substituents which are different, constitutes the stereogenic centre.
They can be represented by the following general formula (IV):

The change from omeprazole (racemic compound) to esomeprazole (pure laevorotatory (−) enantiomer of (S) absolute configuration) constituted, for this class of PPI pharmaceutical compounds, the first chiral switching. It has been shown that this compound, in its racemic form and each of its enantiomers, can exhibit different pharmacological and pharmacokinetic properties.
Omeprazole (racemic compound) was described for the first time in Patent EP 0 005 129 and some of its alkali metal salts in Patents EP 124 495 and U.S. Pat. No. 4,738,974.
The alkali metal and alkaline earth metal salts and more particularly the magnesium salt of omeprazole and those of other PPI prazoles have been shown to be stable and, in some cases, non hygroscopic.
A large number of documents of the prior art describe the preparation of esomeprazole and its alkali metal and alkaline earth metal salts.
Generally, these documents describe conventional methods which can be categorized according to the methods involved:
Erlandsson P. et al. published the first resolution of racemic omeprazole, carried out by chiral phase chromatography, in J. Chromatogr., 1990, 532, 305-319.
Patent Applications DE 40 35 455 and WO 94/27988 describe the resolution of racemic omeprazole and similar prazoles of pyridinylmethylsulphinyl-1H-benzimidazole type by fractional crystallization of diastereomeric salts and/or reverse phase chromatographic separation of covalent diastereomeric ethers of the type of chiral N-acyloxymethyl bonded to the free nitrogen atom N of the benzimidazole ring, followed by basic hydrolysis.
Patent Application US 2006/0089386 describes the resolution of racemic omeprazole using (S)-camphor-sulphonyl chloride by formation of covalent diastereomers separated by fractional crystallization, followed by basic hydrolysis, to give (S)-omeprazole >99% ee.
Patent Application WO 96/01623 describes the formation of the magnesium salts of the (R)- and (S)-omeprazole enantiomers with an enantiomeric excess of 99% ee with the crystalline form I.
Patent Application WO 96/17077 describes a method for the stereoselective bioreduction of the sulphoxide (racemic omeprazole) to give the corresponding sulphide (thioether) using microorganisms, such as Escherichia coli, Proteus mirabilis or Proteus vulgaris, comprising the enzyme DMSO reductase, or using this purified enzyme. This enantioselective bioreduction leaves the omeprazole greatly enriched in (+) enantiomer with an enantiomeric excess of 99% ee. The (−) enantiomer is obtained with 70% ee.
Patent Application WO 96/17076 describes a method for the stereoselective biooxidation of the precursor sulphide (thioether) of omeprazole in the presence of microorganisms, such as Penicillium frequentans, Brevibacterium paraffinolyticum or Mycobacterium sp., to give the (S)-omeprazole enantiomer of 99% ee.
Patent Application WO 96/02535 describes the asymmetric synthesis involving asymmetric oxidation of the prochiral sulphide using the catalytic system Ti(O-isoPr)4/diethyl D-tartrate/H2O in the presence of cumene hydroperoxide, of tertiary amine organic base and of organic solvent, such as toluene, followed by in situ formation of corresponding sodium salts. This catalytic process makes it possible to obtain chiral sulphoxides, in particular the sodium salt of (S)-omeprazole, of 99% ee.
Patent Application WO 2006/040635 describes the enantioselective synthesis of pyridinylmethylsulphinyl-benzimidazoles by catalytic oxidation of the corresponding precursor prochiral sulphide derivatives using the came catalytic system, Ti(O-isoPr)4/diethyl D-tartrate/H2O, cumene hydroperoxide and tertiary amine organic base, without addition of organic solvent, to give the (S)-omeprazole enantiomer and its alkali metal and alkaline earth metal salts, in particular its magnesium salt.
Patent Application WO 03/089408 describes the asymmetric synthesis of (S)-omeprazole by catalytic enantioselective oxidation of the precursor prochiral sulphide using a monodentate chiral ligand of methyl ester of L-mandelic acid type in the presence of cumene hydroperoxide and of Ti(O-isoPr)4/H2O, and in situ preparation of the corresponding sodium salt of 99% ee.
Patent Application WO 98/28294 describes the preparation of solid (S)-omeprazole in an amorphous form, a crystalline form (denoted form A) or a partially crystalline form (denoted form B).
Patent Application WO 98/54171 describes the formation of the magnesium salts of the (S) and (R) enantiomers of omeprazole dihydrate in the crystalline forms A and B and of the trihydrate. This patent also describes the formation of the potassium salts of the (S) and (R) enantiomers of omeprazole.
Patent Application WO 00/44744 describes the formation of a novel potassium salt of (S)-omeprazole hydrate of form B.
Patent Application WO 2004/002982 describes the separation of racemic omeprazole into its pure enantiomers by formation of diastereomeric salts starting from the sodium salt of racemic omeprazole brought together with the coordinating agent diethyl D-tartrate/Ti(iso-Pr)4 in acetone and complexing using L-mandelic acid.
The selective crystallization of the diastereomer comprising the (S)-omeprazole, followed by basic hydrolysis, gives the (S)-omeprazole magnesium salt trihydrate of 99% ee. The corresponding dihydrate is formed by controlled drying.
Patent Application WO 2004/046134 describes the preparation of (S)-omeprazole magnesium salt trihydrate of crystalline form II starting from the amorphous form of the same salt.
Patent Application WO 97/02261 (EP 1 498 416) describes the enantiomeric increase of mixtures of (S)/(R) enantiomers of omeprazole by selective precipitation of the corresponding racemic compound in acetone or acetonitrile solvents The filtrate gives, after evaporation, (S)-omeprazole of 98-99% ee.
In J. Phys. IV, 2004, 113, 11-15, Coquerel G. presents the rationale supporting the formation of the anticonglomerate (corresponding to racemic omeprazole) and its crystallization using binary phase diagrams (see FIG. 5b of this publication).
Patent Application WO 2004/089935 describes the preparation of a novel crystalline form of (S)-omeprazole magnesium salt trihydrate, known as H1, and the access to (S)-omeprazole magnesium salt hemihydrate and (S)-omeprazole magnesium salt monohydrate, each characterized by X-ray powder diffraction diagrams.
Patent Application WO 2006/001753 describes the preparation of (S)-omeprazole and sodium salts obtained in crystalline forms identified as C, E and H starting from the corresponding precursor potassium salt treated in a basic medium.
Patent Application WO 2006/003163 describes the preparation of novel crystalline forms of (S)-omeprazole which is a solvate of methanol, characterized by X-ray powder diffraction diagrams.
Patent Application WO 2006/134605 describes the formation of amorphous (S)-omeprazole hydrate and its conversion to the anhydride by resuspension in an organic solvent and filtering.
Patent Application WO 2004/076440 describes the I and II forms of (S)-omeprazole and its hydrates.
Patent Application WO 2004/020436 describes amorphous hydrates of the magnesium salt of (S)-omeprazole and their preparation.
Patent Application WO 2007/031845 describes the preparation of (S)-omeprazole magnesium salt trihydrate in two novel polymorphous crystalline forms G1 and G2 and the preparation of a corresponding amorphous form.
Patent Application. WO 2007/049914 describes the formation of an (S)-omeprazole strontium salt tetrahydrate in a crystalline form A and an amorphous form.
Deng J. et al., in Tetrahedron: Asymmetry, 2000, 11, 1729-1732, describe the resolution of racemic omeprazole by formation of inclusion complexes using (S)-(−)-2,2′-dihydroxy-1-1′-binaphthyl (BINOL), followed by crystallization and by chromatographic separation, to give (S)-omeprazole of 99% ee.
Patent Application WO 2007/074099 describes the resolution of racemic omeprazole by formation of inclusion complexes using the chiral ligand (S)-1,1,2-triphenyl-1,2-ethanediol. The complex of (S)-omeprazole and 2 equivalents of chiral ligand formed yields crystalline (S)-omeprazole of 99% ee.
While some of these methods are used on the industrial scale, regulatory change, in particular with regard to the safety and quality of pharmaceutical products, and also the economic impact of decisions of official health bodies in the direction of better control of the cost of treatments are forcing the development and the optimization of novel methods for the preparation of the (S)-omeprazole enantiomer and its salts of pharmaceutical interest.
Mention may be made, among the existing methods described in the above patents, without implied limitation, of a body of disadvantages commonly encountered and which are directly related to the use of these methods, it being possible for several of these disadvantages to be found in one and the same method:                In the case of the catalytic asymmetric synthesis involving catalysts of Ti(O-isoPr)4, vanadium trioxide or tungsten acetylacetonate type, the presence of residual heavy metals.        The formation of the sulphone, corresponding to the complete oxidation of the sulphur atom, which can be obtained at up to 40% with respect to the (S)-omeprazole and which is difficult to separate by chromatography or recrystallization.        The need to undergo a stage of chromatographic separation and of enantiomeric purification by recrystallization when the asymmetric synthesis methods provide (S)-omeprazole with a chemical purity <90% and with an enantiomeric purity <95% ee.        The use of a chiral phase HPLC chromatographic separation/purification method for direct chromatographic methods without involving covalent diastereomers or salts.        In the case of insufficient structural purity (Coquerel G., The 'structural purity' of molecular solids—An elusive concept? Chem. Eng. Process, 2006, 45, 857-862), when the enantiomer obtained in its neutral form or in the form of an alkali metal or alkaline earth metal salt, in particular the magnesium salt, is a mixture of forms, of hydrates and/or of solvates of different stabilities.        The removal of residual microorganisms and enzymes in the case of bioconversions.
A specific aim of the present invention is to present a method for the preparation of the pure enantiomer (S)-omeprazole which does not exhibit the disadvantages described above.
This aim is achieved by virtue of the application of the preferential crystallization method to racemic omeprazole in the salt form. Thus, the invention relates very particularly to the application to potassium salts of racemic omeprazole of the resolution by preferential crystallization of each of its enantiomers, making it possible to obtain the eutomer (S)-omeprazole in an enantiomerically and chemically pure form.
In particular, the AS3PC preferential crystallization method has formed the subject of an entirely original development which excludes the restrictive use of crystallization seeds. This method is described, for example, in the following patents and patent applications FR 2 710 337, WO 95/08522, EP 0 720 595 and U.S. Pat. No. 6,022,409 and in G. Coquerel, Preferential Crystallization in Topic in Current Chemistry, Novel Optical Resolution Technologies, Springer, Berlin-Heidelberg, edited by K. Sakai, N. Hirayama and R. Tamura, 2007, 269, 1-51. This method is denoted "AS3PC" for "Auto-Seeded Programmed Polythermic Preferential Crystallization".
The preferential crystallization methods are based on the alternating crystallization of the two (R) and (S) enantiomers of the same racemic chemical entity crystallizing in the conglomerate form in a medium which can be a solvent or a mixture of solvents or a combination of constituents including the solvent or solvents, this being the case for a given temperature range ΔT. Within this temperature range, this racemic mixture, in thermodynamic equilibrium with its saturated solution, is composed of two types of crystals each comprising only molecules with the same absolute configuration. Each enantiomer may incorporate molecules of solvent (solvates) and/or of water (hydrates).


In one aspect, phosphine compounds comprising three adamantyl moieties (PAd3) and associated synthetic routes are described herein. Each adamantyl moiety may be the same or different. For example, each adamantyl moiety (Ad) attached to the phosphorus atom can be independently selected from the group consisting of adamantane, diamantane, triamantane and derivatives thereof. Transition metal complexes comprising PAd3 ligands are also provided for catalytic synthesis including catalytic cross-coupling reactions.

Modern synthetic organic methods utilizing homogeneous transition metal catalysis have benefited immensely from the capacity of phosphines to modify the activity, selectivity and stability of metal catalysts. As a corollary, the behavior of metal catalysts can be manipulated by tuning the steric and electronic properties of supporting ligands such as phosphines. Thus, the discovery of novel phosphine structures with steric and/or electronic properties beyond what can be accessed using existing phosphorus-based ancillary ligands is desirable. Newer applications of phosphines to organocatalysis, frustrated Lewis pair (FLP) catalysis, biorthogonal reactions, and nano-materials should also benefit from access to new phosphine properties.

Tri-(adamantyl)phosphines and applications thereof


An exhaust gas purification control device for an internal combustion engine is provided with: a detection unit for detecting an air-fuel ratio or rich/lean state of exhaust gas that flows out of a first catalyst disposed at upstream side; estimating unit for estimating the oxygen adsorption amount on the first catalyst and a second catalyst; and an enrichment control unit for enriching or set the degree of richness temporarily by varying the degree of richness of injected fuel when the amount of the oxygen adsorption on the first catalyst and the second catalyst is estimated to be equal to or greater than a predetermined value. The enrichment control unit sets the degree of richness of the injected fuel to a first degree of richness that is greater than stoichiometry from the start of the enrichment process, and maintains the first degree of richness even after the output of the detection unit has reached a stoichiometric air-fuel ratio or rich/lean value.

An exhaust gas purification control device is known in which a plurality of catalysts are arranged in series in an exhaust passage and an air-fuel (A/F) ratio is controlled while detecting the status of an upstream side catalyst and a downstream side catalyst, wherein, when the oxygen adsorption amount of respective catalysts becomes excessive during a fuel-cut operation for example, the rich degree or the degree in richness of the air-fuel ratio will be changed based on the detection values across the downstream catalyst (Patent Document 1).

Exhaust gas purification control device for an internal combustion engine


A buffer circuit is arranged for offset cancellation between an input voltage and a buffered voltage. The buffer circuit includes two bias current sources, two p-type transistors, and two n-type transistors. Further, the base-emitter voltages of the two p-type transistors and the two n-type transistors are arranged to form a translinear loop. The translinear loop is arranged to provide the buffered voltage from the input voltage. One of the bias sources is arranged to provide a bias current to one of the p-type transistors, and the other bias circuit is arranged to provide a bias current to one of the n-type transistors. One of the bias current circuits is arranged to actively sense the reverse saturation currents of the p-type transistors and the n-type transistors, and to provide its bias current so that the offset voltage between the input voltage and the buffered voltage is substantially cancelled.

Traditional operational amplifiers use voltage feedback. However, a current-feedback amplifier (CFB) typically has significant bandwidth and slew rate advantages over conventional amplifiers.
With a voltage feedback amplifier (VFA) in a closed loop, the error signal is a voltage. A VFA ideally has high impedance inputs, to achieve substantially zero input current, and employs voltage feedback to maintain approximately zero differential input voltage.
In a CFB in a closed loop, the error signal is a current. A CFB ideally has one high impedance input and one low impedance input. Typically, a buffer is used to force the low impedance input to have a voltage equal to the input voltage at the high impedance input plus a voltage offset. A CFB in a closed loop employs current feedback to maintain low error current at the low impedance input.

Apparatus and method for correction of error caused by reverse saturation current mismatch


A composite plastic lens including: a lens having a convex surface, a lens back surface, and a protrusion formed on at least part of an periphery; and a holder, the lens and the holder being molded integrally, wherein the cross-sectional shape of at least part of the lens including an optical axis on the convex surface side is such that a profile line on the convex surface side is curved in a direction getting closer to the lens back side as it goes from the optical axis side toward a turning point out of an optical effective area, and the cross sectional shape of the protrusion is inverted from the turning point out of the optical effective area toward the periphery in a direction away from the lens back surface, and the holder is fitted to the protrusion so as to include the turning point and is molded integrally on the peripheral side of the resin lens.

Field of the Invention
This disclosure relates to a composite plastic lens in which a resin lens and a resin light-shielding holder are integrated, and a method of manufacturing the same.
Description of the Related Art
The resin lens is used in a wide range of fields such as photographing lenses used in digital cameras or video cameras, recording and reproducing pickup lenses for optical discs, projecting lenses used in projectors. Many of these resin lenses are formed by injection molding for reducing costs. However, in order to cause the resin lens to function in a state of being assembled with a product as a part, the lens may be put into a frame-shaped holder and integrated therewith in a post process. The frame-shaped holder is expressed by terms such as a lens barrel and a lens holder. In this disclosure, a term "holder" is used throughout. In many cases, a gripping portion to be operated in conjunction with an operating portion and a light-shielding portion that limits a light effective area are additionally formed on the holder.
In order to respond requirements such as a reduction in cost and a reduction in weight, the holders used in recent years are made of a resin, and an adhesive agent is generally used for fixing and integrating the holder with the resin lenses. However, for those requiring high degree of positioning accuracy between the lens and holder, the integration with high degree of accuracy is difficult with the adhesive agent. In order to solve the above-described problem, an insert molding technology configured to achieve integration by molding a resin lens in a state in which a resin holder is inserted into a metal mold is disclosed in Japanese Patent Laid-Open NO. 2002-148501. In Japanese Patent Laid-Open NO. 2004-319347, a configuration in which a resin holder inserted into a metal mold at the time of lens formation is held at a predetermined position further reliably is disclosed.
However, the composite mold articles disclosed in the above-described Japanese Patent Laid-Open NO. 2002-148501 and Japanese Patent Laid-Open NO. 2004-319347 each have a problem to be solved.
The configuration of Japanese Patent Laid-Open NO. 2002-148501 has a problem that if a lens resin is injected into a metal mold in a state in which a resin holder is inserted, a colored holder resin fuses and transfers into a transparent lens resin by heat and a shearing force of the lens resin and hence the appearance of the lens is degraded.
In order to solve this problem, in Japanese Patent Laid-Open NO. 2004-319347, occurrence of appearance defects is suppressed by providing a protrusion on a core of a metal mold in which a resin holder is to be inserted so as to hold the holder at a predetermined position by the protrusion even when being subjected to heat and a shearing force during the lens resin is being injected.
However, in a first embodiment of the Japanese Patent Laid-Open NO. 2004-319347, if the injection speed of the lens resin is lowered at the time of lens formation, the time period in which the holder is subjected to heat and a shearing force is increased, so that the colored holder resin cannot be suppressed from fusing and transferring into the transparent lens resin. In particular, the temperature of the lens resin is high, and hence this problem is specifically notable in the vicinity of a gate portion at which the temperature of the resin is high, and which is subjected to a holding pressure. Therefore, there is a problem that the molding conditions are limited at the time of the lens formation.
In a configuration in the embodiment of the Japanese Patent Laid-Open NO. 2004-319347, the holder is embedded around the protrusion of a core, which helps the positioning of insertion of the holder, and if the lens is formed in this state, a level difference of the embedment is transferred to a peripheral portion of the lens. If a ridge caused by the level difference exists on the lens, a problem of ghost caused by a reflection of incident light, which is unexpected in the specification of the lens, may occur.
This disclosure provides a composite plastic lens which prevents a resin light-shielding holder from fusing and transferring into a resin lens and reduces a probability of occurrence of ghost, and a method of manufacturing the composite plastic lens.

Composite plastic lens and method of manufacturing the same


The invention relates to sulfmimidoyl- and sulfonimidoylbenzoyl derivatives of the general formula (I). In said formula (I), R, R′, X, W and Z represent radicals such as hydrogen, organic radicals such as alkyl, and other radicals such as halogens. Q represents a cyclohexandionyl-, pyrazolyl-oder isoxazolyl radical.

1. Field of the Invention
The invention relates to the technical field of the herbicides, in particular to that of the herbicides for the selective control of broad-leafed leaves and weed grasses in crops of useful plants.
2. Description of Related Art
WO 03/014071 A1 and WO 2011/012247 A1 disclose herbicidally active benzoylcyclohexanediones carrying an alkylsulfenyl, alkylsulfinyl or alkylsulfonyl group in the 3-position of the phenyl ring. Herbicidally active benzoylpyrazoles carrying an alkylsulfenyl, alkylsulfinyl or alkylsulfonyl group in the 3-position of the phenyl ring are known from WO 2008/125214 A1 and WO 2009/149806 A2. US 2011/0144345 A1 and WO 2004/052849 A1 each disclose benzoyl derivatives carrying a sulfoximino group in the 3-position of the phenyl ring. However, the herbicidal activity and/or the crop plant compatibility of the compounds mentioned in these publications is not always sufficient.

Herbicidal sulfinimidoyl- and sulfonimidoyl benzoyl derivatives


A portable water-purification system includes a container for holding a liquid and an ultraviolet light source configured for immersion in the liquid. The ultraviolet light source is a straight low-cost tube controlled by electronic circuitry for providing hot-cathode striking at a relatively low voltage using a fly-back inductor. The operation of the water purification system is controlled by a micro-controller within the electronic circuitry.

1. Field of the Invention
The invention relates generally to devices and methods for disinfecting water and, more particularly, to a portable, low-cost system for disinfecting water using ultraviolet light.
2. Description of the Related Art
Every day, an estimated 3,000 to 6,000 die worldwide due to infections from waterborne bacteria. Death typically results from acute dehydration, malnutrition, or other related complications. The majority of victims are young children and older people that live in economically impoverished countries. In these regions, contaminated surface water sources and poorly functioning municipal water distribution systems lead to the transmission of waterborne bacterial diseases. Although the problem is particularly bad in impoverished countries, population groups in developed countries, such as residents in remote rural areas of the United States with poor water treatment and delivery systems, are also at risk. In addition, campers and hikers who do not have access to treated water also commonly fall victim to waterborne bacterial infections.
Conventional centralized water treatment and distribution systems can be very expensive and take years to complete. Furthermore, it is often impractical to provide centralized water treatment in sparsely populated areas. Therefore, to provide the at risk groups with potable water requires innovative practical solutions such as, for example, point-of-use disinfection. In one disinfection method, ultraviolet ("UV") radiation having wavelengths in the range of 200 to 300 nm may be used to kill disease-carrying microorganisms in water. UV radiation has been found to deactivate a broad spectrum of pathogenic contaminates from amoebic sized microorganisms to bacteria, algae and viruses. Water purification by ultraviolet radiation provides numerous advantages over other currently available water treatment methods. For example, UV water purification systems do not require chemicals nor do they require expensive filters.
Existing UV water purification systems are often large installed flow-through systems serving a large number of people. However, in recent years, a number of smaller portable UV water purification systems have become available for use by individuals. Portable UV water purification systems use fluorescent tubes for emitting UV light into the water. A quartz cover is typically provided around the fluorescent tube to protect the light source from mechanical shock and to electrically insulate the light source from the water being disinfected. Quartz covers are commonly used because it has been found that quartz is transparent at germicidal UV wavelengths, such as, around 254 nm. However, quartz covers are very expensive and thereby substantially increase the manufacturing cost.
Existing UV water purification systems also include electronic circuitry for driving the fluorescent tube. The circuitry is typically configured to drive the fluorescent tube using a "cold-cathode" striking method. In this method, a high voltage (e.g., 400-500V RMS) is applied to the anode and cathode terminals of the fluorescent tube. The voltage must be high enough to produce ionization with the anode and cathode terminals at room temperature (i.e., hence "cold-cathode"). In one common cold-cathode striking method, an H-bridge driven, capacitively tuned, step up transformer circuit is used to drive the fluorescent tube with an AC power input. Unfortunately, this type of electronic circuitry is expensive to manufacture, thereby driving up manufacturing costs and making the system prohibitively expensive for many applications. As a result, UV water purification systems and, more particularly, portable UV systems have not met with great commercial success.
Due to the complexity and high costs associated with existing UV water purification systems, an urgent need exists for an improved water purification system that requires fewer components and is easily affordable to large segments of the population. It is desirable that such a system be rugged in construction and easily transportable for disinfecting drinking water in regions wherein water purification is not available. It is also desirable that such a device be lightweight, compact and easy to use. The present invention addresses these needs.

Portable ultraviolet water purification system


A structure and manufacturing method for DRAM capacitors includes providing a semiconductor substrate with a MOS transistor having a gate and source/drain regions formed thereon. A first insulating layer covers the semiconductor substrate. A multi-layered stack, with at least one pair of an alternately deposited second insulating layer followed by a third insulating layer, is formed above the first insulating layer. An opening is formed through the multi-layered structure and the first insulating layer exposing the source/drain region. Then, a plurality of trenches are formed on the sidewalls of the opening. A second conducting layer is formed over the exposed surfaces of the aforementioned layers. A pattern is defined on the second conducting layer so as to form a lower electrode structure. A dielectric layer is formed over the lower electrode layer. A third conducting layer is formed over the dielectric layer, and a pattern is defined on the third conducting layer to form the upper electrode structure.

1. Field of Invention
This invention relates in general to a structure and manufacturing method for dynamic random-access-memory (DRAM) capacitors, and more particularly to the structure and manufacturing method for a stacked type capacitor as well as an improved version using a parallel combination of stacked and trench type capacitors.
2. Description of Related Art
DRAM is a kind of volatile memory whose digital signals are stored according to the charging state of the respective capacitors in each of the memory cells. FIG. 1 shows a conventional circuit diagram of a DRAM cell, which comprises a metal-oxide-semiconductor (MOS) transistor 11 with its gate connected to a word line (WL). One source/drain region is connected to a bit line (BL), while the other source/drain region is connected to ground via a capacitor 12. The capacitor 12 can be regarded as the heart for the storage of digital signals in a DRAM cell. When the charges stored in the capacitor 12 are large, the storage capacity for digital signals is increased. Furthermore, the signal read out from the memory by amplification circuits during a read operation will be less affected by noise. For example, soft errors generated by a-particles will be greatly reduced.
There are several methods to increase the charge storage capacity of the capacitor 12. For example, by increasing the surface area of the capacitor 12, the quantity of charges capable of being stored in the capacitor can be increased. The conventional stacked type capacitor (as shown in FIG. 2K) is one such structure for increasing the surface area of the capacitor in a DRAM memory cell.
FIGS. 2A through 2K are a series of cross-sectional views showing the manufacturing steps of a stacked type DRAM capacitor according to a Taiwan Patent No. 262587. First, referring to FIG. 2A, a semiconductor substrate 20 having a MOS transistor 22, a field oxide layer 26 and a conducting layer 27 already formed above is provided. The MOS transistor 22 includes a gate 23, source/drain regions 24 and spacers 25. Using a chemical vapor deposition (CVD) method, a first insulating layer 28 with a thickness of about 1000 .ANG. to 3000 .ANG. is then deposited covering the aforementioned layers. Thereafter, referring to FIG. 2B, the first insulating layer 28, one of the source/drain regions 24 and the semiconductor substrate 20 are sequentially etched to form a trench 29.
Referring next to FIG. 2C, a first conducting layer 210 is then formed over the first insulating layer 28 and the surfaces of the trench 29. For example, the conducting layer can be an impurity doped polysilicon layer having a thickness of about 500 .ANG. to 1500 .ANG.. An annealing operation is next performed so that heat is supplied to the doped ions causing diffusion and hence forming an expanded region as shown by the dash line of FIG. 2C.
Referring next to FIG. 2D, a second insulating layer 211 is formed above the first conducting layer 210, for example, an oxide layer deposited to a thickness of about 4000 .ANG. to 6000 .ANG.. Subsequently, a first screen layer 212 is formed above the second insulating layer 211, for example, a silicon nitride layer deposited to a thickness of about 500 .ANG. to 2000 .ANG.. Thereafter, using photolithographic and etching processes, a pattern is defined on the second insulating layer 211 and the first screen layer 212 to mark out the boundary of the capacitor structure. This is followed by etching, for example, using a plasma etching method, to form sidewalls 213 on the periphery of the second insulating layer 211 and the first screen layer 212.
Referring next to FIG. 2E, in the subsequent step the sidewalls 213 of the second insulating layer 211 is isotropically etched, for example, using a buffered oxide etchant (BOE) having a concentration ratio of 6:1 of ammonium fluoride mixed with hydrofluoric acid.
Referring next to FIG. 2F, a second conducting layer 214 is formed above the exposed surfaces of the first conducting layer 210, the second insulating layer 211 and the first screen layer 212. For example, the second conducting layer 214 can be an impurity doped polysilicon layer having a thickness of about 1000 .ANG. to 3000 .ANG..
Referring next to FIG. 2G, in a subsequent step the second conducting layer 214 is etched back anisotropically, for example, using a plasma etching method, to form conducting spacers 215. The conducting spacers 215 are electrically connected with the first conducting layer 210 for expanding the overall surface area of the conducting layer.
Referring next to FIG. 2H, the residual second insulating layer 211 and first screen layer 212 are removed leaving behind the first conducting layer 210 together with the conducting spacers 215 which become a lower electrode layer 216 of the capacitor structure. The lower electrode 216 can be created, for example, by isotropically etching away the first screen layer 212 and the second insulating layer 211 in sequence using phosphoric acid (H3PO4) and a buffered oxide etchant having a concentration ratio of 6:1.
Referring next to FIG. 21, a dielectric layer 217 is then formed on the surface of the lower electrode layer 216. The dielectric layer 217, for example, can be a silicon oxide/silicon nitride/silicon oxide (ONO) composite layer formed by first forming a silicon oxide layer through a heat growing method, then forming a silicon nitride layer above, and lastly performing a thermal oxidation operation to form a silicon oxide layer above the silicon nitride layer. Subsequently, a third conducting layer 218a is formed above the dielectric layer 217, for example, by depositing a polysilicon layer containing impurities.
Referring next to FIG. 2J, the third conducting layer 218a is etched to form the boundary of the capacitor structure, for example, by photolithographic and plasma etching processes, thereby forming the upper electrode 218.
Lastly, referring to FIG. 2K, a metalization procedure is performed by first depositing a boro-phosphosilicate glass (BPSG) layer 219 on top of the upper electrode 218, then etching the layer to form contact windows, and finally sputtering a metal layer 220 on top of the boro-phosphosilicate glass layer 219.
Although the above stacked type DRAM capacitor structure is capable of increasing the surface area of the memory capacitor, the main disadvantages lies in its over-complicated manufacturing steps involved, which therefore greatly increases the production cost as well as production time.

Structure and manufacturing method for DRAM capacitors


An isoxazole compound having the following formula: wherein R.sup.1 represents hydrogen, halogen, alkyl, alkoxy, hydroxyl, alkylthio, amino, alkanoyl, alkanoylamino, alkanoyloxy, alkoxycarbonyl, carboxy, (alkylthio)thiocarbonyl, carbamoyl, nitro or cyano; R.sup.2 represents an amino; m is 1; n is 1 to 6; ring A represents a phenyl ring or a naphthyl ring; and X represents oxygen or sulfur. The isoxazole compound has an excellent monoamine oxidase inhibitory activity, and is useful for treating Parkinson's disease, depression and Alzheimer's disease.

Parkinson's disease is a chronic progressive disease which causes akinesia, muscular rigidity and tremor as a result of degeneration of dopaminergic neurons in the substantia nigra. It has been known that Parkinson's disease is caused by a decrease in the cerebral concentration of dopamine, a neurotransmitter, particularly in the caudate nucleus and putamen due to degenerative, vascular and inflammatory changes of the basal nucleus. Administration of levodopa is the most effective therapeutics and widely applied in order to supplement the decreased dopamine in the brain, particularly in the striatum. However, the single therapy with levodopa is problematic since it is associated with serious adverse reactions. Recently, trials to treat Parkinson's disease by inhibiting type-B monoamine oxidase, which is a dopamine decomposing enzyme, and preventing decomposition of dopamine are being conducted actively and deprenyl has been launched as a type-B monoamine oxidase inhibitor.
Now, in the Japanese Patent No. Sho 47-6302, it is mentioned that benzisoxazole derivatives, such as Compound A and B, are utilizable as local anaesthetics, antihistaminic agents, anti-inflammatory agents, tonics and antispasmodics with general effects on the nervous system as well as having cardiovascular effects. ##STR1##
Moreover, in Farmaco Ed. Sci., 23, 1081 (1968)., ibid., 24, 440 (1969)., it is mentioned that Compound B possesses anti-inflammatory effects and local (infiltration) anaesthetic effect. However, it is fully unknown that Compounds A and B have monoamine oxidase inhibitory activity.


Data items such as files or database records associated with particular applications (such as messaging applications and other applications) can be stored in one or more remote locations, such as a cloud storage system, and synchronized with other devices. The remote storage can be configured such that each application executing on a client device can only view data items stored at the remote location to which the application has permission to access. An access manager on each client device enforces application specific access policies. Storage at the remote location can be secured for each application associated with a user or user account, for example, using isolated containers. The cloud storage of data can be anonymized and anonymous group data can be stored in the cloud storage.

Cloud storage is a model of data storage in which digital data is stored in logical pools and the physical storage underlying the logical pools can span multiple servers and/or locations. A cloud service provider can a provide access to the cloud storage system to remote client devices. The cloud service provider can host the physical environment of the cloud storage or contract a portion of the underlying storage from an enterprise cloud storage vendor. Users of a cloud storage system can store data within the cloud storage system and such data can be accessed from multiple devices. Additionally, applications can be configured to store configuration data within the cloud storage system. Cloud storage systems can be configured using any number of underlying storage systems. These storage systems can be encrypted using one of several types of encryption algorithms and techniques.


A system for mounting a wireless antenna and equipment to a stealth communication tower in coastal areas and inland waterways, camouflaged as a sailboat. The Cellboat is retrofitted to securely and discreetly store wireless transceiver equipment, and an antenna is attached at the top of the mast. Access doors are disposed in the side of the Cellboat to provide access to the equipment for maintenance purposes. The Cellboat is stored at drydock, allowing for access and protection from flooding of the equipment. Alternatively, when the Cellboat is deployed in the water, the access doors will be located on the top deck of the Cellboat.

1. Technical Field
The present invention relates to wireless communications facilities, and more particularly to techniques for mounting and camouflaging wireless communications antennas and equipment to be deployed in an appropriate setting.
2. Description of the Related Art
At the present time, it is difficult to get wireless communication coverage in coastal areas and inland waterways at or near the water, often due to difficulty in obtaining approvals for constructing wireless communication facilities. There is a need for some means by which wireless communication providers can provide access to these currently underserved areas. The available choices for mounting antennas are limited by height, topography, man-made and natural clutter, and other obstructions. The available choices for constructing wireless communications facilities at or near a waterfront are far more limited.
Currently, the available conventional wireless communication facility installations include the following: 1) rooftop installations; 2) tower structures (such as lattice, monopole, guyed and high-tension towers); and 3) water tanks. These conventional installations are not always available to wireless communications providers. The reasons a conventional site may not be suitable or available could include municipal zoning code restrictions.
A further concern regarding conventional wireless communication facilities is the possibility of damage that arises when the wireless equipment is exposed to the elements. Moreover, in a waterfront environment, sand, salt, wind and water can pose a substantial risk of corrosion, leading to the possibility of both mechanical and electrical failure. Finally, a further concern regarding conventional wireless communication facilities is the possibility that the wireless equipment could be stolen or damaged by vandals.
There is therefore a need for a product or system that provides sufficient height while being a discreet and secure housing for wireless communication antennas and equipment in an underserved area.

Stealth wireless communications facility


Provided is an apparatus and method for monitoring a status of a satellite, including classifying satellite telemetry information and space weather information and storing the information in a storage unit including respective databases, predicting whether a predetermined type of satellite failure occurs based on the space weather information, and generating satellite control command information to change a status of a predetermined satellite configuration when a satellite failure determining index used to determine a possibility of the satellite failure is beyond a predetermined critical alert range.

1. Field of the Invention
The present invention relates to an apparatus and method for monitoring a status of a satellite that may monitor the status of the satellite in consideration of an influence of space weather conditions, and thus automatically control a satellite configuration based on a result of an analysis.
2. Description of the Related Art
A general satellite transponder monitoring and control (TMC) system may manually receive telemetry information of a satellite transponder, store the received information in a database, display a result of the storing on a display, and transmit telecommand information commanded by a system operator at a particular time.
A general satellite transponder monitoring apparatus may receive telemetry information of a satellite transponder, parse the telemetry information, send a result of the parsing to a database management system (DBMS) to store the result in a database, and indicate each telemetry value graphically or numerically through a telemetry viewer.
Also, the general satellite transponder monitoring apparatus may make reference to analog telemetries of telemetries stored in the database, perform a statistical analysis involving a minimum value, a maximum value, a mean value, distribution, and the like, and display a result of the analysis through an analysis data indicator. Further, the general satellite transponder monitoring apparatus may transmit a satellite control command in response to a manual input of the system operator based on a particular schedule or at a scheduled time according to a series of a selected command procedure.
The satellite transponder may be affected directly by a weather phenomenon occurring in space, for example, a solar storm, because a satellite transponder is located in space beyond the atmosphere, and thus may be prone to malfunctions or failure.
In a case in which the TMC system receives telemetry information of the satellite transponder at regular time intervals, although space weather conditions are quite likely to cause malfunctions or failure, rapid collection of information and prompt measures for responding to an event may be required.
However, during operation of the system, even in an ordinary status, similar to a case of an emergency status, a ground system may be unnecessarily overloaded. Thus, research on development a system that may precisely diagnose and monitor a status of a satellite is necessary.

Apparatus and method for monitoring status of satellite

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


This invention provides a method of and an apparatus for sticking a paper web to a paper web threading member superposed on the paper web through the intermediary of an adhesive material. The apparatus comprises a paper web threading member moving device (1) for moving the paper web threading member to a predetermined position where a paper web engaging member (La1) secured to the paper web threading member (La) is stuck to a paper web and/or moving it from that position along a predetermined path; a detector device (2) for detecting the presence of paper web threading member and outputting a signal; a paper web moving device (3); a detector device (4) for detecting movement of the paper web (W) to the predetermined position where the paper web is stuck to the paper web engaging means and outputting a signal; and an adhesive material applying device (5) provided near the predetermined position for applying an adhesive material onto the paper web engaging member and the paper web to connect the paper web threading member located at the predetermined position with the paper web.

1. Field of the Invention
This invention relates to a method of and apparatus for sticking a paper web threading member to a paper web in a paper web threading operation wherein a paper web is threaded along a predetermined path in a paper web handling machine such as a rotary printing machine or the like through the intermediary of the paper web threading member adapted to be moved along the predetermined path, and more particularly, to a method of and apparatus for sticking a paper web to a paper web threading member superposed on the paper web through the intermediary of an adhesive material such as an adhesive tape or the like.
2. Description of the Prior Art
As a prior art arrangement, there is an apparatus for sticking one of the two paper webs obtained by division of a paper web in two portions on the way of a predetermined paper web threading path in the longitudinal direction to a paper web engaging member connected to a paper web threading member which stands by on the downstream side of the position where the paper web is divided, as disclosed in Laid-open Publication No. Hei 2-29727 of Japanese Utility Model Registration Application.
In this apparatus, with continued threading of the other one of the two divided paper webs through a relevant path, one of the paper webs is sent to a position where it is stuck to a paper web engaging member which stands by. When one of the paper webs arrives at a predetermined position, a detector means detects the arrival thereof and renders an adhesive applying means operative. The adhesive applying means holds an adhesive material and, when rendered operative, serves to bring one end of the adhesive material into contact with the paper web engaging member and apply it to the latter, and at the same time press the paper web engaging member and one of the paper webs in superposed condition. Immediately thereafter, the paper web threading member is moved together with one of the paper webs along the predetermined paper web threading path at substantially the same speed as the feeding speed of one of the paper webs so as not to prevent one of the paper webs from being fed into the paper web threading path. The arrangement is made such that this movement causes the adhesive material whose one end is applied to the paper web engaging member to be drawn out and applied onto and over the paper web engaging member and one of the paper webs, thereby connecting both of them.
Hereupon, threading of a paper web through a paper web handling machine is conducted only before processing operation such as printing by the machine is effected, or when an accident such as severing of a paper web occurs during the processing operation. And, the above-mentioned prior art apparatus is arranged such that in case a paper web threading operation is conducted a series of operations for sticking a paper web to the paper web engaging member are made continuously after the paper web arrives at a predetermined position where it is stuck to the paper web engaging member.
However, since the adhesive material for sticking a paper web to the paper web engaging member is held on an adhesive applying device in such a condition as the adhesive surface on one end of the adhesive material is always exposed to the outside air, and also since during the paper web handling operation paper dust scattered by the paper web which is running adheres to the adhesive surface or the quality of the adhesive surface is deteriorated by drying, the adhesive force thereof is deteriorated in most cases. Therefore, even if the above-mentioned series of operations are commenced after the arrival of the paper web at the predetermined position, because the time during which one end of the adhesive material is pressed against the paper web engaging member is extremely short, one end of the adhesive material is not applied to the paper web engaging member so that the paper web cannot be stuck to the paper web engaging member, thus making it impossible to thread the paper web through the predetermined path using the paper web threading member.

Method of and apparatus for connecting a paper web threading member with a paper web


A word line driver includes a CMOS inverter constituted by a P channel MOS transistor in which a row decode signal having the amplitude of an internal logic power supply voltage is supplied to a gate, one end of the source-drain current path is connected to a node to which a power supply voltage (VWLh) is applied, and the other end of the source-drain current path is connected to a word line, and an N channel MOS transistor in which the input signal is supplied to a gate, one end of the source-drain current path is connected to a node to which a power supply voltage (VWLl) having a negative value is applied, and the other end of the source-drain current path is connected to the word line. The circuit threshold voltage of the CMOS inverter is set to be larger than the circuit threshold voltages of other CMOS inverters which operate using internal logic power supply voltages.

The present invention relates to a dynamic semiconductor memory device and, more particularly, to an improvement of a word line driver for driving a word line.
In the memory cell of a dynamic semiconductor memory device (DRAM), a bit line voltage is written in a memory capacitor through a transfer gate using an N channel MOS transistor. In the write access, to prevent the high-level voltage on the bit line from lowering by an amount corresponding to the threshold voltage of the transfer gate before being written in the memory capacitor, a signal voltage for driving the transfer gate is boosted to a level higher than the power supply voltage. The gate electrode of the transfer gate is connected to a word line. The high-level voltage on the word line is set at step-up voltage VPP having a value corresponding to (high-level voltage on bit line)+(threshold voltage of N channel MOS transistor)+(margin for process variations) (this scheme will be referred to as a word line boosting scheme).
In a word line driver which applies step-up voltage VPP to one word line selected from a plurality of word lines by a row decoder and applies a low-level voltage to nonselected word lines, step-up voltage VPP is supplied as a power supply voltage and is also supplied as a high-level input signal.
In the word line driver of a DRAM according to the above-mentioned word line boosting scheme, each gate of the P channel and first N channel MOS transistors connected to the word line receives from the row decoder a decode output signal which becomes circuit ground voltage VSS when the word line is to be selected. The source of the P channel MOS transistor receives word line drive signal WDLV which becomes step-up voltage VPP when the word line is to be selected. The gate of the second N channel MOS transistor receives signal /WDLV of regular power supply voltage VDD. The logical level of signal /WDLV is inverted from that of word line drive signal WDLV, and the voltage of the high level of signal /WDLV is smaller than step-up voltage VPP.
In the word line driver having such a circuit arrangement, when the decode output signal from the row decoder is circuit ground voltage VSS in the selected state wherein signal WDLV is step-up voltage VPP, the P channel MOS transistor is turned on, and step-up voltage VPP is output to word line WL. When the decode output signal from the row decoder is VPP in the selected state, the N channel MOS transistor is turned on, and circuit ground voltage VSS is output to word line WL. When the word line driver is in a nonselected state, signal /WDLV becomes VDD. Then, the second N channel MOS transistor is turned on, so that word line WL is held at circuit ground voltage VSS.
As the decoder for decoding an address signal and generating a signal to be supplied to the word line driver on the basis of the decode output signal, there is a level converter based on a dynamic circuit scheme wherein a predetermined circuit node is precharged with step-up voltage VPP and determining the input level of the input signal having an internal circuit voltage level (VDD or VSS).
However, the above-mentioned prior art has the following problems.
(1) The voltage to be applied to the word line is VPP. For this reason, when the stored charges in the memory capacitor are at level "0", and the word line is set at level "1", the step-up voltage is applied to the gate oxide film of the transfer gate, so the reliability of the oxide film is degraded as compared to other logic transistors.
(2) To obtain almost the same reliability as that of other logic transistors for the gate oxide film of the transfer gate, the film must be made thicker to equalize the electric field applied to the gate oxide film, resulting in a decrease in conductance of the transfer gate. This decrease in conductance lowers the speed of the entire DRAM.
(3) It takes a longer time to charge a load capacity such as the capacitance of a word line with the step-up voltage than to charge using the internal power supply voltage. The increase in charge time also lowers the speed of the entire DRAM.
As a technique of avoiding these problems, a negative voltage driven word line scheme disclosed in the below literature is known:
1995 IEEE INTERNATIONAL SOLID-STATE CIRCUITS CONFERENCE; ISSCC95/SESSION 14/DRAM/PAPER FA 14.3, pp 248-249, "Circuit Design Techniques for Low-Voltage Operating and/or Giga-Scale DRAMs", T. Yamada et al.
In this technique, while holding the amplitude of the word line, the voltage level on the low level side is set at a negative potential, i.e., the voltage level on the low level side of the amplitude of the word line signal is lowered, and simultaneously, the threshold voltage of the transfer gate is lowered.
FIG. 11 exemplifies the relationship in voltages between the above word line boosting scheme and the negative voltage driven word line scheme.
The left side illustration in FIG. 11 shows the former word line boosting scheme. The high-level voltage on the word line is set at step-up voltage VPP (e.g., 4.5V), and the low-level voltage is set at circuit ground voltage VSS (0V). High-level voltage VDD of the internal circuit is set at, e.g., 3.3V. Vth in FIG. 11 represents the threshold voltage (e.g., 0.9V) of the transfer gate in the memory cell.
The right side illustration in FIG. 11 shows the latter negative voltage driven word line scheme. Low-level voltage VWLl on the word line is set to be lower (e.g., -0.6V) than circuit ground voltage VSS. High-level voltage VWLh on the word line is set at 3.9V which is lower than step-up voltage VPP by 0.6V. In this scheme, threshold voltage Vth* of the transfer gate in the memory cell is set to be lower than threshold voltage Vth of the word line boosting scheme by (VPP-VWLh).
According to the negative voltage driven word line scheme, when the signal voltage on the word line is at high level, the write voltage for the memory cell capacitor is VWLh-Vth*=VPP-Vth, i.e., equal to the write voltage in the word line boosting scheme. When the signal voltage on the word line is at low level, the charge hold characteristic of the memory cell capacitor is represented by Vth*-VWLl=Vth-VSS, i.e., the same characteristic as that in the word line boosting scheme.
That is, in the negative voltage driven word line scheme, the high-level signal voltage on the word line can be lowered without degrading the write characteristic and charge hold characteristic, so the reliability of the gate oxide film of the transfer gate can be prevented from lowering.
FIG. 4 on page 249 of said literature "ISSCC95/SESSION 14/DRAM/PAPER FA 14.3" exemplifies a prior art word line driver circuit used for a DRAM of the negative voltage driven word line scheme. This circuit comprises a first MOS transistor pair having low threshold voltages, a P channel MOS transistor pair of the Vpp (2.2V) side, and a second N channel MOS transistor pair of the Vbb (-0.5V) side.
In this circuit, the one gate of the first MOS transistor pair is connected to a circuit with a predetermined potential Vcc (1.2V), and the other gate thereof is circuit-grounded. The respective one electrodes (sources or drains) of the MOS transistor pairs of the gate-Vcc side and of the gate-grounded side receive the row decode output.
The Vpp-side MOS transistor pair and the Vbb-side MOS transistor pair have cross-coupled circuit connections. The one drain of the Vpp-side MOS transistor pair is connected to the other electrode (drain or source) of the gate-Vcc side MOS transistor pair, and the one drain of the Vbb-side MOS transistor pair is connected to the other electrode (drain or source) of the gate-grounded side MOS transistor pair. The respective other drains of the Vpp-side MOS transistor pair and the Vbb-side MOS transistor pair are connected to each other at a connection node, and a word line drive signal corresponding to the row decode output is supplied from the connection node to word line WL.
In the word line driver having this arrangement, the output signal from the row decoder is level-converted into a signal having an amplitude between Vpp and Vbb and supplied to word line WL.
However, the word line driver of the above ISSCC95 requires six MOS transistors, i.e., the six MOS transistors must be arranged in units of word lines. This makes a pattern layout of the word line driver according to the decoder pitch difficult. Thus, an increase in occupied area of the driver lowers the cell occupation ratio, resulting in an increase in manufacturing cost.
In addition, since a relatively large voltage of Vpp-Vbb is applied to the gate oxide film of the Vpp-side and Vbb-side MOS transistor pairs in the word line driver, these MOS transistor pairs also have a problem of poor reliability with respect to the withstanding voltage of their gate.

Word line driver and semiconductor device