An object is to provide a method for manufacturing a highly reliable semiconductor device which includes a thin film transistor using an oxide semiconductor and having stable electric characteristics. In manufacture of a semiconductor device in which an oxide semiconductor is used for a channel formation region, after an oxide semiconductor film is formed, a conductive film including a metal, a metal compound, or an alloy that can absorb or adsorb moisture, a hydroxy group, or hydrogen is formed to overlap with the oxide semiconductor film with an insulating film provided therebetween. Then, heat treatment is performed in the state where the conductive film is exposed; in such a manner, activation treatment for removing moisture, oxygen, hydrogen, or the like adsorbed onto a surface of or in the conductive film is performed.

A thin film transistor in which a semiconductor film is formed on an insulating surface is a semiconductor element that is essential to a flat panel display such as a liquid crystal display device or a light-emitting device and a semiconductor device such as an IC. Since there is limitation on manufacture of a thin film transistor in terms of allowable temperature limit of a substrate, a thin film transistor in which amorphous silicon that can be deposited at relatively low temperature, polysilicon that can be obtained by crystallization with use of laser light or a catalytic element, or the like is included in an active layer is mainly used for a semiconductor display device.
In recent years, as a novel semiconductor material which has a mobility as high as polysilicon and realizes such uniform element characteristics as are obtained with the use of amorphous silicon, a metal oxide having semiconductor characteristics which is called an oxide semiconductor has attracted attention. A metal oxide is used for various applications. For example, indium oxide is a well-known metal oxide and used as a transparent electrode material included in a liquid crystal display device or the like. Examples of such metal oxides having semiconductor characteristics include tungsten oxide, tin oxide, indium oxide, and zinc oxide. Thin film transistors including such metal oxide having semiconductor characteristics in its channel formation region have been proposed (Patent Documents 1 to 4 and Non-Patent Document 1).
As metal oxides, multi-component oxides as well as single-component oxides are known. For example, InGaO3(ZnO)m (m: natural number) having a homologous series is known as a multi-component oxide semiconductor including In, Ga, and Zn (Non-Patent Documents 2 to 4). Furthermore, it is confirmed that an oxide semiconductor including such an In—Ga—Zn-based oxide is applicable to a channel layer of a thin film transistor (Patent Document 5, Non-Patent Documents 5 and 6).

Semiconductor device and method for manufacturing the same

Semiconductor Energy Laboratory Co., Ltd.


Positive photoresist compositions and methods using the photoresist compositions for making submicron patterns in the production of semiconductor devices are disclosed. The photoresists contain sensitizers that are mixed naphthoquinonediazide 4- and 5- sulfonic acid esters of bis and tris(mono, di and trihydroxyphenyl) alkanes.

The production of 4 megabit or larger DRAM semiconductors involves the creation of images having submicron dimensions. These are commonly produced by optical lithography using I-line (365 nm) radiation. The resists used in lithographic production of very large scale integration (VLSI) circuits must have sufficient imageability to produce straight walled features in the resist, high resistance to etching of unexposed areas, high contrast, and high operational photospeed. Straight walls are important because sloping walls lead to changes in dimensions and loss of resolution as the resist is eroded by the etching process. Resistance to etching is important for the same reason. High photospeed increases throughput and thereby minimizes the investment in very expensive equipment. High contrast allows tools with lower numerical aperture and larger fields of exposure to be used. Contrast is defined as the ratio of the dissolution rate of the exposed resin (R) to the dissolution rate of the unexposed resin (R.sub.0).
Positive resists are preferred for VLSI. Known I-line photoresist compositions are naphthoquinone diazide sulfonate esters of hydroxyaromatic compounds dispersed in novolak resins as disclosed in U.S. Pat. Nos. 3,130,048 and 3,106,465. Since the function of the unexposed naphthoquinone diazide ester is to inhibit the dissolution of the novolak resin, it is important it be highly miscible with the novolak resin in the film and in solution.
Among the different phenols with which the naphthoquinone diazide sulfonates can be esterified, hydroxy benzophenones and biphenyls have been the most widely used. Molecules that do not contain a benzophenone chromophore are preferred for VLSI applications because the absorbance of benzophenone at 365 nm leads to a residual unbleachable component which can give sloped sidewalls in photoresist images.
4-Sulfonate esters are said to possess advantages for image reversal [G. Buhr, Proc. SPIE 1086, 117(1989)]. In addition, they have the potential to be faster resists than the 5-sulfonates since irradiation produces both a sulfonic acid and a carboxylic acid in the case of the 4-sulfonate, but only a carboxylic acid in the case of the 5-sulfonate. [G. Buhr. Proc. SPIE, 1086, 117(1989); Blum, Proc. SPIE, 771, 148(1987)]. The irradiation products of the 4-sulfonate facilitate the development of the exposed image in simple metal ion free developers (tetramethylammonium hydroxide) which, in the case of 5-sulfonates, usually require surfactants to remove the exposed photoresist completely. The 4-sulfonic acid esters also possess higher absorbance at the I line than the corresponding 5-sulfonates, thus providing higher photospeed and improved internal masking.
Despite the theoretical advantages of the 4-sulfonates, 5-sulfonates remain by far the more popular esters for use in photoresists because of their superior solubility in the novolak resin and casting solvents (U.S. Pat. Nos. 4,266,000 and 4,906,549). For example, it is difficult to achieve more than 15% by weight of solid film with 4-sulfonic acid esters of hydroxybenzophenone. One of the earlier attempts to induce solubility in 4-sulfonic acid esters of benzophenone relied upon leaving free hydroxy groups in di and trihydroxybenzophenones (U.S. Pat. No. 3,130,048). However, the resistance to alkaline developers of compositions containing free hydroxyls is inadequate for practical purposes, especially for VLSI where any loss of unexposed resist results in undesirable, sloping wall profiles. Producing a photoresist that takes advantage of the superior intrinsic characteristics of naphthoquinonediazide 4-sulfonates while maintaining high contrast and good solubility has, until the present invention, remained elusive.
U.S. Pat. No. 4,266,000 discloses naphthoquinone diazide 5-sulfonic acid esters of halogenated benzophenones and bisphenols. Additives to the composition include trihydroxybenzophenone and naphthoquinonediazide 4-sulfonyl chloride. The sulfonyl chloride would be expected to readily hydrolyze to free acid, reducing the shelf life of the resist in solution and introducing the potential for corroding metal surfaces.
U.S. Pat. No. 4,839,256 discloses ink repellent printing plates containing perfluoroalkyl monoethers of dihydroxyaromatics in which the naphthoquinonediazidosulfonate esterfies the other (non-ether) hydroxy site on the benzene ring.
U.S. Pat. No. 4,732,836 discloses photoresist compositions containing tri- and tetrahydroxybenzophenones esterified with mixtures of 4-naphthoquinone diazide sulfonyl chloride and other acid chlorides. Although the generic disclosure would encompass diphenylmethane esters, in fact the single example is of 2,3,4-trihydroxybenzophenone. Moreover, the benzophenone contains no 5-sulfonate esters but rather uses only photochemically inert aliphatic and aromatic acids to block the hydroxyls that are unesterified by 4-sulfonyl chloride. This provides solubility and a lower R.sub.0 but at the expense of photospeed.
U.S. Pat. No. 4,732,837 discloses analogous esters from the 5-sulfonyl chloride.
U.S. Pat. No. 4,873,169 discloses a process for the preparation of low metal content napththoquinonediazide 5-sulfonic acid esters using organic amines as esterification agents.
U.S. Pat. No. 4,906,549 discloses specific phenolic formaldehyde resins for use in conjunction with naphthoquinonediazide 5-sulfonate esters of tri and tetrahydroxy benzophenones in photoresist compositions.
European patent application EP 335,836 discloses positive photoresist compositions containing an alkali soluble resin, a naphthoquinonediazide 5-sulfonate ester with 1,3,5 trihydroxybenzene and an additive of an aromatic hydroxy compound.
U.S. Pat. No. 4,397,937 discloses naphthoquinonediazide 5-sulfonyl esters of unsymmetrical aliphatic diols. Although the generic description includes mixed esters of the diols with 5- and 4-sulfonic acids, no examples of such are disclosed.
U.S. Pat. No. 4,943,511 discloses mono, di- and triesters of 2,3,4-trihydroxybenzophenone with 1,2-naphthoquinone-2-diazo-4-sulfonic acid. Photoresist compositions comprise these esters in combination with particularly chosen cresol formaldehyde resins. The patent demonstrates two approaches (partial esterification and resin choice) that the art has suggested for achieving solubility of 4-sulfonate esters.
There remains a need for a positive working photoresist composition that is based on readily available novolak resins and that provides high photospeed, high contrast, good resistance to etching in unexposed areas, straight-walled profiles, clean development with simple, nonmetallic bases, rapid development in simple, nonmetallic bases, and high solubility in the casting solution.

Fast diazoquinone positive resists comprising mixed esters of 4-sulfonate and 5-sulfonate compounds

International Business Machines Corporations


An automatic buckling device comprising a tongue attached to a seat belt and a buckle for latching the tongue. The tongue includes a cover case, a tongue plate which can project from the forward end of the cover case, a spring for urging the tongue plate in the direction in which the tongue plate is withdrawn into the cover case, and a recessed portion provided on the surface of the tongue plate at the forward end thereof so as to engage a ball. The buckle includes an insertion passage into which the tongue is inserted, a solenoid for drawing the tongue plate into the buckle, a ball which is engageable with the recessed portion of the tongue plate which is inserted into the insertion passage, a ball holder for holding only a part of the ball so that the ball can enter the insertion passage, a ball stopper which moves to a latch-holding position at which the ball stopper comes into close contact with the ball when a part of the ball enters the insertion passage so as to check the withdrawal of the ball from the insertion passage, and a stopper moving mechanism for moving the ball stopper to the latch-holding position when the tongue plate has completely entered the insertion passage and moving ball stopper from the latch-holding position by remote switching control in order to separate the tongue from the buckle.

1. Field of the Invention
The present invention relates to an improvement of a mechanism for connecting a tongue and a buckle of a seat belt apparatus which is installed in vehicles or the like and, more particularly, to an automatic buckling device for automatically connecting the tongue with the buckle when the tongue is brought close to the buckle.
2. Description of the Related Art
When an occupant uses a seat belt apparatus installed in an automobile, a tongue having a ring portion at the forward end thereof through which the seat belt is run is manually inserted into a buckle.
Since the buckle is disposed on one side of a seat, the occupant must twist the upper half of his body in an uncomfortable posture in order to insert the tongue into the buckle.


In the process according to this invention, an amplification procedure is performed on a first sample in which one or more of the four normal ribonucleoside triphosphates (rNTPs) or deoxyribonucleoside triphosphates (dNTPs) is replaced with an exo-sample nucleotide. After amplification, any contaminating amplified product that may be remaining is subjected to a physical, chemical, enzymatic, or biological treatment which renders nucleic acid containing the exo-sample nucleotide substantially unamplifiable. The treatment may be done as a separate step or it may be done in the presence of a second sample containing nucleic acid sequences to be amplified. The amplified nucleic acid sequences derived from the first sample which contaminate the second sample are not further substantially amplified during amplification of nucleic acid sequences of the second sample.

1. Field of the Invention
The present invention relates to processes which amplify nucleic acid sequences. In particular, the present invention discloses a means for eliminating the products of an execution of a nucleic acid amplification process that contaminate subsequent executions of the amplification process.
2. Description of Related Disclosures
The polymerase chain reaction (PCR) procedure amplifies specific nucleic acid sequences through a series of manipulations including denaturation, annealing of primers, and extension of the primers with DNA polymerase (Mullis KB et al., U.S. Pat. No. 4,683,202, U.S. Pat. No. 4,683,195; Mullis KB, EP 201,184; Erlich H, EP 50,424, EP 84,796, EP 258,017, EP 237,362; Erlich H, U.S. Pat. No. 4,582,788; Saiki R et al., U.S. Pat. No. 4,683,202; Mullis KB et al. (1986) in Cold Spring Harbor Symp. Quant. Biol. 51:263; Saiki R et al. (1985) Science 230:1350; Saiki R et al. (1988) Science 231 487; Loh EY et al. (1988) Science 243:217; etc.). (References cited herein are hereby incorporated by reference.) These steps can be repeated many times, potentially resulting in large amplifications of the number of copies of the original specific sequence. It has been shown that even single molecules of DNA can be amplified to produce hundreds of nanograms of product (Li H et al. (1988) Nature 335:414).
Other known nucleic acid amplification procedures include the transcription-based amplification system of Kwoh D et al. (1989) Proc. Natl. Acad. Sci. USA 86:1173.
"Uracil DNA glycosylase" (UDG), a term of art, refers to an enzyme which cleaves the glycosidic bond between the base uracil and the sugar deoxyribose, only when the monomeric nucleotide dUTP is incorporated into a DNA molecule, resulting in incorporation of a deoxyuridine moiety (Duncan B (1981) in The Enzymes 14:565, ed.: Boyer P). The enzyme does not act upon free dUTP, free deoxyuridine, or RNA (Duncan, supra).
A consequence of amplification processes such as PCR is that the amplification products themselves can be substrates for subsequent PCR procedures. Furthermore, because the quantities of the amplification products can be large, the dispersal of even an extremely small fraction of a reaction such as a PCR reaction into the laboratory area potentially can lead to contamination of later attempts to amplify other samples.
The present invention represents an improvement upon in vitro nucleic acid amplification procedures in general by making amplification products distinguishable from naturally occurring DNA. Accordingly, such products are rendered inactive as templates for further amplification prior to the start of the succeeding amplification reaction.

Process for controlling contamination of nucleic acid amplification reactions


A vacuum drier apparatus capable of preventing the thermal deformation of the protection member as well as scattering of the tempered glass plate in a case of an accidental breaking of the tempered glass plate. The apparatus includes elastic supporter members located between the glass plate and the protection member, for supporting the glass plate and the protection member with respect to each other, such that the glass plate can be pressed tightly to seal off the opening section of the vacuum drying space, while the protection member can be pushed away from an edge of the front side of the opening window by an external pressure exerting on the protection member. The protection member is preferably a transparent plastic plate in an outwardly curving dome-shaped form.

1. Field of the Invention
The present invention relates to a vacuum drier apparatus for drying materials such as heat sensitive chemical materials and powders, for example.
2. Description of the Background Art
A vacuum drier apparatus has been used for drying materials such as heat sensitive chemical materials and powders, for example.
Such a conventional vacuum drier apparatus is usually equipped with an openable door having an observation window made from a piece of tempered glass plate. This tempered glass plate is designed to have such a thickness that it can endure the atmospheric pressure, and may be shaped in a protruding form.
However, it is necessary to provide a protection against an accidental breaking of this tempered glass plate due to an exertion of external forces. Such a protection is usually provided in a form of a protection plate such as that made of metallic mesh or transparent plastic plate which is placed in front of the tempered glass plate. This protection plate also serves, in a case of an accidental breaking of the tempered glass plate, to prevent the scattering of the broken glass pieces which are sucked into a vacuum drying chamber because of the reduction of pressure inside the vacuum drying chamber, and then bounce off a backside wall of the vacuum drying chamber.
For such a protection plate, the plastic plate is more commonly employed than a metallic mesh because it becomes easier to observe the inside of the vacuum drying chamber.
However, the protection plate made of a plastic plate also has a problem that it is subject to a thermal deformation due to the heat inside the vacuum drying chamber.
Also, conventionally, the protection plate made of a plastic plate has a problem in its strength, such that it sometimes does not function sufficiently as the protection plate because of its inadequate strength.
In a case when the protection plate made of a plastic plate and is attached with a slight clearance for entering the air from outside in order to prevent the reduction of pressure inside, there is a problem of contamination of the interior due to the external objects entering along with the air.


A remote control includes a touch pad operable in two or more touch pad modes and a switching mechanism for controlling devices having display screens such as home entertainment (HE) devices, slide projectors, and computers. The switching mechanism is operable with the touch pad for switching the touch pad between the touch pad modes. The touch pad modes include an absolute touch pad mode, a relative touch pad mode, and an annotate touch pad mode. The remote control includes a control button operable in two or more control button modes. Each of the control button modes corresponds to a respective touch pad mode. The switching mechanism is operable with the control button for switching the control button to the control button mode corresponding to the respective touch pad mode. The remote control also includes an indicator operable for displaying control button indicator modes each indicative of a respective control button mode. The switching mechanism is operable with the indicator for switching the indicator to the control button indicator mode corresponding to the control button mode. The touch pad may include two control icons representative of remote control commands. The control icons are enabled when the touch pad is in a first touch pad mode and disabled when the touch pad is in a second touch pad mode.

The present invention relates generally to remote controls and, more particularly to a remote control having a touch pad operable in a plurality of modes.
Operators use remote controls for remotely controlling a variety of devices including home entertainment, computer, and presentation devices. Such home entertainment devices include televisions, video cassette recorders, set top boxes, and stereos. Such computer devices include desktop and laptop computers. Such presentation devices include slide projectors. Operators use remote controls to control basic functions of the devices such as turning the device on and off. Remote controls are often used in conjunction with display screens of the devices to facilitate simple control of the devices. For instance, the display screens may have a cursor which the operator can navigate the cursor on the display screen by manipulating the remote control. Further, the display screens may have a menu of choices and the operator can select a choice in the menu by manipulating the remote control. The display screens may also have graphical user interfaces (GUI) or the like and the operator can enter information into the GUI by manipulating the remote control. Remote controls may also be used to facilitate advanced control of the devices for applications such as electronic commerce, communications, and the like.
Typically, remote controls include a set of buttons which correspond to control functions of a device. Remote controls have been improved such that the buttons may be used to control functions of multiple devices. Touch pads or other position sensing devices have been incorporated into remote controls to provide the operator with greater control functionality. Touch pads sense the position of an object such as the operator""s finger or stylus touching the touch pad and convey the position information to the display screen of the device. In response, an object on the display screen such as a cursor moves in correspondence with the position of the object touching the touch pad.
A problem with typical remote controls having integrated touch pads is that the touch pads are only operable in one mode. It is desired that the touch pads be operable in a plurality of modes depending upon the needs of the operator. For example, there are conflicting purposes for remote controls in a slide show meeting environment. On the one hand, there is the executive presenter who has no time to learn about the sophisticated control capabilities that remote controls offer. The executive presenter simply wants to push a forward button to advance slides, a backwards button to reverse slides, and, perhaps, a laser button to embellish message points. On the other hand, another presenter may need extended remote control functions such as computer mousing, program launching, and menu selection. In short, this presenter needs point, click, and drag functionality as well as the forwards, backwards, and laser functionality of the executive presenter. Currently, two different remote controls are used to address the needs of both presenters.
Accordingly, it is an object of the present invention to provide a remote control having a touch pad operable in a plurality of modes.
In carrying out the above object and other objects, the present invention provides a remote control having a touch pad operable in at least two touch pad modes and a switching mechanism operable with the touch pad for switching the touch pad between the at least two touch pad modes. The at least two touch pad modes may include an absolute touch pad mode, a relative touch pad mode, and an annotate touch pad mode.
The remote control may further include at least one control button operable to switch between at least two control button modes. Each of the at least two control button modes corresponds to a respective touch pad mode. The switching mechanism is operable with the at least one control button for switching the at least one control button to the control button mode corresponding to the touch pad mode.
The remote control may also include an indicator operable for displaying at least two control button indicator modes each indicative of a respective control button mode. The switching mechanism is operable with the indicator for switching the indicator to the control button indicator modes corresponding to the control button mode.
The touch pad may include at least two control icons representative of remote control commands. The at least two control icons are enabled when the touch pad is in a first touch pad mode and disabled when the touch pad is in a second touch pad mode. Two respective control icons may be representative of a forward slide remote control command and a backwards slide remote control command. Other respective control icons may be representative of a channel up remote control command, a channel down remote control command, an audio signal up remote control command, and an audio signal down remote control command.
Further, in carrying out the above object and other objects, the present invention provides a remote control for controlling a device having a display screen. This remote control includes a touch pad operable in at least two touch pad modes. In a first touch pad mode the touch pad is mapped relatively to a display screen of a device such that each location of the touch pad corresponds to a respective location of the display screen. In a second touch pad mode the touch pad is mapped absolutely to the display screen as a function of the dimensions of the touch pad and the display screen such that each location of the touch pad corresponds to a respective object displayed on the display screen. The remote control also includes a switching mechanism operable with the touch pad for switching the touch pad between the at least two touch pad modes.
Also, in carrying out the above object and other objects, the present invention provides a remote control for controlling a slide projector device having a display screen. This remote control includes a touch pad operable in at least two touch pad modes. The touch pad includes two control icons respectively representative of a forward slide remote control command for forwarding a slide displayed on the display screen upon actuation and a backwards slide remote control command for reversing a slide displayed on the display screen. The two control icons are enabled when the touch pad is in a first touch pad mode and disabled when the touch pad is in a second touch pad mode. The remote control further includes a switching mechanism operable with the touch pad for switching the touch pad between the at least two touch pad modes.
This remote control may also include at least one control button operable in at least two control button modes including a pointing mode. Each of the at least two control button modes corresponds to a respective touch pad mode. The at least one control button generates a pointing signal for pointing to the display screen when the touch pad is in the first touch pad mode. The switching mechanism is operable with the at least one control button for switching the at least one control button between the at least two control button modes as a function of the at least two positions of the switching mechanism.
In carrying out the above object and other objects, the present invention also provides a remote control for controlling a device. The remote control includes a touch pad operable in at least two touch pad modes. The touch pad includes at least two control icons respectively representative of device control commands. The at least two control icons are enabled when the touch pad is in a first touch pad mode and disabled when the touch pad is in a second touch pad mode. The remote control also includes a switching mechanism operable with the touch pad for switching the touch pad between the at least two touch pad modes.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the present invention when taken in connection with the accompanying drawings.


In a stabilizing device for extending the characteristic diagram of a compressor, which consists of a ring permanently attached to the impeller vanes of the impeller and a recess in the casing of the compressor in the form of a rotationally symmetrical groove, the ring is limited to the inlet region of the impeller and attached there in such a way that on rotation of the impeller, the ring can be moved in the recess, there being only a conventional close clearance between the ring and the wall of the casing. Due to this structure, the formation of a gap flow from the side of the vane at high pressure to that at low pressure is prevented, which leads to an increase in the efficiency of the compressor and to the widening of the compressor characteristic. The vibration loading on the vanes is lowered at the same time.

1. Field of the Invention
The invention relates to a stabilizing device for extending the characteristic diagram of a compressor.
2. Discussion of Background
It is known that during the rotation of a compressor impeller, a gap flow appears in the gap between the rotating outer edges of the impeller vanes and the stationary casing, this flow taking place from the side of the vane at high pressure to that at low pressure. Together with other flow phenomena in the inlet part of the centrifugal impeller, this gap flow can lead to a vortex. Due to this vortex, the efficiency of the compressor is reduced and the stable range of the compressor characteristic becomes narrower.
When turbo-compressors are used, an attempt is made to achieve a steadily falling characteristic, without hysteresis, as the flow increases in order to achieve a high level of reliability during part-load operation. Such continuous characteristics are described as being stable. As the pressure ratio at the design point is increased, however, stable characteristics become more difficult to achieve at part load. For this reason, attempts are made to generate the desired stable characteristics by means of additional stabilizing devices.
The stabilizing device described, for example, in the Patent Specification CH 675 279 consists of a recess in the casing of a centrifugal compressor, a stabilizing ring being integrated in this recess. The recess and the stabilizing ring are arranged in front of the impeller and outside the main flow. Stabilizing vanes are present at the outer periphery of the stabilizing ring and these are anchored on the inner contour of the recess. The disadvantage of this solution consists in the complicated design of the casing, the ring and the stabilizing vanes. In addition, the vibration loading of the impeller vanes in the inlet region, which is large in any case, is further increased by the stabilizing appliance.
A stabilizing device is known to the applicant in which the disadvantages just mentioned are reduced. This device consists of a ring permanently connected to the impeller vanes, a relatively large radial recirculation passage being arranged between the ring and the casing of the compressor. When the compressor is strongly throttled, a recirculation flow is made possible there and this contributes to stabilizing the characteristic diagram. The ring supports the vane inlet edges in both the radial and tangential directions and, by this means, reduces the vane vibrations. The disadvantage of this solution consists in the necessity for a relatively large recirculation passage and the fact that for many centrifugal compressors, the recirculation is undesirably strong.

Stabilizing device for extending the characteristic diagram of a compressor


A 256 Meg dynamic random access memory is comprised of a plurality of cells organized into individual arrays, with the arrays being organized into 32 Meg array blocks, which are organized into 64 Meg quadrants. Sense amplifiers are positioned between adjacent rows in the individual arrays while row decoders are positioned between adjacent columns in the individual arrays. A power bus is provided which minimizes routing of externally supplied voltages, completely rings each of the array blocks, and provides gridded power distribution within each of the array blocks. A plurality of voltage supplies provide the voltages needed in the array and in the peripheral circuits. The power supplies are organized to match their power output to the power demand and to maintain a desired ratio of power production capability and decoupling capacitance. A powerup sequence circuit is provided to control the powerup of the chip.

1. Field of the Invention
The present invention is directed to integrated circuit memory design and, more particularly, to dynamic random access memory (DRAM) designs.
2. Description of the Background
1. Introduction
Random access memories (RAMs) are used in a large number of electronic devices from computers to toys. Perhaps the most demanding applications for such devices are computer applications in which high density memory devices are required to operate at high speeds and low power. To meet the needs of varying applications, two basic types of RAM have been developed. The dynamic random access memory (DRAM) is, in its simplest form, a capacitor in combination with a transistor which acts as a switch. The combination is connected across a digitline and a predetermined voltage with a wordline used to control the state of the transistor. The digitline is used to write information to the capacitor or read information from the capacitor when the signal on the wordline renders the transistor conductive.
In contrast, a static random access memory (SRAM) is comprised of a more complicated circuit which may include a latch. The SRAM architecture also uses digitlines for carrying information to and reading information from each individual memory cell and wordlines to carry control signals.
There are a number of design tradeoffs between DRAM and SRAM devices. Dynamic devices must be periodically refreshed or the data stored will be lost. SRAM devices tend to have faster access times than similarly sized DRAM devices. SRAM devices tend to be more expensive than DRAM devices because the simplicity of the DRAM architecture allows for a much higher density memory to be constructed. For those reasons, SRAM devices tend to be used as cache memory whereas DRAM devices tend to be used to provide the bulk of the memory requirements. As a result, there is tremendous pressure on producers of DRAM devices to produce higher density devices in a cost effective manner.
2. DRAM Architecture
A DRAM chip is a sophisticated device which may be thought of as being comprised of two portions: the array, which is comprised of a plurality of individual memory cells for storing data, and the peripheral devices, which are all of the circuits needed to read information into and out of the array and support the other functions of the chip. The peripheral devices may be further divided into data path elements, address path elements, and all other circuits such as voltage regulators, voltage pumps, redundancy circuits, test logic, etc.
A. The Array
Turning first to the array, the topology of a modern DRAM array 1 is illustrated in FIG. 1. The array 1 is comprised of a plurality of cells 2 with each cell constructed in a similar manner. Each cell is comprised of a rectangular active area, which in FIG. 1 is a N+ active area. A dotted box 3 illustrates where one transistor/capacitor pair is fabricated while a dotted box 4 illustrates where a second transistor/capacitor pair is fabricated. A wordline WL1 runs through dotted box 3, and at least a portion of where that wordline overlays the N+ active area is where the gate of the transistor is formed. To the left of the wordline WL1 in dotted box 3, one terminal of the transistor is connected to a storage node 5 which forms the capacitor. The other terminal of the capacitor is connected to a cell plate. To the right of the wordline WL1, the other terminal of the transistor is connected to a digitline D2 at a digitline contact 6. The transistor/capacitor pair in dotted box 4 is a mirror image of the transistor/capacitor pair in dotted box 3. The transistor within dotted box 4 is connected to its own wordline WL2 while sharing the digitline contact 6 with the transistor in the dotted box 3.
The wordlines WL1 and WL2 may be constructed of polysilicon while the digitline may be constructed of polysilicon or metal. The capacitors may be formed with an oxide-nitride-oxide-dielectric between two polysilicon layers. In some processes, the wordline polysilicon is silicided to reduce the resistance which permits longer wordline segments without impacting speed.
The digitline pitch, which is the width of the digitline plus the space between digitlines, dictates the active area pitch and the capacitor pitch. Process engineers adjust the active area width and the resulting field oxide width to maximize transistor drive and minimize transistor-to-transistor leakage. In a similar manner, the wordline pitch dictates the space available for the digitline contact, transistor length, active area length, field poly width, and capacitor length. Each of those features is closely balanced by process engineers to maximize capacitance and yield and to minimize leakage.
B. The Data Path Elements
The data path is divided into the data read path and the data write path. The first element of the data read path, and the last element of the data write path, is the sense amplifier. The sense amplifier is actually a collection of circuits that pitch up to the digitlines of a DRAM array. That is, the physical layout of each circuit within the sense amplifier is constrained by the digitline pitch. For example, the sense amplifiers for a specific digitline pair are generally laid out within the space of four digitlines. One sense amplifier for every four digitlines is commonly referred to as quarter pitch or four pitch.
The circuits typically comprising the sense amplifier include isolation transistors, circuits for digitline equilibration and bias, one or more N-sense amplifiers, one or more P-sense amplifiers, and I/O transistors for connecting the digitlines to the I/O signal lines. Each of those circuits will be discussed.
Isolation transistors provide two functions. First, if the sense amplifiers are positioned between and connected to two arrays, they electrically isolate one of the two arrays. Second, the isolation transistors provide resistance between the sense amplifier and the highly capacitive digitlines, thereby stabilizing the sense amplifier and speeding up the sensing operation. The isolation transistors are responsive to a signal produced by an isolation driver. The isolation driver drives the isolation signal to the supply potential and then drives the signal to a pumped potential which is equal to the value of the charge on the digit lines plus the threshold voltage of the isolation transistors.
The purpose of the equilibration and bias circuits is to ensure that the digitlines are at the proper voltages to enable a read operation to be performed. The N-sense amplifiers and P-sense amplifiers work together to detect the signal voltage appearing on the digitlines in a read operation and to locally drive the digitlines in a write operation. Finally, the I/O transistors allow data to be transferred between digitlines and I/O signal lines.
After data is read from an mbit and latched by the sense amplifier, it propagates through the I/O transistors onto the I/O signal lines and into a DC sense amplifier. The I/O lines are equilibrated and biased to a voltage approaching the peripheral voltage Vcc. The DC sense amplifier is sometimes referred to as the data amplifier or read amplifier. The DC sense amplifier is a high speed, high gain, differential amplifier for amplifying very small read signals appearing on the I/O lines into full CMOS data signals input to an output data buffer. In most designs, the array sense amplifiers have very limited drive capability and are unable to drive the I/O lines quickly. Because the DC sense amplifier has a very high gain, it amplifies even the slightest separation in the I/O lines into full CMOS levels.
The read data path proceeds from the DC sense amplifier to the output buffers either directly or through data read multiplexers (muxes). Data read muxes are commonly used to accommodate multiple part configurations with a single design. For an x16 part, each output buffer has access to only one data read line pair. For an x8 part, the eight output buffers each have two pairs of data lines available thereby doubling the quantity of mbits accessible by each output. Similarly, for a x4 part, the four output buffers have four pairs of datalines available, again doubling the quantity of mbits available for each output.
The final element in the read data path is the output buffer circuit. The output buffer circuit consists of an output latch and an output driver circuit. The output driver circuit typically uses a plurality of transistors to drive an output pad to a predetermined voltage, Vccx or ground, typically indicating a logic level 1 or logic level 0, respectively.
A typical DRAM data path is bidirectional, allowing data to be both read from and written to the array. Some circuits, however, are truly bidirectional, operating the same regardless of the direction of the data. An example of such bidirectional circuits is the sense amplifiers. Most of the circuits, however, are unidirectional, operating on data in only a read operation or a write operation. The DC sense amplifiers, data read muxes, and output buffer circuits are examples of unidirectional circuits. Therefore, to support data flow in both directions, unidirectional circuits must be provided in complementary pairs, one for reading and one for writing. The complementary circuits provided in the data write path are the data input buffers, data write muxes, and write driver circuits.
The data input buffers consist of both nMOS and pMOS transistors, basically forming a pair of cascaded inverters. Data write muxes, like data read muxes, are often used to extend the versatility of a design. While some DRAM designs connect the input buffer directly to the write driver circuits, most architectures place a block of data write muxes between the input buffers and the write drivers. The muxes allow a given DRAM design to support multiple configurations, such as x4, x8, and x16 parts. For x16 operation, each input buffer is muxed to only one set of data write lines. For x8 operation, each input buffer is muxed to two sets of data write lines, doubling the quantity of mbits available to each input buffer. For x4 operation, each input buffer is muxed to four sets of data writelines, again doubling the number of mbits available to the remaining four operable input buffers. As the quantity of input buffers is reduced, the amount of column address space is increased for the remaining buffers.
A given write driver is generally connected to only one set of I/O lines, unless multiple sets of I/O lines are fed by a single write driver via additional muxes. The write driver uses a tri-state output stage to connect to the I/O lines. Tri-state outputs are necessary because the I/O lines are used for both read and write operations. The write driver remains in a high impedance state unless the signal labeled "write" is high, indicating a write operation. The drive transistors are sized large enough to insure a quick, efficient, write operation.
The remaining element of the data write path is, as mentioned, the bidirectional sense amplifier which is connected directly to the array.
C. The Address Path Elements
Up to this point we have been discussing data paths. The movement of data into or out of a particular location within the array is performed under the control of address information. We next turn to a discussion of the address path elements.
Since the 4 Kb generation of DRAMs, DRAMs have used multiplexed addresses. Multiplexing in DRAMs is possible because DRAM operation is sequential. That is, column operations follow row operations. Thus, the column address is not needed until the sense amplifiers for an identified row have latched, and that does not occur until sometime after the wordline has fired. DRAMs operate at higher current levels with multiplexed addressing, because an entire page (row address) is opened with each row access. That disadvantage is overcome by the lower packaging costs associated with multiplexed addresses. Additionally, because of the presence of the column address strobe signal (CAS*), column operation is independent of row operation, enabling a page to remain open for multiple, high-speed, column accesses. That page mode type of operation improves system performance because column access time is much shorter than row access time. Page mode operation appears in more advanced forms, such as extended data out (EDO) and burst EDO (BEDO), providing even better system performance through a reduction in effective column access time.
The address path for a DRAM can be broken into two parts: the row address path and the column address path. The design of each path is dictated by a unique set of requirements. The address path, unlike the data path, is unidirectional. That is, address information flows only into the DRAM. The address path must achieve a high level of performance with minimal power and die area, just like every other aspect of DRAM design. Both paths are designed to minimize propagation delay and maximize DRAM performance.
The row address path encompasses all of the circuits from the address input pad to the wordline driver. Those circuits generally include the row address input buffers, CAS before RAS counter (CBR counter), predecode logic, array buffers, redundancy logic (treated separately hereinbelow), row decoders, and phase drivers.
The row address buffer consists of a standard input buffer and the additional circuits necessary to implement functions required for the row address path. The CBR counter consists of a single inverter and a pair of inverter latches coupled to a pair of complementary muxes to form a one bit counter. All of the CBR counters from each row address buffer are cascaded together to form a CBR ripple counter. By cycling through all possible row address combinations in a minimum of clock pulses, the CBR ripple counter provides a simple means of internally generating refresh addresses.
There are many types of predecode logic used for the row address path. Predecoded address lines may be formed by logically combining (AND) addresses as shown in Table 1.
TABLE 1Predecoded address truth tablePR01RA<0>RA<1>(n)PR01<0>PR01<1>PR01<2>PR01<3>0001000101010001200101130001The remaining addresses are identically coded except for RA<12>, which is essentially a "don't care". Advantages to predecoded addresses include lower power due to fewer signals making transitions during address changes and higher efficiency because of the reduced number of transistors necessary to decode addresses. Predecoding is especially beneficial in redundancy circuits. Predecoded addresses are used throughout most DRAM designs today.
Array buffers drive the predecoded address signals into the row decoders. In general, the buffers are no more than cascaded inverters, but in some cases they may include static logic gates or level translators, depending upon the row decoder requirements.
Row decoders must pitch up to the mbit arrays. There are a variety of implementations, but however implemented, the row decoder essentially consists of two elements: a wordline driver and an address decoder tree. With respect to the wordline driver, there are three basic configurations: the NOR driver, the inverter (CMOS) driver, and the bootstrap driver. Just about any type of logic may be used for the address decoder tree. Static logic, dynamic logic such as precharge and evaluate logic, pass gate logic, or some combination thereof may be provided to decode the predecoded address signals.
Additionally, the drivers and associated decode trees can be configured either as local row decodes for each array section or as global row decodes that drive a multitude of array sections.
The wordline driver in the row decoder causes the wordline to fire in response to a signal called PHASE. Essentially, the PHASE signal is the final address term to arrive at the wordline driver. Its timing is carefully determined by the control logic. PHASE cannot fire until the row addresses are set up in the decode tree. Normally, the timing of PHASE also includes enough time for the row redundancy circuits to evaluate the current address. The phase driver can be composed of standard static logic gates.
The column address path consists of the input buffers, address transition detection (ATD) circuits, predecode logic, redundancy logic (discussed below), and column decoders. The column address input buffers are similar in construction and operation to the row address input buffers. The ATD circuit detects any transition that occurs on an address pin to which the circuit is dedicated. ATD output signals from all of the column addresses are routed to an equilibration driver circuit. The equilibration driver circuit generates a set of equilibration signals for the DRAM. The first of these signals is Equilibrate I/O (EQIO) which is used in the arrays to force equilibration of the I/O lines. The second signal generated by the equilibration driver is called Equilibrate Sense Amps (EQSA). That signal is generated from address transitions occurring on all of the column addresses, including the least significant address.
The column addresses are fed into predecode logic which is very similar to the row address predecode logic. The address signals emanating from the predecode logic are buffered and distributed throughout the die to feed the column decoders.
The column decoders represent the final elements that must pitch up to the array mbits. Unlike row decoder implementation, though, column decoder implementation is simple and straightforward. Static logic gates may be used for both the decode tree elements and the driver output. Static logic is used primarily because of the nature of column addressing. Unlike row addressing, which occurs once per RAS* cycle with a modest precharge period until the next cycle, column addressing can occur multiple times per RAS* cycle. Each column is held open until a subsequent column appears. In a typical implementation, the address tree consists of combinations of NAND or NOR gates. The column decoder output driver is a simple CMOS inverter.
The row and column addressing scheme impacts the refresh rate for the DRAM. Normally, when refresh rates change for a DRAM, a higher order address is treated as a "don't care" address, thereby decreasing the row address space, but increasing the column address space. For example, a 16 Mb DRAM bonded as a 4 Mb x4 part could be configured in several refresh rates: 1K, 2K, and 4K. Table 1 below shows how row and column addressing is related to those refresh rates for the 16 Mb example. In this example, the 2K refresh rate would be more popular because it has an equal number of row and column addresses, sometimes referred to as square addressing.
TABLE 2Refresh rate versus row and column addressesRefreshRowColumnRateRowsColumnsAddressesAddresses4K4096102412102K2048204811111K102440961012
D. Other Circuits
Additional circuits are provided to enable various other features. For example, circuits to enable test modes are typically included in DRAM designs to extend test capabilities, speed component testing, or subject a part to conditions that are not seen during normal operation. Two examples are address compression and data compression which are two special test modes usually supported by the design of the data path. Compression test modes yield shorter test times by allowing data from multiple array locations to be tested and compressed on-chip, thereby reducing the effective memory size. The costs of any additional circuitry to implement test modes must be balanced against cost benefits derived from reductions in test time. It is also important that operation in test mode achieve 100% correlation to operation of non-test mode. Correlation is often difficult to achieve, however, because additional circuitry must be activated during compression, modifying the noise and power characteristics on the die.
Additional circuitry is added to the DRAM to provide redundancy. Redundancy has been used in DRAM designs since the 256 Kb generation to improve yield. Redundancy involves the creation of spare rows and columns which can be used as a substitute for normal rows and columns, respectively, which are found to be defective. Additional circuitry is provided to control the physical encoding which enables the substitution of a usable device for a defective device. The importance of redundancy has continued to increase as memory density and size have increased.
The concept of row redundancy involves replacing bad wordlines with good wordlines. The row to be repaired is not physically replaced, but rather it is logically replaced. In essence, whenever a row address is strobed into a DRAM by RAS*, the address is compared to the addresses of known bad rows. If the address comparison produces a match, then a replacement wordline is fired in place of the normal (bad) wordline. The replacement wordline can reside anywhere on the DRAM. Its location is not restricted to the array that contains the normal wordline, although architectural considerations may restrict its range. In general, the redundancy is considered local if the redundant wordline and normal wordline must always be on the same subarray.
Column redundancy is a second type of repair available in most DRAM designs. Recall that column accesses can occur multiple times per RAS* cycle. Each column is held open until a subsequent column appears. Because of that, circuits that are very different from those seen in the row redundancy are used to implement column redundancy.
The DRAM circuit also carries a number of circuits for providing the various voltages used throughout the circuit.
3. Design Considerations
U.S. patent application Ser. No. 08/460,234, entitled Single Deposition Layer Metal Dynamic Random Access Memory, filed 17 Aug. 1995 and assigned to the same assignee as the present invention is directed to a 16 Meg DRAM. U.S. patent application Ser. No. 08/420,943, entitled Dynamic Random Access Memory, filed 4 Jun. 1995 and assigned to the same assignee as the present invention is directed to a 64 Meg DRAM. As will be seen from a comparison of the two aforementioned patent applications, it is not a simple matter to quadruple the size of a DRAM. Quadrupling the size of a 64 Meg DRAM to a 256 Meg DRAM poses a substantial number of problems for the design engineer. For example, to standardize the part so that 256 Meg DRAMs from different manufacturers can be interchanged, a standard pin configuration has been established. The location of the pins places constraints on the design engineer with respect to where circuits may be laid out on the die. Thus, the entire layout of the chip must be reengineered so as to minimize wire runs, eliminate hot spots, simplify the architecture, etc.
Another problem faced by the design engineer in designing a 256 Meg DRAM is the design of the array itself. Using prior art array architectures does not provide sufficient space for all of the components which must pitch up to the array.
Another problem involves the design of the data path. The data path between the cells and the output pads must be as short as possible so as to minimize line lengths to speed up part operation while at the same time present a design which can be manufactured using existing processes and machines.
Another problem faced by the design engineer involves the issue of redundancy. A 256 Meg DRAM requires the fabrication of millions of individual devices, and millions of contacts and vias to enable those devices to be interconnected. With such a large number of components and interconnections, even a very small failure rate results in a certain number of defects per die. Accordingly, it is necessary to design redundancy schemes to compensate for such failures. However, without practical experience in manufacturing the part and learning what failures are likely to occur, it is difficult to predict the type and amount of redundancy which must be provided.
Another problem involves latch-up in the isolation driver circuit when the pumped potential is driven to ground. Latch-up occurs when parasitic components give rise to the establishment of low-resistance paths between the supply potential and ground. A large amount of current flows along the low-resistance paths and device failure may result.
Designing the on-chip test capability also presents problems. Test modes, as opposed to normal operating modes are used to test memory integrated circuits. Because of the limited number of pins available and the large number of components which must be tested, without some type of test compression architecture, the time which each DRAM would have to spend in a test fixture would be so long as to be commercially unreasonable. It is known to use test modes to reduce the amount of time required to test the memory integrated circuit, as well as to ensure that the memory integrated circuit meets or exceeds performance requirements. Putting a memory integrated circuit into a test mode is described in U.S. Pat. No. 5,155,704, entitled "Memory Integrated Circuit Test mode Switching" to Walther et al. However, because the test mode operates internal to the memory, it is difficult to determine whether the memory integrated circuit successfully completed one or more test modes. Therefore, a need exists for providing a solution to verify successful or unsuccessful execution of a test mode. Furthermore, it would be desirable that such a solution have minimal impact with respect to additional circuitry. Certain test modes, such as the all row high test mode, must be rethought with respect to a part as large as a 256 Meg chip because the current required for such a test would destroy power transistors servicing the array.
Providing power for a chip as large as a 256 Meg DRAM also presents its own set of unique problems. Refresh rates may cause the power needed to vary greatly. Providing voltage pumps and generators of sufficient size to provide the necessary power may result in noise and other undesirable side effects when maximum power is not required. Additionally, reconfiguring the DRAM to achieve a usable part in the event of component failure may result in voltage pumps and generators ill sized for the smaller part.
Even something as basic as powering up the device must be rethought in the context of such a large and complicated device as a 256 Meg DRAM. Prior art timing circuits use an RC circuit to wait a predetermined period of time and then blindly bring up the various voltage pumps and generators. Such systems do not receive feedback and, therefore, are not responsive to problems during power up. Also, to work reliably, such systems are conservative in the event some voltage pumps or generators operated more slowly than others. As a result, in most cases, the power up sequence was more time consuming than it needed to be. In a device as complicated as a 256 Meg DRAM, it is necessary to ensure that the device powers up in a manner that permits the device to be properly operated in a minimum amount of time.
All of the foregoing problems are superimposed upon the problems which every memory design engineer faces such as satisfying the parameters set for the memory, e.g., access time, power consumption, etc., while at the same time laying out each and every one of millions of components and interconnections in a manner so as to maximize yield and minimize defects. Thus, the need exists for a 256 Meg DRAM which overcomes the foregoing problems.


A method for regenerating foundry sand, in particular for the renewed production of foundry molds and/or foundry mold cores from the regenerated foundry sand, through removal of binding agent, from a foundry sand/binding agent mixture, using a solid support means (6), wherein binding agent and support means (6) are separated from the foundry sand, wherein support means (6) is brought into contact with the foundry sand/binding agent mixture, is preferably added to it, and, together with the binding agent, which adheres thereto and/or which is incorporated therein, is separated from the foundry sand (10).

The invention relates to a method for regenerating foundry sand, in particular for the renewed production of foundry molds and/or foundry mold cores from the regenerated foundry sand, through removal of inorganic binding agent, such as, for example water glass or organic binding agent, from a foundry sand/binding agent mixture, using a preferably absorbent and/or adsorbent, solid (i.e. not having a liquid aggregate state, but being formed by a solid body or solid substance, respectively), support means, wherein binding agent and support means are separated from the foundry sand.
The invention further relates to a (regenerating) device for foundry sand, which is embodied for carrying out the proposed regenerating method, comprising means for bringing solid support means and foundry sand into contact.
For economic reasons, the foundry industry strives to reuse foundry sand, i.e. to supply the foundry sand, which has already been used at least once for cores or molds, to a sand cycle. It is known that the foundry sand comprising increasing binder portions (binding agent portions) no longer meets the sand quality demands for a casting process, i.e. one strives to separate the binding agent from the foundry sand as much as possible. Prior to being reused, the foundry sand has to furthermore be pourable, which requires a drying of the sand for the case of a cleaning with water.
A large variety of foundry sand treatment methods have become known, which are very energy-intensive, in particular for the case that they require the use of larger quantities of water or if the regenerating process requires high temperatures.
Reference is thus made for example to DE-OS-18 06 842. The latter describes a thermal method for regenerating foundry sand, wherein, according to the teaching of the publication, the foundry sand is annealed at 1000° C. and binding residues are removed subsequently, namely by means of sudden cool-down, rubbing or smashing and air separation.
DE 199 343 060 007 A1 describes a regenerating method for water glass-bonded foundry sands, which requires a heating of the sand to above 200° C. A similar demand is made in the case of the method known from DE 20 2008 018 001 U1. Here, the foundry sand is treated in a rotary kiln or in a fluidized bed, whereby a screening and air separation can follow.
WO 2013/026 579 A1 describes a mechanical-thermal regenerating method, by means of which the treated foundry sand is to reach new sand-like properties. The sand to be regenerated is thereby initially treated in a pneumatic treatment chamber and is then supplied to a thermal regenerating stage. However, a hardener for water glass is added to the foundry sand prior to the thermal treatment.
DE-OS-24 08 981 describes a mechanical regenerating method, in which foundry sand is radially accelerated at a high speed by means of a centrifugal plate and smashes into a sand cushion. As a result of the sand flow, which falls to the bottom after the impact, an air stream is guided, which is to discharge fine particles, which were created during the impact.
A different mechanical regenerating principle is described in DE 43 16 610 A1.
To date, the purely mechanical and/or thermal regenerating methods do not provide any satisfactory separating results based on the binding agent on an industrial scale.
DE 100 38 419 A1 describes a wet regenerating method, by means of which the sand is regenerated by adding water until the formation of a mushy mass and movement of the mush by means of external forces, rinsing out the sand with water, discharging the water for the neutralization thereof, as well as draining and drying the sand. Good separating results are assumed here, but the large quantities of water required here are unwanted and also dangerous in foundries. In addition, significant energy inputs are required to dry the sand and to evaporate the large quantities of water. The accumulating washing water also has to be regenerated.
A wet regenerating method has also become known from DE 10 2005 029 742 B3, in which one of two partial sand flows is wet-regenerated, which means that the binding agent is rinsed out with the help of large quantities of water and the free liquid is then separated. It is further known from the publication to mix the cleaned foundry sand after being washed with a substance, which absorbs the moisture of the sand grain surface, so as to reduce the energy input for the drying of the cleaned foundry sand. This substance is added in the form of grains, which are larger than the foundry sand grains, so as to separate the substance grains from the cleaned foundry sand by means of screening. According to the teaching of DE 10 2005 029 742 B3, the drying of the cleaned foundry sand thus takes place without heating the latter.
The cleaned and dried foundry sand is mixed with untreated foundry sand, whereby the binding agent portion increases again. The substance grains, which are separated from the cleaned foundry sand, can then be dried. As mentioned, the known method assumes the mixing of the cleaned and dried foundry sand flow with an untreated foundry sand flow, whereby even though the energy input as a whole is low, the sand properties for the foundry operation need to be improved as a result of the binding agent portion, which is still comparatively high. Large quantities of water are furthermore required for the washing process, which precedes the drying process, which has the disadvantages as already described above.

Method and device for regenerating foundry sand


A MEMS device and a method for manufacturing a MEMS device are provided. The MEMS device includes an anchor, a diaphragm structure, and a sealing film. The diaphragm structure is disposed over the anchor and has an opening through the diaphragm structure. The sealing film covers at least a portion of the opening of the diaphragm structure.

With the advancement of electronic technology, microelectromechanical system (MEMS) devices such as speakers and microphones, are widely used in various electronic products including mobile phones, headphones, and wireless ear pods, due to the advantages such as shrunk dimension, reduced power consumption, and capability of being integrated into on-chip circuits.
Generally, MEMS speakers and microphones include a movable membrane or diaphragm which can make out-of-plane movement during operation. For MEMS speakers, the membrane or diaphragm is actuated to vibrate to generate sound waves, while for MEMS microphones, the membrane or diaphragm is actuated to vibrate by sound pressure. It is required for MEMS speakers to have higher sound pressure level (SPL) and for MEMS microphones to have higher sensitivity of sound. The vibration of the membrane or diaphragm influences the performance of the MEMS speakers and microphones. As the demand for MEMS devices is increased, MEMS devices and methods for manufacturing MEMS devices still need to be optimized in order to achieve better performance and more economic manufacturing.

MEMS device and manufacturing method thereof

TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.


The present disclosure provides an OLED display substrate including a substrate, a pixel defining layer on the substrate, for defining a plurality of sub-pixel regions having different colors; and cavity length adjusting layers in the sub-pixel regions, wherein the cavity length adjusting layers comprise a conductive ink, and the cavity length adjusting layers have different thicknesses in the sub-pixel regions having different colors.

Organic Light-emitting Diode (OLED) display technology has become a research hotspot in the field of optoelectronic display technology due to its advantages of self-illumination, wide viewing angle, high contrast, low power consumption, high reaction speed, ultra-light weight and thinness, flexible display, foldable screen, temperature adaptation, simple manufacturing process, etc. Full color display is an important indicator to verify whether a display device is competitive in the market, so many full colorization technologies are also applied to OLED display devices and are usually divided into three types based on panel types: individual pixel illumination (such as red, green and blue pixels (RGB)), color conversion and color filter. The color filter technology achieves color display by using a white OLED in conjunction with color filters. In order to improve the color purity of the OLED light source, microcavity structures are generally disposed in an OLED display substrate, that is, optical resonant cavities (i.e., the foregoing microcavity structures) are formed between the anode and the cathode of the OLED. The light emitted by a light emitting layer is emitted out after travelling through an optical resonant cavity, which can perform multi-level reflection, total reflection, diffraction or scattering on the light, so that the light emitted from the cathode can be limited to have a wavelength in a small wavelength range, thereby improving the color purity of the light emitted from the OLED. White light emitted from the cathode is filtered by a color filter to obtain a corresponding pixel color, thereby achieving color display.

Organic light-emitting diode display substrate and method for fabricating the same, display device


Vinylamine-containing polymers are disclosed where the amine groups are substituted with (1) cationic functional groups, (2) anionic functional groups, (3) hydrophobic functional groups, (4) hydrophilic functional groups, (5) functional groups that impart amphoteric characteristics to the polymers, or (6) combinations thereof. Also disclosed are processes for preparing such polymers, as well as compositions comprising such polymers. Among other applications, these polymers can be used in papermaking applications as dry strength additives, wet strength additives, retention aids, drainage aids, and pitch and stickies control agents.

Both partially hydrolyzed polyvinylformamide or fully hydrolyzed polyvinylformamide (i.e., polyvinylamine) can be used as dry strength additives, wet strength additives, retention aids, and drainage aids in papermaking. Polyvinylamine is highly cationic due to its high density of primary amine or amidine functionality. These polymers possess strong hydrogen bonding ability as a result of this high density of primary amine groups. U.S. Pat. No. 2,721,140 discloses use of polyvinylamine as an additive to make papers having high wet strength, while U.S. Pat. No. 5,961,782 discloses use of polyvinylamine to make crosslinkable creping adhesive formulations. U.S. Pat. No. 4,421,602 discloses a partially hydrolyzed, water-soluble polymer of N-vinylformamide that contains N-vinylformamide units and vinylamine units. It also discloses use of polyvinylamine and a 50% hydrolyzed polyvinylformamide to increase flocculation efficiencies, fines retention, and the drainage rate of pulp fiber in papermaking processes, while U.S. Pat. No. 6,159,340 discloses the use of such polymers as dry and wet strength additives in paper and paperboard production. U.S. Pat. Nos. 6,616,807 and 6,797,785 disclose use of polyvinylamines as drainage aids, flocculants, and retention aids in the paper making.
Polyvinylamines are typically made by solution, free-radical polymerization of N-vinylformamide monomer, followed by base- or acid-catalyzed hydrolysis, whereby the primary amine in the polymer backbone is deprotected, releasing formic acid. U.S. Pat. No. 4,774,285 discloses that N-vinylformamide monomer may be copolymerized with an additional vinyl monomer, e.g., vinyl acetate, and subsequently hydrolyzed to produce a water-soluble copolymer of vinylamine and vinyl alcohol, which may be used as wet and dry strength additives for papermaking. U.S. Pat. No. 5,630,907 discloses copolymer compositions containing both vinylamine and acrylic acid units, as well as their applications. U.S. Pat. No. 6,824,650 discloses using a polyvinylamine polymer with a polymeric anionic reactive compound to improve paper strength. U.S. Pat. No. 6,797,785 discloses copolymers containing vinylamine units in combination with either diallyldimethylammonium (chloride) (DADMAC) or acrylamide units via reverse emulsion polymerization, and their use as flocculants and coagulants in papermaking. EP 0251182 discloses copolymers containing vinylamine and acrylonitrile units for use in papermaking as drainage aids, retention aids, as well as wet end additives for increasing the dry strength of paper products. In general, these copolymers contain vinylamine units and additional vinyl units linked together randomly through carbon-carbon bonds in a linear fashion, where the additional vinyl units reduce the density of vinylamine units in the polymer backbone, thereby giving it a lower cationic charge density as compared to polyvinylamine homopolymer.
The amine functionality of polyvinylamine can react with a variety of compounds having reactive functional groups. Post-polymerization chemical modification of polyvinylamine with functional groups is an alternative approach to produce polyvinylamine derivatives with altered physical and application properties. U.S. Pat. No. 5,292,441 discloses the use of quaternized polyvinylamines as flocculants for wastewater clarification, where the quaternized polyvinylamines are obtained from the reaction of polyvinylamine with a quaternizing agent, such as methyl chloride, dimethyl sulfate, or benzyl chloride. U.S. Pat. No. 6,864,330 discloses a PEG grafted polyvinylamine derivative and also discloses that primary amines of the grafted polymer can be further cationized by reacting with an epoxide that contains the quaternary ammonium group. The grafted polymers are prepared by polymerizing vinylformamide in the presence of a PEG through free radical polymerization and are structurally different from polyvinylamine homopolymer and the copolymers. U.S. Pat. No. 5,994,449 discloses a resin composition that is the reaction product of epihalohydrin with a mixture of a poly(vinylamine-co-vinyl alcohol) copolymer and a polyaminoamide, as well as the use of these compositions as a creping adhesives.

This patent is subject to a terminal disclaimer.

Modified vinylamine-containing polymers as additives in papermaking


Disclosed is a syringe pump apparatus adapted to have a syringe mounted thereon so as to supply in a specified amount per specified unit of time an aqueous solution such as medication within the syringe. A first shaft is fixed to a slider for causing a piston portion of the syringe to operate. Between this slider and a drive motor there are provided a block and a second shaft, the block being provided with an overload detecting mechanism. When the movement of the slider is forcedly stopped during a time period in which the slider is being moved through driving of the drive motor, the resulting load is transmitted to the first shaft in response to the forced stoppage of the slider. In accordance with this load, the overload detecting mechanism detects the state of overload of the slider. Then, when the value detected has exceeded a specified value, the drive motor is stopped by a drive halting mechanism.

The present invention relates to a syringe pump apparatus which is adapted to deliver to and infuse into a patient a specified amount of aqueous solution per specified unit of time from a syringe within which the aqueous solution such as, for example, a medication is accommodated and, more particularly, to a syringe pump apparatus which is equipped with a drive halting mechanism adapted to halt the driving of the pumping operation when an overload has been produced in a slider section.
Conventionally, in this type of syringe pump apparatus, supply of aqueous solution is performed in the following manner. Firstly, a syringe within which an aqueous solution is accommodated is placed on a syringe holding section and, then, a flange portion of this syringe is fitted into an engaging groove formed in the syringe holding section. Then, a piston portion thereof is engaged with an engaging portion formed in a slider section Thus, the syringe is fixed to the syringe pump. Then, after having adjusted the flow rate of the aqueous solution to be infused into a patient, the syringe is pressed from above by a clamp means to thereby fixedly mount the syringe on a main body of the syringe pump apparatus. The height of the syringe is detected by a photosensor provided in the clamp means and the detection signal thus obtained is sent to the slider mechanism. Thus, the distance of the slider to be moved is determined. Thereafter, when a drive motor involved is caused to rotate, the slider mechanism is caused to operate. As a result, a specified amount of aqueous solution is infused from the syringe into the patient by way of a tube.
By the way, in the syringe pump apparatus having the described construction, it is necessary to stop the driving of the syringe pump apparatus when the aqueous solution within the syringe comes to be zero with the result that an outer casing and the slider abut against each other, or when, for example, the tube connected to the syringe has been bent or squeezed with the result that it is impossible to extrude the aqueous solution within the syringe.
A conventional halting mechanism for halting the syringe pump apparatus is arranged as follows. Namely, a drive motor is installed in the casing and has a rotational gear. This rotational gear is caused to mesh with a gear provided on a feed screw for forward movement of the slider via intermediate gears. The feed screw is thereby caused to rotate. On the other hand, the slider section has a pipe shaft on which there is provided a block section, the block section having a shaft provided thereon Said rotation of the feed screw causes the slider to be forwardly moved by the intermeshing of the feed screw with the shaft provided on the block section.
With this construction, when the slider is brought to the stoppage, it results that the rotation of the feed screw is stopped, while the drive motor is rotated. As a result, the gear provided on the feed screw and the intermediate gears cease to be rotated. For this reason, the rotational gear of the drive motor gradually undergoes application of the load. This load is gradually increased to become an overload, by means of the intermediate gears and by way of a spring. This brings about a state wherein a detecting plate connected to the spring is caused to project outside the box concerned. Changes in area of this projected portion of the detecting plate are detected or sensed by a microswith installed outside the drive motor. When the area of that projection has reached a specified value, a stop signal is delivered from the microswitch to the drive motor, thereby stopping the operation of the syringe pump apparatus.
In the conventional syringe pump apparatus having the described construction, the structure or construction of the halting mechanism becomes very complicated and, at the same time, transmitting stages until the pumping operation is stopped are very large in number. Accordingly, there arises a problem that a large amount of time (6 to 8 hours) is required to be spent from the stoppage of the slide to the halt of the pumping operation.


A method for determining an estimation of a topological support of a tubular based structure comprising an inner wall and a plurality of distinct regions, the method comprising (a) obtaining image data representative of the tubular based structure; (b) placing an initial seed in an initial region selected from one of the distinct regions; (c) performing an initial region growing until an initial resulting area comprises at least a portion of the inner wall and at least a portion of a neighboring region corresponding to one of the distinct regions; (d) starting a tree comprising an initial tree node corresponding to the initial region; (e) for each neighboring region: placing a subsequent seed in the neighboring region; performing a corresponding subsequent region growing until a subsequent resulting area comprises at least a portion of the inner wall and at least a portion of an additional neighboring region; and adding a tree node corresponding to the neighboring region in the tree; (f) performing processing step (e) for each of the additional neighboring regions; and (g) filtering the tree according to predetermined topological parameters to thereby determine the estimation of the topological support of the tubular based structure. Applications of the method for estimating a colon topology for virtual colonoscopy are also disclosed.

Conventional endoscopic procedures typically rely on the use of a flexible fiber optic tube which is inserted in the patient's body to visually examine an inner anatomical structure. The operator can then manipulate the tube inside the anatomical structure to search for any anatomical abnormalities.
Conventional colonoscopies using this procedure, although reliable, are both costly in money and time. Moreover, it is an invasive, uncomfortable and sometimes painful procedure for the patient.
Non-invasive procedures, also called virtual colonoscopies, have been used to reduce at least one of the above mentioned drawbacks of the invasive colonoscopic procedure.
These non-invasive procedures use imaging techniques such as a computed tomography (CT) scanning to obtain image data representative of the anatomical structure to analyze.
They also involve three typical patient preparation procedures: a full cathartic preparation that aims at completely cleansing the colon by using a laxative solution, a mild-laxative preparation that aims at fluidifying the colon materials and tagging any remnant solid of liquid materials, and finally a laxative-free preparation where the materials inside the colon are tagged by a solution drunk by the patient, such as a barium-based preparation.
Different automatic techniques have been proposed to locate the anatomical structure under analysis such as the colon's inner wall. However, these techniques often have difficulties to correctly locate the surface of the inner wall of the colon, especially near the interfaces between air regions and tagged regions extending therein.
In fact, if an air region-tagged region interface is not correctly identified, it may lead to leakage in the identification and location of the colon's inner wall, which is a great concern. For example, a portion of the small bowel lying proximate to the colon may be segmented and identified as a portion of the colon.
Moreover, a poor colon's inner wall segmentation may lead to over- or under-evaluation of a potential colonic lesion, which is also a great concern.
In order to reduce the above-mentioned drawbacks, dynamical algorithms using local parameters for identifying a corresponding portion of the colon's inner wall have been used.
For example, US patent application published under publication number 2008/0008367, describes a two-step segmentation method performing an initial trial segmentation enabling leakage prior to a subsequent tailored segmentation. This method however requires that the air region-tagged region interfaces be properly detected. In the case wherein an interface is too thick or inhomogeneous, the method may not properly provide a correct identification and/or location of the colon's inner wall.
Moreover, in the case the colon of the patient is collapsed due to a spasm of the patient during the image acquisition and/or the presence of an obstructive tumor, the method may not be capable of providing a correct identification of the entire colon.
It would therefore be desirable to provide an improved method for determining an estimation of a topological support of a tubular structure that will reduce at least one of the above-mentioned drawbacks.

Method for determining an estimation of a topological support of a tubular structure and use thereof in virtual endoscopy


A surface inspection apparatus comprises: a light source section that emits a first luminous flux and a second luminous flux; an irradiation optical system that irradiates the first luminous flux and the second luminous flux on the surface of the film-coated inspection subject; a displacement section that relatively displaces the film-coated inspection subject and an irradiation luminous flux from the irradiation optical system; a light-receiving optical system that receives scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the first luminous flux from the irradiation optical system and scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the second luminous flux from the irradiation optical system; a first light-receiving section that transforms the scattered light of the first luminous flux received by the light-receiving optical system into a first light reception signal; a second light-receiving section that transforms the scattered light of the second luminous flux received by the light-receiving optical system into a second light reception signal; and a sensitivity stabilizing section that synthesizes the first light reception signal and the second light reception signal to form a signal for sampling.

1. Field of the Invention
The present invention relates to a surface inspection apparatus to inspect an inspection subject (such as a particle and a flaw) on the surface of a film-coated wafer or other film-coated inspection subjects.
2. Related Art
Conventionally, when inspecting the surface of a transmissive film, a metal film, or the like of the film-coated wafer, a luminous flux has been made incident with a low angle to detect a particle on the surface. However, in surface inspection of the film-coated wafer on which the transmissive film was formed, reflectivity has varied depending on a film thickness and a material of the transmissive film and it has not been possible to ensure detection sensitivity at a constant level when the film thickness was not uniform.
When the film thickness was fixed, a plane of polarization has been switched in P-polarized light, S-polarized light, circular polarized light, and PS-polarized light to find optimum polarization conditions, and thus the particle has been detected.
However, in recent years, a CMP (chemical mechanical polishing) process has been introduced in processing of the film-coated wafer with microfabrication thereof. Once the processing such as the CMP was introduced in the processing of the film-coated wafer, the thickness of a film formed on the film-coated wafer varied in each wafer and the thickness scarcely has become uniform always.
The film thickness varies for each wafer when the CMP is applied for the film-coated wafer on which the transmissive film has been formed. Due to the variation of reflectivity caused by the varied film thickness, it has become difficult to ensure detection sensitivity of a constant level in the surface inspection of the film-coated wafer after the CMP processing. There are cases where particle detection sensitivity drastically reduces in the surface inspection of the film-coated wafer on which the transmissive film has been formed depending on an inspection position.
However, the CMP processing is essential to the microfabrication technology.
In addition, there exists a demand for an apparatus that can detect the particle such as a flaw and a CMP residue with good sensitivity.
Moreover, wafers of a new structure that pursue low electric consumption and high-speed operation such as an SOI wafer, for example, have been available. These wafers have a structure of a plurality of films by a thin Si film, SiO2 film and an Si base, and there have been cases of causing interference to widely vary sensitivity due to the relationship with an incident wavelength depending on the inspection position of the wafer surface.
The object of the present invention is to provide a surface inspection apparatus to perform surface inspection for a film-coated wafer or other film-coated inspection subjects, that is, inspection for a particle, a flaw, or the like, with stable sensitivity.
The present invention is one that has improved a surface inspection apparatus to inspect an inspection subject (such as a particle and a flaw) on the surface of the film-coated wafer or the other film-coated inspection subjects.
In a typical example of the present invention, the surface inspection apparatus comprises: a light source section that emits a first luminous flux and a second luminous flux; an irradiation optical system that irradiates the first luminous flux and the second luminous flux on the surface of the film-coated inspection subject; a displacement section that relatively displaces the film-coated inspection subject and an irradiation luminous flux from the irradiation optical system; a light-receiving optical system that receives scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the first luminous flux from the irradiation optical system and scattered light generated from the inspection subject on the film-coated inspection subject after irradiation of the second luminous flux from the irradiation optical system; a first light-receiving section that transforms the scattered light of the first luminous flux received by the light-receiving optical system into a first light reception signal; a second light-receiving section that transforms the scattered light of the second luminous flux received by the light-receiving optical system into a second light reception signal; and a sensitivity stabilizing section that synthesizes the first light reception signal and the second light reception signal to form a signal for sampling.
Preferably, a first characteristic of the first luminous flux and a second characteristic of the second luminous flux are wavelengths or polarization component of the luminous fluxes. The sensitivity stabilizing section selects either one of the first light reception signal and the second light reception signal for every inspection position of the film-coated inspection subject surface, and synthesizes the first light reception signal and the second light reception signal. Further, the sensitivity stabilizing section selects a light reception signal from which a detection sensitivity closer to a desired detection sensitivity has been obtained out of the first light reception signal and the second light reception signal for every inspection position of the film-coated inspection subject surface, and synthesizes the first light reception signal and the second light reception signal. Furthermore, the sensitivity stabilizing section selects a light reception signal from which a higher sensitivity has been obtained out of the first light reception signal and the second light reception signal for every inspection position of the film-coated inspection subject surface, and synthesizes the first light reception signal and the second light reception signal.
Preferably, a combination of the first luminous flux and the second luminous flux is a combination of luminous fluxes such that either the first light reception signal or the second light reception signal is obtained with predetermined detection sensitivity for every inspection position of the film-coated inspection subject surface.


A method for transcranial magnetic stimulation (TMS) of a stimulation area of medical interest, combined with functional magnetic resonance imaging (fMRI) for visualization of the response of, for example neurons, is disclosed. An ultra-thin magnetic resonance coil, MR coil, positioned in the immediate vicinity over an area where the response of, for example neurons, is to be detected, and preferably sandwiched between the TMS coil and the area, provides an excellent signal-to-noise ratio. The TMS can be performed directly through the MR coil. A great deal of flexibility in the number of the TMS and MR coils in use and their spatial arrangement is provided. A corresponding system for the TMS/fMRI studies is also provided.

For the last fifteen years, transcranial magnetic stimulation combined with functional magnetic resonance imaging studies has firmly established its reputation as a leading non-invasive technique for medical/neurological studies, diagnostic tool and even as a therapeutic device for many medical/neurological and psychiatric conditions, especially in the treatment of certain types of depression.
In a typical prior art arrangement, shown on FIGS. 1 and 2, a TMS coil 1 is positioned next to a scalp 2 of a patient over an area of neurological interest, for example, a part of the brain cortex, so that the stimulation area of neurological interest is within an operational reach of the TMS coil 1. A pulsed magnetic field from the TMS coil 1 induces an electric current in the part of the brain cortex, locally depolarizing its neurons. This stimulates a response from the local neurons, and oftentimes even neurons that are far away from the stimulation area of neurological interest. The response from the neurons may result in subtle changes in a blood oxygenation level in the affected areas, from which brain cortex activity can be inferred. Since the blood oxygenation level can be visualized using fMRI techniques, the visualization effectively amounts to the visualization of brain cortex activity, though indirectly.
For the purpose of visualization, the head of the patient is subjected to a strong static magnetic field, which causes polarization of the nuclear spins in the body. Electromagnetic radiation with a frequency equal to the Larmor frequency of the nucleus of interest, usually hydrogen nuclei (i.e. protons), further referred to as a MR transmit pulse, excites the selected spin system to a higher energy level, and causes the protons to precess around the direction of the static magnetic field, thus, emitting a weak electromagnetic radiation. We will further refer to the weak response of protons as the MR signal.
The MR signal is picked up by an MR receiver coil 3, positioned further away from the TMS coil 1 and the scalp 2 of the patient. The MR receiver coil 3 will be further referred to simply as an MR coil. After appropriate, and often sophisticated, computer processing of the MR signal, an image of the affected area of the brain cortex is formed. More detailed description of the TMS and fMRI can be found, for example, in U.S. Pat. No. 5,732,702 to Edgar Mueller entitled "Method and apparatus for functional imaging" issued on Mar. 31, 1998.
Although the above arrangement for combined TMS/fMRI studies has served the researchers reasonably well in the past, its shortcomings are quickly becoming a limiting factor in meeting new research and application demands.
A problem that requires particular attention of engineers is the low signal-to-noise ratio (SNR), which, in part, is caused by the weak MR signal, but also due to the fact that MR coils in previous combined TMS/fMRI studies had to be large enough to accommodate both, the head and the TMS coil. This required large sized MR coils having a large distance to the head, thereby reducing the achievable SNR.
Since increasing the MR signal itself does not seem to be feasible, because of physical limitations of the MR process, prior art offers various solutions, such as accumulation and subsequent statistical processing of the MR signal using sophisticated algorithms.
Unfortunately, the solutions offered by the prior art have been only partially successful, and have often introduced new problems, which are sometimes difficult to solve. For instance, the accumulation of the weak MR signal requires long measurement time, which may cause discomfort to a patient or be outright impossible for visualization of relatively fast dynamic processes, such as heartbeat etc.
Therefore, there is a need in the industry for further development of an improved TMS/fMRI system and method, which would provide further improvements to the TMS/fMRI studies, and avoid or mitigate the above noted problems of the prior art.

Method and system for combined transcranial magnetic simulation (TMS) and functional magnetic resonance imaging (fMRI) studies


The chewing gum of the present invention contains a coated material prepared by coating Curculigo latifolia fruits, processed Curculigo latifolia fruits or a component containing curculin obtained therefrom with a coating agent.

1. Field of the Invention
This invention relates to a chewing gum capable of stably retaining its flavor and sweetness for a prolonged period of time.
2. Description of the Prior Art
In the case of a common chewing gum, which essentially consists of three components, namely, a gum base, sugars and flavors, the flavors and sweeteners are released within a short period of time after starting chewing. It is, therefore, difficult to retain the flavor and sweetness for a prolonged period of time.
On the other hand, the present inventors formerly developed a method for the application of Curculigo latifolia fruits, dried Curculigo latifolia fruits or a component containing curculin obtained therefrom to chewing gum (refer to Japanese Patent Laid-Open No. 84138/1990).