A digitizing tablet that can control the vibration of an operation panel or a support substrate is disclosed. A piezoelectric substrate having a pair of drive electrodes fixed to the front and rear surfaces of the piezoelectric substrate is fixed directly or via one of the drive electrodes to the operation panel or the support substrate. A drive voltage is applied to the pair of drive electrodes after an input as been detected, and the drive voltage causes the expandable piezoelectric substrate to vibrate the operation panel or the support substrate. An additional vibration source is not required. Therefore, the vibration energy is not dissipated and there is no time delay in transmission since the operation panel or the support substrate are vibrated directly by the piezoelectric substrate. The expansion and contraction of the piezoelectric substrate can be controlled so that the vibration can be controlled precisely.

A digitizing tablet (or digitizer) has an operation panel (or a touch panel) which is supported by a support substrate. An indicator such as a stylus pen or a finger is positioned at an input position as it contacts or is in close proximity to the operation panel. Data relating to the detection of the input position is transmitted to a processing device such as a personal computer.
Components such as the operation panel, the support substrate, an insulating layer, and electrodes may be transparent. Therefore, the digitizing tablet may be disposed on a display screen such as a liquid crystal panel or CRT. An input can be received via the input surface of the operation panel of the digitizing tablet with reference to the display on the display screen. The input position data associated with the location of the input relative to the display on the display screen can be delivered to the processing device.
Typical digitizing tablets are classified according to their methods for detecting input positions relative to the operation panel. Japanese Patent Laid-Open Publication No. Hei 5-289806 discloses the electromagnetic coupling method; Japanese Patent Laid-Open Publication No. Hei 6-242875 discloses the capacitive coupling method; Japanese Utility Model Laid-Open Publication No. Hei 3-6731 discloses the touch method; Japanese Patent Laid-Open Publication No. Hei 5-53715 discloses the resistive method; and Japanese Utility Model Laid-Open Publication No. Hei 5-33235 discloses the optical coupling method. However, the operator must check a processing device such as a personal computer when using these methods to verify that the input was received successfully. Therefore, the operator does not know if the input on the operation panel has been detected by the digitizing tablet.
A force feedback tablet vibrates the operation panel or the support substrate so that the operator can feel the vibration via a stylus pen or a finger that is in contact with the operation panel. The force feedback tablet provides feedback to the operator when an input touch has been detected by the digitizing tablet.
FIG. 9 shows a typical force feedback tablet 100. The force feedback tablet 100 has a main tablet body 100A which includes an operation panel 101, a plastic sheet 102, and a support substrate 103. The operation panel 101 is made of a plastic flexible sheet, and the support substrate 103 is made of glass. A plastic sheet 102 is affixed to the surface of the support substrate 103 which is opposite to the operation panel 101. The operation panel 101 is spaced slightly apart from the support substrate 103, and multiple insulating projections 104 are interposed between the operation panel 101 and the support substrate 103.
The force feedback tablet 100 is a resistive digitizing tablet with an electrically conductive layer (not shown) of a uniform resistive film formed on the opposing surfaces of the operation panel 101 and the plastic sheet 102. The electrically conductive layers contact each other and provide electrical conduction at the input position when the input in the form of a touch is transmitted to the surface of the operation panel 101. The lead electrodes (not shown) are connected electrically to the periphery of the electrically conductive layers to detect the input position.
Truncated conical cushion mounts 106 are provided on the bottom surface of a housing 105 and support the support substrate 103. The entire main tablet body 100A is placed on the cushion mounts 106 made of rubber having a hardness of 50 to 60 degrees. The cushion mounts 106 must be hard enough to provide sufficient resistance to the input touch on the operation panel 101.
A display panel 107 is disposed between the housing 105 and the support substrate 103 which is supported on the cushion mounts 106. Each of the components formed on the support substrate 103 are transparent so that the display appearing on the display panel 107 can be seen when viewed from above the operation panel 101.
A piezoelectric actuator 108 is located at an edge of the rear surface of the support substrate 103. The piezoelectric actuator 108 comprises a plurality of piezoelectric substrates stacked in layers and is made of a piezoelectric material such as piezoelectric ceramic. The piezoelectric actuator 108 vibrates due to the electrostrictive effect of the piezoelectric substrate and serves as a vibration source when a drive voltage is applied to the piezoelectric substrate.
The proximal end of the piezoelectric actuator 108 is fixed to a support base 109, and a support shaft 110 rotatably supports the intermediate portion of the piezoelectric actuator 108. A contact 111 is fixed to the distal end of the piezoelectric actuator 108 and contacts the rear surface of the support substrate 103.
Pressing a position for the input touch on the operation panel 101 will cause the electrically conductive layers to contact each other at the input position. The input position detection means (not shown) detects the input and the input position in order to deliver the data corresponding to the input position to a processing device such as a personal computer.
A drive voltage is applied to the drive electrodes of the piezoelectric actuator 108 causing the piezoelectric actuator 108 to vibrate when the input is detected. The vibration is transmitted to the support substrate 103 via the contact 111 disposed at the distal end of the piezoelectric actuator 108 so that the finger pressing the operation panel 101 senses the vibration.
The operator can verify from the vibration that the input touch has been accomplished successfully after providing the input touch to the digitizing tablet.
The conventional digitizing tablet employs a vibrating element such as a piezoelectric actuator, a vibration motor, and the like as its vibration source in order to vibrate the operation panel 101 or the support substrate 103. The vibration source is separate from the operation panel 101 and the support substrate 103 which constitute the digitizing tablet. Therefore, the housing 105 and the entire input device is larger in order to accommodate the separate vibration source, and the design of the outer shape needs to be limited.
Additionally, the piezoelectric actuator 108, acting as the vibration source, must produce sufficiently large displacements in order to transmit a vibration that can be detected on the main tablet body 100A which contacts the piezoelectric actuator 108. Therefore, a plurality of piezoelectric substrates are stacked in layers in the piezoelectric actuator 108. The layers of piezoelectric substrates increase the thickness of the piezoelectric actuator 108. Furthermore, a pair of drive electrodes are affixed to each piezoelectric substrate and are stacked in the direction of thickness of the piezoelectric actuator 108. The manufacturing process of stacking the layers of piezoelectric substrates requires many steps and is expensive.
Furthermore, a vibration motor is large and expensive if employed as the vibration source.
It is difficult to transmit the vibrations from the vibration source to the main tablet body 100A since the vibrations are indirect and originate from vibration sources which are separate from the main tablet body 100A. The main tablet body 100A is unable to convey precise changes in vibration frequency for transmitting different types of information to the operator, thereby making it impossible to transmit information accurately.
It is difficult to transmit exact changes in vibration directly to the main tablet body 100A since there is a delay in transmitting the vibration from the vibration source to the main tablet body 100A.
The drive circuit for driving the vibration source must include an oscillation circuit so that the vibration source such as the piezoelectric actuator 108 or the vibration motor can vibrate continuously for a certain period of time. This oscillation circuit complicates the drive circuit. A vibration source such as a vibration motor cannot be activated by a drive voltage with an instantaneous pulse waveform and requires a drive circuit having an activation control function to operate continuously for a certain period of time. A vibration source such as the piezoelectric actuator 108 contracts and expands instantaneously in response to the application of a drive voltage with an instantaneous pulse waveform. However, the contraction and expansion is damped when transmitted to the main tablet body 100A, thereby making it impossible for the operator to sense vibration instantaneously.
Securing the piezoelectric actuator 108 to the housing 105 requires a complicated structure for rotatably supporting the intermediate portion of the piezoelectric actuator 108 on the support shaft 110 and for supporting the end of the piezoelectric actuator 108 on the support base 109. The piezoelectric actuator 108 vibrates or generates a noise if not attached securely, thereby making it impossible to transmit the vibration to the main tablet body 100A.
Furthermore, the configuration of the piezoelectric actuator 108 and a vibration transmission mechanism of the main tablet body 100A, such as the support substrate 103, must be manufactured accurately. A gap between the contact 111 and the support substrate 103 would generate noise and vibrations that can damp the amplitude of the vibrations intended for the operator.
Digitizing tablets employing the magnetic coupling method, the capacitive coupling method, and the optical coupling method do not require an indicator such as a stylus pen or the operator's finger to physically contact the operation panel. It is impossible to transmit vibrations to the operator through the operation panel or the support substrate in order to indicate the detection of the input on the digitizing tablet.


A MEMS acoustic transducer is provided, which includes a substrate, a MEMS chip, and a housing. The substrate has a first opening area and a lower electrode layer disposed over a surface of the substrate, wherein the first opening area includes at least one hole allowing acoustic pressure to enter the MEMS acoustic transducer. The MEMS chip is disposed over the surface of the substrate, including a second opening area and an upper electrode layer partially sealing the second opening area, wherein the upper electrode layer and the lower electrode layer, which are parallel to each other and have a gap therebetween, form an induction capacitor. The housing is disposed over the MEMS chip or the surface of the substrate creating a cavity with the MEMS chip or the substrate. In addition, a method for fabricating the above MEMS acoustic transducer is also provided.

With the increasing miniaturization of integrated circuits and the development of consumer electronic devices such as mobile phones, notebook and laptop computers, personal digital assistants, and digital cameras, the obvious market trend is toward making these devices lighter, thinner, and more compact. Thus, various electronic components should be manufactured and integrated into consumer electronic devices in such a way as to take up less space, yet provide more functions and improved performance. In the cell phone industry, smartphones in particular need to integrate various electronic components having a small volume, multi-functionality and low-cost properties in a specific volume, for example, integrating transmission mediums such as microphones with other communication devices.
Electric condenser microphones (hereinafter referred to as ECM), which are constructed using electret materials, are the most-often used microphones in consumer electronic devices. However, the ECM has been gradually replaced with a micro-electro-mechanical system acoustic transducer (hereinafter referred to as MEMS acoustic transducer). In general, both the ECM and the MEMS acoustic transducers detect sound by sensing the capacitance variation produced by acoustic pressure. In the ECM, a capacitor is formed of electret polymer membranes having eternal isolated charges for sensing the capacitance variation. In the MEMS acoustic transducer, there is a MEMS chip and an ASIC chip. The MEMS chip includes a capacitor formed of a membrane and a rigid through-hole back electrode on a silicon substrate for sensing the capacitance variation from the acoustic pressure, and the capacitance variation is processed by the ASIC chip. When comparing the ECM with the MEMS acoustic transducer, the latter may have a lot of advantages such as low cost, at least 30% of height reduction in its packaging structure, and resistance to degradation due to temperature, moisture, vibration, and general wear and tear. Moreover, the MEMS acoustic transducer is capable of being integrated with a band RF filter on ICs to reduce the interference produced by the RF, and the noise can be eliminated using arrays and algorithms. Thus, the MEMS acoustic transducer is especially suitable for RF applications such as cell phones and other devices that operate along similar principles, such as hearing aids, for example.
Thus, it is predicted that the MEMS acoustic transducer will largely replace the electret condenser microphones as the related technology continues to improve. Sensitivity is a key indicator of the MEMS acoustic transducer's effectiveness. Sensitivity is not only determined by a membrane in the MEMS chip, but is also determined by the volume of a back cavity. The volume of the back cavity is a closed volume behind the membrane and stands in contrast to the encountered acoustic pressure, which may provide a flexible recovery force to the membrane and can be used for tuning the acoustic resistive and response properties of the MEMS acoustic transducer. In addition, the fabrication process of the MEMS acoustic transducer is complicated, and therefore it is difficult to increase the sensitivity of the MEMS acoustic transducer while reducing production costs.
FIG. 1 shows a MEMS acoustic transducer packaging structure. In order to increase the volume of the back cavity 107 in a limited space, an interior housing 111 is added. The MEMS acoustic transducer includes a cavity 106 surrounded by a packaging substrate 102 and a housing 104. The housing 104 has a sound-opening 112 for receiving acoustic pressure. A MEMS acoustic transducer 116 and an application-specific integrated circuit (ASIC) chip 126 are disposed on the interior housing 111 within the cavity 106. The MEMS acoustic transducer 116 includes a silicon substrate 120, a membrane 118 (upper electrode), and a backplate (through-hole back electrode) 114 suspended below the membrane 118. The interior housing 111 and the packaging substrate 102 create the back cavity 107 of the MEMS acoustic transducer 116. Thus, the height of the back cavity 107 is similar to that of the MEMS acoustic transducer packaging structure when excluding of the height of the MEMS acoustic transducer 116, and therefore the volume of the back cavity 107 can be increased. However, there is still some space inside the packaging structure that cannot be used efficiently. In addition, the membrane 118 and the backplate 114 of the MEMS acoustic transducer 116 are two thin films which are hard to fabricate and easy to stick to each other. Thus, the MEMS acoustic transducer, as shown in FIG. 1, still cannot meet requirements of future applications.

MEMS acoustic transducer and method for fabricating the same

INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE


An apparatus for assessing a position of an anchorage of a child restraint anchorage system. The apparatus includes a frame, an engagement arm, and a latch pin. The engagement arm is adapted to receive the anchorage and is disposed proximate the frame. The latch pin is disposed at least partially within the engagement arm and is adapted to rotate to secure the engagement arm to the anchorage.

1. Field of the Invention
The present invention relates to an apparatus and a method for assessing the position of an anchorage of a child restraint anchorage system of a vehicle.
2. Background Art
Motor vehicles may include a child restraint anchorage system. A child restraint anchorage system uses a plurality of anchorages to transfer loads from a child safety seat to the vehicle structure. Anchorages may be located where they are partially concealed by or recessed from one or more vehicle surfaces, such as the surfaces of a vehicle seat. These surfaces may interfere with anchorage visibility and position assessments. Previously, vehicle surfaces were cut away and/or material was removed to allow the position of an anchorage to be evaluated. Such destructive evaluation techniques increase development costs.
Before applicant's invention, there was a need for an apparatus and a method for accurately assessing the position of an anchorage of a child restraint anchorage system. In addition, there was a need for an apparatus and a method that could be used with various child restraint anchorage designs and configurations. Moreover, there was the need for an apparatus that could be easily reconfigured to accommodate different seat designs. Also, there was the need for an easy-to-use apparatus and method to reduce training time and associated costs. Problems associated with the prior art as noted above and other problems are addressed by applicant's invention as summarized below.

Apparatus and a method for assessing an anchorage position


A novel system and method provides a concrete relative measure for evaluating coding quality. The novel system and method do not rely on bug counting. Instead, the number of defective lines of code is compared to a total number of opportunities to create such defects. A defective line is a line that is deleted, added or changed subsequent to drafting of the prior version of the code. In an embodiment, a deletion and an addition are each treated as single defects, while modification of a line of code is treated as two defects. In this way, regardless of whether modification is viewed as deletion followed by addition, or rather simply a single step of modification, the number of defects in either case is the same.

As computers and computing devices have become a prevalent part of modern life, the ability to produce appropriate software for these devices has increased in importance. In order to economically produce quality software in a timely fashion, it is often desirable to measure and evaluate the productivity or efficiency of individuals/teams who are responsible for drafting or otherwise controlling the generation of software (hereinafter collectively referred to as "developers"). For example, software that is especially defective may require extensive effort and time to reach production in final form, whereas software that is relatively error free may be marketed with confidence in less time using less effort. In general, inefficient or unproductive developers can cost companies a significant amount of resources due to excess development costs, lost market opportunities, and so forth. Additionally, the instability introduced into the code as a result of rework on the code contributes to reducing the quality of the product.
In other industries, it has long been common to evaluate employee performance by evaluating the quality of the employee's product. For example, an autoworker's skills can be evaluated by examining the quality or performance of a completed automobile, and a chef's proficiency in the kitchen can be judged by the taste and presentation of a meal. However, the software industry presents unique challenges in this regard.
In order to provide accountability for poor developers and rewards for proficient developers, as well as to adjust critical processes, the software industry has long sought an effective measure by which to judge developer skill and performance. A number of such measures have been implemented in the past, however, each such measure has had drawbacks that have prevented widespread adoption and industry satisfaction. For example, one such system involves using the number of bugs found in code, often phrased as bugs per thousand lines of code, or bugs per KLOC, to measure the productivity of the developer. This measure has met with great resistance from developers for a number of reasons. Primary among its drawbacks is the general inability to easily and accurately distinguish bugs that required extensive revision from bugs that could be simply and quickly fixed. For example, some bugs require only that one character be changed, whereas others require many thousands of code lines to be changed. Treating all bugs the same thus introduces significant inaccuracy into the productivity measurement process. Moreover, developers often feel that using bug counting as a productivity measure unfairly favors developers working on simple problems to the detriment of those working on more complex issues. While managers and others who oversee large numbers of developers may feel that the laws of large numbers result in overall statistical accuracy of this measure, that does not operate to alleviate the unfairness of the measure as applied to individuals. Moreover, for those developers so inclined, the bug counting measure is fairly easy to "game" or manipulate in the developer's favor.
Other means of measuring developer productivity have been implemented as well to some extent in the industry. However, none has attained a level of fairness and accuracy sufficient to develop widespread developer support and endorsement. If a particular system for measuring coding productivity does not meet with relatively wide spread developer support, then it will be difficult to use such a system to drive improved productivity. Accordingly, a system and method for accurately and fairly measuring developer productivity is needed.

Process for measuring coding productivity


A storage device stores a plurality of sets of tone setting information, each of the sets of tone setting information including one or more tone setting parameters. The storage device also stores, for each of the sets of tone setting information, a link ID identifying a link set in association with the set of tone setting information. Processing is performed to cause, based on the link IDs, settings of the tone setting parameters to match between a plurality of sets of the tone setting information having a same link ID. A selected set of the tone setting information is editable in accordance with a user operation. In accordance with the editing, processing is performed to cause a setting of any one of the tone setting parameters in one or more other sets of the tone setting information, having a same link ID as the link ID associated with the edited set of the tone setting information, to match a setting of the tone setting parameter in the edited set of the tone setting information.

In the conventionally-known electronic musical instruments, characteristics of a tone to be generated by the electronic musical instrument can be set by tone setting information comprising tone setting parameters intended to set a color (timbre), quality, musical characteristics, etc. of the tone to be generated by the electronic musical instrument. By preparing (registering) a plurality of sets of such tone setting information through creation or editing of tone setting information, it is possible to generate tones of a plurality of different characteristics or types. When a human player (or user) uses tone setting information in such an electronic musical instrument, the human player (user) may often use same tone setting information in different scenes (e.g., in different performance parts and difference phrases). Generally, however, each tone setting information includes a plurality of tone setting parameters, and there are prepared a plurality of sets of such tone setting information. Thus, the total number of parameters can become extremely large. Therefore, in a case where a tone setting parameter of a setting state (setting) is to be used between (among) a plurality of sets of tone setting information, setting or editing of the tone setting parameter of the same setting has to be performed for each of the sets of tone setting information, which is extremely cumbersome.
Thus, there has heretofore been known a technique for collectively setting a plurality of parameters of a same type at a same value. For example, in STAGEA ELS-01/01C/01X typeU, instruction manual (p 94-p 96), [online], published in 2011, [searched on Dec. 18, 2013], Internet URL: http//www2.yamaha.co.jp/manual/pdf/emi/japan/ele/els01v183_ja_om_d0.pdf (hereinafter referred to as "Non-patent Literature 1"), there is disclosed a technique in which a multiplicity of sets (e.g., three hundred sets) of registration data, each of the sets comprising tone setting information for eight performance parts, are registrable, in which a user selects one parameter type (e.g., any one of reverberation, pan, etc.) on which collective editing is to be performed, one or more performance parts (e.g., upper keyboard, lower keyboard, etc.) to which the collective editing is to be applied, and one or more sets of registration data to be set as objects of the collective editing, and in which, in response to the user editing a value of the parameter of the selected type, the edited value of the parameter of the selected type is collectively reflected in all of the selected performance parts in all of the selected register data.

Setting and editing tone setting information via link


A fireworks stand for elevating fixed-position fireworks, especially cone type fountains, having a body with an inner cavity for storing the fireworks and an upper platform for supporting the fireworks during discharge. The platform is nested into an upper end of the body and receives an upper keeper that is sized and shaped to fit inside of the nested platform in order to secure the fireworks. The cavity has a lower keeper and base structure that is removed to provide access to a plurality of inserts, which house the fireworks.

The present invention is directed to fireworks and containers therefor and, more specifically, to an improved pyramid-shaped fireworks base having an inner fireworks storage cavity for transport and sale and a fireworks mount at an upper end of the pyramid that is equipped with a nesting platform and keeper for securely mounting fireworks for discharge and display in an elevated position.
Cones, fountains and related types of display fireworks come in many shapes and sizes designed to produce a variety of displays. Cones and fountains are popular types of firework displays that generally project an upward steady stream or varying stream of sparks to a certain height or varying heights after which the sparks flow downward in a manner intended to emulate the flow of water projected from a traditional water fountain and similar devices. The fountain effect is enhanced by maintaining airborne for as long as possible and that the sparks remain ignited for as long as possible and ideally from when the sparks exit the firework shell until the sparks contact the ground.
Such fireworks are often packaged in a cone shape structure, which are intended to be placed on the ground for safe usage. Such cones have a two fold and opposed problem. In order to be stable during discharge, the cones are manufactured with a wide base for stability such that the size of the cone is much larger than necessary to hold the actual material that is burnt to produce the fireworks effect. A second inherent limitation of such fountain displays is the height at which the display can project sparks. Consequently, cones are normally much taller and have much wider bases than is necessary to simply contain the substance of the display.
Accordingly, it is desirable to have such fountain fireworks where cones or the like can be made relatively small for transport and display at the time of sale, but whereas the cones can be stable during use and the display is elevated to provide advantages of such elevation.
For such fireworks to be used safely, support platforms for the shells must be designed to meet certain safety criteria, including that platforms not explode and provide a stable platform for launching the fireworks. In particular, a fireworks base that is designed to support a firework during discharge needs to have a minimum foot print or base size that engages the ground and stabilize the device for support. In particular, the base size is designed to provide adequate support in order to insure that the base does not upset or tip over during discharge and accidentally project its contents in an undesired sideways or lateral direction which could cause the fireworks to hit bystanders and/or create fire hazards by hitting houses, grassy areas or other highly flammable locations.
Furthermore, fireworks' shipping or merchandising boxes or packaging must be large enough to receive multiple cones. Because conventional cones must be relatively large, such packaging must also take up substantial space which is directly related to shipping, storage and display expense at the time of sale.
Accordingly, it is desirable to have such a fireworks stand where the cones or the like consume a minimal amount of space and where the overall product can be placed in a comparatively low profile package that is economical to ship and store. It is also desirable that such fireworks be lightweight, easy to use and inexpensive, so as to encourage consumers to acquire and use the product.

Combined fireworks shipping container and display stand


An improved photo coating machine of the present disclosure is used to put an evenly distributed coating of chemical fluid on the surface of a photograph so as to form a protective film thereon. The photo coating machine is equipped with a roller assembly, a driving mechanism, a coating device, a drying device, a micro adjustment mechanism, and an adjustment mechanism and a mounting base. The rollers of the roller assembly are disposed with each other in rotational abutment but not in linear alignment. Coating chemical fluid is sprayed between two of the rollers that evenly distribute the chemical fluid upon the surface of a photo that is fed between the rollers. Each roller of the roller assembly is provided with a peripheral groove at each end thereof for the collection of excess chemical fluid on the rollers which is recycled to the coating device so as to prevent the mounting base from contamination. The micro adjustment and the adjustment mechanisms are responsible for varying the space between each pair of the rollers so that photos of different sizes can be fitted therebetween.

The present invention relates to an improved photo coating machine which can put a thin film of chemical fluid on the surface of a photo for protection purpose.
To well protect a favorite or preferred photo, it is the conventional method to put the photo in a plastic cover which is then well sealed all around by way of a heated roller. The previous plastic cover is made of relatively hard polyvinyl chloride ( PVC ); but it has been replaced in recent years by soft plastic material.
In the conventional photo covering process, it is frequently found that some air is left in the cover and sealed therein, resulting in the creation of air bubbles in the cover. Moreover, if the process of covering a photo is performed in a hurry that the photo is easily located in an offset manner due to the carelessness of the person handling the process. Furthermore, the covered photo must be carefully trimmed to provide a quality finish, a time consuming and costly procedure.

Sec. 2, 7 Ling, Nan Cheng, Ts'3 un, Tien Wei Hsiang Chamghua Hsien


The disclosed technology relates to receiving an executable function from a client device, wherein the executable function is to be executed on a function as a service (FaaS) platform. Upon performing a verification and validation process on the received executable function prior to runtime, it is determined when to execute the received executable function based on based on one or more execution initiation techniques upon performing. The verified and validated executable function is executed at the runtime on the FaaS platform based on the determination.

Function as a service (FaaS) is a category of cloud computing services that provides a platform allowing customers to develop, run, and manage application functionalities without the complexity of building and maintaining the infrastructure typically associated with developing and launching an application. In other words, FaaS is a serverless way to execute modular pieces of code on a platform where the developers write and update a piece of code on the fly and the code can then be executed in response to an event. However, for the purpose of detecting and preventing a security threat, prior technologies perform verification and validation of the piece of code during run-time while executing the code in response to an event.
Unfortunately, performing the verification and validation of the piece of code at run-time requires significant runtime resources and therefore results in substantial amount of latency to execute the piece of code. For example, one of the operations performed during this code verification and validation that consumes a significant amount of resources at runtime leading to latency in execution of code involves determining if code is in a valid format and structure. To save these resources, one option is not performing code verification and validation (blind trust). However, failing to perform the code verification and validation can lead to security vulnerabilities being exploited by the third-party code. Accordingly, the prior technologies fails to disclose a technique of performing code verification and validation on a FaaS platform such that there is no latency experienced during the execution of the code.

This patent is subject to a terminal disclaimer.

Methods for managing verification and validation of third-party code and devices thereof


The present invention relates to an antiferroelectric liquid crystal display device, by which a time (namely, a ferroelectric saturation time tr) required for transition of the state of a liquid crystal, which has been in a dark state, to a saturated bright state is reduced. A method of establishing a precedent driving period in such a manner as to be precedent to a selective driving period and of obtaining a value, at which the ferroelectric saturation time tr is minimized, of a synthetic voltage from a scanning signal and a display signal in the precedent driving period. A device using the value obtained by this method. In the precedent driving period, a voltage, whose voltage value is .vertline.Vx.vertline., is applied to the liquid crystal. In a selective driving period, a voltage, which is different in polarity from the voltage value .vertline.Vx.vertline. and has a voltage value is .vertline.Vz.vertline., is applied thereto. In other periods, a voltage having a voltage value of 0 is applied thereto. A value of the voltage .vertline.Vx.vertline., at which the ferroelectric saturation time tr is minimized when changing the value of the voltage .vertline.Vx.vertline. while maintaining the voltage .vertline.Vz.vertline. at a constant value, is set as an optimum precedent driving voltage .vertline.VM.vertline..

An antiferroelectric liquid crystal is stable in an antiferroelectric state when left in a condition that no voltage (zero) is applied to the liquid crystal. Hereinafter, this stable state will be referred to as a neutral state. An antiferroelectric liquid crystal panel may be configured in such a manner as to effect either a dark display or a bright display in the aforesaid neutral state. An antiferroelectric liquid crystal panel of the present invention be applied to both a dark display and a bright display. An antiferroelectric liquid crystal panel which is adapted to effect a dark display in the neutral state, will be described in the following description. However, in the case of an antiferroelectric liquid crystal panel which is adapted to effect a bright display in the neutral state, read "bright" for "dark", and vice versa in the following description.
It is explained that generally, an antiferroelectric liquid crystal has two states, namely, an antiferroelectric state (namely, a dark state) and a ferroelectric state (namely, a bright state), that when a voltage is applied to a liquid crystal panel, the entirety of which has been in the antiferroelectric state, a phase transition therefrom to the ferroelectric state first occurs in micro portions, that the proportion of portions, whose phases are changed into the ferroelectric state, increases with time and that finally the phase of the entire panel is changed into the ferroelectric state and thus the entire panel changes the state thereof into a saturated ferroelectric state.
When zero voltage is applied to a liquid crystal panel, the entirety of which has been in the ferroelectric state, in a similar way, a phase transition therefrom to the antiferroelectric state first occurs in micro portions, that the proportion of portions, whose phases are changed into the antiferroelectric state, increases with time and that, finally, the phase of the entire panel is changed into the antiferroelectric state and thus the entire panel changes the state thereof into the neutral state.
FIG. 1(a) is an example of a graph illustrating the optical transmittance of an antiferroelectric liquid crystal versus a voltage applied thereto. In this graph, the axis of abscissa represents the applied voltage; and the axis of ordinates represents the optical transmittance.
When applying a positive voltage to the crystal, which has been in the neutral state at a point O, and increasing the positive voltage, the transmittance abruptly increases at a voltage Ft. Then, the transmittance reaches nearly the maximum value at a voltage Fs, and the crystal changes the state thereof into the saturated ferroelectric state. Thence, the optical transmittance does not change much even when a higher voltage is applied thereto. Next, when the applied voltage is gradually decreased, the optical transmittance abruptly drops at a voltage At. Further, the transmittance nearly reaches zero at the voltage As, and the state of the crystal returns to an antiferroelectric state. Similarly, if a negative voltage is applied to the crystal from the voltage 0, the transmittance abruptly rises at a voltage (-Ft). Then, the transmittance nearly reaches the maximum value at a voltage (-Fs), and the crystal changes the state thereof into the saturated ferroelectric state. Thence, when the applied negative voltage is gradually reduced to 0 V, the transmittance abruptly drops at a voltage (-At). Further, the transmittance becomes almost zero at a voltage (-As), and, the crystal returns to the antiferroelectric state. As above described, there are two ferroelectric states of the liquid crystal, which are the ferroelectric state caused by the application of the positive voltage and the ferroelectric state caused by the application of the negative voltage. Hereunder, the ferroelectric state caused in the former case will be referred to as the (+) ferroelectric state, while the ferroelectric state caused in the latter case will be referred to as the (-) ferroelectric state. Further, .vertline.Ft.vertline. designates a ferroelectric threshold voltage; .vertline.FS.vertline. a ferroelectric saturation voltage; .vertline.At.vertline. designates an antiferroelectric threshold voltage; and .vertline.As.vertline. an antiferroelectric saturation voltage.
Incidentally, the values of each of the aforementioned ferroelectric threshold voltage .vertline.Ft.vertline., the aforementioned ferroelectric saturation voltage .vertline.FS.vertline., the aforementioned antiferroelectric threshold voltage .vertline.At.vertline. and the aforementioned antiferroelectric saturation voltage .vertline.As.vertline. in the (+) ferroelectric side is sometimes slightly different from the value thereof in the (-) ferroelectric side. However, for simplicity of description, the following description will be made by assuming that each of these voltage has the same value. To make a correction on the driving voltages respectively corresponding to the (+) ferroelectric side and the (-) ferroelectric side as needed is within the scope of the present invention.
Generally, it is the case that the curves (namely, hysteresis curves) of FIG. 1(a) representing the optical transmittance characteristics of a liquid crystal versus the voltage applied thereto are obtained by applying thereto a triangular-wave-like voltage in which the absolute value of the ratio of a change in this voltage relative to time, namely, the value of .vertline.dV/dt.vertline. is constant. However, in this case, if the value of .vertline.dV/dt.vertline. is changed, the shapes of the hysteresis curves also change. Moreover, the values of the aforementioned values As, Ft, Fs and At also vary. It is, accordingly, necessary to define the aforesaid value of .vertline.dV/dt.vertline. to specify these values. However, the inventors obtained data concerning the graph of FIG. 1(a) by the following method (hereunder referred to as a time fixation method 1) so as to obtain values closely corresponding to actual driving conditions.
It is assumed that the length of a time period, in which a selection voltage (to be described later) is applied to a display device at a working temperature, is Wt.
(1) A pulse voltage, whose duration is Wt and voltage level is Vx, is applied to the liquid crystal that is in a stable antiferroelectric state (namely, in the neutral state). Further, the relationship between the optical transmittance and the pulse voltage Vx at the time of completion of the application of this pulse voltage is plotted. When this operation is repeated by changing the value of the voltage Vx, the curve drawn from the point O to Fs through Ft of FIG. 1(a), as well as the curve drawn from the point O to (-Fs) through (-Ft), is obtained. PA1 (2) Next, the liquid crystal is first put into the saturated ferroelectric state by applying thereto a voltage which is not lower than the aforementioned voltage .vertline.FS.vertline.. Then, at a moment 0, the applied voltage is reduced to .vertline.Vz.vertline.. Thence, after the elapse of the assumed relaxation period (to be described later), the relationship between the value of the optical transmittance and the applied voltage Vz is plotted. When this operation is repeated by changing the value of the voltage .vertline.Vz.vertline., the curve drawn from Fs to the point O through At and As of FIG. 1(a) and the curve drawn from (-Fs) to the point O through (-At) and (-As) are obtained.
In the case of using some liquid crystal panels, the curve (namely, the curve drawn from Fs or (-Fs) to the point O in FIG. 1(a)) obtained in the aforementioned case (2) sometimes intersects the ordinate axis. The main cause of this is the responsivity of the liquid crystal. Namely, in the case that the liquid crystal is maintained in the ferroelectric state by applying thereto a voltage, which is not lower than the aforementioned voltage .vertline.FS.vertline., and that at the moment 0, the applied voltage Vz is changed into 0, the liquid crystal finally becomes stable in the antiferroelectric state after the elapse of a certain time period (hereunder referred to as a relaxation time tn). However, if this relaxation time tn is longer than the aforementioned relaxation period, the curve obtained in the aforementioned case (2) intersects the ordinate axis.
When actually driven, it is difficult to bring such a liquid crystal panel into a complete antiferroelectric state. It is, thus, considered that in the case of such a liquid crystal panel, a dark display cannot be effected and that consequently, the contrast is extremely degraded.
Generally, a liquid crystal panel is driven by performing the following process. Namely, first N row electrodes and M column electrodes are formed in such a manner as to be arranged as a matrix of N rows and M columns. Further, a scanning signal is applied to each of the row electrodes through a row-electrode drive circuit, a display signal depending on display data of each pixel (incidentally, a part of the display signal is sometimes not dependent on the display data) is applied to each of the column electrodes through a column-electrode drive circuit. Moreover, a voltage (hereunder referred to simply as a synthetic voltage), which corresponds to the difference between the scanning signal and the display signal, is applied to a liquid crystal layer. The time period required to scan all of the row electrodes (namely, 1 vertical scanning interval) is usually referred to as 1 frame (or 1 field). In the case of driving the liquid crystal panel, the polarity of a driving voltage is reversed each frame (or every frames) in order to prevent the liquid crystal from being adversely affected (for example, the degradation due to the nonuniform distribution of ions).
FIG. 2 illustrates the waveforms of signals flowing through the row electrodes, the column electrodes and the pixel synthesis electrodes of a liquid crystal panel in which the N row electrodes and the M column electrodes are formed in such a manner as to be arranged as a matrix of N rows and M columns. The display states of pixels are assumed as follows. Namely, in the case of a first column (Y1), pixels in all rows are displayed in white. Further, in the case of a second column (Y2), a pixel in a first row is displayed in black, and pixels in the other rows are displayed in white. Moreover, in the case of pixels in a third column (Y3), these pixels are displayed alternately in black and in white. Furthermore, in the case of an Mth column, YM pixels are displayed in black in all rows.
Waveforms of scanning signals are respectively applied to the N row electrodes in sequence from the top row to the bottom row so that each of the waveforms is shifted by a time (1/N). Waveforms of display signals applied to the M column electrodes are synchronized with the scanning signal and the waveforms according to whether the pixels are displayed in white or in black are applied.
Paying attention to a synthetic voltage applied to each pixel, with respect to P11 displayed in white and P12 displayed in black in the first row, the voltage applied to P11 in the selection period tw, which is displayed in white, is a large waveform, whereas the voltage applied to P12 in the selection period tw, which is displayed in black, is a small waveform. The voltage applied to a pixel P21, which is displayed in white in a second row has a waveform which is almost the same as that obtained by shifting the waveform of the synthetic voltage applied to the pixel P11 by (1/N). Here, note that the first and the second frame in the first row and the second row are shifted with respect to each other by (1/N).
Turning attention to a scanning signal applied to a single row electrode, 1 vertical scanning interval thereof is composed of N horizontal scanning intervals (in some cases, an additional period .alpha. is added thereto). In a horizontal scanning interval, a part of a horizontal scanning interval in which a special scanning voltage (set at the selection voltage) to be used for determining the display state of a pixel on the aforesaid row is applied, is referred to as a selection period tw. The other part of horizontal scanning interval is referred to as non-selection periods. Moreover, generally, the selection period tw is a time period obtained by dividing 1 frame interval by (N+.alpha.).
Usually, in the case of the antiferroelectric liquid crystal panel, it is determined on the basis of the aforementioned display signal at the time of applying the selection voltage whether the state of the liquid crystal, which has been in the antiferroelectric state, is maintained or is changed into the ferroelectric state. Thus, there is the necessity of a time period (hereunder referred to as a relaxation period ts) required for setting the liquid crystals in the antiferroelectric state before the application of the selection voltage. During a time period which is other than the selection period tw and the relaxation period ts, the determined state of the liquid crystal should be held. Hereunder, this time period will be referred to as a holding period tk.
FIG. 3 illustrates the waveforms of a scanning signal waveform Pa applied to a given pixel of interest, display signal waveforms (Pb, Pb'), synthetic signal waveforms (Pc, Pc') and optical transmittances (L100, L0) according to a driving method described in FIGS. 1 and 2 of the Japanese Unexamined Patent Publication (Kokai) No. 4-362990/1992. F1 and F2 designate the first frame F1 and the second frame F2, respectively. Although not shown in this figure, a scanning signal, which has a phase shifted by 1 horizontal scanning interval and has a waveform similar to the scanning signal Pa or has a waveform obtained by inverting the polarity of the scanning signal Pa, is applied to a row electrode adjacent to a row electrode of interest.
FIG. 3 illustrates the case where the polarity of the aforementioned driving voltage is inverted every frame. As is apparent from this figure, the first frame Fl is different from the second frame F2 only in that the polarity of the driving voltage is inverted. As is obvious from the aforementioned FIG. 1(a), an operation of the liquid crystal display device is symmetric with respect to the polarity of the driving voltage. Therefore, the following description will be given regarding only the first frame, except in case of necessity. Further, in the following description and drawings of the waveforms of driving signals, the electric potential indicated as "0" does not mean absolute electric potential but means merely a reference electric potential. Therefore, in the case that the reference electric potential varies for some reason, scanning signals and display signals vary relatively. Moreover, in the case that the word "voltage" is used in connection with the scanning signals and the display signals in the following description, the word "voltage" designates the difference between the electric potential indicated by such a signal and the reference electric potential.
As shown in FIG. 3, 1 frame is divided into three time periods, namely, the selection period tw, the holding period tk and the relaxation period ts. The selection period tw is further divided into time periods tw1 and tw2, which have equal lengths. The voltage level of a scanning signal Pa in the first frame F1 is set as follows. Needless to say, in the second frame F2, the polarity of the voltage is inverted. Here, note that .+-.V1 designates the selection voltage and that the length of the time period tw2 corresponds to the aforementioned Wt.
______________________________________ Time Period tw1 tw2 tk ts ______________________________________ Scanning Signal Voltage 0 +V1 +V3 0 ______________________________________
Further, the display signal is set as follows. Here, note that the voltages indicated by the symbol "*" depend on the display data of other pixels in a same column.
______________________________________ Time Period tw1 tw2 tk ts ______________________________________ On-State Display Signal Voltage +V2 -V2 * * Off-State Display Signal Voltage -V2 +V2 * * ______________________________________
In the time period in which the aforementioned selection voltage is applied, each liquid crystal pixel on the selected row is selectively driven on the basis of the display signal. Hereinafter, a time period, in which the scanning signal is the selection voltage, is referred to as a selective driving period (in the case of this conventional example, tw2).
A part, which actually controls a display based on the display data, of the display signal, is a part, which corresponds to the selective driving period, thereof. This part of the display signal is simultaneously applied to liquid crystal pixels arranged on rows which are other than the selected row (and correspond to either the holding period tk or the relaxation period ts in the case of this conventional example) and thus adversely affects the states of the unselected liquid crystal pixels.
For example, in the case that in the hysteresis curves of FIG. 1(a), the curve drawn from As to Ft or from At to Fs is not flat, when the voltage applied to the liquid crystal in the holding period tk is shifted depending on the display signals of the other rows, a change in the brightness in this holding period is caused.
Thus, to compensate for the ill effects of this phenomenon, the period tw1 is established in addition to the selective driving period tw2 and moreover, the polarity of the display signal is inverted in the periods tw1 and tw2 so that the average value thereof in a horizontal scanning interval is 0.
Namely, the display signal in the period tw1 plays a role in compensating for the ill effects of the display signal on the pixels, which are arranged on the unselected rows, in the selective driving period. Therefore, hereinafter, a time period, in which the display signal is used for such compensation, is referred to as a compensation signal period.
In FIG. 3, Pb, Pc and L100 respectively denote the waveform of a display signal, that of a synthetic signal and optical transmittance in the case that all of the pixels provided on a column electrode, to which a pixel of interest belongs, are in an on-state (namely, in the bright state). In this case, if the (synthetic) voltage to be applied to the liquid crystal in the selective driving period tw2 meets the following condition: .vertline.V1+V2.vertline.>.vertline.Fs.vertline. (see FIG. 1(a)), the transition of the state of the liquid crystal into the ferroelectric state is started. As a result, the optical transmittance of the liquid crystal increases. In the holding period tk, if the following condition is satisfied: .vertline.V3-V2.vertline.>.vertline.At.vertline., the bright state can be held. In the relaxation period ts, if the following condition is satisfied: .vertline.V2.vertline.<.vertline.AS.vertline., the transmittance decreases with the elapse of time. Thus, the relaxation of the liquid crystal, by which the state thereof from the ferroelectric state is changed to the stable antiferroelectric state, is attained.
Further, in FIG. 3, reference characters Pb', Pc' and L0 respectively denote the waveform of a display signal, that of a synthetic signal and optical transmittance in the case that all of the pixels provided on a column electrode, to which a pixel of interest belongs, are in an off-state (namely, in the dark state). In this case, if the synthetic voltage to be applied to the liquid crystal in the selective driving period tw2 meets the following condition: .vertline.V1-V2.vertline.<.vertline.Ft.vertline., the voltage applied in the holding period tk meets the following condition: .vertline.V3+V2.vertline.<.vertline.Ft.vertline., and the voltage applied in the relaxation period ts meets the following condition: .vertline.V2.vertline.<.vertline.Ft.vertline., the dark state is displayed.
FIG. 4 is a waveform diagram illustrating the waveform of a driving signal used in the driving method that is described in the Japanese Unexamined Patent Publication (Kokai) No. 6-214215/1994. In the case of this driving method, 1 frame is divided into the selection period tw and the holding period tk. The aforesaid selection period tw is further divided into three time periods, namely, two time periods tw1 and tw2, which have equal lengths, and a time period tw0 which precedes the two periods tw1 and tw2. In the case of this driving method, the aforementioned relaxation period ts is the aforesaid time period tw0. The length of the time period tw0 is not always equal to that of each of the time periods tw1 and tw2. Further, the voltage level of the scanning signal and the display signals in the first frame F1 are set as follows.
______________________________________ Time Period tw0 tw1 tw2 tk ______________________________________ Scanning Signal Voltage 0 0 +V1 +V3 On-State Display Signal Voltage 0 +V2 -V2 * Off-State Display Signal Voltage 0 -V2 +V2 * ______________________________________
In the case of the driving method described in this Japanese Unexamined Patent Publication (Kokai) No. 6-214215/1994, the zero-volt voltage applying time period (tw0) provided in the leading part of the selection period tw is used as the relaxation period ts. Further, the time period tw1 is the compensation signal period. Moreover, the time period tw2 is the selective driving period.
In the case of the two conventional examples, the selective driving periods, during each of which the selection voltage .vertline.V1 .vertline. is applied so as to determine the bright or dark state of the liquid crystal, are tw2. However, if the length of the aforesaid time period tw2 is insufficient, the transition of the state of the liquid crystal to the ferroelectric state cannot be sufficiently achieved. This impedes the display. Namely, in the case that the transition of the state of the liquid crystal, which has been in the stable antiferroelectric state and presented the dark state, to the almost saturated bright state is performed by applying a constant voltage thereto, a time period (hereunder referred to a ferroelectric saturation time tr) having a certain length is required. Therefore, if the period tw2 becomes shorter than the aforesaid ferroelectric saturation time tr, a change in optical transmittance results in a failure in presenting the bright state sufficiently as indicated by dashed lines in a graph L100 of FIG. 3, so that the contrast is degraded.
In the case of the driving method described in FIGS. 1 and 2 of the Japanese Unexamined Patent Publication (Kokai) No. 4-362990/1992, the length of the aforesaid selective driving period tw2 is a half of the selection period tw. In the case of the driving method described in the Japanese Unexamined Patent Publication (Kokai) No. 6-214215/1994, the length of the aforesaid selective driving period tw2 is less than a half of the selection period tw. Further, generally, the length of the aforesaid selection period tw is given by: EQU tw=F/(N+.alpha.)
where F denotes the length of 1 frame. Thus, increasing the length of the frame is sufficient to lengthen the period tw2. However, when F is longer than 20 ms (corresponding to 50 Hz), a flicker phenomenon occurs with the result that the display quality is deteriorated. Thus, there is a limit to the length of 1 frame. Under such a limitation, the length of the period tw (thus, the length of the selective driving period tw2) depends on (N+.alpha.). Therefore, the number N should be small so as to obtain the sufficient length of the period tw2.
The aforementioned ferroelectric saturation time tr changes according to the applied voltage and becomes short when the applied voltage is increased. Hence, when the applied voltage is large, the transition of the state of the liquid crystal to the ferroelectric state can be achieved even if the selective driving period tw2 is short. Usually, the aforementioned column electrode drive circuit and the aforementioned row electrode drive circuit have the maximum ratings, respectively. Consequently, voltages, which exceed the aforesaid ratings, cannot be supplied to the liquid crystals. Furthermore, there are driving restrictions on the selection voltage (.vertline.V1.vertline.) and the display signal voltage (.vertline.V2.vertline.). Thus, there is an upper limit to the voltage which can be applied to the liquid crystals.
Those restrictions result in occurrence of the upper limit to the number of row electrodes on the assumption that the length of the frame is constant. Consequently, it becomes difficult to provide a high resolution display device.
Moreover, the requirement of the large applied voltage results in increase in load imposed on the drive circuit and rise in the power consumption of the display device.


The present disclosure provides a signal processing device that includes: a signal collector configured to obtain an image to be processed, a signal collector configured to collect an input signal, an instruction converter configured to convert the signal into an image processing instruction according to a target signal instruction conversion model, an image processor configured to edit the image to be processed according to the image processing instruction and a target image processing model to obtain a result image. Examples taught in the present disclosure implements a user command to process images, which saves users' time spent in learning image processing software prior to image processing and improves user experience.

After taking photos, users tend to process the images by using Photoshop in an electronic device (such as a mobile phone or a tablet computer) or photo retouch software in a mobile phone to display better images.
However, prior to using Photoshop in the electronic device or the photo retouch software in the mobile phone to process images, users need to learn how to use the software and then input instructions manually to control an electronic device to perform retouch operations. This process is time-consuming for users and leads to unsatisfactory user experience.

Signal processing device, signal processing method and related products

Cambricon (Xi'an) Semiconductor Co., Ltd.


The present invention relates to a photolabile compound including a coumarin family caging group covalently bound to an organic moiety containing a carboxyl group, an amino group, a sulfhydryl group, and/or a hydroxyl group. The photolabile compound, upon absorbing visible light, releases the organic moiety. Also disclosed is a method of making a photolabile compound that releases a biologically active compound upon absorbing visible light by providing an organic moiety and binding a coumarin family caging group to the organic moiety under conditions effective to make the photolabile compound. The present invention also relates to a method of obtaining a biologically active compound in a sample. The method involves adding to a sample a photolabile compound including a coumarin family caging group covalently bound to an organic moiety. The sample is then illuminated with visible light under conditions effective to obtain a biologically active compound including the organic moiety.

The photorelease of bioactive molecules from photoprotected precursors is a powerful tool for studying fast kinetic biochemical responses in cell or tissue culture (Hess et al., "Development and Application of Caged Ligands for Neurotransmitter Receptors in Transient Kinetic and Neuronal Circuit Mapping Studies," Methods in Enzymology 291:443-473 (1998); Pelliccioli et al., "Photoremovable Protecting Groups: Reaction Mechanisms and Applications," Photochem Photobiol Sci 1:441-458 (2000); Goeldner, eds., Dynamic Studies in Biology: Phototriggers, Photoswitches, and Caged Biomolecules; Wiley-VCH: Weinheim, Germany (2005)). The photolabile caged forms of these bioactive molecules do not evoke biological responses when applied. Besides, in addition to temporal resolution, good spatial resolution is also achieved by the use of these precursors. In caged compounds, the biological activity of the molecule is blocked by chemical modification. A photosensitive protecting group is introduced at the functional group of the biologically active molecule that can later be removed by light of a particular wavelength. Thus, fast jumps in the concentration of the biomolecule can be achieved at a definite location.
Photolabile protecting groups for functional groups commonly found in biologically important compounds have been developed during the last 40 years (De Mayo P., "Ultraviolet Photochemistry of Simple Unsaturated Systems," Adv Org Chem 2:367-425 (1960); Barltrop et al., "Photosensitive Protective Groups," J Chem Soc, Chem Commun 822-823 (1966); Knowles J., "Photogenerated Reagents for Biological Receptor-Site Labeling," Acc Chem Res 5:155-160 (1972); Patchornik et al., "Photosensitive Protecting Groups," J Am Chem Soc 92:6333-6335 (1970)). To solve biological problems, they were first used by Kaplan et al. to rapidly generate significant and known concentrations of biologically active compounds (Kaplan et al., "Rapid Photolytic Release of Adenosine 5′-Triphosphate From a Protected Analogue: Utilization by the Na:K Pump of Human Red Blood Cell Ghosts," Biochemistry 17:1929-1935 (1978)). The rapid release of biologically active compounds from photolabile precursors has become a very useful technique in transient kinetic investigations of neurotransmitter receptors. These proteins must be studied on cell surfaces, where rapid mixing techniques do not have the time resolution required for the investigation of the fast (microsecond to millisecond) processes involved in activation and inhibition of neurotransmitters receptors (Udgaonkar et al., "Chemical Kinetic Measurements of a Mammalian Acetylcholine Receptor by a Fast-Reaction Technique," Proc Natl Acad Sci USA 84:8758-8762 (1987); Jayaraman et al., "How Fast Does the Gamma-Aminobutyric Acid Receptor Channel Open? Kinetic Investigations in the Microsecond Time Region Using a Laser-Pulse Photolysis Technique," Biochemistry 38:11372-11378 (1999); Grewer et al., "On the Mechanism of Inhibition of the Nicotinic Acetylcholine Receptor by the Anticonvulsant MK-801 Investigated by Laser-Pulse Photolysis in the Microsecond-to-Millisecond Time Region," Biochemistry 38:7837-7846 (1999); Ramakrishnan et al., "On the Mechanism of a Mutated and Abnormally Functioning γ-Aminobutyric Acid (A) Receptor Linked to Epilepsy," Biochemistry 43:7534-7540 (2004)). This problem is overcome by equilibrating the cell surface receptors with a biologically inactive caged neurotransmitter. The reaction to be investigated is initiated in the As time domain by photolysis of the caged compound (Hess G., "Rapid Chemical Reaction Techniques Developed for Use in Investigations of Membrane-Bound Proteins (Neurotransmitter Receptors)," Biophys Chem 100:493-506 (2003)). The α-carboxy-2-nitrobenzyl photolabile protecting group (Milburn et al., "Synthesis, Photochemistry, and Biological Activity of a Caged Photolabile Acetylcholine Receptor Ligand," Biochemistry 28:49-55 (1989)) was successfully used in such investigations to cage the different neurotransmitters that activate different receptors, carbamoylcholine (a stable analogue of acetylcholine) (Milburn et al., "Synthesis, Photochemistry, and Biological Activity of a Caged Photolabile Acetylcholine Receptor Ligand," Biochemistry 28:49-55 (1989)), N-methyl-D-aspartic acid (Gee et al., "Caged Bioactive Carboxylates. Synthesis, Photolysis Studies, and Biological Characterization of a New Caged N-Methyl-D-Aspartic Acid," J Org Chem 60:4260-4263 (1995)), kainate (Niu et al., "Synthesis and Photochemical Properties of a Kainate Precursor and Activation of Kainate and AMPA Receptor Channels on a Microsecond Time Scale," Biochemistry 35:2030-2036 (1996)), γ-aminobutyric acid (Wieboldt et al., "Synthesis and Photochemistry of Photolabile Derivatives of Gamma-Aminobutyric Acid for Chemical Kinetic Investigations of the Gamma-Aminobutyric Acid Receptor in the Millisecond Time Region," Biochemistry 33:1526-1533 (1994); Gee et al., "Synthesis and Photochemistry of a New Photolabile Derivative of GABA—Neurotransmitter Release and Receptor Activation in the Microsecond Time Region," J Am Chem Soc 116:8366-8367 (1994)), glutamate (Wieboldt et al., "Photolabile Precursors of Glutamate: Synthesis, Photochemical Properties, and Activation of Glutamate Receptors on a Microsecond Time Scale," Proc Natl Acad Sci USA 91:8752-8756 (1994)), glycine (Grewer et al., "A New Photolabile Precursor of Glycine With Improved Properties: A Tool for Chemical Kinetic Investigations of the Glycine Receptor," Biochemistry 39:2063-2070 (2000)), and serotonin (Breitinger et al., "Synthesis and Characterization of Photolabile Derivatives of Serotonin for Chemical Kinetic Investigations of the Serotonin 5-HT(3) Receptor," Biochemistry 39:5500-5508 (2000)). All these compounds are photolyzed in the μs-ms time region and with adequate quantum yield (Hess et al., "Development and Application of Caged Ligands for Neurotransmitter Receptors in Transient Kinetic and Neuronal Circuit Mapping Studies," Methods Enzymol 291:443-473 (1998); Gee et al., "Synthesis, Photochemistry, and Biological Characterization of Photolabile Protecting Groups for Carboxylic Acids and Neurotransmitters," Methods Enzymol 291:30-50 (1998)). This and other caging groups for neurotransmitters (Gee et al., "Desyl Esters of Amino Acid Neurotransmitters. Phototriggers for Biologically Active Neurotransmitters," J Org Chem 61:1228-1233 (1996); Sheehan et al., "Photolysis of Desyl Compounds. A New Photolytic Cyclization," J Am Chem Soc 86:5277-5281 (1964); Kuzmic et al., "Photochemical Hydrolysis of Some Nitrophenyl Acetates," Collect Czech Chem Commun 51:1293-1300 (1986); Ramesh et al., "Photolysis of a Protecting Group for the Carboxyl Function of Neurotransmitters Within 3 Microseconds and With Product Quantum Yield of 0.2," Proc Natl Acad Sci USA 90:11074-11078 (1993)) absorb only in the UV wavelength region and require expensive lasers and special rooms in which the instruments must be housed for safety reasons. Because of potential damage to the receptor-containing cells by prolonged exposure to UV light, only a few measurements can be made with each cell. Compounds that are photolyzed in the UV wavelength region can also be photolyzed by multiphoton excitation in the visible wavelength region (Denk et al., "Two-Photon Laser Scanning Fluorescence Microscopy," Science 248:73-76 (1990); Fedoryak et al., "Brominated Hydroxyquinoline as a Photolabile Protecting Group With Sensitivity to Multiphoton Excitation," Org Lett 4:3419-3422 (2000)). Uncaging, however, occurs only at the focus of the laser beam (Denk et al., "Two-Photon Laser Scanning Fluorescence Microscopy," Science 248:73-76 (1990); Fedoryak et al., "Brominated Hydroxyquinoline as a Photolabile Protecting Group With Sensitivity to Multiphoton Excitation," Org Lett 4:3419-3422 (2000)). The technique is, therefore, suitable for locating the position of a particular receptor in biological membranes, but not for activating sufficient receptors for transient kinetic measurements (Hess et al., "Development and Application of Caged Ligands for Neurotransmitter Receptors in Transient Kinetic and Neuronal Circuit Mapping Studies," Methods Enzymol 291:443-473 (1998)). All these problems can be avoided by use of a photolabile protecting group for neurotransmitters that can be photolyzed in the visible wavelength region.
Many organic molecules suitable for caging absorb in the visible wavelength region (Pillai V., "Photolytic Deprotection and Activation of Functional Group," Org Photochem 9:225-317 (1987); Bochet C., "Photolabile Protecting Groups and Linkers," J Chem Soc, Perkin Trans 1:125-142 (2002); Singh et al., "Synthesis and Photochemical Properties of Nitro-Naphthyl Chromophore and the Corresponding Immunoglobulin Bioconjugate," Bioconjugate Chem 13:1286-1291 (2002); Mizuta et al., "Design, Synthesis, Photochemical Properties and Cytotoxic Activities of Water-Soluble Caged L-Leucyl-L-Leucine Methyl Esters That Control Apoptosis of Immune Cells," Bioorg Med Chem 10:675-683 (2002); Furuta et al., "Brominated 7-Hydroxycoumarin-4-ylmethyls: Photolabile Protecting Groups With Biologically Useful Cross-Sections for Two Photon Photolysis," Proc Natl Acad Sci, USA 96:1193-1200 (1999); Xu et al., "Multiphoton Fluorescence Excitation: New Spectral Windows for Biological Nonlinear Microscopy," Proc Natl Acad Sci USA 93:10763-10768 (1996)). However, they have negligible or no solubility in aqueous medium (Singh et al., "Synthesis and Photochemical Properties of Nitro-Naphthyl Chromophore and the Corresponding Immunoglobulin Bioconjugate," Bioconjugate Chem 13:1286-1291 (2002); Mizuta et al., "Design, Synthesis, Photochemical Properties and Cytotoxic Activities of Water-Soluble Caged L-Leucyl-L-Leucine Methyl Esters That Control Apoptosis of Immune Cells," Bioorg Med Chem 10:675-683 (2002); Furuta et al., "Brominated 7-Hydroxycoumarin-4-Ylmethyls: Photolabile Protecting Groups With Biologically Useful Cross-Sections for Two Photon Photolysis," Proc Natl Acad Sci, USA 96:1193-1200 (1999); Xu et al., "Multiphoton Fluorescence Excitation New Spectral Windows for Biological Nonlinear Microscopy," Proc Natl Acad Sci USA 93:10763-10768 (1996)). Recently, the substituted 2-nitroveratrole group (Bochet C., "Orthogonal Photolysis of Protecting Groups," Angew Chem, Int Ed 40:2071-2073 (2001)), nitroindolines (Canepari et al., "Photochemical and Pharmacological Evaluation of 7-Nitroindolinyl-and 4-Methoxy-7-Nitroindolinyl-Amino Acids as Novel, Fast Caged Neurotransmitters," J Neurosci Methods 112:29-42 (2001)), the phenacyl group (Banerjee et al., "Protecting Group Release Through Photoinduced Electron Transfer: Wavelength Control Through Sensitized Irradiation," Tetrahedron Lett 39:4635-4638 (1998)), and substituted coumarins (Furuta et al., "Brominated 7-Hydroxycoumarin-4-ylmethyls: Photolabile Protecting Groups With Biologically Useful Cross-Sections for Two Photon Photolysis," Proc Natl Acad Sci, USA 96:1193-1200 (1999); Lin et al., "A Strategy for the Construction of Caged Diols Using a Photolabile Protecting Group," J Org Chem 67:2723-2726 (2002); Hagen et al., "Highly Efficient and Ultrafast Phototriggers for cAMP and cGMP by Using Long-Wavelength UV/Vis-Activation," Angew Chem, Int Ed 40:1045-1048 (2001); Takaoka et al., "Synthesis and Photoreactivity of Caged Blockers for Glutamate Transporters," Bioorg Med Chem Lett 13:965-970 (2003); Takaoka et al., "Synthesis of Carbamate-Type Caged Derivatives of a Novel Glutamate Transporter Blocker," Bioorg Med Chem 12:3687-3694 (2004)) have been studied as caging groups that can be deprotected by visible light. However, many of these compounds have undesirable properties limiting their usefulness, such as low solubility in aqueous medium and/or slow photolysis (Takaoka et al., "Synthesis of Carbamate-Type Caged Derivatives of a Novel Glutamate Transporter Blocker," Bioorg Med Chem 12:3687-3694 (2004)), and are, therefore, unsuitable for transient kinetic investigations of membrane-bound proteins on cell surfaces. In the case of the 2-nitroveratrole group, the rate of release of the bioactive compound (Bochet C., "Wavelength-Selective Cleavage of Photolabile Protecting Groups," Tetrahedron Lett 41:6341-6346 (2000)) is slow, in the minutes region. Various coumarin derivatives are stable and/or soluble in DMSO solutions (Takaoka et al., "Synthesis and Photoreactivity of Caged Blockers for Glutamate Transporters," Bioorg Med Chem Lett 13:965-970 (2003). Aqueous solubility is required to investigate membrane-bound proteins. The stability of caged compounds in aqueous medium is also important, because contamination of the receptors with free neurotransmitter while they equilibrate with the caged compound interferes with the kinetic measurements.
All the following characteristics are required for the caged compound to be useful in transient kinetic investigation of neurotransmitter receptors on cell surfaces.                (1) The compound must be soluble and stable in water at physiological pH.        (2) The release of bioactive compound should be sufficiently fast (in the microsecond time scale) so that release of neurotransmitter does not become the rate-determining step.        (3) The photolysis process should have sufficient quantum yield so that the bioactive compound is released in high enough concentration for kinetic measurements.        (4) Both the caged compound and the photolysis byproducts must be biologically inert.        (5) The caged compound should be photolyzed in the visible wavelength region in order to allow more measurements to be made with each cell because photodamage to the cell or the receptors is avoided. Much less expensive and simple-to-use light sources are available for experiments in the visible wavelength region, thereby opening up this important field to an increasing number of investigators.
Transient kinetic measurements with each cell require two control experiments. A standard concentration of neurotransmitter is applied to the cell at the beginning of the experiment, using the cell-flow technique (Udgaonkar et al., "Chemical Kinetic Measurements of a Mammalian Acetylcholine Receptor by a Fast-Reaction Technique," Proc Natl Acad Sci USA 84:8758-8762 (1987)). Although the cell-flow technique has a considerably poorer time resolution (˜10 ms) than the laser-pulse photolysis technique (˜50 μs) (Milburn et al., "Synthesis, Photochemistry, and Biological Activity of a Caged Photolabile Acetylcholine Receptor Ligand," Biochemistry 28:49-55 (1989); Hess et al., "Development and Application of Caged Ligands for Neurotransmitter Receptors in Transient Kinetic and Neuronal Circuit Mapping Studies," Methods Enzymol 291:443-473 (1998)), it can be used to calculate the amount of neurotransmitter that is released from the caged compound in the kinetic measurements (Udgaonkar et al., "Chemical Kinetic Measurements of a Mammalian Acetylcholine Receptor by a Fast-Reaction Technique," Proc Natl Acad Sci USA 84:8758-8762 (1987)). This measurement, with the same standard concentration of the neurotransmitter, is repeated at the end of the laser-pulse photolysis measurement to assess possible damage to the receptors or the cell during the experiment. Additionally, obtaining a good seal between the recording electrode and a cell is time-consuming. The ability to make many kinetic measurements with each cell has, therefore, many advantages, including a reduction in the experimental error. It is, therefore, a necessity that the caged neurotransmitter is stable in water during the time it takes to make the measurements with a cell.
(Coumarin-4-yl)methyl derivatives are newly developed caging groups that have been successfully applied to protect biological activity in phosphates (Givens et al., "Photochemistry of Phosphate Esters: An Efficient Method for the Generation of Electrophiles," J. Am. Chem. Soc. 106:6860-6861 (1984); Furuta et al., "Photochemical Properties of New Photolabile cAMP Derivatives in a Physiological Saline Solution," J. Org. Chem. 60:3953-3956 (1995); Hagen et al., "Synthesis, Photochemistry and Application of (7-Methoxycoumarin-4-yl)Methyl-Caged 8-Bromoadenosine Cyclic 3′,5′-Monophosphate and 8-Bromoguanosine Cyclic 3′,5′-Monophosphate Photolyzed in the Nanosecond Time Region," J Photochem. Photobiol., B 53:91-102 (1999); Hagen et al., "Highly Efficient and Ultrafast Phototriggers for cAMP and cGMP by Using Long-Wavelength UV/Vis-Activation," Angew Chem, Int Ed 40:1045-1048 (2001); Geissler et al., "DMACM-Caged Adenosine Nucleotides Ultrafast Phototriggers for ATP, ADP, and AMP Activated by Long-Wavelength Irradiation," Chem Bio Chem 4:162-170 (2003); Geissler et al., "(Coumarin-4-yl)Methyl Esters as Highly Efficient, Ultrafast Phototriggers for Proton and Their Application to Acidifying Membrane Surfaces," Angew. Chem. Int. Ed. 44:1195-1198 (2005)), carboxylates (Furuta et al., "Brominated 7-Hydroxycoumarin-4-ylmethyls: Photolabile Protecting Groups With Biologically Useful Cross-Sections for Two Photon Photolysis," Proc Natl Acad Sci, USA 96:1193-1200 (1999)), sulfates (Geissler et al., "(Coumarin-4-yl)Methyl Esters as Highly Efficient, Ultrafast Phototriggers for Proton and Their Application to Acidifying Membrane Surfaces," Angew. Chem. Int. Ed. 44:1195-1198 (2005)), sulfonates (Geissler et al., "(Coumarin-4-yl)Methyl Esters as Highly Efficient, Ultrafast Phototriggers for Proton and Their Application to Acidifying Membrane Surfaces," Angew. Chem. Int. Ed. 44:1195-1198 (2005)), diols (Lin et al., "A Strategy for the Construction of Caged Diols Using a Photolabile Protecting Group," J Org Chem 67:2723-2726 (2002)), alcohols (Suzuki et al., "Coumarin-4-ylmethoxycarbonyls as Phototriggers for Alcohols and Phenols," Organic Letters 5:4867-4870 (2003)), and carbonyl compounds (Lu et al., "Bhc-diol as a Photolabile Protecting Group for Aldehydes and Ketones," Org. Lett. 5:2119-2122 (2003)). Amino and hydroxyl functionalities have also been protected via carbamate (Furuta et al., "Brominated 7-Hydroxycoumarin-4-ylmethyls: Photolabile Protecting Groups With Biologically Useful Cross-Sections for Two Photon Photolysis," Proc Natl Acad Sci, USA 96:1193-1200 (1999)) or carbonate (Suzuki et al., "Coumarin-4-ylmethoxycarbonyls as Phototriggers for Alcohols and Phenols," Org. Lett. 5:4867-4870 (2003)) linkers.
7-N,N-Diethylamino-4-hydroxymethyl coumarin (DECM) has been used to cage nucleotides such as ADP and ATP. The DECM-caged nucleotides were photolyzed in the 300-400 nm wavelength region (Hagen et al., "[7-(Dialkylamino)Coumarin-4-yl]Methyl-Caged Compounds as Ultrafast and Effective Long-Wavelength Phototriggers of 8-Bromo-Substituted Cyclic Nucleotides," Chem Bio Chem 4:434-442 (2003)). However, it is unknown if this caging group can be used with carboxylic acids, and whether the quantum yield and rate of photolysis in the visible wavelength region would be sufficient (Hess et al., "Development and Application of Caged Ligands for Neurotransmitter Receptors in Transient Kinetic and Neuronal Circuit Mapping Studies," Methods Enzymol: Caged Compd 291:443-473 (1998)) for transient kinetic measurements.
The present invention is directed to overcoming these deficiencies in the art.

Protecting group for carboxylic acids that can be photolyzed by visible light


A method for selecting amino acid residues is disclosed which upon replacement will give rise to an enzyme with an altered substrate specificity. New mutant glucose isomerases with an altered substrate specificity are provided according to this method. These altered properties are useful in starch degradation and in other sugar conversion reactions.

Glucose isomerases catalyze the reversible isomerization of glucose to fructose. Fructose is nowadays commonly applied as sugar substitute due to its higher sweetness compared to e.g. sucrose and glucose.
Many microorganisms are known to produce glucose isomerase, see for example the review articles by Wen-Pin Chen in Process Biochemistry, 15 June/July (1980) 30-41 and August/September (1980) 36-41, in which a large number of microorganisms, capable of producing glucose isomerase, are listed.
Several microorganisms can be used for the industrial production of glucose isomerases, among these Streptomyces Ampullariella and Actinoplanes are well known. The Wen-Pin Chen reference describes culture conditions for the microorganisms and recovery and purification methods for the produced glucose isomerases.
Generally the naturally occurring glucose isomerases also show a high affinity for sugars other than glucose. In this respect D-xylose, D-ribose, L-arabinose, D-allose and 6-deoxyglucose were found to be substrates of this enzyme. The K.sub.m values of D-glucose, D-xylose and D-ribose, were shown to vary from microorganism to microorganism and were reported to be in the range, of 0.086-0.920, 0.005-0.093 and 0.35-0.65M, respectively.
The K.sub.m values for xylose are significantly lower than for glucose, which implies that the correct name for the enzyme is in fact xylose isomerase. Furthermore, the V.sub.max of the commonly used glucose isomerases is higher on xylose than on glucose, which also suggest that xylose isomerase is a better name.
Since glucose isomerase is active on different substrates it may be advantageous to alter the substrate specificity depending on the desired reaction product, the specific process in which it is used or the wish to avoid unwanted side-products.
For the application of glucose isomerase in HFCS production a higher V.sub.max and a lower K.sub.m on glucose would be useful properties, since the reaction time and the enzyme costs would be reduced.
Another application of glucose isomerase is in the conversion of xylose to ethanol (Jeffries, T. W., Trends Biotechnol. 3 (1985) 208). A higher activity (V.sub.max) on xylose and/or a better affinity for xylose would be useful properties for this application.
The digestibility and the taste of feed for monogastric animals can be improved if glucose is converted enzymatically into fructose. In practice the application of glucose isomerase is hampered by the xylose isomerisation activity, which causes an unwanted formation of xylulose in feed. A glucose isomerase with no or reduced specificity (V.sub.max or K.sub.m) for xylose would be preferred for application in feed pretreatment.
Clearly, there is a need for altering the substrate specificity of glucose isomerases which would at the same time widen the field of the application of this enzyme.
Recently redesigning of the specific activity of enzymes with the aid of protein engineering techniques has been described. Wells et al. (Proc. Natl. Acad. Sci. U.S.A. 84 (1987) 5167) show an example for subtilisin. Bacillus licheniformis and B. amyloliquefaciens serine proteases differ by 31% (86 amino acid residues) in protein sequence and by a factor of 60 in catalytic efficiency on certain substrates. By substituting 3 of the 86 different amino acids from the B. amyloliquefaciens sequence by the corresponding B. licheniformis residues the catalytic activity of the mutant enzyme was improved nearly 60 fold.
In another paper it is described how a lactate dehydrogenase was changed into a malate dehydrogenase by mutating glutamine 102 into arginine 102 (Wilks et al., Science 242 (1988) 1541).
In both cases referred to above, serine protease and lactate dehydrogenase, the modification proposal was based on the comparison of the molecule to be modified and naturally occurring enzymes, which already showed the desired substrate specificity. In the same way the specificity of cytochrome p450.sub.15.alpha. was changed into the specificity of cytochrome p450.sub.coh by replacing Leu209 with Phe209 (Lindberg and Negishi, Nature 339 (1989) 632).
For glucose isomerase no naturally occurring enzyme is known, which shows a better specificity for glucose than for xylose. The above-mentioned method, based on the comparison of active sites of homologous enzymes having a different substrate specificity, can therefore not be applied to glucose isomerase.
WO 89/01520 (Cetus) lists a number of muteins of the xylose isomerase which may be obtained from Streptomyces rubiginosus and that may have an increased stability. The selection of possible sites that may be mutated is based on criteria differing from the ones used in the present invention. More than 300 mutants are listed but no data are presented concerning the characteristics and the alterations therein of the mutant enzyme molecules.

Glucose isomerases having altered substrate specificity


A method of forming a memory device (e.g., a DRAM) including array and peripheral circuitry. A plurality of undoped polysilicon gates 58 are formed. These gates 58 are classed into three groups; namely, first conductivity type peripheral gates 58p, second conductivity type peripheral gates 58n, and array gates 58a. The array gates 58a and the first conductivity type peripheral gates 58n are masked such that the second conductivity type peripheral gates 58p remain unmasked. A plurality of second conductivity type peripheral transistors can then be formed by doping each of the second conductivity type peripheral gates 58p, while simultaneously doping a first and a second source/drain region 84 adjacent each of the second conductivity type peripheral gates 58p. The second conductivity type peripheral gates 58p are then masked such that the first conductivity type peripheral gates 58n remain unmasked. A plurality of first conductivity type peripheral transistors are formed by doping each of the first conductivity type peripheral gates 58n, while simultaneously doping a first and a second source/drain region 82 adjacent each of the first conductivity type peripheral gates 58n.

This invention relates generally to semiconductor devices and specifically to a memory device with surface-channel peripheral transistors.
The manufacture of integrated circuits generally, and dynamic random access memories (DRAMs) particularly, involves hundreds of individual manufacturer or process steps. While any generalization of such a large number of operations necessarily omits much detail, the manufacture of integrated circuits can be generally described with four major divisions: prepare blank wafers of semiconductor material, such as silicon; process the blank wafers to form multiple chips containing the desired circuits; package the individual chips and subject the packaged chips to elevated temperature and voltage operating conditions to eliminate early failing chips, e.g. perform burn-in testing. This last step helps ensure reliability.
To reduce the cost of memory devices, efforts are continuously being made to reduce the number of manufacturing or process steps required to fabricate devices. One objective of cost reduction has been addressed by the DRAM industry in the form of mask reduction; that is, attempting to fabricate the desired DRAM design, while using fewer costly photolithographic steps.
Complementary metal-oxide-semiconductor (CMOS) is the most common technology used to form DRAM devices. As is known, CMOS circuits include both n-channel and p-channel transistors. The choice of the gate material and the channel doping level determines the threshold voltage for the transistors. For enhanced performance of the devices, it is desirable that the threshold voltages of the n- and p-channel transistors are comparable, and preferably, of equal magnitude. It is also desirable that the threshold voltages are as low as possible without introducing excessive off-state current.
The most common choice for gate material for modem CMOS technologies is n-type polysilicon that is doped heavily enough to make the polysilicon degenerate. This is usually combined with a silicide layer to lower the sheet resistance. The work function of n+ polysilicon is ideal for an n-channel device since it yields a threshold voltage of less than 0.7 V for reasonable values of channel doping and oxide thickness.
When the n+ polysilicon gate is used, the p-channel threshold voltage is not as ideally adjusted with the substrate doping. The threshold voltage of the p-channel device is adjusted by simply reducing the p-channel substrate doping. For doping levels necessary to prevent short-channel effects, the threshold voltage magnitude is above 1 V.
A technique that allows the p-channel threshold voltage to be adjusted to the desired level is to implant a shallow boron layer into the channel region. The boron shifts the threshold voltages towards more positive values by forming a compensating layer. The boron threshold adjustment can also be used to raise the threshold voltage of the n-channel transistor. A single boron implant dose can be used to set the threshold voltages of both the n- and p-channel transistors if the background dopings are chosen correctly. The magnitude of VTP, the threshold voltage of the p-channel transistor, is reduced because the boron implant charge to the channel region of the n-well. Lower n-well doses allow the boron implant to have a greater effect on the value of VTP. One disadvantage to this approach is that the p-channel transistor is more susceptible to short-channel effects with the compensated surface channel.
Another choice for the gate material is p+-polysilicon. The work function of p+ polysilicon is about 1.1V greater than for n+ polysilicon. This makes it ideal for the p-channel transistor in terms of having the threshold voltage easily adjusted to xe2x88x920.7 V or less with channel doping of 1015 to 1017 cmxe2x88x923. However, the n-channel transistor must now be compensated to reduce the threshold voltage to reasonably low values.
Other choices of gate material, such as MoSi2, have metal work functions that are between those of n+ and p+ polysilicon, which allows both transistors to be slightly compensated to get the desired threshold voltages. To optimize both devices simultaneously, both n+- and p+-type polysilicon gates can be used for the n- and p-channel transistors respectively. This approach allows both transistor threshold voltages to be easily adjusted to the desired threshold voltages without sacrificing short-channel effects, but adds to the processing complexity. See S. M. Sze, VLSI Technology, McGraw-Hill, New York, 1988, Ch. 11, pp. 483-493.
The present invention discloses a memory device which can be manufactured in fewer process steps than prior art memory devices. An array of memory cells, such as DRAM cells, is formed in a semiconductor chip. Peripheral circuitry (e.g., decoders, buffers, voltage generators) is disposed adjacent the array. The peripheral circuitry includes both n-channel transistors and p-channel transistors. Each of the n-channel transistors includes a polysilicon gate doped with n-type impurities while each of the p-channel transistors includes a polysilicon gate doped with p-type impurities.
The present invention further provides a method of forming a memory device including array and peripheral circuitry. A plurality of undoped polysilicon gates are formed. These gates may be classed into three groups; namely, first conductivity type peripheral gates, second conductivity type peripheral gates, and array gates. The array gates and the first conductivity type peripheral gates are masked such that the second conductivity type peripheral gates remain unmasked. A plurality of second conductivity type peripheral transistors can then be formed by doping each of the second conductivity type peripheral gates while simultaneously doping a first and a second source/drain region adjacent each of the second conductivity type peripheral gates. The second conductivity type peripheral gates are then masked such that the first conductivity type peripheral gates remain unmasked. As before, a plurality of first conductivity type peripheral transistors are formed by doping each of the first conductivity type peripheral gates while simultaneously doping a first and a second source/drain region adjacent each of the first conductivity type peripheral gates.
One advantage of the present invention is the elimination of ion implantation steps to control the threshold voltage in the p-channel peripheral transistors. Since the p-channel transistors have p-doped polysilicon gates, no threshold voltage adjustment is necessary. This feature shortens the length of the memory device manufacturing process.

Memory device with surface-channel peripheral transistor


A projection apparatus for projecting a first image and a second image is disclosed. The projection apparatus has a casing, a light source module providing an illumination beam, a light valve device, a first prism, a second prism, a third prism, a fourth prism, a first projection lens, and a second projection lens. The illumination beam enters the first prism, the second prism, the third prism, the fourth prism, and the light valve device. The illumination beam is reflected and converted into a first image beam and a second image beam. The first image beam enters the first prism and is totally reflected to the first projection lens to form the first image. The second image beam enters the third prism and is totally reflected to the second projection lens to form the second image.

1. Field of the Invention
The present invention relates to a projection apparatus; more particularly, the present invention relates to a projection apparatus capable of projecting a first image and a second image.
2. Description of the Related Art
Most commonly used projection apparatuses are designed to project only one image because one projection apparatus is equipped with a single digital micro-mirror device (DMD). If two images need to be projected, two projection apparatuses can be used, or splitters can be employed to project two images. However, due to the divergence of light, if the splitter is far from the light source, a larger splitter is needed, and the volume of the projection apparatus will be correspondingly increased. Furthermore, from the manufacturer's perspective, producing a projection apparatus with two DMDs in one projection apparatus is not economical because the DMD, a key element of a projection apparatus, is quite expensive.
Therefore, there is a need to provide a new projection apparatus capable of projecting two images with only a single DMD to solve the problem of the prior art.

Multi-projection system using a single illumination source and a single imaging device