An exposure operation evaluation method for an exposure apparatus for arranging a predetermined number of at least one evaluation pattern in an overlapping area and printing the at least one evaluation pattern on a substrate when performing a plurality of exposures and printing on the substrate while sequentially step-moving an exposure area in quadrangle, the exposure area having evaluation patterns arranged on an outer peripheral side of a circuit pattern, the overlapping area overlapping respective exposure areas adjacent to four sides of the exposure area, the method including: measuring a printing misalignment between each evaluation pattern of adjacent exposure areas printed on the substrate; and calculating a plurality of linear components in an exposure operation of the exposure apparatus based on the result of the measurement of the printing misalignment and suppressing and controlling the printing misalignment based on the plurality of linear components.

1. Field of the Invention
The present invention relates to: an exposure operation evaluation method for an exposure apparatus for adjusting and controlling an exposure operation by measuring a printing result of a predetermined evaluation pattern which has been printed on a substrate by the exposure operation; and a manufacturing method for semiconductor device for manufacturing a semiconductor device by using the adjusted and controlled exposure apparatus based on the evaluation result obtained by the exposure operation evaluation method for the exposure apparatus.
2. Description of the Related Art
When factories for manufacturing semiconductor elements (e.g., ultra large scale integrated circuit) form a pattern (e.g., circuit pattern) on a substrate, they mainly print on the substrate the pattern (e.g., circuit pattern), which has been drawn on a reticle, by using a reduced projection exposure apparatus through a projection lens, perform a step of forming the pattern such as the circuit pattern on the substrate a plurality of times so as to manufacture a semiconductor element in a laminated structure on the substrate. This exposure step has been increasingly performed by using exposure apparatuses, which have different accuracy from each other, for an exposure step in each different manufacturing step during the process of manufacturing one type of semiconductor device in consideration of processing accuracy and manufacturing cost of each pattern to be formed.
For example, for each semiconductor device, formed according to a new generation rule, with its processing line width being reduced, process construction of all layers for a semiconductor element to be manufactured by newly utilizing exposure apparatuses whose accuracy has been improved in each factor does not satisfy the manufacturing cost. Thus, a combination of exposure apparatuses which were used in each generation before the previous generation and new exposure apparatuses which can achieve a required new technique with excellent accuracy is often used to construct a process which achieves a rule for a new generation. Accordingly, in a process of manufacturing one type of a semiconductor device, exposure apparatuses with different functions and performance from each other have been increasingly used for the exposure process of each processed layer.
For exposure apparatuses in each generation, in order to obtain the resolution which is required in each generation along with the miniaturization of a circuit pattern, exposure light is caused to be short-wavelengthened. As exposure light which has been short-wavelengthened, for example, i ray (wavelength 365 nm) from mercury lamp, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm) have been put into practice, and exposure apparatuses which use further short-wavelengthened F2 (wavelength 157 nm) excimer laser, electronic beam drawing technology, EUV (wavelength 13 nm) light and the like have been pursued.
When a pattern (e.g. circuit pattern) on a reticle is reduced-projected onto a substrate by using the light source thereof, in exposure apparatuses (e.g., full-field-type (stepper) and scanning-type (scanner) which have been used in each generation), a processing technique and a lens material for a reduced projection lens, a table driving control accuracy, an exposure method, an exposure field area, a reduced projection magnification, an alignment accuracy and the like are different between each exposure apparatus.
When each layer is formed, for example, a structure is being established such that exposure in each step is performed using the following so-called mix and match method: (i) a scanning-type reduced projection exposure apparatus (scanner) is used for exposure of a critical layer which requires high alignment accuracy; (ii) a full-field-type reduced projection exposure apparatus (stepper), which has been used for the critical layer in the previous generation, is used for exposure of a sub-critical layer which does not require the alignment accuracy as high as that for the critical layer but requires a certain degree of alignment accuracy; and (iii) a full-field-type reduced projection exposure apparatus (stepper), which was used in the generations before the previous generation, or a full-field-type reduced projection exposure apparatus (stepper), which has a low-reduced magnification and is intended for improving the throughput, is used for exposure of a rough layer.
When a first layer is exposed to light on a semiconductor substrate, accuracy relating to alignment of a printed pattern is not normally measured. This is because it is considered that a variety of accuracy of the exposure apparatus, for example, stage stepping accuracy, reduced projection magnification control accuracy, reticle rotation accuracy, shot alignment accuracy, distortion, stage synchronization accuracy between an original plate and a substrate by the scanning-type reduced projection exposure apparatus (scanner) and the like are regularly measured, managed and corrected, and the results which are used in an allowable range are reflected.
Additionally, when the exposure apparatus for the first layer is the full-field-type reduced projection exposure apparatus (stepper) and the exposure apparatus for the second layer and its subsequent layers is the scanning-type reduced projection exposure apparatus (scanner), and the result of alignment for the second layer is to be improved, then the number of items of linear components to be corrected which can be corrected by the scanning-type reduced projection exposure apparatus (scanner) is the same as that by the full-field-type reduced projection exposure apparatus (stepper) and furthermore there are other items to be corrected other than them. Therefore, correction can be performed with high accuracy. Alternatively, as another example, when the exposure apparatus for the first layer is the full-field-type reduced projection exposure apparatus (stepper) and the exposure apparatus for the second layer and its subsequent layers is also the full-field-type reduced projection exposure apparatus (stepper), then it is possible to improve the alignment result by conducting a setting (grouping) of an exposure apparatus group in which each exposure apparatus has a similar misalignment tendency for distortion to each other.
Reference 1 discloses a technology that the position of a destroyed pattern image such as in thin line portion is obtained as a printed error of an evaluation pattern which has been printed on a substrate (wafer) while moving (scanning) an original plate (reticle) and the substrate in synchronization by using the scanning-type reduced projection exposure apparatus (scanner) so as to evaluate the exposure operation with excellent accuracy at high speed. Based on this evaluation result, an exposure condition of the scanning-type reduced projection exposure apparatus (scanner) is evaluated, and the evaluation result is then fed back in order to adjust and control the scanning-type reduced projection exposure apparatus (scanner).
Reference 2 discloses an alignment and exposure method for calculating the position of a particular exposure area (hereinafter, referred to as "shot") among shots, which have been printed on a substrate (wafer), relative to other shots by employing a mix and match method for exposing mask patterns one above another on the substrate by using two exposure apparatuses in which exposure field sizes are different from each other. According to this technology, deformation in the wafer and deformation in the shot can be learned with the minimum number of alignment, and the alignment between an upper layer and a lower layer can be improved, thereby being able to improve the throughput of the exposure.
[Reference 1] Japanese Laid-Open Publication No. 11-186155
[Reference 2] Japanese Laid-Open Publication No. 11-195596

Exposure operation evaluation method for exposure apparatus and manufacturing method for semiconductor device


A structure for fixing light guide element to an electric connector includes a connector case internally defining at least one socket, and externally provided on a top surface with at least one locating plate above the socket, at least one hold-down tab behind the locating plate, and at least one elastic stopper behind the hold-down tab; and a light guide element consisting of a plurality of parallelly arranged light guide units interconnected via a transverse bridge section having at least one slit formed on a front side thereof. When the straight front end section of each light guide unit is forward extended through a corresponding locating plate, the elastic stopper would abut on a rear side of the bridge section, and the slit on the bridge section would engage with the hold-down tab, enabling the light guide element to be flatly assembled to the top surface of the connector case.

Electric connectors provided with indicating lamps have been widely known and are often employed on many modular sockets or other similar electric devices. The modular sockets are mounted on a circuit board for a corresponding modular plug to insert thereinto to enable an electric connection thereat. In a conventional electric connector with an indicating lamp, a light emitting diode (LED) is embedded in a front side of a case for the electric connector, so that light emitted from the LED is used to indicate an operational or functional state of the electric connector, such as, for example, the receiving or transmitting of data or signals, the normal connection of different parts in an apparatus, the on or off of a power supply, an abnormal condition in data transmission over a network, etc. However, with the tendency of miniaturization, there is no longer sufficient space in the connector cases of miniaturized electronic and telecommunication products for mounting an LED therein, which inevitably causes confusions in product design.
FIGS. 1 to 3 illustrate a conventional structure for fixing a light guide element to an electric connector. As shown, the structure mainly includes a connector case 3, a holding bracket 4, and a light guide element 20.
The connector case 3 is provided at lower edges with a plurality of downward projected insertion tabs 31 for inserting into holes correspondingly formed on a circuit board to serve as locating and grounding means. The connector case 3 is also provided at a front side with a plurality of sockets 32, into which a correspondingly formed plug may be plugged to enable an electric connection thereat. A plurality of raised strips 33 are formed on a top surface of the connector case 3 above each of the sockets 32 to extend in a direction parallel to an extension direction of the socket 32, so that a guide path 331 is formed between any two adjacent raised strips 33 on each socket 32. The connector case 3 is also externally provided on each of two lateral surfaces with a plurality of hooks 34.
The holding bracket 4 has a front side being bent to form a raised end portion 43. The raised end portion 43 is formed at an outer edge with a plural set of notches 431 corresponding to the guide paths 331 on the connector case 3, and on a top thereof with a plural set of channels 42 corresponding to and extended rearward from the notches 431. At least one set of two longitudinally spaced clamping plates 45 are formed on the holding bracket 4 near a middle portion thereof behind the raised end portion 43. The holding bracket 4 is also provided at each of two lateral sides with a plurality of downward bent vertical sections 44 and a plurality of upward bent vertical sections 41. Each of the downward bent vertical sections 44 has a retaining hole 441 formed thereon corresponding to the hooks 34 on the connector case 3. Through engagement of the retaining holes 441 with the hooks 34, the holding bracket 4 may be fixed to the top surface of the connector case 3.
The light guide element 20 consists of a plurality of parallelly arranged light guide units 21 interconnected with one another via a transversely extended bridge section 22. Each of the light guide units 21 is of L-shaped to have a straight front portion defining an upper end section 211 and a downward bent rear portion defining a lower end section 212. The bridge section 22 is provided at each of two lateral sides thereof with a sideward opened recess 203 corresponding to the upward bent vertical sections 41 on the holding bracket 4. Each of the lower end sections 212 is provided at one side thereof with a downward projected insertion section 24.
The light guide element 20 is assembled to the top surface and a rear outer side of the connector case 3 via the holding bracket 4 by extending the upper end sections 211 of the light guide element 20 into the channels 42 on the holding bracket 4 to forward project from the notches 431, locating the bridge section 22 between the set of two longitudinally spaced clamping plates 45 with the upward bent vertical sections 41 at two lateral sides of the holding bracket 4 separately abutting on the two sideward opened recesses 203 at two lateral sides of the bridge section 22, and inserting the downward projected insertion sections 24 at the lower end sections 212 into the circuit board (not shown).
With the above structure, the light guide element 20 is fixed to an outside of the connector case 3 to enable effective reduction of the volume of the connector case 3. However, the light guide element 20 is fixed to the connector case 3 via the holding bracket 4, which inevitably complicates the assembling of the electric connector and increases the component cost of the electric connector to disadvantageously lower the competitive ability of a finished product of the electric connector in the market.
It is therefore tried by the inventor to develop a simplified structure for fixing a light guide element to an electric connector to eliminate the drawbacks in the conventional electric connector having a light source provided therewith.

Structure for fixing light guide element to an electric connector


A communications driver is provided for establishing communications sessions between a computer system and a remote device, such as another computer system. The computer system includes a plurality of ports which are connected to a number of diverse types of communications media. At least one of the ports comprises a network port controlled by a network socket driver, so that the communications driver can be used in connection with lower-level networking drivers which may be provided by a variety of manufacturers. The communications driver selectively establishes a communications session such that the computer system will operate as a terminal with the remote device over one of the communications media, as selected by an operator. The communications driver initially enables the operator to identify a communications medium and a remote device, and the driver thereafter selects one of the ports in response to identification by the operator of a communications medium and a remote device. After selecting the port, the driver attempts to establish a communications session with the remote device over the communications medium using the port as selected by said communications path selection element. If successful in establishing the communications session, the communications driver enables communications to proceed such that the computer system will operate as a terminal on the remote device, regardless of the communications media over which they communicate.

In modern "enterprise" computing, personal computers and workstations distributed among workers in the enterprise are replacing the previously-used large and expensive, centrally-located and maintained mainframe computer systems. One advantage that mainframe systems have over more modern distributed arrangements, however, is that, since they are centrally-located, they more easily provide for sharing of data and programs, which can be important in an enterprise environment. To facilitate program and data sharing among personal computers and workstations, networks have been developed over which one personal computer or workstation can make use of data and programs on another "remote" device, in general by causing the data and programs to be "downloaded," that is, transferred to it for processing. In addition, a personal computer or workstation can, typically over a communications medium such as the public telephony system, engage in a communications session with another remote device in which it effectively operates as a terminal on the remote device, enabling the remote device to process programs using data input that it provides.

Communications driver subsystem for enabling a digital computer system to establish a communications session with a remote device over a selected one of a plurality of diverse communication media


Improved fatigue strength properties are achieved in an induction hardened microalloy steel useful for demanding service environments. The microalloy steel has low carbon and sulfur contents, comprising in % by weight, 0.15% to 0.45% C, 0.50% to 1.60% Mn, up to 0.20% V, 0.0001% to 0.01% S, balance Fe. The material is fabricated to a selected configuration, such as an engine crankshaft, for example. Selected surfaces of the fabricated article are hardened by induction heating. The article can be used directly after induction hardening or it may be tempered at low to moderate temperatures of from about 100.degree. C. (200.degree. F.) to 290.degree. C. (550.degree. F.) to achieve a desired surface hardness and compressive residual stress level. The controlled alloy chemistry and low tempering temperature provide a substantial increase in bending fatigue strength over conventional higher carbon grade steels.

The present invention relates generally to microalloy steels and, more particularly, to microalloy steels that can be forged and subsequently surface hardened by induction heating. Microalloy forging steels have been finding increasing usage in many applications, but perhaps the fastest growing domestic microalloy application is that of gasoline and diesel engine crankshafts. Most new crankshaft applications specify microalloy steel, and many current applications are being converted from cast iron or forged and heat treated plain carbon or alloy steels to as-forged microalloy steels. The engines range from small automotive to large diesel engines. Induction hardening is applied mainly in the larger diesel engine size ranges to enhance fatigue strength of the bearing and crankpin fillets. It has been previously shown that a microalloy steel could uniformly attain the necessary core properties for large diesel engine crankshafts in the as-forged condition. However, until recently, the induction hardening characteristics of the as-forged microalloy crankshaft and resultant fatigue life had not been fully studied.
Induction hardening is a selective hardening process that has been traditionally applied to plain carbon and alloy steel components to increase the local hardness in highly stressed regions of the part. During induction hardening, the surface region of the part adjacent to the induction coil is rapidly heated to within the austenite regime, held at temperature for a brief period of time, and then rapidly quenched. The goal is to fully austenitize the heated region to a specified depth, and then form a martensitic structure in the heated region during the quench. The part is then tempered to the desired case hardness. The final strength/hardness of this induction hardened region has been the primary design criteria used to predict or establish the life of the part. Typically, the fatigue strength is considered to be approximately 1/2 that of the tensile strength of the hardened region. Whereas this general rule gives a good approximation of the performance characteristics of the part, optimizing the fatigue strength of an induction hardened component requires an understanding of how a number of metallurgical factors influence fatigue. In addition to the strength of the hardened region, the cleanliness of the steel and the resultant residual stress state in the highly stressed region will affect fatigue performance. Additionally, an understanding of how the induction hardening process affects the microalloy precipitate distribution in the base material is of importance.
With the progression towards cleaner steels in recent years, the effect of material cleanliness on bending fatigue is tending to play a smaller overall role with respect to fatigue properties. Whereas the oxide level has been dramatically decreased, the use of some level of sulfur to aid in machinability is still widely accepted in the art for many applications. Crankshafts in particular are subjected to a variety of forging and subsequent machining operations. Therefore, the use of sulfur is critical to allow the productive drilling of various holes required in a finished crankshaft. The presence of sulfides in steels has been known to play an insignificant role in regard to fatigue due to the lack of significant stress field around this type of inclusion. Heretofore, it has been shown that sulfides can actually improve fatigue resistance when they act to displace or coat more harmful oxide-type inclusions. However, in very clean steels, sulfides have been reported to initiate fatigue, and decreasing sulfur level has been shown to improve the endurance limit in both carburized and through-hardened steels. It is, therefore, of benefit to characterize the role of sulfur in the ultra clean air melt steels to find the proper balance between machinability and fatigue strength in critical applications.
Induction hardening to increase the hardness in fatigue critical regions of components also influences the resultant residual stress state. The expansion that accompanies the austenite to martensite transformation in the induction heated surface region normally results in a highly compressive residual stress at the hardened surface. This compressive stress, in combination with the increased hardness level, further enhances the fatigue strength of the component. Since a tensile stress is required to initiate a fatigue crack, the applied stress must overcome both the residual compressive stress present at the surface and the inherent strength of the steel to initiate a crack. One prior art investigator, Koster, "Surface Integrity of Machined Materials", Technical Report AFML-TR-60 (1974), working with SAE 4340 steels hardened to 50 HRC over a wide range of surface residual stress states, reported a near linear relationship between residual stress level and bending fatigue strength. It is also reported in the prior art that relaxation of harmful tensile residual stress by annealing will improve the fatigue strength for the finished part.

Induction hardened microalloy steel having enhanced fatigue strength properties


Administration of sPLA2 inhibitors has been found to decrease cholesterol levels, atherosclerotic plaque formation and aortic aneurysm in mice, and to decrease cholesterol and triglyceride levels in humans. Interestingly, administration of sPLA2 inhibitors was found to decrease cholesterol levels even when the inhibitors were administered only once per day. Therefore, provided herein are methods of treating dyslipidemia, CVD, and conditions associated with CVD such as atherosclerosis and metabolic syndrome, by administering one or more sPLA2 inhibitors. Significantly, administration of sPLA2 inhibitors and various compounds used in the treatment of CVD, such as for example statins, resulted in greater decreases in LDL and LDL particle levels in a synergistic manner. In addition, administration of sPLA2 inhibitors and statins resulted in a synergistic decrease in plaque content. Therefore, also provided herein are compositions comprising one or more sPLA2 inhibitors and one or more compounds used in the treatment of CVD, such as for example statins, and methods of using these compositions to treat dyslipidemia, CVD, and conditions associated with CVD such as atherosclerosis and metabolic syndrome.

In 2004, it was estimated that over 75 million Americans had one or more forms of cardiovascular disease (CVD). Coronary heart disease (CHD) and coronary artery disease (CAD) are the most common types of CVD. CHD and CAD occur when coronary arteries that supply blood to the heart become hardened and narrowed due to atherosclerosis. A variety of therapeutic options are currently employed in the treatment of CVD and conditions associated with CVD. Many of these therapeutic options function by lowering cholesterol levels, particularly LDL levels. Among the most popular and effective of these therapeutic options are statins, a class of compounds that inhibit cholesterol biosynthesis and prevent the build-up of arterial plaque. Statin administration has been shown to lower LDL and triglyceride levels and to substantially reduce coronary events and death from CVD. However, statin therapy alone is insufficient to completely treat CVD. Therefore, there is a need in the art for more effective methods of treating CVD and conditions associated with CVD.

Treatment of cardiovascular disease and dyslipidemia using secretory phospholipase A


The size of each of the plurality of characters or graphics is modified while the size of each of the plurality of virtual areas included in the display area is maintained, so that the visual recognizability (ease of reading, or ease of recognition through reading) of characters or graphics is improved without changing the layout thereof. A character/graphic display apparatus of the present invention includes a display device including a display area for displaying a plurality of characters or graphics; and a control section for controlling the display device. The display area includes a plurality of virtual areas. The control section modifies the size of each of the plurality of characters or graphics while maintaining the size of each virtual area included in the display area; and controls the display device to display each of the plurality of characters or graphics having the modified size in the respective virtual area.

Recently, there have been more and more opportunities for reading characters displayed by a display device included in a mobile information device. A mobile information device includes modification means for modifying character sizes, inter-character spaces, and the like. The user operates the modification means to modify, for example, the character size or the inter-character space provided by the display device to a desired character size or a desired inter-character space.
FIG. 18 shows a display screen which displays characters.
A display screen 18A shows an example in which the characters are displayed densely. It is difficult to read the characters displayed densely.
A display screen 18B shows an example in which the characters are displayed less densely. The user of a mobile information device reads the characters displayed by a display device included therein. The user operates the mobile information device so as to enlarge the inter-character space on the display screen 18A for the purpose of easily reading the characters.
There are two methods (1) and (2) usable by the user to enlarge the inter-character space for easily reading the characters. With method (1), the character size is enlarged and the inter-character space is enlarged. With method (2), the character size is not changed and the inter-character space is enlarged.
FIG. 19 shows an example of a display area which displays characters, the space between which is enlarged by method (1). A display area 19A is a display area before the inter-character space is enlarged. A display area 19B is a display area after the inter-character space is enlarged. It is assumed herein that in each of the hatched zones in the display areas, a character having the same size as that of the corresponding hatched zone is displayed.
FIG. 20 shows an example of a display area which displays characters, the space between which is enlarged by method (2). A display area 20A is a display area before the inter-character space in a length direction is enlarged. A display area 20B is a display area after the inter-character space in the length direction is enlarged. It is assumed herein that in each of the hatched zones in the display areas, a character having the same size as that of the corresponding hatched zone is displayed.
FIG. 21 shows an example of a display area which displays characters, the space between which is enlarged by method (2). A display area 21A is a display area before the inter-character space in the width direction is enlarged. A display area 21B is a display area after the inter-character space in a width direction is enlarged. It is assumed herein that in each of the hatched zones in the display areas, a character having the same size as that of the corresponding hatched zone is displayed.
FIG. 22 shows an example of a display area which displays characters, the space between which is enlarged by method (2). A display area 22A is a display area before the inter-character space in the width direction and the length direction is enlarged. A display area 22B is a display area after the inter-character space in the width direction and the length direction is enlarged. It is assumed herein that in each of the hatched zones in the display areas, a character having the same size as that of the corresponding hatched zone is displayed.
Japanese Laid-Open Publication No. 2002-171457 discloses a method for prohibiting the characters from being displayed and a method for displaying the characters in an enlarged state, both when the characters displayed by the display device are difficult to read as a result of being reduced (see Patent Document 1).
Japanese Laid-Open Publication No. 2001-265480 discloses a method for modifying the character size in compliance with the size of the display area (see Patent Document 2).
Japanese Laid-Open Publication No. 4-177295 discloses a method for first enlarging a plurality of characters and then reducing the inter-character space (see Patent Document 3).
Japanese Laid-Open Publication No. 5-257450 discloses a method for modifying the enlargement ratio of a character and a virtual area (see Patent Document 4).
Patent Document 1: Japanese Laid-Open Publication No. 2002-171457
Patent Document 2: Japanese Laid-Open Publication No. 2001-265480
Patent Document 3: Japanese Laid-Open Publication No. 4-177295
Patent Document 4: Japanese Laid-Open Publication No. 5-257450

Character/graphic display apparatus, character/graphic display method, program, and recording medium


The disclosed embodiments relate to approaches for diagnosing and resolving wireless network connectivity issues on an electronic device. The system includes a tool for automatically diagnosing and resolving wireless network connectivity issues on the electronic device. The tool may monitor and manage the wireless network connection on the electronic device. If a lack of wireless network connectivity is detected on the electronic device, the tool may run a series of test cases associated with wireless network connectivity issues on the electronic device. The tool may then notify the user of the results of the test cases, provide recommendations associated with the results to the user, and/or log data associated with the test cases.

Recent improvements in computing power and wireless networking technology have significantly increased the capabilities of electronic devices. For example, laptop computers, tablet computers, portable media players, smartphones, and/or other modern electronic devices are often equipped with WiFi capabilities that allow the electronic devices to stream audio and/or video, share desktops and/or user interfaces (UIs), and/or transfer files wirelessly among one another.
Electronic devices may sometimes experience wireless network connectivity issues. These issues may be caused and/or influenced by a variety of factors at different layers of the network stack and/or locations within the wireless environment, making straightforward diagnosis and/or resolution of these issues difficult. Consequently, mechanisms for diagnosing and resolving wireless connectivity issues would be advantageous.

Automatically diagnosing and resolving wireless network connectivity issues in electronic devices


A method and system are provided for restricting the use of a vehicle such as an automobile to a person or persons whose fingerprints match biometric data stored within a memory in the vehicle's control system. A user's digitized fingerprints are stored in a non-volatile permanent ROM in the BIOS of a microcontroller on in a ROM accessed by a microprocessor. The microprocessor's primary task is that of executing instructions related to the operation of the vehicle, such as regulating the fuel flow rate, and performing other such tasks. Before the microprocessor can execute its instructions related to its primary task it, must complete and exit a conditional loop of instructions that relate to validating a user's "real-input" biometric data. Real scanned fingerprints must be compared with fingerprint(s) stored in ROM. If the result of the compare is a true, i.e. is a match, then the conditional loop is satisfied and the microprocessor can execute its instructions relating to operating the vehicle.

The use of security systems is generally well known. There use is becoming even greater with increased availability of digital electronic components at a relatively low cost. Such systems are known for securing buildings, banks, automobiles, computers and many other devices. For example, U.S. Pat. No. 4,951,249 discloses a computer security system which protects computer software from unauthorized access by requiring the user to supply a name and a password during the operating system loading procedure ("boot-up") of a personal computer (PC). This is accomplished by the insertion of a special card into an input/output expansion slot of the PC. During the loading of the operating system of the PC, the basic input/output system (BIOS) scans memory addresses of the card for an identification code, consisting of a 55AA hex code. When this hex code is located, the BIOS instructions are vectored to the address where the target hex code resides and instructions at the following address are executed as part of the initialization routines of the system boot-up procedure.
This PC security system, utilizing a password board, is typical of many systems that are currently available. Password boards require a user's name and a password associated with that user's name. Only once a password board detects a valid user's name and password does it allow the PC to complete the boot-up routine. Though password boards may be useful in some instances, they are inadequate in many respects.
For example, an unauthorized skilled user with a correct password in hand, can gain entry to such a processor based system. Yet another undesirable feature of the foregoing system is that passwords on occasion are forgotten; and furthermore, and more importantly, passwords have been known to be decrypted.
As of late one of the most ubiquitous electronic components is the digital processor. Multi-purpose and dedicated processors of various types control devices ranging from bank machines, to cash registers and automobiles. With ever increasing use of these processor based devices, there is greater concern that unauthorized use will become more prevalent. Thus, the verification and/or authentication of authorized users of processor based systems is a burgeoning industry.
Alarms and security systems to warn of unauthorized use of automobiles and other processor controlled systems are available, however, these security systems have been known to be circumvented. Furthermore, automobile alarms that sound, are often ignored by passers-by. Unfortunately, many commercially available solutions aimed at preventing theft or unauthorized use of automobiles have also been circumvented.
Thus, it is an object of this invention to provide a method and relatively inexpensive system for preventing unauthorized use of a vehicle controlled by a processor based control system.

Biometrically secured control system for preventing the unauthorized use of a vehicle


A sidewall shape correction function is determined in advance which represents the relationship of the difference between contour positions of two or more items of pattern contour position data of different thresholds obtained from an SEM image and optical pattern contour positions determined through an optical method. Two or more items of pattern contour position data of different thresholds are obtained from SEM image data on which a lithographic simulation is to be conducted. Pseudo-optical pattern contour position data are determined from the contour position difference and the sidewall shape correction function. A lithographic simulation is conducted using the pseudo-optical pattern contour position data.

1. Field of the Invention
The present invention relates to a method of inspecting the dimensions of a mask pattern of a photomask and a mask pattern dimensional inspection apparatus using this method.
2. Description of the Related Art
In recent years, various problems are becoming apparent in the photolithographic process used in the manufacture of semiconductor devices. As the dimensions of semiconductor devices have been scaled down, the demand has increased for fine patterning in the photolithographic process. The device design rules have already been scaled down to 45 nm. It is severely required that the accuracy of pattern dimensions be controlled below 5 nm. Furthermore, the mask pattern is formed into a very complex shape because of proximity-effect correction. For this reason, conventional one-dimensional dimensional uniformity inspection, such as mere measurements of the width of pattern lines and the diameter of holes, is insufficient and two-dimensional dimensional control is required. To meet the requirement, a method has been adopted which inspects whether or not a mask pattern has been finished to desired dimensions by converting the mask pattern into image data through SEM, extracting the pattern contour from the image data and conducting a lithographic simulation to determine whether a desired lithographic margin is obtained or not (see "Mask pattern quality assurance based on lithographic simulation with fine pixel SEM image" by M. Kariya et al, Proceedings of SPIE Vol. 5992).
The greatest merit of this method is that the finish of a mask pattern can be evaluated in a state very close to conditions in which the mask pattern is actually used to expose a wafer in a semiconductor manufacturing process. That is, the method can provide necessary and sufficient dimensional control and neither unnecessarily stringent dimensional control nor soft dimensional control.
However, in more stringent mask dimensional control nowadays, an insufficient point in terms of accuracy has emerged in the method as well. This is that the numerical aperture of wafer exposure apparatus has become large and the influence of sidewall shapes of mask pattern has become unnegligible. Specifically, the sidewall shapes of mask pattern vary according to the coverage of the mask pattern and positions in the mask plane. For this reason, trying to extract pattern contour data from SEM image data while neglecting sidewall shapes as in the conventional method has resulted in a case where the result of lithographic simulation using the contour data and the result of the actual exposure of wafer do not match.
It is generally known that the optical approach to obtain mask pattern contour data can provide accurate contour positions that better match the result of actual exposure of wafer than with the approach to obtain contour data from SEM image data. However, the optical approach is very laborious and hence the incorporation of it into the semiconductor device manufacturing process is not practical. In contrast, the approach to obtain pattern contour data from SEM image data can be easily implemented incorporated into the manufacturing process. However, when lithographic simulation is conducted using pattern contour data obtained by the conventional method, the result does not match the result of actual exposure of wafer. It is therefore difficult to accurately inspect the finish of a mask pattern.
The mask pattern dimensional inspection method of the invention involves previously determining a sidewall shape correction function representing the relationship of the difference between contour positions of two or more items of pattern contour position data of different thresholds obtained from an SEM image and optical pattern contour positions determined through an optical method, obtaining two or more items of pattern contour position data of different thresholds from SEM image data on which a lithographic simulation is to be conducted, determining pseudo-optical contour position data from the contour position difference and the sidewall shape correction function, conducting a lithographic simulation using the pseudo-optical contour position data, and evaluating whether or not a desired exposure margin is obtained on the basis of the result of the lithographic simulation.

Mask pattern dimensional inspection apparatus and method


A reactor includes a plurality of windings, a coupling core, and an inductor core. A coupling core configured to form a coupling closed magnetic circuit that magnetically couples the plurality of windings, the plurality of windings being wound around the coupling core; and. An inductor core, which includes a main part, a first projection part projecting from one end of the main part, and a second projection part projecting from another end of the main part, and each of the first projection part and the second projection part is magnetically connected to the coupling core. The inductor core forms an inductor closed magnetic circuit together with a part of the coupling core around which one winding of the plurality of windings is wound.

In the related art, there is disclosed a composite transformer (reactor) including a single transformer and a plurality of inductors (see Patent Literature 1, for example).
The composite transformer according to Patent Literature 1 includes a plurality of windings, a transformer core, and a plurality of inductor cores. The transformer core includes a plurality of transformer-core legs, which extend in a direction of axes of the windings, and around which the windings are wound. The plurality of inductor cores include inductor-core legs, which extend in a direction of axes of the windings, and around which the windings are wound. Further, the plurality of inductor cores are arranged so that each of the inductor-core legs is adjacent to one of the transformer-core legs in a direction perpendicular to the direction of the axes of the windings. The plurality of windings are wound around core legs formed with the transformer-core legs and the inductor-core legs in such a manner that magnetic fluxes are produced in the transformer-core legs and the inductor-core legs when currents flow through the windings.
In order to prevent influence of a magnetic field produced in each of the transformer core and the inductor cores, the composite transformer according to Patent Literature 1 further includes a magnetic insulation sheet inserted between the transformer core and the inductor cores.
In the field of the reactor, further downsizing of the reactor is desired.

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.


The compressed air vibrator has a housing (1) with an inlet opening (8) for admitting compressed air to a chamber (14) and an outlet opening (9) for the exit of air from the chamber (14). Ball bearing assemblies (11, 15) are disposed with slight play on the shafts (2a, 2b) of the rotor (2). These ball bearings are fitted, also with slight play, in bores (12a, 13a) of oppositely located covers (12, 13) that close about the rotor (2) and close the open ends of chamber (14). The play is adjusted in such a way that the outer races (11a, 15a) of the ball bearings turn in the bores (12a, 13a) of the covers during the rotational movement of the rotor (2). The vibrator also can include a counter-flow air brake to slow rotor rotation.

A compressed air vibrator of this species is known from U.S. Pat. Nos. 3,932,057 and 3,870,282. The compressed air vibrators of these references use ball bearings that are disposed in the interior of the rotor. Therefore, the bearings are limited as to their size, which, at high frequencies and with strong resonant oscillations, has a disadvantageous effect on the service life of the vibrator and, in particular, on the bearings themselves. In connection with the mentioned vibrators it is also considered to be disadvantageous that the bearings are too weak with respect to their loads. Replacement of the bearings can only be performed by specialists and is a comparatively expensive procedure.

Compressed air vibrator with turbine drive


A gray scale bistable electro-optic display is driven by storing a look-up table containing data representing the impulses necessary for transitions, storing data representing at least an initial state of each pixel of the display, storing data representing temporal and gray level prior states of each pixel, receiving an input signal representing a desired final state of at least one pixel of the display; and generating an output signal representing the impulse necessary for a transition, as determined from the look-up table, dependent upon the temporal and gray level prior states. Other similar methods for driving such displays are also disclosed.

This invention relates to methods for driving electro-optic displays, especially bistable electro-optic displays, and to apparatus for use in such methods. More specifically, this invention relates to driving methods and apparatus (controllers) which are intended to enable more accurate control of gray states of the pixels of an electro-optic display. This invention also relates to a method which enables long-term direct current (DC) balancing of the driving impulses applied to an electrophoretic display. This invention is especially, but not exclusively, intended for use with particle-based electrophoretic displays in which one or more types of electrically charged particles are suspended in a liquid and are moved through the liquid under the influence of an electric field to change the appearance of the display.
In one aspect, this invention relates to apparatus which enables electro-optic media which are sensitive to the polarity of the applied field to be driven using circuitry intended for driving liquid crystal displays, in which the liquid crystal material is not sensitive to polarity.
The term "electro-optic" as applied to a material or a display, is used herein in its conventional meaning in the imaging art to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material. Although the optical property is typically color perceptible to the human eye, it may be another optical property, such as optical transmission, reflectance, luminescence or, in the case of displays intended for machine reading, pseudo-color in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.
The term "gray state" is used herein in its conventional meaning in the imaging art to refer to a state intermediate two extreme optical states of a pixel, and does not necessarily imply a black-white transition between these two extreme states. For example, several of the patents and published applications referred to below describe electrophoretic displays in which the extreme states are white and deep blue, so that an intermediate "gray state" would actually be pale blue. Indeed, as already mentioned the transition between the two extreme states may not be a color change at all.
The terms "bistable" and "bistability" are used herein in their conventional meaning in the art to refer to displays comprising display elements having first and second display states differing in at least one optical property, and such that after any given element has been driven, by means of an addressing pulse of finite duration, to assume either its first or second display state, after the addressing pulse has terminated, that state will persist for at least several times, for example at least four times, the minimum duration of the addressing pulse required to change the state of the display element. It is shown in published U.S. patent application No. 2002/0180687 that some particle-based electrophoretic displays capable of gray scale are stable not only in their extreme black and white states but also in their intermediate gray states, and the same is true of some other types of electro-optic displays. This type of display is properly called "multi-stable" rather than bistable, although for convenience the term "bistable" may be used herein to cover both bistable and multi-stable displays.
The term "gamma voltage" is used herein to refer to external voltage references used by drivers to determine voltages to be applied to pixels of a display. It will be appreciated that a bistable electro-optic medium does not display the type of one-to-one correlation between applied voltage and optical state characteristic of liquid crystals, the use of the term "gamma voltage" herein is not precisely the same as with conventional liquid crystal displays, in which gamma voltages determine inflection points in the voltage level/output voltage curve.
The term "impulse" is used herein in its conventional meaning of the integral of voltage with respect to time. However, some bistable electro-optic media act as charge transducers, and with such media an alternative definition of impulse, namely the integral of current over time (which is equal to the total charge applied) may be used. The appropriate definition of impulse should be used, depending on whether the medium acts as a voltage-time impulse transducer or a charge impulse transducer.
Several types of electro-optic displays are known. One type of electro-optic display is a rotating bichromal member type as described, for example, in U.S. Pat. Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791 (although this type of display is often referred to as a "rotating bichromal ball" display, the term "rotating bichromal member" is preferred as more accurate since in some of the patents mentioned above the rotating members are not spherical). Such a display uses a large number of small bodies (typically spherical or cylindrical) which have two or more sections with differing optical characteristics, and an internal dipole. These bodies are suspended within liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate. The appearance of the display is changed to applying an electric field thereto, thus rotating the bodies to various positions and varying which of the sections of the bodies is seen through a viewing surface. This type of electro-optic medium is typically bistable.
Another type of electro-optic display uses an electrochromic medium, for example an electrochromic medium in the form of a nanochromic film comprising an electrode formed at least in part from a semi-conducting metal oxide and a plurality of dye molecules capable of reversible color change attached to the electrode; see, for example O'Regan, B., et al., Nature 1991, 353, 737; and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. Nanochromic films of this type are also described, for example, in U.S. Pat. No. 6,301,038, International Application Publication No. WO 01/27690, and in U.S. patent application 2003/0214695. This type of medium is also typically bistable.
Another type of electro-optic display, which has been the subject of intense research and development for a number of years, is the particle-based electrophoretic display, in which a plurality of charged particles move through a suspending fluid under the influence of an electric field. Electrophoretic displays can have attributes of good brightness and contrast, wide viewing angles, state bistability, and low power consumption when compared with liquid crystal displays. Nevertheless, problems with the long-term image quality of these displays have prevented their widespread usage. For example, particles that make up electrophoretic displays tend to settle, resulting in inadequate service-life for these displays.
Numerous patents and applications assigned to or in the names of the Massachusetts Institute of Technology (MIT) and E Ink Corporation have recently been published describing encapsulated electrophoretic media. Such encapsulated media comprise numerous small capsules, each of which itself comprises an internal phase containing electrophoretically-mobile particles suspended in a liquid suspending medium, and a capsule wall surrounding the internal phase. Typically, the capsules are themselves held within a polymeric binder to form a coherent layer positioned between two electrodes. Encapsulated media of this type are described, for example, in U.S. Pat. Nos. 5,930,026; 5,961,804; 6,017,584; 6,067,185; 6,118,426; 6,120,588; 6,120,839; 6,124,851; 6,130,773; 6,130,774; 6,172,798; 6,177,921; 6,232,950; 6,249,271; 6,252,564; 6,262,706; 6,262,833; 6,300,932; 6,312,304; 6,312,971; 6,323,989; 6,327,072; 6,376,828; 6,377,387; 6,392,785; 6,392,786; 6,413,790; 6,422,687; 6,445,374; 6,445,489; 6,459,418; 6,473,072; 6,480,182; 6,498,114; 6,504,524; 6,506,438; 6,512,354; 6,515,649; 6,518,949; 6,521,489; 6,531,997; 6,535,197; 6,538,801; 6,545,291; 6,580,545; 6,639,578; 6,652,075; 6,657,772; 6,664,944; 6,680,725; 6,683,333; and 6,704,133; and U.S. Patent Applications Publication Nos. 2002/0019081; 2002/0021270; 2002/0053900; 2002/0060321; 2002/0063661; 2002/0063677; 2002/0090980; 2002/0106847; 2002/0113770; 2002/0130832; 2002/0131147; 2002/0145792; 2002/0171910; 2002/0180687; 2002/0180688; 2002/0185378; 2003/0011560; 2003/0011868; 2003/0020844; 2003/0025855; 2003/0034949; 2003/0038755; 2003/0053189; 2003/0096113; 2003/0102858; 2003/0132908; 2003/0137521; 2003/0137717; 2003/0151702; 2003/0189749; 2003/0214695; 2003/0214697; 2003/0222315; 2004/0008398; 2004/0012839; 2004/0014265; and 2004/0027327; and International Applications Publication Nos. WO 99/67678; WO 00/05704; WO 00/38000; WO 00/38001; WO00/36560; WO 00/67110; WO 00/67327; WO 01/07961; WO 01/08241; WO 03/092077; and WO 03/107,315.
Many of the aforementioned patents and applications recognize that the walls surrounding the discrete microcapsules in an encapsulated electrophoretic medium could be replaced by a continuous phase, thus producing a so-called "polymer-dispersed electrophoretic display" in which the electrophoretic medium comprises a plurality of discrete droplets of an electrophoretic fluid and a continuous phase of a polymeric material, and that the discrete droplets of electrophoretic fluid within such a polymer-dispersed electrophoretic display may be regarded as capsules or microcapsules even though no discrete capsule membrane is associated with each individual droplet; see for example, the aforementioned 2002/0131147. Accordingly, for purposes of the present application, such polymer-dispersed electrophoretic media are regarded as sub-species of encapsulated electrophoretic media.
An encapsulated electrophoretic display typically does not suffer from the clustering and settling failure mode of traditional electrophoretic devices and provides further advantages, such as the ability to print or coat the display on a wide variety of flexible and rigid substrates. (Use of the word "printing" is intended to include all forms of printing and coating, including, but without limitation: pre-metered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating; roll coating such as knife over roll coating, forward and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silk screen printing processes; electrostatic printing processes; thermal printing processes; ink jet printing processes; and other similar techniques.) Thus, the resulting display can be flexible. Further, because the display medium can be printed (using a variety of methods), the display itself can be made inexpensively.
A related type of electrophoretic display is a so-called "microcell electrophoretic display". In a microcell electrophoretic display, the charged particles and the suspending fluid are not encapsulated within capsules but instead are retained within a plurality of cavities formed within a carrier medium, typically a polymeric film. See, for example, International Application Publication No. WO 02/01281, and U.S. Patent Application Publication No. 2002/0075556, both assigned to Sipix Imaging, Inc.
Although electrophoretic media are often opaque (since, for example, in many electrophoretic media, the particles substantially block transmission of visible light through the display) and operate in a reflective mode, many electrophoretic displays can be made to operate in a so-called "shutter mode" in which one display state is substantially opaque and one is light-transmissive. See, for example, the aforementioned U.S. Pat. Nos. 6,130,774 and 6,172,798, and U.S. Pat. Nos. 5,872,552; 6,144,361; 6,271,823; 6,225,971; and 6,184,856. Dielectrophoretic displays, which are similar to electrophoretic displays but rely upon variations in electric field strength, can operate in a similar mode; see U.S. Pat. No. 4,418,346.
The bistable or multi-stable behavior of particle-based electrophoretic displays, and other electro-optic displays displaying similar behavior, is in marked contrast to that of conventional liquid crystal ("LC") displays. Twisted nematic liquid crystals act are not bi- or multi-stable but act as voltage transducers, so that applying a given electric field to a pixel of such a display produces a specific gray level at the pixel, regardless of the gray level previously present at the pixel. Furthermore, LC displays are only driven in one direction (from non-transmissive or "dark" to transmissive or "light"), the reverse transition from a lighter state to a darker one being effected by reducing or eliminating the electric field. Finally, the gray level of a pixel of an LC display is not sensitive to the polarity of the electric field, only to its magnitude, and indeed for technical reasons commercial LC displays usually reverse the polarity of the driving field at frequent intervals.
In contrast, bistable electro-optic displays act, to a first approximation, as impulse transducers, so that the final state of a pixel depends not only upon the electric field applied and the time for which this field is applied, but also upon the state of the pixel prior to the application of the electric field. Furthermore, it has now been found, at least in the case of many particle-based electro-optic displays, that the impulses necessary to change a given pixel through equal changes in gray level (as judged by eye or by standard optical instruments) are not necessarily constant, nor are they necessarily commutative. For example, consider a display in which each pixel can display gray levels of 0 (white), 1, 2 or 3 (black), beneficially spaced apart. (The spacing between the levels may be linear in percentage reflectance, as measured by eye or by instruments but other spacings may also be used. For example, the spacings may be linear in L* (where L* has the usual CIE definition:L*=116(R/R0)1/3−16,
where R is the reflectance and R0 is a standard reflectance value), or may be selected to provide a specific gamma; a gamma of 2.2 is often adopted for monitors, and where the present displays are be used as a replacement for a monitor, use of a similar gamma may be desirable.) It has been found that the impulse necessary to change the pixel from level 0 to level 1 (hereinafter for convenience referred to as a "0-1 transition") is often not the same as that required for a 1-2 or 2-3 transition. Furthermore, the impulse needed for a 1-0 transition is not necessarily the same as the reverse of a 0-1 transition. In addition, some systems appear to display a "memory" effect, such that the impulse needed for (say) a 0-1 transition varies somewhat depending upon whether a particular pixel undergoes 0-0-1, 1-0-1 or 3-0-1 transitions. (Where, the notation "x-y-z", where x, y, and z are all optical states 0, 1, 2, or 3 denotes a sequence of optical states visited sequentially in time, list from earlier to later.) Although these problems can be reduced or overcome by driving all pixels of the display to one of the extreme states for a substantial period before driving the required pixels to other states, the resultant "flash" of solid color is often unacceptable; for example, a reader of an electronic book may desire the text of the book to scroll down the screen, and may be distracted, or lose his place, if the display is required to flash solid black or white at frequent intervals. Furthermore, such flashing of the display increases its energy consumption and may reduce the working lifetime of the display. Finally, it has been found that, at least in some cases, the impulse required for a particular transition is affected by the temperature and the total operating time of the display, and by the time that a specific pixel has remained in a particular optical state prior to a given transition, and that compensating for these factors is desirable to secure accurate gray scale rendition.
In one aspect, this invention seeks to provide a method and a controller that can provide accurate gray levels in an electro-optic display without the need to flash solid color on the display at frequent intervals.
Furthermore, as will readily be apparent from the foregoing discussion, the drive requirements of bistable electro-optic media render unmodified drivers designed for driving active matrix liquid crystal displays (AMLCD's) unsuitable for use in bistable electro-optic media-based displays. However, such AMLCD drivers are readily available commercially, with large permissible voltage ranges and high pin-count packages, on an off-the-shelf basis, and are inexpensive, so that such AMLCD drives are attractive for drive bistable electro-optic displays, whereas similar drivers custom designed for bistable electro-optic media-based displays would be substantially more expensive, and would involve substantial design and production time. Accordingly, there are cost and development time advantages in modifying AMLCD drivers for use with bistable electro-optic displays, and this invention seeks to provide a method and modified driver which enables this to be done.
Also, as already noted, this invention relates to methods for driving electrophoretic displays which enable long-term DC-balancing of the driving impulses applied to the display. It has been found that encapsulated and other electrophoretic displays need to be driven with accurately DC-balanced waveforms (i.e., the integral of current against time for any particular pixel of the display should be held to zero over an extended period of operation of the display) to preserve image stability, maintain symmetrical switching characteristics, and provide the maximum useful working lifetime of the display. Conventional methods for maintaining precise DC-balance require precision-regulated power supplies, precision voltage-modulated drivers for gray scale, and crystal oscillators for timing, and the provision of these and similar components adds greatly to the cost of the display.
(Strictly speaking, DC balance should be measured "internally" having regard to the voltages experienced by the electro-optic medium itself. However, in practice it is impracticable to effect such internal measurements in an operating display which may contain hundreds of thousands of pixels, and in practice DC balance is measured using an "external" measurement, namely the voltages applied to the electrodes disposed on opposed sides of the electro-optic medium. Furthermore, there are two assumptions normally made when discussing DC balance. Firstly, it is assumed, normally with good reason, that the conductivity of the electro-optic medium is not a function of polarity, so that pulse length is an appropriate way to track DC balance, when a constant voltage is applied. Secondly, it is assumed that the conductivity of the electro-optic medium is proportional to the applied voltage, so that one can use impulse to track DC balance.)
Furthermore, even with the addition of such expensive components, true DC balance is still not obtained. Empirically it has been found that many electrophoretic media have asymmetric current/voltage (I/V curves); it is believed, although the invention is in no way limited by this belief, that these asymmetric curves are due to electrochemical voltage sources within the media. These asymmetric curves mean that the current when the medium is addressed to one extreme optical state (say black) is not the same as when the medium is addressed to the opposed extreme optical state (say white), even when the voltage is carefully controlled to be precisely the same in the two cases.
It has now been found that the extent of DC imbalance in an electrophoretic medium used in a display can be ascertained by measuring the open-circuit electrochemical potential (hereinafter for convenience called the "remnant voltage" of the medium. When the remnant voltage of a pixel is zero, it has been perfectly DC balanced. If its remnant voltage is positive, it has been DC unbalanced in the positive direction. If its remnant voltage is negative, it has been DC unbalanced in the negative direction. This invention uses remnant voltage data to maintain long-term DC-balancing of the display.
As described in more detail below, one aspect of the present invention relates to use of a so-called "look-up table" method for driving a bistable electro-optic display having a plurality of pixels, this method taking account of the initial and desired final state of each pixel, and to a device controller for use in this method. In preferred forms of this look-up table method, there are stored not only the initial gray level of each pixel but also one or more prior states of each pixel prior to the initial state thereof, and the output signal is generated dependent upon the one or more prior states and the initial gray level.
The output signal generated in such a look-up table method commonly defines a plurality of separate impulses. For example, FIGS. 11A and 11B below illustrate a so-called "sawtooth" driving scheme which is arranged so that once a given pixel has been driven from one extreme optical state (i.e., white or black) towards the opposed extreme optical state by a pulse of one polarity, the pixel may not receive a pulse of the opposed polarity until it has reached the aforesaid opposed extreme optical state. Depending upon the initial and final states for a given transition, this sawtooth driving scheme may require from one to three pulses alternating in polarity.
Furthermore, the individual pulses within these sequences may themselves be composites of sub-pulses, and some of these sub-pulses may apply zero voltage to a pixel. For example, Table 2 below illustrates a drive scheme in which white-going pulses are applied in odd-numbered frames and black-going pulses are applied in even-numbered frames. In this drive scheme, white-going transitions are driven only on the odd frames, black-going transitions are driven only on the even frames, and in any frame in which the pixel is not being driven, zero voltage is applied; the total impulse applied to any given pixel is controlled by pulse-width modulation, i.e., by the number of odd or even frames in a sequence for which a non-zero voltage is applied to the pixel. This drive scheme may be combined with that shown in FIGS. 11A and 11B to yield a drive scheme in which a given transition may require a large number of sub-pulses. In view of these complications, hereinafter the term "superframe" will be used to denote a sequence of successive display scan frames needed to effect all necessary gray level changes from an initial image to a final image. Typically, a display update is initiated only at the beginning of a superframe.
Finally, it should be noted that, in a look-up table method which stores at least one prior state of each pixel in addition to the initial state, the prior state(s) stored are not necessarily spaced one superframe apart in time, and the first prior state is not necessarily one superframe before the initial state, since in at least some electro-optic displays it has been found that it is the sequence of successive gray levels applied to a given pixel which is most important in determining the impulse needed to effect a given transition rather than the length of time for which the pixel is maintained in these successive gray levels. For example, consider a two-bit (four gray level) display which is updated once per second, i.e., the superframe length is one second, and in which the impulse applied is determined by the initial state, final state and one prior state. If a given pixel is held at gray level 3 for four superframes and then at gray level 1 for five superframes, in calculating the impulse needed to drive that pixel to a final state of gray level 2, it may be desirable to set the single prior state used for the calculation at gray level 3 (i.e., the immediately preceding gray level different from the initial gray level of 1) rather than 1, the actual gray level one superframe prior to the initial level. In other words, in this form of the look-up table method, the list of prior states is changed only when a change in gray level occurs, not at each superframe.
In practice, it has been found that the impulse needed to effect accurate transitions between gray levels in a bistable electro-optic display is affected by both prior gray state levels and gray state levels at specific times prior to the initial state, and in one aspect this invention provides a modified look-up table method and controller which allows adjustment of the impulse of a transition to allow for both types of parameters.
It must also be recognized that, as discussed in more detail below, depending upon the number of prior states stored, the look-up tables used in look-up table methods may become very large. To take an extreme example, consider a look-up table method for a 256 (28) gray level display using an algorithm that takes account of initial, final and two prior states. The necessary four-dimensional look-up table has 232 entries. If each entry requires (say) 64 bits (8 bytes), the total size of the look-up table would be approximately 32 Gbyte. While storing this amount of data poses no problems on a desktop computer, it may present problems in a portable device. In another aspect, this invention provides a method for driving a bistable electro-optic display which achieves results similar to those of the look-up table method but which does not require the storage of very large look-up tables.
A further aspect of the present invention relates to methods and apparatus for driving a bistable electro-optic display in a manner which permits part of the display to operate at a different bit depth (i.e., different number of gray scale levels) from the remainder of the display. From the foregoing description of the sawtooth driving method illustrated in FIGS. 11A and 11B below, it will be apparent to those skilled in the art that transitions between successive images in general image flow of bistable electro-optic displays having numerous gray scale levels can be substantially longer than transitions if the same displays were being driven in monochrome mode. Typically, gray scale transitions may be up to four times as long as the corresponding monochrome transitions. The relatively slow gray scale transitions may not be objectionable when the display is being used to present a series of images, such as a series of photographs or successive pages of an electronic book. However, there are times when it would be useful to achieve rapid updating of a limited area of such a display. For example, consider a situation where a user employs such a display to review of series of photographs stored in a database in order to enter for each photograph key words or other indexing terms intended to facilitate later retrieval of images from the database. In this situation, relatively slow transitions between successive photographs may be tolerable; for example, if the user spends one to two minutes studying each photograph and deciding on the indexing terms, a one to two second transition between successive photographs does not greatly affect the user's productivity. However, as is well known to anyone who has tried to run a word processing program on a computer with inadequate processing power, a one to two second delay in updating a dialog box, in which are displayed the indexing terms being entered by the user, is extremely frustrating and likely to lead to numerous typing errors. Accordingly, in this and similar situations, it would be advantageous to be able to run the dialog box in a monochrome mode to permit swift transitions, while continuing to run the remainder of the display in a gray scale mode to enable the images to be reproduced accurately, and this invention provides a method and apparatus to enable this to be done.
Another aspect of the present invention relates methods to achieve fine control of gray levels of an impulse drive imaging medium without the need for fine voltage control. Although as already indicated, electrophoretic and some other electro-optic displays exhibit bistability, this bistability is not unlimited, and images on the display slowly fade with time, so that if an image is to be maintained for extended periods, the image may have to be refreshed periodically, so as to restore the image to the optical state which it has when first written.
However, such refreshing of the image may give rise to its own problems. As discussed in the aforementioned U.S. Pat. Nos. 6,531,997 and 6,504,524, problems may be encountered, and the working lifetime of a display reduced, if the method used to drive the display does not result in zero, or near zero, net time-averaged applied electric field across the electro-optic medium. A drive method which does result in zero net time-averaged applied electric field across the electro-optic medium is conveniently referred to a "direct current balanced" or "DC balanced". If an image is to be maintained for extended periods by applying refreshing pulses, these pulses need to be of the same polarity as the addressing pulse originally used to drive the relevant pixel of the display to the optical state being maintained, which results in a DC imbalanced drive scheme.
A challenge for achieving accurate gray scale levels in an impulse driven medium is applying the appropriate voltage impulse for achieving the desired gray tone. Satisfactory transitions between optical states can be achieved by fine control of the voltage of all or part of the drive waveform. The need for precision can be understood from the following example. Consider the case where a current image consists of a screen that is half black and half white, and the desired next image is a uniform gray intermediate between black and white. In order to achieve a uniform gray level, the impulses used to go from black to gray and white to gray have to be finely adjusted so that the gray level achieved coming from black matches the gray level coming from white. Fine tuning is further needed if the final gray level achieved is a function of prior gray level history of the display. For example, as already discussed, the optical state achieved when going from black to gray can be a function, not only of the waveform applied, but also of what state was visited before the current black state. It is then desirable to have the display module keep track of some aspects of the display history, such as prior image states, and allow fine tuning of the waveform to compensate for this prior state history (see below for more detailed discussions on this point).
Fine tuning of the impulse can be achieved using only three voltage levels (0, +V, −V), by adjusting the width of the applied pulse with high accuracy. However, this is not desirable for an active matrix display, since the frame rate must be increased in order to achieve high pulse width resolution. A high frame rate increases the power consumption of the display, and puts more strenuous demands on the control and drive electronics. It is therefore not desirable to operate an active matrix display at frame rates substantially above 60–75 Hz.
Fine tuning of the impulse can also be achieved if a number of finely-spaced voltages are available. In an active matrix drive, this requires source drivers that can output one of a numerous set of voltages available over at least a subset of the available voltages. For example, for a driver that outputs between −10 and +10 volts, it may be advantageous to have available 0 V, and two bands of voltages between −10 and −7 volts and between 7 and 10 volts, with 16 distinct voltage levels between −10 and −7 volts and 16 distinct voltage levels between 7 and 10 volts bringing the total number of required voltage levels to 33 (see Table 1). One could then achieve fine control of the optical final state, for example, by varying the voltage between +7 and +10 or between −10 and −7 volts for the last one or more scan frames of the addressing period. This method is an example of a voltage-modulated technique for achieving acceptable display performance.
TABLE 1Example of voltages needed for voltage modulated drive−10.0V−7.8V8.0V−9.8V−7.6V8.2V−9.6V−7.4V8.4V−9.4V−7.2V8.6V−9.2V−7.0V8.8V−9.0V0.0V9.0V−8.8V7.0V9.2V−8.6V7.2V9.4V−8.4V7.4V9.6V−8.2V7.6V9.8V−8.0V7.8V10.0V
The disadvantage of using voltage-modulated techniques is that drivers must have some range of fine voltage control. Display module cost can be reduced by using drivers that offer only two or three voltages.
In another aspect, this invention seeks to provide methods for achieving fine control of gray levels using drivers with only a small set of available voltages, specifically, where the control of impulse is too coarse to achieve the fine tuning necessary for acceptable display performance. Thus, this aspect of the present invention seeks to provide methods to achieve fine control of gray levels of an impulse driven imaging medium without the need for fine voltage control. This aspect of the invention can be applied, for example, to an active matrix display that has source drivers that can output only two or three voltages.
In another aspect, this invention relates to a method of driving an electro-optic display using a drive scheme that contains at least some direct current (DC) balanced transitions. For reasons explained at length in the aforementioned copending applications, when driving an electro-optic display it is desirable to use a drive scheme that is DC balanced, i.e., on which has the property that, for any sequence of optical states, the integral of the applied voltage is zero whenever the final optical state matches the initial optical state. This guarantees that the net DC imbalance experienced by the electro-optic layer is bounded by a known value. For example, a 15V, 300 ms pulse may be used to drive an electro-optic layer from the white to the black state. After this transition, the imaging layer has experienced 4.5 V-s of DC-imbalance impulse. To drive the film back to white, if a −15V, 300 ms pulse is used, then the imaging layer is DC balanced across the series of transitions from white to black and back to white.
It has also been found desirable to use a drive scheme in which at least some of the transitions are themselves DC balanced; such transitions are hereinafter termed "DC balanced transitions". A DC-balanced transition has no net voltage impulse. A drive scheme waveform that employs only DC-balanced transitions leaves the electro-optic layer DC balanced after each transition. For example, a −15V, 300 ms pulse followed by a 15V, 300 ms pulse might be used to drive the electro-optic layer from white to black. The net voltage impulse across the electro-optic layer across this transition is zero. One might then use a 15V, 300 ms pulse followed by a −15V, 300 ms pulse to drive the electro-optic layer back to white. Again, the net voltage impulse is zero across this transition.
A drive scheme composed of all DC-balanced transition elements is, by necessity, a DC-balanced waveform. It is also possible to formulate a DC-balanced drive scheme that contains DC-balanced transitions and DC-imbalanced transitions, as discussed in detail below.

Methods for driving bistable electro-optic displays, and apparatus for use therein


A radio signal is digitized and filtered to derive a digitized pilot signal (210) modulated by channel amplitude and phase distortion. A numerator and a denominator are formed for dividing the digitized radio signal (208) by the digitized pilot signal, the numerator and the denominator requiring a first predetermined number of bits per sample. The bits of the numerator and the denominator are shifted (518) by equal amounts until a highest order bit of one of the numerator and the denominator is non-zero. A second predetermined number of highest order bits of the numerator are divided (524) by the second predetermined number of highest order bits of the denominator in a divider utilizing less than the first predetermined number of bits, to generate a channel compensated radio signal (536) having a minimum number of bits that can accommodate a predetermined maximum dynamic range.

Mobile radio systems encounter amplitude and phase fluctuations associated with the mobile radio channel. Consider the complex envelope representation of a transmitted signal EQU s(t)=p +m.sub.1 (t)+m.sub.2 (t)+j{m.sub.2 (t)-m.sub.1 (t)},
where p is the pilot tone at channel center (i.e., DC in the case of complex baseband representation), m.sub.1 (t) and m.sub.2 (t) are the upper and lower sideband messages, respectively, and m denotes the Hilbert transform of m. The mobile radio channel imposes distortion on the transmitted signal--most notably, Rayleigh fading, which can be modeled as a multiplicative random process EQU r(t)=A(t)e.sup.j.THETA.(t) s(t)=pA(t)e.sup.j.THETA.(t) +A(t)e.sup.j.THETA.(t) (m.sub.1 (t)+m.sub.2 (t)+j{m.sub.2 (t)-m.sub.1 (t)} )
where A(t) is a Rayleigh-distributed envelope process and .THETA.(t) is a uniformly-distributed phase shift. This distortion imposes difficulties in recovering the message information contained in the transmitted signal and should be removed or compensated for best results.
Prior art techniques for compensating for channel distortion have required an undesirably large amount of memory storage and processing power to achieve sufficient accuracy of compensation. This has resulted in increased receiver cost and higher than necessary power consumption--an undesirable characteristic in battery powered devices, such as portable selective call receivers.
Thus, what is needed is a method and apparatus in a communication receiver for compensating for channel amplitude and phase distortion. The method and apparatus preferably will operate in a manner that maximizes computational accuracy while minimizing memory storage requirements and processing power.

Method and apparatus in a communication receiver for compensating for channel amplitude and phase distortion


A compound of the formula (I), and lubricant, and magnetic disk each using the sameA-(CH2—Rf—CH2O—B—O)n—CH2—Rf—CH2-A  (I)wherein n is an integer of 1 to 4, A is a group of the formula (a) below, and B is a group of the formula (b) below, p being 1 or 2, R being C1-4 fluoroalkyl, Rf is —CF2O(CF2CF2O)x(CF2O)yCF2— or —CF2CF2O(CF2CF2CF2O)zCF2CF2—, x, y and z being each a real number of 0 to 50.

With an increase in the recording density of magnetic disks, the distance between the magnetic disk serving as a recording medium and the head for use in recording of information or playback has become almost nil close to contact therebetween. The magnetic disk is provided over the surface thereof with a carbon protective film or lubricant film for the purpose of diminishing abrasion due to the contact or sliding of the head thereon or preventing contamination of the disk surface.
The carbon protective film is produced generally by the sputtering process or CVD process. Since the disk surface is protected with the two films, i.e., the carbon protective film and the lubricant film thereover, the interaction between the carbon protective film and the lubricant is important.
The lubricants generally in use are perfluoropolyethers having functional groups. Examples of functional groups are hydroxyl, amino and cyclophosphazene group. More specific examples of lubricants include Fomblin ZTETRAOL manufactured by Solvay Solexis Inc. and having hydroxyl, and PHOSFAROL A20H, product of MORESCO Corporation and having both hydroxyl and cyclophosphazene groups.
Fomblin ZTETRAOL exhibits good properties to adhere to the disk due to the presence of the hydroxyl at opposite terminals of the molecule, does not spatter even when the disk rotates at a high speed and is capable of retaining the form of a lubricant film. However, this perfluoropolyether compound is low in resistance to Lewis acids, reacts with Al2O3 in the component of the head and becomes cleaved in its main chain (see, for example, Nonpatent Literature 1). When this cleavage progresses, the compound becomes lower in molecular weight, eventually vaporizing off from the magnetic disk surface and failing to retain the form of a lubricant film in systems involving contact or sliding movement between the head and disk.
On the other hand, PHOSFAROL A20H has at one terminal of the molecule a hydroxyl group contributing to the adhesion to the disk and at the other terminal a cyclophosphazene group for inhibiting the cleavage of the perfluoropolyether main chain with Lewis acids. Accordingly, the lubricant does not spatter even if the disk is in high-speed rotation, the compound is inhibited from decomposing with the Al2O3 in the component of the head and the lubricant is capable of retaining the film form. However, if the carbon protective layer under the lubricant lowers in surface polarity, the number of lubricant molecules adsorbing to the ground layer through a hydrogen bond reduces because of the presence of a single hydrogen group, entailing the likelihood that the lubricant will spatter during high-speed rotation.
A straight-chain perfluoropolyether compound has been disclosed which is improved in adhering properties over A20H and which has at one terminal of the molecule a plurality of hydroxyl groups and at the other terminal a cyclophosphazene group (Patent Literature 1). It has been found that the disclosed compound exhibits higher adhering properties than A20H and ZTETRAOL, whereas compounds are expected which are satisfactory in both adhering properties and decomposition resistance.    [Nonpatent Literature 1] Macromolecules, 1992, Vol. 25, pp. 6791-6799    [Patent Literature 1] WO2006/009057
An object of the present invention is to provide a stable compound which remains free of decomposition even when brought into contact with the head and which exhibits good adhering properties on the disk surface.

Perfluoropolyether compound, and lubricant and magnetic disk each using the same


Disclosed herein is a device that includes: a memory cell array including a plurality of memory cells, the memory cell array operates on a first internal voltage; a peripheral circuit accessing selected one or ones of the memory cells, the peripheral circuit operates on a second internal voltage; a first internal voltage generation circuit that supplies the first internal voltage to the memory cell array; and a second internal voltage generation circuit that supplies the second internal voltage to the peripheral circuit. The second internal voltage generation circuit sets the second internal voltage to a first voltage value in a first mode, and to a second voltage value that is different from the first voltage value in a second mode. The first internal voltage generation circuit sets the first internal voltage to a third voltage value in both the first and second modes.

1. Field of the Invention
The present invention relates to a semiconductor device and an information processing system including the semiconductor device, and particularly to a semiconductor device that can dynamically changes an operating frequency and an operating voltage, and an information processing system including the semiconductor device.
2. Description of Related Art
In recent years, a DVFS (Dynamic Voltage Frequency Scaling) function has been often used in logic-based semiconductor devices such as system LSIs (Large-Scale Integration) used for mobile devices and the like and MPUs (Micro-Processing Unit) used for personal computers and server computers so as to achieve a high performance and a low power consumption. The semiconductor devices equipped with the DVFS function can dynamically change an operating frequency and operating voltage of circuit blocks included therein depending on processing power requirements of the circuit blocks (See Japanese Patent Application Laid-Open No. 2011-81800). If the logic-based semiconductor devices are equipped with the DVFS function, it is possible to obtain a high performance during a high load operation, as well as to dramatically reduce current consumption during a low load operation.
However, in semiconductor memory devices such as DRAM (Dynamic Random Access Memory), part of a memory cell array may perform an analog operation that is not in synchronization with a clock signal. Therefore, if the semiconductor memory devices employ the DVFS function, the memory cell array may not work properly. As one example, in the case of DRAM, if the DVFS function is used to change a selection voltage of a word line or an array voltage that is written into a cell capacitor, the problem arises that an operating margin of the memory cell array significantly decreases.

Semiconductor device employing DVFS function


A system and method for detecting channels in a network using messages passing through the network is provided. An embodiment comprises detecting AAL2 channels communicating between a Node B and an radio network controller and also between two radio network controllers. In the case of communication between a NodeB and a radio network controller, the AAL2 channels are detected by matching pairs of Random Access Channel (RACH) and Forward Access Channel (FACH) associated with a user equipment identity along with a Dedicated Channel (DCH) until the AAL2 channels present between the Node B and the RNC are determined to a desired level of confidence. In the case of communication between two radio network controllers, only the DCH channels need to be detected to completely detect the AAL2 channels.

The Universal Mobile Telecommunications System (UMTS) is a third-generation (3G) mobile phone technology standardized first by the European Telecommunications Standards Institute (ETSI) and now by the 3rd Generation Partnership Project (3GPP). UMTS carries both circuit switched (CS) and packet switched (PS) traffic using, for example, Wideband Code Division Multiple Access (W-CDMA) as its air interface. The description of the network components and protocols used in UMTS are well known to those of ordinary skill in the art and are available to the public from 3GPP, ETSI, and other sources. The UMTS network architecture consists of three interacting domains: Core Network (CN), UTRAN, and User Equipment (UE).
The Core Network (CN) provides switching and routing for user traffic and provides network management functions. The Core Network architecture is based on the GSM network with General Packet Radio Service (GPRS). The UTRAN provides an air interface to a subscriber's UE, such as handheld phones, wireless laptop computer cards, or other wireless devices. The UMTS user equipment communicates over an air interface to a base station. Base stations in the UTRAN are referred to as Node-Bs. The UE may be attached to either the PS domain, CS domain, or both. A UE may be capable of simultaneously using PS services and CS services. The control equipment for the Node-Bs is called a Radio Network Controller (RNC).
Data transmissions within the UMTS, except for the air interface (Uu), use Asynchronous Transfer Mode (ATM). Accordingly, ATM is used to transmit on the Tu interfaces. The ATM layer multiplexes, demultiplexes, and routes ATM cells, and ensures that their sequence from end to end. An ATM cell, the smallest unit in ATM, contains two address parameters, Virtual Path Identifier (VPI) and Virtual Channel Identifier (VCI). A Virtual Path is the permanent Virtual Connection for exchanging Node B Application Part (NBAP) and Access Link Control Application Protocol (ALCAP) messages between an RNC and a Node B. By permanent virtual connection it is understood that the connection will be setup once and will run until it is changed or deleted by an operation and maintenance (O&M) process. To transmit higher level protocols via ATM, adaptation layers are used. ATM Adaption Layers (AAL) are responsible for the creation and reception of payloads through the lower layers of ATM on behalf of different applications. ATM Adaption Layer type 2 (AAL2) handles circuit-switched connections, while packet connection protocol AAL5 is designed for data delivery. AAL2 has been developed to transport multiple data streams and a Connection Identifier (CID) identifies each stream. Each AAL2 virtual connection is uniquely associated with an ATM Virtual Path Identifier (VPI), ATM Virtual Channel Identifier (VCI), AAL2 Connection Identifier (CID) and ATM port, which corresponds to the port on which the message arrives and may also be referred to herein as a port identification (PortId).
Network operators, including large telecommunications companies, want to be able to manage their networks to provide their customers, including end users, an appropriate level of service and quality. In order to manage these complicated networks, it is useful to first understand the topology of the network. While the topology of the core may be identified and characterized by hand, for example when the system is being created, as the system spreads out from the core the number of connections increases making manual identification impossible, or at least infeasible. Furthermore, even if the hardware topology is know out to the Node Bs, the data being communicated between end users passes through virtual connections. To more fully manage the network and monitor the level of service and the quality of service, it would be desirable to be able to identify the AAL2 virtual connections. As these connections are virtual, they may be created, changed or deleted over time. To manually identify and track these connections would be impossible, or infeasible.

System and method for real-time AAL2 channel detection in UTRAN