A system and a method for estimating low complexity bandwidth efficient carrier frequency offset for orthogonal frequency division multiple access (OFDMA) and or single carrier frequency division multiple access (SC-FDMA) uplink transmissions in a communication network systems including a group of subscriber stations, a base station including carrier frequency offset unit. The method steps include transmitting a plurality of null subcarrier signals and data subcarrier signals from plurality of said subscriber stations (SS) to the base station; processing transmitted subcarrier signals at the base station by estimating carrier frequency offset (CFO) by carrier frequency offset unit; selecting the subcarrier signals based on carrier assignment scheme (CAS).

Orthogonal Frequency Division Multiplexing (OFDM), the underlying technique behind OFDMA, is a multicarrier communication system which converts a high data rate stream into a group of parallel low data rate streams which transform the frequency selective fading situation being encountered in a wireless channel to tractable flat fading scenario. OFDMA has gained acceptance recently as an important multiple access technique to provide OFDM services to a group of subscribers simultaneously. The downlink of an OFDMA communication system is nearly equivalent to that of an OFDM system and it is characterized by a single carrier frequency offset (CFO) which can be easily estimated using conventional estimation techniques available for OFDM. The CFO estimation problem in the uplink transmission of OFDMA is more challenging than the downlink. In the uplink transmission of OFDMA each active subscriber station (SS) may have a different CFO relative to the common base station (BS) receiver which, if uncompensated, would result in self and multiple access interferences and thereby poor bit error rate (BER) performances.
The first step of OFDMA synchronization takes place in the downlink transmission where the subscriber stations SSs or mobile terminals (MTs) estimate the timing and frequency offsets using the pilot signals transmitted by the base station (BS). A major portion of the frequency offset can be estimated in this step and the CFO estimation techniques available for OFDM can be directly employed for this purpose as the user's signal appear at each SS with a common frequency error (T. M. Schmidl and D. C. Cox, "Robust frequency and timing synchronization for OFDM" IEEE Trans. Commun., vol. 45, no. 12, pp. 1613-1621, December 1997; M. Morelli and U. Mengali, "An improved frequency offset estimator for OFDM applications," IEEE Commun. Left., vol. 3 no. 3, pp. 75-77, March 1999; X. Ma, C. Tepedelenlioglu, G. B. Giannakis, and S. Barbarossa, "Non-data-aided carrier offset estimators for OFDM with null subcarriers: Identifiability, Algorithms, and Performance," IEEE J. Sel. Areas Commun., vol. 19, no. 12, pp. 2504-2511, December 2001; Defeng (David) Huang and K. B. Letaief, "Carrier frequency offset estimation for OFDM systems using null subcarriers," IEEE Trans. Commun., vol. 54, no. 5, pp. 813-822, May 2006.). The SSs use these estimates as a reference for the uplink transmission. But due to Doppler shifts and oscillator phase noise, the signals received at the BS from various SSs will have small frequency offsets within the range of +/−0.5 of subcarrier spacing. Hence the second step of OFDMA CFO estimation is done at the BS by estimating the frequency offsets between the various SSs and the BS receiver. This turns out to be a challenging multiple CFO estimation problem.
CFO estimation in the uplink OFDMA is considered as an active research topic recently and a few methods are proposed in the literature. Most of these schemes are too specific to the carrier assignment schemes (CAS) used within the OFDMA system.
The main difference between OFDM and OFDMA is that in the case of later, in the downlink, each OFDM symbol conveys distinct sets of data to multiple subscribers simultaneously. Thus the available N subcarriers are usually evenly divided among the M users, by dividing N into R subchannels, each consisting of Q=N/R subcarriers. As the maximum number of users that an OFDMA system can support is decided by R, it is assumed that M≦R. Since the carriers allocated to the M users are to be distinct, Ik∩Ij=Ø for k≠j, where Ik and Ij are the sets of sub carriers allocated to kth and jth users respectively. During the uplink transmission M users transmit independently, using the sub-carriers allocated to them by padding zeroes in rest of the sub-carrier locations.
The three CAS proposed for OFDMA are subband CAS, generalized CAS and interleaved CAS.
A timing and frequency offset estimation scheme for OFDMA with subband CAS is proposed in (J. J. van de Beek, P. O. BAorjesson, M. L. Boucheret, D. LandstrAom, J. M. Arenas, O. A Odling, C. A Ostberg, M. Wahlqvist, and S. K. Wilson, "A time and frequency synchronization scheme for multiuser OFDM," IEEE J. Sel. Areas Commun., vol. 17, no. 11, pp. 1900-1914, November 1999.) Here the subbands of each user are filtered first and estimation is done by using the cyclic prefix (CP) associated with each user's data. But the estimator performance deteriorates when the number of subcarriers in a subband becomes smaller due to the high correlation of samples. A CFO estimation scheme for the quasi-synchronous (where the CP duration is greater than two way propagation delay and channel delay spread) subband CAS OFDMA is proposed in (S. Barbarossa, M. Pompili, and G. B. Giannakis, "Channel-independent synchronization of orthogonal frequency division multiple access systems," IEEE J. Sel. Areas Commun., vol. 20, no. 2, pp. 474-486, February 2002) This technique uses the virtual subcarriers employed in each subband and estimates the CFO by means of the energy minimization at the DFT output as done in (X. Ma, C. Tepedelenlioglu, G. B. Giannakis, and S. Barbarossa, "Non-data-aided carrier offset estimators for OFDM with null subcarriers: Identifiability, Algorithms, and Performance," IEEE J. Sel. Areas Commun., vol. 19, no. 12, pp. 2504-2511, December 2001.)
A CFO estimation scheme for the quasi-synchronous interleaved OFDMA, which exploits the inherent periodic structure of this type of OFDMA symbol, is proposed in (Z. Cao, U. Tureli, and Y. D. Yao, "Deterministic multiuser carrier-frequency offset estimation for interleaved OFDMA uplink," IEEE Trans. Commun., vol. 52, no. 9, pp. 1585-1594, September 2004). The accuracy of the method decreases when the number of users approaches the number of available subcarriers.
A maximum likelihood (ML) technique for the timing and frequency offset estimation in OFDMA system with a generalized CAS is proposed in (M. Morelli, "Timing and frequency synchronization for the uplink of an OFDMA system," IEEE Trans. Commun, vol. 52, no. 2, pp. 296-306, February 2004). But it has a serious limitation as it assumes that all other users in the system are already synchronized perfectly. Modified forms of this method for quasi-synchronous scenarios are proposed in (M. O. Pun, M. Morelli, and C-C. J. Kuo, "Maximum-likelihood synchronization and channel estimation for OFDMA uplink transmissions," IEEE Trans. Commun. Vol. 54, no. 4, pp. 726-736, April 2006; M. O. Pun, M. Morelli, and C-C. J. Kuo, "Iterative detection and frequency synchronization for OFDMA uplink transmissions," IEEE Trans. Signal Proc., vol. 6, no. 2, pp. 629-639, February 2007), where timing and frequency offsets are estimated from the training blocks being transmitted by each user at the start of the uplink frame. This results in considerable wastage of bandwidth. Moreover, the computational complexity of (M. O. Pun et al, 2006) is very high. An overview of OFDMA and its synchronization techniques are presented in (M. Morelli, C-C. J. Kuo, and M. O. Pun, "Synchronization Techniques for Orthoganal Frequency Division Multiple Access (OFDMA): A Tutorial Review," Proc. IEEE, vol. 95, no. 7, pp. 1394-1427, July 2007).
A pictorial representation of the three CAS schemes are shown in FIG. 3 for N=16 and Q=R=4. Here each color represents the subcarriers allocated to a specific user and each small rectangle represents one subcarrier.
All the CFO estimation schemes proposed for OFDMA, are carrier assignment scheme (CAS) specific. This introduces considerable in convenience in system design and bandwidth assignment.
In view of the growing popularity, efficient techniques for the CFO estimation with excellent performances are still needed for practical OFDMA system implementations. The present invention proposed a null sub carrier based CFO estimation technique for OFDMA which can be applied to subband CAS, generalized CAS and a modified form of interleaved CAS. Being a null sub carrier based estimator, the proposed CFO estimation scheme does not require the knowledge of fading channel coefficients for deriving the frequency offset estimates. A null sub carrier based CFO estimator where the estimation is done by minimizing a cost function which compute the total energy present in null sub carrier locations due to the CFO. The computational complexity and training overhead of the present invention method are much lower as compared to some of the CFO estimation schemes available in the literature for OFDMA transmissions.

Low complexity bandwidth efficient carrier frequency offset estimation technique for OFDMA uplink transmissions


Medical devices for implantation within a body vessel can include a remodelable material, such as an extracellular matrix material, positioned within a lumen defined by an outer covering material. The covering material is preferably substantially non-remodelable, and can be supported by a radially expandable frame. The medical device can also include a valve means positioned within the covering material. The valve means can include one or more valve leaflets formed from the remodelable material, and a separate valve support frame. One or more therapeutic agents can be associated with the remodelable material or the covering material.

Various implantable medical devices are advantageously inserted within various body vessels, for example to improve or replace the function of native valves therein. For example, native valves within the heart and veins function to regulate blood flow within the body. Heart valves positioned within the heart direct the flow of blood to and from other organs and pump oxygenated blood to the rest of the body. Venous valves are typically bicuspid valves positioned at varying intervals within veins to permit substantially unidirectional blood to flow toward the heart.
Minimally invasive techniques and instruments for placement of intraluminal medical devices have been developed to treat and repair undesirable conditions within body vessels, including treatment of conditions that affect blood flow such as venous valve insufficiency. Various percutaneous methods of implanting medical devices within the body using intraluminal transcatheter delivery systems can be used to treat a variety of conditions. One or more intraluminal medical devices can be introduced to a point of treatment within a body vessel using a delivery catheter device passed through the vasculature communicating between a remote introductory location and the implantation site, and released from the delivery catheter device at the point of treatment within the body vessel. Intraluminal medical devices can be deployed in a body vessel at a point of treatment and the delivery device subsequently withdrawn from the vessel, while the medical device retained within the vessel to provide sustained improvement in vascular valve function or to increase vessel patency.
Various types of medical devices are advantageously implanted within the body, such as within a blood vessel or within the heart, to treat a variety of conditions. One type of implantable medical device is an endovascular prosthesis that is used to strengthen a blood vessel wall in the location of an aneurysm, or to open an occlusion in a blood vessel. Another common type of medical device is a prosthetic valve. Valves have been implanted in and near the heart and at various positions within the venous system using catheter-based delivery techniques, including the implantation of prosthetic venous valves in the femoral and popliteal veins. Prosthetic valves can also be implanted in various body passages to replace natural valves that are defective or diseased. Prosthetic cardiac valves have been used to replace the native cardiac valves within the heart using percutaneous approaches. Prosthetic valves have also been implanted in veins to promote the flow of blood back to the heart. Blood pressure, as provided by heart activity via the arteries, is normally sufficient to maintain the flow of blood in one direction. The blood pressure in the veins can be much lower than in the arteries principally due to their distance from the heart. Venous valves function to limit the backflow of blood through the veins. Numerous such venous valves are located throughout the venous system and are particularly important to maintaining proper blood flow in the lower extremities. Venous valves can become incompetent and lead to chronic venous insufficiency. Various techniques have been developed for treating incompetent venous valves including valvuloplasty, transplantation, and replacement with a prosthetic valve. These techniques include both open and percutaneous approaches.
Inhibiting or preventing thrombosis and platelet deposition on an implantable device within the body is important in promoting continued function of the medical device within the body, particularly within blood vessels. Post-implantation thrombosis and platelet deposition on surfaces of implantable medical devices prosthesis undesirably reduce the patency rate of many implantable medical devices. For example, thrombosis and platelet deposition within an endovascular prosthesis may occlude the conduit defined by the endovascular prosthesis or compromise the function of an implanted valve by limiting the motion or responsiveness of moveable portions of the device such as valve leaflets. Many factors contribute to thrombosis and platelet deposition on the surfaces of implanted prosthesis. The properties of the material or materials forming the endovascular prosthesis are believed to be one important factor that can contribute to the likelihood of undesirable levels of post-implantation thrombus formation or platelet deposition on the implanted device. The formation of blood clots, or thrombus, on the surface of an endovascular prosthesis can both degrade the intended performance of the prosthesis and even undesirably restrict or occlude desirable fluid flow within a body vessel.
What is needed are implantable medical devices configured to mitigate or prevent thrombosis or promote the remodeling of portions of the device within a body vessel. The implantable medical devices provided herein are configured to provide implantable medical devices suitable for percutaneously delivery, such as venous valves or heart valves, that include a remodelable material and can be delivered using a minimally invasive catheter-based delivery system.

Implantable device with remodelable material and covering material


A ceramic substrate support and methods for fabricating the same are provided. In one embodiment, a ceramic substrate support for supporting a substrate includes a ceramic body and a porous member disposed therein. The ceramic body generally has an upper portion and a lower portion. The upper portion includes a support surface while the lower portion includes a bottom surface. At least one passage is disposed in the lower portion of the ceramic body. A first end of the passage is at least partially closed by the upper portion of the ceramic body. At least one outlet is disposed through the portion of the ceramic body through the upper portion of the ceramic body and fluidly couples the passage to the support surface.

1. Field of Invention
The embodiments of the invention generally relate to a ceramic support for supporting a substrate in a process chamber.
2. Background of the Invention
Substrate support chucks are widely used to support substrates within semiconductor processing systems. A particular type of chuck used in semiconductor processing systems, such as etch systems among other processing systems, is a ceramic electrostatic chuck. Electrostatic chucks generally retain a substrate or other workpiece in a stationary position during processing. Typically, electrostatic chucks contain one or more embedded electrodes within a ceramic body. As an electrical potential is applied between the electrodes and a substrate disposed on the ceramic body, an electrostatic attraction is generated which holds the substrate against a support surface of the ceramic body. The force generated may be a capacitive effect due to a potential difference between the substrate and the electrodes or, in the case of ceramic bodies comprised of semiconducting materials having a relatively low resistivity which allow charge migration within the ceramic body to the surface approximate the substrate, a Johnsen-Rahbeck effect. Electrostatic chucks utilizing capacitive and Johnsen-Rahbeck attractive forces are commercially available from a number of sources.
Typically, to control the substrate temperature during processing, a backside gas is provided between the support surface of the ceramic body and the substrate. Generally, the backside gas fills the interstitial area between the ceramic body and the substrate, thus providing a heat transfer medium that enhances the rate of heat transfer between the substrate and the substrate support.
The operation and service life of the electrostatic chuck may be adversely affected if backside gas becomes ignited into a plasma or facilitates arcing between the substrate and the substrate support. Arcing or the creation of plasma between the substrate and the wafer may damage both the substrate and the support surface of the electrostatic chuck. In particular, backside gas outlets disposed in the support surface are vulnerable to erosion or damage due to the concentration of gas flowing therethrough which provides a less resistive current path than the surrounding gas in the interstitial area.
One configuration of an electrostatic chuck that substantially reduces arcing and plasma discharge around the backside gas outlets disposed in the support surface includes a porous dielectric plug inserted in the outlet. The porous material blocks the direct electrical path between the backside of the substrate and the interior portions of the backside gas channel which are closer to the embedded conductive member (e.g., the electrodes). Moreover, the porous flow path provides less surface area surrounding the individual backside gas flows through the plug resulting in less charge accumulation proximate the gas flow. As less charge accumulation results in a lower potential at the outlets, arcing and gas ignition are substantially eliminated. Thus, the backside gas may flow to interstitial space between the substrate and the support surface through the porous material substantially without risk of damage to the chuck and/or substrate.
While the porous material provides good protection against plasma ignition and arcing at the backside gas outlets, fabrication of such chucks is difficult. For example, the porous plugs are typically inserted into a counterbore provided in the support surface and concentric with the backside gas outlet and retained therein using an adhesive. As a plurality of backside gas outlets are typically disposed in one electrostatic chuck, the fabrication steps of applying adhesive and inserting the plugs into the electrostatic chuck is timeconsuming and expensive. Moreover, such chucks having an adhesive bond exposed to the support surface risk chamber contamination during various portions of the processing cycle, particularly during plasma dry cleaning. During plasma dry cleaning, the portions of the adhesive exposed to the plasma may be removed from the plug to ceramic body joint and deposited elsewhere in the chamber, thereby becoming a potential substrate contamination source. Additionally, after a number of cleanings, the plug may become loose and eventually become disengaged from the chuck. Loose plugs are a source of unwanted particle contamination and may also come in contact with the substrate thus damaging the substrate.
Other electrostatic chucks utilizing porous plugs include a dielectric layer deposited over the chuck body after the porous inserts have been deposited in the outlet passages. In order to complete the backside gas flow path to the interstitial area after the deposition of the dielectric material, a passage must be fabricated in the dielectric coupling the plug to the surface of the dielectric material.
Although chucks configured in this manner are more conducive to plasma cleaning, fabrication and other concerns exist. For example, the fabrication of the electrostatic chuck now includes both a subsequent dielectric deposition and machining step. As the plugs are typically inserted without the use of adhesives, inconsistencies between the height of the porous plug and the support surface may result in variations in the topography of the applied dielectric layer. Moreover, if the plug moves away from the applied dielectric layer leaving a gap, gas within the gap is susceptible to plasma ignition. Furthermore, if the plug is loose and moves within the electrostatic chuck, particle generation may occur. Thus, the high fabrication costs along with the remaining possibility of plasma ignition within the passages utilized by the backside gas and the difficulty of maintaining a flat support surface leaves room for improvement in electrostatic chuck design.
Therefore, there is a need for an improved electrostatic chuck along with methods for fabricating the same.
One aspect of the invention generally provides a ceramic substrate support for supporting a substrate. In one embodiment, a ceramic substrate support includes a ceramic body and a porous member disposed therein. The ceramic body generally has an upper portion and a lower portion. The upper portion includes a support surface while the lower portion includes a bottom surface. At least one passage is disposed in the lower portion of the ceramic body. A first end of the passage is at least partially closed by a portion of the upper portion of the ceramic body. At least one outlet is disposed through the portion of the upper portion of the ceramic body closing the passage and fluidly couples the passage to the support surface.
In another embodiment, a ceramic substrate support for supporting a substrate includes a ceramic body having one or more conductive members and a porous ceramic member disposed therein. The ceramic body has an upper portion having a support surface and a lower portion having a bottom surface. At least one passage is disposed in the lower portion of the ceramic body. A first end of the passage is at least partially closed by the upper portion. At least one outlet is disposed through the upper portion of the ceramic body and fluidly couples the passage to the support surface. The porous ceramic member is disposed within the passage and sintered and processed to become a single member with the ceramic body.
In another aspect of the invention, a process chamber for processing a substrate includes an evacuable chamber having an interior volume having a gas supply fluidly coupled thereto and an electrostatic chuck disposed in the interior volume. The electrostatic chuck includes a ceramic body having one or more conductive members and a porous member disposed therein. The ceramic body has an upper portion having a support surface and a lower portion having a bottom surface. At least one passage is disposed in the lower portion of the ceramic body. A first end of the passage is at least partially closed by the upper portion. At least one outlet is disposed through the upper portion of the ceramic body and fluidly couples the passage to the support surface.
In another aspect of the invention, a method for fabricating a ceramic substrate support is provided. In one embodiment, a method for fabricating a ceramic substrate support includes the steps of forming one or more blind holes on a first side of a first ceramic member, inserting a porous ceramic member in each blind hole, disposing a second ceramic member on the first side of the first ceramic member and processing the first ceramic member, second ceramic member and porous ceramic member to form a single ceramic body.
In another embodiment, a method for fabricating a ceramic substrate support pedestal includes forming one or more blind holes in a first side of a first ceramic member having a resistivity between 1xc3x97E9 to about 1xc3x97E11 ohms-cm, inserting a porous ceramic member in each of the blind holes, disposing a second ceramic member having a resistivity higher than the first ceramic member on the first side of the first ceramic member, disposing one or more electrodes between the first ceramic member and the second ceramic member, processing the first ceramic member, the second ceramic member and the porous ceramic member to form a single ceramic body and forming one or more outlets in the first ceramic member to couple each blind hole to a second side of the first ceramic member.


A method for accessing a signal value of an FPGA at runtime, including the steps of loading an FPGA hardware configuration into the FPGA, executing the FPGA hardware configuration in the FPGA, requesting a signal value of the FPGA, sending status data from a functional level of the FPGA to a configuration memory in its configuration level, reading the status data from the configuration memory as readback data, and determining the signal value of the readback data. A method is also provided for making an FPGA build, based on an FPGA model, using a hardware description language, including the steps of creating an FPGA hardware configuration, identifying memory locations of a configuration memory for status data of at least one signal value based on the FPGA hardware configuration, and creating a list with signal values accessible at runtime and the memory locations corresponding thereto.

1. Field of the Invention
The present invention relates to a method for accessing a signal value of an FPGA at runtime. Likewise, the invention relates to a data processing device with a processor unit and an FPGA, whereby the data processing device is configured to carry out the above method. The invention also relates to a computer program product with computer-implemented instructions, said product which after loading and execution in a suitable data processing device performs the steps of the above method, and a digital storage medium with electronically readable control signals, which can interact with a programmable data processing device, so that the above method is executed. Finally, the present invention comprises a method for making an FPGA build based on an FPGA model using a hardware description language.
2. Description of the Background Art
The real-time simulation of complex, dynamic models because of the narrow time constraints imposes high demands on modern computation nodes. In automotive hardware-in-the-loop simulations (HiL), such models are used primarily where rapid control loops must be closed. This is the case, for instance, in the simulation of in-cylinder pressure sensors, which play an increasingly greater role in fuel consumption or exhaust gas reduction. But in controlled systems as well which have high dynamics, such as, for example, in electric motors, short cycle times and low latencies are indispensable. These can hardly be implemented any longer with CPU-based simulations.
Field programmable gate arrays (FPGAs) can support computation nodes during real-time simulation in that they take over the calculation of dynamic parts of a model. High real-time requirements can be easily met by using FPGAs because of the high flexibility and the possibility of parallel processing of signals. The FPGAs can be used as hardware accelerators for the CPUs of computation nodes. The DS5203-FPGA board from dSPACE, for example, represents such an enhancement for a HiL simulator. Accordingly, e.g., very dynamic parts of the environmental model are outsourced to the FPGA, so that sufficiently precise and rapid reaction times are preserved for the control device. An FPGA hardware configuration is typically generated based on an FPGA model using a hardware description language in a build process.
The models of a control system have become increasingly more complex because of more stringent requirements for accuracy and therefore also difficult to manage. In the automotive HiL environment, such models are created as a rule with the MATLAB/Simulink toolset from The MathWorks Inc. Simulink offers a block-based view of such models in the form of a block diagram. In a block diagram model, parts can be combined into subsystems and linked together with signals. The data flow between these blocks is shown by signal lines.
In a CPU-based real-time simulation, the block diagram of a model is first converted into C/C++ source files with the aid of the Simulink coder. These are then converted using a compiler into an executable application, which can be executed on a computation node with a real-time-capable operating system. In addition, in the case of the CPU build a trace file is generated which is a topology file with its graphical modeling, for example, in Simulink.
The conversion of a model into a CPU application has the result that the calculations of the simulation are performed sequentially in a fixed step size. A consistent image of all model states or model variables, such as, for example, data in the signal lines or input/output values of the blocks, is therefore always present in the main memory of the computation node. Due to the direct access to the main memory, the model variables can be analyzed and/or manipulated using an experimentation tool such as, for example, ControlDesk. Random read/write access to variables of the HiL simulation is possible. By using the trace files, signal values such as, e.g., motor rotation speed can be selected and output or manipulated by a display. In the HiL environment, these processes are grouped under the term "measuring" and "calibrating."
An FPGA-based simulation can be modeled in a block diagram with Simulink with the aid of the Xilinx System Generator (XSG) and the FPGA Programming Blockset from dSPACE, similar to a CPU-based simulation.
In contrast to the CPU simulation, this model however is not converted into an iterative program language but into a hardware description language, which describes a customer-specific digital circuit. The description of the customer-specific circuit is converted by a synthesis process into an FPGA configuration data stream.
For debug purposes it is possible for some FPGAs to freeze and read the complete state of the FPGA. Because of the closed input/output behavior of the FPGA, it is not possible, however, in analogy to the main memory of a computation node to access any model states and to change these if necessary. Each model variable, which the user would like to measure or calibrate, must be provided by explicit modeling via signal lines to the interfaces of the FPGA. After this adjustment, the model must be converted again, which can take several hours. This circumstance can lead to very long development cycles of FPGA-based real-time simulations.

Random access to signal values of an FPGA at runtime

dSPACE digital signal processing and control engineering GmbH


An object of the present invention is to provide a sac-like structure enclosing hematopoietic progenitor cells and a method for preparing the sac-like structure as well as a method for efficiently preparing blood cells such as mature megakaryocytes and platelets from the sac-like structure. The present invention provides a sac-like structure enclosing hematopoietic progenitor cells, the sac-like structure being obtained by plating ES cells onto feeder cells and culturing the ES cells under suitable conditions for inducing hematopoietic progenitor cell differentiation. Moreover, the present invention provides a method for producing various blood cells, the method comprising further culturing hematopoietic progenitor cells enclosed in the sac-like structure under suitable conditions for inducing blood cell differentiation.

For the treatment of blood-related diseases including leukemia as a typical example, it is extremely important to stably amplify and supply blood cells in an amount necessary for such treatment. Thus, to date, many researchers have attempted to efficiently amplify hematopoietic stem cells or hematopoietic progenitor cells. Among blood cells, megakaryocytes are cells capable of producing proplatelets, and further, platelets. Hence, they occupy an important place in therapeutic applications. Among blood cells, platelets are cells essential for blood coagulation (hemostasis). Accordingly, the demand for platelets is extremely high in leukemia, bone marrow transplantation, anticancer therapy, etc. To date, the platelets have been supplied by a method involving collection from blood donors. However, such method involving collection from blood donors would hardly achieve stable platelet supply due to chronic shortage of donors, inability to preserve the collected platelets in a frozen state, etc. At the same time, attempts have been made to apply a method involving administration of TPO, a method of differentiating megakaryocytes from umbilical cord blood or myelocytes, etc. However, such TPO administration has not yet been put to practical use because antibodies neutralizing the TPO are produced after administration of the TPO. Also, the method of differentiating megakaryocytes from umbilical cord blood or myelocytes is not suitable as a method of stably providing platelets because it is able to obtain only small quantities of hematopoietic stem cells serving as a source of megakaryocytes.
In recent years, in vitro amplification of hematopoietic stem cells or hematopoietic progenitor cells, which are obtained only in a slight amount from living bodies, has actively been conducted. For example, there have been reports on: a method for establishing, from mouse ES cells, a hematopoietic stem cell line capable of self-renewing and differentiating even into lymphocytes (Patent Document 1); a method comprising inducing in vitro ES cells of a primate to differentiate, then transplanting in utero the obtained cells into a sheep fetus, and obtaining differentiated primate hematopoietic cells from the newborn lamb (Patent Document 2); and a method for conveniently and stably amplifying in vitro CD34-positive/CD38-negative cells that maintain undifferentiation of hematopoietic stem cells (Patent Document 3).
In order to stably supply platelets, a method for allowing hematopoietic stem cells or hematopoietic progenitor cells to efficiently differentiate into megakaryocytes and platelets. Therefore, attempts have actively been made also to induce megakaryocytes, and further, platelets, from ES cells derived from various types of animals. Eto et al. have revealed that mouse ES cells are induced to differentiate into megakaryocytes by coculturing them with OP9 stromal cells (Non-Patent Document 1). Fujimoto et al. have reported that platelet induction had been confirmed using a method similar to that of Eto et al. (Non-Patent Document 2). Moreover, there are also the following reports: a report regarding successful induction of megakaryocyte differentiation from monkey ES cells (Non-Patent Document 3); and a report regarding successful induction of megakaryocyte differentiation from human ES cells (Non-Patent Document 4). However, the release of platelets has not confirmed in any of these documents. Moreover, in order to stably obtain a therapeutically necessary amount of blood cells, other than platelets or megakaryocytes, it is necessary to efficiently obtain hematopoietic stem cells or hematopoietic progenitor cells. However, it is hard to say that such method has been established.
Patent Document 1: Japanese Patent Laid-Open No. 2006-141356
Patent Document 2: Japanese Patent Laid-Open No. 2004-350601
Patent Document 3: Japanese Patent Laid-Open No. 2006-61106
Non-Patent Document 1: Eto et al., Proc. Acad. Sci. USA 2002; 99: 12819-12824.
Non-Patent Document 2: Fujimoto et al., Blood 2003; 102: 4044-4051.
Non-Patent Document 3: Hiroyama et al., Exp. Hematol. 2006; 34: 760-769.
Non-Patent Document 4: Gaur et al., J Thromb Haemost. 2005; 4: 436-442.

Sac-like structure enclosing hematopoietic progenitor cells produced from ES cells and method for preparing blood cells


An automatic transmission apparatus has a transmission 3 having first and second input shafts 31 and 32 as well as a clutch or a brake, and also has a torque converter 2 having a main unit 10, a planetary gear train 11, lock-up clutch device 12 and a one-way clutch 35. The planetary gear train 11 has a ring gear r1 coupled to a turbine 16, planetary gears p1 meshing with the ring gear r1, a carrier 20 coupled to the first input shaft 31 of the transmission 3 and carrying the planetary gears p1, and a sun gear s1 coupled to a stator 17 and meshing with the planetary gears p1. The one-way clutch 35 transmits a power to the second input shaft 32 of the transmission 3 only when the stator 17 rotates reversely to the impeller 15 and turbine 16.

A. Field of the Invention
The present invention relates to an automatic transmission apparatus including a torque converter which has a multi-speed configuration.
B. Description of the Background Art
The assignee of the present application has previously proposed various kinds of structures for automatic transmission apparatuses, in which a four-element torque converter is used with automatic transmissions. In the four element torque converter, the four elements include a turbine, a first stator, a second stator and an impeller. The turbine and at least one of the two stators are coupled to portions of the transmission to produce an output by combining torque transmitted from them. These automatic transmission apparatuses can be classified into the following three types.
According to a first type of an automatic transmission apparatus, which is disclosed in Japanese Patent No. 1,965,369 (Japanese Patent Application Number 60-25906), and U.S. Pat. No. 5,122,104, forward rotation power of a turbine and reverse rotation power of a stator are output from a torque converter when a 1st (forward 1st) speed and a reverse are selected. When a 2nd speed is selected, the stator is fixed and the rotation power is transmitted only from the turbine. When a 3rd speed is selected, the turbine is integrated with the stator. U.S. Pat. No. 5,122,104 is herein incorporated by reference.
A second type of an automatic transmission apparatus, is disclosed in Japanese Patent Nos. 1,871,294, 1,896,991, 1,896,992 and 1,963,199, which correspond to Japanese Patent Application Numbers 61-101504, 61-101505, 62-101506 and 61-101446, respectively. Japanese Patent Application Numbers 61-101504, 61-101505, 62-101506 and 61-101446 were combined and subsequently issued as U.S. Pat. Nos. 4,869,128 and 4,942,779. U.S. Pat. Nos. 4,869,128 and 4,942,779 are both incorporated herein by reference. The second type of an automatic transmission apparatus disclosed in U.S. Pat. Nos. 4,869,128 and 4,942,779. U.S. Pat. Nos. 4,869,128 and 4,942,779 differs from that disclosed in U.S. Pat. No. 5,122,104 in that the reverse driving is performed by fixing the turbine and supplying the rotation power from the stator.
A third type of transmission and torque converter is disclosed in Japanese Patent Nos. 1,785,235 (Application No. 59-195410) and 1,962,867 (Application No. 60-7233). In the third type, the forward rotation power of the turbine and the reverse rotation power of the stator are transmitted at all speed settings of the transmission. The disclosures of Japanese Patent Nos. 1,785,235 and 1,962,867 are herein incorporated by reference.
According to these types of automatic transmission apparatuses, the rotation power can be supplied also from one of the stators in contrast to a general transmission apparatus utilizing only an output of the turbine. Therefore, in the above described transmissions, the power output can be relatively large.
The assignee of the present application has also proposed another novel structure in Japanese Patent Application No. 7-234386 (1995). In this structure, a turbine of a torque converter is coupled to a first output shaft via a planetary gear train, and a stator is coupled to a second output shaft via a one-way clutch. Further, another one-way clutch is arranged between a sun gear of the planetary gear train and the second output shaft, and a reverse rotation power of the sun gear is transmitted to the second output shaft via this one-way clutch.
According to this structure, the transmission can output a further larger power compared with the first and third types, and the number of speeds can be increased.
However, the above structure disclosed in Japanese Patent Application No. 7-234386 suffers from such a problem that an engine brake cannot function during reverse driving in 1st and 3rd speeds when the sun gear reversely rotates faster than the second output shaft, because the one-way clutch is arranged between the sun gear of the planetary gear train and the second output shaft. Further, it suffers from complicated structures, increase in weight and size and increase in manufacturing cost, because two one-way clutches are arranged in the torque converter.

Automatic transmission apparatus with torque convertor planetary gear mechanism


A display rack comprises a frame, at least one dividing base unit and a track. The track supports a follower arrangement. The base unit comprises a partition wall and a support surface. The track is positioned on the support surface and is capable of lateral translation relative to the support surface. The base unit itself is laterally displaceable relative to the frame. The base unit reinforces the track unit against generally vertical bending forces.

1. Field of the Invention
The present invention is generally related to display racks. More particularly, the present invention is related to display racks having follower assemblies supported on a track that is laterally repositionable relative to a supporting shelf
2. Description of the Related Art
Shelving assemblies are used to display products in stores of all types. Due to the fierce competition among stores, great efforts are made to maintain a tidy appearance. For instance, many stores employ stock people who constantly reshelve merchandise or rotate merchandise to maintain an orderly appearance of products on the shelves. Paying people to perform such full time restocking can greatly increase overhead costs. Accordingly, stores have begun to use shelving that will urge the products forward such that a fully stocked appearance can be maintained although the shelves are not constantly being restocked.
Some stores have also recognized that reconfiguring the displays increases the time an individual spends in the store shopping. For instance, if products are not shuffled to some degree within a store, an individual that frequents that store proceeds directly to the location of the product they came looking for, picks up that product, pays for the product and leaves the store. On the other hand, by slightly shuffling product location on a periodic basis, the same individual spends more time wandering the aisles or otherwise browsing the product selection. The increase in time often will increase the number of impulse purchases made within the store.
Shelving that urges products forward, however, suffers from at least one major drawback in the shuffling of products. The shelving is difficult to reconfigure in a rapid manner. In addition, various products have different weights and, in some arrangements, the shelving has differing load-bearing capabilities. Thus, moving a large and heavy product to a shelving assembly previously configured for smaller and lighter products may not be possible. Instead, the products and the shelving assemblies would have to be relocated as a unit. This is a time consuming and tedious job.
Recently, a shelving assembly allowing rapid lateral readjustment has been created. Examples of such adjustable shelving assemblies having follower assemblies are disclosed in copending U.S. patent application Ser. No. 09/518,341, which was filed on Mar. 3, 2000, and co-pending U.S. patent application Ser. No. 09/379,704, which was filed on Aug. 24, 1999, both of which applications are hereby incorporated by reference in their entirety. These shelving assemblies comprise track units that are either integral with, or separately formed of, dividing walls. The track units can be adjusted side to side to increase or decrease the distance between the dividing walls. Thus, larger packages can be readily accommodated.
A drawback to simply adjusting the tracks and the dividers is readily apparent in the combined track and dividing wall configuration. In this configuration, the track, and therefore the follower assembly mounted on the track, are not centrally located between the two adjacent dividing walls. While the failure to centrally position the track and follower assembly may have little consequence in smaller and lighter products, such an off-center arrangement increases the wear rate when used with larger and heavier products. The torque created by the follower assembly can cause rapid system failure in some arrangements.
Similarly, if the track is formed separate of the vertically-extending dividing wall, large loads can cause failures in the track over time. For instance, without the vertically-extending dividing wall, the track is more likely to bow in the center over time if unsupported. The vertically-extending dividing wall stabilizes the attached track and provides reinforcement against vertical bowing. Thus, while separating the track and the dividing wall allows the track to be centralized between the dividing walls, the track can be largely unsupported and more susceptible to bowing and breaking along a central portion of the track.
Accordingly, a need exists for an easily adjusted display system that provides the advantages of forward-feeding display systems that admits of rapid reconfiguration while also allowing a more centralized follower assembly and increased vertical support for improved load-bearing characteristics.
Thus, one aspect of the present invention involves a display rack comprising a frame, a base unit and a track. The base unit comprises a generally vertical dividing wall portion and a generally horizontal support surface portion. The track is disposed on the generally horizontal support surface portion and the track carries a pusher block. The pusher block is capable of translating along the track in a generally longitudinal direction and is biased to a forward direction. The track is capable of translating along the support surface portion of the base unit in a generally lateral direction and the base unit being capable of translating along the frame in a generally lateral direction.
Another aspect of the present invention involves a display rack comprising a front panel, a rear panel spaced from the front panel and at least one divider generally extending between the front panel and the rear panel. The divider comprises a support surface and a partition. The divider is laterally slideable relative to the front panel. A track is laterally slideably positioned on the support surface and the track generally extends between the front panel and the rear panel. The track supports a forward biased pusher block and is connected to at least one of the front panel and the rear panel. The track is generally secured from substantial vertical movement and the track at least partially secures the divider from substantial vertical movement.

Adjustable track system for modular display systems


A fly's eye detector includes a planar imaging array and an optical system that directs light with different incident directions to different sensors in the imaging array. One embodiment of the optical system includes a curved reflector above the planar imaging array to deflect and distribute light to the sensors. Another embodiment of the optical system includes a lens array providing variable offsets of micro-lenses relative to the underlying sensors.

A fly's eye uses multiple lenses to efficiently collect light originating from a wide angular range. FIG. 1 shows a cross-section of a fly's eye 100 that includes an array of lenses 110 covering a curved surface 120. Each lens 110 has an optical axis along a different direction, and each lens 110 forms an image of a different portion of a surrounding scene on a corresponding image plane 130. Fly's eye 100 can locate an object by identifying which of the lenses 110 form images of the object and can track the object as the object moves from the field of one lens 110 to the next.
Astronomical detectors such as cosmic ray detectors have mimicked the properties of a fly's eye using arrays of separate sensors. In such systems, each sensor has a sensing axis pointed in a different direction to enable simultaneous detection of radiation from all directions of sky. These detector systems are generally large, complex, and expensive.
Manufacturing an inexpensive fly's eye detector using integrated circuit technology would be very desirable for applications requiring information from a wide-angle field. However, a solid-state detector having the configuration of fly's eye 100 would be difficult to construct because current semiconductor processing techniques are generally not intended for processing of globally curved surfaces. For example, conventional photolithography generally has a limited depth of focus and may be unable to accurately control patterns on a hemispherical surface. Many other semiconductor manufacturing techniques are similarly ill suited for fabrication of devices such as image sensors or photodiodes on a curved surface.
Methods and structures that provide features of a fly's eye in an inexpensive detector system constructed using conventional semiconductor processing techniques are sought.


A display device is provided that includes a first substrate, a gate wiring formed on the first substrate and extending in a first direction, a data wiring insulated from and crossing the gate wiring and extending in a second direction, and a pixel electrode including a first subpixel electrode to which a first data voltage is applied from the data wiring and a second subpixel electrode to which a second data voltage different from the first data voltage is applied from the data wiring, wherein the first subpixel electrode is surrounded by the second subpixel electrode, and the second subpixel electrode includes a plurality of slit patterns formed in portions thereof which are adjacent to the first subpixel electrode.

1. Field of the Invention
The present invention relates to a display device.
2. Description of the Related Art
Display devices are devices that visually display data. Examples of the display devices include liquid crystal displays (LCDs), electrophoretic displays, organic light-emitting displays, inorganic electroluminescent (EL) displays, field emission displays, surface-conduction electron-emitter displays, plasma displays, and cathode ray displays.
Of the above display devices, LCDs are one of the most widely used types of display devices. Generally, an LCD includes a pair of display panels having electric field generating electrodes, such as pixel electrodes and common electrodes, and a liquid crystal layer interposed between the display panels. In an LCD, voltages are applied to electric field generating electrodes to generate an electric field. Accordingly, the liquid crystal molecules of a liquid crystal layer are aligned, and polarization of incident light is controlled. As a result, a desired image is displayed on the LCD.
In a vertical alignment (VA) mode LCD, liquid crystal molecules are arranged with the main director of the molecules being perpendicular to the upper and lower display panels when no electric field is applied to the liquid crystal molecules. VA mode LCDs are popular due to their high contrast ratios and wide standard viewing angles. However, a drawback of the VA mode LCD is that it may have relatively poor lateral visibility compared to frontal visibility. To overcome this drawback, each pixel may be partitioned into two subpixels, and a switching device may be formed in each subpixel. Then, a different voltage may be applied to each subpixel.
In such a conventional LCD, however, two subpixels to which different voltages are applied are separated from each other. Therefore, texture is created at a boundary between the two subpixels.
To prevent the creation of the texture, a gap between the two subpixels may be reduced. However, it is difficult to reduce the gap to below a certain level due to the limited process capability of current mass production facilities.
Alternatively, a voltage applied to one of the two subpixels may be reduced to prevent the creation of the texture. However, a reduction in the voltage inevitably results in a reduction in the luminance (i.e., light transmittance) of the display device.


A low-powered mixer that is operable at a low voltage by a single positive power supply. A predetermined voltage and a first data signal Ss1 superimposed on the predetermined voltage are input into the drain D of an FET Q1, while a first carrier signal Sc1 is input into the FET Q1's gate G. The FET Q1 thus generates a first mixed signal So1 by mixing the first data signal Ss1 and the first carrier signal Sc1. A predetermined voltage and a second data signal Ss2 superimposed on the predetermined voltage are input into the FET Q2's drain D, while a second carrier signal Sc2 is input into the FET Q2's gate G. The FET Q2 thus generates a second mixed signal So2 by mixing the second data signal Ss2 and the second carrier signal Sc2. A capacitor C5 causes the sources S of the FETs Q1 and Q2 to float for DC and to be grounded for AC.

1. Field of the Invention
The present invention relates generally to a mixer used in various types of modulators, such as orthogonal modulators, demodulators, detectors, multipliers, frequency converters, etc. More specifically, the invention relates to a mixer for mixing a pair of carrier signals 180.degree. out of phase with each other, with a pair of data signals 180.degree. out of phase with each other.
2. Description of the Related Art
Referring to the circuit diagram shown in FIG. 6, a modulator including a conventional mixer has signal input terminals I100, I200 and I300, signal output terminals O100, and 0200, a DC power supply E, choke resistors R100 and R200, a double balanced mixer (hereinafter referred to as "the DBM") 100, a differential amplifier 200, and a constant current circuit 300. A data signal Ss (for example, a sine wave having a frequency fs at 50 kHz) is applied onto the signal input terminal I100. A first carrier signal Sc1 having a frequency higher than the data signal Ss (for example, a sine wave having a frequency fc at 1.5 GHz), is applied onto the signal input terminal I200. Further, a second carrier signal Sc2 180.degree. out of phase with the first carrier signal Sc1, is applied onto the signal input terminal I300. The DBM 100 has four FETs Q100, Q200, Q300 and Q400. The differential amplifier 200 includes two FETs Q500, Q600 and a capacitor C100. The constant current circuit 300 has an FET Q700 and a bias resistor R300. The DBM 100, the differential amplifier 200 and the constant current circuit 300 are connected to each other and are supplied with power from the DC power supply E via the choke resistors R100 and R200.
Referring to the waveform diagram shown in FIG. 7, the operation of the modulator shown in FIG. 6 will now be explained. More specifically, FIG. 7(a) indicates the first and second carrier signals Sc1 and Sc2; FIG. 7(b) designates the first and second data signals Ss1 and Ss2; and FIG. 7(c) represents an amplitude-modulated signal So which is output between the signal output terminals O100 and O200.
The data signal Ss is input to the gate G of the FET Q500 of the differential amplifier 200 via the signal input terminal I100. The total amounts of the currents flowing in the sources S and the drains D of the FETs Q500 and Q600 are each regulated to a constant level by the FET Q700 of the constant current circuit 300. Accordingly, a first data signal Ss1 (indicated by the solid line in FIG. 7(b)) and a second data signal Ss2 (indicated by the dotted line in FIG. 7(b)) 180 degrees out of phase with each other are output from the drain of the FET Q500 and the drain of the FET Q600, respectively. The first data signal Ss1 is supplied to the sources S of the FETs Q100 and Q200 of the DBM 100, while the second data signal Ss2 is fed to the sources S of the FETs Q300 and Q400. On the other hand, the first carrier signal Sc1 (indicated by the solid line in FIG. 7(a)) is supplied to the gates G of the FETs Q100 and Q300, while the second carrier signal (designated by the dotted line in FIG. 7(a)) is fed to the gates G of the FETs Q200 and Q400.
The FET Q100 mixes the first carrier signal Sc1 with the first data signal Ss1 so as to output from the drain D of the FET Q100 a mixed signal So1 including a sideband component in the frequency range (fc.+-.fs). Also, the FET Q200 mixes the second carrier signal Sc2 with the first data signal Ss1 so as to output from the drain D of the FET Q200 a mixed signal So2 including a sideband component in the frequency range (fc.+-.fs). Further, the FET Q300 mixes the first carrier signal Sc1 with the second data signal Ss2 so as to output from the drain D of the FET Q300 a mixed signal So3 including a sideband component in the frequency range (fc.+-.fs). The FET Q400 mixes the second carrier signal Sc2 with the second data signal Ss2 so as to output from the drain D of the FET Q400 a mixed signal So4 including a sideband component in the frequency range (fc.+-.fs).
The mixed signals So1 and So4 are directly coupled and synthesized, so that a mixed signal So1+So4 is output from the signal output terminal O100. On the other hand, the mixed signals So2 and So3 are directly coupled and synthesized, so that a mixed signal So2+So3 is output from the signal output terminal O200. As a result, a balanced amplitude-modulated signal So is output between the signal output terminals O100 and O200.
Since cellular mobile telephones are coming into wide use, there is increasingly a demand for a lower-powered and smaller-sized mixer that is operable at a lower voltage by a single positive power supply.
However, this conventional mixer is connected in series to other circuits (a differential amplifier and a constant current circuit). For rendering this type of mixer operable, it is thus necessary to supply at least 5.5 V from the DC power supply E. The total of 5.5 V equals the sum of the following: a voltage required for making the FETs Q100 to Q400 of the DBM 100 operable (for example, 1.5 V); a voltage required for actuating the FETs Q500 and Q600 of the differential amplifier 200 (for example, 1.5 V); a voltage required for rendering the FET Q700 of the constant current circuit 300 operable (for example, 1.5 V); a voltage drop generated by a current flowing in the bias resistor R300 (for example, 0.5 V); and a voltage drop generated by a current flowing in the choke resistors R100 and R200 (for example, 0.5 V). This makes it difficult to operate the mixer at a lower voltage. Additionally, since a current is necessary to actuate the mixer, it is difficult to satisfy the demand for a lower-powered mixer.
One possible measure to render the DBM 100 operable at a lower voltage may be to insert a capacitor between each element of the DBM 100 and the differential amplifier 200 so as to block DC between those components. Further, a bias circuit may be provided for each of the DBM 100 and the differential amplifier 200, which can thus be individually supplied with power. Additionally, for achieving the downsizing of the mixer, the mixer may be formed as an IC, and the capacitors to be inserted between the DBM 100 and the differential amplifier 200 may be formed within the IC.
However, the above-described techniques not only increase the complexity in the circuit, but also connect the DBM 100 and the differential amplifier 200 in parallel with each other with respect to DC. Since both of the components dissipate current, the total dissipated power is contradictorily increased. Additionally, the capacitance of a capacitor formed within an IC is, in general, restricted to several dozens of pF, which is not sufficient to handle a data signal having a lower frequency.

Mixer for mixing carrier signals and data signals


A capacitive proximity switch which may be used as an actuating device for a variety of control applications, such as windshield wipers and door locks. According to the invention, the actuating element a contact or proximity switch to be actuated in a nonmechanical manner, and a sensor provided on an object being made as part of a capacitive proximity switch, specifically as an operating electrode of the capacitive proximity switch.

1. Field of the Invention
The present invention relates to switching devices and more particularly, to a capacitive proximity switch circuit which may be used as an actuating device for a variety of universal control applications, such as windshield wiper and door lock control.
2. Description of Related Art
Switching devices have a myriad of applications in the emerging technologies of today. One example, is the use of switching devices in the automotive industry for windshield wiper or door lock control. The switching devices may be activated by a detection device that is used to detect a predetermined condition that, when satisfied, causes the switching mechanism to operate. One example of this is found in European Patent Application No. 0 175 362 to Okushima which discloses a capacitive-type detection device for detecting water on a windshield to control windshield wiper systems employed on vehicles, vessels or aircraft.
Traditionally, a vehicle owner's options with regard to locking and unlocking or releasing or securing and opening his vehicle were restricted to a mechanical key. Using radio remote control, infrared remote control, alternating code process and smart card systems for locking and unlocking doors soon evolved but required an additional actuation element for actuating the unlocking and locking mechanisms. These additional actuating elements are therefore provided especially in order that the corresponding door lock of a corresponding motor vehicle is capable of being unlocked by an electronic activation circuit. The response of the electronic activation circuit, however, should not lead easily to the unlocking or locking of the door. This is especially desirable in the smart card system (and in other so-called transponder systems).
Using the teaching of this invention an especially user-friendly circuit of the type under discussion will be devised.


A stable emulsion composition containing cyclosporin, a polyalkyl ester of polycarboxylic acid in the form of liquid at ordinary temperature, an oil component having an I.O.B. of 0 to 0.25 in the form of a liquid at ordinary temperature, and a surfactant.

Cyclosporin has been used as an immunosuppressant or antiinflammatory agent in organ transplants, for example, heart, lung, liver, kidney, pancreas, skin, cornea, and numerous other heterotransplants. In addition, it has been widely used for autoimmune diseases, for example, psoriasis gravis, Behcet's syndrome, Graves' disease, posterior uvetis, Crohn's disease, diabetes mellitus, ulcerative colitis, myasthenia gravis, rheumatoid arthritis, etc. Its efficacy in these has been reported.
In particular, efficacy by oral administration has been confirmed up to now for psoriasis. Many clinical test results have been reported at present (for example, British Journal of Dermatology, vol. 122, suppl. 36, 1990). In the case of oral administration, however, many side effects such so kidney toxicity, liver toxicity, specific to cyclosporin have been reported. Further, the bioavailability when orally administed is as low as about 30% and an amount of administration is difficult to determine due to the individual differences. Thus, there are many problems in treatment by oral administration.
In view of the above situations, methods of treatment involving direct application to the diseased part the psoriasis for transdermal absorption have been tried out and the development of an effective external agent free from the above side effects is desired. However, since cyclosporin is an active agent characterized by a large molecular weight and a high hydrophobicity, transdermal absorption of cyclosporin cannot be expected in the case of some preparations in which cyclosporin is dispersed in lyophilic bases such as white petrolatum and liquid paraffin or hydrophilic base such as polyethylene glycols.
Further, since cyclosporin dissolves well in methanol, ethanol, acetone, ether, chloroform, etc., external administration by a preparation in which cyclosporin is dissolved in an alcohol, particularly ethanol, has been considered. However, since crystals of cyclosporin easily precipitate after the alcohol evaporates, it is not possible to include the active ingredient at a high concentration and therefore it is not possible to ensure a sufficient amount for treatment be absorbed through the skin. Further, in the case of psoriasis or atopic dermatitis requiring long term continuous use, an alcohol-containing preparation cannot necessarily be said to be preferable when considering skin safety.
As prior art relating to cyclosporin-containing compositions, emulsion preparations containing medium chain fatty acid diglycerides or monoglycerides are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-49733, emulsion compositions containing hydrophilic components, medium chain fatty acid triglycerides, and surfactants are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-121929, pharmaceutical compositions composed of fatty acid saccharide monoesters and diluents are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-235817, pharmaceutical compositions composed of fatty acid triglycerides, partical fatty acid glycerides, etc. are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-255623, and emulsion compositions containing medium chain fatty acid triglycerides, vegetable oils, surfactants, etc. are disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2-290809.
However, even with these prior arts, since it was impossible to formulate the cyclosporin at a high concentration and, also since, the stability of the preparations was insufficient, these have not been yet commercialized.


This disclosure provides compositions and methods for enhancing innate immune system activities and responses by combining lunasin with at least one cytokine. The compositions synergistically enhance the effect of these selected cytokine(s), including but not limited to, activating Natural Killer (NK) cells, augmenting NK's cytotoxicity against viruses and tumors, regulating NK mediated anti-allergic inflammation, producing potent NK cells for cellular therapy using adoptive transfer. and facilitating dendritic cells antigen presentation.

The innate immune system comprises cells and mechanisms that defend the host from infection by other organisms in a non-specific manner. In addition to the role as the first line of defense against infection, the innate immune response plays a vital role in killing cancerous cells. Natural killer (NK) cells, a key component of the innate immune response, represent 10-15% of-circulating lymphocytes in the blood. NK cells possess potent cytolytic activity against virus- or pathogen-infected cells and tumor cells by releasing cytotoxic granules that can spontaneously kill target cells. NK cells also possess immunoregulatory functions that influence adaptive immunity by modulating the activity of other immune cells. Aberrant immune responses can lead to excessive inflammation and autoimmune reactions, leading to diseases such as arthritis and allergies. Therefore, modulation of NK cells could lead to a more robust or properly regulated immune response, enhancing immune response to infected cells, enhanced tumor clearance, decreased inflammatory and allergic responses, and increase efficacy of cancer vaccines.
Given its critical role in immunity and tumor targeting, several strategies for the therapeutic use of NK cells has been proposed and tested. Adoptive transfer of NK cells from autologous or allogeneic donors have been used in the clinic to neat various types of cancers, with mixed results. Attempts to enhance the activity of NK cells for adoptive transfer have treated the cells with cytokines, such as IL-2 and IL-12, prior to injecting the cells into the patient. Adoptive transfer of NK cells to make them more active also has been attempted via genetic manipulation of the NK cells prior to injection into patient. Adoptive transfer poses technical and safety concerns, such as increased risk of spreading disease from the donor to host, intense donor screening and selection, technical expertise in handling and manipulation of the cells, great expense, and potential long term health risks to the patient.
Other strategies to manipulate NK activity that has been pursued are the use of immunomodulatory drugs such as thalidomide and cytokines such as IL-2, IL-12, IL-15, IL-18, IL-21 and type I IFNs, to stimulate the patients endogenous NK cells. However, toxicity of cytokines in high doses required for effective stimulation of NK cells prohibits then systemic administration. As such, a novel strategy for activating NK cells with better efficacy and less toxicity is warranted, and described within.

Modulating innate immune cell activity by lunasin and selected cytokines

Indiana University Research & Technology Corporation


A method for processing a video stream of digital images includes: receiving the video stream which includes at least one composite frame containing a pair of stereoscopic digital images according to a predetermined packing format; receiving metadata which describes the format of the composite frame; generating an output video stream which can be reproduced on a visualization device, wherein the method further includes the steps of determining the area in the composite frame which is occupied by one image of the stereoscopic pair within the composite frame based on the metadata; extracting the image contained in the area from the composite frame, and generating an output frame containing the extracted image.

1. Field of the Invention
The present invention relates to a method for decoding a stereoscopic digital video stream, i.e. a video stream which, when appropriately processed in a visualization device, produces sequences of images which are perceived as being three-dimensional by a viewer.
This method allows a user of a conventional (i.e. non-stereoscopic) decoder and/or television set to view stereoscopic images in 2D mode, as well as to use a stereoscopic (3D) decoder and/or television set for 2D display.
2. Present State of the Art
In recent years, the cinematographic production world has paid much attention and has devoted huge resources to the production of stereoscopic 3D contents under the stimulus of new production tools made available by the new digital technologies.
The interest in 3D is now extending to domestic use, i.e. for displaying images on a television set. For example, some pay-TV operators will shortly broadcast 3D programs.
The most common approach to presenting stereoscopic video contents involves displaying two independent video streams intended for the right eye and for the left eye, respectively, which are then reassembled by the human brain into a three-dimensional object.
Stereoscopic contents for domestic use are generally high-definition video contents and may be distributed on a mass memory medium (DVD or Blu-ray discs, magneto-optic or solid-state media, etc.) or via (wired or wireless) broadcasting channels or via a telecommunication network (IP).
In the production environment, however, with the existing structures it may be impossible to transfer and handle separately the two streams produced by stereoscopic video cameras shooting a scene from two different points of view.
Moreover, the distribution networks reaching the final user are so big that it is uneconomical to use two independent high-definition streams for providing a single service. As a consequence, a number of measures must be taken during the production process in order to reduce the bit-rate required for content transfer and fruition.
Since the results of studies carried out on the differences in the perception of details in two-dimensional and three-dimensions images seem to indicate that the quality perceived by the user remains acceptable even when the resolution of stereoscopic contents is lowered compared to that of two-dimensional contents, different techniques have been developed for packing the two images composing the stereoscopic view into a single frame (frame packing).
For example, in the case of a single high-definition frame C (1920×1080 pixels), the two images composing the left and right channels (hereafter referred to as L and R) are acquired with a horizontal resolution equal to half the resolution of a high-definition frame and are then arranged side by side into a single frame (side-by-side format), as shown in FIG. 1a.
In this way, it is possible to use a single high-definition stream for transporting the two independent video channels; at decoding time, the two half-frames are then separated and brought back to the 16/9 format by applying suitable interpolation techniques.
Likewise, an alternative process may be used which involves halving the vertical resolution and leaving the horizontal resolution unchanged, and then arranging the two frames L and R one on top of the other (top-bottom format), as shown in FIG. 1b.
The stereoscopic video stream consisting of composite frames is then compressed in order to reduce its transport bit-rate before distributing it on a broadcasting network, an IP network or a mass memory medium.
One of the most important requirements on which the attention of the various service providers (especially public service broadcasters) is focused is the 2D compatibility of the stereoscopic signals.
In fact, in order to allow those users who already own a high-definition decoder to enjoy the broadcast services, it is desirable that 3D programs can also be displayed as 2D programs. Likewise, it is desirable that a 3D content on a DVD, a Blu-ray disc 3D or an Internet site can be displayed by both 2D and 3D television sets and monitors.
This result can be achieved in two ways: either by simultaneously broadcasting both the 2D and 3D versions of one program or by adopting an appropriate technique for coding the stereoscopic stream.
Of course, the first option involves wasting bandwidth, which is one thing that service providers would rather avoid.
As to the second option, several techniques are known in the art for generating 2D compatible stereoscopic streams.
One of these technique relates to the application of so-called "depth maps", as described, for example, in US patent applications no. US 2002/0048395 and no. US 2004/0101043.
In practice, a signal is associated with the two-dimensional colour video in the form of a supplementary black and white video that carries the depth maps. A suitable decoder can rebuild a stereoscopic video starting from the received data. However, this technique suffers from the very same problems of the aforementioned 2D and 3D transmission of the same program: in fact, two video signals must be transferred in parallel, resulting in a high transport bit-rate.
Another 2D-compatible stereoscopic stream coding technique is, for example, the one referred to as "multiview".
Because the pairs of right and left images making up the stereoscopic video stream are characterized by a high degree of resemblance, the space-time redundancy suppression techniques employed when coding two-dimensional streams can be used in this case as well. In fact, once a certain offset due to the geometric distance between the shooting points (i.e. the interocular distance) has been subtracted, the differences between the right image and the left image are small.
The MPEG2 standard has been extended with a supplementary specification called Multi View Profile (MVP); likewise, the subsequent H.264/AVC standard has been extended by including the Multi View Coding (MVC) specification.
A common characteristic of these two specifications is the use of scalable video coding: the stereoscopic video stream is compressed into a base layer (the 2D base stream) plus an enhancement layer, which transports the second view. The syntax of the coded stream ensures that the 2D video can also be decoded by old-generation decoders, so long as they comply with the MPEG2 or H.264/AVC standards.
However, the bit-rate necessary for coding stereoscopic streams into one of the above described formats is still too high to allow it to be used in the broadcasting environment and, as a consequence, frame packing formats remain the only feasible short-term solution for starting up 3D services.

Method for decoding 2D-compatible stereoscopic video flows

S.I.SV.EL SOCIETA' ITALIANA PER LO SVILUPPO DELL'ELETTRONICA S.P.A.


An electrophotographic photosensitive member is disclosed having a first area layer and a second area layer on a substrate. The first area layer and the second area layer are formed by deposition using different methods, and an intermediate layer is provided therebetween. The intermediate layer is changed continuously in composition in such a manner that the composition at the surface in contact with the first area layer is approximately the same as the composition of the first area layer and that the composition at the surface in contact with the second area layer is approximately the same as the composition of the second area layer, whereby the various characteristics of the electrophotographic photosensitive member is prevented from deteriorating.

1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member and a producing method therefor.
2. Related Background Art
As one of members employed in an electrophotographic photosensitive member, a non-single crystalline deposition film containing silicon atoms as a principal component, for example a deposition film of an amorphous silicon (hereinafter represented as a-Si) compensated with hydrogen and/or halogen, is proposed as a photosensitive member having high performance, high durability and pollution-free properties, and some of such members are already in practical use.
Such a-Si electrophotographic photosensitive members are proposed having various layered structures for meeting requirements for various properties, and in particular a surface layer is recognized as an important layer for realizing various properties of the electrophotographic photosensitive members, such as abrasion resistance, charge holding properties, environmental resistance, light-transmitting properties and the like.
As a shorter wavelength is contemplated for image exposure for achieving a higher definition in a copying apparatus, the surface layer is particularly required to have characteristics of a wide band gap which can transmit short-wavelength light with less absorption.
As materials capable of satisfying such characteristics, for example, a metal fluoride and a silicon nitride may be cited.
As an electrophotographic photosensitive member utilizing such a material, a structure is disclosed utilizing magnesium fluoride in the surface layer (for example cf. Japanese Patent Application Laid-open No. 2003-29437).
Japanese Patent Application Laid-open No. 2003-29437 discloses that magnesium fluoride employed as the surface layer provides excellent properties such as inhibition of image blur or image deletion, and potential variation due to abrasion.
Thus, not only magnesium fluoride but also metal fluorides in general are expected to provide properties preferred as the material of the surface layer of the electrophotographic photosensitive member owing to hardness, light-transmitting properties and low surface energy.
On the other hand, from the standpoint of a process for forming a deposition film, a plasma CVD process is preferable for forming a photoconductive layer or the like because a relatively large film thickness is required and also because a raw material gas is easily available, but a raw material for the surface layer, usable in the plasma CVD process, is not necessarily easily available. For example, in a metal material usable as a raw material for a metal fluoride, raw material atoms are difficult to supply from a gaseous substance, so that a PVD process, typified by sputtering, is suitable for forming the surface layer.
Therefore, the afore-mentioned patent literature discloses an example of forming an electrophotographic photosensitive member constituted of a lower blocking layer, a photoconductive layer, a buffer layer and a surface layer, by utilizing a plasma CVD process for the lower blocking layer, the photoconductive layer and the buffer layer and a sputtering for the surface layer.
It is thus rendered possible, by employing an optimum forming process for each layer, to obtain a practical electrophotographic photosensitive member capable of improving electrical and optical characteristics, resistance to environmental conditions and durability, and further to achieve a higher definition of images.

Electrophotographic photosensitive member and producing method therefore


An alarm clock has a housing provided with a control door having a permanent magnet and an actuating rod capable of pushing a conductive elastic piece located in the housing. The conductive elastic piece is capable of actuating a magnetic sensor which is located in the housing and is composed of an electromagnet and a relay capable of altering the polarity of the electromagnet to attract the permanent magnet of the control door. The magnetic sensor is actuated by the control circuit of the alarm clock at a desired time set to buzz such that the polarity of the electromagnet is changed by the relay, and that the control door is thus repelled to remain open.

The effect of the conventional alarm clock is generally attained by mechanical method consisting of a spring and a hammer, or an electronic method consisting of a quartz oscillator. The housing of the conventional alarm clock is provided with a press device for controlling or stopping the buzzing or the ringing of the alarm clock. Such a conventional alarm clock, either mechanical alarm clock or electronic alarm clock, as described above is not dynamically attractive to the sophisticated consumers.

Device to trigger buzzing of alarm clock


Described herein is a modified EGII cellulase having the amino acid sequence shown in SEQ ID NO:1, compositions comprising the modified EGII and methods of use.

Cellulases or cellulytic enzymes are enzymes involved in hydrolyses of cellulose. In the hydrolysis of native cellulose, it is known that there are three major types of cellulase enzymes involved, namely cellobiohydrolase (1,4-β-D-glucan cellobiohydrolase, EC 188.8.131.52), endo-β-1,4-glucanase (endo-1,4-β-D-glucan β-glucanohydrolase, EC 184.108.40.206) and β-glucosidase (EC 22.214.171.124).
Cellulases are synthesized by a large number of microorganisms which include fungi, actinomycetes, myxobacteria and true bacteria but also by plants. Especially endoglucanases of a wide variety of specificities have been identified.
A very important industrial use of cellulytic enzymes is the use for treatment of cellulosic textile or fabric, e.g. as ingredients in detergent compositions or fabric softener compositions, for bio-polishing of new fabric (garment finishing), and for obtaining a "stone-washed" look of cellulose-containing fabric, especially denim, and several methods for such treatment have been suggested.
An object of the present invention is to provide novel enzyme preparations having substantial cellulytic activity at acid or neutral conditions and improved performance in paper pulp processing, textile treatment, laundry processes or in animal feed; preferably novel cellulases, more preferably well-performing endoglucanases, which are contemplated to be producible or produced by recombinant techniques.
Most newly manufactured cotton fabrics and cotton blend fabrics have a handle that is rather hard and stiff unless they are treated with finishing components. Furthermore, the fabric surface is not always smooth due to small fuzzy fibers protruding from the individual cotton fibers. In addition, after a relatively short period of wear, collections of lint appear on the surface (surface linting) giving the appearance of "pills" on the surface which causes the fabric to have an unappealing, worn look. In polyester fabrics, this phenomena is actually "pilling" and provides a similar unappealing fabric appearance. The term "pilling" will also apply to cellulosic fabrics in the instant application.
Thus, a useful feature of cellulases in the treatment of textiles is their ability to recondition used fabrics by making their colors more vibrant. For example, repeated washing of cotton containing fabrics results in a greyish cast to the fabric which is believed to be due to disrupted and disordered fibrils, sometimes called "pills", caused by mechanical action. This greyish cast is particularly noticeable on colored fabrics. As a consequence, the ability of cellulase to remove the disordered top layer of the fiber and thus improve the overall appearance of the fabric has been of value.
Cellulase treatment of the fabric surface improves fabric quality with respect to handle and appearance without loss of fabric wettability. The most important effects are less fuzz and pilling, increased gloss/luster, improved fabric handle, increased durable softness and improved water absorbency. These effects are referred to as biopolishing effects.
Despite knowledge in the art related to many cellulase compositions, there is a continued need for new cellulases having a varying spectrum of characteristics which are useful in, for example, treating textiles, as a component of detergent compositions, in the treatment of pulp and paper, and in the conversion of biomass.
The cellulase compositions described herein provide improved performance characteristics, especially in textile processing.

Modified endoglucanase II and methods of use


An optical fiber mounting method that mounts a plurality of optical fibers on a substrate includes: bundling the optical fibers together with a bundling member; adjusting a height of the bundling member from a surface of the substrate or an angle of inclination of the bundling member relative to the surface of the substrate; bringing end faces of the optical fibers bundled with the bundling member into contact with end faces of optical waveguides on the substrate, the optical waveguides respectively corresponding to the optical fibers; and bonding the optical fibers to the substrate, in a state where the end faces of the optical fibers are in contact with the end faces of the optical waveguides.

In recent years, optical integration technology called silicon photonics may be used for optical modules, for example, optical modulators. In silicon photonics, ultra-micro photonic chips having highly integrated optical control functions are able to be manufactured by use of, for example, complementary metal oxide semiconductor (CMOS) processes.
An optical waveguide that transmits an optical signal is formed on such a photonic chip. An optical signal that has been generated from a light source, for example, a laser diode, and has been optically modulated passes through the optical waveguide and is output to an optical fiber connected to the photonic chip. At a connecting portion between the optical waveguide and optical fiber, a groove for positioning of the optical fiber has been formed on the photonic chip, for example, and an end face of the optical fiber guided through the groove is butted against an end face of the optical waveguide. That is, the optical waveguide and the optical fiber are directly connected to each other on the photonic chip.
The groove for the positioning of the optical fiber is able to be formed by a wafer process and is thus small in positional error and also small in manufacture variation. Furthermore, this structure for the direct connection between the optical waveguide and the optical fiber enables more accurate positioning of the optical fiber than a structure in which a ferrule fixed with an adhesive onto a photonic chip holds an optical fiber because the structure for the direct connection is without displacement of the ferrule due to curing of the adhesive.    Patent Literature 1: Japanese Laid-open Patent Publication No. 09-178971    Patent Literature 2: Japanese Laid-open Patent Publication No. 08-248254
The number of optical waveguides formed on a photonic chip is not necessarily one, and plural optical waveguides may be formed on a photonic chip. Different optical fibers are then respectively connected to the plural optical waveguides. The plural optical fibers are formed into an optical fiber bundle by being bundled together, and this optical fiber bundle is connected to the photonic chip.
However, lengths of the optical fibers forming the optical fiber bundle are not necessarily the same, and positions of end faces of the optical fibers may vary. Therefore, for the end faces of all of the optical fibers to be brought into contact with end faces of the optical waveguides, an end face of a short optical fiber is brought into contact with an end face of an optical waveguide by bending of a long optical fiber. There is a problem that the long optical fiber is bent by being pushed to the end face of the optical waveguide in a state where the long optical fiber's end face has been butted against the end face of the optical waveguide, and the end faces of the optical fiber and optical waveguide are thereby pressed and the optical fiber or optical waveguide may be thereby damaged.

Optical fiber mounting method and optical module


The present invention relates to a security device comprising a colloidal crystal which exhibits excellent visibility and is also easily manufactured. The security device, according to the present invention, comprises: a substrate; a groove part formed on the substrate; a colloidal crystal positioned in the groove part; and an aging film. The security device, according to the present invention, exhibits excellent security and visibility, and thus may be used for securities, credit cards, security cards, anti-forgery products, etc.

A colloid refers to particles homogeneously dispersed in a particular solvent, and a colloidal crystal refers to a matter in which a matrix and monodisperse particles having different refractive indices are regularly arranged by self-assembly or the like to form a crystal lattice and which exhibits unique optical characteristics depending on geometric properties of unit particles.
A colloidal crystal is manufactured by a gravity precipitation method using precipitation, a two-dimensional monolayer manufacturing method in which a two-dimensional crystal monolayer is formed by evaporation, a three-dimensional self-assembly method in which a regular arrangement among particles is created by controlling colloidal conditions, an induction assembly method in which a three-dimensional structure is made by moving and arranging particles through external force, such as static electricity or magnetic force, and the like.
Regular arrangement of colloidal particles exhibit reflection colors by the same principle and the reflection colors correspond to optical band gaps of colloidal crystals. The reflection colors of colloidal crystals are determined by refractive indices of colloidal and matrix materials, a crystal structure, a particle size, a space between particles, or the like. Therefore, such factors can be controlled to manufacture colloidal crystals having desired reflection colors.
Meanwhile, an attempt has been made to form a thin colloidal crystal to lead to a film form, but adhering a colloidal crystal to a substrate was difficult, and various attempts have been made to form a colloidal crystal on a substrate, but the time for self-assembly was taken long and the colloidal crystal was not uniformly formed.
The induction assembly method has an advantage in that the time for colloidal crystallization can be shortened compared with the self-assembly method, but has problems in that processes and manufacturing apparatuses were complicated and the types of colloidal particle materials were severely constrained.
Moreover, colloidal crystals had limitations in application to products, such as bills and security documents, which require flexibility since the colloidal crystals are difficult to transform.
Therefore, there is a need to develop a film containing a colloidal crystal, for which the manufacturing method is simple compared with conventional methods and which facilitates repetitive production.

Security device using light reflection property

KOREA MINTING, SECURITY PRINTING & ID CARD OPERATING CORP.


In a method of calculating irregularities of a hole, a center coordinate of an actual hole is set. Inner wall coordinates of the actual hole are obtained from the center coordinate of the actual hole. An area of the actual hole is determined based on the inner wall coordinates of the actual hole. A radius of a virtual hole is determined based on the area of the actual hole. A center coordinate of the virtual hole is determined based on the inner wall coordinates of the actual hole to obtain a circumference line of the virtual hole. A standard deviation of the inner wall coordinates of the actual hole relative to the circumference line of the virtual hole is calculated, thereby obtaining the irregularities of the actual hole.

1. Field of the Invention
The present invention relates to a method of determining the irregularities of a hole, for example, a hole in a semiconductor device. More particularly, the present invention relates to a method of determining the irregularities of a hole, for example, a contact hole or a via hole, used for providing electrical connection between layers of a semiconductor device.
2. Description of the Related Arts
Generally, a semiconductor device includes an impurity region of a transistor and a metal layer of a capacitor. An insulation layer is interposed between the impurity region and the metal layer to provide insulation therebetween. To electrically connect the impurity region with the metal layer, or the metal layers with each other, a contact hole or a via hole is formed through the insulation layer. The contact hole or the via hole is filled with a conductive material to electrically connect the impurity region with the metal layer, or the metal layers with each other.
The contact hole and the via hole generally have a cylindrical shape. Thus, the contact hole and the via hole have a circular cross-sectional shape. The size of the contact hole or the via hole is determined in accordance with the design rule of the semiconductor device. As the semiconductor device has been highly integrated, the size of the contact hole or the via hole have become small. This causes difficulty in accurately forming the contact hole or the via hole according to a designed dimension. As a result, it is required to determine whether the size of the contact hole or the via hole is within the design dimension. Accordingly, a process for determining the contact hole or the via hole having an accurately circular shape is needed in semiconductor fabrication processes.
In one conventional method of inspecting the failure of a contact hole, a reference image is set in the inspection equipment. The reference image is compared to an image of the contact hole.
In another conventional method, the inspection region having a contact hole is magnified. An inspection point is set in various directions in the inspection region. The contact hole is inspected based on the inspection point.
In still another conventional method, a scanning electron microscope (SEM) provides image data with respect to a region having a contact hole are read. The image data with respect to a feature of the contact hole are identified. A first parameter related to the image data is computed. The first parameter is compared with predetermined values. The particular feature of the contact hole is then classified in accordance with the comparison result.
However, since the failure of the contact hole is determined using the reference image, the determined result varies according to the reference image employed. When the reference image does not have a precise shape, reliability of determining the accuracy of the contact hole may be reduced. In particular, the reference image is greatly influenced by a striation of a pattern formed on a wafer and the size of the pattern, thereby further reducing the reliability of accurately determining the failure of the contact hole.

Method of determining the irregularities of a hole