An ID-based encryption and signature technique, according to which more efficient and higher speed processing is possible. In generation of public parameters, an element P of a group G1 of order q is selected, and then, g=e(P, P) calculated in advance is added to the public parameters. At the time of encryption and verification, a public key ID is associated with an element PID of the group G1, using uεZq* and two elements P1 and P2 (included in the public parameters) of G1 and calculating PID=P1+uP2. The above-mentioned elements P1 and P2 are determined by P1=s1P and P2=s2P using random numbers s1, s2εZq* as a part of a master key, and a private key of a user is determined by dID=(s1+us2)−1P.

The present invention relates to a cryptographic technique as an information security technique, and in particular, to ID-based encryption and signature technique that can use any character string as a public key.
ID-based encryption, digital signature and Signcryption systems can use any character string as a public key. Signcryption performs encryption and signing (authentication) at the same time. These are realized using a property (called pairing) of a bilinear mapping (See, for example, Identity based encryption from the Weil pairing, by D. Boneh and M. Franklin, SIAM J. of Computing, Vol. 32, No. 3, pp. 586-615, 2003, Extended abstract in proceedings of Crypto '2001, Lecture Notes in Computer Science, Vol. 2139, Springer-Verlag, pp. 213-229, 2001, Full paper: PDF. (http://crypto.stanford.edu/˜dabo/pubs.html) (hereinafter, referred to as Non-patent Document 1), F. Hess, Efficient Identity based Signature Schemes based on Pairings, In K. Nyberg and H. Heys, editors, Proceedings of SAC 2002, LNCS 2595, pp. 310-324, St. Johns, Newfoundl and, 2003. (http://www.math.tu-berlin.de/˜hess/) (hereinafter, referred to as Non-patent Document 2) and Liqun Chen and John Malone-Lee, Improved Identity-Based Signcryption (http://eprint.iacr.org/2004/114/) (hereinafter, referred to as Non-patent Document 3).
Assuming two groups G1 and G2 of order q, pairing means a mapping bilinear e from G1×G1 to G2 that satisfies the following properties:
1. For any P, QεG1, e satisfies e(aP, bQ)=e(P, Q)ab.
2. For any P, QεG1×G1, e satisfies e(P, Q)≠the identity in G2.
For any P, QεG1, there is known an efficient algorithm for calculating e(P, Q). As specific pairing, Weil pairing and Tate pairing defined on an elliptic curve on a finite field are known.
In the following, will be described encryption, digital signature and Signcryption using an ID-based system, i.e., an ID-based public key encryption system, an ID-based digital signature system, and the ID-based Signcryption.
First, will be described an ID-based public key encryption system disclosed in Non-patent Document 1.
A system that realizes the ID-based public key encryption system comprises a private key generation center instead of a certification authority that authenticates a public key. The private key generation center determines public parameters that are used in common in the system. And, for any ID (for example, an E-mail address) that each user selects as a public key, the private key generation center generates a private key for that public key, using a master key that the private key generation center keeps under strict surveillance so that the master key should not be leaked out, and delivers the generated private key to the user concerned. The private key generation center administers the ID (public key) selected by a user and the generated private key, associating the ID with the private key. A method of selecting a public key has been determined as rules in the system.
The ID-based public key encryption system comprises the following four processes. The processes (1) and (2) are performed in the private key generation center, the process (3) on the sender's side, and the process (4) on the receiver's side.
(1) Setup: Public parameters including groups and pairing used commonly in the system are generated. Further, a master key is generated. The public parameters are opened to the public. To ensure security of the entire system, the master key is kept under strict surveillance so that the master key should not be leaked to the outside including users of the system.(2) Extract: For each user, a private key of that user is generated applying the master key to a character string that can be associated with the user (such as an E-mail address of the user). On the other hand, the character string becomes a public key of the user.(3) Encrypt: Using the public parameters and a public key of a sending destination, encryption object data are encrypted.(4) Decrypt: Using the public parameters and a private key of the recipient, the encrypted data are decrypted.
Next, will be described input, output and processing in each of the above processes (1)-(4).
In the following, Z+ means a set of the positive integers, Zq a set of positive integers less than q, and Zq* a set of positive integers less than q, which is relatively prime with Zq. Further, {0, 1}* means all the binary sequences. An expression XOR means exclusive disjunction (exclusive-OR). Further, ∥ means join. In the drawings, exclusive-OR is indicated by a circle cross symbol.
(1) Setup:
Input: security parameter kεZ+
Output: the public parameters params and the master key s
Procedure:
1. Generation of a k bit prime number q
2. Selection of a group G1 of order q
3. Selection of a group G2 of order q
4. Selection of a pairing e: G1×G1→G2
5. Selection of a generator P of G1
6. Random selection of an element s of Zq* (sεZq*), to define Ppub=sP
7. Selection of a hash function H1: {0, 1}*→G1*
8. Selection of a hash function H2: G2→{0, 1}n for some integer n
9. Output of the public parameters params=<q, G1, G2, e, n, P, Ppub, H1, H2>
10. Output of the master key s
(2) Extract:
Input: the public parameters params, the master key s, and any character string ID used as a public key
Output: a private key dID corresponding to ID
Procedure:
1. Calculation of the hash function QID=H1(ID) of ID, for the given ID (IDε{0, 1}*) included in the set of all the binary sequences
2. Calculation of the private key dID corresponding to ID, using the master key s and the hash value of ID (calculation of dID=sQID)
3. Output of the private key dID
(3) Encrypt:
Input: encryption object data M, the public parameters params and the public key ID
Output: encrypted data C=(C1, C2)
Procedure:
1. Calculation of QID=H1(ID)εG1*
2. Random selection of rεZq*
3. Calculation of C1=rP
4. Calculation of gID=e(QID, Ppub)
5. Calculation of h=H2(gIDr)
6. Calculation of C2=M XOR h
7. Output of encrypted data (C1, C2)
(4) Decrypt:
Input: the encrypted data (C1, C2), the public parameters params and the private key dID
Output: decrypted data M
Procedure:
1. Calculation of g=e(dID, C1)
2. Calculation of h=H2(g)
3. Calculation of M=C2 XOR h
4. Output of decrypted data M
Next, will be described an ID-based digital signature system disclosed in Non-patent Document 2.
Fundamentally, the system for realizing an ID-based digital signature is similar to the above-described ID-based public key encryption system. For any character string ID (for example, an E-mail address) that each user selects as a public key, a private key generation center generates a secret key corresponding to that public key and delivers the generated private key to the user concerned. A user on the sender side uses his private key to make his signature. Receiving a massage added with the signature, a user on the receiver side verifies the signature using the public key.
The ID-based digital signature system comprises the following four processes. The processes (1) and (2) are performed in the key generation center, the process (3) on the sender's side, and the process (4) on the receiver's side.
(1) Setup: Public parameters including groups and pairing used commonly in the system are generated. Further, a master key is generated. The public parameters are opened to the public. To ensure security of the entire system, the master key is kept under strict surveillance so that the master key should not be leaked to the outside including users of the system.(2) Extract: For each user, a private key of that user is generated applying the master key to a character string that can be associated with the user (such as an E-mail address of the user). On the other hand, the character string becomes a public key of that user.(3) Sign: Using the public parameters and a private key of a signer, his signature is generated.(4) Verify: Signature verification is performed using the public parameters and a public key of the sender.
Next, will be described input, output and processing specifications in each of the above processes (1)-(4).
(1) Setup:
Input: security parameter kεZ+
Output: the public parameters params and the master key s
Procedure:
1. Generation of a k bit prime number q
2. Selection of a group G1 of order q
3. Selection of a group G2 of order q
4. Selection of a pairing e: G1×G1→G2
5. Selection of a generator P of G1
6. Random selection of sεZq, to define Ppub=sP
7. Selection of a hash function H1: {0, 1}*→G1*
8. Selection of a hash function H2: {0, 1}*→Zq
9. Output of the public parameters params=<q, G1, G2, e, P, Ppub, H1, H2>
10. Output of the master key s
(2) Extract:
Input: the public parameters params, the master key s, any character string ID used as a public key
Output: a private key dID corresponding to ID
Procedure:
1. Calculation of QID=H1(ID)
2. Calculation of dID=sQID
3. Output of the private key dID
(3) Sign:
Input: signature object data M, the public parameters params and the private key dID of the signer
Output: a signature (u, v)
Procedure:
1. Random selection of kεZq*
2. Random selection of P1εG1*
3. Calculation of r=e(P1, P)k
4. Calculation of v=H2(M, r)
5. Calculation of u=vdID+kP1
6. Output of the signature (u, v)
(4) Verify:
Input: the signature (u, v), the signature object data M, the public parameter params and the public key ID of the signer
Output: accept or reject
Procedure:
1. Calculation of QID=H1(ID)εG1*
2. Calculation of r=e(u, P)×e(QID, −Ppub)
3. Output of accept if v=H2(M, r) is satisfied, or reject if not
Next, will be described ID-based Signcryption disclosed in Non-patent Document 3. Fundamentally, the system for realizing the ID-based Signcryption is similar to the above-described ID-based public key encryption system and the ID-based digital signature system.
The ID-based Signcryption comprises the following six processes. The processes (1) and (2) are performed in a private key generation center, the processes (3) and (4) on the sender's side, and the processes (5) and (6) on the receiver's side.
(1) Setup: Public parameters including groups and pairing used commonly in the system are generated. Further, a master key is generated. The public parameters are opened to the public. To ensure security of the entire system, the master key is kept under strict surveillance so that the master key should not be leaked to the outside including users of the system.(2) Extract: A private key of a user is generated applying the master key to a character string that can be associated with that user (such as an E-mail address of the user). The character string becomes a public key of that user.(3) Sign: Using the public parameters and a private key of a signer, his signature is generated.(4) Encrypt: Using the public parameters and a public key of a sending destination, encryption object data added with the signature are encrypted. Or, the signature is added to encrypted data.(5) Decrypt: Using the public parameters and a private key of the recipient, the encrypted data are decrypted and the signature is extracted. Or, after extraction of the signature, the encrypted data are decrypted.(6) Verify: Using the public parameters and the public key of the sender, the signature is verified.
Next, will be described input, output and processing specifications in each of the above processes (1)-(6).
(1) Setup: Generation of the Public Parameters and the Master Key
Input: security parameter kεZ+
Output: the public parameters params and the master key s
Procedure:
1. Generation of a k bit prime number q
2. Selection of a group G1 of order q
3. Selection of a group G2 of order q
4. Selection of a pairing e: G1×G1→G2
5. Selection of a generator P of G1
6. Random selection of sεZq*, to define Ppub=sP
7. Selection of a hash function H0: {0, 1}*→G1*
8. Selection of a hash function H1: {0, 1}*→Zq*
9. Selection of a hash function H2: G2→{0, 1}*
10. Output of the public parameters params=<q, G1, G2, e, P, Ppub, H0, H1, H2>
11. Output of the master key s
(2) Extract:
Input: the public parameters params, the master key s, and any character string ID used as a public key
Output: a private key dID corresponding to ID
Procedure
1. Calculation of QID=H0(ID)εG1*
2. Calculation and output of the secret key dID=sQID
(3) Sign and (4) Encrypt (Signature Generation and Encryption)
Input: signature object data M, the public parameters params and a private key dID of a signer
Output: a signature (u, v)
Sign Procedure:
1. Calculation of QA=H0(IDA)
2. Random selection of rεZq*
3. Calculation of X=rQA
4. Calculation of h=H1(M∥X), where M is the data as the object of signature and encryption
5. Calculation of Z=(r+h)dIDA
6. Sending of the signature (X, Z) together with (M, r, IDA,dIDA) to Encrypt
Encrypt Procedure:
1. Calculation of QB=H0(IDB)εG1*
2. Calculation of w=e(rdIDA, QB)
3. Calculation of Y=H2(w) XOR (Z∥IDA∥M)
4. Output of C=(X, Y) as cipher text added with the signature
(5) Decrypt and (6). Verify (Decryption+Signature Verification)
Input: the cipher text with the signature (X, Y), the public parameters params, and the public key ID of the signer
Output: accept or reject
Decrypt Procedure:
1. Calculation of w=e(X, dIDB)
2. Calculation of Z∥IDA∥M=H2(w) XOR Y
3. Sending of (IDA, M) and (X, Z) to Verify
Verify Procedure:
4. Calculation of QA=H0(IDA)
5. Calculation of h=H1(M∥X)
6. Verification of e(Z, P)=e(Ppub, hQA), and output of accept if e(Z, P)=e(Ppub, hQA) is satisfied, or reject if not

ID-based signature, encryption system and encryption method


A circuit for correcting perturbations in a power system signal operating at a system line frequency includes a capacitor for drawing a capacitive current and a first inductor for drawing an inductive current substantially equal in amplitude and substantially one hundred eighty degrees out of phase with the capacitive current. The first inductor is connected in parallel with the capacitor to form a storage module for storing energy therein wherein the storage module is tuned to resonate at the system line frequency and wherein the storage module is connected in parallel across the load. A second inductor connected in series between a power source and the load isolates the power source from the load.

There is an increasing population of electrical and electronic equipment utilizing alternating current line rectifiers, especially office computers, motor speed controllers and other equipment which draw nonlinear currents. A concern in the power engineering industry focuses on the disruptive harmonic effects of voltage transients and spikes caused by those electronic or nonlinear loads. Many times, the equipment which is causing those harmonics is, at the same time, sensitive to those harmonics that similar devices are creating. In addition to the harmonics damaging the device producing them, those harmonics may also adversely affect other pieces of electrical equipment connected to the power line and may even damage the power generation and distribution system itself.
Nonlinear loads may affect two types of power systems: single-phase, most common in office settings, and three-phase, most common in industrial applications. Harmonic induced problems frequently manifest themselves in improper operation, malfunction, shutdown of the equipment, or premature equipment failures. In three-phase, four wire systems, some harmonic currents, for example, the third harmonic, do not null at the neutral conductor, but rather sum, which may cause over-loading of that neutral conductor. The inherent danger in such overloading is the risk of damage or fire, as there is no circuit breaker on the neutral to limit the current flow.
Known techniques to improve the quality of the power system voltage waveforms are largely ineffective in correcting that problem. One common way to address the harmonics problem is to attempt to restrict harmonic currents by use of passive filters or harmonic traps. Those filters are tuned to a specific frequency, normally the highest amplitude harmonic. Filters operate by "notching out" portions of the disturbance. Such filters may absorb some of the harmonic energy, however, the dissipated energy is wasted as nonproductive heat loss. Further, such absorption is limited to a specific frequency and thus, voltage spikes or dips which occur at frequencies other than the specific frequency of the filter are not corrected nor are they correctable without the addition of an additional filter.
Generic "line clipping devices" do not restore minor voltage dips or harmonic distortion and can not clamp or reduce any electrical disturbances that occur below the peak amplitude of the sine wave. With respect to three-phase systems, to upgrade the present electrical distribution system to reduce the effective power source impedance by substituting larger neutral and phase conductors is both costly and often an impractical solution.
In view thereof, it is an object of the present invention to substantially reduce or eliminate the harmonic effects which nonlinear loads and switched power loads may create on a power distribution system, thereby permitting the distribution system to provide clean, quality power to other sensitive equipment. It is a further object of the invention to provide a local, low impedance alternating current source of quality power to satisfy the requirements of sensitive load equipment which may be connected to its output. It is a feature of the present invention to provide stored energy in a parallel resonant circuit to smooth the effects which nth-order harmonics and voltage spikes or dips may have on that power distribution system. It is a further feature of the present invention to provide an in-line inductance to further isolate the power source from the effects of non-linear loading. It is an advantage of the present invention that when harmonics and/or transient voltage disturbances do occur on the power line, the effects of such disturbances will not impact the equipment attached thereto as the power line waveform will be instantaneously smoothed. A further advantage of the present invention is that a device embodying the present invention may be advantageously applied to any type of sinusoidal, fixed frequency, alternating current power system.

A.C. storage module for reducing harmonic distortion in an A.C. waveform


A compressor unit includes a compressor, an inverter for driving the compressor, and an over-current protective device for protecting the inverter against an output over-current. A control part controls the output voltage of the inverter when the compressor is started based on a ambient temperature detected by a temperature sensor so that the input current of the inverter does not exceed the working current value of the over-current protective device having temperature characteristics varying according to the ambient temperature. Thereby, a start torque can be increased by increasing the output voltage of the inverter without operating the over-current protective device when the compressor is stated at a low temperature when a start load is increased.

Conventionally, there has been a compressor unit that has been used in a refrigerator having refrigerant circuits. The compressor unit has a compressor, an inverter for driving the compressor, and an over-current protective device for protecting the inverter against an output over-current. When the compressor is started, an inverter output voltage is set according to a working current value of the over-current protective device. That is, the inverter output voltage is set so that an inverter output current does not exceed the working current value of the over-current protective device and so that a maximum starting torque is gained. The over-current protective device, however, has characteristics in which a high ambient temperature decreases the working current value and in which a low ambient temperature increases the working current value, as shown in FIG. 6. When the compressor is started at a low ambient temperature, accordingly, a problem is caused in that the inverter output voltage cannot be increased though there is room for increase in the inverter output voltage resulting in increase in starting torque. When the compressor is started at a low temperature, in particular, a load is increased by increase in viscosity of oil in the compressor, accumulation of liquid refrigerant or the like. In such a case, therefore, the larger the driving torque is, the better.

Compressor unit and refrigerator using the unit


A test system (100) for testing electronic devices includes a conveyor (130) to convey the electronic devices, a test fixture (112) to test the electronic devices, and a robot apparatus (102). The robot apparatus (102) has a robot arm (118) positionable within an accessible region (216) to deliver electronic devices from the conveyor (130) to the test fixture (112) via an arcuate path.

For quality control purposes, most manufacturers test the operability of electronic devices they build. In order to remain competitive in the industry, manufacturers must test the electronic devices at a high speed. High speed testing of electronic devices is achieved, at least in part, through automation.
One known automated test system employs a single conveyor for serially transporting electronic devices in pallets to individual test stations positioned alongside the conveyor. Each of the test stations is equipped with a lift and load apparatus for lifting a pallet containing an untested electronic device off of the conveyor and loading the pallet into a test fixture of the test station, and for unloading the pallet from the test fixture after testing of the electronic device and lowering the pallet back onto the conveyor. Unfortunately, the test system has drawbacks. To completely test an electronic device, the electronic device must travel a length of the conveyor dictated by the size and spacing of all of the test stations. Also, the pallets are custom fitted to the dimensions of the electronic devices and must be retrofitted or replaced in order to test differently dimensioned electronic devices. Furthermore, equipping each test station with a lift and load apparatuses results in increased maintenance and increased opportunity for down time.
Therefore what is needed is an improved automated test system that maximizes throughput, increases flexibility in testing differently-sized electronic devices, and minimizes maintenance and downtime.

Test system with robot arm for delivering a device under test


Chlorobenzene derivatives which have the following four-ring structure and are preferably usable for display devices of active matrix mode, and liquid crystal compositions comprising the derivative are provided: ##STR1## wherein ring A, ring B, and ring C independently represent trans-1,4-cyclohexylene group or 1,4-phenylene group, one or more hydrogen atoms on the six-membered ring of which may be replaced by halogen atoms, Z.sub.1, Z.sub.2, and Z.sub.3 represent --CH.sub.2 CH.sub.2 -- or single bond, respectively, provided that at least one of them represents --CH.sub.2 CH.sub.2 --, L.sub.1 and L.sub.2 represent H or halogen atom, and R represents an alkyl group or alkoxy group having 1 to 10 carbon atoms, provided that when Z.sub.1 and Z.sub.3 represent single bond and Z.sub.2 represents --CH.sub.2 CH.sub.2 --, ring A represents 1,4-phenylene group, and when Z.sub.1 and Z.sub.2 represent single bond, and Z.sub.3 represents --CH.sub.2 CH.sub.2 --, in no case does ring A represents trans-1,4-cyclohexylene group and both ring B and ring C represent 1,4-phenylene group at the same time.

Display devices which have employed a liquid crystal composition have widely been used for watches, desktop calculators, and others. These liquid crystal display devices employ the optical anisotropy and dielectric anisotropy of liquid crystal substances. Liquid crystal phase includes a nematic liquid crystal phase, smectic liquid crystal phase, and cholesteric liquid crystal phase. Among the display devices, ones which have employed a nematic liquid crystal phase have most widely been used practically. Mode of liquid crystal display device includes a TN (twisted nematic) mode, DS (dynamic scattering) mode, guest-host mode, and DAP (Deformation of Aligned Phases) mode corresponding to electro-optic effect employed therein. Liquid crystalline compounds used in the display devices of those modes desirably exhibit a liquid crystal phase in a temperature range as wide as possible and are required to be stable against moisture, heat, and air. Particularly, demand for display devices of active matrix mode typified by Thin Film Transistor (TFT) mode has recently been increased. When liquid crystal panels are optically designed, the product .DELTA.n.multidot.d of the thickness of the cell of a display device (d) and the value of optical anisotropy (.DELTA.n) must be adjusted to a certain value. At that time, since d tends to decrease partly due to the progress in the reduction of cell thickness in TFT mode, liquid crystalline compounds having a large .DELTA.n became necessary. Liquid crystalline compounds are also required to exhibit a liquid crystal phase in a wide temperature range and to have a miscibility with other liquid crystalline compounds as high as possible especially at low temperatures. Whereas many liquid crystalline compounds have already been known, there exists no substance at present which satisfies the conditions mentioned above by a single liquid crystalline compound, and thus several kinds of liquid crystalline compounds and further non-liquid crystalline compounds are mixed together and actually provided for practical uses at present.
Liquid crystalline compounds having chlorine atom as substituent for the purpose of improving characteristics of liquid crystal are known, for example, as follows: ##STR2##
Among these, compound 1) is not good in miscibility with known liquid crystalline compounds at low temperatures, and compounds 2), 3), and 4) are small in optical anisotropy. Whereas compounds 5) and 6) exhibit a liquid crystal phase at a comparatively wide temperature range, they are not good in miscibility with known liquid crystalline compounds at low temperatures as in the case of compound 1). Accordingly, these compounds are not satisfactory as liquid crystal material used for TFT mode.

Chlorobenzene derivative and liquid crystal composition containing the same


A dispersion or solution of a fluorescent dye material which emits radiation for detection by automated guidance vehicles (AGV) including a sulfonated fluorescent dye solution in its acid state. The unique product forms a guidepath on a carpet which requires little or no maintenance. The product will cause no carpet discoloration or will it be affected by extended exposure to sunlight.

A wide variety of automated guidance vehicles (AGV) have been developed, for use in an office or industrial environment to perform delivery or work operations. The AGV's track a luminescent guidepath. The guidepath luminesces with a green to yellow color when stimulated with an ultraviolet light incorporated in an AGV's sensor head.
Early versions of the guidepath used on a carpet were made from a fluorescent dye such as benzothiazole derivatives which were dissolved in a non-acidic toluene/methanol solution. This solution worked for light colored carpets such as tan or grey. However, the dye was removed by strong carpet cleaning detergents, and was destroyed by exposure to ultraviolet rays in sunlight.
A second type of carpet guidepath was developed which used toluene as a primary solvent, and again a non-acidic luminescent dye compound such as a benzothiazole derivative, which was not destroyed by sunlight. An acrylic polymer was incorporated into the guidepath formula to bind the dye to the carpet fibers. This guidepath wore away over a few months on most carpets and after repeated applications the material left an unsightly dark line on the surface of the carpet.
A third type of carpet guidepath material was disclosed in U.S. Pat. No. 4,707,297. The neutral to basic material included a fluorescent dye or pigment dispersed in water combined with an acrylic resin crosslinked with zinc or zirconium ions. The guidepath was not visible on carpet and was removable with solutions like ammonia in water. A carpet guidepath made by this method wears away over a three to six month period. This guidepath will also be removed by cleaning with alkaline carpet shampoos.
Alternative systems have been utilized wherein magnetic tapes are being installed beneath the carpet. These systems require no maintenance for the guidepath, however they must be installed before the carpet is put down.
Various other neutral to basic water soluble dyes such as benzothiazole derivatives like sodium 3-(2-benzothiazolyl)-4-hydroxybenzene-sulfonate have been produced and used for guidepaths. The fluorescent emission of these dyes was shifted from green to blue when exposed to these alkaline cleaning materials commonly used in carpet maintenance. The material was also susceptible to discoloration and loss of brightness when exposed to ultraviolet light. Further, the guidepath material's fluorescent emission was not bright enough to be tracked reliably on dark colored carpets.
The present invention provides a guidepath solution of sulfonated luminescent dyes which when applied to carpet in an acid state form a permanent bond between the carpet fiber and the dye. When used in an aqueous solution, the guidepath solution has an adjusted pH below 4.0 and preferably below 2.0. When used in a non-aqueous solution, the acidic dye compound has sulfone groups which are protonated. These compounds luminesce more efficiently, are not affected by conventional alkaline cleaning materials and are not discolored by exposure to ultraviolet radiation.

Litton Industrial Automation Automated Vehicles


A print control apparatus for causing a printer unit to print data input from an information processing apparatus includes an analysis unit and a control unit. The analysis unit analyzes test data on the basis of print setting information. The control unit stores the analysis result obtained by the analysis unit in a memory. A print control method, a storage medium, an information processing apparatus, and an information processing method are also disclosed.

1. Field of the Invention
The present invention relates to a print control apparatus for causing a printer unit to print data input from an information processing apparatus, a print control method, and a storage medium storing control programs used in the print control apparatus.
The present invention also relates to an information processing apparatus for outputting data to a plurality of print control apparatuses via a network, an information processing method, and a storage medium storing control programs used in the information processing apparatus.
2. Related Background Art
As conventional printers, an image printer, a page printer, and the like are known. The image printer receives image data from an external unit such as a host computer and performs a print operation. The page printer receives print data written in a page-description language or the like, and performs a print operation after rasterizing (rendering) the data into a bit image on the basis of the language data.
Print settings in printers of this type vary depending on the features and characteristics of the printers. A user performs setting for each print data as needed.
In a conventional printer, it is difficult for the user to find an optimal setting for a particular document to be printed, and hence it takes time to perform an operation for the setting. When a plurality of printers are set in a network, in particular, the user cannot determine which printer is the optimal one to print a ceratin document.
Such a problem is associated with control done by a host computer, and the performance of each printer cannot be known unless a print operation is actually performed. In addition, when print data are to be distributed and printed, optimal distributed print processing of the print data cannot often be performed.

Print control apparatus, print control method, information processing apparatus, information processing method, and storage medium storing control program


There is provided an image processor and a method thereof for high-speed compensation for taken-image blurs produced by camera shakes or the like. In the first instance, a motion-detecting area is selected for each of two images taken by an image sensor. When projective data is calculated by means of computing in a predetermined direction pixels of the motion-detecting areas, the motion vector between the two images can be acquired based on the projective data. The image correlativity between the two images is then calculated in the direction that the motion vector designates; and the amount of pixel displacement between the two images is calculated based on the correlativity values acquired by the calculation. Moreover, the area that has been produced by displacing an image output area in a camera-shake compensation area designated in the second frame, by the pixel-displacement amount calculated by a displacement calculator is cut away from the camera-shake compensation area, and is outputted as an image for the image output area of the second frame.

1. Field of the Invention
The present invention relates to image processors and processing methods thereof for treating blurs in taken images produced by camera shakes or the like, and particularly to reduction in image-processing time required to compensate the blurs.
2. Description of the Related Art
A great number of digital and movie cameras equipped with an image sensor, such as a CCD (Charge Coupled Device) sensor and a CMOS (Complementary Metal Oxide Semiconductor) sensor, have recently been marketed, and even beginners have been able to readily take still pictures or moving pictures; however, when a general user takes a picture, blurs are inevitably produced in the picture unless a camera is fixed with a tripod or the like; in consequent, various methods have been devised in order to compensate the blurs.
The methods are roughly categorized into two groups. One of the methods is to mechanically control the orientations of lenses and prisms by detecting with an acceleration sensor or the like movement of a camera itself, and the other is to compensate image blurs by applying image processing to the digital data of a taken picture and calculating blurring amounts.
Despite its high accuracy of compensating blurs, the former requires an acceleration sensor and parts for lens control; therefore, there are problems in terms of downsizing and cost reduction of the device. In contrast, despite its disadvantage of deterioration in resolution, the latter can, merely by means of signal processing, provide the compensation for camera shakes, and can be implemented with low cost; therefore, the latter method has been widely utilized.
Japanese Laid-Open Patent Publication 1993-75913 discloses a motion-vector detecting and camera-shake compensating circuits that are examples of conventional arts with regard to the camera-shake compensation utilizing the image processing. In the foregoing Japanese Laid-Open Patent Publication, an input image is divided into a plurality of areas, and motion vectors in selected areas among the plurality of regions are calculated. If the number of the selected areas is increased in order to raise the accuracy of the motion vectors, the calculating amount of the motion vectors increases; therefore, a circuit for determining the reliability of correlativity calculation is provided for each area, and the motion-vector calculation is limited to the areas that are determined by the determining circuit to be reliable; however, when all the areas are reliable, the motion-vector calculation is also carried out in all the areas; thus, processing speed has been an issue to be solved.


In a method of forming an electrode on a ceramic green sheet, an electrode is formed on a support film by a thin film forming method, an adhesion inhibitor is formed on top of the electrode for protecting the same from adhesion of a ceramic slurry, and thereafter a ceramic slurry is applied onto the support film to form a ceramic green sheet, thereby obtaining a ceramic green sheet, provided with a through electrode.

1. Field of the Invention
The present invention relates to a method of forming an electrode on a ceramic green sheet and a method of manufacturing a multilayer ceramic electronic component, and more particularly, it relates to a method of forming an electrode such as a via hole electrode or a through hole electrode passing through a ceramic layer, and a method of manufacturing a multilayer ceramic electronic component having such a through electrode.
2. Description of the Background Art
A multilayer ceramic electronic component or a ceramic multilayer substrate having electronic component elements in its interior is provided with via hole electrodes or through hole electrodes passing through ceramic layers for connecting electrodes which are formed at different vertical positions in a ceramic sintered body FIG. 1 shows an exemplary multilayer ceramic electronic component 1 having such through electrodes.
The multilayer ceramic electronic component 1 shown in FIG. 1 has a sintered body 2 which is prepared by stacking a plurality of ceramic green sheets with each other and firing the obtained laminate. In this sintered body 2, internal electrodes 3 to 6 are formed at different vertical positions. The internal electrodes 3 and 4 are electrically connected with each other by a via hole electrode 7, while the internal electrodes 5 and 6 are also electrically connected with each other by another via hole electrode 8. External electrodes 9 and 10 are formed on both end surfaces of the sintered body 2 respectively.
In order to obtain the ceramic sintered body 2, in general, ceramic green sheets which are provided with the internal electrodes 3 to 6 on single major surfaces thereof respectively and blank ceramic sheets are stacked with each other to obtain a laminate. The ceramic green sheet which is provided with the internal electrode 3 on its upper surface is formed with a through hole, and this through hole is filled up with a conductive material to form the aforementioned via hole electrode 7. Similarly, the ceramic green sheet which is provided with the internal electrode 5 on its upper surface is formed with a through hole, and this through hole is filled up with a conductive material to form the via hole electrode 8.
The laminate obtained in the aforementioned manner is pressurized along its thickness, and thereafter fired at a prescribed temperature, to obtain the sintered body 2.
The ceramic green sheet for forming the via hole electrode 7 is prepared by the following method (see FIG. 2: First, a ceramic green sheet 12 is formed on a support film 11 consisting of synthetic resin such as polyethylene terephthalate by a doctor blade coater, for example, as shown in FIG. 2. Then, the ceramic green sheet 12 is punched with the support film 11, so that through holes 11a and 12a are formed therein. Thereafter the through holes 11a and 12a are filled up with conductive paste 13, and another conductive paste layer 14 is printed to define the internal electrode 3. In order to obtain the laminate, the ceramic green sheet 12 is separated from the support film 11, to be stacked with other ceramic green sheets.
In the conventional method, as hereinabove described, each of the via hole electrodes 7 and 8 must be formed through the complicated steps described with reference to FIG. 2. In other words, it is necessary to form a ceramic green sheet on a carrier film, then correctly form a through hole in a position for forming a via hole electrode, and thereafter fill up the through hole with a conductive material through complicated operations.

Method of forming electrode on ceramic green sheet and method of manufacturing multilayer ceramic electronic component


A cutting board integrated with an associated washing device is provided. The washing device includes a kitchen appliance such as a dishwasher. The cutting board is configurable with the washing device in a variety of ways. The cutting board is incorporated into the washing device and extendable from the front of the washer for use in preparing food. After use, the board is retracted back into the washer for cleaning.

Many living spaces are limited in size, especially in the kitchen area. In such cases, a kitchen may include insufficient countertop space thereby making it difficult to easily prepare food. For example, a kitchen with little countertop space may not enable a person to use a cutting board in tandem with a mixing bowl and a stovetop.
In addition, when a cutting board is used and becomes soiled, using a small sink to clean the cutting board often results in splashing water causing a mess.
Accordingly, there is a need for a cutting board washer system that increases the amount of usable countertop space while providing a mess-free cutting board cleaning procedure.

Cutting board and washer system and method


A motor driven power steering system includes a worm shaft, a bearing installed on the worm shaft, and a bearing bush enclosing the bearing. The bearing bush includes a bearing guide enclosing the bearing and a damper which is mounted on an outer side surface of the bearing guide and absorbs vibrations of the worm shaft. The bearing guide and the damper are integrally formed by injection molding.

1. Technical Field
Embodiments of the present disclosure relate to a motor driven power steering system, and more particularly, to a motor driven power steering system which prevents floating and thereby absorbs shocks by covering a bearing installed on a worm shaft from the outside and at the same time enclosing the bearing.
2. Related Art
Generally, an electric power steering system, i.e., a motor driven power steering system (MDPS) is a system which assists a steering power with a motor power, not using a hydraulic pressure. To this end, the MDPS transmits a rotation force of a worm wheel to a gearbox to thereby assist a steering torque by having a motor which generates power under the control of an Electronic Control Unit (ECU), and a worm shaft which is rotated by a motor and the worm wheel in mesh therewith.
As described above, the MDPS uses the worm shaft and the worm wheel in mesh with each other, and therefore metallic noises, i.e., rattle noises occur as a result of a gap between gear teeth due to the abrasion of gear teeth and other various factors. Therefore there is a need of improvement.
The background technology is disclosed in Korean patent application publication No. 2009-0082821 under the title "a column assist type electric power steering system", published on Jul. 31, 2009.


The system for end-to-end content publishing using XML with an object dependency graph is based on the following two design principles: First, separation of content and style: Information stored in the content management system is independent on how it is going to be presented. The presentation style is encapsulated elsewhere and can be used to customize the look and feel based on the end-user preferences as well as the delivery methods and devices. Second, reusability of information content: By encapsulating common information in fragments and subfragments and making these fragments insertable in other fragments, thereby avoid scattering and duplication of information. This enables a user to restrict the edit operations to a limited number of relevant fragments, to affect global changes. In addition, the present invention provides data consistency and data integrity in the content management.

1. Field of the Invention
The present invention relates to the field of computerized publication of documents, and more particularly to a method for publishing documents using XML on networks such as the Word Wide Web and the ability to publish documents for different device types such as computers, PDAs, cell phones and print.
2. Description of the Related Art
Web sites often present content which is constantly changing. Presenting current information to the outside world without requiring an inordinate amount of human effort and computing power is a major technical challenge to Web site designers.
Multimedia content including text, graphics, video and sound on the Internet needs to be highly adaptive. Recently the World Wide Web Consortium (W3C) adopted the Extensible Markup Language (XML) as a universal format for structured documents and data on the Web. The base specifications are XML 1.0, W3C Recommendation February '98. See online URL (www.w3.org) for more information. A content management system based on XML along with (Extensible Stylesheet Language) XSL enforces separation of content and presentation, thus allowing flexible rendering of the content to multiple device types. Similarly, such a content management system allows maximal reuse of information and data through the composition of XML fragments as well as ensures data integrity through the consistent use of information.
In addition to the availability of XML, new interfaces and devices are emerging, the diversity of users is increasing, machines are acting more and more on users' behalf, and net activities are possible for a wide range of business, leisure, education, and research activities.
Systems and methods are being developed for generating more flexible content and a capability to manage frequent changes to content. One system for achieving maximum flexibility and reuse is disclosed in the patent application entitled "Method and System for Efficiently Constructing And Consistently Publishing Web Documents" filed on Apr. 4, 1999 with application Ser. No. 09/283,542 with inventors JR Challenger et al. now [Pending] and commonly assigned herewith to International Business Machines. Disclosed is a system and method where the multimedia content is broken down into fragments that can be combined into published documents.
The use of XML in content management systems introduces the following new challenges:
1. A need exists to maintain information about the functional and semantic role of each richly tagged fragment. This information describes what the content is about, who the target audience is, and its relationship to a taxonomy or other fragments. The same mechanism should support efficient searches of particular fragments.
2. A need exists for an efficient method to track the effects of changes in a particular richly tagged fragment or style and propagate those changes throughout the information space.
3. A need exists for a user interface that shields the content contributor from knowing the underlying syntax and complexities of the XML documents;
4. A need exists for finding relevant document fragments on demand, keeping track of the dependencies between document fragments, transforming combinations of those document fragments into viewable pages available to multiple device types, and designing a content creation tool that does not overwhelm the contributor with the details and the complexities of the underlying system.
Accordingly, a need exists for a system and method that manages and publishes the information content of a Web site, or an Internet information portal, in a way that separates the information from the form and reuses the stored information and enables the presentation in the user interface to be customized for different audiences and target devices and media.
Other prior art systems/tools that relate to the XML editing include markup languages that use XML to declaratively specify user interfaces, fully functioning editors, and systems that publish XML documents. Bluestone Software's XwingML [for more information refer to URL www.bluestone.com] enables the creation of Java Swing user interfaces without coding. The GUI (Graphical User Interface) is declaratively specified in XML and is translated into working Java code. This approach separates the GUI code from the application logic. Their DTD specifies the entire set of classes and properties for all of Swing components. However, the Bluestone Software's XwingML creates arbitrary interfaces in a declarative fashion rather than creating specific interfaces that reflect the document types for a given publishing environment. Accordingly a need exists for a method and tool to accomplish creating specific interfaces that reflect the document types for a given publishing environment.
Another prior art editor for XML is XmetaL, from Softquad, [refer to online URL www.xmetal.com] which is a flexible XML editor that supports three views into XML files. These views include raw XML mode, Tags-On mode that provides a WYSIWYG presentation with direct access to elements and attributes, and a full WYSIWYG mode in a word-processor like environment. The XmetaL tool although useful has the problem that separate style sheets need to be used to support the editing vs. the publishing process. In addition, one stylesheet may not include all of the elements that would be used on other platforms or for different uses. Accordingly, a content editor is needed that separates the content from presentation and the reusability of that content on different delivery environments such as PCs, PDAs and phones.
Still another prior art content editor system is Interwoven [refer to online URL www.interwoven.com] which is a complete publishing system that supports HTML as well as XML. It provides an end to end solution from content creation to promotion and publishing. It also has a templating tool that provides the means to produce form-based pages. However, its support of reusable fragments within the environment is rather limited and the publishing to viewable pages is performed using non-standard methods.
Accordingly a need exists for a method and tool to accomplish creating and reusing content fragments using standard methods for a given publishing environment.

This patent is subject to a terminal disclaimer.

Method and apparatus for end-to-end content publishing system using XML with an object dependency graph

International Business Machines Corporation


An LDPC code encoding apparatus includes: a code matrix generator for generating and transmitting a parity-check matrix comprising a combination of square matrices having a unique value on each row and column thereof; an encoding means encoding block LDPC codes according to the parity-check matrix received from the code matrix generator; and a codeword selector for puncturing the encoded result of the encoding means to generate an LDPC codeword. The code matrix generator divides an information word to be encoded into block matrices having a predetermined length to generate a vector information word. The encoding means encodes the block LDPC codes using the parity-check matrix divided into the block matrices and a Tanner graph divided into smaller graphs in correspondence to the parity-check matrix.

(a) Field of the Invention
The present invention relates to an apparatus for encoding and decoding of LDPC (Low-Density Parity-Check) codes, and a method thereof. More specifically, the present invention relates to an apparatus for encoding and decoding of LDPC codes that enables a design of encoding and decoding, and a method thereof.
(b) Description of the Related Art
An LDPC code is a linear block code invented by Gallager in 1962 and defined as a sparse parity-check matrix in which most of the elements are zero. Namely, the sparse matrix is one in which most of the elements have a value of zero.
The LDPC code was almost forgotten since the expense of its implementation was too high at that time. Recently, it was rediscovered in 1995 and further improved as an irregular LDPC code by generalization in 1998.
A statistic decoding algorithm for the LDPC code was also invented at the time of Gallager's first discovery of the LDPC code. The performance of the LDPC code decoded by the algorithm is remarkably high and improved by expansion of a codeword from binary codes to non-binary codes.
Like a turbo code, the LDPC code has a bit error rate (BER) very close to the Shannon channel capacity limit. An irregular LDPC code known to have the highest performance needs only 0.13 dB from the Shannon channel capacity to get a bit error rate (BER) of 10−6 when its code length is about one million (106) bits in the additive white Gaussian noise (AWGN) channel environment. For that reason, the irregular LDPC code is suitable for applications that require a high-quality transmission environment having a considerably low bit error rate (BER).
Unlike the algebraic decoding algorithm that is a decoding method for normal block codes, the LDPC code decoding algorithm is a probabilistic decoding method that adopts a belief propagation algorithm based on the graph theory and the statistic prediction theory.
An LDPC decoder calculates the probability that each bit in a codeword received through a channel is equal to 1 or 0. The probability information calculated by the decoder is called the "message," and the quality of the message is checked for each parity defined in a parity-check matrix. The calculated message when a specific parity of the parity-check matrix is satisfied is called the "parity-check message," which indicates the most likely value for each codeword bit. The parity-check message for each parity is used to determine the value of the corresponding bits, and the calculated bit information is called the "bit message."
In this iterative message-passing process, the bit information of each codeword satisfies all the parities in the parity-check matrix. The codeword decoding process ends at the time when all the parities in the parity-check matrix are satisfied. The systematic codes are commonly used in the channel environment having a low signal-to-noise ratio to extract a specific part of the codeword and regenerate information bits. The term "systematic code" as used herein refers to a code made to provide an information word as a part of the codeword. Namely, the systematic code is a code to definitely divide a codeword into an information word part and an additional part provided for error correction.
Generally, codes suitable for graph decoding are LDPC codes, and decoding algorithms for decoding the LDPC codes include a sum-product algorithm and a min-sum algorithm. The sum-product algorithm for decoding the LDPC codes exhibits an optimal performance when the Tanner graph has no cycle. The min-sum algorithm is less complex than the sum-product algorithm but inferior in performance. A structure designed for correction of all losses during the decoding process to solve this problem is too complex to implement hardware or software.
Korean Patent Application No. 2001-33936 (filed on Jun. 15, 2001) discloses an invention under the title of "Graph Decoding Method Using Block Correction", which relates to a graph decoding method using block correction by adding a correction factor to the min-sum algorithm for decoding LDPC codes to achieve a decoding performance close to that of the sum-product algorithm.
More specifically, the cited invention provides a graph decoding method using partial correction by adding a correction factor in consideration of a combination of K sites for the most inputs of a min operation causing a performance deterioration in the min-sum algorithm, i.e., a combination of K sites most frequent in the min-sum algorithm, to achieve a performance approaching that of the sum-product algorithm without increasing the complexity of the min-sum algorithm too much.
According to this cited invention, a correction device is applied to the most effecting codeword to improve the algorithm, guaranteeing a performance equivalent to that of the original decoding algorithm with relatively less hardware.
Korean Patent Application No. 2001-50423 (filed on Aug. 21, 2001) by the applicant of the present invention discloses an invention under the title of "Apparatus for Adaptively Determining Maximum Number of Decoding Iterations for LDPC Decoder Using Signal-to-Noise Ratio Estimation, Method thereof, LDPC Decoding Apparatus Including the Apparatus, and Method thereof."
More specifically, the apparatus for adaptively determining the maximum number of decoding iterations for an LDPC decoder according to the cited invention estimates a signal-to-noise ratio corresponding to a received LDPC encoded signal and adaptively determines the maximum number of decoding iterations corresponding to the estimated signal-to-noise ratio based on a memory storing maximum numbers of decoding iterations corresponding to various signal-to-noise ratios.
According to the cited invention, a signal-to-noise ratio corresponding to a received signal is estimated to adaptively determine the maximum number of decoding iterations to satisfy a required performance. This reduces the average number of decoding iterations and hence a delay of the signal but increases the number of calculations.
U.S. Pat. No. 6,633,856 (filed on Oct. 10, 2001) discloses an invention under the title of "Method and Apparatus for Decoding LDPC codes," which relates to a method and apparatus for decoding a codeword using LDPC codes and a message-passing decoding algorithm used for long codes.
More specifically, the cited invention is directed to a method for encoding a codeword having a large graph comprising a plurality of small graphs of the same size, in which method the large graph is configured from a plurality of small graphs using an algorithm for substitution of columns in a matrix. The column substitution algorithm can be implemented with a message-passing function among the small graphs. The messages corresponding to the small graphs are collectively stored in one memory and written in or read out of the memory by a SIMD write/read command. The graph substitution operation can be configured by a simple message rearrangement command, and the substitution command can also be used for a cyclic substitution. Therefore, a message set read out of one message set memory is rearranged in sequence by cyclic substitution and passed to a processor circuit for a small graph to be processed in the next time.
This cited invention includes a function of efficient storing and reading of a memory for parallel processing of a decoder, thereby simplifying an implementation structure of the decoder with an enhanced high speed.
The LDPC codes are generated using a basically random designing configuration method, so all the information about the random parity-check matrix should be stored in a memory so as to configure an encoder or a decoder for the LDPC codes. This means that all the locations of nonzero elements on the parity-check matrix must be stored. However, the number of 1s increases with an increase in the size of the parity-check matrix for the codes, greatly increasing the value of information to be stored.
In addition, the random characteristic of the parity-check matrix more complicates an address searching and a read/write operation of information for a memory in the encoder/decoder, and also increases the number of factors to be considered in the code generating process, making it difficult to generate codes for high performance.

Apparatus for encoding and decoding of low-density parity-check codes, and method thereof

Electronics and Telecommunications Research Institute


The semiconductor device of the present invention includes a column decoder (select and write circuit), which selects multiple pages that are not located adjacently to each other so as to simultaneously program multiple bits in the memory cells of the selected page, when the multiple bits are programmed in the multiple pages. The page is a selection unit and is composed of a given number of the memory cells located on a same word line. An unnecessary stress of programming is not applied to the memory cells that are not to be programmed, by increasing the distance between the memory cells to be programmed simultaneously.

1. Field of the Invention
The present invention relates to a semiconductor device in which multiple bits of data can be programmed and a programming method thereof.
2. Description of the Related Art
The semiconductor device such as a non-volatile semiconductor device is designed to have a large capacity with the advancements of the processing technology. Programming and erasing are increasingly demanded to be faster in accordance with the large capacity of the semiconductor device.
In a flash memory, all the bits have to be programmed before erasing, and so an increase in the programming speed increases the erasing speed. This is because multiple data are programmed by one byte (eight bits) or one word (16 bits) simultaneously.
However, adjacent memory cells on the same word line share the bit line in the non-volatile semiconductor device of a virtual ground type. If a distance is too short between the memory cells in which multiple bits are programmed simultaneously, there arises a problem in that a stress caused by programming is applied to other memory cells in which nothing is to be programmed.
FIG. 1 shows virtual ground type memory cells 0 through 4 that are connected to a word line WL and share bit lines. FIG. 1 also shows metal bit lines MBL 0 through MBL 5 connected to drain regions and source regions of the memory cells 0 through 4, selector switches Ssel 0 through Ssel 5 that respectively connect the metal bit lines MBL 0 through MBL 5 to a ground line, and selector switches Dsel 0 through Dsel 5 that respectively connect the metal bit lines MBL 0 through MBL 5 to a data line. Here, FIG. 1 shows only a portion of the non-volatile semiconductor device that is necessary for description.
For example, assuming that the metal bit line MBL 0 is set to a low level and the metal bit line MBL 1 is set to a high level so as to write data into the memory cell 0. At the same time, assuming that the metal bit line MBL 2 is set to the low level and the metal bit line MBL 3 is set to the high level so as to write data into the memory cell 2. Here, the memory cell 1 interposed by the memory cell 0 and the memory cell 2 connects the gate thereof to the word line WL, which is also shared by the memory cell 0 and memory cell 2. The metal bit line MBL1 is set to the high level and the metal bit line MBL 2 is set to low level, and the data is also written in the memory cell 1. That is to say, the stress caused by writing is applied to the memory cell into which data does not have to be written.

Semiconductor device and programming method


Catheter-based systems are disclosed for geometrically and temporally controlled deliveries of fluid agents to the heart. Each system includes an elongate catheter shaft, a tissue penetration element at the shaft distal end, and a handle at the shaft proximal end for manipulating the penetrating element. The penetrating element and a proximate conductive coil provide bipolar sensing electrodes. One version of the system includes a fluid lumen through the penetrating element and a contrast fluid lumen open at the catheter shaft distal end. In other versions, the penetrating element contains two fluid lumens. These systems facilitate tissue mapping and therapeutic agent delivery protocols in which several agents can be simultaneously delivered at a depth within heart tissue, prevented from intermingling until they reach the tissue. Treatment and contrast agents can be delivered simultaneously or temporally spaced, directed to the same region or to different regions separated by intervening tissue.

The present invention relates to local biotherapeutic delivery in cardiac regions, and more particularly to devices and processes for locally delivering therapeutic agents such as controlled release proteins, cell based therapies, and gene based therapies for treating heart failure, stenosis, ischemia, arrhythmias, hypertrophic cardiomyopathies, infarction, and vulnerable plaque. The invention also relates to therapeutic strategies incorporating percutaneous intramyocardial delivery catheter systems for transendocardial delivery from within the ventricles of the heart, selected biopharmaceutical agents, sustained delivery means, and geometrical and temporal delivery protocols, targeted towards indications within cardiovascular disease, including coronary artery disease (including stenosis, restenosis, vulnerable plaque, and ischemia), congestive heart failure, myocardial infarction, atrial cardiac conduction disorders, and ventricular cardiac conduction disorders.
Coronary Artery Disease (CAD)
Blood flow to the heart muscle can be severely reduced by atherosclerotic disease of the coronary arteries, which accounts for most ischemic heart disease. Insufficient oxygen to the heart muscle as a result of restricted blood flow can lead to myocardial ischemia, and possibly to a heart attack or death. Restoring blood flow is the most effective method to relieve painful ischemic symptoms and to reduce the long-term risk of a heart attack.
Current treatments for coronary artery disease include drug therapy, coronary artery bypass surgery and catheter-based treatments, including angioplasty, atherectomy and coronary stenting.
Restenosis
Today, local drug therapies are delivered from the surfaces of stents to reduce the potential for restenosis after percutaneous transluminal angioplasty, with or without stent placement.
Vulnerable Plaque
In recent years the cause of a myocardial infarction has been identified as thin walled plaques in relatively open vessels. Vulnerable plaques are predisposed to suddenly come free from the artery wall, and may occlude a vessel. Vulnerable plaques often are characterized as having a lipid core and being "hot" in that they are slightly warmer than surrounding tissue. The ability to identify and treat vulnerable plaques before they cause myocardial infarction is in active development.
Cardiac Ischemia
Cardiac ischemia occurs when a coronary artery is partially or completely obstructed, such as due to atherosclerosis. A sudden, severe blockage of a coronary artery may kill part of the heart muscle (heart attack). Cardiac ischemia may also cause an abnormal heart rhythm (arrhythmia), which can lead to fainting or even sudden death. Treatment is directed at improving blood flow to the heart muscle, and may include medication, exercise, angioplasty, and bypass surgery.
Heart Attack/Myocardial Infarction (MI)
A heart attack occurs when a blockage in a coronary artery severely restricts or stops blood flow to a portion of the heart. When blood supply is greatly reduced or stopped for a sufficient time, heart muscle cells die. Heart muscle cells generally lack the ability to multiply to replace the dead cells. After a heart attack, white blood cells migrate into the area and remove the dead heart muscle cells, and fibroblast cells proliferate and form a fibrous collagen scar in the affected region of the heart. Following a heart attack, the heart's ability to maintain normal function will depend on the location of the damage and the amount of damaged tissue.
Current therapeutic treatments for heart attack include drug therapy to dissolve a blood clot immediately following a heart attack, medicines to alleviate symptoms, and certain lifestyle changes, such as an altered diet, increased exercise levels and cessation of smoking.
Congestive Heart Failure (CHF)
Congestive heart failure is caused when the heart is unable to contract adequately to pump blood throughout the body. The normal physiological stimulation of heart function is generated when chemical transmitters known as catecholamines bind with certain receptors on the surfaces of heart cells, triggering a series of events that result in increased heart rate and increased force of contraction. Typically, in congestive heart failure, the heart is unable to respond adequately to catecholamines.
Current treatments for congestive heart failure include drug therapy, and rarely, heart transplantation. Drug treatments generally treat symptoms only, and have a limited effect on the progression of the disease.
Cardiac Conduction System Disorders
The rhythmic contraction of the heart essential for its function as a pump is enabled by the conduction of electrical signals between cells and along specialized conducting networks within the heart such as the sinoatrial node, the atrioventricular node, and the perkinje fibers. To date, disruptions in these conduction pathways have been treated either by tissue ablation to remove a pathway, or by the implantation of devices designed to pace the heart (pacemakers) or to jump start the heart after disorganization of the electrical signals (defibrillators).
One conduction system disorder, atrial fibrillation (AF), may be treated with an atrial defibrillator to deliver energy to the atrium to terminate arrhythmias. However, this therapy is painful, has the potential to initiate life threatening ventricular arrhythmias, and requires an expensive cosmetically undesirable permanent implant.
Doctors have treated atrial fibrillation with drugs administered intravenously or orally. U.S. Pat. No. 5,527,344 (Arzbaecher) describes a pharmacological atrial defibrillator and method for automatically delivering a defibrillating drug into the blood stream upon detection of atrial arrhythmias. The defibrillating drug is injected in a large initial dose followed by a continuous smaller dose. If the injected drug is to have an effective concentration within the heart, a large amount must be injected into the blood stream, risking undesirable side effects in other organs.
Atrial fibrillation also is treated by atrial ablation by heating tissue with RF energy, laser energy, ultrasound energy, by cooling tissue, by surgically cutting the tissue, or by infusing tissue with an ablative medium such as ethanol or phenol.
Arrhythmias similar to atrial fibrillation also are treated with ablation. For example, conduction over the fast and slow pathways of the AV node can occur simultaneously, leading to a double ventricular response from each atrial beat that may present as symptomatic, incessant, and irregular narrow-complex tachycardia which may be misdiagnosed as atrial fibrillation. Slow AV nodal pathway focal ablation can stop tachycardias and restore ventricular function when cardiomyopathy is present. Other arrhythmias may be treated with similar ablative approaches.
There are two general approaches for providing ablative therapy to the heart to treat atrial fibrillation: the long linear ablative lesion approach, and the focal ablation approach. In the long linear ablative lesion approach, heart tissue is killed along a linear pathway, to segment the heart into regions too small to sustain atrial fibrillation. In the focal ablation approach, the heart tissue is killed at a single site, to ablate the region of the heart that prematurely depolarizes and acts as a trigger to initiate atrial fibrillation. Focal ablations remove triggers that initiate atrial fibrillation, often within the pulmonary veins or in the region near the junction of the veins with the left atrial tissue.
Many of these treatments require sensing electrical activity in cardiac tissue to determine whether a particular location is appropriate for a selected treatment, or to measure electrical activity after ablation therapy to determine whether the intended result has been achieved. Frequently there is a need to image tissue surrounding a selected treatment site.
In conjunction with supplying treatment agents locally to a designated site, there is a need for the option to supply several different agents to a given site while ensuring that the agents do not mingle until reaching, or nearly reaching, the treatment site. Finally, in conjunction with using a contrast fluid to fluoroscopically image a treatment site, there is a need for applying an agent to the treatment site in relative isolation from the contrast fluid.

Bio-interventional therapeutic treatments for cardiovascular diseases


This invention provides an epoxy resin composition for encapsulating a semiconductor exhibiting higher flame resistance, good flowability and adequately higher solder-reflow resistance to allow for the use of a lead-free solder without a flame retardant, as well as a highly reliable semiconductor device in which a semiconductor element is encapsulated with a cured product from the composition.

1. Technical Field
The present invention relates to an epoxy resin composition for encapsulating a semiconductor and a semiconductor device therewith.
2. Related Art
Electronic components such as diodes, transistors and integrated circuits have been typically encapsulated with an epoxy resin composition. Particularly, in integrated circuits, there have been used epoxy resin compositions exhibiting excellent heat resistance and moisture resistance containing an epoxy resin, a phenol resin curing agent and inorganic fillers such as fused silica and crystalline silica. However, recent market trend to size reduction, weight saving and higher performance in electronic devices has led to more integrated semiconductors and accelerated surface mounting of a semiconductor device, while requirements to be met by an epoxy resin composition used for encapsulating a semiconductor element has been increasingly diversified and stricter. In particular, now that surface mounting of a semiconductor device is common, a moistened semiconductor device is exposed to a high temperature during a solder reflow process. Furthermore, as part of eliminating environment burden materials, a solder free from lead has been increasingly used as an alternative material, but a lead-free solder has a higher melting point than a conventional solder. Therefore, it needs a reflow temperature during surface mounting higher by about 20° C. than a conventional case, specifically 260° C. Thus, a semiconductor device is exposed to a further higher temperature, causing de-lamination of a cured epoxy resin composition in its interface with a semiconductor element or lead frame. It tends to defects significantly deteriorating reliability in a semiconductor device such as cracks.
Furthermore, also from environmental considerations, there is a move to limit the use of a halogen-containing flame retardant such as bromine-containing organic compounds and an antimony compound such as diantimony trioxide and diantimony tetroxide which have been used as a flame retardant for a semiconductor encapsulating material, and there has been needed alternative flame resisting means. As alternative flame resisting means for a semiconductor encapsulating material, there has been proposed the use of metal hydroxides such as aluminum hydroxide and magnesium hydroxide. They must be, however, used in a large amount for effectively working as a flame retardant, and when being used in an enough amount to be a flame retardant, it may deteriorate flowability and curability of an epoxy resin composition during molding, mechanical strength of a cured material and thus solder-reflow resistance in a temperature range for mounting the above lead-free solder.
To solve these problems, there have been proposed using a low water-absorbing, flexible and flame-resistant resin for meeting the requirements for both solder reflow resistance and flame resistance (See, for example, Japanese Patent Application Laid Open Nos. 1989-275618, 1993-097965 and 1993-097967). However, there have been needed further higher solder-reflow resistance while recently a semiconductor has been further thinner and interconnections have been further finer, so that improvement in flowability during encapsulating and molding. It has been, therefore, difficult to meet all of these requirements.
Given such circumstances, there has been needed for developing a resin composition for encapsulating a semiconductor exhibiting higher flame resistance, good flowability and adequately higher solder-reflow resistance to allow for the use of a lead-free solder without a flame retardant.
Thus, this invention provides an epoxy resin composition for encapsulating a semiconductor exhibiting higher flame resistance, good flowability and adequately higher solder-reflow resistance to allow for the use of a lead-free solder without a flame retardant, as well as a highly reliable semiconductor device in which a semiconductor element is encapsulated with a cured product from the composition.

Epoxy resin composition for encapsulating semiconductor and semiconductor device


A combination notebook/file folder includes a first side panel having upper and lower edges, a second side panel having upper and lower edges, channels in the upper edges of the first and second side panels. The combination also includes a binding edge which connects together the lower edges of the first and second side panels, a plurality of binding rings in the binding edge for holding a plurality of sheets of paper therein, and left and right hangers selectively retractably and extensively mounted in the channels at the upper edges of each of the first and second side panels. Each hanger includes a main body, a hook at an outer end of the main body and a post extending from each main body and engaged within a respective elongated slot for limiting sliding movement of the hangers in the channels. Each main body is elongated and includes a cut away portion at an inner end opposite the hook to form a reduced width portion. The reduced width portions of the hangers of the first panel overlap each other, and the reduced width portions of the hangers of the second panel overlap each other. The combination notebook/file folder can be used as a hanging file folder when the left and right hangers extend out from the upper edges, and can be used as a notebook when the left and right hangers are retracted into the upper edges.

1. Field of the Invention
The present invention application relates generally to file folders, and more particularly to a combination notebook/file folder having retractable and extendible hangers.
2. Description of the Related Art
Traditional hanging file folders include first and second panels connected together at their lower edges with hangers fixed to the upper edges. The hangers typically extend outwardly from the side edges such that when the folder is placed in a file drawer, the rails within the draw support the hangers.
Traditionally, when it is desired to retrieve papers from a hanging file folder, the papers are removed while the corresponding folder remains in the drawer. As a result, the papers that have been removed are loose, and can quickly become disorganized. Alternatively, the entire hanging folder including the corresponding papers is removed from the drawer. However, in such case, the hangers continue to extend from side edges of the hanging file folder. This makes the file folder difficult to carry because the hangers often get caught on objects and because the hangers do not enable the file folder to readily fit in a standard size briefcase. Further, even when the hanging file folder is removed from the file drawer, the papers are still loosely held therein, making management of the papers difficult and disorganization highly likely.

Combination notebook/file folder having retractable and extendible hangers


A clothes hanger having a transversely extending member for supporting thereon articles of clothing by means of clamps, each of which has a pair of jaws adapted to hold therebetween free edges of the garment to be supported. The jaws of the clamp are adapted to be held in confronting biased condition for retaining the article of clothing in between the jaws of the clamp. A plastic locking device is provided for maintaining the confronting jaws of the clamp in closed condition, whereby the garments are retained by said hanger. The locking device is U-shaped and comprises a pair of legs adapted to straddle the jaws and maintain them in mutually biased condition for retaining any articles of clothing held by said clamps; the locking device is provided with a base which is connected to the transversely extending member of the hanger by a small piece of webbing whereby the locking device is pivotably movable into and out of engagement with said clamping jaws, said locking device being formed as part of a one piece molding operation which includes the hanger.

Hangers of the type involved herein usually comprise a transverse support arm which mounts a pair of spaced clamps. Each clamp includes a fixed jaw and a movable jaw, whereby a free edge of a clothing article to be supported by the hanger is inserted between the stationery and movable jaws, with the movable jaw being brought into confrontation with the stationery jaw.
In order to maintain the clamping jaws biased toward each other, with the clothing article therebetween, it is necessary to provide some kind of locking device. Such locking device is usually "U"-shaped, having a base and a pair of legs extending from opposite ends of the base. The locking device is placed over the clamp so that the legs of the locking device engage the outer sides of the clamping jaws. The legs of the locking device are normally spaced from each other a distance which is slightly less than the distance between the outer sides of the clamping jaws when biased towards each other. Accordingly, the placing of the locking device over the clamp causes the legs to flex and produce an opposite counter-force which biases the clamp jaws toward each other, so as to retain the article of clothing on the hanger. The locking device is usually resilient so that when removed from engagement with the clamp, the legs thereof are restored to their original unflexed condition.
In accordance with the prior art, the clamps are designed so as to be connected to the transverse support arm of the hanger by web means in a way which permits the entire plastic hanger assembly, including the jaws, to be molded in one piece. However, the locking members which are mounted so as to straddle the two clamping jaws and urge them into biasing engagement with each other to retain the garment in position on the hanger, are separate elements which, in the prior art, do not form part of the one piece molded plastic hanger. The prior art is best exemplified by U.S. Pat. No. 3,698,607.
In accordance with the prior art, the locking member is separate and unattached to the rest of the hanger, since the locking member would not be able to function in its intended manner unless it is free to move, and this was believed to be inconsistent with the one piece molded operation. As a result of the inability in the prior art to mold the locking device as part of a one piece plastic molded unit which is used to manufacture the hanger, these locking devices had to be manufactured separately from the hanger with which they are intended to be associated. This creates severe problems in that it becomes time consuming to establish and follow procedures in order to insure that the intended locking device is matched with the intended hanger. Furthermore, the locking device, being separate and distinct from the hanger proper, can easily be lost or separated from the associated hanger, causing severe inconvenience and great economic hardship. Furthermore, it is apparent that the locking device is an essential part of the hanger, as the absence of the locking device makes the hanger totally unusable, since the two clamping jaws would not be biased in confronting manner making it impossible to retain an article of clothing between the two clamping jaws. This is the most serious of all problems with the prior art procedure, as it renders a substantially complete hanger (missing only the locking device) totally useless to the customer. In fact, the mere misplacement of only one of two locking devices is sufficient to render an otherwise perfect hanger totally worthless.

Clothes hanger construction with attached locking device


A method for easily fabricating a thin-film transistor device which has a high reliability. A thin-film transistor is formed on a substrate, the transistor including a first conducting layer deposited on the substrate, a gate insulating layer formed on the first conducting layer, a semiconductor layer deposited on the gate insulating layer, and source and drain electrodes on the semiconductor layer. A multi-layer wiring section is provided adjacent the thin-film transistor, including a first conducting wiring layer formed on the substrate, wiring insulating layer formed on the first conducting wiring layer, and a second conducting wiring layer deposited on the wiring insulating layer and contacting the first conducting wiring layer as well as a portion of the thin-film transistor. The gate insulating layer and the wiring insulating layer are made of the same inorganic material and are of the same thickness.

1. Field of the Invention
The present invention relates to a thin-film transistor device.
More particularly, the invention relates to a thin-film transistor device that has an insulating interlevel wiring dielectric layer formed simultaneously with a gate insulating layer.
2. Background Art
Thin-film transistors which employ thin amorphous semiconductor films as active layers are increasingly used as switching devices or as circuits for driving image sensors because they are easy to fabricate. Also, devices with a large area can be easily manufactured.
In forming an array of thin-film transistors which comprises a plurality of thin-film transistors arranged on a single substrate, it is often required to provide a multi-level wiring section by such means as matrix wiring. A multi-level wiring section is commonly produced by the following method. A gate array of thin-film transistors and a first wiring layer are formed. Then, thin-film transistors are formed by successively depositing a gate insulating layer, an active layer, a source electrode and a drain electrode. Thereafter, an insulating interlevel dielectric layer and a second wiring layer are successively deposited.
The interlevel insulating dielectric layer in the multi-level wiring section is conventionally formed of an organic film made of a polymer such as polyimide. The polyimide film can be deposited with a highly flat surface so that, unlike an inorganic film made of silicon oxide or other inorganic materials, it will not increase the unevenness already introduced by the thickness of the first level pattern. This flatness serves to ensure the integrity of the second level pattern which would otherwise be interrupted at steps edges oft he first level pattern to thereby impair the reliability of the device.
The polyimide film, however, has the disadvantage of being highly susceptible to pin hole formation and a dual structure must be employed in order to prevent unwanted shorts between the first and second level patterns. But the provision of a double-layered polyimide film increases the complexity of the device fabrication process.

Method of fabricating a thin-film transistor and wiring matrix device


A system includes a processor configured to receive parking space environmental characteristics, from a vehicle parked in a parking space. The processor is also configured to download weather data for an area in which the parking space is located, covering a time duration for which the vehicle was parked. The processor is further configured to correlate the weather data to the received environmental characteristics to build a parking space environment profile for the duration of time and update a parking space model based on the environment profile.

The lithium ion batteries for a midrange Battery Electric Vehicle (BEV) can cost between $12,000 and $15,000, making it is the most expensive component of the vehicle (constituting some 38% of the total vehicle cost to the consumer). Accordingly, a major customer concern is the cost of a battery failure, so competitive vehicles must carry a long warrantee on the battery (often, for example, 8 years or 100,000 miles).
Presently BEV battery failures are rare, but BEV vehicles are too expensive to compete with conventional vehicles and they are produced in very low numbers. Cost reduction and increasing assembly volumes can only be maximized by designing batteries that meet the minimum ruggedness requirements consistent with lifetime cost of the vehicle. It is possible to reduce the ruggedness requirements and consequently the manufacturing cost of the battery through several methods often only if significant computational and data acquisition and storage capacity is available.
U.S. Patent Application 2009/0157232 generally relates to a method for preserving battery operation and life during vehicle post idle shutdown, such vehicle having a delayed accessory power mode operative when an ignition state of the vehicle is in a non-engine running condition while an ignition switch of the vehicle is in the ON position to supply accessories in the vehicle the battery. The method includes: detecting whether the vehicle has been in an post idle shutdown condition and brake pedal not pressed and ignition state unchanged; and placing the vehicle in the delayed accessory power mode after detecting that the vehicle has been in an post idle shutdown condition and while the ignition switch is in the ON position.

Method and apparatus for providing parking instructions to reduce environmental vehicle effects


A problem arises with related art liquid crystal displays in that the amount of power consumed will not be reduced any further, as a voltage generator circuit to supply power is kept activated. An exemplary method for driving a display uses a first plurality of operational amplifiers to generate a first plurality of voltages of different levels associated with a first plurality of grayscale levels displayable in the display so as to provide the display with a second plurality of grayscale levels out of the first plurality of grayscale levels. The method includes activating a second plurality of operational amplifiers corresponding to the second plurality of grayscale levels out of the first plurality of operational amplifiers, and deactivating remaining operational amplifiers other than the second plurality of operational amplifiers.

1. Field of Invention
The present invention relates to a display driving method and a driver to drive a display, such as a liquid crystal display (LCD) panel. More particularly, the invention relates to a display driving method and a driver to apply multiple voltages associated with multiple grayscale levels specified by a plurality of image data to a plurality of source lines (data lines) of a number of thin film transistors (TFTs) provided in such an LCD panel.
2. Description of Related Art
To generate multiple potentials, for example, 64 potentials associated with 64 grayscale levels, related art display drivers require 64 operational amplifiers. Assuming that each of the 64 operational amplifiers consumes a current of 100 μA, all of the 64 operational amplifiers consume 6.4 mA (100 μA×64) in total. When using a power voltage of 5 V, for example, this results in a large amount of power consumed, which reaches 32 mW (6.4 mA×5 V).
The LCD disclosed in Japanese Unexamined Patent Publication No. 2003-140618 (p. 1, FIG. 1), which is an example of such a display, is capable of reducing the total amount of power consumed for the LCD by switching the supply of operational power to a voltage generator circuit, corresponding to the operational amplifiers, between multi-grayscale display and dual-grayscale display.

Display grayscale control using operational amplifiers


In a database environment including a plurality of logical object definitions having relationships defined according to a schema, and logical object instances following the logical object definitions include attribute names and respective attribute values indicating status of an enterprise in an enterprise resource planning system, the method can receive a starting exception definition specifying a first query against the logical object instances and derive a new exception definition based on the starting exception definition and one or more stored, acted-upon exception definition proposals. The first query can include one or more initial situational trigger conditions. The new exception definition can specify a second query against the logical object instances and the second query can include one or more modified situational trigger conditions.

Enterprise software generally maintains a database environment that can include a plurality of database tables. Users of the enterprise software can run queries against the database tables. Such queries can retrieve objects from the database tables that satisfy conditions predefined in the queries. While queries based on predefined conditions can be helpful in a business environment to identify when certain business processes may need human intervention, there remains a need for more intelligent queries that can automatically define new conditions that are adaptive to the changing business status, instead of relying on predefined conditions.

Intelligent and automatic exception handling


A proximity detection apparatus for detecting objects within a predetermined region. The apparatus comprises a transmitter, a receiver, a microcontroller, and a power supply that provides electrical potential to the transmitter, the receiver, and the microcontroller. The microcontroller produces transmitted data bursts to the transmitter, the transmitter emits optical data bursts toward the predetermined region where, if the object is present, the optical data bursts reflect off of the object as return optical bursts. The receiver detects the return optical bursts and transmits received data bursts to the microcontroller. The microcontroller compares the received data bursts against the transmitted data bursts to verify that the object is present in the predetermined region. The microcontroller produces an output signal to control equipment based the object being present or absent from the predetermined region.

1. Field of the Invention.
The present invention relates, generally, to object proximity detection methods and apparatus. More particularly, the invention relates to object proximity detection methods using an optical sensor system that transmits and receives light radiation or optical signals. The optical signal may be steady-state, pulsed, digitally encoded, or a sequenced combination of the foregoing. The invention provides a means to control a variety of devices or processes based upon the presence or absence of an object within some predetermined distance from or orientation to a fixed sensor. An object is detected by transmitting digital data bursts of light radiation from a remote optical energy transmitter and verifying the error-free return of the digital data bursts into an optical energy receiver. The verification of the error-free return of the transmitted data bursts provides proof that, depending on the design of the sensor system, an object is either present and has reflected the optical energy into the receiver or is absent and has not blocked the optical energy from being received into the receiver.
The apparatus and methods of this invention have particular utility used in conjunction with commercial and institutional food service beverage and ice dispensing systems, medical/pharmaceutical dispensing systems, automated manufacturing and production systems, food processing systems, packaging systems, and a variety of other commercial, industrial, municipal and residential systems that utilize one or more mechanical, electronic, optical, or similar sensors in their operations.
2. Background Information.
The primary difficulty with using optical signals for object detection is distinguishing valid signals from ambient light energy noise. This invention employs digital data error detection principles to insure that the received signal accurately indicates the presence or absence of an object.
Noise rejection or avoidance in optical sensor systems has usually been attacked using one of two methods. The first method simply looks for "clean" time slots without noise and transmits signals during these clean time slots. The second method transmits a master-clocked continuous pulsed signal and a corresponding master-clocked synchronous signal, and verifies that the received signal exactly matches both the transmitted pulsed and synchronous signals. These described methods for rejecting or avoiding noise in optical sensor systems are generally disclosed in the following United States patents: Skell et al, U.S. Pat. No. 5,550,369; Skell et al., U.S. Pat. No. 5,491,333; Grozinger et al., U.S. Pat. No. 5,250,801; Schiller, U.S. Pat. No. 5,245,177; Kim, U.S. Pat. No. 4,973,834; Hatten et al, U.S. Pat. No. 4,282,430; Hosel, 5,002,102; Fukuyama et al., U.S. Pat. No. 4,306,147; Devale, U.S. Pat. No. 4,437,499; and Upton, U.S. Pat. No. 4,202,387.
This invention differs significantly from known art. No attempt is made to pre-filter the noise to a relatively low level with respect to the signal nor to identify "clean" time slots in which to transmit a signal. Moreover, this method does not depend on a master clock, a continuous pulsed signal, or a corresponding synchronous circuit. Rather, the present invention transmits a burst of digitally encoded data as required to control the equipment, system, or process that is the object of the design. Furthermore, both the data content and period between bursts are varied. This asynchronous transmission of digitally encoded data provides an effective method for distinguishing valid signals from ambient light energy noise.
An object of the invention is to provide a touchless, economical and reliable object proximity device using an optical sensor system. It is a further object of the invention to verify the presence of an object within a predetermined area using principles of digital data transmission, reception and error detection.

Apparatus and method for detecting an object using digitally encoded optical signals