Patents by Inventor Kazuo Okubo
Kazuo Okubo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5872862Abstract: An electron beam tester scans a sample with an electron beam to provide a secondary electron image, matches wiring patterns of the secondary electron image with wiring patterns prepared from CAD data, measures voltages of the wiring patterns, and corrects deformation of the secondary electron image. The electron beam tester comprises a pattern matching unit, a wiring pattern tester, a secondary electron image corrector, a wiring pattern inspection unit, and a pattern matching processor. The pattern matching unit simply and quickly matches the wiring patterns of the secondary electron image with the wiring patterns prepared from the CAD data. The wiring pattern tester detects slippage between layers of a multilayered semiconductor chip and correctly positions the electron beam on the chip during a pattern matching operation. The secondary electron image corrector accurately and automatically corrects deformation of the secondary electron image.Type: GrantFiled: February 6, 1997Date of Patent: February 16, 1999Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Hironori Teguri, Akio Ito
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Patent number: 5825912Abstract: An Electron Beam Tester which corrects deformation of a secondary electron image produced from scanning a sample with an electron beam. The secondary electron image is stored in a storage unit. Luminance data of the stored image is accumulated to obtain a projected luminance distribution. The projected luminance distribution data is then analyzed by a parallelism evaluation unit to obtain a rotation angle. Then the rotation angle is used to determine maximum parallelism and correct deformation of the secondary electron image by providing deflection control which transforms the deflectors .Type: GrantFiled: January 10, 1997Date of Patent: October 20, 1998Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Hironori Teguri, Akio Ito
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Circuit pattern inspecting device and method and circuit pattern arrangement suitable for the method
Patent number: 5641960Abstract: A circuit pattern inspection device includes a stage on which circuit patterns to be inspected are arranged so as to be symmetrical about a center of the stage about which the stage can rotate, a plurality of sensors which are positioned with respect to the center and scan the circuit patterns, and a signal processing circuit which determines whether or not the circuit patterns are normal on the basis of output signals of the plurality of sensors.Type: GrantFiled: November 4, 1994Date of Patent: June 24, 1997Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Masafumi Asai -
Patent number: 5600734Abstract: An electron beam tester scans a sample with an electron beam to provide a secondary electron image, matches wiring patterns of the secondary electron image with wiring patterns prepared from CAD data, measures voltages of the wiring patterns, and corrects deformation of the secondary electron image. The electron beam tester comprises a pattern matching unit, a wiring pattern tester, a secondary electron image corrector, a wiring pattern inspection unit, and a pattern matching processor. The pattern matching unit simply and quickly matches the wiring patterns of the secondary electron image with the wiring patterns prepared from the CAD data. The wiring pattern tester detects slippage between layers of a multilayered semiconductor chip and correctly positions the electron beam on the chip during a pattern matching operation. The secondary electron image corrector accurately and automatically corrects deformation of the secondary electron image.Type: GrantFiled: December 19, 1994Date of Patent: February 4, 1997Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Hironori Teguri, Akio Ito
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Patent number: 5416426Abstract: A method of measuring a voltage with an electron beam apparatus considers a change in a convergence factor due to a change in an S curve, as well as an error in a secondary electron signal level with a phase of measurement being scanned at random, to accurately measure the voltage. The method measures the voltage of a voltage measuring spot on a sample, prepares an analytic voltage by superimposing a probe voltage having an average of 0 V and no correlation with the measured voltage on the measured voltage, measures a secondary electron signal level with the analytic voltage, computes a convergence factor around a slice level set on the S curve according to a correlation between the secondary electron signal level and the probe voltage and according to an autocorrelation of the probe voltage, and updates the analytic voltage according to the convergence factor, thereby updating the measured voltage.Type: GrantFiled: December 30, 1993Date of Patent: May 16, 1995Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Akio Ito, Takayuki Anbe, Hironori Teguri
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Patent number: 5391975Abstract: A constant-frequency electric power source including an A.C. generator having a field coil, to be driven by an engine and a converter unit which includes a rectifying circuit and an inverter. A controller controls the A.C. generator, and the A.C. generator has at least two groups of multi-phase output coils, one group of the at least two groups of multi-phase output coils being connected to the converter unit for providing an A.C. electric power with a constant-voltage and a constant frequency to be supplied to a first load, and the remaining groups of the at least two pairs of multi-phase output coils being connected to other loads respectively. The output of the remaining groups is supplied to the A.C. generator controller thereby controlling the input of the field coil of the A.C. generator. The A.C. electric power used for the first load is different from the A.C. electric power used for the other loads.Type: GrantFiled: April 23, 1993Date of Patent: February 21, 1995Assignee: Shinko Denki Kabushiki KaishaInventor: Kazuo Okubo
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Patent number: 5331275Abstract: A probing device includes a minute probe in which at least an end portion is formed by conductive material, a cantilever having one end to which the probe is attached, and another end fixed to a moving member movable relatively to a sample in each direction of X, Y and Z, a unit for moving the moving member relatively to the sample, a transducing unit for generating information of voltage or current by means of light, a connecting unit having a low electric resistance, for connecting the transducing unit and the end portion of the probe, a detecting unit for detecting a change in a physical amount occurring in the cantilever by a force caused between the probe and the sample by a relative proximity of the moving member to the sample, and a voltage measuring unit for measuring a voltage at a measurement point on the sample, which is determined based on an output of the detecting unit, by way of the transducing unit when the probe is contacted with the measurement point.Type: GrantFiled: December 9, 1992Date of Patent: July 19, 1994Assignee: Fujitsu LimitedInventors: Kazuyuki Ozaki, Shinichi Wakana, Yoshiro Goto, Akio Ito, Kazuo Okubo, Soichi Hama, Akira Fujii, Yoko Sato
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Patent number: 5300880Abstract: A method of measuring a voltage with an electron beam apparatus considers a change in a convergence factor due to a change in an S curve, as well as an error in a secondary electron signal level with a phase of measurement being scanned at random, to accurately measure the voltage. The method measures the voltage of a voltage measuring spot on a sample, prepares an analytic voltage by superimposing a probe voltage having an average of 0 V and no correlation with the measured voltage on the measured voltage, measures a secondary electron signal level with the analytic voltage, computes a convergence factor around a slice level set on the S curve according to a correlation between the secondary electron signal level and the probe voltage and according to an autocorrelation of the probe voltage, and updates the analytic voltage according to the convergence factor, thereby updating the measured voltage.Type: GrantFiled: March 19, 1992Date of Patent: April 5, 1994Assignee: Fujitsu LimitedInventors: Kazuo Okubo, Akio Ito, Takayuki Anbe, Hironori Teguri
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Patent number: 4841216Abstract: An AC exciter and a main AC generator are mounted on a common rotating shaft of an engine, and a power rectifier and a power inverter are connected in series to the output of the main AC generator. In starter mode, an external AC power source is connected by a switch to the input of the power rectifier, and the output of the power inverter is applied to an armature winding of the main AC generator to drive it as a nocommutator motor to start the engine. A permanent magnet AC generator is also mounted on the common shaft of the engine to provide DC excitation to the AC exciter after converting the output of the permanent magnet AC generator into DC current, and the output of the permanent magnet AC generator is further utilized to detect the rotational speed of the engine to control the switch.Type: GrantFiled: May 20, 1988Date of Patent: June 20, 1989Assignee: Shinko Electric Co., Ltd.Inventors: Yoshimi Okada, Masao Kimura, Kazuo Okubo
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Patent number: 4074333Abstract: An A.C. relay system for making and breaking an A.C. power line utilizing an electromagnetic relay having a coil for opening and closing the mechanical switching contacts, a bilateral gated semiconductor such as a triac connected across the contacts, and a control circuit for switching the relay and triac in proper sequence is disclosed. The control circuit comprises a sequence control unit, a phase detector, a triac firing unit and a relay energizing unit. Upon actuation of the sequence control unit, the triac firing unit first fires the triac and then the relay energizing unit energizes the coil to close the mechanical contacts. To break the A.C. power line, the sequence control unit first de-energizes the relay energizing unit and then after a suitable time interval de-energizes the triac firing unit to cut off the gate signal, the triac being turned off when the load current on the power line is below a triac holding current.Type: GrantFiled: July 15, 1976Date of Patent: February 14, 1978Assignee: Shinko Electric Company, Ltd.Inventors: Kanemichi Murakami, Yoshihiro Ishida, Kazuo Okubo