Patents by Inventor Tadashi Ishikawa
Tadashi Ishikawa 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: 5748460Abstract: In a power supply apparatus which is used for an image forming apparatus, even when a resonance frequency extremely changes due to an influence by an inductance load just after a fluorescent lamp was lit on and after completion of the stabilization after the light-on, the apparatus can immediately follow such a change and can generate a stable voltage.Type: GrantFiled: February 11, 1997Date of Patent: May 5, 1998Assignee: Canon Kabushiki KaishaInventor: Tadashi Ishikawa
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Patent number: 5636009Abstract: An image forming apparatus includes a movable image bearing member, having a photosensitive layer; an image forming device for forming an image on the image bearing member: a charging member for charging the image bearing member; and a light radiating device for radiating light on the image bearing member; a detector for detecting a datum rotating to a thickness of the photosensitive layer on the basis of the voltage-current characteristic between the charging member and image bearing member; and a controller for controlling the amount of light radiated from the light radiating device to be increased with decrease in the thickness of the photosensitive layer, in response to the detector.Type: GrantFiled: June 12, 1996Date of Patent: June 3, 1997Assignee: Canon Kabushiki KaishaInventors: Takao Honda, Tsuyoshi Watanabe, Tadashi Ishikawa, Masanori Muramatsu, Isamu Sato, Makoto Yanagida, Fumihiro Arahira, Takeo Yamamoto
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Patent number: 5627434Abstract: An apparatus for operating a fluorescent lamp having first and second power source circuits, the second power source circuit including a high frequency transformer having two or more outputs for supplying pre-heating electric currents to filaments, the second power source circuit being arranged to be controllable individually from the first power source circuit for supplying a tube electric current to turn on a fluorescent lamp so that the electric power level for pre-heating the filaments is switched between a state where a light adjustment is performed by turning on/off a tube electric current at high frequency and a state where the fluorescent lamp is turned off in a standby mode.Type: GrantFiled: October 20, 1994Date of Patent: May 6, 1997Assignee: Canon Kabushiki KaishaInventors: Toshiyuki Sekiya, Tadashi Ishikawa, Atsushi Asayama
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Patent number: 5619403Abstract: In a multi-output power supply apparatus including a primary winding and a plurality of secondary windings, the switching operation of the primary winding is controlled in accordance with the output of one of the secondary windings. The switching operation of a switching device for switching the output of another secondary winding is synchronized with the switching operation of the primary winding, or is controlled in accordance with an input voltage for the primary winding.Type: GrantFiled: July 20, 1993Date of Patent: April 8, 1997Assignee: Canon Kabushiki KaishaInventors: Tadashi Ishikawa, Atsushi Asayama
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Patent number: 5612857Abstract: In a power supply apparatus which is used for an image forming apparatus, even when a resonance frequency extremely changes due to an influence by an inductance load just after a fluorescent lamp was lit on and after completion of the stabilization after the light-on, the apparatus can immediately follow such a change and can generate a stable voltage.Type: GrantFiled: December 29, 1995Date of Patent: March 18, 1997Assignee: Canon Kabushiki KaishaInventor: Tadashi Ishikawa
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Patent number: 5552857Abstract: A multicolor image forming apparatus having a plurality of unicolor imaging units each equipped with at least a developing device anchored to a unit frame and an image carrier drum anchored removably to the unit frame with a predetermined space kept to a roll of the developing device. The unicolor imaging units are installed removably in the apparatus body while being supported respectively by means of slide rails attached to frames of the apparatus body, and toner images produced individually by the unicolor imaging units are transferred onto a recording medium to form a multicolor image.Type: GrantFiled: April 5, 1995Date of Patent: September 3, 1996Assignee: Fuji Xerox Co., Ltd.Inventor: Tadashi Ishikawa
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Patent number: 5414862Abstract: A controller including an analog circuit for controlling a power source of an apparatus and a digital circuit including a CPU for performing sequence control for the apparatus and for controlling the analog circuit. The analog circuit having a comparator for comparing an output of the power source with a reference signal to output a signal for controlling the power source. Both the analog circuit and the digital circuit are integrally formed on a chip.Type: GrantFiled: August 10, 1992Date of Patent: May 9, 1995Assignee: Canon Kabushiki KaishaInventors: Koji Suzuki, Tadashi Ishikawa, Joji Nagahira, Hajime Motoyama
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Patent number: 5392339Abstract: A telephone transfer apparatus for use in a facsimile network system, which is capable of carrying out telephone communications effectively. With a telephone transfer apparatus, it is possible to call up a telephone or an extension telephone having a telephone number registered in advance in case of detecting that a voice request has been established in a transmitting station or that the voice request has been required in a remote station. Accordingly, required information along with facsimile communications can be exchanged without the fall-off of efficiency of main operations.Type: GrantFiled: October 7, 1991Date of Patent: February 21, 1995Assignee: Fuji Xerox Co., Ltd.Inventors: Nobukiyo Sakai, Tadashi Ishikawa, Takashi Sakayama, Michiaki Yoshihara, Takashi Nakajima
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Patent number: 5375220Abstract: A multiprocessor computer system includes main memories and processors which are connected through a crossbar switching network, and a tag copying mechanism having copies of tags of caches of the processors connected to each main memory. When each of the main memories is updated, a corresponding tag copy is checked to discriminate whether or not an updating request hits the cache having an original tag. Upon detection of a hit, a cancel or invalidate request is sent to the processor which corresponds to the hit cache, and which is not a main memory updating request source, thereby invalidating the corresponding cache line of the cache of that processor.Type: GrantFiled: June 30, 1992Date of Patent: December 20, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tadashi Ishikawa
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Patent number: 5289532Abstract: A facsimile terminal capable of automatically dialing a telephone number of location where a remote operator can make a response to a voice request. In case of the remote operator being away from a remote station, a telephone communication becomes possible to send a voice message in addition to facsimile transmission.Type: GrantFiled: September 27, 1991Date of Patent: February 22, 1994Assignee: Fuji Xerox Co., Ltd.Inventors: Tadashi Ishikawa, Takashi Sakayama, Nobukiyo Sakai, Takashi Nakajima, Michiaki Yoshihara
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Patent number: 5285368Abstract: A power source device is disclosed with a transformer having a plurality of windings provided with the secondary of the transformer, first and second smoothing means connected to a predetermined winding in the plurality of windings, a first voltage detection means for detecting a change of an output voltage from the first smoothing means and means for superimposing an output from the first voltage detection means on an output from the second smoothing means and feeding back a superimposed value to the primary of the transformer. The disclosed power source device has less ripple in the output and is stably responsive to an abrupt change of load.Type: GrantFiled: February 27, 1992Date of Patent: February 8, 1994Assignee: Canon Kabushiki KaishaInventor: Tadashi Ishikawa
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Patent number: 5283891Abstract: An error information saving apparatus of a computer includes at least one arithmetic unit, a plurality of storage units, and a control unit, connected to the storage units and the arithmetic unit, for controlling these units to perform a predetermined pipeline operation, wherein the storage units comprise an arithmetic register file consisting of a plurality of registers each of which can be designated as a destination operand in a statement of an operation instruction, a status flag string consisting of a plurality of flags provided in a one-to-one correspondence with the registers of the arithmetic register file, and a destination register number holding unit for sequentially saving and holding the numbers of destination registers of all operations performed while error interrupt processing generated after occurrence of an error is delayed by a predetermined time interval, each time one of the operations is completed.Type: GrantFiled: August 7, 1992Date of Patent: February 1, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Shinichiro Suzuki, Yoichiro Takeuchi, Ikuo Uchihori, Tadashi Ishikawa, Ryuji Sakai
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Patent number: 5175577Abstract: An automatic focusing system for a camera comprises a motor rotatable in opposite directions, a drive member driven for rotation by the motor, a distance-setting member rotatable together with the drive member to place an objective lens in an initial position and movable to a predetermined forward position, and a holding mechanism for holding the distance-setting member in the predetermined forward position. The position of the drive member is identified at each monitoring point, and a position identification signal is generated. The sequence of movement of the distance-setting member is analyzed from a starting position to the predetermined forward position. The system further provides for preventing improper holding of the distance-setting member at its initial position.Type: GrantFiled: November 21, 1991Date of Patent: December 29, 1992Assignee: Seikosha Co., Ltd.Inventors: Nobuo Shinozaki, Hiroyuki Koizumi, Atsushi Takami, Tadashi Ishikawa
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Patent number: 5113501Abstract: An apparatus capable of checking the validity of a microprogram, includes an initializing unit for initializing data representing the validity of each microinstruction of a microprogram to be tested (the validity indicating that each microinstruction is executed), an updating unit for updating the validity data associated with a microinstruction executed when the to-be-tested microprogram is executed, and a reading unit for reading out the validity data when execution of the to-be-tested microprogram is completed.Type: GrantFiled: May 16, 1989Date of Patent: May 12, 1992Assignee: Kabushiki Kaisha ToshibaInventor: Tadashi Ishikawa
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Patent number: 5063530Abstract: A floating-point representation data adding/subtracting apparatus includes first and second adder/subtracter for performing operations of a first mantissa part of first operation data having a larger exponential part and a second mantissa part of second operation data having a smaller exponential part. The first and second adder/subtracter simultaneously execute the operations. One of the operation results of the first and second adder/subtracters is selected as a correct mantissa part operation result.Type: GrantFiled: May 31, 1989Date of Patent: November 5, 1991Assignee: Kabushiki Kaisha ToshibaInventor: Tadashi Ishikawa
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Patent number: 5019840Abstract: A recording apparatus includes: a recording unit for performing a recording onto a recording paper; a paper feeder roller for feeding the recording paper to a recording position of the recording unit; a conveyor for conveying the recording paper in association with the recording by the recording unit; a drive source for driving the conveyor; and a control unit for moving the paper feeder roller from an operation position to a retreat position using the drive power of the drive source.Type: GrantFiled: May 14, 1990Date of Patent: May 28, 1991Assignee: Canon Kabushiki KaishaInventors: Yoshitaka Watanabe, Toshiharu Mamiya, Tadashi Ishikawa, Takashi Endo, Jiro Moriyama
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Patent number: 4945255Abstract: A power source device including a lower voltage inverter transformer having plural secondary windings and a higher voltage inverter transformer having a primary winding connected directly to one of the secondary windings of the lower voltage inverter transformer without any rectifying circuit or inverter circuit interposed therebetween. The lower voltage and higher voltage transformers are contained in the same casing, the internal space of which is filled with an electrically insulative material to provide a unit device.Type: GrantFiled: March 28, 1988Date of Patent: July 31, 1990Assignee: Canon Kabushiki KaishaInventors: Koji Suzuki, George Nagahira, Kazuyoshi Takahashi, Kunio Yoshihara, Toshiro Matsui, Tadashi Ishikawa
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Patent number: 4939580Abstract: A picture reading apparatus is disclosed which comprises a camera which converts a picture to be read to an electric signal, a supporting member for supporting the camera movably, and a voice input unit. A control device serves to minimize the output from the voice input unit during movement of the supporting member. Thus while a mechanism for moving the camera is in operation, the output from the voice input unit is minimized to suppress the output of operational noise. Video output is inhibited during camera movement.Type: GrantFiled: March 6, 1989Date of Patent: July 3, 1990Assignee: Canon Kabushiki KaishaInventors: Tadashi Ishikawa, Yoshitaka Watanabe, Yoshiyuki Mizoguchi
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Patent number: 4929977Abstract: In a camera having a lens shutter and a focal-plane shutter accomplishing the operations of programed exposure and aperture control, a flash photography changeover device includes a first changeover circuit for setting a lens shutter mode for operating the lens shutter as a programed shutter or a focal-plane shutter mode for controlling the shutter speed by the focal-plane shutter and the aperture by the lens shutter; a first driving device for controlling the programed exposure value and/or the aperture value of the lens shutter; a second driving device for controlling the shutter speed of the focal-plane shutter; a sequence control circuit for controlling the operating timings of the two driving devices; a setting circuit for selecting and setting automatic exposures with a natural light and a flash light; and a coercive changeover circuit for setting the lens shutter mode irrespective of the setting of the first changeover circuit when the setting circuit is set to the automatic exposure with the flash ligType: GrantFiled: July 10, 1989Date of Patent: May 29, 1990Assignee: Seikosha Co., Ltd.Inventors: Tadashi Ishikawa, Shigeru Tagami, Kazuo Akimoto, Hiroto Tsuyuki, Michio Kawai, Kanji Ito, Takayuki Sato, Takahito Otora, Teruyo Hayakawa
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Patent number: D308222Type: GrantFiled: September 23, 1986Date of Patent: May 29, 1990Assignee: Canon Kabushiki KaishaInventors: Hiroshi Sano, Tadashi Ishikawa