Patents by Inventor Kenji Yokoyama
Kenji Yokoyama 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: 5264894Abstract: A camera having a red-eye phenomenon preventing emission device, the camera comprising, a shutter having a leading curtain and a trailing curtain, a flash unit capable of flashing in a range of time between immediately after a completion of a running of the leading curtain to immediately before a start of a running of the trailing curtain, and emission control means which disables the red-eye phenomenon preventing emission device when the flash unit is set for flashing immediately before the start of a running of the trailing curtain.Type: GrantFiled: July 10, 1992Date of Patent: November 23, 1993Assignee: Canon Kabushiki KaishaInventors: Ryuichi Kobayashi, Hidehiko Fukahori, Kenji Yokoyama, Tsuyoshi Fukuda
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Patent number: 5262260Abstract: Disclosed is a method for producing an electro-photographic photoreceptor capable of repeated copying without one imagewise exposure for every one copying and which is superior in stability, sensitivity, resolution and tone reproduction. This method comprises converting to an insulator, by irradiation with energy ray, any selected area of a surface of an electrophotographic photoreceptor comprising a conductive substrate, a carrier generation layer and a carrier transport layer composed mainly of a compound which is converted to an insulator by irradiation with energy ray.Type: GrantFiled: May 1, 1992Date of Patent: November 16, 1993Assignee: Toagosei Chemical Industry Co., Ltd.Inventors: Masaaki Yokoyama, Kenji Yokoyama
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Patent number: 5247204Abstract: Interconnection layers are laid on top of one another with an interlayer insulating film therebetween and are electrically connected to each other by a connection portion formed by plating so as to achieve improvement in the initial characteristics and reliability of the multilayer interconnection structure.Type: GrantFiled: May 30, 1991Date of Patent: September 21, 1993Assignee: Seiko Epson CorporationInventor: Kenji Yokoyama
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Patent number: 5227234Abstract: A thermal adhesive vibration damping sheet comprising a sheet substrate having crystalline polyolefin particles attached to a surface thereof, said polyolefin particles having a mean particle size of 1 to 20 .mu.m and exhibiting an endothermic curve having a high temperature side endothermic peak in the range of from 50.degree. to 230.degree. C. as measured by a differential scanning calorimeter. The sheet has improved blocking resistance, adhesion to sheet steel through heat fusion, and impact resistance at low temperatures.Type: GrantFiled: August 7, 1991Date of Patent: July 13, 1993Assignees: Mitsui Petrochemical Industries, Ltd., NEC Environment Engineering, Ltd.Inventors: Kakutaro Kauchi, Youhei Suzuki, Yasumasa Fujii, Kenji Yokoyama, Yoshio Iida, Masahiko Ooyama
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Patent number: 5191616Abstract: An acoustic apparatus comprises a cabinet, and a loudspeaker unit having a pair of input terminal, a first and a second driving systems disposed in the cabinet. The acoustic apparatus is driven by an external power amplifier which normally constant-voltage-drives a conventional loudspeaker. The first driving system supplies the entire of a input driving signal to one input terminal of a loudspeaker unit and the second driving system supplies component signals of the input driving signal other than ones in the specific frequency band. As a result, driving systems drive the loudspeaker unit with the component signals of the input driving signal in the specific frequency band in cooperation with the external amplifier.Type: GrantFiled: December 27, 1990Date of Patent: March 2, 1993Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5182693Abstract: A magnetic disk suitable for high density recording and reproduction of information wherein said disk is a coating type disk comprising a rigid substrate having a magnetic layer coated thereon from a magnetic coating composition of ferromagnetic submicron particles in a binder, wherein the substrate has a surface roughness Ra of up to 0.007 .mu.m, the magnetic layer has a thickness of up to 0.5 .mu.m, a surface roughness Ra of up to 0.005 .mu.m, and a porosity of 4 to 45%.Type: GrantFiled: May 8, 1992Date of Patent: January 26, 1993Assignee: TDK CorporationInventors: Keiji Koga, Jun-ichi Satoh, Kenji Yokoyama, Akinori Nisizawa, Yasumichi Tokuoka
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Patent number: 5160761Abstract: Information is magnetically recorded in and reproduced from a magnetic disk using a flying magnetic head. The disk is a coating type disk comprising a rigid substrate having a magnetic layer coated thereont from a magnetic coating composition of ferromagnetic submicron particles in a binder. High density recording is possible when the substrate has a surface roughness Ra of up to 0.007 .mu.m, the magnetic layer has a thickness of up to 0.5 .mu.m, a surface roughness Ra of up to 0.005 .mu.m, and a porosity of 4 to 45%.Type: GrantFiled: March 24, 1992Date of Patent: November 3, 1992Assignee: TDK CorporationInventors: Keiji Koga, Jun-ichi Satoh, Kenji Yokoyama, Akinori Nisizawa, Yasumichi Tokuoka
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Patent number: 5140486Abstract: Information is magnetically recorded in and reproduced from a magnetic disk using a flying magnetic head. The disk is a coating type disk comprising a rigid substrate having a magnetic layer coated thereon from a magnetic coating composition of ferromagnetic submicron particles in a binder. High density recording is possible when the magnetic layer having a coercive force of at least 1100 Oe and a thickness of up to 0.5 .mu.m is combined with the flying magnetic head whose gap adjoining portion is made of a soft magnetic material having a saturation magnetic flux density of at least 0.7 T.Type: GrantFiled: November 14, 1990Date of Patent: August 18, 1992Assignee: TDK CorporationInventors: Kenji Yokoyama, Akinori Nisizawa, Jun-ichi Satoh, Keiji Koga, Yasumichi Tokuoka
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Patent number: 5140513Abstract: A switching regulated power supply, the output voltage of which is regulated according to a pulse width modulation method, is provided with a reference oscillator for generating first and second synchronizing signals, phases of which are complement each other, first and second time constant circuits, to which the first and second synchronizing signals are supplied respectively, each one of the circuits having a resister and a capacity device including a variable capacity diode, charge speed up diodes coupled in parallel with the resisters, first and second CMOS drive circuits for inputting the output signals of the first and second time constant circuits and for providing drive signals according to the output signals, a DC-DC converter having push-pull switching devices driven by the drive signals of said first and second CMOS drive circuits, and a control circuit for detecting an output voltage of the DC-DC converter and for controlling capacitance of the variable capacity diodes of said first and second timType: GrantFiled: July 30, 1991Date of Patent: August 18, 1992Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5138593Abstract: A device for driving an actuator for tracking-controlling, focus-controlling or otherwise controlling an optical pickup in an optical type recording and/or reproducing device such as a CD (Compact Disc) player, a CD-V (Compact Disc with video) player and an LV (laser vision) player comprises an actuator driving coil for moving an actuator of an optical pickup, a sensor for detecting movement of the actuator, a first servo loop for feeding back detection output of a reflected beam from a recording medium, and a second servo loop for feeding back a detection output of the sensor to the actuator driving coil. The second servo loop functions to restrain an arbitrary movement of the actuator which is not following a command by the first servo loop whereby unnecessary vibration due to transient response is reduced and the actuator becomes easier to handle.Type: GrantFiled: October 3, 1991Date of Patent: August 11, 1992Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5130214Abstract: Disclosed is a method for producing an electrophotographic photoreceptor capable of repeated copying without one imagewise exposure for every one copying and which is superior in stability, sensitivity, resolution and tone reproduction. This method comprises converting to an insualtor, by irradiation with energy ray, any selected area of a surface of an electrophotographic photoreceptor comprising a conductive substrate, a carrier generation layer and a carrier transport layer composed mainly of a compound which is converted to an insulator by irradiation with energy ray.Type: GrantFiled: June 21, 1990Date of Patent: July 14, 1992Assignee: Toagosei Chemical Industry Co., Ltd.Inventors: Masaaki Yokoyama, Kenji Yokoyama
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Patent number: 5080971Abstract: In a magnetic recording medium wherein a metal thin film magnetic layer and an overcoat are formed on a nonmagnetic substrate, durability is improved when the overcoat comprises a plasma-polymerized film and a topcoat of an organic fluorine compound; a plasma-polymerized film, a protective carbon film, and a topcoat of an organic fluorine compound; a plasma-polymerized film containing C, F and H; or a plasma-polymerized organometallic film and a fluorine or silicon-containing topcoat. Oxidation of the upper surface of the magnetic layer with a plasma is also effective.Type: GrantFiled: August 1, 1989Date of Patent: January 14, 1992Assignee: TDK CorporationInventors: Kenji Yokoyama, Masatoshi Nakayama, Toru Shimozawa, Kunihiro Ueda, Fumio Maruta
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Patent number: 5069967Abstract: In a magnetic recording medium wherein a metal thin film magnetic layer and an overcoat are formed on a nonmagnetic substrate, durability is improved when the overcoat comprises a plasma-polymerized film and a topcoat of an organic fluorine compound; a plasma-polymerized film, a protective carbon film, and a topcoat of an organic fluorine compound; a plasma-polymerized film containing C, F and H; or a plasma-polymerized organometallic film and a fluorine or silicon-containing topcoat. Oxidation of the upper surface of the magnetic layer with a plasma is also effective.Type: GrantFiled: August 1, 1989Date of Patent: December 3, 1991Assignee: TDK CorporationInventors: Kenji Yokoyama, Masatoshi Nakayama, Toru Shimozawa, Kunihiro Ueda, Fumio Maruta
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Patent number: 5031221Abstract: The dynamic loudspeaker driving apparatus consists of at least a power amplifier and a feedback circuit. The power amplifier amplifies an input signal so that the dynamic loudspeaker is driven by the amplified input signal. A detecting circuit is further provided in order to accurately detect a motional voltage produced at an equivalent motional impedance of dynamic loudspeaker, and the feedback circuit negatively feedbacks the detected motional voltage to the power amplifier so that distortions due to a transient response of a vibration system of dynamic loudspeaker will be eliminated. The amplified input signal is supplied to a first terminal of dynamic loudspeaker and a voltage at a second input terminal of dynamic loudspeaker is supplied to the feedback circuit, and impedance components other than the equivalent motional impedance can be canceled.Type: GrantFiled: May 27, 1988Date of Patent: July 9, 1991Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5027228Abstract: An analog type magnetic recording and reproducing device such as a tape recorder includes a digital input terminal to which a digital signal is applied, a digital-to-analog converter for converting the digital signal applied to the digital input terminal to an analog signal, an analog magnetic recording and reproducing unit for recording and reproducing an output analog signal of the digital-to-analog converter, an analog-to-digital converter for converting a reproduced analog signal of the analog magnetic recording and reproducing unit to a digital signal; and a digital output terminal from which an output digital signal of the analog-to-digital converter is delivered out. This device is capable of transmitting a signal in digital between an audio source apparatus and this device and between this device and an audio amplifier.Type: GrantFiled: July 25, 1989Date of Patent: June 25, 1991Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5009281Abstract: An acoustic apparatus for improved bass sound reproduction comprises a resonator, a vibrator, and a vibrator drive means. The resonator has a resonance radiation unit for radiating an acoustic wave by resonance, the vibrator has a diaphragm disposed in the resonator, the vibrator drive means has a motional feedback (MFB) means for detecting the movement of the diaphragm and negatively feeding back a motional signal corresponding to the movement of the diaphragm to the input side of the circuit, and the counteraction of the resonator on the diagram is canceled upon driving of the resonator whereby the vibrator may be invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed.Type: GrantFiled: March 1, 1989Date of Patent: April 23, 1991Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5009280Abstract: An acoustic apparatus for improved bass sound reproduction comprising a resonator, a vibrator, and a vibrator drive means, the resnoator having a passive diaphragm serving as a resonance radiation unit for radiating an acoustic wave by resonance, the vibrator having an active diaphragm provided for the resonator, and the vibrator drive means having a drive control means for controlling a drive condition so as to cancel atmospheric counteraction of said resonator at the time of driving of the resonator, whereby the vibrator may be invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed.Type: GrantFiled: March 24, 1989Date of Patent: April 23, 1991Assignee: Yamaha CorporationInventor: Kenji Yokoyama
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Patent number: 5004764Abstract: A composition for a vibration damper, which comprises:100 parts by weight of a resin-forming component comprising (a) a compound containing an epoxy group, and (b) a curing component comprising (i) a polyhydric phenol as a first curing compound and (ii) a second curing compound selected from the group consisting of an acid hydrazide, a urea derivative and an imidazole;50 to 500 parts by weight of a scaly filler;200 parts by weight or less of powdery filler; and100 parts by weight or less of a fibrous filler. A process for the manufacture of the composition, and a vibration damper, also are disclosed.Type: GrantFiled: February 9, 1989Date of Patent: April 2, 1991Assignees: Mitsui Petrochemical Industries, Ltd., NEC Environment Engineering, Ltd.Inventors: Yohzoh Yamamoto, Shuichi Ishiwata, Kenji Yokoyama, Kimio Hasegawa
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Patent number: 4998157Abstract: In a semiconductor device including a substrate of Si or polycrystalline silicon and an interlayer insulation film region, a region for interconnection with the substrate is composed of a refractory metal silicide layer, a refractory metal nitride layer, an Al or Al alloy layer, and possibly a further refractory metal nitride layer, while a region for interconnection on the interlayer insulation film on the substrate is composed of a refractory metal, or refractory metal oxide layer, a refractory metal nitride layer, an Al or Al alloy layer, and possibly a further refractory metal nitride layer, providing interconnections for integrated circuits. In the manufacture of this interconnection structure, rapid thermal annealing is performed at 600.degree.-1000.degree. C. on the refractory metal nitride layer of the region for interconnection with the substrate, followed by the formation of Al or Al alloy layer.Type: GrantFiled: August 1, 1989Date of Patent: March 5, 1991Assignee: Seiko Epson CorporationInventors: Kenji Yokoyama, Juri Kato, Masashi Ogita
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Patent number: 4989187Abstract: An acoustic apparatus comprises a resonator, a vibrator, and a vibrator drive circuit for an improved bass sound reproduction. The resonantor has a resonance radiation unit for radiating an acoustic wave by resonance, and the vibrator has a diaphragm constituting a part of the resonator and disposed in the resonator. The vibrator drive circuit for driving the vibrator has a negative impedance component in an output impedance, and a reaction from the resonator to the diagram is canceled upon driving of the resonator. Accordingly, the presence of the vibrator is invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed. As a result, the resonator can be realized in a compact size, and the resonance acoustic wave can be radiated powerfully.Type: GrantFiled: April 26, 1990Date of Patent: January 29, 1991Assignee: Yamaha CorporationInventor: Kenji Yokoyama