Patents by Inventor Akira Nagumo
Akira Nagumo 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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Publication number: 20120001996Abstract: A driving device that drives a light emitting thyristor array includes: a first driving circuit operated by a second power source; a scanning circuit including plural stages of scanning thyristors and sequentially scanning the plural stages of light emitting thyristors, a second driving circuit operated by a second power source, generating first and second clock signals for driving the scanning circuit, and outputting the first and second clock signals from first and second clock terminals, respectively, a terminal of an odd numbered stage scanning thyristor is commonly connected to the first clock terminal, another terminal of an even numbered stage scanning thyristor is commonly connected to the second clock terminal, and a control terminal of a first stage scanning thyristor is connected to the second clock terminal via a first resistor.Type: ApplicationFiled: June 22, 2011Publication date: January 5, 2012Applicant: Oki Data CorporationInventor: Akira NAGUMO
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Patent number: 8089501Abstract: A light emitting apparatus includes optical thyristors, a driver circuit that supplies a drive current to the thyristors so that the thyristors emit light, and a control circuit that controls the thyristors. Each thyristor includes an anode, a cathode connected to the ground, and a gate. The thyristor emits light when the drive current flows therethrough. The control circuit controls the gate, causing a control current to flow from the anode to the gate to turn on the thyristors. The control circuit applies a control voltage to the gate, the control voltage being higher than a voltage appearing across the gate and the cathode when the thyristor remains turned on.Type: GrantFiled: December 22, 2008Date of Patent: January 3, 2012Assignee: Oki Data CorporationInventor: Akira Nagumo
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Publication number: 20110285805Abstract: A driving device controls light emitting thyristors that each include a scanning circuit sequentially driving each of the plural stages of the light emitting thyristors by controlling scanning thyristors. Herein, terminals of each odd numbered stage of the scanning thyristors is commonly connected to a first clock terminal, and terminals of each even numbered stage of the scanning thyristors is commonly connected to a second clock terminal. A control terminal of a first stage scanning thyristor is connected to the second clock terminal, and another control terminal of a previous scanning thyristor is connected to the second control terminal of a subsequent scanning thyristor.Type: ApplicationFiled: May 20, 2011Publication date: November 24, 2011Applicant: Oki Data CorporationInventor: Akira Nagumo
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Publication number: 20110261138Abstract: A reference voltage generation circuit includes a first current-mirror circuit including a first MOS transistor connected to a first power source and a second MOS transistor of the first conductive type connected to the first power source; a second current-mirror circuit including a third MOS transistor and a fourth MOS transistor; a first resistor connected to the first node; a first bipolar transistor having a collector connected to the first resistor, an emitter connected to a second power source, and a base connected to the first node; a second bipolar transistor having a collector connected to the second node, an emitter connected to the second power source, and a base connected to the first bipolar transistor; a fifth MOS transistor connected between the first power source and an output terminal; and a third resistor connected between the output terminal and the second power source.Type: ApplicationFiled: April 21, 2011Publication date: October 27, 2011Inventor: Akira Nagumo
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Publication number: 20110262184Abstract: A driver apparatus drives a plurality of light emitting thyristors. Each thyristor includes a cathode connected to the ground, an anode, and a gate. A gate driver circuit outputs a drive signal that electrically drives the gate. A level shifter circuit includes an input terminal connected to the driver circuit and an output terminal connected to the gate of the thyristor. The level shifter circuit operates such that the drive signal is shifted down in signal level and is outputted to the output terminal and a signal at the gate inputted to the output terminal is shifted down in signal level and is outputted to the input terminal. In response to the drive signal outputted from the driver circuit, a current supplying circuit supplies drive current to the anode of the thyristor such that the drive current flows from the anode to the cathode.Type: ApplicationFiled: April 22, 2011Publication date: October 27, 2011Applicant: OKI DATA CORPORATIONInventor: Akira Nagumo
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Publication number: 20110234742Abstract: A drive device to drive a plurality of three-terminal light emitting elements, comprising: a drive circuit including a first MOS transistor and configured to drive conducting three-terminal light emitting elements among a plurality of three-terminal light emitting elements based on a received drive signal. The first MOS transistor includes: a third terminal connected to a second power supply having a potential different from a potential of the first power supply; a fourth terminal connected to the second terminals connected in common, a second control terminal configured to control a conduction state between the third terminal and the fourth terminal based on the drive signal; and a substrate terminal set to have a potential different from the potential of the second power supply in a direction of increasing threshold voltage of the first MOS transistor.Type: ApplicationFiled: March 23, 2011Publication date: September 29, 2011Applicant: OKI DATA CORPORATIONInventor: Akira NAGUMO
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Publication number: 20110234001Abstract: A drive circuit is provided for supplying a drive current to drive a plurality of driven elements each having two main electrodes. The drive circuit includes a switch circuit for receiving a drive signal; and a constant current circuit connected to the switch circuit for adjusting the drive current at a constant level. The constant current circuit is formed of a depletion type MOS transistor.Type: ApplicationFiled: June 9, 2011Publication date: September 29, 2011Inventor: Akira Nagumo
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Publication number: 20110234734Abstract: When the cathode of a light emitting thyristor is at the low (L) level, voltage is applied between the anode and cathode of the light emitting thyristor. In addition, because the gate of each thyristor and the gate of each light emitting thyristor are connected to each other in a self scanning circuit 100, voltage is also applied between the gate and cathode of the thyristor. At this time, by selectively turning only the gate of the light emitting thyristor, which is instructed by the self scanning circuit to emit light, to the high (H) level, the light emitting thyristor that is instructed is turned on. In particular, because an output signal of a clock driving circuit is differentiated by an RL differential circuit to generate an undershoot or overshoot waveform, the number of output terminals of the clock driving circuit can be reduced.Type: ApplicationFiled: March 24, 2011Publication date: September 29, 2011Applicant: Oki Data CorporationInventor: Akira NAGUMO
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Publication number: 20110234743Abstract: A drive device to drive a plurality of three-terminal light emitting elements includes a drive circuit. The drive circuit includes a first and second conductive type MOS transistor complementarily connected to each other and configured to drive three-terminal light emitting elements that are in conduction state based on a received drive signal. The first conductive type MOS transistor is formed in a substrate region and includes a channel formation region, which is a region wherein a channel is to be formed. An impurity with the same polarity as that of the substrate region is injected in the channel formation region.Type: ApplicationFiled: March 23, 2011Publication date: September 29, 2011Applicant: OKI DATA CORPORATIONInventor: Akira NAGUMO
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Publication number: 20110234741Abstract: Each of a plurality of gate driving parts outputs a first potential (2 V) during a period in which the gates of a plurality of thyristors belonging to the corresponding set are driven (S1N=Low) and outputs a second potential (5 V) that is higher than the first potential at a rising part of the anode driving voltage during a period in which the gates of a plurality of thyristors belonging to the corresponding set are not driven (S1N=High). Each of a plurality of gate driving parts outputs a third potential (3 V) that is lower than the second potential at periods other than the rising part of the anode driving voltage during a period in which the gates of a plurality of thyristors belonging to the corresponding set are not driven (S1N=High).Type: ApplicationFiled: March 21, 2011Publication date: September 29, 2011Applicant: Oki Data CorporationInventor: Akira NAGUMO
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Publication number: 20110193924Abstract: A driving circuit includes a reference voltage generating circuit and a driver circuit. The driver circuit drives a driven element at a level determined by the reference voltage output by the reference voltage generating circuit. The reference voltage generating circuit includes a regulating section that generates a regulated voltage, a temperature compensation section that applies a temperature compensation to the regulated voltage to compensate for the temperature characteristics of the driven element, and a voltage amplifying section that amplifies the resulting temperature compensated voltage to generate the reference voltage, thereby supplying a reference voltage high enough to avoid noise effects.Type: ApplicationFiled: February 7, 2011Publication date: August 11, 2011Applicant: OKI DATA CORPORATIONInventor: Akira NAGUMO
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Patent number: 7990407Abstract: A drive circuit is provided for supplying a drive current to drive a plurality of driven elements each having two main electrodes. The drive circuit includes a switch circuit for receiving a drive signal; and a constant voltage circuit connected to the switch circuit for adjusting the drive current at a constant level.Type: GrantFiled: February 26, 2009Date of Patent: August 2, 2011Assignee: Oki Data CorporationInventor: Akira Nagumo
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Publication number: 20110181640Abstract: A driver circuit is used for driving a plurality of groups of switch elements connected between a power supply terminal and a common terminal. Each switch element includes anode connected to the power supply terminal, a cathode, and a gate. The anode is connected to the power supply and the cathode connected to a common terminal. The gate controls electrical conduction between the anode and the cathode. The driver circuit includes a switch circuit connected between the power supply terminal and the common terminal, and a driver circuit into which a drive current flows. The switch circuit is in parallel with the switch elements, and the switch circuit electrically connects or disconnects between the power supply terminal and the common terminal in response to a control signal supplied thereto. A transmission line having a specific characteristic impedance, connected between the common terminal and the driver circuit.Type: ApplicationFiled: January 20, 2011Publication date: July 28, 2011Applicant: OKI DATA CORPORATIONInventor: Akira Nagumo
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Patent number: 7961209Abstract: Each of a plurality of driver circuits includes a first 3-terminal switch element, a second 3-terminal switch element, and a 3-terminal light emitting element driven by the first 3-terminal switch element. The first 3-terminal switch element in a first circuit of adjacent driver circuits is driven by one of first and second clocks and the first 3-terminal switch element in a second circuit of the adjacent driver circuits is driven by the other of the first and second clocks. The second 3-terminal switch element in the first circuit supplies a signal to the second driver circuit, the signal representing an operational state of the first circuit. The second 3-terminal switch element in the first circuit includes a control electrode to which a third clock is supplied. The second 3-terminal switch element in the second circuit includes a control electrode to which a fourth clock is supplied.Type: GrantFiled: August 30, 2006Date of Patent: June 14, 2011Assignee: Oki Data CorporationInventor: Akira Nagumo
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Publication number: 20110133789Abstract: A driver circuit drives a plurality of groups of light emitting elements. Each element includes an anode, a cathode connected to the ground, and a gate that controls electrical conduction between the anode and cathode. A first driver section simultaneously drives the anodes of the elements of the plurality of groups of elements. A second driver section simultaneously drives the gates of the elements in a corresponding group of the plurality of groups. The second driver section includes a series connection of a first switch element and a voltage level shifter. The series connection is connected between a power supply and the group of gates. The second driver section further includes a second switch element connected between the group of gates and the ground.Type: ApplicationFiled: December 3, 2010Publication date: June 9, 2011Applicant: OKI DATA CORPORATIONInventor: Akira Nagumo
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Patent number: 7924304Abstract: A light-emitting element array includes: a resistor connected at a first end to a driving unit; and a plurality of light-emitting elements, each of the plurality of light-emitting elements including a three-terminal switching element having a first terminal, a second terminal, and a third terminal, the first terminal in each of the plurality of light-emitting elements being connected to a second end of the resistor, the second terminal in each of the plurality of light-emitting elements being connected to ground, and the third terminal in each of the plurality of light-emitting elements being connected to a control circuit.Type: GrantFiled: May 26, 2009Date of Patent: April 12, 2011Assignee: Oki Data CorporationInventor: Akira Nagumo
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Patent number: 7923737Abstract: A combined semiconductor device can be formed by bonding the thin-film three-terminal switching elements to a surface of an integrated circuit chip including a shift register that shifts data supplied to the control electrodes of the three-terminal switching elements, or by bonding both the thin-film three-terminal switching elements and another thin semiconductor film including the shift register to a substrate. In either case, thin-film wiring can be used to interconnect the shift register and the switching elements, and the need for an array of large transistors to feed driving current to the switching elements is eliminated, reducing the size and cost of the combined semiconductor device, which can be advantageously used in the optical head of an electrophotographic printer.Type: GrantFiled: August 24, 2006Date of Patent: April 12, 2011Assignee: Oki Data CorporationInventor: Akira Nagumo
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Publication number: 20110050838Abstract: A method of manufacturing a semiconductor composite device, including steps of: preparing a substrate comprising circuit elements, which are part of a driving circuit; attaching an array of driven elements onto the substrate via a passivation layer, the array being formed of a semiconductor thin film having a crystal structure wherein the driven elements are arrayed to be driven by the driving circuit; and forming a metal wire by a photo-lithography method such that the circuit elements are electrically connected with the metal wire to form the driving circuit and the driving circuit is electrically connected to the driven elements with the metal wire.Type: ApplicationFiled: September 1, 2010Publication date: March 3, 2011Applicant: OKI DATA CORPORATIONInventor: Akira NAGUMO
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Publication number: 20110001520Abstract: A driver circuit includes a memory cell for storing data and a data switching circuit. The memory cell includes a first inverter having a first output terminal and a first input terminal and a second inverter having a second output terminal and a second input terminal. The first output terminal is connected to the second input terminal and the second output terminal is connected to the first input terminal. A switch is connected to the first input terminal so that the data is fed to the memory cell through the switch. A voltage shifter supplies a first supply voltage to the first inverter and second inverter while the data is being written into the memory cell and a second supply voltage to the first inverter and second inverter after the data has been written into the memory cell.Type: ApplicationFiled: July 2, 2010Publication date: January 6, 2011Applicant: OKI DATA CORPORATIONInventor: Akira Nagumo
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Patent number: 7821211Abstract: A drive circuit is provided for selectively driving a driven element. The drive circuit includes a discharge section for discharging charges, which are accumulated in the driven element when the drive element is turned on, when the drive element is turned off. The drive circuit may include a drive element for driving the driven element. The drive element includes a first ground route disposed separately from a second ground route of the driven element. The first ground route is connected to the second ground route through a connection cable. A diode may be disposed between the connection cable and at least one of the first ground route and the second ground route.Type: GrantFiled: August 21, 2008Date of Patent: October 26, 2010Assignee: Oki Data CorporationInventor: Akira Nagumo