Patents by Inventor Takahiro Urakabe
Takahiro Urakabe 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: 20100007290Abstract: A power converting unit supplies a predetermined current to each of light-emitting elements by controlling a duty ratio of a semiconductor switching element. A light-emitting-element selecting unit sequentially selects a light-emitting element to be supplied with the current from the power converting unit. A duty-ratio control unit controls the duty ratio of the semiconductor switching element based on a value obtained by multiplying a gain by a difference between an output current of the power converting unit and a target current. A gain selecting unit changes the gain according to selected light-emitting element.Type: ApplicationFiled: June 22, 2009Publication date: January 14, 2010Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro URAKABE, Takahiko Yamamuro
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Patent number: 7619907Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the samType: GrantFiled: March 31, 2008Date of Patent: November 17, 2009Assignee: Mitsubishi Electric CorporationInventors: Takahiro Urakabe, Matahiko Ikeda, Masaru Kobayashi, Akihiko Iwata, Tatsuya Okuda, Hirotoshi Maekawa, Toshiyuki Kikunaga
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Patent number: 7612509Abstract: A motor controller is provided which can be reduced in the number of the wirings and power semiconductor devices required while maintaining the function equivalent to or higher than that of the motor controller adopting the existing winding changeover scheme, thereby realizing cost and size reduction and life increase. The motor is made in a structure having motor windings opened at both ends. The one end terminals of phase windings are respectively connected to the output terminals of a first inverter circuit while the other end terminals are respectively connected to the output terminals of a second inverter circuit. During power generation, any one of the inverter circuits is driven on all the phases by means of a same control pulse.Type: GrantFiled: August 8, 2007Date of Patent: November 3, 2009Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tsunenobu Yamamoto, Yoshihito Asao
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Publication number: 20090261793Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.Type: ApplicationFiled: May 31, 2007Publication date: October 22, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro Urakabe, Matahiko Ikeda, Akihiko Iwata, Kiyoharu Anzai, Hirotoshi Maekawa, Toshiyuki Kikunaga, Masaru Kobayashi, Tatsuya Okuda
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Patent number: 7570244Abstract: Signal lines for supplying signal currents to respective pixel circuits having light emitting elements are arranged. A signal line driving circuit generates, on a signal line, a signal current corresponding to the image data, by switching bit weighting currents output from bit weighting current source circuits provided for respective bits of the image data, using a switch circuit turned on/off dependent on the corresponding bit. Each current source circuit has a function of correcting the level of the bit weighting current output from itself, based on a reference current of the bit weighting current supplied from a reference current line. Therefore, even when the characteristics of TFTs forming respective current source circuits vary widely, variation in signal currents among the signal lines can be suppressed, and unevenness in emission luminance can be suppressed.Type: GrantFiled: June 17, 2003Date of Patent: August 4, 2009Assignee: Mitsubishi Denki Kabuhsiki KaishaInventors: Masafumi Agari, Hidetada Tokioka, Ryuichi Hashido, Takahiro Urakabe, Suehiro Gotoh, Masashi Okabe, Mitsuo Inoue
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Publication number: 20080253156Abstract: A DC/DC power conversion device with smoothing capacitors including three column circuits share the smoothing capacitors to be connected in parallel, each column circuit have a plurality of circuits connected in series where two MOSFETs are connected in series between both ends of respective smoothing capacitors and LC serial bodies of capacitors and inductors with the same resonant cycle are disposed between the circuits at two middle terminals. Driving signals for the respective column circuits have the same driving cycle identical with the resonant cycle of the LC serial bodies, and are out of phase with each other by 2?/3(rad), and thus charge-discharge currents towards the smoothing capacitors are circulated among the column circuits and ripple currents flowing through the smoothing capacitors are reduced.Type: ApplicationFiled: April 1, 2008Publication date: October 16, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro Urakabe, Matahiko Ikeda, Masaru Kobayashi
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Publication number: 20080252145Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the samType: ApplicationFiled: March 31, 2008Publication date: October 16, 2008Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiro URAKABE, Matahiko Ikeda, Masaru Kobayashi, Akihiko Iwata, Tatsuya Okuda, Hirotoshi Maekawa, Toshiyuki Kikunaga
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Patent number: 7407025Abstract: This invention provides a power unit for an automobile including a motor 6 for starting an engine by transmitting a power thereto and generating a power by receiving a power from the engine during rotation thereof, a power converting circuit 5 for transmitting a power to the motor 6, a battery 1, an energy storing source 20 for storing energy, and a DC/DC converter including at least two switching elements 10, 11, charging the energy storing source 20, and recovering energy in the energy storing source 20 to the battery 1. Since the switch provided in the DC/DC converter is normally turned on when the motor 6 generates power by receiving a power from the engine and charges the battery 1 through the power converting circuit 5 and the DC/DC converter, generation of heat from the DC/DC converter circuit part can be suppressed greatly.Type: GrantFiled: September 18, 2003Date of Patent: August 5, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Yoshikazu Tsunoda
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Publication number: 20080106220Abstract: A discharge lamp lighting apparatus includes a DC-DC converter for outputting voltages having respective different potentials from two wirings, a switching circuit having input terminals connected to the two wirings, an output terminal connected to one electrode of a discharge lamp, and a capacitor having one electrode terminal connected to a second electrode of the discharge lamp and a second electrode terminal connected to one of the two wirings of the DC-DC converter. The switching circuit includes a switching element for controlling connections between one of the two wirings and the output terminal. The other wiring is connected to the output terminal.Type: ApplicationFiled: December 11, 2007Publication date: May 8, 2008Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Takahiro Urakabe, Akihiko Iwata
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Patent number: 7348739Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.Type: GrantFiled: February 2, 2005Date of Patent: March 25, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Toshiyuki Kikunaga, Yuuji Kuramoto
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Patent number: 7327095Abstract: A discharge lamp lighting apparatus includes a DC-DC converter for outputting voltages having respective different potentials from two wirings, a switching circuit having input terminals connected to the two wirings, an output terminal connected to one electrode of a discharge lamp, and a capacitor having one electrode terminal connected to a second electrode of the discharge lamp and a second electrode terminal connected to one of the two wirings of the DC-DC converter. The switching circuit includes a switching element for controlling connections between one of the two wirings and the output terminal. The other wiring is connected to the output terminal.Type: GrantFiled: December 5, 2000Date of Patent: February 5, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Akihiko Iwata
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Publication number: 20070290647Abstract: A motor controller is provided which can be reduced in the number of the wirings and power semiconductor devices required while maintaining the function equivalent to or higher than that of the motor controller adopting the existing winding changeover scheme, thereby realizing cost and size reduction and life increase. The motor is made in a structure having motor windings opened at both ends. The one end terminals of phase windings are respectively connected to the output terminals of a first inverter circuit while the other end terminals are respectively connected to the output terminals of a second inverter circuit. During power generation, any one of the inverter circuits is driven on all the phases by means of a same control pulse.Type: ApplicationFiled: August 8, 2007Publication date: December 20, 2007Inventors: Takahiro URAKABE, Tsunenobu Yamamoto, Yoshihito Asao
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Patent number: 7310475Abstract: A motor driving apparatus is provided which can minimize ripple current flowing through a DC link capacitor, and downsize the motor driving apparatus. It synchronizes the frequency of the inverter carrier signal for driving an inverter with the frequency of the DC/DC converter carrier signal for driving a DC/DC converter, and carries out control in such a manner that the center of a period during which the input current of the inverter is zero and the center of a period during which the output current of the DC/DC converter is zero are matched.Type: GrantFiled: March 31, 2005Date of Patent: December 18, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Okuda, Takahiro Urakabe, Yuuji Kuramoto
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Patent number: 7294984Abstract: A motor controller is provided which can be reduced in the number of the wirings and power semiconductor devices required while maintaining the function equivalent to or higher than that of the motor controller adopting the existing winding changeover scheme, thereby realizing cost and size reduction and life increase. The motor is made in a structure having motor windings opened at both ends. The one end terminals of phase windings are respectively connected to the output terminals of a first inverter circuit while the other end terminals are respectively connected to the output terminals of a second inverter circuit. During power generation, any one of the inverter circuits is driven on all the phases by means of a same control pulse.Type: GrantFiled: November 18, 2005Date of Patent: November 13, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tsunenobu Yamamoto, Yoshihito Asao
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Patent number: 7221064Abstract: A power circuit for a battery for, even when an idle-stop operation is continuously performed, preventing reduction of an electric power supplied to a motor at start-up to obtain a set engine rpm. The power circuit includes a series-connected power supply in which a battery having a load and a capacitor group are connected in series with each other, a DC/DC converter for shifting electric power between the battery and the capacitor group, and between the battery and the load, and a controller for controlling the DC/DC converter. The controller detects the voltage of the capacitor group, and when the voltage detected is lower than a first threshold voltage, controls the DC/DC converter so that the capacitor group is charged with electricity.Type: GrantFiled: December 21, 2005Date of Patent: May 22, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Okuda, Takahiro Urakabe
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Patent number: 7221349Abstract: A display current of a whole gray scale range according to a display signal of four bits is produced from a sum of output currents of an analog current supply circuit producing a first output current according to lower data bits and two digital current supply circuits operating in accordance with corresponding data bits to execute or stop generation of second and third output currents according to higher data bits. The analog current supply circuit has a calibration function of compensating for output current variations due to transistor characteristics at one point in a control range of the first output current. A display device with light-emitting elements can accurately generate a display current for gray-scale expression without imposing an excessive load on a manufacturing process while suppressing circuit footprint.Type: GrantFiled: May 10, 2004Date of Patent: May 22, 2007Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Ryuichi Hashido, Hidetada Tokioka, Masafumi Agari, Suehiro Goto, Takahiro Urakabe
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Publication number: 20070080659Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.Type: ApplicationFiled: February 2, 2005Publication date: April 12, 2007Applicant: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Toshiyuki Kikunaga, Yuuji Kuramoto
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Patent number: 7079094Abstract: In a compensation mode executed before a supply mode, a current supply circuit for supplying a data current according to display luminance to a current-driven light emitting device allows a reference current to pass through a drive transistor for supplying the data current to a data line in the supply mode. The voltage of a node connected to the gate of the drive transistor at this time is held by a voltage holding capacitor. In the supply mode, the voltage of the node changes according to a data voltage. The data voltage is set according to the difference between the data current to be supplied and the reference current.Type: GrantFiled: June 24, 2003Date of Patent: July 18, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hidetada Tokioka, Ryuichi Hashido, Takahiro Urakabe, Masafumi Agari, Masashi Okabe, Mitsuo Inoue
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Patent number: 7075271Abstract: The invention provides an apparatus for bi-directional power conversion between a DC circuit and an AC circuit, which inexpensively and simply suppresses generation losses of elements and reduces heat generation, wherein a voltage obtained by dividing the U-phase voltage Vu is compared with a voltage obtained by dividing the voltage vpn of a DC circuit by a comparator CP1, and the MOSFET UFETh is turned on at the output timing thereof, and a voltage obtained by dividing the V-phase voltage Vv is compared with a voltage obtained by dividing the voltage Vpn of a DC circuit by a comparator CP2, and the MOSFET UFETh is turned off at the output timing thereof.Type: GrantFiled: September 27, 2004Date of Patent: July 11, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Takahiro Urakabe, Tatsuya Okuda, Takamasa Asai, Sigetada Gotou
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Publication number: 20060126253Abstract: In an inverter circuit configured with main circuit switches each having a control terminal and first and second main terminals through which the main current flows, and driving circuits each of which applies the driving voltage to the control terminal of each main circuit switch, and controls the main current in accordance with the voltage between the control terminal and the first main terminal, to switch the main circuit switch, between the main circuit switch and the driving circuit, noise-suppression circuits are provided, each of which is configured so as to detect fluctuations in the voltage between the first and the second main terminals of each main circuit switch, and, in accordance with the amplitude and the frequency of the detected voltage fluctuations, to bring to approximately zero the impedance across the control terminal and the first main terminal of each main circuit switch.Type: ApplicationFiled: December 14, 2004Publication date: June 15, 2006Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventors: Takahiro Urakabe, Takamasa Asai