Patents by Inventor Toshikazu Nagaki
Toshikazu Nagaki 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: 20110169811Abstract: A sustain pulse generating circuit has a power recovery circuit and an auxiliary circuit. The power recovery circuit has an inductor with a first coil, a second coil, and a third coil, and a capacitor. The auxiliary circuit has a first auxiliary switch and a second auxiliary switch. The sustain pulse generating circuit energizes the first auxiliary switch and stores energy in a forward direction to the first coil immediately before the sustain pulse rise. Immediately before the sustain pulse falls, the sustain pulse generating circuit energizes the second auxiliary switch and stores energy in a reverse direction to the second coil. When the sustain pulse rises and falls, the current flowing between the power recovery circuit and the capacitive load is the current produced by LC resonance plus the current produced by the energy previously stored in the recovery inductor.Type: ApplicationFiled: April 15, 2009Publication date: July 14, 2011Applicant: Panasonic CorporationInventor: Toshikazu Nagaki
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Patent number: 7915832Abstract: A drive circuit for driving a plasma display panel (PDP) includes a pulse voltage generator that contains main switching elements disposed on a high voltage side and on a low voltage side, is operable to generate a pulse voltage by operating the main switching elements in accordance with an output voltage from a first power supply and apply the pulse voltage to a PDP scan electrode and sustain electrode, and a reset voltage generator operable to generate a reset voltage in accordance with an output voltage from a second power supply and apply it to the PDP. The pulse voltage generator contains a first diode that prevents the voltage output by the reset voltage generator from being applied backward to the first power supply and a first switching element connected to the first diode in parallel.Type: GrantFiled: February 8, 2006Date of Patent: March 29, 2011Assignee: PANASONIC CorporationInventors: Yasuhiro Arai, Hideki Nakata, Toshikazu Nagaki, Satoshi Ikeda
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Publication number: 20110001745Abstract: The invention reduces power consumption, reduces EMI, and produces a stable sustain discharge. The sustain pulse generating circuit includes a power recovery circuit, clamping circuit, and auxiliary circuit. The power recovery circuit has a recovery inductor for LC resonance and a recovery capacitor for power recovery, recovers power stored in the capacitive load of the display electrode pairs to the recovery capacitor by LC resonance, and reuses the recovered power to drive the display electrode pairs. A clamping circuit clamps the display electrode pairs to the supply potential and the ground potential. An auxiliary circuit has an auxiliary capacitor connected in series with the recovery capacitor, and an auxiliary inductor that is used for LC resonance with the auxiliary capacitor, and increases the current flowing to the recovery inductor at the sustain pulse rise and fall to greater than the current that flows only as a result of the LC resonance of the recovery inductor and the capacitive load.Type: ApplicationFiled: February 5, 2009Publication date: January 6, 2011Applicant: PANASONIC CORPORATIONInventor: Toshikazu Nagaki
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Patent number: 7852289Abstract: A PDP driving circuit is comprised of a power recovery unit for recovering an electric power from a capacitive load by resonance operation with PDP which is the capacitive load Cp, and reusing the recovered power. The power recovery unit includes a recovery inductor for resonating with the capacitive load, a recovery switch element for connecting the recovery capacitor to the capacitive load and recovery inductor, and forming a channel for passing resonance current, a counterflow preventive diode for blocking flow of current in the recovery switch element in reverse polarity direction, and a protective diode for forming a closed current channel including the recovery inductor and recovery switch element when the counterflow preventive diode is changed from ON state to OFF state.Type: GrantFiled: May 14, 2007Date of Patent: December 14, 2010Assignee: Panasonic CorporationInventors: Yasuhiro Arai, Manabu Inoue, Toshikazu Nagaki
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Publication number: 20100066718Abstract: In a driving device of a plasma display panel including switch circuits (Q1, Q2) that selectively connect either a first node (N1) or a second node (N2) to a scan electrode (SC1), a voltage hold circuit (200) that is provided between the first node (N1) and a third node (N3) for holding a voltage between the first node (N1) and the second node (N2) to a first voltage (Vscn), a protection circuit (300) that is provided between the second node (N2) and the third node (N3), and a potential of the first node (N1) being changed, the protection circuit (300) includes a protective resistance (R1), a rectification circuit composed of a capacitor (C1), a charge restriction resistance (R2), and a diode (Da) connected in parallel to the protective resistance (R1), two discharge resistances (R3, R4) connected in parallel to the capacitor (C1), and a transistor (Q10) that generates an abnormality detection signal (SOS) based on a potential of a connection point (N7) of the two discharge resistances (R3, R4).Type: ApplicationFiled: February 20, 2008Publication date: March 18, 2010Applicant: PANASONIC CORPORATIONInventors: Masaaki Kuranuki, Toshikazu Nagaki, Kazuo Oohira
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Publication number: 20090058310Abstract: A drive circuit for driving a plasma display panel (PDP) includes a pulse voltage generation circuit (5101) that contains main switching elements disposed on the high voltage side and on the low voltage side, is operable to generate a pulse voltage by operating the main switching elements in accordance with an output voltage from a first power supply (V1) and apply the pulse voltage to a PDP scan electrode and sustain electrode, and a reset voltage generation circuit (52) operable to generate a reset voltage in accordance with an output voltage from a second power supply (V2) and apply it to the PDP. The pulse voltage generator C circuit contains a first diode (D11) that prevents the voltage outputted by the reset voltage generation circuit from being applied backward to the first power supply and a first switching element (S11) connected to the first diode in parallel.Type: ApplicationFiled: February 8, 2006Publication date: March 5, 2009Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Yasuhiro Arai, Hideki Nakata, Toshikazu Nagaki, Satoshi Ikeda
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Patent number: 7471264Abstract: A reset pulse generating section applies the total of voltages of a positive voltage source and two constant-voltage sources from a high side ramp wave generating section to a high side scan switching device as the upper limit of a reset voltage pulse, and applies the ground potential from a low side ramp wave generating section to a low side scan switching device as the lower limit of the reset voltage pulse. A sustaining pulse generating section applies the upper and lower limits of a sustaining voltage pulse through a common sustaining pulse transmission path to the low side scan switching device.Type: GrantFiled: April 4, 2005Date of Patent: December 30, 2008Assignee: Panasonic CorporationInventors: Manabu Inoue, Satoshi Ikeda, Yasuhiro Arai, Toshikazu Nagaki, Hideki Nakata, Jumpei Hashiguchi, Fumito Kusama
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Publication number: 20070268216Abstract: A PDP driving circuit is comprised of a power recovery unit for recovering an electric power from a capacitive load by resonance operation with PDP which is the capacitive load Cp, and reusing the recovered power. The power recovery unit includes a recovery inductor for resonating with the capacitive load, a recovery switch element for connecting the recovery capacitor to the capacitive load and recovery inductor, and forming a channel for passing resonance current, a counterflow preventive diode for blocking flow of current in the recovery switch element in reverse polarity direction, and a protective diode for forming a closed current channel including the recovery inductor and recovery switch element when the counterflow preventive diode is changed from ON state to OFF state.Type: ApplicationFiled: May 14, 2007Publication date: November 22, 2007Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Yasuhiro ARAI, Manabu INOUE, Toshikazu NAGAKI
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Patent number: 7288868Abstract: A motor generator is provided with a stator having a winding around each of a plurality of stator teeth, and a rotor having a plurality of permanent magnets by the number larger than that of the stator teeth, arranged in the circumferential direction at equal intervals. The stator teeth are formed of a first stator teeth section including a plurality of stator teeth groups I, II, and III each including the adjacent stator teeth around which a winding to which the same phase voltage is applied is wound and in which winding directions of the stator teeth are opposite to each other, and a second stator teeth section including a stator teeth having a winding wound therearound and being placed among stator teeth groups of different phases such that electric power is independently input and output with respect to the first and second winding sections.Type: GrantFiled: August 26, 2004Date of Patent: October 30, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Satoshi Tamaki, Yasuhiro Kondo, Toshikazu Nagaki, Hideki Nakata
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Publication number: 20070205964Abstract: A plasma display panel (PDP) display device is provided, which can reduce the power consumption in the PDP display device without lowering of the display luminance of the PDP and has excellent reliability in suppressing rise of temperature. The PDP display device has a PDP (1) having a plurality of electrodes, a drive circuit (2) for supplying a driving waveform to the electrode, a power supply circuit (3) for supplying a power to the drive circuit, and a power control circuit (4) for adjusting an output power which can be supplied to an electrode of a plasma display panel by controlling a stop period of the power supply circuit based on emission state of the plasma display panel.Type: ApplicationFiled: March 25, 2005Publication date: September 6, 2007Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventor: Toshikazu Nagaki
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Publication number: 20050285820Abstract: A reset pulse generating section applies the total of voltages of a positive voltage source and two constant-voltage sources from a high side ramp wave generating section to a high side scan switching device as the upper limit of a reset voltage pulse, and applies the ground potential from a low side ramp wave generating section to a low side scan switching device as the lower limit of the reset voltage pulse. A sustaining pulse generating section applies the upper and lower limits of a sustaining voltage pulse through a common sustaining pulse transmission path to the low side scan switching device.Type: ApplicationFiled: April 4, 2005Publication date: December 29, 2005Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Manabu Inoue, Satoshi Ikeda, Yasuhiro Arai, Toshikazu Nagaki, Hideki Nakata, Jumpei Hashiguchi, Fumito Kusama
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Publication number: 20050046304Abstract: A motor generator is provided with a stator having a winding around each of a plurality of stator teeth, and a rotor having a plurality of permanent magnets by the number larger than that of the stator teeth, arranged in the circumferential direction at equal intervals. The stator teeth are formed of a first stator teeth section including a plurality of stator teeth groups I, II, and III each including the adjacent stator teeth around which a winding to which the same phase voltage is applied is wound and in which winding directions of the stator teeth are opposite to each other, and a second stator teeth section including a stator teeth having a winding wound therearound and being placed among stator teeth groups of different phases such that electric power is independently input and output with respect to the first and second winding sections.Type: ApplicationFiled: August 26, 2004Publication date: March 3, 2005Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Satoshi Tamaki, Yasuhiro Kondo, Toshikazu Nagaki, Hideki Nakata
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Publication number: 20040251763Abstract: A motor is provided, which produces a high level of torque, displays minimal distortion of the induced voltage waveform, and is capable of being optimized in accordance with the required levels of controllability and cogging torque. The motor comprises a stator, in which windings are wound around each of a plurality of stator teeth provided on a stator core, and a rotor, in which a plurality of permanent magnets that exceeds the number of stator teeth are disposed at equal intervals around a periphery of a rotor core. In this motor, the stator teeth are arranged into a plurality of stator teeth groups, in which the windings to which the same phase voltage is applied are positioned adjacent to one another, and the windings on adjacent stator teeth in the group are wound in opposite directions.Type: ApplicationFiled: June 10, 2004Publication date: December 16, 2004Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Satoshi Tamaki, Yasuhiro Kondo, Toshikazu Nagaki, Hideki Nakata, Naoyuki Kadoya
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Patent number: 6750637Abstract: A DC—DC conversion switching power supply is provided, including a plurality of DC—DC converters connected in parallel. A three-times frequency waveform which is generated from a three-times frequency waveform generation circuit, and is in sync with an oscillation frequency of the DC—DC converters is superimposed on a control voltage which is compared with a switching current signal in a current mode control circuit for controlling the DC—DC converters, or a signal proportional to the switching current signal to control a switching current pulse. Since superimposing the three-times frequency waveform which falls over one period increases the control voltage decreased by switch-on noise of the other DC—DC converter, malfunction at a switch-on phase of the other DC—DC converter, caused by the decrease of the control pulse width, is prevented.Type: GrantFiled: November 19, 2002Date of Patent: June 15, 2004Assignee: Matsushita Electric Co., Ltd.Inventors: Toshikazu Nagaki, Yoshio Mizutani
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Publication number: 20030095422Abstract: A DC-DC conversion switching power supply is provided, including a plurality of DC-DC converters connected in parallel. A three-times frequency waveform which is generated from a three-times frequency waveform generation circuit, and is in sync with an oscillation frequency of the DC-DC converters is superimposed on a control voltage which is compared with a switching current signal in a current mode control circuit for controlling the DC-DC converters, or a signal proportional to the switching current signal to control a switching current pulse. Since superimposing the three-times frequency waveform which falls over one period increases the control voltage decreased by switch-on noise of the other DC-DC converter, malfunction at a switch-on phase of the other DC-DC converter, caused by the decrease of the control pulse width, is prevented.Type: ApplicationFiled: November 19, 2002Publication date: May 22, 2003Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTDInventors: Toshikazu Nagaki, Yoshio Mizutani
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Patent number: 6344982Abstract: A power supply circuit employed in various types of electronic appliances, telecommunications equipment, and the like, is provided for generating a voltage pulse by resonance effect of a primary side of a transformer, and outputting the voltage pulse from a secondary side after raising a voltage thereof. The power supply suppresses fluctuations of electric current, and prevents noise from being propagated through a device powered by the supply. A control circuit actuates a second switching element into a non-conducting state while a first switching element is in a conducting state. The power supply switches the second switching element into a conducting state when voltage of a primary coil is greater than voltage of a driving power supply after an electric current flows in a first diode while the first switching element is in a non-conducting state.Type: GrantFiled: November 29, 2000Date of Patent: February 5, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Sadao Morimoto, Toshikazu Nagaki
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Patent number: 6252782Abstract: In a switching power supply apparatus, two mutually coupled inductors 41a, 41b are connected to both ends of a primary winding of a transformer, and a pair of switching units 21, 22 and a pair of switching units 23, 24 are connected to the other ends of the inductors 41a, 41b, respectively, while two diodes 51, 52 are connected at one end to both ends of the primary winding of the transformer and at the other end to a power supply, wherein the pair of switching units 21, 22 and the pair of switching units 23, 24 each constitute a series circuit in which the two switching means alternately turn on and off with a dead time period between the turning off of one switching unit and the turning on of the other switching unit, and wherein a voltage phase difference at a connection point between the two series circuits is 180° and the duty ratio of each of switching units is controlled.Type: GrantFiled: December 6, 1999Date of Patent: June 26, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiroki Akashi, Toshikazu Nagaki