Patents by Inventor Michitaka Ohsawa
Michitaka Ohsawa 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: 7557776Abstract: For a drive circuit of a sustaining discharge circuit of an AC plasma display panel, an idea of current flow parts arrangement is provided to reduce inductance. The configuration includes a plasma display panel on which electrodes are formed, an electric conductive conductor for fixing the panel, a pair of circuit boards fixed onto the conductor using a plurality of fixing members, ground terminals and electric power supplies disposed respectively for the circuit boards, and a pair of connecting circuit boards connected to end portions respectively of the circuit boards and an end portion of the panel. The ground terminals are electrically connected via fixing members to a position near an end portion of the conductor.Type: GrantFiled: April 25, 2005Date of Patent: July 7, 2009Assignees: Hitachi, Ltd., Advanced PDP Development Center CorporationInventors: Hirokazu Inoue, Yukio Akiyama, Kiyoshi Watanuki, Michitaka Ohsawa
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Publication number: 20080150837Abstract: For providing a plasma display apparatus of driving a large-sized PDP thereof, with using a sustain discharge drive waveform for enabling to obtain a high light-emission efficiency, which is made up with a narrow-width pulse of high-voltage and a wide-width pulse of low-voltage accompanying with this, a sustain pulse, to be applied between the sustain discharge electrodes during sustain period, is constructed with a base pulse (P2) and a superpose pulse (P1) to be superposed at a front end portion of this base pulse (P2). The superpose pulse (P1) also has voltage (Vp) for starting the sustain discharge and difference voltage (Vdif) from voltage (Vsu) for stopping the sustain discharge through forming wall electric charges, and further pulse width (T1) shorter than a time-period from staring of the sustain discharge up to self-stoppage thereof. Also, the base pulse (P2) has pulse width (Ts) equal to a sum of the above-mentioned T1 and T2 larger than this T1, and it has the voltage (Vsu) mentioned above.Type: ApplicationFiled: August 31, 2007Publication date: June 26, 2008Inventor: Michitaka Ohsawa
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Publication number: 20080122750Abstract: The present invention realizes, in a plasma display device with two systems (X and Y systems) of sustain circuits integrated, a stable drive and improvement of the service life. In the present invention, X-electrodes are set at the ground potential, and Y-electrodes have, in a reset period, an application of reset pulses having a positive polarity and a negative polarity and, in a sustain period, an application of sustain pulses having the positive polarity and the negative polarity are applied and in a sustain period. Address pulses are applied to the address electrodes in an address period. At least either in the reset period or in the sustain period, pulse signals are applied to the address electrodes. Then, the level of the pulse signal is higher than a level of the address pulse.Type: ApplicationFiled: May 11, 2007Publication date: May 29, 2008Inventor: MICHITAKA OHSAWA
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Patent number: 7301264Abstract: Frusto-conical needle-shaped light guide paths are implanted on the surface of a display panel such that output light from display elements propagate through the needle-shaped light guide paths through total reflection, while external light repeats reflections multiple times on wedge-shaped surfaces of the light guide paths, and attenuates. A light absorbing film is coated on the surfaces of the needle-shaped light guide paths to increase a contrast ratio. Thus, a higher contrast can be accomplished in a bright room, and cross-talk between adjacent pixels is reduced. A reduction in contrast due to display light is also alleviated by employing longer implanted needle-shaped light guide paths, and bringing light incident surfaces of the needle-shaped light guide paths into close contact with the surface of the display panel.Type: GrantFiled: January 31, 2005Date of Patent: November 27, 2007Assignee: Hitachi, Ltd.Inventor: Michitaka Ohsawa
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Patent number: 7242372Abstract: A plasma display apparatus, in which a sustain output device (transistor) with a voltage rating in accordance with the sustain voltage can be used even when a voltage greater than the sustain voltage is applied to a sustain electrode in the reset period and the address period, has been disclosed, wherein, an X or a Y drive circuit, to which a voltage greater than the sustain voltage is applied, comprises a first switch provided between a second sustain drive transistor and the supply source of a second voltage, and the voltage is supplied to the sustain drive transistor in the state in which the first switch is open.Type: GrantFiled: April 1, 2002Date of Patent: July 10, 2007Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Michitaka Ohsawa, Tomokatsu Kishi, Yoshikazu Kanazawa
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Patent number: 7224329Abstract: A PDP apparatus of low power consumption and without erroneous malfunctions is equipped with a sustaining circuit that prevents an on/off timing shift and deterioration of a sustaining pulse produced thereby. Phase adjusting circuits, which adjust the timing of the changing edge of the sustaining pulse, are provided for the sustaining circuit; the power recovery circuit is of improved efficiency; and power consumption is reduced by optimizing the timing of a changing edge of the sustaining pulse The circuit devices used in the sustaining circuits are classified according to delay times and sets of the circuit devices are selected so that the timing of a changing edge of the sustaining pulse falls within a predetermined allowance, and the selected sets of the circuit devices are set to the PDP.Type: GrantFiled: November 1, 2000Date of Patent: May 29, 2007Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Michitaka Ohsawa, Kenji Ishiwata, Takeshi Kuwahara, Yoshikazu Kanazawa, Kenji Kimura, Hidenori Ohnuki, Taizo Ohno
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Patent number: 7002535Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.Type: GrantFiled: June 14, 2004Date of Patent: February 21, 2006Assignees: Hitachi, Ltd., Fujitsu LimitedInventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
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Publication number: 20050237275Abstract: For a drive circuit of a sustaining discharge circuit of an AC plasma display panel, an idea of current flow parts arrangement is provided to reduce inductance. The configuration includes a plasma display panel on which electrodes are formed, an electric conductive conductor for fixing the panel, a pair of circuit boards fixed onto the conductor using a plurality of fixing members,.ground terminals and electric power supplies disposed respectively for the circuit boards, and a pair of connecting circuit boards connected to end portions respectively of the circuit boards and an end portion of the panel. The ground terminals are electrically connected via fixing members to a position near an end portion of the conductor.Type: ApplicationFiled: April 25, 2005Publication date: October 27, 2005Inventors: Hirokazu Inoue, Yukio Akiyama, Kiyoshi Watanuki, Michitaka Ohsawa
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Publication number: 20050190321Abstract: Frusto-conical needle-shaped light guide paths are implanted on the surface of a display panel such that output light from display elements propagate through the needle-shaped light guide paths through total reflection, while external light repeats reflections multiple times on wedge-shaped surfaces of the light guide paths, and attenuates. A light absorbing film is coated on the surfaces of he needle-shaped light guide paths to increase a contrast ratio. Thus, a higher contrast can be accomplished in a bright room, and cross-talk between adjacent pixels is reduced, and a reduction in contrast due to display light is also alleviated by employing longer implanted needle-shaped light guide paths, and bringing light incident surfaces of the needle-shaped light guide paths into close contact with the surface of the display panel.Type: ApplicationFiled: January 31, 2005Publication date: September 1, 2005Applicant: Hitachi, Ltd.Inventor: Michitaka Ohsawa
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Publication number: 20040257309Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.Type: ApplicationFiled: June 14, 2004Publication date: December 23, 2004Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Naboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
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Patent number: 6781564Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.Type: GrantFiled: December 17, 2002Date of Patent: August 24, 2004Assignees: Hitachi, Ltd., Fujitsu LimitedInventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
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Patent number: 6741227Abstract: A color image display apparatus which supplies red, green, and blue color video signals to respective red, green, and blue light emitting cells and performs color image display. Assuming that time response characteristics of light emission by red, green, and blue light emitting cells have respective values TR, TG, and TB, and |X| represents an absolute value of X, then |TR-TG|<|TR-TB| and |TR-TG|<|TG-TB| are satisfied. A front color fringe occurring at a front edge of a moving white rectangular pattern displayed on the color image display apparatus is blue and a rear color fringe occurring at a rear edge of the moving white rectangular pattern displayed on the color image display apparatus is yellow, thereby causing the front color fringe and the rear color fringe to be inconspicuous.Type: GrantFiled: August 9, 2002Date of Patent: May 25, 2004Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Display driver integrated circuit and flexible wiring board using a flat panel display metal chassis
Patent number: 6677664Abstract: A low-cost display driver module that shortens the process for connecting an integrated circuit chip and a wiring pattern on a flexible wiring board and uses a metal chassis on a display panel as a radiator. In this display driver module, an integrated circuit chip with bump electrodes on it is joined with pressure applied by the use of an anisotropic conductive film, an anisotropic conductive paste, a non-conductive resin paste, or a non-conductive resin film and the back of the integrated circuit chip is adhered to a metal chassis on a display panel by the use of an integrated-circuit chip adhesive. As a result, the metal chassis can be used as a radiator for the integrated circuit chip. Batch bonding will enable to shorten time for the connection process and to cut down the cost of installations. Furthermore, a radiator is unnecessary, resulting in a low-cost display driver module.Type: GrantFiled: April 6, 2001Date of Patent: January 13, 2004Assignees: Fujitsu Hitachi Plasma Display Limited, Fuji Electric Co., Ltd.Inventors: Hirokazu Inoue, Toyoshi Kawada, Yuji Sano, Michitaka Ohsawa, Osamu Hirohashi -
Publication number: 20030122737Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.Type: ApplicationFiled: December 17, 2002Publication date: July 3, 2003Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
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Patent number: 6538389Abstract: A plasma display apparatus includes a plurality of first electrodes, a plurality of second electrodes which are arranged in substantially parallel to the plurality of first electrodes and generate electric discharge with the plurality of first electrodes at gaps therebetween, a first drive circuit which applies an electric discharge voltage to the plurality of first electrodes, a second drive circuit which applies an electric discharge voltage to the plurality of second electrodes, and voltage fluctuation balancing units which are provided for wiring lines between the first and second drive circuits and the first and second electrodes, and each of which has a conductive plate layer overlapping at least part of the wiring lines so as to reduce a variation in voltage drops specific to the wiring lines by eddy currents generated in the conductive plate layer in response to currents running through the wiring lines.Type: GrantFiled: November 19, 2001Date of Patent: March 25, 2003Assignees: Hitachi, Ltd., Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Michitaka Ohsawa, Takeshi Kuwahara, Taizo Ohno, Yoshimasa Awata, Takayoshi Nakamura
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Patent number: 6518977Abstract: A color image display apparatus which supplies red, green and blue color video signals to respective red, green and blue light emitting cells and performs color image display. Assuming that time response characteristics of light emission by red, green and blue light emitting cells have respective values TR, TG and TB, and |X| represents absolute value of X, then, |TR−TG|<|TR−TB | and |TR−TG|<|TG−TB| are satisfied.Type: GrantFiled: July 26, 2000Date of Patent: February 11, 2003Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Patent number: 6504310Abstract: A display apparatus uses a sub field which illuminates addressed pixels of a display unit to display an image. The display apparatus includes an image signal processing circuit which performs sub field conversion processing on an input image signal, a computational processing circuit which arranges address data of at least one lower sub field of an image displayed on the display unit identical in plural lines, and a drive circuit which addresses and illuminates pixels of the display unit based on the outputs of the input signal processing circuit and the computational processing circuit. An image corresponding to the input image signal is displayed by driving the display unit with the drive circuit when the computational processing circuit performs addressing of the at least one lower sub field simultaneously in plural lines and address periods which select the illuminated pixels of said display unit are shortened.Type: GrantFiled: May 24, 2002Date of Patent: January 7, 2003Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Publication number: 20020191008Abstract: A color image display apparatus which supplies red, green, and blue color video signals to respective red, green, and blue light emitting cells and performs color image display. Assuming that time response characteristics of light emission by red, green, and blue light emitting cells have respective values TR, TG, and TB, and |X| represents an absolute value of X, then |TR-TG|<|TR-TB| and |TR-TG|<|TG-TB| are satisfied. A front color fringe occurring at a front edge of a moving white rectangular pattern displayed on the color image display apparatus is blue and a rear color fringe occurring at a rear edge of the moving white rectangular pattern displayed on the color image display apparatus is yellow, thereby causing the front color fringe and the rear color fringe to be inconspicuous.Type: ApplicationFiled: August 9, 2002Publication date: December 19, 2002Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Patent number: 6496166Abstract: As is obvious from the description in the specification and the attached drawings, the present invention provides a display apparatus for displaying an image on a display panel by turning on pixels of said display panel, said display apparatus comprising: a display panel provided with: address electrodes driven by address pulses based on a video input signal; and sustain electrodes crossing said address electrodes and sandwiching electrical discharging units of pixels with said address electrodes and driven by sustain pulses; a sustain-electrode drive circuit for generating said sustain pulses and scan pulses, provided with a common circuit for generating said sustain pulses or said scan pulses in response to an operating state thereof and for supplying said scan pulses and said sustain pulses to said sustain electrodes.Type: GrantFiled: June 30, 2000Date of Patent: December 17, 2002Assignees: Hitachi, Ltd., Fujitsu LimitedInventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
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Publication number: 20020175883Abstract: A plasma display apparatus, in which a sustain output device (transistor) with a voltage rating in accordance with the sustain voltage can be used even when a voltage greater than the sustain voltage is applied to a sustain electrode in the reset period and the address period, has been disclosed, wherein, an X or a Y drive circuit, to which a voltage greater than the sustain voltage is applied, comprises a first switch provided between a second sustain drive transistor and the supply source of a second voltage, and the voltage is supplied to the sustain drive transistor in the state in which the first switch is open.Type: ApplicationFiled: April 1, 2002Publication date: November 28, 2002Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Michitaka Ohsawa, Tomokatsu Kishi, Yoshikazu Kanazawa