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).

  • Publication number: 20020140366
    Abstract: 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: Application
    Filed: May 24, 2002
    Publication date: October 3, 2002
    Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
  • Publication number: 20020101174
    Abstract: 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: Application
    Filed: November 19, 2001
    Publication date: August 1, 2002
    Inventors: Makoto Onozawa, Michitaka Ohsawa, Takeshi Kuwahara, Taizo Ohno, Yoshimasa Awata, Takayoshi Nakamura
  • Patent number: 6417822
    Abstract: In an operation of an address period for addressing cells of a display device, such as a plasma display panel, comprising a plurality of cells of three kinds, red (R), green (G), blue (B), which are arranged on a plane for forming a display surface thereof, in which each of said cells comprising: a pair of transparent electrodes provided in parallel to each other; an address electrode being positioned opposing the pair of transparent electrodes; luminescence medium provided on the address electrode; and a discharge space being defined between the pair of transparent electrodes and said fluorescence medium on the address electrode, wherein the address discharge is conducted by applying an address voltage to the address electrode, and the address voltage applied is determined depending upon the each kind of the cells, R, G and B.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: July 9, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Sasaki, Seiichi Yasumoto, Kunio Ando, Masaji Ishigaki, Michitaka Ohsawa, Takeo Masuda, Keizo Suzuki, Masatoshi Shiiki
  • Patent number: 6407506
    Abstract: This specification and drawings disclose a display technology which displays an image by illuminating pixels of a display unit. The apparatus comprises an image signal processing circuit which processes an input image signal, a control circuit which controls display resolution information relating to the image displayed on the display unit, and a drive circuit which drives the display unit based on the output of an input signal processing circuit and the control circuit. The display resolution information is limited by the control circuit, and an image corresponding to an input image signal is displayed on the display unit when a time during which illuminated pixels are selected on the display unit, is shortened.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 18, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
  • Publication number: 20010033009
    Abstract: 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: Application
    Filed: April 6, 2001
    Publication date: October 25, 2001
    Inventors: Hirokazu Inoue, Toyoshi Kawada, Yuji Sano, Michitaka Ohsawa, Osamu Hirohashi
  • Patent number: 6208467
    Abstract: A display apparatus for displaying an image having gradation represented by subfields. The display apparatus includes a display panel, a circuit for outputting information in which a plurality of subfields in one field period is arranged so as to have first plural array portions where allotted light emitting weights increase gradually and second plural array portions where allotted light emitting weights decrease gradually, and a driver for forming a drive signal based on the information and for outputting the drive signal to the display panel.
    Type: Grant
    Filed: January 3, 2000
    Date of Patent: March 27, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
  • Patent number: 6081254
    Abstract: The present invention is a color correction system including an imaging apparatus which inputs or outputs an image signal from a signal processor into or from an image device such as an input device such as a scanner or a camera or an output device such as a display device or a print device and which is constituted so as to correct colors by inputting or outputting image signals via a color converter, the conversion characteristic of which can be controlled according to a variation in the setting status or use environment of the imaging apparatus and faithful color reproduction can be realized between a plurality of imaging apparatuses having different characteristics.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: June 27, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Mariko Tanaka, Shinichi Yamada, Tomoko Ogawa, Yuji Sano, Kiyoharu Kishimoto, Takuya Imaide, Michitaka Ohsawa, Eiichi Yamazaki, Masaaki Kurosu, Hitoshi Yamadera, Takeshi Hoshino, Hiroshi Koizumi, Moritaka Taniguchi, Kouji Kitou, Ikuya Arai
  • Patent number: 6078205
    Abstract: In an address electrode drive circuit of a plasma display panel, clamping diodes which yield a small forward voltage drop and have a fast switching speed are connected between the output terminal of the drive circuit and the power source and between the output terminal of the drive circuit and the ground. A backward current and voltage dashing from the load to the output transistors of the drive circuit are initially bypassed and absorbed with the clamping diodes and subsequently bypassed and absorbed with parasitic diodes of the output transistors, and the drive circuit is protected against the incoming surge current and voltage.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: June 20, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Michitaka Ohsawa, Yoshinori Okada, Yuji Sano
  • Patent number: 6014258
    Abstract: In a color image display apparatus, assuming that time response characteristics of light emission by red, green and blue light emitting cells have values TR, TG and TB, the difference between the values TR and TG is less than that between the values TR and TB and that between the values TG and TB. The apparatus has a subfield arrangement including a portion where a light emitting weight gradually decreases and a portion where the light emitting weight gradually increases, or a subfield arrangement to obtain a plurality of light emission peaks in one field.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: January 11, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
  • Patent number: 5939826
    Abstract: A plasma display panel for plasma display system provides excellent optical characteristics, including a color purity, contrast, and luminance, of a plasma display system. Barrier ribs forming a cell has wavelength-selective reflective filters for reflecting only a light of wavelength needed for display and absorbing the other lights coated thereon. The wavelength-selective reflective filters have phosphors coated thereon. A color filter is inserted between a first front panel and second front glass panel for feeding out the light in a sandwich state.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: August 17, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Michitaka Ohsawa, Hiroshi Ohtaka, Keirou Shinkawa, Ken Hashimoto, Nobuyuki Ushifusa, Seiichi Tsuchida, Tatsuro Kawamura, Teruo Takai
  • Patent number: 5892492
    Abstract: To achieve an expansion of color reproducibility and an improvement in contrast ratio, color filters 8R, 8G and 8B formed in stripes are successively arranged on one surface of a front glass substrate 1, interposing a black matrixes 7 between them. Sustaining electrodes 6 are provided thereon and a dielectric layer 9 and a protecting layer 10 are provided. On a rear glass substrate 2, barrier ribs 3 are provided in the manner they face the respective black matrixes 7, and thus the spaces between the barrier ribs 3 facing the respective color filters 8R, 8G and 8B form cells. The cells are respectively provided with the sustaining electrodes 6 falling at right angles with the address electrodes 4, coated with fluorescent substances 5R, 5G and 5B corresponding to the respective colors, and also sealed to hold discharge gas therein. A wave band selecting filter 11 for screening the light emitted from the discharge gas in the respective cells is provided on the other surface of the front glass substrate 1.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: April 6, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Atsuo Osawa, Michitaka Ohsawa, Masaji Ishigaki, Norio Yatsuda, Takashi Sasaki
  • Patent number: 5883476
    Abstract: A plurality of photo detectors are arranged outside the display screen of a projection display apparatus having a built-in digital convergence correction system and a function for adjusting data in the frame memory so as to coincide the photoelectric devices of the photo detectors with the adjustment patterns is provided. The adjusted data when the convergence on the entire screen of the display is adjusted and the adjusted data when the convergence is adjusted by the adjustment function before misconvergence is generated are memorized beforehand. When misconvergence is generated, the convergence is adjusted by the adjustment function again, and a corresponding correction value is obtained on the photo detector by calculating the adjusted data at this time and the prememorized adjusted data, and a correction value on the entire screen is obtained by executing an interpolation calculation from this correction value, and the misconvergence on the entire screen is corrected.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 16, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Yasuji Noguchi, Yuichiro Kimura, Kuninori Matsumi, Kenicji Matsumoto, Mitsuo Okimoto, Michitaka Ohsawa, Akito Takemoto, Sadao Kubota, Kazuhiro Kaizaki, Chiharu Ishino
  • Patent number: 5818168
    Abstract: A gas discharge display panel which provides sufficient contrast and good accuracy and is high in yield. When a voltage is applied to auxiliary discharge electrodes, auxiliary discharge occurs in an auxiliary discharge space and excited charged particles communicate with a main discharge space through a priming path made in a discharge space separation bulkhead. In this state, when an alternating voltage is applied between bus electrodes on a front substrate, main discharge occurs in the main discharge space, causing Xe atoms in the sealed gas to generate ultraviolet rays, causing a phosphor to emit light. However, since the auxiliary discharge is shielded by a bulkhead and a barrier rib, the phosphor does not emit light when only auxiliary discharge occurs.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: October 6, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyuki Ushifusa, Seiichi Tsuchida, Teruo Takai, Ken Hashimoto, Hiroshi Ohtaka, Michitaka Ohsawa, Eiji Matsuzaki, Masaji Ishigaki, Norio Yatsuda, Takashi Sasaki, Yuji Sano
  • Patent number: 5701061
    Abstract: A cathode-ray tube apparatus capable of reducing a high frequency electric field radiated from the deflection yoke and the deflection and high voltage circuit to the outside of the cathode-ray tube apparatus. Mounted on the deflection yoke or on the cathode-ray tube are an induction coil for generating a pulse voltage opposite in polarity to a high pulse voltage applied to the h and an electric field cancellation electrode made of a conductive wire to which the opposite polarity pulse voltage is applied. When the opposite polarity pulse voltage is applied to the electric field cancellation electrode, the electric field cancellation electrode radiates an electric field opposite in polarity to the high frequency electric field radiated from the deflection yoke to the outside of the cathode-ray tube apparatus to reduce the intensity of the high frequency electric field.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: December 23, 1997
    Assignees: Hitachi, Ltd., Hitachi Mizusawa
    Inventors: Nobutaka Okuyama, Soichi Sakurai, Kouji Kitou, Hiroki Oguro, Isao Yoshimi, Masao Obara, Michitaka Ohsawa, Kouji Fukuma, Kazuo Majima, Yoshio Yoshiwara, Minoru Furuya
  • Patent number: 5546048
    Abstract: A push-pull circuit formed of transistors drives a peaking capacitor of an amplifier circuit to enhance charge and discharge of the peaking capacitor. This reduces a bias current, resulting in reduction of a power consumption. A feedback impedance is connected to an emitter of a transistor to feed an output signal back to an input of the amplifier circuit as a current signal in a wide frequency range. Thus, a high-power, wideband amplifier is accomplished.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: August 13, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Sano, Sadao Tsuruga, Kouji Kitou, Michitaka Ohsawa
  • Patent number: 5475287
    Abstract: A cathode-ray tube apparatus capable of reducing a high frequency electric field radiated from the deflection yoke and the deflection and high voltage circuit to the outside of the cathode-ray tube apparatus. Mounted on the deflection yoke or on the cathode-ray tube are an induction coil for generating a pulse voltage opposite in polarity to a high pulse voltage applied to the h and an electric field cancellation electrode made of a conductive wire to which the opposite polarity pulse voltage is applied. When the opposite polarity pulse voltage is applied to the electric field cancellation electrode, the electric field cancellation electrode radiates an electric field opposite in polarity to the high frequency electric field radiated from the deflection yoke to the outside of the cathode-ray tube apparatus to reduce the intensity of the high frequency electric field.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: December 12, 1995
    Assignees: Hitachi, Ltd., Hitachi Mizusawa Electronics Co., Ltd.
    Inventors: Nobutaka Okuyama, Soichi Sakurai, Kouji Kitou, Hiroki Oguro, Isao Yoshimi, Masao Obara, Michitaka Ohsawa, Kouji Fukuma, Kazuo Majima, Yoshio Yoshiwara, Minoru Furuya
  • Patent number: 5400086
    Abstract: A picture tube drive apparatus for driving a color picture tube. The picture tube drive apparatus comprises a video output circuit which receives video signals, amplifies them and outputs the amplified video signals, a picture tube drive circuit which receives the video signals amplified by the video output circuit for driving said color picture tube based on video signals, said picture tube drive circuit having means for detecting a beam current corresponding to the brightness of each color flowing through said picture tube, a picture tube connected with said picture tube drive circuit for displaying the video signals, a white balance control circuit into which a detection value of a beam current detected by said picture tube drive circuit is inputted and for outputting video signal level compensation signals for adjusting the white balance of the video image displayed on said picture tube to said picture tube drive circuit.
    Type: Grant
    Filed: September 21, 1993
    Date of Patent: March 21, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Sano, Kouji Kitou, Ikuya Arai, Michitaka Ohsawa, Yoshio Amemiya
  • Patent number: 5317239
    Abstract: A deflection yoke having cancelling loop coils for reducing undesired portions of a horizontal deflection magnetic field generated by a deflection yoke body without mislanding. The cancelling loop coils generate a cancelling magnetic field which includes two peaks in a front region and a rear region of the deflection yoke body in which the undesired field portions exist, respectively. The peaks are opposite in direction to the horizontal magnetic field generated by the deflection yoke body, respectively, with same ratio to the deflection magnetic field, so that the undesired magnetic field portions are under-corrected in the front portion and over-corrected in the rear portion.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: May 31, 1994
    Assignees: Hitachi, Ltd., Hitachi Mizusawa Electronics Co., Ltd.
    Inventors: Hiroki Ohguro, Yoshio Yoshiwara, Minoru Furuya, Nobutaka Okuyama, Soichi Sakurai, Michitaka Ohsawa
  • Patent number: 5304946
    Abstract: An amplifier circuit includes a grounded-collector circuit for converting an input signal voltage into a first signal current, a second transistor circuit for transmitting the first signal current to an output side, a variable impedance for converting the first signal current transmitted to the output side into a voltage, and a circuit block having a voltage generation circuit connected in series to the variable impedance. A transistor constituting the grounded-collector circuit has a collector connected to a junction of the voltage generation circuit and the variable impedance and an emitter connected to an input side of the second transistor. The amplifier circuit has an operation point in which input and output voltages are maintained constant even if a gain is varied.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: April 19, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Sano, Michitaka Ohsawa
  • Patent number: 5281938
    Abstract: A deflection system for a cathode-ray tube including a horizontal deflection core, a magnetic coil, and a vertical deflection coil toroidally wound on the magnetic core. The vertical deflection coil has a plurality of superimposed winding layers arranged with respect to a vertical axis of the deflection system with at least one of the layers of the vertical deflection coil being disposed asymmetrically with respect to the vertical axis or disposed symmetrically with respect to the vertical axis and having winding portions delimiting at least one gap along an extent thereof at a position other than the vertical axis. In this manner, an induced voltage in the at least one of the layers is substantially equal to an induced voltage in each of another of the layers at least in the region of the vertical axis, whereby ringing is substantially prevented.
    Type: Grant
    Filed: September 17, 1991
    Date of Patent: January 25, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Nobutaka Okuyama, Souichi Sakurai, Masaki Nakahara, Michitaka Ohsawa, Ichiri Niitsu