Patents by Inventor Akihiko Kougami
Akihiko Kougami 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: 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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Patent number: 6633268Abstract: The present invention relates to an AC-type plasma display apparatus, an object of the invention is to provide the AC-type plasma display apparatus improved a quality of a picture of a display image by realizing a multi-sub-field arrangement and a high gray scale arrangement, after by being realized an address discharge at high speed. As illustrated in FIG. 1, an address discharge is constituted so as to be driven at high speed by applying preset pulses 105 of a narrow width prior to time of application of a scanning pulse 106 exceeding a value of a discharge breakdown voltage, and by carrying out growth (growing process of Townsent) of a space charge by the preset pulses 105.Type: GrantFiled: March 20, 2001Date of Patent: October 14, 2003Assignee: Hitachi, Ltd.Inventors: Akihiko Kougami, Keizo Suzuki, Hiroshi Kajiyama
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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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Publication number: 20020140366Abstract: 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: ApplicationFiled: May 24, 2002Publication date: October 3, 2002Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Publication number: 20020109650Abstract: The present invention relates to an AC-type plasma display apparatus, an object of the invention is to provide the AC-type plasma display apparatus improved a quality of a picture of a display image by realizing a multi-sub-field arrangement and a high gray scale arrangement, after by being realized an address discharge at high speed.Type: ApplicationFiled: March 20, 2001Publication date: August 15, 2002Inventors: Akihiko Kougami, Keizo Suzuki, Hiroshi Kajiyama
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Patent number: 6407506Abstract: 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: GrantFiled: March 31, 2000Date of Patent: June 18, 2002Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Patent number: 6333766Abstract: A tone display method for displaying a tone of an image in a display system which divides a time width of a field of an image signal into a plurality of weighted subfields and controls operation of the subfields.Type: GrantFiled: August 8, 2000Date of Patent: December 25, 2001Assignees: Hitachi, Ltd.Inventors: Akihiko Kougami, Masaji Ishigaki, Shigeo Mikoshiba, Takahiro Yamaguchi, Kohsaku Toda
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Patent number: 6208467Abstract: 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: GrantFiled: January 3, 2000Date of Patent: March 27, 2001Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Patent number: 6100939Abstract: A intra-field time division tone display method for dividing the time width in a field of a TV signal into a plurality of subfields in the pixel storing time direction and displaying the TV image by controlling the presence or absence of light emission of the subfields and an apparatus therefor, wherein there are at least two subfields (most significant subfields) whose luminant time widths are longest and almost equal and when it is assumed that the tones are displayed in the ascending order starting from the lowest level of tone in light emission of the subfields, the tone of a TV image signal is displayed under a rule that two or more light emissions are not started from the aforementioned at least two most significant subfields at the same time, accordingly the dynamic false contour noise of a moving image followed by movement of the viewing point can be reduced remarkably and a moving image of high image quality and high quality can be obtained.Type: GrantFiled: September 16, 1996Date of Patent: August 8, 2000Assignees: Hitachi, Ltd., Shigeo Mikoshiba, Takhiro Yamaguchi, Kohsaku TodaInventors: Akihiko Kougami, Masaji Ishigaki, Shigeo Mikoshiba, Takahiro Yamaguchi, Kohsaku Toda
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Patent number: 6028573Abstract: In a method for driving a display device, by which energy stored in a plurality of electrodes serving as a capacitive load is recovered through switches, current paths for charging said electrodes from a charge supplying source differ from current paths for discharging the electrodes for the energy recovery.Type: GrantFiled: September 17, 1996Date of Patent: February 22, 2000Assignee: Hitachi, Ltd.Inventors: Isamu Orita, Akihiko Kougami, Shigeo Mikoshiba, Takeaki Okabe, Kouzou Sakamoto, Masahiro Eto
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Patent number: 6014258Abstract: 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: GrantFiled: July 31, 1998Date of Patent: January 11, 2000Assignee: Hitachi, Ltd.Inventors: Kazutaka Naka, Michitaka Ohsawa, Akihiko Kougami, Hiroshi Ohtaka
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Patent number: 6008687Abstract: A switching circuit has switching elements for passing-through or cutting-off signals of a positive pulse, which is a rectangular pulse rising from a low level and falling after having kept a high level for a certain time as a high voltage input signal, and a negative pulse, which is a rectangular pulse falling from a high level and rising after having kept a low level for a certain time, the switching circuit being applied to a capacitive load driving device.Type: GrantFiled: November 29, 1996Date of Patent: December 28, 1999Assignee: Hitachi, Ltd.Inventors: Isamu Orita, Akihiko Kougami, Shigeo Mikoshiba, Takeaki Okabe, Kouzou Sakamoto, Masahiro Eto
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Patent number: 4799058Abstract: A driving apparatus for a gas discharge display panel having a plurality of cathodes and a plurality of anodes arranged in a matrix includes a cathode pulse generator and an anode pulse generator, with the anode pulse generator generating negative display anode pulses made up of auxiliary discharge pulses (width=tS) and display pulses of smaller pulse width (width=tD, tD.ltoreq.tS) corresponding to information display signals. The anode pulse generator preferably also provides positive display anode pulses so that selection between negative and positive display anode pulses is possible.Type: GrantFiled: October 28, 1985Date of Patent: January 17, 1989Assignee: Hitachi, Ltd.Inventors: Yukio Okamoto, Shinichi Shinada, Kenkichi Suzuki, Akihiko Kougami
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Patent number: 4521816Abstract: A magnetic recording method for digital signals, and more particularly to a magnetic head driving current waveform wherein digital signals to be recorded on a magnetic tape at a high density have the waveform of the head driving current shaped in order to reduce the degradation of the waveform. That is, in a case where the period of the current reversal of the driving current is long and continues for at least 1.5 times the bit period, the amplitude of the current in the rise part of the wave is made small. The driving current of this waveform has a reduced waveform degradation, and the magnetic recording at the high density becomes possible.Type: GrantFiled: August 5, 1982Date of Patent: June 4, 1985Assignee: Hitachi Denshi Kabushiki KaishaInventors: Akihiko Kougami, Seiichi Mita, Toru Kirino, Shusaku Nagahara