Patents by Inventor Eiji Yamakawa

Eiji Yamakawa 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: 20150378319
    Abstract: An electronic timepiece, including: a display section which displays time information; a light emitting section which illuminates a display surface of the display section by emitting light; and a light emitting control section which performs control to turn on the light emitting section by gradually increasing a light emitting amount of the light emitting section to a peak value in a predetermined brightening time according to a predetermined light emitting condition.
    Type: Application
    Filed: June 1, 2015
    Publication date: December 31, 2015
    Applicant: CASIO COMPUTER CO., LTD.
    Inventor: Eiji YAMAKAWA
  • Patent number: 8971155
    Abstract: A radio wave timepiece includes: a display unit, a display drive unit, a receiver unit and a control unit. The display unit displays a current time in a digital manner. The display drive unit drives the display unit by a drive signal of a predetermined drive waveform frequency. The receiver unit is capable of receiving radio waves of a plurality of different frequencies including time information. The control unit sets the drive waveform frequency during the reception of a radio wave by the receiver unit so that harmonic frequencies with respect to the drive waveform frequencies can be different from a receiving frequency of the radio wave.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: March 3, 2015
    Assignee: Casio Computer Co., Ltd.
    Inventors: Takashi Sano, Eiji Yamakawa
  • Publication number: 20150009783
    Abstract: There is provided an illumination device including: a light guide plate in which a light diffusion pattern of diffusing incident light is formed to have density that is coarse on one side and gets denser toward the other side; a first light source which is provided on a side corresponding to the one side of the light diffusion pattern in the light guide plate; and a second light source which is provided on a side corresponding to the other side of the light diffusion pattern in the light guide plate.
    Type: Application
    Filed: July 3, 2014
    Publication date: January 8, 2015
    Inventors: Kei HANZAWA, Eiji YAMAKAWA
  • Publication number: 20120294126
    Abstract: A radio wave timepiece includes: a display unit, a display drive unit, a receiver unit and a control unit. The display unit displays a current time in a digital manner. The display drive unit drives the display unit by a drive signal of a predetermined drive waveform frequency. The receiver unit is capable of receiving radio waves of a plurality of different frequencies including time information. The control unit sets the drive waveform frequency during the reception of a radio wave by the receiver unit so that harmonic frequencies with respect to the drive waveform frequencies can be different from a receiving frequency of the radio wave.
    Type: Application
    Filed: May 14, 2012
    Publication date: November 22, 2012
    Applicant: CASIO COMPUTER CO., LTD.
    Inventors: Takashi SANO, Eiji Yamakawa
  • Patent number: 7218299
    Abstract: This invention is directed to a liquid crystal display apparatus which includes a liquid crystal display element, and a driving device for driving the display element by simple matrix driving. The display element includes a liquid crystal layer exhibiting a cholesteric phase, and has scanning electrodes and signal electrodes. The driving device is configured such that a driving voltage of single polarity including a selection signal voltage is applied to the scanning electrodes in each frame, and the polarity of the driving voltage is reversed in every frame. The selection signal voltage is successively applied to each scanning electrode in a scanning period set for the scanning electrode, while a rewriting signal voltage corresponding to each scanning electrode in the selected state is applied to each signal electrode. An application period of the selection signal voltage to the scanning electrode is ½ the scanning period.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: May 15, 2007
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Naoki Masazumi
  • Patent number: 7145538
    Abstract: A liquid crystal display device which carries out matrix driving of a liquid crystal layer by applying AC pulses to the liquid crystal layer through a plurality of scan electrodes and a plurality of data electrodes which face and cross each other. A method of driving such a liquid crystal display comprises a reset step of applying a reset pulse to liquid crystal to reset the liquid crystal to an initial state, a selection step of applying a selection pulse to the liquid crystal to select a final state of the liquid crystal, an evolution step of applying an evolution pulse to the liquid crystal to cause the liquid crystal to evolve to the selected final state. The reset pulse and the evolution pulse have alternating cycles which are longer than that of the selection pulse, and the adjustment of the alternating cycles of the reset pulse and of the evolution pulse are made by changing the pulse waveform applied to each of the scan electrodes.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: December 5, 2006
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Tsukasa Yagi, Naoki Masazumi
  • Patent number: 7038648
    Abstract: Disclosed herewith is a matrix driving method of liquid crystal which exhibits a cholesteric phase. In the method, there is a selection pulse application step of applying pulses to select the final state of the liquid crystal, and between the selection pulse application step of a scanning line and the selection pulse application step of the next scanned scanning line, a delay step is inserted. During the delay step, a signal pulse is of 0V or of a pulse voltage for a display of a specified density.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: May 2, 2006
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Naoki Masazumi
  • Patent number: 7019737
    Abstract: A display device which is provided with a liquid crystal display which uses reflective type liquid crystal with a memory effect. This display device is used, for example, as a sub display of a personal computer. The liquid crystal display keeps displaying an image after supply of electric power thereto is stopped. When a specified time has passed since completion of writing, supply of electric power at least to a driving section of the liquid crystal display is stopped.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: March 28, 2006
    Assignee: Minolta Co., Ltd.
    Inventors: Katsuhiko Asai, Hiroshi Ootsuka, Kiyofumi Hashimoto, Eiji Yamakawa, Hideo Hotomi
  • Publication number: 20060012556
    Abstract: A display device which has a liquid crystal display which has a plurality liquid crystal pixels arranged in a matrix and which writes an image thereon after resetting the liquid crystal. The method of writing on the liquid crystal display can be selected from driving methods according to interlace scanning in which a frame is divided into a plurality of fields and writing by interlace scanning is performed and driving methods according to sequential scanning in which scanning lines are subjected to writing serially. When high-speed writing is required, for example, when display of a motion picture, display of inputted letters or scroll display is desired, one of the driving methods according to interlace scanning is selected. In interlace scanning, based on the end of a blackout state of a scanning line in a field, selection of a scanning line in the next field for writing is started.
    Type: Application
    Filed: August 10, 2005
    Publication date: January 19, 2006
    Inventors: Shuji Yoneda, Masaaki Nakai, Eiji Yamakawa, Kiyofumi Hashimoto, Naoki Masazumi, Katsuhiko Asai, Koichi Kohriyama, Keizou Ochi, Takashi Kondo, Hideo Hotomi, Kazuaki Okumura, Makiko Mandai
  • Patent number: 6954195
    Abstract: A display device which has a liquid crystal display which has a plurality liquid crystal pixels arranged in a matrix and which writes an image thereon after resetting the liquid crystal. The method of writing on the liquid crystal display can be selected from driving methods according to interlace scanning in which a frame is divided into a plurality of fields and writing by interlace scanning is performed and driving methods according to sequential scanning in which scanning lines are subjected to writing serially. When high-speed writing is required, for example, when display of a motion picture, display of inputted letters or scroll display is desired, one of the driving methods according to interlace scanning is selected. In interlace scanning, based on the end of a blackout state of a scanning line in a field, selection of a scanning line in the next field for writing is started.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: October 11, 2005
    Assignee: Minolta Co., Ltd.
    Inventors: Shuji Yoneda, Masaaki Nakai, Eiji Yamakawa, Kiyofumi Hashimoto, Naoki Masazumi, Katsuhiko Asai, Koichi Kohriyama, Keizou Ochi, Takashi Kondo, Hideo Hotomi, Kazuaki Okumura, Makiko Mandai
  • Patent number: 6927765
    Abstract: A display device which has a liquid crystal display having a liquid crystal material, a driver for driving the liquid crystal display, and a controller for controlling the driver to drive at least a part of the liquid crystal display by selectively using one of a first drive method and a second drive method which are different from each other in operational principle of the liquid crystal material. The pulse voltage to drive at least one pixel of the liquid crystal display can be selectively set to any one of a plurality of kinds. The data pulse voltage applied to a data electrode can be selectively set to any one of a plurality of kinds to drive at least one pixel of the liquid crystal.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: August 9, 2005
    Assignee: Minolta Co., Ltd.
    Inventors: Naoki Masazumi, Eiji Yamakawa, Hideo Hotomi
  • Patent number: 6888522
    Abstract: An information display apparatus which has a liquid crystal display which uses chiral nematic liquid crystal with a memory effect and can be driven by a matrix driving method. The screen of the display is divided along a scanning line into a still picture display area and a motion picture display area. The information display apparatus may have a first display and a second display on one screen. The first display is a reflective type liquid crystal display with a memory effect, which has an advantage of saving energy, and is used exclusively to display a still picture. The second display is a liquid crystal display which requires only a short time for writing. Information to be written in a short time, such as inputted information, is displayed on the second display.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: May 3, 2005
    Assignee: Minolta Co., Ltd.
    Inventors: Yoshifumi Shibata, Kiyofumi Hashimoto, Eiji Yamakawa, Hideo Hotomi, Naoki Masazumi, Koichi Kohriyama
  • Publication number: 20040046705
    Abstract: A liquid crystal display apparatus which has a first display panel and a second display panel which use liquid crystal as display media, a driving circuit which scans matrix-arranged pixels of each of the panels line by line, and a controller which controls the driving circuit. The controller changes the rate of the length of a delay step Td which is inserted between scanning lines to be sequentially scanned to the length of a scanning time Tss in accordance with circumstantial temperature. Also, the way of changing the rate of Td to Tss in a single writing mode and the way of changing the rate Td to Tss in a double writing mode are different.
    Type: Application
    Filed: December 19, 2002
    Publication date: March 11, 2004
    Applicant: MINOLTA CO., LTD.
    Inventors: Naoki Masazumi, Shuji Yoneda, Eiji Yamakawa, Katsuhiko Asai
  • Patent number: 6697039
    Abstract: The disclosed herein is an information display apparatus having first and second liquid crystal displays on a common support plate. Each of the liquid crystal displays includes a plurality of pixels defined by a plurality of scanning electrodes and a plurality of signals electrodes. The scanning electrodes of the first liquid crystal display are respectively connected to the scanning electrodes of the second liquid crystal display so that both of the liquid crystal displays are commonly and simultaneously scanned by a scanning driver commonly provided to the liquid crystal display. The support plate is provided with a folding area between the first and second liquid crystal displays whereby the information display apparatus is capable of carrying with folding and of using with opening just like a conventional book.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: February 24, 2004
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Koichi Kohriyama, Hideo Hotomi, Naoki Masazumi
  • Patent number: 6633319
    Abstract: An image recording device for thermally recording monochrome and color images onto reversible heat-sensitive recording mediums such as a thermal liquid crystal compound that has a cholesteric phase. A heating device, which may include a plurality of heating elements including laser diodes, is scanned across the recording medium and the temperature of the heating element corresponding to a given picture element determines the recorded color for that picture element.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: October 14, 2003
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Hideaki Ueda, Kiyofumi Hashimoto
  • Publication number: 20030156089
    Abstract: This invention is directed to a liquid crystal display apparatus which comprises a liquid crystal display element, and a driving device for driving the display element by simple matrix driving. The display element includes a liquid crystal layer exhibiting a cholesteric phase, and has scanning electrodes and signal electrodes. The driving device is configured such that a driving voltage of single polarity including a selection signal voltage is applied to the scanning electrodes in each frame, and the polarity of the driving voltage is reversed in every frame. The scanning electrodes are successively brought to a selected state by applying the selection signal voltage to each scanning electrode in a scanning period set for the scanning electrode, while a rewriting signal voltage corresponding to each scanning electrode in the selected state is applied to each signal electrode. An application period of the selection signal voltage to the scanning electrode is ½ the scanning period.
    Type: Application
    Filed: February 14, 2003
    Publication date: August 21, 2003
    Applicant: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Naoki Masazumi
  • Publication number: 20030103026
    Abstract: Disclosed herewith is a matrix driving method of liquid crystal which exhibits a cholesteric phase. In the method, there is a selection pulse application step of applying pulses to select the final state of the liquid crystal, and between the selection pulse application step of a scanning line and the selection pulse application step of the next scanned scanning line, a delay step is inserted. During the delay step, a signal pulse is of 0V or of a pulse voltage for a display of a specified density.
    Type: Application
    Filed: November 26, 2002
    Publication date: June 5, 2003
    Inventors: Eiji Yamakawa, Naoki Masazumi
  • Patent number: 6552756
    Abstract: A heat reversible recording medium is disclosed which includes a cholesteric liquid crystal compound. By selective application of differing temperature profiles, regions of the recording medium can be fixed in states which selectively reflect light in different wavelengths thus providing the ability to fix color images in the medium. The disclosure also includes a method of recording a color image using a medium which includes a cholesteric liquid crystal compound, an apparatus for fixing an image in the recording medium as well as several cholesteric liquid crystal compounds which are suitable for use in the method and apparatus.
    Type: Grant
    Filed: May 3, 2000
    Date of Patent: April 22, 2003
    Assignee: Minolta Co., Ltd.
    Inventors: Shoji Kotani, Naoya Suzuki, Hideaki Ueda, Eiji Yamakawa
  • Patent number: 6489983
    Abstract: Disclosed herewith is an image recording apparatus for recording an image on a reversible thermal recording medium that has a thermal recording layer containing a cholesteric liquid crystal compound having medium molecular weight. The image recording apparatus comprises: a recording head for heating the reversible thermal recording medium; a sensor for detecting a kind of the reversible recording medium; and a speed control unit which is capable of changing, based on the detected kind of the reversible image recording medium, a relative print feeding speed of the recording head and the reversible thermal recording medium.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: December 3, 2002
    Assignee: Minolta Co., Ltd.
    Inventors: Tatsuhiko Miyoshi, Eiji Yamakawa
  • Patent number: 6414666
    Abstract: A method of driving a liquid crystal display element having a first substrate provided with a scanning electrode, a second substrate provided with a signal electrode and a liquid crystal display layer held between the first and second substrates, the method comprising the steps of: (a) applying a first pulse voltage to the scanning electrode corresponding to a drive target pixel in the liquid crystal display layer for changing the liquid crystal material of the target pixel to a predetermined changed state; (b) applying, subsequent to the step (a), a second pulse voltage to the scanning electrode corresponding to the target pixel; and (c) controlling a pulse width of a third pulse voltage in accordance with a required display tone of the target pixel, and applying the third pulse voltage to the signal electrode corresponding to the target pixel in synchronization with the second pulse voltage for stabilizing the state of the liquid crystal material of the target pixel in a predetermined stabilized state.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: July 2, 2002
    Assignee: Minolta Co., Ltd.
    Inventors: Eiji Yamakawa, Hideaki Ueda, Naoki Masazumi