Patents by Inventor Yu Kojima

Yu Kojima 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).

  • Patent number: 8274456
    Abstract: The brightness of a light emitting element varies when changes in ambient temperature or changes with time occur. In view of this, the invention provides a display device where the influence of variations in the current value of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention includes a monitoring element that is driven with a constant current, and a voltage applied to the monitoring element is detected and inputted to a light emitting element. In other words, the monitoring element is driven with a low current, and a voltage applied to the monitoring element is inputted to the light emitting element such that the light emitting element is driven with a constant current.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: September 25, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masahiko Hayakawa, Yu Kojima, Yukari Ando, Keisuke Miyagawa, Jun Koyama, Mitsuaki Osame, Aya Anzai, Shunpei Yamazaki, Satoshi Seo, Hiroko Abe, Hajime Kimura
  • Publication number: 20110279441
    Abstract: The brightness of a light emitting element varies when changes in ambient temperature or changes with time occur. In view of this, the invention provides a display device where the influence of variations in the current value of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention includes a monitoring element that is driven with a constant current, and a voltage applied to the monitoring element is detected and inputted to a light emitting element. In other words, the monitoring element is driven with a low current, and a voltage applied to the monitoring element is inputted to the light emitting element such that the light emitting element is driven with a constant current.
    Type: Application
    Filed: July 26, 2011
    Publication date: November 17, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masahiko Hayakawa, Yu Kojima, Yukari Ando, Keisuke Miyagawa, Jun Koyama, Mitsuaki Osame, Aya Anzai, Shunpei Yamazaki, Satoshi Seo, Hiroko Abe, Hajime Kimura
  • Patent number: 8013809
    Abstract: The brightness of a light emitting element varies when changes in ambient temperature or changes with time occur. In view of this, the invention provides a display device where the influence of variations in the current value of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention includes a monitoring element that is driven with a constant current, and a voltage applied to the monitoring element is detected and inputted to a light emitting element. In other words, the monitoring element is driven with a low current, and a voltage applied to the monitoring element is inputted to the light emitting element such that the light emitting element is driven with a constant current.
    Type: Grant
    Filed: June 14, 2005
    Date of Patent: September 6, 2011
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masahiko Hayakawa, Yu Kojima, Yukari Ando, Keisuke Miyagawa, Jun Koyama, Mitsuaki Osame, Aya Anzai, Shunpei Yamazaki, Satoshi Seo, Hiroko Abe, Hajime Kimura
  • Publication number: 20060158458
    Abstract: It is an object of the invention to provide a display device which performs high grayscale display in accordance with display contents and a game machine with an improved realistic sensation. The invention is a display device characterized by including a pixel portion which performs display based on a video signal and a driver circuit portion inputted with the video signal, wherein the driver circuit portion has a unit for controlling a grayscale in accordance with display of the pixel portion. In a liquid crystal display device, luminance of a lighting unit is controlled based on a signal from the unit for controlling a grayscale whereas a current supplied to a light emitting element is controlled in a light emitting device. By applying such a display device to a game machine, a realistic sensation can be improved.
    Type: Application
    Filed: December 2, 2005
    Publication date: July 20, 2006
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yu Kojima, Yuko Tachimura, Shunpei Yamazaki, Yoshifumi Tanada
  • Publication number: 20060139254
    Abstract: The brightness of a light emitting element varies when changes in ambient temperature or changes with time occur. In view of this, the invention provides a display device where the influence of variations in the current value of the light emitting element due to changes in ambient temperature and changes with time can be suppressed. The display device of the invention includes a monitoring element that is driven with a constant current, and a voltage applied to the monitoring element is detected and inputted to a light emitting element. In other words, the monitoring element is driven with a low current, and a voltage applied to the monitoring element is inputted to the light emitting element such that the light emitting element is driven with a constant current.
    Type: Application
    Filed: June 14, 2005
    Publication date: June 29, 2006
    Inventors: Masahiko Hayakawa, Yu Kojima, Yukari Ando, Keisuke Miyagawa, Jun Koyama, Mitsuaki Osame, Aya Anzai, Shunpei Yamazaki, Satoshi Seo, Hiroko Abe, Hajime Kimura