Patents by Inventor Hiroshi Yaguma

Hiroshi Yaguma 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: 20060001619
    Abstract: An organic EL drive circuit includes a reset voltage generator circuit for generating a predetermined constant voltage for constant voltage resetting, reset switches provided between an output of the reset voltage generator circuit and terminal pins of an organic EL display panel and ON/OFF controlled by one of the timing control signal, a reset control signal similar to the timing control signal, a reset pulse, other pulse generated in the reset period in synchronism with these signal, and the pulse and an output terminal for outputting the predetermined constant voltage to other organic EL drive circuits, which have identical circuit constructions to that of the organic EL drive circuit and arranged adjacently to the organic EL drive circuit, as a voltage for constant voltage resetting.
    Type: Application
    Filed: June 21, 2005
    Publication date: January 5, 2006
    Inventors: Hiroshi Yaguma, Shinichi Abe, Masato Kobayashi
  • Publication number: 20050270256
    Abstract: An amplifier circuit for generating a predetermined constant voltage required for resetting organic EL elements or capacitors is provided and an operating current switching circuit switches the operating current of the amplifier circuit to an idling current in a display period and to a steady operation current required to performing a reset operation in a reset period, so that a shifting time of the amplifier circuit from the idling state to the steady operation state can be shortened and a constant control voltage for resetting the organic EL elements or the capacitors can be generated in an initial portion of the reset period.
    Type: Application
    Filed: May 23, 2005
    Publication date: December 8, 2005
    Inventors: Hiroshi Yaguma, Masato Kobayashi
  • Publication number: 20050259050
    Abstract: A current inputted from a first input terminal and a reference current generated by an internal reference current generator circuit, which are in phase, are inputted to a reference current selector circuit by which either the inputted current or the reference current is selected. The selected current is temporarily phase-inverted by a current inverter circuit and drives a current mirror circuit of a current distributor circuit (or a reference current regulator circuit) for duplicating the reference current and distributing them. Currents, each of which is in phase with the reference current or the inputted current and has same current value as that of the reference current or the inputted current, can be generated in the output side transistors of the current mirror circuit.
    Type: Application
    Filed: May 12, 2005
    Publication date: November 24, 2005
    Inventors: Masanori Fujisawa, Shinichi Abe, Hiroshi Yaguma
  • Publication number: 20050237284
    Abstract: A first current mirror circuit including an input side transistor, an output transistor and passive elements respectively connected in series with said input side transistor and said output side transistor, temperature coefficients of said passive elements being opposite in characteristics and a second current mirror circuit provided as a load circuit of the first current mirror circuit, for feeding back an output current of the output side transistor to an input of the input side transistor are provided. A drive current is generated on a basis of a current corresponding to a current generated in the output side transistor as a reference current and an operating current ratio of the input side transistor and the output side transistor is selected such that luminance change of organic EL elements with respect to temperature change is restricted.
    Type: Application
    Filed: April 26, 2005
    Publication date: October 27, 2005
    Inventors: Hiroshi Yaguma, Masanori Fujisawa, Shinichi Abe
  • Publication number: 20040207580
    Abstract: An organic EL drive circuit comprises a timing signal generator circuit for generating a plurality of second timing control signals sequentially delayed from a first timing control signal, a reset pulse generator circuit for selecting one of the plurality of the second timing control signals according to the predetermined data and generating a reset pulse having a front edge determined according to the selected second timing control signal and a rear edge determined by the first timing control signal and a switch circuit responsive to the reset pulse for connecting the terminal pins to a predetermined bias line to reset an organic EL element of an organic EL panel connected to the terminal pins. Luminance of the organic EL panel is regulated by regulating the display period according to the predetermined data.
    Type: Application
    Filed: April 13, 2004
    Publication date: October 21, 2004
    Inventors: Hiroshi Yaguma, Shinichi Abe, Jun Maede, Akio Fujikawa