Patents by Inventor Hisanobu Tanigawa

Hisanobu Tanigawa 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).

  • Multiplexed photocurrent monitoring circuit comprising current mirror circuits
    Patent number: 8569674
    Abstract: A low cost photocurrent monitoring circuit is provided. A photocurrent monitoring circuit, which performs monitoring by converting photocurrents output from a plurality of photodiodes (PD1 to PDn) into voltage, includes: a multiplexer circuit (MUX) for selecting one of input terminals to establish a connection of the selected input terminal to an output terminal, wherein the photodiodes (PD1 to PDn) are respectively connected to the input terminals; and an amplifier (LA) for converting a photocurrent which flows from a selected photodiode via the multiplexer circuit (MUX) into a voltage, and for outputting the voltage.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: October 29, 2013
    Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics Corporation
    Inventors: Ryosuke Saito, Hisanobu Tanigawa, Takashi Goh, Ryoichi Kasahara
  • PHOTOCURRENT MONITORING CIRCUIT
    Publication number: 20110101208
    Abstract: A low cost photocurrent monitoring circuit is provided. A photocurrent monitoring circuit, which performs monitoring by converting photocurrents output from a plurality of photodiodes (PD1 to PDn) into voltage, includes: a multiplexer circuit (MUX) for selecting one of input terminals to establish a connection of the selected input terminal to an output terminal, wherein the photodiodes (PD1 to PDn) are respectively connected to the input terminals; and an amplifier (LA) for converting a photocurrent which flows from a selected photodiode via the multiplexer circuit (MUX) into a voltage, and for outputting the voltage.
    Type: Application
    Filed: August 21, 2007
    Publication date: May 5, 2011
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Ryosuke Saito, Hisanobu Tanigawa, Takashi Goh, Ryoichi Kasahara
  • Temperature control device and arrayed waveguide grating optical wavelength multiplexer/demultiplexer
    Patent number: 7050673
    Abstract: In a temperature control device which maintains an object to be controlled at a preset constant temperature and an arrayed waveguide grating optical wavelength multiplexer/demultiplexer, the adverse effect of the junction temperature of the semiconductor control element is eliminated for the purpose of simplifying the overall structure and improving operation efficiency. The object to be controlled and semiconductor control element are fixed on the soaking plate. A negative feedback control is applied to the conduction condition of the semiconductor control element. Consequently, the junction temperature of the semiconductor control element is effectively used as a heating source not as a loss, thereby reducing the power consumption and stabilizing the performance.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: May 23, 2006
    Assignees: Sumiden Opcom, Ltd., NTT Electronics Corporation
    Inventors: Kazuo Iiduka, Toshiyuki Watanabe, Noriyuki Ikuta, Hisanobu Tanigawa, Takatsuga Yuasa
  • Temperature controller and array waveguide lattice type optical wavelength multiplexer/demultiplexer
    Publication number: 20040202421
    Abstract: In a temperature control device which maintains an object to be controlled at a preset constant temperature and an arrayed waveguide grating optical wavelength multiplexer/demultiplexer, the adverse effect of the junction temperature of the semiconductor control element is eliminated for the purpose of simplifying the overall structure and improving operation efficiency sufficiently without any trouble.
    Type: Application
    Filed: February 2, 2004
    Publication date: October 14, 2004
    Inventors: Kazuo Iiduka, Toshiyuki Watanabe, Noriyuki Ikuta, Hisanobu Tanigawa, Takatsugu Yuasa