Patents by Inventor Hiroyuki Sawamoto

Hiroyuki Sawamoto 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).

  • Television tuner having level of harmonics of oscillation signal suppressed low
    Patent number: 7129994
    Abstract: The level of the harmonics of oscillation signals for synchronous detection to be inputted to a mixer circuit for converting frequencies is suppressed low.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: October 31, 2006
    Assignee: Alps Electric Co., Ltd.
    Inventors: Michinori Sasaki, Hiroyuki Sawamoto
  • Television tuner having level of harmonics of oscillation signal suppressed low
    Publication number: 20040046898
    Abstract: The level of the harmonics of oscillation signals for synchronous detection to be inputted to a mixer circuit for converting frequencies is suppressed low.
    Type: Application
    Filed: September 4, 2003
    Publication date: March 11, 2004
    Applicant: Alps Electric Co., Ltd.
    Inventors: Michinori Sasaki, Hiroyuki Sawamoto
  • Intermediate frequency circuit in television tuner with large attenuation of audio if signal in adjacent channel
    Patent number: 6583826
    Abstract: The present invention resides in the provision of an intermediate frequency circuit in a television tuner capable of enlarging the attenuation of a audio IF carrier in an adjacent channel without increasing a loss in an intermediate frequency band. The intermediate frequency circuit comprises a mixer which outputs an intermediate frequency signal, an intermediate frequency amplifier for amplifying the intermediate frequency signal outputted from the mixer 1, and a feedback circuit disposed between an input end and an output end of the intermediate frequency amplifier, and in the intermediate frequency circuit, a audio IF carrier of an adjacent intermediate frequency signal adjacent to the intermediate frequency signal is fed back from the output end to the input end of the intermediate frequency amplifier by the feedback circuit.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: June 24, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Hiroyuki Sawamoto, Masaki Yamamoto
  • Fuel evaporative-gas emission preventing apparatus
    Patent number: 5657734
    Abstract: A fuel evaporative-gas emission preventing apparatus capable of reducing the quantity of adsorption of a canister as low as possible by a single breather at any fueling speeds and allowing emissions to fall within given limits. One end of the breather is coupled to a portion near a port of an inlet pipe for a fuel tank and a differential pressure regulating valve is connected to the other end of the breather. The canister is coupled to the differential pressure regulating valve. An opening-area variable device is provided at an intermediate portion of the breather and adjusts the quantity of a fuel evaporative-gas in the breather according to an internal pressure of the fuel tank.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: August 19, 1997
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hiroyuki Sawamoto, Naohiro Asada, Katsuyuki Kido
  • Method and apparatus for determining deterioration of three-way catalysts in double air-fuel ratio sensor system
    Patent number: 5088281
    Abstract: In a double air-fuel ratio sensor system having three-way catalysts, a full O.sub.2 storage amount of the three-way catalysts is estimated and compared with a predetermined amount. When the estimated full O.sub.2 storage amount is smaller than the predetermined amount, the three-way catalysts are determined to have deteriorated.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: February 18, 1992
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Takahide Izutani, Nobuaki Kayanuma, Michio Furuhashi, Yukihiro Sonoda, Hiroyuki Sawamoto, Kouichi Hoshi, Kouichi Osawa, Hironori Bessho