Patents by Inventor Noriko Obitsu

Noriko Obitsu 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).

  • Optical disk player having beam correction means
    Patent number: 5471446
    Abstract: An optical disk player having a tracking servo apparatus and a focusing servo apparatus. By amplifying a focusing error at a predetermined gain and adding it to a tracking error, the rolling which occurs due to a mass balance distortion of a pickup is electrically suppressed. Thus, an adverse influence on the tracking servo by the rolling upon focusing driving can be prevented.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: November 28, 1995
    Assignee: Pioneer Electronic Corporation
    Inventors: Yuji Tawaragi, Satoshi Kusano, Toshio Suzuki, Noriko Obitsu
  • Optical disk player having tilt servo control absent tilt sensor
    Patent number: 5206848
    Abstract: An optical disk player provided with tilt servo unit. A quadrant type photodetector is used as disk tilt detecting means, and the push-pull output is issued as a disk tilt detecting signal. By simultaneous use of the photodetector of the pickup, there is no need to use special-purpose tilt sensor, and this contributes to compact design of the pickup and to the reduction of manufacturing cost.
    Type: Grant
    Filed: February 21, 1991
    Date of Patent: April 27, 1993
    Assignee: Pioneer Electronic Corporation
    Inventors: Satoshi Kusano, Shinichi Takahashi, Toshio Suzuki, Yuji Tawaragi, Noriko Obitsu
  • Tracking servo system
    Patent number: 5164646
    Abstract: A tracking servo system of disk player uses the time difference detection method for generating the tracking error signal. A time gate is provided for detecting the zero-crossing of the tracking error level in an on-track condition during a jumping operation. As the result, negative effects due to unstableness in timing of the zero-crossing can be eliminated.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: November 17, 1992
    Assignee: Pioneer Electronic Corporation
    Inventors: Yuji Tawaragi, Satoshi Kusano, Toshio Suzuki, Noriko Obitsu
  • Optical disk player
    Patent number: 5130963
    Abstract: An optical disk player using quadrant type photodetector as light receiving means. The phase difference output by the time difference detection method is issued as a tracking error, and a DC component of differential output by the push-pull method is issued as a tilt error, and zero cross of said differential output is detected. By using this detection output for the detection of zero-cross timing on off-track, stable operation of the tracking servo unit is ensured.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: July 14, 1992
    Assignee: Pioneer Electronic Corporation
    Inventors: Satoshi Kusano, Toshio Suzuki, Yuji Tawaragi, Noriko Obitsu