Patents Assigned to Pioneer Coorperation
  • Patent number: 7164631
    Abstract: An information recording apparatus is provided, which can control over the power of light beams emitted from a light source and various types of servo control with higher accuracy. A laser beam is emitted from a semiconductor laser to write information onto an optical disc. A detection signal indicative of the power of the laser beam output from a light-receiving device is sampled and held with a sample and hold circuit via an I-V converter at a timing delayed by the time corresponding to the delay time of the I-V converter. A tracking error generation circuit and a focus error generation circuit generate a tracking error signal and a focus error signal, respectively, on the basis of a detection signal having information about tracking error and focus error and output from a light-receiving device. Sample and hold circuits sample and hold the tracking error signal and the focus error signal at a timing delayed by the time corresponding to the delay time of each of the generation circuits, respectively.
    Type: Grant
    Filed: June 3, 2003
    Date of Patent: January 16, 2007
    Assignee: Pioneer Coorperation
    Inventors: Kiyoshi Tateishi, Junichi Furukawa