Patent · US Expired

Optical disc apparatus, driving control method for objective lens, control method for optical head and recording/reproducing method for optical head

US6246647A · kind A · utility

8Cited by
3References
28Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 16, 1998
Grant dateJun 12, 2001
Priority date
Expiry dateOct 16, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B2007/0013
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A malfunction during focussing pull-in in an optical disc recording/reproducing apparatus is to be prevented. To this end, the optical disc recording/reproducing apparatus includes an optical pickup 7 having an objective lens 8 and a biaxial actuator, a photodetector for generating tracking error signals from the return light of the laser light illuminated on the optical disc and a position sensor for detecting the position of the objective lens relative to the optical disc. The optical disc recording/reproducing apparatus also includes an actuator driving circuit for controlling the servo operation of a biaxial actuator 9, based on the tracking error signals, so that the converging point of the light beam will be on the signal recording surface of the optical disc, and a pull-in range decision unit for outputting a permission signal according permission for the servo operation when the position of the objective lens 8 is within a preset range.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.