Patent · US Expired

Optical disk apparatus

US6298019A · kind A · utility

23Cited by
7References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 29, 1999
Grant dateOct 2, 2001
Priority date
Expiry dateOct 29, 2019

Classification

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

Abstract

An optical disk apparatus comprises a focusing means for focusing a light beam on a recording medium having first and second information faces; means for moving a focal point of the light beam in a direction substantially perpendicular to the information faces of the recording medium; means for detecting a reflected light from the recording medium; means for detecting a focus condition of the light beam on the basis of an output signal from the reflected light detecting means; a focus control means for driving the focal point moving means on the basis of an output signal from the focus condition detecting means, and controlling the light beam so that the focus condition of the light beam becomes a prescribed focus condition; and a focus jumping means for moving the focal point of the light beam from the first information face to the second information face by driving the focal point moving means.

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