Patent · US Expired

Optical disk apparatus and information recording/reproduction method

US7660222B2 · kind B2 · utility

0Cited by
3References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 19, 2004
Grant dateFeb 9, 2010
Priority date
Expiry dateJun 15, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/1263
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An optical disk apparatus including: a light source; an objective lens for converging light emitted from the light source toward an optical disk; a first photodetection device for detecting reflected light from the optical disk and outputting a first signal; a signal processing section for receiving the first signal and generating a signal containing information recorded on the optical disk; a second photodetection device for detecting a portion of the light emitted from the light source and outputting a second signal; a light source driving section for receiving the second signal, and based on the second signal, driving the light source so that output power of the light source equals a target value; and an amplitude fluctuation detection section for detecting an amplitude fluctuation amount of the second signal, and if the amplitude fluctuation amount exceeds a predetermined value, changing driving characteristics of the light source driving section.

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