Patent · US Expired

Laser power controller and optical disk device

US6621779B1 · kind B1 · utility

12Cited by
4References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 11, 2001
Grant dateSep 16, 2003
Priority date
Expiry dateMay 11, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/0055
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A power control device for controlling a power of a light source of an optical beam directed to an optical medium. The power control device includes a reflected light detector for detecting reflected light from the optical medium when irradiated by an optical beam which is following a track; an arithmetic unit for calculating from the reflected light a transmissivity of light transmitted from a disk surface to a recording layer or an amount of directed light on the recording layer of the medium; and power control means for controlling the power of the light source for emission based on a calculation result produced by the arithmetic unit.

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