Patent · US Expired

Track-accessing controller for optical disks

US5193081A · kind A · utility

12Cited by
5References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 28, 1990
Grant dateMar 9, 1993
Priority date
Expiry dateFeb 28, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/0938
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Disclosed is an optical disk apparatus applied to a data writing/reproducing operation of a sample-servo formatted optical disk having a clock pit and two wobbled pits in each of servo regions. A photodetector receives reflected light of a light beam from the optical disk to produce a reflected light signal. A clock detection unit detects a change in intensity of reflected light components from the clock pit in response to the reflected light signal to produce a binary clock pit detection signal. A tracking error detection unit detects a change in peak intensity of reflected light components from the wobbled pits in each servo region in response to the reflected light signal to produce a binary tracking error signal representing the detected intensity difference. A determination unit is connected to the clock detection unit and the tracking error detection unit. The determination unit compares a phase of a clock pit detection signal with that of a tracking error signal to determine a crossing direction of a beam spot with respect to some of the tracks on the optical disk in accordance with the comparison result of the phases.

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