Patent · US Expired

Information recording apparatus having automatic focusing

US4556965A · kind A · utility

3Cited by
16References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 9, 1981
Grant dateDec 3, 1985
Priority date
Expiry dateMar 9, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/0909
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In an information recording apparatus for recording predetermined information on a recording medium by means of a laser beam, an optical system and a light detector are arranged for detecting a reflected version of the laser beam from the recording medium, whereby the focusing of the laser beam on the recording medium is automatically controlled.

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