Patent · US Expired

Optical disc humidity protected

US4517574A · kind A · utility

3Cited by
5References
27Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 21, 1983
Grant dateMay 14, 1985
Priority date
Expiry dateMar 21, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/24015
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A protected optical disc intended for the recording of information is protected against the harmful consequences of humidity by the presence of a hydrophylous material situated at a particular distance from the recording surface, which thus retains a high sensitivity during the write or read operations. The invention may be applied especially to discs intended for digital recording.

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