Patent · US Expired

Optical disk and optical disk apparatus

US7408869B2 · kind B2 · utility

1Cited by
7References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 18, 2004
Grant dateAug 5, 2008
Priority date
Expiry dateJan 23, 2026

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/263
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In an optical disk of the invention composed of two substrates bonded to each other, the level of double refraction is set to 60 nm or less in a read-only disk, to 60 nm or less in a write-once type disk, and to 40 nm or less in a rewritable type disk, respectively.

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