Patent · US Expired

Magneto-optical recording medium having pit pitch greater than groove pitch

US6654337B2 · kind B2 · utility

4Cited by
6References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 7, 2001
Grant dateNov 25, 2003
Priority date
Expiry dateFeb 21, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/24085
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A recording medium and a recoding medium master, and a method of manufacturing the recording medium which comply with the standard of recording/reproducing characteristic established in the MD standard while enabling precise discrimination of the pit track and groove track and optical detection of the pits by optical pickup and the like are provided. Pits and grooves are arranged on a surface of a disc-shaped substrate so as to form a grooves and the ratio is from 1.00 exclusive to 1.13 inclusive. It is preferable that the track pitch of the grooves is from 1.50 &mgr;m inclusive to 1.70 &mgr;m exclusive. The width of the pits and grooves in the radial direction of the substrate is the same.

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