Optical information medium
US6493312B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1999 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Jul 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information medium is made up of a transparent substrate for a reproducing laser beam to penetrate therethrough, a recording layer formed on the transparent substrate and a reflective layer for reflecting the reproducing laser beam thereupon, thereby enabling the recording of optically readable signals by a recording laser beam incident upon the transparent substrate. This optical information medium has a spiral-like tracking guide on a side surface of the transparent substrate, on which the recording layer is formed, and on lands defined between the spiral-like tracking guide are formed land pre pits indicative of the sector information, including the address and so on, wherein the length of the land pre pits is selected to be from 50% to 83% of the length of the minimum pit and to be from 1.5 to 2.5 times the length of the channel clock. Also, the film thickness of the recording layer in the area of the land pre pits is selected to differ from the film thickness of the recording layer in the area of the tracking guide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.