Optical disk
US6262969A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Feb 12, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/2595
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc having a transparent substrate, being recordable with a signal (s) by irradiating recording light at the side of the transparent substrate thereof, comprises a cover sheet being attached on the transparent substrate at a surface side for incidence of recording light and reproducing light, in detachable manner, wherein the stretching rate of the cover sheet is selected to be equal or less than 200%. Further, the thermal contraction rate of the cover sheet is selected to be equal or less than 1.5%, and the bonding force thereof onto a surface of the transparent substrate per 25 mm width to be from 10 g/25 mm width to 300 g/25 mm width. Thereby, the curve on the optical disc can be suppressed, if it is attached with the cover sheet of the surface of the transparent substrate thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.