Optical disc pressure-collapsible cover
US4510508A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 1983 |
| Grant date | Apr 9, 1985 |
| Priority date | — |
| Expiry date | Apr 15, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24015
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optically readable storage disc comprises a transparent substrate 1 on which a recording layer 2 is deposited which can be modified locally by means of a radiation beam, which recording layer is covered by a cover disc 3 which is secured to the substrate in a gas-tight manner at some distance from the part of the recording layer which is intended for recording, so that a sealed space 4 is enclosed between the substrate 1 and the cover disc 3. The cover disc 3 will be deformed to the greatest extent under the influence of differences between the gas pressure in the sealed space 4 and the barometric pressure because its resistance to deformation is substantially smaller, so that deformation of the substrate 1 is substantially precluded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.