Cover assembly for optical recording medium
US4499477A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1983 |
| Grant date | Feb 12, 1985 |
| Priority date | — |
| Expiry date | Mar 14, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24097
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A cover assembly for use with a disk-shaped optical recording medium, having two substantially identical halves, each having an inner surface adapted to provide upon assembly with the medium an air gap adjacent an optical recordable coating on the medium. Each cover half is transparent and has substantially no birefringent characteristics on the region overlying the air gap, thus allowing light to pass unimpeded therethrough. The cover assembly is adapted to be coupled to the central hub of the optical recording medium and to have a raised annulus adjacent thereto to support the assembly and minimize contact with the transparent portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.