Optical disc unit, fabrication method and cooperating write and/or read apparatus
US4449139A · kind A · utility
5Cited by
10References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1982 |
| Grant date | May 15, 1984 |
| Priority date | — |
| Expiry date | Aug 26, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/2009
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc-unit including (i) a flexible, disc-shaped support bearing a record layer, (ii) a flexible disc-shaped cover sheet which is transparent to write/read light and (iii) annular retaining means which engage the support and sheet, in spaced relation, substantially continuously around peripheral regions. In preferred embodiments the retaining means symmetrically tension the sheet and support into substantially flat dispositions. Cooperative optical disc write/read apparatus and optical disc-unit fabrication methods are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.