Apparatus for reading an optical radiation-reflecting record carrier including a narrow focus control beam
US4135207A · kind A · utility
8Cited by
6References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1977 |
| Grant date | Jan 16, 1979 |
| Priority date | — |
| Expiry date | Jun 30, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0924
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus is described for reading an optically encoded radiation-reflecting information carrier, using an opto-electronic focussing error detection system. The path of the read beam which is directed towards the information carrier includes a radiation-deflecting element producing a narrow focussing beam that co-operates with two focussing detectors to produce an error signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.