Pick-up device for use in an optical information recording system
US4849825A · kind A · utility
2Cited by
5References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1986 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Nov 10, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/123
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pick-up device which includes a light source and a condenser lens for effecting recording and reproduction of information by projecting a light beam as collected by the condenser lens onto a recording medium. A diffraction grating is provided between the light source and the condenser lens for dividing light returning from the recording medium by a diffraction grating so as to be directed to a photo-detector, to thereby obtain an optical detection signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.