Device for the optical read-out of a diffractive track belonging to a data carrier in the form of a disc or tape
US3971002A · kind A · utility
48Cited by
3References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1974 |
| Grant date | Jul 20, 1976 |
| Priority date | — |
| Expiry date | Jun 26, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to the optical read-out of a diffractive track carried by a data carrier. The object of the invention is an optical read-out device in which concentrated illumination of the track is effected by at least two collateral read-out spots straddling same, in order to produce a track eccentricity signal by subtraction of the voltages furnished by two groups of photo-electric transducers sensitive to the spread in the beams which form said spots.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.