Reading apparatus and photodetector for optical recording medium
US5053610A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 1989 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | Feb 10, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A reading apparatus for reading an optical recording medium having a clock track, data tracks and a tracking guide line. The apparatus comprises a photodetector which receives light images of the clock track, data tracks and tracking guide line; a clock detecting circuit which is responsive to a signal from the clock track by the photodetector to output a clock signal; data detecting circuit which encodes data read from the data tracks by the photodetector into a binary code in response to the clock signal; a focus error detecting circuit for detecting a focus error and a tracking error circuit for detecting a tracking error in response to a signal from the tracking guide line by the photodetector. The photodetector comprises first to fourth light-sensitive elements which receive a light image of the tracking guide line, a fifth light-sensitive element which receives a light image of the clock track and a sixth light-sensitive element which receives a light image of the data track. With the compact arrangement of the photodetector, the reading apparatus is reduced in weight and size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.