Photodisc apparatus with means for canceling offset of tracking servo loop
US5048002A · kind A · utility
22Cited by
2References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1990 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Apr 26, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/094
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A servo tracking system enables a beam spot formed on a photodisc through an objective lens to trace a track on the disc. After opening the tracking servo loop, a drive signal is supplied to a lens actuator so as to move the objective lens across the tracks thereby generating a tracking error signal. The tracking error signal is sampled for detection of the central value of the same. An offset control is conducted so as to make the central value of the tracking error signal fall within an allowable standard range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.