Focus acquisition servo system and associated method
US5020045A · kind A · utility
19Cited by
10References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1988 |
| Grant date | May 28, 1991 |
| Priority date | — |
| Expiry date | Dec 19, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0908
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A focus acquisition servo system and method which speeds the acquisition process by focusing on the recording media of an optical disk while the disk is coming up to speed. Focus is accomplished by jumping the focus actuator from a start position close to the focus position and by ramping the focus actuator away from the surface of the disk while monitoring focus gain. When the focus gain reaches a peak amplitude the disk is in rough focus, ramping is stopped and the focus servo system is activated to lock the focus actuator onto a fine focus on the disk's recording media.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.