Optical disk reproducing device with automatic focus control loop
US6603717B1 · kind B1 · utility
3Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 28, 2000 |
| Grant date | Aug 5, 2003 |
| Priority date | — |
| Expiry date | Apr 28, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08511
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an optical disk reproducing device, through a provision of a control circuit, movement of focus point of laser beams is set at positions ahead or back to the focus position causing to enter into an automatic focus control loop, and a retry search signal for searching the focusing position is caused to be generated by the search signal generation means, thereby, a refocusing control in case when an automatic focusing servo loop can not be maintained can be started from the positions ahead or back to the focus position causing to enter into the automatic focus control loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.