Focus control method, and optical disk unit with focus offset correction
US5970032A · kind A · utility
13Cited by
6References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1996 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Apr 1, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A focus control method controls a focus servo system which controls a focus of a light irradiated on an optical disk in an optical disk unit which has a plurality of operation modes. The focus control method includes the steps of (a) reading focus offset information from a memory which prestores focus offset information depending on the operation modes of the optical disk unit, and (b) controlling the focus with respect to the optical disk by supplying the focus offset information read in the step (a) to the focus servo system when the operation mode of the optical disk unit is switched from one mode to another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.