Techniques for controlling beam position and focus in optical disk drives
US5251194A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1990 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Apr 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0946
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk drive for recording and reproducing information on an optical disk medium includes a servo circuit for controlling tracking of a light beam on a predetermined track and a servo circuit for controlling focus of the light beam on the disk surface. The disk surface is divided into a plurality of regions, and calibration values for adjusting the servo circuits are determined in each region. The calibration values are stored in a memory and are used to adjust the servo circuits during tracking on a predetermined track. The calibration values include tracking offset values, focus offset values, servo deviation threshold values and sensor gain values. A number of techniques are disclosed for automatically determining the calibration values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.