Focus servo control method in optical disc device
US7623420B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 2006 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | Oct 25, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0908
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A focus servo control method for an optical disc device is provided which compensates for variations present on the disc while printing a label on a label surface of the disc. The label surface of the disc is radially divided into a plurality of areas arranged about the center of the disc, and a focus swing operation is performed for each of the radially divided areas to detect an RF signal. Respective center points of pulses in the detected RF signal are regarded as optimal focus points, and focus driving voltages corresponding respectively to the center points are detected and stored in association with the corresponding areas. When a label is printed on the label surface, feed-forward focus servo control is performed based on the stored focus driving voltages. Accordingly, feed-forward focus servo control can be performed while compensating for variations the disc, thereby improving the label printing operation and quality of the resulting label.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.