Optical disc apparatus
US7751298B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 2007 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Sep 6, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1369
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A liquid crystal element for correcting wave aberration included in an optical disc apparatus, is controlled by a liquid crystal element control unit which has a memory portion that stores information about a variation with time of orientation direction of liquid crystal in the case where a voltage is applied to the liquid crystal, with respect to at least one type of voltage value. The liquid crystal element control unit has a drive voltage deciding portion that obtains time period after a predetermined drive voltage is applied to the liquid crystal element until a reproduced signal obtained by processing an electric signal converted by the light detecting unit becomes optimal, and decides a drive voltage to be applied to the liquid crystal element based on the obtained time period, the information stored in the memory portion, and the predetermined drive voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.