Method and device for measuring the tilt of an optical disc
US7457217B2 · kind B2 · utility
1Cited by
4References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2004 |
| Grant date | Nov 25, 2008 |
| Priority date | — |
| Expiry date | Mar 31, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and device for measuring the tilt in an optical disc drive (1) is disclosed. The optical disc drive (1) comprises two lasers (31, 41) generating two laser beams (32, 42) having mutually different optical characteristics. One of these laser beams (32) is continuously ON, and is used for writing or reading data to or form the disc. The other laser beam (42) is repeatedly switched ON and OFF. Tilt is measured by comparing a normalized error signal (RES(ON)) during the ON-phase (TON) with a normalized error signal (RES(OFF)) during the OFF-phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.