Optical disc device
US7969844B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2007 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Jun 9, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0948
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc apparatus includes: a defect detecting section 124 for detecting, based on a light detection signal and with respect to a preset detection reference level, a fingerprint or a bubble on the disc 102 as a defect to output a defect detection signal; and a waveform shaping section 126 to output a hold signal that holds, in response to the defect detection signal, a signal from a tracking control section 109 at a level just before the defect has occurred. The apparatus is initially operated not to hold the signal from the tracking control section 109 even if there is a defect. But once a tracking failure has occurred during a read operation, settings are changed to hold the signal from the tracking control section 109 against the defect while the read operation is retried.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.