Wobble-signal detecting device and information recording apparatus
US6556523B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2000 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Mar 29, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2566
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A wobble-signal detecting device detects a wobble signal based on a signal which is the difference between outputs of two divisions of a light receiving device. These two divisions are located on both sides of a line parallel to a target portion of an information recording track. This light receiving device receives light reflected by a recording medium as a result of an optical beam being incident on the recording medium. This recording medium contains the information recording track, which wobbles at a predetermined frequency, and has pre-pits formed at predetermined intervals in areas between the information recording tracks. This light receiving device comprises a pre-pit controlling portion which removes or reduces the pre-pit components of the signal which is the difference between the outputs of the two divisions of the light receiving device, and outputs a pre-pit-component-controlled signal; and a wobble-frequency-component extracting portion which extracts wobble-frequency components from the pre-pit-component-controlled signal and outputs a wobble-frequency-component signal, the wobble signal being obtained based on the wobble-frequency-component signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.