Optical pickup device for detecting tracking error of optical disks with different track pitches
US5815473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1996 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | Apr 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0943
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup device includes an optical system which forms a main spot and a set of sub-spots on an optical disk by a beam of light passing the optical system. A photodetector unit outputs first signals in response to a reflection beam from the main spot, and outputs second signals in response to reflection beams from the sub-spots. A tracking error detector includes a first detection circuit designed to output a first tracking error signal for a first track pitch, and a second detection circuit designed to output a second tracking error signal for a second track pitch different from the first track pitch. A switch selectively connects one of the first detection circuit and the second detection circuit to an output of the tracking error detector in response to a track pitch of the optical disk, so that one of the first and second tracking error signals appropriate for the track pitch of the optical disk is output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.