Optical head with light receiving element surfaces divided into at least three light receiving areas
US6567353B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2000 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Jan 19, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0941
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head is provided with a beam splitting element which divides a beam reflected by a data recording surface of an optical disc into two beams with generating opposite defocus therebetween, and a pair of light receiving elements which receive the two beams divided by the beam splitting element, respectively, the pair of light receiving elements being arranged substantially on a same plane. A light receiving surface of each of the pair of light receiving elements is divided, by two lines extending in a direction corresponding to a tracking direction on the optical disc, into at least three light receiving areas. A focusing error signal is generated in accordance with outputs of the at least three light receiving areas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.