Optical detector with two detecting regions for reproducing and recording information on two kinds of disks having different thicknesses
US5802037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1996 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Sep 6, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup device which is capable of reproducing and recording information from/onto at least two kinds of discs having different thicknesses includes a light source, an objective lens provided along the light path from the light source facing the plane of a disc and having a predetermined effective diameter, a beam splitter provided between the objective lens and the light source, and a photodetector for detecting the beam split from the light splitter and reflected from the disc, wherein the photodetector has a first detection region and a second detection region provided in the peripheral portion of the first detection region. The optical pickup device is simplified and the manufacturing cost therefor is low. Also, by reducing the spherical aberration effect for the light, discs having different thicknesses can be used for a single disc drive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.