Disc discriminator of optical disc player system
US6466531B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1997 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | May 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disc discriminator of an optical disc player system is disclosed. The disc discriminator has a 4-split photo-detector for converting the beam concentrated by the optical pickup unit into an electric signal by means of a plurality of photo diodes divided into first through fourth quadrants. A push-pull signal generator is provided for amplifying a difference between signals generated from two pairs of photo diodes which are symmetrical in the upper and lower sides from the center of a track direction, and generating a push-pull signal. A comparator compares the push-pull signal generated from the push-pull signal generator with a predetermined reference voltage, and generates a digital video disc/compact disc discrimination signal discriminating between a digital video disc having the thickness of 0.6 mm and a compact disc having the thickness of 1.2 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.