Patent · US Expired

Method for the correction of a tracking error signal during optical scanning of a recording medium in the form of a disc

US6195318A · kind A · utility

0Cited by

2References

4Claims

0Family size

Assignee

Deutsche Thomson-Brandt GmbH · DE

Inventors

Stefan Rapp · Schramberg, DE
Heinz-Jorg Schroeder · Villingen-Schwenningen, DE
Friedhelm Zucker · Mönchweiler, DE

Key dates

Filing date	Dec 8, 1998
Grant date	Feb 27, 2001
Priority date	—
Expiry date	Dec 8, 2018

Classification

Technology area (CPC G)Physics
CPC primaryG11B11/10597
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

Method for the correction of a tracking error signal during optical scanning of a recording medium in the form of a disc. In the case of MO discs, the Kerr rotation angle is in general very small, so that so-called enhancement is used for processing. This leads to birefringence effects which are thermally induced on the WO disc during the writing process producing a noise level on the track error signal. According to the invention, an optical scanner arrangement is used to determine light intensities from two mutually perpendicular polarization planes. A noise element, which is produced by interfering polarization rotation of the light, in the tracking error signal is compensated by linking the electrical output signals of the scanner arrangement. Applicable both to MO and WO as well as CD audio, CD video and CD-ROM.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.