The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 11, 2007
Filed:
Jan. 24, 2003
Johannes Hendrikus Maria Spruit, Eindhoven, NL;
Johannes Hendrikus Maria Spruit, Eindhoven, NL;
Koninklijke Phillips Electronics N.V., Eindhoven, NL;
Abstract
A device for recording and/or reading a record carrier has an optical head with a laser for generating a beam via a scanning spot on a track of the carrier. A detector detects a read signal and a sensor detects a sense signal from the beam. A control unit controls the laser power to a desired value. A correction unit generates a correction signal that depends on local optical properties of the record carrier derived from the sense signal measured on at least one part of the track near the scanning spot. The device corrects the power control using the correction signal. Furthermore, the record carrier can have prerecorded control parameters for setting the correction unit.