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:
Jan. 02, 2007
Filed:
Oct. 29, 2001
Holger Hofmann, Neustetten, DE;
Hartmut Richter, Villingen-Schwenningen, DE;
Holger Hofmann, Neustetten, DE;
Hartmut Richter, Villingen-Schwenningen, DE;
Thomson Licensing, Boulogne-Billancourt, FR;
Abstract
The invention refers to a device and a method for scanning an optical data carrier by means of a main scanning beam being reflected by the data carrier and being detected by means of a photodetector, the data carrier having first and second layers to be scanned, the second layer being scanned through the first layer, light passing the first layer being shaded dependent on local properties of the first layer. An object of the invention is to propose a device having increased performance even for use with multi layer disks having a layer causing light fluctuations on a layer to be scanned, as well as a respective method. According to the invention such device is provided with means for keeping an output signal of the photodetector independent of variations of shading.