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. 04, 2007
Filed:
Dec. 05, 2001
Christian Büchler, Villingen-Schwenningen, DE;
Christian Büchler, Villingen-Schwenningen, DE;
Thomson Licensing, Boulogne-Billancourt, FR;
Abstract
In order to generate a lens position signal, which describes the position of the optical axis of an objective lens of an apparatus for reading from and/or writing to an optical recording medium with regard to the optical axis of the remaining components contained in an optical scanner, the application of the DPP method is proposed in accordance with a first exemplary embodiment, wherein a primary-beam error signal and a secondary-beam error signal are obtained with the aid of the DPP method, wherein the desired lens position signal is generated by addition of the primary-beam error signal and the secondary-beam error signal. In accordance with a second exemplary embodiment, it is not necessary to generate a primary beam, rather it suffices to detect the secondary beams reflected from the optical recording medium in order to obtain the lens position signal by addition of the secondary-beam error signals generated in a manner dependent thereon.