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:
Mar. 31, 2009
Filed:
Nov. 26, 2004
Stefan Basler, Brigachtal, DE;
Stefan Basler, Brigachtal, DE;
Thomson Licensing, Boulogne Billancourt, FR;
Abstract
The present invention relates to an apparatus for reading from and/or writing to optical recording media capable of playback of an optical recording medium based on one single focus search cycle. The apparatus distinguishes between the types of optical recording media on the basis of the focus error signal and the data signal obtainable during focus search operation. An S-CurveOK signal, derived from the focus error signal, is the indication whether at all an optical medium is loaded. When a FocusOK signal, derived from the data signal, is active with dedicated settings for a high-reflectivity medium, this means that a high-reflectivity medium is loaded. However, when the FocusOK signal is not active, the apparatus deduces that a low-reflectivity medium is loaded. The operation mode for the second type of optical recording medium is adapted during the focus search cycle based on the combination of the S-CurveOK and FocusOK signals. The switching of the settings is performed before a focus search cycle has been completed. Hence, only one focus search cycle is required to find the focus point for both high- and low-reflectivity media settings.