Patent ID: 7426160
Filing Date: 2008-09-16
Classification: G11B

Abstract:
1. An apparatus for scanning an optical record carrier having substantially parallel tracks for recording user information in a pattern of optically detectable marks, the tracks being provided with grooves having a series of substantially monotonous undulations formed therein in which position information is stored within excursions contained within the undulations, the apparatus comprising: an optical system for scanning tracks by a radiation beam, a detector for detecting a radiation beam coming from the record carrier, and a signal processor for deriving position information from an output signal of the detector, wherein the signal processor is provided with a high pass filter for filtering the output signal and providing a filtered signal, a first filter for passing first signal components of the filtered signal at a first frequency and forming a clock signal therefrom, and a second filter for passing second signal components of the filtered signal at a second, higher, frequency than the first frequency and forming a signal representing the position information contained in the excursions contained within the undulations.