Patent ID: 6952386
Filing Date: 2005-10-04
Classification: G11B

Abstract:
1. Disc speed control device for use in a player or recorder of a disc shaped information carrier to read or record data along data tracks, the data being read or recorded using a pick-up, the device comprising: disc actuating means for rotating the disc in a first mode at a constant linear velocity or a second mode at a constant angular velocity; the pick-up for reading the data from the rotating disc and producing an output signal representative of scanned data from the rotating disc; frequency generating means for generating a rotation speed frequency representative of a rotation speed of the rotating disc; signal processing means for processing the output signal of the pick-up and creating a data frequency signal, the data frequency signal being related to a frequency at which the data is scanned by the pick-up; a speed processing means for receiving the data frequency signal and computing a determined rotation speed value for said first mode and said second mode wherein in the first mode the determined rotation speed value further depends on a location of the rotating disc at which the pick-up scans the data; and speed servo means including a speed comparator used in both the first and second modes for receiving and comparing the rotation speed frequency signal and the determined rotation speed value and for regulating the disc actuating means in response to the determined rotation speed value.