Patent ID: 6163513
Filing Date: 2000-12-19
Classification: G11B

Abstract:
A track servo control apparatus for an optical disk, comprising:an optical head for recording and reproducing information in a track of a rotating optical disk;a lens actuator provided on said optical head for displacing a light spot in a direction traversing said track of said optical disk;a positioner associated with said optical head for displacing said optical head in a radial direction of said optical disk, said optical head generating a positional deviation signal indicative of a positional deviation between said light spot and said track, so that in a track following control operation, said lens actuator is driven on the basis of a high frequency component of said positional deviation signal and said positioner is driven on the basis of a low frequency component of said positional deviation signal; anda variable filter circuit for receiving said positional deviation signal to separate said positional deviation signal into said high frequency component and said low frequency component, said variable filter circuit having a frequency threshold for separating said positional deviation signal into said high frequency component and said low frequency component, wherein said frequency threshold can be changed by an external signal.