Patent ID: 6721246
Filing Date: 2004-04-13
Classification: G11B

Abstract:
A semiconductor integrated circuit device used for an optical disc apparatus having converging means for converging a light spot on the surface of an optical disc, an optical head which has first moving means for moving the light spot applied to the surface of the optical disc, radially across the surface of an optical disc, and second moving means for moving the optical head radially across the surface of the optical disc, for recording or reproducing information, comprising:spot position detection means for generating a spot position signal which indicates a positional difference in a radial direction of the optical disc, between a center of the optical head and the light spot on a receiving element on the optical head, from an electrical signal outputted by the optical head; first control means for causing a spot position loop filter to filter the spot position signal to generate a first processed signal and outputting the first processed signal to the first moving means; second control means for causing a traverse loop filter to filter the spot position signal to generate a second processed signal and outputting the second processed signal to the second moving means; and system operation control means for sequentially operating the first control means the second control means.