Patent ID: 6301212
Filing Date: 2001-10-09
Classification: G11B

Abstract:
A focusing and tracking servo circuit used in an optical disk device, which performs recording by increasing light beam power applied onto an optical disk, and performs focusing and tracking servo, said circuit comprising:a detector unit that detects the light beam reflected from the optical disk, said detector unit having a plurality of detecting parts, each of the detecting parts having two memory portions so as to store detection sensitivity parameters for recording and reproduction;a first storage unit that stores a parameter corresponding to light beam power at a time of recording;a second storage unit that stores a parameter corresponding to light beam power at a time of reproduction; anda selector unit that selects a parameter from the parameters stored in the first and second storage units upon switching between recording and reproduction, each of the parameters is a detection sensitivity of said detector unit and the selected parameter is set in said detector unit, wherein the detection sensitivity parameters for recording and reproduction are detected by said detecting parts in accordance with the type of optical disk attached to the optical disk device, and are serially transferred and sequentially stored in said two memory portions.