| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that an error arises when correction is made on the basis of a detected signal because a detection means for inclination is located at a position different from that of an object lens and a disk is radially deflected. SOLUTION: The inclination angle between a light beam at the position of the lens and the moving direction of an optical pickup on the face of the disk is expressed byθlens=θmr+θdr-θand an error arises between the value ofθlens and an ideal angle corrected by an inclination correction means 8 and given byθideal=θmr+θdr. When the angle between the position of the inclination detection means at the inner periphery of the disk and the moving direction of the optical pickup is expressed byβ0 and the inclination angle in the radial direction of the inner periphery of the disk is expressed byθmr0, a correction angleθ0 of the correction means obtained by the inclination correction means for the inner periphery of the disk is expressed byθ0=θmr0cos(α-β0)/cosα+θdr+θdttanα. Because the inclination in the radial direction in the inner periphery of the disk is nearly equal to zero, the first term of the equation is set '0' andαis made small in the remaining second and the third terms.
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