| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk reproducing apparatus and a focus control method capable of ensuring stable disk reproduction by reducing the occurrence of a fault resulting from an individual difference in a length between a disk and an object lens.SOLUTION: A disk reproducing apparatus calculates an average value of voltage levels of a focus drive signal for time &Dgr;t while a disk d is reproduced, and calculates an average value &Dgr;FCD of differences between this average value and a voltage level C that is a servo reference voltage of a focus servo for a preset number of times of reproduction. Each of or any of the voltage level C, a voltage level A corresponding to a moving-up upper limit position, and a voltage level B corresponding to a moving-down lower limit position among the voltage levels of the focus drive signal in a focus control for obtaining a servo error signal is changed to be higher than an initial level before the focus control if the average value &Dgr;FCD is a positive value, and changed to be lower than the initial level if the average value &Dgr;FCD is a negative value.SELECTED DRAWING: Figure 1 |
