| 摘要 |
PROBLEM TO BE SOLVED: To perform shifting from a search operation for a recording surface to a focus control state in a short time. SOLUTION: When a focus actuator is moved in one direction and the recording surface is detected (a prescribed level A or more is attained), the moving direction is reversed after movement is continued for a specified time c, movement is driven in the decelarating direction until the polarity of the differential value of an output signal of a focus deviation detecting means is changed by a braking means at a prescribed level of an output of the focus deviation detecting means, and a focus control operation is performed (b section) when the polarity of the differential value is changed. Thus, the search operation for the recording surface (d section) is shortened. Also, the moving direction is inverted when the recording surface is not detected even by being moved up to a prescribed amount in one direction. Movement is performed in the same direction as the reversed moving direction when the recording surface is searched again.
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