摘要 |
The present invention measures first and second detection signals respectively obtained at two focuses during a focus search(by means of an optical head 2. Then, a type of a disk-shaped optical record medium is determined by a microcomputer in a system controller 7, from a comparison between characteristics of the first and second measured detection signals. Moreover, the present invention can measure an amplitude and a frequency of the detection signal obtained at the focus during the focus search to thereby determine the type of the disk by using the measured result. After the parameters are set in accordance with the determined result, the focus servo control is turned on. The present invention comprises a selecting means for suitably switching and selecting between two types of tracking error signals, measures first and second detection signals respectively obtained at two focuses during a focus search, determine a type of a disk-shaped optical record medium by using the first and second measured detection signals and then controls the selecting means in accordance with the determined disk type. Moreover, the present invention measures an amplitude and a frequency of the detection signal obtained at one focus during the focus search, determines the disk type by using the measured result and then controls a timing at which a servo control is turned on in accordance with a conformity of a lens to the disk.
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