| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk device for achieving a stable focus servo pull-in operation, and its focus control method. SOLUTION: This device is provided with a motor driving part 10 for moving an objective lens 14 with respect to an optical disk 1, a division optical sensor 18 for inputting a reflection signal from the optical disk 1, an adder 24 for generating a focus error signal based on the reflection signal, an FEp attenuator 20 for amplifying the first component of the reflection signal for generating the plus component of the amplitude waveform of the focus error signal, an FEn attenuator 21 for amplifying the second component of the reflection signal for generating the minus component of the amplitude waveform of the focus error signal, and a controller 13 for changing the amplification rate of at least one of the FEp attenuator 20 and the FEn attenuator 21 according to a first absolute value from a reference value to a maximum value in the amplitude waveform of the focus error signal and a second absolute value from the reference value to a minimum value. COPYRIGHT: (C)2007,JPO&INPIT
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