| 摘要 |
PURPOSE: To provide a method for adjusting a control circuit for optical disk drive which can improve the S/N ratio of track signals while maintaining a required jitter level. CONSTITUTION: A laser module 1 is provided with a semiconductor laser 3, a microprism 4, a front photoreceptor element 5, a rear photoreceptor element and an amplifier 9, and an amplifier unit 10 which outputs RF signals and track error signals is also installed. Defocus adjustment is applied to the maximum point of the amplitude of RF signals by changing the injection amount of electric offset to focus error signals while monitoring the amplitude of the RF signals. Next, in the condition that track servo is once made off and focus servo alone is made on, an optical disk 8 is rotated to output a track traverse signal and to adjust defocus in the direction of increasing this track traverse signal. The amount of defocus is set at, e.g. 0.3μm to l.0μm.
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