| 摘要 |
PURPOSE:To stabilize quickly the operation of a deflecting means for track jump by providing an acceleration/deceleration pulse generating circuit with a time detecting means, which detects the time to a zero-crossing point near an inflection of a tracking error signal, and a crest value operating means which calculates an optimum crest value of an acceleration pulse. CONSTITUTION:An acceleration/deceleration pulse generating circuit 12 is provided with a time detecting means 3a, which detects the time from the leading edge of the acceleration pulse to the zero-crossing point near the inflection point of the tracking error signal from a tracking error detecting means for track jump, and a crest value operating means 3b which calculates an optimum crest value of the acceleration pulse on a basis of the detection output of the time detecting means 3a. The time from the leading edge of the acceleration pulse to the zero-crossing point near the inflection point of the tracking error signal from the tracking error detecting means for track jump is detected by the time detecting means 3a, and the optimum crest value of the acceleration pulse is calculated on a basis of the detection output by the crest value operating means 3b. Thus, the operation of the deflecting means for track jump is stabilized quickly.
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