| 摘要 |
PURPOSE:To attain stable high speed positioning of an optical head by using a difference between a speed signal of the optical head and a difference signal subject to amplitude limit so as to apply drive control to a linear motor. CONSTITUTION:A DC voltage representing an object position of the optical head at an input (a) is compared with an output voltage of a position detector 8 by a comparator 1 and its difference is fed to a limiter 3 via an equalizer 2. Then the moving speed of the motor 6 is detected by a speed detector 7. On the other hand, the motor 6 continues coasting, the output of the detector 7 is kept to a prescribed value, an output of the comparator 4 is changed in opposite direction, a voltage giving a reverse torque is outputted at the output of a drive amplifier 5 to stop the motor 6 suddenly. A limiter 3 is provided to the output of the detector 8 and the object value and a minor loop comparing the output of the limiter 3 with the output of the detector 8 is provided in this way, allowing to realize smooth acceleration/deceleration thereby applying high speed positioning of the optical head.
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