| 摘要 |
PURPOSE:To accurately stop an optical part its home position even when the necessary time for its backward movement is shortened by providing a pulse generating means, a backward movement position detecting means, a time means, a time setting means, and a driving means. CONSTITUTION:An S/D signal and an F/R signal are both lowered to a low level to drive a DC motor M reversely and thus the optical part 2' is moved backward, and the timer is put in clocking operation for backward moving speed detection when a sensor S2 outputs a timing signal, encoder pulses are counted, and it is decided whether a set number of encoder pulses are counted or not. Then, when it is decided that encoder pulses are counted up to the set number, measured time data obtained by the timer is read in to calculate the backward moving speed and the measured time of the timer for controlling the braking operation time by forward driving is set to a value corresponding to the calculated backward movement time, thereby setting a supply voltage for driving the motor forward.
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