| 摘要 |
PURPOSE:To speed up the backward movement of an optical system by providing a switch which is operated by the optical system in its backward movement and a means which switches a motor which drives said optical system from backward drive to forward drive by the operation of said switch. CONSTITUTION:The 1st carriage 2 is provided with a switching operating piece 6 for operating a home position switch 4 and a timing switch 5. The optical system is moved back by using the turning force of the motor at a maximum without speed control, and when the timing switch 5 installed in front of the home position is turned on by the operating piece 6, the current backward moving speed of the optical system is detected to determine a braking time T according to the detected speed and drives the motor forward for the time T, braking the backward movement. Consequently, the optical system is stopped accurately at the home position and the backward scan of the optical system is speeded up. |
