| 摘要 |
PURPOSE:To allow a scanning system to move back and stop securely and speedily by comparing a detected speed at a stored reference speed and correcting and determining braking timing, or determining current braking timing on the basis of data on the last braking timing selectively during the backward movement of the scanning system. CONSTITUTION:The scanning system 1 having a lighting system is scanned forth by a DC motor 2 in a direction A at a high speed, and also returned in the opposite direction of A while accelerated through the reversing of the motor 2. An encoder 3 detects the rotating speed of the motor 2 and the position of the scanning system 1 and makes a comparison with the 1st reference speed which is stored in an unshown control part corresponding to the position, thereby applying a brake 5 when the speed exceeds the reference speed. The motion of the scanning system during this braking operation is measured and stored in the control part as the 2nd reference data for correcting the timing of next braking. The 1st or 2nd reference data is selected according to scanning conditions. Consequently, the copy necessary time is shortened by the simple constitution according to various conditions of the size of a copy form, etc. |
