| 摘要 |
PURPOSE:To facilitate control over an automatic original feeding device by detecting the feed position of an original by the automatic original feeding device from the number of driving pulses of a motor for original feeding even after a specific sensor detects the original, and detecting it with the invariably constant counted number even when the feed speed varies. CONSTITUTION:The original 1 is fed at a variable speed according to variable magnification. When the original 1 advances by 115mm. after its front end is detected by the sensor 6, transfer paper 14 is sent out from a registration roller 16. In this case, the time up to the driving timing of the roller 16 varies with the variable magnification. A motor which drives a belt 4 for conveying the original 1 has its speed brought under PLL control and variation in speed corresponding to the variable magnification is attained by setting the frequency of oscillation pulses of the oscillator in a PLL loop. Thus, motor driving pulses varying with the variable magnification are counted to detect the feed position of the original, thereby obtaining registration timing. |
