| 摘要 |
PURPOSE:To make a copying device small-sized and prevent the deviation of a back and forth moving member from the movement start position, by controlling collectively operation, driving, home position detection, speed corresponding to magnification in the forward and backward motion for exposure scanning of an original. CONSTITUTION:An electromagnetic clutch driving motor 19 is operated simultaneously with rotation of a photosensitive drum 14 by a copy start signal, and an optical system 10 is returned to its home position and is stopped temporarily in the position of a sensor 3. When a home position 16 of the photosensitive drum reaches to a sensor 32, the surface is charged electrostatically and the charged surface reaches the position of incidence of a picture of an original 1 by the rotation at a prescribed angle, one of electromagnetic clutches 20-23 is operated, and the optical system 10 is moved in the direction of an arrow 26 to start and exposure scanning. The scanning is so performed that the reflected picture at a front end 30 of the original 1 coincides with a position 31 on the drum 14, and the scanning is stopped when it reaches a sensor 4 in the inversion position, and the scanning is inverted to the direction of an arrow 25. The optical system 10 is scanned in a speed of several stages, and the scanning start time is made later in case of a reduction copy than unmagnification and is made earlier in case of enlargement copy so that the front end 30 of the picture coincides with the fixed position of the drum 14. |
