| 摘要 |
PURPOSE:To obtain always optimum registration by measuring beforehand the extent of clearance of a moving original platen, and correcting the extent of clearance in accordance with the measured value in the stage of copying. CONSTITUTION:A moving original platen 1 on which an original 2 is placed is connected to a rotating and driving source 3 by means of a driving mechanism such as a wire. A detector 15 which detects the arrival of the platen 1 at its home position is provided near the plate 1. An optical detector 14 which detects the boundary between the image part 1b and shielding part 1c on the platen 1a is also provided on a mirror 11 nearest the photoreceptor 13 of an optical system. The plate 1 is moved by the source 3 and the extent of clearance is beforehand measured. The correction value for the extent of clearance is inputted to a control system which controls the source 3 to correct the extent of clearance. The extent of clearance is detected as an optical detector 14 detects the image part 1b, the shielding part 1c, etc., and is controlled and corrected successively according to the movement of the platen 1. |
