| 摘要 |
PURPOSE:To detect with high accuracy without need for providing a size detecting mechanism for each cassette by making driving control of paper restricting members so as to position a sheet of paper in a prescribed position in a paper refeeding tray in accordance with the directly detected size of a sheet of paper. CONSTITUTION:At the start of both side copying, the side restricting boards 62, 63 of a paper refeeding unit 103 are placed in the most widely spread home position while the back restricting board 65 thereof is placed in the home position of a minimum picture-plane size (longitudinally placed B5 size) position. When the first sheet of copying paper is sent onto a paper refeeding tray 58 through invertingly conveying rollers 56, 57 and, as its front end is detected by a sensor, after a prescribed timer time, the back restricting board 65 is moved in the g' direction and then stopped when the detection of the rear end is detected, to be displaced by the amount of the length of the sheet of copying paper that exceeds the size of the shorter side of B5. Then, the side restricting boards 62, 63 are moved in the mutually approaching directions h' and stopped when sensors 381, 382 are brought into contact with the sheet of copying paper 81 and turned on, to carry out positioning in accordance with the size. Thus, the detection of a paper size can be directly carried out enabling positioning with high accuracy. |
