SUCCESSIVE PRESSING STRUCTURE FOR DEVELOPING DEVICE

摘要

PROBLEM TO BE SOLVED: To make structure simple and compact by setting the relative phases of respective cam shafts so that the pressing states of corresponding developing devices are respectively released by the other cam shafts when the corresponding developing device is pressed and the position thereof is set at a proximate position by one cam shaft. ;SOLUTION: By driving a first and a second driving motors 391 and 392 with prescribed time lag, a pressing plate 316 is pressed so that a yellow developing unit 3a is proximate to a photoreceptor drum by an eccentric cam for yellow 383a at the first clockwise rotating time of the photoreceptor drum. Thereafter, the photoreceptor drum is rotated counterclockwise so that the pressing state of the plate 316 is released. Continuously, respective eccentric cams for cyan, magenta and black 383b, 383c and 383d are similarly actuated. The shapes of the respective cams 383 are set so that the toner of respective colors are successively supplied to the surface of the photoreceptor drum by the rotation of the photoreceptor drum executed four times. Besides, the phases of one cam 383 and the other cams 383 are set so as to maintain relative positional relation between them.;COPYRIGHT: (C)1999,JPO