METHODE DE TRANFERT ELECTROSTATIQUE

摘要

1284355 Electrostatic printing XEROX CORP 28 May 1970 [4 June 1969] 25641/70 Heading B6C Powder images are electrostatically transferred to a single copy sheet under-conditions wherein at each transfer after the first transfer the applied electric field in the transfer zone is greater than in the preceding transfer. In the multicolour copier shown, in each revolution of the photoconductive drum 30 a charge image is formed, the image is developed (using apparatus described in co-pending Application 25638/70), and the toned image transferred to a copy sheet on transfer drum 201, the voltage upon which is automatically stepped up after each transfer. The drum 201 has a hollow conductive core 102 with a layer of insulating material 104 on its peripheral surface and a conductive ring 116 is fastened to an end plate to transmit the bias voltage from stationary brush 117 to the core of the drum 102. The drum 201 has copy sheet registration stops 113 and gripper fingers 112 (described in co-pending Application 25643/70). A copy sheet misfeed detector 43. e.g. one or more photo-cells is provided which when actuated rotates the transfer drum 201 away from the drum 30.