Toner image transfer unit for photocopier with copy sheet charge control - has independent corona discharge units for phased charge and discharge of copy sheet during image transfer stage

摘要

The toner image transfer apparatus for the image development of an electrostatic photocopier also incorporates a charge transfer/discharge module (26) for controlling the copy sheet charge. The module's first section (26a) imposes a DC charge of opposite polarity to the charge on the imaging drum (16) giving enhanced transfer of the toner image to the copy sheet. The second section (26b) is AG energised and promotes a timed discharge of the copy sheet to facilitate its release from the drum (16) prior to fixing. A leaf-spring and roller assembly provided between the feed rollers (28) and the drum (16) ensures constant spacing of the drum (16), copy sheet and charge/discharge module (26) to maintain copy quality. ADVANTAGE - Offers compact assembly for combined unit without impairing functional efficiency of system.