LEAD EDGE TRANSFER SWITCHING
Original Publication Date: 1979-Apr-30
Included in the Prior Art Database: 2004-Apr-01
Xerox Disclosure Journal
In an electrostatographic copying apparatus in which the imaging material is trans-ferred to the copy member by electrical transfer means 1, which leave electrostatic charges on the copy member resisting stripping of the copy member from the original image support surface, and in which a detacking corona generator 2 is provided to partially neutralize those charges before the stripping of the lead edge of the copy member; there is provided an automatic switching system 3 to apply a non-uniform increased transfer charge to the lead edge area of each copy member in comparison to the body of the copy prior to the detacking to improve the effective image transfer to the lead edge area of the copy even though the detacking system is also switched to a higher detacking level for the lead edge. This is preferably provided by generating a transient over-shoot in the output voltage (as shown in Figure 2) of a constant current power supply 4 for the transfer means 1 for the lead edge. The power supply 4 is switched between the transfer corona generator and a dummy load 5 of different impedance by the machine controller 6 in coordination with the movement of the copy sheet lead edge. Figure 3 is an alternative embodiment using corona generators with an insulative coating on the corona wires.