Electrophotographic toner transfer apparatus

Abstract

An improved apparatus is disclosed for transferring toner from the surface of a toner-bearing drum, such as a xerographic drum, to a support medium for the toner, such as plain paper. The improvement relates to apparatus of the type which employs a transfer web or belt to remove toner from the toner-bearing drum and to transfer it to a support medium. In such apparatus, it is typical for the transfer web to be at least partially driven by means of its contact with the toner-bearing drum and/or transfer rollers. The improvement described herein comprises providing means for simultaneously disengaging the toner-bearing drum and at least one of the transfer rollers from the transfer web at least once per web cycle, and also providing means for mechanically correcting web alignment and registration while the toner-bearing drum and transfer roller are disengaged. Suitable means for disengaging the toner-bearing drum and transfer roller include the provision of indented surfaces on the drum and transfer roller. Suitable means for mechanically correcting web alignment and registration includes an independent driving means, such as a chain drive, for the transfer web. Thus, in this embodiment, the indented portions of the toner-bearing drum and transfer roller simultaneously disengage the web which is forced back into proper alignment and registration by the chain drive.

Dependencies are inferred from the claim text.