Patent ID: 7308221

Claim:
A high developing voltage supply apparatus, comprising: a high developing voltage supply supplying a high developing voltage to developing roll shafts of developers in order for toner to move from a plurality of fixed color development rollers to an OPC drum; a high developing voltage driver for selectively outputting a high voltage driving signal based on an image to be printed in order for the high developing voltage to be selectively applied to the fixed color development rollers; developer power switches to selectively switch the high developing voltage to a select fixed color development roller, of the plurality of fixed color development rollers, in response to the high voltage driving signal; and a voltage divider dividing and supplying the high developing voltage, as selectively switched-to the select fixed color development roller, to remaining fixed color development rollers, of the plurality of fixed color development rollers except the select fixed color development roller, to bias the remaining fixed color development rollers through voltage dividing of the high development voltage provided to the select fixed color development roller, wherein the high developing voltage comprises a DC voltage and an AC voltage superimposed.