Patent ID: 6954597
Filing Date: 2005-10-11
Classification: G03G

Abstract:
1. An electrophotographic image-forming apparatus using a two-component developer, comprising: a charging roller for charging a surface of a photosensitive medium at a predetermined potential; a developing unit for developing with a developer an electrostatic latent image formed on the photosensitive medium; a control unit for determining a bias voltage to be applied to a developing roller of the developing unit in relation to a print density level selected by a predetermined selection unit out of a plurality of print density levels set in varying degrees, calculating a surface potential of the photosensitive medium charged by the charging roller, and controlling a charging voltage to be applied to the charging roller in order that an absolute value of a potential difference between the determined developing bias voltage and calculated surface potential becomes higher than a predetermined potential; and a charging voltage adjustment unit controlled by the control unit, and for variably adjusting the charging voltage to be applied to the charging roller.