Patent ID: 6263178
Filing Date: 2001-07-17
Classification: G03G

Abstract:
An image forming apparatus, comprising:a plurality of image forming units each including a single image carrier;a single writing means and a plurality of developing means each including a single developing roller for developing a latent image formed on said single image carrier by said single writing means with a developer to thereby produce a toner image, said plurality of image forming units being spaced by a preselected distance along a same surface of an intermediate image transfer belt to which said toner image is to be transferred from said image carrier;selecting means for selectively causing said plurality of developing means to perform development;a single bias applying means for applying a bias voltage for development to said plurality of developing means; andbias switching means for applying the bias voltage output from said single bias applying means to one of said plurality of developing means selected by said selecting means,wherein said selecting means operates in response to outputs of sensors respectively included in said plurality of image forming units for sensing a switching between said developing means.