TRANSFER DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME

摘要

An image forming apparatus includes a plurality of image forming units, a plurality of image bearers, a transfer device, and a controller. The image forming units form a process color toner image and a special color toner image. The transfer device transfers the process color toner image and the special color toner image from the image bearers onto the intermediate transfer member. The controller is configured to correct a transfer bias applied to transfer the special color toner image onto the intermediate transfer member. The controller is configured to decrease the bias in a special color mode in which image formation is performed with only a special color and increase the bias in a full color mode in which image formation is performed with all of the special color and a process color, according to a degree of degradation of a developer used to form the special color toner image.

主权项

1. An image forming apparatus comprising:
a plurality of image forming units to form a process color toner image and a special color toner image; a plurality of image bearers to bear the process color toner image and the special color toner image; and a transfer device including an intermediate transfer member, to transfer the process color toner image and the special color toner image from the plurality of image bearers onto the intermediate transfer member; and a controller configured to correct a transfer bias applied to transfer the special color toner image onto the intermediate transfer member, the controller configured to decrease the transfer bias in a special color mode in which image formation is performed with only a special color and increase the transfer bias in a full color mode in which image formation is performed with all of the special color and a process color, according to a degree of degradation of a developer used to form the special color toner image.