Patent ID: 7424233
Filing Date: 2008-09-09
Classification: G03G

Abstract:
1. An image forming apparatus that forms a multiple-color image with at least two process speeds, the image forming apparatus comprising: an image carrier on which a latent image is formed; a latent-image forming unit that forms the latent image on the image carrier; a color developing unit of a plurality of colors that forms a toner image on the latent image; a primary transfer unit that sequentially transfers the toner image formed on the image carrier to an intermediate transfer member in a superposed manner; a secondary transfer unit that transfers the toner image from the intermediate transfer member to a transfer medium, the secondary transfer unit including a secondary-transfer-bias applying member configured to be moveable relative to an outer surface of the intermediate transfer member and to apply a secondary bias from a transfer-bias source to the intermediate transfer member; a secondary-transfer-bias control unit that controls the bias applied to the secondary transfer applying member to a predetermined value; and a secondary-transfer-output detecting unit that detects a first output value of the secondary-transfer-bias applying member with respect to a first one of the at least two processing speeds and a second output value with respect to a second one of the at least two processing speeds, both the first output value and the second output value being further detected at a non-image-formation time and when the secondary-transfer-bias applying member is directly engaged with the intermediate transfer member, wherein the secondary-transfer-bias control unit determines the predetermined value based on the first output value and the second output value detected by the secondary-transfer-output detecting unit.