Transfer device

摘要

A Transfer device (10) includes an intermediate transfer belt (41), a plurality of intermediate transfer roller (34A-34D) and a transfer member moving mechanism (20). The transfer member moving mechanism moves the intermediate transfer rollers (34A-34D) between pressing positions causing the intermediate transfer belt (41) to be pressed against respective photoreceptor drums (31A-31D) and separate positions causing the intermediate transfer belt (41) to be separate from the respective photoreceptor drums (31A-31D). The transfer member moving mechanism (20) causes a second pressing position of the intermediate transfer roller for monochrome (34A) in monochromatic image forming to be different from a first pressing position of the intermediate transfer roller for monochrome (34A) in full-color image forming so that an amount of pressing of the intermediate transfer belt (41) by the intermediate transfer roller for monochrome (34A) becomes greater in monochromatic image forming than in full-color image forming.

主权项

1. A transfer device in which an outer circumferential surface of an endless belt moving along a predetermined loop-like path of movement is disposed so as to face a plurality of image bearing members including one image bearing member for monochrome and one or more image bearing members for color that bear developer images of mutually different hues and are aligned with each other, the transfer device comprising:
the endless belt; a plurality of transfer members that are disposed so as to be opposed to the respective plurality of image bearing members across the endless belt on respective downstream sides of the plurality of image bearing members in a direction of movement of the endless belt and that sequentially transfer developer images borne by the respective plurality of image bearing members onto the endless belt; and a transfer member moving mechanism that moves the plurality of transfer members between pressing positions to cause the endless belt to be pressed against the respective plurality of image bearing members and separate positions to cause the endless belt to be separate from the respective plurality of image bearing members, the transfer member moving mechanism arranging a transfer member for monochrome corresponding to the image bearing member for monochrome and transfer members for color corresponding to the image bearing members for color at the respective pressing positions in full-color image forming, and arranging the transfer member for monochrome at the pressing position and the transfer members for color at the separate positions in monochromatic image forming, the transfer member moving mechanism including:
a first link member which has a first slit long in a direction perpendicular to the direction of movement of the endless belt and of which movement toward the upstream side in the direction of movement of the endless belt causes the transfer member for monochrome to move to the pressing position and of which movement toward the downstream sides causes the transfer member for monochrome to move to the separate position;a second link member which has one or more second slits along in the direction perpendicular to the direction of movement of the endless belt and of which movement toward the upstream side in the direction of movement of the endless belt causes the transfer members for color to move to the pressing positions and of which movement toward the downstream side causes the transfer members for color to move to the separate positions;an eccentric cam which is disposed between the first link member and the second link member and with which the first link member and the second link member are in contact with pressure; anda plurality of arms each of which gives a L-shape with a first end portion thereof rotatably supported by a frame and a second end portion thereof rotatably supporting each of the plurality of transfer member and has at a bent thereof a protruding portion that is displaced in the first slit or the second slit, wherein the transfer member moving mechanism causes a second pressing position of the transfer member for monochrome in monochromatic image forming to be different from a first pressing position of the transfer member for monochrome in full-color image forming so that an amount of pressing of the endless belt by the transfer member for monochrome becomes greater in monochromatic image forming than in full-color image forming.