Image forming device

Abstract

Arranged on the inner side of the endless moving path formed by the intermediate transfer belt (11) stretched between the drive roller (11A) and the driven roller (11B): contacting the inner peripheral surface of the intermediate transfer belt (11) The first eccentric cams (211, 221), the second eccentric cams (212, 222) which rotate integrally with the first eccentric cams (211, 221), contact with the peripheral surface of the second eccentric cams (212, 222) The cam followers (214, 224) and the transmission members (215A-215D) holding the transfer rollers (413A-13D) respectively with the cam followers (214, 224). The vertical positions of the transfer rollers (13A-13D) held by the transmission members (215A-215D) are changed according to the state of contact between the first eccentric cams (211, 221) and the inner peripheral surface of the intermediate transfer belt (11).

Description

technical field [0001] The present invention relates to arranging a plurality of image forming units that form images with different color tones by electrophotographic image formation in parallel in one direction, and can form a complete image on a recording medium such as paper through an intermediate transfer belt or a transfer conveyor belt. An image forming apparatus of a cascade system for full color images. Background technique [0002] In recent years, electrophotographic image forming apparatuses have been increasingly required to form not only monochrome images but also full-color images, and the development of electrophotographic full-color image forming apparatuses has been advanced. Generally, a full-color image forming apparatus performs image formation using a toner of a corresponding color tone for each of image data of a plurality of color tones obtained by color-separating a color image. For example, the same color image is read through color filters of eac...

AI Technical Summary

Problems solved by technology

[0015] However, in the conventional structure described above, when forming a monochrome image and when forming a full-color image, the position of the annular zone is obviously shifted. Adverse effects, it is necessary to increase the amount of movement of the driving roller or driven roller, and there is a problem of increasing the size of the device

[0016] In addition, the image carrier and the endless belt included in each image forming unit are in contact with a transfer area of ​​a predetermined width called a transfer nip. In this transfer area, the endless belt is curved according to the curvature of the surface of the image carrier. In the structure in which the distance between the shafts of the driving roller and the driven roller is always kept constant, the endless belt away from the image carrier in the image forming unit that is not used for forming monochrome images loosens, causing the endless belt to creep.

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