Image forming apparatus

Abstract

An image forming apparatus has: an image forming section that forms a toner image corresponding to image information; an intermediate transfer belt, which is an endless belt stretched between a plurality of rollers and traveling between the plurality of rollers, the toner image being transferred to a surface thereof or a recording sheet placed on the surface thereof; a driving roller, which is one of the plurality of rollers and drives the intermediate transfer belt; a bending roller, which touches an outer circumferential surface of the intermediate transfer belt and presses and bends the intermediate transfer belt in an inner circumferential direction; and a speed detecting part which detects a movement speed of an outer circumference of the intermediate transfer belt by measuring a rotational speed of the bending roller. Consequently, the invention may accurately measure the movement speed of an intermediate transfer belt to be controlled, and output an image with no density fluctuation and color registration error by accurately controlling the movement speed of the intermediate transfer belt of the image forming apparatus.

Description

technical field [0001] The present invention relates to an image forming apparatus having an intermediate transfer belt. Background technique [0002] An image forming apparatus employing dry electrophotography (xerography), such as a laser printer or a copier, has rotating members such as a photosensitive drum, a transfer roller, and an intermediate transfer belt. These rotating members are used to output the toner images formed through the electrostatic latent image forming process onto recording paper. In order to obtain an output result free from density unevenness, image shift, etc., it is necessary to precisely control these rotating parts. In particular, the intermediate transfer belt needs to accurately measure the moving speed of the intermediate transfer belt and control the moving speed of the intermediate transfer belt to keep constant since the toner image to be transferred onto the recording paper is transferred. Especially in a tandem image forming apparatus...

AI Technical Summary

Problems solved by technology

However, in the case where the thickness of the intermediate transfer belt is not uniform due to a dimensional error in the manufacture of the intermediate transfer belt, or when the intermediate transfer belt is deteriorated or the intermediate transfer belt is partially elongated, etc., Then the speed conversion cannot be performed accurately

Therefore, the previous method of detecting the inner peripheral surface speed of the intermediate transfer belt has the problem that the speed measurement and speed control accuracy of the intermediate transfer belt is not good.

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