Image forming apparatus

Abstract

The present invention discloses an image forming device, which is provided with a laser light source having a plurality of laser elements capable of scanning a plurality of lines in parallel in a sub-scanning direction at a second resolution, which is higher than a first resolution of an image to be formed in a main scanning direction, a multiplexer and a laser driver that set a scaling ratio of an image in the sub-scanning direction in response to the first and second resolutions and an image size for image forming, and perform control so as to select and drive any of the plurality of laser elements of the laser light source in response to the scaling ratio that has been set, and an image forming unit that forms an image of lines scanned using laser elements driven by the laser driver ona print medium.

Description

technical field [0001] The present invention relates to an electrophotographic image forming apparatus, which is achieved by developing a latent image that has been formed on a photosensitive member with toner, transferring the toner image to a transfer material (sheet), and performing fixing imaging. Background technique [0002] figure 1 is a diagram of the configuration of a conventional color image forming apparatus. [0003] The color image forming apparatus is provided with two cassette feeding units 1 and 2 and a manual feeding unit 3 , and a sheet S is selectively fed from each of the feeding units 1 , 2 , 3 . Sheets S are loaded on cassettes 4 , 5 or tray 6 of paper feeding units 1 , 2 , 3 , and due to rotation of pickup roller 7 , sheets S are sequentially drawn out starting from the uppermost sheet. Then, only the uppermost sheet among the sheets S drawn out by the pickup roller 7 is separated by a pair of separation rollers consisting of a feed roller 8A and a...

AI Technical Summary

Problems solved by technology

Specifically, in the case of an apparatus capable of superimposing four color images to form a full-color image as a conventional example, there is a problem that poor color registration occurs and image quality deteriorates

As a result, the images of each color on the sheet that has been transferred from the intermediate transfer belt as a batch are displaced from their ideal positions, and the image quality deteriorates

There is also the problem that the position of images formed on multiple sheets fluctuates

However, the speed of response of the motor rotation rate is limited

For this reason, although this method is effective for long-term scaling ratio inhomogeneity, it is less effective for short-term scaling ratio non-uniform position shifting

[0035] Also, there is the problem that there is a front-to-back deviation in the image during duplex printing

However, this makes it necessary to change the rotational speed of the motor between sheets, so that unnecessary time for changing the speed between sheets must be kept

This is counterproductive to printing efficiency

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