Apparatus and method for forming color image

Abstract

The present invention provides an apparatus and method for forming color image. The color image forms an image by correcting registration shifts during an image forming process by using image data and which prevents toner from being blown away and scattered during a fixing process by thinning pixels without making an erroneous decision. When multivalued color image is binarized, the threshold is corrected by using information on grayscale level correction. Further, when trailing phenomenon prevention operation is performed on the binarized image data, the patterns to be used for pattern matching are changed and selected according to whether the subscan direction line shifting point lies within the reference window.

Description

technical field [0001] The present invention relates to an image forming apparatus and an image forming method that correct the curvature of scanning lines and control the amount of toner applied to a printing medium in the process of forming an image. Background technique [0002] In order to achieve a faster image forming speed in electrophotographic color image forming apparatuses, more and more in-line color image forming apparatuses have come to be used in recent years. This device has the same number of developing devices and photosensitive drums as the number of color materials, and sequentially transfers images of different colors onto an image bearing belt or a printing medium. The in-line color image forming apparatus is known to have problems causing registration shifts and various countermeasures have been proposed to solve the above-mentioned respective problems. [0003] One of the problems is non-uniformity of the lens of the deflection scanning device, displ...

AI Technical Summary

Problems solved by technology

When printing an image of a line extending in the main scanning direction, a problem occurs that the toner applied to the printing medium 11 scatters at the trailing edge of the line 81 in the sub scanning direction, thereby disturbing the printed image (such as Figure 8 shown)

As mentioned above, fusion operations can lead to wrong decisions about whether to perform interval operations

[0010] Another problem is that the fact that the image changes in the sub-scanning direction when an image pattern is selected prevents the extraction of correct pattern

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