Image processing apparatus with six colour toners

Abstract

The electrophotographic image recording apparatus includes a photoconductive image bearing member, a charging unit, an exposure unit, developing means, a transferring unit suited to superimpose and transfer the plural kinds of toner images obtained by the developing means, and a processing unit adapted to execute halftone processing image data to be sent to the exposure unit, wherein the plural kinds of toners include two kinds of toners of the same hue and differing in density from each other, and the processing unit tone-processes by the use of a screen pattern having different screen angles for the respective toners. In an electrophotographic image recording apparatus for forming an image by the use of a plurality of colorants including two kinds of colorants of substantially the same hue and differing in density from each other, and an image processing apparatus, a higher quality of image is achieved. Tone processing is effected by the use of a screen pattern having different screen angles for the respective toners.

Description

Image processing device with six color toners technical field The present invention relates to an electrophotographic image recording apparatus used in, for example, a copier, a printer, a facsimile apparatus, a plate making system, etc., and an image processing apparatus used for the electrophotographic image recording apparatus. Background technique As high-speed image forming apparatuses with high image quality, copiers and laser beam printers employing electrophotographic processing are known. With the advancement of digital technology in recent years, in the POD market for consumer markets such as offices and homes, there is an increasing demand for higher image quality of electrophotographic image recording devices, and for those who have undergone screen processing such as printing (screen processing) There is an increasing demand for images with very high gradation and image characteristics such as silver halide photographs with a wide range of color reproduction a...

AI Technical Summary

Problems solved by technology

When a screen of 200 lines has been formed, the screen structure is repeated at a period of the order of 120 μm, and when the above-mentioned positional shift of the order of 100 μm to 150 μm has occurred, the phase of the screen structure is just reversed, and therefore, juxtaposed positions are repeated and positions overlapping each other, resulting in large concentration unevenness

In this case, there are also practices of performing direct transfer from the image bearing member to the final supporting member, or employing a cylindrical intermediate transfer drum having a rigidity relatively higher than that of the intermediate transfer device, thereby avoiding the above-mentioned disadvantages, but this can't make a big difference

In addition, screens having five or more different angles are combined to thereby form an image, the degree of freedom in setting the screen angle is low, and the Rosetta mode that appears when screens of different angles are combined occurs at low frequencies and becomes noticeable

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