Register bias criterion method, register sign of full color printing and color image forming apparatus

Abstract

A misregistration judging method, registration mark for color printing, color slippage detection mark, color slippage correction chart, color registration correction chart, color slippage detection method color slippage correction method, and color image forming apparatus are provided. The color image forming apparatus prints registration marks (110, 120, 130) for color printing respectively including marks of reference colors (111, 121, 131) and marks of colors for measurement (112, 122, 132) that are centered at same positions and having similar figures and judges any relative positional displacement, if any, of a mark of a reference color and the corresponding mark of the color for measurement as misregistration.

Description

technical field [0001] The present invention relates to a registration shift judgment method for judging color shift in color printing, a registration mark for color printing, a mark for color shift detection, a color shift correction chart, a color registration correction chart, a color shift detection method, A color shift correction method, and a color image forming apparatus. [0002] This application is based on Japanese Patent Application No. 2005-300657 filed on October 14, 2005, Japanese Patent Application No. 2006-035476 filed on February 13, 2006, and Japanese Patent Application No. 2006-035477 in Japan and claims priority, these applications are hereby incorporated by reference in this application. Background technique [0003] Conventionally, a color printed matter is composed of four colors of Y (yellow), M (magenta), C (cyan), and BL (black) printed in overlapping layers. At this time, the position of the four colors of Y, M, C, and BL is called color registr...

AI Technical Summary

Problems solved by technology

[0007] However, as in the above-mentioned method of detecting color shift by overlapping circles of the same shape, it is difficult to judge color shift by visual inspection when two circles of the same shape are overlapped.

[0008] In addition, in a printing system that is composed of register mark element groups corresponding to each color one by one and having different shapes, it is possible to detect the amount of misregistration of each color based on the position of the register mark element of the reference color. Among the registration marks, since the color shift of the registration marks is printed small so that it can be measured with an instrument, it is not suitable for visual inspection.

In addition, since all four colors are printed around one reference color, there is a problem that it is hard to see

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