A method for controlling dot tone in electrostatic digital printing

Abstract

The invention provides a control method for static digital printing dot halftone. The control method includes the steps of (a) correcting a printing machine, (b) designing four primary colors (C, M, Y, and K) step-wedge control strip color lumps and three secondary color (R, G, and B) step-wedge control strip color lumps, (c) measuring the sizes of the dots of the seven step-wedge control strip color lumps, and obtaining measuring values, (d) obtaining variation of the sizes of the dots through the method that the measuring value minus the input value, (e) building adjustment models of the three secondary colors of red, green and blue, (f) obtaining coefficients in a model by the adoption of all the variations of the step-wedge control strip color lumps, and (g) obtaining primary color compensation dosages (delta C<t>, delta M<t> and delta Y<t>) according to the a given secondary color compensation dosage so as to compensate a file. According to the control method for static digital printing dot halftone, the disadvantage of conducting compensation through the four primary colors (C, M, Y, and K) in the prior art is changed, the three secondary colors of red, green and blue are selected, a model relationship between the secondary colors and the primary colors is built, compensation to a digital file image is achieved, and a vivid output image with the minimum degree of distortion can be obtained.

Description

technical field [0001] The present invention relates to a method for controlling dot tone of electrostatic digital printing, and more specifically, relates to a method for controlling dot tone of electrostatic digital printing which realizes correction of primary colors by using constraints on output dot difference of secondary colors. Background technique [0002] In digital printing production, one of the key points of control is the control of tone, and the focus of tone control is to control the stability and consistency of tone reproduction. In the electrostatic digital printing process, the quality of consumables (paper, toner, etc.) is unstable, the environment (temperature, humidity, etc.) changes, the process control parameters (maximum ink volume, color gamut mapping method, etc.) , CMYK, etc.), the inconsistency of the file format (JPG, TIFF, PDF, etc.) will have an impact on the stability and consistency of tone reproduction. [0003] The common methods used for...

AI Technical Summary

Problems solved by technology

[0007] For each correction of digital printing output, the above process must be repeated. Although compared with traditional printing, it does not need to make a separate plate, nor does it need to print a test plate separately, but this kind of correction only uses 4 primary color ladders, which is different from traditional printing. As far as digital printing is concerned, the role of pre-press image processing is ignored, and it takes a lot of time to correct and measure data. For digital printing, these need to be paid by digital printing companies alone, which increases printing costs.

In addition, the fluctuation of the dot gain curve in actual production is generally large, and the matching guarantee between the output after compensation and the target curve is insufficient, resulting in a large gap between the compensation range of the monochrome ladder and the actual compensation amount required, resulting in the need for multiple compensations. The corresponding production efficiency and production quality are also reduced

Moreover, this method also directly compensates the dot gain of the zero dot compensation curve of the four primary color steps to the target dot gain, but does not take into account whether the secondary colors formed by the primary colors match the electronic image before and after printing. , resulting in a certain degree of distortion in the printed image file

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