How to accurately restore the color output from inkjet equipment?

When it comes to color management, it can be seen in all kinds of control of pre-press software and back-end printing hardware, and even in the most front-end delivery of printing manuscript, selection of post-press materials and supplies, printing inspection and other links.

The essence of printing is the faithful and reliable copy of pictures and texts on all kinds of substrates. The key to achieve this goal is efficient color management, which converts irrelevant graphic data of front-end equipment into print data related to output equipment through color management, so that it can be correctly presented on the substrate. Its importance is reflected in the background technical support of data collection, transformation and presentation. Printing without color management can not be called printing manufacturing.

Printing quality control needs color management from beginning to end, involving elements in four aspects: equipment calibration, equipment characterization, color matching and closed-loop control. Among them, closed-loop color management will be the collection of printing color data, feedback and data optimization at one go, realize the printing quality control without dead Angle.

The WYSIWYG of printing is mainly reflected in the consistency of color, which is the restoration of color consistency under different printing conditions. Reasonable control of the four key elements of color management can effectively control the color quality of printing products under different printing conditions within a reasonable range. The core control index is the accurate copy and mapping of grey balance. The core of quality control of a complete printing system is the gray balance control of color. Through the above control methods, the gray balance of the current system is accurately reproduced, so as to ensure the correct restoration of the color of the whole system. Thus, ensuring the consistency of printing color will be simplified to the reproduction and mapping accuracy of grey balance under different printing conditions, and the higher the accuracy, the higher the consistency.

Taking Founder Printing Jet color digital inkjet printing machine of Peking University and Founder Brilliant color process color management software as an example, after adjusting the hardware state of the equipment, the inkjet equipment calibration is carried out first, and the chroma and density of each order of the target substrate are standardized and regulated. Then in the equipment characteristic data acquisition stage, dynamic calculation of the maximum ink bearing capacity of the substrate, combined with intelligent GCR color separation algorithm to generate characteristic data. In the subsequent color matching phase, the program accurately locates the black and white field of the color gamut of the equipment, and uses the gray axis compensation technology and chroma microcontrol technology to achieve stable and efficient color gamut and gray axis mapping of the target color gamut and the device color gamut. Finally, according to the color mapping results, the software system will automatically feed back the measured chromaticity value of each node in the color gamue of the equipment to The Software, and make color difference comparison with the target color. According to the color difference value, the corresponding correction is made before output, so as to ensure that the output color of the inkjet equipment is close to the target color to the maximum extent. The closed-loop is a continuous working mode in production. By constantly correcting the color gamut mapping error, the high color matching degree and color output stability of the inkjet equipment and the target equipment are achieved, and the color seen by the target equipment can be accurately restored by the inkjet equipment.

Through the production practice of many customers, it is verified that the software and hardware system can not only achieve ISO high standard color consistency simulation, but also meet customers‘ requirements of color matching under non-standard printing mode, truly interpreting the printing concept of "what you see is what you get".