Automatic registration method and device

Abstract

The invention discloses an automatic registration method and device, and the method employs a trigger target and a sensor as triggers, and an image collection device is started according to a trigger signal sent by the sensor, thereby precisely controlling the image collection time; and correspondingly, the visual field range of the image collector is reduced into a single target registration target, angle errors of the target registration target are eliminated, so that the collected target registration target image has higher resolution, and a registration offset value can be calculated and updated on each printing plate periphery in combination with physical quantities such as relative stretching amount of a printing material. Overprinting parameters are adjusted in real time according to an overprinting deviation value, so that the printing precision of printed matters can be improved.

Description

technical field [0001] The application belongs to the field of printing methods, in particular to an automatic registration method and device. Background technique [0002] Multi-color group printing machines print complex color patterns, which are generally formed by overlapping printing of different color groups. Before official printing, it is necessary to debug the printing machine to make the multiple color groups match accurately, so that the printed matter can meet the printing accuracy requirements. This process is called registration. High-quality printed matter usually requires higher registration accuracy. In order to achieve registration accuracy control, it is necessary to measure the registration offset value in time and accurately, so as to continuously correct the registration parameters. [0003] In the prior art, the method for real-time detection of registration deviation includes a registration scheme based on a vision method. Usually, the registration s...

AI Technical Summary

Problems solved by technology

Those skilled in the art can understand that reducing the shooting interval or adopting a continuous shooting method will result in redundant shooting, firstly filter the redundant images, and then calculate the offset value of each color group, which will cause a decrease in calculation efficiency; and Expanding the field of view of the image acquisition device will lead to a decrease in the proportion of the target image of each color group in the entire image, low resolution, and poor measurement accuracy, which will lead to inaccurate calculation of the offset value of the set, and further lead to a loss of the set of color set parameters. The correction is not accurate, and it is difficult to meet the offset value requirements of high-precision printed products; and, after changing the printing task and printing plate, it is necessary to find the position of the color mark again, which is complicated and time-consuming.

[0005] In addition, the above solution still has at least the following problems: 1. The camera used to take pictures requires a large field of view, resulting in low resolution and poor measurement accuracy; 2. It is necessary to find the position of the color mark every time after changing the printing plate; 3. It is impossible to adjust the timing of the photo in real time. Due to the inevitable time difference between the actual timing of a single photo and the theoretical timing, as the printing length continues to increase, the cumulative error also continues to increase, resulting in the target registration in the image collected according to this timing The target image is incomplete or not located in the center of the image, and the finally collected registration target image cannot be used to calculate the registration deviation value or cannot reflect the registration deviation value of the target color group; 4. The traditional registration deviation calculation method is only based on the image results. Other factors such as fluctuations in printing press acceleration are not taken into account, therefore, there is always a requirement that it is difficult to adjust the registration parameters to high precision by directly using the registration offset value

[0006] In traditional printing equipment, some are equipped with photoelectric sensors. The photoelectric sensors in these printing equipment are used to detect the offset value of the sleeve. However, due to the principle of calculating the offset value of the photoelectric sensor, the accuracy of the offset value will be low.

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