Book and periodical rotary press and method

Abstract

The invention provides a book and periodical rotary press and method. The method comprises the steps that a printing image obtained after first-time color overprinting is collected; identifying the image-text deviation of the first color overprinting from the printing image; according to the optical density of the printing area after the first-time color overprinting, determining a dot expansion value of color dots after the first-time color overprinting under the condition that ink is emulsified, and according to the dot expansion value and the image-text deviation, determining the pigment combination degree of the ink between the second-time color overprinting and the first-time color overprinting; according to the residue deposition amount of # imgabs0 # sediment in the fountain solution in the first color overprinting process, the plate pasting defect of secondary color overprinting is predicted; and the pressure compensation amount of secondary color overprinting is determined based on the pigment combination degree and the plate pasting defect, and the book and periodical rotary press is controlled to conduct secondary color overprinting according to the pressure compensation amount. By the adoption of the scheme, the screen dot size of the ink can be adjusted in real time in multi-color printing, and therefore the quality of books and periodicals after rotary printing is improved.

Description

Technical Field

[0001] The present application relates to the field of industrial printing control technology, and more specifically, to a book and periodical rotary printing press and method. Background Art

[0002] Industrial printing control refers to the real-time monitoring, adjustment and optimization of various process parameters, equipment operation status and printing quality of printing machines through hardware and software technology in the process of industrial printing production, so as to ensure efficient production and maintain the consistency of printing quality. Industrial printing control involves many aspects such as the automated operation of printing machines, precise control of the production process, and quality management. Generally speaking, in the process of industrial printing control, the printing quality is monitored in real time through visual perception mechanisms, and the various mechanisms in the industrial printing machine are automatically controlled to work according to the monitoring results.

[0003] With the development of technology, industrial robots are used more and more widely in the printing industry. They have promoted the automation and intelligentization of rotary printing of books and periodicals by improving production efficiency, reducing labor costs, and improving printing quality. For example, rotary printing presses for books and periodicals can be integrated with industrial robots and are specifically used for intelligent printing of paper publications such as books, magazines, and newspapers, which reduces manual intervention and improves production efficiency.

[0004] In addition, the printing method commonly used by rotary printing presses for books and periodicals for multi-color printing is CMYK (Cyan, Magenta, Yellow, Black) printing, which produces various colors by superimposing yellow, magenta, and cyan pigments in different proportions to absorb different wavelengths in the spectrum. Black is used to enhance the depth and contrast of the image. The image is printed on yellow, magenta, cyan, and black plates respectively through a four-color color separation printing press. The ink is superimposed on the paper with different dot sizes and shapes to form a continuous tone visually. However, in actual production, due to the emulsification of the ink, the dot size of each color ink will change, which makes the color presented by the combination of different colors of ink deviate from the expected color, and too large dots will cause the plate to be blurred. Therefore, how to adjust the dot size of the ink in real time in multi-color printing to improve the quality of books and periodicals after rotary printing has become a difficult problem faced by the industry. Summary of the invention

[0005] The present application provides a rotary printing machine and method for books and periodicals, which can adjust the dot size of ink in real time during multi-color printing to ensure that different colors of ink can present the desired color after combination, thereby improving the quality of books and periodicals after rotary printing.

[0006] In a first aspect, the present application provides a multi-color printing method of a book rotary printing press, wherein the book rotary printing press comprises a printing mechanism, a visual perception mechanism, and a mechanical arm, and the multi-color printing method comprises:

[0007] Starting the printing mechanism of the book and periodical rotary printing press to perform the first color overprinting, and collecting the printed image after the first color overprinting through the visual perception mechanism;

[0008] Identifying a first color process deviation from the printed image;

[0009] Obtaining the optical density of the printed area after the first color overprinting, determining the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density, and predicting the overprinting result of the second color overprinting according to the dot expansion value and the image deviation, and obtaining the pigment bonding degree of the ink between the second color overprinting and the first color overprinting;

[0010] According to the first color overprint process Predicting the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting;

[0011] The pressure compensation amount of the robot arm in the secondary color overprinting is determined based on the pigment binding degree and the plate sticking defect, and then the book and periodical rotary printing press is controlled to perform the secondary color overprinting according to the pressure compensation amount.

[0012] In some embodiments, identifying the image and text deviation of the first color overprint from the printed image specifically includes:

[0013] determining edge curves in the printed image;

[0014] The graphic deviation of the pattern in the printing area after the first color overprinting is determined according to the edge curve and the preset printing pattern.

[0015] In some embodiments, determining the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density specifically includes:

[0016] Get the solid density of printed paper;

[0017] Determining the blank reflectivity of the unprinted portion after the first color overprint according to the paper density;

[0018] determining the printing reflectivity of the printed area after the first color overprinting according to the optical density;

[0019] The dot expansion value of the color dots when the ink is emulsified after the first color overprinting is determined according to the blank reflectivity and the printing reflectivity.

[0020] In some embodiments, predicting the overprinting result of the secondary color overprinting according to the dot gain value and the image-text deviation to obtain the pigment bonding degree of the ink between the secondary color overprinting and the primary color overprinting specifically includes:

[0021] Obtaining component content and drying speed of secondary color overprinting ink;

[0022] Determining the ink bonding degree according to the component content and the drying speed;

[0023] Determine an emulsification penalty according to the dot gain value and the image-text deviation;

[0024] The pigment binding degree of the ink between the secondary color process printing and the primary color process printing is determined based on the ink binding degree and the emulsification penalty.

[0025] In some embodiments, according to the first color process printing process The residual deposition amount of the shaped deposits and the preset pressure of the robot arm during the secondary color overprinting process predict the plate sticking defects of the secondary color overprinting specifically include:

[0026] Determine the content of the fountain solution according to the original performance of the fountain solution during the first color overprinting process. The amount of residual deposits in the sediment;

[0027] Obtaining a preset pressure of the mechanical arm during the secondary color overprinting process and a viscosity of the ink during the secondary color overprinting process;

[0028] Determining a predicted laminar flow coefficient of the ink during the secondary color overprinting process according to a dot gain value in the primary color overprinting process, a preset pressure of the mechanical arm during the secondary color overprinting process, and a viscosity of the ink during the secondary color overprinting process;

[0029] The plate smearing defect of the secondary color overprinting is determined according to the residue deposition amount and the predicted laminar flow coefficient.

[0030] In some embodiments, the content of the fountain solution is determined based on the original properties of the fountain solution during the first color overprinting process. The residual deposition amount of the precipitate specifically includes:

[0031] Obtaining the pH, surface tension and conductivity of the fountain solution during the first color overprinting process, and using the pH, surface tension and conductivity as the original solution properties of the fountain solution during the first color overprinting process;

[0032] determining the amount of acid-base deposition according to the pH and a preset optimal pH;

[0033] Determining a tension deposition amount according to the surface tension and a preset optimal tension;

[0034] Determine the content of the fountain solution according to the acid-base deposition amount, the tension deposition amount and the conductivity The amount of residual deposition in the precipitate.

[0035] In some embodiments, determining the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the smearing defect specifically includes:

[0036] Determining a limit value of pressure adjustment according to the pigment binding degree and the plate sticking defect;

[0037] Comparing the pressure adjustment limit value with a preset limit threshold value, and when the limit value is less than or equal to the limit threshold value, setting the pressure compensation amount of the robot arm in the secondary color overprinting to 0;

[0038] When the limiting value is greater than the limiting threshold, the pressure compensation amount of the robot arm in the secondary color overprinting is determined according to the limiting value and the limiting threshold.

[0039] In a second aspect, a rotary printing press for books and periodicals includes a printing mechanism, a visual perception mechanism, a mechanical arm, and a control unit, wherein the control unit is used to control the rotary printing press for books and periodicals to perform multi-color printing, and the control unit includes:

[0040] A collection module, used for collecting the printed image after the first color overprinting through the visual perception mechanism after the printing mechanism of the book and periodical rotary printing press is started to perform the first color overprinting;

[0041] A processing module, used for identifying the image deviation of the first color overprint from the printed image;

[0042] The processing module is also used to obtain the optical density of the printed area after the first color overprinting, determine the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density, and predict the overprinting result of the second color overprinting according to the dot expansion value and the image deviation, and obtain the pigment bonding degree of the ink between the second color overprinting and the first color overprinting;

[0043] The processing module is also used to adjust the content of the fountain solution in the first color overprinting process according to the Predicting the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting;

[0044] The execution module is used to determine the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the plate sticking defect, and then control the book and periodical rotary printing machine to perform the secondary color overprinting according to the pressure compensation amount.

[0045] In a third aspect, the present application provides a computer device, comprising a memory and a processor, wherein the memory stores codes, and the processor is configured to obtain the codes and execute the above-mentioned multi-color printing method of the book rotary printing press.

[0046] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the multi-color printing method of the above-mentioned book rotary printing press.

[0047] The technical solution provided by the embodiments disclosed in this application has the following beneficial effects:

[0048] In the rotary printing press and method for books and periodicals provided in the present application, the printing mechanism of the rotary printing press for books and periodicals is first started to perform the first color overprinting, and the printed image after the first color overprinting is collected by the visual perception mechanism; the image and text deviation of the first color overprinting is identified from the printed image; the optical density of the printed area after the first color overprinting is obtained, and the dot expansion value of the color dots under the emulsification of the ink after the first color overprinting is determined according to the optical density, and the overprinting result of the secondary color overprinting is predicted according to the dot expansion value and the image and text deviation, and the pigment binding degree of the ink between the secondary color overprinting and the first color overprinting is obtained; according to the dot expansion value and the image and text deviation in the fountain solution during the first color overprinting, the ink pigment binding degree between the secondary color overprinting and the first color overprinting is obtained; The residual deposition amount of the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting process predict the plate sticking defect of the secondary color overprinting; based on the pigment binding degree and the plate sticking defect, the pressure compensation amount of the robot arm in the secondary color overprinting is determined, and then the book and periodical rotary printing press is controlled to perform the secondary color overprinting according to the pressure compensation amount.

[0049] It can be seen that the present application determines the emulsification degree of the ink in the first color overprinting (i.e., the dot expansion value) by the optical density of the printed area after the first color overprinting, and then predicts the printing quality of the second color overprinting (i.e., the pigment binding degree) according to the dot expansion value and the image deviation of the pattern in the printed area after the first color overprinting, thereby measuring the deviation between the color presented by the combination of different colors of ink after the two color overprinting and the expected color; then, according to the value of the dot expansion value in the fountain solution during the first color overprinting process, the color of the second color overprinting is estimated. The amount of residue deposition of the shaped sediment is used to predict the plate sticking defect of the secondary color overprinting, so as to avoid the plate sticking in the secondary color overprinting. Finally, the overprinting pressure of the robot arm in the secondary color overprinting process is adjusted according to the pigment binding degree and the plate sticking defect, so as to adjust the size of the dots in the secondary color overprinting process. In summary, the scheme of the present application can make real-time adjustment to the dot size of the ink in multi-color printing, thereby improving the quality of books and periodicals after rotary printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1is an exemplary flow chart of a multi-color printing method of a book and periodical rotary printing press according to some embodiments of the present application;

[0051] Figure 2 is an exemplary flow chart of determining a dot spread value according to some embodiments of the present application;

[0052] Figure 3 is an exemplary flow chart for determining the amount of residue deposition according to some embodiments of the present application;

[0053] Figure 4 is a schematic diagram of the structure of a control unit according to some embodiments of the present application;

[0054] Figure 5 It is a structural schematic diagram of a computer device for implementing a multi-color printing method of a book rotary printing press according to some embodiments of the present application. DETAILED DESCRIPTION

[0055] In order to better understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0056] refer to Figure 1 , which is an exemplary flow chart of a multi-color printing method of a rotary printing press for books and periodicals according to some embodiments of the present application. The multi-color printing method 100 of the rotary printing press for books and periodicals mainly includes the following steps:

[0057] In step 101, the printing mechanism of the book rotary printing press is started to perform the first color overprinting, and the printed image after the first color overprinting is collected by the visual perception mechanism.

[0058] It should be noted that the printing mechanism in this application refers to the core component used to complete multi-color printing operations, which is responsible for transferring the ink of each color overprint to the paper to be printed according to pre-set parameters.

[0059] In addition, it should be noted that the visual perception mechanism in this application refers to a system that collects images, texts or other symbols during the printing process through visual technologies such as optics, sensors, and cameras.

[0060] In specific implementation, the image of the surface of the book after the first color overprinting can be captured by a visual perception mechanism carried by a rotary printing press, and the image can be used as a printed image. The visual perception mechanism can be a camera capable of capturing the image of the surface of the book. In other embodiments, it can also be other devices capable of capturing the image of the surface of the book, which is not limited here.

[0061] In step 102, the image and text deviation of the first color process is identified from the printed image.

[0062] In some embodiments, identifying the image deviation of the first color overprint from the printed image can be achieved by using the following steps:

[0063] determining edge curves in the printed image;

[0064] The graphic deviation of the pattern in the printing area after the first color overprinting is determined according to the edge curve and the preset printing pattern.

[0065] In some embodiments, determining the edge curve in the printed image may be achieved by the following steps:

[0066] sharpening the printed image to obtain a printed sharpened image;

[0067] All edge curves are extracted in the printed sharpened image.

[0068] In a specific implementation, the printed image is sharpened to obtain a printed sharpened image, which can be achieved in the following manner, namely: the printed image is sharpened by Laplace sharpening in the prior art, and the obtained image is used as the printed sharpened image. In other embodiments, the printed image can also be sharpened by other prior arts, which is not limited here.

[0069] It should be noted that the printed sharpened image in the present application refers to an image obtained by sharpening the printed image.

[0070] In a specific implementation, all edge curves are extracted from the printed sharpened image in the following manner, namely, all contours in the printed sharpened image are extracted by using the Canny edge detection algorithm in the prior art, and all the obtained contours are used as edge curves. In other embodiments, edge curves can also be extracted from the printed sharpened image by using other prior arts, which is not limited here.

[0071] It should be noted that the edge curve in the present application refers to the edge of the pattern on the surface of the book or periodical after the first color overprinting, which includes the edge of the first color overprinting pattern and the edge formed by the abnormal protrusion of the first color overprinting ink.

[0072] In some embodiments, determining the image deviation of the pattern in the printed area after the first color overprinting according to the edge curve and the preset printing pattern can be achieved by the following steps:

[0073] Obtaining a pre-set printing pattern for the first color overprint;

[0074] determining a standard profile according to the printed pattern;

[0075] The graphic deviation of the pattern in the printing area after the first color overprinting is determined according to the standard contour and the edge curve.

[0076] It should be noted that the printing pattern in the present application refers to a pre-set area on a book or periodical that needs to be subjected to the first color overprinting. During the first color overprinting, the ink for the first color overprinting needs to be printed in the area.

[0077] In specific implementation, determining the standard contour according to the printed pattern may be achieved in the following manner, namely: extracting all contours in the printed pattern by using the Canny edge detection algorithm in the prior art, and using all the obtained contours as standard contours.

[0078] It should be noted that the standard outline in this application refers to the edge of the pattern on the surface of the book or periodical after the first color overprinting.

[0079] In specific implementation, determining the graphic deviation of the pattern in the printed area after the first color overprinting based on the standard contour and the edge curve can be achieved in the following manner, namely: first, calculating the area enclosed by each closed curve in the standard contour, and summing the areas corresponding to all closed curves in the standard contour, and using the obtained value as the standard area of ​​the standard contour; then, calculating the area enclosed by each closed curve in the edge curve, and summing the areas corresponding to all closed curves in the edge curve, and using the obtained value as the total area of ​​the edge curve; subsequently, subtracting the standard area from the total area, and dividing the obtained difference by the standard area; finally, using the obtained value as the graphic deviation of the pattern in the printed area after the first color overprinting.

[0080] It should be noted that the image and text deviation in the present application is a parameter that indicates the degree of deviation between the pattern and text on the surface of the book or periodical after the first color overprinting and the pre-set printed pattern and text of the first color overprinting. The larger the image and text deviation, the greater the deviation between the emulsification degree of the ink used in the first color overprinting process and the optimal emulsification degree, that is, the worse the quality of the printed image after the first color overprinting. The smaller the image and text deviation, the smaller the deviation between the emulsification degree of the ink used in the first color overprinting process and the optimal emulsification degree, that is, the better the quality of the printed image after the first color overprinting.

[0081] In step 103, the optical density of the printed area after the first color overprinting is obtained, and the dot expansion value of the color dots under the emulsified ink after the first color overprinting is determined based on the optical density, and the overprinting result of the second color overprinting is predicted based on the dot expansion value and the graphic deviation to obtain the pigment binding degree of the ink between the second color overprinting and the first color overprinting.

[0082] In specific implementation, the optical density of the printed area after the first color overprinting can be collected by a spectroscopic densitometer. In other embodiments, the optical density of the printed area after the first color overprinting can also be obtained by other existing technologies, which is not limited here.

[0083] In some embodiments, reference Figure 2 , which is an exemplary flow chart for determining the dot gain value according to some embodiments of the present application. In the present application, the dot gain value of the color dots after the first color overprinting under the emulsification of the ink can be determined according to the optical density by the following steps:

[0084] In step 1031, the solid density of the printed paper is obtained;

[0085] In step 1032, the blank reflectivity of the unprinted portion after the first color overprinting is determined according to the paper density;

[0086] In step 1033, the printing reflectivity of the printing area after the first color overprinting is determined according to the optical density;

[0087] In step 1034, the dot expansion value of the color dots when the ink is emulsified after the first color overprinting is determined according to the blank reflectivity and the printing reflectivity.

[0088] In a specific implementation, the optical density of the unprinted area after the first color overprinting can be collected by a spectrophotometer, and the optical density of the unprinted area can be used as the solid density of the printed paper.

[0089] It should be noted that the solid density in this application refers to the optical density of the printed paper itself.

[0090] In specific implementation, determining the blank reflectivity of the unprinted portion after the first color overprinting according to the paper density can be achieved in the following manner, namely: first, taking the opposite of the paper density, then using the obtained value as an exponent of ten, and finally using the obtained value as the blank reflectivity of the unprinted portion after the first color overprinting.

[0091] It should be noted that the blank reflectivity in the present application is a parameter indicating how much light is reflected from the unprinted area on a book or periodical. The larger the blank reflectivity, the more light is reflected from the unprinted area on the book or periodical, and the smaller the blank reflectivity, the less light is reflected from the unprinted area on the book or periodical. For example, in the present application, the sum of the radiation intensities of light reflected from the unprinted area on the book or periodical can be used as the blank reflectivity.

[0092] In specific implementation, determining the printing reflectivity of the printed area after the first color overprinting based on the optical density can be achieved in the following manner, namely: first, taking the opposite of the optical density, then using the obtained value as an exponent of ten, and finally using the obtained value as the printing reflectivity of the printed area after the first color overprinting.

[0093] It should be noted that the printing reflectivity in the present application is a parameter indicating how much light is reflected by the printed area on a book or periodical. The larger the blank reflectivity, the more light is reflected by the printed area on the book or periodical, and the smaller the blank reflectivity, the less light is reflected by the printed area on the book or periodical. For example, in the present application, the sum of the radiation intensities of light reflected by the printed area on the book or periodical can be used as the printing reflectivity.

[0094] In specific implementation, the dot expansion value of the color dots when the ink is emulsified after the first color overprinting is determined based on the blank reflectivity and the printing reflectivity, which can be achieved in the following manner, namely: first, the blank reflectivity is subtracted from one, and the obtained value is used as the denominator; then, the printing reflectivity is subtracted from one, and the obtained value is used as the numerator, and then the ratio of the numerator to the denominator is obtained; finally, the ratio is used as the dot expansion value of the color dots when the ink is emulsified after the first color overprinting.

[0095] It should be noted that the dot expansion value in the present application is a parameter indicating the degree of color dot expansion caused by the emulsification of the ink after the first color overprinting. The larger the dot expansion value, the more the color dots expand when the ink is emulsified after the first color overprinting. The smaller the dot expansion value, the less the color dots expand when the ink is emulsified after the first color overprinting.

[0096] In some embodiments, the following steps may be used to predict the overprinting result of the secondary color overprinting according to the dot gain value and the image-text deviation to obtain the pigment bonding degree of the ink between the secondary color overprinting and the primary color overprinting:

[0097] Obtaining component content and drying speed of secondary color overprinting ink;

[0098] Determining the ink bonding degree according to the component content and the drying speed;

[0099] Determine an emulsification penalty according to the dot gain value and the image-text deviation;

[0100] The pigment binding degree of the ink between the secondary color process printing and the primary color process printing is determined based on the ink binding degree and the emulsification penalty.

[0101] It should be noted that in the present application, predicting the overprinting result of the secondary color overprinting based on the dot gain value and the image deviation refers to obtaining the component content and drying speed of the secondary color overprinting ink; determining the ink binding degree according to the component content and the drying speed; determining the emulsification penalty according to the dot gain value and the image deviation; and determining the pigment binding degree of the ink between the secondary color overprinting and the first color overprinting according to the ink binding degree and the emulsification penalty.

[0102] In a specific implementation, the component content, viscosity and drying speed of the secondary color overprinting ink can be obtained through the product manual of the ink used for the secondary color overprinting.

[0103] It should be noted that the component content in the present application refers to the proportion of each component in the ink, including the proportion of pigments, binders, solvents and additives in the ink. In other embodiments, the component content may also include the proportion of other components in the ink, which is not limited here.

[0104] In specific implementation, determining the ink binding degree according to the component content and the drying speed can be achieved in the following manner, namely: first, adding the pigment content in the component content to the inverse of the drying speed, adding one to the obtained value, and finally, using the obtained value as the ink binding degree.

[0105] It should be noted that the ink bonding degree in this application is a parameter indicating the printing quality when the ink in the secondary color overprinting is directly printed on paper. The greater the ink bonding degree, the better the bonding of the ink in the secondary color overprinting when it is directly printed on paper, and the better the printing quality. The smaller the ink bonding degree, the worse the bonding of the ink in the secondary color overprinting when it is directly printed on paper, and the worse the printing quality.

[0106] In specific implementation, the emulsification penalty may be determined according to the dot gain value and the image-text deviation in the following manner: first, the natural logarithm of the image-text deviation is calculated, then the obtained value is multiplied by the dot gain value, and finally, the obtained value is used as the emulsification penalty.

[0107] It should be noted that the emulsification penalty in the present application is a parameter that indicates the degree of decline in the printing quality of the secondary color overprinting due to the emulsification degree of the ink in the first color overprinting. The larger the emulsification penalty, the more the printing quality of the secondary color overprinting is declined due to the emulsification degree of the ink in the first color overprinting. The smaller the emulsification penalty, the less the printing quality of the secondary color overprinting is declined due to the emulsification degree of the ink in the first color overprinting.

[0108] In addition, it should be noted that the pigment binding degree in the present application is a parameter indicating the degree of binding between the inks of two color overprints. The greater the pigment binding degree, the better the binding between the inks of the two color overprints, that is, the higher the printing quality. The smaller the pigment binding degree, the worse the binding between the inks of the two color overprints, that is, the lower the printing quality. As a preferred embodiment, in the present application, determining the pigment binding degree of the ink between the secondary color overprint and the first color overprint based on the ink binding degree and the emulsification penalty can be achieved in the following manner, namely: the value obtained by subtracting the emulsification penalty from the ink binding degree is used as the pigment binding degree between the corresponding inks of the two color overprints.

[0109] In step 104, according to the first color overprinting process, the fountain solution The residual deposition amount of the slag-like deposits and the preset pressure of the robot arm during the secondary color overprinting process predict the plate sticking defect of the secondary color overprinting.

[0110] In some embodiments, according to the first color process printing process The following steps can be used to predict the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting:

[0111] Determine the content of the fountain solution according to the original performance of the fountain solution during the first color overprinting process. The amount of residual deposits in the sediment;

[0112] Obtaining a preset pressure of the mechanical arm during the secondary color overprinting process and a viscosity of the ink during the secondary color overprinting process;

[0113] Determining a predicted laminar flow coefficient of the ink during the secondary color overprinting process according to a dot gain value in the primary color overprinting process, a preset pressure of the mechanical arm during the secondary color overprinting process, and a viscosity of the ink during the secondary color overprinting process;

[0114] The plate smearing defect of the secondary color overprinting is determined according to the residue deposition amount and the predicted laminar flow coefficient.

[0115] In some embodiments, reference Figure 3 , which is an exemplary flow chart for determining the amount of residue deposition according to some embodiments of the present application. In the present application, the amount of residue deposition in the fountain solution is determined according to the original liquid performance of the fountain solution during the first color overprinting process. The amount of residue deposited in the form of sediment can be achieved by the following steps:

[0116] In step 1041, the pH, surface tension and conductivity of the fountain solution in the first color overprinting process are obtained, and the pH, surface tension and conductivity are used as the original solution properties of the fountain solution in the first color overprinting process;

[0117] In step 1042, the acid-base deposition amount is determined according to the pH and a preset optimal pH;

[0118] In step 1043, a tension deposition amount is determined according to the surface tension and a preset optimal tension;

[0119] In step 1044, the content of the fountain solution is determined based on the acid-base deposition amount, the tension deposition amount, and the conductivity. The amount of residual deposition in the precipitate.

[0120] In specific implementation, the pH meter can be used to collect the pH value of the fountain solution during the first color overprinting process, and the automatic tension meter can be used to collect the surface tension of the fountain solution during the first color overprinting process. Finally, the conductivity of the fountain solution during the first color overprinting process can be collected by the conductivity meter.

[0121] In addition, in the specific implementation, the acid-base deposition amount can be determined according to the pH and the preset optimal pH in the following manner, namely: first, the pH is subtracted from the preset optimal pH, then the obtained value is squared, and finally, the obtained value is used as the acid-base deposition amount, wherein the optimal pH can be preset according to actual needs. For example, in the present application, the optimal pH is preset to 5.

[0122] It should be noted that the acid-base deposition amount in this application refers to the acid-base deposition on the paper surface caused by the pH of the fountain solution during the first color overprinting process. The larger the amount of acid-base deposit, the higher the pH value of the fountain solution during the first color overprinting process will cause the deposit on the paper surface. The more the deposits are, the smaller the amount of acid-base deposits. The pH of the fountain solution during the first color overprinting causes the deposits to form on the paper surface. The less the sediment.

[0123] In specific implementation, the tension deposition amount can be determined based on the surface tension and the preset optimal tension in the following manner: first, the surface tension is divided by the optimal tension, then the quotient is subtracted from one, then the difference is squared, and finally, the obtained value is used as the tension deposition amount.

[0124] It should be noted that the tension deposition amount in this application refers to the surface tension of the fountain solution deposited on the paper surface during the first color overprinting process. The larger the tension, the more the surface tension of the fountain solution during the first color overprinting causes the fountain solution to deposit on the paper surface. The more the deposits are, the smaller the tension deposition is. The surface tension of the fountain solution during the first color overprinting causes the deposits to form on the paper surface. The less the sediment.

[0125] In a specific implementation, the amount of acid-base deposition, the amount of tension deposition and the conductivity are used to determine the content of the fountain solution. The residual deposition of the deposit can be achieved in the following way: first, the acid-base deposition and the tension deposition are added together, then the sum is multiplied by the natural logarithm of the conductivity, and finally, the value obtained is used as the value in the fountain solution. The amount of residual deposition in the precipitate.

[0126] It should be noted that the amount of residue deposited in this application refers to the amount of residue deposited on the surface of the book or periodical after the first color overprint. The larger the amount of residue, the more the dampening solution will remain on the surface of the book after the first color overprint. The more the residue, the more likely it is that the second color overprint will be smeared. The smaller the amount of residue, the more likely it is that the fountain solution will remain on the surface of the book after the first color overprint. The less the sediment.

[0127] In a specific implementation, the viscosity of the ink in the secondary color overprinting process may be obtained through the product manual of the ink in the secondary color overprinting process.

[0128] It should be noted that the preset pressure of the robotic arm during the secondary color overprinting process in the present application is a parameter pre-set by the staff, which is used to control the pressure applied by the robotic arm to the surface of the paper to be printed during the secondary color overprinting process. The pressure is used to adjust the dot size of the ink during the secondary color overprinting process.

[0129] In specific implementation, the predicted laminar flow coefficient of the ink during the secondary color overprinting process is determined according to the dot expansion value in the first color overprinting, the preset pressure of the robot arm during the secondary color overprinting process, and the viscosity of the ink during the secondary color overprinting process. This can be achieved in the following manner, namely: first, multiply the fourth power of the dot expansion value by pi, then multiply the obtained value by the preset pressure during the secondary color overprinting process, then divide the obtained value by the viscosity of the ink during the secondary color overprinting process, and finally, use the obtained value as the predicted laminar flow coefficient of the ink during the secondary color overprinting process.

[0130] It should be noted that the predicted laminar flow coefficient in the present application is a parameter indicating the flow ability of the ink when it flows in a laminar flow on the surface of paper or the printing medium. The larger the predicted laminar flow coefficient, the stronger the flow ability of the ink when it flows in a laminar flow on the surface of paper or the printing medium. The smaller the predicted laminar flow coefficient, the weaker the flow ability of the ink when it flows in a laminar flow on the surface of paper or the printing medium.

[0131] In addition, in a specific implementation, determining the plate sticking defect of the secondary color overprinting based on the residue deposition amount and the predicted laminar flow coefficient can be achieved in the following manner, namely: first, dividing the residue deposition amount by the predicted laminar flow coefficient, then dividing the obtained value by the viscosity of the ink in the secondary color overprinting, and finally, using the obtained value as a characterization quantity of the plate sticking defect of the secondary color overprinting.

[0132] It should be noted that the "plate smearing defect" in the present application refers to a product defect in which the surface of a book or periodical after color overprinting is smeared. The larger the characterization amount of the plate smearing defect is, the more likely the surface of the book or periodical after color overprinting is to be smeared, that is, the worse the quality of the color overprinting is. The smaller the characterization amount of the plate smearing defect is, the less likely the surface of the book or periodical after color overprinting is to be smeared, that is, the better the quality of the color overprinting is.

[0133] In step 105, the pressure compensation amount of the robot arm in the secondary color overprinting is determined based on the pigment binding degree and the plate smearing defect, and then the book rotary printing press is controlled to perform the secondary color overprinting according to the pressure compensation amount.

[0134] In some embodiments, determining the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the smearing defect can be implemented by the following steps:

[0135] Determining a limit value of pressure adjustment according to the pigment binding degree and the plate sticking defect;

[0136] Comparing the pressure adjustment limit value with a preset limit threshold value, and when the limit value is less than or equal to the limit threshold value, setting the pressure compensation amount of the robot arm in the secondary color overprinting to 0;

[0137] When the limiting value is greater than the limiting threshold, the pressure compensation amount of the robot arm in the secondary color overprinting is determined according to the limiting value and the limiting threshold.

[0138] In specific implementation, the limit value of pressure adjustment can be determined according to the pigment binding degree and the plate sticking defect in the following manner: first, the inverse of the pigment binding degree is calculated, then the inverse is added to the plate sticking defect, and finally, the obtained value is used as the limit value of pressure adjustment.

[0139] It should be noted that the limit value of pressure adjustment in the present application is a limit parameter used to determine whether the printing pressure in the secondary color overprinting needs to be adjusted.

[0140] It should be noted that the definition threshold in the present application can be preset according to actual needs. For example, multiple printings can be performed using a rotary printing press for books and periodicals, and the definition value for each printing pressure adjustment can be determined according to the method of the present application. The average value of all definition values ​​corresponding to books and periodicals that become blurred after printing can be used as the definition threshold.

[0141] In specific implementation, when the boundary value is greater than the boundary threshold, the pressure compensation amount for the secondary color overprinting can be determined based on the boundary value and the boundary threshold in the following manner, namely: first, the boundary threshold is subtracted from the boundary value, and the sum is multiplied by the preset pressure of the book rotary printing press during the secondary color overprinting process, and the obtained value is used as the pressure compensation amount for the secondary color overprinting.

[0142] It should be noted that the pressure compensation amount in the present application refers to the pressure value for compensating the printing pressure of the book rotary printing press during the secondary color overprinting process.

[0143] In some embodiments, controlling the book and periodical rotary printing press to perform secondary color overprinting according to the pressure compensation amount can be achieved by the following steps:

[0144] Obtaining the preset pressure corresponding to the secondary color overprinting;

[0145] The overprinting pressure of the robot arm during the secondary color overprinting process is determined according to the preset pressure and the pressure compensation amount.

[0146] It should be noted that the preset pressure of the robotic arm during the secondary color overprinting process in the present application is a parameter pre-set by the staff, which is used to control the pressure applied by the robotic arm to the surface of the paper to be printed during the secondary color overprinting process. The pressure is used to adjust the dot size of the ink during the secondary color overprinting process.

[0147] In specific implementation, determining the overprinting pressure of the robot arm during the secondary color overprinting process according to the preset pressure and the pressure compensation amount can be achieved in the following manner, namely: taking the sum of the preset pressure and the pressure compensation amount as the overprinting pressure of the robot arm during the secondary color overprinting process.

[0148] It should be noted that the robot arm in this application is an automated mechanical device for accurately controlling the pressure during the printing process. Its main function is to adjust the contact pressure between the plate cylinder, the impression cylinder and the rubber cylinder to adjust the ink dot size during each color overprinting process.

[0149] In addition, in another aspect of the present application, in some embodiments, the present application provides a book rotary printing press, the book rotary printing press includes a printing mechanism, a visual perception mechanism, a mechanical arm and a control unit control unit, the control unit is used to control the book rotary printing press to perform multi-color printing, reference Figure 4 , which is a schematic diagram of the structure of a control unit according to some embodiments of the present application, the control unit 400 includes: a collection module 401, a processing module 402 and an execution module 403, which are described as follows:

[0150] The acquisition module 401 in the present application is mainly used to acquire the printed image after the first color overprinting through the visual perception mechanism after the printing mechanism of the book rotary printing press is started to perform the first color overprinting;

[0151] Processing module 402, in this application, processing module 402 is mainly used to identify the image deviation of the first color overprint from the printed image;

[0152] It should be noted that the processing module 402 in the present application is also used to obtain the optical density of the printed area after the first color overprinting, determine the dot expansion value of the color dots under the emulsification of the ink after the first color overprinting according to the optical density, and predict the overprinting result of the second color overprinting according to the dot expansion value and the image deviation, and obtain the pigment binding degree of the ink between the second color overprinting and the first color overprinting;

[0153] It should be noted that the processing module 402 in the present application is also used to adjust the ink content of the fountain solution according to the first color overprinting process. Predicting the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting;

[0154] Execution module 403, in this application, execution module 403 is mainly used to determine the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the plate sticking defect, and then control the book rotary printing press to perform secondary color overprinting according to the pressure compensation amount.

[0155] In addition, the present application also provides a computer device, which includes a memory and a processor, wherein the memory stores codes, and the processor is configured to obtain the codes and execute the above-mentioned multi-color printing method of the book rotary printing press.

[0156] In some embodiments, reference Figure 5 , which is a schematic diagram of the structure of a computer device for implementing a multi-color printing method for a rotary printing press for books and periodicals according to some embodiments of the present application. The multi-color printing method for a rotary printing press for books and periodicals in the above embodiments can be achieved by Figure 5 The computer device 500 shown in the figure is implemented, and the computer device 500 includes at least one processor 501, a communication bus 502, a memory 503 and at least one communication interface 504.

[0157] The processor 501 may be a general-purpose central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0158] The communication bus 502 may be used to transmit information between the above-mentioned components.

[0159] The memory 503 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a disk or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 503 may exist independently and be connected to the processor 501 via the communication bus 502. The memory 503 may also be integrated with the processor 501.

[0160] The memory 503 is used to store the program code for executing the solution of the present application, and the execution is controlled by the processor 501. The processor 501 is used to execute the program code stored in the memory 503. The program code may include one or more software modules. The multi-color printing method of the rotary printing press for books and periodicals in the above embodiment can be implemented by the processor 501 and one or more software modules in the program code in the memory 503.

[0161] The communication interface 504 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0162] In a specific implementation, as an embodiment, a computer device may include multiple processors, each of which may be a single-CPU processor or a multi-CPU processor. The processor here may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0163] The above-mentioned computer device can be a general-purpose computer device or a special-purpose computer device. In a specific implementation, the computer device can be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device or an embedded device. The embodiment of the present application does not limit the type of computer device.

[0164] In addition, the present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the multi-color printing method of the book rotary printing press is implemented.

[0165] In summary, in the rotary printing press and method for books and periodicals disclosed in the embodiments of the present application, first, the printing mechanism of the rotary printing press for books and periodicals is started to perform the first color overprinting, and the printed image after the first color overprinting is collected by the visual perception mechanism; the image and text deviation of the first color overprinting is identified from the printed image; the optical density of the printed area after the first color overprinting is obtained, and the dot expansion value of the color dots under the emulsification of the ink after the first color overprinting is determined according to the optical density, and the overprinting result of the secondary color overprinting is predicted according to the dot expansion value and the image and text deviation, and the pigment binding degree of the ink between the secondary color overprinting and the first color overprinting is obtained; according to the value of the dot expansion value and the image and text deviation in the fountain solution during the first color overprinting, the ink pigment binding degree between the secondary color overprinting and the first color overprinting is obtained. The residual deposition amount of the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting process predict the plate sticking defect of the secondary color overprinting; based on the pigment binding degree and the plate sticking defect, the pressure compensation amount of the robot arm in the secondary color overprinting is determined, and then the book and periodical rotary printing press is controlled to perform the secondary color overprinting according to the pressure compensation amount.

[0166] It can be seen that the present application determines the emulsification degree of the ink in the first color overprinting (i.e., the dot expansion value) by the optical density of the printed area after the first color overprinting, and then predicts the printing quality of the second color overprinting (i.e., the pigment binding degree) according to the dot expansion value and the image deviation of the pattern in the printed area after the first color overprinting, thereby measuring the deviation between the color presented by the combination of different colors of ink after the two color overprinting and the expected color; then, according to the value of the dot expansion value in the fountain solution during the first color overprinting process, the color of the second color overprinting is estimated. The amount of residue deposition of the shaped sediment is used to predict the plate sticking defect of the secondary color overprinting, so as to avoid the plate sticking in the secondary color overprinting. Finally, the overprinting pressure of the robot arm in the secondary color overprinting process is adjusted according to the pigment binding degree and the plate sticking defect, so as to adjust the size of the dots in the secondary color overprinting process. In summary, the scheme of the present application can make real-time adjustment to the dot size of the ink in multi-color printing, thereby improving the quality of books and periodicals after rotary printing.

[0167] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0168] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A multi-color printing method for a rotary printing press for books and periodicals, the rotary printing press for books and periodicals comprising a printing mechanism, a visual perception mechanism and a mechanical arm, characterized in that: The multicolor printing method comprises: Starting the printing mechanism of the book and periodical rotary printing press to perform the first color overprinting, and collecting the printed image after the first color overprinting through the visual perception mechanism; Identifying a first color process deviation from the printed image; Obtaining the optical density of the printed area after the first color overprinting, determining the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density, and predicting the overprinting result of the second color overprinting according to the dot expansion value and the image deviation, and obtaining the pigment bonding degree of the ink between the second color overprinting and the first color overprinting; According to the first color overprint process Predicting the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting; The pressure compensation amount of the robot arm in the secondary color overprinting is determined based on the pigment binding degree and the plate sticking defect, and then the book and periodical rotary printing press is controlled to perform the secondary color overprinting according to the pressure compensation amount.

2. The method according to claim 1, characterized in that Identifying the image deviation of the first color overprint from the printed image specifically includes: determining edge curves in the printed image; The graphic deviation of the pattern in the printing area after the first color overprinting is determined according to the edge curve and the preset printing pattern.

3. The method according to claim 1, characterized in that Determining the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density specifically includes: Get the solid density of printed paper; Determining the blank reflectivity of the unprinted portion after the first color overprint according to the paper density; determining the printing reflectivity of the printed area after the first color overprinting according to the optical density; The dot expansion value of the color dots when the ink is emulsified after the first color overprinting is determined according to the blank reflectivity and the printing reflectivity.

4. The method according to claim 1, characterized in that Predicting the overprinting result of the secondary color overprinting according to the dot gain value and the image deviation to obtain the pigment bonding degree of the ink between the secondary color overprinting and the primary color overprinting specifically includes: Obtaining component content and drying speed of secondary color overprinting ink; Determining the ink bonding degree according to the component content and the drying speed; Determine an emulsification penalty according to the dot gain value and the image-text deviation; The pigment binding degree of the ink between the secondary color process printing and the primary color process printing is determined based on the ink binding degree and the emulsification penalty.

5. The method according to claim 1, characterized in that According to the first color overprint process The residual deposition amount of the shaped deposits and the preset pressure of the robot arm during the secondary color overprinting process predict the plate sticking defects of the secondary color overprinting specifically include: Determine the content of the fountain solution according to the original performance of the fountain solution during the first color overprinting process. The amount of residual deposits in the sediment; Obtaining a preset pressure of the mechanical arm during the secondary color overprinting process and a viscosity of the ink during the secondary color overprinting process; Determining a predicted laminar flow coefficient of the ink during the secondary color overprinting process according to a dot gain value in the primary color overprinting process, a preset pressure of the mechanical arm during the secondary color overprinting process, and a viscosity of the ink during the secondary color overprinting process; The plate smearing defect of the secondary color overprinting is determined according to the residue deposition amount and the predicted laminar flow coefficient.

6. The method according to claim 5, characterized in that Determine the content of the fountain solution according to the original performance of the fountain solution during the first color overprinting process. The residual deposition amount of the precipitate specifically includes: Obtaining the pH value, surface tension and conductivity of the fountain solution during the first color overprinting process, and using the pH value, surface tension and conductivity as the original solution properties of the fountain solution during the first color overprinting process; determining the amount of acid-base deposition according to the pH and a preset optimal pH; Determining a tension deposition amount according to the surface tension and a preset optimal tension; Determine the content of the fountain solution according to the acid-base deposition amount, the tension deposition amount and the conductivity The amount of residual deposition in the precipitate.

7. The method according to claim 1, characterized in that Determining the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the plate sticking defect specifically includes: Determining a limit value of pressure adjustment according to the pigment binding degree and the plate sticking defect; Comparing the pressure adjustment limit value with a preset limit threshold value, and when the limit value is less than or equal to the limit threshold value, setting the pressure compensation amount of the robot arm in the secondary color overprinting to 0; When the limiting value is greater than the limiting threshold, the pressure compensation amount of the robot arm in the secondary color overprinting is determined according to the limiting value and the limiting threshold.

8. A rotary printing press for books and periodicals, comprising a printing mechanism, a visual perception mechanism, a mechanical arm and a control unit, characterized in that: The control unit comprises: A collection module, used for controlling the visual perception mechanism to collect the printed image after the first color overprinting after the printing mechanism of the book rotary printing press is started to perform the first color overprinting; A processing module, used for identifying the image deviation of the first color overprint from the printed image; The processing module is also used to obtain the optical density of the printed area after the first color overprinting, determine the dot expansion value of the color dots after the first color overprinting under the emulsification of the ink according to the optical density, and predict the overprinting result of the second color overprinting according to the dot expansion value and the image deviation, and obtain the pigment bonding degree of the ink between the second color overprinting and the first color overprinting; The processing module is also used to adjust the content of the fountain solution in the first color overprinting process according to the Predicting the plate sticking defect of the secondary color overprinting based on the amount of residue deposited in the shaped deposit and the preset pressure of the robot arm during the secondary color overprinting; The execution module is used to determine the pressure compensation amount of the robot arm in the secondary color overprinting based on the pigment binding degree and the plate sticking defect, and then control the book and periodical rotary printing machine to perform the secondary color overprinting according to the pressure compensation amount.

9. A computer device, characterized in that: The computer device comprises a memory and a processor, wherein the memory stores codes, and the processor is configured to obtain the codes and execute the multi-color printing method of a rotary printing press for books and periodicals according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the multi-color printing method of the book rotary printing press according to any one of claims 1 to 7 is implemented.

Images