A book rotary printing machine and method

Abstract

The application provides a book rotary printing machine and method, which comprises the following steps: collecting a printed image after first color overprint; identifying a text and image deviation of the first color overprint from the printed image; determining a dot expansion value of a color dot of the first color overprint under ink emulsification according to an optical density of a printing area after the first color overprint, and determining a pigment combination degree of ink between the second color overprint and the first color overprint according to the dot expansion value and the text and image deviation; predicting a dampening solution residue deposition amount of a second color overprint based on a residue deposition amount of a sediment in a dampening solution during the first color overprint; determining a pressure compensation amount of the second color overprint based on the pigment combination degree and the dampening solution residue deposition amount, and controlling the book rotary printing machine to perform the second color overprint according to the pressure compensation amount. The scheme of the application can adjust the dot size of ink in real time in multi-color printing, thereby improving the quality of the printed book.

Description

Technical Field

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

[0002] Industrial printing control refers to the real-time monitoring, adjustment, and optimization of various process parameters, equipment operating status, and print quality of printing presses through hardware and software technologies during industrial printing production to ensure efficient production and maintain consistent print quality. Industrial printing control involves multiple aspects, including automated operation of the printing press, precise control of the production process, and quality management. Typically, in the industrial printing control process, visual sensing mechanisms are used to monitor print quality in real time, and the various mechanisms within the industrial printing press are automatically controlled based on the monitoring results.

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

[0004] In addition, the CMYK (Cyan, Magenta, Yellow, Black) printing method is commonly used in multicolor printing for books and periodicals on rotary printing presses. This involves layering yellow, magenta, and cyan pigments in different proportions to absorb different wavelengths of the spectrum, producing various colors. Black is used to enhance the depth and contrast of the image. The image is printed separately on yellow, magenta, cyan, and black plates using a four-color separation printing press. The inks are layered on the paper with different dot sizes and shapes, visually creating a continuous color tone. However, in actual production, due to ink emulsification, the dot size of each color ink can change. This causes the color produced after combining different colors of ink to deviate from the expected color, and excessively large dots can lead to ink smearing. Therefore, how to adjust the dot size of inks in real time during multicolor printing to improve the quality of books and periodicals after rotary printing has become a challenge for the industry. Summary of the Invention

[0005] This application provides a rotary printing press and method for books and periodicals, which can adjust the dot size of inks in real time during multicolor printing to ensure that the inks of different colors can be combined to present the desired color, thereby improving the quality of books and periodicals after rotary printing.

[0006] In a first aspect, this application provides a multi-color printing method for a book and periodical rotary printing press, the book and periodical rotary printing press including a printing mechanism, a vision sensing mechanism, and a robotic arm, the multi-color printing method including:

[0007] The printing mechanism of the book and periodical rotary printing press is started to perform the first color overprint, and the printed image after the first color overprint is acquired through the visual perception mechanism;

[0008] Identify the image misregistration during the first color printing from the printed image;

[0009] The optical density of the printed area after the first color overprint is obtained. Based on the optical density, the dot expansion value of the color dots after the first color overprint under ink emulsification is determined. Based on the dot expansion value and the image deviation, the overprinting result of the second color overprint is predicted, and the pigment binding degree of the ink between the second color overprint and the first color overprint is obtained.

[0010] According to the dampening solution during the first color overprinting process The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting.

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

[0012] In some embodiments, identifying the image misregistration of the first color printing from the printed image specifically includes:

[0013] Determine the edge curves in the printed image;

[0014] The graphic deviation of the printed area pattern after the first color overprint is determined based on the edge curve and the pre-set printing pattern.

[0015] In some embodiments, determining the dot gain value of the color dots after the first color overprint under ink emulsification based on the optical density specifically includes:

[0016] To obtain the solid density of printed paper;

[0017] The blank reflectance of the unprinted portion after the first color overprint is determined based on the paper density.

[0018] The printing reflectance of the printed area after the first color overprint is determined based on the optical density.

[0019] The dot gain value of the color dots after the first color overprint is determined based on the blank reflectance and the printing reflectance, under the condition of ink emulsification.

[0020] In some embodiments, predicting the overprinting result of secondary color printing based on the dot gain value and the image deviation, and obtaining the pigment binding degree of the ink between the secondary color printing and the primary color printing, specifically includes:

[0021] To obtain the component content and drying speed of secondary color overprinting inks;

[0022] The ink adhesion is determined based on the component content and the drying speed.

[0023] The emulsification penalty is determined based on the dot expansion value and the image deviation.

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

[0025] In some embodiments, based on the dampening solution during the initial color overprinting process The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting, specifically including:

[0026] The properties of the original dampening solution during the initial color overprinting process are used to determine the content of the dampening solution in the dampening solution. The amount of residual sediment in the sedimentary deposits;

[0027] The preset pressure of the robotic arm and the viscosity of the ink during the secondary color overprinting process are obtained.

[0028] The predicted laminar flow coefficient of the ink during the second color overprinting process is determined based on the dot gain value in the first color overprinting, the preset pressure of the robotic arm during the second color overprinting process, and the viscosity of the ink during the second color overprinting process.

[0029] The smearing defects in secondary color printing are determined based on the amount of residue deposited and the predicted laminar flow coefficient.

[0030] In some embodiments, the concentration of the dampening solution in the dampening solution is determined based on the original properties of the dampening solution during the initial color overprinting process. The specific amount of residue deposited in the sedimentary sediments includes:

[0031] The pH, surface tension, and conductivity of the dampening solution during the first color overprinting process are obtained, and the pH, surface tension, and conductivity are all taken as the original properties of the dampening solution during the first color overprinting process.

[0032] The amount of acid and alkali deposition is determined based on the pH value and the preset optimal pH value.

[0033] The tension deposition amount is determined based on the surface tension and the preset optimal tension;

[0034] The amount of acid-base deposition, the amount of tension deposition, and the conductivity are determined based on the dampening solution. The amount of residue deposited in the sedimentary deposits.

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

[0036] The pressure adjustment threshold is determined based on the pigment bonding degree and the smearing defects.

[0037] The pressure adjustment threshold is compared with the preset threshold. When the threshold is less than or equal to the threshold, the pressure compensation of the robotic arm in the secondary color overprinting is set to 0.

[0038] When the defined value is greater than the defined threshold, the pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the defined value and the defined threshold.

[0039] Secondly, a book and magazine rotary printing press includes a printing mechanism, a vision sensing mechanism, a robotic arm, and a control unit. The control unit is used to control the book and magazine rotary printing press to perform multi-color printing. The control unit includes:

[0040] The acquisition module is used to acquire the printed image after the first color overprint is performed by the printing mechanism of the book and periodical rotary printing press through the visual perception mechanism.

[0041] The processing module is used to identify the image deviation of the first color registration from the printed image;

[0042] The processing module is also used to obtain the optical density of the printed area after the first color overprint, determine the dot expansion value of the color dots after the first color overprint under ink emulsification based on the optical density, and predict the overprinting result of the second color overprint based on the dot expansion value and the image deviation, so as to obtain the pigment binding degree of the ink between the second color overprint and the first color overprint.

[0043] The processing module is also used to determine the amount of dampening solution in the initial color overprinting process. The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting.

[0044] An execution module is used to determine the pressure compensation amount of the robotic arm in secondary color overprinting based on the pigment binding degree and the smearing defect, and then control the book and magazine rotary printing press to perform secondary color overprinting according to the pressure compensation amount.

[0045] Thirdly, this application provides a computer device including a memory and a processor, the memory storing code, and the processor being configured to acquire the code and execute the multicolor printing method of the book and periodical rotary printing press described above.

[0046] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the multicolor printing method of the book and magazine rotary printing press described above.

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

[0048] The book and periodical rotary printing press and method provided in this application first start the printing mechanism of the book and periodical rotary printing press to perform the first color overprint, and acquire the printed image after the first color overprint through the visual perception mechanism; identify the image deviation of the first color overprint from the printed image; obtain the optical density of the printed area after the first color overprint, determine the dot expansion value of the color dots after the first color overprint under ink emulsification based on the optical density, and predict the overprinting result of the second color overprint based on the dot expansion value and the image deviation, thereby obtaining the pigment binding degree of the ink between the second color overprint and the first color overprint; and determine the dot expansion value of the ink in the dampening solution during the first color overprint. The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process are used to predict the smearing defects in the secondary color overprinting; the pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the pigment binding degree and the smearing defects, and then the book and magazine rotary printing press is controlled to perform secondary color overprinting according to the pressure compensation amount.

[0049] Therefore, this application determines the degree of ink emulsification (i.e., dot gain) in the first color overprint by the optical density of the printed area after the first color overprint. Then, based on the dot gain and the image deviation of the printed area after the first color overprint, it predicts the printing quality (i.e., pigment binding) of the second color overprint, thereby measuring the deviation between the color presented after the inks of different colors have combined in the two color overprints and the desired color. Subsequently, based on the dampening solution in the first color overprint process... The amount of residue deposited in the sediment is used to predict the smearing defects in secondary color printing, so as to avoid smearing in secondary color printing. Finally, the printing pressure of the robotic arm in the secondary color printing process is adjusted by the pigment binding degree and smearing defects to adjust the dot size in the secondary color printing process. In summary, the solution of this application can adjust the dot size of ink in real time in multicolor printing, thereby improving the quality of books and periodicals after rotary printing. Attached Figure Description

[0050] Figure 1This is an exemplary flowchart of a multicolor printing method for a book and magazine rotary printing press according to some embodiments of this application;

[0051] Figure 2 This is an exemplary flowchart illustrating the determination of branch expansion values ​​according to some embodiments of this application;

[0052] Figure 3 This is an exemplary flowchart illustrating the determination of the amount of residue deposited according to some embodiments of this application;

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

[0054] Figure 5 This is a schematic diagram of the structure of a computer device for implementing a multicolor printing method for a book and magazine rotary printing press, according to some embodiments of this application. Detailed Implementation

[0055] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] refer to Figure 1 The figure is an exemplary flowchart of a multicolor printing method for a book and magazine rotary printing press according to some embodiments of this application. The multicolor printing method 100 of the book and magazine rotary printing press mainly includes the following steps:

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

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

[0059] Additionally, it should be noted that in this application, the visual perception mechanism refers to a system that uses visual technologies such as optics, sensors, and cameras to collect images, text, or other markings during the printing process.

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

[0061] In step 102, the image misregistration during the first color printing is identified from the printed image.

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

[0063] Determine the edge curves in the printed image;

[0064] The graphic deviation of the printed area pattern after the first color overprint is determined based on the edge curve and the pre-set printing pattern.

[0065] In some embodiments, determining the edge curves in the printed image can be achieved using the following steps:

[0066] The printed image is sharpened to obtain a sharpened printed image;

[0067] Extract all edge curves from the printed sharpened image.

[0068] In a specific implementation, the printed image is sharpened to obtain a sharpened printed image. This can be achieved by sharpening the printed image using Laplacian sharpening, a technique known in the prior art, and using the resulting image as the sharpened printed image. In other embodiments, other existing techniques can also be used to sharpen the printed image, which is not limited here.

[0069] It should be noted that, in this application, a printed sharpened image refers to an image after the printed image has been sharpened.

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

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

[0072] In some embodiments, determining the graphic deviation of the printed area pattern after the first color overprint based on the edge curve and a pre-defined printing pattern can be achieved through the following steps:

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

[0074] Determine the standard outline based on the printed pattern;

[0075] The graphic deviation of the printed area pattern after the first color overprint is determined based on the standard outline and the edge curve.

[0076] It should be noted that, in this application, the printed pattern refers to the area on the book or periodical that needs to be printed with the first color overprint. During the first color overprint, the ink for the first color overprint needs to be printed in this area.

[0077] In practice, determining the standard contour based on the printed pattern can be achieved by extracting all contours in the printed pattern using the Canny edge detection algorithm in the prior art, and using all the obtained contours as the standard contours.

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

[0079] In specific implementation, the graphic deviation of the printed area pattern after the first color overprint can be determined according to the standard contour and the edge curve in the following way: First, calculate the area enclosed by each closed curve in the standard contour, and sum the areas corresponding to all closed curves in the standard contour. The obtained value is taken as the standard area of ​​the standard contour. Then, calculate the area enclosed by each closed curve in the edge curve, and sum the areas corresponding to all closed curves in the edge curve. The obtained value is taken as the total area of ​​the edge curve. Subsequently, the difference between the standard area and the total area is calculated, and the difference is divided by the standard area. Finally, the obtained value is taken as the graphic deviation of the printed area pattern after the first color overprint.

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

[0081] In step 103, the optical density of the printed area after the first color overprint is obtained, the dot expansion value of the color dots after the first color overprint is determined according to the optical density, and the overprinting result of the second color overprint is predicted according to the dot expansion value and the image deviation, so as to obtain the pigment binding degree of the ink between the second color overprint and the first color overprint.

[0082] In practice, the optical density of the printed area after the first color overprint can be collected by a spectrophotometer. In other embodiments, the optical density of the printed area after the first color overprint can also be obtained by other existing technologies, which are not limited here.

[0083] In some embodiments, reference Figure 2 The figure is an exemplary flowchart illustrating the determination of dot gain values ​​according to some embodiments of this application. The determination of dot gain values ​​of color dots after the first color overprint under ink emulsification, based on the optical density, can be achieved using the following steps:

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

[0085] In step 1032, the blank reflectance of the unprinted portion after the first color overprint is determined based on the paper density;

[0086] In step 1033, the printing reflectance of the printing area after the first color overprint is determined based on the optical density;

[0087] In step 1034, the dot expansion value of the color dots after the first color overprint is determined based on the blank reflectance and the printing reflectance, under the condition that the ink emulsifies.

[0088] In practice, the optical density of the unprinted area after the first color overprint can be collected by a spectrophotometer, and the optical density of the unprinted area can be used as the solid density of the printing paper.

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

[0090] In practice, the blank reflectance of the unprinted portion after the first color overprint can be determined based on the paper density in the following way: First, take the opposite of the paper density; then, use the obtained value as the exponent of ten; finally, use the obtained value as the blank reflectance of the unprinted portion after the first color overprint.

[0091] It should be noted that, in this application, blank reflectance is a parameter representing the amount of light reflected by the unprinted areas of a book or periodical. The higher the blank reflectance, the more light is reflected by the unprinted areas of the book or periodical; the lower the blank reflectance, the less light is reflected by the unprinted areas of the book or periodical. For example, in this application, the sum of the radiation intensity of the light reflected by the unprinted areas of the book or periodical can be used as the blank reflectance.

[0092] In practice, the printing reflectance of the printing area after the first color overprint can be determined based on the optical density in the following way: First, take the opposite of the optical density, then use the obtained value as the exponent of ten, and finally use the obtained value as the printing reflectance of the printing area after the first color overprint.

[0093] It should be noted that, in this application, printing reflectance is a parameter representing the amount of light reflected by the printed area on a book or periodical. The higher the blank reflectance, the more light is reflected by the printed area on the book or periodical; the lower the blank reflectance, the less light is reflected by the printed area on the book or periodical. For example, in this application, the total radiation intensity of the light reflected by the printed area on the book or periodical can be used as the printing reflectance.

[0094] In specific implementation, the dot gain value of the color dots after the first color overprint under ink emulsification can be determined according to the blank reflectance and the printing reflectance in the following way: First, the blank reflectance is subtracted from the blank reflectance and the result is used as the denominator. Then, the printing reflectance is subtracted from the blank reflectance and the result is used as the numerator. The ratio of the numerator to the denominator is then obtained. Finally, this ratio is used as the dot gain value of the color dots after the first color overprint under ink emulsification.

[0095] It should be noted that the dot gain value in this application is a parameter representing the degree of dot gain caused by ink emulsification after the first color overprint. The larger the dot gain value, the more the dot gain is caused by ink emulsification after the first color overprint, and the smaller the dot gain value, the less the dot gain is caused by ink emulsification after the first color overprint.

[0096] In some embodiments, predicting the overprinting result of secondary color printing based on the dot gain value and the image deviation, and obtaining the pigment binding degree of the inks between the secondary color printing and the primary color printing, can be achieved through the following steps:

[0097] To obtain the component content and drying speed of secondary color overprinting inks;

[0098] The ink adhesion is determined based on the component content and the drying speed.

[0099] The emulsification penalty is determined based on the dot expansion value and the image deviation.

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

[0101] It should be noted that, in this application, predicting the overprinting result of 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 adhesion based on the component content and the drying speed; determining the emulsification penalty based on the dot gain value and the image deviation; and determining the pigment adhesion between the inks in the secondary color overprinting and the primary color overprinting based on the ink adhesion and the emulsification penalty.

[0102] In practice, the component content, viscosity, and drying speed of the inks used in secondary color overprinting can be obtained from the product manual of the inks used in secondary color overprinting.

[0103] It should be noted that the component content in this 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 practice, the ink binding degree can be determined based on the component content and the drying speed in the following way: First, add the pigment content in the component content to the reciprocal of the drying speed, add one to the resulting value, and finally use the resulting value as the ink binding degree.

[0105] It should be noted that, in this application, ink adhesion is a parameter representing the printing quality when ink in secondary color overprinting is directly printed onto paper. The higher the ink adhesion, the better the ink adheres when it is directly printed onto paper in secondary color overprinting, and the better the printing quality. The lower the ink adhesion, the worse the ink adheres when it is directly printed onto paper in secondary color overprinting, and the worse the printing quality.

[0106] In practice, the emulsification penalty can be determined based on the dot gain value and the image deviation in the following way: First, calculate the natural logarithm of the image deviation; then, multiply the obtained value by the dot gain value; finally, use the obtained value as the emulsification penalty.

[0107] It should be noted that, in this application, emulsification penalty is a parameter representing the degree of decline in printing quality of secondary color printing caused by the degree of emulsification of ink in the first color printing. The larger the emulsification penalty, the greater the decline in printing quality of secondary color printing caused by the degree of emulsification of ink in the first color printing; the smaller the emulsification penalty, the less the decline in printing quality of secondary color printing caused by the degree of emulsification of ink in the first color printing.

[0108] Additionally, it should be noted that in this application, pigment binding degree is a parameter representing the degree of bonding between inks in two color overprints. The higher the pigment binding degree, the better the bonding between inks in two color overprints, i.e., the higher the printing quality. The lower the pigment binding degree, the worse the bonding between inks in two color overprints, i.e., the lower the printing quality. As a preferred embodiment, in this application, the pigment binding degree of the inks between the second color overprint and the first color overprint can be determined based on the ink binding degree and the emulsification penalty in the following manner: the value obtained by subtracting the emulsification penalty from the ink binding degree is taken as the pigment binding degree between the corresponding inks in the two color overprints.

[0109] In step 104, based on the dampening solution during the initial color overprinting process... The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting.

[0110] In some embodiments, based on the dampening solution during the initial color overprinting process The prediction of the amount of residue deposited in the secondary color printing process and the preset pressure of the robotic arm during the secondary color printing process can be achieved by the following steps:

[0111] The properties of the original dampening solution during the initial color overprinting process are used to determine the content of the dampening solution in the dampening solution. The amount of residual sediment in the sedimentary deposits;

[0112] The preset pressure of the robotic arm and the viscosity of the ink during the secondary color overprinting process are obtained.

[0113] The predicted laminar flow coefficient of the ink during the second color overprinting process is determined based on the dot gain value in the first color overprinting, the preset pressure of the robotic arm during the second color overprinting process, and the viscosity of the ink during the second color overprinting process.

[0114] The smearing defects in secondary color printing are determined based on the amount of residue deposited and the predicted laminar flow coefficient.

[0115] In some embodiments, reference Figure 3 This figure is an exemplary flowchart illustrating the determination of residue deposition amount according to some embodiments of this application. In this application, the amount of residue in the dampening solution is determined based on the original properties of the dampening solution during the first color overprinting process. The amount of residue deposited in the sedimentary sediments can be achieved by the following steps:

[0116] In step 1041, the pH, surface tension, and conductivity of the dampening solution during the first color overprint are obtained, and the pH, surface tension, and conductivity are all used as the original properties of the dampening solution during the first color overprint.

[0117] In step 1042, the amount of acid and alkali deposited is determined based on the pH and the preset optimal pH.

[0118] In step 1043, the tension deposition amount is determined based on the surface tension and the preset optimal tension;

[0119] In step 1044, the amount of acid-base deposition, the amount of tension deposition, and the conductivity are determined in the dampening solution. The amount of residue deposited in the sedimentary deposits.

[0120] In practice, the pH of the dampening solution during the first color overprint can be collected using a pH meter, the surface tension of the dampening solution during the first color overprint can be collected using an automatic tension meter, and finally, the conductivity of the dampening solution during the first color overprint can be collected using a conductivity meter.

[0121] In addition, in specific implementation, the determination of acid and alkali deposition amount based on the pH and the preset optimal pH can be achieved in the following way: First, the pH and the preset optimal pH are subtracted. Then, the obtained value is squared. Finally, the obtained value is used as the acid and alkali deposition amount. The optimal pH can be preset according to actual needs. For example, in this application, the optimal pH is preset to 5.

[0122] It should be noted that, in this application, the amount of acid and alkali deposited refers to the amount deposited on the paper surface due to the acidity or alkalinity of the dampening solution during the initial color printing process. The parameter indicating the amount of deposits is related to the pH level of the dampening solution during the initial color printing process. A higher pH level indicates that the deposits will accumulate on the paper surface due to the pH of the dampening solution. The more deposits there are, the smaller the amount of acid and alkali deposited. The pH of the dampening solution during the initial color printing process causes deposits on the paper surface. The less sediment, the better.

[0123] In practice, the tension deposition amount can be determined based on the surface tension and the preset optimal tension in the following way: First, divide the surface tension by the optimal tension; then, subtract one from the quotient; subsequently, square the difference; and finally, use the obtained value as the tension deposition amount.

[0124] It should be noted that, in this application, tension deposition amount refers to the amount deposited on the paper surface due to the surface tension of the dampening solution during the initial color printing process. The parameter indicating the amount of surface tension deposits affects the amount of deposits. A higher surface tension deposit indicates that the surface tension of the dampening solution during the initial color printing process causes deposits to accumulate on the paper surface. The more surface-tension deposits there are, the less the amount of surface-tension deposits. During the initial color printing process, the surface tension of the dampening solution causes deposits to form on the paper surface. The less sediment, the better.

[0125] In practice, the amount of acid-base deposition, the amount of tension deposition, and the conductivity are determined based on the dampening solution. The amount of residue deposited in the dampening solution can be determined as follows: First, add the amount of acid-base deposit and the amount of tension deposit; then, multiply the sum by the natural logarithm of conductivity; finally, use the resulting value as the amount of residue in the dampening solution. The amount of residue deposited in the sedimentary deposits.

[0126] It should be noted that, in this application, the amount of residue deposited refers to the amount of dampening solution remaining on the surface of the book or periodical after the first color overprint. The parameter for the amount of sediment deposited indicates the amount of residue remaining on the surface of the book or periodical after the initial color printing. The more sediment buildup, the more likely the secondary color printing will be smeared; the smaller the amount of residue, the less likely it is to remain in the dampening solution on the surface of the book after the initial color printing. The less sediment, the better.

[0127] In practice, the viscosity of the ink during the secondary color overprinting process can be obtained from the product manual of the ink used in the secondary color overprinting process.

[0128] It should be noted that the preset pressure of the robotic arm in the secondary color overprinting process in this application is a parameter set by the operator in advance. It 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. This pressure is used to adjust the dot size of the ink during the secondary color overprinting process.

[0129] In practice, the predicted laminar flow coefficient of the ink in the secondary color overprinting process can be determined based on the dot gain value in the first color overprinting, the preset pressure of the robotic arm in the secondary color overprinting process, and the viscosity of the ink in the secondary color overprinting process. This can be achieved in the following way: First, multiply the fourth power of the dot gain value by pi. Then, multiply the resulting value by the preset pressure in the secondary color overprinting process. Subsequently, divide the resulting value by the viscosity of the ink in the secondary color overprinting process. Finally, use the resulting value as the predicted laminar flow coefficient of the ink in the secondary color overprinting process.

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

[0131] In addition, in specific implementation, the determination of the smudging defect in secondary color printing based on the amount of residue deposition and the predicted laminar flow coefficient can be achieved in the following way: First, divide the amount of residue deposition by the predicted laminar flow coefficient; then, divide the obtained value by the viscosity of the ink in secondary color printing; finally, use the obtained value as the characterization of the smudging defect in secondary color printing.

[0132] It should be noted that, in this application, the "smearing defect" refers to a product defect in which smearing occurs on the surface of a book or periodical after color overprinting. The greater the characterization of the smearing defect, the more likely smearing will occur on the surface of the book or periodical after color overprinting, which means the quality of color overprinting is worse. The smaller the characterization of the smearing defect, the less likely smearing will occur on the surface of the book or periodical after color overprinting, which means the quality of color overprinting is better.

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

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

[0135] The pressure adjustment threshold is determined based on the pigment bonding degree and the smearing defects.

[0136] The pressure adjustment threshold is compared with the preset threshold. When the threshold is less than or equal to the threshold, the pressure compensation of the robotic arm in the secondary color overprinting is set to 0.

[0137] When the defined value is greater than the defined threshold, the pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the defined value and the defined threshold.

[0138] In practice, the determination of the pressure adjustment threshold based on the pigment bonding degree and the smearing defects can be achieved in the following way: First, take the reciprocal of the pigment bonding degree; then, add the reciprocal to the smearing defects; finally, use the obtained value as the pressure adjustment threshold.

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

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

[0141] In specific implementation, when the defined value is greater than the defined threshold, the pressure compensation amount for secondary color overprinting can be determined based on the defined value and the defined threshold in the following way: First, subtract the defined threshold from the defined value, and multiply the sum by the preset pressure of the book and magazine rotary printing press during the secondary color overprinting process, and use the resulting value as the pressure compensation amount for secondary color overprinting.

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

[0143] In some embodiments, controlling a rotary printing press to perform secondary color overprinting based on the pressure compensation amount can be achieved through the following steps:

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

[0145] The printing pressure of the robotic arm during the secondary color overprinting process is determined based on the preset pressure and the pressure compensation amount.

[0146] It should be noted that the preset pressure of the robotic arm in the secondary color overprinting process in this application is a parameter set by the operator in advance. It 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. This pressure is used to adjust the dot size of the ink during the secondary color overprinting process.

[0147] In specific implementation, the registration pressure of the robotic arm during the secondary color registration process can be determined by the following method based on the preset pressure and the pressure compensation amount: the sum of the preset pressure and the pressure compensation amount is used as the registration pressure of the robotic arm during the secondary color registration process.

[0148] It should be noted that the robotic arm in this application is an automated mechanical device used for precise control of pressure during the printing process. Its main function is to adjust the dot size of the ink in each color registration process by adjusting the contact pressure between the printing plate cylinder, impression cylinder, and blanket cylinder.

[0149] In another aspect, in some embodiments, this application provides a book and magazine rotary printing press, which includes a printing mechanism, a vision sensing mechanism, a robotic arm, and a control unit. The control unit is used to control the book and magazine rotary printing press to perform multi-color printing. (Refer to...) Figure 4 The figure is a schematic diagram of the structure of a control unit according to some embodiments of this application. The control unit 400 includes: a data acquisition module 401, a processing module 402, and an execution module 403, which are described below:

[0150] The acquisition module 401 in this application is mainly used to acquire the printed image after the first color overprint is performed by the visual perception mechanism after the printing mechanism of the book and periodical rotary printing press is started.

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

[0152] It should be noted that the processing module 402 in this application is also used to obtain the optical density of the printing area after the first color overprint, determine the dot expansion value of the color dots after the first color overprint under ink emulsification based on the optical density, and predict the overprinting result of the second color overprint based on the dot expansion value and the image deviation, so as to obtain the pigment binding degree of the ink between the second color overprint and the first color overprint.

[0153] It should be noted that the processing module 402 in this application is also used to determine the amount of dampening solution in the initial color overprinting process. The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting.

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

[0155] In addition, this application also provides a computer device, the computer device including a memory and a processor, the memory storing code, the processor being configured to acquire the code and execute the multicolor printing method of the above-described book and periodical rotary printing press.

[0156] In some embodiments, reference Figure 5 The figure is a schematic diagram of the structure of a computer device for implementing a multi-color printing method for a book and periodical rotary printing press according to some embodiments of this application. The multi-color printing method for the book and periodical rotary printing press in the above embodiments can be achieved through... Figure 5 The computer device shown is used to implement this, 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] Processor 501 can be a general-purpose central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0158] The communication bus 502 can be used to transmit information between the aforementioned components.

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

[0160] The memory 503 stores program code for executing the scheme of this application, and its execution is controlled by the processor 501. The processor 501 executes the program code stored in the memory 503. The program code may include one or more software modules. The multicolor printing method of the book and magazine rotary printing press 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] Communication interface 504 uses any transceiver-like device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc.

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

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

[0164] In addition, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described multicolor printing method for a rotary printing press.

[0165] In summary, in the book and periodical rotary printing press and method disclosed in this application, firstly, the printing mechanism of the book and periodical rotary printing press is started to perform the first color overprint, and the printed image after the first color overprint is acquired by the visual perception mechanism; the image deviation of the first color overprint is identified from the printed image; the optical density of the printed area after the first color overprint is obtained, and the dot gain value of the color dots after the first color overprint is determined according to the optical density under ink emulsification, and the overprinting result of the second color overprint is predicted according to the dot gain value and the image deviation, so as to obtain the pigment binding degree of the ink between the second color overprint and the first color overprint; according to the dampening solution in the first color overprint process... The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process are used to predict the smearing defects in the secondary color overprinting; the pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the pigment binding degree and the smearing defects, and then the book and magazine rotary printing press is controlled to perform secondary color overprinting according to the pressure compensation amount.

[0166] Therefore, this application determines the degree of ink emulsification (i.e., dot gain) in the first color overprint by the optical density of the printed area after the first color overprint. Then, based on the dot gain and the image deviation of the printed area after the first color overprint, it predicts the printing quality (i.e., pigment binding) of the second color overprint, thereby measuring the deviation between the color presented after the inks of different colors have combined in the two color overprints and the desired color. Subsequently, based on the dampening solution in the first color overprint process... The amount of residue deposited in the sediment is used to predict the smearing defects in secondary color printing, so as to avoid smearing in secondary color printing. Finally, the printing pressure of the robotic arm in the secondary color printing process is adjusted by the pigment binding degree and smearing defects to adjust the dot size in the secondary color printing process. In summary, the solution of this application can adjust the dot size of ink in real time in multicolor printing, thereby improving the quality of books and periodicals after rotary printing.

[0167] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0168] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A multi-color printing method for a book and periodical rotary printing press, the book and periodical rotary printing press comprising a printing mechanism, a vision sensing mechanism, and a robotic arm, characterized in that, The multicolor printing method includes: The printing mechanism of the book and periodical rotary printing press is started to perform the first color overprint, and the printed image after the first color overprint is acquired through the visual perception mechanism; Identify the image misregistration during the first color printing from the printed image; The optical density of the printed area after the first color overprint is obtained. Based on the optical density, the dot expansion value of the color dots after the first color overprint under ink emulsification is determined. Based on the dot expansion value and the image deviation, the overprinting result of the second color overprint is predicted, and the pigment binding degree of the ink between the second color overprint and the first color overprint is obtained. According to the dampening solution during the first color overprinting process The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting. The pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the pigment binding degree and the smearing defect, and then the book and magazine rotary printing press is controlled to perform secondary color overprinting according to the pressure compensation amount.

2. The method as described in claim 1, characterized in that, The specific methods for identifying image discrepancies in the initial color registration of the printed image include: Determine the edge curves in the printed image; The graphic deviation of the printed area pattern after the first color overprint is determined based on the edge curve and the pre-set printing pattern.

3. The method as described in claim 1, characterized in that, Determining the dot gain value of color dots after the first color overprint under ink emulsification based on the optical density specifically includes: To obtain the solid density of printed paper; The blank reflectance of the unprinted portion after the first color overprint is determined based on the paper density. The printing reflectance of the printed area after the first color overprint is determined based on the optical density. The dot gain value of the color dots after the first color overprint is determined based on the blank reflectance and the printing reflectance, under the condition of ink emulsification.

4. The method as described in claim 1, characterized in that, Based on the dot gain value and the image deviation, the overprinting result of the secondary color overprinting is predicted, and the pigment binding degree of the ink between the secondary color overprinting and the primary color overprinting is obtained, specifically including: To obtain the component content and drying speed of secondary color overprinting inks; The ink adhesion is determined based on the component content and the drying speed. The emulsification penalty is determined based on the dot expansion value and the image deviation. The pigment binding degree of the ink between the secondary color overprint and the primary color overprint is determined based on the ink binding degree and the emulsification penalty.

5. The method as described in claim 1, characterized in that, According to the dampening solution during the first color overprinting process The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting, specifically including: The properties of the original dampening solution during the initial color overprinting process are used to determine the content of the dampening solution in the dampening solution. The amount of residual sediment in the sedimentary deposits; The preset pressure of the robotic arm and the viscosity of the ink during the secondary color overprinting process are obtained. The predicted laminar flow coefficient of the ink during the second color overprinting process is determined based on the dot gain value in the first color overprinting, the preset pressure of the robotic arm during the second color overprinting process, and the viscosity of the ink during the second color overprinting process. The smearing defects in secondary color printing are determined based on the amount of residue deposited and the predicted laminar flow coefficient.

6. The method as described in claim 5, characterized in that, The properties of the original dampening solution during the initial color overprinting process are used to determine the content of the dampening solution in the dampening solution. The specific amount of residue deposited in the sedimentary sediments includes: The pH, surface tension, and conductivity of the dampening solution during the first color overprinting process are obtained, and the pH, surface tension, and conductivity are all taken as the original properties of the dampening solution during the first color overprinting process. The amount of acid and alkali deposition is determined based on the pH value and the preset optimal pH value. The tension deposition amount is determined based on the surface tension and the preset optimal tension; The amount of acid-base deposition, the amount of tension deposition, and the conductivity are determined based on the dampening solution. The amount of residue deposited in the sedimentary sediments.

7. The method as described in claim 1, characterized in that, Determining the pressure compensation amount of the robotic arm in secondary color overprinting based on the pigment bonding degree and the smearing defects specifically includes: The pressure adjustment threshold is determined based on the pigment bonding degree and the smearing defects. The pressure adjustment threshold is compared with the preset threshold. When the threshold is less than or equal to the threshold, the pressure compensation of the robotic arm in the secondary color overprinting is set to 0. When the defined value is greater than the defined threshold, the pressure compensation amount of the robotic arm in the secondary color overprinting is determined based on the defined value and the defined threshold.

8. A book and magazine rotary printing press, comprising a printing mechanism, a vision sensing mechanism, a robotic arm, and a control unit, characterized in that, The control unit includes: The acquisition module is used to control the visual perception mechanism to acquire the printed image after the printing mechanism of the book and periodical rotary printing press performs the first color overprint. The processing module is used to identify the image deviation of the first color registration from the printed image; The processing module is also used to obtain the optical density of the printed area after the first color overprint, determine the dot expansion value of the color dots after the first color overprint under ink emulsification based on the optical density, and predict the overprinting result of the second color overprint based on the dot expansion value and the image deviation, so as to obtain the pigment binding degree of the ink between the second color overprint and the first color overprint. The processing module is also used to determine the amount of dampening solution in the initial color overprinting process. The amount of residue deposited in the sediment and the preset pressure of the robotic arm during the secondary color overprinting process predict the smearing defects in the secondary color overprinting. An execution module is used to determine the pressure compensation amount of the robotic arm in secondary color overprinting based on the pigment binding degree and the smearing defect, and then control the book and magazine rotary printing press to perform secondary color overprinting according to the pressure compensation amount.

9. A computer device, characterized in that, The computer device includes a memory and a processor, the memory storing code, and the processor being configured to retrieve the code and execute a multicolor printing method for a book and periodical rotary printing press as described in 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 the processor, it implements the multicolor printing method of the book and magazine rotary printing press as described in any one of claims 1 to 7.

Images