Printing quality closed-loop control system and printing equipment

Abstract

The invention provides a printing quality closed-loop control system and printing equipment, the printing quality closed-loop control system is applied to the printing equipment, and the printing quality closed-loop control system comprises a quality detection device, an analysis device, a printing quality control device and a parameter adjustment execution device; the quality detection device is used for detecting the quality of the printed matter and determining whether the printed matter is a qualified printed matter or a defective printed matter; the analysis device is connected with the quality detection device and is used for analyzing the defective printed matter and determining that the defect type of the defective printed matter is a first type of defect or a second type of defect; and the printing quality control device is connected with the analysis device and the parameter adjustment execution device, and can control the parameter adjustment execution device to work to adjust the working parameters of the printing equipment under the condition that the analysis device analyzes that the defect type of the defective printed matter is the first type of defect.

Description

[0001] This application is a divisional application of Chinese patent application No. 202311257262.1, filed on September 26, 2023, entitled "Printing Quality Closed-Loop Control System and Printing Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of printing technology, and more specifically, to a closed-loop control system for printing quality and printing equipment. Background Technology

[0003] The quality control of printing equipment involves many factors, such as printing pressure, temperature, plate wiping effect, plate condition, ink volume control, and so on. Currently, the quality control of existing printing equipment mainly relies on manual adjustments. Operators manually adjust and maintain parameters based on quality information fed back by online / offline quality detection devices, which is highly dependent on the operator's technical experience, sense of responsibility, and manual effort.

[0004] Therefore, providing a printing device capable of automatically controlling printing quality has become an urgent problem to be solved. Summary of the Invention

[0005] The present invention aims to solve or improve at least one of the above-mentioned technical problems.

[0006] The first aspect of the present invention is to provide a closed-loop control system for printing quality.

[0007] A second aspect of the present invention is to provide a printing apparatus.

[0008] The first aspect of this invention provides a closed-loop control system for printing quality, applied to printing equipment. The closed-loop control system includes: a quality detection device, an analysis device, a printing quality control device, and a parameter adjustment execution device. The quality detection device is used to detect the quality of printed materials and determine whether they are qualified or defective. The analysis device is connected to the quality detection device and is used to analyze defective printed materials and determine whether the defect type is a first type defect or a second type defect. The printing quality control device is connected to the analysis device and the parameter adjustment execution device, and can control the parameter adjustment execution device to adjust the operating parameters of the printing equipment when the analysis device determines that the defect type of the defective printed material is a first type defect.

[0009] The printing quality closed-loop control system provided by this invention first uses a quality inspection device to inspect the printed matter and determine whether it is qualified or defective. Then, an analysis device analyzes the defective printed matter and determines whether the defect type is a first-type defect or a second-type defect. A first-type defect refers to a defect that can be overcome by changing the operating parameters of the printing equipment, while a second-type defect refers to a defect that cannot be overcome by changing the operating parameters of the printing equipment, i.e., a defect requiring machine shutdown. When the analysis device determines that the defect type of the printed matter is a first-type defect, the printing quality control device controls the parameter adjustment actuator to adjust the operating parameters of the printing equipment. This invention can automatically adjust the operating parameters of the printing equipment when printing defects exist, thus eliminating the need for machine shutdown and greatly improving printing efficiency.

[0010] Optionally, the quality inspection device includes an online quality inspection device and an offline quality inspection device. The printing quality closed-loop control system also includes a re-judgment device, which is connected to the quality inspection device and is used to re-judge defective printed materials.

[0011] In this technical solution, the present invention not only includes an online quality inspection device but also an offline quality inspection device for offline inspection of printed materials, determining whether the printed materials are qualified or defective. The online and offline quality inspection devices each have advantages in terms of inspection items, precision, and accuracy, complementing each other, thus resulting in high inspection precision and high result accuracy. Furthermore, the printing quality closed-loop control system provided by the present invention adds a re-judgment device, allowing for selective inspection of defective printed materials detected by the quality inspection device, avoiding misjudgments by traditional quality inspection devices. The offline quality inspection device of the present invention can partition each image and then compare the partitions, improving the accuracy of judgment. It can also adjust the operating parameters of the printing equipment online based on the defect causes analyzed by the analysis device, ensuring printing quality. The printing equipment can be a gravure printing machine.

[0012] Optionally, due to factors such as large fluctuations in imaging brightness and poor flatness at the end of the printing plate, the detection algorithms of traditional online quality inspection devices based on statistical features have poor stability. In particular, they are prone to false detection and missed detection of defects such as slight deformation and ink color deviation. The online quality inspection device of this invention utilizes deep learning technology to develop a real-time intelligent analysis algorithm for online applications. Combined with traditional algorithms, it improves the accuracy of defect detection and can adapt to problems that traditional methods cannot solve, such as gravure paper deformation and imaging shadows, greatly reducing false alarms in the detection system.

[0013] In some technical solutions, optional first-type defects include ink quantity defects, ink temperature defects, printing pressure defects, wiping plate pressure defects, roller temperature defects, squeegee position defects, and registration position defects.

[0014] In some technical solutions, optionally, the printing quality control device can adjust at least one of the following parameters of the printing equipment based on the analysis results of the analysis device: ink volume, ink temperature, printing pressure, wiping pressure, roller temperature, squeegee position, and registration position.

[0015] In some technical solutions, optionally, the offline quality inspection device is specifically used to perform offline inspection of the ink color, printing pressure, and line width of printed materials. If any of the ink color, printing pressure, or line width does not meet the standard, the printed material is determined to be a defective printed material.

[0016] In this technical solution, the offline quality inspection device is specifically used to perform offline inspection of the ink color, printing pressure, and line width of printed materials. Since the offline quality inspection device has a precise gravure printing quality evaluation capability, it can score and evaluate each element such as ink color, printing pressure, and line width separately, and establish a mapping relationship between each element and printing quality. In this way, it is possible to analyze whether the printed material is a qualified printed material or a defective printed material.

[0017] In some technical solutions, optionally, when an offline quality inspection device inspects the ink color of printed matter, the offline quality inspection device is specifically used to divide the image of printed matter into different partitions according to different colors using a color segmentation method, compare the color of each partition with the standard color of the corresponding partition, determine the color difference value between the color of each partition and the standard color of the corresponding partition based on a quantization table, and determine whether the printed matter is a qualified printed matter or a defective printed matter based on the color difference value of each partition.

[0018] In this technical solution, the present invention first acquires an image of a standard printed product, uses color segmentation to divide it into different color block partitions, and establishes the color information of each color block partition as a standard model. Then, after acquiring the printed product to be inspected, the image of the printed product to be inspected is divided into different partitions according to different colors using color segmentation. The color of each partition is compared with the standard color, and then the color difference value between the color of each partition and the corresponding standard color is determined based on a quantization table. Finally, the color difference value of each partition is used to determine whether the printed product is qualified. The quantization table includes the correspondence between color difference and color difference value. In the actual judgment process, for example, if the color difference value exceeds a threshold, it is judged as a defective printed product. The present invention uses color segmentation to analyze printed products, resulting in higher accuracy.

[0019] In some technical solutions, optionally, when the offline quality inspection device determines that the printed matter is defective, the printing quality control device adjusts the ink volume of the printing equipment by controlling the parameter adjustment actuator according to the correspondence between the adjustment amount and the color difference value.

[0020] In this technical solution, the printing quality control device can control the parameter adjustment actuator to adjust the ink volume of the printing equipment based on the correspondence between the adjustment amount and the color difference value. A large color difference value indicates that the ink volume of the printing equipment is too small, and more ink needs to be added.

[0021] In some technical solutions, optionally, based on different printed materials and different printing plate densities, the printing quality control device can control the parameter adjustment actuator to adjust the ink volume of the printing equipment according to the correspondence between different adjustment amounts and color difference values.

[0022] In this technical solution, due to the different printing plate densities, the correspondence between the adjustment amount and the color difference value changes during the ink volume adjustment process. Based on different printed materials and different printing plate densities, the printing quality control device can control the parameter adjustment actuator to adjust the ink volume of the printing equipment according to the different correspondence between the adjustment amount and the color difference value. This makes the present invention more applicable to different types of printed materials, and even for different printing plate densities, it can accurately control the ink volume, providing accuracy.

[0023] In some technical solutions, optionally, when the printing quality control device adjusts the ink volume of the printing equipment, the ink color change value of the adjusted amount is greater than or equal to 1 NBS (color difference unit, National Bureau of Standards Unir).

[0024] The second aspect of this invention provides a printing apparatus, including a printing quality closed-loop control system as provided in the first aspect of this invention. Since the second aspect of this invention provides a printing apparatus including a printing quality closed-loop control system as provided in the first aspect of this invention, the printing apparatus provided by this invention possesses all the beneficial effects of the printing quality closed-loop control system provided in any of the first aspects of this application, which will not be elaborated further here.

[0025] In some technical solutions, the printing equipment may optionally include a cover with an opening, and a quality inspection device is installed inside the cover, which can inspect the printed matter through the opening.

[0026] In this technical solution, since the detection device is installed at the position of the impression cylinder, it is easily contaminated by high temperature and ink splatter, which affects the accuracy of detection. For example, the detection capability fluctuates greatly, the false alarm rate is high, and the maintenance frequency is high. This invention sets the quality detection device inside the enclosure, leaving only a narrow slit for imaging, which can effectively reduce the contamination of the imaging equipment by dust and ink splatter, thereby improving system stability and reducing maintenance frequency.

[0027] Optionally, the printing equipment also includes a blower flattening device, which is installed on the cover and has a corresponding opening, for blowing air onto the surface of the printed matter so that the printed matter can be stably attached to the rollers of the printing equipment.

[0028] In this technical solution, a blower flattening device blows air onto the surface of the printed material, allowing the printed material to adhere smoothly to the rollers of the printing equipment. This enables the quality inspection device to clearly capture the image of the printed material, improving inspection efficiency.

[0029] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of embodiments of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0031] Figure 1 A block diagram of a printing quality closed-loop control system provided by an embodiment of the present invention is shown;

[0032] Figure 2 A second block diagram of the printing quality closed-loop control system provided by an embodiment of the present invention is shown;

[0033] Figure 3 A control flowchart of the printing quality closed-loop control system provided by an embodiment of the present invention is shown.

[0034] Figure 4 A flowchart illustrating the operation of a printing equipment adjustment process for a closed-loop control system for printing quality provided in an embodiment of the present invention is shown.

[0035] Figure 5 A schematic diagram of the detection process of the offline detection device of the printing quality closed-loop control system provided in an embodiment of the present invention is shown.

[0036] Figure 6 A schematic diagram of the defect analysis process of the offline detection device of the printing quality closed-loop control system provided in an embodiment of the present invention is shown.

[0037] Figure 7The diagram illustrates the ink volume adjustment of the printing quality closed-loop control system provided by an embodiment of the present invention, compared with conventional ink volume adjustment.

[0038] Figure 8 A partial structural schematic diagram of a printing apparatus provided in an embodiment of the present invention is shown.

[0039] in, Figure 1 , Figure 2 and Figure 8 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0040] 1 Printing equipment, 11 Printing quality closed-loop control system, 111 Quality inspection device, 1112 Online quality inspection device, 1113 Offline quality inspection device, 112 Re-judgment device, 114 Analysis device, 115 Printing quality control device, 116 Parameter adjustment and execution device, 12 Cover, 13 Blowing and flattening device. Detailed Implementation

[0041] To better understand the above aspects, features, and advantages of the embodiments of the present invention, optional detailed descriptions of the embodiments of the present invention are provided below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0042] Many specific details are set forth in the following description in order to provide a full understanding of the embodiments of the present invention. However, the embodiments of the present invention may also be implemented in other ways different from those described herein. Therefore, the protection provided by the embodiments of the present invention is not limited to the specific embodiments disclosed below.

[0043] like Figure 1 As shown, an embodiment of the first aspect of the present invention provides a printing quality closed-loop control system 11, applied to a printing equipment 1. The printing quality closed-loop control system 11 includes: a quality detection device 111, an analysis device 114, a printing quality control device 115, and a parameter adjustment execution device 116. The quality detection device 111 is used to detect the quality of printed matter and determine whether the printed matter is qualified or defective. The analysis device 114 is connected to the quality detection device 111 and is used to analyze defective printed matter and determine whether the defect type of the defective printed matter is a first type defect or a second type defect. The printing quality control device 115 is connected to the analysis device 114 and the parameter adjustment execution device 116, and can control the parameter adjustment execution device 116 to work to adjust the operating parameters of the printing equipment 1 when the analysis device 114 determines that the defect type of the defective printed matter is a first type defect.

[0044] The printing quality closed-loop control system 11 provided by this invention first performs quality inspection on the printed matter through a quality inspection device 111 to determine whether the printed matter is qualified or defective. Then, an analysis device 114 analyzes the defective printed matter and determines whether the defect type is a first type defect or a second type defect. A first type defect refers to a defect that can be overcome by changing the operating parameters of the printing equipment 1, while a second type defect refers to a defect that cannot be overcome by changing the operating parameters of the printing equipment 1, i.e., a defect requiring machine shutdown. When the analysis device 114 determines that the defect type of the defective printed matter is a first type defect, the printing quality control device 115 controls the parameter adjustment execution device 116 to adjust the operating parameters of the printing equipment 1. This invention can automatically adjust the operating parameters of the printing equipment 1 when printing defects exist, thus eliminating the need for machine shutdown and greatly improving printing efficiency.

[0045] Optional, such as Figure 2 As shown, the quality inspection device 111 includes an online quality inspection device 1112 and an offline quality inspection device 1113. The printing quality closed-loop control system 11 also includes a re-judgment device 112, which is connected to the quality inspection device 111 and is used to re-judge defective printed products.

[0046] In this embodiment, the present invention not only includes an online quality inspection device 1112 but also an offline quality inspection device 1113 for offline inspection of printed materials and determination of whether the printed materials are qualified or defective. The online and offline quality inspection devices 1112 and 1113 each have advantages in terms of inspection items, precision, and accuracy, complementing each other, thus resulting in high inspection precision and high accuracy of the present invention. Furthermore, the printing quality closed-loop control system 11 provided by the present invention adds a re-judgment device 112, which allows for selective inspection of defective printed materials detected by the quality inspection device 111, avoiding misjudgments by traditional quality inspection devices. The offline quality inspection device 1113 of the present invention can partition each image and then compare the partitions, improving the accuracy of judgment. It can also adjust the operating parameters of the printing equipment 1 online based on the defect causes analyzed by the analysis device 114, ensuring printing quality. The printing equipment 1 can be a gravure printing machine.

[0047] Optionally, due to factors such as large fluctuations in imaging brightness and poor flatness at the end of the printing plate, the detection algorithms of traditional online quality inspection devices based on statistical features have poor stability. In particular, they are prone to false detection and missed detection of defects such as slight deformation and ink color deviation. The online quality inspection device 1112 of the present invention utilizes deep learning technology to develop a real-time intelligent analysis algorithm for online applications. Combined with traditional algorithms, it improves the accuracy of defect detection and can adapt to problems that traditional methods cannot solve, such as gravure paper deformation and imaging shadows, greatly reducing false alarms in the detection system.

[0048] In some embodiments, optionally, the first type of defect includes ink quantity defect, ink temperature defect, printing pressure defect, wiping plate pressure defect, roller temperature defect, squeegee position defect, and registration position defect.

[0049] In some embodiments, optionally, the printing quality control device 115 can control the parameter adjustment execution device 116 to adjust at least one of the following parameters of the printing equipment 1 based on the analysis results of the analysis device 114: ink volume, ink temperature, printing pressure, wiping pressure, roller temperature, squeegee position, and registration position.

[0050] In some embodiments, optionally, the offline quality inspection device 1113 is specifically used to perform offline inspection of the ink color, printing pressure, and line width of the printed matter, and to determine that the printed matter is a defective printed matter when one of the ink color, printing pressure, or line width does not meet the standard.

[0051] In this embodiment, the offline quality inspection device 1113 is specifically used to perform offline inspection of the ink color, printing pressure, and line width of the printed matter. Since the offline quality inspection device 1113 has a fine gravure printing quality evaluation capability, it can score and evaluate each element such as ink color, printing pressure, and line width separately, and establish a mapping relationship between each element and printing quality. In this way, it can be analyzed whether the printed matter is a qualified printed matter or a defective printed matter.

[0052] In some embodiments, optionally, when the offline quality inspection device 1113 inspects the ink color of the printed matter, the offline quality inspection device 1113 is specifically used to divide the image of the printed matter into different partitions according to different colors using a color segmentation method, compare the color of each partition with the standard color of the corresponding partition, determine the color difference value between the color of each partition and the standard color of the corresponding partition based on a quantization table, and determine whether the printed matter is a qualified printed matter or a defective printed matter based on the color difference value of each partition.

[0053] In this embodiment, the present invention first acquires an image of a standard printed matter, segments it into different color blocks using a color segmentation method, and establishes color information for each color block as a standard model. Then, after acquiring the printed matter to be inspected, the image of the printed matter to be inspected is segmented into different blocks according to different colors using the color segmentation method. The color of each block is compared with the standard color. Then, based on a quantization table, the color difference between the color of each block and the corresponding standard color is determined. Finally, the color difference value of each block is used to determine whether the printed matter is a qualified printed matter. The quantization table includes the correspondence between color difference and color difference value. In the actual judgment process, for example, if the color difference value exceeds a threshold, it is judged as a defective printed matter. The present invention uses a color segmentation method to analyze printed matter, resulting in higher accuracy.

[0054] In some embodiments, optionally, when the offline quality inspection device 1113 determines that the printed matter is a defective printed matter, the printing quality control device 115 controls the parameter adjustment execution device 116 to adjust the ink volume of the printing equipment 1 according to the correspondence between the adjustment amount and the color difference value.

[0055] In this embodiment, the printing quality control device 115 can control the parameter adjustment execution device 116 to adjust the ink volume of the printing equipment 1 according to the correspondence between the adjustment amount and the color difference value. A larger color difference value indicates that the ink volume of the printing equipment 1 is less at this time, and more ink needs to be added.

[0056] In some embodiments, optionally, based on different printed materials and different printing plate densities, the printing quality control device 115 can control the parameter adjustment execution device 116 to adjust the ink volume of the printing equipment 1 according to the correspondence between different adjustment amounts and color difference values.

[0057] In this embodiment, due to the different printing plate densities, the correspondence between the adjustment amount and the color difference value changes during the ink volume adjustment process. Based on different printed materials and different printing plate densities, the printing quality control device 115 can control the parameter adjustment execution device 116 to adjust the ink volume of the printing equipment 1 according to the different correspondence between the adjustment amount and the color difference value. This makes the present invention more applicable to different types of printed materials. Even for different printing plate densities, the ink volume can be accurately controlled, providing accuracy.

[0058] In some embodiments, optionally, when the printing quality control device 115 controls the parameter adjustment execution device 116 to adjust the ink volume of the printing equipment 1, the ink color change value of the adjustment amount is greater than or equal to 1 NBS.

[0059] The following example uses printing equipment, such as... Figure 3As shown, the specific control flow of the printing quality closed-loop control system includes the following steps:

[0060] S202: Prepare printing equipment;

[0061] S204: Prepare large sheets of gravure printing products;

[0062] S206: Equipment status information acquisition system collects status information of printing equipment;

[0063] S208: The offline quality inspection device performs offline inspection of gravure printing paper;

[0064] S210: Onboard image acquisition system acquires images of gravure printing paper;

[0065] S212: Online quality inspection algorithm for online inspection of gravure printing paper;

[0066] S214: The printing quality control device adjusts the operating parameters of the printing equipment based on the detection results and control parameters.

[0067] S216: Parameter adjustment actuator adjusts the working parameters of the printing equipment.

[0068] The printing quality closed-loop control system 11 of this application first collects the status information of the printing equipment through the equipment status information acquisition system, and sends the collected status information of the printing equipment to the printing quality control device 115. The offline quality inspection device 1113 randomly samples and inspects the printed products, and sends the quality error information to the analysis device 114. The analysis device 114 sends the analysis results to the printing quality control device 115. The online quality inspection device 1112 acquires real-time images of all printed products through the on-machine image acquisition unit, and performs online inspection on each real-time image, and sends the detected quality error information to the analysis device 114. The analysis device 114 sends the analysis results to the printing quality control device 115. The printing quality control device 115 can adjust the working parameters of the printing equipment by the control parameter adjustment execution device 116 based on the status information of the printing equipment and the analysis results of the analysis device 114. This mainly includes adjusting the ink volume, ink temperature, printing pressure, wiping pressure, roller temperature, doctor blade position, and registration position of the printing equipment.

[0069] During the process of inspecting the quality of printed materials, the online quality inspection device 1112 utilizes deep learning technology to develop a real-time intelligent analysis algorithm for online applications. This algorithm is combined with traditional algorithms to improve the accuracy of defect detection. The system can adapt to problems that traditional methods cannot solve, such as gravure paper deformation and imaging shadows, and greatly reduces false alarms in the inspection system.

[0070] Optionally, after the online quality inspection device 1112 performs the inspection, the re-judgment device 112 also performs the re-judgment to avoid treating qualified printed materials as waste.

[0071] like Figure 4 As shown, the re-evaluation process specifically includes the following steps:

[0072] S302: Obtain defective printed materials detected by an online quality inspection device;

[0073] S304: Artificial intelligence defect review to determine whether it is a qualified product; if yes, proceed to S306; if no, proceed to S308.

[0074] S306: Confirm the printed matter is a qualified product; End;

[0075] S308: Determine that the printed matter is waste;

[0076] S310: Upload actual waste images to the analysis device;

[0077] S312: Upload quality defect data.

[0078] This application uses the review device 112 to perform another automatic analysis and screening to identify which are false alarms and which are truly invalid. For printed materials that are falsely alarmed by the online quality inspection device 1112, the system outputs that the printed material is qualified and confirms that the online quality inspection device 1112 is falsely alarmed. For truly invalid materials, the system outputs that the printed material is invalid. At the same time, the system acquires the image of the invalid material and uploads the quality defect data to the analysis device 114 for analysis.

[0079] Optionally, the offline quality inspection device 1113 has the capability to evaluate the quality of fine gravure printing, and can accurately evaluate various printing elements. The following describes the specific working steps of the offline quality inspection device 1113 of this application, taking the accurate evaluation of ink color differences as an example:

[0080] like Figure 5 As shown, the detection steps of the offline quality inspection device include:

[0081] S402: Obtain the product to be inspected;

[0082] S404: By using color segmentation to divide the image of the inspected product into multiple zones based on different colors;

[0083] S406: Obtain the color information for each partition;

[0084] S408: Compare the color information of each partition with the standard color information of the model;

[0085] S410: Quantify the color differences according to the quantification table;

[0086] S412: Outputs the color difference between the color of this partition and the standard color.

[0087] Optionally, the offline quality inspection device 1113 can also simultaneously monitor information such as wiring, printing pressure, and line width. It also uses the same method as described above to accurately evaluate the difference in ink color, and determines the corresponding adjustment methods for wiring defects, printing pressure defects, and line width defects, which can greatly improve the stability and consistency of product quality.

[0088] The analysis device 114 automatically classifies and grades the received defect images, categorizing defects into different scrap types and severity levels. The specific process is as follows: Figure 6 As shown, it includes:

[0089] S502: Acquire images of defective products after inspection by the online quality inspection device;

[0090] S504: Intelligent Defect Extraction;

[0091] S506: Determine whether the defect features are within the allowable error range. If yes, proceed to S508; otherwise, proceed to S510.

[0092] S508: Intelligent judgment indicates the product is qualified; execute the termination procedure;

[0093] S510: Intelligent judgment indicates it is a defective product;

[0094] S512: Intelligent Defect Calculation;

[0095] S514: Intelligent sorting of waste materials.

[0096] During the judgment process, each defective image is analyzed to determine whether it is a qualified product or a genuine defective product. If it is determined to be a qualified product, it indicates that the online quality inspection device 1112 has a false alarm. If it is determined to be a genuine defective product, it indicates that the printed product is defective. Then, the defective printed products are intelligently recorded and classified. Finally, the cause of the defect is analyzed. There are two types of defect causes. One type is the cause that the system can automatically repair, such as ink volume, ink temperature, printing pressure, roller temperature, etc. When the analysis device 114 analyzes that the defect cause is of this type, the printing quality control device 115 controls the parameter adjustment execution device 116 to automatically adjust the parameters.

[0097] Taking ink color adjustment as an example, during the process of ink volume adjustment by the control parameter adjustment execution device 116 of the printing quality control device 115, the system can pre-establish the correspondence between the ink color adjustment amount and the color difference value, that is, determine the color difference value of the printed color corresponding to each unit adjustment amount of the ink key, and then determine the ink color adjustment amount based on the color difference value between the printed color difference and the standard color difference detected by the offline quality detection device 1113. Specifically, since numerous experiments were conducted before detection and recorded in the system using artificial intelligence, the offline quality inspection device 1113 can determine the color difference value based on the detected image. For example, if the offline quality inspection device 1113 determines the color difference between the printed product and the standard color to be "10 color differences" according to the quantization table, and since the printing quality control device 115 stores the correspondence between ink adjustment amount and color difference value, if "1 color difference" corresponds to "1 unit adjustment amount," then the printing quality control device 115 will adjust the parameter adjustment execution device 116 by "10 units of adjustment amount" based on "10 color differences," thereby achieving automatic control of printing quality. Optionally, the correspondence between ink adjustment amount and color difference value is related to various factors such as paper whiteness, printing plate density, and color evaluation measures. Extensive testing is required beforehand for different papers and different printed products, and a regression model is established using deep learning technology, with the current color difference value as input and the unit adjustment amount as output. The system employs deep learning technology to correlate ink color changes with ink volume adjustment values. The input layer of the deep network takes the ink color change value as input, and the output layer takes the adjustment value as output. By learning from the modeling data, the network trains a "black box" mathematical equation that minimizes the sum of squared errors, thereby achieving a precise mapping between input and output values. The modeling data can be obtained through various methods, including instrument measurements and manual adjustment records by machine operators.

[0098] like Figure 7 As shown, the ink adjustment steps in the prior art include:

[0099] S602: Differences in ink color determined by manual visual inspection;

[0100] S604: Adjust the ink knife adjustment amount based on experience;

[0101] S606: Manually adjust ink volume.

[0102] The ink adjustment steps of the closed-loop control system for printing quality in this application include:

[0103] S612: Machine measurement of ink color difference;

[0104] S614: Artificial intelligence analyzes differences in ink color;

[0105] S616: Automatic ink volume control.

[0106] Of course, the system will still automatically adjust for other defects using the same principle, such as printing pressure and line width.

[0107] like Figure 8 As shown, an embodiment of the second aspect of the present invention provides a printing apparatus 1, including a printing quality closed-loop control system 11 as provided in the embodiment of the first aspect of the present invention. Since the embodiment of the second aspect of the present invention provides a printing apparatus 1, including a printing quality closed-loop control system 11 as provided in the embodiment of the first aspect of the present invention, the printing apparatus 1 provided by the present invention has all the beneficial effects of the printing quality closed-loop control system 11 provided in any embodiment of the first aspect of the present application, which will not be elaborated further here.

[0108] In some embodiments, the printing equipment 1 may optionally include a cover 12 with an opening, and an online quality inspection device 1112 is disposed inside the cover 12, which can perform online inspection of the printed matter through the opening.

[0109] In this embodiment, since the online quality inspection device 1112 is installed at the position of the impression cylinder, it is easily contaminated by high temperature and ink splatter, which affects the accuracy of the inspection. For example, the detection capability fluctuates greatly, the false alarm rate is high, and the maintenance frequency is high. The present invention sets the online quality inspection device 1112 inside the cover 12, leaving only a narrow slit for imaging, which can effectively reduce the contamination of the imaging equipment by dust and ink splatter, thereby improving the system stability and reducing the maintenance frequency.

[0110] Optionally, the printing equipment 1 also includes a blower flattening device 13, which is disposed on the cover 12 and has a corresponding opening, for blowing air onto the surface of the printed matter so that the printed matter can be stably attached to the roller of the printing equipment 1.

[0111] In this embodiment, the air blowing device 13 blows air onto the surface of the printed material, so that the printed material can be stably attached to the roller of the printing equipment. This allows the online quality inspection device 1112 to clearly capture the image of the printed material, thereby improving the inspection efficiency.

[0112] In embodiments of the present invention, the terms "first," "second," and "third" are used only for descriptive purposes and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in embodiments of the present invention according to the specific circumstances.

[0113] Furthermore, although the operations are described in a specific order, this should be understood as requiring that such operations be performed in the specific order shown or in sequential order, or requiring that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0114] Although the subject matter has been described using language describing specific structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

[0115] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the embodiments. Those skilled in the art will recognize that various modifications and variations are possible with respect to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of the present invention should be included within the protection scope of the embodiments of the present invention.

Claims

1. A closed-loop control system for printing quality, characterized in that, Applied to printing equipment, the printing quality closed-loop control system includes: a quality detection device, an analysis device, a printing quality control device, and a parameter adjustment and execution device; The quality inspection device is used to inspect the quality of printed materials and determine whether the printed materials are qualified or defective. The analysis device is connected to the quality inspection device and is used to analyze the defective printed matter and determine whether the defect type of the defective printed matter is a first type defect or a second type defect. The printing quality control device is connected to the analysis device and the parameter adjustment execution device. When the analysis device determines that the defect type of the defective printed product is a first type of defect, the device controls the parameter adjustment execution device to work and adjust the working parameters of the printing equipment. The quality inspection device includes an online quality inspection device and an offline quality inspection device, and the printing quality closed-loop control system further includes: A re-judgment device, connected to the quality inspection device, is used to re-judge the defective printed matter; The first type of defect includes ink quantity defects, ink temperature defects, printing pressure defects, wiping plate pressure defects, roller temperature defects, doctor blade position defects, and registration position defects; The printing quality control device can control the parameter adjustment execution device to adjust at least one of the following parameters of the printing equipment based on the analysis results of the analysis device: ink volume, ink temperature, printing pressure, wiping pressure, roller temperature, squeegee position, and registration position. The offline quality inspection device is specifically used to perform offline inspection of the ink color, printing pressure, and line width of the printed matter. If any one of the ink color, printing pressure, or line width does not meet the standard, the printed matter is determined to be a defective printed matter.

2. The printing quality closed-loop control system according to claim 1, characterized in that, When the offline quality inspection device inspects the ink color of the printed matter, the offline quality inspection device is specifically used to divide the image of the printed matter into different partitions according to different colors using a color segmentation method, compare the color of each partition with the standard color of the corresponding partition, determine the color difference value between the color of each partition and the standard color of the corresponding partition based on a quantization table, and determine whether the printed matter is a qualified printed matter or a defective printed matter based on the color difference value of each partition.

3. The printing quality closed-loop control system according to claim 2, characterized in that, If the offline quality inspection device determines that the printed matter is a defective printed matter, the printing quality control device controls the parameter adjustment execution device to adjust the ink volume of the printing equipment according to the correspondence between the adjustment amount and the color difference value.

4. The printing quality closed-loop control system according to claim 3, characterized in that, Based on different printed materials and different printing plate densities, the printing quality control device can control the parameter adjustment execution device to adjust the ink volume of the printing equipment according to the correspondence between different adjustment amounts and the color difference value.

5. The printing quality closed-loop control system according to claim 4, characterized in that, When the printing quality control device controls the parameter adjustment execution device to adjust the ink volume of the printing equipment, the ink color change value of the adjustment amount is greater than or equal to 1 NBS.

6. A printing apparatus, characterized in that, include: The printing quality closed-loop control system as described in any one of claims 1 to 5.

7. The printing equipment according to claim 6, characterized in that, Also includes: The cover has an opening, and the quality inspection device is installed inside the cover, enabling it to inspect the printed matter through the opening.

8. The printing equipment according to claim 7, characterized in that, Also includes: A blower flattening device is installed on the cover and corresponding to the opening. It is used to blow air onto the surface of the printed material so that the printed material can be stably attached to the roller of the printing equipment.

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