Automatic negative pressure circulating ink supply system, method and medium for UV digital printing machine

Abstract

The present invention belongs to the field of UV digital printing and relates to data analysis technology. Specifically, it provides an automatic negative pressure circulation ink supply system, method and medium for a UV digital printing machine. The system comprises a digital printing module, an ink leakage detection module, a chromaticity detection module and a storage module. The digital printing module, the ink leakage detection module, the chromaticity detection module and the storage module are communicatively connected in sequence, and the ink leakage detection module is also communicatively connected to the storage module. The present invention can detect and analyze the printing effect during the printing process, compare the detection image of the completed printed product with the standard printed image, evaluate the printing effect based on the comparison result, adopt different processing means to perform secondary processing on the detection image according to the evaluation result of the printing effect, and provide timely feedback when the printing effect is abnormal, so as to avoid the subsequent products from being printed when the UV digital printing machine is operating abnormally.

Description

Technical Field

[0001] The present invention belongs to the field of UV digital printing and relates to data analysis technology, in particular to an automatic negative pressure circulating ink supply system, method and medium for a UV digital printing machine. Background Art

[0002] The automatic negative pressure circulation ink supply method of the UV digital printing machine is realized through a fully enclosed double negative pressure circulation ink supply system. Through precise control and adjustment, the system ensures the stable supply and recovery of ink, improves printing quality and efficiency, and ensures the continuity of production.

[0003] The UV digital printing machines in the existing technology do not have the function of detecting the printing effect of the completed products. The detection process is performed uniformly after all the products in a batch are printed. This method cannot provide timely feedback when the printing effect is abnormal, and improve the printing effect of subsequent products, which leads to high printing cost frequency and low overall printing efficiency. Summary of the Invention

[0004] The object of the present invention is to provide an automatic negative pressure circulating ink supply system, method and medium for a UV digital printing machine, which is used to solve the problem in the prior art that timely feedback cannot be provided when the printing effect is abnormal.

[0005] The technical problem to be solved by the present invention is: how to provide an automatic negative pressure circulating ink supply system, method and medium for a UV digital printing machine that can provide timely feedback when the printing effect is abnormal.

[0006] The object of the present invention can be achieved by the following technical solution: an automatic negative pressure circulating ink supply system for a UV digital printing machine, comprising a digital printing module, an ink leakage detection module, a chromaticity detection module, and a storage module, wherein the digital printing module, the ink leakage detection module, the chromaticity detection module, and the storage module are communicatively connected in sequence, and the ink leakage detection module is also communicatively connected to the storage module;

[0007] The ink leakage detection module is used to detect and analyze ink leakage during the printing process: marking the product printed by the printing unit as a detection object, capturing an image of the printed surface of the detection object and marking the captured image as a detection image, amplifying the detection image into a pixel grid image and performing grayscale conversion, retrieving a standard printing image of the corresponding product through a storage module, comparing the detection image with the standard printing image, and marking the detection image as a normal image or an abnormal image based on the comparison result; and performing abnormal processing analysis on the abnormal image;

[0008] The color detection module is used to detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process.

[0009] Furthermore, the digital printing module includes an ink supply unit, an ink return unit and a printing unit. The ink supply unit is used to control the ink supply to the printing unit, the ink return unit is used to control the ink reflux, and the printing unit includes a print head for printing, and the print head adopts a dual negative pressure print head.

[0010] Furthermore, the specific process of comparing the detection image with the standard printed image includes: using a binary method to extract and segment the printed area in the detection image and the printed area in the standard printed image and mark them as detection area and standard area respectively, performing overlap comparison on the detection area and the standard area and marking the maximum value of the overlapping area between the detection area and the standard area as a compliance value, marking the ratio of the compliance value to the area value of the detection area as a compliance coefficient of the detection image, obtaining a compliance threshold through a storage module, and comparing the compliance coefficient with the compliance threshold: if the compliance coefficient is greater than or equal to the compliance threshold, it is determined that the printing effect of the detection image corresponding to the detection object meets the requirements, the corresponding detection image is marked as a normal image, and the normal image is sent to the chromaticity detection module; if the compliance coefficient is less than the compliance threshold, it is determined that the printing effect of the detection image corresponding to the detection object does not meet the requirements, and the corresponding detection image is marked as an abnormal image.

[0011] Furthermore, the specific process of performing abnormal processing analysis on abnormal images includes: overlapping the abnormal image with the standard printed image and placing them in a grid diagram of the same rectangular coordinate system, the grids in the grid diagram correspond to the pixel grids, and marking the grids in the grid diagram of the rectangular coordinate system as re-qualified, deviation grids or blank grids; forming a deviation combination from the deviation grids that are in contact with each other, and determining whether there is a re-qualified grid among the grids that are in contact with the deviation grids at the edge of the deviation combination: if so, determining that the detection object corresponding to the abnormal image has a printing deviation phenomenon, generating a pressure difference adjustment signal and sending the pressure difference adjustment signal to the mobile phone terminal of the administrator; if not, determining that the detection object corresponding to the abnormal image has an ink leakage phenomenon, generating an ink leakage processing signal and sending the ink leakage processing signal to the mobile phone terminal of the administrator.

[0012] Furthermore, the specific process of marking squares as re-qualified, deviation squares or blank squares includes: marking the squares whose corresponding two pixel grids are respectively located in the detection area and the standard area as re-qualified, and setting the grayscale value of the re-qualified squares to zero; marking the squares whose corresponding two pixel grids are not located in the detection area and the standard area as blank squares, and setting the grayscale value of the blank squares to two hundred and fifty-five; marking the remaining squares as deviation squares, and setting the grayscale value of the deviation squares to one hundred and twenty-eight.

[0013] Furthermore, the specific process of the chromaticity detection module for detecting and analyzing the color transition smoothness of the printed pattern of the product that has completed the printing process includes: obtaining the color requirement value of the normal image and determining whether the normal image has the necessity of smoothing analysis through the color requirement value, and performing smoothing analysis on the normal image when it is necessary: ​​setting a scanning frame of L1*L2 specifications in the upper left corner of the normal image, where L1*L2 indicates that the shape of the scanning frame is a rectangular frame with a length of L1 pixels and a width of L2 pixels; performing horizontal scanning processing on the scanning frame and obtaining a horizontal smoothing value HP; performing vertical scanning processing on the scanning frame and obtaining a vertical smoothing value HP. To the smoothing value ZP; the smoothing coefficient PH of the normal image is obtained by the formula PH=k1*HP+k2*ZP, where k1 and k2 are both proportional coefficients, and k1>k2>1; the smoothing threshold PHmax is obtained through the storage module, and the smoothing coefficient PH is compared with the smoothing threshold PHmax: if the smoothing coefficient PH is less than the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image meets the requirements; if the smoothing coefficient PH is greater than or equal to the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image does not meet the requirements, and a chromaticity optimization signal is generated and sent to the mobile phone terminal of the administrator.

[0014] Furthermore, the specific process of determining whether a normal image requires smoothing analysis includes: marking the difference between the maximum grayscale value and the minimum grayscale value of all pixels in the normal image as the color requirement value of the normal image, obtaining the color requirement threshold through the storage module, and comparing the color requirement value with the color requirement threshold: if the color requirement value is less than the color requirement threshold, it is determined that the normal image does not require smoothing analysis; if the color requirement value is greater than or equal to the color requirement threshold, it is determined that the normal image requires smoothing analysis.

[0015] Furthermore, the specific process of performing horizontal scanning processing on the scanning frame includes: horizontally translating the scanning frame from left to right, calculating the difference between the maximum grayscale value and the minimum grayscale value of the pixel grid in the scanning frame in real time during the horizontal translation process and marking it as the horizontal scanning value of the scanning frame; when the scanning frame is horizontally translated to the longitudinal edge of the normal image, the scanning frame is translated downward by L1 pixel grids, and then the horizontal translation direction of the scanning frame is switched, and so on, until all pixel grids in the normal image have completed the horizontal scanning processing, and the maximum value of the horizontal scanning value of the scanning frame in the horizontal scanning processing is marked as the horizontal smoothing value HP.

[0016] Furthermore, the scanning frame is vertically translated from top to bottom. During the vertical translation process, the difference between the maximum grayscale value and the minimum grayscale value of the pixel grid in the scanning frame is calculated in real time and marked as the vertical scanning value. When the scanning frame is vertically translated to the horizontal edge of the normal image, the scanning frame is translated L2 pixel grids to the right, and then the vertical translation direction of the scanning frame is switched. This process is repeated until all pixel grids in the normal image have completed the vertical scanning process, and the maximum vertical scanning value of the scanning frame in the vertical scanning process is marked as the vertical smoothing value ZP.

[0017] The present invention also provides an automatic negative pressure circulating ink supply method for a UV digital printing machine, which is applied to an automatic negative pressure circulating ink supply system of a UV digital printing machine, and comprises the following steps:

[0018] Step 1: Detect and analyze ink leakage during the printing process: Mark the product printed by the printing unit as the detection object, capture an image of the printed surface of the detection object, and mark the captured image as the detection image;

[0019] Step 2: Enlarge the inspection image into a pixel grid image and perform grayscale conversion. Retrieve the standard printing image of the corresponding product through the storage module. Compare the inspection image with the standard printing image and determine whether the printing effect of the inspection object meets the requirements based on the comparison results. If the requirements are met, proceed to step 3; otherwise, proceed to step 4.

[0020] Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product that has been printed. Smoothness analysis is necessary for normal images. Smoothness analysis is performed on the normal image to obtain a smoothing coefficient PH of the normal image. The smoothing coefficient PH is used to determine whether the color transition smoothness of the normal image meets the requirements;

[0021] Step 4: Perform abnormal processing analysis on the abnormal image and determine whether the detection object corresponding to the abnormal image has ink leakage and printing deviation.

[0022] Furthermore, a computer storage medium stores a computer program, which, when executed by a processor, implements an automatic negative pressure circulating ink supply method for a UV digital printing machine.

[0023] Among them, a computer device includes a processor and a memory; the memory stores a computer program, and the processor executes the computer program stored in the memory to enable the computer device to execute the automatic negative pressure circulation ink supply method of the UV digital printing machine.

[0024] The present invention has the following beneficial effects:

[0025] 1. By controlling the vacuum degree at the ink outlet to be higher than that at the ink inlet, a stable supply and recovery of ink is ensured. The ink supply unit and the ink return unit control the ink pressure in the ink cartridge by means of the flow difference of the dual ink pumps. The vacuum degree difference at both ends of the print head effectively and smoothly controls the circulating ink volume of the print head, realizing dynamic printing and having strong adaptability.

[0026] 2. The ink leakage detection module can detect and analyze the printing effect during the printing process. The detection image of the completed printed product is compared with the standard printing image. The printing effect is evaluated based on the comparison results. Different processing methods are adopted to perform secondary processing on the detection image according to the evaluation results of the printing effect. In addition, timely feedback is provided when the printing effect is abnormal, so as to avoid subsequent products being printed when the UV digital printing machine is operating abnormally, thereby reducing the scrap rate of the printing production line.

[0027] 3. By performing abnormal processing analysis on abnormal images, the abnormal printing effect features of the abnormal images can be extracted, and then corresponding processing signals can be generated according to the extracted abnormal printing effect features to improve the abnormal processing efficiency of the UV digital printing machine;

[0028] 4. The chromaticity detection module can be used to detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process. The necessity of smoothing analysis of the normal image can be determined based on the color requirement value. Then, when necessary, the normal image can be smoothed and the smoothing coefficient can be obtained. The smoothing coefficient can be used to evaluate the smoothness of the local color transition of the normal image. When the color transition smoothness is abnormal, timely feedback and optimization can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a system block diagram of Embodiment 1 of the present invention;

[0031] Figure 2 This is a flow chart of the method of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1: Figure 1 As shown, an automatic negative pressure circulation ink supply system for a UV digital printing machine includes a digital printing module, an ink leakage detection module, a chromaticity detection module and a storage module. The digital printing module, the ink leakage detection module, the chromaticity detection module and the storage module are communicatively connected in sequence, and the ink leakage detection module is also communicatively connected to the storage module.

[0034] The digital printing module includes an ink supply unit, an ink return unit and a printing unit. The ink supply unit is used to control the ink supply to the printing unit, and the ink return unit is used to control the ink reflux. The printing unit includes a print head for printing. The print head adopts a double negative pressure print head. The vacuum degree at the ink outlet end is higher than the vacuum degree at the ink inlet end, ensuring the stable supply and recovery of ink. The ink supply unit and the ink return unit control the ink pressure in the ink cartridge through the flow difference of the dual ink pumps. The vacuum degree difference at both ends of the print head effectively and smoothly controls the circulating ink volume of the print head, realizing dynamic printing, and has strong adaptability.

[0035] The ink leakage detection module is used to detect and analyze the ink leakage phenomenon during the printing process: the product printed by the printing unit is marked as the detection object, the printed surface of the detection object is imaged and the captured image is marked as the detection image, the detection image is enlarged into a pixel grid image and grayscale conversion is performed, the standard printing image of the corresponding product is retrieved through the storage module, and the detection image is compared with the standard printing image: the printing area in the detection image and the printing area in the standard printing image are extracted and segmented using the binary method and marked as the detection area and the standard area respectively, the detection area and the standard area are overlapped and compared and the maximum value of the overlapping area between the detection area and the standard area is marked as the compliance value, the ratio of the compliance value to the area value of the detection area is marked as the compliance coefficient of the detection image, the compliance threshold is obtained through the storage module, and the compliance coefficient is compared with the compliance threshold: if the compliance coefficient is greater than or equal to the compliance threshold, it is determined that the printing effect of the detection image corresponding to the detection object meets the requirements, the corresponding detection image is marked as a normal image, and the normal image is sent to the color detection module; if the compliance coefficient is less than the compliance threshold, it is determined that the detection image meets the requirements, the corresponding detection image is marked as a normal image, and the normal image is sent to the color detection module; If the printing effect of the test object corresponding to the test image does not meet the requirements, the corresponding test image is marked as an abnormal image, and an abnormal processing analysis is performed on the abnormal image: the abnormal image and the standard printed image are overlapped and placed in a grid diagram of the same rectangular coordinate system, and the grids in the grid diagram correspond to the pixel grids. Then, the grids whose corresponding two pixel grids are respectively located in the test area and the standard area are marked as re-qualified, and the grayscale value of the re-qualified grid is set to zero; the grids whose corresponding two pixel grids are not located in the test area and the standard area are marked as blank grids, and the grayscale value of the blank grid is set to 255; the remaining grids are marked as deviation grids, and the grayscale value of the deviation grid is set to 128; the deviation grids that contact each other form a deviation combination, and it is determined whether there is a re-qualified grid among the grids that contact the deviation grids at the edge of the deviation combination: if so, it is determined that the test object corresponding to the abnormal image has a printing deviation phenomenon, a pressure difference adjustment signal is generated and the pressure difference adjustment signal is sent to the mobile phone terminal of the administrator; if not, it is determined that the test object corresponding to the abnormal image has an ink leakage phenomenon, an ink leakage processing signal is generated and the ink leakage processing signal is sent to the mobile phone terminal of the administrator.

[0036] The chromaticity detection module is used to detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process: the difference between the maximum grayscale value and the minimum grayscale value of all pixels in the normal image is marked as the color requirement value of the normal image, the color requirement threshold is obtained through the storage module, and the color requirement value is compared with the color requirement threshold: if the color requirement value is less than the color requirement threshold, it is determined that the normal image does not need smoothing analysis; if the color requirement value is greater than or equal to the color requirement threshold, it is determined that the normal image needs smoothing analysis, and a smoothing analysis is performed on the normal image: a scanning frame with a specification of L1*L2 is set in the upper left corner of the normal image, L 1*L2 means that the shape of the scanning frame is a rectangular frame with a length of L1 pixels and a width of L2 pixels. L1 and L2 are both numerical constants. The specific values ​​of L1 and L2 are set by the administrator. The scanning frame is scanned horizontally: the scanning frame is translated horizontally from left to right. During the horizontal translation process, the difference between the maximum grayscale value and the minimum grayscale value of the pixel grid in the scanning frame is calculated in real time and marked as the horizontal scanning value of the scanning frame. When the scanning frame is translated horizontally to the vertical edge of the normal image, the scanning frame is translated downward by L1 pixels, and then the horizontal translation direction of the scanning frame is switched. This process is repeated until all the pixels in the normal image are scanned horizontally. All pixels have completed the horizontal scanning process, and the maximum horizontal scanning value of the scanning frame in the horizontal scanning process is marked as the horizontal smoothing value HP; the scanning frame is subjected to vertical scanning: the scanning frame is vertically translated from top to bottom, and the difference between the maximum grayscale value and the minimum grayscale value of the pixel grid in the scanning frame is calculated in real time during the vertical translation process and marked as the vertical scanning value. When the scanning frame is vertically translated to the horizontal edge of the normal image, the scanning frame is translated to the right by L2 pixel grids, and then the vertical translation direction of the scanning frame is switched, and so on, until all pixel grids in the normal image have completed the vertical scanning process, and the vertical scanning value of the scanning frame in the vertical scanning process is marked as HP. The maximum value is marked as the longitudinal smoothing value ZP; the smoothing coefficient PH of the normal image is obtained by the formula PH=k1*HP+k2*ZP, where k1 and k2 are both proportional coefficients, and k1>k2>1; the smoothing threshold PHmax is obtained through the storage module, and the smoothing coefficient PH is compared with the smoothing threshold PHmax: if the smoothing coefficient PH is less than the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image meets the requirements; if the smoothing coefficient PH is greater than or equal to the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image does not meet the requirements, and a chromaticity optimization signal is generated and sent to the administrator's mobile phone terminal.

[0037] Example 2: Figure 2 As shown, the present invention also proposes an automatic negative pressure circulation ink supply method for a UV digital printing machine, comprising the following steps:

[0038] Step 1: Detect and analyze ink leakage during the printing process: Mark the product printed by the printing unit as the detection object, capture an image of the printed surface of the detection object, and mark the captured image as the detection image;

[0039] Step 2: Enlarge the inspection image into a pixel grid image and perform grayscale conversion. Retrieve the standard printing image of the corresponding product through the storage module. Compare the inspection image with the standard printing image and determine whether the printing effect of the inspection object meets the requirements based on the comparison results. If the requirements are met, proceed to step 3; otherwise, proceed to step 4.

[0040] Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product that has been printed. Smoothness analysis is necessary for normal images. Smoothness analysis is performed on the normal image to obtain a smoothing coefficient PH of the normal image. The smoothing coefficient PH is used to determine whether the color transition smoothness of the normal image meets the requirements;

[0041] Step 4: Perform abnormal processing analysis on the abnormal image and determine whether the detection object corresponding to the abnormal image has ink leakage and printing deviation.

[0042] The present invention also includes a computer-readable storage medium storing a computer program. When executed by a processor, this program implements the aforementioned method for automatic negative pressure circulation ink supply for a UV digital printing press. Those skilled in the art will appreciate that all or part of the steps in the aforementioned method embodiments can be accomplished using hardware associated with the computer program. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps in the aforementioned method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0043] The terminal of the present invention includes a processor and a memory; the memory is used to store a computer program; the processor is connected to the memory and is used to execute the computer program stored in the memory, thereby enabling the terminal to implement a method for automatic negative pressure circulation ink supply for any UV digital printing machine. Specifically, the memory includes various media capable of storing program code, such as ROM, RAM, a magnetic disk, a USB flash drive, a memory card, or an optical disk.

[0044] Preferably, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0045] When the present invention is in operation, the product printed by the printing unit is marked as a detection object, the printed surface of the detection object is imaged and the image obtained is marked as a detection image;

[0046] Step 2: Enlarge the detection image into a pixel grid image and perform grayscale conversion, retrieve the standard printing image of the corresponding product through the storage module, compare the detection image with the standard printing image, and judge whether the printing effect of the detection object meets the requirements through the comparison result. If the requirements are met, the color transition smoothness of the printed pattern of the product that has completed the printing process is detected and analyzed. Normal images have the necessity of smoothing analysis. The normal image is smoothed and the smoothing coefficient PH of the normal image is obtained. The color transition smoothness of the normal image is judged by the smoothing coefficient PH. If the requirements are not met, the abnormal image is analyzed for abnormal processing and whether the detection object corresponding to the abnormal image has ink leakage and printing deviation.

[0047] The above content is merely an example and explanation of the structure of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

[0048] The above formulas are all obtained by collecting a large amount of data and performing software simulation to obtain a formula that is close to the actual value. The coefficients in the formula are set by those skilled in the art based on actual conditions; for example, in the formula PH = k1*HP + k2*ZP, those skilled in the art collect multiple sets of sample data and set corresponding smoothing coefficients for each set of sample data; the set smoothing coefficients and the collected sample data are substituted into the formula, and any two formulas form a system of linear equations of two variables. The calculated coefficients are screened and averaged, and the values ​​of k1 and k2 are obtained as 2.85 and 2.13, respectively;

[0049] The size of the coefficient is to quantify each parameter to obtain a specific numerical value, which is convenient for subsequent comparison. The size of the coefficient depends on the amount of sample data and the preliminary setting of the corresponding smoothing coefficient for each set of sample data by technical personnel in this field; as long as it does not affect the proportional relationship between the parameter and the quantized value, such as the smoothing coefficient is proportional to the value of the horizontal smoothing value.

[0050] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0051] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An automatic negative pressure circulating ink supply system for a UV digital printing press, characterized in that: It includes a digital printing module, an ink leakage detection module, a chromaticity detection module and a storage module, wherein the digital printing module, the ink leakage detection module, the chromaticity detection module and the storage module are communicatively connected in sequence, and the ink leakage detection module is also communicatively connected to the storage module; The ink leakage detection module is used to detect and analyze ink leakage during the printing process: marking the product printed by the printing unit as a detection object, capturing an image of the printed surface of the detection object and marking the captured image as a detection image, amplifying the detection image into a pixel grid image and performing grayscale conversion, retrieving a standard printing image of the corresponding product through a storage module, comparing the detection image with the standard printing image, and marking the detection image as a normal image or an abnormal image based on the comparison result; and performing abnormal processing analysis on the abnormal image; The color detection module is used to detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process; The specific process of the color detection module to detect and analyze the color transition smoothness of the printed pattern of the product after printing processing includes: obtaining the color requirement value of the normal image and using the color requirement value to determine whether the normal image has the necessity of smooth analysis, and performing smooth analysis on the normal image if it is necessary: ​​setting a color requirement value in the upper left corner of the normal image. Specifications of the scanning frame, The shape of the scan frame is a rectangular frame with a length of L1 pixels and a width of L2 pixels; Perform horizontal scanning on the scanning frame and obtain the horizontal smoothing value HP; perform vertical scanning on the scanning frame and obtain the vertical smoothing value ZP; Obtain a smoothing coefficient PH of the normal image, where k1 and k2 are both proportional coefficients, and k1>k2>1; obtain a smoothing threshold PHmax through a storage module, and compare the smoothing coefficient PH with the smoothing threshold PHmax: if the smoothing coefficient PH is less than the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image meets the requirements; if the smoothing coefficient PH is greater than or equal to the smoothing threshold PHmax, it is determined that the color transition smoothness of the normal image does not meet the requirements, generate a chroma optimization signal, and send the chroma optimization signal to the administrator's mobile phone terminal; The specific process of determining whether a normal image is necessary for smoothing analysis includes: marking the difference between the maximum grayscale value and the minimum grayscale value of all pixels in the normal image as the color requirement value of the normal image, obtaining the color requirement threshold through the storage module, and comparing the color requirement value with the color requirement threshold: if the color requirement value is less than the color requirement threshold, it is determined that the normal image is not necessary for smoothing analysis; if the color requirement value is greater than or equal to the color requirement threshold, it is determined that the normal image is necessary for smoothing analysis; The specific process of performing horizontal scanning processing on the scanning frame includes: horizontally translating the scanning frame from left to right, calculating the difference between the maximum grayscale value and the minimum grayscale value of the pixel grids in the scanning frame in real time during the horizontal translation process and marking it as the horizontal scanning value of the scanning frame; when the scanning frame is horizontally translated to the longitudinal edge of the normal image, the scanning frame is translated downward by L1 pixel grids, and then the horizontal translation direction of the scanning frame is switched, and so on, until all pixel grids in the normal image have completed the horizontal scanning processing, and the maximum horizontal scanning value of the scanning frame in the horizontal scanning processing is marked as the horizontal smoothing value HP; The scanning frame is translated vertically from top to bottom. During the vertical translation process, the difference between the maximum grayscale value and the minimum grayscale value of the pixel grid in the scanning frame is calculated in real time and marked as the vertical scanning value. When the scanning frame is translated vertically to the horizontal edge of the normal image, the scanning frame is translated to the right by L2 pixel grids, and then the vertical translation direction of the scanning frame is switched. This process is repeated until all pixel grids in the normal image have completed the vertical scanning process. The maximum vertical scanning value of the scanning frame in the vertical scanning process is marked as the vertical smoothing value ZP.

2. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 1, characterized in that: The digital printing module includes an ink supply unit, an ink return unit and a printing unit. The ink supply unit is used to control the ink supply to the printing unit, the ink return unit is used to control the ink reflux, and the printing unit includes a print head for printing, which adopts a dual negative pressure print head.

3. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 2, characterized in that: The specific process of comparing the detection image with the standard printed image includes: using a binary method to extract and segment the printed area in the detection image and the printed area in the standard printed image and mark them as detection area and standard area respectively, performing overlap comparison on the detection area and the standard area and marking the maximum value of the overlapping area between the detection area and the standard area as the compliance value, marking the ratio of the compliance value to the area value of the detection area as the compliance coefficient of the detection image, obtaining the compliance threshold through the storage module, and comparing the compliance coefficient with the compliance threshold: if the compliance coefficient is greater than or equal to the compliance threshold, it is determined that the printing effect of the detection image corresponding to the detection object meets the requirements, the corresponding detection image is marked as a normal image, and the normal image is sent to the chromaticity detection module; if the compliance coefficient is less than the compliance threshold, it is determined that the printing effect of the detection image corresponding to the detection object does not meet the requirements, and the corresponding detection image is marked as an abnormal image.

4. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 3, characterized in that: The specific process of abnormal processing analysis of abnormal images includes: overlapping the abnormal image with the standard printed image and placing them in a grid diagram of the same rectangular coordinate system, the grids in the grid diagram correspond to the pixel grids, and marking the grids in the grid diagram of the rectangular coordinate system as re-qualified, deviation grids or blank grids; forming a deviation combination from the deviation grids that contact each other, and determining whether there is a re-qualified image among the grids that contact the deviation grids at the edge of the deviation combination: if so, determining that the detection object corresponding to the abnormal image has a printing deviation phenomenon, generating a pressure difference adjustment signal and sending the pressure difference adjustment signal to the administrator's mobile phone terminal; if not, determining that the detection object corresponding to the abnormal image has an ink leakage phenomenon, generating an ink leakage processing signal and sending the ink leakage processing signal to the administrator's mobile phone terminal.

5. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 4, characterized in that: The specific process of marking squares as re-qualified, deviation squares or blank squares includes: marking squares whose corresponding two pixel grids are respectively located in the detection area and the standard area as re-qualified; marking squares whose corresponding two pixel grids are not located in the detection area and the standard area as blank squares; and marking the remaining squares as deviation squares.

6. A UV digital printing machine automatic negative pressure circulation ink supply method, characterized in that: The automatic negative pressure circulating ink supply system for a UV digital printing machine as claimed in any one of claims 1 to 5 comprises the following steps: Step 1: Detect and analyze ink leakage during the printing process and mark the inspection image of the completed printed product; Step 2: Determine whether the printing effect of the inspection object meets the requirements. If it meets the requirements, proceed to step 3; if it does not meet the requirements, proceed to step 4; Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product after printing; Step 4: Determine whether the detection object corresponding to the abnormal image has ink leakage and printing deviation.

7. A computer storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the automatic negative pressure circulating ink supply method for a UV digital printing machine described in claim 6 is implemented.

8. A computer device, characterized in that: include: processor and memory; The memory stores a computer program, and the processor executes the computer program stored in the memory to enable the computer device to execute the automatic negative pressure circulation ink supply method for a UV digital printing machine according to claim 6.

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