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

Abstract

The invention belongs to the field of UV digital printing, and relates to a data analysis technology, in particular to an automatic negative-pressure circulating ink supply system and method for a UV digital printing machine and a medium, comprising 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 sequentially in communication connection, and the ink leakage detection module is further in communication connection with the storage module; according to the method, the printing effect in the printing process can be detected and analyzed, a detection image of a printed product is compared with a standard printing image, the printing effect is evaluated according to the comparison result, and different processing means are adopted to perform secondary processing on the detection image according to the evaluation result of the printing effect, so that the printing quality is improved. And the printing effect is timely fed back when being abnormal, so that subsequent products are prevented from being printed under the condition that the UV digital printing machine operates abnormally.

Description

Technical Field

[0001] The invention belongs to the field of UV digital printing, relates to data analysis technology, and specifically is an automatic negative pressure circulation 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. This system ensures the stable supply and recovery of ink through precise control and adjustment, improves printing quality and efficiency, and ensures the continuity of production.

[0003] The UV digital printing machine in the prior art does not have the function of detecting the printing effect of the finished products. The detection process is performed uniformly after a batch of products has completed printing processing. 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, so as 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 circulation ink supply system, method and medium for a UV digital printing machine which can provide timely feedback when the printing effect is abnormal.

[0006] The object of the present invention can be achieved by the following technical scheme: 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 sequentially connected in communication, and the ink leakage detection module is also connected in communication with the storage module;

[0007] The ink leakage detection module is used to detect and analyze the ink leakage phenomenon during the printing process: marking the product printed by the printing unit as the detection object, taking an image of the printed surface of the detection object and marking the captured image as the detection image, enlarging the detection image into a pixel grid image and performing grayscale conversion, calling the standard printing image of the corresponding product through the 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; performing abnormal processing analysis on the abnormal image;

[0008] 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.

[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 areas and standard areas respectively, comparing the detection area with the standard area for overlap and marking the maximum value of the overlap 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; a deviation combination is formed by the deviation grids that contact each other, and it is determined whether there is a re-qualified image in the grids that contact the deviation grids at the edge of the deviation combination: if so, it is determined that the detection 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 detection 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.

[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 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 the smoothing analysis is necessary: ​​setting a scanning frame of L1*L2 specification 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, wherein 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 needs 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 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.

[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, 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 maximum value of the 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 for a UV digital printing machine, and comprises the following steps:

[0018] Step 1: Detect and analyze the ink leakage phenomenon during the printing process: mark the product printed by the printing unit as the detection object, capture the 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 through the comparison result. If the requirements are met, execute step 3; if not, execute step 4;

[0020] Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process. Normal images need smoothing analysis. The normal images are smoothed and analyzed to obtain the smoothing coefficient PH of the normal images. The smoothing coefficient PH is used to determine whether the color transition smoothness of the normal images 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 circulation ink supply method for a UV digital printing machine.

[0023] 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, so that the computer device executes an automatic negative pressure circulation ink supply method for a 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, the 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 circulating ink volume of the print head is effectively and steadily controlled by the vacuum degree difference at both ends of the print head, realizing dynamic printing, which has strong adaptability.

[0026] 2. The ink leakage detection module can detect and analyze the printing effect during the printing process, compare the detection image of the completed printed product with the standard printing image, evaluate the printing effect through the comparison result, and take different processing methods to perform secondary processing on the detection image according to the evaluation result of the printing effect. In addition, timely feedback is given when the printing effect is abnormal, so as to avoid the subsequent products from being printed when the UV digital printing machine is running abnormally, and reduce the scrap rate of the printing production line;

[0027] 3. By performing abnormal processing analysis on abnormal images, the abnormal printing effect features of 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 UV digital printing machines;

[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 according to 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, and timely feedback and optimization can be performed when the color transition smoothness is abnormal. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0030] Figure 1 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 solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1: Figure 1 As shown, an automatic negative pressure circulating 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 by means of the flow difference of the dual ink pumps. The circulating ink volume of the print head is effectively and smoothly controlled by the vacuum degree difference at both ends of the print head, realizing dynamic printing, and having strong adaptability.

[0035] The ink leakage detection module is used to detect and analyze the ink leakage phenomenon during the printing process: mark the product printed by the printing unit as the detection object, capture the image of the printed surface of the detection object and mark the captured image as the detection image, 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, and compare the detection image with the standard printing image: use the binary method to extract and segment the printing area in the detection image and the printing area in the standard printing image and mark them as the detection area and the standard area respectively, compare the detection area with the standard area for overlap and mark the maximum value of the overlap area between the detection area and the standard area as the compliance value, mark the ratio of the compliance value to the area value of the detection area as the compliance coefficient of the detection image, obtain the compliance threshold through the storage module, and compare 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, and 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 detection image meets the requirements, and the corresponding detection image is marked as a normal image, and the normal image is sent to the chromaticity detection module; If the printing effect of the test object corresponding to the measured image does not meet the requirements, the corresponding test image is marked as an abnormal image, and the abnormal image is subjected to abnormal processing analysis: the abnormal image is overlapped with the standard printed image and placed in a grid diagram of the same rectangular coordinate system, the grids in the grid diagram correspond to the pixel grids, and then the grids corresponding to the two pixel grids 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 corresponding to the two pixel grids 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 two hundred and fifty-five; the remaining grids are marked as deviation grids, and the grayscale value of the deviation grid is set to one hundred and twenty-eight; the deviation grids that contact each other form a deviation combination, and it is determined whether there is a re-qualified grid in 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, and the color requirement threshold is obtained through the storage module. 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 management personnel. Perform horizontal scanning on the scanning frame: translate the scanning frame 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 longitudinal 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, and so on, until all the images in the normal image are After all pixels have completed the horizontal scanning process, 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 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 mobile phone terminal of the administrator.

[0037] Embodiment 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 the ink leakage phenomenon during the printing process: mark the product printed by the printing unit as the detection object, capture the 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 through the comparison result. If the requirements are met, execute step 3; if not, execute step 4;

[0040] Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process. Normal images need smoothing analysis. The normal images are smoothed and analyzed to obtain the smoothing coefficient PH of the normal images. The smoothing coefficient PH is used to determine whether the color transition smoothness of the normal images 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 readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned UV digital printing machine automatic negative pressure circulation ink supply method is realized. A person skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to the computer program. The aforementioned computer program can be stored in a computer readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[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, so that the terminal executes any UV digital printing machine automatic negative pressure circulation ink supply method. Specifically, the memory includes: ROM, RAM, disk, U disk, memory card or CD and other media that can store program codes.

[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 gates or transistor logic devices, discrete hardware components.

[0045] When the present invention is working, 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. Smoothing analysis is performed on the normal image and the smoothing coefficient PH of the normal image is obtained. Whether the color transition smoothness of the normal image meets the requirements is judged by the smoothing coefficient PH; if the requirements are not met, abnormal processing analysis is performed on the abnormal image and it is judged whether there is ink leakage and printing deviation in the detection object corresponding to the abnormal image.

[0047] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described 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 protection scope of the present invention.

[0048] The above formulas are obtained by collecting a large amount of data for software simulation and selecting a formula close to the real value. The coefficients in the formula are set by technicians in this field according to the actual situation; for example: formula PH = k1*HP + k2*ZP; technicians in this field collect multiple groups of sample data and set corresponding smoothing coefficients for each group of sample data; substitute the set smoothing coefficients and the collected sample data into the formula, any two formulas constitute a set of two-variable linear equations, screen the calculated coefficients and take the average, and obtain the values ​​of k1 and k2 as 2.85 and 2.13 respectively;

[0049] The size of the coefficient is to quantify each parameter to obtain a specific value for subsequent comparison. The size of the coefficient depends on the amount of sample data and the initial 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] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. 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 machine, 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 with the storage module; The ink leakage detection module is used to detect and analyze the ink leakage phenomenon during the printing process: marking the product printed by the printing unit as the detection object, capturing the image of the printed surface of the detection object and marking the captured image as the detection image, amplifying the detection image into a pixel grid image and performing grayscale conversion, retrieving the standard printing image of the corresponding product through the 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; Perform abnormal processing analysis on abnormal images; 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.

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, and the print head adopts a double negative pressure print head.

3. The automatic negative pressure circulating ink supply system for a UV digital printing machine 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 areas and standard areas respectively, comparing the detection area with the standard area for overlap and marking the maximum value of the overlap 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.

4. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 3 is 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; a deviation combination is formed by the deviation grids that contact each other, and it is determined whether there is a re-qualified in the grids that contact the deviation grids at the edge of the deviation combination: if so, it is determined that the detection 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 detection 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.

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; marking the remaining squares as deviation squares.

6. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 5, characterized in that: The specific process of the chromaticity detection module 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 there is the necessity of smoothing analysis: setting a scanning frame of L1*L2 specification in the upper left corner of the normal image, where L1*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; 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. value ZP; the smoothing coefficient PH of the normal image is obtained by the formula PH=k1*HP+k2*ZP, wherein 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 requirement; 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 requirement, and a chromaticity optimization signal is generated and sent to the mobile phone terminal of the administrator.

7. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 6, characterized in that: The specific process of determining whether a normal image needs 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 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.

8. The automatic negative pressure circulating ink supply system for a UV digital printing press according to claim 7, characterized in that: 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.

9. The automatic negative pressure circulating ink supply system for a UV digital printing machine according to claim 8, characterized in that: 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, and so on, until all pixel grids in the normal image have completed the vertical scanning process. The maximum value of the vertical scanning value of the scanning frame in the vertical scanning process is marked as the vertical smoothing value ZP.

10. A method for automatic negative pressure circulation ink supply for a UV digital printing machine, 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 9 comprises the following steps: Step 1: Detect and analyze ink leakage during the printing process and mark the detection 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, execute step 3; if it does not meet the requirements, execute step 4; Step 3: Detect and analyze the color transition smoothness of the printed pattern of the product that has completed the printing process; Step 4: Determine whether the detection object corresponding to the abnormal image has ink leakage and printing deviation.

11. 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 circulation ink supply method for a UV digital printing machine described in claim 10 is implemented.

12. 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 so that the computer device executes the automatic negative pressure circulation ink supply method for a UV digital printing machine as claimed in claim 10.

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