Large-scale intelligent printing press and printing correction method for large-scale intelligent printing press

Abstract

The present application provides a large-scale intelligent printing machine and a printing correction method for a large-scale intelligent printing machine. The method can collect the reflected light intensity of different ink samples; perform feature conversion based on the fluctuation characteristics of the reflected light intensity of each ink sample to obtain multiple optical characteristic values, and divide multiple printing color intervals based on each optical characteristic value; then perform a primary ratio matching on the content of each ink during printing to obtain a primary ratio value for each ink; identify multiple characteristic bands of the target printed object, determine the reference energy distribution under each characteristic band, determine the diffusion ratio based on all the reference energy distributions, and adaptively correct the primary ratio values ​​of various inks during printing based on the diffusion ratio to obtain secondary ratio values ​​for various inks; and control the ejection volume of each ink based on each secondary ratio value. Using the solution of the present application, the optimal ink ratio of the target printed object can be adjusted when the spectral reflectance characteristics of the ink sample change.

Description

Technical Field

[0001] The present application relates to the field of industrial printing control technology, and more specifically, to a large-scale intelligent printing press and a printing correction method for the large-scale intelligent printing press. Background Art

[0002] Industrial printing control is a highly complex technology that integrates mechanics, electrical engineering, computer image processing, and automated control. Its core goal is to ensure that the color, pattern, and material accuracy of the printing process meet strict quality standards while maximizing production efficiency. To achieve high-quality printing, the industrial printing control system will accurately analyze the color and image before printing, and implement dynamic monitoring and adjustment during the printing process to ensure that every detail of industrial printing reaches the optimal level, thereby achieving high-quality and stable mass production.

[0003] Print correction for large-scale intelligent printing presses is a crucial step in the industrial printing process. It aims to adjust printing parameters in real time through automated and intelligent means to ensure stable and consistent print quality. This technology combines advanced intelligent sensors, real-time machine data analysis, and automated machine control systems to precisely adjust various variables in the industrial printing process, significantly reducing color difference, improving printing accuracy, and adapting to changing production environments. Existing print correction technology for large-scale intelligent printing presses divides the printed color gamut composed of ink samples into multiple subspaces. The subspace affiliation of the target spectrum is determined by the distance between the target spectrum of the target print and the characteristic spectrum of each subspace. The optimal ink ratio is then determined based on the inverse solution of the characteristic band and the full band to achieve print color difference correction. However, mixing various inks according to the obtained optimal ink ratio causes changes in the spectral reflectance characteristics of the ink samples, which in turn affects the accuracy of the characteristic band and causes color difference in intelligent printing. Therefore, how to adjust the optimal ink ratio for the target print when the spectral reflectance characteristics of the ink samples change has become a difficult problem facing the industry. Summary of the Invention

[0004] The present application provides a large-scale intelligent printing press and a printing correction method for the large-scale intelligent printing press, which can adjust the optimal ink ratio of a target printed object when the spectral reflectance characteristics of an ink sample change.

[0005] In a first aspect, the present application provides a printing correction method for a large-scale intelligent printing press, wherein the large-scale intelligent printing press includes a sensing system, a control system, and a printing end effector. The method includes the following steps:

[0006] The sensing system collects the reflected light intensity of different ink samples in each visible light band;

[0007] The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values;

[0008] The control system also performs primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains a primary matching value for each ink;

[0009] The sensing system automatically identifies multiple characteristic bands of reflected light from a target printed object during printing, determines a reference energy distribution of the reflected light in each characteristic band, determines a diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing using the diffusion ratio to obtain secondary ratio values ​​of various inks;

[0010] The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0011] In some embodiments, the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain a plurality of optical characteristic values, specifically including:

[0012] Determine the fluctuation characteristics of the reflected light intensity of various ink samples across all visible light bands;

[0013] Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples;

[0014] The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

[0015] In some embodiments, dividing the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values ​​specifically includes:

[0016] Constructing color feature vectors of various ink samples based on the respective optical feature values;

[0017] Determining the degree of vector proximity between color feature vectors of various ink samples;

[0018] The printing color gamut formed by all ink samples is divided into multiple printing color intervals according to the approximation of all vectors.

[0019] In some embodiments, the control system performs a primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains the primary matching value of each ink specifically including:

[0020] Determine the center spectral vector of each printed color interval;

[0021] Obtaining the color spectrum vector of the target printed object;

[0022] determining the spectral similarity between the color of the target printed object and each printed color interval based on the central spectral vector of each printed color interval and the color spectral vector of the target printed object;

[0023] Determine the optimal color range of the target printed object based on all spectral similarities;

[0024] Setting an optimal matching function for all inks based on the optimal color range;

[0025] The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value for each ink.

[0026] In some embodiments, determining the reference energy distribution of reflected light in each characteristic wavelength band specifically includes:

[0027] Obtain the reflected light intensity of each ink in each characteristic band;

[0028] Determine the reflected composite light intensity of the target printed object in each characteristic band according to the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic band;

[0029] The reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band.

[0030] In some embodiments, determining the diffusion ratio of the energy distribution after ink mixing according to all reference energy distributions specifically includes:

[0031] Determine the energy distribution diffusion model through all reference energy distributions;

[0032] The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

[0033] In some embodiments, adaptively correcting the primary ratio values ​​of various inks during printing by using the diffusion ratio to obtain the secondary ratio values ​​of various inks specifically includes:

[0034] Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted;

[0035] Determining a compensation ratio value of each ink according to the diffusion ratio and the offset characteristic band;

[0036] Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected to obtain the secondary ratio values ​​of various inks.

[0037] In the second aspect, the present application provides a large-scale intelligent printing machine, including a sensing system, a control system, and a printing end effector, wherein

[0038] The sensing system collects the reflected light intensity of different ink samples in each visible light band;

[0039] The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values;

[0040] The control system also performs primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains a primary matching value for each ink;

[0041] The sensing system automatically identifies multiple characteristic bands of reflected light from a target printed object during printing, determines a reference energy distribution of the reflected light in each characteristic band, determines a diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing using the diffusion ratio to obtain secondary ratio values ​​of various inks;

[0042] The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0043] In a third aspect, the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned printing correction method for a large-scale intelligent printing press when executing the computer program.

[0044] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-mentioned printing correction method for a large-scale intelligent printing press.

[0045] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects:

[0046] In the large-scale intelligent printing machine and the printing correction method for a large-scale intelligent printing machine provided in the present application, the perception system collects the reflected light intensity of different ink samples in various visible light bands; the control system performs characteristic conversion on all reflected light intensities based on the fluctuation characteristics of the reflected light intensity of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on the various optical characteristic values; the control system also performs a primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printing color interval to obtain a primary matching value for each ink; the perception system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the inks are mixed based on all the reference energy distributions, and adaptively corrects the primary matching values ​​of various inks during printing based on the diffusion ratio to obtain secondary matching values ​​for various inks; the printing end effector controls the injection amount of each ink according to each secondary matching value.

[0047] It can be seen that in the present application, first, after collecting the reflected light intensity of different ink samples in each visible light band, a plurality of printing color intervals are divided based on the reflected light intensity corresponding to each ink sample. Then, the primary matching ratio value of each ink when printing the target printed object is determined according to the spectral similarity between the color of the target printed object and each printing color interval. The inks are mixed according to all the primary matching ratio values. Then, the positions of those wavelengths that best represent the color characteristics, differences or changes in the spectral data of the target printed object are identified, namely: characteristic bands. Then, in each characteristic band, the comparison between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the ink mixing is determined, namely: reference energy distribution. Then, the color performance after the ink mixing is determined according to all reference energy distributions. The difference between the colors of the target printed objects, that is, the diffusion ratio. Finally, the primary ratio values ​​of various inks during intelligent printing are adaptively corrected by the diffusion ratio to obtain the secondary ratio values ​​of various inks; the ejection volume of each ink in the special intelligent printing machine is controlled according to each secondary ratio value; the present application uses the difference between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the ink mixing as a reference (reference energy distribution), thereby judging the difference between the color performance after the ink mixing and the color of the target printed object (diffusion ratio), and then adjusting the ejection volume of each ink in the large-scale intelligent printing machine according to the degree of difference; in summary, the present application can adjust the optimal ink ratio of the target printed object when the spectral reflectance characteristics of the ink sample change. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1is a flow chart of a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application;

[0049] Figure 2 is a schematic diagram of a process for dividing printing color intervals according to some embodiments of the present application;

[0050] Figure 3 is a schematic diagram of a process for determining a reference energy distribution according to some embodiments of the present application;

[0051] Figure 4 is a schematic structural diagram of a large-scale intelligent printing machine according to some embodiments of the present application;

[0052] Figure 5 It is a diagram of the internal structure of a computer device for implementing a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application. DETAILED DESCRIPTION

[0053] In order to better understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0054] refer to Figure 1 , which is a flow chart of a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application. The printing correction method 100 for a large-scale intelligent printing press mainly includes the following steps:

[0055] In step 101, the sensing system collects the reflected light intensity of different ink samples in various visible light bands.

[0056] In specific implementation, the ink can be mixed with a transparent diluent in a specific proportion (for example, 0.1, 0.2, 0.3, 0.4, 0.5) to obtain ink samples with different ratios. The mixed ink samples are then evenly coated on a standardized sample plate or paper to ensure consistent coating thickness. Light of a predetermined band (multiple visible light bands) is then emitted through the sensing system, and the light intensity reflected by the ink sample is measured to obtain the reflected light intensity of the ink samples in each visible light band under different ratios.

[0057] It should be noted that the perception system described in this application may use a spectrophotometer. The spectrophotometer has a stable light source, usually a tungsten halogen lamp or a xenon lamp, and can emit all bands of the visible light range (380nm to 780nm). When measuring the reflected light intensity, the spectrophotometer uses the different structures of ink samples with different ratios and their different absorption capabilities for light in different bands. That is, by separating each monochromatic light from the mixed light containing various wavelengths and measuring its intensity, the reflected light intensity of the ink sample can be obtained.

[0058] In step 102, the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on the various optical characteristic values.

[0059] It should be noted that the ink sample has a corresponding reflected light intensity in each visible light band, that is, one ink sample corresponds to multiple reflected light intensities. Therefore, in some embodiments, the control system performs characteristic conversion on all reflected light intensities based on the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values. This can be achieved by the following steps:

[0060] Determine the fluctuation characteristics of the reflected light intensity of various ink samples across all visible light bands;

[0061] Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples;

[0062] The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

[0063] It should be noted that the fluctuation characteristic represents the fluctuation amplitude of the light intensity of the ink sample in the visible light band as the wavelength changes, reflecting the variability of the reflected light intensity of the corresponding ink sample at different wavelengths. The larger the fluctuation characteristic, the higher the variability of the reflected light intensity of the corresponding ink sample at different wavelengths, which means that the greater the change in the reflected light intensity of the ink sample at different wavelengths, the less smooth the spectral reflection curve. The smaller the fluctuation characteristic, the lower the variability of the reflected light intensity of the corresponding ink sample at different wavelengths, which means that the spectral reflection curve of the corresponding ink sample is relatively smooth and the change in reflected light intensity at different wavelengths is small. In specific implementation, determining the fluctuation characteristics of the reflected light intensity of various ink samples in all visible light bands can be achieved in the following way, that is, taking the standard deviation of all reflected light intensities corresponding to various ink samples as the fluctuation characteristics of the reflected light intensity of the ink sample in all visible light bands. In other embodiments, it can also be determined by other methods, which are not limited here.

[0064] In specific implementation, the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample is determined according to the fluctuation characteristics corresponding to various ink samples. This can be achieved in the following manner: first, an ink sample is selected as the selected ink sample, and then the average value of the reflected light intensity corresponding to the selected ink sample is determined. Secondly, a reflected light intensity is selected, and the average value is subtracted from the reflected light intensity and then divided by the value of the fluctuation characteristic as the light intensity fluctuation ratio of the reflected light intensity. The above steps are repeated to determine the light intensity fluctuation ratios of the remaining reflected light intensities, thereby obtaining the light intensity fluctuation ratio of each reflected light intensity corresponding to the selected ink sample, and the light intensity fluctuation ratios of the reflected light intensities corresponding to the remaining ink samples are continued to be determined.

[0065] It should be noted that the light intensity fluctuation ratio described in this application represents the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity, and is used to quantitatively evaluate the deviation of the reflected light intensity of the ink sample in a specific band from its overall performance. The larger the light intensity fluctuation ratio, the higher the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity, and the smaller the light intensity fluctuation ratio, the lower the degree of deviation of the corresponding reflected light intensity from the average reflected light intensity.

[0066] In a specific implementation, the fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical eigenvalues ​​by all light intensity fluctuation ratios. This can be achieved in the following manner: first, all light intensity fluctuation ratios corresponding to various ink samples are combined into a light intensity fluctuation matrix. Then, the covariance matrix of the light intensity fluctuation matrix is ​​determined. Secondly, the eigenvalue decomposition algorithm in the prior art is used to perform eigenvalue decomposition on the covariance matrix to obtain multiple eigenvalues ​​and eigenvectors corresponding to each eigenvalue, and all eigenvalues ​​are used as the optical eigenvalues ​​in this application, thereby obtaining multiple optical eigenvalues. In other embodiments, other methods can also be used for determination, which are not limited here. In addition, it should be noted that the optical eigenvalue is the main feature of the corresponding ink sample, which characterizes the contribution of the main feature to the reflected light intensity of all ink samples. The larger the optical eigenvalue, the higher the contribution of the main feature to the reflected light intensity of all ink samples. The smaller the optical eigenvalue, the lower the contribution of the main feature to the reflected light intensity of all ink samples.

[0067] In some embodiments, reference Figure 2 As shown in FIG, this figure is a schematic diagram of a process for dividing printing color intervals according to some embodiments of the present application. Dividing the printing color gamut composed of all ink samples into multiple printing color intervals based on various optical characteristic values ​​can be achieved by using the following steps:

[0068] First, in step 1021 , color feature vectors of various ink samples are constructed based on the respective optical feature values;

[0069] Then, in 1022, the vector closeness between the color feature vectors of various ink samples is determined;

[0070] Finally, in step 1023 , the printing color gamut formed by all ink samples is divided into a plurality of printing color intervals according to the approximation of all vectors.

[0071] It should be noted that, in the present application, when determining the optical characteristic values, each optical characteristic value has a unique corresponding characteristic vector. Therefore, in a specific implementation, the color characteristic vectors of various ink samples can be constructed based on the respective optical characteristic values ​​in the following manner: first, the first two largest optical characteristic values ​​are obtained from all the optical characteristic values; then, the characteristic vectors corresponding to these two optical characteristic values ​​are obtained, and the elements in these two characteristic vectors are used as a column in a matrix to form a characteristic vector matrix; then, the characteristic vector matrix is ​​multiplied by the light intensity fluctuation matrix to obtain a color characteristic matrix; finally, the vector composed of the matrix elements in each row of the color characteristic matrix is ​​used as the color characteristic vector of the corresponding ink sample, thereby obtaining the color characteristic vectors of various ink samples. In other embodiments, other methods can be used for determination, which are not limited here. In addition, as a preferred embodiment, the vector closeness between the color characteristic vectors of various ink samples can be determined in the following manner, namely, the cosine similarity between vectors in the prior art is used as the vector closeness between the color characteristic vectors of various ink samples in the present application, thereby obtaining the vector closeness between the color characteristic vectors of various ink samples. In other embodiments, other methods can be used for determination, which are not repeated here.

[0072] It should be noted that the color feature vector is a mathematical representation of the spectral reflectance characteristics of the ink sample after eigenvalue decomposition, which contains the color information of the ink sample and reflects the main color change trend of the ink sample under different spectral characteristics. The larger the vector element in the color feature vector, the more significant the performance of the ink sample in a specific optical feature dimension (such as color, reflectivity, etc.); the smaller the vector element in the color feature vector, the less significant the performance of the ink sample in a specific optical feature dimension (such as color, reflectivity, etc.); in addition, the vector closeness characterizes the color similarity of the two corresponding ink samples. The larger the vector closeness, the higher the color similarity of the two corresponding ink samples, and the smaller the vector closeness, the lower the color similarity of the two corresponding ink samples.

[0073] In specific implementation, the printing color gamut composed of all ink samples is divided into multiple printing color intervals based on all vector proximity. This can be achieved in the following manner: first, all vector proximity is used as a similarity index between every two ink samples. Then, all vector proximity is used as input, and the K-means clustering algorithm in the prior art is used to classify all ink samples into multiple ink sample clusters. At random, the printing color gamut composed of all ink samples is obtained. Finally, an ink sample cluster is selected, and the color intervals represented by various ink samples in the printing color gamut in the ink sample cluster are obtained. The union of all color intervals is used as the printing color interval corresponding to the ink sample cluster. The above steps are repeated to determine the printing color intervals corresponding to the remaining ink sample clusters, thereby dividing the printing color gamut composed of all ink samples into multiple printing color intervals. In other embodiments, other methods can also be used for determination, which is not limited here.

[0074] It should be noted that the printing color interval refers to the color range that the corresponding ink sample cluster can express in the printing color gamut composed of all ink samples. The larger the printing color interval, the wider the color variation that the ink sample cluster can express, that is, it has better mixing ability and can cover more printing colors. The smaller the printing color interval, the more limited the color range that the ink sample cluster expresses, that is, it is used for more specific color scenes.

[0075] In step 103, the control system further performs primary matching on the content of various inks during printing according to the spectral similarity between the color of the target printed object and each printed color interval, and obtains a primary matching value of each ink.

[0076] In some embodiments, the control system performs a primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval. The primary matching value of each ink can be obtained by the following steps:

[0077] Determine the center spectral vector of each printed color interval;

[0078] Obtaining the color spectrum vector of the target printed object;

[0079] determining the spectral similarity between the color of the target printed object and each printed color interval based on the central spectral vector of each printed color interval and the color spectral vector of the target printed object;

[0080] Determine the optimal color range of the target printed object based on all spectral similarities;

[0081] Setting an optimal matching function for all inks based on the optimal color range;

[0082] The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value for each ink.

[0083] It should be noted that the central spectral vector described in this application represents the representative spectral distribution of the printed color interval, and characterizes the reflectance characteristics of the corresponding color interval in different bands; in specific implementation, the central spectral vector of each printed color interval can be determined in the following manner, namely: first, select a printed color interval, then obtain multiple ink samples corresponding to the printed color interval, and sort each spectral value in the spectral data of the various ink samples in the order of the size of the corresponding band to form the spectral vectors of the various ink samples; secondly, select a band, obtain the spectral values ​​of the various ink samples in the band, and take the average value of the spectral values ​​of the various ink samples in the band as the central spectral value of the printed color interval in the band, repeat the above steps to determine the central spectral value of the printed color interval in the remaining bands, and finally, sort all the central spectral values ​​in the order of the size of the corresponding bands as vector elements to obtain the central spectral vector of the printed color interval, and repeat the above steps to determine the central spectral vector of the remaining printed color intervals.

[0084] It should be noted that, in this application, after measuring the reflected light intensity of the target printed matter in each visible light band by a spectrophotometer, a vector composed of all reflected light intensities sorted according to the size of the corresponding band is used as the color spectrum vector of the target printed matter. In other embodiments, other methods can also be used to determine the color spectrum vector, which is not limited here.

[0085] In a specific implementation, determining the spectral similarity between the color of the target printed object and each printed color interval based on the central spectral vector of each printed color interval and the color spectral vector of the target printed object can be achieved in the following manner, namely: first, selecting a printed color interval as the selected printed color interval, then obtaining the central spectral vector of the printed color interval, secondly determining the square of the difference between the spectral values ​​of the central spectral vector and the color spectral vector in each band, then adding the results corresponding to each band and taking the square root of the sum as the spectral similarity between the color of the target printed object and the selected printed color interval, and continuing to determine the spectral similarity between the color of the target printed object and the remaining printed color intervals; as a preferred embodiment, determining the optimal color interval of the target printed object based on all spectral similarities can be achieved in the following manner, namely: taking the printed color interval with the greatest spectral similarity to the color of the target printed object as the optimal color interval of the target printed object. In other embodiments, other methods can also be used for determination, which are not limited here.

[0086] It should be noted that the spectral similarity reflects the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval. The greater the spectral similarity, the higher the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval. The smaller the spectral similarity, the lower the degree of similarity between the color spectrum vector of the target printed object and the central spectrum vector of the corresponding printed color interval.

[0087] In specific implementation, setting the optimal matching function for all inks based on the optimal color interval can be achieved in the following manner, namely: the objective function of minimizing the difference between the spectral vector after the ink sample is mixed and the central spectral vector of the optimal color interval is used as the optimal matching function in this application. As a preferred embodiment, the error function that minimizes the sum of squares of the errors between the target spectrum and the mixed spectra of all inks can be used as the optimal matching function in this application. In other embodiments, other methods can be used to determine it, which is not limited here. In addition, as a preferred embodiment, determining the content of all inks during printing by the optimal matching function to obtain the primary matching value of each ink can be achieved in the following manner, namely: after derivatizing the optimal matching function and setting the derivative result to 0, the closed-form solution of the least squares method in the prior art is used to solve the matching values ​​corresponding to various inks when the difference between the spectral vector after the ink sample is mixed and the central spectral vector of the optimal color interval is minimized, and the matching values ​​corresponding to various inks are used as the primary matching values ​​of the corresponding inks during printing, thereby obtaining the primary matching value of each ink. In other embodiments, other methods can be used to determine it, which is not limited here.

[0088] It should be noted that the optimal matching function is an objective function for calculating the mixing ratio of all ink samples. The goal of the optimal matching function is to make the spectral vector of the mixed ink samples match the central spectral vector of the optimal color interval as much as possible, that is, to minimize the spectral difference between the two. By optimizing the optimal matching function, the present application can determine the optimal ink matching ratio, thereby achieving a result that is closest to the target printed color. In addition, the primary matching value is the content ratio of various inks that should be used in the printing process calculated based on the optimal matching function. The larger the primary matching value, the higher the content ratio of the corresponding ink that should be used in the printing process, and the smaller the primary matching value, the lower the content ratio of the corresponding ink that should be used in the printing process.

[0089] In step 104, the sensing system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the ink is mixed based on all the reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing through the diffusion ratio to obtain secondary ratio values ​​of various inks.

[0090] In specific implementation, the characteristic band refers to the position of those wavelengths in the spectral data of the target printed object that best represent the color characteristics, differences or changes. In some preferred embodiments, after the spectral data of the target printed object is constructed into a spectral curve, the bands corresponding to the inflection points of the spectral curve (i.e., the positions where the slope of the curve changes the most) are obtained as multiple characteristic bands of the target printed object, thereby automatically identifying multiple characteristic bands of the reflected light when the target printed object is printed. In other embodiments, other methods can also be used for determination, which is not limited here. In addition, the characteristic band belongs to the visible light band, that is, each ink has a unique corresponding reflected light intensity under the characteristic band.

[0091] In some embodiments, reference Figure 3 As shown in FIG, this figure is a schematic diagram of a process for determining a reference energy distribution according to some embodiments of the present application. Determining the reference energy distribution of reflected light in each characteristic band can be achieved by using the following steps:

[0092] First, in step 1041, the reflected light intensity of each ink in each characteristic band is obtained;

[0093] Then, in step 1042 , the reflected composite light intensity of the target printed object in each characteristic waveband is determined based on the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic waveband;

[0094] Finally, in 1043 , the reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band.

[0095] It should be noted that the reflected composite light intensity described in the present application represents the overall reflected light intensity of the target printed object after a mixture of multiple inks with corresponding primary matching ratio values ​​in each characteristic band; as a preferred embodiment, determining the reflected composite light intensity of the target printed object in each characteristic band based on the primary matching ratio value of each ink and the reflected light intensity of the ink in each characteristic band can be achieved in the following manner, namely: first, selecting a characteristic band as the selected characteristic band, then multiplying the reflected light intensity of various inks in the selected characteristic band by the primary matching ratio value of the corresponding ink, and then adding the corresponding results of all inks as the reflected composite light intensity of the target printed object in the selected characteristic band, and continuing to determine the reflected composite light intensity of the target printed object in the remaining characteristic bands.

[0096] In a specific implementation, the reference energy distribution of the reflected light in each characteristic band is determined by the reflected light intensity of the target printed object in each characteristic band and the composite reflected light intensity of the target printed object in each characteristic band. This can be achieved in the following manner: first, the reflected light intensity of the target printed object in each characteristic band is obtained; then, a characteristic band is selected as the selected characteristic band; the difference between the reflected light intensity of the target printed object in the selected characteristic band and the composite reflected light intensity of the target printed object in the selected characteristic band is determined; the result of the logarithm with base 10 of the obtained result is determined and the negative value is taken; the obtained result is used as the reference energy distribution of the reflected light of the target printed object in the selected characteristic band; and the reference energy distribution of the reflected light of the target printed object in the remaining characteristic bands is further determined.

[0097] It should be noted that the reference energy distribution in this application is based on the comparison between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the ink mixing. This application uses the difference between the actual reflected light intensity of the target printed object and the reflected synthetic light intensity generated by the ink mixing as a reference to judge the degree of adjustment of the ratio values ​​of various ink samples. The larger the reference energy distribution, the greater the difference between the actual reflected light intensity of the target printed object and the expected reflected synthetic light intensity, that is, the ink ratio in the characteristic band does not meet the actual needs and needs further adjustment. The smaller the reference energy distribution, the smaller the difference between the actual reflected light intensity of the target printed object and the expected reflected synthetic light intensity, that is, the current ratio is relatively reasonable and the performance of the target printed object in this band is consistent with expectations.

[0098] In some embodiments, determining the diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions can be achieved by the following steps:

[0099] Determine the energy distribution diffusion model through all reference energy distributions;

[0100] The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

[0101] In specific implementation, the energy distribution diffusion model determined by all reference energy distributions can be implemented in the following manner, namely: first, after setting the intercept parameter and the slope parameter, according to the linear regression model in the prior art, a characteristic band is selected as the selected characteristic band, and the reflected light intensity of various inks in the selected characteristic band is obtained, and the logarithm of the reflected light intensity corresponding to various inks with a base of 10 is determined and multiplied by the negative result of the quotient of the slope parameter and the corresponding primary matching ratio value, and the result after adding the results corresponding to various inks is equal to the reference energy distribution corresponding to the selected characteristic band, and the equations corresponding to the remaining characteristic bands are continuously constructed, so that the model composed of all the equations is used as the energy distribution diffusion model in this application. In other embodiments, other methods can be used for determination, which are not limited here. In addition, as a preferred embodiment, the diffusion ratio of the energy distribution after ink mixing can be extracted based on the energy distribution diffusion model. This can be achieved in the following manner, namely: first, the mean square error of the results obtained by fitting the reference energy distribution corresponding to each characteristic band with the energy distribution diffusion model is minimized, and then an objective function is constructed. Then, the derivative of the objective function with respect to the slope parameter is obtained, and after setting the derivative to zero, the optimal slope parameter is solved to obtain the optimal slope parameter, and the optimal slope parameter is used as the diffusion ratio of the energy distribution after ink mixing in this application. In other embodiments, other methods can be used for determination, which are not described here.

[0102] It should be noted that the energy distribution diffusion model described in this application describes how the energy distribution of inks diffuses with time or conditions after they are mixed during the printing process. This application uses the energy distribution diffusion model to consider the changes in reflected light intensity in different characteristic bands, thereby predicting the optical properties of the final printed product. In addition, the diffusion ratio of the energy distribution after the inks are mixed is a descriptive quantity of the degree of diffusion of the energy distribution in each characteristic band after the inks are mixed. The larger the diffusion ratio, the stronger the interaction between different inks in terms of reflected light intensity, resulting in a greater difference in the color after mixing, that is, a higher degree of diffusion. The smaller the diffusion ratio, the smaller the change in the optical properties of the ink, the better the mixing effect, and the closer the reflected light intensity is to expectations, that is, a lower degree of diffusion.

[0103] In some embodiments, adaptively correcting the primary ratio values ​​of various inks during printing by using the diffusion ratio to obtain the secondary ratio values ​​of various inks can be achieved by the following steps:

[0104] Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted;

[0105] Determining a compensation ratio value of each ink according to the diffusion ratio and the offset characteristic band;

[0106] Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected to obtain the secondary ratio values ​​of various inks.

[0107] In specific implementation, the shifted characteristic band after the spectral reflectance characteristics of the ink sample are shifted can be obtained by measuring the ink sample after it is proportioned according to all the primary proportioning values ​​through a spectrum analyzer to obtain the band position in the spectral data of the ink sample that best represents the color characteristics, differences or changes. In some preferred embodiments, after the spectral data of the ink sample is constructed into a spectral curve, the band corresponding to the inflection point of the spectral curve (i.e., the position where the slope of the curve changes the most) is obtained as the shifted characteristic band of the ink sample. In other embodiments, other methods can be used for determination, which are not limited here.

[0108] In some embodiments, determining the compensation ratio value of each ink by using the diffusion ratio and the offset characteristic band can be achieved in the following manner:

[0109] Acquiring the offset reflected light intensity of the ink sample in the offset characteristic band;

[0110] determining the offset energy distribution of the ink sample in the offset characteristic band based on the reflected composite light intensity of the ink sample;

[0111] The compensation ratio value of each ink is determined according to the offset energy distribution and the diffusion ratio.

[0112] Preferably, the offset reflected light intensity of the ink sample in the offset characteristic band can be measured by a spectrophotometer. It should be noted that the offset characteristic band is the band position that best represents the color characteristics, differences or changes of the ink sample after the spectral reflectance characteristics of the ink sample change due to the mixing of various inks. The offset reflected light intensity is: the reflected light intensity of the mixed ink sample in the offset characteristic band.

[0113] It should be noted that the compensation ratio value, that is, the additional ink ratio calculated to correct the color deviation on the offset characteristic band, is used to correct the primary ratio value. The present application compensates for the printing deviation caused by color offset by reflecting the difference in reflection intensity on the offset characteristic band. In specific implementation, the offset energy distribution of the ink sample on the offset characteristic band is determined based on the reflected synthetic light intensity of the ink sample, which can be achieved in the following manner: first, the difference between the offset reflected light intensity and the reflected synthetic light intensity is determined; secondly, the result obtained is logarithmized to the base 10 and the negative value is taken as the offset energy distribution of the ink sample on the offset characteristic band. In addition, as a preferred embodiment, the compensation ratio value of each ink is determined by the offset energy distribution and the diffusion ratio, which can be achieved in the following manner: after taking the offset energy distribution and the diffusion ratio as inputs of the energy distribution diffusion model, the model equation is solved, and the result obtained is used as the compensation ratio value of the corresponding ink. In other embodiments, other methods can also be used for determination, which is not limited here.

[0114] In specific implementation, the primary ratio value of the corresponding ink is adaptively corrected based on the compensation ratio value corresponding to each ink, so as to obtain the secondary ratio values ​​of various inks. This can be achieved in the following way: first, one ink is selected as the selected ink, and then the result of adding the primary ratio value of the selected ink and the compensation ratio value corresponding to the selected ink is used as the secondary ratio value of the selected ink, and the secondary ratio values ​​of the remaining inks are further determined.

[0115] In step 105 , the printing end effector controls the ejection amount of each ink according to each secondary ratio value.

[0116] It should be noted that when the printing end effector described in this application includes a flow control valve, the printing end effector controls the injection amount of each ink according to each secondary ratio value in the following manner, namely: first, a precise flow control valve is installed on each nozzle of the large-scale intelligent printing machine to adjust the injection amount of each ink, and then, the opening and closing degree of the flow control valve of the corresponding nozzle is regulated according to the secondary ratio value corresponding to each ink. For example: the larger the secondary ratio value, the higher the opening and closing degree of the flow control valve of the nozzle of the corresponding ink, and the smaller the secondary ratio value, the lower the opening and closing degree of the flow control valve of the nozzle of the corresponding ink; thereby controlling the injection amount of each ink in the large-scale intelligent printing machine. In other embodiments, it can also be regulated by other methods, which are not limited here.

[0117] It should be noted that after calculating the primary ratio values ​​of various inks, this application conducted further spectral optimization based on the difference between the actual reflected light intensity and the theoretical synthetic light intensity of the target printed material (ink mixing causes changes in the spectral reflection characteristics), and adjusted the primary ratio value of each ink by analyzing the difference, thereby avoiding the printing color difference caused by the change in spectral reflection characteristics due to ink mixing, thereby realizing the correction of the printing color difference of the intelligent printing machine.

[0118] In addition, in another aspect of the present application, in some embodiments, the present application provides a large-scale intelligent printing machine, referring to Figure 4 , which is a schematic structural diagram of a large-scale intelligent printing machine according to some embodiments of the present application. The large-scale intelligent printing machine 200 includes: a sensing system 201, a control system 202, and a printing end effector 203, which are described as follows:

[0119] The sensing system 201 in this application is mainly used to collect the reflected light intensity of different ink samples in various visible light bands;

[0120] Control system 202. In this application, control system 202 is mainly used to perform characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divide the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values;

[0121] In addition, the control system 202 in the present application is also used to perform primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtain a primary matching value for each ink;

[0122] In addition, the sensing system 201 in the present application is also used to automatically identify multiple characteristic bands of reflected light when the target printed object is printed, determine the reference energy distribution of the reflected light in each characteristic band, determine the diffusion ratio of the energy distribution after the ink is mixed based on all the reference energy distributions, and adaptively correct the primary ratio values ​​of various inks during printing based on the diffusion ratio to obtain the secondary ratio values ​​of various inks;

[0123] The printing end effector 203 in this application is mainly used to control the ejection amount of each ink according to each secondary ratio value.

[0124] In addition, the present application also provides a computer device, which includes a memory and a processor, wherein the memory stores code, and the processor is configured to obtain the code and execute the above-mentioned printing correction method for a large-scale intelligent printing press.

[0125] In some embodiments, reference Figure 5 , which is an internal structure diagram of a computer device for implementing a printing correction method for a large-scale intelligent printing press according to some embodiments of the present application. The printing correction method for an intelligent printing press in the above embodiment can be Figure 5 The computer device 300 shown in FIG. 1 is implemented as shown in FIG. 1 , and the computer device 300 includes at least one processor 301 , a communication bus 302 , a memory 303 , and at least one communication interface 304 .

[0126] The processor 301 may be a general-purpose central processing unit (CPU), or an application-specific integrated circuit (ASIC) or one or more processors for controlling the execution of the printing correction method for the intelligent printer in the present application.

[0127] The communication bus 302 is used to transmit information between the above components.

[0128] The memory 303 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 303 may exist independently and be connected to the processor 301 via the communication bus 302. The memory 303 may also be integrated with the processor 301.

[0129] Memory 303 is used to store program code for implementing the present invention, and is controlled by processor 301 for execution. Processor 301 is configured to execute the program code stored in memory 303. The program code may include one or more software modules. The print correction method for a smart printer in the above embodiment can be implemented by processor 301 and one or more software modules in the program code stored in memory 303.

[0130] The communication interface 304 uses any device such as a transceiver to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc.

[0131] In a specific implementation, as an example, a computer device may include multiple processors, each of which may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0132] The aforementioned computer device may be a general-purpose computer device or a dedicated computer device. In a specific implementation, the computer device may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. The embodiments of the present application do not limit the type of computer device.

[0133] In addition, the present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the printing correction method for the intelligent printer is implemented.

[0134] In summary, in the large-scale intelligent printing machine and the printing correction method for the large-scale intelligent printing machine disclosed in the embodiment of the present application, the reflected light intensity of different ink samples in each visible light band is collected by the sensing system; the control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensity of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut composed of all ink samples into multiple printing color intervals based on the various optical characteristic values; the control system also performs spectral similarity between the color of the target printed object and each printing color interval during printing. The first-level ratio of each ink is obtained by performing a first-level ratio matching based on the ink content; the perception system automatically identifies multiple characteristic bands of reflected light when the target printed object is printed, determines the reference energy distribution of the reflected light in each characteristic band, determines the diffusion ratio of the energy distribution after the inks are mixed based on all the reference energy distributions, and adaptively corrects the first-level ratio values ​​of various inks during printing through the diffusion ratio to obtain the second-level ratio values ​​of various inks; the printing end effector controls the injection amount of each ink based on each second-level ratio value; and can adjust the optimal ink ratio of the target printed object when the spectral reflectance characteristics of the ink sample change.

[0135] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0136] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if such changes and modifications fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such changes and modifications.

Claims

1. A printing correction method for a large-scale intelligent printing press, wherein the large-scale intelligent printing press includes a sensing system, a control system, and a printing end effector, characterized in that: The method comprises the following steps: The sensing system collects the reflected light intensity of different ink samples in each visible light band; The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values; The control system also performs primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains a primary matching value for each ink; The sensing system automatically identifies multiple characteristic bands of reflected light from a target printed object during printing, determines a reference energy distribution of the reflected light in each characteristic band, determines a diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing using the diffusion ratio to obtain secondary ratio values ​​of various inks; The printing end effector controls the ejection amount of each ink according to each secondary ratio value; Determining the reference energy distribution of reflected light in each characteristic band specifically includes: Obtain the reflected light intensity of each ink in each characteristic band; Determine the reflected composite light intensity of the target printed object in each characteristic band according to the primary ratio value of each ink and the reflected light intensity of the ink in each characteristic band; Determining the reference energy distribution of the reflected light in each characteristic band by the reflected light intensity of the target printed object in each characteristic band and the reflected composite light intensity of the target printed object in each characteristic band; The adaptive correction of the primary ratio values ​​of various inks during printing by using the diffusion ratio to obtain the secondary ratio values ​​of various inks specifically includes: Obtaining a shifted characteristic band of the ink sample after the spectral reflectance characteristic is shifted; Determining a compensation ratio value of each ink according to the diffusion ratio and the offset characteristic band; Based on the compensation ratio value corresponding to each ink, the primary ratio value of the corresponding ink is adaptively corrected to obtain the secondary ratio values ​​of various inks.

2. The method according to claim 1, wherein The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands, and obtains multiple optical characteristic values, specifically including: Determine the fluctuation characteristics of the reflected light intensity of various ink samples across all visible light bands; Determine the light intensity fluctuation ratio of the reflected light intensity corresponding to each ink sample according to the fluctuation characteristics corresponding to the various ink samples; The fluctuation characteristics of each ink sample in all visible light bands are converted into multiple optical characteristic values ​​through the ratio of all light intensity fluctuations.

3. The method according to claim 1, wherein The printing color gamut composed of all ink samples is divided into multiple printing color intervals based on various optical characteristic values, including: Constructing color feature vectors of various ink samples based on the respective optical feature values; Determining the degree of vector proximity between color feature vectors of various ink samples; The printing color gamut formed by all ink samples is divided into multiple printing color intervals according to the approximation of all vectors.

4. The method according to claim 1, wherein The control system performs primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains the primary matching value of each ink specifically including: Determine the center spectral vector of each printed color interval; Obtaining the color spectrum vector of the target printed object; determining the spectral similarity between the color of the target printed object and each printed color interval based on the central spectral vector of each printed color interval and the color spectral vector of the target printed object; Determine the optimal color range of the target printed object based on all spectral similarities; Setting an optimal matching function for all inks based on the optimal color range; The optimal ratio function is used to determine the ratio of the contents of all inks during printing to obtain a primary ratio value for each ink.

5. The method according to claim 1, wherein Determining the diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions specifically includes: Determine the energy distribution diffusion model through all reference energy distributions; The diffusion ratio of the energy distribution after ink mixing is extracted based on the energy distribution diffusion model.

6. A large intelligent printing press, which uses the method according to any one of claims 1 to 5 to perform printing correction, characterized in that: The large-scale intelligent printing machine includes a sensing system, a control system, and a printing end effector. The sensing system collects the reflected light intensity of different ink samples in each visible light band; The control system performs characteristic conversion on all reflected light intensities according to the fluctuation characteristics of the reflected light intensities of each ink sample in all visible light bands to obtain multiple optical characteristic values, and then divides the printing color gamut formed by all ink samples into multiple printing color intervals based on the respective optical characteristic values; The control system also performs primary matching of the content of various inks during printing based on the spectral similarity between the color of the target printed object and each printed color interval, and obtains a primary matching value for each ink; The sensing system automatically identifies multiple characteristic bands of reflected light from a target printed object during printing, determines a reference energy distribution of the reflected light in each characteristic band, determines a diffusion ratio of the energy distribution after ink mixing based on all reference energy distributions, and adaptively corrects the primary ratio values ​​of various inks during printing using the diffusion ratio to obtain secondary ratio values ​​of various inks; The printing end effector controls the ejection amount of each ink according to each secondary ratio value.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the printing correction method for a large-scale intelligent printing press according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the printing correction method for a large-scale intelligent printing press according to any one of claims 1 to 5 are implemented.

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