Ink-jet printing calibration method, ink-jet printing equipment, storage medium and program product

Abstract

The invention discloses an ink-jet printing calibration method, ink-jet printing equipment, a storage medium and a program product, and relates to the technical field of ink-jet printing.The ink-jet printing calibration method comprises the steps that a first nozzle module is controlled to print a double-head reference pattern on a printing medium; the printing medium is controlled to move by a first stepping distance, and the first spray head module is controlled to print a stepping reference pattern on the printing medium; after the printing module is aligned with the printed image, the first spray head module and the second spray head module are controlled to perform ink-jet printing at least including a bidirectional reference pattern, a double-head comparison pattern and a stepping comparison pattern on the printing medium in the first printing direction; the first spray head module and the second spray head module are controlled to perform ink-jet printing on the two-way comparison pattern on the printing medium in the second printing direction opposite to the first printing direction; and performing image acquisition on the printing medium to obtain an overall calibration image for calibration. The technical problem that the calibration efficiency of existing ink-jet printing equipment is low is solved.

Description

Technical Field

[0001] The present application relates to the technical field of inkjet printing, and in particular, to an inkjet printing calibration method, an inkjet printing device, a storage medium, and a program product. Background Art

[0002] As a non-contact printing method, inkjet printing technology, with its high resolution, wide medium adaptability, and high flexibility, not only meets the basic needs of daily office work and advertising, but is also widely used in fields such as clothing production, handicraft production, and electronic product manufacturing.

[0003] To ensure printing accuracy and consistency, there are various calibration requirements for inkjet printing devices (such as step calibration, dual-head X-axis calibration, dual-head Y-axis calibration, bidirectional calibration, etc.). However, in related technologies, calibration methods usually require printing a calibration chart independently for different calibration requirements and performing corresponding calibration operations based on this calibration chart. Once multiple calibration requirements exist simultaneously, it is necessary to print calibration charts one by one and perform calibration operations one by one. This process is not only cumbersome and complex, but also requires a large amount of time and effort, seriously reducing the efficiency of inkjet printing calibration.

[0004] The above content is only used to assist in understanding the technical solution of the present application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the present application is to provide an inkjet printing calibration method, an inkjet printing device, a storage medium, and a program product, aiming to solve the technical problem of low calibration efficiency of existing inkjet printing devices.

[0006] To achieve the above object, the present application proposes an inkjet printing calibration method, which is applied to an inkjet printing device. The inkjet printing device includes a first printhead module and a second printhead module. The inkjet printing calibration method includes:

[0007] Controlling the first printhead module to print a first image on a printing medium, where the first image includes a dual-head reference pattern;

[0008] Controlling the printing medium to move a first step distance, and controlling the first printhead module to print a second image on the printing medium, where the second image includes a step reference pattern;

[0009] Controlling the printing medium to move a second step distance so that in the first printing direction, the first image is aligned with the second printhead module, and the second image is aligned with the first printhead module;

[0010] Control the first printhead module and the second printhead module to inkjet print a third image on a print medium, where the third image at least includes a bidirectional reference pattern, a dual-head comparison pattern corresponding to the dual-head reference pattern, and a step comparison pattern corresponding to the step reference pattern;

[0011] Control the first printhead module and the second printhead module to inkjet print a fourth image on the print medium along a second printing direction, where the second printing direction is opposite to the first printing direction, and the fourth image includes a bidirectional comparison pattern corresponding to the bidirectional reference pattern;

[0012] Perform image acquisition on the print medium to obtain an overall calibration image, so as to obtain calibration parameters of the inkjet printing device based on the overall calibration image.

[0013] In addition, to achieve the above object, the present application also proposes an inkjet printing device, where the inkjet printing device includes: a slide rail;

[0014] A first printhead module and a second printhead module, which are arranged on the slide rail;

[0015] A conveying device, which is arranged below the slide rail and is used to convey the print medium;

[0016] A control unit, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the inkjet printing calibration method as described above.

[0017] In addition, to achieve the above object, the present application also proposes a storage medium, where the storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by a processor, it implements the steps of the inkjet printing calibration method as described above.

[0018] In addition, to achieve the above object, the present application also provides a computer program product, where the computer program product includes a computer program, and when the computer program is executed by a processor, it implements the steps of the inkjet printing calibration method as described above.

[0019] One or more technical solutions proposed by the present application have at least the following technical effects:

[0020] This application is applied to an inkjet printing device, which includes a first printhead module and a second printhead module. By controlling the first printhead module to print a first image on a printing medium, where the first image includes a dual-head reference pattern as a reference for dual-head calibration between the first printhead module and the second printhead module. Then, control the printing medium to move a first step distance, and control the first printhead module to print a second image on the printing medium. The second image includes a step reference pattern as a reference for step calibration of the first printhead module. Then, it is possible to control the printing medium to move a second step distance so that in the first printing direction, the first image is aligned with the second printhead module, and the second image is aligned with the first printhead module. Then, control the first printhead module and the second printhead module to inkjet-print a third image on the printing medium along the first printing direction, where the third image at least includes a bidirectional reference pattern, a dual-head comparison pattern, and a step comparison pattern; control the first printhead module and the second printhead module to inkjet-print a fourth image on the printing medium along a second printing direction, where the second printing direction is opposite to the first printing direction, and the fourth image includes a bidirectional comparison pattern. Thus, compared with the traditional calibration method where at least six inkjet printing operations are required for the calibration patterns needed for independent dual-head calibration, step calibration, and bidirectional calibration, this application can complete the printing of the reference patterns and comparison patterns required for at least dual-head calibration, step calibration, and bidirectional calibration through four inkjet printing operations. Then, perform image acquisition on the printing medium to obtain an overall calibration image, and obtain the calibration parameters of the inkjet printing device based on the overall calibration image. Therefore, compared with the traditional calibration method where calibration work such as dual-head calibration, step calibration, and bidirectional calibration needs to be carried out separately, this application integrates and simplifies the printing process, and can integrate multiple calibration diagrams for the inkjet printing device on the same printing medium with fewer printing times, and then can realize the synchronous execution of multiple calibrations for the inkjet printing device, thereby improving the calibration efficiency of the inkjet printing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic flowchart provided for an embodiment of the inkjet printing calibration method of the present application;

[0024] Figure 2 Schematic diagram of the double-headed longitudinal reference line segment related to the embodiment of the present application;

[0025] Figure 3 Schematic diagram of the double-headed transverse reference line segment related to the embodiment of the present application;

[0026] Figure 4 Schematic diagram of the double-headed longitudinal comparison line segment related to the embodiment of the present application;

[0027] Figure 5 Schematic diagram of the double-headed transverse comparison line segment related to the embodiment of the present application;

[0028] Figure 6 Schematic diagram of the step reference pattern related to the embodiment of the present application;

[0029] Figure 7 Schematic diagram of the step comparison pattern related to the embodiment of the present application;

[0030] Figure 8 Schematic diagram of the bidirectional reference pattern and the bidirectional comparison pattern related to the embodiment of the present application;

[0031] Figure 9 Schematic diagram of the break detection line segment related to the embodiment of the present application;

[0032] Figure 10 Schematic diagram of the overprint detection pattern related to the embodiment of the present application;

[0033] Figure 11 Schematic flow chart provided by another embodiment of the inkjet printing calibration method of the present application;

[0034] Figure 12 Schematic diagram of the marking of the line segment deviation parameter related to the embodiment of the present application;

[0035] Figure 13 Schematic diagram of the scenario of the inkjet printing calibration method related to the embodiment of the present application;

[0036] Figure 14 Example diagram of the overall calibration image related to the embodiment of the present application;

[0037] Figure 15 Schematic diagram of the structure of the inkjet printing device related to the embodiment of the present application.

[0038] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0039] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0040] To better understand the technical solutions of the present application, the following will be described in detail in conjunction with the accompanying drawings of the specification and specific embodiments.

[0041] Based on this, an embodiment of the present application provides an inkjet printing calibration method. Refer to Figure 1 , Figure 1 which is a schematic flow chart of the first embodiment of the inkjet printing calibration method of the present application.

[0042] In this embodiment, it can be applied to an inkjet printing device. The inkjet printing device includes a first printhead module and a second printhead module. The inkjet printing calibration method includes steps S10 to S60:

[0043] Step S10, controlling the first printhead module to print a first image on a printing medium, where the first image includes a double-head reference pattern;

[0044] It should be noted that the inkjet printing device includes a first printhead module and a second printhead module. The first printhead module and the second printhead module are the color ink printhead module and the white ink printhead module of the inkjet printing device. The color ink printhead module is used to eject color ink for inkjet printing of color graphics, and the white ink printhead module is used to eject white ink for inkjet printing of white graphics. It can be understood that the color ink generally includes inks of four basic colors: cyan, magenta, yellow, and black. Of course, according to different actual requirements, the color ink may also include other colors of ink except the four basic colors, such as light cyan, light magenta, photo black, gray, etc. The first printhead module is the color ink printhead module and the second printhead module is the white ink printhead module, or the first printhead module is the white ink printhead module and the second printhead module is the color ink printhead module. The printing medium is a medium for carrying the graphics of inkjet printing, such as paper, fabric, plastic plate, wafer, film material (such as PET film), etc. The first printing direction is a direction perpendicular to the stepping direction of the printing medium. Exemplarily, the printing medium moves step by step along the front-back direction, and the first printing direction can be from left to right or from right to left.

[0045] In addition, it should be noted that the first image includes a double-head reference pattern, and the double-head reference pattern is a pattern used as a double-head detection reference, such as a line segment, a cross, a rhombus, etc. It can be understood that the double-head detection is used to detect the consistency of the printing positions of the two printheads, namely the first printhead module and the second printhead module, to avoid color deviation or overlap of these two printheads.

[0046] After receiving a calibration instruction for the inkjet printing device in this embodiment, the first printhead module and the second printhead module can be controlled to move along the first printing direction on the guide rail, and the first printhead module can be controlled to inkjet print a first image on the printing medium, where the first image includes a double-head reference pattern. Since the double-head reference pattern is a pattern used as a double-head detection reference, the double-head reference pattern can include a double-head reference longitudinal pattern and a double-head reference transverse pattern. The double-head reference longitudinal pattern and the double-head reference transverse pattern can be patterns such as line segments, crosses, diamonds, etc. that can be used for double-head calibration. Exemplarily, the double-head reference longitudinal pattern is at least one reference line segment perpendicular to the first printing direction, and the double-head reference transverse pattern is at least one reference line segment parallel to the first printing direction. Thus, in the subsequent inkjet printing process, when the second printhead module prints a double-head comparison longitudinal line segment corresponding to the double-head reference longitudinal pattern and a double-head comparison transverse line segment corresponding to the double-head reference transverse pattern, the deviation between the first printhead module and the second printhead module in the transverse and longitudinal directions can be used to calibrate the inkjet printing device. In another example, to improve the calibration accuracy, in this embodiment, the double-head reference pattern includes a double-head reference longitudinal pattern and a double-head reference transverse pattern; the double-head reference longitudinal pattern includes several groups of first reference line segments perpendicular to the first printing direction, and at least some groups of the first reference line segments in the double-head reference longitudinal pattern are equally spaced in the first printing direction, or are equally spaced according to a first spacing difference; the double-head reference transverse pattern includes several groups of second reference line segments parallel to the first printing direction, and at least some groups of the second reference line segments in the double-head reference transverse pattern are equally spaced in a direction perpendicular to the first printing direction, or are equally spaced according to a second spacing difference. It can be understood that the double-head reference longitudinal pattern and the double-head reference transverse pattern are independent of each other.

[0047] In a feasible implementation manner, the double-head reference pattern includes a double-head reference longitudinal pattern and a double-head reference transverse pattern;

[0048] The double-head reference longitudinal pattern includes several groups of first reference line segments perpendicular to the first printing direction, and at least some groups of the first reference line segments in the double-head reference longitudinal pattern are equally spaced in the first printing direction, or are equally spaced according to a first spacing difference;

[0049] The double-head reference transverse pattern includes several groups of second reference line segments parallel to the first printing direction, and at least some groups of the second reference line segments in the double-head reference transverse pattern are equally spaced in a direction perpendicular to the first printing direction, or are equally spaced according to a second spacing difference.

[0050] In this embodiment, the double-head reference pattern includes a double-head reference longitudinal pattern and a double-head reference transverse pattern. AsFigure 2 As shown, the double-headed reference longitudinal pattern includes several groups of first reference line segments perpendicular to the first printing direction. At least some groups of the first reference line segments in the double-headed reference longitudinal pattern are equally spaced in the first printing direction, that is, the spacing between each group of the first reference line segments in the first printing direction is equal. Since the specifications of different inkjet printing devices are different, the spacing between each group of the first reference line segments can be set according to requirements. In addition, the groups of the first reference line segments in this embodiment can also be equally spaced in an arithmetic progression according to a first spacing difference in the first printing direction, that is, in the first printing direction, with at least one group of the first reference line segments as the center, the spacing between adjacent first reference line segments is an arithmetic progression that gradually increases or gradually decreases according to the first spacing difference. Exemplarily, taking the first spacing difference as 1, the spacing between the group of the first reference line segments as the center and the first reference line segments on both sides is 10, and the spacing between the first reference line segments on both sides and the adjacent first reference line segments in the direction away from the group of the first reference line segments as the center is 11. Thus, the spacing between adjacent first reference line segments gradually increases, 12, 13, 14... It can be understood that each group of the first reference line segments can be a single line segment, and each group of the first reference line segments can also include at least two line segments. In the case where each group of the first reference line segments includes at least two line segments, it is possible to avoid the absence of the first reference line segment caused by abnormal situations such as nozzle clogging and failure to successfully inkjet, which affects the determination of subsequent calibration parameters.

[0051] As Figure 3As shown, the double-headed reference transverse pattern includes several groups of second reference line segments parallel to the first printing direction. Each group of second reference line segments is equally spaced in the first printing direction, that is, the spacing between each group of second reference line segments in the first printing direction is equal. Since the specifications of different inkjet printing devices are different, the spacing between each group of second reference line segments can be set according to requirements. In addition, in this embodiment, each group of second reference line segments can also be equally spaced with an arithmetic progression according to the second spacing difference in the direction perpendicular to the first printing direction, that is, with at least one group of second reference line segments as the center in the first printing direction, the spacing between adjacent second reference line segments is an arithmetic progression that gradually increases or gradually decreases according to the second spacing difference. Exemplarily, taking the second spacing difference as 1, the spacing between the group of second reference line segments as the center and the second reference line segments on both sides is 10, and the spacing between the second reference line segments on both sides and the adjacent second reference line segments in the direction away from the group of second reference line segments as the center is 11. Thus, the spacing between adjacent second reference line segments gradually increases, 12, 13, 14... Similarly, each group of second reference line segments can be a single line segment, and each group of second reference line segments can also include at least two line segments. In the case where each group of second reference line segments includes at least two line segments, it is possible to avoid the missing of the second reference line segment caused by abnormal situations such as nozzle clogging and failure to successfully inkjet, which affects the determination of subsequent calibration parameters.

[0052] In this embodiment, by setting multiple groups of first reference line segments as the double-headed reference longitudinal pattern and setting multiple groups of second reference line segments as the double-headed reference transverse pattern, the double-headed reference pattern can be used as the reference for deviation detection of the two printhead modules, namely the first printhead module and the second printhead module, in the transverse and longitudinal directions by independent multiple groups of first reference line segments and multiple groups of second reference line segments. Compared with a single line segment or a composite figure, the recognition complexity is lower and the calibration accuracy is higher.

[0053] In a feasible embodiment, the double-headed comparison pattern includes double-headed comparison longitudinal line segments and double-headed comparison transverse line segments;

[0054] The double-headed comparison longitudinal line segments include several groups of first comparison line segments corresponding to the first reference line segments, and at least one group of first comparison line segments is preset to be aligned with the corresponding first reference line segments. The spacing between the first comparison line segments other than the preset-aligned first comparison line segments and the corresponding first reference line segments is equally spaced with an arithmetic progression according to the third spacing difference in sequence;

[0055] The double-headed comparison transverse line segments include several groups of second comparison line segments corresponding to the second reference line segments, and at least one group of second comparison line segments is preset to be aligned with the corresponding second reference line segments. The spacing between the second comparison line segments other than the preset-aligned second comparison line segments and the corresponding second reference line segments is equally spaced with an arithmetic progression according to the fourth spacing difference in sequence.

[0056] As Figure 4 shown, the black line segment in the figure is the first reference line segment printed by the first printhead module, and the purple line segment is the first comparison line segment printed by the second printhead module. The double-head comparison longitudinal line segment includes several groups of first comparison line segments corresponding to the first reference line segment, and at least one group of first comparison line segments is preset to be aligned with the corresponding first reference line segment, that is, there is a group of first comparison line segments among the groups of first comparison line segments in this embodiment that overlap with the corresponding first reference line segment in the first printing direction. It can be understood that the groups of first comparison line segments and their corresponding first reference line segments may or may not overlap in the direction perpendicular to the first printing direction. Preferably, the groups of first comparison line segments and their corresponding first reference line segments may partially overlap in the direction perpendicular to the first printing direction, which is convenient for subsequent image recognition operations. The distances between the first comparison line segments other than the preset-aligned first comparison line segments and the corresponding first reference line segments are distributed at equal intervals according to the third interval difference, that is, the distances between the groups of first comparison line segments and their corresponding first reference line segments in the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the third interval difference. Exemplarily, taking the third interval difference as 1, the group of first comparison line segments in the center overlaps with the corresponding first reference line segment in the first printing direction (i.e., the distance is zero), and the distances between the first comparison line segments on both sides and the corresponding first reference line segments in the first printing direction are 1. Thus, the distances between adjacent first comparison line segments and their corresponding first reference line segments in the first printing direction increase sequentially, 2, 3, 4... Further, according to the relative positions of the first comparison line segments and the first reference line segments (i.e., whether the first comparison line segments are on the right or left side of the first reference line segments) being different, the intervals can be set to +1 / -1, +2 / -2, +3 / -3, etc. Thus, in this embodiment, it can be determined whether the preset-aligned first comparison line segments and the corresponding first reference line segments are aligned (i.e., whether the distance between the preset-aligned first comparison line segments and the corresponding first reference line segments in the first printing direction is zero). If the preset-aligned first comparison line segments and the corresponding first reference line segments are not aligned, it indicates that there is a deviation between the first printhead module and the second printhead module in the horizontal (X-axis direction). Moreover, since the distances between the groups of first comparison line segments and their corresponding first reference line segments in the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the third interval difference, in this embodiment, the line deviation value corresponding to the first comparison line segment can also be obtained according to the distribution position of the first comparison line segment actually aligned with the first reference line segment in the equal-interval distribution according to the third interval difference as the calibration parameter.

[0057] As Figure 5As shown in the figure, the black line segment in the figure is the second reference line segment printed by the first printhead module, and the purple line segment is the second comparison line segment printed by the second printhead module. The double-head comparison horizontal line segment includes several groups of second comparison line segments corresponding to the second reference line segment, and at least one group of second comparison line segments is preset to be aligned with the corresponding second reference line segment, that is, there is a group of second comparison line segments among the groups of second comparison line segments in this embodiment that overlap with the corresponding second reference line segment in the direction perpendicular to the first printing direction. It can be understood that the groups of second comparison line segments and their corresponding second reference line segments may or may not overlap in the first printing direction. Preferably, the groups of second comparison line segments and their corresponding second reference line segments may partially overlap in the first printing direction, which is convenient for subsequent image recognition operations. The distances between the second comparison line segments other than the preset-aligned second comparison line segments and the corresponding second reference line segments are distributed in an arithmetic progression according to the fourth distance difference in sequence, that is, the distances between the groups of second comparison line segments and their corresponding second reference line segments in the direction perpendicular to the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the fourth distance difference. Exemplarily, taking the fourth distance difference as 1, the group of second comparison line segments in the center overlaps with the corresponding second reference line segment in the direction perpendicular to the first printing direction (i.e., the distance is zero), and the distances between the second comparison line segments on both sides and the corresponding second reference line segments in the direction perpendicular to the first printing direction are 1. Thus, the distances between adjacent second comparison line segments and their corresponding second reference line segments in the direction perpendicular to the first printing direction gradually increase, 2, 3, 4... Further, according to the different relative positions of the second comparison line segments and the second reference line segments (i.e., the second comparison line segments are on the right or left side of the second reference line segment), the distances can be set to +1 / -1, +2 / -2, +3 / -3, etc. Thus, in this embodiment, it can be determined whether the preset-aligned second comparison line segments and the corresponding second reference line segments are aligned (i.e., whether the distance between the preset-aligned second comparison line segments and the corresponding second reference line segments in the first printing direction is zero). If the preset-aligned second comparison line segments and the corresponding second reference line segments are not aligned, it indicates that there is a deviation between the first printhead module and the second printhead module in the longitudinal (Y-axis direction). And, since the distances between the groups of second comparison line segments and their corresponding second reference line segments in the direction perpendicular to the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the fourth distance difference, in this embodiment, the line deviation value corresponding to the second comparison line segment can also be obtained according to the distribution position of the actually aligned second comparison line segment in the arithmetic progression distribution according to the fourth distance difference as a calibration parameter. In addition, the reference pattern and the comparison pattern for inkjet printing calibration in this embodiment adopt linear patterns, so that whether it is machine vision or naked-eye observation, it is easy to distinguish the aligned reference pattern and comparison pattern, which can effectively improve the calibration accuracy.

[0058] In this embodiment, the distances between the first comparison line segments other than the preset aligned first comparison line segments and the corresponding first reference line segments are sequentially distributed at an equal difference interval according to a third distance difference, and the distances between the second comparison line segments other than the preset aligned second comparison line segments and the corresponding second reference line segments are sequentially distributed at an equal difference interval according to a fourth distance difference. Thus, by directly identifying the comparison line segments that align with the reference line segments subsequently, the line segment deviation values of the first printhead module and the second printhead module in the horizontal and vertical directions can be quickly obtained, effectively improving the recognition efficiency of the calibration parameters.

[0059] Step S20: Control the print medium to move a first step distance, and control the first printhead module to print a second image on the print medium, where the second image includes a step reference pattern.

[0060] It should be noted that the first step distance is the sum of the printhead module distance between the first printhead module and the second printhead module in a direction perpendicular to the first printing direction and the double-head longitudinal calibration distance. The double-head longitudinal calibration distance is the maximum distance for calibrating the double-head reference pattern longitudinally. Exemplarily, the double-head longitudinal calibration distance is the maximum distance between the double-head comparison horizontal line segment and its corresponding double-head reference horizontal pattern.

[0061] In this embodiment, since double-head calibration requires the first printhead module to print a reference line segment and the second printhead module to print a comparison line segment respectively to identify whether there is a deviation when these two printhead modules print graphics, this embodiment can control the print medium to move a first step distance in a predetermined step direction, so as to move the first image printed by the first printhead module in the predetermined step direction, leaving a printing space for the first printhead module to print a second image on the print medium. Furthermore, this embodiment can control the first printhead module to print a second image on the print medium along the first printing direction, or can control the first printhead module to print on the print medium along the second printing direction, where the second printing direction is opposite to the first printing direction, so as to save the time for the first printhead module to return and further improve the efficiency. Exemplarily, taking the example that the first printhead module and the second printhead module perform inkjet printing operations on the print medium by moving left and right, if the first printing direction is from left to right, then the second printing direction is from right to left; if the first printing direction is from right to left, then the second printing direction is from left to right. See Figure 6, the second image includes a stepping reference pattern, and the stepping reference pattern is at least one reference line segment parallel to the first printing direction. Thus, during the subsequent inkjet printing process, when the first printhead module prints a stepping comparison pattern corresponding to the stepping reference pattern, the line segment deviation value can be obtained according to the spacing between the stepping comparison patterns corresponding to the stepping reference pattern, so as to be used for calibrating the stepping distance of the inkjet printing device. In another example, to improve the calibration accuracy, in this embodiment, the stepping reference pattern may include several groups of third reference line segments parallel to the first printing direction, and at least some groups of the third reference line segments in the stepping reference pattern are equally spaced or distributed at an equal difference spacing according to a fifth spacing difference in a direction perpendicular to the first printing direction.

[0062] Step S30, controlling the print medium to move a second stepping distance so that in the first printing direction, the first image is aligned with the second printhead module, and the second image is aligned with the first printhead module;

[0063] It should be noted that the second stepping distance is the maximum distance for calibrating the stepping reference pattern in the longitudinal direction. Exemplarily, the second stepping distance is the maximum spacing between the third comparison line segment and the corresponding third reference line segment in each group of stepping reference patterns.

[0064] In addition, it should also be noted that if the position of the second printhead module and the printing start position of the double-head reference pattern on the print medium are on the same straight line in the first printing direction, it is determined that the first image and the second printhead module are aligned in the first printing direction. If the position of the first printhead module and the printing start position of the stepping reference pattern on the print medium are on the same straight line in the first printing direction, it is determined that the second image and the first printhead module are aligned in the first printing direction.

[0065] Since it is necessary to control the first printhead module to inkjet-print the second image on the print medium along the second printing direction, the first stepping distance does not directly align the first image with the second printhead module. In order to align the first image with the second printhead module and the second image with the first printhead module in the first printing direction, the print medium can be controlled to move a second stepping distance in a predetermined stepping direction to compensate for the maximum spacing between the third comparison line segment and the corresponding third reference line segment in the stepping reference pattern, so that the preset aligned third comparison line segment is aligned with the corresponding third reference line segment. Thus, at this time, in the first printing direction, the first image is aligned with the second printhead module, and the second image is aligned with the first printhead module, so that in the subsequent inkjet printing operation, the double-head comparison pattern in the third image overlaps with the double-head reference pattern in the first image, and the stepping comparison pattern in the third image overlaps with the stepping reference pattern in the second print.

[0066] Step S40: Control the first printhead module and the second printhead module to inkjet print a third image on the print medium along a first printing direction, where the third image at least includes a two-way reference pattern, a double-head comparison pattern, and a step comparison pattern;

[0067] It should be noted that the third image at least includes a two-way reference pattern, a double-head comparison pattern, and a step comparison pattern. The double-head comparison pattern is obtained by the second printhead module inkjet printing on the print medium along the first printing direction. The step comparison pattern is obtained by the first printhead module inkjet printing on the print medium along the first printing direction. The two-way reference pattern is obtained by the first printhead module and the second printhead module jointly inkjet printing on the print medium along the first printing direction.

[0068] In this embodiment, since the double-head calibration is used to calibrate the deviation between the two printhead modules, namely the first printhead module and the second printhead module, and the double-head reference pattern is printed by the first printhead module. Therefore, in this embodiment, it can be to control the second printhead module to inkjet print the double-head comparison pattern on the print medium along the first printing direction. The step reference pattern in the second image is aligned with the first printhead module, so the first printhead module can inkjet print the step comparison pattern on the print medium along the first printing direction. Since both the first printhead module and the second printhead module need to be calibrated bidirectionally, in this embodiment, it can be to control the first printhead module and the second printhead module to synchronously inkjet print the two-way reference pattern on the print medium along the first printing direction as the basis for subsequent bidirectional calibration.

[0069] In a feasible embodiment, the step reference pattern includes several groups of third reference line segments parallel to the first printing direction, and at least some groups of the third reference line segments in the step reference pattern are equidistantly distributed or distributed at an equal difference interval according to a fifth interval difference in a direction perpendicular to the first printing direction;

[0070] The step comparison pattern includes several groups of third comparison line segments corresponding to the third reference line segments, where at least one group of the third comparison line segments is preset to be aligned with the corresponding third reference line segment, and the intervals between the third comparison line segments other than the preset-aligned third comparison line segments and the corresponding third reference line segments are distributed at an equal difference interval in sequence according to a sixth interval difference.

[0071] In this embodiment, as Figure 7As shown, among several groups of third reference line segments parallel to the first printing direction in the step reference pattern, the third reference line segments in each group can also be evenly spaced with a fifth pitch difference in the direction perpendicular to the first printing direction, that is, with at least one group of third reference line segments as the center in the first printing direction, the pitch between adjacent third reference line segments is an arithmetic progression that gradually increases or gradually decreases according to the fifth pitch difference. Exemplarily, taking the fifth pitch difference as 1, the pitch between the group of third reference line segments serving as the center and the third reference line segments on both sides is 10, and the pitch between the third reference line segments on both sides and the adjacent third reference line segments in the direction away from the group of third reference line segments serving as the center is 11, so the pitch between adjacent third reference line segments gradually increases. It can be understood that each group of third reference line segments can be a single line segment, and each group of third reference line segments can also include at least two line segments. In the case where each group of third reference line segments includes at least two line segments, it is possible to avoid the absence of the third reference line segment caused by abnormal situations such as nozzle blockage and failure to successfully inkjet, which affects the determination of subsequent calibration parameters.

[0072] The step contrast pattern includes several groups of third contrast line segments corresponding to the third reference line segments, and at least one group of the third contrast line segments is preset to be aligned with the corresponding third reference line segment, that is, in this embodiment, there is a group of third contrast line segments among the groups of third contrast line segments that overlap with the corresponding third reference line segment in the direction perpendicular to the first printing direction. It can be understood that the groups of third contrast line segments and the corresponding third reference line segments may or may not overlap in the first printing direction. Preferably, the groups of third contrast line segments and the corresponding third reference line segments may partially overlap in the first printing direction, which is convenient for subsequent image recognition operations. The distances between the third contrast line segments other than the preset-aligned third contrast line segments and the corresponding third reference line segments are distributed at equal intervals according to a sixth interval difference, that is, the distances between the groups of third contrast line segments and the corresponding third reference line segments in the direction perpendicular to the first printing direction are an arithmetic progression that gradually increases or gradually decreases according to the sixth interval difference. Exemplarily, taking the sixth interval difference as 1, the group of third contrast line segments in the center overlaps with the corresponding third reference line segment in the direction perpendicular to the first printing direction (i.e., the distance is zero), and the distances between the third contrast line segments on both sides and the corresponding third reference line segments in the direction perpendicular to the first printing direction are 1. Thus, the distances between adjacent third contrast line segments and the corresponding third reference line segments in the direction perpendicular to the first printing direction gradually increase, 2, 3, 4... Further, according to the different relative positions of the third contrast line segments and the third reference line segments (i.e., the third contrast line segments are on the right or left side of the third reference line segments), the intervals can be set to +1 / -1, +2 / -2, +3 / -3, etc. Thus, in this embodiment, it can be determined whether the preset-aligned third contrast line segments and the corresponding third reference line segments are aligned (i.e., whether the distance between the preset-aligned third contrast line segments and the corresponding third reference line segments in the first printing direction is zero). If the preset-aligned third contrast line segments and the corresponding third reference line segments are not aligned, it indicates that there is a deviation in the step of the inkjet printing device. Moreover, since the distances between the groups of third contrast line segments and the corresponding third reference line segments in the direction perpendicular to the first printing direction are an arithmetic progression that gradually increases or gradually decreases according to the sixth interval difference, in this embodiment, the line deviation value corresponding to the third contrast line segment can also be obtained according to the distribution position of the actually aligned third contrast line segment in the equal-interval distribution according to the sixth interval difference as a calibration parameter.

[0073] Step S50: Control the first printhead module and the second printhead module to inkjet print a fourth image on the printing medium along the second printing direction, where the fourth image includes a bidirectional contrast pattern;

[0074] It should be noted that the bidirectional contrast pattern is obtained by jointly inkjet printing of the first printhead module and the second printhead module on the printing medium along the second printing direction.

[0075] Since the bidirectional reference pattern in this embodiment is obtained by inkjet printing along the first printing direction, in this embodiment, the first printhead module and the second printhead module can be controlled to inkjet print a fourth image on the printing medium along the second printing direction, where the fourth image includes a bidirectional comparison pattern, so as to obtain the bidirectional reference pattern and the bidirectional comparison pattern in the opposite printing directions for checking whether there are deviations in the inkjet printing operations of the first printhead module and the second printhead module in the opposite first printing direction and second printing direction in the inkjet printing device.

[0076] In some embodiments, the bidirectional reference pattern includes several groups of fourth reference line segments perpendicular to the first printing direction, and at least some groups of the fourth reference line segments in the bidirectional reference pattern are equidistantly distributed in the first printing direction, or are distributed at an equal difference interval according to a seventh interval difference;

[0077] The bidirectional comparison pattern includes several groups of fourth comparison line segments corresponding to the fourth reference line segments, where at least one group of the fourth comparison line segments is preset to be aligned with the corresponding fourth reference line segment, and the intervals between the fourth comparison line segments other than the preset-aligned fourth comparison line segments and the corresponding fourth reference line segments are distributed at an equal difference interval according to an eighth interval difference in sequence.

[0078] It should be noted that the bidirectional reference pattern includes the fourth reference line segments corresponding to the first printhead module and the fourth reference line segments corresponding to the second printhead module, and the bidirectional comparison pattern includes the fourth comparison line segments corresponding to the first printhead module and the fourth comparison line segments corresponding to the second printhead module.

[0079] As Figure 8 shown, the black line segments in the figure are the fourth reference line segments and the fourth comparison line segments corresponding to the first printhead module, and the purple line segments are the fourth reference line segments and the fourth comparison line segments corresponding to the second printhead module.

[0080] The bidirectional reference pattern includes several groups of fourth reference line segments perpendicular to the first printing direction. At least some groups of the fourth reference line segments in the bidirectional reference pattern are equally spaced in the first printing direction, or are distributed at an arithmetic progression with a seventh pitch difference, that is, the pitch between each group of the fourth reference line segments in the first printing direction is equal. Since the specifications of different inkjet printing devices are different, the pitch between each group of the fourth reference line segments can be set according to requirements. In addition, each group of the fourth reference line segments in this embodiment can also be distributed at an arithmetic progression with a seventh pitch difference in the first printing direction, that is, with at least one group of the fourth reference line segments as the center in the first printing direction, the pitch between adjacent fourth reference line segments is an arithmetic progression that gradually increases or gradually decreases according to the seventh pitch difference. Exemplarily, taking the seventh pitch difference as 1, the pitch between the group of the fourth reference line segments serving as the center and the fourth reference line segments on both sides is 10, and the pitch between the fourth reference line segments on both sides and the adjacent fourth reference line segments in the direction away from the group of the fourth reference line segments serving as the center is 11. Thus, the pitch between adjacent fourth reference line segments gradually increases, 12, 13, 14... It can be understood that each group of the fourth reference line segments can be a single line segment, and each group of the fourth reference line segments can also include at least two line segments. In the case where each group of the fourth reference line segments includes at least two line segments, it is possible to avoid the absence of the fourth reference line segment caused by abnormal situations such as nozzle clogging and unsuccessful inkjetting, which affects the determination of subsequent calibration parameters.

[0081] The two-way comparison pattern includes several groups of fourth comparison line segments corresponding to the fourth reference line segment, and at least one group of the fourth comparison line segments is preset to be aligned with the corresponding fourth reference line segment, that is, there is a group of fourth comparison line segments among the groups of fourth comparison line segments in this embodiment that overlap with the corresponding fourth reference line segment in the first printing direction. It can be understood that the groups of fourth comparison line segments and their corresponding fourth reference line segments may or may not overlap in the direction perpendicular to the first printing direction. Preferably, the groups of fourth comparison line segments and their corresponding fourth reference line segments may partially overlap in the direction perpendicular to the first printing direction, which is convenient for subsequent image recognition operations. The distances between the fourth comparison line segments other than the preset-aligned fourth comparison line segments and the corresponding fourth reference line segments are distributed at equal intervals according to an eighth interval difference, that is, the distances between the groups of fourth comparison line segments and their corresponding fourth reference line segments in the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the eighth interval difference. Exemplarily, taking the eighth interval difference as 1, the group of fourth comparison line segments in the center overlaps with the corresponding fourth reference line segment in the first printing direction (i.e., the distance is zero), and the distances between the fourth comparison line segments on both sides and their corresponding fourth reference line segments in the first printing direction are 1. Thus, the distances between adjacent fourth comparison line segments and their corresponding fourth reference line segments in the first printing direction increase sequentially, 2, 3, 4... Further, according to the relative positions of the fourth comparison line segments and the fourth reference line segments (i.e., whether the fourth comparison line segments are on the right or left side of the fourth reference line segments), the distances can be set to +1 / -1, +2 / -2, +3 / -3, etc. Thus, in this embodiment, it can be determined whether the preset-aligned fourth comparison line segments and the corresponding fourth reference line segments are aligned (i.e., whether the distance between the preset-aligned fourth comparison line segments and the corresponding fourth reference line segments in the first printing direction is zero). If the fourth comparison line segments corresponding to the first printhead module and the corresponding fourth reference line segments are not aligned, it indicates that there is a deviation between the first printhead module in the first printing direction and the second printing direction. If the fourth comparison line segments corresponding to the second printhead module and the corresponding fourth reference line segments are not aligned, it indicates that there is a deviation between the second printhead module in the first printing direction and the second printing direction. Moreover, since the distances between the groups of fourth comparison line segments and their corresponding fourth reference line segments in the first printing direction are in an arithmetic progression that gradually increases or gradually decreases according to the eighth interval difference, this embodiment can also obtain the line deviation value corresponding to the fourth comparison line segment as a calibration parameter according to the distribution position of the fourth comparison line segment actually aligned with the fourth reference line segment in the equal-interval distribution according to the eighth interval difference.

[0082] In addition, it can be understood that the third image and / or the fourth image may further include other calibration patterns that can be printed in one pass, such as break detection lines for break detection and color registration detection lines for color registration detection. Alternatively, before step S60, the first printhead module and the second printhead module are controlled to ink-jet print a fifth image on the print medium, where the fifth image includes at least one of break detection lines for break detection and color registration detection lines for color registration detection.

[0083] Step S60: Image acquisition is performed on the print medium to obtain an overall calibration image, and calibration parameters of the inkjet printing device are obtained based on the overall calibration image.

[0084] In this embodiment, the print medium can be image-acquired by an image acquisition device such as a camera or a scanner to obtain an overall calibration image, which includes the first image, the second image, the third image, and the fourth image, that is, at least includes a double-head reference pattern and a corresponding double-head comparison pattern, a step reference pattern and a corresponding step comparison pattern, and a bidirectional reference pattern and a corresponding bidirectional comparison pattern. Furthermore, the overall calibration image can be recognized by means of edge recognition algorithms such as Canny, Sobel, and Prewitt, convolutional neural networks, image segmentation algorithms, etc., to obtain the line deviation value between the target reference line segment and the target comparison line segment as the calibration parameter, and then the inkjet printing device is calibrated based on the calibration parameter. Exemplarily, the calibration parameter describes the line deviation value between the target reference line segment and the corresponding target comparison line segment, and the target reference line segment includes at least one of the double-head reference pattern, the step reference pattern, and the bidirectional reference pattern. It can be understood that the step of obtaining the calibration parameters of the inkjet printing device based on the overall calibration image can be executed by the inkjet printing device or by the host computer of the inkjet printing device. Thus, in this embodiment, the stepping of the inkjet printing device and the relative position of the printed pattern can be corrected by the line deviation value to calibrate the inkjet printing device. Further, in this embodiment, after the inkjet printing device is calibrated based on the calibration parameter, step S10 can be continued until the line deviation values are all less than a predetermined difference threshold, and then the calibration parameter can be determined as a valid parameter to further improve the accuracy of calibrating the inkjet printing device.

[0085] An embodiment of the present application provides an inkjet printing calibration method, which is applied to an inkjet printing device. The inkjet printing device includes a first printhead module and a second printhead module. By controlling the first printhead module to print a first image on a printing medium, where the first image includes a double-head reference pattern, as a reference for double-head calibration between the first printhead module and the second printhead module. Then, control the printing medium to move a first step distance, and control the first printhead module to print a second image on the printing medium, where the second image includes a step reference pattern, as a reference for step calibration of the first printhead module. Then, the printing medium can be controlled to move a second step distance so that in the first printing direction, the first image is aligned with the second printhead module, and the second image is aligned with the first printhead module. Then, control the first printhead module and the second printhead module to inkjet print a third image on the printing medium along the first printing direction, where the third image at least includes a bidirectional reference pattern, a double-head comparison pattern, and a step comparison pattern; control the first printhead module and the second printhead module to inkjet print a fourth image on the printing medium along the second printing direction, where the second printing direction is opposite to the first printing direction, and the fourth image includes a bidirectional comparison pattern. Thus, compared with the traditional calibration method where at least six inkjet printing operations are required for the calibration graphics needed for independent double-head calibration, step calibration, and bidirectional calibration, in this embodiment, at least the reference line segments and comparison line segments required for double-head calibration, step calibration, and bidirectional calibration can be printed through four inkjet printing operations. Then, image acquisition is performed on the printing medium to obtain an overall calibration image, so as to obtain the calibration parameters of the inkjet printing device based on the overall calibration image. Therefore, compared with the traditional calibration method where calibration work such as double-head calibration, step calibration, and bidirectional calibration needs to be carried out separately, in this embodiment, by integrating and simplifying the printing process, multiple calibration graphs for the inkjet printing device can be integrated on the same printing medium with fewer printing times, and then synchronous execution of multiple calibrations for the inkjet printing device can be achieved, thereby improving the calibration efficiency of the inkjet printing device.

[0086] Based on the first embodiment of the present application, in the second embodiment of the present application, for the same or similar content as in the above-mentioned embodiment 1, reference can be made to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 9 , the third image further includes a break detection pattern, and the break detection pattern includes a first break detection line segment corresponding to the first printhead module and a second break detection line segment corresponding to the second printhead module;

[0087] The number of the first break detection line segments is not less than the number of printheads of the first printhead module, and the first break detection line segments are parallel to the first printing direction;

[0088] The number of the second blank detection line segments is not less than the number of nozzles of the second nozzle module, and the second blank detection line segments are parallel to the first printing direction.

[0089] It should be noted that the blank detection pattern is used to detect abnormal conditions such as clogging and damage of the nozzles in the first nozzle module and the second nozzle module.

[0090] In this embodiment, the third image further includes a blank detection pattern, which includes a first blank detection line segment corresponding to the first nozzle module and a second blank detection line segment corresponding to the second nozzle module. The number of the first blank detection line segments is not less than the number of nozzles of the first nozzle module, and the first blank detection line segments are parallel to the first printing direction. Thus, each nozzle in the first nozzle module can print at least one first blank detection line segment. Similarly, the number of the second blank detection line segments is not less than the number of nozzles of the second nozzle module, and the second blank detection line segments are parallel to the first printing direction. Thus, each nozzle in the second nozzle module can print at least one second blank detection line segment.

[0091] In a feasible embodiment, the adjacent first blank detection line segments in the same row in the direction parallel to the first printing direction partially overlap or do not overlap, and the distance between the adjacent first blank detection line segments in the same row in the direction perpendicular to the first printing direction is equal to the nozzle pitch of the first nozzle module, so that the first blank detection line segments in the same row are distributed in a stepped manner;

[0092] The adjacent second blank detection line segments in the same row in the direction parallel to the first printing direction partially overlap or do not overlap, and the distance between the adjacent second blank detection line segments in the same row in the direction perpendicular to the first printing direction is equal to the nozzle pitch of the second nozzle module, so that the second blank detection line segments in the same row are distributed in a stepped manner.

[0093] It should be noted that the nozzle pitch of the first nozzle module is the distance between adjacent nozzles in the first nozzle module in the direction perpendicular to the first printing direction. The nozzle pitch of the second nozzle module is the distance between adjacent nozzles in the second nozzle module in the direction perpendicular to the first printing direction.

[0094] Such as Figure 9As shown, between adjacent first break detection line segments in the same row parallel to the first printing direction, there is partial overlap or no overlap, and the spacing between adjacent first break detection line segments in the same row in the direction perpendicular to the first printing direction is equal to the nozzle pitch of the first printhead module, so that the first break detection line segments in the same row are distributed in a stepped manner. Therefore, in step S40, in this embodiment, the first printhead module and the second printhead module are controlled to perform inkjet printing on the printing medium along the first printing direction. At this time, since the spacing between adjacent first break detection line segments is equal to the nozzle pitch of the first printhead module, during the inkjet printing process of the first printhead module along the first printing direction, each first break detection line segment corresponds to a nozzle. When moving to the printing position of a certain first break detection line segment, the first printhead module just aligns with this printing position to eject ink droplets, so that the printed first break detection line segments correspond to the nozzles in the first printhead module.

[0095] Similarly, between adjacent second break detection line segments in the same row parallel to the first printing direction, there is partial overlap or no overlap, and the spacing between adjacent second break detection line segments in the same row in the direction perpendicular to the first printing direction is equal to the nozzle pitch of the second printhead module, so that the second break detection line segments in the same row are distributed in a stepped manner. Therefore, in step S40, in this embodiment, the second printhead module and the second printhead module are controlled to perform inkjet printing on the printing medium along the second printing direction. At this time, since the spacing between adjacent second break detection line segments is equal to the nozzle pitch of the second printhead module, during the inkjet printing process of the second printhead module along the second printing direction, each second break detection line segment corresponds to a nozzle. When moving to the printing position of a certain second break detection line segment, the second printhead module just aligns with this printing position to eject ink droplets, so that the printed second break detection line segments correspond to the nozzles in the second printhead module.

[0096] In some embodiments, the third image further includes a color registration detection pattern, and the color registration detection pattern includes a first color registration line segment corresponding to the first printhead module and a second color registration line segment corresponding to the second printhead module;

[0097] The first color registration line segment includes a first color registration reference line segment and a first color registration comparison line segment. The first color registration reference line segment includes several groups of fifth reference line segments perpendicular to the first printing direction, and each group of fifth reference line segments is equidistantly distributed in the first printing direction, or is distributed at an equal difference interval according to a ninth spacing difference;

[0098] The first set of color comparison line segments includes several groups of fifth comparison line segments corresponding to the fifth reference line segments, where at least one group of fifth comparison line segments is preset to be aligned with the corresponding fifth reference line segment, and the distances between the fifth comparison line segments other than the preset-aligned fifth comparison line segments and the corresponding fifth reference line segments are distributed in an arithmetic progression according to a tenth distance difference in sequence;

[0099] The second set of color line segments includes a second set of color reference line segments and second set of color comparison line segments. The second set of color reference line segments includes several groups of sixth reference line segments perpendicular to the first printing direction, and each group of sixth reference line segments is equidistantly distributed in the first printing direction, or is distributed in an arithmetic progression according to an eleventh distance difference;

[0100] The second set of color comparison line segments includes several groups of sixth comparison line segments corresponding to the sixth reference line segments, where at least one group of sixth comparison line segments is preset to be aligned with the corresponding sixth reference line segment, and the distances between the sixth comparison line segments other than the preset-aligned sixth comparison line segments and the corresponding sixth reference line segments are distributed in an arithmetic progression according to a twelfth distance difference in sequence.

[0101] In this embodiment, the first color registration reference line segments include several groups of fifth reference line segments perpendicular to the first printing direction. Each group of fifth reference line segments is equidistantly distributed in the first printing direction, or is distributed at an arithmetic progression with a ninth pitch difference, that is, the pitch between each group of fifth reference line segments in the first printing direction is equal. Since the specifications of different inkjet printing devices are different, the pitch between each group of fifth reference line segments can be set according to requirements. In addition, each group of fifth reference line segments in this embodiment can also be distributed at an arithmetic progression with a ninth pitch difference in the first printing direction, that is, with at least one group of fifth reference line segments as the center in the first printing direction, the pitch between adjacent fifth reference line segments is an arithmetic progression that gradually increases or gradually decreases according to the ninth pitch difference. Each group of fifth reference line segments can be a single line segment, or each group of fifth reference line segments can include at least two line segments. The first color registration comparison line segments include several groups of fifth comparison line segments corresponding to the fifth reference line segments, and at least one group of fifth comparison line segments is preset to be aligned with the corresponding fifth reference line segment, that is, there is a group of fifth comparison line segments among each group of fifth comparison line segments in this embodiment that overlaps with the corresponding fifth reference line segment in the first printing direction. It can be understood that each group of fifth comparison line segments and the corresponding fifth reference line segments may or may not overlap in the direction perpendicular to the first printing direction. Preferably, each group of fifth comparison line segments and the corresponding fifth reference line segments can partially overlap in the direction perpendicular to the first printing direction, which is convenient for subsequent image recognition operations. The pitch between the fifth comparison line segments other than the preset-aligned fifth comparison line segments and the corresponding fifth reference line segments is distributed at an arithmetic progression with a tenth pitch difference in sequence, that is, the pitch between each group of fifth comparison line segments and the corresponding fifth reference line segments in the first printing direction is an arithmetic progression that gradually increases or gradually decreases according to the tenth pitch difference in sequence. Thus, in this embodiment, it can be determined whether the preset-aligned fifth comparison line segments and the corresponding fifth reference line segments are aligned (that is, whether the pitch between the preset-aligned fifth comparison line segments and the corresponding fifth reference line segments in the first printing direction is zero). If the fifth comparison line segments corresponding to the first nozzle module and the corresponding fifth reference line segments are not aligned, it indicates that there is a color registration deviation in the first nozzle module. Moreover, since the pitch between each group of fifth comparison line segments and the corresponding fifth reference line segments in the first printing direction is an arithmetic progression that gradually increases or gradually decreases according to the tenth pitch difference in sequence, in this embodiment, the line segment deviation value corresponding to the fifth comparison line segment can also be obtained according to the distribution position of the fifth comparison line segment actually aligned with the fifth reference line segment in the distribution at an arithmetic progression with a tenth pitch difference as a calibration parameter.

[0102] The second set of color reference line segments includes several groups of sixth reference line segments perpendicular to the first printing direction. Each group of sixth reference line segments is equidistantly distributed in the first printing direction, or is distributed at an arithmetic difference interval according to an eleventh pitch difference, that is, the pitch between each group of sixth reference line segments in the first printing direction is equal. Since the specifications of different inkjet printing devices are different, the pitch between each group of sixth reference line segments can be set according to requirements. In addition, each group of sixth reference line segments in this embodiment can also be distributed at an arithmetic difference interval according to an eleventh pitch difference in the first printing direction, that is, with at least one group of sixth reference line segments as the center in the first printing direction, the pitch between adjacent sixth reference line segments is an arithmetic sequence that gradually increases or gradually decreases according to the eleventh pitch difference. Each group of sixth reference line segments can be a single line segment, or each group of sixth reference line segments can include at least two line segments. The second set of color comparison line segments includes several groups of sixth comparison line segments corresponding to the sixth reference line segments, and at least one group of sixth comparison line segments is preset to be aligned with the corresponding sixth reference line segment, that is, there is a group of sixth comparison line segments that overlap with the corresponding sixth reference line segment in the first printing direction in each group of sixth comparison line segments in this embodiment. It can be understood that each group of sixth comparison line segments and the corresponding sixth reference line segments may or may not overlap in the direction perpendicular to the first printing direction. Preferably, each group of sixth comparison line segments and the corresponding sixth reference line segments can partially overlap in the direction perpendicular to the first printing direction, which is convenient for subsequent image recognition operations. The pitch between the sixth comparison line segments other than the preset-aligned sixth comparison line segments and the corresponding sixth reference line segments is distributed at an arithmetic difference interval according to a twelfth pitch difference, that is, the pitch between each group of sixth comparison line segments and the corresponding sixth reference line segments in the first printing direction is an arithmetic sequence that gradually increases or gradually decreases according to the twelfth pitch difference. Thus, in this embodiment, it can be determined whether the preset-aligned sixth comparison line segments and the corresponding sixth reference line segments are aligned (that is, whether the pitch between the preset-aligned sixth comparison line segments and the corresponding sixth reference line segments in the first printing direction is zero). If the sixth comparison line segments corresponding to the first nozzle module and the corresponding sixth reference line segments are not aligned, it indicates that there is a color registration deviation in the first nozzle module. Moreover, since the pitch between each group of sixth comparison line segments and the corresponding sixth reference line segments in the first printing direction is an arithmetic sequence that gradually increases or gradually decreases according to the twelfth pitch difference, in this embodiment, the line segment deviation value corresponding to the sixth comparison line segment can also be obtained according to the distribution position of the actually aligned sixth comparison line segment in the arithmetic difference interval distribution according to the twelfth pitch difference as a calibration parameter.

[0103] In some embodiments, if the first nozzle module is a color ink nozzle module, the color ink nozzle module includes inkjet units for printing a first primary color, a second primary color, a third primary color, and a fourth primary color. The first color matching reference line segment includes a fifth reference line segment of the first primary color, and the first color matching comparison line segment includes fifth comparison line segments of the second primary color, the third primary color, and the fourth primary color.

[0104] At least one fifth comparison line segment of the second primary color is preset to be aligned with the corresponding fifth reference line segment, and the distances between the fifth comparison line segments of the second primary color and the corresponding fifth reference line segment, except for the preset-aligned ones, are distributed in an arithmetic progression according to a tenth pitch difference.

[0105] At least one fifth comparison line segment of the third primary color is preset to be aligned with the corresponding fifth reference line segment, and the distances between the fifth comparison line segments of the third primary color and the corresponding fifth reference line segment, except for the preset-aligned ones, are distributed in an arithmetic progression according to a tenth pitch difference.

[0106] At least one fifth comparison line segment of the fourth primary color is preset to be aligned with the corresponding fifth reference line segment, and the distances between the fifth comparison line segments of the fourth primary color and the corresponding fifth reference line segment, except for the preset-aligned ones, are distributed in an arithmetic progression according to a tenth pitch difference.

[0107] In this embodiment, it should be noted that the first primary color is one of the four primary colors: black, yellow, cyan, and magenta, and the second primary color, the third primary color, and the fourth primary color are the other three primary colors except the first primary color.

[0108] Such as Figure 10As shown, the black line segments in the figure are the fifth reference line segments of the first set of color reference line segments including the first primary color, the yellow line segments are the fifth comparison line segments of the second primary color, the cyan line segments are the fifth comparison line segments of the third primary color, and the magenta line segments are the fifth comparison line segments of the fourth primary color. Thus, in this embodiment, at least one group of the fifth comparison line segments of the second primary color in the color registration detection pattern is preset to be aligned with the corresponding fifth reference line segments. Except for the preset-aligned fifth comparison line segments of the second primary color, the distances between the fifth comparison line segments of the second primary color and the corresponding fifth reference line segments are distributed at equal intervals according to the tenth interval difference. Thus, it can be determined whether the preset-aligned fifth comparison line segments of the second primary color are aligned with the corresponding fifth reference line segments. If not aligned, it indicates that there is a color registration deviation in the second primary color. And by identifying the fifth comparison line segments of the second primary color that are aligned with the fifth reference line segments, the corresponding line segment deviation values are determined. At least one group of the fifth comparison line segments of the third primary color is preset to be aligned with the corresponding fifth reference line segments. Except for the preset-aligned fifth comparison line segments of the third primary color, the distances between the fifth comparison line segments of the third primary color and the corresponding fifth reference line segments are distributed at equal intervals according to the tenth interval difference. Thus, it can be determined whether the preset-aligned fifth comparison line segments of the third primary color are aligned with the corresponding fifth reference line segments. If not aligned, it indicates that there is a color registration deviation in the third primary color. And by identifying the fifth comparison line segments of the third primary color that are aligned with the fifth reference line segments, the corresponding line segment deviation values are determined. At least one group of the fifth comparison line segments of the fourth primary color is preset to be aligned with the corresponding fifth reference line segments. Except for the preset-aligned fifth comparison line segments of the fourth primary color, the distances between the fifth comparison line segments of the fourth primary color and the corresponding fifth reference line segments are distributed at equal intervals according to the tenth interval difference. Thus, it can be determined whether the preset-aligned fifth comparison line segments of the fourth primary color are aligned with the corresponding fifth reference line segments. If not aligned, it indicates that there is a color registration deviation in the fourth primary color. And by identifying the fifth comparison line segments of the fourth primary color that are aligned with the fifth reference line segments, the corresponding line segment deviation values are determined.

[0109] In this embodiment, break detection lines and / or color registration detection lines are added to the third image. Thus, without increasing more printing movement times, break calibration and color registration calibration can be achieved, and further, the calibration efficiency of the inkjet printing device is improved.

[0110] Based on the first embodiment of the present application, in the third embodiment of the present application, for the same or similar content as in the above-mentioned first embodiment, reference can be made to the above introduction and will not be elaborated hereinafter. On this basis, please refer to Figure 11 , step S60 may include steps S61 and S62:

[0111] Step S61, identifying the target comparison line segments in the overall calibration image that are aligned with the target reference line segments, where the target reference line segments include at least one of a double-headed reference pattern, a step reference pattern, and a bidirectional reference pattern;

[0112] Step S62: Determine a line segment deviation value according to the distribution position of the target reference line segment aligned with the target comparison line segment, and use the line segment deviation value as a calibration parameter.

[0113] It should be noted that the target reference line segment is a reference line segment selected for calibrating the inkjet printing device, including at least one of a double-headed reference pattern, a stepping reference pattern, and a bidirectional reference pattern. The target comparison line segment is a comparison line segment corresponding to the target reference line segment, such as a double-headed comparison pattern, a stepping comparison pattern, and a bidirectional comparison pattern.

[0114] In this embodiment, the target reference line segment and the target comparison line segment in the overall calibration image can be recognized by means of edge recognition algorithms such as Canny, Sobel, and Prewitt, convolutional neural networks, image segmentation algorithms, etc. Since the target reference line segment and the target comparison line segment are arranged in an arithmetic spacing distribution with a predetermined spacing difference in this embodiment, the line segment deviation value can be determined according to the distribution position of the target reference line segment aligned with the target comparison line segment. The distribution position is the position relative to the target comparison line segment aligned with the preset. Exemplarily, if the distribution position is two spacings away from the target comparison line segment aligned with the preset, the line segment deviation value is 2 * the predetermined spacing difference. Then, the line segment deviation value is used as a calibration parameter. Thus, in this embodiment, the line segment deviation value can be quickly determined through the distribution position of the target comparison line segment aligned with the target reference line segment. Compared with the method of using graph recognition to calculate the distance between line segments as the line segment deviation value, the recognition efficiency of the calibration parameter can be further improved in this embodiment.

[0115] In a feasible implementation manner, the target reference line segment is marked with a line segment deviation parameter; Step S60 may include Step S63 and Step S64:

[0116] Step S63: Recognize the target comparison line segment aligned with the target reference line segment in the overall calibration image, where the target reference line segment includes at least one of a double-headed reference pattern, a stepping reference pattern, and a bidirectional reference pattern;

[0117] Step S64: Recognize the line segment deviation parameter marked on the target reference line segment aligned with the target comparison line segment, and use the line segment deviation parameter as the line segment deviation value.

[0118] It should be noted that the target reference line segment is marked with a line segment deviation parameter, and the line segment deviation parameter is used to describe the predetermined spacing between the target reference line segment and the corresponding target comparison line segment. The predetermined spacing is determined by the spacing difference corresponding to the target reference line segment and the relative position (i.e., the distribution position) between the target reference line segment and the target comparison line segment aligned with the preset.

[0119] See Figure 12 Figure 12 , taking the target reference line segment as an example of the step reference pattern, -4, -3, -2, -1, 0, +1, +2, +3, +4 in the figure are line segment deviation parameters, which are used to describe the predetermined distance between the step reference pattern and the corresponding step comparison pattern. The predetermined distance is a multiple of the sixth distance difference.

[0120] After identifying the target comparison line segment aligned with the target reference line segment in the overall calibration image in this embodiment, the line segment deviation parameter marked by the target reference line segment aligned with the target comparison line segment can be directly identified, and the line segment deviation parameter is used as the line segment deviation value. Compared with the method of using figure recognition to calculate the distance between line segments as the line segment deviation value and determining the line segment deviation value according to the distribution position, this embodiment can further improve the recognition efficiency of calibration parameters.

[0121] In a feasible implementation manner, the third image further includes a break detection pattern;

[0122] Step S60 may further include steps A10 and A20:

[0123] Step A10, identifying the line segment form of the break detection line segment in the overall calibration image to obtain line segment form information;

[0124] Step A20, according to the line segment form information, taking the nozzle corresponding to the break detection line segment with an abnormal line segment form as an abnormal nozzle, and using the description information of the abnormal nozzle as a calibration parameter.

[0125] It should be noted that the line segment form information is a description of the line segment form of the break detection pattern. For example, whether there are abnormal conditions such as vacancies, breaks in the line segment, and unclear lines in the break detection pattern.

[0126] Different from calibration requirements such as double - head calibration, step calibration, and two - way calibration, since the purpose of break detection is to identify nozzles with abnormalities, this embodiment can identify the line segment form of the break detection line segment in the overall calibration image to obtain line segment form information. Then, according to the line segment form information, the break detection line segments with abnormal line segment forms are screened out. Subsequently, the nozzles corresponding to the break detection line segments with abnormal line segment forms are taken as abnormal nozzles, and the description information of the abnormal nozzles is used as a calibration parameter. The description information of the abnormal nozzles may be information such as the code of the abnormal nozzle, its position on the first nozzle module or the second nozzle module, and the line segment form. Furthermore, this embodiment can perform processing operations such as repairing and deactivating the abnormal nozzles according to the description information of the abnormal nozzles in the calibration parameters.

[0127] In this embodiment, the line shape of the break detection line segment in the overall calibration image is recognized to obtain line shape information. According to the line shape information, the nozzle corresponding to the break detection line segment with an abnormal line shape is used as an abnormal nozzle, and the description information of the abnormal nozzle is used as a calibration parameter. Thus, this embodiment realizes the break detection for the inkjet printing device.

[0128] In a feasible implementation manner, the third image further includes a color registration detection pattern, and the color registration detection pattern includes a first color registration line segment corresponding to the first nozzle module and a second color registration line segment corresponding to the second nozzle module;

[0129] Step S60 may further include steps B10 to B40:

[0130] Step B10, identify a first color registration comparison line segment in the first color registration line segment that aligns with the first color registration reference line segment, and a second color registration comparison line segment in the second color registration line segment that aligns with the second color registration reference line segment;

[0131] Step B20, determine the line segment deviation value corresponding to the first nozzle module according to the distribution position of the first color registration reference line segment aligned with the first color registration comparison line segment or the marked line segment deviation parameter;

[0132] Step B30, determine the line segment deviation value corresponding to the second nozzle module according to the distribution position of the second color registration reference line segment aligned with the second color registration comparison line segment or the marked line segment deviation parameter;

[0133] Step B40, use the line segment deviation value corresponding to the first nozzle module and the line segment deviation value corresponding to the second nozzle module as calibration parameters.

[0134] It should be noted that the third image further includes a color registration detection pattern, and the color registration detection pattern includes a first color registration line segment corresponding to the first nozzle module and a second color registration line segment corresponding to the second nozzle module. The first color registration line segment is used for the color registration detection of the first nozzle module, and the second color registration line segment is used for the color registration detection of the second nozzle module. The first color registration line segment includes a first color registration reference line segment and a first color registration comparison line segment, and the second color registration line segment includes a second color registration reference line segment and a second color registration comparison line segment.

[0135] In this embodiment, the first color matching comparison line segment aligned with the first color matching reference line segment in the first color matching line segment and the second color matching comparison line segment aligned with the second color matching reference line segment in the second color matching line segment can be identified by means of edge recognition algorithms such as Canny, Sobel, and Prewitt, convolutional neural networks, image segmentation algorithms, etc. Since the first color matching reference line segment and the first color matching comparison line segment are arranged in an arithmetic spacing distribution with a predetermined spacing difference in this embodiment, the line segment deviation value can be determined according to the distribution position of the first color matching reference line segment aligned with the first color matching comparison line segment, and the distribution position is relative to the position of the first color matching comparison line segment aligned with the preset. Exemplarily, if the distribution position is two spacings away from the first color matching comparison line segment aligned with the preset, the line segment deviation value is 2 * the predetermined spacing difference. Then, the line segment deviation value is used as the calibration parameter. Of course, when the line segment deviation parameter is marked on the first color matching reference line segment, the line segment deviation parameter marked on the first color matching reference line segment aligned with the first color matching comparison line segment can be identified, and the line segment deviation parameter is used as the line segment deviation value. Thus, in this embodiment, the line segment deviation value can be quickly determined by the line segment deviation parameter marked on the distribution position of the first color matching comparison line segment aligned with the first color matching reference line segment. Similarly, since the second color matching reference line segment and the second color matching comparison line segment are arranged in an arithmetic spacing distribution with a predetermined spacing difference in this embodiment, the line segment deviation value can be determined according to the distribution position of the second color matching reference line segment aligned with the second color matching comparison line segment, and the distribution position is relative to the position of the second color matching comparison line segment aligned with the preset. Exemplarily, if the distribution position is two spacings away from the second color matching comparison line segment aligned with the preset, the line segment deviation value is 2 * the predetermined spacing difference. Then, the line segment deviation value is used as the calibration parameter. Of course, when the line segment deviation parameter is marked on the second color matching reference line segment, the line segment deviation parameter marked on the second color matching reference line segment aligned with the second color matching comparison line segment can be identified, and the line segment deviation parameter is used as the line segment deviation value. Thus, in this embodiment, the line segment deviation value can be quickly determined by the line segment deviation parameter marked on the distribution position of the second color matching comparison line segment aligned with the second color matching reference line segment. Then, in this embodiment, the line segment deviation value corresponding to the first nozzle module and the line segment deviation value corresponding to the second nozzle module can be used as the calibration parameter. Compared with the method of using the figure recognition to calculate the distance between line segments as the line segment deviation value, the recognition efficiency of the calibration parameter can be further improved in this embodiment.

[0136] See Figure 13 , Figure 13This is a schematic diagram of the scenario of the inkjet printing calibration method involved in the embodiments of the present application. During the first pass printing, the color inkjet head module is controlled to print a double-headed reference pattern (double-headed reference vertical pattern and double-headed reference horizontal pattern) from left to right on the printing medium, and then the printing medium is controlled to move a first step distance in the direction of the white inkjet head module, and during the second pass printing, the color inkjet head module is controlled to print a step reference pattern from right to left on the printing medium. Then, the printing medium is controlled to move a second step distance in the direction of the white inkjet head module; during the third pass printing, the color inkjet head module and the white inkjet head module are controlled to print void detection lines, color registration detection lines, and bidirectional reference patterns from left to right on the printing medium. In addition, the white inkjet head module prints a double-headed comparison pattern alone, and the color inkjet head module prints a step comparison pattern alone. During the fourth pass printing, the color inkjet head module and the white inkjet head module are controlled to print a bidirectional comparison pattern from right to left on the printing medium. Then, the printing medium is image-captured to obtain an overall calibration image, so as to obtain the calibration parameters of the inkjet printing device based on the overall calibration image. In this embodiment, through four-pass printing, the void detection lines, color registration detection lines, double-headed reference lines and double-headed comparison lines, step reference patterns and step comparison patterns, and bidirectional reference patterns and bidirectional comparison patterns can be printed to complete void calibration, color registration calibration, double-headed calibration, step calibration, and bidirectional calibration, effectively improving the calibration efficiency. See Figure 14 , Figure 14 This is an example diagram of the overall calibration image involved in the embodiments of the present application. As Figure 14 shown, after the four-pass printing operations in Figure 13 , in this embodiment, the calibration graphics required for void calibration, color registration calibration, double-headed calibration, step calibration, and bidirectional calibration are integrated on the same printing medium, thereby obtaining Figure 14 this overall calibration image.

[0137] It should be noted that the above examples are only for understanding the present application and do not constitute a limitation on the inkjet printing calibration method of the present application. Based on this technical concept, more forms of simple transformations are within the protection scope of the present application.

[0138] As Figure 15 shown, the embodiments of the present application provide an inkjet printing device, and the inkjet printing device includes:

[0139] A slide rail;

[0140] A first print head module and a second print head module, which are arranged on the slide rail;

[0141] A conveying device, which is arranged below the slide rail and is used for conveying the printing medium;

[0142] A control unit, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the inkjet printing calibration method as described above.

[0143] As Figure 15 shown, in this embodiment, an inkjet printing device is provided. The inkjet printing device includes a slide rail, a first print head module, a second print head module, a conveying device, and a control unit. A printing medium for carrying printing content can be placed on the conveying device, and the conveying device can convey the printing medium below the slide rail for the first print head module and the second print head module to perform printing. Exemplarily, the conveying device can be a belt conveyor, a roller conveyor, or other devices for conveying. The first print head module and the second print head module are arranged on the slide rail, so that the first print head module and the second print head module can slide on the slide rail to perform inkjet printing on the printing medium while moving. The control unit can include a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the inkjet printing calibration method as described above. Thus, when executing the computer program, the control unit can implement the steps of the inkjet printing calibration method in the above embodiments of the present application by controlling the slide rail, the first print head module, the second print head module, and the conveying device. It can be understood that the control unit can be an element integrated inside the inkjet printing device (such as a microcontroller), or an element independent of the inkjet printing device (such as a desktop computer, a tablet computer, etc. communicatively connected to the inkjet printing device).

[0144] The inkjet printing device provided by the present application adopts the inkjet printing calibration method in the above embodiment, and can solve the technical problem of low calibration efficiency of existing inkjet printing devices. Compared with the prior art, the beneficial effects of the inkjet printing device provided by the present application are the same as those of the inkjet printing calibration method provided in the above embodiment, and other technical features in the inkjet printing device are the same as those disclosed in the method of the previous embodiment, and will not be elaborated here.

[0145] It should be understood that the various parts disclosed in the present application can be implemented by hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0146] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0147] The present application provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the inkjet printing calibration method in the above embodiments. The computer-readable storage medium provided by the present application may be, for example, a USB flash drive, but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system or device, or any combination of the above.

[0148] The present application further provides a computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the inkjet printing calibration method as described above are implemented.

[0149] The computer program product provided by the present application can solve the technical problem of low calibration efficiency of existing inkjet printing devices. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as those of the inkjet printing calibration method provided by the above embodiments, and will not be elaborated herein.

[0150] The above are only partial embodiments of the present application, and thus do not limit the patent scope of the present application. All equivalent structural transformations made under the technical concept of the present application by using the content of the specification and drawings of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An inkjet printing calibration method, characterized in that: Applied to an inkjet printing device, the inkjet printing device includes a first nozzle module and a second nozzle module, and the inkjet printing calibration method includes: Controlling the first nozzle module to print a first image on a printing medium, wherein the first image includes a double-head reference pattern; Controlling the printing medium to move a first step distance, and controlling the first nozzle module to print a second image on the printing medium, wherein the second image includes a step reference pattern; Controlling the printing medium to move a second step distance so that the first image is aligned with the second nozzle module in a first printing direction, and the second image is aligned with the first nozzle module; Controlling the first nozzle module and the second nozzle module to inkjet print a third image on a printing medium along a first printing direction, wherein the third image at least includes a bidirectional reference pattern, a dual-head contrast pattern corresponding to the dual-head reference pattern, and a step contrast pattern corresponding to the step reference pattern; Controlling the first nozzle module and the second nozzle module to inkjet print a fourth image on a printing medium along a second printing direction, wherein the second printing direction is opposite to the first printing direction, and the fourth image includes a bidirectional contrast pattern corresponding to the bidirectional reference pattern; An image is captured on the printing medium to obtain an overall calibration image, so as to obtain calibration parameters of the inkjet printing device based on the overall calibration image.

2. The inkjet printing calibration method according to claim 1, characterized in that: The double-head reference pattern includes a double-head reference longitudinal pattern and a double-head reference transverse pattern; The double-head reference longitudinal pattern comprises a plurality of groups of first reference line segments perpendicular to the first printing direction, and at least some of the first reference line segments in the double-head reference longitudinal pattern are distributed equidistantly in the first printing direction, or are distributed equidistantly according to a first spacing difference; The double-head reference transverse pattern includes a plurality of groups of second reference line segments parallel to the first printing direction, and at least some of the second reference line segments in the double-head reference transverse pattern are equidistantly distributed perpendicular to the first printing direction, or are equidistantly distributed according to a second spacing difference.

3. The inkjet printing calibration method according to claim 2, characterized in that: The double-end contrast pattern includes a double-end contrast longitudinal pattern and a double-end contrast transverse pattern; The double-head contrast longitudinal pattern comprises a plurality of groups of first contrast line segments corresponding to the first reference line segments, wherein at least one group of first contrast line segments is preset aligned with the corresponding first reference line segments, and the spacings between the first contrast line segments other than the preset aligned first contrast line segments and the corresponding first reference line segments are sequentially distributed in arithmetic intervals according to the third spacing difference; The double-head contrast transverse pattern includes several groups of second contrast line segments corresponding to the second reference line segments, wherein at least one group of second contrast line segments is preset aligned with the corresponding second reference line segments, and the spacing between the second contrast line segments other than the preset aligned second contrast line segments and the corresponding second reference line segments is distributed in arithmetic intervals according to the fourth spacing difference.

4. The inkjet printing calibration method according to claim 1, characterized in that: The step reference pattern comprises a plurality of groups of third reference line segments parallel to the first printing direction, and at least some groups of the third reference line segments in the step reference pattern are equidistantly distributed in a direction perpendicular to the first printing direction, or are equidistantly distributed according to a fifth spacing difference; The step comparison pattern includes several groups of third comparison line segments corresponding to the third reference line segments, wherein at least one group of third comparison line segments is preset aligned with the corresponding third reference line segments, and the spacing between the third comparison line segments other than the preset aligned third comparison line segments and the corresponding third reference line segments is distributed in arithmetic intervals according to the sixth spacing difference.

5. The inkjet printing calibration method according to claim 1, characterized in that: The bidirectional reference pattern comprises a plurality of groups of fourth reference line segments perpendicular to the first printing direction, and at least some of the fourth reference line segments in the bidirectional reference pattern are equidistantly distributed in the first printing direction, or are equidistantly distributed according to a seventh spacing difference; The bidirectional contrast pattern includes several groups of fourth contrast line segments corresponding to the fourth reference line segments, wherein at least one group of fourth contrast line segments is preset aligned with the corresponding fourth reference line segments, and the spacing between the fourth contrast line segments other than the preset aligned fourth contrast line segments and the corresponding fourth reference line segments is distributed in arithmetic intervals according to the eighth spacing difference.

6. The inkjet printing calibration method according to claim 1, characterized in that: The third image further includes a break detection pattern, wherein the break detection pattern includes a first break detection line segment corresponding to the first nozzle module and a second break detection line segment corresponding to the second nozzle module; The number of the first print head break detection line segments is not less than the number of the print heads of the first print head module, and the first print head break detection line segments are parallel to the first printing direction; The number of the second break detection line segments is not less than the number of nozzles of the second nozzle module, and the second break detection line segments are parallel to the first printing direction.

7. The inkjet printing calibration method according to claim 6, characterized in that: The adjacent first break detection line segments in the same row parallel to the first printing direction partially overlap or do not overlap, and the spacing between the adjacent first break detection line segments in the same row perpendicular to the first printing direction is equal to the nozzle spacing of the first nozzle module, so that the first break detection line segments in the same row are distributed in a step-like manner; The second gap detection line segments adjacent to each other in the same row parallel to the first printing direction partially overlap or do not overlap, and the spacing between the second gap detection line segments adjacent to each other in the same row perpendicular to the first printing direction is equal to the nozzle spacing of the second nozzle module, so that the second gap detection line segments in the same row are distributed in a stepped manner.

8. The inkjet printing calibration method according to any one of claims 1 to 7, characterized in that: The third image also includes a color detection pattern, and the color detection pattern includes a first color line segment corresponding to the first nozzle module and a second color line segment corresponding to the second nozzle module; The first color line segment includes a first color reference line segment and a first color comparison line segment, the first color reference line segment includes a plurality of groups of fifth reference line segments perpendicular to the first printing direction, each group of fifth reference line segments is equidistantly distributed in the first printing direction, or is equidistantly distributed according to a ninth spacing difference; The first set of color contrast line segments includes a plurality of groups of fifth contrast line segments corresponding to the fifth reference line segments, wherein at least one group of fifth contrast line segments is preset aligned with the corresponding fifth reference line segment, and the spacings between the fifth contrast line segments other than the preset aligned fifth contrast line segments and the corresponding fifth reference line segments are sequentially distributed in arithmetic intervals according to the tenth spacing difference; The second color line segments include a second color reference line segment and a second color comparison line segment, the second color reference line segments include a plurality of groups of sixth reference line segments perpendicular to the first printing direction, each group of sixth reference line segments is equidistantly distributed in the first printing direction, or is equidistantly distributed according to an eleventh spacing difference; The second set of color contrast line segments includes several groups of sixth contrast line segments corresponding to the sixth baseline line segments, wherein at least one group of sixth contrast line segments is preset aligned with the corresponding sixth baseline line segments, and the spacing between the sixth contrast line segments other than the preset aligned sixth contrast line segments and the corresponding sixth baseline line segments is distributed in arithmetic intervals according to the twelfth spacing difference.

9. The inkjet printing calibration method according to claim 8, characterized in that: The first nozzle module is a color ink nozzle module, the color ink nozzle module includes inkjet units for printing a first primary color, a second primary color, a third primary color, and a fourth primary color, the first color reference line segment includes a fifth reference line segment of the first primary color, and the first color contrast line segment includes a fifth contrast line segment of the second primary color, a third primary color, and a fourth primary color; At least one set of fifth contrast line segments of the second primary color is preset aligned with the corresponding fifth reference line segments, and the spacings between the fifth contrast line segments of the second primary color and the corresponding fifth reference line segments are sequentially distributed in arithmetic intervals according to the tenth spacing difference value, except for the preset alignment of the fifth contrast line segments of the second primary color; At least one set of fifth contrast line segments of the third primary color is preset aligned with the corresponding fifth reference line segments, and the spacings between the fifth contrast line segments of the third primary color and the corresponding fifth reference line segments are sequentially distributed in arithmetic intervals according to the tenth spacing difference except for the preset alignment of the fifth contrast line segments of the third primary color; At least one group of fifth contrast line segments of the fourth primary color is preset aligned with the corresponding fifth reference line segments, and in addition to the preset alignment of the fifth contrast line segments of the fourth primary color, the spacing between the fifth contrast line segments of the fourth primary color and the corresponding fifth reference line segments is distributed in arithmetic intervals according to the tenth spacing difference.

10. The inkjet printing calibration method according to any one of claims 1 to 7, characterized in that: The step of identifying the overall calibration image to obtain calibration parameters includes: identifying a target comparison line segment in the overall calibration image that is aligned with a target reference line segment, wherein the target reference line segment comprises at least one of a double-headed reference pattern, a stepped reference pattern, and a bidirectional reference pattern; According to the distribution position of the target reference line segment aligned with the target comparison line segment, a line segment deviation value is determined, and the line segment deviation value is used as a calibration parameter.

11. The inkjet printing calibration method according to any one of claims 1 to 7, characterized in that: The target reference line segment is marked with a line segment deviation parameter; The step of identifying the overall calibration image to obtain calibration parameters further includes: identifying a target comparison line segment in the overall calibration image that is aligned with a target reference line segment, wherein the target reference line segment comprises at least one of a double-headed reference pattern, a stepped reference pattern, and a bidirectional reference pattern; The line segment deviation parameter of the target reference line segment marked with the target comparison line segment is used as the line segment deviation value.

12. The inkjet printing calibration method according to any one of claims 1 to 7, characterized in that: The third image also includes a break detection pattern; The step of identifying the overall calibration image to obtain calibration parameters further includes: Identifying the line segment morphology of the gap detection line segment in the overall calibration image to obtain line segment morphology information; According to the line segment morphology information, the nozzle corresponding to the break detection line segment with abnormal line segment morphology is taken as an abnormal nozzle, and the description information of the abnormal nozzle is taken as a calibration parameter.

13. The inkjet printing calibration method according to any one of claims 1 to 7, characterized in that: The third image also includes a color detection pattern, and the color detection pattern includes a first color line segment corresponding to the first nozzle module and a second color line segment corresponding to the second nozzle module; The step of identifying the overall calibration image to obtain calibration parameters further includes: Identifying a first color comparison line segment in the first color line segment that is aligned with the first color reference line segment, and a second color comparison line segment in the second color line segment that is aligned with the second color reference line segment; Determine the line segment deviation value corresponding to the first nozzle module according to the distribution position of the first color reference line segment aligned with the first color comparison line segment or the marked line segment deviation parameter; Determine the line segment deviation value corresponding to the second nozzle module according to the distribution position of the second color reference line segment aligned with the second color comparison line segment or the marked line segment deviation parameter; The line segment deviation value corresponding to the first nozzle module and the line segment deviation value corresponding to the second nozzle module are used as calibration parameters.

14. An inkjet printing device, characterized in that: The inkjet printing device comprises: a slide rail; A first nozzle module and a second nozzle module are arranged on the slide rail; A conveying device, disposed below the slide rail, for conveying the printing medium; A control unit comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the inkjet printing calibration method according to any one of claims 1 to 13.

15. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the inkjet printing calibration method according to any one of claims 1 to 13 are implemented.

16. A computer program product, characterized in that The computer program product comprises a computer program, which implements the steps of the inkjet printing calibration method according to any one of claims 1 to 13 when executed by a processor.

Images