Variable two-dimensional code printing control method

Abstract

This invention belongs to the field of QR code printing control technology, specifically disclosing a variable QR code printing control method. This method includes: importing order parameters containing QR code printing position, content type, and application scenario characteristics; real-time acquisition of the flatness and colorimetric features of the substrate surface; quantifying and generating integrity assurance coefficient and clarity maintenance coefficient based on flatness features and printing position; quantifying and generating color stability coefficient and readability maintenance coefficient based on colorimetric features; comparing and verifying each quality indicator with quality indicator thresholds dynamically generated based on order parameters; if verification passes, printing is executed; otherwise, printing parameters are dynamically adjusted before printing is executed. This invention, through multi-feature fusion and dynamic verification adjustment, significantly improves the printing quality, physical durability, and visual readability of QR codes in complex outdoor environments, and overall enhances the adaptability of the QR code printing process.

Description

Technical Field

[0001] This invention belongs to the field of QR code printing control technology, and more specifically, relates to a variable QR code printing control method. Background Technology

[0002] Outdoor equipment requires identification codes for identification and full lifecycle management. However, the open-air environment can easily cause traditional identification codes to be damaged or lose information. Therefore, the printing process of these identification codes must be strictly controlled to ensure the effectiveness of subsequent equipment maintenance.

[0003] Currently, the printing of QR codes for outdoor equipment involves only minor adjustments to the process and parameters based on the equipment type, essentially using fixed parameters and the same process. However, the drastic changes in temperature and humidity, dust erosion, and vibrations and impacts from the equipment itself all affect the durability and recognition stability of the QR codes. The lack of personalized printing configurations based on the specific scene and the importance of the content results in QR codes that generally suffer from insufficient environmental adaptability and inadequate protection of critical information. Furthermore, their lifespan is shortened under complex outdoor conditions, and the readability of the content is difficult to guarantee, ultimately affecting maintenance decisions. Summary of the Invention

[0004] In view of this, in order to solve the above problems, a variable QR code printing control method is proposed.

[0005] The objective of this invention can be achieved through the following technical solution: This invention provides a variable QR code printing control method, including: importing current printing order parameters, wherein the order parameters include at least the QR code printing position, QR code content type and application scenario characteristics.

[0006] The flatness and color features of the substrate surface are collected in real time. Based on the flatness features and the QR code printing position, the integrity guarantee coefficient and clarity maintenance coefficient are quantified and generated. Based on the color features, the color stability coefficient and readability maintenance coefficient are quantified and generated.

[0007] Each quantification coefficient is labeled as a quality indicator. Each quality indicator is compared with the quality indicator threshold dynamically generated based on the order parameters. If all quality indicators exceed the corresponding quality indicator threshold, the current printing strategy is verified as passed; otherwise, the verification fails.

[0008] If the verification passes, printing will proceed according to the current printing strategy. If the verification fails, the printing parameters of the QR code will be dynamically adjusted based on the unmet quality indicators, and printing will be carried out according to the adjusted parameters.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention generates completeness guarantee coefficient and clarity maintenance coefficient by quantifying based on the imported current printing order parameters and the real-time collected surface features of the substrate, and compares them with the dynamically generated quality index threshold, so that the printing strategy can automatically adapt to different surface flatness conditions, effectively avoid the problem of incomplete or blurry printing caused by depressions or protrusions, thereby improving the physical stability of QR codes in outdoor vibration and collision environments.

[0010] (2) By combining the QR code content type and application scenario characteristics, the present invention dynamically adjusts the quality index threshold and adjusts the printing parameters in a timely manner for indicators that do not meet the standards, such as the error correction level or the moving speed, thereby realizing personalized printing configuration of important information carriers, enhancing the protection strength of key data such as the device's unique identifier code, and thus effectively preventing information loss due to environmental factors.

[0011] (3) This invention utilizes color stability coefficient and readability maintenance coefficient generated by chromaticity feature quantization, and introduces environmental load parameters to predict color difference loss, providing a reliable reference and clear direction for subsequent printing parameter adjustment, thereby effectively extending its service life under harsh outdoor conditions.

[0012] (4) By collecting surface reflectivity in real time and simulating different lighting conditions to calculate the readability maintenance coefficient, this invention ensures that the QR code maintains high contrast and low reflection interference in variable lighting environments, thereby maintaining stable readability and significantly improving the practicality and reliability of the QR code in complex lighting environments.

[0013] (5) Based on the multi-parameter fusion calculation of surface flatness and color features, as well as dynamic verification and printing parameter adjustment, the present invention improves the overall adaptability of the QR code printing process, enabling it to comprehensively cope with the challenges of complex outdoor environments and achieve comprehensive optimization from physical durability to visual readability. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall implementation process of the present invention.

[0016] Figure 2 This is a schematic diagram illustrating the complete implementation steps of the coefficient quantification method of this invention.

[0017] Figure 3This is a schematic diagram illustrating the steps involved in maintaining coefficient quantification in this invention.

[0018] Figure 4 This is a schematic diagram of the implementation steps for quantifying the color stability coefficient of the present invention.

[0019] Figure 5 This is a schematic diagram illustrating the implementation steps of the readable maintenance coefficient quantization method of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Given that the printing of QR codes for outdoor devices generally uses fixed process parameters, it fails to fully consider the local differences in the surface characteristics of the substrate, the importance level of the QR code content itself, and the complex and ever-changing application scenarios. This one-size-fits-all production model results in QR codes that, when faced with challenges such as physical wear and tear, chemical corrosion, and changes in lighting in actual outdoor environments, generally suffer from insufficient environmental adaptability, inadequate protection of critical information, short lifespan, and decreased readability.

[0022] Therefore, this embodiment elaborates on a technical solution that enables personalized and adaptive printing control, thereby improving the printing quality, durability, and reliability of QR codes in complex outdoor environments.

[0023] In one specific embodiment, please refer to Figure 1 As shown, the present invention provides a variable QR code printing control method, which includes: S1, importing current printing order parameters, wherein the order parameters include at least one or more of the following: QR code printing position, QR code content type, and application scenario characteristics.

[0024] Because ignoring location characteristics and using uniform printing parameters may lead to substandard printing quality in some areas, the QR code printing location is imported as the main order parameter to provide a spatial reference for subsequent local feature collection and targeted adjustments.

[0025] Secondly, because the importance and expected lifespan of the information carried by different types of QR codes vary—for example, unique device identifiers need to be stable over a long period, while dynamic data carriers may only need to be valid for a short period—differentiated quality requirements need to be set for different content types. Furthermore, applying a uniform durability standard to all QR codes would lead to either wasted resources or insufficient protection. Therefore, QR code content type is used as the second primary order parameter and imported into the system, thus providing a basis for decision-making to achieve tiered and precise quality control.

[0026] Meanwhile, considering that outdoor QR codes will face complex and varied environmental conditions and changes in lighting at different times and weather conditions in actual use, these factors will significantly affect the durability and visual readability of the materials. Therefore, it is necessary to incorporate application scenario characteristics to provide data support for predictively assessing the environmental adaptability of QR codes and formulating targeted protection strategies.

[0027] As a preferred example, the application scenario features include environmental load parameters, ambient lighting conditions, etc., wherein the environmental load parameters include, but are not limited to, ultraviolet radiation intensity, temperature and humidity fluctuation range, and chemical corrosion risk level.

[0028] By importing order parameters, this invention ensures that all subsequent quantitative analysis, threshold setting, and parameter adjustment are closely aligned with the specific application scenario, thereby guaranteeing the accuracy and relevance of subsequent printing strategy adjustments.

[0029] S2. Real-time acquisition of the flatness and color features of the substrate surface. Based on the flatness features and the QR code printing position, quantify and generate the integrity guarantee coefficient and clarity maintenance coefficient, and quantify and generate the color stability coefficient and readability maintenance coefficient based on the color features.

[0030] Considering that unevenness of the substrate surface will directly change the effective contact area between the printing head and the substrate surface and the printing state, it is preferable to introduce real-time acquisition of surface flatness.

[0031] In one specific embodiment, the flatness feature acquisition process includes: first, activating the conveying mechanism to transport the substrate to the designated detection area, and immediately triggering a pneumatic clamp or vacuum adsorption device to fix it. This ensures that the relative position of the substrate and the detection reference surface remains constant throughout the measurement process, providing a stable mechanical environment for subsequently obtaining accurate height data.

[0032] After fixation is completed, the laser displacement sensor array is activated to perform grid-like scanning of the area to be printed on the substrate at a preset sampling density. The height data of each grid point relative to the reference plane is collected in real time, thereby comprehensively capturing the surface micro-morphology and laying the data foundation for subsequent accurate identification of local features.

[0033] Based on the collected height data, the absolute value of the height difference between each grid point and its adjacent grid points is calculated to establish a height gradient distribution map. Histogram statistics are performed on all height gradient values ​​to identify the interval with the highest frequency as the main height gradient interval. Subsequently, the main height gradient interval is expanded to both sides, and the frequency ratio of its adjacent intervals is calculated. This expansion includes expansion in the direction of increasing gradient value and expansion in the direction of decreasing gradient value. The positions of the two intervals where the frequency ratio first falls below a preset attenuation threshold are determined, and the gradient values ​​corresponding to the two intervals below the preset attenuation threshold constitute the normal height fluctuation range.

[0034] As a preferred example, the preset attenuation threshold is set based on the statistical characteristics of the gradient distribution histogram. Specifically, the implementation includes: firstly, statistical analysis of the gradient value-frequency distribution maps of a large number of normal substrate samples is performed, recording the gradient interval positions corresponding to the first decrease of more than half in the frequency ratio from the main height gradient interval towards both increasing and decreasing gradient values. The frequency ratios corresponding to these two positions for all normal substrate samples are statistically analyzed. Based on these ratios, a preset attenuation threshold is determined according to a percentile determination rule defined by the implementer. Furthermore, to reduce the false alarm rate, this invention can preferably calculate the 10th percentile as the preset attenuation threshold.

[0035] All grid points are traversed to identify outliers whose height gradients exceed the normal fluctuation range. The DBSCAN clustering algorithm is used to spatially cluster these outliers, resulting in cluster regions. Isolated noise points within each cluster region are removed, retaining groups of outliers that are spatially close and have consistent gradient directions. The average height is calculated for each cluster region. Cluster regions with an average height below the reference plane are marked as concave feature regions, while those with an average height above the reference plane are marked as convex feature regions.

[0036] It should be noted that the DBSCAN clustering algorithm is an existing algorithm and will not be described in detail here.

[0037] Finally, for the recessed feature areas, mark their spatial location, area, and depth as flatness features of the recessed feature areas. For the raised feature areas, mark their spatial location, area, and height as flatness features of the raised feature areas. Combine the flatness features of the recessed and raised feature areas to form the final flatness features of the substrate.

[0038] This invention achieves accurate identification and quantification of substrate surface features in real time through gridded scanning, anomaly detection, and spatial clustering of anomalies. This effectively distinguishes between inherent material textures and actual defects, providing reliable data support for subsequent printing quality control and significantly improving the adaptability and reliability of QR code printing under complex surface conditions.

[0039] Furthermore, color deviations, batch differences, and surface oil stains on the substrate can lead to problems such as insufficient contrast between the QR code and the background, reduced ink adhesion, and color distortion.

[0040] Based on this, the present invention introduces real-time acquisition of color features, thereby providing a data basis for subsequent printing parameter adjustments, ensuring that the printed markings can maintain stable visual recognizability and mechanical durability on substrates with different background colors.

[0041] In one specific embodiment, the colorimetric feature acquisition process includes: First, referring to the illumination setting standards for measurement conditions, the spectrophotometer measurement probe can be activated in a constant light environment illuminated by a D65 standard light source, thereby effectively eliminating the interference of ambient light changes on the color measurement results and providing a stable optical reference for obtaining accurate colorimetric data. Then, the measurement probe is controlled to scan the area to be printed along a preset path at preset intervals, simultaneously acquiring spectral reflectance data in the visible and near-infrared bands at each scanning point. Finally, the acquired spectral reflectance data is converted into chromaticity coordinate values ​​in a standard colorimetric space in real time. The converted Lab chromaticity coordinate values ​​are spatially encoded according to the scanning position to generate a colorimetric feature dataset containing positional information and three-dimensional chromaticity values. This dataset completely records the color distribution characteristics of the substrate surface, providing an accurate color reference for subsequent printing parameter optimization.

[0042] Understandably, the real-time conversion of the collected spectral reflectance data into chromaticity coordinates in a standard chromaticity space is an existing technique and will not be elaborated further. Furthermore, the preset spacing can be defined by the implementer; a preferred example in this invention is 0.5 mm.

[0043] When printing QR codes onto a substrate, surface depressions in the printing area can lead to insufficient ink filling and localized gaps, directly impacting the reliability of machine reading. During flatness feature acquisition, a quantized integrity assurance coefficient is used to reflect the ability to overcome the effects of surface depressions required for complete QR code printing. However, considering that surface protrusions in the printing area can cause ink to spread beyond the printing boundary, reducing image contrast and edge sharpness, a quantized clarity maintenance coefficient is used to reflect the ability to suppress the effects of surface protrusions to ensure edge sharpness.

[0044] Based on this, in one specific embodiment, please refer to Figure 2As shown, the specific quantification process of the complete guarantee coefficient includes: based on the QR code printing position, locating all recessed feature areas within the area to be printed, and extracting the Euclidean distance between the center point of each recessed area and the center point of the printed area, the overlap area ratio between each recessed feature area and the area to be printed, and the maximum recess depth value among all recessed areas. The overlap area ratio refers to the ratio of the overlap area between the recessed feature area and the area to be printed to the area of ​​the area to be printed.

[0045] The distance coefficient is obtained by comparing the Euclidean distance with the diagonal length of the area to be printed. The farther away from the center, the closer the ratio of the Euclidean distance to the diagonal length of the area to be printed becomes. In this case, the distance has a smaller impact, the larger the corresponding distance coefficient value, and the higher the integrity guarantee. Considering that the substrate has acceptable standards for maximum indentation depth and maximum protrusion height based on the material specifications, the maximum indentation depth value is compared with the maximum indentation depth acceptance standard. If the maximum indentation depth value is greater than the maximum indentation depth acceptance standard, the normalized result of the indentation depth coefficient is output as 0; otherwise, the ratio of the maximum indentation depth value to the maximum indentation depth acceptance standard is used as the indentation depth coefficient, and the indentation depth coefficient is denoted as [value missing]. Simultaneously, the average overlap ratio between each recessed feature region and the area to be printed is calculated and denoted as . .

[0046] The integrity protection coefficient is output by linearly fusing the distance coefficient, the average overlap area ratio, and the indentation depth coefficient. , .

[0047] It should be noted that in actual production, the substrate material itself has a clearly defined maximum acceptable standard for indentation depth. If the indentation depth exceeds the material specification, it means that the substrate should have been judged as a defective product during incoming material inspection. In this case, further adjustments to the printing process are meaningless. Therefore, this invention introduces the raw material acceptance standard as a pre-judgment condition. When the detected value exceeds the raw material standard, the relevant items of the integrity guarantee coefficient are directly set to zero.

[0048] It should also be noted that the distance coefficient reflects the degree to which the depression deviates from the printed center area, the coverage ratio characterizes the overlap between the depression and the critical printed area, and the depression depth coefficient is directly related to the physical limit of ink filling. These three factors are interconnected; calculating them collaboratively can comprehensively reflect the overall risk of depressions to print integrity, avoiding the one-sidedness of evaluating a single parameter. Setting the value to no more than 1 is to facilitate the comparability of subsequent data.

[0049] In another specific embodiment, please refer to Figure 3As shown, the quantification process of the clarity maintenance coefficient includes: locating all raised feature regions within the area to be printed, and extracting the maximum height, raised distribution density, and edge slope of each raised feature region. The raised distribution density is obtained by comparing the number of raised feature regions with the area of ​​the area to be printed.

[0050] The specific implementation of edge slope extraction includes: identifying the boundary of the raised area using the Canny edge detection algorithm to obtain each edge point; then, for each edge point, taking its two adjacent left and right edge points to form a local edge line segment; calculating the direction vector of the local edge line segment in three-dimensional space; projecting the direction vector onto a plane perpendicular to the printing area; establishing a reference straight line on the plane consistent with the movement direction of the printing equipment, denoted as the horizontal baseline; calculating the angle between the projection vector and the horizontal baseline; using this angle as the edge slope of the edge point; calculating the average of the edge slopes corresponding to all edge points; and outputting the final extracted edge slope.

[0051] It should be noted that the Canny edge detection algorithm is an existing edge detection algorithm, and will not be described in detail here.

[0052] The maximum height is compared with the maximum convex height acceptance standard to obtain the normalized value of the maximum height. The edge slope and convex distribution density are compared with the edge slope allowable threshold and convex distribution density allowable threshold obtained by experimental statistics to obtain the normalized values ​​of the edge slope and convex distribution density respectively.

[0053] If the normalized values ​​of maximum height, edge slope, and bulge distribution density are all greater than 1, the output clarity maintenance coefficient is 0; otherwise, the normalized values ​​of maximum height, edge slope, and bulge distribution density are denoted as follows: , and Calculate the clarity maintenance coefficient , .

[0054] It should be noted that the maximum height determines the limit of the gap between the ink and the substrate, the edge slope affects the flow characteristics of the ink at the boundary, and the distribution density determines the degree of concentration of defects.

[0055] When the maximum height, edge slope, and distribution density all exceed the allowable threshold, it indicates that the protrusion defect has seriously deteriorated in terms of height, steepness, and density. The combined effect will lead to unacceptable printing clarity, so the clarity maintenance coefficient is directly determined to be zero.

[0056] In cases where not all parameters exceed the limit, since exceeding any parameter such as maximum height, edge slope, or distribution density may lead to a complete loss of sharpness, this invention preferably adopts a multiplication method. This ensures zero tolerance for serious defects while also enabling a comprehensive assessment of minor defects, further improving the accuracy and persuasiveness of the sharpness maintenance coefficient quantification.

[0057] Furthermore, during QR code printing, chromaticity deviations in the printed area can cause the color to deviate from expectations, directly impacting the reliability of machine reading. Therefore, a quantized color stability coefficient is used during chromaticity feature acquisition to reflect the ability to overcome chromaticity deviations and ensure consistent QR code printing colors. Simultaneously, insufficient chromaticity contrast in the printed area can cause the QR code to blend with the background, reducing image contrast and reading success rate. Therefore, a quantized readability maintenance coefficient is used to reflect the ability to maintain sufficient chromaticity contrast to ensure QR code readability.

[0058] Based on this, in one specific embodiment, please refer to Figure 4 As shown, the quantification process of the color stability coefficient includes: based on the precise printing position of the QR code, dividing the surface of the substrate into a QR code printing area and a background area. Cluster analysis is performed on the chromaticity coordinate values ​​of each scanning point within the QR code printing area, for example, using the K-means algorithm, and the chromaticity coordinate value with the highest frequency is used as the foreground chromaticity coordinate value. Similarly, the same cluster analysis is performed on the background area to obtain the background chromaticity coordinate values. The difference between the foreground and background chromaticity coordinate values ​​is then calculated to obtain the initial color difference.

[0059] The K-means algorithm is an existing clustering algorithm and will not be described in detail here.

[0060] Environmental load parameters are extracted from the application scenario characteristics. A preset material aging database is queried to obtain the annualized color difference decay rate of the current substrate and ink combination under the environmental load parameters. The material aging database is constructed based on accelerated aging test data and stores the color difference decay rate of different substrates and ink combinations under environmental conditions such as ultraviolet light, temperature, and humidity.

[0061] The product of the expected color difference attenuation coefficient and the service life is used as the color difference loss, and the ratio of the color difference loss to the initial color difference is used as the color stability coefficient.

[0062] This invention, by introducing environmental load parameters to predict color difference loss, provides a reliable reference and clear direction for subsequent printing parameter adjustments, thereby effectively extending its service life under harsh outdoor conditions.

[0063] In another specific embodiment, please refer to Figure 5As shown, the quantification process of the readable maintenance coefficient includes: first, under standard light source illumination conditions, measuring the spectral reflectance of the substrate surface using a spectrophotometer, and using this as a standard reflectance benchmark. Then, extracting ambient lighting conditions from application scenario characteristics, including typical light intensity, incident angle range, and spectral distribution, etc., reproducing these lighting conditions in an environmental simulation test chamber, and measuring the surface reflectance under different lighting angles. For example, the present invention can... For intervals at to The change in reflectivity of the substrate surface is measured within the incident angle range.

[0064] The attenuation of measured reflectance relative to standard reflectance at each illumination angle is calculated. This attenuation is quantified by the relative deviation between the standard reflectance and the measured reflectance. Based on the attenuation attenuation at all illumination angles, the arithmetic mean is calculated as the average attenuation, and the maximum value is selected as the maximum attenuation. Finally, the ratio of the average attenuation to the maximum attenuation is taken as a correction factor.

[0065] The calculated average attenuation amplitude is compared with the allowable attenuation amplitude threshold set based on the minimum reading contrast requirement of the QR code. If the average attenuation amplitude is less than or equal to the preset attenuation amplitude threshold, the complement of the ratio of the average attenuation amplitude to the preset allowable attenuation amplitude threshold is taken as the initial readable maintenance coefficient. Then, the correction coefficient is multiplied by the initial readable maintenance coefficient to obtain the final readable maintenance coefficient. If the average attenuation amplitude is greater than the preset attenuation amplitude threshold, the final readable maintenance coefficient is directly output as 0.

[0066] This invention, by simulating multi-angle lighting conditions in real-world applications, accurately evaluates the visual readability of QR codes from different viewing angles. Simultaneously, by introducing a correction coefficient, it effectively reflects the uniformity of reflectivity changes with angle. Furthermore, the threshold-based judgment mode ensures that only QR codes that maintain sufficient contrast under various lighting conditions achieve a high readability maintenance coefficient. This guarantees that QR codes maintain high contrast and low reflection interference in varying lighting environments, thus ensuring stable readability. Consequently, it significantly improves the practicality and reliability of QR codes in complex lighting environments.

[0067] S3. Mark each quantification coefficient as a quality indicator, and compare each quality indicator with the quality indicator threshold dynamically generated based on the order parameters. If all quality indicators exceed the corresponding quality indicator threshold, output that the current printing strategy has passed verification; otherwise, the verification has failed.

[0068] Given that fixed quality thresholds cannot meet the diverse requirements of different orders regarding QR code lifespan, environmental tolerance, and readability levels, customer needs are quantified into targeted benchmarks with various coefficients. Based on this, the pass / fail standards for each quality indicator are dynamically adjusted to achieve dynamic evaluation deeply tied to specific application scenarios. This ensures basic quality while avoiding excessive constraints on non-critical indicators that could lead to increased costs, and also allows for zero tolerance for critical quality defects, thus achieving a balance between quality, cost, and reliability.

[0069] Based on this, in a specific embodiment, the dynamically generated quality index threshold includes: classifying the corresponding durability level based on the QR code content type, wherein the durability level is one of high, medium and low. As a preferred example, if the QR code content type is a device unique identifier, the durability level is set to high; if the QR code content type is a dynamic data carrier, the durability level is set to medium; and if the QR code content type is other, the durability level is set to low.

[0070] The ultraviolet radiation intensity, temperature and humidity fluctuation range, and chemical corrosion risk level are extracted from the characteristics of the application scenarios and used as environmental assessment items.

[0071] If two or more of the environmental assessment items exceed the preset range, the current durability requirement level will be raised by one level and updated as the current durability level.

[0072] Convert the current durability level into a numerical level, denoted as . Calculate the quality index threshold , , As the benchmark threshold for quality indicators, The preset process tolerance indicates the allowable range of quality fluctuations. The value is set based on the equipment accuracy and historical process data, and is usually between 0.05 and 0.1. This represents the total number of durability levels.

[0073] in, It is typically determined based on historical printing data, industry standards, or experimental statistics. It represents the lower limit of quality requirements under minimum durability requirements. As a preferred example, it can first be determined by statistically analyzing the corresponding printing quality evaluation indicators of historical successful printing cases, then generating a sequence of printing quality evaluation indicators based on the statistically analyzed indicators, and finally selecting the lowest value of the printed quality evaluation indicators as the benchmark value of the corresponding printing quality evaluation indicators.

[0074] This indicates the maximum possible adjustment range relative to the reference value. This represents an adjustment factor based on equipment precision. Higher precision results in a larger adjustment factor, allowing for a smaller fluctuation range. Consequently, the final threshold for setting the printing quality evaluation index is also higher. Furthermore, by introducing... This feature performs precision compensation on the threshold to ensure that the quality requirements are more stringent under high-precision equipment, while also ensuring that the set threshold is not too high and that the set threshold can be triggered in actual implementation.

[0075] This represents the durability factor. The higher the durability level, the larger the durability factor, and the higher the threshold for setting printing quality assessment indicators. It can be quantified into numerical levels 3, 2, and 1 for high, medium, and low durability levels, respectively. For example, if the current durability level is high... The value is 3, and the current durability level is medium. A value of 2 indicates a low durability level. The value is 1.

[0076] This invention sets durability levels in real time based on the content type of the QR code and updates the durability levels according to environmental assessment items, which fully fits the actual application scenarios and dynamically raises the assessment threshold in key application scenarios. This avoids excessive quality control for ordinary application scenarios and can automatically implement stricter quality standards for high-value equipment identification codes or applications in harsh environments, significantly improving the pertinence of QR code printing quality control.

[0077] S4. If the verification passes, print according to the current printing strategy. If the verification fails, dynamically adjust the printing parameters of the QR code based on the unmet quality indicators, and execute the printing according to the adjusted parameters.

[0078] In a specific embodiment of the present invention, the process of dynamically adjusting the QR code printing parameters is achieved through the following steps: when the quality indicator that fails to meet the standard is the integrity guarantee coefficient, the error correction level configuration of the current QR code is automatically queried. For example, if the current QR code standard is used and the error correction level is A (7%), it is increased to B (15%); if it is already at level B, it is increased to C (25%), and so on. By increasing the error correction level, the error tolerance capability of the QR code in the case of partial defects can be enhanced.

[0079] When the quality indicator that fails to meet the standard is the sharpness maintenance coefficient, the absolute value of the difference between the sharpness maintenance coefficient and its threshold is first calculated as the speed adjustment ratio. The product of the speed adjustment ratio and the current printing head movement speed is used as the adjustment range. The difference between the current printing head movement speed and the adjustment range is used as the updated movement speed value, and printing is performed according to the updated movement speed value. This reduces ink diffusion caused by protrusions.

[0080] When the quality indicator that fails to meet the standard is the color stability coefficient, select the next scheme with a higher contrast level from the preset color scheme library. For example, switch from the dark blue and light gray scheme to the black and white scheme, or from the red and light yellow scheme to the dark red and white scheme, in order to compensate for color attenuation by enhancing contrast when color stability is insufficient.

[0081] When the quality indicator that fails to meet the standard is the readability maintenance coefficient, the absolute value of the difference between the readability maintenance coefficient and its threshold is calculated as the thickness adjustment ratio. The product of the thickness adjustment ratio and the current anti-reflective coating material spraying thickness is used as the adjustment thickness range. The sum of the current anti-reflective coating material spraying thickness and the adjustment thickness range is used as the updated spraying thickness. The anti-reflective coating material is then sprayed according to the updated spraying thickness, thereby improving the readability of the QR code under different lighting conditions.

[0082] This invention, based on multi-parameter fusion calculations of surface flatness and color features, and through dynamic verification and printing parameter adjustment, comprehensively enhances the adaptability of the QR code printing process, enabling it to cope with the challenges of complex outdoor environments and achieve full optimization from physical durability to visual readability. It also enables targeted optimization for different quality defects, ensuring rapid and accurate corrective measures can be implemented when quality risks are detected.

[0083] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A variable QR code printing control method, characterized in that, The method includes: Import the parameters of the current printing order, which include at least the QR code printing location, QR code content type, and application scenario characteristics; The flatness and color features of the substrate surface are collected in real time. Based on the flatness features and the QR code printing position, the integrity guarantee coefficient and clarity maintenance coefficient are quantified and generated. Based on the color features, the color stability coefficient and readability maintenance coefficient are quantified and generated. Each quantification coefficient is labeled as a quality indicator. Each quality indicator is compared with the quality indicator threshold dynamically generated based on the order parameters. If all quality indicators exceed the corresponding quality indicator threshold, the current printing strategy is verified as passed; otherwise, the verification fails. If the verification passes, printing will proceed according to the current printing strategy. If the verification fails, the printing parameters of the QR code will be dynamically adjusted based on the unmet quality indicators, and printing will be performed according to the adjusted parameters. The dynamically adjusted printing parameters of the QR code include: If the quality indicator that fails to meet the standard is the complete assurance coefficient, then the QR code error correction level will be upgraded to the next higher error correction level; If the quality indicator that fails to meet the standard is the sharpness maintenance coefficient, calculate the absolute value of the difference between the sharpness maintenance coefficient and its threshold, obtain the speed adjustment ratio, and reduce the printing head movement speed according to the speed adjustment ratio. If the quality indicator that fails to meet the standard is the color stability coefficient, then switch from the current color scheme to the next color scheme with a higher contrast level; If the quality indicator that fails to meet the standard is the readability maintenance coefficient, calculate the absolute value of the difference between the readability maintenance coefficient and its threshold, use it as the thickness adjustment ratio, and increase the spraying thickness of the anti-reflective coating material according to the thickness adjustment ratio.

2. The variable QR code printing control method as described in claim 1, characterized in that: The process of acquiring the flatness features includes: The conveyor mechanism is activated to transport the substrate to the designated inspection area, and the pneumatic clamp or vacuum adsorption device is triggered to precisely fix the substrate in the inspection area. The laser displacement sensor array placed in the detection area performs grid-based scanning of the area to be printed on the substrate at a preset sampling density, and collects the height data of each grid point in each grid unit relative to the reference plane in real time. Based on the height data, the surface's concave and convex feature regions are identified; The area, spatial location, depth, or height of the feature region are extracted as the flatness feature.

3. The variable QR code printing control method as described in claim 2, characterized in that: The recessed and raised feature areas of the identification surface include: Calculate the absolute value of the height difference between each grid point and its adjacent grid points, and establish a height gradient distribution map; Perform histogram statistics on all height gradient values ​​in the height gradient distribution map to generate a gradient value-frequency distribution map; Identify the gradient value interval with the highest frequency in the gradient value-frequency distribution map and use it as the main height gradient interval; The normal height fluctuation range is determined based on the main height gradient range, and grid points that exceed the normal fluctuation range are identified as outliers. Spatial clustering is performed on the anomalies, and the resulting clustered regions are classified into concave feature regions or convex feature regions.

4. The variable QR code printing control method as described in claim 1, characterized in that: The process of acquiring the chromaticity features includes: Under standard lighting conditions, start the spectrophotometer measuring probe and control the measuring probe to scan the area to be printed along a preset path; Acquire spectral reflectance data in the visible and near-infrared bands at each scanning point; The collected spectral reflectance data is converted into chromaticity coordinate values ​​in a standard chromaticity space in real time, and these chromaticity coordinate values ​​are used as chromaticity features.

5. The variable QR code printing control method as described in claim 2, characterized in that: The quantification process of the complete guarantee coefficient includes: Based on the QR code printing location, locate all recessed feature areas within the area to be printed; The distance coefficient of each recessed feature region is obtained by comparing the distance between the center point of the recessed feature region and the center point of the region to be printed with the length of the diagonal of the region to be printed. Calculate the overlap ratio between each recessed feature region and the area to be printed, extract the maximum depth of the recessed feature region, normalize the depth, and output the recess depth coefficient. Based on the distance coefficient, overlap area ratio, and depression depth coefficient, a complete protection coefficient is obtained through fusion calculation.

6. The variable QR code printing control method as described in claim 2, characterized in that: The quantification process of the clarity maintenance coefficient includes: Locate all raised feature areas within the area to be printed; Extract the maximum height of each raised feature region and calculate the ratio of the number of raised feature regions to the area to be printed to obtain the raised distribution density; The boundary contour of the raised feature region is identified by an edge detection algorithm, and the edge slope is identified based on the boundary contour. Based on the edge slope, maximum height, and protrusion distribution density, a clarity maintenance coefficient is obtained through multi-parameter fusion calculation.

7. The variable QR code printing control method as described in claim 4, characterized in that: The quantification process of the color stability coefficient includes: Based on the location of the QR code printing, the surface of the substrate is divided into a QR code printing area and a background area; Cluster analysis was performed on the chromaticity coordinate values ​​of each scanning point within the QR code printing area, and the chromaticity coordinate value with the highest frequency was taken as the chromaticity coordinate value of the foreground color. Similarly, obtain the background color's chromaticity coordinates using the same method as for obtaining the foreground color's chromaticity coordinates. Subtract the foreground and background color's chromaticity coordinates to obtain the initial color difference. Environmental load parameters are extracted from application scenario characteristics, and the annualized color difference decay rate of the current substrate and ink combination under environmental load parameters is obtained by querying the preset material aging database. Based on the annualized color difference decay rate, calculate the amount of color difference loss within the expected service life. The ratio of color difference loss to initial color difference is used as the color stability coefficient.

8. The variable QR code printing control method as described in claim 4, characterized in that: The quantization process of the readability maintenance coefficient includes: The surface reflectance of the substrate was measured under standard test light source conditions and used as the standard reflectance. Ambient lighting conditions were extracted from the application scenario characteristics, and the ambient lighting conditions of the application scenario were simulated to measure the surface reflectance under different lighting angles. Calculate the attenuation of surface reflectivity relative to standard reflectivity under different illumination angles, calculate the average attenuation, and select the maximum attenuation. Take the ratio of the average attenuation to the maximum attenuation as a correction coefficient. Compare the average attenuation magnitude with the preset allowable attenuation magnitude threshold. If the average attenuation magnitude is less than or equal to the preset attenuation magnitude threshold, take the complement of the ratio of the average attenuation magnitude to the preset allowable attenuation magnitude threshold as the initial readable maintenance coefficient, and multiply the correction coefficient and the initial readable maintenance coefficient as the final readable maintenance coefficient. If the average attenuation magnitude is greater than the preset attenuation magnitude threshold, the final readable maintenance coefficient will be output as 0.

9. The variable QR code printing control method as described in claim 1, characterized in that: The dynamically generated quality indicator thresholds include: Based on the content type of the QR code, a corresponding durability level is defined, which is one of high, medium and low. Ultraviolet radiation intensity, temperature and humidity fluctuation range, and chemical corrosion risk level are extracted from the characteristics of the application scenarios and used as environmental assessment items. If two or more of the environmental assessment items exceed the preset range, the current durability requirement level will be raised by one level and updated as the current durability level. Convert the current durability level into a numerical level, denoted as . Calculate the quality index threshold , , As the benchmark threshold for quality indicators, To preset process tolerance, This represents the total number of durability levels.

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