A defect detection system and method for thin film printing

Abstract

This invention relates to the field of printing defect detection, specifically providing a defect detection system and method for thin film printing, comprising: an unwinding detection module equipped with a line scanning camera for scanning the roll of film to be printed and determining placement defects; a printing detection module equipped with a printing correction mechanism for performing printing placement correction detection and printing correction during the printing of the roll of film; a vision detection module equipped with a detection camera for visually inspecting the printed roll of film and determining whether printing errors exist; an oven detection module equipped with a constant temperature control component and an infrared heating component, wherein the constant temperature control component performs constant temperature sensing and adjusts the real-time temperature of the infrared heating component; and a rewinding detection module equipped with a sampling camera for sampling the dried printed roll of film and calculating the probability of printing defects.

Description

Technical Field

[0001] This invention relates to the field of thin film printing technology, and in particular to a defect detection system and method for thin film printing. Background Technology

[0002] Currently, modern industrial production lines, operating at high speeds, frequently produce products with surface defects and inaccuracies. Examples include stains and misregistration on high-speed printing presses, foreign objects like insects, metal filaments, and hair on high-speed PVC production lines, and visible foreign objects such as glass shards, aluminum shavings, rubber shavings, and hair in pharmaceutical filling processes. If these quality issues are not detected promptly, they can not only damage product reputation but also potentially threaten the lives of users. Traditional inspection methods for these production line products rely on manual visual inspection to remove defective items. However, manual inspection is slow, inefficient, prone to fatigue, and has a high rate of missed inspections.

[0003] Patent CN113815303A proposes a method for thin film printing to address the issues of poor quality in screen-printed products and film winding. This method comprises an unwinding mechanism, a film fixing mechanism, a deviation correction mechanism, a tensioning mechanism, a screen printing mechanism, a detection mechanism, a drying mechanism, and a winding mechanism. However, it only possesses traditional thin film printing functions and cannot perform deviation correction, constant-temperature drying, target detection of the printed image, or subsequent random inspection. Therefore, it still has many technical shortcomings. Summary of the Invention

[0004] This invention provides a defect detection system and method for thin film printing, which solves the problems of existing thin film printing methods being unable to achieve deviation correction processing, constant temperature drying processing, target detection processing of thin film printed images, and subsequent sampling inspection functions.

[0005] This application proposes a defect detection system for thin film printing, comprising:

[0006] The unwinding detection module is equipped with a wired scanning camera, which is used to scan the roll of film to be printed and determine placement defects.

[0007] The printing inspection module is equipped with a printing correction mechanism, which is used to detect and correct printing placement during the printing of the roll film to be printed.

[0008] The visual inspection module is equipped with an inspection camera, which performs visual inspection on the printed roll film and determines whether there are any printing errors.

[0009] The oven detection module is equipped with a constant temperature control component and an infrared heating component. The constant temperature control component performs constant temperature sensing and adjusts the real-time temperature of the infrared heating component.

[0010] The winding inspection module is equipped with a sampling camera to conduct random inspections of the dried printed film rolls and calculate the probability of printing defects.

[0011] Preferably, the unwinding detection module includes:

[0012] Positioning unit: used to pre-set the linear scanning position on the vacuum traction roller of the unwinding mechanism;

[0013] Virtual positioning: Based on the linear scanning position, a virtual positioning coordinate system is set on a pre-created virtual unwinding platform;

[0014] Scanning module: Based on a line scan camera, it acquires the real-time placement position of the roll film to be printed and projects the position parameters of the real-time placement position onto a virtual positioning coordinate system;

[0015] Comparison unit: Used to determine whether there is a placement defect based on the virtual positioning coordinate system and positioning protocol parameters.

[0016] Preferably, the unwinding detection module further includes:

[0017] Correction sensing unit: used to determine correction parameters based on the virtual positioning coordinate system and acquire real-time correction parameters when placement defects exist;

[0018] Transition roller control unit: used to control the stable operation of the film roll according to real-time correction parameters;

[0019] Tension control unit: Used to control the displacement of the tension control shaft according to real-time correction parameters, and to perform displacement correction;

[0020] Correction unit: Used to correct the displacement and adjust the film roll position to be consistent through the correction mechanism.

[0021] Preferably, the printing inspection module includes:

[0022] Film pressing control unit: used to press the film roll after unwinding inspection and to control the flatness of the film roll; wherein,

[0023] During the lamination process, a printing correction mechanism is used to detect and correct printing deviations.

[0024] Screen adjustment unit: used to transfer the film roll to the screen after lamination and to set the printing area of ​​the film roll on the screen;

[0025] Lifting unit: Used to control the Z-axis of the lifting unit to rise according to the printing area, transporting the roll film to the printing height;

[0026] Printing squeegee control unit: Used to perform roll film printing when the roll film reaches the printing height.

[0027] Preferably, the visual detection module further includes:

[0028] Film roll position adjustment unit: used to adjust the real-time position of the film roll after printing, and to adjust the real-time position of the film roll to be directly below the inspection camera;

[0029] Printing inspection unit: used to acquire printed images on the roll film via an inspection camera;

[0030] Adsorption control unit: used to adsorb the printed roll film and control the adsorption position by the real-time position of the printed image;

[0031] Printing inspection and comparison unit: used to compare the preset printing template with the printed image to determine whether there are printing defects.

[0032] Preferably, the printing inspection and comparison unit includes:

[0033] Pre-set a linear printing contrast model;

[0034] Based on the linear printing contrast model, target contrast detection is performed on the printing template and the printing target in the printing image to determine the contrast data;

[0035] The comparative data is imported into the multi-feature hierarchical CVA change detection model to perform a change detection on the printed image and obtain a set of change regions.

[0036] Based on the improved U-Net network model, printing target segmentation is performed on the printing template and printing image to obtain the printing target segmentation result;

[0037] A secondary comparison of changes is performed based on the comparative data, the set of changed areas, and the printing target segmentation results to determine whether printing defects exist.

[0038] Preferably, the oven detection module includes:

[0039] Wake-up unit: used to dynamically acquire a preset constant temperature wake-up indicator after the film roll enters the oven;

[0040] Thermostatic start-up unit: Activates the infrared heating component according to the preset thermostatic wake-up indicator;

[0041] Parameter acquisition unit: After the infrared heating component is started, it dynamically acquires the status parameters of the infrared heating component and the real-time surface temperature of the film roll.

[0042] Temperature control unit: Based on the real-time surface temperature, a temperature control axis is constructed to determine whether the surface of the film is in a constant temperature state, and if it is not in a constant temperature state, the adjustment mode is activated.

[0043] Thermostatic control unit: used to determine the thermostatic compensation parameters of the infrared heating component according to the adjustment mode and status parameters, and control the infrared heating component to output a constant temperature through the thermostatic compensation parameters.

[0044] Preferably, the isothermal compensation parameters include the following steps for obtaining them:

[0045] Based on the state parameters, determine the driving current and heating gain parameters, and determine the first heating control value of the infrared heating component;

[0046] Determine the constant temperature setpoint based on the adjustment mode;

[0047] Based on the first heating control value and the constant temperature setting value, determine the voltage compensation value of the infrared heating component;

[0048] Based on the voltage compensation value, voltage compensation is performed on the infrared heating component to generate periodic constant temperature compensation commands.

[0049] The infrared heating component is controlled to operate at a constant temperature according to the periodic constant temperature compensation command.

[0050] Preferably, the winding detection module includes:

[0051] The winding and correction unit is used to set up the winding queue and generate target sampling tasks according to a random algorithm; among which,

[0052] The rewind queue is used to mark the printed film rolls and generate queue parameters;

[0053] The target sampling inspection task includes objects based on random time and random queue parameters, as well as a pass / fail determination mechanism; among them,

[0054] Random timestamps are automatically generated according to random algorithms to time-mark the target objects of the sampling.

[0055] The random queue parameter object is the marker parameter of the target sampling object in the printing queue, which is randomly detected according to a random algorithm.

[0056] The pass / fail determination mechanism is based on the accuracy of the printed image on the target sample.

[0057] Sampling inspection unit: Used to obtain the sampling inspection results of the target sampling objects according to the target sampling inspection task.

[0058] A defect detection method for thin film printing, the method comprising:

[0059] The roll of film to be printed is scanned using a wired scanning camera to determine placement defects;

[0060] The printing correction mechanism detects and corrects printing deviations during the printing of the roll film.

[0061] The printed roll film is visually inspected using a camera to determine if there are any printing errors.

[0062] The printed roll film is dried by sensing the temperature through a constant temperature control component and adjusting the real-time temperature of the infrared heating component.

[0063] The probability of printing defects is calculated by randomly inspecting the dried printed film using a sampling camera.

[0064] The beneficial effects of this invention are as follows:

[0065] (1) The five modules of this application can be scanned by a wired camera during unwinding, perform correction and detection during printing, perform visual inspection after printing, perform constant temperature control during film drying, and finally perform defect calculation by sampling inspection. It can perform step-by-step inspection and judgment according to the film printing steps, determine whether there are defects in the entire printing system, thereby realizing the correction of defective films and the detection of defective printed films, realizing a comprehensive film printing system that integrates fully automated film printing process and intelligent detection and correction.

[0066] (2) In response to the traditional technical solutions for thin film printing, this application adds a wired scanning camera and a correction mechanism to achieve a technical solution that combines the functions of immediate placement, immediate measurement, and immediate correction, which is more efficient than the traditional solution.

[0067] (3) Regarding the post-printing inspection of films, this application sets up an inspection mechanism directly after printing, rather than setting up a visual inspection mechanism after drying, which is beneficial to screen out films with printing defects in advance and prevent defective products from being produced.

[0068] (4) In the process of drying the film, constant temperature sensing is achieved by infrared heating components and constant temperature control components. The drying effect is kept constant by dynamically balancing the baking temperature through constant temperature sensing.

[0069] (5) Based on the sampling camera, the film is used to detect the final printing defects and determine the defect rate of the finished product.

[0070] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0071] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0072] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0073] Figure 1 This is a system composition diagram of a defect detection system for thin film printing according to an embodiment of the present invention;

[0074] Figure 2 This is a diagram showing the composition of the winding assembly in an embodiment of the present invention;

[0075] Figure 3 This is a diagram showing the composition of the printing component system in an embodiment of the present invention;

[0076] Figure 4 This is a diagram showing the composition of the visual detection component in an embodiment of the present invention;

[0077] Figure 5 This is a diagram illustrating the composition of the oven components in an embodiment of the present invention;

[0078] Figure 6 This is a diagram showing the composition of the unwinding assembly in an embodiment of the present invention;

[0079] Figure 7 This is an overall composition diagram of the thin film printing instrument in an embodiment of the present invention. Detailed Implementation

[0080] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0081] This application provides a defect detection system for thin film printing, comprising:

[0082] The unwinding detection module is equipped with a wired scanning camera, which is used to scan the roll of film to be printed and determine placement defects.

[0083] The printing inspection module is equipped with a printing correction mechanism, which is used to detect and correct printing deviations during the printing of the roll film to be printed.

[0084] The visual inspection module is equipped with an inspection camera, which performs visual inspection on the printed roll film and determines whether there are any printing errors.

[0085] The oven detection module is equipped with a constant temperature control component and an infrared heating component. The constant temperature control component performs constant temperature sensing and adjusts the real-time temperature of the infrared heating component.

[0086] The winding inspection module is equipped with a sampling camera to conduct random inspections of the dried printed film rolls and calculate the probability of printing defects.

[0087] The principle behind the above technical solution is as follows:

[0088] As attached Figure 1 ~Attached Figure 7 As shown, the present invention is a comprehensive printing defect detection system achieved by adding detection equipment to a thin film printing system.

[0089] In this embodiment, the unwinding detection module scans the film using a line scan camera and determines whether the film is correctly positioned according to a specific planar coordinate system, thereby achieving correction detection during the placement stage. The unwinding detection module has specific unwinding components, as shown in the attached figure. Figure 2 As shown.

[0090] In this embodiment, the printing inspection module performs correction detection through a printing correction mechanism, and performs printing correction simultaneously with the correction. The printing components of the printing inspection module are shown in the attached figure. Figure 3 As shown.

[0091] In this embodiment, the visual inspection module uses a detection camera to visually inspect the printed pattern and determine whether there are any specific printing errors.

[0092] In this embodiment, the oven detection module performs constant temperature control and periodically checks the temperature to prevent uneven temperature from occurring.

[0093] Finally, in terms of winding inspection, random inspection is carried out using a sampling camera to determine the probability of printing defects.

[0094] This application is a combined thin film printing correction system. In terms of defect detection, in addition to performing correction detection to achieve steady correction of the most important problem in the printing stage, it can also perform visual inspection of the printed pattern after printing to determine whether there are printing errors.

[0095] The beneficial effects of the above technical solution are as follows:

[0096] (1) The five modules of this application can be scanned by a wired camera during unwinding, perform correction and detection during printing, perform visual inspection after printing, perform constant temperature control during film drying, and finally perform defect calculation by sampling inspection. It can perform step-by-step inspection and judgment according to the film printing steps, determine whether there are defects in the entire printing system, thereby realizing the correction of defective films and the detection of defective printed films, realizing a comprehensive film printing system that integrates fully automated film printing process and intelligent detection and correction.

[0097] (2) In response to the traditional technical solutions for thin film printing, this application adds a wired scanning camera and a correction mechanism to achieve a technical solution that combines the functions of immediate placement, immediate measurement, and immediate correction, which is more efficient than the traditional solution.

[0098] (3) Regarding the post-printing inspection of films, this application sets up an inspection mechanism directly after printing, rather than setting up a visual inspection mechanism after drying, which is beneficial to screen out films with printing defects in advance and prevent defective products from being produced.

[0099] (4) In the process of drying the film, constant temperature sensing is achieved by infrared heating components and constant temperature control components. The drying effect is kept constant by dynamically balancing the baking temperature through constant temperature sensing.

[0100] (5) Based on the sampling camera, the film is used to detect the final printing defects and determine the defect rate of the finished product.

[0101] Preferably, the unwinding detection module includes:

[0102] Positioning unit: used to pre-set the linear scanning position on the vacuum traction roller of the unwinding mechanism;

[0103] Virtual positioning: Based on the linear scanning position, a virtual positioning coordinate system is set on a pre-created virtual unwinding platform;

[0104] Scanning module: Based on a line scan camera, it acquires the real-time placement position of the roll film to be printed and projects the position parameters of the real-time placement position onto a virtual positioning coordinate system;

[0105] Comparison unit: Used to determine whether there is a placement defect based on the virtual positioning coordinate system and positioning protocol parameters.

[0106] The principle of the above technical solution is as follows:

[0107] As attached Figure 6The unwinding mechanism shown in the diagram sets a specific scanning position on the vacuum traction roller during unwinding inspection. It then uses a linear scanning method and sets a virtual unwinding platform. The virtual coordinate system on the virtual unwinding platform is used to calibrate and compare the film to be printed to determine whether the film is placed correctly. Based on the specific clamping parameters, it determines whether there are any defects.

[0108] The beneficial effects of the above technical solution are as follows:

[0109] This application uses a linear scanning method to determine the specific position of the unwound film. Then, through a virtual unwound platform and a virtual positioning coordinate system, the specific placement of the film can be detected. Finally, by digitally projecting the real-time printing position of the film to be printed, it can determine whether there are any defects in the film placement, thus achieving accurate detection of the unwound process.

[0110] Preferably, the unwinding detection module further includes:

[0111] Correction sensing unit: used to determine correction parameters based on the virtual positioning coordinate system and acquire real-time correction parameters when placement defects exist;

[0112] Transition roller control unit: used to control the stable operation of the film roll according to real-time correction parameters;

[0113] Tension control unit: Used to control the displacement of the tension control shaft according to real-time correction parameters, and to perform displacement correction;

[0114] Correction unit: Used to correct the displacement and adjust the film roll position to be consistent through the correction mechanism.

[0115] The principle of the above technical solution is as follows:

[0116] As attached Figure 6 As shown, the unwinding assembly of this application includes a web-correcting device. When there are defects in the film to be placed, the web-correcting device can determine the specific parameters of the web-correcting through a virtual positioning coordinate system. By using the specific web-correcting parameters, the printing roll film is controlled to operate stably, and displacement correction adjustment is performed based on the tension control axis, thereby ensuring that the web-correcting mechanism can be consistent with the position adjustment of the roll film. When the roll film is placed in an incorrect position, the web-correcting operation is realized.

[0117] The beneficial effects of the above technical solution are as follows:

[0118] The unwinding detection module performs real-time correction processing during virtual positioning using a correction sensor. This real-time correction process then controls stable unwinding operation, achieving displacement correction and ensuring that the continuously printed film and the specific printing position are consistent.

[0119] Preferably, the printing inspection module includes:

[0120] Film pressing control unit: used to press the film roll after unwinding inspection and to control the flatness of the film roll; wherein,

[0121] During the lamination process, a printing correction mechanism is used to detect and correct printing deviations.

[0122] Screen adjustment unit: used to transfer the film roll to the screen after lamination and to set the printing area of ​​the film roll on the screen;

[0123] Lifting unit: Used to control the Z-axis of the lifting unit to rise according to the printing area, transporting the roll film to the printing height;

[0124] Printing squeegee control unit: Used to perform roll film printing when the roll film reaches the printing height.

[0125] The principle of the above technical solution is as follows:

[0126] As attached Figure 3 As shown, in the printing inspection process of this application, the unwound film is first pressed to ensure the flatness of the film. When flattening the film, the same correction device and correction process in the unwound assembly can also be used for printing correction.

[0127] Then, based on the screen during the printing process, the screen can determine the specific area for roll film printing. Then, by raising the Z-axis, the roll film is controlled to reach the specific printing height. When the specific printing height is reached, the roll film printing operation is performed.

[0128] The beneficial effects of the above technical solution are as follows:

[0129] The printing inspection module of this application ensures the flatness of the printing through film pressing control, and performs printing correction during the flat pressing process. It can also control the roll film to print under the printing squeegee by continuously lifting the screen plate during the correction process.

[0130] Preferably, the visual detection module further includes:

[0131] Film roll position adjustment unit: used to adjust the real-time position of the film roll after printing, and to adjust the real-time position of the film roll to be directly below the inspection camera;

[0132] Printing inspection unit: used to acquire printed images on the roll film via an inspection camera;

[0133] Adsorption control unit: used to adsorb the printed roll film and control the adsorption position by the real-time position of the printed image;

[0134] Printing inspection and comparison unit: used to compare the preset printing template with the printed image to determine whether there are printing defects.

[0135] The principle behind the above technical solution is as follows:

[0136] As attached Figure 4 As shown, this application achieves specific printing on the roll film by adjusting the specific printing position during the printing process, and then adjusting the roll film directly below the detection camera based on the real-time position of the roll film, thereby determining the printed image on the roll film.

[0137] Meanwhile, this application also includes an adsorption control mechanism for adsorbing the printed roll film, thereby allowing the printed roll film to change its printing position. At the same time, the detection camera can compare the printing template and the printed image to determine whether there is any inconsistency between the image printed on the roll film and the image on the printing template.

[0138] The beneficial effects of the above technical solution are as follows:

[0139] During the visual inspection process, the roll film is positioned directly below the inspection camera through real-time position adjustment. Then, the inspection camera prints a specific image on the roll film. The printed roll film is then adsorbed, thereby enabling a direct comparison between the printed template and the printed image, and thus determining printing defects.

[0140] Preferably, the printing inspection and comparison unit includes:

[0141] Pre-set a linear printing contrast model;

[0142] Based on the linear printing contrast model, target contrast detection is performed on the printing template and the printing target in the printing image to determine the contrast data;

[0143] The comparative data is imported into the multi-feature hierarchical CVA change detection model to perform a change detection on the printed image and obtain a set of change regions.

[0144] Based on the improved U-Net network model, printing target segmentation is performed on the printing template and printing image to obtain the printing target segmentation result;

[0145] A secondary comparison of changes is performed based on the comparative data, the set of changed areas, and the printing target segmentation results to determine whether printing defects exist.

[0146] The principle behind the above technical solution is as follows:

[0147] This application establishes a linear printing comparison model to achieve linear comparison between the printed image on the roll film and the target object detection of the printed template and the specific printed image, thereby determining the comparison data. The comparison data is used to characterize the specific differences between the printed image on the printing template and the printed image already printed on the roll film.

[0148] Then, the multi-feature hierarchical CVA change detection model (multiple image features on the printed image are divided into different importance levels, and CVA change represents the vector change of the printed image) is used to detect the printed image, determine the areas of change on the printed image, and the corresponding data set of the areas;

[0149] Finally, the U-Net network model is used to segment the variable regions on the printed image to obtain the segmentation results. Based on the segmentation results, the set of variable regions and the comparison data, a variable region data triplet is formed. The data triplet is then used for secondary transformation and comparison to determine whether there are defects on the printed image.

[0150] The beneficial effects of the above technical solution are as follows:

[0151] This application can perform linear detection on printed images, determine data of printing changes during the printing process based on linear detection, and then achieve target segmentation through the data of printing changes, thereby determining the presence of defects in the printed image. However, for printed images without defects, the printing process will proceed according to normal printing procedures.

[0152] Preferably, the oven detection module includes:

[0153] Wake-up unit: used to dynamically acquire a preset constant temperature wake-up indicator after the film roll enters the oven;

[0154] Thermostatic start-up unit: Activates the infrared heating component according to the preset thermostatic wake-up indicator;

[0155] Parameter acquisition unit: After the infrared heating component is started, it dynamically acquires the status parameters of the infrared heating component and the real-time surface temperature of the film roll.

[0156] Temperature control unit: Based on the real-time surface temperature, a temperature control axis is constructed to determine whether the surface of the film is in a constant temperature state, and if it is not in a constant temperature state, the adjustment mode is activated.

[0157] Thermostatic control unit: used to determine the thermostatic compensation parameters of the infrared heating component according to the adjustment mode and status parameters, and control the infrared heating component to output a constant temperature through the thermostatic compensation parameters.

[0158] The principle behind the above technical solution is as follows:

[0159] As attached Figure 5As shown, this application considers that the detection module first wakes up the constant temperature control system after the printed roll film enters the oven through the wake-up unit. The process of waking up the constant temperature control system is to call the constant temperature wake-up flag to perform constant temperature wake-up. Finally, through the activation of the infrared heating component, the real-time surface temperature of the roll film and the status parameters of the infrared heating component are detected and extracted in real time.

[0160] By using real-time surface temperature, a constant temperature axis is constructed to determine whether the surface of the film roll is always in a constant temperature state.

[0161] In non-constant temperature conditions, the infrared heating component is adjusted based on the constant temperature axis in the adjustment mode. In other words, the infrared heating component is dynamically adjusted to a constant temperature through constant temperature compensation parameters.

[0162] The beneficial effects of the above technical solution are as follows:

[0163] This application enables temperature control during film drying by activating a temperature control indicator and managing the real-time surface temperature of the film to maintain a constant temperature. Furthermore, in situations where constant temperature control is not feasible, dynamic temperature control of the infrared heating component can be achieved via a temperature control axis.

[0164] Preferably, the isothermal compensation parameters include the following steps for obtaining them:

[0165] Based on the state parameters, determine the driving current and heating gain parameters, and determine the first heating control value of the infrared heating component;

[0166] Determine the constant temperature setpoint based on the adjustment mode;

[0167] Based on the first heating control value and the constant temperature setting value, determine the voltage compensation value of the infrared heating component;

[0168] Based on the voltage compensation value, voltage compensation is performed on the infrared heating component to generate periodic constant temperature compensation commands.

[0169] The infrared heating component is controlled to operate at a constant temperature according to the periodic constant temperature compensation command.

[0170] The principle behind the above technical solution is as follows:

[0171] In the process of obtaining constant temperature compensation parameters, this application can determine the driving current and heating gain parameters (the parameters that increase continuously during the heating process) of the infrared heating component through state parameters (driving parameters and temperature control parameters of the infrared heating component, as well as the temperature parameters detected by the film winding), and then determine the specific heating control value of the infrared heating component. Based on the heating control value, the constant temperature setpoint is set by setting the adjustment mode and the constant temperature axis. These two values ​​are used as a feedback compensation mechanism to form a periodic constant temperature compensation command, thereby realizing the constant temperature control of the infrared heating component.

[0172] The beneficial effects of the above technical solution are as follows:

[0173] This application can achieve constant temperature control of the infrared heating component through constant temperature compensation parameters, so as to enable the infrared heating component to operate at a constant temperature.

[0174] Preferably, the winding detection module includes:

[0175] The winding and correction unit is used to set up the winding queue and generate target sampling tasks according to a random algorithm; among which,

[0176] The rewind queue is used to mark the printed film rolls and generate queue parameters;

[0177] The target sampling inspection task includes objects based on random time and random queue parameters, as well as a pass / fail determination mechanism; among them,

[0178] Random timestamps are automatically generated according to random algorithms to time-mark the target objects of the sampling.

[0179] The random queue parameter object is the marker parameter of the target sampling object in the printing queue, which is randomly detected according to a random algorithm.

[0180] The pass / fail determination mechanism is based on the accuracy of the printed image on the target sample.

[0181] Sampling inspection unit: Used to obtain the sampling inspection results of the target sampling objects according to the target sampling inspection task.

[0182] The principle behind the above technical solution is as follows:

[0183] The winding correction unit of this application sets up a winding queue, generates queue parameters for each roll of film, and constructs a target sampling inspection task for the roll of film by using the queue parameters and a random algorithm.

[0184] Then, based on queued tasks, random checks of the roll film printing effect are implemented to determine whether there are defects in the printed roll film.

[0185] The beneficial effects of the above technical solution are as follows:

[0186] This application allows for the determination of printing accuracy through random sampling after printing, thereby enabling the measurement of printing results.

[0187] A defect detection method for thin film printing, the method comprising:

[0188] The roll of film to be printed is scanned using a wired scanning camera to determine placement defects;

[0189] The printing correction mechanism detects and corrects printing deviations during the printing of the roll film.

[0190] The printed roll film is visually inspected using a camera to determine if there are any printing errors.

[0191] The printed roll film is dried by sensing the temperature through a constant temperature control component and adjusting the real-time temperature of the infrared heating component.

[0192] The probability of printing defects is calculated by randomly inspecting the dried printed film using a sampling camera.

[0193] The principle behind the above technical solution is as follows:

[0194] As attached Figure 1 ~Attached Figure 7 As shown, the present invention is a comprehensive printing defect detection system achieved by adding detection equipment to a thin film printing system.

[0195] In this embodiment, the unwinding detection module scans the film using a line scan camera and determines whether the film is correctly positioned according to a specific planar coordinate system, thereby achieving correction detection during the placement stage. The unwinding detection module has specific unwinding components, as shown in the attached figure. Figure 2 As shown.

[0196] In this embodiment, the printing inspection module performs correction detection through a printing correction mechanism, and performs printing correction simultaneously with the correction. The printing components of the printing inspection module are shown in the attached figure. Figure 3 As shown.

[0197] In this embodiment, the visual inspection module uses a detection camera to visually inspect the printed pattern and determine whether there are any specific printing errors.

[0198] In this embodiment, the oven detection module performs constant temperature control and periodically checks the temperature to prevent uneven temperature from occurring.

[0199] Finally, in terms of winding inspection, random inspection is carried out using a sampling camera to determine the probability of printing defects.

[0200] This application is a combined thin film printing correction system. In terms of defect detection, in addition to performing correction detection to achieve steady correction of the most important problem in the printing stage, it can also perform visual inspection of the printed pattern after printing to determine whether there are printing errors.

[0201] The beneficial effects of the above technical solution are as follows:

[0202] (1) The five modules of this application can be scanned by a wired camera during unwinding, perform correction and detection during printing, perform visual inspection after printing, perform constant temperature control during film drying, and finally perform defect calculation by sampling inspection. It can perform step-by-step inspection and judgment according to the film printing steps, determine whether there are defects in the entire printing system, thereby realizing the correction of defective films and the detection of defective printed films, realizing a comprehensive film printing system that integrates fully automated film printing process and intelligent detection and correction.

[0203] (2) In response to the traditional technical solutions for thin film printing, this application adds a wired scanning camera and a correction mechanism to achieve a technical solution that combines the functions of immediate placement, immediate measurement, and immediate correction, which is more efficient than the traditional solution.

[0204] (3) Regarding the post-printing inspection of films, this application sets up an inspection mechanism directly after printing, rather than setting up a visual inspection mechanism after drying, which is beneficial to screen out films with printing defects in advance and prevent defective products from being produced.

[0205] (4) In the process of drying the film, constant temperature sensing is achieved by infrared heating components and constant temperature control components. The drying effect is kept constant by dynamically balancing the baking temperature through constant temperature sensing.

[0206] (5) Based on the sampling camera, the film is used to detect the final printing defects and determine the defect rate of the finished product.

[0207] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A defect detection system for thin film printing, characterized in that, include: The unwinding detection module is equipped with a wired scanning camera, which is used to scan the roll of film to be printed and determine placement defects. The printing inspection module is equipped with a printing correction mechanism, which is used to detect and correct printing placement during the printing of the roll film to be printed. The visual inspection module is equipped with an inspection camera, which performs visual inspection on the printed roll film and determines whether there are any printing errors. The oven detection module is equipped with a constant temperature control component and an infrared heating component. The constant temperature control component performs constant temperature sensing and adjusts the real-time temperature of the infrared heating component. The winding inspection module is equipped with a sampling camera for sampling inspection of the dried printed film rolls and calculating the probability of printing defects. The unwinding detection module includes: Positioning unit: used to pre-set the linear scanning position on the vacuum traction roller of the unwinding mechanism; Virtual positioning: Based on the linear scanning position, a virtual positioning coordinate system is set on a pre-created virtual unwinding platform; Scanning module: Based on a wired scanning camera, it acquires the real-time placement position of the roll film to be printed and projects the position parameters of the real-time placement position onto a virtual positioning coordinate system; Comparison unit: Used to determine whether there are placement defects based on the virtual positioning coordinate system and positioning protocol parameters; The unwinding detection module also includes: Correction sensing unit: used to determine correction parameters based on the virtual positioning coordinate system and acquire real-time correction parameters when placement defects exist; Transition roller control unit: used to control the stable operation of the film roll according to real-time correction parameters; Tension control unit: Used to control the displacement of the tension control shaft according to real-time correction parameters, and to perform displacement correction; Correction unit: Used to correct the displacement and adjust the film roll position to be consistent through the correction mechanism; The visual inspection module also includes: Film roll position adjustment unit: used to adjust the real-time position of the film roll after printing, and to adjust the real-time position of the film roll to be directly below the inspection camera; Printing inspection unit: used to acquire printed images on the roll film via an inspection camera; Adsorption control unit: used to adsorb the printed roll film and control the adsorption position by the real-time position of the printed image; Printing inspection and comparison unit: used to compare the preset printing template with the printed image to determine whether there are printing defects; The printing inspection and comparison unit includes: Pre-set a linear printing contrast model; Based on the linear printing contrast model, target contrast detection is performed on the printing template and the printing target in the printing image to determine the contrast data; The comparative data is imported into the multi-feature hierarchical CVA change detection model to perform a change detection on the printed image and obtain a set of change regions. Based on the improved U-Net network model, printing target segmentation is performed on the printing template and printing image to obtain the printing target segmentation result; A secondary comparison of changes is performed based on the comparative data, the set of changed areas, and the printing target segmentation results to determine whether printing defects exist. The winding detection module includes: The winding and correction unit is used to set up the winding queue and generate target sampling tasks according to a random algorithm; among which, The rewind queue is used to mark the printed film rolls and generate queue parameters; The target sampling inspection task includes objects based on random time and random queue parameters, as well as a pass / fail determination mechanism; among them, Random timestamps are automatically generated according to random algorithms to time-mark the target objects of the sampling. The random queue parameter object is the marker parameter of the target sampling object in the printing queue, which is randomly detected according to a random algorithm. The pass / fail determination mechanism is based on the accuracy of the printed image on the target sample. Sampling inspection unit: Used to obtain the sampling inspection results of the target sampling objects according to the target sampling inspection task.

2. The defect detection system for thin film printing as described in claim 1, characterized in that, The printing inspection module includes: Film pressing control unit: used to press the film roll after unwinding inspection and to control the flatness of the film roll; wherein, During the lamination process, a printing correction mechanism is used to detect and correct printing deviations. Screen adjustment unit: used to transfer the roll film to the screen after lamination and to set the printing area of ​​the roll film on the screen; Lifting unit: Used to control the Z-axis of the lifting unit to rise according to the printing area, transporting the roll film to the printing height; Printing squeegee control unit: Used to perform roll film printing when the roll film reaches the printing height.

3. The defect detection system for thin film printing as described in claim 1, characterized in that, The oven detection module includes: Wake-up unit: used to dynamically acquire a preset constant temperature wake-up indicator after the film roll enters the oven; Thermostatic start-up unit: Activates the infrared heating component according to the preset thermostatic wake-up indicator; Parameter acquisition unit: After the infrared heating component is started, it dynamically acquires the status parameters of the infrared heating component and the real-time surface temperature of the film roll. Temperature control unit: Based on the real-time surface temperature, a temperature control axis is constructed to determine whether the surface of the film is in a constant temperature state, and if it is not in a constant temperature state, the adjustment mode is activated. Thermostatic control unit: used to determine the thermostatic compensation parameters of the infrared heating component according to the adjustment mode and status parameters, and control the infrared heating component to output a constant temperature through the thermostatic compensation parameters.

4. The defect detection system for thin film printing as described in claim 3, characterized in that, The isothermal compensation parameters are obtained through the following steps: Based on the state parameters, determine the driving current and heating gain parameters, and determine the first heating control value of the infrared heating component; Determine the constant temperature setpoint based on the adjustment mode; Based on the first heating control value and the constant temperature setting value, determine the voltage compensation value of the infrared heating component; The voltage of the infrared heating component is compensated based on the voltage compensation value, and a periodic constant temperature compensation command is generated. The infrared heating component is controlled to operate at a constant temperature according to the periodic constant temperature compensation command.

5. A defect detection method for thin film printing, applicable to the defect detection system for thin film printing as described in any one of claims 1 to 4, characterized in that, The method includes: The roll of film to be printed is scanned using a wired scanning camera to determine placement defects; The printing correction mechanism detects and corrects printing deviations during the printing of the roll film. The printed roll film is visually inspected using a camera to determine if there are any printing errors. The printed roll film is dried by sensing the temperature through a constant temperature control component and adjusting the real-time temperature of the infrared heating component. The probability of printing defects is calculated by randomly inspecting the dried printed film using a sampling camera.

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