High-precision post-printing defect real-time detection device and printing device

Abstract

The utility model discloses a high-precision post-printing defect real-time detection device and a printing device. The high-precision post-printing defect real-time detection device comprises a base frame, a lifting structure, a detection structure and a control module, the lifting structure is connected with the base frame; the detection structure is installed at the moving end of the lifting structure, the detection end of the detection structure is suitable for facing the printing base material, and the detection structure is used for collecting a printing image on the printing base material; the lifting structure is suitable for driving the detection structure to move in the direction close to or away from the printing base material. The control module is suitable for receiving the printing image and controlling the printer to adjust parameters after analyzing and processing. The high-precision post-printing defect real-time detection device with the structure can be used for automatic detection, manual or off-line detection is not needed, a printer does not need to be shut down, the repair time is shortened, automatic cycle completion is achieved, manual work is reduced, the repair efficiency is improved, and the reject ratio is reduced.

Description

Technical Field

[0001] This utility model relates to the field of printing technology, specifically to a high-precision real-time post-printing defect detection device and a printing device. Background Technology

[0002] During the digital printing process, due to environmental factors such as temperature and humidity, and also due to problems with electronic components, the digital print head may occasionally malfunction, resulting in deviations in print color depth and reduced yield. Furthermore, when the production speed is too high, the human eye cannot accurately identify defects, leading to significant waste.

[0003] Traditional methods require manual or offline inspection, which cannot be performed in real time. Manual inspection is greatly affected by individual differences, making it difficult to standardize. Manual inspection is also prone to oversights. Offline inspection has a long time cycle, and once color difference occurs, it can easily produce a large number of defective products. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is that traditional methods require manual or offline inspection, which cannot be carried out in real time. Manual inspection is greatly affected by individual differences, making it difficult to unify standards. Manual inspection is prone to omissions, and offline inspection has a long time cycle. Once color difference occurs, it is easy to produce a large number of defective products.

[0005] Therefore, this utility model provides a high-precision real-time post-printing defect detection device, comprising:

[0006] Base frame;

[0007] A lifting structure, wherein the lifting structure is connected to the base frame;

[0008] A detection structure is installed on the moving end of the lifting structure, the detection end of the detection structure is adapted to face the printing substrate, and the detection structure is used to acquire the printed image on the printing substrate; the lifting structure is adapted to drive the detection structure to move in a direction closer to or farther from the printing substrate.

[0009] A control module, which is adapted to receive the printed image, analyze and process it, and then control the printer to adjust its parameters.

[0010] Optionally, two base frames are provided, which are arranged opposite each other on both sides of the printing substrate. A fixing beam is installed between the two base frames, and guide rails are provided on the inner walls of both base frames.

[0011] The detection structure includes;

[0012] A lifting beam, with its two ends respectively mounted on two guide rails;

[0013] A mounting beam is mounted on the lifting beam, and a camera is mounted on the side of the mounting beam closest to the printing substrate.

[0014] Optionally, the shooting end of the camera described above is parallel to the printing substrate.

[0015] Optionally, the above-mentioned lifting structure includes: a lifting assembly and a driving component, wherein the lifting assembly is mounted on the fixed beam, and the lifting end of the lifting assembly is connected to the lifting beam; the output end of the driving component is connected to the lifting assembly to drive the lifting end of the lifting assembly to move along a direction closer to or further away from the printing substrate.

[0016] Optionally, two lifting components are provided, and the two lifting components are mounted on the fixed beam along a first direction perpendicular to the direction of movement of the printing substrate.

[0017] Optionally, the above-mentioned lifting assembly includes:

[0018] A reduction gearbox is mounted on the fixed beam and is connected to the drive component;

[0019] A lifting rod, one end of which is connected to a reduction gearbox, and the other end of which is adapted to pass through the fixed beam and connect to the lifting beam.

[0020] Optionally, the above-mentioned high-precision real-time post-printing defect detection device further includes a linkage, the two ends of which are respectively connected to the two reduction gearboxes.

[0021] Optionally, the camera described above includes an imaging sensor and a light-emitting element, the light-emitting element being mounted on the imaging sensor, and both the detection end of the imaging sensor and the light-emitting end of the light-emitting element being adapted to face the printing substrate.

[0022] Optionally, the above-mentioned high-precision real-time post-printing defect detection device further includes: a base frame and a first conveyor belt, the first conveyor belt being mounted on the base frame, and the base frame being mounted on top of the base frame so that the printing substrate is located between the first conveyor belt and the camera.

[0023] A printing apparatus includes a printer and the aforementioned high-precision real-time post-printing defect detection device, wherein the printer is disposed upstream of the high-precision real-time post-printing defect detection device.

[0024] The printer includes several printheads, and the high-precision real-time post-printing defect detection device is adapted to detect and adjust the parameters of the printheads.

[0025] The technical solution provided by this utility model has the following advantages:

[0026] 1. The high-precision real-time post-printing defect detection device provided by this utility model includes: a base frame, a lifting structure, a detection structure, and a control module; the lifting structure is connected to the base frame; the detection structure is installed on the moving end of the lifting structure, the detection end of the detection structure is adapted to face the printing substrate, and the detection structure is used to collect the printed image on the printing substrate; the lifting structure is adapted to drive the detection structure to move towards or away from the printing substrate; the control module is adapted to receive the printed image, analyze and process it, and then control the printer to adjust parameters.

[0027] This high-precision real-time post-printing defect detection device can perform automatic detection without manual or offline inspection. The printer does not need to be stopped, shortening the repair time. It automatically completes the process in cycles, reducing manual labor, improving repair efficiency, and reducing the defect rate.

[0028] 2. The lifting structure includes a drive component, a linkage component, and two lifting assemblies. The two lifting assemblies are mounted at intervals on the fixed beam along a first direction perpendicular to the direction of movement of the printing substrate. In the figure, the first direction is the length direction of the fixed beam. Describing the structure of one of the lifting assemblies, it includes: a reduction gearbox and a lifting rod. The reduction gearbox is fixed to the top of the fixed beam. The lifting rod is a lead screw, with one end passing through the reduction gearbox to connect its outer surface to the transmission components inside the reduction gearbox. The lifting rod and the reduction gearbox form a lead screw structure. The other end of the lifting rod passes through the fixed beam and connects to the detection structure below. The drive component is a motor, fixed to one of the reduction gearboxes. The output end of the drive component is connected to the input end of the corresponding reduction gearbox. The linkage component is located between the two reduction gearboxes, with both ends connected to the two reduction gearboxes to ensure synchronous movement of the two reduction gearboxes.

[0029] The drive unit is activated, which drives a nearby gearbox to work. Through a linkage, it drives another gearbox to work synchronously. The two gearboxes simultaneously drive the lifting rods mounted on them to move up and down. That is, the two lifting rods move up and down in the direction of approaching or moving away from the printing substrate. This drives the lifting beam to move up and down along the guide rail, which in turn drives the mounting beam and camera mounted at the lower end of the lifting beam to move up and down along the guide rail in the direction of approaching or moving away from the printing substrate. This adjusts the distance between the imaging sensor, the light-emitting element, and the printing substrate, making it suitable for substrates of different thicknesses and avoiding defocusing that could affect detection accuracy. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the high-precision real-time post-printing defect detection device for detecting printing substrates provided in this embodiment.

[0032] Figure 2 This is a schematic diagram of the overall structure of the high-precision real-time post-printing defect detection device provided in this embodiment.

[0033] Figure 3 This is a side view of the printing device provided in this embodiment;

[0034] Figure 4 This is a top view of the printing apparatus provided in this embodiment;

[0035] Figure 5 This is a diagram illustrating the acquisition of images on the printing substrate by the high-precision real-time post-printing defect detection device in this embodiment;

[0036] Figure 6 The control module provided in this embodiment is for Figure 5 Processing area map;

[0037] Figure 7 A diagram illustrating the color difference detection area for the control module provided in this embodiment;

[0038] Figure 8 This is a diagram illustrating the acquisition of the state diagram provided in this embodiment;

[0039] Figure 9 This is a processing area diagram of the state diagram provided in this embodiment;

[0040] Explanation of reference numerals in the attached figures:

[0041] 1 - Base frame;

[0042] 2 - Guide rail;

[0043] 3 - Fixed beam;

[0044] 4 – Lifting structure; 41 – Lifting assembly; 411 – Gearbox; 412 – Lifting rod; 42 – Driving component; 43 – Linking component;

[0045] 5 – Inspection structure; 51 – Lifting beam; 52 – Mounting beam; 53 – Camera;

[0046] 6 - Base frame;

[0047] 7 - First conveyor belt;

[0048] 8 - Printer;

[0049] 9 - Printing substrate. Detailed Implementation

[0050] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0051] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0053] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0054] Example 1

[0055] This embodiment provides a high-precision real-time post-printing defect detection device, such as... Figures 1 to 2 As shown, it includes a base frame 6, a first conveyor belt 7, a base frame 1, a lifting structure 4, a detection structure 5, and a control module.

[0056] like Figure 1 and Figure 2 As shown, the base frame 6 is set on the ground, and the first conveyor belt 7 is installed on the upper end of the base frame 6. The first conveyor belt 7 is used to transport the printing substrate 9. There are two base frames 1, and the bottom ends of the two base frames 1 are fixed to the base frame 6 on both sides of the first conveyor belt 7. The two base frames 1 have the same structure and are set vertically relative to each other. A fixing beam 3 is horizontally fixed between the top ends of the two base frames 1. Guide rails 2 are vertically installed on the inner side walls of both base frames 1. The two base frames 1 and the fixing beam 3 form an inverted U-shaped structure. The printing substrate 9 is transported on the upper surface of the first conveyor belt 7, and the printing substrate 9 is located between the first conveyor belt 7 and the camera 53.

[0057] The lifting structure 4 includes a drive component 42, a linkage component 43, and two lifting assemblies 41. The two lifting assemblies 41 are mounted at intervals on the fixed beam 3 along a first direction perpendicular to the direction of movement of the printing substrate 9. In the figure, the first direction is the length direction of the fixed beam 3. Taking one of the lifting assemblies 41 as an example, the lifting assembly 41 includes a reduction gearbox 411 and a lifting rod 412. The reduction gearbox 411 is fixed to the top of the fixed beam 3. The lifting rod 412 is a lead screw, with one end passing through the reduction gearbox 411 so that its outer surface connects to the transmission parts inside the reduction gearbox 411. The lifting rod 412 and the reduction gearbox 411 form a lead screw structure. The other end of the lifting rod 412 passes through the fixed beam 3 and connects to the detection structure 5 below. The driving component 42 is a motor, which is fixed on one of the reduction gearboxes 411. The output end of the driving component 42 is connected to the input end of the corresponding reduction gearbox 411. The linkage 43 is arranged between the two reduction gearboxes 411, and the two ends of the linkage 43 are connected to the two reduction gearboxes 411 respectively to ensure that the two reduction gearboxes 411 move synchronously.

[0058] The detection assembly includes a lifting beam 51 and a mounting beam 52. The lifting beam 51 has an inverted U-shaped structure, with its two sides mounted on guide rails 2 on the inner walls of two base frames 1. The top of the lifting beam 51 is fixed to the bottom of two lifting rods 412, and the entire lifting beam 51 is placed horizontally. The mounting beam 52 is horizontally mounted at the bottom of the lifting beam 51. A camera 53 is horizontally mounted on the bottom of the lifting beam 51 near the bottom of the printing substrate 9. Preferably, the length of the camera 53 in the first direction is greater than the width of the printing substrate 9 in the first direction to avoid omissions.

[0059] In this embodiment, the camera 53 is preferably a line scan camera 53. The line scan camera 53 has a fast acquisition speed and high accuracy, making it suitable for large-format field-of-view inspection. The camera 53 includes an imaging sensor and a light-emitting element. The imaging sensor is mounted on the mounting beam 52, and the light-emitting element is mounted on the imaging sensor. Both the detection end of the imaging sensor and the light-emitting end of the light-emitting element are adapted to face the printing substrate 9. The detection end of the imaging sensor on the camera 53 should be parallel to the printing substrate 9.

[0060] During the printing process, the printed substrate 9, printed by printer 8, is conveyed by the first conveyor belt 7 and passes under camera 53. Driver 42 is activated, driving a nearby gearbox 411 to operate. Through linkage 43, another gearbox 411 operates synchronously. Both gearboxes 411 simultaneously drive the lifting rods 412 mounted on them to move up and down. This causes the lifting beam 51 to move up and down along guide rail 2, which in turn causes the mounting beam 52 and camera 53, mounted at the lower end of the lifting beam 51, to move up and down along guide rail 2 towards or away from the printing substrate 9. This adjusts the distance between the imaging sensor, the light-emitting element, and the printing substrate 9, allowing for the application of substrates of different thicknesses and preventing defocusing from affecting detection accuracy.

[0061] When it is necessary to image the printed pattern on the printing substrate 9, after the substrate enters the high-precision real-time post-printing defect detection device, the following steps are included:

[0062] S1, the light source emitted by the light-emitting component illuminates the printing substrate 9, and the camera 53 captures the image.

[0063] S2, the control module receives the acquired image and converts it into grayscale to obtain different color channels, such as... Figure 5 The grayscale image shown.

[0064] S3. Divide the grayscale image into several image blocks along the first direction according to the positions corresponding to the several print heads on printer 8. Figure 5 The three areas printed by the three printheads have different color differences, according to Figure 6 The black frame in the image is divided into three image blocks. Each image block is slightly reduced in size and then stitched together to form a test image. This can shield the undesirable effects of black or white lines printed at the nozzle splicing point.

[0065] S4. Blur the image to be detected to eliminate interference from stitching marks. When detecting the image, the average brightness of each image block is measured.

[0066] S5, such as Figure 7 As shown, find the straight line along the printing direction that changes from relatively deep to relatively shallow or from relatively shallow to relatively deep in the region at the nth and n+1th printhead splicing points.

[0067] S6. If a straight line is found in the printing direction where the color value changes from dark to light in the area where the printheads are joined at the m and m+1 printheads, and a straight line is found in the printing direction where the color value changes from light to dark in the area where the printheads are joined at the m+k and m+k+1 printheads, then it is determined that k printheads in the range from m+1 to m+k have printed colors that are lighter.

[0068] For example, when m=1, along the first direction, a line is found in the area where the color value changes from dark to light at the junction of the first and second printheads. When k=2, a line is found in the area where the third and fourth printheads are joined, where the color value changes from light to dark along the printing direction. It is determined that the second and third printheads print lighter colors.

[0069] If a straight line is found in the printing direction where the color value changes from lighter to darker in the area where the printheads are joined at the m and m+1 printheads, and a straight line is found in the printing direction where the color value changes from darker to lighter in the area where the printheads are joined at the m+k and m+k+1 printheads, then it is determined that k printheads within the range of m+1 to m+k have printed colors that are darker.

[0070] For example, when m=1, along the first direction, a line is found in the area where the color value changes from lighter to darker at the junction of the first and second printheads. When k=2, a line is found in the area where the color value changes from darker to lighter along the printing direction at the junction of the third and fourth printheads. It is determined that the second and third printheads print darker colors.

[0071] S7. When a color difference is detected, the post-printing inspection system sends a print status diagram instruction to the printer.

[0072] After receiving the instruction to print the status diagram, printer 8 (S8) prints the status diagram in the next printing action. The status diagram is... Figure 8 As shown.

[0073] S9. After the high-precision post-printing defect real-time detection device collects the status diagram, it identifies the color and detects the average color value of each color printed by each printhead according to the printhead width. The average color value of adjacent printheads decreases from each other, and the color difference deviation value of the printhead that produces the color difference is calculated.

[0074] S10. The high-precision real-time post-printing defect detection device calculates the position of the color difference printhead and displays it on the acquisition status diagram, such as... Figure 9 As shown.

[0075] S11, The high-precision real-time post-printing defect detection device calculates the new printing parameters required for the color difference printhead based on the color difference deviation value.

[0076] S12. The high-precision real-time post-printing defect detection device sends the new printing parameters to printer 8. After receiving the printing parameters, printer 8 adjusts the printhead printing parameters and continues printing subsequent products. The above process is repeated until all printheads are fully compensated.

[0077] Throughout the entire testing and repair process described above, the printer 8 does not need to be stopped, shortening the repair time. It is completed automatically in a loop, reducing manual labor, improving repair efficiency, and reducing the defect rate.

[0078] Example 2

[0079] This embodiment provides a printing device, such as... Figure 3 and Figure 4 As shown, the device includes a printer 8 and the high-precision real-time post-printing defect detection device from Embodiment 1. The printer 8 is positioned upstream of the high-precision real-time post-printing defect detection device. The printer 8 includes a printer body, printheads, and a second conveyor belt. The second conveyor belt is horizontally mounted on the printer body. A first conveyor belt 7 is positioned close to the second conveyor belt so that the printing substrate 9 can be transferred from the second conveyor belt to the first conveyor belt 7. A plurality of printheads are provided, and the plurality of printheads are mounted at the top of the second conveyor belt. The high-precision real-time post-printing defect detection device is adapted to detect and adjust the parameters of the printheads. The printing device in this embodiment has all the beneficial effects of the high-precision real-time post-printing defect detection device from Embodiment 1.

[0080] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A high-precision real-time post-printing defect detection device, characterized in that, include: Base frame (1); A lifting structure (4) is connected to the base frame (1); A detection structure (5) is installed on the moving end of the lifting structure (4). The detection end of the detection structure (5) is adapted to face the printing substrate (9). The detection structure (5) is used to acquire the printed image on the printing substrate (9). The lifting structure (4) is adapted to drive the detection structure (5) to move toward or away from the printing substrate (9). The control module is adapted to receive the printed image, analyze and process it, and then control the printer (8) to adjust its parameters.

2. The high-precision real-time post-printing defect detection device according to claim 1, characterized in that, There are two base frames (1), which are arranged opposite each other on both sides of the printing substrate (9). A fixing beam (3) is installed between the two base frames (1), and guide rails (2) are provided on the inner walls of both base frames (1). The detection structure (5) includes; A lifting beam (51) is provided, with its two ends mounted on two guide rails (2). Mounting beam (52) is mounted on the lifting beam (51), and a camera (53) is mounted on the side of the mounting beam (52) near the printing substrate (9).

3. The high-precision real-time post-printing defect detection device according to claim 2, characterized in that, The shooting end of the camera (53) is parallel to the printing substrate (9).

4. The high-precision real-time post-printing defect detection device according to claim 3, characterized in that, The lifting structure (4) includes a lifting assembly (41) and a driving member (42). The lifting assembly (41) is mounted on the fixed beam (3), and the lifting end of the lifting assembly (41) is connected to the lifting beam (51). The output end of the driving member (42) is connected to the lifting assembly (41) to drive the lifting end of the lifting assembly (41) to move in a direction close to or away from the printing substrate (9).

5. The high-precision real-time post-printing defect detection device according to claim 4, characterized in that, Two lifting components (41) are provided, and the two lifting components (41) are installed on the fixed beam (3) along a first direction perpendicular to the moving direction of the printing substrate (9).

6. The high-precision real-time post-printing defect detection device according to claim 5, characterized in that, The lifting assembly (41) includes: A reduction gearbox (411) is mounted on the fixed beam (3) and is connected to the drive unit (42); A lifting rod (412) is provided, one end of which is connected to a reduction gearbox (411), and the other end of which is adapted to pass through the fixed beam (3) and connect to the lifting beam (51).

7. The high-precision real-time post-printing defect detection device according to claim 6, characterized in that, The high-precision real-time post-printing defect detection device also includes a linkage (43), the two ends of which are connected to the two reduction gearboxes (411) respectively.

8. The high-precision real-time post-printing defect detection device according to claim 7, characterized in that, The camera (53) includes an imaging sensor and a light-emitting element. The light-emitting element is mounted on the imaging sensor, and the detection end of the imaging sensor and the light-emitting end of the light-emitting element are both adapted to face the printing substrate (9).

9. The high-precision real-time post-printing defect detection device according to claim 3, characterized in that, The high-precision real-time post-printing defect detection device further includes: a base frame (6) and a first conveyor belt (7), the first conveyor belt (7) being mounted on the base frame (6), and the base frame (1) being mounted on top of the base frame (6) so that the printing substrate (9) is located between the first conveyor belt (7) and the camera (53).

10. A printing apparatus, characterized in that, The device includes a printer (8) and a high-precision real-time post-printing defect detection device according to any one of claims 1-9, wherein the printer (8) is disposed upstream of the high-precision real-time post-printing defect detection device; The printer (8) includes several printheads, and the high-precision real-time post-printing defect detection device is adapted to detect and adjust the parameters of the printheads.

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