Method, device and system for measuring the printing accuracy of an alignment film of a display substrate

Abstract

The embodiment of the application discloses a kind of display substrate's alignment film printing precision measurement method, device and system, measurement method includes obtaining the scanning image of display substrate;In scanning image, first detection point and second detection point are obtained;According to the first position information of first detection point, multiple first candidate boundaries are determined in first detection point, and the one in all first candidate boundaries is determined as first target boundary in first identification direction and is arranged in front;According to the second position information of second detection point, multiple second candidate boundaries are determined in second detection point, and the one in all second candidate boundaries is determined as second target boundary in second identification direction and is arranged in front;The automatic measurement distance between first target boundary and second target boundary is output, and the printing precision of alignment film is determined according to automatic measurement distance.This scheme can improve measurement efficiency, while ensuring the accuracy of measurement result.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a method, apparatus and system for measuring the printing accuracy of alignment film on a display substrate. Background Technology

[0002] In liquid crystal display panels, the alignment layer is the core functional layer that controls the initial orientation of liquid crystal molecules. After the alignment layer is printed, the printing accuracy needs to be checked.

[0003] Testing printing accuracy includes testing positional printing accuracy. Existing technology characterizes the positional printing accuracy of the alignment film by measuring the distance between the boundary of the alignment film and the boundary of the display area. If the measured distance is within the set upper and lower limits of the target distance, the positional printing accuracy meets the standard.

[0004] Currently, some measurement methods involve manually selecting two points using a mouse after magnifying the image with a microscope lens to measure the distance between the points. This approach lacks automation, resulting in low efficiency and wasted labor costs. Other methods involve taking fixed-point photographs with a microscope, followed by automatic distance measurement using add-on software. However, fixed-point photography typically uses only one lens. When there are many measurement points, the measurement time per piece increases, leading to low efficiency and failing to meet production cycle time. Furthermore, adding more photographing lenses increases equipment costs. Summary of the Invention

[0005] This invention provides a method, apparatus, and system for measuring the printing accuracy of alignment film on a display substrate, thereby improving measurement efficiency while ensuring the accuracy of measurement results.

[0006] According to one aspect of the present invention, a method for measuring the printing accuracy of an alignment film on a display substrate is provided. The display substrate includes a display area and a non-display area surrounding the display area, wherein the alignment film covers the display area and the boundary of the alignment film is located within the non-display area; the measurement method includes: Scanned images of the display substrate are acquired using automated optical inspection equipment; On the scanned image, target detection points and their location information are acquired; the target detection points include first detection points and second detection points, and the location information includes first location information of the first detection point and second location information of the second detection point. Based on the first location information, multiple first candidate boundaries are determined within the first detection point; and based on the second location information, multiple second candidate boundaries are determined within the second detection point. A first identification direction is determined based on the first position information, and the first candidate boundary ranked first in the first identification direction is identified as the first target boundary; and a second identification direction is determined based on the second position information, and the first candidate boundary ranked first in the second identification direction is identified as the second target boundary; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction; Output the automatically measured distance between the first target boundary and the second target boundary to determine the printing accuracy of the alignment film based on the automatically measured distance.

[0007] According to another aspect of the present invention, a measuring apparatus for the printing accuracy of an alignment film on a display substrate is provided. The display substrate includes a display area and a non-display area surrounding the display area, wherein the alignment film covers the display area and the boundary of the alignment film is located within the non-display area; the measuring apparatus includes: The image acquisition module is used to acquire scanned images of the display substrate based on an automated optical inspection device; The point location acquisition module is used to acquire target detection points and their location information on the scanned image; the target detection points include a first detection point and a second detection point, and the location information includes the first location information of the first detection point and the second location information of the second detection point; The candidate boundary determination module is used to determine multiple first candidate boundaries within a first detection point based on first location information; and to determine multiple second candidate boundaries within a second detection point based on second location information; The target boundary determination module is used to determine a first identification direction based on first position information, and determine the first target boundary as the one that ranks first in the first identification direction among all first candidate boundaries; and to determine a second identification direction based on second position information, and determine the second target boundary as the one that ranks first in the second identification direction among all second candidate boundaries; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction; The distance measurement output module is used to output the automatically measured distance between the first target boundary and the second target boundary, so as to determine the printing accuracy of the alignment film based on the automatically measured distance.

[0008] According to another aspect of the present invention, a system for measuring the printing accuracy of alignment film on a display substrate is provided, comprising: an automatic optical inspection device and a processing device; Automated optical inspection equipment is used to acquire scanned images of display substrates; The processing device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the measurement method provided in any embodiment of the present invention.

[0009] The technical solution of this invention involves acquiring a scanned image of a display substrate using an automatic optical inspection device. On the scanned image, target detection points (first detection point and second detection point) are obtained. Based on the first position information of the first detection point, multiple first candidate boundaries are determined within the first detection point. Based on the second position information of the second detection point, multiple second candidate boundaries are determined within the second detection point. A first recognition direction is determined based on the first position information, and the first candidate boundary ranked first in the first recognition direction is determined as the first target boundary. A second recognition direction is determined based on the second position information, and the first candidate boundary ranked first in the second recognition direction is determined as the second target boundary. An automatically measured distance between the first target boundary and the second target boundary is then output, and the printing accuracy of the alignment film is determined based on the automatically measured distance. In this way, on the one hand, automatic optical inspection equipment can be used to simultaneously measure and output printing accuracy data at multiple inspection points, greatly improving measurement efficiency. On the other hand, by determining the identification direction of the target boundary within the inspection point based on the location information of the inspection point, the target boundary can be selected from multiple candidate boundaries according to the identification direction, which can effectively avoid the influence of interfering boundaries among the candidate boundaries, ensure the identification accuracy of the alignment film boundary and the display area boundary, and thus ensure the accuracy of the printing accuracy measurement results.

[0010] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0012] Figure 1 This is a flowchart illustrating a method for measuring the printing accuracy of an alignment film according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a scanned image of a display substrate provided in an embodiment of the present invention; Figure 3 This is a detection point marker diagram on a scanned image of a display substrate provided in an embodiment of the present invention; Figure 4 yes Figure 3 An enlarged schematic diagram of the target detection point on the left side of the middle section; Figure 5 yes Figure 3An enlarged schematic diagram of the target detection point on the right side of the middle section; Figure 6 yes Figure 3 An enlarged schematic diagram of the target detection point on the upper middle side; Figure 7 yes Figure 3 An enlarged schematic diagram of the target detection points on the lower middle side; Figure 8 yes Figure 3 Another enlarged schematic diagram of the target detection point on the left side of the middle; Figure 9 This is a flowchart illustrating another method for measuring the printing accuracy of alignment film provided in an embodiment of the present invention; Figure 10 This is a flowchart illustrating another method for measuring the printing accuracy of alignment film provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of a grayscale screenshot provided in an embodiment of the present invention; Figure 12 This is a schematic diagram of another grayscale screenshot provided in an embodiment of the present invention; Figure 13 This is a schematic diagram of another grayscale screenshot provided in an embodiment of the present invention; Figure 14 This is a schematic diagram of another grayscale screenshot provided in an embodiment of the present invention; Figure 15 This is a schematic diagram of the structure of a device for measuring the printing accuracy of alignment film provided in an embodiment of the present invention; Figure 16 This is a schematic diagram of the structure of a system for measuring the printing accuracy of alignment film provided in an embodiment of the present invention. Detailed Implementation

[0013] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0014] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation methods provided in the embodiments of this application can be combined with each other without contradiction.

[0015] It should be noted that the terms "first," "second," "target," "candidate," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Figure 1 This is a flowchart illustrating a method for measuring the printing accuracy of alignment film according to an embodiment of the present invention. This method is suitable for efficiently and automatically measuring the distance between the display area boundary and the alignment film boundary at all detection points after the alignment film is printed, while ensuring high accuracy of the measurement results. This measurement method can be executed by a processing device in the measurement system. Figure 1 As shown, the measurement method includes the following steps: S101. Obtain a scanned image of the display substrate based on an automated optical inspection device.

[0017] For example, Figure 2 This is a schematic diagram of a scanned image of a display substrate provided in an embodiment of the present invention, such as... Figure 2 As shown, the display substrate includes a display area (marked B2-AA to indicate the boundary of the display area) and a non-display area NA surrounding the display area. The alignment film covers the display area and the boundary B1-PI of the alignment film is located within the non-display area NA.

[0018] It should be noted that, Figure 2 This illustration uses a single display substrate comprising a single display area surrounded by a non-display area NA and covered by an alignment film. In other embodiments, the display substrate may include multiple independent display areas; in other words, the display substrate may include multiple display sub-boards, each including both display and non-display areas, with alignment films on adjacent sub-boards independently spaced. In this case, the printing accuracy of the alignment films on multiple small-sized display sub-boards can be measured simultaneously, improving measurement efficiency.

[0019] For example, Figure 2This can be understood as a scanned image of a large-size display substrate, or as a partial scanned image of a display substrate with multiple display sub-boards, specifically a scanned image of an area where one display sub-board is located on the display substrate. It should be noted that when the display substrate includes multiple display sub-boards, the dimensions of each display sub-board can be the same or different; this embodiment of the invention does not limit this.

[0020] The Automated Optical Inspection (AOI) equipment can automatically acquire scanned images (grayscale images) of the display substrate using a camera, light source, and image processing algorithms. It can also perform defect detection through grayscale comparison. In this embodiment, the AOI equipment utilizes its grayscale comparison function to determine the boundaries of the display area and the alignment film (see S102-S104), thereby obtaining the distance between the display area boundary and the alignment film boundary (see S105) and determining the printing accuracy of the alignment film. This solution can output distance data for hundreds of inspection points within 1 minute, significantly improving testing efficiency.

[0021] S102. On the scanned image, acquire the target detection points and their position information; the target detection points include the first detection point and the second detection point, and the position information includes the first position information of the first detection point and the second position information of the second detection point.

[0022] The target detection point is the location used to measure the printing accuracy of the alignment film. As mentioned above, the printing accuracy of the alignment film is characterized by the distance between the boundary of the display area and the boundary of the alignment film. Therefore, a target detection point includes two detection points, namely the first detection point and the second detection point. One of the first detection point and the second detection point is used to detect the boundary of the display area, and the other is used to detect the boundary of the alignment film.

[0023] For example, Figure 3 This is a detection point marker diagram on a scanned image of a display substrate provided in an embodiment of the present invention, referring to... Figure 3 Using the display substrate (display sub-board) as a polygon, optionally, at least one target detection point is obtained on each side of the display substrate to achieve omnidirectional measurement of printing accuracy.

[0024] For example, taking a rectangular shape as an example, a display substrate (display sub-board) can acquire at least four target detection points P, for example. Figure 3 The target detection points shown are PT (top), PD (bottom), PL (left), and PR (right).

[0025] Continue to refer to Figure 3Each target detection point P includes a first detection point P1 and a second detection point P2. Optionally, the first detection point P1 is used to detect the boundary of the alignment film, and the second detection point P2 is used to detect the boundary of the display area. The technical solution of the present invention will be explained using this as an example thereafter.

[0026] The first position information of the first detection point P1 may include the overall position information of the target detection point where the first detection point P1 is located on the display substrate (display sub-board) and the relative position information of the first detection point P1 relative to the second detection point P2 in the target detection point.

[0027] Similarly, the second position information of the second detection point P2 may include the overall position information of the target detection point where the second detection point P2 is located on the display substrate (display sub-board) and the relative position information of the second detection point P2 relative to the first detection point P1 in the target detection point.

[0028] For example, taking the left-side target detection point PL as an example, the first position information of the first detection point P1 can include "left-left", indicating that the first detection point P1 is located in the left-side target detection point PL of the display substrate (display sub-board), and is the left-hand detection point in the left-side target detection point PL, that is, it is located to the left of another detection point (i.e., the second detection point P2); the second position information of the second detection point P2 can include "left-right", indicating that the second detection point P2 is located in the left-side target detection point PL of the display substrate (display sub-board), and is the right-hand detection point in the left-side target detection point PL, that is, it is located to the right of another detection point (i.e., the first detection point P1). Therefore, the first detection point P1 on the left can be used to detect the boundary of the alignment film, and the second detection point P2 on the right can be used to detect the boundary of the display area.

[0029] Similarly, when the first detection point P1 is used to detect the boundary of the alignment film and the second detection point P2 is used to detect the boundary of the display area, in the right-side target detection point PR, the first position information of the first detection point P1 can include "right-right", and the second position information of the second detection point P2 can include "right-left"; in the upper-side target detection point PT, the first position information of the first detection point P1 can include "up-up", and the second position information of the second detection point P2 can include "up-down"; in the lower-side target detection point PD, the first position information of the first detection point P1 can include "down-down", and the second position information of the second detection point P2 can include "down-up". Furthermore, the first position information can also include the coordinate area information specifically occupied by the first detection point P1 on the entire display substrate; the second position information can also include the coordinate area information specifically occupied by the second detection point P2 on the entire display substrate.

[0030] Optionally, the first detection point P1 and the second detection point P2 of any target detection point can be obtained by the operator through a box selection action on the scanned image. In this way, the first detection point P1 and the second detection point P2 can be selected based on the actual product after the alignment film is printed. This makes it easier for the operator to select the position that is more conducive to identifying the boundary of the alignment film and the boundary of the display area as the target detection point according to the actual product, which helps to ensure the accuracy of the measurement results.

[0031] Optionally, the first location information of the first detection point P1 can be pre-configured by the staff, and the second location information of the second detection point P2 can be pre-configured by the staff for subsequent parameter calls.

[0032] S103. Based on the first location information, determine multiple first candidate boundaries within the first detection point; and based on the second location information, determine multiple second candidate boundaries within the second detection point.

[0033] Specifically, after acquiring the first location information, the processor can determine multiple first candidate boundaries within the corresponding area using an image processing algorithm. Similarly, after acquiring the second location information, the processor can determine multiple second candidate boundaries within the corresponding area using an image processing algorithm.

[0034] For example, multiple boundary lines can be captured within the first detection point using grayscale comparison as the first candidate boundary; and multiple boundary lines can be captured within the second detection point using grayscale comparison as the second candidate boundary.

[0035] Figure 4 yes Figure 3 An enlarged schematic diagram of the target detection point on the left side of the middle, as shown below. Figure 4 As shown, there are multiple first candidate boundaries E1 within the first detection point P1, and multiple second candidate boundaries E2 within the second detection point P2. Subsequently, the boundary of the alignment film can be determined from the multiple first candidate boundaries, and the boundary of the display area can be determined from the multiple second candidate boundaries.

[0036] S104. Determine a first identification direction based on the first position information, and determine the first target boundary as the one that ranks first in the first identification direction among all first candidate boundaries; and determine a second identification direction based on the second position information, and determine the second target boundary as the one that ranks first in the second identification direction among all second candidate boundaries; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction.

[0037] S105, Output the automatically measured distance between the first target boundary and the second target boundary to determine the printing accuracy of the alignment film based on the automatically measured distance.

[0038] In this design, one of the first target boundary and the second target boundary is the display area boundary, and the other is the alignment film boundary. When the first detection point is used to detect the alignment film boundary and the second detection point is used to detect the display area boundary, the first target boundary is the alignment film boundary, and the second target boundary is the display area boundary. The distance between the first target boundary and the second target boundary can characterize the printing accuracy of the alignment film.

[0039] As mentioned above, the (first / second) candidate boundaries are determined by grayscale comparison, meaning there is a significant grayscale difference between the candidate boundaries and surrounding pixels. The applicant's research found that after capturing multiple first and second candidate boundaries, if the boundary with the largest corresponding grayscale difference among all first candidate boundaries is used as the alignment film boundary, and the boundary with the largest corresponding grayscale difference among all second candidate boundaries is used as the display area boundary for printing accuracy measurement, the high rate of misidentification of the alignment film boundary and / or display area boundary due to numerous interference factors in the grayscale pattern leads to a decrease in the accuracy of the measurement results.

[0040] To solve this problem, embodiments of the present invention determine a first identification direction based on first position information, and determine the first target boundary as the one that ranks first in the first identification direction among all first candidate boundaries. They also determine a second identification direction based on second position information, and determine the second target boundary as the one that ranks first in the second identification direction among all second candidate boundaries. This can effectively ensure the accuracy of the measurement results.

[0041] Specifically, when the first detection point P1 is used to detect the alignment film boundary, refer to Figure 4 Within the first detection point P1, only one first candidate boundary E1 is the first target boundary E1a (corresponding to the alignment film boundary), while the others are interference items (corresponding to other patterns or steps in the display substrate). To facilitate the identification of the first target boundary E1a, when selecting the first detection point P1 on the scanned image, the operator can select the area where the first detection point P1 is located based on the relative positional relationship between the alignment film boundary and other interference patterns such as patterns or steps. This reduces the difficulty of identifying the alignment film boundary (first target boundary E1a) and ensures the accuracy of alignment film boundary identification.

[0042] Reference Figure 4 Optionally, the plurality of first candidate boundaries E1 include a first target boundary E1a and a plurality of first interference boundaries E1b, all of which are located on the same side of the first target boundary E1a; the first identification direction D1 is consistent with the direction from the first target boundary E1a to the first interference boundary E1b.

[0043] As described above, the first target boundary E1a corresponds to the alignment film boundary, and the first interference boundary E1b corresponds to other patterns (such as lines) or steps in the display substrate. Figure 2 In the scanned image, the alignment film boundary, lines, and step differences will have a large gray level difference with the surrounding area. Based on this feature, a region that includes the alignment film boundary and ensures that the interference pattern is only on one side of the alignment film boundary can be selected as the first detection point P1.

[0044] Furthermore, referring to Figure 4 Since the first identification direction D1 is the direction from the first target boundary E1a to the first interference boundary E1b, by determining the first target boundary E1a (alignment membrane boundary) as the one that ranks first in the first identification direction D1 among all the first candidate boundaries E1, the identification of the first target boundary can start from the side without interference, avoiding the interference of the first interference boundary, thereby ensuring the accuracy of the automatic identification of the alignment membrane boundary by the device.

[0045] It should be noted that the first identification direction D1 is pre-configured based on the first position information of the first detection point P1. The statement that "the first identification direction D1 is consistent with the direction from the first target boundary E1a to the first interference boundary E1b" is a result-oriented interpretation; it defines the relationship between the first identification direction and the first interference boundary E1b after they have been determined. Understandably, only when the first identification direction D1 is configured can the processing device automatically determine which of the multiple first candidate boundaries E1 is the first target boundary E1a and which are the first interference boundaries E1b.

[0046] Similarly, refer to Figure 4 Optionally, the plurality of second candidate boundaries E2 include a second target boundary E2a and a plurality of second interference boundaries E2b, all of which are located on the same side of the second target boundary E2a; the second identification direction D2 is consistent with the direction from the second target boundary E2a to the second interference boundary E2b.

[0047] Specifically, refer to Figure 2 and Figure 3 In the scanned image, the graphic differences between the display area and the non-display area are significant, as are the grayscale differences. Based on this feature, a region that includes the boundary of the display area and ensures that the interference pattern (non-display area pattern) is only present on one side of the boundary of the display area can be selected as the second detection point P2.

[0048] Furthermore, referring to Figure 4Since the second identification direction D2 is the direction from the second target boundary E2a to the second interference boundary E2b, by determining the first of all the second candidate boundaries E2 in the second identification direction D2 as the second target boundary E2a (display area boundary), the identification of the second target boundary can start from the side without interference, avoiding interference from the second interference boundary, thereby ensuring the accuracy of the device's automatic identification of the display area boundary.

[0049] Furthermore, refer to Figure 4 For any target detection point, after accurately identifying the alignment film boundary (first target boundary E1a) and the display area boundary (second target boundary E2a), the device can automatically measure the distance EM between the two boundaries and output the result of the automatic measurement distance EM (for example, displayed on the display screen of the processing device) so that the staff can know the printing accuracy corresponding to the target detection point.

[0050] Figure 5 yes Figure 3 An enlarged schematic diagram of the target detection point on the right side of the center. Figure 6 yes Figure 3 An enlarged schematic diagram of the target detection point on the upper middle side. Figure 7 yes Figure 3 An enlarged schematic diagram of the target detection points on the lower middle side, see reference. Figures 5-7 In other target detection points, the same scheme can be followed. Staff can pre-define the first detection point P1 and the second detection point P2, configuring the first position information and first recognition direction D1 for the first detection point P1, and the second position information and second recognition direction D2 for the second detection point P2. After all target detection points are selected and the corresponding parameter information is configured, the processing device can determine multiple first candidate boundaries E1 within the selected first detection point P1, thereby determining the first target boundary E1a; and multiple second candidate boundaries E2 within the selected second detection point P2, thereby determining the second target boundary E2a. The device can also automatically measure and output the distance between the first target boundary E1a and the second target boundary E2a. All target measurement points can simultaneously complete the above-mentioned target boundary identification and distance measurement, greatly improving measurement efficiency while ensuring the accuracy of the measurement results.

[0051] In summary, this embodiment of the invention acquires a scanned image of a display substrate using an automated optical inspection device. On the scanned image, target detection points (first detection point and second detection point) are obtained. Based on the first position information of the first detection point, multiple first candidate boundaries are determined within the first detection point. Based on the second position information of the second detection point, multiple second candidate boundaries are determined within the second detection point. A first recognition direction is determined based on the first position information, and the first candidate boundary ranked highest in the first recognition direction is determined as the first target boundary. A second recognition direction is determined based on the second position information, and the second candidate boundary ranked highest in the second recognition direction is determined as the first target boundary. The first and second target boundaries are determined as the first target boundary. The automatic measurement distance between the first and second target boundaries is then output. The printing accuracy of the alignment film is determined based on the automatic measurement distance. On the one hand, the automatic optical inspection equipment can be used to simultaneously measure and output the printing accuracy data of multiple inspection points, which greatly improves the measurement efficiency. On the other hand, by determining the identification direction of the target boundary within the inspection point based on the position information of the inspection point, the target boundary can be selected from multiple candidate boundaries according to the identification direction. This can effectively avoid the influence of interfering boundaries among the candidate boundaries, ensure the identification accuracy of the alignment film boundary and the display area boundary, and thus ensure the accuracy of the printing accuracy measurement results.

[0052] Based on the above embodiments, referring to Figures 3-7 Optionally, the second target boundary E2a is the boundary of the display area; the second recognition direction D2 points along the display area to the non-display area and is perpendicular to the boundary of the display area; the first recognition direction D1 is opposite to the second recognition direction D2.

[0053] Specifically, the circuits, wiring, and other patterns in the display area are usually arranged in an array, which is quite different from the patterns in the non-display area. By setting the second recognition direction D2 as the direction from the display area to the non-display area, when filtering the second target boundary E2a from multiple second candidate boundaries E2, the filtering can be carried out from the side without interference to the side with interference. In this way, the first second candidate boundary E2 found in the second detection point P2 along the second recognition direction D2 is the second target boundary E2a, ensuring the recognition accuracy of the display area boundary.

[0054] For the alignment film boundary (first target boundary E1a), since the boundary of the alignment film is close to the edge of the display sub-board, there are some lines or steps in the non-display area inside, which can be identified as the second candidate boundary (interference item). Therefore, the first identification direction D1 can be from the outside to the inside, which is opposite to the second identification direction D2. In this way, when screening the first target boundary E1a from multiple first candidate boundaries E1, the screening can be carried out from the side without interference to the side with interference. The first first candidate boundary E1 found in the first detection point P1 along the first identification direction D1 is the first target boundary E1a, which ensures the accuracy of the alignment film boundary identification.

[0055] In other embodiments, the second recognition direction D2 may point from the display area to the non-display area, and the first recognition direction D1 may be the same as the second recognition direction D2.

[0056] For example, Figure 8 yes Figure 3 Another enlarged schematic diagram of the target detection point on the left side of the middle, as shown below. Figure 8 As shown, in other embodiments, the location of the interference item on the side of the alignment film boundary away from the display area (i.e., the outside of the alignment film) can also be selected as the first detection point P1 in the scanned image. In this case, the first recognition direction D1 is the same as the second recognition direction D2. In this way, the recognition accuracy of the alignment film boundary can be guaranteed.

[0057] For example, in this embodiment, the interference items at the alignment membrane boundary may include, but are not limited to, patterns located outside the alignment membrane boundary such as alignment marks.

[0058] Figure 9 This is a flowchart illustrating another method for measuring the printing accuracy of alignment films provided in an embodiment of the present invention. The measurement method is further refined based on the above embodiments. For example... Figure 9 As shown, in this embodiment, the measurement method may include the following steps: S201. Obtain a scanned image of the display substrate based on an automated optical inspection device.

[0059] S202. On the scanned image, acquire the target detection points and their position information; the target detection points include the first detection point and the second detection point, and the position information includes the first position information of the first detection point and the second position information of the second detection point.

[0060] S203. Based on the first position information, determine the target grayscale comparison method and the first grayscale comparison threshold.

[0061] S204. Within the first detection point, multiple first candidate regions whose gray level difference exceeds the first gray level comparison threshold are determined by the target gray level comparison method.

[0062] S205. Determine the first centerline of the first candidate region as the first candidate boundary.

[0063] S206. Based on the second position information, determine the target grayscale comparison method and the second grayscale comparison threshold.

[0064] S207. Within the second detection point, multiple second candidate regions whose gray level difference exceeds the second gray level comparison threshold are determined by the target gray level comparison method.

[0065] S208. Determine the second centerline of the second candidate region as the second candidate boundary.

[0066] Specifically, S203-S208 are further details of S103 in the above embodiments.

[0067] Reference Figure 8 Within the first detection point P1, multiple first candidate regions Q1 can be determined using the target grayscale comparison method, and the first center line of the first candidate region Q1 can be determined as the first candidate boundary E1. Similarly, within the second detection point P2, multiple second candidate regions Q2 can be determined using the grayscale comparison method, and the second center line of the second candidate region Q2 can be determined as the second candidate boundary E2.

[0068] Reference Figure 8 The first center line (first candidate boundary E1) passes through the midpoint of the first candidate region Q1, and the second center line (second candidate boundary E2) passes through the midpoint of the second candidate region Q2. Both the first center line (first candidate boundary E1) and the second center line (second candidate boundary E2) are perpendicular to the direction from the first detection point P1 to the second detection point P2. In other words, both the first center line (first candidate boundary E1) and the second center line (second candidate boundary E2) are perpendicular to the first recognition direction D1 (second recognition direction D2).

[0069] Optionally, within the same target detection point, the target grayscale comparison method corresponding to the first detection point and the second detection point is the same.

[0070] Among them, the target grayscale comparison method is related to the position of the target detection point, or in other words, it is related to the extension direction of the display area boundary / alignment film boundary in the target detection point.

[0071] Specifically, refer to Figure 4 For the target detection point PL on the left, both the display area boundary and the alignment film boundary extend vertically. Accordingly, the target grayscale comparison method includes a horizontal comparison method. Using the horizontal comparison method, regions within the first detection point P1 whose grayscale difference exceeds the first grayscale comparison threshold are filtered out, thus obtaining multiple first candidate regions Q1.

[0072] The first grayscale comparison threshold can be understood as the lower limit of the grayscale difference within the first detection point P1 used to identify the first candidate region Q1. Only regions with grayscale differences exceeding the first grayscale comparison threshold can be used as the first candidate region Q1.

[0073] Similarly, refer to Figure 5 For the target detection point PR on the right, the horizontal comparison method can also be used to filter out the areas in the second detection point P2 whose gray level difference exceeds the second gray level comparison threshold, thus obtaining multiple second candidate areas Q2.

[0074] It should be noted that the first grayscale comparison threshold and the second grayscale comparison threshold can be the same value or different values, and the embodiments of the present invention do not limit this.

[0075] Reference Figure 6 and Figure 7 For the upper target detection point PT and the lower target detection point PD, both the display area boundary and the alignment film boundary extend horizontally. Correspondingly, the target grayscale comparison method includes a vertical comparison method. Using the vertical comparison method, regions within the first detection point P1 whose grayscale difference exceeds the first grayscale comparison threshold are selected, resulting in multiple first candidate regions Q1. Similarly, regions within the second detection point P2 whose grayscale difference exceeds the second grayscale comparison threshold are selected, resulting in multiple second candidate regions Q2.

[0076] Specifically, the target grayscale comparison direction and the first grayscale comparison threshold corresponding to the first detection point can be pre-configured, or a mapping relationship can be established with the first location information. After determining the first location information, the processing device can determine the target grayscale comparison direction and the first grayscale comparison threshold according to the mapping relationship.

[0077] Similarly, the target grayscale comparison direction and the second grayscale comparison threshold corresponding to the second detection point can be pre-configured, or a mapping relationship can be established with the second location information. After determining the second location information, the processing device can determine the target grayscale comparison direction and the second grayscale comparison threshold according to the mapping relationship.

[0078] S209. Based on the first position information and the preset mapping relationship between position information and recognition direction, determine the first recognition direction corresponding to the first position information.

[0079] S210. Determine the first target boundary as the one that ranks first in the first identification direction among all the first candidate boundaries.

[0080] S211. Based on the second position information and the preset mapping relationship between position information and recognition direction, determine the second recognition direction corresponding to the second position information.

[0081] S212. Determine the second target boundary as the one that ranks first in the second identification direction among all the second candidate boundaries.

[0082] S209-S212 are specific refinements of S104.

[0083] Specifically, the mapping relationship between position information and recognition direction can be preset. In this way, the first recognition direction can be determined based on the first position information of the first detection point, and the second recognition direction can be determined based on the second position information of the second detection point.

[0084] For example, refer to Figure 4 Taking the second recognition direction D2 as an example where the display area points to the non-display area, and the first recognition direction D1 is opposite to the second recognition direction D2, for the left target detection point PL, the first position information of the first detection point P1 includes "left-left", which is mapped to left to right in the first recognition direction D1. The second position information of the second detection point P2 includes "left-right", which is mapped to right to left in the second recognition direction D2. The mapping relationship between other position information and recognition directions will not be explained one by one here.

[0085] In other embodiments, the first and second recognition directions can also be pre-configured. In this way, the corresponding recognition direction can be determined according to the actual situation of the first and second detection points of different display sub-boards, thereby improving the flexibility of the solution.

[0086] S213, Output the automatically measured distance between the first target boundary and the second target boundary to determine the printing accuracy of the alignment film based on the automatically measured distance.

[0087] For example, for any target detection point, parameters such as first position information, target grayscale comparison method, first recognition direction, and first grayscale comparison threshold can be pre-configured for the first detection point P1. For the second detection point P2, parameters such as second position information, target grayscale comparison method, second recognition direction, and second grayscale comparison threshold can be pre-configured. Based on these configured parameters, the processing device can determine the first candidate boundary and the first target boundary in the first detection point P1, and determine the second candidate boundary and the second target boundary in the second detection point P2, thereby obtaining the distance between the first target boundary and the second target boundary and determining the printing accuracy corresponding to the target detection point.

[0088] For example, refer to Figure 3 Taking a display sub-board with four target detection points P (top, bottom, left, and right) as an example, Table 1 provides a parameter configuration example for the detection points, with the first recognition direction and the second recognition direction being opposite.

[0089] Table 1 Parameter configuration of detection points Referring to Table 1, by pre-setting parameters such as the position information, grayscale comparison method, recognition direction, and grayscale comparison threshold of the first and second detection points, the processing equipment can automatically measure the alignment film printing accuracy of each target detection point.

[0090] Referring to Table 1, in addition to the parameters mentioned above, target values, upper limits, and lower limits can also be configured. The target value represents the theoretical design value for printing accuracy; the ideal printing accuracy is achieved when the target value falls within the upper and lower limits. If the actual measured printing accuracy falls within the upper and lower limits, it indicates that the printing accuracy of the alignment film at the current position is acceptable; otherwise, it indicates that the printing accuracy of the alignment film is unacceptable.

[0091] In addition, refer to Figure 1 When the display substrate includes multiple display sub-boards, the configuration parameters may also include panel ID, i.e., the number of the display sub-board, in order to determine the display sub-board corresponding to the output printing precision.

[0092] Optionally, when the display substrate includes multiple display sub-boards, acquiring target detection points on the scanned image includes: acquiring N target detection points in the area where each display sub-board is located on the scanned image; N is greater than or equal to the number of sides of the display sub-board.

[0093] Specifically, when the display substrate includes multiple display sub-boards, each display sub-board acquires N target detection points. Each detection point is pre-configured with parameters as shown in Table 1. In this way, after the detection points of all display sub-boards are selected and the parameters are configured, the processing equipment can automatically measure the alignment film printing accuracy of each target detection point according to the configured parameters, which greatly improves the measurement efficiency and ensures the accuracy of the measurement results.

[0094] Figure 10 This is a flowchart illustrating another method for measuring the printing accuracy of alignment film provided in an embodiment of the present invention. The measurement method has been further supplemented and optimized based on the above embodiments. For example... Figure 10 As shown, the measurement method may include the following steps: S301. Obtain a scanned image of the display substrate based on an automated optical inspection device.

[0095] S302. On the scanned image, acquire the target detection points and their position information; the target detection points include the first detection point and the second detection point, and the position information includes the first position information of the first detection point and the second position information of the second detection point.

[0096] S303. Based on the first location information, determine multiple first candidate boundaries within the first detection point; and based on the second location information, determine multiple second candidate boundaries within the second detection point.

[0097] S304. Determine a first identification direction based on the first position information, and determine the first target boundary as the one that ranks first in the first identification direction among all first candidate boundaries; and determine a second identification direction based on the second position information, and determine the second target boundary as the one that ranks first in the second identification direction among all second candidate boundaries; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction.

[0098] S305, Output the automatically measured distance between the first target boundary and the second target boundary to determine the printing accuracy of the alignment film based on the automatically measured distance.

[0099] S306. Output a grayscale screenshot including the boundaries of the first and second targets.

[0100] Specifically, the system can output a grayscale screenshot containing both the first and second target boundaries simultaneously with or after outputting the automatically measured distance between them. This allows staff to measure printing precision (EM) using the grayscale screenshot and verify the accuracy of the automatically measured distance output by the equipment.

[0101] It should be noted that staff can review all the output data (automatic distance measurement) one by one, or they can review only a portion of the output data (see S307-S308 for details). This embodiment of the invention does not limit this.

[0102] S307. Based on the location information of the target detection point and the preset mapping relationship between the location information and the target distance, determine the target distance range corresponding to the target detection point.

[0103] S308. If the automatically measured distance is not within the target distance range, the automatically measured distance shall be specifically marked so that staff can verify the automatically measured distance with the specific mark based on the grayscale screenshot.

[0104] The target distance range can be understood as the distance range defined by the upper and lower limits in Table 1 above. It is understood that if the automatically measured distance is within the target distance range, the printing accuracy is acceptable; if the automatically measured distance is not within the target distance range, the printing accuracy is unacceptable.

[0105] For data indicating printing accuracy defects due to automatic distance measurement, these data can be specifically marked (e.g., highlighted or highlighted in red) during output so that staff can clearly see the defects. For this type of data, staff can retrieve a grayscale screenshot and manually measure the distance between the display area boundary and the printing boundary to verify the accuracy of the automatic measurement. If correct, it indicates that the printing accuracy is indeed substandard, and a defect can be reported for improvement measures to increase the product pass rate. If incorrect, the manual measurement result can be used to correct the printing accuracy.

[0106] For other automatically measured distances that are not specifically marked, the user may choose whether to perform a verification, and this embodiment of the invention does not limit this.

[0107] For example, Figures 11-14 This is a schematic diagram of a grayscale screenshot provided by an embodiment of the present invention, illustrating grayscale screenshots at four positions: Top, Down, Left, and Right. Figures 11-14 As shown, optionally, the grayscale screenshot includes at least a first scale K1, the extension direction of the first scale K1 being perpendicular to the extension direction of the first target boundary E1a. By outputting a grayscale screenshot with the first scale K1, it is convenient to read the distance between the first target boundary and the second target boundary through the first scale K1, and to determine the printing accuracy.

[0108] Reference Figures 11-14 Optionally, the grayscale screenshot also includes a second scale K2, which is orthogonal to the first scale K1.

[0109] Specifically, by setting the grayscale screenshot to include a first orthogonal scale K1 and a second scale K2, the scales of the grayscale screenshots at different locations can be made consistent, making it easier to read the distance between the first target boundary and the second target boundary at different locations.

[0110] For example, comparison Figure 11 and Figure 13 In the grayscale screenshots on the left and the top, the extension direction of the first target boundary E1a is different. Therefore, the extension direction of the ruler (first ruler K1) used for reading needs to be different. For all grayscale screenshots, this embodiment sets each grayscale screenshot to have two mutually orthogonal rulers, so that distance readings in different directions can be realized.

[0111] Reference Figures 11-14Optionally, outputting a grayscale screenshot including the first target boundary and the second target boundary (S306) includes the following steps: determining the midpoint of the distance between the first target boundary and the second target boundary; taking the midpoint of the distance as the center, cropping a grayscale image of a preset size to obtain a grayscale screenshot.

[0112] Specifically, after determining the first target boundary and the second target boundary, the processing device can capture a grayscale image of a preset size centered at the midpoint of the distance between the two, thus obtaining a grayscale screenshot. The preset size can be set arbitrarily, and this embodiment of the invention does not impose any limitations on it.

[0113] For example, a grayscale image of N×N CCD pixels can be cropped from the midpoint to obtain a grayscale screenshot. If the CCD resolution is 5µm×5µm and the screenshot size is 800×800, the resulting image would be a magnified image of the actual object, which would be 40mm×40mm.

[0114] This embodiment uses the midpoint of the distance between the first target boundary and the second target boundary as the center for taking a screenshot. On the one hand, it allows for the reasonable setting of the grayscale screenshot size, ensuring that the grayscale screenshot necessarily includes the first and second target boundaries (i.e., the alignment membrane boundary and the display area boundary). This avoids coordinate offset during screenshotting, which could result in a single screenshot failing to display the alignment membrane boundary and the display area boundary at the same target detection point, making it impossible to take a reading. On the other hand, it also helps reduce the difficulty of reading the distance (distance value = scale value of the display area boundary (or alignment membrane boundary) × 2), enabling the reading of the distance value between the display area boundary and the alignment membrane boundary within 1 second, effectively improving the verification efficiency.

[0115] Based on the same inventive concept, embodiments of the present invention also provide a measuring device for the printing accuracy of the alignment film on a display substrate. For example, Figure 15 This is a schematic diagram of a device for measuring the printing accuracy of alignment film provided in an embodiment of the present invention, as shown below. Figure 15As shown, the measuring device includes: an image acquisition module 401, a point location acquisition module 402, a candidate boundary determination module 403, a target boundary determination module 404, and a measurement distance output module 405. The image acquisition module 401 is used to acquire a scanned image of the display substrate based on an automatic optical inspection device; the point position acquisition module 402 is used to acquire target detection points and their position information on the scanned image; the target detection points include a first detection point and a second detection point, and the position information includes a first position information of the first detection point and a second position information of the second detection point; the candidate boundary determination module 403 is used to determine multiple first candidate boundaries within the first detection point based on the first position information; and to determine multiple second candidate boundaries within the second detection point based on the second position information; the target boundary determination module 404 is used to determine a first recognition direction based on the first position information, and to determine the first target boundary as the one that ranks first in the first recognition direction among all the first candidate boundaries; and to determine a second recognition direction based on the second position information, and to determine the second target boundary as the one that ranks first in the second recognition direction among all the second candidate boundaries; the first recognition direction intersects with the extension direction of the first candidate boundary; the second recognition direction is parallel to the first recognition direction; the measurement distance output module 405 is used to output the automatic measurement distance between the first target boundary and the second target boundary, so as to determine the printing accuracy of the alignment film based on the automatic measurement distance.

[0116] The measuring device provided in the embodiments of the present invention can execute the measuring method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of executing the method.

[0117] Optionally, the candidate boundary determination module 403 is specifically used to: determine a target grayscale comparison method and a first grayscale comparison threshold based on the first location information; within the first detection point, determine multiple first candidate regions whose grayscale difference exceeds the first grayscale comparison threshold using the target grayscale comparison method; determine the first center line of the first candidate region as the first candidate boundary; determine a target grayscale comparison method and a second grayscale comparison threshold based on the second location information; within the second detection point, determine multiple second candidate regions whose grayscale difference exceeds the second grayscale comparison threshold using the target grayscale comparison method; and determine the second center line of the second candidate region as the second candidate boundary.

[0118] The first center line passes through the midpoint of the first candidate region, and the second center line passes through the midpoint of the second candidate region. Both the first center line and the second center line are perpendicular to the direction from the first detection point to the second detection point. In the same target detection point, the target grayscale comparison method corresponding to the first detection point and the second detection point is the same.

[0119] Optionally, the target boundary determination module 404 is used to determine the first identification direction corresponding to the first position information based on the first position information and the preset mapping relationship between position information and identification direction; and is also used to determine the second identification direction corresponding to the second position information based on the second position information and the preset mapping relationship between position information and identification direction.

[0120] Optionally, the plurality of first candidate boundaries include a first target boundary and a plurality of first interference boundaries, all of which are located on the same side of the first target boundary; the first identification direction is consistent with the direction from the first target boundary to the first interference boundary; the plurality of second candidate boundaries include a second target boundary and a plurality of second interference boundaries, all of which are located on the same side of the second target boundary; the second identification direction is consistent with the direction from the second target boundary to the second interference boundary.

[0121] Optionally, the second target boundary is the boundary of the display area; the second recognition direction points along the display area to the non-display area and is perpendicular to the boundary of the display area; the first recognition direction is opposite to the second recognition direction; or, the first recognition direction is the same as the second recognition direction.

[0122] Optionally, multiple display sub-boards are integrated on the display substrate, each display sub-board including a display area and a non-display area, and the alignment films on adjacent display sub-boards are independently spaced; the point position acquisition module 402 is used to acquire N target detection points in the area where each display sub-board is located on the scanned image; N is greater than or equal to the number of sides of the display sub-board.

[0123] Optionally, the measuring device further includes a screenshot output module, which outputs a grayscale screenshot including the first target boundary and the second target boundary while outputting the automatically measured distance between the first target boundary and the second target boundary.

[0124] Optionally, the grayscale screenshot includes at least a first scale, the extension direction of which is perpendicular to the extension direction of the first target boundary.

[0125] Optionally, the screenshot output module is specifically used to determine the midpoint of the distance between the first target boundary and the second target boundary; and to extract a grayscale image of a preset size with the midpoint of the distance as the center to obtain a grayscale screenshot.

[0126] Optionally, the measuring device further includes a verification module, which, after outputting the automatic measurement distance between the first target boundary and the second target boundary, determines the target distance range corresponding to the target detection point based on the position information of the target detection point and the preset mapping relationship between the position information and the target distance; if the automatic measurement distance is not within the target distance range, the automatic measurement distance is specifically marked so that the staff can verify the automatic measurement distance with the specific mark based on the grayscale screenshot.

[0127] Based on the same inventive concept, embodiments of the present invention also provide a system for measuring the printing accuracy of alignment film on a display substrate. For example, Figure 16 This is a schematic diagram of the structure of a measurement system for alignment film printing accuracy provided in an embodiment of the present invention, as shown below. Figure 16 As shown, the measurement system 500 includes an automatic optical inspection device 510 and a processing device 520; the automatic optical inspection device 510 is used to acquire scanned images of the display substrate 100; the processing device 520 includes a memory 521, a processor 522, and a computer program stored in the memory 521 and executable on the processor 522. When the processor 522 executes the computer program, it implements the measurement method provided in any of the embodiments of the present invention, and has the same beneficial effects as the above-described measurement method.

[0128] The type of memory 521 includes, but is not limited to, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the above, and the embodiments of the present invention do not limit this.

[0129] The processor 522 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processors include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor performs the various methods described above, such as measurement methods.

[0130] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0131] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for measuring the printing accuracy of an alignment film on a display substrate, the display substrate comprising a display area and a non-display area surrounding the display area, the alignment film covering the display area and the boundary of the alignment film located within the non-display area; characterized in that, The measurement method includes: The display substrate is scanned using an automated optical inspection device; On the scanned image, target detection points and their location information are acquired; the target detection points include a first detection point and a second detection point, and the location information includes a first location information of the first detection point and a second location information of the second detection point. Based on the first location information, multiple first candidate boundaries are determined within the first detection point; and based on the second location information, multiple second candidate boundaries are determined within the second detection point. A first identification direction is determined based on the first location information, and the first candidate boundary ranked first in the first identification direction is determined as the first target boundary; and a second identification direction is determined based on the second location information, and the first candidate boundary ranked first in the second identification direction is determined as the second target boundary; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction; Output the automatically measured distance between the first target boundary and the second target boundary to determine the printing accuracy of the alignment film based on the automatically measured distance.

2. The measurement method according to claim 1, characterized in that, Based on the first location information, multiple first candidate boundaries are determined within the first detection point. And based on the second location information, multiple second candidate boundaries are determined within the second detection point, including: Based on the first location information, the target grayscale comparison method and the first grayscale comparison threshold are determined; Within the first detection point, multiple first candidate regions whose gray level difference exceeds the first gray level comparison threshold are determined by the target gray level comparison method; The first centerline of the first candidate region is defined as the first candidate boundary. Based on the second location information, the target grayscale comparison method and the second grayscale comparison threshold are determined; Within the second detection point, multiple second candidate regions whose grayscale difference exceeds the second grayscale comparison threshold are determined by the target grayscale comparison method; The second centerline of the second candidate region is defined as the second candidate boundary; Wherein, the first center line passes through the midpoint of the first candidate region, the second center line passes through the midpoint of the second candidate region, and both the first center line and the second center line are perpendicular to the direction from the first detection point to the second detection point; Within the same target detection point, the target grayscale comparison method corresponding to the first detection point and the second detection point is the same.

3. The measurement method according to claim 1, characterized in that, Determining the first identification direction based on the first location information includes: Based on the first location information and the preset mapping relationship between location information and recognition direction, the first recognition direction corresponding to the first location information is determined; Determining the second identification direction based on the second location information includes: Based on the second location information and the preset mapping relationship between location information and recognition direction, the second recognition direction corresponding to the second location information is determined.

4. The measurement method according to claim 1, characterized in that, The plurality of first candidate boundaries include the first target boundary and a plurality of first interference boundaries, all of which are located on the same side of the first target boundary; the first identification direction is consistent with the direction from the first target boundary to the first interference boundary; The plurality of second candidate boundaries include the second target boundary and a plurality of second interference boundaries, all of which are located on the same side of the second target boundary; the second identification direction is consistent with the direction from the second target boundary to the second interference boundary.

5. The measurement method according to claim 1, characterized in that, The second target boundary is the boundary of the display area; The second identification direction points along the display area to the non-display area and is perpendicular to the boundary of the display area; The first identification direction is opposite to the second identification direction; or, the first identification direction is the same as the second identification direction.

6. The measurement method according to claim 1, characterized in that, The display substrate integrates multiple display sub-boards, each of which includes a display area and a non-display area, and the alignment films on adjacent display sub-boards are independently spaced apart. On the scanned image, the target detection points are obtained, including: On the scanned image, N target detection points are obtained in the area where each of the display sub-panels is located; N is greater than or equal to the number of sides of the display sub-panel.

7. The measurement method according to claim 1, characterized in that, While outputting the automatically measured distance between the first target boundary and the second target boundary, the measurement method further includes: Output a grayscale screenshot that includes the boundaries of the first target and the second target.

8. The measurement method according to claim 7, characterized in that, The grayscale screenshot includes at least a first scale, the extension direction of which is perpendicular to the extension direction of the first target boundary.

9. The measurement method according to claim 7, characterized in that, Output a grayscale screenshot including the boundaries of the first target and the second target, including: Determine the midpoint of the distance between the first target boundary and the second target boundary; Using the midpoint of the distance as the center, a grayscale image of a preset size is cropped to obtain the grayscale screenshot.

10. The measurement method according to claim 7, characterized in that, After outputting the automatically measured distance between the first target boundary and the second target boundary, the measurement method further includes: Based on the location information of the target detection point and the preset mapping relationship between the location information and the target distance, the target distance range corresponding to the target detection point is determined; If the automatically measured distance is not within the target distance range, the automatically measured distance is specifically marked so that staff can verify the automatically measured distance with the specific mark based on the grayscale screenshot.

11. A measuring device for the printing accuracy of an alignment film on a display substrate, the display substrate comprising a display area and a non-display area surrounding the display area, the alignment film covering the display area and the boundary of the alignment film located within the non-display area; characterized in that, The measuring device includes: An image acquisition module is used to acquire scanned images of the display substrate based on an automated optical inspection device; The point location acquisition module is used to acquire target detection points and their location information on the scanned image; the target detection points include a first detection point and a second detection point, and the location information includes a first location information of the first detection point and a second location information of the second detection point; The candidate boundary determination module is used to determine multiple first candidate boundaries within the first detection point based on the first location information; and to determine multiple second candidate boundaries within the second detection point based on the second location information. The target boundary determination module is used to determine a first identification direction based on the first position information, and determine the first target boundary as the one that ranks first in the first identification direction among all the first candidate boundaries; and to determine a second identification direction based on the second position information, and determine the second target boundary as the one that ranks first in the second identification direction among all the second candidate boundaries; the first identification direction intersects with the extension direction of the first candidate boundary; the second identification direction is parallel to the first identification direction; A distance measurement output module is used to output the automatic measurement distance between the first target boundary and the second target boundary, so as to determine the printing accuracy of the alignment film based on the automatic measurement distance.

12. A system for measuring the printing accuracy of alignment film on a display substrate, characterized in that, include: Automated optical inspection and processing equipment; The automated optical inspection device is used to acquire scanned images of the display substrate; The processing device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the measurement method as described in any one of claims 1-10.

Images