Autofocus system and autofocus method

Abstract

An autofocus system and an autofocus method. The autofocus system comprises: a primary inspection microscope module (20), a defocus information measurement module (10), a main control module (30), and a drive motor module (40). The defocus information measurement module (10) comprises an adjustable array light source (1011) configured to adjust a light-emitting region on the basis of a preset condition. Measurement light emitted from the light-emitting region sequentially passes through a second beam-splitter prism (102) and a first beam-splitter prism (202), and is then projected by a microscope objective lens (203) to each of sub-regions to be inspected, generating reflected light; the reflected light sequentially passes through the first beam-splitter prism (202) and the second beam-splitter prism (102), forming a pair of light spots on the defocus information measurement module (10) and corresponding to each of said sub-regions; and on the basis of light spot information of each pair of light spots, the main control module (30) instructs the drive motor module (40) to drive the primary inspection microscope module (20), so as to sequentially focus on each of said sub-regions and to capture an image of each of said sub-regions after focusing is completed. On the basis of the autofocus system and the autofocus method, focusing efficiency can be improved.

Description

An autofocus system and autofocus method Technical Field

[0001] This application relates to the field of image processing, and more particularly to an autofocus system and autofocus method. Background Technology

[0002] Semiconductor automated optical inspection (AOI) equipment requires acquiring clear, magnified microscopic images of the target area when inspecting samples (e.g., display panels, wafers, printed circuit boards, etc.). Image processing techniques are then used to identify defects in the target area. Low-magnification microscope objectives used for AOI typically have a depth of field of tens of micrometers, while high-magnification objectives have a depth of field of only about one micrometer. Therefore, due to factors such as sample warping and surface three-dimensional structures, the region of interest (ROI) often exceeds the depth of field of the microscope objective and cannot be clearly imaged. Thus, rapid AOI inspection requires an autofocus system to acquire multiple AOI images through multiple focusing attempts.

[0003] However, for devices under test (DUTs) with complex three-dimensional structures, such as re-distribution layers (RDLs) and multilayer glass substrates, there are multiple areas of interest (ROIs) to be detected in the current field of view under the microscope objective. Furthermore, the heights of these ROIs vary, and the height differences may exceed the depth of field range of the microscope objective. Therefore, it is necessary to acquire and analyze the defocus information of each ROI to obtain its defocus direction and distance. This allows for focus adjustment during image acquisition for that ROI. The same steps are repeated for other ROIs within the current field of view until a clear image of the area is obtained. This focusing method lacks flexibility and is difficult to adapt to complex application requirements. Summary of the Invention

[0004] This application provides an autofocus system and autofocus method, which can improve autofocus efficiency. The technical solution is as follows:

[0005] In a first aspect, embodiments of this application provide an autofocus system, the autofocus system comprising: a main inspection microscope module, a defocus information measurement module, a main control module, and a drive motor module;

[0006] The main inspection microscope module includes an image acquisition unit, a first beam splitter prism, and a microscope objective.

[0007] The defocus information measurement module includes an adjustable array light source, a second beam splitter prism, and a defocus information acquisition unit; wherein, the adjustable array light source is configured to adjust the light-emitting area of ​​the adjustable array light source according to preset conditions, the preset conditions including the accuracy requirements of the acquired image and / or the area information of the area to be measured, the area to be measured including at least one sub-area to be measured, and the adjustment of the light-emitting area includes at least one of the following adjustment directions: the size and shape of the light-emitting area, and the density of the light-emitting units in the light-emitting area;

[0008] The measurement light emitted by each light-emitting unit in the light-emitting region is transmitted through the second beam splitter and reflected vertically by the first beam splitter in sequence. After passing through the microscope objective, the measurement light spot is generated. The measurement light spot is projected onto each of the sub-regions to be tested to generate reflected light. The reflected light is reflected vertically by the first beam splitter and the second beam splitter in sequence, and then forms a light spot pair corresponding to each sub-region to be tested on the defocus information acquisition unit.

[0009] The main control module obtains the defocus information of each sub-region under test based on the spot pair corresponding to each sub-region under test, and instructs the drive motor module to drive the main inspection microscope module to focus on each sub-region under test in sequence, so that the image acquisition unit can sequentially acquire the image of each sub-region under test after focusing.

[0010] Secondly, embodiments of this application provide an autofocus method, applicable to the autofocus system as described in the first aspect, the method comprising:

[0011] According to the accuracy requirements of the acquired image and / or the regional information of the area to be tested, the luminous area of ​​the adjustable array light source is adjusted; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the luminous area includes at least one of the following adjustment directions: the size and shape of the luminous area, and the density of the luminous units in the luminous area;

[0012] Collect defocus measurement images of the area to be measured, including multiple spot pairs;

[0013] Analyze each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the light spot pair;

[0014] Focus and acquire images of the sub-region under test sequentially based on each defocus information until images corresponding to all sub-regions under test are acquired.

[0015] Thirdly, embodiments of this application provide an autofocus method, the apparatus being adapted to the autofocus system as described in the first aspect, the apparatus comprising:

[0016] The first acquisition module is used to adjust the luminous area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the area information of the area to be tested; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the luminous area includes at least one of the following adjustment directions: the size and shape of the luminous area, and the density of the luminous units in the luminous area;

[0017] The second acquisition module is used to acquire a defocus measurement image corresponding to the area to be measured, including multiple light spot pairs;

[0018] The information analysis module is used to analyze each pair of light spots on the defocus measurement image and obtain the defocus information of each sub-region to be measured associated with the pair of light spots.

[0019] The third acquisition module is used to sequentially focus and acquire images of the sub-region under test according to each of the defocus information, until images corresponding to all sub-regions under test included in the region under test are acquired.

[0020] Fourthly, embodiments of this application provide a computer storage medium storing a plurality of instructions adapted for loading by a processor and executing the above-described method steps.

[0021] Fifthly, embodiments of this application provide an electronic device that may include: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to execute the above-described method steps.

[0022] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following:

[0023] In this application, an autofocus system is based on modules including a main inspection microscope module, a defocus information measurement module, a main control module, and a drive motor module. The main control module adjusts the luminous area of ​​the adjustable array light source in the defocus information measurement module according to the accuracy requirements of the acquired image and / or the area information of the region to be measured. The region to be measured includes at least one sub-region. Adjusting the luminous area includes at least one of the following: the size and shape of the luminous area, and the density of the luminous units in the luminous area. In other words, based on the accuracy requirements of the acquired image and / or the area information of the region to be measured, the number of light spot pairs required for the acquired image is determined, thereby adjusting the number of luminous units in the luminous area of ​​the adjustable array light source according to the number of light spot pairs, and further adjusting the shape of the luminous area.

[0024] The process involves acquiring defocus measurement images of multiple spot pairs corresponding to the area under test. A spot pair is obtained through a defocus information acquisition unit when the measurement spot generated by the measurement light emitted from the luminous area is focused on the area under test. Further, defocus information of the sub-regions under test associated with the spot pairs is acquired. Based on each defocus information, the system sequentially focuses and acquires images of the sub-regions under test until the entire area under test is captured. In other words, by performing a single defocus measurement image acquisition operation on the area under test within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions under test can be obtained. This allows for sequential focusing of each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies that require multiple defocus image acquisitions to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 is a schematic diagram of an autofocus scene provided in an embodiment of this application;

[0027] Figure 2 is a schematic diagram of the principle of autofocus provided in an embodiment of this application;

[0028] Figure 3 is a schematic diagram of an autofocus system provided in an embodiment of this application;

[0029] Figure 4 is a schematic diagram of a light spot pair provided in an embodiment of this application;

[0030] Figure 5 is a schematic diagram of an autofocus system provided in an embodiment of this application;

[0031] Figure 6 is a schematic diagram of the light-emitting region in an adjustable array light source provided in an embodiment of this application;

[0032] Figure 7 is a flowchart illustrating an autofocus method provided in an embodiment of this application;

[0033] Figure 8 is a flowchart illustrating an autofocus method provided in an embodiment of this application;

[0034] Figure 9 is a flowchart illustrating an autofocus method provided in an embodiment of this application;

[0035] Figure 10 is a schematic diagram of an adjustable array light source provided in an embodiment of this application;

[0036] Figure 11 is a schematic diagram of an adjustable array light source provided in an embodiment of this application;

[0037] Figure 12 is a flowchart illustrating an autofocus method provided in an embodiment of this application;

[0038] Figure 13 is a schematic diagram of an autofocus device provided in an embodiment of this application;

[0039] Figure 14 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0042] The present application will now be described in detail with reference to specific embodiments.

[0043] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in the embodiments of this specification are all authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the features, information, and data involved in this specification were all obtained under full authorization.

[0044] Semiconductor automated optical inspection (AOI) equipment requires acquiring clear, magnified microscopic images of the sample under test (e.g., display panels, wafers, printed circuit boards, etc.) before using image processing technology to identify defects. Low-magnification microscope objectives used for AOI typically have a depth of field of tens of micrometers, while high-magnification microscope objectives have a depth of field of only about one micrometer. Therefore, due to factors such as warping and surface three-dimensional structures of the sample, the region of interest (ROI) often exceeds the depth of field of the microscope objective and cannot be clearly imaged. Thus, rapid AOI inspection requires an autofocus system to acquire multiple AOI images through multiple focusing attempts.

[0045] Existing autofocus devices, based on the characteristics of the light spot measured for out-of-focus information, are mainly divided into single-spot autofocus systems, multi-spot / array-spot autofocus systems, and line-spot autofocus systems.

[0046] Single-spot autofocus systems are the simplest and most common, such as WDI's ATF-4 autofocus product, as shown in Figure 1. Figure 1 is a schematic diagram of an autofocus scenario provided by an embodiment of this application. This type of autofocus system uses only a single spot (usually located in the center of the microscope objective's field of view) to measure the defocus information of the current central area of ​​the field of view. Measurement light is focused by the objective onto the central area of ​​the field of view to form a single spot; the defocus information of the central area of ​​the field of view can be obtained through the spot information of this single spot.

[0047] A major problem with this type of autofocus system is that it can only acquire defocus information of the central region of the field of view, and can only focus on the image of the central region of the field of view for acquisition. For devices under test (DUTs) with complex three-dimensional structures, such as re-distribution layers (RDLs) and multilayer glass substrates, when the region of interest (ROI) is not located at the center of the field of view, and there is a height difference between the ROI and the central region of the field of view that exceeds the depth of field range of the microscope objective, it is impossible to acquire a clear image of the ROI.

[0048] As shown in Figure 2, Figure 2 is a schematic diagram of the principle of autofocus provided in an embodiment of this application. The edge region imaging beam and the center region imaging beam emitted from the objective lens are focused on the edge region and the center region of the field of view, respectively, forming a focal plane and a depth of field range centered on the focal plane. When the height difference between the area to be measured and the center region of the field of view exceeds this depth of field range, the objective lens cannot focus on the area to be measured or acquire a high-resolution image.

[0049] Multi-spot / array-spot autofocus systems are a variant of single-spot autofocus systems. They introduce multiple spots to acquire defocus information in different areas of the field of view under the microscope objective, which can compensate for the problems of single-spot autofocus systems to a certain extent.

[0050] For RDLs with fine and dense lines, the resolution of multi-spot / array-spot autofocus systems is insufficient, or their spot size cannot flexibly adapt to complex structural changes. This can lead to inaccurate focusing on critical details of the ROI, thus affecting detection accuracy and reliability. Therefore, when dealing with RDLs with high-density linewidth / spacing, existing multi-spot / array-spot autofocus systems cannot provide sufficient performance to ensure that every area of ​​interest is correctly focused and clearly imaged.

[0051] Linear spot autofocus systems improve the density of defocus information measurement by changing the spot used to measure defocus information from a single point or array of spots to a linear spot perpendicular to the defect detection scanning direction. In this system, the defocus measurement beam is projected obliquely onto the surface of the device under test (DUT) from one side of the objective lens's principal optical axis. Therefore, in the dimension perpendicular to the defect detection scanning direction, the density of defocus measurement is effectively increased, improving efficiency. However, in the dimension along the defect detection scanning direction, only the defocus information in the central region of the field of view can be measured; defocus information in other regions including the center of the field of view cannot be measured.

[0052] In other words, existing autofocus systems, for multiple areas of interest (ROIs) within the objective lens's field of view, need to acquire and analyze the defocus information of each ROI to determine its defocus direction and distance. This allows for focus adjustment based on the image acquisition for that ROI. The same steps are repeated for other ROIs within the current field of view until a clear image of the current area is obtained. This focusing method lacks flexibility and is difficult to adapt to complex usage requirements.

[0053] To address the aforementioned problems, this application provides an autofocus system. As shown in Figure 3, which is a schematic diagram of the autofocus system provided in this application embodiment, the autofocus system includes: a main inspection microscope module 20, a defocus information measurement module 10, a main control module 30, and a drive motor module 40.

[0054] The main inspection microscope module 20 includes an image acquisition unit 201, a first beam splitter prism 202, and a microscope objective 203.

[0055] The defocus information measurement module 10 includes an adjustable array light source 1011, a second beam splitter prism 102, and a defocus information acquisition unit 103. The defocus information acquisition unit 103 can be understood as an image sensor or photodetector, used to acquire multiple light spot pairs.

[0056] The adjustable array light source 1011 is configured to adjust the light-emitting area of ​​the adjustable array light source according to preset conditions, including the accuracy requirements of the acquired image and / or the area information of the area to be measured. The area to be measured 200 includes at least one sub-area to be measured. Adjusting the light-emitting area includes at least one of the following adjustment directions: the size and shape of the light-emitting area, and the density of the light-emitting units in the light-emitting area.

[0057] The measurement light emitted by each light-emitting unit in the light-emitting region is transmitted through the second beam splitter prism 102 and reflected vertically by the first beam splitter prism 202 in sequence. After being reflected by the microscope objective 203, the measurement light spot is generated. The measurement light spot is projected onto each sub-region to be measured to generate reflected light. The reflected light is reflected vertically by the first beam splitter prism 202 and the second beam splitter prism 102 in sequence, and then forms a pair of light spots corresponding to each sub-region to be measured on the defocus information acquisition unit 103.

[0058] Figure 4 is a schematic diagram of a light spot pair provided in an embodiment of this application, taking the example that only one light-emitting unit in the light-emitting area of ​​the adjustable array light source 1011 generates the measurement light and only one pair of light spots is displayed on the defocus information acquisition unit 103.

[0059] As shown in the left image of Figure 4, the defocus information acquisition unit 103 displays a pair of light spots, including light spot A and light spot B. As shown in the middle image of Figure 4, the defocus information acquisition unit 103 displays a pair of light spots, including light spot C and light spot D. As shown in the right image of Figure 4, the defocus information acquisition unit 103 displays a pair of light spots, including light spot E and light spot F.

[0060] The main control module 30 obtains the defocus information of each sub-region under test according to the spot pair corresponding to each sub-region under test, and instructs the drive motor module 40 to drive the main inspection microscope module 20 to focus on each sub-region under test in sequence, so that the image acquisition unit 201 can sequentially acquire the image of each sub-region under test after focusing.

[0061] Specifically, the main control module 30 determines the defocus information of the sub-region under test by comparing the spot shape at position A and the spot shape at position B on the defocus information acquisition unit 103. This sub-region under test is also a certain surface of the DUT.

[0062] When the sub-region to be tested is located on the focal plane of the main inspection microscope module 20, the spot morphology at position A on the defocus information acquisition unit 103 is the same as that at position B, as shown in the left figure of Figure 4.

[0063] When the sub-region to be tested is located above the focal plane of the main inspection microscope module 20 (in front of the focal plane), the size of the spot at position C on the defocus information acquisition unit 103 is smaller than the size of the spot at position D, as shown in the middle figure of Figure 4.

[0064] When the sub-region to be tested is located below the focal plane of the main inspection microscope module 20 (below focal plane), the spot size at position E on the defocus information acquisition unit 103 is larger than the spot size at position F, as shown in the right figure of Figure 4.

[0065] In this way, the defocus direction and specific defocus amount of the sub-region under test can be determined by using the difference between the two light spots included in the light spot pair on the defocus information acquisition unit 103 and the size of each light spot.

[0066] The main control module 30 can also instruct the drive motor module 40 to drive the main inspection microscope module 20 and the defocus information measurement module 10 to move together, and sequentially focus each sub-region to be tested, so that the image acquisition unit 201 can sequentially acquire the image of each sub-region to be tested after focusing.

[0067] After the main control module 30 determines that the image of the area to be tested under the current field of view of the microscope objective 203 has been acquired, it will drive the stage motor of the DUT (not shown in the figure) to move laterally, so that the next area to be tested of the DUT gradually enters the field of view of the microscope objective 203.

[0068] In this application, the adjustable array light source 1011 is configured to adjust the light-emitting area of ​​the adjustable array light source according to preset conditions. The adjustment of the light-emitting area includes at least one of the following adjustment directions: the size and shape of the light-emitting area, and the density of the light-emitting units in the light-emitting area.

[0069] The adjustable array light source 1011 includes multiple light-emitting units, some of which are designated as light-emitting units and others as non-light-emitting units. The size and shape of the light-emitting area are formed by at least one light-emitting unit, while other areas are non-light-emitting areas. The density of light-emitting units in the light-emitting area represents the number of light-emitting units per unit area.

[0070] As shown in Figure 5, which is a schematic diagram of an autofocus system provided in an embodiment of this application, the light-emitting area of ​​the adjustable array light source 1011 includes multiple light-emitting units. The measurement light emitted by the multiple light-emitting units is transmitted through the second beam splitter prism 102 and reflected vertically by the first beam splitter prism 202 in sequence, and then generates multiple measurement light spots through the microscope objective 203. The multiple measurement light spots are respectively projected onto each sub-region to be measured to generate multiple reflected light. The multiple reflected light is reflected vertically by the first beam splitter prism 202 and the second beam splitter prism 102 in sequence, and then forms at least one light spot pair corresponding to each sub-region to be measured on the defocus information acquisition unit 103, that is, multiple light spot pairs are formed on the defocus information acquisition unit 103.

[0071] In one embodiment, the adjustable array light source is a Micro-led display screen, and the adjustable array light source is configured to adjust the shape of the light-emitting area according to preset conditions. The shape of the light-emitting area includes at least one of the following shapes: dot-shaped, line-shaped, and surface-shaped.

[0072] Micro-LED displays can be viewed as a two-dimensional array of micron-sized LED beads (the size of a single LED bead can be as small as 5µm). The adjustable array light source includes luminous and non-luminous areas. The LED beads in the luminous areas work normally and emit light, while the LED beads in the non-luminous areas do not work. The switching between luminous units (i.e., luminous beads) and non-luminous units (i.e., luminous beads not emitting light) is achieved through commands issued by the main control module.

[0073] Using a Micro-LED display as an adjustable array light source allows for flexible setting of the size and shape of the Micro-LED emitting and non-emitting areas, as well as the spacing between emitting and non-emitting areas, to adapt to RDL test samples with different line widths / spacings, or test samples with more complex three-dimensional structures.

[0074] The shape of the luminescent area can be dot-shaped, line-shaped, or surface-shaped. It can be understood as a shape composed of multiple luminescent units. For example, if the luminescent area includes only one luminescent unit, then the luminescent area is dot-shaped.

[0075] Figure 6 is a schematic diagram of the light-emitting region in an adjustable array light source provided in an embodiment of this application. In the left image of Figure 6, the light-emitting region 501 includes only one light-emitting unit, and the shape of the light-emitting region 501 is dot-shaped. In the middle image of Figure 6, the light-emitting region 501 includes multiple light-emitting units, and the multiple light-emitting units are arranged linearly, and the shape of the light-emitting region 502 is linear. In the right image of Figure 6, the light-emitting region 503 includes multiple light-emitting units, and the multiple light-emitting units are uniformly distributed in a planar shape, and the shape of the light-emitting region 503 is planar.

[0076] It is understood that the light-emitting area of ​​the adjustable array light source can also be other shapes, and the number of light-emitting units included in the light-emitting area shown in Figure 6 is only for illustration, and this application does not limit it.

[0077] In this application, the number of light spot pairs required for image acquisition is determined based on the accuracy requirements of the acquired image and / or the regional information of the area to be tested. This allows for the adjustment of the number of light-emitting units in the luminous region of the adjustable array light source, and further adjustment of the shape of the luminous region. By performing a single defocus measurement image acquisition operation on the area to be tested within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions can be obtained. This allows for sequential focusing on each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies where multiple defocus image acquisitions are required to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition.

[0078] In one embodiment, the defocus information measurement module 10 further includes: a collimating lens group 107, a lens group 104, a third beam splitter prism 105, and a plane mirror 106.

[0079] The collimating lens group 107 is located between the adjustable array light source 1011 and the second beam splitter prism 102.

[0080] The reflected light passes through the microscope objective 203, the first beam splitter prism 202 for vertical reflection, the second beam splitter prism 102 for vertical reflection, and the lens group 104 for convergence. It is then reflected by the third beam splitter prism 105 to form the first reflected light and transmitted through the third beam splitter prism 105 to form the second reflected light.

[0081] After being reflected by the plane mirror 106, the first reflected light forms a first light spot on the defocus information acquisition unit 103, corresponding to each sub-region to be measured. Specifically, the focal plane formed by the first reflected light is plane A, and the first light spot is formed at position A on the defocus information acquisition unit 103 as shown in Figure 4.

[0082] The second reflected light forms a second light spot on the defocus information acquisition unit 106, corresponding to the sub-region to be measured. The first light spot and the second light spot form a light spot pair corresponding to the sub-region to be measured. Specifically, the focal plane formed by the second reflected light is plane B, and the second light spot is formed at position B on the defocus information acquisition unit 103 as shown in Figure 4. The first light spot and the second light spot form a light spot pair.

[0083] Based on the structure of the defocus information measurement module provided in this application embodiment, multiple measurement lights emitted by the light-emitting area of ​​the adjustable array light source can form a light spot pair on the defocus information acquisition unit based on each sub-region to be measured, thereby enabling the main control module to analyze and obtain the defocus information of the sub-region to be measured based on the light spot pair.

[0084] In one embodiment, the main inspection microscope module 20 further includes a focusing lens group 204, which is located between the image acquisition unit 201 and the first beam splitter prism 202.

[0085] The adjustable array light source 1011, collimating lens group 107, second beam splitter prism 102, and first beam splitter prism 202 have a coaxial first optical axis.

[0086] The image acquisition unit 201, the focusing lens group 204, the first beam splitter prism 202, and the microscope objective 203 have a coaxial second optical axis, and the first optical axis is perpendicular to the second optical axis.

[0087] Based on the autofocus system provided in this embodiment, multiple modules work collaboratively and adopt a coaxial layout design, making the autofocus system structure not only simple and compact, but also effectively reducing space occupation and improving the overall stability and reliability of the autofocus system. Furthermore, the modular design gives the autofocus system high flexibility and maintainability, allowing for rapid adjustment and replacement according to actual needs, effectively reducing the difficulty of maintenance and upgrades, and improving the overall performance of the product.

[0088] In one embodiment, as shown in FIG7, an autofocus method according to an embodiment of this application is illustrated. This method can be implemented using a computer program and can run on an autofocus device based on the von Neumann architecture, and is applicable to the autofocus system proposed in this application. The computer program can be integrated into the application or run as a standalone utility application.

[0089] Specifically, the autofocus method includes:

[0090] S101. Adjust the luminous area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the area information of the area to be measured.

[0091] The area to be tested includes at least one sub-area. Adjusting the luminescent area includes at least one of the following adjustment directions: the size and shape of the luminescent area, and the density of luminescent units in the luminescent area. The density of luminescent units can be understood as the number of luminescent units per unit area or the distance between multiple luminescent units.

[0092] The accuracy requirements for image acquisition in an autofocus system can be understood as the resolution, sharpness, and detail capture capability of the image acquisition unit for the measured area within the current field of view. The accuracy requirement ensures that the autofocus system can clearly present the details of the RDL (Range Density Line) with its fine and dense lines, and that the image is free from blurring caused by factors such as inaccurate focus. Therefore, it is necessary to refocus the RDL on the measured area within the current field of view multiple times. The defocus information required for each refocusing operation needs to be obtained from the spot information of a single spot pair.

[0093] Therefore, based on the required image accuracy, the necessary light spot pairs can be determined, as well as the number and distribution of light-emitting units in the luminous region. For example, the required image accuracy is positively correlated with the number of light-emitting units in the luminous region.

[0094] Based on the regional information of the test area, the emission area of ​​the adjustable array light source is adjusted. The regional information of the test area characterizes how to determine the sub-regions included in the test area, the number and distribution of the sub-regions, the size of the test area, and other characteristic information. Different DUTs of different materials or with different acquisition requirements present different test areas in the field of view of the image acquisition unit. The regional information of the test area can characterize the differences between different test areas.

[0095] For example, in the detection of Rearrangement Line Arrays (RDLs), the surface of each RDL is a Region of Interest (ROI) to be measured. Based on the line width / spacing of the RDL, the shape and size of the light-emitting area of ​​the Micro-LED display, which serves as an adjustable array light source, as well as the distance between light-emitting units, can be flexibly set, so that each light-emitting unit can project its defocus information measurement spot onto the ROI area where the defocus information needs to be measured.

[0096] It is understood that in this application, the luminous area of ​​the adjustable array light source can be adjusted according to the accuracy requirements of the acquired image, or according to the area information of the area to be measured, or according to the accuracy requirements of the acquired image and the area information of the area to be measured.

[0097] S102. Acquire defocus measurement images of the area to be measured, including multiple light spot pairs.

[0098] The measurement light emitted by each light-emitting unit in the light-emitting area passes sequentially through the defocus information measurement module and the main inspection microscope module of the autofocus system, and then generates a measurement spot through the microscope objective. The measurement spot is then projected onto each sub-region to be tested to generate reflected light. The reflected light passes sequentially through the main inspection microscope module and the defocus information measurement module, and then forms a pair of light spots corresponding to each sub-region to be tested on the defocus information acquisition unit.

[0099] The defocus measurement image, which includes multiple spot pairs, is acquired by the defocus information acquisition unit. Each sub-region to be measured in the area to be measured corresponds to at least one spot pair.

[0100] S103. Analyze each pair of light spots on the defocus measurement image to obtain the defocus information of each sub-region to be measured associated with the light spot pair.

[0101] As shown in Figure 4, the defocus information of the sub-region under test is determined by comparing the spot morphology at position A and position B on the defocus information acquisition unit. For example, when the sub-region under test is located on the focal plane of the main inspection microscope module 20, the spot morphology at position A and position B on the defocus information acquisition unit 103 is the same, as shown in the left figure of Figure 4.

[0102] S104. Focus and acquire images of the sub-region to be tested sequentially according to each defocus information until images corresponding to all sub-regions to be tested are acquired.

[0103] Based on the defocus information of each sub-region to be tested, the image is focused and images of the sub-regions are acquired sequentially. For example, if the defocus information of the sub-region to be tested requires the image acquisition unit to move 1mm in the z-axis direction and 1.5mm in the x-axis direction, then the image acquisition unit is controlled to move according to the above path and acquire the image of the sub-region to be tested after the movement is completed. Based on the above steps, the image of each sub-region to be tested is acquired sequentially until images corresponding to all sub-regions to be tested are obtained.

[0104] After the main control module determines that the image of the test area under the current microscope objective has been acquired, it will drive the stage motor to move laterally, so that the next test area of ​​the DUT gradually enters the field of view of the microscope objective and is acquired.

[0105] In this application, the number of light spot pairs required for image acquisition is determined based on the accuracy requirements of the acquired image and / or the regional information of the area to be tested. This allows for the adjustment of the number of light-emitting units in the luminous region of the adjustable array light source, and further adjustment of the shape of the luminous region. By performing a single defocus measurement image acquisition operation on the area to be tested within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions can be obtained. This allows for sequential focusing on each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies where multiple defocus image acquisitions are required to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition.

[0106] Please refer to Figure 7 and Figure 8 together for a flowchart illustrating an autofocus method according to an embodiment of this application. S103 may include the following steps:

[0107] S201. Based on the first and second light spots included in each light spot pair on the defocus measurement image, obtain the light spot information of the light spot pair.

[0108] The light spot information includes at least one of the following: the size information of the first light spot, the size information of the second light spot, and the difference information between the first light spot and the second light spot. The difference information between the first light spot and the second light spot is used to characterize the difference data between the size information of the first light spot and the size information of the second light spot, as well as the size comparison between the first light spot and the second light spot.

[0109] As shown in the middle figure of Figure 4, the light spot information of the light spot pair includes the size information of the light spot at position C, which is the first light spot, the size information of the light spot at position D, which is the second light spot, the size of the light spot at position C is smaller than the size of the light spot at position D, and the size difference.

[0110] The spot information of a spot pair may also include other information used to obtain defocus information; the above is just an example.

[0111] S202. Analyze the spot information of the spot pair based on the preset algorithm to obtain the defocus information of each sub-region to be tested associated with the spot pair.

[0112] Defocus information typically reflects the deviation between the focal position in an optical system and the actual measured position. Prediction algorithms can be understood as the conversion relationship between spot information and defocus information for a spot pair. For example, prediction algorithms include image processing algorithms (such as template matching, edge detection, or Fourier transform) to process the defocus measurement image, and optimization algorithms can be used to fit the measurement data to the expected optical model (such as a Gaussian beam propagation model, optical transfer function, etc.) to obtain more accurate defocus information in order to calculate the degree of defocus more precisely.

[0113] For example, when the sub-region to be tested is located on the focal plane of the main inspection microscope module, the spot morphology at position A on the defocus information acquisition unit is the same as that at position B, as shown in the left figure of Figure 4.

[0114] When the sub-region to be tested is located above the focal plane of the main inspection microscope module (in front of the focal plane), the spot size at position C on the defocus information acquisition unit is smaller than the spot size at position D, as shown in the middle figure of Figure 4.

[0115] When the sub-region to be tested is located below the focal plane of the main inspection microscope module (below focal plane), the spot size at position E on the defocus information acquisition unit is larger than the spot size at position F, as shown in the right figure of Figure 4.

[0116] In this way, the defocus direction and specific defocus amount of the sub-region under test can be determined by using the difference between the two light spots included in the light spot pair on the defocus information acquisition unit and the size of each light spot.

[0117] In another embodiment, each spot pair on the defocus measurement image is analyzed according to a preset reference spot pair to obtain defocus information of the sub-region to be measured associated with each spot pair. The reference spot pair is obtained by the defocus information acquisition unit when the measurement spot generated by the measurement light emitted from the adjustable array light source is focused on the measurement area.

[0118] Before the autofocus system performs the autofocus method, it is necessary to obtain a reference spot pair through the measurement area in the focus state. This reference spot pair serves as a reference for analyzing the spot pair to obtain the defocus information of the sub-region to be measured.

[0119] Specifically, multiple image processing algorithms, such as image comparison algorithms, determine that the measurement area under the current field of view of the image acquisition unit is in focus. The measurement light emitted by each light-emitting unit in the light-emitting area of ​​the adjustable array light source is transmitted through the second beam splitter prism and reflected vertically by the first beam splitter prism in sequence. After passing through the microscope objective, the measurement light spot is generated. The measurement light spot is projected onto the measurement area to generate reflected light. After the reflected light is reflected vertically by the first beam splitter prism and the second beam splitter prism in sequence, a light spot pair corresponding to the measurement area is formed on the defocus information acquisition unit. This light spot pair is the basic light spot pair.

[0120] Furthermore, based on the preset reference spot pairs, each spot pair on the defocus measurement image is compared and analyzed. The first spot and the second spot included in the spot pair are compared with the first reference spot and the second reference spot included in the reference spot pair, thereby obtaining the defocus information of the sub-region to be measured associated with the spot pair.

[0121] In this embodiment, each spot pair on the defocus measurement image is analyzed using a preset reference spot pair to obtain defocus information. The analysis of the reference spot pairs provides a reliable reference for the autofocus system. By measuring the position and shape changes of each spot pair on the defocus measurement image, the autofocus algorithm can more intelligently adjust the focal length, quickly and accurately achieve the optimal focus state, helping to reduce human intervention and improve the accuracy of evaluating the focus position of the sub-region under test.

[0122] In this embodiment, the reference spot pair is the one obtained by the defocus information acquisition unit when the measurement spot is focused on the measurement area and the size difference between the first reference spot and the second reference spot included in the reference spot pair is less than a preset threshold.

[0123] Specifically, when the measurement spot is focused on the measurement area to generate a reference spot pair, the relative position between the measurement area and the image acquisition unit is adjusted to adjust the reference spot pair on the defocus information acquisition unit. The adjustment of the reference spot pair includes adjusting the size of the first reference spot and the size of the second reference spot. When the size difference between the first and second reference spots is less than a preset threshold, for example, when the sizes of the first and second reference spots are the same, it is determined that the measurement area is in focus, and the spot pair acquired by the defocus information acquisition unit at this time is determined to be the reference spot pair.

[0124] Based on this embodiment, a reliable method for obtaining reference spot pairs is provided, so as to analyze the spot pairs on the defocus measurement image through preset reference spot pairs to obtain defocus information. The analysis of reference spot pairs provides a reliable reference for the autofocus system. Moreover, the method for obtaining reference spot pairs provided in this embodiment is highly accurate and easy to operate.

[0125] Please refer to Figure 7 and Figure 9 together for a flowchart illustrating an autofocus method according to an embodiment of this application. S101 may include the following steps:

[0126] S301. Based on the number of sub-regions to be measured and the number of light spot pairs required to analyze the defocus information of each sub-region to be measured, determine the number of light-emitting units required to acquire the defocus measurement image.

[0127] The number of luminescent units required to acquire data from the current microscope objective region is determined by the number of sub-regions under test and the number of spot pairs required to analyze the defocus information of each sub-region. In one embodiment, the number of luminescent units is positively correlated with the number of sub-regions under test, and / or, the density of luminescent units in the luminescent region is positively correlated with the density of sub-regions under test in the region under test. Here, the sub-regions under test in the region under test can be understood as the number of sub-regions under test per unit area, characterizing the distribution of at least one sub-region under test per unit area.

[0128] For example, if N spot pairs are needed to analyze the defocus information of each sub-region under test, and the test area includes M sub-regions, then the emitting area includes N×M emitting units. The higher the density of the sub-regions under test in the test area, the higher the density of emitting units in the emitting area.

[0129] Understandably, the number of spot pairs required to acquire defocus information for each sub-region under test can be the same or different. For example, the number of spot pairs required to acquire a certain sub-region under test may be N1, and the number of spot pairs required to acquire a certain sub-region under test may be N2, where N1 and N2 are not the same.

[0130] S302. Based on the spatial distribution of each sub-region to be tested in the test area, determine the spatial distribution of at least one light-emitting unit associated with the sub-region to be tested in the light-emitting area.

[0131] The spatial distribution of the sub-regions to be tested within the test area characterizes their location, arrangement, and distribution within the test area. Specifically, the spatial distribution of the sub-regions to be tested can include: their position within the test area, which can be described by coordinates, such as the specific coordinates of each sub-region in two-dimensional or three-dimensional space; their spatial arrangement, such as whether multiple sub-regions are uniformly distributed or exhibit a specific geometric shape (e.g., lines, rectangles, circles, grids); and the density of multiple sub-regions within the test area. Based on the spatial distribution of the sub-regions to be tested within the test area, the spatial distribution of at least one light-emitting unit associated with each sub-region within the light-emitting area can be obtained.

[0132] As shown in Figure 10, Figure 10 is a schematic diagram of an adjustable array light source provided in an embodiment of this application. Taking the test area as the DUT surface as an example, the RDL linewidth / spacing of the DUT on the left side of Figure 10 is relatively large, including a small number of sparsely distributed test sub-regions. Therefore, for the Micro-LED display screen as an adjustable array light source, the size of the light-emitting area is small, the spacing of the light-emitting units in the light-emitting area is relatively large, and the number of light-emitting units is small.

[0133] The DUT on the right side of Figure 10 has a relatively small RDL line width / spacing, and includes a large number of densely distributed test sub-regions. Therefore, the size of the light-emitting area should be adjusted to be larger, the spacing of the light-emitting units in the light-emitting area should be set to be relatively smaller, and a larger number of light-emitting units should be set.

[0134] By further acquiring the spot information corresponding to the spots in regions A and B through the defocus information acquisition unit, the defocus information of each ROI region can be obtained. For example, as shown in the left image of Figure 10, the spots at positions A and B on the defocus information acquisition unit corresponding to ROI region No. 2 are the same, therefore ROI region No. 2 is currently at the focal plane of the main inspection microscope objective; while the spots at positions A and B on the defocus information acquisition unit corresponding to ROI regions No. 1, 3, and 4 are different, therefore ROI regions No. 1, 3, and 4 are currently defocused to different degrees. Based on this defocus measurement image, the main control module can calculate the specific defocus direction and defocus distance of each ROI region corresponding to spots No. 1, 3, and 4. The drive motor module can then focus on each ROI region according to its respective defocus direction and defocus distance, so that the main inspection microscope module can obtain a clear image of each ROI region.

[0135] In one embodiment, determining the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting region based on the spatial distribution of each sub-region under test in the test region includes:

[0136] When it is determined that the area to be tested includes only one sub-area and the sub-area to be tested corresponds to only one light-emitting unit, the light-emitting units associated with the sub-area to be tested are distributed in a dotted manner on the light-emitting area.

[0137] Alternatively, when multiple sub-regions to be tested are linearly distributed on the test area, multiple light-emitting units are linearly distributed on the light-emitting area, making the light-emitting area linear; wherein each sub-region to be tested is associated with at least one light-emitting unit; as shown in Figure 10, when multiple sub-regions to be tested are linearly distributed on the test area, the multiple light-emitting units are linearly distributed to make the light-emitting area linear. It can be understood that each sub-region to be tested shown in Figure 10 corresponds to only one light spot pair, that is, one light-emitting unit. Each sub-region to be tested can also correspond to two or other numbers of light-emitting units, and the spatial distribution of multiple light-emitting units in the light-emitting area is also based on the above logic.

[0138] Alternatively, when multiple sub-regions to be tested are uniformly distributed on the region to be tested, multiple light-emitting units are uniformly distributed on the light-emitting region, and the light-emitting region is planar; wherein each sub-region to be tested is associated with at least one light-emitting unit.

[0139] As shown in Figure 11, Figure 11 is a schematic diagram of an adjustable array light source provided in an embodiment of this application;

[0140] When the RDL substrate itself is warped, causing each ROI (region under test) to have a height difference in the Z direction along the X-axis (as shown in regions 1, 2, and 3 in the figure), and also causing a height difference in the Z direction along the Y-axis of the RDL surface (as shown in regions 1, 4, and 7 in the figure), then a corresponding two-dimensional light-emitting area array needs to be set on the Micro-LED display. Next, the measurement principle will be outlined using the measurement of defocus information of each ROI region of a DUT with a complex three-dimensional structure as an example.

[0141] As shown in Figure 11, when performing defect detection on a DUT surface with a relatively complex three-dimensional structure (using 3×3 ROI regions as an example), if the height difference between any two ROI regions (the height difference of the surface of each ROI region in the Z-axis direction) exceeds the depth of field of the main inspection microscope objective, it is necessary to measure the defocus information of each ROI region and refocus it so that the main inspection microscope objective can obtain a clear image of each ROI region.

[0142] Therefore, a 3×3 two-dimensional array of light-emitting areas needs to be set on the Micro-LED display screen, which is used as an adjustable array light source. That is, the light-emitting area is planar, with multiple light-emitting units evenly distributed to measure the defocus information of each ROI area, as shown in Figure 11 (here, we still use one ROI area corresponding to one defocus information measurement spot as an example to illustrate the basic measurement principle. In actual applications, the shape and size of the ROI area on the DUT surface may be irregular and unpredictable. Therefore, the setting of the two-dimensional array of light-emitting areas on the Micro-LED display screen should be determined according to the actual situation of the DUT to ensure that at least one defocus information measurement spot is projected onto the surface of each ROI area. The light-emitting units distributed in the two-dimensional array are not necessarily evenly distributed).

[0143] Multiple light-emitting units project onto the surface of the DUT, generating multiple light spot pairs. The light spot images acquired by the defocus information acquisition unit are shown in the lower part of Figure 11. Among them, the light spot pair corresponding to the ROI region No. 5 includes the first light spot A5 and the second light spot B5. The light spot information of the first light spot A5 and the second light spot B5 indicates that their sizes are the same, indicating that this region is currently on the focal plane of the main inspection microscope objective.

[0144] The light spots at positions A and B corresponding to other ROI regions are different, indicating that they are currently out of focus. By analyzing the light spot information of the light spot pairs at positions A and B, the main control module can calculate the defocus direction and defocus distance (i.e., defocus information) of the corresponding ROI region. This information is then used to drive the motor module to focus each ROI region according to its defocus information, enabling the main inspection microscope objective to acquire a clear image of the DUT surface.

[0145] In one embodiment, as shown in FIG12, an autofocus method according to an embodiment of this application is illustrated. This method can be implemented using a computer program and can run on an autofocus device based on the von Neumann architecture, and is applicable to the autofocus system proposed in this application. The computer program can be integrated into the application or run as a standalone utility application.

[0146] Specifically, the autofocus method includes:

[0147] S401. Based on the number of sub-regions to be measured and the number of light spot pairs required to analyze the defocus information of each sub-region to be measured, determine the number of light-emitting units required to acquire the defocus measurement image.

[0148] See S301, which will not be repeated here.

[0149] S402. Based on the spatial distribution of each sub-region to be tested in the test area, determine the spatial distribution of at least one light-emitting unit associated with the sub-region to be tested in the light-emitting area.

[0150] See S302, which will not be repeated here.

[0151] S403. Acquire defocus measurement images of the area to be measured, including multiple spot pairs.

[0152] See S102, which will not be repeated here.

[0153] S404. Based on the first and second light spots included in each light spot pair on the defocus measurement image, obtain the light spot information of the light spot pair.

[0154] The light spot information includes at least one of the following: the size information of the first light spot, the size information of the second light spot, and the difference information between the first and second light spots. See S201, which will not be repeated here.

[0155] S405. Analyze the spot information of the spot pair based on the preset algorithm to obtain the defocus information of each sub-region to be tested associated with the spot pair.

[0156] See S202, which will not be repeated here.

[0157] S406. Based on each defocus information, focus sequentially and acquire images of the sub-region to be tested until images corresponding to all sub-regions to be tested, including the region to be tested, are obtained.

[0158] See S103, which will not be repeated here.

[0159] S407. The images corresponding to all the sub-regions to be tested included in the region to be tested are fused to obtain the image of the region to be tested.

[0160] Image fusion is the process of combining multiple images into a single image to enable more accurate subsequent analysis of the test area. In other words, it involves fusing the images corresponding to all sub-regions of the test area under the current microscope objective, with the ultimate goal of obtaining a complete image of the entire test area and, further, an image of the entire DUT surface.

[0161] Image fusion processing may include pixel-level fusion, multi-resolution fusion, region-level fusion, deep learning fusion methods, or a combination of the above methods, and this application does not impose any limitations on this.

[0162] In this application, the number of light spot pairs required for image acquisition is determined based on the accuracy requirements of the acquired image and / or the regional information of the area to be tested. This allows for the adjustment of the number of light-emitting units in the luminous region of the adjustable array light source, and further adjustment of the shape of the luminous region. By performing a single defocus measurement image acquisition operation on the area to be tested within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions can be obtained. This allows for sequential focusing on each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies where multiple defocus image acquisitions are required to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition.

[0163] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0164] Please refer to Figure 13, which shows a schematic diagram of an autofocus device provided in an exemplary embodiment of this application. This autofocus device can be implemented as all or part of a device through software, hardware, or a combination of both, and is applicable to the autofocus system provided in this embodiment. The autofocus device includes a first acquisition module 601, a second acquisition module 602, an information analysis module 603, and a third acquisition module 604.

[0165] The first acquisition module 601 is used to adjust the light-emitting area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the area information of the area to be tested; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the light-emitting area includes at least one of the following adjustment directions: the size and shape of the light-emitting area, and the density of the light-emitting units in the light-emitting area.

[0166] The second acquisition module 602 is used to acquire a defocus measurement image corresponding to the area to be measured, including multiple light spot pairs;

[0167] The information analysis module 603 is used to analyze each pair of light spots on the defocus measurement image and obtain the defocus information of each sub-region to be measured associated with the pair of light spots;

[0168] The third acquisition module 604 is used to sequentially focus and acquire images of the sub-region to be tested according to each of the defocus information, until images corresponding to all sub-regions to be tested included in the region to be tested are acquired.

[0169] In one embodiment, the information analysis module 603 includes:

[0170] The first analysis unit is used to obtain spot information of the spot pair based on the first spot and the second spot included in each spot pair on the defocus measurement image; wherein the spot information includes at least one of the following: size information of the first spot, size information of the second spot, and difference information between the first spot and the second spot;

[0171] The second analysis unit is used to analyze the spot information of the spot pair based on a preset algorithm to obtain the defocus information of each sub-region to be tested associated with the spot pair.

[0172] In one embodiment, the information analysis module 603 includes:

[0173] The reference analysis unit is used to analyze each spot pair on the defocus measurement image according to the preset reference spot pair to obtain the defocus information of each sub-region to be measured associated with the spot pair; wherein, the reference spot pair is obtained by the defocus information acquisition unit when the measurement spot generated by the measurement light emitted by the adjustable array light source is focused on the measurement area.

[0174] In one embodiment, the reference spot pair is the one obtained by the defocus information acquisition unit when the measurement spot is focused on the measurement area and the size difference between the first reference spot and the second reference spot included in the reference spot pair is less than a preset threshold.

[0175] In one embodiment, the first acquisition module 601 includes:

[0176] The first acquisition unit is used to determine the number of light-emitting units required to acquire the defocus measurement image based on the number of the sub-regions to be measured and the number of light spot pairs required to analyze the defocus information of each sub-region to be measured.

[0177] The second acquisition unit is used to determine the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting area based on the spatial distribution of each sub-region under test in the test area.

[0178] In one embodiment, the number of light-emitting units is positively correlated with the number of sub-regions to be tested, and / or the density of light-emitting units in the light-emitting region is positively correlated with the density of the sub-regions to be tested in the region to be tested.

[0179] In one embodiment, the second acquisition unit includes:

[0180] The first acquisition subunit is used to determine that the light-emitting units associated with the sub-region under test are distributed in a dotted manner on the light-emitting area when it is determined that the area under test includes only one sub-region under test and the sub-region under test corresponds to only one light-emitting unit.

[0181] Alternatively, the second acquisition subunit is used to determine, when it is determined that multiple sub-regions to be tested are linearly distributed on the region to be tested, that multiple light-emitting units are linearly distributed on the light-emitting region, wherein the light-emitting region is linear; wherein each sub-region to be tested is associated with at least one light-emitting unit;

[0182] Alternatively, a third acquisition subunit is used to determine, when it is determined that multiple sub-regions to be tested are uniformly distributed on the region to be tested, that multiple light-emitting units are uniformly distributed on the light-emitting region, wherein the light-emitting region is planar; wherein each sub-region to be tested is associated with at least one light-emitting unit.

[0183] In one embodiment, the autofocus device further includes:

[0184] The fusion processing module is used to perform fusion processing on the images corresponding to all the sub-regions to be tested included in the region to be tested, so as to obtain the image of the region to be tested.

[0185] In this application, the number of light spot pairs required for image acquisition is determined based on the accuracy requirements of the acquired image and / or the regional information of the area to be tested. This allows for the adjustment of the number of light-emitting units in the luminous region of the adjustable array light source, and further adjustment of the shape of the luminous region. By performing a single defocus measurement image acquisition operation on the area to be tested within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions can be obtained. This allows for sequential focusing on each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies where multiple defocus image acquisitions are required to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition.

[0186] It should be noted that the autofocus device provided in the above embodiments is only illustrated by the division of the above functional modules when executing the autofocus method. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the autofocus device and the autofocus method embodiments provided in the above embodiments belong to the same concept, and the implementation process is detailed in the method embodiments, which will not be repeated here.

[0187] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0188] This application also provides a computer storage medium that can store multiple instructions. The instructions are adapted to be loaded by a processor and executed as shown in the embodiments of Figures 1-12 above. For the specific execution process, please refer to the detailed description of the embodiments shown in Figures 1-12, which will not be repeated here.

[0189] This application also provides a computer program product that stores at least one instruction. The at least one instruction is loaded by a processor and executed as shown in the embodiments of Figures 1-12 above. For the specific execution process, please refer to the detailed description of the embodiments shown in Figures 1-12, which will not be repeated here.

[0190] Please refer to Figure 14, which is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. As shown in Figure 14, the electronic device 700 may include: at least one processor 701, at least one network interface 704, a user interface 703, a memory 705, and at least one communication bus 702.

[0191] The communication bus 702 is used to enable communication between these components.

[0192] The user interface 703 may include a display screen and a camera. Optionally, the user interface 703 may also include a standard wired interface and a wireless interface.

[0193] The network interface 704 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0194] The processor 701 may include one or more processing cores. The processor 701 connects to various parts of the server 700 using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 705, and by calling data stored in the memory 705. Optionally, the processor 701 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 701 may integrate one or more of the following: a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), and a modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content to be displayed on the screen; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 701 and may be implemented as a separate chip.

[0195] The memory 705 may include random access memory (RAM) or read-only memory. Optionally, the memory 705 may include a non-transitory computer-readable storage medium. The memory 705 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 705 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), instructions for implementing the various method embodiments described above, etc.; the data storage area may store data involved in the various method embodiments described above, etc. Optionally, the memory 705 may also be at least one storage device located remotely from the aforementioned processor 701. As shown in FIG14, the memory 705, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and an autofocus application.

[0196] In the electronic device 700 shown in Figure 14, the user interface 703 is mainly used to provide an input interface for the user and to acquire user input data; while the processor 701 can be used to call the autofocus application stored in the memory 705 and specifically perform the following operations:

[0197] According to the accuracy requirements of the acquired image and / or the regional information of the area to be tested, the luminous area of ​​the adjustable array light source is adjusted; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the luminous area includes at least one of the following adjustment directions: the size and shape of the luminous area, and the density of the luminous units in the luminous area;

[0198] Collect defocus measurement images of the area to be measured, including multiple spot pairs;

[0199] Analyze each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the light spot pair;

[0200] Focus and acquire images of the sub-region under test sequentially based on each defocus information until images corresponding to all sub-regions under test are acquired.

[0201] In one embodiment, the processor 705 performs the analysis of each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the pair of light spots, specifically by:

[0202] Based on the first spot and the second spot included in each spot pair on the defocus measurement image, the spot information of the spot pair is obtained; wherein, the spot information includes at least one of the following: the size information of the first spot, the size information of the second spot, and the difference information between the first spot and the second spot;

[0203] The spot information of the spot pairs is analyzed based on a preset algorithm to obtain the defocus information of each sub-region to be tested associated with the spot pairs.

[0204] In one embodiment, the processor 705 performs the analysis of each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the pair of light spots, specifically by:

[0205] Based on the preset reference spot pairs, each spot pair on the defocus measurement image is analyzed to obtain the defocus information of each sub-region to be measured associated with the spot pair; wherein, the reference spot pair is obtained by the defocus information acquisition unit when the measurement spot generated by the measurement light emitted by the adjustable array light source is focused on the measurement area.

[0206] In one embodiment, the reference spot pair is the one obtained by the defocus information acquisition unit when the measurement spot is focused on the measurement area and the size difference between the first reference spot and the second reference spot included in the reference spot pair is less than a preset threshold.

[0207] In one embodiment, the processor 705 performs the step of adjusting the luminous area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the area information of the area to be measured, specifically by:

[0208] Based on the number of the sub-regions to be tested and the number of light spot pairs required to analyze the defocus information of each sub-region to be tested, the number of light-emitting units required to acquire the defocus measurement image is determined.

[0209] Based on the spatial distribution of each sub-region under test in the test area, determine the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting area.

[0210] In one embodiment, the number of light-emitting units is positively correlated with the number of sub-regions to be tested, and / or the density of light-emitting units in the light-emitting region is positively correlated with the density of the sub-regions to be tested in the region to be tested.

[0211] In one embodiment, the processor 705 performs the step of determining the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting region based on the spatial distribution of each sub-region under test in the test region, specifically by:

[0212] When it is determined that the area to be tested includes only one sub-area to be tested and the sub-area to be tested corresponds to only one light-emitting unit, the light-emitting units associated with the sub-area to be tested are determined to be distributed in a dotted manner on the light-emitting area;

[0213] Alternatively, when it is determined that multiple sub-regions to be tested are linearly distributed on the region to be tested, multiple light-emitting units are determined to be linearly distributed on the light-emitting region, wherein the light-emitting region is linear; wherein each sub-region to be tested is associated with at least one light-emitting unit;

[0214] Alternatively, when it is determined that multiple sub-regions to be tested are uniformly distributed on the region to be tested, multiple light-emitting units are determined to be uniformly distributed on the light-emitting region, wherein the light-emitting region is planar; wherein each sub-region to be tested is associated with at least one light-emitting unit.

[0215] In one embodiment, after the processor 705 executes the step of acquiring the images corresponding to all the sub-regions to be tested included in the region to be tested, it further executes:

[0216] The images corresponding to all the sub-regions included in the region to be tested are fused to obtain the image of the region to be tested.

[0217] In this application, the number of light spot pairs required for image acquisition is determined based on the accuracy requirements of the acquired image and / or the regional information of the area to be tested. This allows for the adjustment of the number of light-emitting units in the luminous region of the adjustable array light source, and further adjustment of the shape of the luminous region. By performing a single defocus measurement image acquisition operation on the area to be tested within the current field of view of the main inspection microscope module, defocus information corresponding to multiple sub-regions can be obtained. This allows for sequential focusing on each sub-region and acquisition of its image until all images within the field of view of the main inspection microscope module are acquired. This application solves the problem in existing technologies where multiple defocus image acquisitions are required to complete focusing, reducing the number of focusing attempts and improving focusing efficiency. It simplifies the focusing and image acquisition process, greatly enhancing the flexibility of image acquisition.

[0218] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory, or random access memory, etc.

[0219] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0220] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. An autofocus system, characterized in that, The automatic focusing system includes: a main inspection microscope module, a defocus information measurement module, a main control module, and a drive motor module; The main inspection microscope module includes an image acquisition unit, a first beam splitter prism, and a microscope objective. The defocus information measurement module includes an adjustable array light source, a second beam splitter prism, and a defocus information acquisition unit; wherein, the adjustable array light source is configured to adjust the light-emitting area of ​​the adjustable array light source according to preset conditions, the preset conditions including the accuracy requirements of the acquired image and / or the area information of the area to be measured, the area to be measured including at least one sub-area to be measured, and the adjustment of the light-emitting area includes at least one of the following adjustment directions: the size and shape of the light-emitting area, and the density of the light-emitting units in the light-emitting area; The measurement light emitted by each light-emitting unit in the light-emitting region is transmitted through the second beam splitter and reflected vertically by the first beam splitter in sequence. After passing through the microscope objective, the measurement light spot is generated. The measurement light spot is projected onto each of the sub-regions to be tested to generate reflected light. The reflected light is reflected vertically by the first beam splitter and the second beam splitter in sequence, and then forms a light spot pair corresponding to each sub-region to be tested on the defocus information acquisition unit. The main control module obtains the defocus information of each sub-region under test based on the spot pair corresponding to each sub-region under test, and instructs the drive motor module to drive the main inspection microscope module to focus on each sub-region under test in sequence, so that the image acquisition unit can sequentially acquire the image of each sub-region under test after focusing.

2. The autofocus system according to claim 1, characterized in that, The defocus information measurement module also includes: a collimating lens group, a lens group, a third beam splitter prism, and a plane mirror; The collimating lens group is located between the adjustable array light source and the second beam splitter prism; The reflected light passes sequentially through the microscope objective, the first beam splitter prism for vertical reflection, the second beam splitter prism for vertical reflection, and the lens group for convergence. It is then reflected by the third beam splitter prism to form the first reflected light and transmitted through the third beam splitter prism to form the second reflected light. After being reflected by the plane mirror, the first reflected light forms a first light spot on the defocus information acquisition unit corresponding to each of the sub-regions to be tested; The second reflected light forms a second light spot on the defocus information acquisition unit that corresponds to the sub-region to be tested, and the first light spot and the second light spot form a light spot pair corresponding to the sub-region to be tested.

3. The autofocus system according to claim 2, characterized in that, The main inspection microscope module also includes a focusing lens group, which is located between the image acquisition unit and the first beam splitter prism. The adjustable array light source, the collimating lens group, the second beam splitter, and the first beam splitter have a coaxial first optical axis. The image acquisition unit, the focusing lens group, the first beam splitter prism, and the microscope objective have a coaxial second optical axis, and the first optical axis is perpendicular to the second optical axis.

4. The autofocus system according to claim 1, characterized in that, The adjustable array light source is a Micro-led display screen. The adjustable array light source is configured to adjust the shape of the light-emitting area according to the preset conditions. The shape of the light-emitting area includes at least one of the following shapes: dot-shaped, line-shaped, and surface-shaped.

5. An autofocus method, characterized in that, The method, applicable to any of the autofocus systems described in claims 1-4, comprises: According to the accuracy requirements of the acquired image and / or the regional information of the area to be tested, the luminous area of ​​the adjustable array light source is adjusted; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the luminous area includes at least one of the following adjustment directions: the size and shape of the luminous area, and the density of the luminous units in the luminous area; Collect defocus measurement images of the area to be measured, including multiple spot pairs; Analyze each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the light spot pair; Focus and acquire images of the sub-region under test sequentially based on each defocus information until images corresponding to all sub-regions under test are acquired.

6. The autofocus method according to claim 5, characterized in that, The step of analyzing each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the pair of light spots includes: Based on the first spot and the second spot included in each spot pair on the defocus measurement image, the spot information of the spot pair is obtained; wherein, the spot information includes at least one of the following: the size information of the first spot, the size information of the second spot, and the difference information between the first spot and the second spot; The spot information of the spot pairs is analyzed based on a preset algorithm to obtain the defocus information of each sub-region to be tested associated with the spot pairs.

7. The autofocus method according to claim 5, characterized in that, The step of analyzing each pair of light spots on the defocus measurement image to obtain defocus information of each sub-region to be measured associated with the pair of light spots includes: Based on the preset reference spot pairs, each spot pair on the defocus measurement image is analyzed to obtain the defocus information of each sub-region to be measured associated with the spot pair; wherein, the reference spot pair is obtained by the defocus information acquisition unit when the measurement spot generated by the measurement light emitted by the adjustable array light source is focused on the measurement area.

8. The autofocus method according to claim 7, characterized in that, The reference spot pair is obtained by the defocus information acquisition unit when the measurement spot is focused on the measurement area and the size difference between the first reference spot and the second reference spot included in the reference spot pair is less than a preset threshold.

9. The autofocus method according to claim 5, characterized in that, Adjusting the luminous area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the regional information of the area to be measured includes: Based on the number of the sub-regions to be tested and the number of light spot pairs required to analyze the defocus information of each sub-region to be tested, the number of light-emitting units required to acquire the defocus measurement image is determined. Based on the spatial distribution of each sub-region under test in the test area, determine the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting area.

10. The autofocus method according to claim 9, characterized in that, The number of light-emitting units is positively correlated with the number of sub-regions to be tested, and / or the density of light-emitting units in the light-emitting region is positively correlated with the density of the sub-regions to be tested in the region to be tested.

11. The autofocus method according to claim 9, characterized in that, The step of determining the spatial distribution of at least one light-emitting unit associated with the sub-region under test in the light-emitting region based on the spatial distribution of each sub-region under test in the test region includes: When it is determined that the area to be tested includes only one sub-area to be tested and the sub-area to be tested corresponds to only one light-emitting unit, the light-emitting units associated with the sub-area to be tested are determined to be distributed in a dotted manner on the light-emitting area; Alternatively, when it is determined that multiple sub-regions to be tested are linearly distributed on the region to be tested, multiple light-emitting units are determined to be linearly distributed on the light-emitting region, wherein the light-emitting region is linear; wherein each sub-region to be tested is associated with at least one light-emitting unit; Alternatively, when it is determined that multiple sub-regions to be tested are uniformly distributed on the region to be tested, multiple light-emitting units are determined to be uniformly distributed on the light-emitting region, wherein the light-emitting region is planar; wherein each sub-region to be tested is associated with at least one light-emitting unit.

12. The autofocus method according to claim 5, characterized in that, After obtaining the images corresponding to all the sub-regions to be tested included in the region to be tested, the method further includes: The images corresponding to all the sub-regions included in the region to be tested are fused to obtain the image of the region to be tested.

13. An automatic focusing device, characterized in that, Suitable for an autofocus system as described in any one of claims 1-4, the autofocus device comprises: The first acquisition module is used to adjust the luminous area of ​​the adjustable array light source according to the accuracy requirements of the acquired image and / or the area information of the area to be tested; wherein, the area to be tested includes at least one of the sub-areas to be tested, and the adjustment of the luminous area includes at least one of the following adjustment directions: the size and shape of the luminous area, and the density of the luminous units in the luminous area; The second acquisition module is used to acquire a defocus measurement image corresponding to the area to be measured, including multiple light spot pairs; The information analysis module is used to analyze each pair of light spots on the defocus measurement image and obtain the defocus information of each sub-region to be measured associated with the pair of light spots. The third acquisition module is used to sequentially focus and acquire images of the sub-region under test according to each of the defocus information, until images corresponding to all sub-regions under test included in the region under test are acquired.

14. A computer storage medium, characterized in that, The computer storage medium stores a plurality of instructions, which are adapted to be loaded by a processor and executed as the method steps of any one of claims 5 to 12.

15. An automatic focusing device, characterized in that, include: A processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and executed the method steps as claimed in any one of claims 5 to 12.

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