An exposure machine alignment method, system, computer and storage medium

Abstract

This invention provides an alignment method, system, computer, and storage medium for an exposure machine. The method includes the following steps: acquiring an alignment spot image on a PCB board to be exposed; preprocessing the image to eliminate noise; extracting edges from the preprocessed alignment spot image to obtain a target image; calculating the center coordinates of the spot based on the grayscale value of the target image; obtaining the alignment displacement of the PCB board to be exposed based on the alignment mark coordinates and the center coordinates; adjusting the input voltage of a moving motor based on the alignment displacement to move the PCB board to be exposed to the target position, thus completing the alignment with the film board. By identifying the distance difference between the alignment coordinates and the center coordinates, the alignment displacement required for precise alignment of the PCB board to be exposed is calculated, achieving accurate alignment between the film board and the PCB board, reducing the need for film board position identification, and improving alignment efficiency.

Description

Technical Field

[0001] This invention relates to the field of exposure machine technology, and in particular to an exposure machine alignment method, system, computer, and storage medium. Background Technology

[0002] An exposure machine is a device that uses UVA wavelength ultraviolet light emitted by a light source to transfer image information from film or other transparent materials to a surface coated with a photosensitive substance. Before exposure, the film and PCB board need to be aligned and adjusted.

[0003] In existing technologies, alignment is usually performed by setting alignment marks on both the film board and the PCB board, identifying the coordinates of the film board and the PCB board based on a vision system, and then performing alignment manually, which results in low alignment efficiency. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an alignment method, system, computer and storage medium for an exposure machine, in order to solve the technical problem of low alignment efficiency in the prior art.

[0005] To achieve the above objectives, the present invention provides a method for aligning an exposure machine, comprising the following steps:

[0006] Acquire alignment spot images on the PCB board to be exposed, and preprocess the alignment spot images to eliminate noise effects;

[0007] Edge extraction is performed on the preprocessed alignment spot image to obtain the target image, and the center coordinates of the spot are calculated based on the gray value of the target image.

[0008] The alignment displacement of the PCB board to be exposed is obtained based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates.

[0009] The input voltage of the moving motor is adjusted based on the alignment displacement, so that the PCB board to be exposed is moved to the target position by the moving motor to complete the alignment operation with the film board.

[0010] According to one aspect of the above technical solution, the step of extracting the edge of the preprocessed alignment spot image to obtain the target image specifically includes:

[0011] The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components.

[0012] The connected component with the largest area is retained as the target image.

[0013] According to one aspect of the above technical solution, the step of adjusting the input voltage of the moving motor based on the alignment displacement specifically includes:

[0014] The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula:

[0015]

[0016] In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential symbol, and t is time.

[0017] According to one aspect of the above technical solution, the step of calculating the center coordinates of the light spot based on the grayscale value of the target image specifically includes:

[0018] The center coordinates of the light spot were calculated using the gray-scale centroid method.

[0019]

[0020] In the formula, x is the x-axis coordinate of the light spot, y is the y-axis coordinate of the light spot, and P M I is the sum of the gray values ​​of all pixels of the light spot, P1 and P2 are the products of the gray value of the pixel and its coordinates, I is the alignment light spot image, M is the target image, i is the x-axis coordinate of the pixel, and j is the y-axis coordinate of the pixel.

[0021] According to one aspect of the above technical solution, the step of preprocessing the alignment spot image to eliminate noise effects specifically includes:

[0022] The image of the corresponding light spot is smoothed and connected based on the mean filtering algorithm, and the interconnected patches are closed by dilatation and erosion to fill the holes in the light spot and thus eliminate the influence of noise.

[0023] According to one aspect of the above technical solution, before the step of obtaining the collimated image of the light spot on the PCB board to be exposed, the method further includes:

[0024] Move the film plate on one side of the PCB board to be exposed to the target position;

[0025] Move the PCB board to be exposed for coarse alignment so that the light beam on the film board stage can fully illuminate the PCB board to be exposed.

[0026] On the other hand, the present invention also provides an exposure machine alignment system, comprising:

[0027] The preprocessing module is used to acquire the alignment spot image on the PCB board to be exposed, and to preprocess the alignment spot image to eliminate the influence of noise.

[0028] The light spot module is used to extract the edges of the preprocessed aligned light spot image to obtain the target image, and to calculate the center coordinates of the light spot based on the gray value of the target image;

[0029] The alignment module is used to obtain the alignment displacement of the PCB board to be exposed based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates.

[0030] The moving module is used to adjust the input voltage of the moving motor based on the alignment displacement, so as to move the PCB board to be exposed to the target position based on the moving motor and complete the alignment operation with the film board.

[0031] According to one aspect of the above technical solution, the light spot module is specifically used for:

[0032] The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components.

[0033] The connected component with the largest area is retained as the target image.

[0034] According to one aspect of the above technical solution, the mobile module is specifically used for:

[0035] The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula:

[0036]

[0037] In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential symbol, and t is time.

[0038] According to one aspect of the above technical solution, the preprocessing module is specifically used for:

[0039] The image of the corresponding light spot is smoothed and connected based on the mean filtering algorithm, and the interconnected patches are closed by dilatation and erosion to fill the holes in the light spot and thus eliminate the influence of noise.

[0040] According to one aspect of the above technical solution, the system further includes:

[0041] The coarse alignment module is used to move the film board on one side of the PCB board to be exposed to the target position;

[0042] Move the PCB board to be exposed for coarse alignment so that the light beam on the film board stage can fully illuminate the PCB board to be exposed.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows: by setting a light source on the fixed worktable of the film board to obtain the alignment spot image on the PCB board to be exposed, the image is processed to obtain the center coordinates of the light beam, and then the distance difference between the alignment coordinates and the center coordinates is identified to calculate the alignment displacement required for the precise alignment of the PCB board to be exposed, thereby achieving precise alignment between the film board and the PCB board, reducing the identification of the film board position, and improving alignment efficiency. At the same time, by adjusting the input voltage of the moving motor based on the alignment displacement, the automatic alignment operation of the PCB board can be realized. After the PCB board is flipped, the error can be quickly obtained, further improving the alignment efficiency. Attached Figure Description

[0044] Figure 1 This is a flowchart of the exposure machine alignment method in the first embodiment of the present invention;

[0045] Figure 2 This is a structural block diagram of the exposure machine alignment system in the second embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the hardware structure of the computer in the third embodiment of this application;

[0047] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0048] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0049] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] Please see Figure 1 Figure 1 shows a flowchart of the exposure machine alignment method in the first embodiment of the present invention. The method includes the following steps:

[0052] Step S100: Obtain the alignment spot image on the PCB board to be exposed, and preprocess the alignment spot image to eliminate noise effects.

[0053] Specifically, in this embodiment, the alignment spot image is formed by a light source set on the film board stage illuminating the PCB board to be exposed. Since the acquired image often contains various noises, such as electronic noise, sensor noise, and ambient light interference, it affects the image quality and consequently the accuracy of subsequent edge detection, contour extraction, and center coordinate calculation. Image preprocessing, such as filtering and denoising, can effectively reduce the impact of noise, improve image clarity and signal-to-noise ratio, and facilitate subsequent coordinate extraction.

[0054] Furthermore, in this embodiment, before the step of acquiring the collimated image of the light spot on the PCB board to be exposed, the method further includes:

[0055] Move the film plate on one side of the PCB board to be exposed to the target position;

[0056] The PCB board to be exposed is moved for coarse alignment to ensure that the light beam on the film stage fully illuminates the PCB board. Specifically, by placing the light source on the film board, the alignment error between the film board and the PCB can be directly obtained.

[0057] Preferably, in this embodiment, the step of preprocessing the alignment spot image to eliminate noise effects specifically includes:

[0058] The image of the aligned light spot is smoothed and connected using a mean filtering algorithm, and then connected patches are closed by dilatation and erosion to fill the holes in the light spot and eliminate noise. Since the goal of this method is to obtain the center coordinates of the light spot, the integrity of the light spot affects the accuracy of center coordinate recognition. Preprocessing the image can reduce the incompleteness of the light spot caused by reflections and other environmental factors, thus improving recognition accuracy.

[0059] Step S200: Edge extraction is performed on the preprocessed alignment spot image to obtain the target image, and the center coordinates of the spot are calculated based on the gray value of the target image.

[0060] Specifically, in this embodiment, the step of extracting the edges of the preprocessed alignment spot image to obtain the target image includes:

[0061] The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components.

[0062] The connected component with the largest area is retained as the target image.

[0063] Furthermore, in this embodiment, the step of calculating the center coordinates of the light spot based on the grayscale value of the target image specifically includes:

[0064] The center coordinates of the light spot were calculated using the gray-scale centroid method.

[0065]

[0066] In the formula, x is the x-axis coordinate of the light spot, y is the y-axis coordinate of the light spot, and P M I is the sum of the gray values ​​of all pixels of the light spot, P1 and P2 are the products of the gray value of the pixel and its coordinates, I is the alignment light spot image, M is the target image, i is the x-axis coordinate of the pixel, and j is the y-axis coordinate of the pixel.

[0067] Step S300: Obtain the alignment displacement of the PCB board to be exposed based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates.

[0068] Step S400: Adjust the input voltage of the moving motor based on the alignment displacement, so as to move the PCB board to be exposed to the target position based on the moving motor, and complete the alignment operation with the film board.

[0069] Specifically, in this embodiment, the step of adjusting the input voltage of the moving motor based on the alignment displacement includes:

[0070] The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula:

[0071]

[0072] In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential symbol, and t is time.

[0073] Preferably, in this embodiment, during the movement of the PCB board, its position information can be monitored in real time by sensors such as encoders or laser rangefinders and compared with the target position. The motor control strategy can also be fine-tuned based on the real-time feedback results to further improve the alignment accuracy.

[0074] In summary, the exposure machine alignment method in the above embodiments of the present invention obtains an alignment spot image on the PCB board to be exposed by setting a light source on a fixed worktable of the film board, processing the image to obtain the center coordinates of the light beam, and then further calculating the alignment displacement required for precise alignment of the PCB board to be exposed by identifying the distance difference between the alignment coordinates and the center coordinates. This achieves accurate alignment between the film board and the PCB board, reduces the identification of the film board position, and improves alignment efficiency. At the same time, by adjusting the input voltage of the moving motor based on the alignment displacement, automatic alignment of the PCB board can be achieved. After the PCB board is flipped, the error can be quickly obtained, further improving alignment efficiency.

[0075] Example 2

[0076] A second embodiment of this application also provides an exposure machine alignment system for implementing the embodiments and preferred embodiments described herein, which will not be repeated hereafter. As used below, the terms "module," "unit," "subunit," etc., can refer to a combination of software and / or hardware that performs a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0077] like Figure 2 As shown, the system includes: a preprocessing module 100, a spot module 200, an alignment module 300, and a moving module 400.

[0078] The preprocessing module 100 is used to acquire the alignment spot image on the PCB board to be exposed, and to preprocess the alignment spot image to eliminate the influence of noise.

[0079] The aforementioned spot module 200 is used to extract the edges of the preprocessed aligned spot image to obtain a target image, and to calculate the center coordinates of the spot based on the gray value of the target image;

[0080] The alignment module 300 described above is used to obtain the alignment displacement of the PCB board to be exposed based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates.

[0081] The aforementioned moving module 400 is used to adjust the input voltage of the moving motor based on the alignment displacement, so as to move the PCB board to be exposed to the target position based on the moving motor and complete the alignment operation with the film board.

[0082] Preferably, in this embodiment, the light spot module 200 is specifically used for:

[0083] The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components.

[0084] The connected component with the largest area is retained as the target image.

[0085] Preferably, in this embodiment, the moving module 400 is specifically used for:

[0086] The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula:

[0087]

[0088] In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential symbol, and t is time.

[0089] Preferably, in this embodiment, the preprocessing module 100 is specifically used for:

[0090] The image of the corresponding light spot is smoothed and connected based on the mean filtering algorithm, and the interconnected patches are closed by dilatation and erosion to fill the holes in the light spot and thus eliminate the influence of noise.

[0091] According to one aspect of the above technical solution, the system further includes:

[0092] The coarse alignment module is used to move the film board on one side of the PCB board to be exposed to the target position;

[0093] Move the PCB board to be exposed for coarse alignment so that the light beam on the film board stage can fully illuminate the PCB board to be exposed.

[0094] In summary, the exposure machine alignment system in the above embodiments of the present invention uses a preprocessing module 100 to set a light source on a fixed worktable of the film board to acquire an alignment spot image on the PCB board to be exposed. Based on the spot module 200, the image is processed to obtain the center coordinates of the light beam. Then, the alignment module 300 identifies the distance difference between the alignment coordinates and the center coordinates to calculate the alignment displacement required for precise alignment of the PCB board to be exposed. The moving module 400 achieves precise alignment between the film board and the PCB board, reducing the need for film board position identification and improving alignment efficiency. At the same time, by adjusting the input voltage of the moving motor based on the alignment displacement, automatic alignment of the PCB board can be achieved. After the PCB board is flipped, the error can be quickly obtained, further improving alignment efficiency.

[0095] It should be noted that the modules can be functional modules or program modules, and can be implemented in software or hardware. For modules implemented in hardware, the modules can reside in the same processor; or the modules can be located in different processors in any combination.

[0096] Example 3

[0097] The third embodiment of this application provides a computer. It is understood that the principles mentioned in the exposure machine alignment system in this embodiment correspond to the exposure machine alignment method in the first embodiment of this application. For related principles not described, please refer to the first embodiment for details, which will not be elaborated here.

[0098] The computer may include a processor 81 and a memory 82 storing computer program commands.

[0099] Specifically, the processor 81 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0100] The memory 82 may include a mass storage device for data or commands. For example, and not limitingly, the memory 82 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 82 may include removable or non-removable (or fixed) media. Where appropriate, the memory 82 may be internal or external to a data processing device. In a particular embodiment, the memory 82 is non-volatile memory. In a particular embodiment, the memory 82 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), an electrically alterable read-only memory (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random-Access Memory (FPMDRAM), Extended Data Out Dynamic Random-Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0101] The memory 82 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program commands executed by the processor 81.

[0102] The processor 81 implements any of the exposure machine alignment methods in the above embodiments by reading and executing computer program commands stored in the memory 82.

[0103] In some embodiments, the computer may further include a communication interface 83 and a bus 80. For example, Figure 3 As shown, the processor 81, memory 82, and communication interface 83 are connected through bus 80 and complete communication with each other.

[0104] The communication interface 83 is used to enable communication between the various modules, devices, units, and / or equipment in the embodiments of this application. The communication interface 83 can also enable data communication with other components such as external devices, image / data acquisition devices, databases, external storage, and image / data processing workstations.

[0105] Bus 80 includes hardware, software, or both, that couples computer components together. Bus 80 includes, but is not limited to, at least one of the following: data bus, address bus, control bus, expansion bus, and local bus. For example, and not as a limitation, bus 80 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses, or a combination of two or more of these. Where appropriate, bus 80 may include one or more buses. Although specific buses are described and illustrated in the embodiments of this application, this application considers any suitable bus or interconnection.

[0106] Example 4

[0107] In conjunction with the exposure machine alignment methods in the above embodiments, the fourth embodiment of this application provides a readable storage medium. This readable storage medium stores computer program commands; when executed by a processor, these computer program commands implement any one of the exposure machine alignment methods in the above embodiments.

[0108] 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 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.

[0109] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An alignment method for an exposure machine, characterized in that, Includes the following steps: Acquire alignment spot images on the PCB board to be exposed, and preprocess the alignment spot images to eliminate noise effects; Edge extraction is performed on the preprocessed alignment spot image to obtain the target image, and the center coordinates of the spot are calculated based on the gray value of the target image. The alignment displacement of the PCB board to be exposed is obtained based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates. The input voltage of the moving motor is adjusted based on the alignment displacement, so that the PCB board to be exposed is moved to the target position by the moving motor to complete the alignment operation with the film board. The specific steps for edge extraction of the preprocessed alignment spot image to obtain the target image include: The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components. The connected component with the largest area is retained as the target image; The steps for adjusting the input voltage of the moving motor based on the alignment displacement specifically include: The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula: ； In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential sign, and t is time. The specific steps for calculating the center coordinates of the light spot based on the grayscale values ​​of the target image include: The center coordinates of the light spot were calculated using the gray-scale centroid method. ； ； ； ； ； In the formula, Let x be the x-axis coordinate of the light spot. Let be the y-coordinate of the light spot. This is the sum of the grayscale values ​​of all pixels in the light spot. , These are the products of the grayscale value of a pixel and its coordinates, respectively; I is the alignment spot image; M is the target image; i is the x-axis coordinate of the pixel; and j is the y-axis coordinate of the pixel. The steps of preprocessing the alignment spot image to eliminate noise effects specifically include: The image of the corresponding light spot is smoothed and connected based on the mean filtering algorithm, and the interconnected patches are closed by dilatation and erosion to fill the holes in the light spot and thus eliminate the influence of noise.

2. The exposure machine alignment method according to claim 1, characterized in that, Before the step of acquiring the spot image on the PCB board to be exposed, the method further includes: Move the film plate on one side of the PCB board to be exposed to the target position; Move the PCB board to be exposed for coarse alignment so that the light beam on the film board stage can fully illuminate the PCB board to be exposed.

3. An exposure machine alignment system, characterized in that, include: The preprocessing module is used to acquire the alignment spot image on the PCB board to be exposed, and to preprocess the alignment spot image to eliminate the influence of noise. The light spot module is used to extract the edges of the preprocessed aligned light spot image to obtain the target image, and to calculate the center coordinates of the light spot based on the gray value of the target image; The alignment module is used to obtain the alignment displacement of the PCB board to be exposed based on the alignment mark coordinates on the PCB board to be exposed and the center coordinates. The moving module is used to adjust the input voltage of the moving motor based on the alignment displacement, so as to move the PCB board to be exposed to the target position based on the moving motor and complete the alignment operation with the film board. The light spot module is specifically used for: The preprocessed alignment spot image is binarized, and the pixels in the binarized image are grouped and labeled by row to generate different connected components. The connected component with the largest area is retained as the target image; The mobile module is specifically used for: The input voltage of the moving motor is adjusted based on the alignment displacement according to the following formula: ； In the formula, U is the rated voltage of the moving motor, L is the rated stroke of the moving motor, c is the stiffness of the piezoelectric ceramic, m is the mass of the moving stage of the PCB board to be exposed, l is the alignment displacement, u is the input voltage, d is the differential sign, and t is time. The light spot module is specifically used for: The center coordinates of the light spot were calculated using the gray-scale centroid method. ； ； ； ； ； In the formula, Let x be the x-axis coordinate of the light spot. Let be the y-coordinate of the light spot. This is the sum of the grayscale values ​​of all pixels in the light spot. , These are the products of the grayscale value of a pixel and its coordinates, respectively; I is the alignment spot image; M is the target image; i is the x-axis coordinate of the pixel; and j is the y-axis coordinate of the pixel. The preprocessing module is specifically used for: The image of the corresponding light spot is smoothed and connected based on the mean filtering algorithm, and the interconnected patches are closed by dilatation and erosion to fill the holes in the light spot and thus eliminate the influence of noise.

4. A computer, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the exposure machine alignment method as described in claim 1 or 2.

5. A storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the exposure machine alignment method as described in claim 1 or 2 above.

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