Focusing distance out-of-range pre-adjusting device and method and automatic focusing system and method

Abstract

The invention belongs to the technical field of automatic optical detection, and particularly discloses a focusing distance out-of-range pre-adjustment device and method and an automatic focusing system and method.The focusing distance out-of-range pre-adjustment device comprises distance detection equipment and a first controller which are electrically connected; the distance detection equipment is parallel to a target microscope objective, aligned with a to-be-detected object, in the automatic focusing device, and is used for detecting first height information of a to-be-detected area of the to-be-detected object and sending the first height information to the first controller; the first controller is used for judging whether a first height difference between the first height information and the first standard height information exceeds a preset focusing range of the target microscope objective or not; if yes, in the process that the to-be-detected area moves from the detection range of the distance detection equipment to the view center of the target microscope objective, the automatic focusing device and the distance detection equipment are controlled to synchronously carry out focusing coarse adjustment movement in advance along the Z axis based on the first height difference, and the over-range focusing condition of microscopic automatic focusing imaging is effectively handled.

Description

Technical Field

[0001] This application belongs to the technical field of automatic optical inspection, and more specifically, relates to a pre-adjustment device and method for out-of-range focusing distance, an autofocus system and method. Background Art

[0002] With the continuous iteration and optimization of the chip packaging process, the chip packaging structure has become smaller and more densely packed. This also poses higher requirements for the detection of chip defects. How to quickly and accurately detect smaller and smaller circuits, structures, etc. during the detection process and improve the yield rate during the chip manufacturing process has become a key issue.

[0003] As the number of chips that can be packaged on a single wafer or board-shaped substrate increases, especially in the packaging method based on the fan-out panel-level packaging (FOPLP) technology, the substrate size becomes larger, and at the same time, the edge warping becomes more obvious, resulting in a significant height difference between the edge and the center position.

[0004] The microscopic autofocus imaging technology operates within a preset focusing range, which defines the farthest and nearest distances at which the autofocus camera can effectively adjust the focal length to achieve clear imaging. Once the height difference between the substrate edge and the center position exceeds this range, it will cause the autofocus system to fail, unable to accurately identify and adjust to the correct focal length, resulting in problems such as blurred images and lost details, seriously affecting the imaging quality. How to effectively identify and handle the out-of-range focusing situation is an urgent problem to be solved. Summary of the Invention

[0005] In view of the above-mentioned defects existing in the prior art, this application provides a pre-adjustment device and method for out-of-range focusing distance, an autofocus system and method, aiming to solve the problems of out-of-range focusing identification and handling.

[0006] In a first aspect, this application provides a pre-adjustment device for out-of-range focusing, including: a distance detection device and a first controller electrically connected; The distance detection device is arranged in parallel with the target microscope objective lens that aligns with the object to be measured in the autofocus device, and is used to detect the first height information of the area to be detected of the object to be measured and send it to the first controller; The first controller is configured to determine whether a first height difference between the first height information and the first standard height information exceeds a preset focusing range of the target microscope objective; if the preset focusing range is exceeded, during the process of moving the to-be-detected area from the detection range of the distance detection device to the field of view center of the target microscope objective, the autofocus device and the distance detection device are controlled to perform synchronous rough focusing movement along the Z-axis based on the first height difference; wherein, the first standard height information is the first height information of the origin detection area detected by the distance detection device.

[0007] In a second aspect, the present application provides a method for pre-adjusting over-focus range, including: Obtaining first height information of a to-be-detected area of a to-be-detected object detected by a distance detection device arranged in parallel with a target microscope objective; Determining whether a first height difference between the first height information and the first standard height information exceeds a preset focusing range of the target microscope objective; the first standard height information is the first height information of the origin detection area detected by the distance detection device; If the preset focusing range is exceeded, during the process of moving the to-be-detected area from the detection range of the distance detection device to the field of view center of the target microscope objective, the autofocus device and the distance detection device are controlled to perform synchronous rough focusing movement along the Z-axis based on the first height difference.

[0008] In a third aspect, the present application provides an autofocus system, including: Including an over-focus distance pre-adjustment device and an autofocus device as described in the first aspect, the autofocus device is configured to perform autofocus imaging on the to-be-detected area within the preset focusing range of the target microscope objective when the to-be-detected area moves to the field of view center of the target microscope objective.

[0009] In a fourth aspect, the present application provides an autofocus method, including: Performing over-focus distance detection and adjustment on the to-be-detected area in advance based on the over-focus distance pre-adjustment method as described in the second aspect; Performing autofocus imaging on the to-be-detected area within the preset focusing range of the target microscope objective when the to-be-detected area moves to the field of view center of the target microscope objective.

[0010] Fifth aspect, the present application further provides an electronic device, including: at least one memory for storing a program; at least one processor for executing the program stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the second aspect or any possible implementation manner of the second aspect, or the processor is used to execute the method described in the fourth aspect or any possible implementation manner of the fourth aspect.

[0011] Sixth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program runs on a processor, it causes the processor to execute the method described in the second aspect or any possible implementation manner of the second aspect, or execute the method described in the fourth aspect or any possible implementation manner of the fourth aspect.

[0012] Seventh aspect, the present application further provides a computer program product. When the computer program product runs on a processor, it causes the processor to execute the method described in the second aspect or any possible implementation manner of the second aspect, or execute the method described in the fourth aspect or any possible implementation manner of the fourth aspect.

[0013] The provided focus distance out-of-range pre-adjustment device and method, automatic focusing system and method of the present application, without significantly increasing the hardware cost of the existing automatic focusing device and changing the device structure of the existing automatic focusing device, by adding a controller and a distance detection device arranged in parallel with the target microscope objective lens aligned with the object to be measured on the basis of the existing automatic focusing device, pre-detect the first height difference between each detection area to be detected of the object to be measured and the origin detection area, and control the automatic focusing device and the distance detection device to synchronously perform rough focusing movement along the Z-axis in advance when exceeding the preset focus range of the target microscope objective lens, effectively identify and cope with the out-of-range focusing situation in the microscopic automatic focusing imaging process, ensure that the detection area to be detected falls within the preset focus range of the target microscope objective lens when moving to the center of the field of view of the target microscope objective lens, thereby ensuring the focusing effect of the automatic focusing device. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of the focus distance out-of-range pre-adjustment device provided by the embodiment of the present application; Figure 2It is a schematic flowchart of a pre - adjustment method for out - of - range focusing distance provided by an embodiment of the present application; Figure 3 It is one of the schematic structural diagrams of an autofocus system provided by an embodiment of the present application; Figure 4 It is the second schematic structural diagram of an autofocus system provided by an embodiment of the present application; Figure 5 It is a schematic flowchart of an autofocus method provided by an embodiment of the present application; In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 11 - distance detection device, 12 - first controller, 211 - target microscope objective lens, 212 - other microscope objective lenses, 22 - microscope objective turntable, 23 - focusing drive member, 24 - second controller, 25 - beam splitter, 26 - optical focusing device, 27 - imaging sensor, 3 - platform for placing the object to be measured. Detailed implementation manners

[0016] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" refers to two or more. For example, a plurality of microscope objective lenses refers to two or more microscope objective lenses, etc.

[0018] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly defined and limited, the terms "connection" and "arrangement" should be understood in a broad sense. For example, it can be a fixed connection and arrangement, or a detachable connection and arrangement, or an integral connection and arrangement.

[0019] The orientation terms mentioned in the embodiments of the present application, such as "above", "horizontal", "along the Z - axis", etc., are only with reference to the direction of the drawings. Therefore, the orientation terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation to the embodiments of the present application.

[0020] In addition, in the embodiments of the present application, the mathematical concepts mentioned, such as parallel, are in view of the current technological level, rather than a strictly defined concept in mathematics. A small deviation is allowed and it can refer to approximately parallel. For those of ordinary skill in the art, the specific meanings of the relevant terms in the present application can be specifically understood.

[0021] Figure 1 This is a schematic structural diagram of a pre-adjustment device for out-of-range focus distance provided by an embodiment of the present application. As Figure 1 shown, the pre-adjustment device for out-of-range focus distance at least includes a distance detection device 11 and a first controller 12 that are electrically connected.

[0022] The target microscope objective lens 211 is the microscope objective lens that aligns with the object to be measured in the autofocus device. During the actual detection process, both the distance detection device 11 and the target microscope objective lens 211 are placed above the object placement platform 3 for the object to be measured and aligned with the object to be measured. The distance detection device 11 performs distance detection on different detection areas on the surface of the object to be measured, and the target microscope objective lens 211 performs focus imaging and takes pictures of different detection areas on the surface of the object to be measured.

[0023] The distance detection device 11 and the target microscope objective lens 211 are arranged in parallel. Considering the high-precision requirements for the focus distance in the microscopic focus imaging scenario, even if the distance detection device 11 and the target microscope objective lens 211 are arranged at the same height, for the same detection area, the height information detected by the distance detection device 11 is not the same as the height information between the detection area and the lens when it is aligned with the target microscope objective lens 211; however, when the distance detection device 11 and the target microscope objective lens 211 are arranged in parallel and relatively stationary, for any two detection areas on the surface of the object to be measured, the first height difference between the first height information detected by the distance detection device 11 is equal to the height difference between these two detection areas and the target microscope objective lens 211 when they are aligned with the target microscope objective lens 211.

[0024] When the distance detection device 11 is aligned with the detection area, it detects the first height information of the detection area and uploads the detected first height information to the first controller 12. After receiving the first height information of the detection area of the object to be measured uploaded by the distance detection device 11, the first controller 12 determines whether the first height difference between the first height information of the detection area and the first standard height information exceeds the preset focus range of the target microscope objective lens 211.

[0025] The first standard height information refers to the first height information of the origin detection area of the object to be measured detected by the distance detection device 11. Optionally, before determining whether each detection area of the object to be measured exceeds the preset focus range of the target microscope objective lens 211, the target microscope objective lens 211 moves to the focus position, and the detection area aligned with the target microscope objective lens 211 at this time is recorded as the origin detection area, and the first height information of the origin detection area is detected by the distance detection device 11 and uploaded to the first controller 12 as the first standard height information. Before this, the focus position reference (Mark) point calibration has been performed in advance. In the autofocus device, the Mark point is used to determine the focus position of the lens to ensure the accuracy of autofocus.

[0026] If the first height difference does not exceed the preset focusing range of the target microscope objective lens 211, it indicates that when the area to be detected moves into the field of view of the target microscope objective lens 211, the target microscope objective lens 211 can achieve autofocus on the area to be detected by moving along the Z-axis within the preset focusing range.

[0027] If the first height difference exceeds the preset focusing range of the target microscope objective lens 211, it indicates that when the area to be detected moves into the field of view of the target microscope objective lens 211, the target microscope objective lens 211 cannot achieve autofocus on the area to be detected by moving along the Z-axis within the preset focusing range. Then, it is necessary to consider moving the entire autofocus device so that the area to be detected falls within the preset focusing range of the target microscope objective lens 211. However, due to the load limitation of the entire autofocus device and the equipment control precision limitation, it is difficult to complete the overall movement of the autofocus device in real time and accurately.

[0028] Therefore, it is considered to move the entire autofocus device in advance before the area to be detected moves to the center of the field of view of the target microscope objective lens 211. The distance detection device 11 is arranged in parallel with the target microscope objective lens 211 that aligns with the object to be measured, and there is a certain distance between them in the horizontal direction. Completing the overall movement of the autofocus device within this distance can reduce the real-time requirement for pre-adjustment of out-of-range focusing.

[0029] After the first controller 12 determines that the first height difference between the Z height information of the area to be detected and the first standard height information exceeds the preset focusing range of the target microscope objective lens 211, during the process of the area to be detected moving horizontally from the detection range of the distance detection device 11 to the center of the field of view of the target microscope objective lens 211, the first controller 12 controls the autofocus device to perform a rough focusing movement along the Z-axis based on the first height difference, roughly completing the Z-axis height compensation of the autofocus device, so that when the area to be detected moves to the center of the field of view of the target microscope objective lens 211, the target microscope objective lens 211 can achieve autofocus on the area to be detected by moving along the Z-axis within the preset focusing range.

[0030] In addition, the first controller 12 also controls the distance detection device 11 and the autofocus device to move synchronously to ensure the relative stillness between the distance detection device 11 and the target microscope objective lens 211. Specifically, the first controller 12 drives the distance detection device 11 and the autofocus device to perform a rough focusing movement along the Z-axis synchronously through a driving member.

[0031] Figure 2 is a schematic flowchart of a method for pre-adjusting out-of-range focusing distance provided by an embodiment of the present application. As Figure 2 shown, the method at least includes the following steps: S201. Obtain the first height information of the area to be detected of the object to be measured detected by the distance detection device arranged in parallel with the target microscope objective lens; S202. Determine whether the first height difference between the first height information and the first standard height information exceeds the preset focusing range of the target microscope objective lens; S203. If it exceeds the preset focusing range, during the process of moving the area to be detected from the detection range of the detection device to the center of the field of view of the target microscope objective lens, based on the first height difference, control the autofocus device and the distance detection device to synchronously perform a rough focusing movement along the Z-axis in advance.

[0032] The focusing distance out-of-range pre-adjustment method and device provided by the embodiments of the present application, without significantly increasing the hardware cost of the existing autofocus device and changing the device structure of the existing autofocus device, by adding a controller and a distance detection device arranged in parallel with the target microscope objective lens for aligning the object to be detected on the basis of the existing autofocus device, pre-detect the first height difference between each area to be detected of the object to be detected and the origin detection area for out-of-range, and control the autofocus device and the distance detection device to synchronously perform a rough focusing movement along the Z-axis in advance when it exceeds the preset focusing range of the target microscope objective lens, effectively identifying and coping with the out-of-range focusing situation in the microscopic autofocus imaging process, ensuring that the area to be detected falls within the preset focusing range of the target microscope objective lens when it moves to the center of the field of view of the target microscope objective lens, thereby ensuring the focusing effect of the autofocus device.

[0033] Figure 3 is one of the structural schematic diagrams of the autofocus system provided by the embodiments of the present application, as Figure 3 shown, the autofocus system at least includes a focusing distance out-of-range pre-adjustment device and an autofocus device. The focusing distance out-of-range pre-adjustment device is used to pre-detect and adjust the out-of-range focusing distance of the area to be detected before the area to be detected moves to the center of the field of view of the target microscope objective lens; the autofocus device is used to perform autofocus imaging on the area to be detected within the preset focusing range of the target microscope objective lens when the area to be detected moves to the center of the field of view of the target microscope objective lens.

[0034] Furthermore, the autofocus device includes an autofocus camera, a focusing detection device, and a second controller. The second controller is electrically connected to the autofocus camera and the focusing detection device respectively. The focusing detection device is used to detect the second height information of the area to be detected aligned by the target microscope objective lens and upload it to the second controller. The second controller controls the target microscope objective lens to perform a fine focusing movement along the Z-axis within the preset focusing range based on the second height difference between the second height information and the second standard height information, and performs autofocus imaging on the area to be detected. Specifically, the second controller drives the target microscope objective lens to move along the Z-axis within the preset focusing range through a driving member. The second standard height information refers to the second height information of the origin detection area detected by the focusing detection device when the origin detection area is aligned with the target microscope objective lens.

[0035] Based on the principle of autofocus, the embodiments of this application control the synchronous coarse adjustment movement of the autofocus device and the distance detection device along the Z-axis for pre-adjustment of the out-of-range focus distance in the case of out-of-range focus, and control the fine adjustment movement of the target microscope objective along the Z-axis for autofocus in the case of the focus within the range. The focus error after movement can be improved from the micron level to the depth-of-field level determined by the microscope objective, which can be compatible with microscope objectives of different magnifications and depth-of-field distances, and keep the object to be measured within the depth of field of the target microscope objective during the movement process, realizing highly compatible, highly repeatable and highly accurate optical detection.

[0036] Figure 4 is the second structural schematic diagram of the autofocus system provided by the embodiments of this application. As Figure 4 shown, the autofocus camera specifically includes an objective lens module, an optical focusing device 26 and an imaging sensor 27. The objective lens module includes a target microscope objective 211 for aligning the object to be measured, other microscope objectives 212 with different magnifications, and a microscope objective turntable 22.

[0037] The focus detection device specifically includes a light source, a beam splitter 25 and a light detector. The beam splitter 25 is arranged between the optical focusing device 26 and the optical path of the target microscope objective 211. When the area to be detected moves into the field of view of the target microscope objective 211, the emitted light of the light source sequentially passes through the beam splitter 25 and the target microscope objective 211 along the first optical path and is projected onto the area to be detected. The light detector detects the reflected light of the area to be detected along the second optical path sequentially passing through the target microscope objective 211 and the beam splitter 25, converts it into a measured electrical signal, and sends it to the second controller 24. That is, the second height information of the area to be detected is characterized by the measured electrical signal detected by the light detector.

[0038] The second controller 24 is used to compare the measured electrical signal with the standard electrical signal to determine the second height difference; and control the target microscope objective 211 to perform fine adjustment movement along the Z-axis within the preset focus range based on the second height difference. The standard electrical signal is the electrical signal converted from the reflected light of the origin detection area detected by the light detector. Specifically, the second controller 24 drives the target microscope objective 211 to cooperate with other microscope objectives 212 and the microscope objective turntable 22 to perform fine adjustment movement along the Z-axis through the focusing driving member 23.

[0039] Furthermore, the autofocus device further includes a defect detection device, which is used to acquire the measured image of the area to be detected collected by the autofocus camera; perform defect detection on the area to be detected based on the measured image; if there are defects, re-inspect the area to be detected based on the target microscope objective after magnification switching, so as to optimize the packaging production process of the object to be measured.

[0040] Figure 5It is a schematic flowchart of the autofocus method provided by an embodiment of the present application. As Figure 5 shown, the method at least includes the following steps: S501. Perform pre-detection and adjustment on the focus distance of the area to be detected for exceeding the range; S502. When the area to be detected moves to the center of the field of view of the target microscope objective lens, perform autofocus imaging on the area to be detected within the preset focus range of the target microscope objective lens.

[0041] In some embodiments, S502 specifically includes: Detect the second height information of the area to be detected; Compare the second height information with the second standard height information to determine the second height difference; control the target microscope objective lens to perform fine focus movement along the Z-axis within the preset focus range based on the second height difference, and perform autofocus imaging on the area to be detected; the second standard height information is the second height information of the origin detection area of the object to be measured.

[0042] In some embodiments, detecting the second height information of the area to be detected specifically includes: Control the emitted light of the light source to sequentially pass through the beam splitter and the target microscope objective lens along the first optical path and project onto the area to be detected; Detect the reflected light that sequentially passes through the target microscope objective lens and the beam splitter along the second optical path after being reflected by the area to be detected and convert it into an electrical signal to be measured.

[0043] In some embodiments, determining the second height difference includes: Compare the electrical signal to be measured with the standard electrical signal to determine the second height difference; the standard electrical signal is the electrical signal converted from the reflected light of the origin detection.

[0044] In some embodiments, the method further includes: Obtain the image to be measured of the area to be detected; Perform defect detection on the area to be detected based on the image to be measured; If there are defects, perform a re-inspection on the area to be detected based on the target microscope objective lens after magnification switching.

[0045] The autofocus method provided by the embodiment of the present application uses a distance detection device arranged in parallel with a microscope objective lens aligned with the object to be measured to detect the first height information of different regions to be detected of the object to be measured, and determines whether the first height difference between the detected first height information and the first standard height information exceeds the preset focusing range of the autofocus system. In the case of exceeding the preset focusing range, during the process of moving the region to be detected from the detection range of the distance detection device to the center of the field of view of the microscope objective lens, the autofocus system and the distance detection device are controlled in advance to move synchronously along the Z-axis to achieve pre-compensation of the focusing distance of the autofocus system. This compensation process does not have high requirements for real-time performance and focusing accuracy.

[0046] Based on the method in the above embodiment, the embodiment of the present application provides an electronic device. The device may include: at least one memory for storing a program and at least one processor for executing the program stored in the memory. Among them, when the program stored in the memory is executed, the processor is used to execute the focusing distance out-of-range pre-adjustment method or the autofocus method described in the above embodiment.

[0047] Based on the method in the above embodiment, the embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program runs on a processor, the processor is caused to execute the focusing distance out-of-range pre-adjustment method or the autofocus method described in the above embodiment.

[0048] Based on the method in the above embodiment, the embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor is caused to execute the focusing distance out-of-range pre-adjustment method or the autofocus method described in the above embodiment.

[0049] It can be understood that the processor in the embodiment of the present application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0050] The method steps in the embodiments of this application can be implemented in a hardware manner or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory (RAM), flash memory, read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, hard disks, removable hard disks, CD-ROMs, or any other form of storage medium well-known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0051] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or a wireless manner (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server, data center, etc. that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0052] It can be understood that the various numerical numbers involved in the embodiments of this application are only for the convenience of description and are not used to limit the scope of the embodiments of this application.

[0053] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A pre-adjustment device for the focusing distance beyond the range, characterized in that Comprising: An electrically connected distance detection device and a first controller; The distance detection device is arranged in parallel with the target microscope objective lens that aligns with the object to be measured in the autofocus device, and is used to detect the first height information of the area to be detected of the object to be measured and send it to the first controller; The first controller is used to judge whether the first height difference between the first height information and the first standard height information exceeds the preset focusing range of the target microscope objective lens; if it exceeds the preset focusing range, during the process of the area to be detected moving from the detection range of the distance detection device to the field center of the target microscope objective lens, based on the first height difference, control the autofocus device and the distance detection device to synchronously perform a rough focusing movement along the Z-axis in advance; wherein, the first standard height information is the first height information of the origin detection area detected by the distance detection device.

2. A pre-adjustment method for the focusing distance beyond the range, characterized in that, Comprising: Obtain the first height information of the area to be detected of the object to be measured detected by a distance detection device arranged in parallel with the target microscope objective lens; Judge whether the first height difference between the first height information and the first standard height information exceeds the preset focusing range of the target microscope objective lens; the first standard height information is the first height information of the origin detection area detected by the distance detection device; If it exceeds the preset focusing range, during the process of the area to be detected moving from the detection range of the distance detection device to the field center of the target microscope objective lens, based on the first height difference, control the autofocus device and the distance detection device to synchronously perform a rough focusing movement along the Z-axis in advance.

3. An autofocus system, characterized in that, Comprising the focusing distance out-of-range pre-adjustment device and the autofocus device as described in claim 1, and the autofocus device is used to perform autofocus imaging on the area to be detected within the preset focusing range of the target microscope objective lens when the area to be detected moves to the field center of the target microscope objective lens.

4. The autofocus system according to claim 3, wherein The autofocus device includes an autofocus camera, a focusing detection device and a second controller. The second controller is electrically connected to the autofocus camera and the focusing detection device respectively, and the autofocus camera includes the target microscope objective lens; The focusing detection device is used to detect the second height information of the area to be detected and send it to the second controller; The second controller is used to compare the second height information with the second standard height information to determine the second height difference; based on the second height difference, control the target microscope objective lens to perform a fine focusing movement along the Z-axis within the preset focusing range to perform autofocus imaging on the area to be detected; the second standard height information is the second height information of the origin detection area detected by the focusing detection device.

5. The autofocus system according to claim 4, characterized in that, The focusing detection device includes a light source, a beam splitter and a photodetector. The emitted light of the light source sequentially passes through the beam splitter and the target microscope objective lens along the first optical path and is projected onto the area to be detected. The photodetector is used to detect the reflected light that sequentially passes through the target microscope objective lens and the beam splitter along the second optical path after being reflected by the area to be detected, convert it into an electrical signal to be measured, and then send it to the second controller; The second controller is configured to compare the to-be-detected electrical signal with a standard electrical signal to determine the second height difference; Based on the second height difference, control the target microscope objective lens to perform fine focusing movement along the Z-axis within the preset focusing range; The standard electrical signal is an electrical signal converted from the reflected light of the origin detection area detected by the light detector.

6. The autofocus system according to claim 4, wherein The automatic focusing device further includes a defect detection device, configured to obtain a to-be-detected image of the to-be-detected area collected by the automatic focusing camera; perform defect detection on the to-be-detected area based on the to-be-detected image; If there are defects, perform a re-inspection on the to-be-detected area based on the target microscope objective lens after magnification switching.

7. An autofocus method, characterized in that, Including: Perform over-range detection and adjustment of the focusing distance on the to-be-detected area in advance based on the over-range pre-adjustment method of the focusing distance as described in claim 2; When the to-be-detected area moves to the center of the field of view of the target microscope objective lens, perform automatic focusing and image acquisition on the to-be-detected area within the preset focusing range of the target microscope objective lens.

8. The autofocus method according to claim 7, wherein The performing automatic focusing and image acquisition on the to-be-detected area within the preset focusing range of the target microscope objective lens includes: Detect the second height information of the to-be-detected area; Compare the second height information with second standard height information to determine the second height difference; Based on the second height difference, control the target microscope objective lens to perform fine focusing movement along the Z-axis within the preset focusing range to perform automatic focusing and image acquisition on the to-be-detected area; Wherein, the second standard height information is the second height information of the origin detection area of the to-be-detected object.

9. The autofocus method according to claim 8, wherein, The detecting the second height information of the to-be-detected area includes: Control the emitted light of the light source to sequentially pass through the beam splitter and the target microscope objective lens along the first optical path and project onto the to-be-detected area; Detect the reflected light that sequentially passes through the target microscope objective lens and the beam splitter along the second optical path after being reflected by the to-be-detected area and convert it into a to-be-detected electrical signal; The determining the second height difference includes: Compare the to-be-detected electrical signal with a standard electrical signal to determine the second height difference; the standard electrical signal is an electrical signal converted from the reflected light of the origin detection area.

10. The autofocus method according to claim 7, characterized in that, The method further includes: Obtain a to-be-detected image of the to-be-detected area; Perform defect detection on the to-be-detected area based on the to-be-detected image; If there are defects, perform a re-inspection on the to-be-detected area based on the target microscope objective lens after magnification switching.

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