Camera module optical axis calibration and distance simulation tool based on teleconverter

Abstract

The invention discloses a teleconverter-based camera module optical axis calibration and distance simulation tool, and relates to the field of security monitoring, the teleconverter-based camera module optical axis calibration and distance simulation tool comprises a base and a camera module, the top of the base is provided with a horizontal lead screw mechanism, and an output structure of the horizontal lead screw mechanism is provided with a vertical lead screw mechanism in a transmission manner; a vertical lead screw mechanism is arranged on the base, an output structure of the vertical lead screw mechanism is in transmission connection with a camera mounting seat, an optical assembly is arranged at the top of one side of the base and comprises a three-order distance increasing clamping seat and a distance increasing lens, the distance increasing lens is arranged on the inner side of the top of the three-order distance increasing clamping seat in a sleeving mode, and the bottom of the three-order distance increasing clamping seat is fixed to the top of one side of the base. When the camera module optical axis calibration and distance simulation tool based on the teleconverter is used, the problem that ideal calibration of a telephoto lens cannot be achieved within a short distance can be successfully solved by accurately adjusting the positions of the camera module and the teleconverter, and the camera module optical axis calibration and distance simulation tool based on the teleconverter is particularly suitable for application scenes such as security monitoring, road monitoring and night imaging.

Description

Technical Field

[0001] This invention relates to the field of security monitoring, and in particular to a tooling for calibrating the optical axis and simulating the distance of a camera module based on a teleconverter. Background Technology

[0002] Security cameras, as core devices in intelligent security systems, are widely used across various scenarios including home monitoring and industrial inspection. However, existing long-zoom security camera modules still face a series of unresolved challenges during ISP calibration, as follows: First, space limitations: Existing security cameras generally use 12-50mm telephoto lenses (such as road surveillance cameras), and their focusing distance (WDV) is usually greater than 1.5 meters, which exceeds the capacity of a standard lightbox (60cm), resulting in the display area of ​​the image card not being able to clearly occupy 80%; Secondly, stringent optical requirements: Security cameras have extremely high requirements for image distortion and low-light noise when performing road monitoring and nighttime imaging. During ISP calibration, any tiny calibration error can lead to significant image distortion, affecting image clarity and accuracy, especially under low-light conditions where image quality is particularly important; Furthermore, there are bottlenecks in the application of teleconverters: teleconverters help telephoto lenses focus in limited spaces such as light boxes by simulating long distances, but the distance (D_STOP) between the teleconverter and the camera module needs to be precisely controlled. The error range is usually required to be within ±0.05mm. Otherwise, even a small deviation may cause optical axis shift, affecting the image sharpness. The distance (WDR) between the teleconverter and the camera module needs to be precisely controlled between 200mm and 350mm. Excessive deviation will affect the image display effect and fail to meet the ideal standard. The optical axis of the teleconverter and the camera module must be strictly aligned. The optical axis offset is usually required to be controlled within ±0.05mm, otherwise it will cause distortion in the image display area.

[0003] In recent years, with the further development of related technologies, existing technologies have proposed that space problems can be solved by customizing longer light boxes. However, the construction cost of the solution is extremely high, and it is only applicable to a single scenario. Furthermore, traditional fixtures cannot adjust both horizontal and vertical parameters at the same time, resulting in large calibration errors and unstable accuracy. Summary of the Invention

[0004] This application proposes a camera module optical axis calibration and distance simulation fixture based on a teleconverter, which solves the technical problems mentioned in the background.

[0005] To achieve the above objectives, this application adopts the following technical solution: a camera module optical axis calibration and distance simulation fixture based on a teleconverter, including a base and a camera module. A horizontal lead screw mechanism is installed on the top of the base, and a vertical lead screw mechanism is driven by the output structure of the horizontal lead screw mechanism. The output structure of the vertical lead screw mechanism is driven by a camera mounting base. An optical component is provided on the top of one side of the base. The optical component includes a third-order teleconverter holder and a teleconverter. The teleconverter is fitted inside the top of the third-order teleconverter holder, and the bottom of the third-order teleconverter holder is fixed to the top of one side of the base.

[0006] By precisely adjusting the positions of the camera module and the teleconverter, the problem of achieving ideal calibration of telephoto lenses at short distances has been successfully solved. This technology is particularly suitable for applications such as security monitoring, road monitoring, and nighttime imaging, meeting a variety of real-world usage needs.

[0007] Preferably, the horizontal screw mechanism includes a horizontal slider mounting base and a horizontal ball screw. The end of the horizontal ball screw is fitted with a bearing seat fixed to the top of the base via a bearing sleeve. The surface of the horizontal ball screw is threaded with a first nut fitted inside the horizontal slider mounting base. One end of the horizontal ball screw passes through one side wall of the base and is connected to a horizontal handwheel. A horizontal guide rail is mounted at the bottom of the horizontal slider mounting base and fixed to the top of the base. Horizontal guide rods fitted inside the horizontal slider mounting base are mounted at the top of both the front and rear ends of the horizontal guide rail. The front and rear ends of the horizontal guide rods are threaded with first positioning screws capable of pressing against and contacting the horizontal guide rail. The surface of the front end of the horizontal guide rail is provided with horizontal scale lines.

[0008] Preferably, the vertical screw mechanism includes a vertical ball screw and a vertical slider mounting base. A vertical guide rail is fitted on the outer side of the vertical ball screw, and the bottom of the vertical guide rail is connected to the horizontal slider mounting base, which serves as the output structure of the horizontal screw mechanism. A second nut, fitted inside the vertical slider mounting base, is threaded onto the surface of the vertical ball screw. One side of the vertical slider mounting base engages with one side of the vertical guide rail and can slide on the surface of the vertical guide rail. One end of the vertical ball screw passes through the top structure of the vertical guide rail and is connected to a vertical handwheel. Vertical guide rods, fitted inside the vertical slider mounting base, are installed at both the front and rear ends of one side of the vertical guide rail. A second positioning screw, capable of pressing against and contacting the vertical guide rail, is threaded onto the front and rear ends of the vertical slider mounting base. Vertical scale lines are installed on the surface of the front end of the vertical guide rail.

[0009] Preferably, the camera mounting base is configured with an L-shaped structure, and one side of the bottom of the camera mounting base is provided with an assembly space for mounting a camera module, and the other side of the camera mounting base is connected to a vertical slider mounting base, which serves as the output structure of a vertical lead screw mechanism.

[0010] Preferably, the top inner side of the three-stage teleconverter holder has an internal threaded hole, and the surface of the middle part of the teleconverter lens has an external thread that can be threadedly connected to the internal threaded hole through the external thread, so that the teleconverter lens can be detachably installed with the three-stage teleconverter holder.

[0011] Preferably, a clamping component is provided on one side of the three-stage teleconverter holder, and the three-stage teleconverter holder can clamp and limit the teleconverter lens installed inside itself through the clamping component.

[0012] Preferably, the clamping assembly includes an inner support cylinder and an internal threaded cylinder. The inner support cylinder and the internal threaded cylinder are arranged concentrically, and one end of the inner support cylinder and one end of the internal threaded cylinder are both fixed to the surface of the top side of the three-stage teleconverter. Several pressing rods are arranged and installed along the circumference of the middle part of the side wall of the inner support cylinder. The internal thread of the internal threaded cylinder is connected to an internal conical screw cylinder. During the thread engagement between the internal conical screw cylinder and the internal threaded cylinder, the internal conical screw cylinder can simultaneously press one end of the several pressing rods, so that two pressing rods in adjacent positions can relatively clamp and limit one end of the teleconverter.

[0013] Preferably, the other end of the internal threaded cylinder is configured as a T-shaped structure, and a limiting collar is fitted on the outer side of the other end of the internal threaded cylinder. One end of the limiting collar is fitted on the outer side of the end of the internal conical screw cylinder away from the third-stage spacing bracket. The top pressure member includes a composite top rod. The middle part of the composite top rod is engaged in the side wall of the middle part of the inner support cylinder, and both ends of the composite top rod are configured as spherical structures.

[0014] Preferably, a first spring and a positioning ring are respectively fitted on one end surface of the composite top rod inside the inner support cylinder. The two ends of the first spring are respectively fixed on the surface of the positioning ring and the inner wall of the inner support cylinder. When the first spring is not compressed, it can pull the composite top rod away from the teleconverter to make non-clamping clearance.

[0015] Preferably, a damping ring outer support plate is movably sleeved on one end of the composite top rod inside the inner support cylinder. The top of the damping ring is movably connected to the surface of the positioning ring, and the damping ring is fixedly sleeved inside the outer support plate. A second spring is installed between the side surface of the outer support plate away from the composite top rod and the inner wall of the inner support cylinder.

[0016] In summary, the present invention has the following beneficial effects: 1. This camera module optical axis calibration and distance simulation fixture based on a teleconverter can solve the problem of the inability of telephoto lenses to achieve ideal calibration at short distances by precisely adjusting the positions of the camera module and the teleconverter. It is particularly suitable for applications such as security monitoring, road monitoring, and night imaging, and meets a variety of different real-world usage needs.

[0017] 2. This camera module optical axis calibration and distance simulation fixture based on teleconverter can achieve high-precision calibration in a limited space during use, and is also compatible with various models of teleconverters during use and turnover.

[0018] 3. The camera module optical axis calibration and distance simulation fixture based on teleconverter has a clamping component as an auxiliary structure, which can expand the use of the fixture device to quickly detach and assemble different types of teleconverters and third-order teleconverter holders, and center the installation, thereby further improving the overall range of use of the device. Attached Figure Description

[0019] Figure 1 This is a front view schematic diagram of the structure of the present invention; Figure 2 This is a three-dimensional schematic diagram of the horizontal lead screw mechanism in the structure of this invention; Figure 3 This is a three-dimensional schematic diagram of the vertical lead screw mechanism in the structure of the present invention; Figure 4 This is a three-dimensional schematic diagram of the three-stage extension card holder in the structure of this invention; Figure 5 This is a cross-sectional schematic diagram of the clamping component in the structure of the present invention; Figure 6 This is a front view schematic diagram of the clamping component in the structure of the present invention; Figure 7 This is a right-side view of the clamping component in the structure of the present invention; Figure 8 It is in the structure of this invention Figure 5 Enlarged view of point A in the middle; Figure 9 It is in the structure of this invention Figure 7 Enlarged view of point B in the middle; Figure 10 This is a schematic representation of the parameters for optical axis calibration in this invention.

[0020] Explanation of reference numerals in the attached figures: 1. Horizontal handwheel; 2. Horizontal guide rod; 3. Horizontal slider mounting base; 4. Horizontal guide rail; 5. Horizontal ball screw; 6. Vertical handwheel; 7. Vertical guide rod; 8. Vertical slider mounting base; 9. Vertical guide rail; 10. Camera mounting base; 11. Three-stage teleconverter holder; 12. Teleconverter lens; 13. Horizontal scale line; 14. Vertical scale line; 15. Vertical ball screw; 16. Base; 17. Inner support cylinder; 18. Composite top rod; 19. Positioning ring; 20. First spring; 21. Internal threaded cylinder; 22. Internal tapered screw cylinder; 23. Limiting collar; 24. Damping ring; 25. Outer support plate; 26. Second spring; 27. First positioning screw; 28. Second positioning screw. Detailed Implementation

[0021] like Figures 1-4 , Figure 10 A camera module optical axis calibration and distance simulation fixture based on a teleconverter includes a base 16 and a camera module. A horizontal lead screw mechanism is installed on the top of the base 16. The horizontal lead screw mechanism includes a horizontal slider mounting seat 3 and a horizontal ball screw 5. The end of the horizontal ball screw 5 is fitted with a bearing seat fixed to the top of the base 16 via a bearing. The surface of the horizontal ball screw 5 is threaded with a first nut fitted inside the horizontal slider mounting seat 3. One end of the horizontal ball screw 5 passes through one side wall of the base 16 and is connected to a horizontal handwheel 1. A horizontal guide rail 4 is installed at the bottom of the horizontal slider mounting seat 3 and fixed to the top of the base 16. Horizontal guide rods 2 fitted inside the horizontal slider mounting seat 3 are installed at the top of both the front and rear ends of the horizontal guide rail 4. The front and rear ends of the horizontal guide rods 2 are threaded with a first positioning screw 27 that can press against and contact the horizontal guide rail 4, thereby satisfying the automatic height accuracy displacement adjustment of the relevant structure in the horizontal direction. Furthermore, the output structure of the horizontal lead screw mechanism is equipped with a vertical lead screw mechanism, which includes a vertical ball screw 15 and a vertical slider mounting seat 8. A vertical guide rail 9 is fitted on the outside of the vertical ball screw 15, and the bottom of the vertical guide rail 9 is connected to the horizontal slider mounting seat 3, which serves as the output structure of the horizontal lead screw mechanism. A second nut fitted inside the vertical slider mounting seat 8 is threaded onto the surface of the vertical ball screw 15, and one side of the vertical slider mounting seat 8 is engaged with one side of the vertical guide rail 9 and can slide on the surface of the vertical guide rail 9. One end of the vertical ball screw 15 passes through the top structure of the vertical guide rail 9 and is connected to a vertical handwheel 6. Vertical guide rods 7 fitted inside the vertical slider mounting seat 8 are installed at both the front and rear ends of one side of the vertical guide rail 9, and a second positioning screw 28 that can press against and contact the vertical guide rail 9 is threaded onto both the front and rear ends of the vertical slider mounting seat 8. A vertical scale line 14 is installed on the surface of the front end of the vertical guide rail 9, thereby satisfying the automatic height precision displacement adjustment of the relevant structure in the vertical direction. Furthermore, the output structure of the vertical screw mechanism is connected to a camera mounting base 10. The camera mounting base 10 is configured as an L-shaped structure, and one side of the bottom of the camera mounting base 10 is provided with an assembly space for installing a camera module to meet the installation and support requirements of the target to be tested. The other side of the camera mounting base 10 is connected to the vertical slider mounting base 8, which is the output structure of the vertical screw mechanism. An optical assembly is provided on the top side of one side of the base 16. The optical assembly includes a three-stage teleconverter 11 and a teleconverter 12. The teleconverter 12 is fitted inside the top of the three-stage teleconverter 11, and the bottom of the three-stage teleconverter 11 is fixed to the top side of one side of the base 16. An internal threaded hole is opened on the inner side of the top of the three-stage teleconverter 11. An external thread is opened on the surface of the middle part of the teleconverter 12, and it can be threaded to the internal threaded hole through the external thread, so that the teleconverter 12 can be detachably installed and removed from the three-stage teleconverter 11, thereby providing convenient replacement conditions for multiple teleconverters 12 in the future.

[0022] When using, Step 1: Installation and Initialization According to the testing requirements, a teleconverter 12 is installed on the third-order teleconverter holder 11. Specifically, the middle structure of the teleconverter 12 is threadedly connected to the internal threaded hole provided in the top of the third-order teleconverter holder 11, thereby enabling detachable installation. The teleconverter 12 used, taking the RL2188ARL2188A teleconverter as an example, has the following specifications: maximum FOV=90°, distortion rate=0.5%. After installation, with the third-order teleconverter holder 11 vertically installed on the top of the base 16, it can be confirmed that the optical axis of the teleconverter 12 is perpendicular to the plane of the base 16. Fix the camera module under test with a focal length in the range of 12-50mm on the camera mounting base 10, and record the key parameters of the camera module: sensor size such as 1 / 2.8", focal length, resolution, and confirm that the end face of the camera lens and the teleconverter 12 maintain an initial distance of about 30-40cm. Place an existing calibration light box 60cm in front of the overall device. The calibration light box has a built-in calibration plate and can be connected to the image acquisition system to display the camera's captured image in real time. Use the existing optical axis calibration parameter table to look up the parameters required for this test, such as WDV, WDR, and Chart size. Step 2: Adjustment Operation In the coarse adjustment stage, rotate the horizontal handwheel 1 clockwise to move the horizontal slider mounting base 3 toward the teleconverter 12, and set the pitch of the horizontal ball screw 5 to 0.5mm. Therefore, when the horizontal handwheel 1 rotates one revolution, the camera module under test moves forward 0.5mm. Read the scale line 13 until the camera module under test is pushed to a position 1220mm away from the teleconverter.

[0023] Fine-tuning stage: Using the precision of the horizontal scale line 13, with the smallest scale division of the horizontal scale line 13 being 0.01mm, fine adjustments are made until the distance between the camera module under test and the teleconverter 12 is within the range of 20.67±0.03mm. At this time, the camera mounting base 10, the vertical guide rail 9, and the vertical slider mounting base 8 move together with the horizontal mechanism to the specified precise position. Then, the first positioning screws 27 set at the front and rear ends of the horizontal slider mounting base 3 are turned and tightened to fix the distance between the camera module under test and the teleconverter 12. After adjustment, verification is performed by measuring the actual distance from the rear surface of the teleconverter to the end face of the camera lens using an existing micrometer or range sensor. The error is confirmed to be within ±0.03mm. This parameter remains unchanged throughout the calibration process, providing a stable reference for subsequent adjustments. Step 3: Set the WDV and WDR parameters to simulate focal length. According to the Relay Lens user manual, WDV represents the measured distance, which is the actual focusing distance of the camera module under test, also known as the virtual imaging distance. WDR represents the physical distance from the front surface of the teleconverter to the test card. FOV represents the size of the field of view that can be covered, which depends on the diagonal direction of the camera module under test; Chart size represents the required calibration board size, which is related to WDV and FOV; Ratio represents the magnification ratio, which is equal to the length and width of the WDR test card divided by the required aspect ratio of the WDV test card. Key relationship: WDV determines the focal length scenarios to be simulated, such as simulating close-up shots at 30cm, long-distance shots at 3m, and long-distance shots at 5m; WDR is the physical distance that needs to be actually adjusted, and the two establish a corresponding relationship through the optical design of the teleconverter 12. Determine the parameters by referring to the table. Based on the test requirements, determine the WDV value to be simulated. For example, to simulate focusing at a distance of 5m, WDV = 5000mm. The corresponding WDR value in the data table is 302.9mm and the chart size is 665.7mm. Record this set of parameters as the adjustment target. The following operations are carried out according to different situations. First adjustment operation scenario: With teleconverter 12 fixed in position, adjust the distance between the entire device and the calibration plate. Keeping the distance between the camera module under test and the teleconverter 12 constant, move the entire device and adjust the distance from the front surface of the teleconverter 12 to the calibration plate. Use an existing laser rangefinder or steel tape measure to measure the distance and adjust it to WDR=302.9mm. Record the reference position of the device at this time through the horizontal scale line 13.

[0024] The second type of adjustment operation: using horizontal adjustment to achieve fine-tuning of relative distance. If you need to quickly switch between different WDV scenes, use horizontal scale line 13 to record the position corresponding to different WDRs; For example: when WDV=3000mm, WDR=297.3mm; when WDV=5000mm, WDR=302.9mm; The difference between the two is 5.6mm. The switch can be made by turning the horizontal handwheel 1 11 times. Then, the horizontal scale line 13 is used for precise reading to achieve quick scene switching.

[0025] Step 4: Chart size calibration board size adaptation The meaning of the Chart size parameter: Different WDVs correspond to different Chart sizes according to the data table; Chart size is related to WDV and FOV: the larger the WDV, the larger the required chart size. Therefore, the goal is to ensure that the calibration board completely covers the effective field of view of the camera module under test. Operational verification: Based on the table lookup results, taking WDV=5000mm and Chart size=665.7mm as an example, select a calibration board of appropriate size, place the calibration board inside the light box, ensure uniform illumination, observe the image acquisition system screen, and confirm that all four corners of the calibration board are within the field of view and that there is an appropriate margin. If the field of view does not match, it is necessary to recheck whether the WDV and WDR parameter settings are correct. Step 5: Fine-tuning the optical axis alignment The importance of optical axis alignment: If the optical axis of the camera module under test is offset from the optical axis of the teleconverter 12, it will lead to increased image distortion, the calibration board being off-center in the image, a reduction in the effective calibration area, and a decrease in the accuracy of AWB, CCM, and MTF tests.

[0026] Control targets: Optical axis offset ≤ ±0.05mm horizontally, ≤ ±0.03mm vertically; Vertical adjustment; observe the image acquisition screen. The center point of the calibration plate should be located in the center of the image. If the calibration plate is tilted up or down, it indicates that there is a vertical offset. Rotate the vertical handwheel 6. If the vertical handwheel 6 rotates clockwise, the relevant structure will move upward. If the vertical handwheel 6 rotates counterclockwise, the relevant structure will move downward. Subsequently, the vertical ball screw 15, in conjunction with the second nut, pushes the vertical slider mounting seat 8 to move precisely along the vertical guide rail 9. The vertical guide rod 7 ensures smooth and vibration-free movement. The reading is obtained through the vertical scale line 14, and the adjustment amount is controlled within 0.01-0.05mm each time. Judgment criteria: When the horizontal center line of the calibration plate coincides with the horizontal center line of the image, and the deviation is less than 80% of the field of view, that is, the calibration point is located in the 80% area of ​​the center of the image, tighten the second positioning screw 28 to fix the vertical position of the vertical slider mounting base 8. Secondary fine-tuning in the horizontal direction; Although the horizontal position has been adjusted in step 2, the optical axis alignment may need fine-tuning. Specifically, it is necessary to further observe whether the vertical center line of the calibration board coincides with the vertical center line of the image. The detailed operation method is to fine-tune the horizontal handwheel 1, with the adjustment amount within ±0.05mm. Note that the adjustment at this time will slightly affect the distance between the camera module under test and the teleconverter 12. It is necessary to weigh the distance within the allowable accuracy range. Record the final position through the horizontal scale line 13. Verification method: Place precision markers at the four corners and center of the screen, measure the distance from each marker to the center of the screen, confirm symmetry, and the symmetry error should be <2%. Further comprehensive verification: after completing vertical and horizontal adjustments, the calibration board should be displayed perfectly centered. Use image processing software to analyze screen distortion and confirm that the edge distortion rate is <0.5%. Record the readings of the horizontal scale line 13 and the vertical scale line 14 at this time as the calibration reference for the camera module under test.

[0027] like Figures 5-9 A clamping assembly is provided on one side of the three-stage teleconverter holder 11, which can clamp and limit the teleconverter 12 housed inside it. The clamping assembly includes an inner support cylinder 17 and an internal threaded cylinder 21. The inner support cylinder 17 and the internal threaded cylinder 21 are concentrically arranged, and one end of the inner support cylinder 17 and one end of the internal threaded cylinder 21 are fixed to the surface of the top side of the three-stage teleconverter holder 11. Several top pressure rods are arranged and installed along the circumference of the middle of the side wall of the inner support cylinder 17. The internal thread of the internal threaded cylinder 21 is connected to an internal tapered screw cylinder 22, and the internal tapered screw cylinder 22 can clamp and limit the internal thread of the internal threaded cylinder 21 during the thread engagement. One end of each pressing rod is simultaneously pressed, so that two pressing rods in adjacent positions can clamp and limit one end of the teleconverter 12, thereby satisfying the stability effect of the teleconverter 12 during use. The other end of the internal threaded cylinder 21 is set with a T-shaped structure, and a limiting collar 23 is fitted on the outer side of the other end of the internal threaded cylinder 21. One end of the limiting collar 23 is fitted on the outer side of the end of the inner conical screw cylinder 22 away from the third-stage teleconverter seat 11. The pressing rod includes a composite pressing rod 18. The middle part of the composite pressing rod 18 is clamped in the side wall of the middle part of the inner support cylinder 17, and both ends of the composite pressing rod 18 are set with spherical structures to provide convenient contact conditions for subsequent pressing. One end of the composite push rod 18, which is fitted inside the inner support cylinder 17, is fitted with a first spring 20 and a positioning ring 19. The two ends of the first spring 20 are fixed to the surface of the positioning ring 19 and the inner wall of the inner support cylinder 17, respectively. When the first spring 20 is not compressed, it can pull the composite push rod 18 away from the teleconverter 12 to make non-clamping clearance, providing flexible clearance conditions for the subsequent disassembly of the teleconverter 12. The end of the composite push rod 18, which is fitted inside the inner support cylinder 17, is movably sleeved with a damping ring 24 and an outer support plate 25. The top of the damping ring 24 is movably connected to the surface of the positioning ring 19, and the damping ring 24 is fixedly sleeved inside the outer support plate 25. A second spring 26 is installed between the side surface of the outer support plate 25 away from the composite push rod 18 and the inner wall of the inner support cylinder 17.

[0028] In use, considering the need to replace teleconverters 12 of different specifications, the set clamping components are used to conveniently assemble and fix the third-order teleconverter holder 11 and the teleconverter 12. The specific operation is as follows. The middle part of the teleconverter 12 is fitted into the pre-set clearance space at the top of the three-stage teleconverter holder 11. Then, the inner conical screw 22 is turned so that the inner conical screw 22 can synchronously push and drive the multiple composite push rods 18 fitted inside the inner support cylinder 17 under the helical meshing support of the inner threaded cylinder 21. Then, the multiple composite push rods 18, supported by the inner support cylinder 17, clamp one end of the teleconverter 12 toward the center of the teleconverter 12. Thus, while realizing the rapid assembly of the teleconverter 12 and the three-stage teleconverter holder 11, it can also clamp and fix teleconverters 12 of different specifications in an appropriate manner, fully meeting different usage needs in reality. When replacing the teleconverter 12, simply turn the inner conical screw 22 to reset and move it. Multiple composite push rods 18 will automatically move away from the teleconverter 12 under the elastic pull of their respective first springs 20. Then, pull out the teleconverter 12, reinstall the teleconverter 12 to be used, and repeat the above operation steps.

Claims

1. A camera module optical axis calibration and distance simulation fixture based on a teleconverter, comprising a base (16) and a camera module, characterized in that: A horizontal lead screw mechanism is installed on the top of the base (16), and a vertical lead screw mechanism is installed in the output structure of the horizontal lead screw mechanism. The output structure of the vertical lead screw mechanism is connected to a camera mounting base (10). An optical component is provided on the top of one side of the base (16). The optical component includes a third-order teleconverter bracket (11) and a teleconverter lens (12). The teleconverter lens (12) is fitted inside the top of the third-order teleconverter bracket (11), and the bottom of the third-order teleconverter bracket (11) is fixed to the top of one side of the base (16).

2. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 1, characterized in that: The horizontal screw mechanism includes a horizontal slider mounting base (3) and a horizontal ball screw (5). The end of the horizontal ball screw (5) is fitted with a bearing seat fixed to the top of the base (16) via a bearing. The surface of the horizontal ball screw (5) is threaded with a first nut fitted inside the horizontal slider mounting base (3). One end of the horizontal ball screw (5) passes through one side wall of the base (16) and is connected to a horizontal handwheel (1). The bottom of the horizontal slider mounting base (3) is fitted with a horizontal guide rail (4) fixed to the top of the base (16). The top of the front and rear ends of the horizontal guide rail (4) is fitted with a horizontal guide rod (2) fitted inside the horizontal slider mounting base (3). The front and rear ends of the horizontal guide rod (2) are threaded with a first positioning screw (27) that can press against the horizontal guide rail (4). The surface of the front end of the horizontal guide rail (4) is provided with a horizontal scale line (13).

3. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 2, characterized in that: The vertical screw mechanism includes a vertical ball screw (15) and a vertical slider mounting base (8). A vertical guide rail (9) is fitted on the outside of the vertical ball screw (15), and the bottom of the vertical guide rail (9) is connected to the horizontal slider mounting base (3), which is the output structure of the horizontal screw mechanism. A second nut is threadedly connected to the surface of the vertical ball screw (15) and fitted inside the vertical slider mounting base (8). One side of the vertical slider mounting base (8) is engaged with one side of the vertical guide rail (9) and can slide on the surface of the vertical guide rail (9). One end of the vertical ball screw (15) passes through the top structure of the vertical guide rail (9) and is connected to a vertical handwheel (6). A vertical guide rod (7) fitted inside the vertical slider mounting base (8) is installed on the front and rear ends of one side of the vertical guide rail (9). A second positioning screw (28) that can press against and contact the vertical guide rail (9) is threadedly connected to the front and rear ends of the vertical slider mounting base (8). A vertical scale line (14) is installed on the surface of the front end of the vertical guide rail (9).

4. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 3, characterized in that: The camera mounting base (10) is configured as an L-shaped structure, and one side of the bottom of the camera mounting base (10) is provided with an assembly space for mounting camera modules. The other side of the camera mounting base (10) is connected to the vertical slider mounting base (8), which is the output structure of the vertical lead screw mechanism.

5. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 1, characterized in that: The top inner side of the three-stage teleconverter bracket (11) has an internal thread hole, and the surface of the middle part of the teleconverter (12) has an external thread and can be threaded to the internal thread hole through the external thread, so that the teleconverter (12) can be detachably installed with the three-stage teleconverter bracket (11).

6. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 1, characterized in that: The three-stage teleconverter holder (11) is provided with a clamping component on one side, and the three-stage teleconverter holder (11) can clamp and limit the teleconverter (12) installed inside itself through the clamping component.

7. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 6, characterized in that: The clamping assembly includes an inner support cylinder (17) and an inner threaded cylinder (21). The inner support cylinder (17) and the inner threaded cylinder (21) are arranged at the same center. One end of the inner support cylinder (17) and one end of the inner threaded cylinder (21) are fixed on the surface of the top side of the three-stage telemeter extender (11). Several top-pressing rods are arranged and installed in the middle of the side wall of the inner support cylinder (17) along its circumference. The inner threaded cylinder (21) is connected to an inner conical screw cylinder (22) by its internal thread. During the thread engagement with the inner threaded cylinder (21), the inner conical screw cylinder (22) can simultaneously press one end of several top-pressing rods, so that two top-pressing rods in adjacent positions can clamp and limit one end of the telemeter extender (12) relative to each other.

8. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 7, characterized in that: The other end of the internal threaded cylinder (21) is configured as a T-shaped structure, and a limiting collar (23) is fitted on the outer side of the other end of the internal threaded cylinder (21). One end of the limiting collar (23) is fitted on the outer side of the inner conical cylinder (22) away from the third-stage spacer (11). The top pressure member includes a composite top rod (18). The middle part of the composite top rod (18) is engaged in the side wall of the middle part of the inner support cylinder (17), and both ends of the composite top rod (18) are configured as spherical structures.

9. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 8, characterized in that: The composite top rod (18) is fitted with a first spring (20) and a positioning ring (19) on one end surface inside the inner support cylinder (17). The two ends of the first spring (20) are fixed on the surface of the positioning ring (19) and the inner wall of the inner support cylinder (17), respectively. When the first spring (20) is not compressed, it can pull the composite top rod (18) away from the teleconverter (12) to make non-clamping clearance.

10. The camera module optical axis calibration and distance simulation fixture based on a teleconverter according to claim 8, characterized in that: The composite top rod (18) is fitted inside the inner support cylinder (17) and is movably connected to the outer support plate (25) of the damping ring (24). The top of the damping ring (24) is movably connected to the surface of the positioning ring (19), and the damping ring (24) is fixedly fitted inside the outer support plate (25). A second spring (26) is installed between the side surface of the outer support plate (25) away from the composite top rod (18) and the inner wall of the inner support cylinder (17).

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