A miniaturized triangulation testing device

Abstract

This utility model relates to the technical field of camera module testing, specifically to a miniaturized triangulation testing device. It includes a base plate, on which a collimator module, a four-axis pendulum stage, and a terminal analysis module are mounted. The collimator module further includes a mounting plate connected to the base plate, on which at least one pair of collimators are symmetrically arranged. The camera module under test is fixed on the four-axis pendulum stage. The four-axis pendulum stage drives the camera module under test to acquire feature images from one pair of collimators at multiple angles. The terminal analysis module calculates the intrinsic parameter calibration accuracy of the camera module under test based on its intrinsic parameters and the acquired feature images. This device uses a collimator module instead of a traditional real-scene target, significantly reducing the space occupied by the device and achieving miniaturization. Furthermore, the four-axis pendulum stage drives the camera module under test to acquire feature images from multiple angles, enabling multi-angle testing and greatly improving testing accuracy.

Description

Technical Field

[0001] This utility model relates to the technical field of camera module testing, specifically to a miniaturized triangulation testing device. Background Technology

[0002] During the production of camera modules, the assembled modules need to undergo intrinsic parameter calibration. Intrinsic parameters are parameters describing the camera's optical characteristics and imaging geometry, including focal length, principal point coordinates, radial distortion coefficient, and tangential distortion coefficient. Intrinsic parameter calibration of camera modules is a crucial step in computer vision and image processing. Its purpose is to determine the camera's internal parameters through mathematical modeling and calibration algorithms, thereby achieving a precise mapping from three-dimensional world coordinates to two-dimensional image coordinates. The accuracy of the intrinsic parameter calibration directly affects the use of the camera module; therefore, after the intrinsic parameter calibration is completed, the calibration accuracy must be tested.

[0003] The method for testing the accuracy of camera module intrinsic parameter calibration is usually triangulation. The camera module under test is used to photograph two target points. The coordinates of the camera module under test and the two target points are known. Therefore, the image distance between the two target points can be calculated based on the intrinsic parameters of the camera module under test and the images of the two target points. The actual distance between the two target points is known. Therefore, the accuracy of intrinsic parameter calibration can be calculated based on the image distance and the actual distance between the two target points.

[0004] The imaging distance of camera modules is usually quite far, which means that during triangulation, the target point needs to be placed far away from the camera module, making the testing equipment very bulky. There are also solutions in the industry to miniaturize triangulation equipment, such as the existing patent solution with publication number CN219225550U. This solution uses a collimator or a teleconverter with a target composed of a pattern with extractable feature points to replace real-scene shooting, greatly reducing the space occupied by the equipment. However, this solution cannot control the camera module to perform multi-degree-of-freedom movements to acquire images of two target points (the pattern built into the collimator) from multiple angles, resulting in insufficient testing accuracy. Utility Model Content

[0005] The purpose of this utility model is to provide a miniaturized triangulation testing device, including a device base plate. The device base plate is equipped with a collimator module, a four-axis pendulum stage, and a terminal analysis module. The collimator module includes a mounting plate connected to the device base plate, and at least one pair of collimators are symmetrically arranged on the mounting plate. The camera module under test is fixed on the four-axis pendulum stage. The four-axis pendulum stage drives the camera module under test to acquire feature images of one pair of collimators at multiple angles. The terminal analysis module calculates the intrinsic parameter calibration accuracy of the camera module under test based on the intrinsic parameters of the camera module under test and the acquired feature images.

[0006] In one specific embodiment, the mounting plate is a semi-circular plate, and the arc edge of the mounting plate is provided with scale markings; the mounting plate is horizontally arranged and located on one side of the four-axis swing table, or the mounting plate is vertically arranged and located above the four-axis swing table.

[0007] In one specific embodiment, two arc-shaped guide grooves concentric with the mounting plate are symmetrically arranged on the mounting plate, and a pair of parallel light tubes respectively cooperate with the two arc-shaped guide grooves, and the parallel light tubes and the arc-shaped guide grooves have a relatively sliding state and a relatively fixed state.

[0008] In one specific embodiment, the mounting plate is provided with at least one pair of completely fixed parallel light tubes.

[0009] In one specific embodiment, the equipment base plate is further provided with an X-axis linear module and a Y-axis linear module. The drive block of the X-axis linear module is provided with a loading and unloading robot. The four-axis swing table is provided on the drive block of the Y-axis linear module. The loading and unloading robot is used to load the camera module to be tested from the previous machine onto the four-axis swing table, and to transfer the camera module that has been tested on the four-axis swing table to the next machine.

[0010] In one specific embodiment, the four-axis stage includes a first rotary table, a mounting bracket is provided on the rotation axis of the first rotary table, a rotating frame and a second rotary table for driving the rotating frame to rotate are provided on the mounting bracket, the rotation axes of the mounting bracket and the rotating frame are orthogonal, a torque motor is provided on the rotating frame, a turntable is provided on the rotation axis of the torque motor, and a camera module fixture is provided on the turntable, the rotation axis of the camera module fixture is orthogonal to the rotation axis of the rotating frame.

[0011] In one specific embodiment, both the mounting bracket and the rotating frame are concave frames formed by a flat plate and side plates respectively perpendicularly arranged on both sides of the flat plate.

[0012] In one specific embodiment, the camera module fixture includes a base plate, a stage, and a clamping mechanism. The stage is disposed on the base plate, and the camera module to be tested is placed on the stage and located in the middle of the clamping mechanism. The clamping mechanism includes a side slider disposed on the side wall of the stage. A cylinder is disposed on the base plate to drive the side slider to slide along the height direction of the stage. A gripper is slidably disposed on the top of the side slider. The gripper is provided with an inclined guide groove. A fixed seat is disposed on the stage. A cam follower that cooperates with the inclined guide groove is disposed on the fixed seat. The gripper is driven by the cylinder to approach and clamp the camera module or to move away from and release the camera module under the cooperation of the inclined guide groove and the cam follower.

[0013] In one specific embodiment, a first slide rail is provided on the side wall of the platform, the first slide rail is arranged along the height direction of the platform, the side slider is slidably disposed on the first slide rail, a second slide rail is provided on the top of the side slider, the second slide rail is perpendicular to the platform, and the gripper is slidably disposed on the second slide rail.

[0014] In one specific embodiment, a connecting block is provided at the bottom of one side of the gripper, and the inclined guide groove is provided on the connecting block. The trajectory of the inclined guide groove includes an inclined section and a vertical section from bottom to top, and the inclined guide groove is a through groove.

[0015] This utility model has at least the following beneficial effects: by using a parallel light tube module to replace the traditional real-scene target, the space occupied by the equipment is greatly reduced, the equipment is miniaturized, and a four-axis stage is used to drive the camera module under test to acquire feature images from multiple angles, thereby achieving multi-angle test calibration accuracy and greatly improving test accuracy. Attached Figure Description

[0016] Figure 1 This is an overall structural diagram of an embodiment of the present utility model;

[0017] Figure 2 This is a structural diagram of a parallel light tube module in one embodiment of the present invention;

[0018] Figure 3 This is a structural diagram of a four-axis pendulum table in one embodiment of the present invention;

[0019] Figure 4 This is a structural diagram of the mounting bracket in one embodiment of the present invention;

[0020] Figure 5 This is a structural diagram of a camera module fixture in one embodiment of the present invention;

[0021] Figure 6This is an overall structural diagram of another embodiment of the present utility model.

[0022] Reference numerals: Equipment base plate 1, parallel light tube module 2, mounting plate 21, scale mark 211, arc-shaped guide groove 212, parallel light tube 22, four-axis swing table 3, first rotary table 31, mounting bracket 32, flat plate 321, side plate 322, rotating frame 33, second rotary table 34, torque motor 35, turntable 36, camera module fixture 37, base plate 371, platform 372, first slide rail 3721, side slider 374, second slide rail 3741, cylinder 375, gripper 376, inclined guide groove 3761, connecting block 3762, fixed seat 377, cam follower 378, X-axis linear module 4, Y-axis linear module 5, camera module 10. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0024] Example 1:

[0025] Please see Figures 1-2This utility model provides a miniaturized triangulation testing device, including a base plate 1. The base plate 1 is equipped with a collimator module 2, a four-axis pendulum stage 3, and a terminal analysis module (not shown in the figure). The collimator module 2 further includes a mounting plate 21 connected to the base plate 1 via a column (not shown in the figure). Three pairs of collimators 22 are symmetrically arranged on the mounting plate 21. The mounting plate 21 is a semi-circular plate, and its arc edge is marked with graduation marks 211, facilitating the quick and easy installation of the three pairs of collimators 22 to designated angle positions on the mounting plate 21. Two concentric arc-shaped guide grooves 212 are symmetrically arranged on the mounting plate 21. A pair of collimators 22 respectively engage with the two arc-shaped guide grooves 212, and the collimators 22 and the arc-shaped guide grooves 212 have relative sliding and relatively fixed states, thereby allowing the installation angle of the pair of collimators 22 to be adjusted for testing wide-angle camera modules and for adjusting the installation angle of the pair of collimators 22 according to the field of view of different wide-angle camera modules. The other two pairs of collimators 22 are completely fixed to the area between the two arc-shaped guide grooves 212 on the mounting plate 21 by bolts. In order to avoid interference, the two pairs of collimators 22 are completely fixed to two sides of the mounting plate 21 respectively, so that one pair of collimators 22 can be selected to test narrow-angle camera modules. The camera module 10 under test is fixed on the four-axis stage 3. The mounting plate 21 is set horizontally and located on one side of the four-axis stage 3. The four-axis stage 3 drives the camera module under test to acquire feature images of a pair of collimators 22 at multiple angles. The terminal analysis module calculates the intrinsic parameter calibration accuracy of the camera module under test 10 based on the intrinsic parameters of the camera module under test 10 and the acquired feature images.

[0026] In this embodiment, two sets of parallel light tube module 2 and quadrature stage 3 are set to improve testing efficiency.

[0027] It should be noted that the technology of the terminal analysis module to calculate the intrinsic parameter calibration accuracy of the camera module 10 under test based on the feature images acquired at each angle is an existing technology. Then, the intrinsic parameter calibration accuracy calculated at multiple angles is averaged through its built-in algorithm to obtain the final intrinsic parameter calibration accuracy.

[0028] For details, please refer to Figure 3In this embodiment, the four-axis stage 3 includes a first rotary table 31, a mounting bracket 32 ​​is provided on the rotating shaft of the first rotary table 31, a rotating frame 33 and a second rotary table 34 for driving the rotating frame 33 to rotate are provided on the mounting bracket 32, the rotation axes of the mounting bracket 32 ​​and the rotating frame 33 are orthogonally arranged, a torque motor 35 is provided on the rotating frame 33, a turntable 36 is provided on the rotating shaft of the torque motor 35, a camera module fixture 37 is provided on the turntable 36, the rotation axis of the camera module fixture 37 is orthogonally arranged with the rotation axis of the rotating frame 33, the camera module 10 can complete four degrees of freedom of movement under the drive of the four-axis stage 3, thereby realizing the acquisition of feature images of a pair of parallel light tubes 22 at multiple angles and improving the testing accuracy.

[0029] For details, please refer to Figure 4 In this embodiment, both the mounting bracket 32 ​​and the rotating frame 33 are concave frames constructed from a flat plate 321 and side plates 322 respectively vertically arranged on both sides of the flat plate 321. This concave frame structure design makes the overall structure of the four-axis swing table 3 very compact, further reducing the space occupied by the equipment.

[0030] For details, please refer to Figure 5 In this embodiment, the camera module fixture 37 includes a base plate 371, a stage 372 and a clamping mechanism. The stage 372 is disposed on the base plate 371, and the camera module 10 to be tested is placed on the stage 372 and located in the middle of the clamping mechanism. The clamping mechanism includes a side slider 374 disposed on the side wall of the stage 372, a cylinder 375 disposed on the base plate 371 to drive the side slider 374 to slide along the height direction of the stage 372, a gripper 376 slidably disposed on the top of the side slider 374, a slanted guide groove 3761 disposed on the gripper 376, a fixed seat 377 disposed on the stage 372, a cam follower 378 disposed on the fixed seat 377 to cooperate with the slanted guide groove 3761, and the gripper 376 is driven by the cylinder 375 to approach and clamp the camera module 10, or to move away from and release the camera module 10 under the cooperation of the slanted guide groove 3761 and the cam follower 378. The camera module fixture 37 has high structural reliability and stability. It adopts a cooperative structure of inclined guide groove 3761 and cam follower 378, which realizes that the movement direction of the gripper 376 is not in the same direction as the driving force direction, that is, it realizes spatial folding and reduces the space occupied by the overall structure of the camera module fixture 37.

[0031] For details, please refer to Figure 5In this embodiment, a first slide rail 3721 is provided on the side wall of the stage 372. The first slide rail 3721 is arranged along the height direction of the stage 372. The side slider 374 is slidably disposed on the first slide rail 3721. A second slide rail 3741 is provided on the top of the side slider 374. The second slide rail 3741 is perpendicular to the stage 372. The gripper 376 is slidably disposed on the second slide rail 3741. This slide rail structure design makes the movement of the gripper 376 more stable and reliable.

[0032] For details, please refer to Figure 5 In this embodiment, a connecting block 3762 is provided at the bottom of one side of the gripper 376, and an inclined guide groove 3761 is provided on the connecting block 3762. The trajectory of the inclined guide groove 3761 includes an inclined section and a vertical section from bottom to top. The inclined guide groove 3761 is a through groove. Compared with a blind hole groove, this through groove design is less prone to dust accumulation and is more convenient to clean and maintain.

[0033] Example 2:

[0034] Compared to Embodiment 1, the mounting plate 21 in this embodiment is vertically arranged and located above the four-axis swing table 3. This design reduces the space occupied by the device in the horizontal direction.

[0035] Example 3:

[0036] Compared to Embodiment 1, in this embodiment, the collimators 22 on the mounting plate 21 are completely fixed, and at least one pair of collimators 22 are provided. Although this design cannot adjust the angle of the collimators 22 to adapt to the field of view of the camera module 10 as needed, it can test camera modules 10 with known field of view.

[0037] Example 4:

[0038] Compared to Embodiment 1, in this embodiment, the mounting plate 21 has two concentric arc-shaped guide grooves 212 symmetrically arranged on it. A pair of collimators 22 respectively cooperate with the two arc-shaped guide grooves 212, and the collimators 22 and the arc-shaped guide grooves 212 have a relative sliding state and a relatively fixed state. That is to say, the mounting plate 21 is only provided with a pair of collimators 22 whose mounting angle can be adjusted according to the field of view of the camera module 10 under test. The adjustment range of the mounting angle of the collimators 22 covers the testing of both narrow-angle and wide-angle camera modules 10. This structure is very convenient to use, but the reliability of the collimators 22 after the angle is adjusted and then fixed must be ensured.

[0039] Example 5:

[0040] Please see Figure 6Compared to Embodiment 1, in this embodiment, the equipment base plate 1 is further provided with a Y-axis linear module 5, and the four-axis stage 3 is set on the drive block of the Y-axis linear module. This facilitates the adjustment of the working distance between the camera module 10 under test and the collimator 22 according to the design parameters of the collimator 22 during equipment debugging. The equipment base plate 1 is also provided with an X-axis linear module 4, and the drive block of the X-axis linear module 4 is provided with a loading and unloading robot. The loading and unloading robot is used to load the camera module 10 under test transferred from the previous machine onto the four-axis stage 3, and to transfer the camera module 10 that has completed testing on the four-axis stage 3 to the next machine. This achieves automated loading of the camera module 10 under test onto the four-axis stage 3 and automated transfer of the camera module 10 that has completed testing on the four-axis stage 3 to the next machine, thus achieving automated testing. The loading / unloading robot and the four-axis swing table 3 can move and dock in the Y direction. This can be achieved by driving the four-axis swing table 3 to move through the Y-axis linear module 5, or by setting the loading / unloading robot or the entire X-axis linear module 4 on another Y-axis linear module.

[0041] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions and substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A miniaturized triangulation testing device, characterized in that, The system includes a base plate (1), on which a collimator module (2), a four-axis stage (3), and a terminal analysis module are mounted. The collimator module (2) includes a mounting plate (21) connected to the base plate (1), on which at least one pair of collimators (22) are symmetrically arranged. The camera module (10) under test is fixed on the four-axis stage (3). The four-axis stage (3) drives the camera module (10) under test to acquire feature images of one pair of collimators (22) at multiple angles. The terminal analysis module calculates the intrinsic parameter calibration accuracy of the camera module (10) under test based on the intrinsic parameters of the camera module (10) under test and the acquired feature images.

2. The miniaturized triangulation testing device according to claim 1, characterized in that, The mounting plate (21) is a semi-circular plate, and the arc edge of the mounting plate (21) is provided with scale marks (211); the mounting plate (21) is horizontally set and located on one side of the four-axis swing table (3), or the mounting plate (21) is vertically set and located above the four-axis swing table (3).

3. The miniaturized triangulation testing device according to claim 2, characterized in that, The mounting plate (21) has two arc-shaped guide grooves (212) symmetrically arranged on it and concentric with the mounting plate (21). A pair of parallel light tubes (22) are respectively engaged with the two arc-shaped guide grooves (212), and the parallel light tubes (22) and the arc-shaped guide grooves (212) have a relatively sliding state and a relatively fixed state.

4. The miniaturized triangulation testing device according to claim 2 or 3, characterized in that, At least one pair of completely fixed parallel light tubes (22) are provided on the mounting plate (21).

5. The miniaturized triangulation testing device according to claim 1, characterized in that, The equipment base plate (1) is also provided with an X-axis linear module (4) and a Y-axis linear module (5). The drive block of the X-axis linear module (4) is provided with a loading and unloading robot. The four-axis swing table (3) is provided on the drive block of the Y-axis linear module (5). The loading and unloading robot is used to load the camera module (10) to be tested from the previous machine onto the four-axis swing table (3) and to transfer the camera module (10) that has been tested on the four-axis swing table (3) to the next machine.

6. The miniaturized triangulation testing device according to claim 1, characterized in that, The four-axis stage (3) includes a first rotating stage (31), a mounting bracket (32) is provided on the rotating shaft of the first rotating stage (31), a rotating frame (33) and a second rotating stage (34) for driving the rotating frame (33) to rotate are provided on the mounting bracket (32), the rotation axes of the mounting bracket (32) and the rotating frame (33) are arranged orthogonally, a torque motor (35) is provided on the rotating frame (33), a turntable (36) is provided on the rotating shaft of the torque motor (35), a camera module fixture (37) is provided on the turntable (36), and the rotation axis of the camera module fixture (37) is arranged orthogonally to the rotation axis of the rotating frame (33).

7. The miniaturized triangulation testing device according to claim 6, characterized in that, Both the mounting bracket (32) and the rotating frame (33) are concave frames formed by a flat plate (321) and side plates (322) respectively perpendicularly arranged on both sides of the flat plate (321).

8. The miniaturized triangulation testing device according to claim 6, characterized in that, The camera module fixture (37) includes a base plate (371), a stage (372), and a clamping mechanism. The stage (372) is disposed on the base plate (371), and the camera module (10) to be tested is placed on the stage (372) and located in the middle of the clamping mechanism. The clamping mechanism includes a side slider (374) disposed on the side wall of the stage (372). The base plate (371) is provided with a cylinder (375) for driving the side slider (374) to slide along the height direction of the stage (372). The top of the 74) is provided with a gripper (376), the gripper (376) is provided with an inclined guide groove (3761), the stage (372) is provided with a fixed seat (377), the fixed seat (377) is provided with a cam follower (378) that cooperates with the inclined guide groove (3761), the gripper (376) is driven by the cylinder (375) to approach and clamp the camera module (10) or move away from and release the camera module (10) under the cooperation of the inclined guide groove (3761) and the cam follower (378).

9. The miniaturized triangulation testing device according to claim 8, characterized in that, A first slide rail (3721) is provided on the side wall of the stage (372), the first slide rail (3721) is arranged along the height direction of the stage (372), the side slider (374) is slidably disposed on the first slide rail (3721), a second slide rail (3741) is provided on the top of the side slider (374), the second slide rail (3741) is perpendicular to the stage (372), and the gripper (376) is slidably disposed on the second slide rail (3741).

10. The miniaturized triangulation testing device according to claim 9, characterized in that, A connecting block (3762) is provided at the bottom of one side of the gripper (376), and the inclined guide groove (3761) is provided on the connecting block (3762). The trajectory of the inclined guide groove (3761) includes an inclined section and a vertical section from bottom to top, and the inclined guide groove (3761) is a through groove.

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