An analytical power testing device for a camera module

Abstract

The utility model discloses a kind of analytic power testing devices of camera module, it is related to camera module test field, including the machine body with mesa, mesa is equipped with clamping jig, clamping jig is fixed with the camera module to be measured, the side of mesa is fixed with stand, light source plate is slidably connected on stand, chart is equipped on light source plate, there is distance mirror between the camera module to be measured and chart, distance correction module is equipped on stand;Through the sliding of light source plate and chart relative to the camera module to be measured, Peak point, Tilt and field curvature of camera module are calculated according to test data, to quantify Tilt and field curvature, whether the analytic power of the camera module to be measured is caused by peak point, Tilt and field curvature can be analyzed, it is convenient to improve the front process of camera module, and simultaneously through distance mirror simulation far and near object distance, shorten the volume of test equipment, save space.

Description

Technical Field

[0001] This utility model relates to the field of camera module testing technology, and in particular to a camera module resolution testing device. Background Technology

[0002] Resolution testing of camera modules is typically used to evaluate their resolution, sharpness, and detail rendering capabilities. Camera resolution, also known as sharpness or clarity, reflects the camera's ability to reproduce the details of the scene being photographed. It is one of the important performance parameters reflecting camera quality; the higher the camera's resolution, the clearer the image. After the camera module is completed, resolution testing is necessary to verify the camera's shooting quality.

[0003] Chinese patent application number 202420552897.8 discloses a camera module resolution testing device, comprising: a machine base, a host, a moving mechanism, a test chart, and a 3D imaging device. The moving mechanism is mounted on the machine base, and the test chart is connected to the moving mechanism. The 3D imaging device is mounted on the machine base, with its lens facing the test chart to capture image information of multiple markers on the test chart. The host is connected to the 3D imaging device and the moving mechanism to obtain the 3D coordinates of the multiple markers based on their image information, compare them with preset coordinates to obtain an adjustment amount for the test chart, and then control the moving mechanism to move the test chart based on the adjustment amount. In this scheme, the test chart is obtained by... Figure 3 The three-dimensional coordinate position is determined, and the positional accuracy of the chart is automatically adjusted with the help of a three-axis moving platform to improve the centering accuracy of the chart and enhance the quality of resolution testing.

[0004] In the optical design and testing of camera modules, peak point, tilt, and field curvature are three important indicators that directly affect image quality and module optimization. In actual production, the poor resolution of FF modules (fixed lens, non-autofocus) requires specialized testing equipment to identify the peak position of resolution, tilt, and field curvature, etc., in order to guide improvements in the front-end manufacturing process. Existing equipment often can only measure resolution but cannot simultaneously quantify tilt and field curvature. Therefore, this utility model discloses a resolution testing device for camera modules to solve the above problems. Utility Model Content

[0005] Based on this, it is necessary to provide a resolution testing device for camera modules to address the aforementioned technical problems. By sliding the camera module under test against the light source plate and chart, the peak point, tip, and field curvature of the camera module are calculated based on the test data. This quantifies the tip and field curvature, enabling analysis to determine whether the poor resolution of the camera module under test is caused by the peak point, tip, and field curvature. This facilitates improvements in the front-end manufacturing process of the camera module. Simultaneously, by using a teleconverter to simulate near and far object distances, the size of the testing equipment is reduced, saving space.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A camera module resolution testing device includes a body with a table, a clamping fixture on the table, a camera module to be tested fixed on the clamping fixture, a stand fixed on one side of the table, a light source plate slidably connected to the stand and adjustable relative to the distance of the camera module to be tested, a chart on the light source plate, a teleconverter between the camera module to be tested and the chart, and a distance correction module on the stand for calibrating the initial object distance. A control screen is fixed on the table.

[0008] As a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the stand is provided with a vertical groove, a lead screw is movably connected in the vertical groove, the lead screw is driven and connected to a servo motor, a frame is fixedly connected to the outside of the light source plate, a protrusion is provided on the frame, the protrusion slides along the vertical groove, and the lead screw passes through the protrusion and is threadedly connected to the protrusion.

[0009] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the frame is provided with T-shaped blocks on both sides of the protrusion, the stand is provided with T-shaped grooves, and the T-shaped blocks slide along the T-shaped grooves.

[0010] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the T-shaped groove and the vertical groove are both connected from the top surface of the stand, the top surface of the stand is provided with a cover plate, and the servo motor is mounted on the cover plate.

[0011] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the calibration module is a photoelectric sensor, which is fixed on the side of the stand, and the frame is provided with a reflector that matches the photoelectric sensor.

[0012] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the stand is fixed with a scale along the sliding direction of the light source plate.

[0013] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, a side support is fixed on the upright frame, the side support is fixedly connected to the upright frame by bolts, a fixing ring is provided on the side support, a locking member is provided on the fixing ring, and the teleconverter is located inside the fixing ring and fixed by the locking member.

[0014] As a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the side of the stand is provided with a plurality of equally spaced screw holes, and the bolts are threadedly connected to the screw holes.

[0015] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the center of the chart, the central axis of the teleconverter, and the central axis of the camera module under test are on the same straight line.

[0016] In a preferred embodiment of the resolution testing device for the camera module provided by this utility model, the chart is an MTF drawing or a checkerboard drawing.

[0017] Compared with the prior art, the present invention has the following advantages: The resolution testing device for camera modules provided by the present invention slides the camera module under test in conjunction with the light source plate and the chart, and calculates the peak point, tip, and field curvature of the camera module based on the test data, thereby quantifying the tip and field curvature. It can analyze whether the poor resolution of the camera module under test is caused by the peak point, tip, and field curvature, which facilitates the improvement of the front-end process of the camera module. At the same time, the teleconverter simulates the distance between near and far objects, shortens the size of the testing equipment, and saves space. Attached Figure Description

[0018] To more clearly illustrate the solutions in this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A three-dimensional schematic diagram of the overall structure of the resolution testing device for the camera module provided by this utility model;

[0020] Figure 2 A front view of the overall structure of the resolution testing device for the camera module provided by this utility model;

[0021] Figure 3 A side view of the overall structure of the resolution testing device for the camera module provided by this utility model.

[0022] The markings in the diagram are explained as follows:

[0023] 1. Machine body; 2. Table; 3. Clamping fixture; 4. Camera module; 5. Stand; 6. Light source board; 7. Chart; 8. Teleconverter; 9. Control panel; 10. Vertical slot; 11. Lead screw; 12. Servo motor; 13. Frame; 14. Protrusion block; 15. T-block; 16. T-slot; 17. Cover plate; 18. Photoelectric sensor; 19. Reflector; 20. Scale; 21. Side support frame; 22. Bolt; 23. Fixing ring; 24. Locking element; 25. Screw hole. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0025] As described in the background section, peak point, tilt, and field curvature are three important indicators in the optical design and testing of camera modules, directly affecting image quality and module optimization. In actual production, for the problem of poor resolution in FF modules (fixed lens, non-autofocus), it is necessary to use specialized testing equipment to find the peak position of resolution, tilt, and field curvature, etc., in order to guide the improvement of the front-end process. Existing equipment can often only measure resolution, but it is difficult to quantify tilt and field curvature at the same time.

[0026] To address this technical problem, this invention provides a camera module resolution testing device, which is applied in the field of camera module testing.

[0027] For details, please refer to Figure 1-3 The resolution testing device for the camera module specifically includes a body 1 with a platform 2, a clamping fixture 3 on the platform 2, a camera module 4 to be tested fixed on the clamping fixture 3, a stand 5 fixed on one side of the platform 2, a light source plate 6 slidably connected to the stand 5, which is capable of adjusting the distance to the camera module 4 to be tested, a chart 7 on the light source plate 6, a teleconverter 8 between the camera module 4 to be tested and the chart 7, and a distance correction module on the stand 5 for calibrating the initial object distance, and a control screen 9 fixed on the platform 2.

[0028] The resolution testing device for the camera module 4 provided by this utility model calculates the peak point, tip, and field curvature of the camera module 4 based on the sliding of the light source plate 6 and the chart 7 relative to the camera module 4 under test, thereby quantifying the tip and field curvature. This allows analysis to determine whether the poor resolution of the camera module 4 under test is caused by the peak point, tip, and field curvature, facilitating improvements in the front-end manufacturing process of the camera module 4. At the same time, the teleconverter 8 simulates the distance between near and far objects, shortening the size of the testing equipment and saving space.

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] Example 1

[0033] Please refer to Figure 1-3A resolution testing device for a camera module 4 is provided, comprising a body 1 with a platform 2, the body 1 being an integral support device containing a testing unit (a conventional structure not described in detail here). A clamping fixture 3 is provided on the platform 2, and a camera module 4 to be tested is fixed on the clamping fixture 3. The camera module 4 is a front-facing (FF) module with a fixed lens. After being mounted on the clamping fixture 3, the camera module 4 is electrically connected to the testing unit. The clamping fixture 3 is a conventional structure. A stand 5 is fixed to one side of the platform 2, and a light source plate 6, adjustable in distance to the camera module 4, is slidably connected to the stand 5. A chart 7 is provided on the light source side of the light source plate 6, close to the camera module 4, ensuring uniform light reception of the chart 7. A teleconverter 8 is provided between the camera module 4 and the chart 7, and the teleconverter 8 is fixed to the stand 5. The stand 5 is equipped with a distance correction module for calibrating the initial object distance and for calibrating the reference distance of the measurement platform before testing. It also includes a data acquisition and processing unit, which is located inside the body 1. The data acquisition and processing unit includes a resolving force measurement device, an image acquisition module, and a calculation and processing module. The structure of this module is a conventional structure that can be directly applied by those skilled in the art and will not be described in detail here. The data acquisition and processing unit is connected to the camera module 4 under test and is used to acquire the image of chart 7 and analyze the MTF data. Specifically, after the image acquisition module acquires the image of chart 7, it calculates the MTF curve and finds the peak position to obtain the peak point. Based on the peak deviation of different test positions, the tip angle and field curvature of the camera module 4 under test can be calculated. A control screen 9 is fixed on the table 2. The touch screen is used to display the test data in real time and to adjust the object distance.

[0034] Furthermore, the support frame 5 is provided with a vertical groove 10, and a lead screw 11 is movably connected in the vertical groove 10. The lead screw 11 is connected to the servo motor 12 for transmission. A frame 13 is fixedly connected to the outside of the light source plate 6. A protrusion 14 is provided on the frame 13. The protrusion 14 slides along the vertical groove 10, and the lead screw 11 passes through the protrusion 14 and is threadedly connected to the protrusion 14. The lead screw 11 is connected to the protrusion 14 through a threaded sleeve. The servo motor 12 drives the lead screw 11 to rotate, which drives the frame 13 to move, thereby driving the light source plate 6 and the chart 7 to move up and down in the vertical direction. The resolution of the camera module 4 is tested every time the light source plate 6 and the chart 7 move up and down a certain distance. The pitch of the lead screw 11 is 1mm.

[0035] Furthermore, T-shaped blocks 15 are provided on both sides of the protrusion 14 in the frame 13, and T-shaped grooves 16 are provided on the upright 5. The T-shaped blocks 15 slide along the T-shaped grooves 16. When the frame 13 moves up and down, the T-shaped blocks 15 slide along the T-shaped grooves 16, which can ensure the levelness and stability of the frame 13 during movement and avoid movement deviation, thus affecting the test accuracy. The T-shaped grooves 16 and the vertical grooves 10 are connected from the top surface of the upright 5. The top surface of the upright 5 is provided with a cover plate 17, and the servo motor 12 is mounted on the cover plate 17, which facilitates the placement of the T-shaped blocks 15 in the T-shaped grooves 16 and facilitates the threaded connection between the protrusion 14 and the lead screw 11.

[0036] The calibration module is a photoelectric sensor 18, which is fixed on the side of the stand 5. The frame 13 is provided with a reflector 19 that matches the photoelectric sensor 18. The photoelectric sensor 18 is used to calibrate the reference distance of the measurement platform before the test to ensure that the object distance is consistent in each test. The stand 5 is fixed with a scale 20 along the sliding direction of the light source plate 6. The scale 20 is embedded in the side of the stand 5 and is used to calibrate the object distance before each test.

[0037] Example 2

[0038] The resolution testing device for the camera module 4 provided in Embodiment 1 is further optimized, specifically, as follows: Figure 1-3 As shown, a side support frame 21 is fixed on the support frame 5. The side support frame 21 is fixedly connected to the side of the support frame 5 by bolts 22. A fixing ring 23 is provided on the side support frame 21. A flexible pad, such as a cotton layer or a rubber layer, is provided on the inner wall of the fixing ring 23 to protect the teleconverter 8. A locking member 24 is provided on the fixing ring 23. The teleconverter 8 is placed inside the fixing ring 23 and fixed by the locking member 24. The locking member 24 can be a hand-tightening screw. By using the contact between the locking member 24 and the teleconverter 8, the purpose of fixing the teleconverter 8 is greatly enhanced. The purpose of adding the teleconverter 8 is to shorten a very long distance, such as simulating infinity to 10cm. When converting to object distance, the chart needs to be adjusted. The actual physical distance is replaced with the physical distance simulated by the teleconverter 8. By replacing the teleconverter 8, the distance between objects of different lengths can be adjusted. Several equally spaced screw holes 25 are provided on the side of the support frame 5. The screw holes 25 are distributed on both sides of the side support frame 21 and are equally spaced along the height direction of the support frame 5. The bolts 22 are threaded to the screw holes 25. The multiple screw holes 25 can be used to adjust the installation position of the teleconverter 8 and further adjust the distance between objects.

[0039] Example 3

[0040] The resolution testing device for the camera module 4 provided in Embodiment 2 is further optimized, specifically, as follows: Figure 1-3As shown, the center of chart 7, the central axis of teleconverter 8, and the central axis of the camera module 4 under test are on the same straight line. They remain on the same straight line as chart 7 moves, ensuring the uniformity of the test position. At the same time, chart 7 is an MTF chart or a checkerboard chart. MTF charts and checkerboard charts will not cause fluctuations in the test position due to the distance between chart 7 and the camera module 4 under test, thus ensuring the accuracy of the test.

[0041] The working principle of the resolution testing device for the camera module 4 provided by this utility model is as follows: Before testing, the photoelectric sensor 18 in the distance correction module is used to determine the initial object distance. Then, the servo motor 12 drives the lead screw 11 to rotate, which in turn drives the light source plate 6 and the chart 7 in the frame 13 to move up and down. After moving a certain distance, the resolution of the camera module 4 is tested. The teleconverter 8 can shorten a very long distance, simulating infinity to a short distance. When converting to object distance, the actual physical distance in the chart 7 should be replaced with the physical distance simulated by the teleconverter 8. After the data acquisition and processing unit acquires the image of the chart 7, the MTF curve is calculated and the peak position is obtained. Based on the peak deviation of different test positions, the tilt angle and field curvature of the camera module 4 under test can be calculated, thereby quantifying the tilt and field curvature. It is possible to analyze whether the poor resolution of the camera module 4 under test is caused by the peak point, tilt, and field curvature, which is conducive to improving the front-end process of the camera module 4.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A camera module resolution testing device, comprising a body having a platform, wherein a clamping fixture is provided on the platform, and a camera module to be tested is fixed on the clamping fixture, characterized in that, A stand is fixed to one side of the platform, and a light source plate that can adjust the distance to the camera module under test is slidably connected to the stand. A chart is provided on the light source plate, and a teleconverter is provided between the camera module under test and the chart. A distance correction module is provided on the stand for calibrating the initial object distance. A control screen is fixed on the platform.

2. The resolution testing device for a camera module according to claim 1, characterized in that, The support frame is provided with a vertical groove, and a lead screw is movably connected in the vertical groove. The lead screw is driven by a servo motor. A frame is fixedly connected to the outside of the light source board. A protrusion is provided on the frame. The protrusion slides along the vertical groove, and the lead screw passes through the protrusion and is threadedly connected to the protrusion.

3. The resolution testing device for a camera module according to claim 2, characterized in that, The frame has T-shaped blocks on both sides of the protrusion, and the upright has T-shaped grooves, along which the T-shaped blocks slide.

4. The resolution testing device for a camera module according to claim 3, characterized in that, The T-shaped groove and the vertical groove are connected from the top surface of the upright, and the top surface of the upright is provided with a cover plate, on which the servo motor is mounted.

5. The resolution testing device for a camera module according to claim 2, characterized in that, The calibration module is a photoelectric sensor, which is fixed to the side of the stand, and the frame is provided with a reflector that matches the photoelectric sensor.

6. The resolution testing device for a camera module according to claim 5, characterized in that, The support frame is fixed with a scale along the sliding direction of the light source plate.

7. The resolution testing device for a camera module according to claim 1, characterized in that, A side support frame is fixed on the upright frame. The side support frame is fixedly connected to the upright frame by bolts. A fixing ring is provided on the side support frame. A locking element is provided on the fixing ring. The teleconverter is located inside the fixing ring and is fixed by the locking element.

8. The resolution testing device for a camera module according to claim 7, characterized in that, The side of the support frame is provided with several equally spaced screw holes, and the bolts are threadedly connected to the screw holes.

9. The resolution testing device for a camera module according to claim 1, characterized in that, The center of the chart, the central axis of the teleconverter, and the central axis of the camera module under test are on the same straight line.

10. The resolution testing device for a camera module according to claim 1, characterized in that, The chart is an MTF chart or a checkerboard chart.

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