Lens batch detection device and detection method

Abstract

The application belongs to the technical field of optical device detection, and discloses a lens batch detection equipment and a detection method, which can quickly and automatically perform batch detection and recording on MTF values of a large number of to-be-detected lenses, and can realize accurate measurement and analysis on image-side focal length f, object-side focal length and illumination uniformity parameters of the to-be-detected lenses by integrating advanced image processing and data analysis algorithms in the equipment, so that the efficiency and accuracy of lens detection are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of optical device testing technology, and in particular to a lens batch testing device and testing method. Background Technology

[0002] In modern manufacturing, lens quality inspection is a crucial step in ensuring product quality and performance. Traditional lens quality inspection requires manual fine-tuning of the lens position to ensure a clear image of the test pattern on the target surface. Then, specific algorithms are used to detect indicators such as the lens's MTF value, focal length, and illuminance to control the lens's quality.

[0003] Because manufacturing errors in the lenses result in slight variations in the focal length of each lens, technicians must manually adjust the position of each lens individually, use a test pattern to create a clear image, and then measure and record the data for each lens using specialized equipment. This method is highly dependent on the skill level of the operators, leading to low inspection efficiency and a high false positive rate. Summary of the Invention

[0004] The purpose of this invention is to provide a lens batch inspection device with a simple structure and a high degree of automation.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A lens batch inspection device, comprising:

[0007] A material tray is mounted on a platform and can move along a first direction and a second direction. Multiple lenses to be tested are evenly spaced on the material tray along the first direction and the second direction. The first direction and the second direction are orthogonal and located on the same horizontal plane. The working surface of the lens to be tested faces downward and is exposed on the material tray.

[0008] An imaging assembly includes a CCD, a light source, and a pattern. The CCD is mounted on the platform, positioned below the material tray with its working surface facing upwards. The CCD is capable of moving vertically up and down. The light source is located above the material tray. The pattern includes a printed center target circle, a brightness circle, and an MTF bevel. The center of the center target circle coincides with the center of the pattern. The pattern is affixed to the side of the light source facing the material tray, with the center of the center target circle directly opposite the center of the CCD.

[0009] A detection system is provided, wherein the detection system is used to control the stepping of the material tray in the first direction and the second direction and the stepping of the CCD in the vertical direction, and the detection system is connected to the CCD for detecting the MTF, image-side focal length f, object-side focal length and illuminance uniformity of the lens under test.

[0010] Preferably, the lens batch inspection device further includes a bracket, which is mounted above the material tray, and the light source is located on the side of the bracket facing the material tray.

[0011] Preferably, the pattern is fully imaged onto the CCD.

[0012] Preferably, the lens batch inspection device further includes a driving assembly, which includes a first driving unit, a second driving unit, and a third driving unit. The first driving unit includes a first guide rail, a first driving component, and a slider. The first guide rail is mounted on the platform along the first direction, and the slider is slidably disposed on the first guide rail. The first driving component is used to drive the slider to slide. The second driving unit includes a second guide rail, a second driving component, and a support component. The second guide rail is connected to the slider along the second direction, and the support component is slidably disposed on the second guide rail. The second driving component is used to drive the support component to slide. The material tray is connected to the support component. The third driving unit includes a lifting platform, and the CCD is disposed on the lifting platform. The lifting platform is used to drive the CCD to move in the vertical direction. The first driving component, the second driving component, and the lifting platform are connected to the inspection system.

[0013] Preferably, the pattern is printed using film.

[0014] The purpose of this invention is to provide a method for batch inspection of lenses, which has high inspection efficiency and accuracy, and a high degree of automation.

[0015] To achieve this objective, the present invention adopts the following technical solution:

[0016] A method for batch inspection of lenses, using the aforementioned lens batch inspection equipment, includes the following steps:

[0017] S1. Install the aforementioned lens batch testing equipment;

[0018] S2. Solve the MTF curve of one of the lenses under test, and calculate the image-side focal length f, object-side focal length and illuminance uniformity of one of the lenses under test.

[0019] S3, Moving material tray;

[0020] S4. Repeat S2 and S3 until all the lenses to be tested have been tested.

[0021] Preferably, S2 includes:

[0022] S2.1. Set the height Z range of the CCD (21) to Z1-Z2, Z=LH, where L is the distance between the lens to be tested and the platform, and H is the distance between the lens to be tested and the CCD.

[0023] S2.2, Adjust the center of the working surface of one of the lenses under test to align with the center of the CCD;

[0024] S2.3 Control the CCD to move from top to bottom, and acquire an image once at a certain time interval t;

[0025] S2.4 Calculate the MTF curve of the lens under test;

[0026] S2.5 Record the height position of the CCD and calculate the sharpness value of the image acquired at the corresponding position to obtain the image-side focal length f of the lens under test;

[0027] S2.6 Calculate the object-side focal length of the lens under test based on the imaging size of the central target circle and the size of the patterns collected at different positions;

[0028] S2.7 Calculate the illuminance uniformity of the lens under test based on the grayscale change of the brightness circle.

[0029] Preferably, in section 2.1,

[0030] Z1=F0-D, Z2=F0+D, where F0 is the standard image-side focal length of a qualified lens, and D is the manufacturing tolerance of the lens under test.

[0031] Preferably, in section 2.5,

[0032] , where d n Let m be the sharpness at Z, where m is an integer greater than 1, and Z is the resolution at Z. opt The position with the best clarity;

[0033] The formula for calculating the image-side focal length f of the lens under test is: f = LZ opt L is the distance between the lens under test and the platform.

[0034] Preferably, S3 includes:

[0035] S3.1 Set the step size x of the material tray along the first direction, where x is the distance between two adjacent lenses to be tested in the first direction;

[0036] S3.2 Set the step size y of the material tray along the second direction, where y is the distance between two adjacent lenses to be tested in the second direction;

[0037] S3.3 Control the material tray to step x along the first direction or y along the second direction so that the center of the working surface of the other lens under test is aligned with the center of the CCD.

[0038] The beneficial effects of this invention are:

[0039] This invention provides a lens batch inspection device and method, which can quickly and automatically perform batch inspection and recording of MTF values ​​of a large number of lenses to be tested. By integrating advanced image processing and data analysis algorithms into the device, it can accurately measure and analyze the image-side focal length f, object-side focal length and illuminance uniformity parameters of the lenses to be tested, greatly improving the efficiency and accuracy of lens inspection. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a lens batch inspection device provided in Embodiment 1 of the present invention;

[0041] Figure 2 This is a flowchart of a batch lens inspection method provided in Embodiment 2 of the present invention.

[0042] In the picture:

[0043] 100. Lens under test; 200. Platform;

[0044] 1. Material tray; 21. CCD; 22. Support component; 23. Lifting platform; 24. Drawing; 25. Bracket. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0046] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0049] Example 1

[0050] This embodiment provides a lens batch inspection device that can quickly and automatically perform batch inspection and recording of MTF values ​​for a large number of lenses under test. By integrating advanced image processing and data analysis algorithms into the device, it can accurately measure and analyze the image-side focal length f, object-side focal length, and illuminance uniformity parameters of the lenses under test, greatly improving the efficiency and accuracy of the inspection.

[0051] Specifically, please refer to Figure 1 A batch lens inspection device includes a material tray 1, an imaging component, and an inspection system. The material tray 1 is used to carry a large number of lenses 100 to be tested. The imaging component is used to image through the lenses 100 to be tested. The inspection system is used to accurately measure the MTF, image-side focal length f, object-side focal length, and illuminance uniformity of the lenses 100 to determine whether the lenses 100 to be tested are qualified.

[0052] The material tray 1 is installed on the platform 200 and can move along the first direction and the second direction. Multiple lenses 100 to be tested are evenly spaced on the material tray 1 along the first direction and the second direction. The first direction and the second direction are orthogonal and on the same horizontal plane, that is, the first direction is the X-axis and the second direction is the Y-axis. Furthermore, the working surface of the lens 100 to be tested faces downward and is exposed on the material tray 1.

[0053] Furthermore, a lens batch inspection device also includes a drive assembly, which includes a first drive unit and a second drive unit. The first drive unit is used to drive the material tray 1 to move along a first direction, and the second drive unit is used to drive the material tray 1 to move along a second direction.

[0054] Further, the first driving unit includes a first guide rail, a first driving component, and a slider. The first guide rail is mounted on the platform 200 along a first direction, and the slider is slidably disposed on the first guide rail. The first driving component is used to drive the slider to slide. The second driving unit includes a second guide rail, a second driving component, and a support member 22. The second guide rail is connected to the slider along a second direction, and the support member 22 is slidably disposed on the second guide rail. The second driving component is used to drive the support member 22 to slide, and the material tray 1 is connected to the support member 22. The first driving component drives the slider to slide along the first guide rail, causing the support member 22 and the material tray 1 to move along the first direction. The second driving component drives the support member 22 to slide along the second guide rail, causing the material tray 1 to move along the second direction.

[0055] The imaging component includes CCD21, which is short for charge coupled device. It can convert light into electric charge and store and transfer the charge. It can also take out the stored charge to change the voltage. In this embodiment, CCD21 is mounted on platform 200 and is located below material tray 1. The working surface of CCD21 faces upward. Furthermore, CCD21 can move up and down in the vertical direction.

[0056] For example, the drive assembly also includes a third drive unit for driving the CCD 21 to move vertically. The third drive unit includes a lifting platform 23, on which the CCD 21 is disposed, and the lifting platform 23 is used to drive the CCD 21 to move vertically.

[0057] Furthermore, the imaging assembly also includes a light source and a pattern 24. The light source is located above the material tray 1. The pattern 24 is printed with a central target circle, a brightness circle, and an MTF bevel. The center of the central target circle coincides with the center of the pattern 24. The pattern 24 is attached to the side of the light source facing the material tray 1, and the center of the central target circle is directly opposite the center of the CCD 21.

[0058] Preferably, pattern 24 is printed using film.

[0059] It should be noted that before using this type of lens batch inspection equipment to inspect lenses, the light source, the first driving component, the second driving component, and the lifting platform 23 should be adjusted to ensure that the pattern 24 can be completely imaged on the CCD 21.

[0060] Optionally, a lens batch inspection device further includes a bracket 25, which is mounted above the material tray 1, and a light source is located on the side of the bracket 25 facing the material tray 1.

[0061] The detection system is connected to the first drive unit, the second drive unit and the lifting platform 23, thereby controlling the stepping of the material tray 1 in the first and second directions and the stepping of the CCD 21 in the vertical direction. Furthermore, the detection system is also connected to the CCD 21. The detection system integrates advanced image processing and data analysis algorithms to detect the MTF, image-side focal length f, object-side focal length and illuminance uniformity of the lens 100 under test.

[0062] Example 2

[0063] This embodiment provides a method for batch testing of lenses. By using the above-mentioned batch testing equipment, a large number of lenses to be tested can be batch tested, which has high testing efficiency and accuracy, and a high degree of automation.

[0064] For a method of batch inspection of lenses, please refer to [link / reference]. Figure 2 The testing process includes the following steps:

[0065] S1. Install a lens batch inspection device;

[0066] S2. Solve the MTF curve of one of the lenses under test 100, and calculate the image-side focal length f, object-side focal length and illuminance uniformity of one of the lenses under test 100.

[0067] S3, Moving material tray 1;

[0068] S4. Repeat S2 and S3 until all lenses under test are 100% complete.

[0069] Specifically, S1 includes: an integrated detection system, a drive assembly and a material tray 1 installed on the platform 200, and a CCD 21 fixed on the lifting platform 23. Preferably, the center of the material tray 1 and the center of the CCD 21 are aligned. The pattern 24 is printed on a film and flatly pasted onto the surface of the light source. The center of the target circle is adjusted to be aligned with the center of the CCD 21. The light source is fixed by the bracket 25. Further, the light source, the first drive component, the second drive component, and the lifting platform 23 are adjusted to ensure that the pattern 24 can be completely imaged on the CCD 21.

[0070] Furthermore, S2 includes:

[0071] S2.1. Set the height Z range of the CCD (21) to Z1-Z2, Z=LH, where L is the distance between the lens 100 under test and the platform 200, and H is the distance between the lens 100 under test and the CCD 21.

[0072] S2.2. Adjust the center of the working surface of one of the lenses under test 100 to align with the center of CCD 21;

[0073] S2.3 Control CCD21 to step from top to bottom, and acquire an image once at a certain time interval t;

[0074] S2.4 Calculate the MTF curve of the lens under test 100;

[0075] S2.5 Record the height position of CCD21 and calculate the sharpness value of the image acquired at the corresponding position to obtain the image-side focal length f of the lens 100 under test.

[0076] S2.6 Calculate the object-side focal length of the lens 100 under test based on the imaging size of the central target circle and the size of the pattern 24 collected at different positions.

[0077] S2.7 Calculate the illuminance uniformity of the lens under test 100 based on the grayscale change of the brightness circle.

[0078] In S2.1, Z1 and Z2 are determined based on the lens manufacturing tolerance and the standard image-side focal length of a qualified lens. Specifically, Z1 = F0 - D, Z2 = F0 + D, where F0 is the standard image-side focal length of a qualified lens and D is the manufacturing tolerance of the lens 100 under test.

[0079] Furthermore, the center of the working surface of one of the lenses 100 to be tested in the material tray 1 is aligned with the center of the CCD 21, and the CCD 21 is controlled to move from top to bottom by driving the lifting platform 23, and an image is acquired once at a certain time interval t.

[0080] The image processing algorithm of the detection system analyzes the MTF curves of the lens under test 100 at different positions to determine whether the item is qualified.

[0081] Furthermore, in version 2.5,

[0082] , where d n Let m be the sharpness at Z, where m is an integer greater than 1, and Z is the resolution at Z. opt The position with the best clarity;

[0083] The formula for calculating the image-side focal length f of the lens under test (100) is: f = LZ opt L is the distance between the lens 100 under test and the platform 200;

[0084] It should be noted that, based on the working characteristics of the lens under test 100, the sharpness d n The change in the height position Z of the CCD is a single-peak function. The centroid method can effectively calculate the independent variable value corresponding to the peak value of this type of function, and at the same time, it requires less calculation than the curve fitting method. In order to improve the effect of the centroid method on the sharpness d n Regarding the sensitivity to changes, this embodiment has been improved. In section 2.5,

[0085] , where d n Let m be the sharpness at Z, where m is an integer greater than 1, and Z is the resolution at Z. opt The position with the best clarity;

[0086] By adding a power calculation to the dependent variable, the sharpness d can be increased. n The variation between these values ​​makes the peaks sharper, thus improving clarity. n Optimal accuracy of location calculation;

[0087] Furthermore, the formula for calculating the image-side focal length f of the lens 100 under test is: f = LZ opt L represents the distance between the lens under test and the platform.

[0088] The object-side focal length of the lens under test is calculated based on the imaging size of the central target circle and the size of the pattern 24 collected at different positions.

[0089] The illuminance uniformity of the lens under test is calculated based on the grayscale changes of the brightness circle.

[0090] This completes the quality inspection of one of the lenses under test, number 100.

[0091] Furthermore, S3 includes:

[0092] S3.1 Set the step size x of the material tray 1 along the first direction, where x is the distance between two adjacent lenses 100 to be tested in the first direction;

[0093] S3.2 Set the step size y of the material tray 1 along the second direction, where y is the distance between two adjacent lenses 100 to be tested in the second direction;

[0094] S3.3 Control the material tray 1 to step x in the first direction or y in the second direction so that the center of the working surface of the other lens to be tested 100 is aligned with the center of CCD 21.

[0095] Preferably, before S3.1, the lifting shaft is driven to descend to avoid affecting the movement of the material tray 1 and causing it to collide with the lens under test 100.

[0096] Specifically, the material tray 1 is moved forward x in the first direction or y in the second direction to control the center of the working surface of the other lens under test 100 to be aligned with the center of the CCD 21. S2 and S3 are repeated until the testing of all lenses under test 100 is completed.

[0097] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A lens batch inspection device, characterized in that, include: Material tray (1), the material tray (1) is installed on platform (200) and can move along a first direction and a second direction. Multiple lenses to be tested (100) are evenly spaced on the material tray (1) along the first direction and the second direction. The first direction and the second direction are orthogonal and located on the same horizontal plane. The working surface of the lens to be tested (100) faces down and is exposed on the material tray (1). An imaging component, comprising a CCD (21), a light source, and a pattern (24), wherein the CCD (21) is mounted on the platform (200), positioned below the material tray (1) with its working surface facing upward, the CCD (21) is capable of moving up and down in the vertical direction, the light source is located above the material tray (1), the pattern (24) is printed with a center target circle, a brightness circle, and an MTF bevel, the center of the center target circle coincides with the center of the pattern (24), the pattern (24) is affixed to the side of the light source facing the material tray (1), and the center of the center target circle is directly opposite the center of the CCD (21); The detection system is used to control the stepping of the material tray (1) in the first direction and the second direction and the stepping of the CCD (21) in the vertical direction. The detection system is connected to the CCD (21) and is used to detect the MTF, image-side focal length f, object-side focal length and illuminance uniformity of the lens under test (100).

2. The lens batch inspection device according to claim 1, characterized in that, The lens batch inspection device also includes a bracket (25), which is mounted above the material tray (1), and the light source is located on the side of the bracket (25) facing the material tray (1).

3. The lens batch inspection device according to claim 1, characterized in that, The pattern (24) can be completely imaged onto the CCD (21).

4. The lens batch inspection device according to claim 1, characterized in that, The lens batch inspection equipment further includes a driving component, which includes a first driving unit, a second driving unit, and a third driving unit. The first driving unit includes a first guide rail, a first driving component, and a slider. The first guide rail is installed on the platform (200) along the first direction, and the slider is slidably disposed on the first guide rail. The first driving component is used to drive the slider to slide. The second driving unit includes a second guide rail, a second driving component, and a support component (22). The second guide rail is connected to the slider along the second direction, and the support component (22) is slidably disposed on the second guide rail. The second driving component is used to drive the support component (22) to slide. The material tray (1) is connected to the support component (22). The third driving unit includes a lifting platform (23). The CCD (21) is disposed on the lifting platform (23). The lifting platform (23) is used to drive the CCD (21) to move in the vertical direction. The first driving component, the second driving component, and the lifting platform (23) are connected to the inspection system.

5. The lens batch inspection device according to claim 1, characterized in that, The pattern (24) is printed using film.

6. A method for batch inspection of lenses, using the batch inspection equipment for lenses as described in claim 1, characterized in that, Includes the following steps: S1. Install the aforementioned lens batch testing equipment; S2. Solve the MTF curve of one of the lenses under test (100), and calculate the image-side focal length f, object-side focal length and illuminance uniformity of one of the lenses under test (100). S3, Moving material tray (1); S4. Repeat S2 and S3 until all the lenses to be tested (100) have been tested.

7. The method for batch inspection of lenses according to claim 6, characterized in that, S2 includes: S2.

1. Set the height Z range of the CCD (21) to Z1-Z2, Z=LH, where L is the distance between the lens (100) under test and the platform (200), and H is the distance between the lens (100) under test and the CCD (21); S2.2, Adjust the center of the working surface of one of the lenses under test (100) to align with the center of the CCD (21); S2.3 Control the CCD (21) to move from top to bottom, and acquire an image once at a certain time interval t; S2.4 Calculate the MTF curve of the lens (100) under test; S2.5 Record the height position of the CCD (21) and calculate the sharpness value of the image acquired at the corresponding position to obtain the image-side focal length f of the lens (100) under test; S2.6 Calculate the object-side focal length of the lens under test (100) based on the imaging size of the central target circle and the size of the patterns (24) collected at different positions; S2.7 Calculate the illuminance uniformity of the lens under test (100) based on the grayscale change of the brightness circle.

8. The method for batch inspection of lenses according to claim 7, characterized in that, In section 2.1, Z1=F0-D, Z2=F0+D, where F0 is the standard image-side focal length of a qualified lens, and D is the manufacturing tolerance of the lens (100) under test.

9. A method for batch inspection of lenses according to claim 7, characterized in that, In section 2.5, , where d n Let m be the sharpness at Z, where m is an integer greater than 1, and Z is the resolution at Z. opt The position with the best clarity; The formula for calculating the image-side focal length f of the lens under test (100) is: f = LZ opt L is the distance between the lens (100) under test and the platform (200).

10. A method for batch inspection of lenses according to claim 6, characterized in that, S3 includes: S3.1 Set the step size x of the material tray (1) along the first direction, where x is the distance between two adjacent lenses (100) to be tested in the first direction; S3.

2. Set the step size y of the material tray (1) along the second direction, where y is the distance between two adjacent lenses (100) to be tested in the second direction; S3.3 Control the material tray (1) to step x along the first direction or y along the second direction so that the center of the working surface of the other lens under test (100) is aligned with the center of the CCD (21).

Images