Turning lens testing method and system

Abstract

According to the turning lens test method and system provided by the invention, a collimator can rotate in a rotation plane by taking an entrance pupil point of a to-be-tested turning lens as a center, and the rotation plane can rotate around an incident optical axis of the to-be-tested turning lens, so that measurement of any field of view point is realized, and a detection lens can realize three-axis high-precision movement, so that the detection precision is improved. The objective of detecting the whole image surface and performing out-of-focus detection on any view field point is achieved, the measurement problem of a non-rotational symmetry optical system can be solved, and various optical specifications of the bent lens can be effectively detected.

Description

Technical Field

[0001] This application relates to the field of lens inspection, specifically to a testing method and system for a tilting lens. Background Technology

[0002] After the optical lens is assembled, its optical performance parameters need to be tested, such as effective focal length, relative illumination, distortion, transfer function, principal ray angle, and defocus parameters. These parameters are tested using optical testing equipment.

[0003] Most optical lenses are designed as circular cylindrical shapes with a single optical axis, belonging to rotationally symmetric systems. Therefore, current optical lens testing equipment on the market is also designed around rotationally symmetric systems to meet the testing needs of most optical systems. For example, there is a lens testing device with publication number CN208953254U, and a testing platform for wide-angle lens ring testing with publication number CN108036924A.

[0004] like Figure 1 The existing detection equipment structure shown rotates in a single plane around the entrance pupil of the lens via a collimator (rotation path is...). Figure 1 The red dashed line represents the field of view. The center point is 0°, and the two ends represent the positive and negative field limits (typically ±105°), used for measuring different field points. The testing principle is as follows: Figure 2 The collimator 2 images the target to infinity, and then the lens under test 1 images the target onto the image plane P. The image is analyzed by the detection lens 3 and the camera (not shown), thereby achieving the purpose of optical detection.

[0005] In addition to the inspection lens and camera, the inspection system of the inspection equipment also includes a two-axis motorized displacement stage for moving the position of the inspection lens. Figure 1 The displacement direction is distinguished by "left and right" and "front and back". During the test, after the collimator rotates, the image position of the target on the image plane of the lens under test will also change accordingly (see...). Figure 2 In the process, when the collimator is rotated to a specific objective lens angle α, the imaging position will be at a specific image height H. At this time, the detection lens needs to move left and right to align with the imaging position. This process also measures the relationship between the field of view and the image height. In addition, after aligning the image, the detection lens 3 also needs to move back and forth to accurately focus and find a sharp image plane. This process is also a way to measure the defocus parameters.

[0006] Clearly, the rotational trajectory of the collimator corresponds to a horizontal line on the image plane of the lens under test. However, the actual image plane of the lens is a circular area (called the image circle). This means that rotating the collimator can only measure a single diameter on the image circle. Measurements of other areas on the image circle beyond this diameter are achieved by utilizing the lens's rotational symmetry, specifically by rotating the lens itself. For example, rotating the lens 90° around its optical axis allows for the measurement of diameters orthogonal to the current direction.

[0007] However, there are some special applications that require optical lenses to be designed in a non-straight shape, such as right-angle bent lenses. In such systems, the optical axis is reversed (here, the two optical axes before and after the reversal are distinguished as "incident optical axis" and "outcrystal optical axis"), causing the entire system to lose its rotational symmetry.

[0008] When the lens under test is changed to a right-angle tilting lens, the existing equipment is no longer applicable, mainly due to the following problems: 1. Existing detection equipment can only move the detection lens in two dimensions. Scanning the entire image circle requires the use of the lens's rotational symmetry. However, right-angle turning lenses do not have this characteristic and require three-dimensional movement to measure the entire image circle. 2. The optical axes of the existing testing lens and the lens under test are parallel, but the optical axis of the right-angle turning lens is turned, so the optical axis of the testing lens needs to be parallel to the output optical axis of the turning lens; 3. Existing detection equipment's collimator can only rotate within a single plane, and its trajectory forms a horizontal line on the image plane. Measurement of the entire image plane depends on the rotational symmetry of the lens. However, right-angle turning lenses do not possess rotational symmetry; therefore, for measurement of the entire image plane, the collimator's rotation trajectory itself needs to cover the entire hemisphere. Therefore, existing testing systems on the market cannot test such right-angle bent lenses. Currently, the industry lacks effective testing methods for bent lenses, and there is an urgent need to develop a testing device capable of effectively testing the various optical specifications of bent lenses. Summary of the Invention

[0009] The purpose of this invention is to design a highly flexible optical inspection system that can be used for testing bent lenses, and to solve the measurement problem of non-rotationally symmetric optical systems.

[0010] The technical solution adopted in this application is as follows: A testing system for a tilting lens includes at least a collimator module and a test lens module disposed on one side of the tilting lens. The collimator module is used to drive the collimator to rotate in a rotation plane with the entrance pupil of the lens under test as the center, and to drive the collimator to rotate around the incident optical axis of the lens under test. The detection lens module can move the detection lens in the XYZ three-axis direction in space. After the collimator rotates, it moves the detection lens relative to the lens under test to the imaging position aligned with the image plane of the lens under test, and moves the lens under test relative to the lens under test for focusing.

[0011] Another objective of this application is to provide a method for testing transition shots, comprising the following steps: The collimator rotates in the plane of rotation with the entrance pupil of the lens to be tested as the center. The collimator rotates around the incident optical axis of the lens under test. After the collimator is rotated, the detection lens is moved relative to the lens under test and positioned to align with the image plane of the lens under test. Move the lens to be tested relative to the lens to be tested for focusing.

[0012] Compared with the prior art, the beneficial effects of this application are as follows: This application provides a testing method and system for bending lenses. The collimator can rotate in a rotation plane with the entrance pupil of the bending lens under test as the center. At the same time, the rotation plane itself can also rotate around the incident optical axis of the bending lens under test, so as to realize measurement at any field of view. The testing lens can realize high-precision three-axis movement to achieve the purpose of detecting the entire image plane and detecting defocus at any field of view. This invention can solve the measurement problem of non-rotationally symmetric optical systems and can effectively test various optical specifications of bending lenses. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0014] Figure 1 This is a schematic diagram of the principle of existing testing equipment; Figure 2 This is a schematic diagram of the testing principle of existing testing equipment; Figure 3 This is a schematic diagram of the principle of a test system for a tilting lens according to this application; Figure 4 This is a schematic diagram of the frame of the collimator module of this application; Figure 5 This is a schematic diagram of the frame of the lens module tested in this application; Figure 6 This is a schematic diagram of another embodiment of the detection lens module of this application; In the diagram: lens under test 1, collimator 2, detection lens 3, lens under test 4, collimator module 5, first rotation mechanism 51, second rotation mechanism 52, first lifting mechanism 53, detection lens module 6, three-axis displacement stage 61, second lifting mechanism 62, two-dimensional displacement stage 63, lens entrance pupil point O, collimator rotation path O1 around the lens entrance pupil point, incident optical axis I, collimator rotation path I1 around the incident optical axis, and exit optical axis E. Detailed Implementation

[0015] This application provides a testing system for a tilting lens, comprising at least a collimator module 5 and a testing lens module 6 disposed on one side of the tilting lens. The collimator module 5 is used to drive the collimator 2 to rotate in the rotation plane with the entrance pupil point of the lens 4 to be tested as the center, and to drive the collimator 2 to rotate around the incident optical axis of the lens 4 to be tested. The detection lens module 6 can move the detection lens 3 in the XYZ three-axis direction in space. After the collimator 2 is rotated, the detection lens 3 is moved relative to the test lens 4 to the imaging position on the image plane of the test lens 4, and the test lens 4 is moved relative to the test lens 4 for focusing.

[0016] A method for testing transition shots includes the following steps: S1. Drive the collimator 2 to rotate in the plane of rotation with the entrance pupil point of the lens 4 to be tested as the center. S2, drives the collimator 2 to rotate around the incident optical axis of the lens 4 to be tested; S3. After the collimator 2 is rotated, the detection lens 3 is moved relative to the test lens 4 to the imaging position on the image plane of the test lens 4. S4. Move the lens to be tested 4 relative to the lens to be tested 4 to focus.

[0017] This application provides a testing system and method for a tilting lens. The collimator can rotate in a rotation plane with the entrance pupil of the tilting lens under test as the center. At the same time, the rotation plane itself can also rotate around the incident optical axis of the tilting lens under test, so as to realize measurement at any field of view. The detection lens can realize high-precision three-axis movement to achieve the purpose of detecting the entire image plane and detecting defocus at any field of view. This invention can solve the measurement problem of non-rotationally symmetric optical systems.

[0018] Furthermore, the collimator module 5 includes a collimator 2, a first rotation mechanism 51, and a second rotation mechanism 52. The first rotation mechanism 51 drives the collimator 2 to rotate within a rotation plane around the entrance pupil point of the lens 4 under test. The second rotation mechanism 52 drives the collimator 2 to rotate around the incident optical axis of the lens 4 under test. This application not only allows the collimator 2 to rotate around the sample to obtain data from different fields of view, but also allows the rotation plane of the collimator 2 to rotate around the sample to rotate around the 0° optical axis of the collimator 2, enabling measurement at any point in the field of view. In contrast, existing products can only achieve rotation of the collimator 2 around the sample, but cannot achieve rotation of the rotation plane, thus only enabling one-dimensional field-of-view measurement and not measurement of any point on the two-dimensional image plane.

[0019] Specifically, the first rotating mechanism 51 and the second rotating mechanism 52 are driven by a rotary motor, and the first rotating mechanism 51 and the second rotating mechanism 52 are mounted on... Figure 3 The collimator 2, located on the upper and lower sides of the C-shaped support, can rotate within a rotation plane centered on the entrance pupil point O of the lens under test. Specifically, the objective lens angle at the middle position of the rotation plane is 0°, and the collimator 2 rotates along a path O1 centered on the entrance pupil point O, with the positive and negative field limits at its two ends, typically ±105°. Simultaneously, the rotation plane itself can also rotate around the incident optical axis I of the lens under test (via...). Figure 3 The C-shaped support structure is used to achieve the rotation path of the collimator 2 around the incident light axis as I1, with positive and negative rotation limits of ±90°, enabling measurement at any field of view point.

[0020] More preferably, the collimator module 5 further includes a first lifting mechanism 53 for driving the collimator 2 up and down. The first lifting mechanism 53 is used to adjust the rotation center of the first rotating mechanism 51 to the entrance pupil of the lens 4 under test. This invention can solve the measurement problem of non-rotationally symmetric optical systems. In contrast, existing testing equipment has limitations and can only test rotationally symmetric systems.

[0021] Furthermore, the inspection lens module 6 includes a three-axis displacement stage 61 and an inspection lens 3 mounted on the three-axis displacement stage 61. The three-axis displacement stage 61 is used to move the inspection lens 3 in the XYZ three-axis directions in space. The inspection lens 3, mounted on the three-dimensional displacement stage, can achieve high-precision XYZ three-axis movement (the three axes are mutually orthogonal), achieving the purpose of inspecting the entire image plane and detecting defocus at any point in the field of view. The inspection lens module 6 of this application has three-dimensional displacement capabilities, enabling three-dimensional traversal of the image space, meeting the inspection requirements of bent lenses. In contrast, existing products only have two-dimensional displacement capabilities, only enabling two-dimensional scanning of the image space, and cannot meet the inspection requirements of non-rotationally symmetric optical systems.

[0022] As another implementation scheme, the electric displacement stage (displacement direction: up and down) of the detection system can also be replaced by a lifting stage, which can then serve as a support platform for the two-dimensional displacement stage 63 and be installed below the two-dimensional displacement stage 63. The detection lens module 6 includes a second lifting mechanism 62, a two-dimensional displacement stage 63 disposed on the second lifting mechanism 62, and a detection lens 3 disposed on the two-dimensional displacement stage 63. The two-dimensional displacement stage 63 is used to drive the detection lens 3 to move in the XY axis direction, and the second lifting mechanism 62 is used to drive the two-dimensional displacement stage 63 to move in the Z axis direction.

[0023] Specifically, the 0° optical axis of the collimator 2 always coincides with the incident optical axis of the bending lens 4 under test (even if the rotating plane of the collimator 2 is rotated to other angles, the 0° direction remains unchanged), and the exit optical axis of the bending lens 4 under test is parallel to the optical axis of the detection lens 3, in order to match the incident and exit characteristics of the right-angle bending lens, ensuring that the image is always within the field of view of the detection lens 3, thus enabling detection. In contrast, when the optical axis of the existing product detection system and the collimator 2 are at 0°, the optical axes coincide, which is suitable for conventional straight lenses, but not for right-angle bending lenses.

[0024] In a preferred embodiment, the lens under test is mounted on a lens fixture, which is in turn mounted on a five-dimensional adjustment frame (the lens fixture and the five-dimensional adjustment frame are not shown in the figure). This supports the degrees of freedom for measuring right-angle turning lenses. The lens stage has a multi-degree-of-freedom adjustment frame (five-dimensional), which can be flexibly aligned with the collimator 2 and the detection platform, allowing for rapid measurement when switching between different specifications of right-angle turning lenses. In contrast, existing products typically only offer three-dimensional or four-dimensional adjustment, which can only meet the measurement needs of rotationally symmetric systems and cannot meet the measurement needs of non-rotationally symmetric systems. Specifically, this includes the lens fixture structure, the specific structure of the electric displacement stage, the lifting mechanism of the collimator 2, the camera mounted on the detection lens 3, and the structural components of the detection system. It should be noted that for those skilled in the art, the above structures are common components in the field, and omitting these structures will not hinder the realization of the present invention.

[0025] This device can measure most parameters that are measurable by existing equipment, including but not limited to effective focal length, relative illumination, distortion, transfer function, principal ray angle, defocus parameters, and other indicators.

[0026] The technical solution of the present invention is not limited to right-angle bending lenses. Other angle bending lenses can also be implemented with minor modifications based on the technical principle of the present invention. That is, it is only necessary to ensure that the optical axis of the detection lens 3 is aligned with the output optical axis of the bending lens according to the actual bending angle.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A testing system for a tilting lens, characterized in that: It includes at least a collimator module and a detection lens module located on one side of the turning lens: The collimator module is used to drive the collimator to rotate in a rotation plane with the entrance pupil of the lens under test as the center, and to drive the collimator to rotate around the incident optical axis of the lens under test. The detection lens module can move the detection lens in the XYZ three-axis direction in space. After the collimator rotates, it moves the detection lens relative to the lens under test to the imaging position aligned with the image plane of the lens under test, and moves the lens under test relative to the lens under test for focusing.

2. The testing system for a tilting lens according to claim 1, characterized in that: The parallel light tube module includes: collimator; The first rotating mechanism is used to drive the collimator to rotate in the rotating plane with the entrance pupil point of the lens to be tested as the center. The second rotating mechanism is used to drive the collimator to rotate around the incident optical axis of the lens to be tested.

3. The testing system for a tilting lens according to claim 2, characterized in that: The collimator module also includes a first lifting mechanism for driving the collimator up and down. The first lifting mechanism is used to adjust the rotation center of the first rotating mechanism to the entrance pupil of the lens to be tested.

4. The testing system for a tilting lens according to claim 1, characterized in that: The inspection lens module includes a three-axis displacement stage and an inspection lens mounted on the three-axis displacement stage. The three-axis displacement stage is used to drive the inspection lens to move in the XYZ three-axis directions in space.

5. The testing system for a tilting lens according to claim 1, characterized in that: The detection lens module includes a second lifting mechanism, a two-dimensional displacement stage mounted on the second lifting mechanism, and a detection lens mounted on the two-dimensional displacement stage. The two-dimensional displacement stage is used to move the detection lens in the XY axis direction, and the second lifting mechanism is used to move the two-dimensional displacement stage in the Z axis direction.

6. The testing system for a tilting lens according to claim 1, characterized in that: The 0° optical axis of the collimator always coincides with the incident optical axis of the lens under test.

7. The testing system for a tilting lens according to claim 1, characterized in that: The optical axis of the lens under test is parallel to the optical axis of the lens being tested.

8. The testing system for a tilting lens according to claim 1, characterized in that: The positive and negative limits of the parallel light tube's rotation around the incident optical axis of the lens under test are ±90°.

9. The testing system for a tilting lens according to claim 1, characterized in that: The objective lens angle at the center of the rotation plane is 0°, with the positive and negative field limits at the two ends, typically ±105°.

10. A method for testing a tilting camera lens, characterized in that: Includes the following steps: The collimator rotates in the plane of rotation with the entrance pupil of the lens to be tested as the center. The collimator rotates around the incident optical axis of the lens under test. After the collimator is rotated, the detection lens is moved relative to the lens under test and positioned to align with the image plane of the lens under test. Move the lens to be tested relative to the lens to be tested for focusing.

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