Multi-angle annular uniform illumination device and design method

Abstract

The present application relates to a kind of multi-angle annular uniform illumination device and design method, device includes camera, imaging lens, displacement mechanism, motor, annular light source mounting base, angle adjusting mechanism, LED light source mounting base, dimming LED light source.Design method includes: according to actual application scene, determine the key parameters such as working distance and illumination area of light source;According to the preset result parameter, calculate the non-spherical plane-convex dimming lens generatrix, construct three-dimensional dimming lens;Dimming lens and LED are combined as dimming LED light source;Several dimming LED light sources are arranged at the same azimuth on annular light source mounting base, and the illumination of the center-symmetric dimming LED light source is superimposed and compensated to form annular uniform illumination light source;Increase displacement mechanism, angle adjusting mechanism to realize the working distance adjustable multi-angle adjustable annular light source.The present application has the advantages of small light source divergence angle, high illumination uniformity and strong adaptability to detection elements, which can reduce the interference of strong light in defect detection.

Description

Technical Field

[0001] This invention belongs to the field of lighting equipment for machine vision inspection, and specifically relates to a multi-angle ring uniform lighting device and its design method. Background Technology

[0002] With the continuous development of advanced optical technology, curved optical precision components are being applied in various fields. However, surface defects in curved optical components can cause scattering of the incident light beam, affecting the performance of the optical system. Therefore, surface defect detection is one of the key steps to ensure the normal operation of the system.

[0003] As a key component of machine vision defect detection systems, the light source directly affects the quality of acquired images. To improve the contrast between defects and the background and achieve accurate extraction and analysis of surface defects, defect detection systems often employ ring light sources. A patent application for an LED ring light source with adjustable illumination angle (publication number: CN 20220061535 U) discloses a method of reflecting and directly projecting light emitted from two ring-shaped LED strips using a ring-shaped refractive plate, thus achieving adjustment of the illumination angle. A patent application titled "A Multi-Channel High-Brightness Ring Light Source" (publication number: CN 115264459 A) discloses a cylindrical lens that controls the divergence angle by controlling the emission angle, changing the relationship between the distance of the LED strip cylindrical lens and the focal length of the cylindrical lens to flexibly adjust the lighting direction. Although the above patent applications all achieve adjustable incident angles of the light source, they mostly use LED strip lighting, which may lead to an increased illuminated area and strong reflected light. In the application entitled "A Rotating LED Omni-Angle Ring Lighting Device" (Publication No.: CN 118031175 A), it was disclosed that 360° omni-angle uniform lighting and lighting angle adjustment were achieved by using a hollow conductive slip ring and an outer rotor hollow motor. The reflected light was reduced by adding an LED collimating lens. However, the structure is relatively complex and the ability to adapt to complex curved surface elements is limited by adjusting the incident range with multiple collimating lenses and reflectors. Summary of the Invention

[0004] To overcome the shortcomings of existing ring light sources in the field of defect detection, this invention provides a multi-angle ring uniform illumination device and design method. The device reduces the divergence angle of the light source by adding an aspherical plano-convex lens outside the LED light source; multiple dimming light sources are symmetrically and uniformly installed on the ring light source mounting base to achieve uniform illumination; while adjusting the working distance, the light source can be adjusted at multiple angles by controlling the angle adjustment mechanism through a motor, thereby effectively reducing the interference of strong reflected light.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A multi-angle ring-shaped uniform lighting device includes a camera, an imaging lens, a displacement mechanism, a motor, a ring-shaped light source mounting base, an angle adjustment mechanism, an LED light source mounting base, and several dimming LED light sources.

[0007] The camera and imaging lens form the imaging optical path, with the camera positioned directly above the imaging lens to detect the illumination effect of the light source; the motor, the ring light source mounting base, the angle adjustment mechanism, the LED light source mounting base, and the dimming LED light source form the ring light source, and the displacement mechanism is located on both sides of the imaging optical path and connected to the ring light source mounting base below, used to adjust the distance between the ring light source and the component under test.

[0008] Multiple LED light source mounting bases are installed at equal angles below the ring light source mounting base to fix each dimming LED light source. An angle adjustment mechanism is located on the outer side of the ring light source mounting base and is connected to each dimming LED light source. A motor is located above the ring light source mounting base and is used to control the angle adjustment mechanism of each dimming LED light source. The motor, dimming LED light source, and angle adjustment mechanism are matched one by one, and each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

[0009] Furthermore, the dimming lens of the dimming LED light source is an aspherical plano-convex lens, used to focus the emitted light from the light source.

[0010] Furthermore, the angle adjustment mechanism is connected to the end of the dimming LED light source, allowing each dimming LED light source to rotate independently.

[0011] Furthermore, the displacement mechanism is used to adjust the vertical movement of the ring light source, enabling the ring light source to have multiple adjustable working distances; the motor is used to adjust the angle adjustment mechanism, controlling the sway angle of each dimming LED light source to achieve multiple adjustable angles.

[0012] On the other hand, the present invention provides a design method for a multi-angle ring-shaped uniform lighting device, the method comprising the following steps:

[0013] Step S1: Determine the working distance H of the LED light source and the radius R of the illumination area based on the actual application scenario;

[0014] Step S2: Calculate the generatrix of the aspherical plano-convex dimming lens and construct a three-dimensional dimming lens model;

[0015] Step S3: Combine the dimming lens with the LED to form a dimming LED light source;

[0016] Step S4: Arrange several dimming LED light sources at the same azimuth angle below the ring light source mounting base through several LED light source mounting bases. The illuminance of the centrally symmetrical dimming LED light sources is superimposed and compensated to form a ring-shaped uniform lighting source.

[0017] Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor. The displacement mechanism is located on both sides of the imaging optical path formed by the camera and the imaging lens, and is connected to the ring light source mounting base below. The angle adjustment mechanism is located on the outer side of the ring light source mounting base and is connected to each dimming LED light source. The motor is located above the ring light source mounting base. The motor, dimming LED light source, and angle adjustment mechanism are matched one by one. Each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

[0018] Furthermore, the construction of the three-dimensional dimming lens model in step S2 includes:

[0019] Step S2.1: Determine the structural parameters of the dimming LED light source and the dimming lens;

[0020] The relationship between the structural parameters of the dimming lens and the divergence angle of the emitted light from the dimming LED light source is as follows:

[0021] (1)

[0022] in, , H1 represents the initial positions of the inner and outer surfaces of the aspherical plano-convex lens, and H1 represents the position of the object-side principal plane of the aspherical plano-convex lens. H is the distance from the inner surface of the aspherical plano-convex lens to the object-side principal plane, and H is the working distance of the dimming LED light source. , denoted as , where is the radius of curvature of the inner and outer surfaces of the aspherical plano-convex lens, r is the aperture radius of the aspherical plano-convex lens, R is the radius of the illumination area, d is the diameter of the dimming LED light source, n is the refractive index of the aspherical plano-convex lens material, and α is the divergence angle of the emitted light from the dimming LED light source.

[0023] Step S2.2: Determine the positional relationship of the emitted light rays from the dimming LED light source;

[0024] The illuminated area is divided into M concentric rings of equal area. Based on the conservation of luminous flux and the principle of edge rays, the luminous flux of each ring in the illuminated area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the emitted light ray is determined.

[0025] (2)

[0026] in, This represents the total spatial luminous flux. This represents the light intensity distribution of the Lambertian light source. The angle of the emitted light from the dimming LED light source, where i represents the i-th ring starting from the center of the illuminated area. , This indicates the minimum and maximum angles at which the lens receives the light emitted from the dimmed LED light source. , This represents the angle between the two edges of the i-th ring and the central ray;

[0027] Step S2.3: Determine the generatrix of the inner surface of the aspherical plano-convex switching lens;

[0028] The coordinates of the incident point of each outgoing ray from the dimming LED light source on the inner surface of the plano-convex dimming lens are determined based on geometric relationships, and each incident point is a sampling point; the formula for the generatrix of the inner surface is determined by performing plane fitting based on the coordinates of the sampling points.

[0029] Step S2.4: Determine the generatrix of the outer surface of the aspherical plano-convex switching lens;

[0030] Calculate the unit vector of the outgoing ray at each sampling point on the inner surface of the plano-convex switching lens and the outgoing ray at the initial point on the outer surface of the plano-convex switching lens using the law of refraction:

[0031] (3)

[0032] The intersection of the tangent at the previous sampling point on the outer surface and the second incident ray is used as the second sampling point to calculate the generatrix of the outer surface of the plano-convex switching lens:

[0033] (4)

[0034] in, , Let be the refractive index of the medium containing the incident and outgoing rays. , Let be the unit vector of the outgoing and incoming rays from the sampling point on the outer surface of the plano-convex switching lens. This is the normal vector at the sampling point on the outer surface of the plano-convex switching lens. Let be the slope of the tangent at the sampling point corresponding to the i-th ring in the illumination area on the outer surface of the plano-convex dimming lens. Let be the angle between the unit vector of the light ray emitted from the i-th ring corresponding to the sampling point in the illumination area on the inner surface of the plano-convex switching lens and the normal vector of that point. These represent the x and y coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens, respectively.

[0035] Step S2.5: Generate an aspherical plano-convex lens;

[0036] The lens profile generatrix is ​​formed by fitting the sampling points and then rotating it around the center line to establish a three-dimensional model of the lens.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention achieves adjustable incident angles and adjustable working distances for multiple light sources while allowing adjustment of the incident angle of a single dimming light source. By adding a dimming lens to the LED light source to reduce the divergence angle of the emitted light, the overall structure is simple. Combining the dimming lens with the angle adjustment mechanism can reduce strong reflective interference from the component surface and improve defect detection efficiency. By adopting a symmetrical compensation method for the center illuminance, the eight dimmed light sources are arranged at equal azimuth angle intervals to achieve ring illumination, improving illuminance uniformity and making it suitable for defect detection of various curved optical components. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a multi-angle ring-shaped uniform lighting device according to the present invention;

[0040] Figure 2 This is a top view schematic diagram of a multi-angle ring-shaped uniform lighting device according to the present invention;

[0041] Figure 3 The diagram shows the profile generatrix of the dimming lens and a 3D schematic diagram of the dimming lens. (a) is the fitted curve of the dimming lens generatrix, and (b) is a schematic diagram of the three-dimensional lens model.

[0042] Figure 4 This is a distribution diagram of the eight dimming LED light sources in the embodiment;

[0043] Figure 5 The following are illuminance distribution diagrams of the ring light source at different incident angles in the embodiment. (a), (b), and (c) are the illuminance distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°, respectively, and (d), (e), and (f) are the illuminance distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°, respectively.

[0044] Figure 6 The following are schematic diagrams of the ring light source illuminating the concave and convex optical elements in the embodiment, where (a) is a schematic diagram of illuminating the concave optical element and (b) is a schematic diagram of illuminating the convex optical element.

[0045] Figure 7 The diagram shows the distribution of reflected light when the ring light source illuminates the convex element at incident angles of 45° and 50°, respectively, in the embodiment. (a) shows the convex element illuminated at 45°, and (b) shows the convex element illuminated at 50°.

[0046] Figure label:

[0047] 1. Camera; 2. Imaging lens; 3. Displacement mechanism; 4. Motor; 5. Ring light source mounting base; 6. Angle adjustment mechanism; 7. LED light source mounting base; 8. Dimmable LED light source; 9. Component under test. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the scope of protection of the present invention is not limited to the scope described in the embodiments.

[0049] like Figures 1-2 As shown, this invention proposes a multi-angle annular uniform illumination device suitable for detecting defects on curved optical surfaces. The device includes a camera 1, an imaging lens 2, a displacement mechanism 3, a motor 4, an annular light source mounting base 5, an angle adjustment mechanism 6, an LED light source mounting base 7, a dimming LED light source 8, and a device under test 9. The camera 1 and imaging lens 2 form the imaging optical path, with the camera 1 positioned directly above the imaging lens 2 to detect the illumination effect of the light source. The motor 4, annular light source mounting base 5, angle adjustment mechanism 6, LED light source mounting base 7, and dimming LED light source 8 form the annular light source. The light emitted from the dimming LED light source 8 is scattered by the device and enters the imaging optical path. The displacement mechanism 3 is located on both sides of the camera 1 and imaging lens 2, and is connected to the annular light source mounting base 5, used to adjust the distance between the annular light source and the device under test 9, thereby achieving adjustable working distances for the annular light source. The annular light source mounting base 5 is a uniform shape, such as a regular polygon or circle with a central opening, located at the bottom of the displacement mechanism 3, used to fix the entire annular light source. Lens 2 can pass through the central opening of the ring light source mounting base 5; angle adjustment mechanism 6 is located on the outer side of the ring light source mounting base 5 and is connected to the end of each dimming LED light source 8 to adjust the incident angle of each dimming LED light source 8; motor 4 is located above the ring light source mounting base 5 and is used to control the angle adjustment mechanism 6 of each dimming LED light source 8. Motor 4, dimming LED light source 8, and angle adjustment mechanism 6 are matched one-to-one. Each motor 4 independently controls the angle adjustment mechanism 6 and the corresponding dimming LED light source 8, thereby enabling multi-angle adjustment of each unit dimming LED light source 8; multiple LED light source mounting bases 7 are installed at equal angles on the ring light source mounting base 5 to fix each dimming LED light source 8.

[0050] On the other hand, the present invention also provides a design method for a multi-angle ring-shaped uniform lighting device, the method comprising the following steps:

[0051] Step S1: Determine the working distance H of the LED light source and the radius R of the illumination area based on the actual application scenario;

[0052] Step S2: Calculate the generatrix of the aspherical plano-convex dimming lens and construct a three-dimensional dimming lens model;

[0053] Step S3: Combine the dimming lens with the LED to form a dimming LED light source;

[0054] Step S4: Arrange several dimming LED light sources at the same azimuth angle below the ring light source mounting base through several LED light source mounting bases. The illuminance of the centrally symmetrical dimming LED light sources is superimposed and compensated to form a ring-shaped uniform lighting source.

[0055] Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor. The displacement mechanism is located on both sides of the imaging optical path formed by the camera and the imaging lens, and is connected to the ring light source mounting base below. The angle adjustment mechanism is located on the outer side of the ring light source mounting base and is connected to each dimming LED light source. The motor is located above the ring light source mounting base. The motor, dimming LED light source, and angle adjustment mechanism are matched one by one. Each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

[0056] Furthermore, the construction of the three-dimensional dimming lens model in step S2 includes:

[0057] Step S2.1: Determine the structural parameters of the dimming LED light source and the dimming lens;

[0058] The relationship between the structural parameters of the dimming lens and the divergence angle of the emitted light from the dimming LED light source is as follows:

[0059] (1)

[0060] in, , H1 represents the initial positions of the inner and outer surfaces of the aspherical plano-convex lens, and H1 represents the position of the object-side principal plane of the aspherical plano-convex lens. H is the distance from the inner surface of the aspherical plano-convex lens to the object-side principal plane, and H is the working distance of the dimming LED light source. , denoted as , where is the radius of curvature of the inner and outer surfaces of the aspherical plano-convex lens, r is the aperture radius of the aspherical plano-convex lens, R is the radius of the illumination area, d is the diameter of the dimming LED light source, n is the refractive index of the aspherical plano-convex lens material, and α is the divergence angle of the emitted light from the dimming LED light source.

[0061] Step S2.2: Determine the positional relationship of the emitted light rays from the dimming LED light source;

[0062] The illuminated area is divided into M concentric rings of equal area. Based on the conservation of luminous flux and the principle of edge rays, the luminous flux of each ring in the illuminated area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the emitted light ray is determined.

[0063] (2)

[0064] in, This represents the total spatial luminous flux. This represents the light intensity distribution of the Lambertian light source. The angle of the emitted light from the dimming LED light source, where i represents the i-th ring starting from the center of the illuminated area. , This indicates the minimum and maximum angles at which the lens receives the light emitted from the dimmed LED light source. , This represents the angle between the two edges of the i-th ring and the central ray;

[0065] Step S2.3: Determine the generatrix of the inner surface of the aspherical plano-convex switching lens;

[0066] The coordinates of the incident point of each outgoing ray from the dimming LED light source on the inner surface of the plano-convex dimming lens are determined based on geometric relationships, and each incident point is a sampling point; the formula for the generatrix of the inner surface is determined by performing plane fitting based on the coordinates of the sampling points.

[0067] Step S2.4: Determine the generatrix of the outer surface of the aspherical plano-convex switching lens;

[0068] Calculate the unit vector of the outgoing ray at each sampling point on the inner surface of the plano-convex switching lens and the outgoing ray at the initial point on the outer surface of the plano-convex switching lens using the law of refraction:

[0069] (3)

[0070] The intersection of the tangent at the previous sampling point on the outer surface and the second incident ray is used as the second sampling point to calculate the generatrix of the outer surface of the plano-convex switching lens:

[0071] (4)

[0072] in, , Let be the refractive index of the medium containing the incident and outgoing rays. , Let be the unit vector of the outgoing and incoming rays from the sampling point on the outer surface of the plano-convex switching lens. This is the normal vector at the sampling point on the outer surface of the plano-convex switching lens. Let be the slope of the tangent at the sampling point corresponding to the i-th ring in the illumination area on the outer surface of the plano-convex dimming lens. Let be the angle between the unit vector of the light ray emitted from the i-th ring corresponding to the sampling point in the illumination area on the inner surface of the plano-convex switching lens and the normal vector of that point. These represent the x and y coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens, respectively.

[0073] Step S2.5: Generate an aspherical plano-convex lens;

[0074] The lens profile generatrix is ​​formed by fitting the sampling points and then rotating it around the center line to establish a three-dimensional model of the lens.

[0075] Example

[0076] A ring light source was designed for a surface defect detection device for practical curved optical components. The imaging lens 2 of the defect detection device has a working distance of 170mm, a field of view of 35mm×35mm at low magnification and 7mm×7mm at high magnification, and can detect curved optical components with a 300mm aperture and an R / D ratio greater than 1. Therefore, the working distance range of the ring light source was determined to be 100mm to 200mm, and the incident angle was adjustable from 30° to 60°.

[0077] First, the dimming lens generatrix is ​​calculated. In this embodiment, a light source chip with actual dimensions of 2 mm × 2 mm is used, and the initial positions of the inner and outer surfaces of the lens are 5 mm and 10.5 mm, respectively. The output light range of the dimming lens is... to The lens radius is 5.3 mm. Substituting these values ​​into the formula, the generatrix of the dimming lens is fitted as follows: Figure 3 As shown in (a), the three-dimensional lens model formed by rotating the lens generatrix outline around the centerline is as follows. Figure 3 As shown in (b). This dimming lens controls the divergence angle of the emitted light from the light source to within ±7°.

[0078] Eight dimming LED light sources 8, each equipped with a dimming lens as described above, are mounted at 45° azimuth angles on the side of the ring light source mounting base 5 via the LED light source mounting base 7. The distribution of the dimming LED light sources 8 is as follows: Figure 2 or Figure 4 As shown. Among them, the angle adjustment mechanism 6 on the side of the LED light source mounting base 7 can control the incident angle of the ring light source, realizing multi-angle adjustment.

[0079] The ring light source is mounted on the displacement mechanism 3 to realize a ring lighting device with adjustable working distance.

[0080] Figure 5 The illumination effect of the ring light source within the incident angle range of 30° to 60° is shown, with an average illuminance uniformity of 90.69%. Among them, (a), (b), and (c) are the illuminance distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°, respectively, and (d), (e), and (f) are the illuminance distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°.

[0081] Figure 6The test elements are convex optical elements (Figure (b)) and concave optical elements (Figure (a)). When the incident angle of the ring light source is uniformly adjusted to 45°, the element aperture is 200 mm, and the radius of curvature is 250 mm to 300 mm, the average illuminance uniformity is 90.78% and 90.62%, respectively.

[0082] like Figure 7 As shown, when the ring light source illuminates the convex element at incident angles of 45° (Figure (a)) and 50° (Figure (b)), the illumination effects are strong reflected light appearing at the edge of the field of view and no strong reflection light within the effective field of view, respectively.

[0083] In summary, this invention can be used for defect detection of various curved surface components, and has the advantages of small divergence angle and reduced strong reflective interference.

[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a multi-angle ring-shaped uniform lighting device, characterized in that, The device includes a camera, an imaging lens, a displacement mechanism, a motor, a ring light source mounting base, an angle adjustment mechanism, an LED light source mounting base, and several dimming LED light sources, wherein... The camera and imaging lens form the imaging optical path, with the camera positioned directly above the imaging lens to detect the illumination effect of the light source; the motor, the ring light source mounting base, the angle adjustment mechanism, the LED light source mounting base, and the dimming LED light source form the ring light source, and the displacement mechanism is located on both sides of the imaging optical path and connected to the ring light source mounting base below, used to adjust the distance between the ring light source and the component under test. Multiple LED light source mounting bases are installed at equal angles below the ring light source mounting base to fix each dimming LED light source. An angle adjustment mechanism is located on the outer side of the ring light source mounting base and is connected to each dimming LED light source. A motor is located above the ring light source mounting base and is used to control the angle adjustment mechanism of each dimming LED light source. The motor, dimming LED light source, and angle adjustment mechanism are matched one-to-one. Each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source. The dimming lens of the dimming LED light source is an aspherical plano-convex lens. The method includes the following steps: Step S1: Determine the working distance H of the LED light source and the radius R of the illumination area based on the actual application scenario; Step S2: Calculate the generatrix of the aspherical plano-convex dimming lens and construct a three-dimensional dimming lens model; Step S3: Combine the dimming lens with the LED to form a dimming LED light source; Step S4: Arrange several dimming LED light sources at the same azimuth angle below the ring light source mounting base through several LED light source mounting bases. The illuminance of the centrally symmetrical dimming LED light sources is superimposed and compensated to form a ring-shaped uniform lighting source. Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor. The displacement mechanism is located on both sides of the imaging optical path formed by the camera and the imaging lens, and is connected to the ring light source mounting base below. The angle adjustment mechanism is located on the outer side of the ring light source mounting base and is connected to each dimming LED light source. The motor is located above the ring light source mounting base. The motor, dimming LED light source, and angle adjustment mechanism are matched one by one. Each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source. The construction of the three-dimensional dimming lens model in step S2 includes: Step S2.1: Determine the structural parameters of the dimming LED light source and the dimming lens; The relationship between the structural parameters of the dimming lens and the divergence angle of the emitted light from the dimming LED light source is as follows: （1） in, , H1 represents the initial positions of the inner and outer surfaces of the aspherical plano-convex lens, and H1 represents the position of the object-side principal plane of the aspherical plano-convex lens. H is the distance from the inner surface of the aspherical plano-convex lens to the object-side principal plane, and H is the working distance of the dimming LED light source. , denoted as , where is the radius of curvature of the inner and outer surfaces of the aspherical plano-convex lens, r is the aperture radius of the aspherical plano-convex lens, R is the radius of the illumination area, d is the diameter of the dimming LED light source, n is the refractive index of the aspherical plano-convex lens material, and α is the divergence angle of the emitted light from the dimming LED light source. Step S2.2: Determine the positional relationship of the emitted light rays from the dimming LED light source; The illuminated area is divided into M concentric rings of equal area. Based on the conservation of luminous flux and the principle of edge rays, the luminous flux of each ring in the illuminated area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the emitted light ray is determined. （2） in, This represents the total spatial luminous flux. This represents the light intensity distribution of the Lambertian light source. The angle of the emitted light from the dimming LED light source, where i represents the i-th ring starting from the center of the illuminated area. , This indicates the minimum and maximum angles at which the lens receives the light emitted from the dimmed LED light source. , This represents the angle between the two edges of the i-th ring and the central ray; Step S2.3: Determine the generatrix of the inner surface of the aspherical plano-convex switching lens; The coordinates of the incident point of each outgoing ray from the dimming LED light source on the inner surface of the plano-convex dimming lens are determined based on geometric relationships, and each incident point is a sampling point; the formula for the generatrix of the inner surface is determined by performing plane fitting based on the coordinates of the sampling points. Step S2.4: Determine the generatrix of the outer surface of the aspherical plano-convex switching lens; Calculate the unit vector of the outgoing ray at each sampling point on the inner surface of the plano-convex switching lens and the outgoing ray at the initial point on the outer surface of the plano-convex switching lens using the law of refraction: （3） The intersection of the tangent at the previous sampling point on the outer surface and the second incident ray is used as the second sampling point to calculate the generatrix of the outer surface of the plano-convex switching lens: （4） in, , Let be the refractive index of the medium containing the incident and outgoing rays. , Let be the unit vector of the outgoing and incoming rays from the sampling point on the outer surface of the plano-convex switching lens. This is the normal vector at the sampling point on the outer surface of the plano-convex switching lens. Let be the slope of the tangent at the sampling point corresponding to the i-th ring in the illumination area on the outer surface of the plano-convex dimming lens. Let be the angle between the unit vector of the light ray emitted from the i-th ring corresponding to the sampling point in the illumination area on the inner surface of the plano-convex switching lens and the normal vector of that point. These represent the x and y coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens, respectively. Step S2.5: Generate an aspherical plano-convex lens; The lens profile generatrix is ​​formed by fitting the sampling points and then rotating it around the center line to establish a three-dimensional model of the lens.

2. The design method of a multi-angle annular uniform lighting device according to claim 1, characterized in that, The aspherical plano-convex lens is used to focus the emitted light from the light source.

3. The design method of a multi-angle annular uniform lighting device according to claim 1, characterized in that, The angle adjustment mechanism is connected to the end of the dimming LED light source, allowing each dimming LED light source to rotate independently.

4. The design method of a multi-angle annular uniform lighting device according to claim 1, characterized in that, The displacement mechanism is used to adjust the vertical movement of the ring light source, enabling the ring light source to have multiple adjustable working distances; the motor is used to adjust the angle adjustment mechanism, controlling the sway angle of each dimming LED light source to achieve multiple adjustable angles.

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