Multi-angle annular uniform lighting device and design method

Abstract

The invention relates to a multi-angle annular uniform lighting device and a design method. The device comprises a camera, an imaging lens, a displacement mechanism, a motor, an annular light source mounting base, an angle adjusting mechanism, an LED light source mounting base and a dimming LED light source. The design method comprises the following steps: determining key parameters such as a working distance and an illumination area of a light source according to an actual application scene; according to a preset result parameter, an aspheric plano-convex dimming lens generatrix is calculated, and a three-dimensional dimming lens is constructed; the dimming lens and the LED are combined to serve as a dimming LED light source; a plurality of dimming LED light sources are arranged on an annular light source mounting base at equal azimuth angles, and the illumination of the centrosymmetric dimming LED light sources is superposed and compensated to form an annular uniform illumination light source; a displacement mechanism and an angle adjusting mechanism are additionally arranged to achieve the annular light source with the adjustable working distance and the adjustable multiple angles. The invention has the advantages of small light source divergence angle, high illumination uniformity and strong adaptability to detection elements, and can reduce the interference of strong reflection in defect detection.

Description

Technical Field

[0001] The present invention belongs to the field of lighting equipment for machine vision detection, and in particular relates to a multi-angle annular uniform lighting device and a design method. Background Art

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

[0003] As a key component of the machine vision defect detection system, the light source directly affects the quality of the acquired image. In order to improve the contrast between defects and background and realize the accurate extraction and analysis of surface defects, the defect detection system often uses an annular light source. In a patent application for an LED annular light source with adjustable illumination angle (publication number: CN 20220061535 U), it is disclosed that the light emitted by two annular LED light strips is reflected and directly emitted by an annular refraction plate, thereby realizing the adjustment of the illumination angle; in a patent application named a multi-channel high-brightness annular light source (publication number: CN 115264459 A,), it is disclosed that the cylindrical lens controls the divergence angle by controlling the light-emitting angle, changes the relationship between the distance between the LED light strip cylindrical lens and the focal length of the cylindrical lens, and flexibly adjusts the lighting direction. Although the above patent applications can all realize the adjustable incident angle of the light source, the use of light strip lighting may increase the illuminated area and cause strong reflected light. In the application entitled A Rotating LED Full-angle Ring Lighting Device (Publication No.: CN 118031175 A), it is disclosed that 360° ring-shaped uniform lighting and lighting angle adjustment are achieved by hollow conductive slip rings and outer rotor hollow motors, and reflected light is reduced by adding LED collimating lenses. However, the incident range is adjusted by multiple collimating lenses and reflectors, and the structure is relatively complex, and the ability to adapt to complex curved surface elements is limited. Summary of the invention

[0004] In order to overcome the shortcomings of existing ring-shaped light sources in the field of defect detection, the present invention provides a multi-angle ring-shaped uniform lighting device and a design method. The device reduces the divergence angle of the light source by adding an aspheric plano-convex lens outside the LED light source; multiple dimming light sources are symmetrically and evenly installed on the ring-shaped light source mounting base to achieve uniform lighting; 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 purpose, the present invention adopts the following technical solutions:

[0006] A multi-angle annular uniform lighting device, comprising a camera, an imaging lens, a displacement mechanism, a motor, an annular light source mounting base, an angle adjustment mechanism, an LED light source mounting base, and a plurality of dimming LED light sources, wherein:

[0007] The camera and the imaging lens constitute an imaging optical path, and the camera is located directly above the imaging lens to detect the irradiation 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 constitute a ring light source, and the displacement mechanism is located on both sides of the imaging optical path and is connected to the ring light source mounting base at the bottom to adjust the distance between the ring light source and the component to be tested;

[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. The angle adjustment mechanism is located on the outside side of the ring light source mounting base to connect each dimming LED light source. The motor is located above the ring light source mounting base 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 individually 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, which is used to converge the outgoing light of the light source.

[0010] Furthermore, the angle adjustment mechanism is connected to the end of the dimming LED light source, so that a single dimming LED light source can rotate independently.

[0011] Furthermore, the displacement mechanism is used to adjust the movement of the annular light source in the vertical direction to achieve multi-angle adjustment of the annular light source; the motor is used to adjust the angle adjustment mechanism to control the deflection angle of each dimming LED light source to achieve multi-angle adjustment.

[0012] In another aspect, the present invention provides a method for designing a multi-angle annular uniform lighting device, the method comprising the following steps:

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

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

[0015] Step S3: combining the dimming lens and the LED as a dimming LED light source;

[0016] Step S4: Arrange a plurality of dimming LED light sources at equal azimuth angles below the annular light source mounting base through a plurality of LED light source mounting bases, and superimpose and compensate the illumination of the centrally symmetrical dimming LED light sources to form an annular uniform lighting source;

[0017] Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor, wherein the displacement mechanism is located on both sides of the imaging light path formed by the camera and the imaging lens, and is connected to the ring light source mounting base at the bottom; the angle adjustment mechanism is located on the outside 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, and the motor, the dimming LED light source, and the angle adjustment mechanism are matched one by one, and each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

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

[0019] Step S2.1, determining the dimming LED light source and dimming lens structure parameters;

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

[0021] (1)

[0022] in, , is the initial position of the inner and outer surfaces of the aspheric plano-convex lens, H1 represents the position of the object principal plane of the aspheric plano-convex lens, is the distance from the inner surface of the aspheric plano-convex lens to the object principal plane, H is the working distance of the dimming LED light source, , is the radius of curvature of the inner and outer surfaces of the aspheric plano-convex lens, r is the aperture radius of the aspheric 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 aspheric plano-convex lens material, and α is the divergence angle of the light emitted by the dimming LED light source;

[0023] Step S2.2, determining the position relationship of the light emitted by the dimming LED light source;

[0024] The lighting area is divided into M concentric rings of equal area. According to the principle of luminous flux conservation and edge light, the luminous flux of each ring in the lighting area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the outgoing light is determined:

[0025] (2)

[0026] in, is the total spatial luminous flux, is the intensity distribution of the Lambertian light source, is the light output angle of the dimming LED light source, i represents the i-th circle starting from the center of the lighting area, , Indicates the minimum and maximum angles at which the lens receives the light emitted by the dimming LED light source. , represents the angle between the two edges of the i-th ring and the central light;

[0027] Step S2.3, determining the inner surface generatrix of the aspheric plano-convex dimming lens;

[0028] Determine the coordinates of the incident point of each outgoing light ray of the dimming LED light source on the inner surface of the plano-convex dimming lens according to the geometric relationship, and each incident point is a sampling point; perform plane fitting according to the coordinates of the sampling points to determine the inner surface generatrix formula;

[0029] Step S2.4, determining the outer surface generatrix of the aspheric plano-convex dimming lens;

[0030] The law of refraction is used to calculate the unit vector of the outgoing light at each sampling point on the inner surface of the plano-convex dimming lens and the outgoing light at the initial point on the outer surface of the plano-convex dimming lens:

[0031] (3)

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

[0033] (4)

[0034] in, , is the refractive index of the medium where the incident and outgoing light rays are located, , is the unit vector of the outgoing and incident light rays at the sampling point on the outer surface of the plano-convex dimming lens, is the normal vector at the sampling point on the outer surface of the plano-convex dimming lens, is the tangent slope at the sampling point corresponding to the i-th circular ring in the illumination area on the outer surface of the plano-convex dimming lens, is the angle between the unit vector of the outgoing light at the sampling point corresponding to the i-th circular ring in the illumination area on the inner surface of the plano-convex dimming lens and the normal vector of the point, Respectively represent the horizontal and vertical coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens;

[0035] Step S2.5, generating an aspheric plano-convex lens;

[0036] The sampling points are fitted to form the generatrix of the lens contour and then rotated around the center line to establish a three-dimensional model of the lens.

[0037] The beneficial effects of the present invention are:

[0038] The present invention realizes adjustable incident angles of multiple light sources and adjustable working distances while the incident angle of a single dimming light source is adjustable; a dimming lens is added to the LED light source to converge the divergence angle of the emitted light, and the overall structure is simple; the dimming lens is combined with the angle adjustment mechanism to reduce the interference of strong reflective light on the surface of the component and improve the efficiency of defect detection; a symmetrical compensation center illumination method is adopted to arrange the eight dimmed light sources at equal azimuth intervals to realize ring illumination, thereby improving the illumination uniformity and being suitable for defect detection of various curved optical components. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0041] Figure 3 : The outline generatrix of the dimming lens and the 3D schematic diagram of the dimming lens, where (a) is the fitted dimming lens generatrix curve, and (b) is the schematic diagram of the 3D lens model;

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

[0043] Figure 5 : are illumination distribution diagrams of the annular light source in the embodiment at different incident angles, wherein (a), (b), and (c) are illumination distribution diagrams of the annular light source at incident angles of 60°, 45°, and 30°, respectively, and (d), (e), and (f) are illumination distribution diagrams of the annular light source at incident angles of 60°, 45°, and 30°;

[0044] Figure 6 Schematic diagrams of the annular light source irradiating the concave and convex elements in the embodiments, wherein (a) is a schematic diagram of irradiating the concave optical element, and (b) is a schematic diagram of irradiating the convex optical element;

[0045] Figure 7 1 and 1 , which are distribution diagrams of reflected light when the annular light source in the embodiment illuminates the convex element at incident angles of 45° and 50°, respectively, wherein (a) is the convex element illuminated at 45°, and (b) is the convex element illuminated at 50°.

[0046] Reference numerals:

[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. Dimming LED light source; 9. Component to be tested. DETAILED DESCRIPTION

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

[0049] like Figure 1-Figure 2 As shown, a multi-angle annular uniform lighting device proposed by the present invention is suitable for curved optical surface defect detection, and 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 component to be tested 9. Among them, the camera 1 and the imaging lens 2 form an imaging light path, and the camera 1 is located directly above the imaging lens 2 and is used to detect the irradiation effect of the light source; the motor 4, the annular light source mounting base 5, the angle adjustment mechanism 6, the LED light source mounting base 7, and the dimming LED light source 8 form an annular light source, and the light emitted by the dimming LED light source 8 enters the imaging light path after being scattered by the component; the displacement mechanism 3 is located on both sides of the camera 1 and the imaging lens 2, and is connected to the annular light source mounting base 5 at the same time, and is used to adjust the distance between the annular light source and the component to be tested 9, thereby realizing the adjustable multi-working distance of the annular light source; the annular light source mounting base 5 is in a uniform shape such as a regular polygon or a circle with a hole in the middle, and is located at the bottom of the displacement mechanism 3, and is used to fix the entire annular light source, wherein the dimming LED light source 8 is formed. The imaging lens 2 can pass through the middle opening of the annular light source mounting base 5; the angle adjustment mechanism 6 is located on the outside side of the annular light source mounting base 5, connected to the ends of each dimming LED light source 8, and is used to adjust the incident angle of each dimming LED light source 8; the motor 4 is located above the annular light source mounting base 5, and is used to control the angle adjustment mechanism 6 of each dimming LED light source 8. The motor 4, the dimming LED light source 8, and the angle adjustment mechanism 6 are matched one by one. Each motor 4 independently controls the angle adjustment mechanism 6 and the corresponding dimming LED light source 8, thereby realizing 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 annular light source mounting base 5 to fix each dimming LED light source 8.

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

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

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

[0053] Step S3: combining the dimming lens and the LED as a dimming LED light source;

[0054] Step S4: Arrange a plurality of dimming LED light sources at equal azimuth angles below the annular light source mounting base through a plurality of LED light source mounting bases, and superimpose and compensate the illumination of the centrally symmetrical dimming LED light sources to form an annular uniform lighting source;

[0055] Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor, wherein the displacement mechanism is located on both sides of the imaging light path formed by the camera and the imaging lens, and is connected to the ring light source mounting base at the bottom; the angle adjustment mechanism is located on the outside 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, and the motor, the dimming LED light source, and the angle adjustment mechanism are matched one by one, and each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

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

[0057] Step S2.1, determining the dimming LED light source and dimming lens structure parameters;

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

[0059] (1)

[0060] in, , is the initial position of the inner and outer surfaces of the aspheric plano-convex lens, H1 represents the position of the object principal plane of the aspheric plano-convex lens, is the distance from the inner surface of the aspheric plano-convex lens to the object principal plane, H is the working distance of the dimming LED light source, , is the radius of curvature of the inner and outer surfaces of the aspheric plano-convex lens, r is the aperture radius of the aspheric 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 aspheric plano-convex lens material, and α is the divergence angle of the light emitted by the dimming LED light source;

[0061] Step S2.2, determining the position relationship of the light emitted by the dimming LED light source;

[0062] The lighting area is divided into M concentric rings of equal area. According to the principle of luminous flux conservation and edge light, the luminous flux of each ring in the lighting area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the outgoing light is determined:

[0063] (2)

[0064] in, is the total spatial luminous flux, is the intensity distribution of Lambertian light source, is the light output angle of the dimming LED light source, i represents the i-th circle starting from the center of the lighting area, , Indicates the minimum and maximum angles at which the lens receives the light emitted by the dimming LED light source. , represents the angle between the two edges of the i-th ring and the central light;

[0065] Step S2.3, determining the inner surface generatrix of the aspheric plano-convex dimming lens;

[0066] Determine the coordinates of the incident point of each outgoing light ray of the dimming LED light source on the inner surface of the plano-convex dimming lens according to the geometric relationship, and each incident point is a sampling point; perform plane fitting according to the coordinates of the sampling points to determine the inner surface generatrix formula;

[0067] Step S2.4, determining the outer surface generatrix of the aspheric plano-convex dimming lens;

[0068] The law of refraction is used to calculate the unit vector of the outgoing light at each sampling point on the inner surface of the plano-convex dimming lens and the outgoing light at the initial point on the outer surface of the plano-convex dimming lens:

[0069] (3)

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

[0071] (4)

[0072] in, , is the refractive index of the medium where the incident and outgoing light rays are located, , is the unit vector of the outgoing and incident light rays at the sampling point on the outer surface of the plano-convex dimming lens, is the normal vector at the sampling point on the outer surface of the plano-convex dimming lens, is the tangent slope at the sampling point corresponding to the i-th circular ring in the illumination area on the outer surface of the plano-convex dimming lens, is the angle between the unit vector of the outgoing light at the sampling point corresponding to the i-th circular ring in the illumination area on the inner surface of the plano-convex dimming lens and the normal vector of the point, Respectively represent the horizontal and vertical coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens;

[0073] Step S2.5, generating an aspheric plano-convex lens;

[0074] The sampling points are fitted to form the generatrix of the lens contour and then rotated around the center line to establish a three-dimensional model of the lens.

[0075] Example

[0076] The ring light source is designed for the actual surface defect detection device of curved optical components. The working distance of the imaging lens 2 of the defect detection device is 170mm, the field of view of the imaging lens 2 is 35mm×35mm at a small magnification, and the field of view is 7mm×7mm at a large magnification. It can detect curved optical components with a diameter of 300mm and R / D greater than 1. Therefore, the working distance range of the equipped ring light source is determined to be 100mm to 200mm, and the adjustable range of the incident angle is 30° to 60°.

[0077] First, calculate the dimming lens busbar. In the embodiment, a light source chip with an actual size of 2 mm × 2 mm is used, the initial positions of the inner and outer surfaces of the lens are 5 mm and 10.5 mm respectively, and the dimming lens emits light in a range of to , the lens radius is 5.3 mm, and the formula is used to fit the dimming lens generatrix. Figure 3 (a) is shown. The three-dimensional lens model formed by rotating the lens generatrix contour around the center line is shown in Figure 3 The dimming lens controls the divergence angle of the light emitted from the light source to within ±7°.

[0078] Eight dimming LED light sources 8 equipped with the above-designed dimming lenses are installed at 45° azimuth angles on the side of the annular light source mounting base 5 through the LED light source mounting base 7. The distribution of the dimming LED light sources 8 is as follows: Figure 2 or Figure 4 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 to achieve multi-angle adjustment.

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

[0080] Figure 5 It is the lighting effect of the ring light source within the incident angle range of 30° to 60°, and the average illumination uniformity is 90.69%, where (a), (b), and (c) are the illumination distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°, respectively; (d), (e), and (f) are the illumination distribution diagrams of the ring light source at incident angles of 60°, 45°, and 30°.

[0081] Figure 6The components to be tested are convex optical components ((b) in the figure) and concave optical components ((a) in the figure). When the incident angle of the annular light source is uniformly adjusted to 45°, the component diameter is 200mm, and the curvature radius is 250mm to 300mm, the average illumination uniformity is 90.78% and 90.62% respectively.

[0082] like Figure 7 As shown, the annular light source is taken as an example to illuminate the convex element at an incident angle of 45° ((a) in the figure) and 50° ((b) in the figure), and the lighting effects are respectively strong reflected light appearing at the edge of the field of view and no strong reflection in the effective field of view.

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

[0084] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is 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 in the scope of protection of the present invention.

Claims

1. A multi-angle annular 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 a plurality of dimming LED light sources, wherein: The camera and the imaging lens constitute an imaging optical path, and the camera is located directly above the imaging lens to detect the irradiation 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 constitute a ring light source, and the displacement mechanism is located on both sides of the imaging optical path and is connected to the ring light source mounting base at the bottom to adjust the distance between the ring light source and the component to be tested; 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. The angle adjustment mechanism is located on the outside side of the ring light source mounting base to connect each dimming LED light source. The motor is located above the ring light source mounting base 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 individually controls the angle adjustment mechanism and the corresponding dimming LED light source.

2. A multi-angle annular uniform lighting device according to claim 1, characterized in that: The dimming lens of the dimming LED light source is an aspherical plano-convex lens, which is used to converge the outgoing light of the light source.

3. The 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, so that a single dimming LED light source can rotate independently.

4. The multi-angle annular uniform lighting device according to claim 1, characterized in that: The displacement mechanism is used to adjust the movement of the annular light source in the vertical direction to achieve multi-angle adjustment of the annular light source; the motor is used to adjust the angle adjustment mechanism to control the deflection angle of each dimming LED light source to achieve multi-angle adjustment.

5. A design method for a multi-angle annular uniform lighting device, characterized in that: The method comprises the following steps: Step S1: Determine the working distance H and the illumination area radius R of the LED light source according to the actual application scenario; Step S2: Calculate the generatrix of the aspheric plano-convex dimming lens and construct a three-dimensional dimming lens model; Step S3: combining the dimming lens and the LED as a dimming LED light source; Step S4: Arrange a plurality of dimming LED light sources at equal azimuth angles below the annular light source mounting base through a plurality of LED light source mounting bases, and superimpose and compensate the illumination of the centrally symmetrical dimming LED light sources to form an annular uniform lighting source; Step S5: Add a displacement mechanism, an angle adjustment mechanism, and a motor, wherein the displacement mechanism is located on both sides of the imaging light path formed by the camera and the imaging lens, and is connected to the ring light source mounting base at the bottom; the angle adjustment mechanism is located on the outside 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, and the motor, the dimming LED light source, and the angle adjustment mechanism are matched one by one, and each motor independently controls the angle adjustment mechanism and the corresponding dimming LED light source.

6. The method for designing a multi-angle annular uniform lighting device according to claim 5, characterized in that: The step S2 of constructing the three-dimensional dimming lens model includes: Step S2.1, determining the dimming LED light source and dimming lens structure parameters; The relationship between the structural parameters of the dimming lens and the divergence angle of the emitted light of the dimming LED light source is as follows: （1） in, , is the initial position of the inner and outer surfaces of the aspheric plano-convex lens, H1 represents the position of the object principal plane of the aspheric plano-convex lens, is the distance from the inner surface of the aspheric plano-convex lens to the object principal plane, H is the working distance of the dimming LED light source, , is the radius of curvature of the inner and outer surfaces of the aspheric plano-convex lens, r is the aperture radius of the aspheric 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 aspheric plano-convex lens material, and α is the divergence angle of the light emitted by the dimming LED light source; Step S2.2, determining the position relationship of the light emitted by the dimming LED light source; The lighting area is divided into M concentric rings of equal area. According to the principle of luminous flux conservation and edge light, the luminous flux of each ring in the lighting area is obtained from the total spatial luminous flux of the dimming LED light source, and then the position of the outgoing light is determined: （2） in, is the total spatial luminous flux, is the intensity distribution of the Lambertian light source, is the light output angle of the dimming LED light source, i represents the i-th circle starting from the center of the lighting area, , Indicates the minimum and maximum angles at which the lens receives the light emitted by the dimming LED light source. , represents the angle between the two edges of the i-th ring and the central light; Step S2.3, determining the inner surface generatrix of the aspheric plano-convex dimming lens; Determine the coordinates of the incident point of each outgoing light ray of the dimming LED light source on the inner surface of the plano-convex dimming lens according to the geometric relationship, and each incident point is a sampling point; perform plane fitting according to the coordinates of the sampling points to determine the inner surface generatrix formula; Step S2.4, determining the outer surface generatrix of the aspheric plano-convex dimming lens; The law of refraction is used to calculate the unit vector of the outgoing light at each sampling point on the inner surface of the plano-convex dimming lens and the outgoing light at the initial point on the outer surface of the plano-convex dimming lens: （3） The intersection of the tangent line of the previous sampling point on the outer surface and the second incident light is used as the second sampling point to calculate the outer surface generatrix of the plano-convex dimming lens: （4） in, , is the refractive index of the medium where the incident and outgoing light rays are located, , is the unit vector of the outgoing and incident light rays at the sampling point on the outer surface of the plano-convex dimming lens, is the normal vector at the sampling point on the outer surface of the plano-convex dimming lens, is the tangent slope at the sampling point corresponding to the i-th circular ring in the illumination area on the outer surface of the plano-convex dimming lens, is the angle between the unit vector of the outgoing light at the sampling point corresponding to the i-th circular ring in the illumination area on the inner surface of the plano-convex dimming lens and the normal vector of the point, Respectively represent the horizontal and vertical coordinates of the sampling points on the inner and outer surfaces of the plano-convex dimming lens; Step S2.5, generating an aspheric plano-convex lens; The sampling points are fitted to form the generatrix of the lens contour and then rotated around the center line to establish a three-dimensional model of the lens.

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