A design method for an LED sea sweeping light lighting system

Abstract

This invention discloses a design method for an LED sea-sweeping lamp lighting system, comprising: sequentially arranging an LED light source array module, a uniform collimating lens array module, and a beam-expanding Fresnel lens array module; causing the light emitted from the LED light source array module to sequentially pass through the uniform collimating lens array module, the focusing Fresnel lens array, and the collimating Fresnel lens array; determining the distance between the LED light source array module and the uniform collimating lens array module, the thickness of the uniform collimating lens array module, the distance between the uniform collimating lens array module and the focusing Fresnel lens array unit, the thickness of the focusing Fresnel lens array, the thickness of the collimating Fresnel lens array, the focal length of the focusing Fresnel lens array, and the focal length of the collimating Fresnel lens array; and obtaining the length of the LED sea-sweeping lamp lighting system. This design method for the LED sea-sweeping lamp lighting system solves the problem that existing methods cannot achieve miniaturized lamp head design.

Description

Technical Field

[0001] This invention relates to the field of lighting, and in particular to a design method for an LED sea sweeping light lighting system. Background Technology

[0002] LED light sources possess advantages such as being green, energy-saving, having a small luminous area, and being highly controllable. They have gradually replaced traditional light sources like incandescent and fluorescent lamps in marine lighting fixtures, better achieving the various optical performance indicators required for these fixtures. Due to the extremely high controllability of light distribution in LED light sources, specific beam angle requirements can be achieved entirely through secondary light distribution design. The design of lens-based lighting optical systems is an effective means of enabling LED light sources to form small-angle beams and create uniform illumination spots on the target plane.

[0003] To achieve a small beam angle design, freeform lenses are currently used to achieve this goal. Although freeform lenses can achieve the desired illumination on the target plane, the following problems still exist: (1) Due to the large light emission size and uniform light emission of COB light source, more stray light will be generated in the secondary light distribution process compared with LED light source; (2) COB light source and the lighting optical system composed of collimation module, optical integrator and collimation beam expansion system can only be set up with long focal length fixed focus system to achieve small angle uniform light illumination. Therefore, the miniaturized lamp head design of lamps cannot be achieved. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a design method for an LED sea-sweeping light system to solve the aforementioned problems.

[0005] The technical solution adopted by this invention to solve its technical problem is: a design method for an LED sea-sweeping light illumination system, comprising:

[0006] Array unit design steps: LED light source array module, uniform collimating lens array module, and beam expanding Fresnel lens array module are sequentially set up, wherein the beam expanding Fresnel lens array module includes a focusing Fresnel lens array and a collimating Fresnel lens array; the light emitted by the LED light source array module passes sequentially through the uniform collimating lens array module, the focusing Fresnel lens array, and the collimating Fresnel lens array;

[0007] Length design steps: Determine the distance between the LED light source array module and the uniform collimating lens array module. Thickness of the homogenizing collimating lens array module The distance from the uniform collimating lens array module to the focusing Fresnel lens array Thickness of the focusing Fresnel lens array Thickness of collimated Fresnel lens array Focal length of a condenser Fresnel lens array Focal length of collimating Fresnel lens array ; Calculate the distance from the focusing Fresnel lens array to the collimating Fresnel lens array. ,in and Satisfying the proportional relationship; obtaining the length of the LED sea-sweeping light illumination system. .

[0008] It is worth noting that the design method also includes a beam-expanding performance design step:

[0009] Design the diameter of the concentrated Fresnel lens array. and the diameter of the collimating Fresnel lens array The beam-expanding performance of the LED sea-sweeping light illumination system was obtained. .

[0010] Optionally, the design method further includes a light energy utilization design step:

[0011] The luminous flux of the LED light source array module is designed. and the luminous flux of the homogenizing collimating lens array module The light energy utilization rate of the LED sea-sweeping light lighting system was obtained. .

[0012] Specifically, in the light energy utilization design step, the luminous flux of the LED light source array module... Where L is the brightness of the LED light source array module, and dA is the area of ​​an element at a certain distance from the LED light source array module. The light emission angle of the uniform collimating lens array module corresponds to that of the LED light source array module. The aperture of the homogenizing collimating lens array module is [missing information]. The distance between the LED light source array module and the uniform collimating lens array module.

[0013] Preferably, in the array unit design step, the uniform light collimating lens array module's freeform surface faces the LED light source array module, and the collimating freeform surface of the uniform light collimating lens array module faces the focusing Fresnel lens array.

[0014] It is worth noting that the array unit design steps also include:

[0015] Establish a coordinate system;

[0016] Establish the coordinates of the uniformly illuminated freeform surface in the coordinate system as follows:

[0017] Given an initial point on a uniform freeform surface, iteratively calculate the coordinates of points on the first contour line of the light rays emitted from the surface. Thus, the first contour line is obtained, wherein... The coordinates of the point to be calculated in the current iteration. The coordinates of the previous point. The slope corresponding to the coordinates of the previous point. The light emission angle of the light source corresponding to the current point coordinates is given; the first contour line is rotated 360° around the y-axis of the coordinate system to obtain the coordinates of the uniform freeform surface in the coordinate system.

[0018] Optionally, during the process of establishing the coordinates of the uniform light freeform surface in the coordinate system in the array unit design step, the initial point coordinates of the uniform light freeform surface are set to (0, 3), and the slope corresponding to the point coordinates of the uniform light freeform surface is set. ,in, Let the angle be the angle at which the light ray is incident on the uniform freeform surface. The angle of the light rays emitted from the uniform freeform surface, where n is the refractive index of the medium of the uniform collimating lens in the uniform collimating lens array module.

[0019] Specifically, the array unit design steps further include:

[0020] Establish the coordinates of the collimated freeform surface in the coordinate system as follows:

[0021] An initial point is set for the collimated freeform surface, wherein the initial point of the collimated freeform surface is the point on the edge of the uniform light collimating lens array module based on the thickness of the uniform light collimating lens array module. The requirement is to select a point, where The thickness of the uniform collimating lens array module;

[0022] Iterative calculation of the point coordinates on the second profile of the light rays emitted from the collimated freeform surface

[0023] The second contour line is obtained, wherein The coordinates of the current point on the collimated freeform surface. β represents the coordinates of the point preceding the current point on the collimated freeform surface. i+1 The angle of the incident ray is the current point coordinate of the collimated freeform surface; rotating the second contour curve 360° around the y-axis of the coordinate system yields the coordinates of the collimated freeform surface in the coordinate system. This represents the slope corresponding to the coordinates of the point preceding the current point.

[0024] Preferably, the array unit design step further includes:

[0025] A focusing plane and a focusing Fresnel surface are set in a focusing Fresnel lens array;

[0026] The focusing plane vertically receives the outgoing light from the uniform collimating lens array module. The focusing Fresnel plane is divided into equal widths to obtain the curvature radius of the incident light corresponding to different rings, so that the outgoing light from the uniform collimating lens array module is converged to an optimal image plane by the focusing Fresnel lens array.

[0027] It is worth noting that the array unit design steps also include:

[0028] A collimation plane and a collimation Fresnel surface are provided in the collimating Fresnel lens array;

[0029] The collimating plane receives the light rays emitted from the optimal image plane of the focusing Fresnel lens array. The collimating Fresnel plane is divided into equal-width sections to obtain the radius of curvature of the incident light rays corresponding to different rings, so that the light rays emitted from the optimal image plane of the focusing Fresnel lens array are collimated into collimated light rays at a small angle after passing through the collimating Fresnel lens array.

[0030] The beneficial effects of this invention are as follows: In the design method of the LED sea-sweeping light illumination system, since the ideal illumination effect can be achieved as long as the focal length of the focusing Fresnel lens array and the collimating Fresnel lens array satisfy a proportional relationship, the length of the LED sea-sweeping light illumination system can be adjusted by changing the focal length ratio between the collimating Fresnel lens array and the focusing Fresnel lens array in the beam-expanding Fresnel lens array module. Thus, by adopting the imaging design principle, the length of the LED sea-sweeping light illumination system can be adjusted by changing the focal length ratio between the collimating Fresnel lens array and the focusing Fresnel lens array, which can better compress the length of the LED sea-sweeping light illumination system and achieve uniform illumination at a small angle. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the design method of an LED sea-sweeping light lighting system in one embodiment of the present invention;

[0032] Figure 2 This is a light path diagram of an LED sea-sweeping light illumination system in one embodiment of the present invention;

[0033] Figure 3 This is a structural diagram of an LED sea-sweeping light illumination system according to one embodiment of the present invention;

[0034] Figure 4 This is an optical path diagram of a single-channel LED sea-sweeping light illumination system in another embodiment of the present invention;

[0035] Figure 5This is a structural diagram of a uniform collimating lens array module in one embodiment of the present invention;

[0036] Figure 6 This is a mathematical modeling diagram of the uniform collimating lens array module in one embodiment of the present invention;

[0037] Figure 7 This is a structural diagram of a focusing Fresnel lens in one embodiment of the present invention.

[0038] Figure 8 This is a structural diagram of a collimating Fresnel lens in one embodiment of the present invention;

[0039] In the diagram: 1 LED light source array module; 2 Uniform collimating lens array module; 21 Uniform freeform surface; 22 Collimating freeform surface; 3 Beam expanding Fresnel lens array module; 31 Concentrating Fresnel lens array; 311 Concentrating plane; 312 Concentrating Fresnel surface; 32 Collimating Fresnel lens array; 321 Collimating plane; 322 Collimating Fresnel surface. Detailed Implementation

[0040] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] like Figure 1-8 As shown, a design method for an LED sea-sweeping light lighting system includes:

[0042] Array unit design steps: LED light source array module 1, uniform collimating lens array module 2, and beam expanding Fresnel lens array module 3 are sequentially arranged, wherein the beam expanding Fresnel lens array module 3 includes a focusing Fresnel lens array 31 and a collimating Fresnel lens array 32; the light emitted from the LED light source array module 1 passes sequentially through the uniform collimating lens array module 2, the focusing Fresnel lens array 31, and the collimating Fresnel lens array 32;

[0043] Length design steps: Determine the distance between LED light source array module 1 and uniform collimating lens array module 2. Thickness of the uniform collimating lens array module 2 The distance from the uniform collimating lens array module 2 to the focusing Fresnel lens array 31 Thickness of the focusing Fresnel lens array 31 Thickness of the collimated Fresnel lens array 32 The focal length of the condenser Fresnel lens array 31 The focal length of the collimating Fresnel lens array 32 ; Calculate the distance from the focusing Fresnel lens array 31 to the collimating Fresnel lens array 32. ,in and Satisfying the proportional relationship; obtaining the length of the LED sea-sweeping light illumination system. .

[0044] In the design method of the LED sea-sweeping light illumination system, since the ideal illumination effect can be achieved as long as the focal length of the focusing Fresnel lens array 31 and the focal length of the collimating Fresnel lens array 32 meet the proportional relationship, the length of the LED sea-sweeping light illumination system can be adjusted by changing the focal length ratio between the collimating Fresnel lens array 32 and the focusing Fresnel lens array 31 in the beam-expanding Fresnel lens array module 3. Thus, by adopting the imaging design principle, the length of the LED sea-sweeping light illumination system can be adjusted by adjusting the focal length ratio between the collimating Fresnel lens array 32 and the focusing Fresnel lens array 31, which can better compress the length of the LED sea-sweeping light illumination system and achieve uniform illumination at a small angle.

[0045] It is worth noting that the design method also includes a beam-expanding performance design step:

[0046] The diameter of the focusing Fresnel lens array 31 is designed. and the diameter of the collimating Fresnel lens array 32 The beam-expanding performance of the LED sea-sweeping light illumination system was obtained. .

[0047] The beam-expanding performance of the LED sea-sweeping lamp lighting system can be changed by altering the diameter ratio of the collimating Fresnel lens array 32 to the focusing Fresnel lens array 31 in the beam-expanding Fresnel lens array module 3.

[0048] Specifically, the design method further includes a light energy utilization design step:

[0049] The luminous flux of the LED light source array module 1 is designed to be... and the luminous flux of the uniform collimating lens array module 2 The light energy utilization rate of the LED sea-sweeping light lighting system was obtained. .

[0050] The luminous flux of the light emitted from the LED light source array module 1 into the uniform collimating lens array module 2 depends on the aperture of the uniform collimating lens array module 2. The ratio of the luminous flux entering the uniform collimating lens array module 2 to the luminous flux emitted from the LED light source array module 1 determines the light energy utilization rate of the optical system.

[0051] Optionally, in the light energy utilization design step, the luminous flux of the LED light source array module 1 is... Where L is the brightness of the LED light source array module 1, and dA is the area of ​​an element at a certain distance from the LED light source array module 1. The light output angle of the LED light source array module 1 corresponds to the light-uniform collimating lens array module 2. The aperture of the homogenizing collimating lens array module 2 is [missing information]. The distance between the LED light source array module 1 and the uniform light collimating lens array module 2.

[0052] Preferably, in the array unit design step, the uniform light collimating lens array module 2 has its uniform light freeform surface 21 facing the LED light source array module 1, and its collimating freeform surface 22 facing the focusing Fresnel lens array 31.

[0053] like Figure 2-6 As shown, the uniform freeform surface 21 refracts the light emitted by the LED light source array module 1, making the refracted light uniformly distributed. After passing through the collimating freeform surface 22, the refracted light forms collimated rays parallel to the y-axis of the coordinate system, and then enters the focusing Fresnel lens array 31. The focusing Fresnel lens array 31 is used to converge the collimated rays emitted from the collimating freeform surface 22 to an optimal image point; the collimating Fresnel lens array 32 is used to collimate the light emitted from the optimal image point again to form small-angle illumination.

[0054] It is worth noting that, such as Figure 6 As shown, the array unit design steps further include:

[0055] Establish a coordinate system;

[0056] Establish the coordinates of the uniform freeform surface 21 in the coordinate system as follows:

[0057] Set the initial point of the uniform freeform surface 21, and iteratively calculate the coordinates of the points on the first contour line of the light rays emitted from the uniform freeform surface 21. Thus, the first contour line is obtained, wherein... The coordinates of the point to be calculated in the current iteration. The coordinates of the previous point. The slope corresponding to the coordinates of the previous point. The light emission angle of the light source corresponding to the current point coordinates; rotate the first contour line 360° with the y-axis of the coordinate system as the center axis to obtain the coordinates of the uniform light freeform surface 21 in the coordinate system.

[0058] like Figure 7As shown, the uniform freeform surface 21 divides the spatial distribution of light energy emitted by the LED light source array module 1 into N equal-flux circular energy units according to the law of conservation of energy. The target plane is divided into N equal-area circular units. According to the law of conservation of energy and the principle of edge lines, the equal-flux circular energy units are incident on the equal-area circular units, thereby achieving a uniform irradiance distribution on the target surface.

[0059] The current point coordinates correspond to the light emission angle of the light source. The direction of the edge light rays is obtained based on the refraction through the uniform freeform surface 21. The beam-expanding performance of the LED sea-sweeping light illumination system can be changed by altering the diameter ratio of the collimating Fresnel lens array 32 to the focusing Fresnel lens array 31 in the beam-expanding Fresnel lens array module 3.

[0060] In some embodiments, during the process of establishing the coordinates of the uniform light freeform surface 21 in the coordinate system during the array unit design step, the initial point coordinates of the uniform light freeform surface 21 are set to (0, 3), and the slope corresponding to the point coordinates of the uniform light freeform surface 21 is set. ,in, Let be the angle at which the light ray is incident on the uniform freeform surface 21. The angle of the light rays emitted from the uniform freeform surface 21, where n is the refractive index of the medium of the uniform collimating lens in the uniform collimating lens array module.

[0061] According to the law of conservation of energy: ;in, The light intensity before homogenization. The light intensity after homogenization. Let be the angle at which the light ray is incident on the uniform freeform surface 21. The angle of the light ray emerging from the uniform freeform surface 21 is given by Ω, which is the solid angle. Solve the integral and then find... and The functional relationship between them is: ,in The light intensity is at the center; according to Snell's law, we know that: ,in The refractive index of a substance Given the refractive index of another material; obtain the slope corresponding to the point coordinates of the uniform freeform surface: .

[0062] Optionally, the array cell design step further includes:

[0063] Establish the coordinates of the collimated freeform surface 22 in the coordinate system as follows:

[0064] An initial point is set for the collimating freeform surface 22, wherein the initial point of the collimating freeform surface 22 is determined based on the thickness of the collimating lens array module on the light rays emitted from the edge of the uniform light freeform surface 21. The requirement is to select a point, where The thickness of the uniform collimating lens array module 2;

[0065] Iterative calculation of the point coordinates on the second profile of the light rays emitted from the collimated freeform surface 22

[0066] The second contour line is obtained, wherein The coordinates of the current point on the collimated freeform surface 22 are: Let β be the coordinate of the point preceding the current point on the collimated freeform surface 22. i+1 The angle of the incident light ray is the current point coordinate of the collimated freeform surface 22; the coordinates of the collimated freeform surface 22 in the coordinate system are obtained by rotating the second contour curve 360° with the y-axis of the coordinate system as the center axis.

[0067] Points on the collimating freeform surface 22 of the uniform collimating lens array module 2 correspond one-to-one with points on the uniform freeform surface 21. According to the law of refraction, the outgoing light rays passing through the uniform freeform surface 21 are refracted into collimated light rays by the collimating freeform surface 22. According to Snell's law, the slope corresponding to the coordinates of the previous point... .

[0068] Preferred, such as Figure 7 As shown, the array unit design steps further include:

[0069] A focusing plane 311 and a focusing Fresnel surface 312 are provided in the focusing Fresnel lens array 31;

[0070] The focusing plane 311 vertically receives the outgoing light from the uniform collimating lens array module 2. The focusing Fresnel surface 312 is divided into equal widths to obtain the curvature radius of the incident light corresponding to different rings, so that the outgoing light from the uniform collimating lens array module 2 is converged to an optimal image plane by the focusing Fresnel lens array 31.

[0071] It is worth noting that, such as Figure 8 As shown, the array unit design steps further include:

[0072] A collimation plane 321 and a collimation Fresnel surface 322 are provided in the collimating Fresnel lens array 32;

[0073] The collimating plane 321 receives the light emitted from the optimal image plane of the focusing Fresnel lens array 31. The collimating Fresnel plane 322 is divided into equal widths to obtain the curvature radius of the incident light corresponding to different rings, so that the light emitted from the optimal image plane of the focusing Fresnel lens array 31 is collimated into collimated light rays at a small angle after passing through the collimating Fresnel lens array 32.

[0074] The LED sea-sweeping light illumination system exhibits optimal optical performance when the aperture of the uniform collimating lens array module 2 is 20mm, the light energy utilization rate is 0.7, and the beam expansion performance value is 1.6. The length of the optical system is 130mm. The average beam angle of the LED sea-sweeping light illumination system is 1.8°, forming an area of ​​1.2m² on a 200m receiving surface. The LED sea-sweeping light system features a uniform light spot size of 1.2m, with an average irradiance of 193 lux and an illuminance uniformity of 0.8. This system demonstrates high light energy utilization and excellent uniformity.

[0075] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A design method for an LED sea-sweeping light illumination system, characterized in that, include: Array unit design steps: LED light source array module, uniform collimating lens array module, and beam expanding Fresnel lens array module are sequentially set up, wherein the beam expanding Fresnel lens array module includes a focusing Fresnel lens array and a collimating Fresnel lens array; the light emitted by the LED light source array module passes sequentially through the uniform collimating lens array module, the focusing Fresnel lens array, and the collimating Fresnel lens array; In the array unit design step, the uniform light collimating lens array module's freeform surface is oriented towards the LED light source array module, and the collimating freeform surface of the uniform light collimating lens array module is oriented towards the focusing Fresnel lens array. The array unit design steps also include: Establish a coordinate system; Establish the coordinates of the uniformly illuminated freeform surface in the coordinate system as follows: Given an initial point on a uniform freeform surface, iteratively calculate the coordinates of points on the first contour line of the light rays emitted from the surface. Thus, the first contour line is obtained, wherein... The coordinates of the point to be calculated in the current iteration. The coordinates of the previous point. The slope corresponding to the coordinates of the previous point. The light emission angle of the light source corresponding to the current point coordinates; rotate the first contour line 360° around the y-axis of the coordinate system to obtain the coordinates of the uniform light freeform surface in the coordinate system; Establish the coordinates of the collimated freeform surface in the coordinate system as follows: An initial point is set for the collimated freeform surface, wherein the initial point of the collimated freeform surface is the point on the edge of the uniform light collimating lens array module based on the thickness of the uniform light collimating lens array module. The requirement is to select a point, where The thickness of the uniform collimating lens array module; Iterative calculation of the point coordinates on the second profile of the light rays emitted from the collimated freeform surface The second contour line is obtained, wherein The coordinates of the current point on the collimated freeform surface. β represents the coordinates of the point preceding the current point on the collimated freeform surface. i+1 The angle of the incident ray is the current point coordinate of the collimated freeform surface; rotating the second profile curve 360° around the y-axis of the coordinate system yields the coordinates of the collimated freeform surface in the coordinate system. The slope corresponding to the coordinates of the point preceding the current point; Length design steps: Determine the distance between the LED light source array module and the uniform collimating lens array module. Thickness of the homogenizing collimating lens array module The distance from the uniform collimating lens array module to the focusing Fresnel lens array Thickness of the focusing Fresnel lens array Thickness of collimated Fresnel lens array Focal length of a condenser Fresnel lens array Focal length of collimating Fresnel lens array ; Calculate the distance from the focusing Fresnel lens array to the collimating Fresnel lens array. ,in and Satisfying the proportional relationship; obtaining the length of the LED sea-sweeping light illumination system. .

2. The design method of an LED sea-sweeping light illumination system according to claim 1, characterized in that, The design method also includes a beam-expanding performance design step: Design the diameter of the condensing Fresnel lens in the aforementioned condensing Fresnel lens array. The diameter of the collimating Fresnel lens in the collimating Fresnel lens array The beam-expanding performance of the LED sea-sweeping light illumination system was obtained. .

3. The design method of an LED sea-sweeping light illumination system according to claim 2, characterized in that: The design method also includes a light energy utilization design step: The luminous flux of the LED light source array module is designed. and the luminous flux of the homogenizing collimating lens array module The light energy utilization rate of the LED sea-sweeping light lighting system was obtained. .

4. The design method of an LED sea-sweeping light illumination system according to claim 3, characterized in that: In the light energy utilization design step, the luminous flux of the LED light source array module Where L is the brightness of the LED light source array module, and dA is the area of ​​an element at a certain distance from the LED light source array module. The light emission angle of the uniform collimating lens array module corresponds to that of the LED light source array module. The aperture of the homogenizing collimating lens array module is [missing information]. The distance between the LED light source array module and the uniform collimating lens array module.

5. The design method of an LED sea-sweeping light illumination system according to claim 4, characterized in that, In the process of establishing the coordinates of the uniform light freeform surface in the coordinate system during the array unit design step, the initial point coordinates of the uniform light freeform surface are set to (0, 3), and the slope corresponding to the point coordinates of the uniform light freeform surface is set. ,in, Let the angle be the angle at which the light ray is incident on the uniform freeform surface. The angle of the light rays emitted from the uniform freeform surface, where n is the refractive index of the medium of the uniform collimating lens in the uniform collimating lens array module.

6. The design method of an LED sea-sweeping light illumination system according to claim 5, characterized in that, The array unit design steps also include: A focusing plane and a focusing Fresnel surface are set in a focusing Fresnel lens array; The focusing plane vertically receives the outgoing light from the uniform collimating lens array module. The focusing Fresnel plane is divided into equal widths to obtain the curvature radius of the incident light corresponding to different rings, so that the outgoing light from the uniform collimating lens array module is converged to an optimal image plane by the focusing Fresnel lens array.

7. The design method of an LED sea-sweeping light illumination system according to claim 6, characterized in that, The array unit design steps also include: A collimation plane and a collimation Fresnel surface are provided in the collimating Fresnel lens array; The collimating plane receives the light rays emitted from the optimal image plane of the focusing Fresnel lens array. The collimating Fresnel plane is divided into equal-width sections to obtain the radius of curvature of the incident light rays corresponding to different rings, so that the light rays emitted from the optimal image plane of the focusing Fresnel lens array are collimated into collimated light rays at a small angle after passing through the collimating Fresnel lens array.

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