Collimating lens and collimating lens design method

Abstract

The invention relates to the technical field of optical lenses, and discloses a collimating lens and a collimating lens design method.The collimating lens is of a non-rotational-symmetry structure, the center of a light source is arranged on the optical axis of the collimating lens, and the collimating lens comprises an incident plane, a light guide plate and a light guide plate; the free-form surface protrudes towards the opposite direction of the light emitting direction by taking the optical axis of the collimating lens as an original point; the emergent surface is a free-form surface which protrudes towards the emergent direction of the light by taking the optical axis of the collimating lens as an original point; the reflecting surfaces are connected with the peripheries of the incident surface and the emergent surface, the number of the reflecting surfaces is four, each reflecting surface is arranged to be a free-form surface protruding towards the optical axis direction of the collimating lens, and a ridge line of the collimating lens is formed at the joint of every two adjacent reflecting surfaces. The collimating lens is of an integrated non-rotational symmetric structure, uniform collimating rectangular illumination can be directly achieved, the purchasing and assembling cost of optical elements is reduced, the complex requirement for cooperation of machining precision of multiple parts is avoided, the design period is shortened, and the mass production difficulty is lowered.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, specifically to a collimating lens and a collimating lens design method. Background Technology

[0002] In the field of secondary optical design for LED lighting, TIR (Total Internal Reflection) lenses are a common solution for achieving light collimation and uniformity. However, traditional technologies have obvious limitations: existing TIR lenses can only achieve collimated and uniform circular lighting. To obtain uniform and collimated rectangular lighting commonly used in industrial and display scenarios, it is necessary to use a combination of various optical lenses such as TIR lenses, integrating lenses, field lenses, MLA (microlens array), and diffusion films.

[0003] This combination of multiple optical lenses is currently the mainstream technology for achieving rectangular lighting in the industry. However, the combination of multiple optical lenses requires the purchase of multiple optical components, and the processing precision requirements of each component are high, which leads to a significant increase in material costs and manufacturing costs.

[0004] Light must pass through multiple optical lenses for refraction and reflection in sequence. Each optical lens will absorb and scatter light, ultimately leading to a significant reduction in the luminous efficiency of the optical system. Furthermore, when multiple optical lenses are combined, sufficient installation gaps and space need to be reserved for their assembly, resulting in an increased size of the lighting system, making it unsuitable for miniaturized and compact applications.

[0005] In addition, the optical parameters of each optical lens need to be coordinated to ensure that the light can still meet the collimation and uniformity requirements after passing through multiple stages, which greatly increases the difficulty and cycle of optical design. Summary of the Invention

[0006] In order to solve the problems of high cost, reduced luminous efficiency, low space utilization and complex optical design in the prior art of rectangular illumination by combining TIR lenses and various optical lenses, this invention provides a collimating lens and a collimating lens design method.

[0007] According to an embodiment of the present invention, a collimating lens is provided, wherein the collimating transparent element has a non-rotationally symmetric structure, and the center of the light source is disposed on the optical axis of the collimating lens. The collimating lens comprises: The incident surface is configured as a freeform surface that bulges in the opposite direction to the direction of light emission with the optical axis of the collimating lens as the origin. The exit surface is configured as a free-form surface that bulges outward toward the direction of light emission with the optical axis of the collimating lens as the origin. The outer periphery of the reflective surface connects the incident surface and the exit surface. There are four reflective surfaces, each of which is a free-form surface that convexes toward the optical axis of the collimating lens. The connection between two adjacent reflective surfaces forms the ridge of the collimating lens.

[0008] In some alternative implementations, a ridge is formed on the emitting surface from the optical axis of the collimating lens to the top of the ridge line. The ridge protrudes in the direction of light emission from the optical axis of the collimating lens to form a protrusion. The ridge protrudes in the opposite direction of light emission from the ridge line of the collimating lens to form a first recess. The protrusion and the first recess are connected in a transitional manner.

[0009] In some alternative implementations, the incident surface protrudes in the direction of light emission to form a second recess, and a plurality of the second recesses are provided, which are spaced apart around the optical axis of the collimating lens.

[0010] In some alternative implementations, the ends of several of the second recesses near the optical axis of the collimating lens are connected as a single unit.

[0011] In some alternative implementations, the bottom view of the incident surface is circular, and the top view of the exiting surface is square; the connection end of each reflecting surface to the exiting surface is connected to one side of the exiting surface.

[0012] In some alternative implementations, the radius of curvature of the reflecting surface gradually increases from the incident surface to the reflecting surface along the ray exit direction.

[0013] In some alternative implementations, the emitting surface protrudes to a greater extent in the direction of light emission than the incident surface protrudes in the opposite direction of light emission.

[0014] In some alternative implementations, the collimating lens is made of PMMA or PC material.

[0015] According to another objective of the present invention, a collimating lens design method is provided for designing a collimating lens as described in any one of the above embodiments; the collimating lens design method includes the following steps: Based on the position of the light source and the positional relationship between the incident light and the target emitted light, a set of light transmission equations between the incident surface and the emitted surface are obtained. Based on Fresnel's law, optical constraint equations are established between two adjacent points on the incident surface and the exit surface, respectively. Based on the initial coordinates of the generatrix of the collimating lens, the light transmission equations and the constraint equations are solved to iteratively generate a complete set of point coordinates for the exit surface and the reflecting surface. A 3D model of the collimating lens is constructed using the complete set of point coordinates; Optical simulation was performed on the 3D model of the collimating lens; The iteration parameters are adjusted based on the simulation results to obtain a definite 3D model of the collimating lens.

[0016] In some alternative implementations, the following is also included before obtaining the ray transmission equations: A coordinate system is established with the center of the light source as the origin, the X-axis as the major axis of the collimating lens, the Y-axis as the minor axis of the collimating lens, the generatrix of the collimating lens located in the XY plane, and the Z-axis as the direction of the light emitted from the light source. The incident light starts from the center of the light source, enters the collimating lens through the incident surface, and then, after being acted upon by the reflecting surface, the outgoing light is collimated and transmitted along the Z-axis, forming a rectangular light spot on the target plane to complete the light transmission path design. Construct the incident light equation, the refraction or reflection equation, and the target constraint equation; Iteratively generating a complete set of point coordinates for the incident surface and the exit surface, specifically including: Several incident rays are generated based on the initial coordinates of the collimating lens generatrix and the incident light equation; Solve the system of ray propagation equations for each incident ray to obtain the coordinates of the point on the exiting surface and the reflecting surface of the incident ray; Based on the set of constraint equations, a complete set of point coordinates for the incident surface, the exit surface, and the reflecting surface is generated iteratively.

[0017] Compared with the prior art, the present invention has the following advantages: The collimating lens provided by this invention is an integrated non-rotationally symmetric structure combining an incident surface, an exit surface, and four reflecting surfaces. It eliminates the need for additional optical components such as integrating lenses, field lenses, MLAs, and diffusion films, achieving uniform collimated rectangular illumination directly through a single lens. This reduces the procurement and assembly costs of optical components, avoids the complex requirements of coordinating the processing precision of multiple components, and alleviates the problems of high cost, reduced luminous efficiency, low space utilization, and complex optical design associated with achieving rectangular illumination through TIR lenses and various optical lens combinations in existing technologies.

[0018] The above description is merely an overview of the technical solutions of the embodiments of the present invention. In order to better understand the technical means of the embodiments of the present invention and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of a collimating lens provided in an embodiment of the present invention is shown.

[0020] Figure 2 A side view of a collimating lens provided in an embodiment of the present invention is shown.

[0021] Figure 3 This diagram illustrates another angle structure of a collimating lens provided in an embodiment of the present invention.

[0022] Figure 4 A top view of a collimating lens provided in an embodiment of the present invention is shown.

[0023] Figure 5 This diagram illustrates another angle structure of a collimating lens provided in an embodiment of the present invention.

[0024] Figure 6 The image shows a bottom view of a collimating lens provided in an embodiment of the present invention.

[0025] Figure 7 The diagram shows a flowchart of a collimating lens design method provided by an embodiment of the present invention.

[0026] Figure 8 This diagram illustrates the structure of the collimating lens's irradiation surface, which is part of a collimating lens design method provided by an embodiment of the present invention.

[0027] Figure 9 This diagram illustrates an iterative data representation of the collimating lens incident and exit surfaces, based on a coordinate system, according to an embodiment of the present invention.

[0028] Figure 10 This diagram illustrates the collimating lens generatrix iteration data of a collimating lens design method provided by an embodiment of the present invention. Detailed Implementation

[0029] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0030] In order to solve the problems of high cost, reduced light efficiency and low space utilization in the prior art of rectangular illumination by combining TIR lenses and various optical lenses, this invention provides a collimating lens.

[0031] An embodiment of the present invention provides a collimating lens, such as... Figure 1-2 As shown, the collimating transparent lens has a non-rotationally symmetric structure. The center of the light source is set on the optical axis 100 of the collimating lens. The collimating lens includes: an incident surface 10, an exit surface 20, and a reflecting surface 30.

[0032] The incident surface 10 is configured as a freeform surface that bulges in the opposite direction to the direction of light emission, with the optical axis 100 of the collimating lens as the origin.

[0033] The exit surface 20 is set as a freeform surface that bulges outward toward the direction of light emission with the optical axis 100 of the collimating lens as the origin.

[0034] The outer periphery of the reflecting surface 30 is connected to the exiting surface 20 and the reflecting surface 30. There are 4 reflecting surfaces 30. Each reflecting surface 30 is a free-form surface that protrudes in the direction of the optical axis 100 of the collimating lens. The connection between two adjacent reflecting surfaces 30 forms the ridge line 40 of the collimating lens.

[0035] In this embodiment, it can also be understood that the incident surface 10 is a freeform surface protruding along the first direction, and the exit surface 20 is a freeform surface protruding along the second direction opposite to the first direction, while the first direction and the second direction are opposite to the optical axis 100 of the collimating lens.

[0036] Four reflecting surfaces 30 connect the outer periphery of the incident surface 10 and the exit surface 20, and the incident surface 10, the exit surface 20 and the four reflecting surfaces 30 form the collimating lens of this embodiment.

[0037] All four reflective surfaces 30 are free-form curves convex toward the optical axis, and ridges 40 are formed between adjacent reflective surfaces 30. Combined with the shape design of the incident surface 20 and the exit surface 30, the light is directed and converged after total internal reflection by the reflective surfaces 30, forming a rectangular light spot with clear edges on the target plane.

[0038] The collimating lens in this embodiment is an integrated non-rotationally symmetric structure. It does not require additional optical components such as integrating lenses, field lenses, MLA, and diffusion films. It can directly achieve uniform collimated rectangular illumination through a single lens, reducing the procurement and assembly costs of optical components, avoiding the complex requirements of coordinating the processing precision of multiple parts, and reducing the problems of high cost, reduced light efficiency, low space utilization, and complex optical design in existing technologies that achieve rectangular illumination through TIR lenses and various optical lens combinations.

[0039] Preferably, in this embodiment, the collimating lens is made of PMMA or PC material.

[0040] Therefore, the collimating lens in this embodiment is an integrated non-rotationally symmetric structure, which can avoid reflection and scattering losses when light is transmitted between multiple components. Combined with the high light transmittance of PMMA or PC material, the light efficiency of the collimating lens is improved.

[0041] This embodiment is a preferred embodiment, and the specific structure of the exit surface 20 has been optimized.

[0042] In this embodiment, as Figure 3-4 As shown, a ridge 50 is formed on the exit surface 20 from the optical axis 100 of the collimating lens to the top of the ridge 40. The ridge 50 protrudes in the direction of the light emission direction near the optical axis 100 of the collimating lens to form a protrusion. The ridge 50 protrudes in the opposite direction of the light emission direction near the ridge 40 of the collimating lens to form a first recess. The protrusion and the first recess are connected in a transitional manner.

[0043] Specifically, the height of the protrusion gradually decreases from the optical axis 100 of the collimating lens toward the direction away from the optical axis 100 of the collimating lens, the depth of the first recess gradually increases from the ridge line 40 away from the collimating lens toward the ridge line 40 of the collimating lens, and the transition connection between the protrusion and the first recess is flush with the exit surface 20.

[0044] In this embodiment, since there are four reflective surfaces 30, there are also four ridge lines 40, and therefore, there are also four ridge lines 50.

[0045] In this embodiment, the protrusion of the ridge 50 to the first recess is designed as a transition structure, which allows the emission surface 20 to adjust the light intensity distribution of the optical axis region and the edge region in a targeted manner, avoiding the problem of the center of the rectangular light spot being too bright and the edge being too dark, thus optimizing the illumination uniformity of the collimating lens and solving the problem of insufficient uniformity that is prone to occur in a single freeform surface.

[0046] This embodiment is a preferred embodiment, and the specific structure of the incident surface 10 has been optimized.

[0047] In this embodiment, as Figure 5-6 As shown, a second recess 101 is formed by protrusions on the incident surface 10 facing the direction of light emission. A plurality of second recesses 101 are provided, and the plurality of second recesses 101 are spaced apart around the optical axis 100 of the collimating lens.

[0048] Preferably, there are four second recesses 101. Since a number of second recesses 101 are spaced around the optical axis 100 of the collimating lens, the portion of the incident surface 10 with the second recesses 101 is concave-convex.

[0049] In this preferred embodiment, the shape of the second recess 101 can be designed as a fan blade, a petal, or a pen tip. The specific shape can also be adjusted and optimized according to the design parameters.

[0050] Preferably, the ends of several second recesses 101 near the optical axis 100 of the collimating lens are connected as a single unit.

[0051] In this embodiment, by providing a plurality of second recesses 101 spaced around the optical axis on the incident surface 10, and connecting the ends of the plurality of second recesses 101 into one piece, the diverging light from the Lambertian light source can be efficiently focused into the collimating lens, reducing incident light escape and improving incident efficiency.

[0052] The second recess 101 is adapted to the light emission characteristics of the light source, so that the light is uniformly incident on the reflecting surface 30 and the emitting surface 20, further optimizing the uniformity and collimation of subsequent light transmission.

[0053] The incident surface 10 is circular in its bottom view and square in its top view; the connection end of each reflecting surface 30 to the exiting surface 20 is connected to one side of the exiting surface 20.

[0054] In this embodiment, based on the fact that all four reflective surfaces 30 are free-curved and convex towards the optical axis, and that ridges 40 are formed between adjacent reflective surfaces 30, combined with the shape design of the circular incident surface 20 and the square exit surface 30, the light is directed and converged after total internal reflection by the reflective surfaces 30, forming a rectangular light spot with clear edges on the target plane.

[0055] Preferably, the radius of curvature of the reflecting surface 30 gradually increases from the incident surface 10 to the reflecting surface 30 along the direction of light emission.

[0056] In this embodiment, the radius of curvature of the reflective surface 30 gradually increases along the direction of light emission to ensure that incident light at different angles can be collimated and transmitted along the Z-axis, thereby optimizing the divergence angle of the collimating lens and improving its collimation performance.

[0057] In this preferred embodiment, the degree to which the exiting surface 20 protrudes in the direction of light emission is greater than the degree to which the incident surface 10 protrudes in the opposite direction of light emission.

[0058] In this embodiment, the exit surface 20 protrudes more than the incident surface 10, so that the collimating lens takes into account both light refraction and the structural strength of the collimating lens, avoids processing deformation caused by excessive protrusion of the curved surface, and ensures mass production consistency.

[0059] In some optional embodiments, this invention provides a collimating lens design method to address the problems of high optical design difficulty and long design cycle in the prior art of achieving rectangular illumination through TIR lenses and various optical lens combinations.

[0060] This embodiment provides a collimating lens design method for designing collimating lenses in any of the above embodiments.

[0061] This embodiment provides a collimating lens design method, such as... Figure 7 As shown, it includes the following steps: S10. Based on the position of the light source and the positional relationship between the incident light and the target outgoing light, the set of light transmission equations between the incident surface 10 and the outgoing surface 20 is obtained.

[0062] S20. Based on Fresnel's law, establish a set of optical constraint equations between two adjacent points on the incident surface 10 and the exit surface 20, respectively.

[0063] That is, optical constraint equations are established between two adjacent points on the incident surface 10 and between two adjacent points on the exit surface 20.

[0064] S30. Based on the initial coordinates of the generatrix of the collimating lens, solve the system of light transmission equations and constraint equations, and iteratively generate a complete set of point coordinates for the incident surface 10, the exit surface 20, and the reflecting surface 30.

[0065] S40. Construct a 3D model of the collimating lens using a complete set of point coordinates.

[0066] S50. Perform optical simulation on the 3D model of the aligned lens.

[0067] S60. Adjust the iteration parameters based on the simulation results to obtain a definite 3D model of the collimating lens.

[0068] Specifically, based on step S50, if the verification lighting effect does not meet the design requirements of collimation, uniformity, and rectangular light spot, then return to adjust the iteration parameters until the design requirements of collimation, uniformity, and rectangular light spot are met, thereby obtaining the determined 3D model of the collimating lens.

[0069] In this embodiment, a mathematical model is established by using the light transmission equation set and the optical constraint equation set, and a complete set of point coordinates is generated iteratively to ensure that the surface parameters of the incident surface 10, the exit surface 20 and the reflecting surface 30 accurately match the light transmission requirements.

[0070] By combining optical simulation and parameter adjustment, the light spot shape, uniformity, collimation and other indicators of the collimating lens can be verified in advance, avoiding performance deviations in the later stages of mass production and improving product yield.

[0071] In this embodiment, before performing step S10, it is necessary to first clarify the design target parameters, tool selection and environmental configuration of the collimating lens according to the actual application scenario of the collimating lens, so as to ensure that the subsequent design has a clear basis.

[0072] Specific parameters include: 1. Target illumination plane distance: The vertical distance from the LED light source to the plane containing the rectangular light spot of the target, which is the distance in the Z-axis direction.

[0073] 2. Target rectangular spot size: The length and width of the rectangular spot on the target plane.

[0074] 3. Collimation requirement: the maximum divergence angle between the outgoing ray and the Z-axis.

[0075] 4. Uniformity requirement: Illumination uniformity on the target plane.

[0076] 5. LED light source parameters: The light source type is Lambertian light source, peak wavelength, luminous flux, and half-power angle.

[0077] 6. Lens material parameters: The refractive index, transmittance, and Abbe number of the selected material, specifically PMMA or PC material.

[0078] This embodiment, as a preferred embodiment, establishes a coordinate system and a light transmission model based on the parameter design of the collimating lens.

[0079] Specifically, it includes: Coordinate system definition: The coordinate system is established with the center of the light source as the origin, the X-axis as the major axis of the collimating lens, the Y-axis as the minor axis of the collimating lens, the generatrix of the collimating lens located in the XY plane, and the Z-axis as the direction of the light emitted from the light source.

[0080] Light transmission path definition: Incident light originates from the center of the light source, enters the collimating lens through the incident surface 10, and then, after being reflected by the reflecting surface 30, the outgoing light is collimated and transmitted along the Z-axis, forming a rectangular light spot on the target plane, thus completing the light transmission path design, such as... Figure 9 As shown.

[0081] Constructing a mathematical model: Construct the incident light equation, the refraction or reflection equation, and the target constraint equation.

[0082] Specifically: Construct the incident light equation and determine the direction vector of any incident light ray based on the characteristics of the Lambertian light source.

[0083] Construct refraction or reflection equations, and establish light transmission constraints on each surface of the lens based on Snell's law and the condition of total internal reflection.

[0084] The target constraint equation requires that all outgoing light rays form a rectangular spot on the target plane. That is, the projection coordinates of the outgoing light rays on the target plane must fall within the size range of the rectangular spot, and the divergence angle of the light rays must meet the collimation requirement.

[0085] In this step, based on the mathematical model, and combined with the coordinate system, the light transmission path, and the design target parameters of the collimating lens, the light transmission equations of steps S10 and S20 above, and the optical constraint equations between two adjacent points on the incident surface 10 and the exit surface 20 are realized.

[0086] In this embodiment, as Figure 9-10 As shown, step S30 specifically includes: Several incident rays are generated based on the initial coordinates of the collimating lens generatrix and the incident light equation.

[0087] Specifically, the starting point of the collimating lens generatrix is ​​selected in the XY plane. This starting point is the intersection of the incident surface 10 and the exit surface 20, and the initial coordinates are set to P0.

[0088] Input the initial coordinates P0, and generate several representative incident rays according to the incident light equation.

[0089] For each incident ray, solve the system of ray propagation equations to obtain the coordinates of the refraction or reflection point of the incident ray on the exit surface 20 and the reflecting surface 30.

[0090] The system of constraint equations is used to verify whether the outgoing light rays meet the target constraints, namely the rectangular light spot and collimation requirements. If they do not meet the requirements, the parameters of the system of equations are adjusted and the process is repeated.

[0091] Repeat the above steps until all incident rays meet the target constraints, and output the coordinate set of the collimating lens generatrix, including the complete point coordinate set of the incident surface 10, the exit surface 20 and the reflecting surface 30, to ensure that the incident rays can be accurately converged into a rectangular light spot after being refracted by the curved surface.

[0092] Using the collimating lens generatrix as a reference, several meridians are generated by rotating around the Z-axis at preset angular intervals.

[0093] All meridian point coordinates are categorized into incident surface 10, exit surface 20, and reflection surface 30, generating complete coordinate files for three surfaces to ensure smooth surfaces during 3D modeling.

[0094] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. Similarly, for the sake of brevity and to aid in understanding one or more aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the embodiments are sometimes grouped together in a single embodiment, figure, or description thereof. The claims, which follow the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0095] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components, except that at least some of such features and / or processes or units are mutually exclusive.

[0096] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A collimating lens, characterized in that, The collimating lens has a non-rotationally symmetric structure, with the center of the light source positioned on the optical axis (100) of the collimating lens. The collimating lens comprises: The incident surface (10) is configured as a freeform surface that bulges in the opposite direction to the outgoing direction of the light with the optical axis (100) of the collimating lens as the origin. The exit surface (20) is configured as a free-form surface that bulges outward toward the direction of light emission with the optical axis (100) of the collimating lens as the origin; A reflecting surface (30) connects the outer periphery of the incident surface (10) and the exit surface (20). There are four reflecting surfaces (30), each of which is a free-form surface protruding toward the optical axis (100) of the collimating lens. The connection between two adjacent reflecting surfaces (30) forms the ridge line (40) of the collimating lens.

2. The collimating lens according to claim 1, characterized in that, A ridge (50) is formed on the exit surface (20) from the optical axis (100) of the collimating lens to the top of the ridge (40). The ridge (50) protrudes in the direction of light emission from the optical axis (100) of the collimating lens to form a protrusion. The ridge (50) protrudes in the opposite direction of light emission from the ridge (40) of the collimating lens to form a first recess. The protrusion and the first recess are connected in a transitional manner.

3. The collimating lens according to claim 1, characterized in that, The incident surface (10) has a second recess (101) protruding in the direction of light emission. A plurality of the second recesses (101) are provided, and the plurality of the second recesses (101) are spaced apart around the optical axis (100) of the collimating lens.

4. The collimating lens according to claim 3, characterized in that, The ends of several second recesses (101) near the optical axis (100) of the collimating lens are connected as one unit.

5. The collimating lens according to claim 1, characterized in that, The incident surface (10) has a circular shape in its bottom view and a square shape in its top view; the connecting end of each of the reflecting surfaces (30) to the exiting surface (20) is connected to one side of the exiting surface (20).

6. The collimating lens according to claim 1, characterized in that, The radius of curvature of the reflecting surface (30) gradually increases from the incident surface (10) to the reflecting surface (30) along the direction of light emission.

7. The collimating lens according to claim 1, characterized in that, The degree to which the exit surface (20) protrudes in the direction of light emission is greater than the degree to which the incident surface (10) protrudes in the opposite direction of light emission.

8. The collimating lens according to claim 1, characterized in that, The collimating lens is made of PMMA or PC material.

9. A collimating lens design method, characterized in that, Used to design the aforementioned claim 1 8. Collimating lens as described in any one of the following; The collimating lens design method includes the following steps: Based on the position of the light source and the positional relationship between the incident light and the target emitted light, a set of light transmission equations between the incident surface (10) and the emitted surface (20) is obtained; Based on Fresnel's law, optical constraint equations are established between two adjacent points on the incident surface (10) and the exit surface (20), respectively. Based on the initial coordinates of the generatrix of the collimating lens, the light transmission equations and the constraint equations are solved to iteratively generate a complete set of point coordinates for the incident surface (10), the exit surface (20), and the reflecting surface (30); A 3D model of the collimating lens is constructed using the complete set of point coordinates; Optical simulation was performed on the 3D model of the collimating lens; The iteration parameters are adjusted based on the simulation results to obtain a definite 3D model of the collimating lens.

10. A collimating lens design method according to claim 9, characterized in that, Before obtaining the equations for ray transmission, the following is also included: A coordinate system is established with the center of the light source as the origin, the X-axis as the major axis of the collimating lens, the Y-axis as the minor axis of the collimating lens, the generatrix of the collimating lens located in the XY plane, and the Z-axis as the direction of the light emitted from the light source. The incident light starts from the center of the light source, enters the collimating lens through the incident surface (10), and after being acted upon by the reflecting surface (30), the outgoing light is collimated and transmitted along the Z-axis, forming a rectangular light spot on the target plane to complete the light transmission path design; Construct the incident light equation, the refraction or reflection equation, and the target constraint equation; Iteratively generate a complete set of point coordinates for the incident surface (10), the exit surface (20), and the reflecting surface (30), specifically including: Several incident rays are generated based on the initial coordinates of the collimating lens generatrix and the incident light equation; Solve the system of ray propagation equations for each incident ray to obtain the point coordinates of the incident ray on the exit surface (20) and the reflecting surface (30); Based on the set of constraint equations, a complete set of point coordinates for the incident surface (10), the exit surface (20), and the reflecting surface (30) is generated iteratively.

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