Scattering homogenizing element, design method and point spread lens

Abstract

This invention relates to the field of optical element technology, and discloses a scattering and homogenizing element, a design method, and a point diffuser lens. The scattering and homogenizing element includes a microlens array, which includes several sub-lenses. The aperture boundaries of the sub-lenses are made of Thiessen polygons, and the seed point coordinates of the Thiessen polygons are randomly distributed. The geometric center point of any Thiessen polygon is the vertex position of the corresponding sub-lens. This invention can effectively suppress interference speckle caused by regular arrays, improve the uniformity of the light field, and has a better homogenizing effect in terms of irradiance distribution and intensity.

Description

Technical Field

[0001] The present invention relates to the technical field of optical elements, and particularly relates to a scattering light homogenizing element, a design method and a point spread lens. Background Art

[0002] Optical scattering light homogenizing elements are used to spatially randomly or engineer the modulation of the phase / amplitude of incident light, so as to achieve the broadening, homogenization, glare suppression, speckle reduction or shaping of the energy distribution at specific angles of the outgoing light. According to the scattering mechanism and structural form, they generally include volume scattering / turbid material type optical scattering light homogenizing elements, surface microstructure / engineered scattering light homogenizing elements and novel metasurface / metamaterial scattering light homogenizing elements.

[0003] Benefiting from the progress of the micro-lens array (MLA) processing technology, its commercial applications have been widely carried out. In imaging systems, micro-lens arrays are used in integrated displays, compound eye imaging and light field imaging, and their multi-microhole characteristics and excellent light splitting and homogenizing performance are also widely used in the lighting field. At present, micro-lens arrays based on surface microstructures generally adopt regular and uniform arrangements (such as rectangular, radially equally spaced arrangements). Although such micro-lens arrays can also produce a uniform beam shaping effect, interference effects are likely to occur between sub-lenses, forming a non-uniform speckle distribution, resulting in a decline in the light homogenizing effect. Summary of the Invention

[0004] The present invention provides a scattering light homogenizing element, a design method and a point spread lens to solve the technical problem of insufficient light homogenizing effect of the scattering light homogenizing element.

[0005] In a first aspect, the present invention provides a scattering light homogenizing element, including: a micro-lens array, the micro-lens array includes a plurality of sub-lenses, the aperture boundary of the sub-lenses adopts a Thiessen polygon, the seed point coordinates of the Thiessen polygon are randomly distributed, and the geometric center point of any Thiessen polygon is the vertex position of the corresponding sub-lens.

[0006] In an optional implementation manner, the value range of the average size of the aperture of the sub-lens is 0.001 mm < p < 10 mm, and p is the average size of the aperture of the sub-lens.

[0007] In an optional implementation manner, the value range of the radius of curvature of the sub-lens is 0.002 mm < │r│ < 20 mm, and r is the radius of curvature of the sub-lens.

[0008] In a second aspect, the present invention provides a design method of a scattering light homogenizing element, which is applied to design the scattering light homogenizing element as described in the first aspect and any one of the first aspect of the present invention. The design method includes: Generating initial seed point coordinates arranged according to a preset uniform rule in the design area of the micro-lens array; Add random perturbations to the initial seed point coordinates to obtain seed point coordinates with random perturbation distribution; The aperture boundary of the sub-lenses arranged in Thiessen polygons is constructed based on the coordinates of the seed point. The sub-lenses are constructed with the geometric center point of any Thiessen polygon as the vertex position of the corresponding sub-lens, thus obtaining the surface height distribution of the microlens array.

[0009] In one alternative implementation, the process of constructing a sub-lens with the geometric center point of any Thiessen polygon as the vertex position of the corresponding sub-lens includes: The average size of the aperture of the sub-lens and / or the radius of curvature of the sub-lens are adjusted based on the preset divergence angle.

[0010] In one alternative implementation, the process of constructing a sub-lens with the geometric center point of any Thiessen polygon as the vertex position of the corresponding sub-lens includes: Adjust the surface offset of the sub-lens based on the preset output beam direction angle.

[0011] In one alternative implementation, after obtaining the surface height distribution of the microlens array, the following steps are included: Gaussian smoothing is applied to the surface height distribution map of the sub-lens.

[0012] Thirdly, the present invention provides a point diffusion lens, comprising: a lens body, the lens body including a scattering region and a light-transmitting region corresponding to the human eye, wherein a plurality of optical scattering points are distributed in the scattering region, and the optical scattering points employ scattering and light-uniforming elements as described in the first aspect and any one of the first aspects of the present invention.

[0013] In one alternative implementation, the optical scattering points are arranged in a uniform density within the scattering region.

[0014] In one optional embodiment, the lens body is a binocular lens corresponding to the left and right eyes of a human body. The light-transmitting area includes a first light-transmitting area and a second light-transmitting area respectively corresponding to the left and right eyes of a human body. The optical scattering points are arranged in a gradually denser pattern from the center of the first light-transmitting area outwards within the scattering area, and are arranged in a gradually denser pattern from the center of the second light-transmitting area outwards within the scattering area; or, the optical scattering points are arranged in a gradually denser pattern from the center of the lens body outwards within the scattering area.

[0015] In one alternative embodiment, the lens body is a monocular lens corresponding to the left or right eye of a human body, and the density of optical scattering points gradually increases from the center of the lens body outward in the scattering area.

[0016] The present invention has at least the following advantages: The scattering and homogenizing element of the present invention constructs the surface shape of each sub-lens by using Thiessen polygons as the aperture boundary of each sub-lens in the microlens array, and the geometric center point of each Thiessen polygon region as the vertex position of the corresponding sub-lens surface. Since the seed point coordinates of the Thiessen polygons are randomly distributed, a microlens array with irregular aperture shape and random position can be formed, which effectively suppresses interference speckle caused by regular arrays, improves the uniformity of the light field, and has a better homogenizing effect in terms of irradiance and intensity. The scattering and homogenizing element of the present invention can achieve a highly uniform homogenizing design with a single element, reducing system complexity and manufacturing cost; Furthermore, by adjusting the average size of the aperture of the sub-lens and / or the radius of curvature of the sub-lens, a preset divergence angle is achieved, and by adjusting the surface offset of the sub-lens, a preset beam direction angle is achieved. This allows the scattering homogenizing element of the present invention to maintain homogenization performance under conditions of multiple beams and eccentric incidence, and it has low tolerance sensitivity and high system robustness. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a 3D structural schematic diagram of the scattering and homogenizing element according to an embodiment of the present invention; Figure 2(a) is a partial schematic diagram of the surface shape of the scattering uniform light element according to an embodiment of the present invention; Figure 2(b) is a schematic diagram of the surface profile and height distribution of the scattering uniform element according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the basic principle of the scattering and homogenizing element according to an embodiment of the present invention; Figure 4 This is a flowchart of the design method for a scattering homogenizing element according to an embodiment of the present invention; Figure 5(a) is a schematic diagram of the distribution of the initial seed points arranged in an equilateral triangle according to an embodiment of the present invention; Figure 5(b) is a schematic diagram of the distribution of seed points after adding random perturbation to Figure 5(a); Figure 6(a) is a schematic diagram of the distribution of the initial seed points in the rectangular arrangement according to an embodiment of the present invention; Figure 6(b) is a schematic diagram of the distribution of seed points after adding random perturbation to Figure 6(a); Figure 7(a) is a schematic diagram of the scattering uniform light element in a design example of the present invention; Figure 7(b) is a 3D schematic diagram of the ray tracing simulation of the scattering homogenizing element in Figure 7(a); Figure 7(c) is the YZ view of the ray tracing of the scattering homogenizing element in Figure 7(a); Figure 7(d) is the XY view of the ray tracing of the scattering homogenizing element in Figure 7(a); Figure 7(e) is a schematic diagram of the irradiance distribution generated on the target surface by the scattering homogenizing element in Figure 7(a); Figure 7(f) is a schematic diagram of the intensity distribution of the light emitted from the scattering homogenizing element in Figure 7(a); Figure 8(a) is a schematic diagram of the surface profile and height distribution of the scattering uniform light element in a design example of the present invention; Figure 8(b) is a schematic diagram of the scattering homogenizing element in Figure 8(a); Figure 8(c) is a schematic diagram of the irradiance distribution generated on the target surface by the scattering homogenizing element in Figure 8(a); Figure 8(d) is a schematic diagram of the intensity distribution of the light emitted from the scattering homogenizing element in Figure 8(a); Figure 9 A schematic diagram illustrating the principle of adjusting the direction angle of the emitted beam; Figure 10(a) is a schematic diagram of the surface profile and height distribution of the scattering uniform light element in a design example of the present invention; Figure 10(b) is a schematic diagram of the scattering homogenizing element in Figure 10(a) in 3D. Figure 10(c) is a 3D schematic diagram of the ray tracing simulation of the scattering homogenizing element in Figure 10(a); Figure 10(d) is the XY view of the ray tracing of the scattering homogenizing element in Figure 10(a); Figure 10(e) is a schematic diagram of the irradiance distribution generated on the target surface by the scattering homogenizing element in Figure 10(a); Figure 10(f) is a schematic diagram of the intensity distribution of the light emitted from the scattering homogenizing element in Figure 10(a); Figure 11(a) is a schematic diagram of the surface profile and height distribution of the scattering uniform light element in a design example of the present invention; Figure 11(b) is a schematic diagram of the scattering homogenizing element in Figure 11(a) in 3D. Figure 11(c) is a 3D schematic diagram of the ray tracing simulation after four different distributions of Gaussian beams are incident on the scattering homogenizing element in Figure 11(a); Figure 11(d) is a schematic diagram of the irradiance distribution of four Gaussian beams incident on the back surface of the scattering homogenizer in Figure 11(a). Figure 11(e) is a schematic diagram of the irradiance distribution generated on the target surface by the scattering homogenizing element in Figure 11(a); Figure 11(f) is a schematic diagram of the intensity distribution of the light emitted from the scattering homogenizing element in Figure 11(a); Figure 12(a) is a front view of a dot diffuser lens according to an embodiment of the present invention; Figure 12(b) is a 3D view of the point diffuser lens in Figure 12(a); Figure 13(a) is a front view of another dot diffuser lens according to an embodiment of the present invention; Figure 13(b) is a 3D view of the point diffuser lens in Figure 13(a); Figure 14(a) is a front view of another dot diffuser lens according to an embodiment of the present invention; Figure 14(b) is a 3D view of the point diffuser lens in Figure 14(a).

[0019] Figure 15 This is a 3D view of a circular aperture monocular point diffuser lens according to an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Collimated beam; 2. Scattering and homogenizing element; 21. Rear surface; 22. Front surface; 3. First solid angle light distribution; 3A. Second solid angle light distribution; 4. Target surface; 5. High uniformity irradiance distribution; 5A. Offset uniformity irradiance distribution; DP1. Lens body; DP2. Optical scattering point; DP3. First light-transmitting area; DP4. Second light-transmitting area. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. The terms "parallel," "perpendicular," and "equal" include the described situation and situations that are similar to the described situation, where the range of similarity is within an acceptable deviation range, which is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism can be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, within 5°; "equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, the difference between the two equals being less than or equal to 5% of either one. For a person skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0022] Among current scattering homogenizers, volume scattering optical scattering homogenizers broaden the beam through Mie / Rayleigh scattering. Their advantages are low cost and ease of large-area fabrication. However, their disadvantages include the coupling of transmittance / haze and angular distribution, making it difficult to simultaneously optimize dispersion and efficiency.

[0023] Surface microstructures / engineered scattering homogenizing elements quantitatively distribute incident energy to a set diffusion angle or intensity target through pseudo-random or deterministic microstructures, achieving controlled angle distribution and homogenization while maintaining high transmittance. They are widely used in solid-state lighting, laser homogenization, machine vision, and projection.

[0024] Metasurface / metamaterial scattering homogenizers utilize subwavelength structures to achieve wavefront engineering, possessing greater degrees of freedom in angle / polarization / wavelength. The development trend is "broadband, wide field of view, high efficiency, and thinness," but they are still constrained by processing tolerance, bandwidth and angle coupling, and physical limits of thickness.

[0025] Currently, for surface microstructure / engineered scattering and homogenizing elements, although regularly and uniformly arranged microlens arrays can produce uniform beam shaping effects, they still have the following problems: First, the highly uniform aperture shape and arrangement of regular array microlenses lead to significant coherent interference effects between sublenses, easily forming interference speckle and reducing homogenization uniformity. Second, traditional solutions typically require stacking two or more microlens arrays to achieve good homogenization, increasing device complexity and cost. Furthermore, the performance of regular arrays degrades significantly under eccentric incidence conditions, resulting in insufficient system tolerance robustness. Therefore, there is an urgent need for a scattering homogenizing element that can achieve high uniformity, low speckle, and insensitivity to incident eccentricity in a monolithic structure.

[0026] In view of this, embodiments of the present invention provide a scattering homogenizing element, a design method, and a point diffuser lens.

[0027] The scattering and homogenizing element of this invention belongs to the category of surface microstructure / engineered scattering and homogenizing elements. It is based on the boundary of each sub-lens in the microlens array constructed by Thiessen polygons. By arranging microlens microstructures with random position and random sub-lens shape, the incident energy is quantitatively distributed to a set diffusion angle or intensity target, achieving controlled angle distribution and homogenization while maintaining high transmittance. In addition, the scattering and homogenizing element based on the Thiessen polygon microlens array has a low eccentricity tolerance sensitivity, that is, when the incident beam is allowed to have a large eccentricity range.

[0028] The light-scattering and homogenizing element of this invention can be widely used in various fields and scenarios such as solid-state lighting, laser light homogenization, machine vision and projection.

[0029] The specific implementation of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are provided so that the present invention is fully and completely disclosed and that the concept of the present invention is fully conveyed to those skilled in the art.

[0030] According to an embodiment of the present invention, a scattering homogenizing element is provided, combined with Figure 1 As shown in Figure 2(a), the scattering homogenizing element includes: A microlens array, comprising several sublenses, wherein the aperture boundaries of the sublenses are defined by Thiessen polygons, the seed point coordinates of the Thiessen polygons are randomly distributed, and the geometric center point of any Thiessen polygon is the vertex position of the corresponding sublens.

[0031] Specifically, the microlens array is disposed on the surface of the optical substrate, which is a transparent substrate, and the sub-lenses are closely arranged on at least one surface of the optical substrate.

[0032] A Voronoi diagram is a geometric structure that divides space into regions using a spatial partitioning method based on discrete seed points. Specifically, it divides a plane or space into regions where the distance from any point within a region to its corresponding seed point is less than the distance to any other seed point. Its core characteristics are that the boundary is formed by the perpendicular bisectors of the lines connecting adjacent seed points, exhibiting convexity, non-overlapping, and complete coverage. The mathematical definition of a Voronoi diagram is as follows: For a set of points on a plane P ={ p 1 ,p 2 ,p 3 ,…,p n}, the first of the Thiessen polygons i each region V i for:

[0033] in, d ( x , p i ) represents any point in the plane x To the seed point p i The distance.

[0034] According to the mathematical definition of Thiessen polygons, each sub-lens region has the following characteristics: (1) Each region corresponds to a seed point, and the regions do not overlap. (2) The boundary between two adjacent regions is the perpendicular bisector of the line connecting the two points (under Euclidean distance). (3) Thiessen polygons completely divide the space into convex polygons (convexity holds under Euclidean distance). Based on the scattering uniform light element constructed using Thiessen polygons, the shape of each sub-lens is random, and the size difference of each sub-lens is guaranteed to be within a certain range, avoiding large size aberrations of the sub-lens, which is beneficial to improving the uniformity of the light field after scattering.

[0035] Figure 2(a) is a partial schematic diagram of the surface shape of the scattering uniform light element according to an embodiment of the present invention. The basic trend and situation of the surface shape change of the sub-lens can be obtained from the gray-scale change corresponding to the surface shape of the sub-lens in Figure 2(a). Among them, sub-lens 221 is a sub-lens in a microlens array based on the arrangement of Thiessen polygons. The aperture boundary 221A of the sub-lens is the Thiessen polygon. The point in the middle of each sub-lens 221 is the geometric center point 221C of the corresponding Thiessen polygon region. The geometric center point 221C is taken as the vertex position of the sub-lens surface.

[0036] Figure 3 This is a schematic diagram illustrating the basic principle of the scattering and homogenizing element according to an embodiment of the present invention. Figure 3As shown, the incident collimated beam 1 is incident perpendicularly on the scattering homogenizing element 2. The collimated beam 1 first passes through the rear surface 21 of the scattering homogenizing element 2, and then is scattered out by the front surface 22 of the scattering homogenizing element 2. The scattering homogenizing element 2 is composed of elements with a refractive index of 1. n The base thickness is d The light distribution 3, generated by the light scattering and homogenizing element 2 emanating from its front surface 22, is centered on the incident direction of the light beam (the dotted line in the figure). α The solid angle distribution is a conical scattering beam at the apex. The first solid angle light distribution 3 after scattering is transmitted over a certain distance, which is the distance between the scattering homogenizing element 2 and the target surface 4. L Finally, it reaches the target surface 4, forming a highly uniform irradiance distribution 5. This highly uniform irradiance distribution 5 is circular, with a radius of [missing information]. R It can be represented as:

[0037] Furthermore, in order to achieve the solid angle of the first solid angle light distribution 3 that generates scattering, the solid angle is... α It needs to meet the following requirements:

[0038] in, p Let be the average aperture size of the sub-lens in the scattering homogenizing element, with a value ranging from 0.001 mm. p <10mm, the specific value depends on the actual application requirements and processing capabilities. r Let be the radius of curvature of the sub-lens, with a value ranging from 0.002mm < |r| < 20mm. The sub-lens can be concave or convex, corresponding to a negative or positive radius of curvature r. The specific value depends on the actual application requirements and manufacturing capabilities. The radius of curvature r of the sub-lens determines the divergence angle of the emitted light, and the achievable solid angle of the scattered light distribution is... α Satisfying 2° < α< 60°. Thickness of the optical substrate. d There are no restrictions; users can consider the required thickness for specific applications.

[0039] The scattering and homogenizing element of this invention constructs the surface shape of each sub-lens by using Thiessen polygons as the aperture boundary of each sub-lens in the microlens array, and the geometric center point of each Thiessen polygon region as the vertex position of the corresponding sub-lens surface. Since the seed point coordinates of the Thiessen polygons are randomly distributed, a microlens array with irregular aperture shape and random position can be formed, effectively suppressing interference speckle caused by regular arrays, improving light field uniformity, and achieving good irradiance and intensity homogenization. High-uniformity homogenization design can be achieved with a single element, reducing system complexity and manufacturing costs. Furthermore, a preset divergence angle is achieved by adjusting the average aperture size and / or radius of curvature of the sub-lens, and a preset beam direction angle is achieved by adjusting the surface shape offset of the sub-lens, ensuring homogenization performance even under multi-beam and eccentric incidence conditions, exhibiting low tolerance sensitivity and high system robustness.

[0040] This invention also provides a design method for a scattering and homogenizing element, applicable to the design of scattering and homogenizing elements as described in the above embodiments of this invention, such as... Figure 4 As shown, the design method includes: Step S401: Generate the coordinates of initial seed points arranged according to a preset uniform rule in the design area of ​​the microlens array.

[0041] Specifically, the coordinates of the initial seed points generated according to the preset uniform arrangement rules are relatively regular and orderly.

[0042] The preset uniform rules can be equilateral triangle arrangement, rectangular arrangement, parallelogram arrangement, isosceles trapezoid arrangement, etc.

[0043] Step S402: Add random perturbation to the initial seed point coordinates to obtain seed point coordinates with random perturbation distribution.

[0044] Using the initial seed points of the Thiessen polygon as the optical axis positions (XY coordinates) of the sub-lenses on the scattering homogenizer, random perturbations are introduced on top of the uniform and regular arrangement, thereby introducing randomness into the sub-lens arrangement. The coordinates of the randomly perturbed seed points, i.e., the sub-lens arrangement coordinates, can be expressed as:

[0045] in( X , Y ) are the coordinates of the seed point after random perturbation, ( X 0, Y 0) represents the coordinates of the initial seed point for the regular arrangement. d It is the maximum value of the random perturbation. rand It is a random number within the range (-1, 1). The spacing between the seed points arranged according to the above rules is equal to the average size of the required sub-lens aperture.p , where its value range is 0.001 mm < p < 10 mm, and the specific value is determined according to the actual application requirements and processing capabilities.

[0046] In one example, Fig. 5(a) corresponds to the initial seed points arranged in a regular triangle. Based on the regular triangle arrangement, by introducing a random perturbation amount in the XY direction, as shown in Fig. 5(b), the seed point coordinates 221B with random perturbation characteristics are further realized, that is, the XY coordinate points of the optical axis position of the sub-lens; Fig. 6(a) corresponds to the initial seed points arranged in a rectangle. Based on the rectangle arrangement, by introducing a random perturbation amount in the XY direction, as shown in Fig. 6(b), the seed point coordinates 221B with random perturbation characteristics are further realized.

[0047] Step S403: Based on the seed point coordinates, construct the aperture boundary of the sub-lenses arranged in a Voronoi polygon. Taking the geometric center point of any Voronoi polygon as the vertex position of the corresponding sub-lens, construct the sub-lenses to obtain the surface height distribution of the microlens array.

[0048] Specifically, according to the seed point coordinates 221B with random perturbation characteristics, the arrangement of sub-lenses with Voronoi polygon arrangement characteristics can be constructed to obtain the aperture boundaries of each sub-lens. Further, set the curvature radius of the sub-lenses according to requirements. Taking the geometric center point of any Voronoi polygon as the vertex position of the corresponding sub-lens, construct the sub-lenses, and determine the surface height distribution of each sub-lens in the microlens array. The surface height distribution diagram of the sub-lenses in the scattering light homogenizing element shown in Fig. 2(a) can be obtained. From the gray-scale change corresponding to the surface shape of the sub-lenses in Fig. 2(a), we can obtain the basic trend and situation of the surface shape change of the sub-lens.

[0049] According to the design method of the scattering light homogenizing element of the embodiment of the present invention, first generate the initial seed point coordinates arranged in a preset uniform and regular manner in the design region plane, then introduce random perturbations to obtain the seed point coordinate distribution. The Voronoi polygon region formed based on this is used as the aperture boundary of each sub-lens. The geometric center of each Voronoi polygon region is used as the vertex position of the sub-lens surface. Taking the geometric center point of any Voronoi polygon as the vertex position of the corresponding sub-lens, construct the sub-lenses, determine the surface height distribution of the microlens array, and further form a microlens array with irregular aperture morphology and position randomness, which can effectively suppress the interference speckles caused by the regular array, improve the light field uniformity, and have a good light homogenizing effect on irradiance and intensity.

[0050] The scattering and homogenizing element designed according to the design method of the present invention can achieve high uniformity of light homogenization design with a single element, reducing system complexity and manufacturing cost; the preset divergence angle can be achieved by adjusting the average size of the aperture of the sub-lens and / or the radius of curvature of the sub-lens, and the preset beam direction angle can be achieved by adjusting the surface offset of the sub-lens; the homogenizing performance is maintained under multi-beam and eccentric incidence conditions, and it has low tolerance sensitivity and high system robustness.

[0051] In some embodiments, after obtaining the surface height distribution of the microlens array in step S403, the following steps are included: Step S404: Perform Gaussian smoothing on the surface height distribution map of the sub-lens.

[0052] Specifically, in optical surface modeling, the surface height map is treated as a two-dimensional function, and Gaussian blurring is used to simulate the precision limitations in the manufacturing process. Therefore, to realize a machinable scattering and homogenizing element, the obtained Thiessen polygon-based microlens array is further subjected to Gaussian smoothing of its surface shape. The two-dimensional Gaussian function is defined as:

[0053] in, s It is the standard deviation that determines the degree of fuzziness, and is usually related to the point spread function (PSF) of the manufacturing equipment or the precision of the machining tools.

[0054] Given the original face height Zo ( x , y Gaussian smoothed surface Zp ( x , y That is, the surface shape after being disturbed during the manufacturing process can be represented as:

[0055] Where * denotes convolution. e ( x , y () represents other error functions. In practical applications, the main focus is on the systematic error caused by Gaussian blur; other error functions can be ignored. The standard deviation is set according to the specific application. s Its value range is 0.5μm< s< 50μm, the specific value needs to take into account the optical processing method and precision.

[0056] Furthermore, Figure 2(b) fully shows a 5mm×5mm grayscale image of the surface profile and height distribution of the scattering uniform element based on the Thiessen polygonal microlens array after Gaussian smoothing.

[0057] It should be understood that the size of the light-scattering and homogenizing element proposed in the embodiments of the present invention can be expanded to the size of the actual optical element as needed, that is, it can be 0.1mm×0.1mm or even 100mm×100mm. The optical substrate of the light-scattering and homogenizing element can also be any other shape and size, such as a circular, square, arbitrary polygonal or curved closed aperture lens. The material of the optical substrate can also be various uniform transparent media, such as glass, resin and other materials.

[0058] In this embodiment of the invention, by applying Gaussian smoothing to the surface shape of the sub-lenses, a relatively smooth transition can be achieved at the edge of each sub-lens joint, avoiding sharp abrupt changes in surface shape. Using Gaussian smoothing to optimize the surface shape of the sub-lens joint boundaries improves surface continuity and processing feasibility.

[0059] The scattering homogenizing element obtained by the design method in the above embodiments can realize the homogenization design of irradiance and intensity to resist diffraction interference speckle. For the homogenization of collimated incident beam, it is reflected in the homogenization of irradiance distribution and intensity distribution in spatial angle on the target surface to resist diffraction interference speckle.

[0060] Figure 7(a) shows a 3D structural diagram of a scattering homogenizing element in a design example, which consists of numerous concave microlenses with polygonal apertures. Figure 7(b) shows a 3D schematic diagram of the ray tracing simulation of this scattering homogenizing element, using a collimated Gaussian beam as the incident light source. Figure 7(c) shows the YZ view of the ray tracing, with the scattering homogenizing element 300mm away from the target surface. Figure 7(d) shows the XY view of the ray tracing of this scattering homogenizing element, showing a circular scattering spot distribution on the target surface. Figure 7(e) shows the irradiance distribution on the target surface. The curves in the slice show that the scattering homogenizing element homogenizes the incident beam, and the irradiance distribution forms a distinct flat-top distribution characteristic within a spatial range of ±50mm on the target surface. Figure 7(f) shows the intensity distribution of the emitted light from the scattering uniform light element. It can be seen that the intensity distribution forms a distinct flat-top distribution within the range of ±10°, which proves that the scattering uniform light element designed in this embodiment of the invention has a good irradiance distribution and intensity uniform light effect. Moreover, a single element can achieve a highly uniform light uniform design, reducing system complexity and manufacturing cost.

[0061] In some embodiments, step S403, in the process of constructing a sub-lens with the geometric center point of any Thiessen polygon as the vertex position of the corresponding sub-lens, includes: Step a1: Adjust the average size of the aperture of the sub-lens and / or the radius of curvature of the sub-lens based on the preset divergence angle.

[0062] Specifically, the scattering uniform light element designed based on the design method of this invention can have its emitted beam divergence angle changed according to the average size and radius of curvature of the sub-lens.

[0063] The preset divergence angle is the divergence angle required by the scattering and homogenizing element. By adjusting the average size of the aperture of the sub-lens or the radius of curvature of the sub-lens, or by adjusting both simultaneously, the actual divergence angle of the scattering and homogenizing element can be made equal to or close to the preset divergence angle.

[0064] The average aperture size of the sub-lenses is achieved by adjusting the spacing of the initial seed points of the Thiessen polygons, while the radius of curvature of the sub-lenses is set after determining the Thiessen polygon regions of each sub-lens. By adjusting the seed point spacing and the range of random perturbation, the size distribution of the sub-lenses can be changed, thereby controlling the scattering angle range of the overall light field.

[0065] Figures 8(a)-(d) show the results of adding a convex sub-lens with a radius of curvature of 0.75 mm, and initial seed point spacing of 0.5 mm for the Thiessen polygon with an equilateral triangle arrangement. d After a random perturbation radius of 0.2 mm, an optical scattering homogenizer based on a microlens array of Thiessen polygons is generated. In this embodiment, the optical scattering homogenizer is 300 mm away from the target surface. Figure 8(a) shows its surface elevation distribution, and Figure 8(b) shows the 3D structure of the optical scattering homogenizer. Figure 8(c) shows the irradiance distribution on the target surface. The irradiance distribution exhibits a flat-top characteristic within a spatial range of ±75 mm in the XY plane, indicating a uniform irradiance distribution. Figure 8(d) shows the intensity distribution, demonstrating that an optical scattering effect with a solid angle of ±15° is achieved, and the scattering intensity exhibits a clear flat-top effect. This confirms that for a collimated incident beam, different exit beam divergence angles can be achieved by changing the average size and radius of curvature of the sub-lens aperture.

[0066] Furthermore, by adjusting the radius of curvature of the sub-lens surface... r The initial seed point spacing of the Thiessen polygon can be used to generate optical scattering homogenizers with different divergence angles.

[0067] In some embodiments, step S403, in the process of constructing a sub-lens with the geometric center point of any Thiessen polygon as the vertex position of the corresponding sub-lens, includes: Step b1: Adjust the surface offset of the sub-lens based on the preset outgoing beam direction angle.

[0068] The surface offset refers to the positional offset of the vertex of the sub-lens surface relative to the geometric center of the Thiessen polygon.

[0069] Specifically, for a collimated incident beam, the direction angle of the outgoing beam can be changed by adjusting the offset of the sub-lens surface, thus achieving different outgoing beam direction angles.

[0070] The preset output beam direction angle is the required output beam direction angle for the scattering and homogenizing element. By adjusting the surface offset of the sub-lens, the actual output beam direction angle of the scattering and homogenizing element can be made equal to or close to the preset output beam direction angle. By shifting the surface of the sub-lens as a whole, the output beam direction angle can be controlled while maintaining the beam divergence angle.

[0071] The embodiments of the present invention can achieve the effect of having different emitted light direction angles. Figure 9 The diagram shows the principle of adjusting the direction angle of the emitted beam. Figure 9 As shown, the incident collimated beam 1 is perpendicularly incident on the scattering and homogenizing element 2 proposed in this embodiment of the invention. The collimated beam 1 first passes through the rear surface 21 of the scattering and homogenizing element 2, and then is scattered and exited by the front surface 22 of the scattering and homogenizing element 2. The scattering and homogenizing element 2 is composed of a refractive index of 2. n The base thickness is d The light is fabricated on a transparent optical substrate. The second solid angle light distribution 3A, generated by the light scattering uniform element 2 emanating from its front surface 22, is... α The scattering solid angle distribution is a cone with a apex, but the direction of the axial center of the scattered light distribution cone makes a certain angle with the perpendicular line to the surface of the optical substrate. β The second solid angle light distribution 3A travels through a distance of... L The transmission eventually reaches the target surface 4, forming an eccentric uniform irradiance distribution 5A.

[0072] Furthermore, the relationship between the emitted beam direction angle and the radius of curvature and surface offset of the sub-lens:

[0073] in, β x It is the direction angle of the emitted beam relative to the X direction. Δx It is the surface offset of the sub-lens. r It is the radius of curvature of the sub-lens. n It is the refractive index of the scattering homogenizing element 2. The above equation also holds true in the Y direction.

[0074] Furthermore, the offset of irradiance distribution on target surface 4 dX The calculation formula is:

[0075] in, L Let be the distance between the scattering homogenizing element 2 and the target surface. The above equation also holds true in the Y direction.

[0076] The specific implementation effects are given below to illustrate that the embodiments of the present invention can achieve the effect of having different emitted light direction angles.

[0077] As shown in Figures 10(a)-(f), based on the radius of curvature of the convex sublens... r =1.0mm, and the initial seed point spacing of the Thiessen polygon is 0.5mm and the equilateral triangle arrangement is added. d After a random perturbation radius of 0.2 mm, the surface shape of all sub-lenses was offset by 0.1 mm in the XY direction, resulting in a microlens array optical scattering homogenizer based on Thiessen polygons. Figure 10(a) shows the sag distribution of the surface shape of the scattering homogenizer, and Figure 10(b) shows the 3D structure of the scattering homogenizer. Figure 10(c) shows a 3D schematic diagram of the ray tracing simulation of the scattering homogenizer, and Figure 10(d) is the XY direction view corresponding to Figure 10(c). It is clear that the irradiance distribution on the target surface has been shifted in the XY direction. As shown in Figure 10(e), the irradiance distribution on the target surface has shifted by 5 mm in each of the XY directions. In addition, as shown in Figure 10(f), the intensity distribution of the light emitted from the scattering homogenizer has shifted by nearly 2.5° in each of the XY directions.

[0078] The scattering homogenizing element obtained by the design method in the above embodiments can still achieve homogenization of multiple collimated incident beams when multiple collimated incident beams with different distributions are incident. This is reflected in the homogenization of the irradiance distribution and the intensity distribution in the spatial angle of the anti-diffraction interference speckle on the target surface. At the same time, it proves that the system has low sensitivity to eccentric incident and exhibits good eccentricity tolerance.

[0079] Referring to Figures 11(a)-(f), this is an optical scattering homogenizer based on a lens array with a convex sub-lens, a radius of curvature r=1.0mm, an initial seed point spacing of 0.5m for the Thiessen polygons, and an equilateral triangle arrangement, generated after adding a random perturbation radius of δ=0.2mm. Figure 11(a) shows the surface shape and height distribution of the scattering homogenizer corresponding to the sub-lens with a radius of curvature r=1.0mm. Figure 11(b) shows the 3D structure of this optical scattering homogenizer. Figure 11(c) is a schematic diagram of ray tracing simulation achieved after using four different distributions of Gaussian beams incident on the scattering homogenizer. Figure 11(d) shows the irradiance distribution of the four Gaussian beams incident on the back surface of the scattering homogenizer. Figure 11(e) shows the irradiance distribution generated on the target surface. As can be seen from the figure, although four different distributions of incident Gaussian beams are used in the system and the incident beams are eccentrically incident, the irradiance distribution on the target surface still has a flat-top characteristic, that is, a uniform irradiance distribution is achieved. Figure 11(f) shows the light intensity distribution emitted by the scattering homogenizer element corresponding to the embodiment of the present invention, thus demonstrating that the system has low sensitivity to eccentric incidence and exhibits good eccentricity tolerance. Since the outer aperture shape of each sub-lens in the scattering surface of the scattering homogenizer element is significantly different, the sub-lens aperture is relatively large (greater than 0.5 mm), and the microlens arrangement is random, it has a suppressive effect on the generation of diffraction and interference bright spots.

[0080] The design method of the scattering homogenizing element in this invention generates a seed point distribution by introducing random perturbations on a regularly arranged coordinate system, and forms the aperture boundaries of sub-lenses based on Thiessen polygons. The geometric center point of each sub-lens serves as the vertex of the surface, and the radius of curvature is adjustable, thereby constructing a microlens array with irregular aperture shape and random position. This array can achieve dual homogenization of irradiance and intensity distribution by aligning with a directly incident beam, effectively suppressing diffraction speckle generated by a regular array. Its divergence angle and the direction angle of the outgoing beam can be flexibly adjusted through geometric and curvature parameters. A single-piece structure can achieve high uniformity homogenization, and it still has low tolerance sensitivity under multi-beam and eccentric incident conditions.

[0081] The scattering and homogenizing element of this invention can achieve dual homogenization of irradiance and intensity distribution by aligning with a directly incident beam, forming a flat-top light intensity distribution and effectively suppressing diffraction interference speckle. Through parameter adjustment, controllable designs of different outgoing beam divergence angles can be achieved to meet the needs of various lighting or display applications. By offsetting the sub-lens surface, the outgoing light direction angle can be flexibly adjusted to adapt to multi-directional projection or specific optical path designs. Even under multi-beam or eccentric incident conditions, the scattering and homogenizing element of this invention can still maintain a high degree of uniformity distribution, demonstrating low tolerance sensitivity.

[0082] The scattering and homogenizing element and its design method according to the present invention have both theoretical innovation and engineering practicality, and can be widely used in fields such as solid-state lighting, laser homogenization, projection display, machine vision and optometry.

[0083] Studies have found that abnormally elevated retinal contrast signals can stimulate stronger bipolar cell activity. This stimulation also affects axial growth by regulating dopamine secretion and altering choroidal thickness. When the human retina is exposed to high-contrast signals for a prolonged period, it can lead to excessive axial elongation, causing and exacerbating myopia. Dot diffuser lenses, based on Diffusion Optics Technology (DOT), scatter light through numerous uniformly distributed random microstructure regions on the lens surface corresponding to the viewing field. This reduces the contrast signal of the external environment image received by the retina when observing the external environment, thereby inhibiting axial elongation and ultimately achieving myopia control. The scattering homogenizing element in this invention can be used to design scattering points in dot diffuser lenses to achieve optical scattering effects at specific angles, thereby reducing the contrast signal of the observed image, inhibiting axial elongation, and ultimately achieving myopia control.

[0084] The light-diffusing element of this invention can be extended to optical dot diffuser lenses for myopia control. By arranging discrete scattering points in the area of ​​the lens corresponding to the peripheral vision of the human eye, it reduces the contrast signal of the human retina, thereby suppressing excessive elongation of the eye axis. Based on this, this invention provides a dot diffuser lens, as shown in Figure 12(a) and Figure 15 As shown, the point diffuser lens includes: The lens body DP1 includes a scattering area and a light-transmitting area corresponding to the human eye. Several optical scattering points DP2 are distributed in the scattering area. The optical scattering points DP2 adopt the scattering and light-uniforming element as described in the above embodiment of the present invention.

[0085] Specifically, the lens body DP1 is a transparent flat plate or transparent curved lens, made of a uniform transparent medium, such as glass or resin. A large number of discrete scattering points are arranged on the lens body DP1, and the optical scattering regions corresponding to these scattering points are all composed of microlens arrays in the scattering and homogenizing elements of the above embodiments.

[0086] The light-transmitting areas are set according to the human eye. Binocular lenses corresponding to the left and right eyes generally include a first light-transmitting area DP3 and a second light-transmitting area DP4 respectively corresponding to the left and right eyes. Monocular lenses corresponding to the left or right eye only have a light-transmitting area specifically for the left or right eye.

[0087] In the embodiment shown in Figure 12(a), the light-transmitting area of ​​the lens body DP1 includes a first light-transmitting area DP3 and a second light-transmitting area DP4 respectively corresponding to the left and right eyes. The first light-transmitting area DP3 and the second light-transmitting area DP4 can be circular, square, or triangular, etc. Preferably, the first light-transmitting area DP3 and the second light-transmitting area DP4 adopt a circular structure, and the radius of the first light-transmitting area DP3 and the second light-transmitting area DP4 is within the range of 10mm. R DP3 = R DP4 <16mm. The center-to-center distance between the two circular areas is 52mm. d e <62mm. External dimensions of the DP1 lens body. dx and day The range is: 100< dx< 150mm, 40< day < 60mm. The thickness of the DP1 lens body ranges from 1mm to 2mm.

[0088] Furthermore, as shown in Figure 12(a), in the lens body DP1, optical scattering points DP2 are uniformly distributed within the scattering region. Specifically, in the spatial arrangement of the optical scattering points DP2 on the lens, the spacing between each optical scattering point DP2 is close (the arrangement is dense and consistent), but the position of the optical scattering points DP2 has a certain degree of randomness. At the same time, the number of optical scattering points DP2 distributed per unit area is close. The diameter of a single optical scattering point DP2 is... f DP2 The range is: 0.1mm< f DP2 <0.2mm. And the spacing between each discrete optical scattering point DP2 d a Satisfy: 1.5 f DP2 < d a <2.5 f DP2 .

[0089] The uniformly arranged optical scattering points DP2 enable the scattering region to scatter the light beam uniformly.

[0090] Figure 12(b) shows the 3D structure of the point diffuser lens and the 3D surface structure of the local scattering point. Furthermore, the optical scattering point DP2 has various optical properties and structural features of the scattering surface in all the aforementioned embodiments, which will not be repeated here.

[0091] In some embodiments, as shown in Figures 13(a) and 13(b), the lens body DP1 is a binocular lens corresponding to the left and right eyes of the human body. The light-transmitting area includes a first light-transmitting area DP3 and a second light-transmitting area DP4 corresponding to the left and right eyes of the human body. Multiple optical scattering points DP2 are arranged in a gradually denser manner from the center of the first light-transmitting area DP3 in the left scattering area and in a gradually denser manner from the center of the second light-transmitting area DP4 in the right scattering area.

[0092] As shown in Figures 13(a) and 13(b), the parameter requirements and definitions of the point diffuser are basically the same as those described in Figures 12(a) and 12(b). The difference is that, in the point diffuser shown in Figures 13(a) and 13(b), the optical scattering points DP2 are relatively sparsely distributed near the first light-transmitting region DP3 and the second light-transmitting region DP4, and the spacing between the optical scattering points DP2 is... d a Satisfy: 3 f DP2 < d a <8 f DP2 Outward from the circular center of the first light-transmitting region DP3 and the second light-transmitting region DP4, the optical scattering points DP2 gradually become denser, with the spacing between the scattering points at the densest point increasing. d a Satisfies 1.5 f DP2 < d a <2.5 f DP2 .

[0093] In some embodiments, as shown in Figures 14(a) and 14(b), the optical scattering points DP2 are arranged in a gradually denser pattern outward from the center of the lens body DP1 within the scattering region.

[0094] As shown in Figures 14(a) and 14(b), the parameter requirements and definitions of the point diffuser are basically the same as those described in Figures 12(a) and 12(b). The difference is that, in the point diffuser shown in Figures 14(a) and 14(b), the arrangement of optical scattering points DP2 at the center of the lens body DP1 is relatively sparse, and the spacing of the optical scattering points DP2 is... d a Satisfy: 3 f DP2 < d a <8 f DP2 Along the center of the entire lens body DP1 outwards, the scattering points gradually become denser, with the spacing between the scattering points at the densest point increasing. d aSatisfies 1.5 f DP2 < d a <2.5 f DP2 .

[0095] Furthermore, in the two types of point diffuser lenses shown in Figures 13(a) and 14(a), the optical scattering regions corresponding to the optical scattering points DP2 arranged on them are composed of microlens arrays in the scattering homogenizing elements in the above embodiments; the optical scattering points DP2 have various optical properties and structural features of the scattering surfaces in all the aforementioned embodiments, which will not be described in detail here.

[0096] When a user observes the external environment or a book through the lens in the optical system, the brightness is higher near the central field of view of the human eye, and the brightness gradually decreases from the central field of view to the peripheral field of view. Therefore, by gradually increasing the density of the optical scattering points DP2 along the center of the first light-transmitting area DP3 and along the center of the second light-transmitting area DP4 in the scattering area, or along the center of the lens body DP1, the lens transmittance near the central area observed by the human eye can be enhanced, which conforms to the normal usage pattern of the human eye.

[0097] Furthermore, in some embodiments, the lens body DP1 is a monocular lens corresponding to the left or right eye of a human body.

[0098] like Figure 15 As shown, a circular aperture monocular point diffuser lens is given, with a light-transmitting area diameter of [missing information]. R The optical scattering region corresponding to the optical scattering points DP2 arranged on the lens is composed of a microlens array in the scattering homogenizing element in the above embodiments. The optical scattering points DP2 have various optical properties and structural features of the scattering surface in all the aforementioned embodiments, as well as various optical properties and structural dimensions of the point diffuser lens in all the aforementioned embodiments, which will not be elaborated here. Similarly, the arrangement of optical scattering points on the lens can also be uniform or the optical scattering points DP2 can be arranged to gradually become denser outward from the center of the lens body DP1 within the scattering region, which will not be elaborated here.

[0099] The dot diffuser lens of this invention arranges optical scattering points DP2 composed of microlens arrays evenly or with varying density on the lens body DP1, thereby reducing the contrast signal received by the retina while ensuring light transmittance, thus inhibiting excessive elongation of the eye axis. It can not only achieve the conventional light uniformity function, but also meet the visual physiological needs of the human eye, and has application value in eyeglasses and vision correction products.

[0100] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A light-scattering homogenizing element, characterized in that, Comprising: A microlens array, the microlens array includes a number of sub-lenses, the aperture boundary of the sub-lenses adopts a Thiessen polygon, the seed point coordinates of the Thiessen polygon are randomly distributed, and the geometric center point of any Thiessen polygon is the vertex position corresponding to the sub-lens.

2. The scattering and homogenizing element according to claim 1, characterized in that, The value range of the average size of the aperture of the sub-lens is 0.001mm < p < 10mm, where p is the average size of the aperture of the sub-lens.

3. The scattering and homogenizing element according to claim 1 or 2, characterized in that, The value range of the radius of curvature of the sub-lens is 0.002mm < │r│ < 20mm, where r is the radius of curvature of the sub-lens.

4. A design method for a scattering uniform light element, characterized in that, Applied to the design of the scattering and light homogenizing element as described in any one of claims 1 to 3, the design method includes: Generating initial seed point coordinates arranged in a preset uniform rule in the design area of the microlens array; Adding random perturbations to the initial seed point coordinates to obtain seed point coordinates with a random perturbation distribution; Based on the seed point coordinates, constructing the aperture boundary of the sub-lenses arranged in Thiessen polygons, and constructing the sub-lenses with the geometric center point of any Thiessen polygon as the vertex position corresponding to the sub-lens, to obtain the surface height distribution of the microlens array.

5. The design method of the scattering homogenizing element according to claim 4, characterized in that, During the process of constructing the sub-lenses with the geometric center point of any Thiessen polygon as the vertex position corresponding to the sub-lens, it includes: Adjusting the average size of the aperture of the sub-lens and / or the radius of curvature of the sub-lens based on a preset divergence angle.

6. The design method of the scattering homogenizing element according to claim 4, characterized in that, During the process of constructing the sub-lenses with the geometric center point of any Thiessen polygon as the vertex position corresponding to the sub-lens, it includes: Adjusting the surface shape offset of the sub-lens based on a preset exit beam direction angle.

7. The design method of the scattering uniform element according to claim 4, 5, or 6, characterized in that, After obtaining the surface height distribution of the microlens array, it includes: Performing Gaussian smoothing processing on the surface height distribution diagram of the sub-lens.

8. A dot diffusion lens, characterized in that, Comprising: A lens body, the lens body includes a scattering area and a light-transmitting area corresponding to the human eye, and a number of optical scattering points are distributed in the scattering area, and the optical scattering points adopt the scattering and light homogenizing element as described in any one of claims 1 to 3.

9. The dot diffusion lens according to claim 8, characterized in that, The optical scattering points are evenly arranged in the scattering area.

10. The dot diffusion lens according to claim 8, characterized in that, The lens body is a binocular lens corresponding to the left and right eyes of the human body, the light-transmitting area includes a first light-transmitting area and a second light-transmitting area respectively corresponding to the left and right eyes of the human body, and the optical scattering points are gradually denser from the center of the first light-transmitting area outward in the scattering area, and gradually denser from the center of the second light-transmitting area outward; or, the optical scattering points are gradually denser from the center of the lens body outward in the scattering area.

11. The dot diffusion lens according to claim 8, characterized in that, The lens body is a monocular lens corresponding to the left or right eye of the human body, and the optical scattering points are gradually denser from the center of the lens body outward in the scattering area.

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