Combined microlens array homogenization structure and manufacturing method thereof, lens and device

Abstract

The application discloses a combined microlens array light-uniform structure, a manufacturing method thereof, a lens and equipment, and the light-uniform structure comprises a first lens group and a second lens group; the first lens group comprises a substrate layer and a microlens array formed on one side surface of the substrate layer, a plurality of microlenses are arranged in dislocation to form the microlens array, and the plurality of microlenses are arranged without spacing; the second lens group comprises a double-convex lens, and the first lens group and the second lens group are arranged in opposition and side by side. The light-uniform structure disclosed by the application can make the light emitted by a dot matrix light source converge and then diverge after passing through the microlens array through cooperation of the microlens array and the double-convex lens, so that the light-emitting aperture is reduced under the condition of ensuring a large field of view.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional perception, and in particular to a combined microlens array light-uniforming structure with a large field of view and a small light-emitting aperture, as well as its fabrication method, lens, and device. Background Technology

[0002] Indirect Time of Flight (ITOF) technology enables 3D perception and distance measurement. The optical components of ITOF mainly consist of three parts: a laser array light source, a homogenizing structure, and an ITOF lens. ITOF works by emitting a specific light field onto the surface of an object through an ITOF light-emitting module. The ITOF detector then identifies the phase changes reflected back from this light field, thereby sensing the depth information at different locations on the object.

[0003] Currently, ITOF needs to meet the trend of miniaturization of electronic devices, and the microlens uniform light structure, as an important component of the ITOF light-emitting module, also needs to meet this miniaturization trend.

[0004] With the addition of protective glass, current ITOF uniform light structures require an aperture diameter of at least 5mm to achieve a large field of view so that all light can be emitted from the aperture. If the aperture diameter is less than 5mm, a large amount of reflected stray light will be generated. If current ITOF uniform light structures are to meet the requirement of a small aperture diameter, the field of view will be greatly reduced, reducing the range of depth information perceived. This seriously restricts the development of device miniaturization and the miniaturization trend and aesthetics of electronic devices using ITOF.

[0005] Therefore, there is an urgent need to propose a new technical solution to address the above problems. Summary of the Invention

[0006] Currently, in ITOF technology, the field of view of the homogenizing device decreases significantly after reducing the output aperture, leading to a reduction in the range of depth information perceived. To address this issue, one aspect of this invention proposes a combined microlens array homogenizing structure, the specific technical solution of which is as follows:

[0007] A combined microlens array light-uniforming structure includes a first lens group and a second lens group; the first lens group includes a base layer and a microlens array formed on one side surface of the base layer, wherein a plurality of microlenses are staggered to form the microlens array, and the plurality of microlenses are arranged without gaps; the second lens group includes a biconvex lens; the first lens group and the second lens group are arranged side by side opposite to each other.

[0008] Furthermore, in the above technical solution, the biconvex lens is located near the other side surface of the substrate layer, and the biconvex lens and the microlens array are respectively disposed opposite to each other on both sides of the substrate layer.

[0009] Furthermore, the biconvex lens is located close to the microlens array, and the biconvex lens and the microlens array are disposed on the same side of the substrate layer.

[0010] Furthermore, the optical surface profiles of the plurality of microlenses constituting the microlens array include deformed aspherical surface profiles.

[0011] Furthermore, the second lens group includes a biconvex lens having two opposing convex surfaces, the optical profile of which is a deformed aspherical surface.

[0012] Furthermore, the radius of curvature of the microlenses constituting the microlens array ranges from 10 μm to 300 μm in the transverse coordinate direction and from 10 μm to 300 μm in the longitudinal coordinate direction, and the conic coefficient of the microlenses ranges from -0.95 to -8.

[0013] Furthermore, the radius of curvature of the individual microlenses constituting the microlens array ranges from 8 μm to 360 μm.

[0014] Furthermore, one of the outer convex surfaces of the biconvex lens is a front convex surface close to the base layer, and the other outer convex surface of the biconvex lens is a rear convex surface away from the base layer.

[0015] Furthermore, the radius of curvature of the convex surface in the transverse coordinate direction ranges from 200μm to 700μm, the radius of curvature in the longitudinal coordinate direction ranges from 200μm to 700μm, and the conic coefficient of the convex surface ranges from -1 to -8.

[0016] Furthermore, the radius of curvature of the rear convex surface ranges from 5μm to 500μm in the transverse coordinate direction and from 5μm to 500μm in the longitudinal coordinate direction, and the conic coefficient of the rear convex surface ranges from -1 to -8.

[0017] Furthermore, the refractive index of the microlens array is in the range of 1.5 to 1.8.

[0018] Furthermore, the refractive index of the biconvex lens is in the range of 1.5 to 1.8.

[0019] Furthermore, the base layer is a transparent glass base.

[0020] Furthermore, the microlenses are arranged in a staggered manner to form the microlens array, specifically including:

[0021] After a number of microlenses are arranged in a dot matrix pattern, each microlens is randomly staggered within a preset distance range along the horizontal and / or vertical directions.

[0022] After a number of microlenses are arranged in a dot matrix, the distance between the center points of two adjacent combined microlenses is 5 to 60 μm.

[0023] The preset distance range is n times the distance between the center points of two adjacent combined microlenses, where n ranges from 8% to 20%.

[0024] Another aspect of the present invention provides a method for fabricating a combined microlens array homogenizing structure, comprising: fabricating a first lens group of the combined microlens array homogenizing structure, specifically including:

[0025] A base layer is provided, wherein the base layer is a light-transmitting glass layer;

[0026] A pattern forming template is provided, the surface of which is formed with a first pattern structure, the first pattern structure being opposite to the structure of the microlens array pattern of the first lens group;

[0027] A molding compound is provided, and the pattern forming template is used as a mold. The molding compound is formed onto the substrate layer by pressing, and the microlens array pattern is formed on the surface of the substrate layer to obtain the first lens group.

[0028] Furthermore, the method for manufacturing the pattern forming template as described above specifically includes:

[0029] A patterning layer is provided, and a second pattern structure is formed on the surface of the patterning layer, the second pattern structure being consistent with the structure of the microlens array pattern;

[0030] A pattern transfer layer is provided, and the pattern forming layer is used as a template. Plastic is molded onto the pattern transfer layer by embossing to form the first pattern structure on the surface of the pattern transfer layer, thereby obtaining the pattern forming template.

[0031] Furthermore, a second pattern structure is formed on the surface of the pattern forming layer, specifically including:

[0032] The pattern forming layer includes a photosensitive material layer attached to a substrate. Different exposure amounts are applied to different positions of the photosensitive material layer according to the morphology of the microlens array pattern. After the photosensitive material layer is exposed, a second pattern structure with the same structure as the microlens array pattern is formed on it.

[0033] The photosensitive material layer is divided into several layers based on the exposure depth formed after exposure, and the exposure amount of each layer has a non-linear relationship with the exposure depth.

[0034] Based on the above-mentioned combined microlens array light-uniformation structure, the present invention also provides an ITOF lens, which includes the above-mentioned combined microlens array light-uniformation structure, wherein the combined microlens array light-uniformation structure has a microlens array, and an air layer with a thickness ranging from 0.1 mm to 0.5 mm is provided between the microlens array and the laser array light source.

[0035] Based on the above-described combined microlens array light-uniformation structure, the present invention also provides a device equipped with an ITOF lens, which includes the above-described ITOF lens, on which the above-described combined microlens array light-uniformation structure is mounted.

[0036] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0037] 1. This invention provides a combined microlens array homogenizing structure, which includes a first lens group and a second lens group arranged opposite to each other. The first lens group includes a microlens array, and the second lens group includes a biconvex lens. The microlens array restricts the shape of the light spot and disrupts the image of the light source from the lattice light source. The biconvex lens forms a larger field of view and a desired light field distribution. By combining the microlens array and the biconvex lens, this invention allows the light emitted from the lattice light source to converge and then diverge after passing through the microlens array, thereby reducing the output aperture while maintaining a larger field of view. This solves the problem in existing ITOF technology where the field of view is significantly reduced after reducing the output aperture, leading to a decrease in the range of perceived depth information.

[0038] 2. The combined microlens array homogenizing structure provided by this invention can control the light field distribution formed by adjusting the surface parameters of the microlenses and the biconvex lenses in the microlens array, thereby forming the desired light field pattern of the coherent light emitted by the array laser. The combination of the microlens array and the biconvex lens can reduce the output aperture of the homogenizing structure to meet the current miniaturization requirements of electronic products. Furthermore, the random arrangement of the microlens array eliminates the interference phenomenon caused by the array laser. The light emitted by the laser array can achieve a larger divergence angle after passing through the microlens array and the biconvex lens.

[0039] 3. The light-uniforming structure provided by this invention combines a microlens array with a biconvex lens, which can effectively eliminate the array light source image and interference fringes. Experiments have shown that the light-uniforming structure has a divergence angle of more than 90 degrees for the light source beam. Furthermore, if the light-emitting aperture is set at a distance of 1.05 mm from the rear convex surface of the biconvex lens of the light-uniforming structure, the light-emitting aperture size is less than 2.5 mm. Compared with the prior art, where the light-emitting aperture is less than 5 mm, which leads to a large amount of reflected stray light, the light-uniforming structure provided by this invention reduces the light-emitting aperture and expands the diffusion angle, thus solving the defects in the prior art.

[0040] 4. The fabrication method of the combined microlens array uniform light structure described in this invention reduces the processing difficulty of the microlens uniform light structure compared with the existing fabrication method, and increases the adjustable parameters to make it easier to achieve the light field distribution of the desired light spot. In the fabrication method described in this invention, a processing master is obtained by photolithography, and the microlens array of the first lens group can be mass-produced by using the master to imprint nanotechnology.

[0041] 5. In the combined microlens array uniform light structure of the present invention, among the microlenses of the microlens array that make up the first lens group, there is no discontinuity between two adjacent microlenses, and the transition is smooth, which reduces the difficulty of imprinting. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the combined microlens array light-uniforming structure of the present invention in one embodiment;

[0044] Figure 2 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source according to one embodiment of the present invention;

[0045] Figure 3 yes Figure 2 Surface structure diagram of the microlens array shown;

[0046] Figure 4 yes Figure 2 The light path diagram of the combined microlens array structure shown;

[0047] Figure 5 yes Figure 2 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown.

[0048] Figure 6 It is distance Figure 2 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0049] Figure 7 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source described in another embodiment of the present invention;

[0050] Figure 8 yes Figure 7 Surface structure diagram of the microlens array shown;

[0051] Figure 9 yes Figure 7 The light path diagram of the combined microlens array structure shown;

[0052] Figure 10 yes Figure 7 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown.

[0053] Figure 11 It is distance Figure 7 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0054] Figure 12 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source described in this invention in another embodiment;

[0055] Figure 13 yes Figure 12 Surface structure diagram of the microlens array shown;

[0056] Figure 14 yes Figure 12 The light path diagram of the combined microlens array structure shown;

[0057] Figure 15 yes Figure 12 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown.

[0058] Figure 16 It is distance Figure 12 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0059] Figure 17 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source according to one embodiment of the present invention;

[0060] Figure 18 yes Figure 17 Surface structure diagram of the microlens array shown;

[0061] Figure 19 yes Figure 17 The light path diagram of the combined microlens array structure shown;

[0062] Figure 20 yes Figure 17 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown.

[0063] Figure 21 It is distance Figure 17 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0064] Figure 22 This is a flowchart illustrating the fabrication process of the master template for the combined microlens array homogenizing structure of the present invention in one embodiment.

[0065] Figure 23 This is a flowchart illustrating the fabrication of the combined microlens array homogenizing structure of the present invention in one embodiment. Detailed Implementation

[0066] 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, and 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.

[0067] The essence of the present invention will be further explained below with reference to the accompanying drawings and embodiments.

[0068] Example 1

[0069] This invention provides a combined microlens array homogenizing structure, which includes a first lens group and a second lens group arranged opposite to each other. The first lens group includes a microlens array, and the second lens group includes a biconvex lens. The microlens array restricts the shape of the light spot and disrupts the image of the light source from the lattice light source. The biconvex lens forms a larger field of view and a desired light field distribution. By combining the microlens array and the biconvex lens, this invention allows the light emitted from the lattice light source to converge and then diverge after passing through the microlens array. This reduces the output aperture while maintaining a larger field of view, thus solving the problem in existing ITOF technology where reducing the output aperture leads to a significant decrease in the field of view, resulting in a reduced range of depth information.

[0070] Please see Figure 1 , Figure 1A schematic diagram illustrates a combined microlens array light-uniformation structure. In this structure, 100 represents the combined microlens array light-uniformation structure, 110 represents the first lens group, 111 represents the base layer, 112 represents the microlens array, 120 represents the second lens group, 121 represents the anterior convex surface, and 122 represents the posterior convex surface.

[0071] In one embodiment, the combined microlens array homogenizing structure of the present invention may include a first lens group 110 and a second lens group 120 arranged opposite to each other. (Continue to see...) Figure 1 The first lens group 110 includes a base layer 111 and a microlens array 112 formed on one surface of the base layer 111. The microlens array 112 includes a plurality of microlenses arranged without spacing. The second lens group 120 may be a biconvex lens, which includes two opposing convex surfaces: a front convex surface 121 close to the base layer and a rear convex surface 122 away from the base layer. Figure 1 The diagram illustrates a cross-sectional view of a combined microlens array homogenizing structure in one embodiment. Figure 1 The combined microlens array homogenizing structure in the image consists of two lens groups arranged side-by-side. In a specific application scenario, the microlens array of the first lens group faces the laser array light source. The light emitted from the laser array light source passes sequentially through the microlens array of the first lens group, the substrate layer, and the biconvex lens, which serves as the second lens group. The light then diverges from an outer convex surface of the biconvex lens away from the substrate layer. After passing through the microlens array, the light spot shape is restricted, and the image of the light source is disrupted. After passing through the biconvex lens, the light is diffused to a larger field of view, forming the desired light field distribution.

[0072] The combined microlens array homogenizing structure provided by this invention can control the light field distribution formed by adjusting the surface parameters of the microlenses and the biconvex lenses in the microlens array, thereby forming the desired light field pattern of the coherent light emitted by the array laser. The combination of the microlens array and the biconvex lens can reduce the output aperture of the homogenizing structure to meet the current miniaturization requirements of electronic products. Furthermore, the random arrangement of the microlens array eliminates the interference phenomenon caused by the array laser. The light emitted by the laser array can achieve a larger divergence angle after passing through the microlens array and the biconvex lens.

[0073] The combined microlens array uniform light structure described in this invention can be directly simplified as being composed of two parts: a microlens array and a biconvex lens. The microlenses that make up the microlens array are composed of deformable aspherical microlenses, and the two convex surfaces of the biconvex lens are composed of double-sided deformable aspherical surfaces.

[0074] In one embodiment, the reference formula for the deformable aspherical surface is as follows:

[0075]

[0076] Where Z is the sag of the microlens, and C x Let C be the curvature of the microlens in the X direction. y Let A be the curvature in the y-direction of the microlens. 2n With B 2n For deformable aspherical surfaces, the aspherical coefficient is denoted as .

[0077] In a preferred embodiment, the microlenses constituting the microlens array have an X-direction radius of curvature of 10 micrometers to 300 micrometers and a conicity of -0.95 to -8; and a Y-direction radius of curvature of 10 micrometers to 300 micrometers and a conicity of -0.95 to -8.

[0078] In one embodiment, the optical surface of the biconvex lens is a deformed aspherical surface, and the reference formula for this deformed aspherical surface is as follows:

[0079]

[0080] Where Z is the sag of the outer convex surface of the biconvex lens, and C x Let C be the curvature of the outer convex surface of the biconvex lens in the X direction. y Let A be the curvature of the convex surface of the biconvex lens in the y-direction. 2n With B 2n For deformable aspherical surfaces, the aspherical coefficient is denoted as .

[0081] See also Figure 1 The biconvex lens (second lens group) of the present invention has two convex surfaces arranged opposite to each other. The optical surface type of the two convex surfaces is a deformed aspherical surface type. One of the convex surfaces of the biconvex lens is a front convex surface 121 close to the base layer 111, and the other convex surface of the biconvex lens is a rear convex surface 122 away from the base layer 111.

[0082] In a preferred embodiment, the front convex surface 121 of the biconvex lens has a radius of curvature of 200 micrometers to 700 micrometers in the X direction and a conic coefficient of -1 to -8; and a radius of curvature of 200 micrometers to 700 micrometers in the Y direction and a conic coefficient of -1 to -8; the rear convex surface 122 of the biconvex lens has a radius of curvature of 5 micrometers to 500 micrometers in the X direction and a conic coefficient of -1 to -8; and a radius of curvature of 5 micrometers to 500 micrometers in the Y direction and a conic coefficient of -1 to -8.

[0083] In one embodiment, the preferred material refractive index range of the microlens array is 1.5-1.8, and the refractive index range of the biconvex lens is 1.5-1.8.

[0084] In one embodiment, a plurality of microlenses in the microlens array of the first lens group of the present invention follow the following random arrangement rule:

[0085] First, several microlenses are arranged in an array. The distance between the center points of two adjacent combined microlenses after the array arrangement is denoted as L. Each microlens is then displaced by n*L along the X and Y axes, starting from its own center point after the array arrangement, to achieve a random arrangement of the microlenses. The randomly arranged microlenses are then subjected to a union operation to obtain a randomly arranged microlens array. Here, n ranges from 8% to 20%, and L ranges from 5 micrometers to 60 micrometers.

[0086] In one embodiment, the array arrangement of microlenses described above can be a dot matrix arrangement, a matrix, or other dot matrix (in fact, this step is a specific rule arrangement, and the distance between the center points of two adjacent microlenses after the dot matrix arrangement is L, where L ranges from 5 micrometers to 60 micrometers). After the dot matrix arrangement of several microlenses, each microlens is randomly staggered along the horizontal and / or vertical directions within a preset distance range (each microlens is displaced by n*L along the X-axis and Y-axis respectively, with its own center point after the array arrangement as the initial point). After the staggered arrangement of several microlenses is processed to remove the gaps, a continuous surface is formed. The above-mentioned gap removal process can be achieved by performing a union of the microlenses. There are overlapping parts between the microlenses after the union. The overlapping parts are removed to ensure that multiple microlenses are located on the same horizontal plane and form a continuous surface.

[0087] In one embodiment, the surface shapes of several microlenses constituting the microlens array of the present invention are randomly arranged, following the following random arrangement rules: First, a parent lens array capable of achieving the target light field distribution for the entire module is determined. The surface shapes of the microlenses in this parent lens array are then determined, while other surface shape parameters remain unchanged. Using the radius of curvature of the microlenses in the parent lens array as the initial radius of curvature R, the radius of curvature of the randomly generated microlenses is N*R. This determines the surface shape parameters of the microlenses used to fabricate the microlens array of the present invention. In a preferred embodiment, the value range of R is from 10 micrometers to 300 micrometers, and the value range of N is 80%-120%.

[0088] The light-uniform structure provided by this invention combines a microlens array with a biconvex lens, which can effectively eliminate the array light source image and interference fringes. Experiments have shown that the light-uniform structure has a divergence angle of more than 90 degrees for the light source beam. Furthermore, if the light-emitting aperture is set at a distance of 1.05 mm from the back convex surface of the biconvex lens of the light-uniform structure, the light-emitting aperture size is less than 2.5 mm. Compared with the prior art, where the light-emitting aperture is less than 5 mm, which leads to a large amount of reflected stray light, the light-uniform structure provided by this invention reduces the light-emitting aperture and expands the diffusion angle, thus solving the defects in the prior art.

[0089] Example 2

[0090] This embodiment proposes a combined microlens array light-uniforming structure, combined with Figures 2 to 6 , Figure 2 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source according to one embodiment of the present invention; Figure 3 yes Figure 2 Surface structure diagram of the microlens array shown; Figure 4 yes Figure 2 The light path diagram of the combined microlens array structure shown; Figure 5 yes Figure 2 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown. Figure 6 It is distance Figure 2 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0091] Among them, 100-combined microlens array uniform light structure, 110-first lens group, 111-base layer, 112-microlens array, 120-second lens group, 121-front convex surface, 122-back convex surface, 130-laser array light source.

[0092] In this embodiment, the combined microlens array homogenizing structure of the present invention includes a first lens group 110 and a second lens group 120 arranged opposite to each other. The first lens group 110 includes a microlens array 112, and the second lens group 120 includes a biconvex lens. Both the microlens array and the biconvex lens have a refractive index of 1.52. Figures 2 to 6 The initial spacing between two adjacent microlenses in the microlens array is 10 micrometers. The lens optical profile of the microlens is a deformed aspherical surface with a radius of curvature of 33 micrometers in the X direction and a conic coefficient of -1.5, and a radius of curvature of 33 micrometers in the Y direction and a conic coefficient of -1.5. The double-sided surface of the biconvex lens is a deformed aspherical surface. The radius of curvature in the X direction of the surface closer to the microlens array (front convex surface 121) is 476 micrometers and a conic coefficient of -2.5, and the radius of curvature in the Y direction is 476 micrometers and a conic coefficient of -2.5. The radius of curvature in the X direction of the surface farther from the microlens array (back convex surface 122) is 50 micrometers and a conic coefficient of -3.8, and the radius of curvature in the Y direction is 50 micrometers and a conic coefficient of -4.55.

[0093] In this embodiment, the light spot formed after passing through the uniform light microlens array reaches its peak energy at 56 degrees in the X direction, which is 120% of the center energy. The peak energy also reaches its peak energy at 48 degrees in the Y direction, which is 121% of the center energy. In the X direction, the energy drops to 80% of the center energy at 68 degrees, and the field of view is 92° when the energy drops to 0. Similarly, in the Y direction, the energy drops to 80% of the center energy at 56 degrees, and the field of view is 72° when the energy drops to 0. The distance between the microlens array and the rear surface of the lens in the biconvex lens uniform light module is 1.05 mm, and the light exit aperture is 2.4 mm. Figure 5 In one embodiment, the projected light spot is obtained by converting the linear quantity of the light spot into an angular quantity, and then analyzing the grayscale ratio at each angular quantity to obtain the energy peak information described in this embodiment.

[0094] Example 3

[0095] This embodiment proposes a combined microlens array light-uniforming structure, combined with Figures 7 to 11 , Figure 7 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source described in another embodiment of the present invention; Figure 8 yes Figure 7 Surface structure diagram of the microlens array shown; Figure 9 yes Figure 7 The light path diagram of the combined microlens array structure shown; Figure 10 yes Figure 7 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown. Figure 11 It is distance Figure 7 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0096] Among them, 200-combined microlens array uniform light structure, 210-first lens group, 211-base layer, 212-microlens array, 220-second lens group, 221-front convex surface, 222-back convex surface, 230-laser array light source.

[0097] In this embodiment, the combined microlens array homogenizing structure of the present invention includes a first lens group 210 and a second lens group 220 arranged opposite to each other. The first lens group 210 includes a microlens array 212, and the second lens group 220 includes a biconvex lens. In this embodiment, the refractive index of both the microlens array and the biconvex lens is 1.52. Figures 7 to 11The initial spacing between two adjacent microlenses in the microlens array is 10 micrometers. The lens optical profile of the microlens is a deformed aspherical surface with a radius of curvature of 33 micrometers in the X direction and a conic coefficient of -1.5, and a radius of curvature of 33 micrometers in the Y direction and a conic coefficient of -1.5. The double-sided surface of the biconvex lens is also a deformed aspherical surface. The radius of curvature of the surface closer to the microlens array is 476 micrometers in the X direction and a conic coefficient of -2.5, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -6, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -7.

[0098] In this embodiment, the light spot formed after the light passes through the uniform light microlens array reaches its peak energy at 48 degrees in the X direction, which is 163% of the center energy. The light spot also reaches its peak energy at 38 degrees in the Y direction, which is 140% of the center energy. The energy in the X direction drops to 80% of the center energy at 58 degrees, and the field of view is 76° when the energy drops to 0. The energy in the Y direction drops to 80% of the center energy at 47 degrees, and the field of view is 60° when the energy drops to 0. The light exit aperture is 2mm, which is 1.05mm away from the rear surface of the lens in the biconvex lens uniform light module.

[0099] Example 4

[0100] This embodiment proposes a combined microlens array light-uniforming structure, combined with Figures 12 to 16 , Figure 12 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source described in this invention in another embodiment; Figure 13 yes Figure 12 Surface structure diagram of the microlens array shown;

[0101] Figure 14 yes Figure 12 The light path diagram of the combined microlens array structure shown; Figure 15 yes Figure 12 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown. Figure 16 It is distance Figure 12 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0102] Among them, 300-combined microlens array uniform light structure, 310-first lens group, 311-base layer, 312-microlens array, 320-second lens group, 321-front convex surface, 322-back convex surface, 330-laser array light source.

[0103] In this embodiment, the combined microlens array homogenizing structure of the present invention includes a first lens group 310 and a second lens group 320 arranged opposite to each other. The first lens group 310 includes a microlens array 312, and the second lens group 320 includes a biconvex lens. In this embodiment, the refractive index of both the microlens array and the biconvex lens is 1.52. Figures 12 to 16 The initial spacing between two adjacent microlenses in the microlens array is 10 micrometers. The lens optical profile of the microlens is a deformed aspherical surface with a radius of curvature of 33 micrometers in the X direction and a conic coefficient of -1.5, and a radius of curvature of 33 micrometers in the Y direction and a conic coefficient of -1.5. The double-convex lens has a deformed aspherical surface profile on both sides. The radius of curvature of the surface closer to the microlens array is 476 micrometers in the X direction and a conic coefficient of -3.5, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -3.8, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -4.55.

[0104] In this embodiment, the light spot formed after passing through the uniform light microlens array reaches its peak energy at 55 degrees in the X direction, which is 163% of the center energy. The peak energy also reaches its peak energy at 46 degrees in the Y direction, which is 156% of the center energy. The energy in the X direction drops to 80% of the center energy at 68 degrees, and the field of view is 89° when the energy drops to 0. The energy in the Y direction drops to 80% of the center energy at 57 degrees, and the field of view is 68° when the energy drops to 0. The light exit aperture is 2.2mm, which is 1.05mm away from the rear surface of the lens in the biconvex lens uniform light module.

[0105] Based on Examples 2 to 4, the following conclusions can be drawn:

[0106] 1. The uniform light structure composed of the microlens array and the biconvex lens can effectively eliminate the image of the array light source.

[0107] 2. This light-uniforming structure (also known as a light-uniforming module) can effectively eliminate interference fringes.

[0108] 3. This uniform light structure can achieve a divergence angle of over 90 degrees.

[0109] 4. If the light-emitting aperture is located 1.05 mm from the rear surface of the biconvex lens of the uniform light structure, the aperture size is less than 2.5 mm.

[0110] 5. In this uniform light structure, if the conicity of the biconvex lens in the microlens array surface parameters decreases, the field of view of the corresponding light spot will increase and the peak value will decrease. If the conicity increases, the field of view of the corresponding light spot will decrease and the peak value will increase.

[0111] 6. In this uniform light structure, if the conicity of the surface parameters of the biconvex lens near the microlens array decreases, the field of view of the corresponding light spot will increase, the peak value will decrease, and the energy will decrease proportionally from the peak value to the cutoff value with the difference in field of view. If the conicity of the surface parameters of the biconvex lens near the microlens array decreases, the field of view corresponding to the peak value of the light spot will decrease, the peak value will increase, and the energy will decrease proportionally from the peak value to the cutoff value with the difference in field of view. Regardless of whether the conicity of the surface parameters of the biconvex lens near the microlens array increases or decreases, the field of view corresponding to the peak value of the light spot remains basically unchanged.

[0112] Example 5

[0113] This embodiment proposes a combined microlens array light-uniforming structure, combined with Figures 17 to 21 , Figure 17 This is a schematic diagram of the installation position of the combined microlens array structure and the laser array light source according to one embodiment of the present invention; Figure 18 yes Figure 17 Surface structure diagram of the microlens array shown; Figure 19 yes Figure 17 The light path diagram of the combined microlens array structure shown; Figure 20 yes Figure 17 A schematic diagram of the far-field output light distribution of the combined microlens array homogenizing structure shown. Figure 21 It is distance Figure 17 A schematic diagram of the light-emitting aperture at 1.05 mm on the back convex surface of the biconvex lens in the combined microlens array homogenizing structure shown.

[0114] Among them, 400-combined microlens array uniform light structure, 410-first lens group, 411-base layer, 412-microlens array, 420-second lens group, 421-front convex surface, 422-back convex surface, 430-laser array light source.

[0115] In this embodiment, the combined microlens array homogenizing structure of the present invention includes a first lens group 410 and a second lens group 420 arranged side by side. The first lens group 410 includes a microlens array 412, and the second lens group 420 includes a biconvex lens. Unlike embodiments 1-4, in this embodiment, the microlens array 412 and the biconvex lens are located on the same side of the substrate layer. The light beam first passes through the substrate layer, then through the microlens array 412, and then through the biconvex lens. In this embodiment, the refractive index of both the microlens array and the biconvex lens is 1.52. Figures 17 to 21The initial spacing between two adjacent microlenses in the microlens array is 10 micrometers. The lens optical profile of the microlens is a deformed aspherical surface with a radius of curvature of 33 micrometers in the X direction and a conic coefficient of -1.5, and a radius of curvature of 33 micrometers in the Y direction and a conic coefficient of -1.5. The double-sided surface of the biconvex lens is also a deformed aspherical surface. The radius of curvature of the surface closer to the microlens array is 476 micrometers in the X direction and a conic coefficient of -2.5, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -3.8, and the radius of curvature of the surface further away from the microlens array is 50 micrometers in the X direction and a conic coefficient of -4.55.

[0116] In this embodiment, the light spot formed after passing through the uniform light microlens array reaches its peak energy at 57 degrees in the X direction, which is 117% of the center energy. The peak energy also reaches its peak energy at 43 degrees in the Y direction, which is 121% of the center energy. The energy in the X direction drops to 80% of the center energy at 70 degrees, and the field of view is 94° when the energy drops to 0. The energy in the Y direction drops to 80% of the center energy at 56 degrees, and the field of view is 73° when the energy drops to 0. The light exit aperture is 2.7mm, which is 1.05mm away from the rear surface of the lens in the biconvex lens uniform light module.

[0117] Example 6

[0118] This embodiment provides a method for fabricating a combined microlens array uniform light structure. The microlens array in the combined microlens array uniform light structure can be obtained by a master plate transfer and imprinting method. The master plate used in the process can be processed by photolithography. First, a photosensitive material layer is attached to a glass substrate, and then different exposure amounts are added to different positions of the photosensitive material layer. When making the template, it is necessary to control the depth that can be reached by different laser energies by using a layered photolithography method according to the morphology of the microlens array in the target combined microlens array uniform light structure. The fabrication of the master plate of the microlens array uniform light structure with good surface structure is completed in one step. The morphology of the microlens array on the master plate is consistent with the morphology of the target microlens array.

[0119] See also Figure 22 The illustration shows a flowchart of the fabrication process of the microlens array master template for the combined microlens array homogenizing structure described in this invention, wherein: 60 - photosensitive material layer; 61 - microlens array with a morphological structure consistent with the target microlens array, formed by layered photolithography. Figure 22 As can be seen, the master template is made by layered photolithography. During the fabrication process, different exposure amounts need to be added to different positions of the photosensitive material layer according to the morphology of the microlens array pattern. After the photosensitive material layer is exposed, a second pattern structure with the same structure as the microlens array pattern is formed on it.

[0120] The photosensitive material layer is divided into several layers based on the exposure depth formed after exposure, and the exposure amount of each layer has a non-linear relationship with the exposure depth. By using different exposure amounts for different number of layers, the exposure amount of each layer in the photolithography equipment is precisely controlled to fabricate the microlens array master. The aforementioned microlens array master is fabricated using a layer-by-layer photolithography method, and the mass production of the microlens array can be accomplished using a nanoimprinting method.

[0121] In one embodiment, fabricating a microlens array with a combined microlens array homogenizing structure using the prepared master template includes the following steps, which can be found in [reference needed]. Figure 23 Among them, 62-base layer, 63-pattern forming template, 64-first pattern structure, 65-molding adhesive, 66-microlens array pattern, 67-pattern forming layer, 68-second pattern structure, 69-pattern transfer layer:

[0122] A substrate layer 62 is provided, which is a light-transmitting glass layer and serves as a carrier for a microlens array;

[0123] A pattern forming template 63 is provided, and a first pattern structure 64 is formed on the surface of the pattern forming template 63, the first pattern structure 64 being opposite to the structure of the microlens array pattern 66.

[0124] A molding compound is provided, and the pattern forming template 63 is used as a mold. The molding compound is formed onto the base layer 62 by pressing, and the microlens array pattern 66 is formed on the surface of the base layer 62 to obtain a microlens array uniform light structure.

[0125] In one embodiment, the method for manufacturing the pattern forming template 63 specifically includes the following:

[0126] A patterning layer 67 is provided, and a second pattern structure 68 is formed on the surface of the patterning layer 67, the second pattern structure 68 being consistent with the structure of the microlens array pattern 66;

[0127] A pattern transfer layer 69 is provided, and the pattern forming layer 67 is used as a template. Plastic is molded onto the pattern transfer layer 69 by embossing, and the first pattern structure 64 is formed on the surface of the pattern transfer layer 69 to obtain the pattern forming template 63.

[0128] Figure 23 The diagram illustrates the above production process. Because the production process proposed in this embodiment involves transfer and imprinting, therefore... Figure 23 There are multiple instances of borrowing and sharing, but it is understandable that after the microlens array pattern is transferred onto the pattern transfer layer 69, it becomes the pattern forming template 63.

[0129] The biconvex lens of the combined microlens array uniform light structure described in this invention can be mass-produced using optical lens molding technology.

[0130] The combined microlens array uniform light structure of the present invention is mass-produced by nanoimprinting. A transfer adhesive layer is attached to a resin substrate, and the reverse structure of the master template is transferred to the transfer adhesive layer by imprinting. An imprinting adhesive layer is attached to a glass substrate, and the structure on the transfer adhesive layer on the resin substrate is transferred to the imprinting adhesive layer by imprinting, thus completing the mass production of the combined microlens array uniform light structure.

[0131] The combined microlens array homogenizing structure fabricated by the above method can eliminate interference fringes in the resulting light spot, meeting the requirements of ITOF receivers, and can be mass-produced, reducing the processing difficulty.

[0132] Furthermore, based on the combined microlens array light-uniforming structure described in this invention, this invention also provides an ITOF lens, which includes the aforementioned combined microlens array light-uniforming structure. The combined microlens array light-uniforming structure has a microlens array, and an air layer with a thickness ranging from 0.1 mm to 0.5 mm is provided between the microlens array and the laser array light source.

[0133] Furthermore, based on the aforementioned ITOF lens, the present invention also provides a device equipped with an ITOF lens, which includes the aforementioned ITOF lens, wherein the ITOF lens is mounted with a combined microlens array homogenizing structure according to the aforementioned design.

[0134] The light-uniform structure composed of a microlens array and a biconvex lens proposed in this invention can eliminate interference fringes in the obtained light spot through the random arrangement of microlenses in the microlens array, meeting the requirements of the ITOF receiver. The light-uniform structure combining the microlens array and the biconvex lens proposed in this invention can significantly reduce the output aperture size while ensuring a large field of view. Furthermore, the light-uniform structure combining the microlens array and the biconvex lens proposed in this invention allows the microlenses in the microlens array to achieve a large field of view with a low curvature, thereby achieving a larger ITOF detection range.

[0135] The light-uniform structure combining a microlens array and a biconvex lens proposed in this invention allows both the microlens array and the biconvex lens to modulate the light field in different ways, increasing the modulation variables and reducing the difficulty of master plate production.

[0136] The light-uniforming structure combining a microlens array and a biconvex lens proposed in this invention can effectively disrupt the light source image formed by the biconvex lens through the microlens array, creating a smooth light spot. Furthermore, the light-uniforming structure combining the microlens array and biconvex lens proposed in this invention features smooth transitions between microlenses without any breaks, increasing light transmittance and reducing the difficulty of imprinting.

[0137] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0138] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications and variations to the above embodiments within the scope of the present invention.

Claims

1. A combined microlens array light-uniforming structure, characterized in that, It includes a first lens group and a second lens group; The first lens group includes a base layer and a microlens array formed on one side surface of the base layer. A plurality of microlenses are staggered to form the microlens array, and the plurality of microlenses are arranged without gaps. The second lens group includes a biconvex lens, which has two opposing convex surfaces; The first lens group and the second lens group are arranged side by side opposite to each other; The radius of curvature of the microlenses constituting the microlens array ranges from 10 μm to 300 μm in the transverse coordinate direction and from 10 μm to 300 μm in the longitudinal coordinate direction, and the conic coefficient of the microlenses ranges from -0.95 to -8. One of the outer convex surfaces of the biconvex lens is a forward convex surface close to the first lens group, and the other outer convex surface of the biconvex lens is a rearward convex surface away from the first lens group. The radius of curvature of the convex surface in the transverse coordinate direction is in the range of 200μm to 700μm, the radius of curvature in the longitudinal coordinate direction is in the range of 200μm to 700μm, and the conicity coefficient of the convex surface is in the range of -1 to -8. The radius of curvature of the rear convex surface ranges from 5μm to 500μm in the transverse coordinate direction and from 5μm to 500μm in the longitudinal coordinate direction, and the conic coefficient of the rear convex surface ranges from -1 to -8.

2. The combined microlens array uniform light structure according to claim 1, characterized in that, The biconvex lens is located near the other side of the substrate layer, and the biconvex lens and the microlens array are respectively disposed opposite to each other on both sides of the substrate layer.

3. The combined microlens array homogenizing structure according to claim 1, characterized in that, The biconvex lens is located close to the microlens array, and the biconvex lens and the microlens array are disposed on the same side of the substrate layer.

4. The combined microlens array homogenizing structure according to claim 1, characterized in that, The optical surface profiles of the microlenses comprising the microlens array include deformable aspherical surface profiles; The optical profiles of the two convex surfaces are deformed aspherical profiles.

5. The combined microlens array homogenizing structure according to claim 4, characterized in that, One of the outer convex surfaces of the biconvex lens is a front convex surface close to the base layer, and the other outer convex surface of the biconvex lens is a rear convex surface away from the base layer.

6. The combined microlens array homogenizing structure according to claim 1, characterized in that, The refractive index of the microlens array is in the range of 1.5 to 1.8; The refractive index of the biconvex lens is in the range of 1.5 to 1.8; The base layer is a transparent glass base.

7. The combined microlens array homogenizing structure according to claim 1, characterized in that, The microlens array is formed by a series of microlenses arranged in a staggered manner, specifically including: After a number of microlenses are arranged in a dot matrix pattern, each microlens is randomly staggered within a preset distance range along the horizontal and / or vertical directions. After a number of microlenses are arranged in a dot matrix, the distance between the center points of two adjacent combined microlenses is 5 to 60 μm. The preset distance range is n times the distance between the center points of two adjacent combined microlenses, where n ranges from 8% to 20%.

8. A method for fabricating a combined microlens array homogenizing structure, characterized in that, A method for fabricating a combined microlens array homogenizing structure as described in any one of claims 1-7, comprising: fabricating a first lens group of the combined microlens array homogenizing structure, specifically including: A base layer is provided, wherein the base layer is a light-transmitting glass layer; A pattern forming template is provided, the surface of which is formed with a first pattern structure, the first pattern structure being opposite to the structure of the microlens array pattern of the first lens group; A molding compound is provided, and the pattern forming template is used as a mold. The molding compound is formed onto the substrate layer by pressing, and the microlens array pattern is formed on the surface of the substrate layer to obtain the first lens group.

9. The method for fabricating a combined microlens array homogenizing structure according to claim 8, characterized in that, The method for making the pattern forming template specifically includes: A patterning layer is provided, and a second pattern structure is formed on the surface of the patterning layer, the second pattern structure being consistent with the structure of the microlens array pattern; A pattern transfer layer is provided, and the pattern forming layer is used as a template. Plastic is molded onto the pattern transfer layer by embossing to form the first pattern structure on the surface of the pattern transfer layer, thereby obtaining the pattern forming template.

10. The method for fabricating a combined microlens array homogenizing structure according to claim 9, characterized in that, A second pattern structure is formed on the surface of the pattern forming layer, specifically including: The pattern forming layer includes a photosensitive material layer attached to a substrate. Different exposure amounts are applied to different positions of the photosensitive material layer according to the morphology of the microlens array pattern. After the photosensitive material layer is exposed, a second pattern structure with the same structure as the microlens array pattern is formed on it. The photosensitive material layer is divided into several layers based on the exposure depth formed after exposure, and the exposure amount of each layer has a non-linear relationship with the exposure depth.

11. An ITOF lens, characterized in that, It includes the combined microlens array light-uniforming structure according to any one of claims 1-7, wherein the combined microlens array light-uniforming structure has a microlens array, and an air layer with a thickness ranging from 0.1 mm to 0.5 mm is provided between the microlens array and the laser array light source.

12. A device equipped with an ITOF lens, characterized in that, It includes the ITOF lens of claim 11, wherein the ITOF lens is equipped with a combined microlens array homogenizing structure according to any one of claims 1-7.

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