Dodging element and manufacturing method thereof

Abstract

The invention provides a method for manufacturing a dodging element, and the method comprises the steps: designing a microlens array, and the design of the microlens array comprises the steps: determining a target light field; according to the target light field, multiple groups of light fields are determined, each group of light fields comprises multiple light fields, and the multiple light fields are mutually compensated, so that the light field formed after superposition is basically consistent with the target light field; multiple groups of micro lenses are determined according to the multiple groups of light fields, each group of micro lenses comprises multiple types of micro lenses, the multiple groups of light fields correspond to the multiple groups of micro lenses respectively, and the multiple light fields in each group of light fields correspond to the multiple types of micro lenses in the corresponding group of micro lenses in a one-to-one mode; determining the number of various micro lenses in the plurality of groups of micro lenses; the micro lens array is formed on a substrate, and the micro lens array comprises the multiple sets of micro lenses.

Description

Technical Field

[0001] The present invention generally relates to the field of optical technology, and in particular to a light homogenizing element and a manufacturing method thereof. Background Art

[0002] As a rising star in the field of imaging, 3D imaging technology is widely used in industrial inspection, scientific research, life medicine, consumer electronics and other fields. High-precision 3D imaging technology is mainly divided into two categories: structured light and time of flight (TOF).

[0003] In the TOF solution, the light homogenizer is a key component, which cooperates with the VCSEL (vertical cavity surface emitting laser) light source or LD (laser diode) light source to form the required target light field. The quality of the target light field directly affects the accuracy of the three-dimensional imaging system.

[0004] Commonly used light homogenizer solutions include DOE (diffractive optical element) devices based on the diffraction principle and MLA (microlens array) devices based on the refraction light source principle.

[0005] Refractive optical MLA devices have the advantages of no zero order, easy to make, cost-effective, easy to mass produce, small size and easy to integrate. The deflection of light by an ordinary single lens depends on the parameters of the lens surface. The far-field light intensity of the homogenizer based on the periodic microlens array is the superposition result of the incident light of each microlens. The periodic single microlens array will have a strong interference effect, which makes the homogenizer prone to poor homogenization effect, for example, the target light spot is uneven, there are interference bright spots, interference fringes, etc. For example, periodic superposition will lead to the existence of obvious light and dark fringes, and such periodic fringes will affect the imaging effect of the terminal device.

[0006] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0007] In view of one or more deficiencies in the prior art, the present invention provides a light homogenizing element and a method for manufacturing the same.

[0008] According to one aspect of the present invention, there is provided a method for manufacturing a light homogenizing element, comprising:

[0009] Designing a microlens array, the designing the microlens array comprising:

[0010] Determine the target light field;

[0011] Determine multiple groups of light fields according to the target light field, wherein each group of light fields includes multiple light fields, and the multiple light fields compensate each other so that the light field formed after superposition is basically consistent with the target light field; determine multiple groups of microlenses according to the multiple groups of light fields, wherein each group of microlenses includes multiple types of microlenses, the multiple groups of light fields correspond to the multiple groups of microlenses respectively, and the multiple light fields in each group of light fields correspond to the multiple types of microlenses in the corresponding group of microlenses one by one;

[0012] determining the number of each type of microlenses in the plurality of groups of microlenses;

[0013] The microlens array is formed on a substrate, wherein the microlens array includes the multiple groups of microlenses.

[0014] According to an embodiment of the present invention, forming the microlens array on a substrate includes: dividing the substrate into a plurality of grid areas, and arranging various microlenses in the plurality of groups of microlenses according to the plurality of grid areas.

[0015] According to an embodiment of the present invention, various microlenses in the plurality of groups of microlenses are matched with the grid areas in which they are located.

[0016] According to an embodiment of the present invention, determining a plurality of groups of light fields according to the target light field includes: determining the plurality of groups of light fields by performing a plurality of different decompositions on the target light field.

[0017] According to an embodiment of the present invention, the target light field is decomposed into at least three different types to determine at least three groups of light fields.

[0018] According to an embodiment of the present invention, the multiple groups of light fields include at least one group of light fields, which includes two light fields that compensate each other.

[0019] According to an embodiment of the present invention, the two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high at the top and bottom and low in the middle, or low at the top and bottom and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

[0020] According to an embodiment of the present invention, a field of view difference between each light field in the plurality of groups of light fields and the target light field does not exceed a predetermined range.

[0021] According to an embodiment of the present invention, the field of view difference does not exceed ±3°.

[0022] According to an embodiment of the present invention, determining the number of various microlenses in the plurality of groups of microlenses includes: adjusting the number of various microlenses in the plurality of groups of microlenses to adjust the light field formed on the target plane.

[0023] According to an embodiment of the present invention, the numbers of various microlenses in the multiple groups of microlenses are consistent, so that the light field formed on the target plane is consistent with the target light field.

[0024] According to an embodiment of the present invention, the number of at least one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one type of microlens.

[0025] According to an embodiment of the present invention, the microlens array further includes target microlenses determined according to the target light field, and the number of the at least one microlens is also higher than the number of the target microlenses.

[0026] According to an embodiment of the present invention, the arrangement of various microlenses in the plurality of groups of microlenses is random.

[0027] According to an embodiment of the present invention, microlenses of the same kind in the multiple groups of microlenses are not arranged adjacent to each other.

[0028] According to an embodiment of the present invention, various microlenses in the plurality of groups of microlenses are arranged irregularly.

[0029] According to an embodiment of the present invention, the central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

[0030] According to another aspect of the present invention, there is provided a light homogenizing element, comprising:

[0031] substrate;

[0032] A microlens array is formed on the substrate, wherein the microlens array includes multiple groups of microlenses, each group of microlenses includes multiple types of microlenses,

[0033] Among them, the multiple groups of microlenses correspond to multiple groups of light fields respectively, each group of light fields includes multiple light fields, the multiple light fields in each group of light fields correspond one-to-one to the multiple microlenses in the corresponding group of microlenses, and the multiple light fields compensate each other, so that the light field formed after superposition is basically consistent with the target light field.

[0034] According to an embodiment of the present invention, the multiple groups of light fields include at least one group of light fields, which includes two light fields that compensate each other.

[0035] According to an embodiment of the present invention, the two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high at the top and bottom and low in the middle, or low at the top and bottom and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

[0036] According to an embodiment of the present invention, the numbers of various microlenses in the multiple groups of microlenses are consistent, so that the light field formed on the target plane is consistent with the target light field.

[0037] According to an embodiment of the present invention, the number of at least one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one type of microlens.

[0038] According to an embodiment of the present invention, the microlens array further includes target microlenses determined according to the target light field, and the number of the at least one microlens is also higher than the number of the target microlenses.

[0039] According to an embodiment of the present invention, the arrangement of various microlenses in the plurality of groups of microlenses is random.

[0040] According to an embodiment of the present invention, microlenses of the same kind in the multiple groups of microlenses are not arranged adjacent to each other.

[0041] According to an embodiment of the present invention, various microlenses in the plurality of groups of microlenses are arranged irregularly.

[0042] According to an embodiment of the present invention, the central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

[0043] According to another aspect of the present invention, a light homogenizing element is provided, which is manufactured by the above method.

[0044] By using the method for manufacturing a light homogenizing element provided by the present invention, multiple groups of light fields can be designed, and multiple light fields in each group of light fields are superimposed to form a target light field. Since different light fields correspond to different microlenses, multiple microlenses are used in the microlens array instead of a single microlens, thereby increasing the randomness of the microlens array, which is beneficial to suppressing the interference effect of the microlens array, improving the light homogenizing effect of a light homogenizing sheet based on the microlens array, making the target light spot more uniform, that is, the light spot distribution is more compact, the light spot brightness difference is smaller, and interference bright spots, interference fringes, etc. are eliminated; and since different microlenses correspond to different light fields, the light field on the target plane can be regulated by adjusting the ratio of the microlenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0046] Figure 1 A schematic flow chart of a method for manufacturing a light homogenizing element according to an embodiment of the present invention is shown.

[0047] Figure 2 The embodiment of the present invention is shown Figure 1 A schematic flow chart of step S1 is shown.

[0048] 3(a)-(g) are schematic diagrams showing an example of designing multiple groups of light fields according to a target light field according to an embodiment of the present invention.

[0049] Figure 4 A schematic diagram showing an example of decomposing the target light field A0 shown in FIG. 3( a ) into four light fields according to an embodiment of the present invention is shown.

[0050] FIG. 5( a ) is a schematic diagram showing details of energy distribution of the light field A1 shown in FIG. 3( b ) according to an embodiment of the present invention.

[0051] FIG5( b ) is a schematic diagram showing details of energy distribution of the light field A2 shown in FIG3( b ) according to an embodiment of the present invention.

[0052] 6( a ) and ( b ) are schematic diagrams showing the arrangement of a comparative example of a microlens array according to an embodiment of the present invention and the light field formed thereby.

[0053] 7( a ) and ( b ) are schematic diagrams showing the arrangement of a first application example of a microlens array according to an embodiment of the present invention and the light field formed thereby.

[0054] 8( a ) and ( b ) are schematic diagrams showing the arrangement of a second application example of a microlens array according to an embodiment of the present invention and the light field formed thereby.

[0055] 9( a ) and ( b ) are schematic diagrams showing the arrangement of a third application example of a microlens array according to an embodiment of the present invention and the light field formed thereby. DETAILED DESCRIPTION

[0056] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0060] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0061] As can be seen from the background technology, in the prior art, since the microlens array of the light homogenizer uses a periodic single microlens, it is easy to have the problem of poor light homogenization effect, for example, the target light spot is uneven, there are interference fringes, interference bright spots, etc.

[0062] In order to solve the technical problem, the present invention provides a method for manufacturing a light homogenizing element, comprising:

[0063] Designing a microlens array, the designing the microlens array comprising:

[0064] Determine the target light field;

[0065] Determine multiple groups of light fields according to the target light field, wherein each group of light fields includes multiple light fields, and the multiple light fields compensate each other so that the light field formed after superposition is basically consistent with the target light field; determine multiple groups of microlenses according to the multiple groups of light fields, wherein each group of microlenses includes multiple types of microlenses, the multiple groups of light fields correspond to the multiple groups of microlenses respectively, and the multiple light fields in each group of light fields correspond to the multiple types of microlenses in the corresponding group of microlenses one by one;

[0066] determining the number of each type of microlenses in the plurality of groups of microlenses;

[0067] The microlens array is formed on a substrate, wherein the microlens array includes the multiple groups of microlenses.

[0068] In the technical solution of the present invention, multiple groups of light fields can be designed, and multiple light fields in each group of light fields are superimposed to form a target light field. Since different light fields correspond to different microlenses, multiple microlenses are used in the microlens array instead of a single microlens, thereby increasing the randomness of the microlens array, which is beneficial to suppressing the interference effect of the microlens array, improving the uniform light effect of the uniform light sheet based on the microlens array, making the target light spot more uniform, that is, the light spot distribution is more compact, the light spot brightness difference is smaller, and interference bright spots, interference fringes, etc. are eliminated; and since different microlenses correspond to different light fields, the light field on the target plane can be controlled by adjusting the ratio of the microlenses.

[0069] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0070] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0071] Figure 1 FIG. 2 is a schematic flow chart of a method for manufacturing a light homogenizing element according to an embodiment of the present invention. Figure 1 As shown, the method may include the following steps:

[0072] S1: Design microlens array;

[0073] S2: forming the microlens array on a substrate.

[0074] The substrate material may be, for example, glass, PET (polyethylene terephthalate), PC (polycarbonate), etc. The microlens array (i.e., microstructure) is disposed on one side of the substrate layer, and the microstructure includes a plurality of microlenses, and the material of the microlenses may be, for example, UV (ultraviolet) glue, etc. For example, the microlens array may be formed on the substrate by a transfer process, specifically, by nano-imprinting UV glue on the glass material to form the desired microlens morphology on the glass surface.

[0075] Figure 2 The embodiment of the present invention is shown Figure 1 The schematic flow chart of step S1 is shown in FIG. Figure 2 As shown, step S1 may include the following steps:

[0076] S11: Determine the target light field;

[0077] S12: determining multiple groups of light fields according to the target light field, wherein each group of light fields includes multiple light fields, and the multiple light fields compensate each other so that a light field formed after superposition is substantially consistent with the target light field;

[0078] S13: determining multiple groups of microlenses according to the multiple groups of light fields, wherein each group of microlenses includes multiple types of microlenses, the multiple groups of light fields correspond to the multiple groups of microlenses respectively, and the multiple light fields in each group of light fields correspond one-to-one to the multiple types of microlenses in the corresponding group of microlenses;

[0079] S14: Determine the number of each type of microlenses in the plurality of groups of microlenses.

[0080] Multiple groups of light fields are designed for the target light field, and each group of light fields includes multiple light fields. These multiple light fields compensate each other and can form the target light field after superposition. A corresponding group of microlenses is designed for each group of light fields, that is, multiple groups of light fields correspond to multiple groups of microlenses respectively. The corresponding groups of microlenses include multiple types of microlenses, and the multiple light fields in each group of light fields correspond one-to-one to the multiple types of microlenses in the corresponding group of microlenses, that is, the number of designed light fields is consistent with the number of types of designed microlenses. Since the designed microlens array includes multiple types of microlenses instead of a single microlens, the randomness of the microlens array is increased, which is beneficial to suppress the interference effect of the microlens array and improve the uniform light effect of the uniform light sheet based on the microlens array.

[0081] Since multiple light fields in each group of light fields are superimposed to form a target light field, the multiple light fields in each group of light fields correspond one-to-one to the multiple microlenses in the corresponding group of microlenses. For example, if the number of various microlenses in each group of microlenses is made consistent, the light field formed on the target plane is consistent with the target light field; for another example, if the number of a certain type of microlens in a certain group of microlenses is made higher, the light field formed on the target plane is closer to the light field corresponding to the type of microlens. Therefore, by determining the number of various microlenses in the multiple groups of microlenses, the light field formed on the target plane can be determined. Because different types of microlenses correspond to different light fields, when the design goal changes or compensation for process errors is required, the light field can be flexibly changed by simply adjusting the proportion of different types of microlenses without redesigning, reducing the difficulty of design processing and testing.

[0082] In some embodiments of the present invention, the microlens array may also include a microlens corresponding to the target light field (ie, a target microlens), that is, a microlens that can directly form the target light field.

[0083] The light field formed by other types of microlenses in the microlens array is different from the target light field, but the target light field can be formed by superimposing multiple light fields corresponding to each group of other types of microlenses.

[0084] In some embodiments of the present invention, step S2, i.e. forming the microlens array on a substrate, includes: dividing the substrate into a plurality of grid areas, and arranging the plurality of microlenses according to the plurality of grid areas.

[0085] That is, each microlens in the microlens array is arranged in a corresponding grid on the substrate.

[0086] In some embodiments of the present invention, each microlens matches the grid area in which it is located.

[0087] That is, each microlens in the microlens array matches the corresponding grid on the substrate in size and shape.

[0088] Specifically, a plurality of microlenses in the microlens array are arranged on a plurality of grid regions of the substrate, and each grid region of the substrate may be of a regular shape or an irregular shape.

[0089] That is to say, the arrangement of the multiple microlenses in the microlens array may be regular or irregular.

[0090] In the present invention, since the microlens array includes a plurality of microlenses rather than a single microlens, the randomness of the microlens array is increased. Therefore, even under the premise that the microlenses are arranged regularly, the interference effect can be well suppressed.

[0091] In some embodiments of the present invention, step S12, ie, determining a plurality of groups of light fields according to the target light field, comprises: determining the plurality of groups of light fields by performing a plurality of different decompositions on the target light field.

[0092] Specifically, the multiple groups of light fields include at least one group of light fields, and the group of light fields includes two light fields that compensate each other.

[0093] More specifically, the two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high at the top and bottom and low in the middle, or low at the top and bottom and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

[0094] The intensity difference between each group of light fields and the target light field can be flexibly adjusted. The principle is that the multiple light fields in each group of light fields are basically consistent with the target light field after superposition. The greater the difference between each group of light fields and the target light field, the better the effect of eliminating the interference effect.

[0095] Preferably, according to an embodiment of the present invention, the target light field is subjected to at least three different decompositions to determine at least three groups of light fields.

[0096] In this way, more light fields can be determined, thereby designing more types of microlenses, the randomness of the microlens array is better, the interference effect is better suppressed, and more light fields can be achieved in the target plane.

[0097] In some embodiments of the present invention, the field of view difference between each light field in the plurality of groups of light fields and the target light field does not exceed a predetermined range.

[0098] Preferably, the field of view difference does not exceed ±3°.

[0099] According to experience, such a setting can better meet the design requirements and obtain the required energy distribution.

[0100] Specifically, step S14, ie determining the number of various microlenses in the plurality of groups of microlenses, includes: adjusting the number of various microlenses in the plurality of groups of microlenses to adjust the light field formed on the target plane.

[0101] In some embodiments of the present invention, the numbers of various microlenses in the multiple groups of microlenses are consistent, so that the light field formed on the target plane is consistent with the target light field.

[0102] The microlens array may also include a microlens corresponding to the target light field (i.e., a target microlens), that is, a microlens that can directly form the target light field. The light field formed by other types of microlenses in the microlens array is different from the target light field, but the multiple light fields corresponding to each group of other types of microlenses can form the target light field after superposition. In this way, the number of other types of microlenses in the microlens array is consistent, so that the light field formed on the target plane is consistent with the target light field.

[0103] In some embodiments of the present invention, the number of at least one type of microlens in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one microlens.

[0104] Specifically, the number of one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the one type of microlenses.

[0105] Specifically, the number of the multiple types of microlenses in the multiple groups of microlenses is higher than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the superimposed light field of the multiple light fields corresponding to the multiple types of microlenses.

[0106] In particular, when the microlens array further includes target microlenses, the number of at least one microlens with a higher number in the plurality of groups of microlenses is also higher than the number of the target microlenses.

[0107] In this way, when the design goal changes or compensation for process errors is needed, the light field can be flexibly changed simply by adjusting the ratio of different microlenses without the need for redesign, reducing the difficulty of design, processing and testing.

[0108] In some embodiments of the present invention, the arrangement of various microlenses in the multiple groups of microlenses is random.

[0109] Specifically, microlenses of the same kind in the multiple groups of microlenses are not arranged adjacent to each other.

[0110] Specifically, various microlenses in the plurality of groups of microlenses are arranged irregularly.

[0111] More specifically, the central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

[0112] In this way, the randomness of the microlens array is further increased, and the interference effect is better suppressed.

[0113] Fig. 3(a)-(g) are schematic diagrams showing examples of designing multiple groups of light fields according to a target light field according to an embodiment of the present invention. Fig. 3(a) shows an example of a target light field A0. Fig. 3(b)-(f) show examples of five groups of light fields designed according to the target light field A0, i.e., five groups of light fields obtained by performing five different decompositions on the target light field A0.

[0114] FIG3( b ) shows an example of the first group of light fields, including two light fields A1 and A2 that compensate each other, wherein the light intensity distribution of the light field A1 is high on both sides and low in the middle, and the light intensity distribution of the light field A2 is low on both sides and high in the middle.

[0115] FIG3( c ) shows an example of a second group of light fields, including two light fields B1 and B2 that compensate each other, wherein the light intensity distribution of the light field B1 is high in the middle and low around, and the light intensity distribution of the light field B2 is low in the middle and high around.

[0116] FIG3( d ) shows an example of a third group of light fields, including two light fields C1 and C2 that compensate each other, wherein the light intensity distribution of the light field C1 gradually increases from left to right, and the light intensity distribution of the light field C2 gradually decreases from left to right.

[0117] FIG3( e ) shows an example of the fourth group of light fields, including two mutually compensating light fields D1 and D2 , wherein the light intensity distribution of the light field D1 is high at the top and bottom and low in the middle, and the light intensity distribution of the light field D2 is low at the top and bottom and high in the middle.

[0118] FIG3( f ) shows an example of the fifth group of light fields, including two mutually compensating light fields E1 and E2 , wherein the light intensity distribution of the light field E1 gradually increases from top to bottom, and the light intensity distribution of the light field E2 gradually decreases from top to bottom.

[0119] As shown in Figure 3(b)-(f), five groups of light fields are designed for the target light field A0, namely A1, A2, B1, B2, C1, C2, D1, D2, E1, and E2, which are 10 light fields different from the target light field A0. The intensity differences between these 10 light fields and the target light field A0 can be flexibly adjusted. The principle is that the superposition of two light fields in each group is basically consistent with the target light field A0. The greater the difference between these light fields and the target light field, the better the effect of eliminating the interference effect.

[0120] Ten types of microlenses are designed for these 10 light fields (i.e., A1, A2, B1, B2, C1, C2, D1, D2, E1, and E2), and these 10 types of microlenses correspond to these 10 light fields one by one. In the microlens array, these 10 types of microlenses can be arranged in an interlaced manner, that is, microlenses of the same type are not arranged adjacent to each other, which increases the randomness of the microlens array and suppresses the interference effect of the microlens array. In the microlens array, the number of these 10 types of microlenses can be made consistent (i.e., the number is equal), even if these 10 light fields are superimposed in equal proportion, so that these 10 types of microlenses finally form a light field consistent with the target light field A0. Figure 3(g) shows an example of the light field after the 10 light fields are superimposed in equal proportion. As shown in Figure 3(g), the light field after the 10 light fields are superimposed in equal proportion is consistent with the target light field A0 shown in Figure 3(a).

[0121] If the proportion of one or several of the 10 types of microlenses is increased, the light field finally formed will be closer to the light field corresponding to one microlens with a higher proportion or the superposition of the light fields corresponding to several microlenses.

[0122] In addition to designing these 10 microlenses for these 10 light fields (i.e., A1, A2, B1, B2, C1, C2, D1, D2, E1, and E2), a target microlens can also be designed for the target light field A0, and the target microlens corresponds to the target light field A0, that is, a total of 11 microlenses are designed. In the microlens array, these 11 microlenses can be arranged in an interlaced manner, that is, microlenses of the same type are not arranged adjacently, which increases the randomness of the microlens array and suppresses the interference effect of the microlens array. In the microlens array, the number of these 11 microlenses can be made consistent (i.e., the number is equal), even if these 11 light fields are superimposed in equal proportion, so that these 11 microlenses finally form a light field consistent with the target light field A0. If the number ratio of one or several non-target microlenses among these 11 microlenses is increased, the light field finally formed will be closer to the light field corresponding to a microlens with a higher proportion or the superposition of light fields corresponding to several microlenses.

[0123] In FIG3(b)-(f), each group of light fields includes two mutually compensating light fields, that is, the target light field can be decomposed into two mutually compensating light fields. However, the present invention is not limited thereto, and each group of light fields may include more than two mutually compensating light fields, that is, the target light field can be decomposed into more than two mutually compensating light fields. Figure 4 FIG. 3( a ) is a schematic diagram showing an example of decomposing the target light field A0 shown in FIG. 3( a ) into four light fields according to an embodiment of the present invention. Figure 4As shown, for the target light field A0 shown in FIG3(a), a group of light fields can be designed, which includes four mutually compensating light fields A1, A2, A3 and A4, wherein the light intensity distribution of light field A1 is high on both sides and low in the middle, the light intensity distribution of light field A2 is low on both sides and high in the middle, the light intensity distribution of light field A3 is high in the middle and low around, and the light intensity distribution of light field A4 is low in the middle and high around. These four light fields (i.e., A1, A2, A3 and A4) compensate each other, so that the light field formed after superposition is basically consistent with the target light field A0.

[0124] The corresponding microlens can be designed according to the obtained light field (i.e., the target light field or a decomposed light field in each group). As for the mirror surface of a single microlens, its surface shape formula can be in the form of an xy polynomial. The surface shape formula of the mirror surface of the microlens can be specifically:

[0125]

[0126] Wherein, in the above formula, x and y are respectively the abscissa and ordinate of the surface point of the microlens in the local coordinate system of the microlens, the x-axis and the y-axis are perpendicular to the height direction of the microlens, the origin of the local coordinate system of the microlens is the position of the vertex of the microlens (i.e., the center of the microlens), and the surface point of the microlens is a point on the mirror surface of the microlens;

[0127] c is the curvature;

[0128] k is the cone constant;

[0129] NR is the normalized radius;

[0130] A ij For x i y j The coefficient of

[0131] i, j are pointers to the items in the polynomial;

[0132] is the distance between the current coordinate (x, y) position and the center of the microlens.

[0133] All parameters in the surface formula are obtained by the optimization algorithm. For example, by setting an optimization function, such as the target energy distribution (i.e. the obtained light field), the function is used to optimize the various parameters in the surface formula, thereby designing the microlens. The purpose of optimizing the surface is to make the microlens array meet the design requirements and obtain the required target energy distribution.

[0134] Figure 5(a) is a schematic diagram showing the details of the energy distribution of the light field A1 shown in Figure 3(b) according to an embodiment of the present invention. The curve in Figure 5(a) shows that the planar illumination distribution of the light field A1 is low in the middle and high on both sides. Figure 5(b) is a schematic diagram showing the details of the energy distribution of the light field A2 shown in Figure 3(b) according to an embodiment of the present invention. The curve in Figure 5(b) shows that the planar illumination distribution of the light field A2 is high in the middle and low on both sides. Figure 3(b) shows an example of light fields A1 and A2, which compensate each other so that the light field formed after superposition is basically consistent with the target light field A0 shown in Figure 3(a), wherein the light intensity distribution of the light field A1 is high on both sides and low in the middle, and the light intensity distribution of the light field A2 is low on both sides and high in the middle.

[0135] Design parameters include at least:

[0136] FOV (field of view) of the target light field (i.e., target light field A0): 24°x13°;

[0137] The FOV of the decomposed light field (i.e., light fields A1 and A2) differs from the FOV of the target light field by ±3°;

[0138] Single microlens size: 25umx25um;

[0139] Substrate material: glass (0.3mm);

[0140] Microstructure material: UV glue;

[0141] Transfer process: Through UV glue nano-imprinting on the glass material, the desired microlens morphology is formed on the glass surface.

[0142] According to the details of the energy distribution of the light field A1 shown in FIG5(a), an optimization function can be set to optimize the parameters in the surface shape formula of the microlens corresponding to the light field A1. Table 1 shows the surface shape parameters of the microlens corresponding to the light field A1.

[0143] Table 1

[0144] A1 Curvature 0 k 0 NR 0.3286 <![CDATA[X 2 The coefficient of]]> 2.00 <![CDATA[Y 2 The coefficient of]]> 0.93 <![CDATA[X 4 The coefficient of]]> -100 <![CDATA[Y 4 The coefficient of]]> -9

[0145] According to the details of the energy distribution of the light field A2 shown in FIG5( b ), an optimization function can be set to optimize the parameters in the surface shape formula of the microlens corresponding to the light field A2. Table 2 shows the surface shape parameters of the microlens corresponding to the light field A2.

[0146] Table 2

[0147] A2 Curvature 0 k 0 NR 0.3286 <![CDATA[X 2 The coefficient of]]> 1.60 <![CDATA[Y 2 The coefficient of]]> 0.94 <![CDATA[X 4 The coefficient of]]> 40 <![CDATA[Y 4 The coefficient of]]> -10

[0148] Correspondingly, the present invention also provides a light homogenizing element, which is manufactured by adopting the above method.

[0149] Correspondingly, the present invention further provides a light homogenizing element, comprising:

[0150] substrate;

[0151] A microlens array is formed on the substrate, wherein the microlens array includes multiple groups of microlenses, each group of microlenses includes multiple types of microlenses,

[0152] Among them, the multiple groups of microlenses correspond to multiple groups of light fields respectively, each group of light fields includes multiple light fields, the multiple light fields in each group of light fields correspond one-to-one to the multiple microlenses in the corresponding group of microlenses, and the multiple light fields compensate each other, so that the light field formed after superposition is basically consistent with the target light field.

[0153] In some embodiments of the present invention, the plurality of groups of light fields include at least one group of light fields, the group of light fields including two light fields that compensate each other.

[0154] Preferably, the two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high above and below and low in the middle, or low above and below and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

[0155] In some embodiments of the present invention, the number of various microlenses in the multiple groups of microlenses is consistent, so that the light field formed on the target plane is consistent with the target light field.

[0156] The microlens array may also include a microlens corresponding to the target light field (i.e., a target microlens), that is, a microlens that can directly form the target light field. The light field formed by other types of microlenses in the microlens array is different from the target light field, but the multiple light fields corresponding to each group of other types of microlenses can form the target light field after superposition. In this way, the number of other types of microlenses in the microlens array is consistent, so that the light field formed on the target plane is consistent with the target light field.

[0157] In some embodiments of the present invention, the number of at least one type of microlens in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one microlens.

[0158] Specifically, the number of one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the one type of microlenses.

[0159] Specifically, the number of the multiple types of microlenses in the multiple groups of microlenses is higher than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the superimposed light field of the multiple light fields corresponding to the multiple types of microlenses.

[0160] In particular, when the microlens array further includes target microlenses, the number of at least one microlens with a higher number in the plurality of groups of microlenses is also higher than the number of the target microlenses.

[0161] In this way, the light field can be flexibly changed simply by changing the ratio of different microlenses without the need for redesign, which reduces the difficulty of design, processing and testing.

[0162] In some embodiments of the present invention, the arrangement of various microlenses in the multiple groups of microlenses is random.

[0163] Specifically, microlenses of the same kind in the multiple groups of microlenses are not arranged adjacent to each other.

[0164] Specifically, various microlenses in the plurality of groups of microlenses are arranged irregularly.

[0165] More specifically, the central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

[0166] In this way, the randomness of the microlens array is further increased, and the interference effect is better suppressed.

[0167] FIG6(a) and (b) show the arrangement of a comparative example of a microlens array according to an embodiment of the present invention and a schematic diagram of the light field formed. As shown in FIG6(a), the microlens array is regularly arranged by a single lens (for example, a target lens corresponding to the target light field A0 shown in FIG3(a)), so there will be a strong interference effect. Compared with the target light field A0 shown in FIG3(a), the light field shown in FIG6(b) interferes into a dot matrix.

[0168] Figures 7(a) and (b) show the arrangement of the first application example of the microlens array according to an embodiment of the present invention and a schematic diagram of the light field formed. Multiple groups of light fields are designed for the target light field (such as the target light field A0 shown in Figure 3(a)) by different decomposition methods, and corresponding microlenses are designed for each light field to increase the randomness of the microlens array, suppress the interference effect of the microlens array, and make the number of each microlens substantially equal to form a light field consistent with the target light field. As shown in Figure 7(a), a variety of microlenses are interspersed and arranged to further increase the randomness of the microlens array, so that the interference effect is significantly suppressed. Compared with the light field shown in Figure 6(b), the uniformity of the light field shown in Figure 7(b) is significantly improved, the spot distribution is more compact, the spot brightness difference is smaller, and the interference bright spots are reduced.

[0169] 8(a) and (b) show the arrangement of the second application example of the microlens array according to an embodiment of the present invention and a schematic diagram of the light field formed. Multiple groups of light fields are designed for the target light field (e.g., the target light field A0 shown in FIG. 3(a)) by different decomposition methods, and corresponding microlenses are designed for each light field to increase the randomness of the microlens array, suppress the interference effect of the microlens array, and make the number of each microlens substantially equal to form a light field consistent with the target light field. As shown in FIG. 8(a), the microlenses in the microlens array are arranged irregularly, for example, the center coordinates of each microlens are randomly displaced (i.e., randomly offset), further increasing the randomness of the microlens array and better suppressing the interference effect. Compared with the light field shown in FIG. 6(b), the uniformity of the light field shown in FIG. 8(b) is significantly improved, the spot distribution is more compact, the spot brightness difference is smaller, and the interference bright spots and interference fringes are reduced.

[0170] Figures 9(a) and (b) show the arrangement of the third application example of the microlens array according to an embodiment of the present invention and a schematic diagram of the light field formed. Multiple groups of light fields are designed for the target light field (for example, the target light field A0 shown in Figure 3(a)) through the different decomposition methods shown in Figures 3(b)-(f), and corresponding microlenses are designed for each light field, and the number of microlenses corresponding to the light field A2 shown in Figure 3(b) (that is, the light intensity distribution is low on both sides and high in the middle) accounts for the highest proportion, so as to form a light field closer to the light field A2. As shown in Figure 9(a), there are multiple microlenses in the microlens array, which increases the randomness of the microlens array and significantly suppresses the interference effect. Compared with the light field shown in Figure 6(b), the light field shown in Figure 9(b) is closer to the light field A2 shown in Figure 3(b), and the light field has better uniformity, the spot distribution is more compact, and the interference bright spots are reduced.

[0171] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a light homogenizing element, comprising: Designing a microlens array, the designing the microlens array comprising: Determine the target light field; Determining multiple groups of light fields according to the target light field, wherein each group of light fields includes multiple light fields, and the multiple light fields compensate each other so that a light field formed after superposition is substantially consistent with the target light field; Determine multiple groups of microlenses according to the multiple groups of light fields, wherein each group of microlenses includes multiple types of microlenses, the multiple groups of light fields correspond to the multiple groups of microlenses respectively, and the multiple light fields in each group of light fields correspond one-to-one to the multiple types of microlenses in the corresponding group of microlenses; determining the number of each type of microlenses in the plurality of groups of microlenses; The microlens array is formed on a substrate, wherein the microlens array includes the multiple groups of microlenses.

2. The method according to claim 1, characterized in that: Forming the microlens array on a substrate includes dividing the substrate into a plurality of grid areas, and arranging various microlenses in the plurality of groups of microlenses according to the plurality of grid areas.

3. The method according to claim 2, characterized in that Various microlenses in the plurality of groups of microlenses are matched with the grid areas in which they are located.

4. The method according to claim 1, characterized in that: Determining a plurality of groups of light fields according to the target light field includes: determining the plurality of groups of light fields by performing a plurality of different decompositions on the target light field.

5. The method according to claim 4, characterized in that The target light field is decomposed into at least three different types to determine at least three groups of light fields.

6. The method according to claim 1, characterized in that The multiple groups of light fields include at least one group of light fields, which includes two light fields that compensate each other.

7. The method according to claim 6, characterized in that The two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high at the top and bottom and low in the middle, or low at the top and bottom and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

8. The method according to claim 1, characterized in that The field of view difference between each light field in the multiple groups of light fields and the target light field does not exceed a predetermined range.

9. The method according to claim 8, characterized in that The field of view difference does not exceed ±3°.

10. The method according to claim 1, characterized in that Determining the number of various microlenses in the plurality of groups of microlenses includes: adjusting the number of various microlenses in the plurality of groups of microlenses to adjust a light field formed on a target plane.

11. The method according to claim 10, characterized in that The number of various microlenses in the multiple groups of microlenses is consistent, so that the light field formed on the target plane is consistent with the target light field.

12. The method according to claim 10, characterized in that The number of at least one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one type of microlens.

13. The method according to claim 12, characterized in that The microlens array further includes target microlenses determined according to the target light field, and the number of the at least one microlens is also higher than the number of the target microlenses.

14. The method according to claim 1, characterized in that The arrangement of various micro-lenses in the plurality of groups of micro-lenses is random.

15. The method according to claim 14, characterized in that The same type of microlenses in the multiple groups of microlenses are not arranged adjacent to each other.

16. The method according to claim 14 or 15, characterized in that Various microlenses in the multiple groups of microlenses are arranged irregularly.

17. The method according to claim 16, characterized in that The central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

18. A light homogenizing element, comprising: substrate; A microlens array is formed on the substrate, wherein the microlens array includes multiple groups of microlenses, each group of microlenses includes multiple types of microlenses, Among them, the multiple groups of microlenses correspond to multiple groups of light fields respectively, each group of light fields includes multiple light fields, the multiple light fields in each group of light fields correspond one-to-one to the multiple microlenses in the corresponding group of microlenses, and the multiple light fields compensate each other, so that the light field formed after superposition is basically consistent with the target light field.

19. The light homogenizing element according to claim 18, characterized in that: The multiple groups of light fields include at least one group of light fields, which includes two light fields that compensate each other.

20. The light homogenizing element according to claim 19, characterized in that: The two mutually compensating light fields include the following light intensity distribution: high in the middle and low around, or low in the middle and high around, or low on both sides and high in the middle, or high on both sides and low in the middle, or high at the top and bottom and low in the middle, or low at the top and bottom and high in the middle, or gradually increasing from left to right and gradually decreasing from left to right, or gradually increasing from top to bottom and gradually decreasing from top to bottom, or gradually increasing from upper left to lower right and gradually decreasing from upper left to lower right, or gradually increasing from upper right to lower left and gradually decreasing from upper right to lower left.

21. The light homogenizing element according to claim 18, characterized in that: The number of various microlenses in the multiple groups of microlenses is consistent, so that the light field formed on the target plane is consistent with the target light field.

22. The light homogenizing element according to claim 18, characterized in that: The number of at least one type of microlenses in the multiple groups of microlenses is greater than the number of other types of microlenses in the multiple groups of microlenses, so that the light field formed on the target plane is closer to the light field corresponding to the at least one type of microlenses.

23. The light homogenizing element according to claim 22, characterized in that: The microlens array further includes target microlenses determined according to the target light field, and the number of the at least one microlens is also higher than the number of the target microlenses.

24. The light homogenizing element according to claim 18, characterized in that: The arrangement of various micro-lenses in the plurality of groups of micro-lenses is random.

25. The light homogenizing element according to claim 24, characterized in that: The same type of microlenses in the multiple groups of microlenses are not arranged adjacent to each other.

26. The light homogenizing element according to claim 24 or 25, characterized in that: Various microlenses in the multiple groups of microlenses are arranged irregularly.

27. The light homogenizing element according to claim 26, characterized in that: The central coordinates of various microlenses in the plurality of groups of microlenses are randomly offset.

28. A light homogenizing element, characterized in that: It is manufactured by the method according to any one of claims 1 to 17.

Images