Homogenizing system and preparation method of microlens array

Abstract

The application provides a light homogenizing system, a preparation method of a microlens array and a computer readable storage medium. The light homogenizing system comprises a light source and a microlens array. The light source comprises a plurality of sub-light sources with synchronous control switches or individual control switches, and the sub-light sources are divided into a plurality of sub-light source groups according to a preset rule. The microlens array is arranged downstream of the light path of the light source and comprises two or more sub-zones that do not overlap with each other. The sub-zones correspond to the sub-light source groups one by one, and the illumination areas of the sub-light sources in the same sub-light source group on the microlens array do not overlap with each other. The microlens structure in each sub-zone receives the light beams emitted by the sub-light sources in the corresponding sub-light source group to form a light homogenizing light field. The embodiment of the application can simultaneously or in time form light homogenizing light fields that meet different requirements, the light homogenizing light fields do not interfere with each other, the production cost of the light homogenizing system with the requirement of forming a plurality of different light homogenizing light fields is reduced, and structural conditions are provided for the miniaturization of the light homogenizing system.

Description

Technical Field

[0001] This invention relates to the field of optical components and equipment technology, and in particular to a method for fabricating a light homogenizing system and a microlens array. Background Technology

[0002] In optical equipment, the light beam emitted from a light source often cannot be output directly but needs to be preprocessed to meet different application requirements. Diffusion and homogenization of the emitted light beam are crucial aspects of this preprocessing. Homogenizing components can distribute the emitted light beam uniformly into the target light field through refraction or diffraction. Currently, microlens arrays based on the principle of refraction are increasingly widely used due to their ease of mass production, high efficiency, and high uniformity. Microlens arrays can diffuse incident light into the target light field angle through the microlens structure on their surface, uniformly illuminating the target area and facilitating subsequent light field processing or information acquisition of the target area.

[0003] Using microlens arrays designed according to the target light field as homogenizing components to form a uniform light field within a specific angular range with a specific light source is a common optical shaping requirement, often used for uniform illumination with a single light field requirement along the optical axis. However, in practical applications, some optical devices often have multiple different homogenizing illumination needs simultaneously, or require switching the distance or divergence angle of the homogenizing illumination according to the specific application scenario. To solve this need, existing homogenizing systems typically embed multiple light sources simultaneously within the optical device, and design a corresponding homogenizing component for each light source based on each different application requirement. In actual use, the corresponding light source is lit according to the requirements, and the corresponding homogenizing component forms a light field that meets the usage requirements. However, this traditional structure often leads to increased costs, and it is also difficult to further miniaturize the optical device.

[0004] The content of the background section is merely the technology known to the inventor and does not necessarily represent the prior art in this field. Summary of the Invention

[0005] To address one or more deficiencies in the prior art, the present invention provides a light homogenizing system, comprising:

[0006] The light source includes multiple sub-light sources controlled by synchronous or individual control switches, and the sub-light sources are grouped into multiple sub-light source groups according to a preset rule; and

[0007] A microlens array is disposed downstream of the light source's optical path. The effective area of ​​the microlens array includes two or more non-overlapping sub-regions. The light source and the microlens array are configured such that the sub-regions correspond one-to-one with the sub-light source groups. The illumination areas of the sub-light sources in different sub-light source groups on the microlens array do not overlap. The microlens structure in each sub-region is configured to receive the light beam emitted by the sub-light source in the corresponding sub-light source group to form a uniform light field.

[0008] According to one aspect of the invention, sub-light sources within the same sub-light source group are controlled to emit light or turn off simultaneously;

[0009] The boundary of each sub-partition is defined by the illumination range of the sub-light source within the sub-light source group corresponding to that sub-partition on the microlens array.

[0010] According to one aspect of the present invention, the light source is a VCSEL (Vertical Cavity Surface Emitting Laser) light source, and the sub-light sources in each sub-light source group are arranged in a one-dimensional or two-dimensional array, with multiple sub-light source groups disposed on the same light-emitting surface.

[0011] According to one aspect of the invention, the sub-light sources within different sub-light source groups are arranged in the same manner; the distance between adjacent sub-light sources within the same sub-light source group is equal, and the distance between different sub-light source groups is equal.

[0012] According to one aspect of the invention, the light beam emitted by each of the sub-light source groups passes through the corresponding sub-partition to form a linear uniform light field; the multiple sub-light source groups are arranged in parallel to form multiple linear uniform light fields that are parallel to each other on the target surface.

[0013] According to one aspect of the invention, the linear uniform light fields formed by adjacent sub-light source groups are closely adjacent or partially overlap.

[0014] According to one aspect of the invention, the microlenses in each of the sub-regions are configured to diffuse the light beam emitted by the sub-light source in the corresponding sub-light source group at an angle of 40-90° in the vertical direction and at an angle of no more than 2° in the horizontal direction; the distance between the light source and the microlens array is in the range of 30-300 micrometers.

[0015] According to one aspect of the invention, the different sub-regions have different field-of-view diffusion angles to form light fields with different energy densities; the fields of view of the different sub-regions at least partially overlap.

[0016] According to one aspect of the invention, the effective region of the microlens array includes a first sub-region and a second sub-region, wherein the diffusion angle of the first sub-region is greater than the diffusion angle of the second sub-region.

[0017] According to one aspect of the invention, the homogenizing system further includes a control device configured to individually control the grouped emission of beams from the sub-light sources.

[0018] The control device is configured to: control the sub-light source group corresponding to the first sub-partition to emit light beams to form a first uniform light field with the diffusion angle of the first sub-partition;

[0019] The sub-light source partition corresponding to the first sub-partition is closed, and the sub-light source group corresponding to the second sub-partition is controlled to form a second uniform light field with the diffusion angle of the second sub-partition.

[0020] According to one aspect of the present invention, the uniform light system further includes a processing device and an image acquisition device, wherein the image acquisition device is configured to acquire images within the first uniform light field and the second uniform light field, the processing device is coupled to the image processing device and configured to: identify a region of interest in the image of the first uniform light field; when the region of interest is identified, by means of the control device, shut down the sub-light source partition corresponding to the first sub-partition and drive the sub-light source partition corresponding to the second sub-partition to form a second uniform light field with the diffusion angle of the second sub-partition.

[0021] According to one aspect of the present invention, the present invention also includes a method for fabricating a microlens array, the method comprising:

[0022] The initial lens surface shape is obtained, and a simulated microlens array is formed by closely packing the lenses;

[0023] The simulated microlens array is partitioned;

[0024] Templates are prepared based on the initial lens surface shape and microlens array partitioning;

[0025] A microlens array is formed on a substrate using a template.

[0026] According to one aspect of the invention, the initial lens profile is calculated based on the target light field and the light distribution curve of the light source; the initial lens profile is a convex lens or a concave lens with a spherical, aspherical, or freeform surface.

[0027] According to one aspect of the invention, the step of partitioning the simulated microlens array includes dividing the simulated microlens array into multiple partitions based on: the design distance between the light source and the microlens array; the diffusion angle of the light source; and the target light field, such that the boundaries of the partitions correspond to the illumination areas of the light source group on the microlens array;

[0028] The initial lens surface shape within the partition is designed based on the optical characteristics of the emitted beam from the corresponding light source group.

[0029] According to one aspect of the present invention, the initial lens surface pattern is randomly arranged in the corresponding partition; the method for fabricating the microlens array further includes:

[0030] The microlens surface shape of the simulated microlens array is optimized.

[0031] According to one aspect of the invention, the invention also includes a computer-readable storage medium comprising computer-executable commands stored thereon, the executable commands, when executed by a processor, implementing the fabrication method of the microlens array as described above.

[0032] Compared with existing technologies, embodiments of the present invention provide a uniform light system in which multiple sub-light sources in the light source are divided into multiple groups, and the microlens array also includes multiple non-overlapping sub-regions. The sub-light source groups in the light source correspond to the sub-regions in the microlens array, and the illumination areas on the microlens array do not overlap. Embodiments of the present invention utilize the microlens array to simultaneously or sequentially form uniform light fields that can meet different requirements, and the uniform light fields do not interfere with each other, reducing the production cost of uniform light systems that require the formation of multiple different uniform light fields, and providing structural conditions for the miniaturization of uniform light systems. The present invention also includes an embodiment of a method for fabricating a microlens array, used to fabricate microlens arrays with different regions, wherein the microlens structures in different regions can be adapted to the corresponding light source to form a preset uniform light field. Embodiments of the present invention also include a computer-readable storage medium for executing the aforementioned method for fabricating a microlens array. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the structure of a light-uniforming system in one embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of a light source in one embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the projected light field when multiple sub-light sources are lit simultaneously in one embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the uniform light system in another embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of a light source in another embodiment of the present invention;

[0039] Figure 6A and Figure 6B This is a schematic diagram of the projected light field under different viewing diffusion angles in one embodiment of the present invention;

[0040] Figure 7 This is a structural block diagram of a light-uniforming system in one embodiment of the present invention;

[0041] Figure 8 This is a schematic flowchart of a microlens array fabrication method in one embodiment of the present invention. Detailed Implementation

[0042] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0047] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0048] Figure 1 A schematic diagram of the structure of a light homogenizing system 100 according to an embodiment of the present invention is shown. Figure 2 The following illustrates a specific grouping method of the light source 110 according to an embodiment of the present invention, in conjunction with... Figure 1 and Figure 2 Detailed description.

[0049] According to a preferred embodiment of the present invention, the light homogenizing system 100 includes a light source 110 and a microlens array 120. For example... Figure 2As shown, the light source 110 includes multiple sub-light sources 111-1 that are synchronously controlled to turn on or individually controlled to turn on. These sub-light sources 111-1 are divided into multiple sub-light source groups 111 according to a preset rule. According to different embodiments of the present invention, the number of sub-light sources 111-1 in a sub-light source group 111 can be one or more, and the number of sub-light sources 111-1 in different sub-light source groups 111 can be the same or different. The grouping rules, specific number, and optical parameters of the sub-light sources 111-1, such as the wavelength of the emitted beam and the diffusion angle of the beam in different directions, can be designed according to the specific requirements of the target homogenizing light field. Preferably, the sub-light source 111-1 is a VCSEL light source, with the laser beam emitted vertically from the end face. VCSEL light sources occupy little space, are easy to position, have stable performance, and can further reduce the volume of the homogenizing system 100.

[0050] like Figure 1 As shown, the microlens array 120 is positioned downstream of the optical path of the light source 110. The effective region of the microlens array 120 includes two or more non-overlapping sub-regions 121. Due to the extremely small size of the microlens structures in the microlens array 120, in Figure 1 The text uses black and white to distinguish the sub-partitions, but this does not necessarily mean that the microlens array 120 in this embodiment only includes two types of sub-partitions 121 with different microlens structures. In different embodiments of the present invention, the microlens structures within the sub-partitions 121 of the microlens array 120 can be the same or different. Specifically, the design is based on the target uniform light field and can be optimized through simulation. Different sub-partitions 121 in the microlens array 120 do not overlap. Adjacent sub-partitions 121 can be spaced apart or closely fitted together. Preferably, adjacent sub-partitions 121 are adjacent to each other to fully utilize the space in the microlens array 120.

[0051] According to a specific embodiment of the present invention, the microlens array 120 generates a microlens structure by optimizing the target light field requirements and the light distribution curve of the light source, and then generates sub-sections 121 in the microlens array 120 by densely arranging the microlens structures. The surface shape of the microlens structure can be a rectangular convex / concave lens with a spherical, aspherical, or freeform surface shape. Multiple different target uniform light fields are individually designed with corresponding sub-sections 121.

[0052] The microlens array 120 can be a single-sided or double-sided structure. When a single-sided structure is used, the microlens surface can face the light source or face away from the light source. The cross-sectional characteristic dimensions of the initial microlens structure are generally maintained at 10-100 micrometers, and the depth or thickness of the microlens structure is generally 20-200 micrometers.

[0053] Periodic or quasi-periodic arrangements of microlens structures can easily produce striped ripples in the final generated light field, affecting the uniform light effect. Therefore, according to a preferred embodiment of the present invention, the microlens structures in the microlens array 120 are arranged in random coordinates to break the periodicity of the arrangement between lenses, so as to avoid the generation of stripes in the final light field.

[0054] In this embodiment, the sub-light source groups 111 in the light source 110 correspond one-to-one with the sub-regions 121 in the microlens array 120, and the illumination areas of the sub-light sources 111-1 in different sub-light source groups 111 on the microlens array 120 do not overlap. The microlens structure in each sub-region is configured to receive the light beam emitted by the sub-light sources in the corresponding sub-light source group to form a uniform light field. For example, in Figure 1 From the cross-sectional view shown, six sub-light source groups 111 can be observed. The light beam emitted by sub-light source 111-1 in sub-light source group 111 illuminates the microlens array 120 at a fixed diffusion angle. Similarly, six sub-regions 121 can be observed in the microlens array 120, corresponding to the illumination areas of the six sub-light source groups 111 on the microlens array 120. The illumination area of ​​the sub-light source group 111 on the microlens array 120 is not larger than the range of the corresponding sub-region 121. Preferably, the boundary of the illumination area of ​​sub-light source 111-1 in sub-light source group 111 on the microlens array 120 coincides with the boundary of the sub-region 121. The boundary of each sub-region 121 is defined by the illumination range of sub-light source 111-1 in the corresponding sub-light source group 111 on the microlens array 120. For example, when designing the homogenizing system 100, this can be achieved by changing the beam diffusion angle of sub-light source 111-1 and the distance between sub-light source 111-1 and microlens array 120.

[0055] According to a preferred embodiment of the present invention, sub-light sources 111-1 within the same sub-light source group 111 are controlled to emit light or turn off simultaneously. For example, each sub-light source 111-1 within the same sub-light source group 111 may be provided with a separate control switch. For multiple different sub-light source groups 111, each may be provided with a separate corresponding control switch, or some sub-light source groups 111 may share a single control switch. The control switch settings between sub-light source groups 111 are designed according to the target uniform light field.

[0056] like Figure 1 and Figure 2As shown, according to a preferred embodiment of the present invention, the sub-light sources 111-1 in the light source 110 are VCSEL light sources, and the sub-light sources 111-1 in each sub-light source group 111 are arranged in a one-dimensional or two-dimensional array, with multiple sub-light source groups 111 disposed on the same light-emitting surface. Further, the light-emitting surface of the light source 110 is parallel to the microlens array 120. By adjusting the distance between the light source 110 and the microlens array 120, the boundary of the illumination area of ​​the sub-light source group 111 on the microlens array 120 coincides with the boundary of the sub-section 121.

[0057] like Figure 2 As shown, in different embodiments of the present invention, the sub-light sources 111-1 within the sub-light source group 111 are arranged in a one-dimensional array or a two-dimensional array. For example, multiple sub-light sources 111-1 within the same sub-light source group 111 are arranged in a column, a row, or multiple columns and rows. Preferably, multiple sub-light sources 111-1 within the same sub-light source group 111 form an array with the same spacing and azimuth angle. Of course, in other embodiments of the present invention, multiple sub-light sources 111-1 within the same sub-light source group 111 can also be arranged randomly.

[0058] Furthermore, according to a preferred embodiment of the present invention, the light source 110 includes a plurality of sub-light source partitions 111, wherein the sub-light sources 111-1 within different sub-light source groups 111 are arranged in the same manner, and the distance between adjacent sub-light sources 111-1 within the same sub-light source group 111 is equal, and the distance between different sub-light source groups 111 is equal. Further still, the sub-light sources 111-1 within different sub-light source groups 111 are arranged in the same manner, and all the sub-light sources 111-1 within the light source 110 form an array containing multiple sub-light source partitions 111 with the same distance and azimuth angle.

[0059] For example, in a specific embodiment of the present invention, the light source 110 includes six sub-light source groups 111. The sub-light sources 111-1 in different sub-light source groups 111 are arranged in the same way, and the relative positional relationship between adjacent sub-light sources 111-1 within the light source 110 satisfies the same constraint conditions, for example, in Figure 2 The horizontal spacing is 40.5 micrometers, the vertical spacing is 26 micrometers, and the azimuth angle is fixed.

[0060] The six sub-light source groups 111 are tessellated in parallel. Correspondingly, the microlens array 120 also includes six sub-sections 121, arranged in parallel downstream of the light source 110. Although the six sub-light source groups 111 are in width ( Figure 2The lateral distances of the sub-light source groups 111 are equal, but the boundary widths of the corresponding sub-regions 121 may be the same or different, depending on the illumination area of ​​different groups of sub-light source groups 111 on the microlens array 120. This is influenced by the distance between the light source 110 and the microlens array 120, as well as the lateral diffusion angles of different sub-light source groups 111. The distance between the microlens array 120 and the target surface 130 is a system parameter of the homogenizing system 100. Preferably, the diffusion angles of different sub-light source groups 111 are the same. After the light beam passes through the microlens array 120, each group of sub-light source groups 111 forms a linear homogenizing light field on the target surface 130. When multiple sub-light source groups 111 are activated simultaneously, multiple parallel linear homogenizing light fields are formed on the target surface 130, such as... Figure 3 As shown.

[0061] In this embodiment, different sub-light source partitions 111 are individually controlled to emit light and turn off. In specific applications, for example, different sub-light source partitions 111 in the light source 110 can be controlled to emit light sequentially from left to right or in reverse order. As different sub-light source partitions 111 switch between emitting light and turning off, linear scanning stripes that change in a preset order are generated on the target surface 130. This can be applied in multiple fields such as precision structure inspection and surface flatness measurement. According to other embodiments of the present invention, multiple sub-light source partitions 111 can be controlled to emit light simultaneously, forming a linear array light field on the target surface 130. This can be applied in multiple fields such as shape recognition and panel inspection. Furthermore, by adjusting the lateral diffusion angle of different sub-light source groups 111, or changing parameters such as the distance between the target surface 130 and the microlens array 120, so that the linear uniform light fields formed by adjacent sub-light source groups 111 on the target surface 130 are closely adjacent or partially overlapped, multiple independent outgoing light fields can be spliced ​​together to form a uniform light field with a large lateral viewing angle.

[0062] The aforementioned applications are difficult to achieve with a single microlens array in existing technologies. They often require multiple light sources and corresponding light homogenizers, which increases the manufacturing cost of the light homogenizing system and makes its internal structure complex, limiting its application in confined spaces.

[0063] In this embodiment, the beam emitted by sub-light source 111-1 within sub-light source group 111 has a vertical diffusion angle of 40-90°, preferably 60°, and a horizontal diffusion angle of no more than 2°, for example, 1°, where vertical direction represents... Figure 2 The vertical and horizontal directions in the text represent Figure 2The horizontal diffusion angle is chosen to reduce the width of the illumination area of ​​the sub-light source group 111 on the microlens array 120, thereby achieving reasonable tiling of the sub-sections 121 in the microlens array 120 and making full use of the space on the microlens array 120. Simultaneously, it expands the range of distances between the light source 110 and the microlens array 120, helping to reduce the assembly difficulty of the homogenizing system 100 and improve assembly accuracy. In this embodiment, the distance between the light source 110 and the microlens array 120 ranges from 30 to 300 micrometers. A suitable distance is selected based on the horizontal and vertical diffusion angles of the sub-light source section 111 to fully utilize the effective area of ​​the microlens array 120. Since the light beam emitted by the light source 110 has a fixed diffusion angle, to avoid crosstalk caused by light emitted from different sub-light sources 111-1 illuminating other sub-sections 121, and to facilitate control of the correspondence between the diffusion angle of the light source 110 and the boundary of the sub-section 121, it is preferable to keep the distance between the light source 110 and the microlens array 120 within a small range.

[0064] Furthermore, the emitted light fields corresponding to different sub-light source groups 111 also have a certain angular deflection in the horizontal direction, so that the linear stripes formed on the target surface 130 are discrete or aggregated. This can be achieved by designing the microlens structure in the corresponding sub-partition 121.

[0065] Figure 4 The structure of a uniform light system 200 according to another embodiment of the present invention is shown. Figure 5 The arrangement of sub-light sources 211-1 in the light source 210 in a preferred embodiment of the present invention is shown below, in conjunction with... Figure 4 and Figure 5 Detailed explanation.

[0066] In another embodiment of the invention, different sub-regions 221 in the microlens array 220 have different field-of-view diffusion angles, which is achieved by adjusting the surface design of the microlens structures in different sub-regions 221. For example Figure 4 As shown, where is located Figure 4 The field of view spread angle of the first sub-region 221A in the upper center is FOV A, for example, 80°, located in Figure 4 The field of view diffusion angle of the second sub-partition 221B in the lower middle is FOV B, for example, 60°. On the target surface 230 at the same distance from the microlens array 120, the spot sizes formed by the corresponding sub-light source group 211A and sub-light source group 211B are different.

[0067] like Figure 5As shown, preferably, the number of sub-light sources 211-1 within sub-light source groups 211A and 211B of light source 210 is the same. Furthermore, the distance and azimuth angle between adjacent sub-light sources 211-1 within sub-light source groups 211A and 211B are also the same, forming a sub-light source array. In other embodiments of the present invention, the number of sub-light sources 211-1 in different sub-light source groups 211 can also be set to meet a preset ratio, specifically designed according to the target uniform light field.

[0068] The microlens structures in the first sub-region 221A and the second sub-region 221B of the microlens array 220 have different surface features, so that the first sub-region 221A and the second sub-region 221B have different field-of-view diffusion angles. Preferably, the first sub-region 221A and the second sub-region 221B are closely arranged in the microlens array 220, and their boundary line coincides with the illumination area boundary of the sub-light source group 211A and the sub-light source group 211B on the microlens array 220, so that the light emitted by the sub-light source group 211A and the sub-light source group 211B can only illuminate the range of the first sub-region 221A and the second sub-region 221B, respectively.

[0069] Preferably, in this embodiment, the number, arrangement, and optical parameters of sub-light sources 211-1 in sub-light source group 211A and sub-light source group 211B are the same, that is, sub-light source group 211A and sub-light source group 211B can form the same emitted light. However, due to the different surface shapes of the microlens structures in their corresponding first sub-partition 221A and second sub-partition 221B, the light field diffusion angles formed after the emitted light passes through the first sub-partition 221A and second sub-partition 221B are different, and the range of the light spot formed on the target surface 230 is different, as shown below. Figure 6A and Figure 6B As shown.

[0070] Since FOV A is greater than FOV B in this embodiment, and increasing the field of view diffusion angle significantly reduces the energy density per unit spatial angle in the light field, the uniform light field corresponding to FOV A is suitable for close-range scenes in this embodiment, while the uniform light field corresponding to FOV B has a higher energy density.

[0071] It can be applied to a longer application distance. In practical applications, the sub-light source group 211A can be controlled to emit light first. After passing through the first sub-section 221A, a first uniform light field is formed, which provides initial illumination to the target with a large field of view diffusion angle and low energy density. After obtaining the initial information, the sub-light source group 211A is turned off and the sub-light source group 211B is turned on to form a second uniform light field, which provides further illumination to the target with a higher energy density, so as to obtain more accurate scene features. By using the sub-light source group 211A and the sub-light source group 211B in combination, the region of interest can be found and detected more efficiently. However, in order to achieve the same effect, the existing uniform light device often requires two different light sources or two different uniform light sheets. This not only increases the production cost, but also makes the internal structure of the uniform light device complex, difficult to assemble, and difficult to further reduce the size of the uniform light device, thus limiting the application range of the uniform light device.

[0072] Furthermore, such as Figure 7 As shown, in a preferred embodiment of the present invention, the homogenizing system 200 further includes a processing device 240 and an image acquisition device 250. The image acquisition device 250 is capable of acquiring images within the first homogenizing light field and the second homogenizing light field, such as a color camera or an infrared camera. The processing device 240 is coupled to the image processing device 250 and is capable of controlling the light source 210. A region of interest is identified in the image of the first homogenizing light field. When the region of interest is identified, the control device 240 shuts down the sub-light source partition 211A and drives the sub-light source partition 211B to emit light, forming a second homogenizing light field with the diffusion angle of the second sub-partition, thereby obtaining more accurate information about the region of interest.

[0073] Figure 8 The following illustrates a detailed process of a microlens array fabrication method 300 according to an embodiment of the present invention, in conjunction with... Figure 8 Detailed description.

[0074] In step S301, an initial lens profile is obtained and densely packed to form a simulated microlens array. Specifically, the initial lens profile is obtained after calculation based on the requirements of the target uniform light field and the light distribution curve of the light source that matches the microlens array. The initial lens profile can be a convex or concave lens with a spherical, aspherical, or freeform surface shape. The microlens array can be a single-sided or double-sided structure, meaning the initial lens profile can be generated on one or both sides of the substrate. When a single-sided structure is selected, the lens profile in the microlens array can face the light source or face away from the light source; this invention does not impose any restrictions. Dense packing can improve the utilization rate of the substrate space, control the size of the microlens array, and further reduce the volume of optical devices using microlens arrays. The cross-sectional characteristic dimensions of the initial lens are generally maintained at 10-100 micrometers, and the vertex height or depth of the initial lens is generally 20-200 micrometers.

[0075] Because the microlens array generated by the initial periodic or quasi-periodic arrangement of lenses is prone to producing striped interference ripples in the final optical field, affecting the homogenization effect, in a preferred embodiment of the present invention, the initial lenses are arranged in random coordinates to break the periodicity of the lens arrangement, thereby avoiding the generation of stripes in the final optical field.

[0076] Furthermore, since the common random arrangement of single lenses often leads to overlap between lenses, the degree of overlap becomes more severe the farther away from the center of the lens cross-section. This results in a significant decrease in energy in the edge regions of the target light field, failing to meet the requirements of a uniform light field. Therefore, in a preferred embodiment of the present invention, after the initial lenses are densely arranged, the surface shape of the initial lenses is further corrected and optimized to ensure that the light performance meets the requirements.

[0077] Since the light beam emitted by the light source has a fixed diffusion angle, in order to avoid crosstalk caused by the light emitted by different emitters in the light source illuminating other partitions, in order to facilitate the control of the correspondence between the diffusion angle of the light source and the partition boundary of the microlens array, it is preferable that the distance between the light source and the microlens array be kept within a small distance, for example, 30-300 micrometers, in optical devices that use microlens arrays.

[0078] In step S302, the simulated microlens array is partitioned. In this embodiment, the microlens array is used to form a complex target homogenized light field to adapt to specific application requirements. Preferably, the microlens array is partitioned according to the specific requirements of the target homogenized light field and the optical parameters of the beam emitted by the corresponding light source, forming different partitions. The initial lens surface shape within each partition is designed based on the optical characteristics of the beam emitted by the light source corresponding to that partition. In this step, the initial lens surface shape can be adjusted according to design requirements, forming non-overlapping partitions on the simulated microlens array. Preferably, different partitions are adjacent or close to each other to fully utilize the space of the substrate. Simultaneously, the boundaries between different partitions can be designed according to the diffusion angle of the beam emitted by the corresponding light source and the designed distance between the light source and the microlens array, so that the illumination area of ​​the beam emitted by the corresponding light source on the microlens array corresponds to the partition boundaries on the microlens array.

[0079] In step S303, a template is prepared based on the initial lens surface shape and the partitioning of the microlens array. The template can be fabricated using various methods such as imprinting, photolithography, and laser etching. The substrate for the template can be made of various materials such as metal, silicon substrate, and photoresist. Based on the initial lens surface shape and the partitioning of the microlens array, the reverse structure of the microlens array is formed on the substrate to obtain the template.

[0080] In step S304, a microlens array is formed on the substrate using a template. The microlens surface shape is formed on the substrate using a template, for example, through nanoimprint lithography or photolithography, to form the designed microlens structure. The substrate for the microlens array can be glass or other organic polymer materials, and is a uniformly thick plate. Preferably, the thickness of the substrate ranges from 0.05 to 0.5 mm.

[0081] The present invention also includes an embodiment of a computer-readable storage medium, such as a hard disk, an optical disk, or other storage medium. The computer-readable storage medium includes computer-executable commands stored thereon. When executed by a processor, the executable commands implement the fabrication method of the microlens array as described above, for example, by executing the aforementioned fabrication method in microlens structure design software or by controlling a microlens array fabrication device to execute the aforementioned fabrication method.

[0082] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A light homogenizing system, comprising: The light source includes multiple sub-light sources with synchronous control switches or individual control switches, and the sub-light sources are divided into multiple sub-light source groups according to preset rules; and A microlens array is disposed downstream of the light source's optical path. The effective area of ​​the microlens array includes two or more non-overlapping sub-regions. Adjacent sub-regions are spaced apart or closely fitted together. The light source and the microlens array are configured such that each sub-region corresponds one-to-one with a sub-light source group. The illumination areas of the sub-light sources in different sub-light source groups on the microlens array do not overlap. The microlens structure in each sub-region is configured to receive the light beam emitted by the sub-light source in the corresponding sub-light source group to form a uniform light field. The sub-partitions are designed individually based on the target uniform light field corresponding to multiple different target uniform light fields.

2. The uniform light system according to claim 1, wherein the sub-light sources within the same sub-light source group are controlled to emit light or turn off simultaneously; The boundary of each sub-partition is defined by the illumination range of the sub-light source within the sub-light source group corresponding to that sub-partition on the microlens array.

3. The uniform light system according to claim 2, wherein the light source is a VCSEL light source, the sub-light sources in each sub-light source group are arranged in a one-dimensional or two-dimensional array, and multiple sub-light source groups are set on the same light-emitting surface.

4. The uniform light system according to claim 3, wherein the sub-light sources in different sub-light source groups are arranged in the same way; the distance between adjacent sub-light sources in the same sub-light source group is equal, and the distance between different sub-light source groups is equal.

5. The uniform light system according to claim 3 or 4, wherein the light beam emitted by each of the sub-light source groups passes through the corresponding sub-partition to form a linear uniform light field; the multiple sub-light source groups are arranged in parallel to form multiple linear uniform light fields that are parallel to each other on the target surface.

6. The uniform light system according to claim 5, wherein the linear uniform light fields formed by adjacent sub-light source groups are closely adjacent or partially overlap.

7. The uniform light system according to claim 5, wherein the microlenses in each sub-region are configured to diffuse the light beam emitted by the sub-light source in the corresponding sub-light source group at an angle of 40-90° in the vertical direction and at an angle of no more than 2° in the horizontal direction; the distance between the light source and the microlens array is in the range of 30-300 micrometers.

8. The uniform light system according to claim 2, wherein different sub-regions have different field-of-view diffusion angles to form light fields with different energy densities; the fields of view of the different sub-regions at least partially overlap.

9. The light-uniforming system according to claim 8, wherein the effective region of the microlens array includes a first sub-region and a second sub-region, wherein the diffusion angle of the first sub-region is greater than the diffusion angle of the second sub-region.

10. The homogenizing system of claim 9 further includes a control device configured to individually control the grouped emission of beams from the sub-sources. The control device is configured to: control the sub-light source group corresponding to the first sub-partition to emit light beams to form a first uniform light field with the diffusion angle of the first sub-partition; The sub-light source partition corresponding to the first sub-partition is closed, and the sub-light source group corresponding to the second sub-partition is controlled to form a second uniform light field with the diffusion angle of the second sub-partition.

11. The uniform light system according to claim 10 further includes a processing device and an image acquisition device, wherein the image acquisition device is configured to acquire images within the first uniform light field and the second uniform light field, the processing device is coupled to the image acquisition device and configured to: identify a region of interest in the image of the first uniform light field; when the region of interest is identified, through the control device, shut down the sub-light source partition corresponding to the first sub-partition and drive the sub-light source partition corresponding to the second sub-partition to form a second uniform light field with the diffusion angle of the second sub-partition.

12. A method for fabricating a microlens array, used to fabricate a microlens array in a light-uniforming system as described in any one of claims 1-11, the fabrication method comprising: The initial lens surface shape is obtained, and a simulated microlens array is formed by closely packing the lenses; The simulated microlens array is partitioned; Templates are prepared based on the initial lens surface shape and microlens array partitioning; A microlens array is formed on a substrate using a template.

13. The preparation method according to claim 12, wherein the initial lens surface shape is calculated based on the target light field and the light distribution curve of the light source; the initial lens surface shape is a convex lens or a concave lens with a spherical, aspherical, or freeform surface.

14. The preparation method according to claim 12, wherein the step of partitioning the simulated microlens array includes: the designed distance between the light source and the microlens array; and the diffusion angle of the light source; The simulated microlens array is divided into multiple partitions based on the target light field, so that the boundaries of the partitions correspond to the illumination areas of the light source group on the microlens array. The initial lens surface shape within the partition is designed based on the optical characteristics of the emitted beam from the corresponding light source group.

15. The fabrication method according to claim 12, wherein the initial lens surface pattern is randomly arranged in the corresponding partition; the fabrication method of the microlens array further includes: The microlens surface shape of the simulated microlens array is optimized.

16. A computer-readable storage medium comprising computer-executable commands stored thereon, the executable commands, when executed by a processor, implementing the method for fabricating a microlens array as described in any one of claims 12-15.

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