Mixed light structure of projection system and projection system

Abstract

The utility model provides a light mixing structure of a projection system and a projection system. The light mixing structure of the projection system includes a first reflection surface and a second reflection surface, the first reflection surface is arranged opposite to the second reflection surface, the first reflection surface includes a plurality of first sub-microlens surfaces arranged in an array, the second reflection surface includes a plurality of second sub-microlens surfaces arranged in an array, the number of the first sub-microlens surfaces is equal to the number of the second sub-microlens surfaces, and the plurality of the first sub-microlens surfaces corresponds one to one with the plurality of the second sub-microlens surfaces. The utility model solves the problem of a long light mixing optical path length in the light mixing structure of the projection system in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging equipment, in particular to a light mixing structure of a projection system and a projection system. Background Art

[0002] With the rapid development of projection technology, the light mixing structure of the projection system has always been a key part of research and optimization. In practical applications, existing projection systems usually use refractive compound eye lenses and light rods to achieve the purpose of light mixing. However, due to the limitations of the existing light mixing structure on light path transmission and the need to cooperate with multiple optical elements, the light mixing structure is large in size and the overall length of the light mixing path is long, requiring a large space for placement, making it difficult to apply in miniaturized systems.

[0003] That is to say, the light mixing structure of the projection system in the prior art has the problem of a long light mixing optical path length. Utility Model Content

[0004] The main purpose of the utility model is to provide a light mixing structure of a projection system and a projection system, so as to solve the problem that the light mixing structure of the projection system in the prior art has a long light mixing optical path length.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the utility model, a light mixing structure of a projection system is provided, comprising a first reflection surface and a second reflection surface, the first reflection surface and the second reflection surface are arranged opposite to each other, the first reflection surface comprises a plurality of first sub-microlens surfaces arranged in an array, the second reflection surface comprises a plurality of second sub-microlens surfaces arranged in an array, the number of the first sub-microlens surfaces is equal to the number of the second sub-microlens surfaces and the plurality of first sub-microlens surfaces correspond one to one to the plurality of second sub-microlens surfaces.

[0006] Furthermore, the shapes of the plurality of first sub-microlens surfaces include one or more of a concave surface, a convex surface and a plane, and the shapes of the plurality of second sub-microlens surfaces include one or more of a concave surface, a convex surface and a plane.

[0007] Furthermore, the first reflecting surface and the second reflecting surface are arranged at an angle; and / or an angle θ between the first reflecting surface and the second reflecting surface satisfies: 20°<θ<70°.

[0008] Furthermore, the focal length of the first sub-microlens surface is equal to the center distance between the first sub-microlens surface and the corresponding second sub-microlens surface.

[0009] Furthermore, the combined focal length f0 of a corresponding set of first sub-microlens surfaces and second sub-microlens surfaces satisfies: 0.2 mm <f0<15mm。

[0010] Further, there is no gap between adjacent two of the plurality of first sub-microlens surfaces, and there is no gap between adjacent two of the plurality of second sub-microlens surfaces; and / or the projection shape of the first sub-microlens surface on the first reflection surface is rectangular, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm; the projection shape of the second sub-microlens surface on the second reflection surface is rectangular, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm.

[0011] Further, a linear proportional relationship is satisfied between the radius of curvature R1 of the first sub-microlens surface and the focal length f1 of the first sub-microlens surface, and the radius of curvature R1 of the first sub-microlens surface satisfies: 0.5 mm < R1 < 50 mm; the focal length f1 of the first sub-microlens surface satisfies: 1.5 mm < f1 < 50 mm; and / or the first reflection surface and the second reflection surface are arranged at an angle, and the distance S0 between the sides of the first reflection surface and the second reflection surface that are close to each other satisfies: 0.01 mm < S0 < 10 mm.

[0012] Further, the light mixing structure includes a first substrate and a second substrate, and the first reflection surface and the second reflection surface are respectively formed on the first substrate and the second substrate; or the light mixing structure includes a base body, and the first reflection surface and the second reflection surface are formed on the base body.

[0013] Further, the light mixing structure further includes a reflective film layer, and the reflective film layer is selectively arranged on the first reflection surface and the second reflection surface; and / or the optical surface types of the plurality of first sub-microlens surfaces include one or more of a spherical surface, an aspherical surface, and a free-form surface, and the optical surface types of the plurality of second sub-microlens surfaces include one or more of a spherical surface, an aspherical surface, and a free-form surface.

[0014] According to another aspect of the present invention, a projection system is provided, including: a light source; a reflector, the reflector being located on the light-emitting side of the light source; the light mixing structure of the above-mentioned projection system, the light mixing structure being located on the reflection path of the reflector, and the light mixing structure being used for receiving the light emitted by the light source and reflected by the reflector, and mixing and reflecting the light.

[0015] Applying the technical solution of the present invention, the light mixing structure of the projection system includes a first reflection surface and a second reflection surface, the first reflection surface and the second reflection surface are oppositely arranged, the first reflection surface includes a plurality of first sub-microlens surfaces arranged in an array, the second reflection surface includes a plurality of second sub-microlens surfaces arranged in an array, the number of the first sub-microlens surfaces is equal to the number of the second sub-microlens surfaces, and the plurality of first sub-microlens surfaces and the plurality of second sub-microlens surfaces correspond one by one.

[0016] The light mixing structure of the projection system of the present application is provided with a first reflecting surface and a second reflecting surface opposite to each other, so that after the light enters the light mixing structure, the light mixing path is turned by the reflection of the first reflecting surface and the second reflecting surface, thereby playing the role of folding the light mixing path, which is beneficial to compressing the overall length of the light mixing path, and is beneficial to the application of the light mixing structure in a small-sized projection system, thereby ensuring the miniaturization of the projection system. The first reflecting surface is composed of a plurality of first sub-microlens surfaces arranged in an array, ensuring that the plurality of first sub-microlens surfaces can divide the incident wide light beam into a plurality of fine light beams, and at the same time realize the deflection of the light beam transmission direction, and change the light beam transmission direction, and the second reflecting surface is arranged to be composed of a plurality of second sub-microlens surfaces arranged in an array, and the number of the first sub-microlens surfaces is equal to the number of the second sub-microlens surfaces, and the plurality of first sub-microlens surfaces correspond one-to-one with the plurality of second sub-microlens surfaces, so as to ensure that the plurality of second sub-microlens surfaces can receive the plurality of fine light beams of the plurality of first sub-microlens surfaces one-to-one and perform light mixing and reflection, so as to achieve sufficient light mixing and ensure the light mixing uniformity of the outgoing light beam. In addition, the light mixing structure of the present application achieves a good light mixing effect and, at the same time, folds the light mixing optical path through reflection, thereby compressing the length of the entire light mixing optical path and reducing the volume occupied by the light mixing optical path. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0018] Figure 1 A schematic structural diagram of a light mixing structure of a projection system according to a first embodiment of the present utility model is shown;

[0019] Figure 2 Shows Figure 1 A top view of a light mixing structure of a projection system;

[0020] Figure 3 Shows Figure 1 A schematic diagram of another angle of the light mixing structure of the projection system;

[0021] Figure 4 Shows Figure 1 A cross-sectional view of a light mixing structure of a projection system;

[0022] Figure 5 Shows Figure 1 Schematic diagram of structural parameters of the light mixing structure of the projection system;

[0023] Figure 6 Shows Figure 1 Light path diagram of the mixed light structure of the projection system;

[0024] Figure 7 A schematic structural diagram of a light mixing structure of a projection system according to a second embodiment of the present utility model is shown;

[0025] Figure 8 A cross-sectional view of a light mixing structure of a projection system according to a second embodiment of the present utility model is shown;

[0026] Fig. 9 A schematic structural diagram of a projection system according to an optional embodiment of the utility model is shown.

[0027] The above drawings include the following reference numerals:

[0028] 10. First reflecting surface; 11. First sub-microlens surface; 20. Second reflecting surface; 21. Second sub-microlens surface; 31. First collimating mirror; 32. Second collimating mirror; 40. Reflector; 50. Field lens; 60. Polarization beam splitter; 70. Imaging chip; 80. Light source; 90. Base; 91. First substrate; 92. Second substrate. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0031] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0032] In order to solve the problem of a long light mixing optical path length in a light mixing structure of a projection system in the prior art, the present application provides a light mixing structure of a projection system and a projection system.

[0033] Embodiment 1

[0034] like Figures 1 to 6As shown, the light mixing structure of the projection system of the first embodiment is described. The light mixing structure of the projection system includes a first reflection surface 10 and a second reflection surface 20, the first reflection surface 10 and the second reflection surface 20 are arranged opposite to each other, the first reflection surface 10 includes a plurality of first sub-microlens surfaces 11 arranged in an array, the second reflection surface 20 includes a plurality of second sub-microlens surfaces 21 arranged in an array, the number of the first sub-microlens surfaces 11 is equal to the number of the second sub-microlens surfaces 21, and the plurality of first sub-microlens surfaces 11 correspond to the plurality of second sub-microlens surfaces 21 one by one.

[0035] The light mixing structure of the projection system of the present application sets a first reflecting surface 10 and a second reflecting surface 20 relative to each other, so that after the light enters the light mixing structure, the light mixing light path is turned by reflection from the first reflecting surface 10 and the second reflecting surface 20, thereby playing the role of folding the light mixing light path, which is beneficial to compressing the overall length of the light mixing light path, and is beneficial to the application of the light mixing structure in a small-sized projection system, thereby ensuring the miniaturization of the projection system. The first reflection surface 10 is composed of a plurality of first sub-microlens surfaces 11 arranged in an array, ensuring that the plurality of first sub-microlens surfaces 11 can divide the incident wide light beam into a plurality of fine light beams, and at the same time realize the deflection of the light beam transmission direction, and change the light beam transmission direction. The second reflection surface 20 is arranged to be composed of a plurality of second sub-microlens surfaces 21 arranged in an array, and the number of the first sub-microlens surfaces 11 is equal to the number of the second sub-microlens surfaces 21, and the plurality of first sub-microlens surfaces 11 correspond one-to-one with the plurality of second sub-microlens surfaces 21, so as to ensure that the plurality of second sub-microlens surfaces 21 can receive the plurality of fine light beams of the plurality of first sub-microlens surfaces 11 one-to-one and perform light mixing and reflection, so as to realize full light mixing and ensure the light mixing uniformity of the outgoing light beam. In addition, the light mixing structure of the present application can achieve a good light mixing effect, and at the same time, fold the light mixing optical path by reflection, thereby compressing the length of the overall light mixing optical path and reducing the volume occupied by the light mixing optical path.

[0036] It should be noted that the multiple first sub-microlens surfaces 11 of the first reflecting surface 10 can be arranged in a periodic array or in a random array, and the multiple second sub-microlens surfaces 21 of the second reflecting surface 20 can be arranged in a periodic array or in a random array. Regardless of whether they are periodic or random, it is necessary to ensure that the multiple first sub-microlens surfaces 11 correspond to the multiple second sub-microlens surfaces 21 one by one, and the sizes of a corresponding group of first sub-microlens surfaces 11 and second sub-microlens surfaces 21 are equal.

[0037] It should also be noted that the first sub-microlens surface 11 and the second sub-microlens surface 21 are both surfaces of lenses.

[0038] Specifically, the shapes of the multiple first sub-microlens surfaces 11 include one or more of a concave surface, a convex surface and a plane, and the shapes of the multiple second sub-microlens surfaces 21 include one or more of a concave surface, a convex surface and a plane. In order to ensure the uniform light mixing effect of the light mixing structure, it is necessary to reasonably set the shape of each first sub-microlens surface 11 and the shape of the multiple second sub-microlens surfaces 21. In an optional embodiment of the present application, the shapes of the multiple first sub-microlens surfaces 11 are the same or the shapes of some of the first sub-microlens surfaces 11 are different, and the shapes of the multiple second sub-microlens surfaces 21 are the same or the shapes of some of the second sub-microlens surfaces 21 are different, which can be set according to actual conditions. Preferably, the shape of each first sub-microlens surface 11 of the first reflection surface 10 is a concave surface, and the shape of each second sub-microlens surface 21 of the second reflection surface 20 is a concave surface, a convex surface and a plane. By reasonably setting the surface shapes of the first sub-microlens surface 11 and the second sub-microlens surface 21, it is helpful to ensure that the directions of each fine light beam emitted from the light mixing structure are consistent, and the uniformity of light mixing is guaranteed.

[0039] like Figure 4 As shown, in this embodiment, the first reflecting surface 10 and the second reflecting surface 20 are set at an angle, specifically an acute angle. More specifically, the angle θ between the first reflecting surface 10 and the second reflecting surface 20 satisfies: 20°<θ<70°. By rationally planning the angle between the first reflecting surface 10 and the second reflecting surface 20, it is helpful to ensure the stability of the optical path transmission between the first reflecting surface 10 and the second reflecting surface 20, and ensure that the second reflecting surface 20 can stably receive the light reflected from the first reflecting surface 10. Preferably, θ=45°.

[0040] In this embodiment, the projection shape of the first sub-microlens surface 11 on the first reflecting surface 10 is a rectangle, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm; the projection shape of the second sub-microlens surface 21 on the second reflecting surface 20 is a rectangle, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm. There is no spacing between two adjacent first sub-microlens surfaces 11 in the plurality of first sub-microlens surfaces 11, and there is no spacing between two adjacent second sub-microlens surfaces 21 in the plurality of second sub-microlens surfaces 21. By rationally planning the shape and size of the first sub-microlens surface 11 and the second sub-microlens surface 21, it is beneficial to the subdivision effect of the light beam to ensure the light mixing effect, and at the same time, setting the microlens surfaces arranged without spacing is beneficial to increase the overlapping range of adjacent sub-light beams, increase the sufficiency and uniformity of light mixing.

[0041] In this embodiment, the focal length of the first sub-microlens surface 11 is equal to the center distance from the first sub-microlens surface 11 to the corresponding second sub-microlens surface 21. Such a setting is beneficial to ensure that the light beam reflected by the first sub-microlens surface 11 can converge onto the corresponding second sub-microlens surface 21, and the focal point of the first sub-microlens surface 11 is exactly on the corresponding second sub-microlens surface 21. Such a setting enables the light to correspond one by one when propagating between the first sub-microlens surface 11 and the corresponding second sub-microlens surface 21, which is beneficial to enhancing the light mixing effect.

[0042] As Figures 1 to 5 shown, the first reflection surface 10 of the present application is formed by an array of m*n first sub-microlens surfaces 11, and the array form of the second reflection surface 20 is the same as that of the first reflection surface 10. The first reflection surface 10 and the second reflection surface 20 are arranged at an angle. The distance Lmn from the center point of the first sub-microlens surface 11 in the m-th row and n-th column on the first reflection surface 10 to the first sub-microlens surface 11 corresponding perpendicularly to it in the row of the first sub-microlens surfaces 11 on the first reflection surface 10 close to the second reflection surface 20 satisfies: where lmn is the side length of the second sub-microlens surface 21 in the m-th row and n-th column on the second reflection surface 20. In addition, the center distance Smn from the first sub-microlens surface 11 in the m-th row and n-th column to the corresponding second sub-microlens surface 21 in the m-th row and n-th column satisfies: Smn = 2*Lmn*sin(θ) + S0. Where S0 is the distance between the side of the first reflection surface 10 and the second reflection surface 20 that are close to each other. Such a setting is beneficial to ensuring that the convergence point of the first sub-microlens surface 11 is on the corresponding second sub-microlens surface 21 and ensuring the stability of light transmission between the two.

[0043] As Figure 5 shown, the horizontal distance S0 between the side of the first reflection surface 10 and the second reflection surface 20 that are close to each other satisfies: 0.01mm < S0 < 10mm; by controlling the distance between the side of the first reflection surface 10 and the second reflection surface 20 that are close to each other, while ensuring the light mixing effect, the occupied volume of the light mixing optical path of the light mixing structure can be effectively controlled, ensuring the miniaturization of light mixing, and at the same time avoiding the situation where the distance between the first reflection surface 10 and the second reflection surface 20 is too large or too small. Preferably, 0.1mm < S0 < 2mm.

[0044] In this embodiment, the corresponding first sub-microlens surface 11 and the second sub-microlens surface 21 form a group, and the combined focal lengths of different groups of the first sub-microlens surfaces 11 and the second sub-microlens surfaces 21 are the same. The combined focal length f0 of the corresponding group of the first sub-microlens surface 11 and the second sub-microlens surface 21 satisfies: 0.2 mm < f0 < 15 mm. Specifically, the focal length f1mn of the first sub-microlens surface 11 in the m-th row and the n-th column on the first reflection surface 10, the focal length f2mn of the second sub-microlens surface 21 in the m-th row and the n-th column on the second reflection surface 20, the combined focal length f0 of the corresponding group of the first sub-microlens surface 11 and the second sub-microlens surface 21, and the center distance Smn from the corresponding group of the first sub-microlens surface 11 to the second sub-microlens surface 21 satisfy: 1 / f0 = 1 / f1mn + 1 / f2mn - Smn / f1mn / f2mn. Such a setting is beneficial to ensure that the positions and focal lengths of the sub-microlens surfaces can match each other, and is beneficial to realizing a spot distribution with uniform color and illuminance.

[0045] Specifically, the optical surface types of the multiple first sub-microlens surfaces include one or more of a spherical surface, an aspherical surface, and a free-form surface, and the optical surface types of the multiple second sub-microlens surfaces include one or more of a spherical surface, an aspherical surface, and a free-form surface. In a specific embodiment, there is a linear proportional relationship between the radius of curvature R1 of the first sub-microlens surface 11 and the focal length f1 of the first sub-microlens surface 11. The radius of curvature R1 of the first sub-microlens surface 11 satisfies: 0.5 mm < R1 < 50 mm; the focal length f1 of the first sub-microlens surface 11 satisfies: 1.5 mm < f1 < 50 mm. For example, the radius of curvature R1mn of the first sub-microlens surface 11 in the m-th row and the n-th column satisfies: R1mn = 2 * f1mn = 2 * [2 * Lmn * sin(θ) + S0]. Among them, R1mn satisfies 0.5 mm < R1mn < 50 mm, and f1mn satisfies 1.5 mm < f1mn < 50 mm.

[0046] As Figures 1 to 6 shown, the light mixing structure of this embodiment further includes a substrate 90, and the first reflection surface 10 and the second reflection surface 20 are formed on the substrate 90. That is to say, the first reflection surface 10 and the second reflection surface 20 are arranged on the same element. It can be understood that one side surface of the substrate 90 is V-shaped for arranging the first reflection surface 10 and the second reflection surface 20.

[0047] In this embodiment, the material of the first reflective surface 10 and the second reflective surface 20 is a transparent material or a non-transparent material, and the light mixing structure further includes a reflective film layer, which is selectively disposed on the first reflective surface 10 and the second reflective surface 20. Specifically, whether the reflective film layer is disposed on the first reflective surface 10 and the second reflective surface 20 depends on the material selection and surface reflectivity of the first reflective surface 10 and the second reflective surface 20. When a transparent material is used, a reflective film layer needs to be disposed; when a non-transparent material is selected and the surface reflectivity is less than 70%, a reflective film layer needs to be disposed. By disposing the reflective film layer, the surface reflectivity of the reflective surface is made higher than 90%.

[0048] Specifically, the first sub-microlens surface 11 and the second sub-microlens surface 21 can be manufactured by injection molding, machining, nano-imprinting, etc. When the required width of the first sub-microlens surface 11 or the second sub-microlens surface 21 is less than 50 μm, nano-imprinting and machining are preferably used for processing, which can not only improve the processing accuracy, but also improve the production efficiency and facilitate mass production.

[0049] Table 1 below describes basic structural parameters of the first reflecting surface 10 and the second reflecting surface 20 of the light mixing structure of the first embodiment (unit: mm).

[0050] Line number m L S0 S f1 f2 fl / S0 1 0.300 0.200 0.424 0.600 -0.644 3.000 2 0.500 0.200 0.707 1.000 -0.595 5.000 3 0.700 0.200 0.990 1.400 -0.550 7.000 4 0.900 0.200 1.273 1.800 -0.509 9.000 5 1.100 0.200 1.556 2.200 -0.473 11.000 6 1.300 0.200 1.838 2.600 -0.439 13.000 7 1.500 0.200 2.121 3.000 -0.410 15.000 8 1.700 0.200 2.404 3.400 -0.383 17.000 9 1.900 0.200 2.687 3.800 -0.359 19.000 10 2.100 0.200 2.970 4.200 -0.337 21.000 11 2.300 0.200 3.253 4.600 -0.317 23.000 12 2.500 0.200 3.536 5.000 -0.299 25.000 13 2.700 0.200 3.818 5.400 -0.283 27.000 14 2.900 0.200 4.101 5.800 -0.268 29.000

[0051] Table 1

[0052] Embodiment 2

[0053] like Figures 7 and 8 As shown, the light mixing structure of the projection system of the second embodiment is described.

[0054] The difference between this embodiment and the first embodiment is that the first reflection surface 10 and the second reflection surface 20 of the light mixing structure are respectively arranged on different components. Specifically, the light mixing structure includes a first substrate 91 and a second substrate 92, and the first reflection surface 10 and the second reflection surface 20 are respectively formed on the first substrate 91 and the second substrate 92. In this embodiment, by arranging the first reflection surface 10 and the second reflection surface 20 on different components, it is conducive to flexibly adjusting the spacing distance between the first reflection surface 10 and the second reflection surface 20, and is more conducive to the practical application of the light mixing structure of the present application.

[0055] Table 2 describes the basic structural parameters of the first reflecting surface 10 and the second reflecting surface 20 of the light mixing structure of the second embodiment (unit: mm).

[0056] Line number m L S0 S f1 f2 fl / S0 1 1.100 1.000 1.556 2.200 -0.380 2.200 2 1.300 1.000 1.838 2.600 -0.350 2.600 3 1.500 1.000 2.121 3.000 -0.323 3.000 4 1.700 1.000 2.404 3.400 -0.300 3.400 5 1.900 1.000 2.687 3.800 -0.279 3.800 6 2.100 1.000 2.970 4.200 -0.261 4.200 7 2.300 1.000 3.253 4.600 -0.244 4.600 8 2.500 1.000 3.536 5.000 -0.229 5.000 9 2.700 1.000 3.818 5.400 -0.216 5.400 10 2.900 1.000 4.101 5.800 -0.204 5.800 11 3.100 1.000 4.384 6.200 -0.193 6.200 12 3.300 1.000 4.667 6.600 -0.184 6.600 13 3.500 1.000 4.950 7.000 -0.175 7.000 14 3.700 1.000 5.233 7.400 -0.166 7.400

[0057] Table 2

[0058] In summary, the present application further provides a projection system, including a light source 80, a reflector 40 and the above-mentioned light mixing structure of the projection system, wherein the reflector 40 is located on the light-emitting side of the light source 80; the light mixing structure is located on the reflection path of the reflector 40, and the light mixing structure is used to receive the light emitted by the light source 80 and reflected by the reflector 40, and to mix and reflect the light. By selecting the above-mentioned light mixing structure, the light path from the light source 80 to the light mixing structure is folded while ensuring the light mixing effect, thereby achieving the compression of the volume of the projection system by folding the light mixing light path.

[0059] like Fig. 9 As shown, Fig. 9 The projection system in the embodiment adopts the light mixing structure of the above-mentioned embodiment 2. The projection system further includes a first collimator 31, a second collimator 32, a field lens 50, a polarization beam splitter prism 60, an imaging chip 70 and a plurality of lenses. The first collimator 31 and the second collimator 32 are sequentially arranged between the light source 80 and the reflector 40 in a direction away from the light source 80. The reflector 40 is a plane reflector. The field lens 50 and the polarization beam splitter prism 60 are sequentially arranged in a direction away from the second reflection surface 20. The imaging chip 70 is located between the polarization beam splitter prism 60 and the reflector 40.

[0060] Specifically, the light beam emitted by the light source 80 passes through the first collimator 31 and the second collimator 32 in sequence and then enters the reflector 40. The reflector 40 reflects the light beam to the first reflective surface 10. The first reflective surface 10 subdivides the received light beam into multiple fine light beams and reflects and converges them to the second reflective surface 20. Then, the second reflective surface 20 further mixes and reflects the light beams, and then enters the polarization beam splitter prism 60 through the field lens 50. Since the combined focal lengths of the first sub-microlens surface 11 and the second sub-microlens surface 21 of different groups are the same, the divergence angles of the multiple fine light beams reflected by the second reflective surface 20 are consistent. The fine light beams at different positions will diverge to the same or similar ranges and overlap in the subsequent propagation, so as to obtain a light spot with uniform color and illumination distribution. The polarization beam splitter prism 60 is used to transmit the received S light to the right, and after passing through two lenses, it is incident on the imaging chip 70, which is an LCOS chip. The imaging chip 70 reflects the received light and passes through two imaging lenses, the polarization beam splitter prism 60, and the other two imaging lenses in sequence to realize the output of imaging light.

[0061] It should be noted that the light beam incident on the light mixing structure has a small divergence angle, which is less than 20°. Preferably, the divergence angle is less than 5°.

[0062] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0063] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0064] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0065] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A light mixing structure of a projection system, characterized in that: It includes a first reflecting surface (10) and a second reflecting surface (20). The first reflecting surface (10) is disposed opposite to the second reflecting surface (20). The first reflecting surface (10) includes a plurality of first sub-micro lens surfaces (11) arranged in an array. The second reflecting surface (20) includes a plurality of second sub-micro lens surfaces (21) arranged in an array. The number of the first sub-micro lens surfaces (11) is equal to the number of the second sub-micro lens surfaces (21), and the plurality of first sub-micro lens surfaces (11) correspond to the plurality of second sub-micro lens surfaces (21) one by one.

2. The light mixing structure of the projection system according to claim 1, characterized in that: The shapes of the plurality of first sub-micro lens surfaces (11) include one or more of concave surfaces, convex surfaces, and flat surfaces. The shapes of the plurality of second sub-micro lens surfaces (21) include one or more of concave surfaces, convex surfaces, and flat surfaces.

3. The light mixing structure of the projection system according to claim 1, characterized in that: The first reflecting surface (10) and the second reflecting surface (20) are arranged at an angle; and / or the included angle θ between the first reflecting surface (10) and the second reflecting surface (20) satisfies: 20° < θ < 70°.

4. The light mixing structure of the projection system according to claim 1, characterized in that: The focal length of the first sub-micro lens surface (11) is equal to the center distance from the first sub-micro lens surface (11) to the corresponding second sub-micro lens surface (21).

5. The light mixing structure of the projection system according to claim 1, characterized in that: The combined focal length f0 of a corresponding set of the first sub-micro lens surface (11) and the second sub-micro lens surface (21) satisfies: 0.2 mm < f0 < 15 mm.

6. The light mixing structure of the projection system according to any one of claims 1 to 5, characterized in that There is no gap between adjacent two of the plurality of first sub-micro lens surfaces (11) among the plurality of first sub-micro lens surfaces (11), and there is no gap between adjacent two of the plurality of second sub-micro lens surfaces (21) among the plurality of second sub-micro lens surfaces (21); and / or The projected shape of the first sub-micro lens surface (11) on the first reflecting surface (10) is rectangular, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm; the projected shape of the second sub-micro lens surface (21) on the second reflecting surface (20) is rectangular, and the side length of the rectangle is greater than or equal to 0.05 mm and less than or equal to 2 mm.

7. The light mixing structure of the projection system according to any one of claims 1 to 5, characterized in that: There is a linear proportional relationship between the radius of curvature R1 of the first sub-micro lens surface (11) and the focal length f1 of the first sub-micro lens surface (11). The radius of curvature R1 of the first sub-micro lens surface (11) satisfies: 0.5 mm < R1 < 50 mm; the focal length f1 of the first sub-micro lens surface (11) satisfies: 1.5 mm < f1 < 50 mm; and / or The distance S0 between the sides of the first reflecting surface (10) and the second reflecting surface (20) that are close to each other satisfies: 0.01 mm < S0 < 10 mm.

8. The light mixing structure of the projection system according to any one of claims 1 to 5, characterized in that The light mixing structure includes a first substrate (91) and a second substrate (92), and the first reflecting surface (10) and the second reflecting surface (20) are respectively formed on the first substrate (91) and the second substrate (92); or The light mixing structure comprises a base (90), and the first reflecting surface (10) and the second reflecting surface (20) are formed on the base (90).

9. The light mixing structure of the projection system according to any one of claims 1 to 5, characterized in that: The light mixing structure further comprises a reflective film layer, which is selectively arranged on the first reflective surface (10) and the second reflective surface (20); and / or the optical surface types of the first sub-microlens surfaces (11) include one or more of a spherical surface, an aspherical surface and a free-form surface, and the optical surface types of the second sub-microlens surfaces (21) include one or more of a spherical surface, an aspherical surface and a free-form surface.

10. A projection system, characterized in that: include: Light source (80); A reflector (40), the reflector (40) being located on the light-emitting side of the light source (80); The light mixing structure of the projection system according to any one of claims 1 to 9, wherein the light mixing structure is located on a reflection path of the reflector (40), and is used to receive light emitted by the light source (80) and reflected by the reflector (40), and to mix and reflect the light.

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