Projection module based on microlens array, preparation process and projection system

Abstract

The application discloses a kind of projection module based on microlens array, including field lens array, projection source, projection lens array, prism array, interval area is formed between prism array and projection lens array, prism array surface is divided into interval part and mirror surface part, interval part and mirror surface part are arranged at intervals and are communicated with each other through interval area, interval part is parallel with the surface of base one, mirror surface part forms a certain angle with the surface of base one;Prism array is divided into M layers along the direction of light propagation, M layer prism array uses different materials, and the contact interface of every two adjacent prism array forms alternately arranged interface area one, interface area two, interface area one corresponds interval part, and interface area two corresponds mirror surface part;Projection lens array is divided into N layers along the direction of light propagation, N layer projection lens array uses different materials, and in the two side face types of every layer projection lens array, at least one side face type is optical face type except plane.

Description

Technical Field

[0001] This invention relates to optical projection structures, and more particularly to a projection module based on a microlens array, a fabrication process for the projection module, and a projection system comprising the projection module. Background Technology

[0002] A microlens array (MLA) is a group of precision-manufactured miniature lenses or "microlenses." This array is a custom-designed module. Its optical principle is based on a combination of illumination optics and projection optics. First, light emitted from a light source is projected onto the field lens array, and then converges at the focal plane of the projection lens array. At the focal plane is a projection source with numerous micro-apertures that allow light to pass through, projecting distinct light patterns of light and shadow. Microlens arrays have a wide range of applications, such as in vehicle lighting systems and projection displays.

[0003] While prior art has achieved large depth-of-field projection of patterns through microlens splicing and large-angle projection of patterns through optical devices to deflect light paths, it has not solved the color difference problem under composite light source (such as white light) illumination. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a projection module based on a microlens array, a fabrication process, and a projection system, thereby overcoming the aforementioned technical problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A projection module based on a microlens array includes a field lens array, a projection source, a projection lens array, and a prism array arranged sequentially along the light propagation direction. The prism array is fixed to one side surface of a substrate, and the projection lens array is fixed to one side surface of a substrate. A gap is formed between the prism array and the projection lens array. The gap is either a vacuum or filled with gas. The surface of the prism array is divided into a gap portion and a mirror portion. The gap portion and the mirror portion are arranged alternately and are interconnected through the gap. The gap portion is parallel to the surface of the substrate, and the mirror portion forms a certain angle with the surface of the substrate.

[0007] The prism array is divided into M layers along the direction of light propagation, where M is a positive integer greater than or equal to 1. When M is greater than 1, the M layers of prism array are made of different materials. The contact interface between every two adjacent prism arrays forms an alternately arranged interface region one and interface region two. Interface region one corresponds to the interval part and is parallel to the surface of the substrate one. Interface region two corresponds to the mirror part and forms a certain angle with the surface of the substrate one.

[0008] The projection lens array is divided into N layers along the direction of light propagation, where N is a positive integer greater than or equal to 1. When N is greater than 1, the N layers of the projection lens array are made of different materials. Among the two side profiles of each layer of the projection lens array, at least one side profile is an optical surface profile other than a plane.

[0009] Furthermore, the prism array is divided into two or more layers along the direction of light propagation.

[0010] Furthermore, the projection lens array is divided into a first-layer projection lens array and a second-layer projection lens array along the direction of light propagation. The side of the first-layer projection lens array that is in contact with the substrate is planar, the side of the first-layer projection lens array and the second-layer projection lens array that are in contact is aspherical, and the side of the second-layer projection lens array that is in contact with the gap is aspherical.

[0011] Furthermore, the projection lens array is fixed on one side surface of the second substrate, the projection source is fixed on the other side surface of the second substrate opposite to the projection lens array, and the field lens array is fixed on the projection source.

[0012] Furthermore, a support member is provided between the first base and the second base to fix the first base and the second base and to isolate the gap area from the outside air.

[0013] Furthermore, the first substrate is a single-layer glass plate or a multi-layer glass plate bonded together, and the second substrate is a single-layer glass plate.

[0014] A fabrication process for the above-mentioned projection module includes: curing a prism array onto one side surface of a substrate by imprinting adhesive, curing a projection lens array onto one side surface of a substrate by imprinting adhesive, curing a projection source onto the other side of the substrate opposite to the projection lens array by optical coating and semiconductor etching, and curing a field lens array onto the surface of the projection source by imprinting adhesive.

[0015] The imprinting adhesive curing molding process for prism arrays includes:

[0016] A prism array mold is prepared, having a contoured profile that matches the surface of the prism array;

[0017] Place the prism array mold on top of the substrate, fill the area between the contour of the prism array mold and the substrate with glue, and after the glue cures, form a prism array.

[0018] Remove the prism array mold.

[0019] Furthermore, when the prism array is divided into two or more layers, the imprinting adhesive curing process of the prism array includes:

[0020] Prepare prism array molds. The number of prism array molds is the same as the number of prism array layers. Each prism array mold corresponds to one layer of prism array and has a contour that matches the contact interface of the two adjacent prism array layers.

[0021] First, fill the area between the contour of the prism array mold and the base with glue. After the glue cures, a prism array is formed.

[0022] Take the previous prism array mold, place the next prism array mold on top of the previous prism array, and fill the area formed between the contour of the prism array mold and the previous prism array with glue; after the glue cures, another prism array is formed. Repeat this step to form a predetermined number of prism arrays.

[0023] A projection system includes a light source and a plurality of the above-described projection modules.

[0024] Furthermore, the optical parameters of the multiple projection modules may be the same or different. The optical parameters include: the focal length of the field lens array, the focal length of the projection lens array, the distance from the field lens array to the projection lens array, the distance from the projection lens array to the projection source, and the angle formed between the mirror portion of the prism array and the surface of the substrate.

[0025] Beneficial effects: This invention employs a multi-layer projection lens and a multi-layer prism structure, utilizing the different dispersion characteristics of different materials and the geometric parameters of different interfaces to solve the color difference problem in projection imaging under composite light source (such as white light) illumination. Specifically, the multi-layer projection lens ensures that the focal lengths for different colors of light are the same or so small that, under composite light source (such as white light) illumination, projection patterns at different distances do not exhibit color difference; the multi-layer prism array ensures that the deflection angles for different colors of light are the same or so small that, under composite light source (such as white light) illumination, projection patterns at different angles do not exhibit color difference.

[0026] The microlens array of the projection module is formed by pressing adhesive. The surface of the prism array is divided into a spacer part and a mirror part. The spacer part and the mirror part are arranged at intervals and are interconnected through the spacer area formed between the prism array and the projection lens array. This helps to improve the fluidity of the adhesive during the pressing process, avoids the formation of voids in the adhesive, and ensures product performance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the projection module according to Embodiment 1 of the present invention;

[0028] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0029] Figure 3 This is a schematic diagram of the projection module according to Embodiment 2 of the present invention;

[0030] Figure 4 yes Figure 3 Enlarged view at point B in the middle;

[0031] Figure 5 This is a schematic diagram of the projection module according to Embodiment 3 of the present invention;

[0032] Figure 6 This is a schematic diagram of the manufacturing process of the projection module according to Embodiment 1 of the present invention;

[0033] Figure 7 This is a schematic diagram of the manufacturing process of the projection module in Embodiment 2 of the present invention. Figure 1 ;

[0034] Figure 8 This is a schematic diagram of the manufacturing process of the projection module in Embodiment 2 of the present invention. Figure 2 ;

[0035] Figure 9 This is a schematic diagram of the projection system of the present invention.

[0036] In the diagram: 1-Substrate 1; 2-Prism array; 2-1-Prism array 1; 2-2-Prism array 2; 2-3-Prism array 3; 3-Support component; 4-Gap area; 5-Projection lens array; 5-1-First layer projection lens array; 5-2-Second layer projection lens array; 6-Substrate 2; 7-Projection source; 8-Field lens array; 9-Gap section; 10-Mirror section; 11-Interface area 1; 12-Interface area 2; 13-Prism array mold; 13-1-Prism array mold 1; 13-2-Prism array mold 2; 100-Projection module; 200-Light source. Detailed implementation method:

[0037] The invention will now be further explained with reference to the accompanying drawings.

[0038] like Figure 1 and 2 As shown, a projection module based on a microlens array according to the present invention includes a field lens array 8, a projection source 7, a projection lens array 5, and a prism array 2 arranged sequentially along the light propagation direction. The prism array 2 is fixed to one side surface of substrate 1, the projection lens array 5 is fixed to one side surface of substrate 2, the projection source 7 is fixed to the other side surface of substrate 2 opposite to the projection lens array 5, and the field lens array 8 is fixed on top of the projection source 7. Substrate 1 is a single-layer glass plate or a multi-layer glass plate bonded together, and substrate 2 is a single-layer glass plate.

[0039] A gap region 4 is formed between the prism array 2 and the projection lens array 5. The gap region 4 is either a vacuum or filled with gas. The surface of the prism array 2 is divided into a gap portion 9 and a mirror portion 10. The gap portion 9 and the mirror portion 10 are arranged at intervals and are interconnected through the gap region 4. The gap portion 9 is parallel to the surface of the substrate-1. The mirror portion 10 forms a certain angle α with the surface of the substrate-1. The distance from the gap portion 9 to the surface of the substrate-1 is d1, and the distance from the mirror portion 10 to the surface of the substrate-1 is d2.

[0040] The projection module also includes a support member 3 disposed between substrate 1 and substrate 2 6. The support member 3 is used to fix substrate 1 and substrate 2 6 and to isolate the interval area 4 from the outside air.

[0041] The prism array is divided into M layers along the direction of light propagation, where M is a positive integer greater than or equal to 1. When M is greater than 1, the M layers of the prism array are made of different materials. The contact interface between any two adjacent prism arrays forms an alternating interface region 11 and interface region 12. Interface region 11 corresponds to the spacer 9 and is parallel to the surface of substrate 1, while interface region 12 corresponds to the mirror portion 10 and forms a certain angle β with the surface of substrate 1. The multilayer prism array made of different materials has different refractive indices and Abbe numbers, so that the deflection angles for different colors of light are the same or the difference is so small that under the illumination of a composite light source (such as white light), the projected patterns at different angles do not show color differences.

[0042] In Example 1, the prism array is a single layer. For example... Figure 3 and 4 As shown, in Embodiment 2, the prism array 2 is divided into two layers along the light propagation direction, namely prism array 2-2 and prism array 2-1. The distance from interface region 11 to the surface of substrate 1 is d3, and the distance from interface region 212 to the surface of substrate 1 is d4. Figure 5 As shown in Embodiment 3, the prism array 2 is divided into three layers along the direction of light propagation, namely prism array three 2-3, prism array two 2-2, and prism array one 2-1.

[0043] The projection lens array is divided into N layers along the direction of light propagation, where N is a positive integer greater than or equal to 1. In Embodiments 1 and 2, the projection lens array is a single layer. In Embodiment 3, the projection lens array is a two-layer array. When N is greater than 1, the N layers of the projection lens array are made of different materials, and at least one side of each layer of the projection lens array is an optical surface other than a plane. The function of the multi-layer projection lens is to ensure that the focal length for different colors of light is the same or the difference is so small that under the illumination of a composite light source (such as white light), the projected patterns at different distances do not show color difference.

[0044] like Figure 1 and 3As shown, the projection lens array 5 is a single layer. The side of the projection lens array 5 that contacts the substrate 6 is planar, and the side of the projection lens array 5 that contacts the interval area 4 is convex.

[0045] like Figure 5 As shown, the projection lens array 5 is divided into a first-layer projection lens array 5-1 and a second-layer projection lens array 5-2 along the light propagation direction. The side of the first-layer projection lens array 5-1 that contacts the substrate 6 is planar, the side of the first-layer projection lens array 5-1 and the second-layer projection lens array 5-2 that contacts each other is aspherical, and the side of the second-layer projection lens array 5-2 that contacts the spacer region 4 is aspherical. In Embodiment 3, the side of the first-layer projection lens array 5-1 that contacts the second-layer projection lens array 5-2 is convex, the side of the second-layer projection lens array 5-2 that contacts the first-layer projection lens array 5-1 is concave, and the side of the second-layer projection lens array 5-2 that contacts the spacer region 4 is convex.

[0046] The present invention discloses a manufacturing process for a projection module, the manufacturing process comprising: curing a prism array onto one side surface of a substrate by means of imprinting adhesive; curing a projection lens array onto one side surface of a substrate by means of imprinting adhesive; curing a projection source onto the other side of the substrate opposite to the projection lens array by means of optical coating and semiconductor etching; and curing a field lens array onto the surface of the projection source by means of imprinting adhesive.

[0047] like Figure 6 As shown, the imprint adhesive curing process for prism array 2 includes:

[0048] A prism array mold 13 is prepared, which has a contour that is compatible with the surface of the prism array 2.

[0049] Place the prism array mold 13 above the substrate 1, fill the area formed between the contour of the prism array mold 13 and the substrate 1 with glue, and after the glue cures, form the prism array 2.

[0050] Remove prism array mold 13.

[0051] During the glue filling process, since the spaced portions 9 and mirror portions 10 on the surface of the prism array 2 are arranged at intervals and are interconnected through the spaced area 4, the glue helps to flow along the contour of the prism array mold 13 and fill the entire glue filling area, avoiding the formation of voids inside the glue and ensuring product performance.

[0052] For this manufacturing process, when the prism array is divided into two or more layers, the imprint adhesive curing process for the prism array includes:

[0053] Prepare prism array molds. The number of prism array molds is the same as the number of prism array layers. Each prism array mold corresponds to one layer of prism array and has a contour that matches the contact interface of the two adjacent prism array layers.

[0054] First, fill the area between the contour of the prism array mold and the base with glue. After the glue cures, a prism array is formed.

[0055] Take the previous prism array mold, place another prism array mold on top of the previous prism array, and fill the area formed between the contour of the prism array mold and the previous prism array with glue; after the glue cures, another prism array is formed. Repeat this step to form a prism array with a predetermined number of layers.

[0056] like Figure 7 and 8 As shown, the two-layer prism array imprinting adhesive curing molding process in Example 2 is taken as an example:

[0057] The prism array 2 is divided into two layers along the direction of light propagation, namely prism array 2-2 and prism array 1-1. Prism array mold 1-13-1 and prism array mold 2-2 are prepared. Prism array mold 1-13-1 has a contour that matches the contact interface of prism array 2-2 and prism array 1-1. Prism array mold 2-13-2 has a contour that matches the surface of prism array 2.

[0058] Place the prism array mold 13-1 on top of the substrate 1, and fill the area formed between the contour of the prism array mold 13-1 and the substrate 1 with glue. After the glue cures, the prism array 2-1 is formed.

[0059] Remove prism array mold 13-1, place prism array mold 23-2 above prism array 2-1, and fill the area formed between the contour of prism array mold 23-2 and prism array 2-1 with glue. After the glue cures, prism array 2-2 is formed.

[0060] like Figure 9 As shown, a projection system of the present invention includes a light source 200 and a plurality of projection modules 100 as described above. The prism array 2 of the projection module 100 may adopt a single-layer structure as in Embodiment 1, or a double-layer structure as in Embodiment 2, or a double-layer structure as in Embodiment 2. The projection lens array may adopt a single-layer structure or a double-layer structure.

[0061] Among them, the optical parameters of multiple projection modules 100 are the same or different. The optical parameters include: the focal length of the field lens array, the focal length of the projection lens array, the distance from the field lens array to the projection lens array, the distance from the projection lens array to the projection source, and the angle formed between the mirror portion of the prism array and the surface of the substrate.

[0062] When different optical parameters are used, the projection distance and angle of the projection area of ​​each projection module 100 are different, and projections at different angles and distances can be stitched together to form a pattern with a larger angle and a wider range.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A projection module based on a microlens array, comprising a field mirror array, a projection source, a projection lens array, and a prism array arranged sequentially along the direction of light propagation, characterized in that: The prism array is solidified on one side surface of substrate one, and the projection lens array is solidified on one side surface of substrate two. A gap is formed between the prism array and the projection lens array. The gap is either a vacuum or filled with gas. The surface of the prism array is divided into a gap portion and a mirror portion. The gap portion and the mirror portion are arranged at intervals and are interconnected through the gap. The gap portion is parallel to the surface of substrate one, and the mirror portion forms a certain angle with the surface of substrate one. The prism array is solidified on one side surface of substrate one by imprinting adhesive. The prism array is divided into M layers along the direction of light propagation, where M is a positive integer greater than 1. The M layers of prism array are made of different materials. The contact interface between every two adjacent prism arrays forms an alternately arranged interface region one and interface region two. Interface region one corresponds to the interval part and is parallel to the surface of the substrate one. Interface region two corresponds to the mirror part and forms a certain angle with the surface of the substrate one. The projection lens array is divided into N layers along the direction of light propagation, where N is a positive integer greater than 1. The N layers of the projection lens array are made of different materials, and at least one side of each layer of the projection lens array is an optical surface other than a plane. By using the N layers of the projection lens array, the focal length of different colors of light is the same, and under the illumination of the composite light source, the projected patterns at different distances do not show color difference.

2. The projection module based on a microlens array according to claim 1, characterized in that: The projection lens array is divided into a first-layer projection lens array and a second-layer projection lens array along the direction of light propagation. The side of the first-layer projection lens array that is in contact with the substrate is planar, the side of the first-layer projection lens array and the second-layer projection lens array that are in contact is aspherical, and the side of the second-layer projection lens array that is in contact with the interval area is aspherical.

3. A projection module based on a microlens array according to claim 1, characterized in that: The projection lens array is fixed on one side surface of the second substrate, the projection source is fixed on the other side surface of the second substrate opposite to the projection lens array, and the field lens array is fixed on the projection source.

4. A projection module based on a microlens array according to claim 1, characterized in that: A support member is provided between the first base and the second base to fix the first base and the second base and to isolate the gap area from the outside air.

5. A projection module based on a microlens array according to claim 1, characterized in that: The first substrate is a single-layer glass plate or a multi-layer glass plate bonded together, and the second substrate is a single-layer glass plate.

6. A manufacturing process for a projection module as described in claim 1, characterized in that, The fabrication process includes: curing a prism array onto one side surface of a substrate by imprinting adhesive, curing a projection lens array onto one side surface of a substrate by imprinting adhesive, curing a projection source onto the other side of the substrate opposite to the projection lens array by optical coating and semiconductor etching, and curing a field lens array onto the surface of the projection source by imprinting adhesive. The imprinting adhesive curing molding process for prism arrays includes: A prism array mold is prepared, having a contoured profile that matches the surface of the prism array; Place the prism array mold on top of the substrate, fill the area between the contour of the prism array mold and the substrate with glue, and after the glue cures, form a prism array. Remove the prism array mold.

7. The manufacturing process of a projection module according to claim 6, characterized in that, When the prism array is divided into two or more layers, the prism array imprint adhesive curing process includes: Prepare prism array molds. The number of prism array molds is the same as the number of prism array layers. Each prism array mold corresponds to one layer of prism array and has a contour that matches the contact interface of the two adjacent prism array layers. First, place a prism array mold on top of the mold base. Fill the area formed between the contour of the prism array mold and the base with glue. After the glue cures, a prism array is formed. Take the previous prism array mold, place the next prism array mold on top of the previous prism array, and fill the area formed between the contour of the prism array mold and the previous prism array with glue; after the glue cures, another prism array is formed. Repeat this step to form a predetermined number of prism arrays.

8. A projection system comprising a light source and a plurality of projection modules as described in claim 1.

9. A projection system according to claim 8, characterized in that: Multiple projection modules may have the same or different optical parameters, which include: the focal length of the field lens array, the focal length of the projection lens array, the distance from the field lens array to the projection lens array, the distance from the projection lens array to the projection source, and the angle formed between the mirror portion of the prism array and the surface of the substrate.

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