Optical display module and augmented reality glasses

Abstract

The invention provides an optical display module. The optical display module comprises a fixing support, an optical waveguide element, an optical engine, an elastic piece and sealant. The fixing support is provided with a through hole. The optical waveguide element is fixed on the fixing support. A part of the optical waveguide element is exposed through the through hole. The optical engine and the optical waveguide element are located on the opposite sides of the fixing support respectively. The light engine directly faces the through hole. And the deformable elastic sheet is fixedly sleeved on the optical engine. The elastic piece is connected with the fixing support and completely covers the through hole. The sealant is arranged at the connecting position of the elastic piece and the fixing support so that the elastic piece can be fixed to the fixing support. In the process of applying the sealant, the sealant cannot penetrate through the elastic sheet to reach the through hole, so that the sealant cannot reach the surface of the optical waveguide element. The invention further provides augmented reality glasses comprising the optical display module.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to an optical display module and augmented reality glasses including the optical display module. Background Art

[0002] An augmented reality (AR) near-eye display device generally includes a light engine (or optical machine) and an optical waveguide element. The light engine is used to generate image light, while the optical waveguide element is used to transmit the image light from the light engine to a specific location (human eye). In the manufacture of high-precision products such as optical modules and display panels, the alignment process of the optical waveguide element and the light engine is very critical. In the prior art, after the light engine and the optical waveguide element are aligned, a sealant is usually used to fix the light engine on a fixed frame, so that the light engine and the optical waveguide element are relatively fixed. The sealant can ensure a stable connection between the optical waveguide element and the light engine, while providing protection to prevent the external environment from affecting the optical components. However, during the application of the sealant, the sealant that has not yet solidified is easy to overflow to the surface of the optical waveguide element, causing damage to the optical system of the optical waveguide element. Summary of the invention

[0003] In view of this, the present application provides an optical display module, which can effectively prevent the sealant from overflowing onto the surface of the optical waveguide element during the sealing process by providing a spring sheet, thereby improving the assembly efficiency and yield of the product.

[0004] An optical display module comprises: A fixed bracket is provided with a through hole; An optical waveguide element is fixed on the fixing bracket, and a part of the optical waveguide is exposed through the through hole; A light engine is disposed on the fixing bracket, the light engine and the optical waveguide element are respectively located on opposite sides of the fixing bracket, and the light engine faces the through hole; A deformable spring sheet fixedly sleeved on the light engine, the spring sheet connected to the fixing bracket and completely covering the through hole; A sealant is arranged at the connection position between the spring sheet and the fixing bracket so as to fix the spring sheet on the fixing bracket.

[0005] The optical display module of the embodiment of the present application is provided with a spring sheet fixedly mounted on the light engine at the periphery of the light engine, and the spring sheet is connected to a fixing bracket, and the spring sheet covers the through hole of the fixing bracket. In this way, during the process of applying the sealant, the sealant cannot pass through the spring sheet to reach the through hole, and thus will not reach the surface of the optical waveguide element.

[0006] In some embodiments, the spring piece includes a coupling portion and an extension portion surrounding and connected to the coupling portion, the coupling portion is provided with an opening extending therethrough for the light engine to pass through, the extension portion extends radiating outward from the coupling portion, one end of the extension portion away from the coupling portion overlaps the fixed bracket, the extension portion encloses an accommodating space connected to the opening, and the light engine passes through the opening and extends into the accommodating space.

[0007] In some embodiments, the cross-sectional area of ​​the accommodating space gradually increases from the direction of the combining portion toward the fixing bracket.

[0008] In some embodiments, the light engine includes a lens barrel and a lens group disposed in the lens barrel, and the coupling portion is fixedly mounted on the lens barrel.

[0009] In some embodiments, the diameter of the opening is equal to the outer diameter of the lens barrel, and the outer diameter of the lens barrel is smaller than the diameter of the through hole.

[0010] In some embodiments, a portion of the light engine extends into the through hole.

[0011] In some embodiments, the spring sheet is provided with at least one exhaust hole extending therethrough.

[0012] In some embodiments, the spring sheet is provided with a plurality of exhaust holes arranged at intervals.

[0013] In some embodiments, the spring sheet includes an inner surface and an outer surface relative to each other, wherein the inner surface is a surface facing the fixing bracket, the sealant is disposed on the outer surface of the spring sheet, and the sealant is connected between the light engine and the fixing bracket.

[0014] The present application also provides an augmented reality glasses, comprising the above-mentioned optical display module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. 4 is a cross-sectional schematic diagram of an optical display module according to an embodiment of the present application.

[0016] Figure 2 FIG. 1 is a three-dimensional schematic diagram of a spring piece according to an embodiment of the present application.

[0017] Figure 3 for Figure 1 Schematic diagram of the assembly process of an optical display module.

[0018] Description of main component symbols: Optical display module 100, light engine 10, optical waveguide element 20, fixing bracket 30, through hole 301, spring 50, Combination portion 51, extension portion 53, sealant 60, opening 501, accommodating space 503, exhaust hole 505, Inner surface 512 , outer surface 514 . DETAILED DESCRIPTION

[0019] The optical display module of the embodiment of the present application can effectively prevent the sealant from overflowing onto the surface of the optical waveguide element during the alignment packaging process of the optical waveguide element and the light engine, thereby improving the packaging efficiency.

[0020] like Figure 1 As shown, the optical display module 100 of the embodiment of the present application includes a light engine 10, an optical waveguide element 20, a fixed bracket 30 and a spring 50. The light engine 10 is used to generate a projection light beam with image information. The optical waveguide element 20 is used to transmit the image light from the light engine 10 to a specified position (human eye). The fixed bracket 30 is arranged between the light engine 10 and the optical waveguide element 20, and is respectively connected to the light engine 10 and the optical waveguide element 20. The fixed bracket 30 is a medium that provides support and fixation for the light engine 10 and the optical waveguide element 20, thereby achieving relative fixation of the light engine 10 and the optical waveguide element 20. The light engine 10 and the optical waveguide element 20 are located on opposite sides of the fixed bracket 30. The optical waveguide element 20 is fixed on the fixed bracket 30. As shown in FIG. Figure 1 As shown, the fixing bracket 30 at least partially surrounds the optical waveguide element 20. The fixing bracket 30 is provided with a through hole 301, and the optical waveguide element 20 is partially exposed through the through hole 301. The light engine 10 is disposed on the fixing bracket 30 and is disposed opposite to the through hole 301. The light engine 10 is located on one side of the optical waveguide element 20. In this way, the image light generated by the light engine 10 passes through the through hole 301 to reach the optical waveguide element 20 and is conducted by the optical waveguide element 20.

[0021] The material of the spring 50 itself has a certain degree of deformability, and the material can be metal (such as stainless steel, titanium alloy, etc.) or plastic. Figure 1 and Figure 2 As shown, the spring sheet 50 is a thin sheet with certain elasticity, and the overall shape of the spring sheet 50 is a ring around the light engine 10. The spring sheet 50 is fixedly sleeved on the light engine 10, and is arranged on the fixing bracket 30 and directly contacts and connects the fixing bracket 30, and the spring sheet 50 completely covers the through hole 301.

[0022] In the present application embodiment, Figure 2As shown, the spring piece 50 includes a connecting portion 51 and a connecting portion 53. The connecting portion 51 is generally ring-shaped to surround and connect the light engine 10. That is, the connecting portion 51 is provided with an opening 501 passing through it, and the light engine 10 passes through the opening 501. The connecting portion 51 includes an inner wall and an outer wall opposite to each other, the inner wall is tightly attached to the light engine 10, and the outer wall is connected to the extension portion 53. The extension portion 53 surrounds and connects the connecting portion 51, and the extension portion 53 extends divergently from the connecting portion 51 toward the direction close to the fixed bracket 30. One end of the extension portion 53 is connected to the connecting portion 51, and the other end (the end away from the connecting portion 51) is overlapped on the fixed bracket 30. The extension portion 53 encloses a receiving space 503 connected to the opening 501. The light engine 10 passes through the opening 501 and extends into the receiving space 503. From the connecting portion 51 to the direction of the fixed bracket 30, the cross-sectional area of ​​the receiving space 503 gradually increases.

[0023] In some embodiments, the connecting portion 51 and the extending portion 53 may be made of the same material and integrally formed, but the present invention is not limited thereto. In other embodiments, the connecting portion 51 and the extending portion 53 may be made of different materials.

[0024] like Figure 1 As shown, the optical display module 100 further includes a sealant 60. The sealant 60 is at least disposed at the connection position between the spring 50 and the fixing bracket 30, so that the spring 50 is fixed on the fixing bracket 30. It can be understood that the sealant 60 can also be disposed at the connection position between the spring 50 and the light engine 10 to strengthen the fixed connection between the spring 50 and the light engine 10. In the embodiment of the present application, the sealant 60 is disposed on the surface of the spring 50 away from the fixing bracket 30, and the sealant 60 completely covers the surface of the spring 50 away from the fixing bracket 30, and the sealant 60 is connected between the fixing bracket 30 and the light engine 10.

[0025] In some embodiments, the light engine 10 includes a micro display (not shown), a collimating optical system (not shown) and a lens barrel. The micro display is used to generate a high-brightness, high-resolution image source. The collimating optical system is used to convert the divergent light emitted by the micro display into parallel light to meet the total reflection condition. The collimating optical system includes a lens group, and the lens group may include a plurality of aspheric lenses and Fresnel lenses. The lens barrel is a mechanism for fixing the lens group of the collimating optical system. The micro display may be located on one side of the lens barrel, or the micro display may be located on one side of the lens barrel and at least part of the micro display may be located in the lens barrel.

[0026] The microdisplay may be a Micro-OLED microdisplay, a Liquid Crystal on Silicon (LCoS) microdisplay, a Digital Light Processing (DLP) microdisplay or a Laser Beam Scanning (LBS) microdisplay.

[0027] Micro-OLED microdisplay is a display technology that integrates organic light-emitting diodes (OLEDs) directly on a single-crystal silicon substrate. It combines the self-luminous advantages of OLEDs with the miniaturization characteristics of semiconductor processes. It is currently a cutting-edge solution in the field of AR / VR and near-eye display. LCoS microdisplay is a microdisplay technology that combines liquid crystal technology and silicon-based CMOS circuits. It modulates light through reflective liquid crystals to achieve high-resolution, high-contrast image display. DLP microdisplay is a display technology based on a microelectromechanical system (MEMS) mirror array. Its core is to modulate light through the rapid deflection of millions of micro-mirrors to achieve efficient and high-contrast image generation. LBS microdisplay is a display technology that uses microelectromechanical system (MEMS) mirrors or rotating prisms to control high-speed scanning of laser beams to form images directly on the retina or screen. Its core features are ultra-small size, high brightness, and infinite depth of focus.

[0028] In the embodiment of the present application, the spring piece 50 surrounds and connects the lens barrel of the light engine 10. The lens barrel is cylindrical. The corresponding opening 501 is also set to be circular to match the shape of the lens barrel, and the lens barrel passes through the opening 501 of the joint 51. In the embodiment of the present application, the diameter of the opening 501 is equal to the outer diameter of the lens barrel of the light engine 10, so that the spring piece 50 can tightly surround the lens barrel of the light engine 10.

[0029] In the embodiment of the present application, the through hole 301 has a certain depth, a portion of the light engine 10 extends into the through hole 301, and there is a distance between the light engine 10 and the optical waveguide element 20. In the embodiment of the present application, the diameter of the through hole 301 is larger than the outer diameter of the lens barrel of the light engine 10, so that the lens barrel can be easily inserted into the through hole 301 to achieve the alignment of the light engine 10 and the optical waveguide element 20. However, just because the diameter of the through hole 301 is larger than the outer diameter of the lens barrel of the light engine 10, the lens barrel of the light engine 10 is not necessarily set at the center of the through hole 301 during the alignment packaging, resulting in the subsequent application of sealant between the light engine 10 and the fixing bracket 30. The sealant easily overflows through the through hole 301 to the surface of the optical waveguide element 20. In the embodiment of the present application, the spring sheet 50 is arranged to surround the light engine 10 and cover the through hole 301, and the sealant 60 is applied to the surface of the spring sheet 50 facing away from the fixing bracket 30. In this way, the sealant 60 cannot pass through the spring sheet 50 to reach the through hole 301, and thus will not reach the surface of the optical waveguide element 20.

[0030] The extension portion 53 of the spring sheet 50 is provided with at least one exhaust hole 505 extending therethrough. Figure 2 As shown, the extension portion 53 is provided with a plurality of exhaust holes 505 arranged at intervals. In the embodiment of the present application, the plurality of exhaust holes 505 are arranged at equal intervals around the joint portion 51. Each exhaust hole 505 extends from one end of the extension portion 53 away from the joint portion 51 toward the joint portion 51, and each exhaust hole 505 passes through one end of the extension portion 53 away from the joint portion 51. It can be understood that the shape of the exhaust hole 505 is not limited to Figure 2 As shown, it can be various other shapes, such as a slit shape. The location of the exhaust hole 505 is also not limited to Figure 2 As shown, for example, it may be located between the two ends of the extension portion 53 .

[0031] Although not shown, the extension portion 53 of the spring sheet 50 may also have only one exhaust hole 505 . For example, the exhaust hole 505 extends to form a circle around the connecting portion 51 .

[0032] It is understandable that, since the spring piece 50 itself is relatively small in size, the opening of the vent hole 505 is also relatively small, so that the sealant cannot pass through the relatively small vent hole 505 .

[0033] like Figure 1 As shown, the spring sheet 50 includes an inner surface 512 and an outer surface 514 that are opposite to each other, wherein the inner surface 512 is a surface facing the fixing bracket 30. The sealant 60 is disposed on the outer surface 514 of the spring sheet 50.

[0034] Correspondingly, the distance between the inner surface 512 and the outer surface 514 of the extension portion 53 is the thickness of the extension portion 53. In some embodiments, the extension portion 53 has a uniform thickness.

[0035] In the embodiment of the present application, the thickness of the extension portion 53 is not uniform, and the thickness of the extension portion 53 is thinner as it is closer to the end away from the coupling portion 51. This arrangement facilitates the extension portion 53 to be better buckled on the fixing bracket 30.

[0036] In some embodiments, the optical waveguide element 20 may be a geometric optical waveguide element or a diffractive optical waveguide element, wherein the diffractive optical waveguide element technology is divided into a surface relief grating waveguide and a volume holographic grating waveguide. The diffractive optical waveguide element utilizes the diffraction effect of light and mainly uses a grating structure to modulate the light beam. The process principle of the volume holographic optical waveguide element is relatively simple, and the grating structure can be formed by laser interference exposure.

[0037] The surface relief grating is a process of carving peaks and valleys on the surface of the material through processes such as photolithography and etching, so as to achieve a periodic structure that can meet the required optical performance. In some embodiments, the optical waveguide element 20 is a grating waveguide. Although not shown in the figure, the optical waveguide element 20 includes a substrate and a grating disposed on the substrate, and the grating is disposed in a plurality of grating regions spaced apart from each other. Each grating region includes a plurality of optical microstructures convexly disposed on a surface of the substrate and spaced apart from each other. Each optical microstructure is columnar and has a nanometer size. In some embodiments, the height of the optical microstructure is 80nm-200nm, for example, 80nm-120nm. The substrate can conduct the optical machine image by total internal reflection and output the light to the human eye through a grating. It can be understood that, according to the different functions of each grating region, the contour shape of each grating region, and the cross-sectional shape, arrangement mode, size, etc. of the optical microstructure in each grating region may be different. In some embodiments, the plurality of grating regions include mutually spaced light coupling-in regions, light turning regions, and light coupling-out regions. In the embodiment of the present application, the light coupling-in region of the optical waveguide element 20 is exposed relative to the through hole 301 , and the light coupling-in region faces the light engine 10 .

[0038] The working principle of the optical waveguide element 20 is as follows: the light with image information is projected onto the light coupling-in area, and the grating diffraction in the light coupling-in area generates diffracted light. When the diffracted light meets the total reflection condition of the optical substrate, that is, the angle of incidence on the optical surface is greater than the critical angle of total reflection of the substrate, the light beam generates total reflection and is almost losslessly transmitted in the substrate. The diffracted light beam is transmitted toward the light turning area. When it is incident on the light turning area, it is diffracted by the grating in the light turning area. While continuing to be transmitted along the grating in the light turning area, a series of diffracted light is generated and transmitted toward the light coupling-out area. This part of light is transmitted to the light coupling-out area, and after being diffracted by the grating in the light coupling-out area, it no longer meets the total reflection condition of the optical substrate and is guided out of the substrate, enters the human eye and is perceived.

[0039] In some embodiments, the optical waveguide element 20 includes one grating waveguide or two grating waveguides stacked. When two grating waveguides are included, the two grating waveguides are spaced apart to form an air layer between them. In other embodiments, the number of grating waveguides may be 3 or more, and the specific number may be set according to actual needs.

[0040] In some embodiments, the material of the fixing bracket 30 may be metal, plastic (such as phenolic plastic) or rubber.

[0041] In some embodiments, the sealant 60 may be a UV curing adhesive, which can be cured quickly by initiating a polymerization reaction by irradiating ultraviolet rays.

[0042] See also Figure 3 The assembly process of the optical reality module 100 includes the following steps (1) to (4).

[0043] (1) First, the spring piece 50 is mounted on the lens barrel of the light engine 10 .

[0044] (2) Align the light engine 10 with the through hole 301 of the fixing bracket 30 , and place the spring sheet 50 and the light engine 10 on the fixing bracket 30 so that the extended portion 53 of the spring sheet 50 contacts the fixing bracket 30 . At this time, a space is enclosed between the spring sheet 50 and the fixing bracket 30 .

[0045] (3) Press the light engine 10 downward to move it toward the fixing bracket 30. Part of the light engine 10 extends into the through hole 301 of the fixing bracket 30. At this time, the extension portion 53 of the spring sheet 50 is squeezed and deformed to expand outward, that is, the extension portion 53 stretches outward and the air between the spring sheet 50 and the fixing bracket 30 is discharged through the exhaust hole 505. In this step, even if the light engine 10 is tilted relative to the fixing bracket 30, the spring sheet 50 will be squeezed and expand outward.

[0046] (4) Finally, a sealant 60 is applied to the outer surface 514 of the spring 50 and the sealant 60 is cured. In this way, the assembly of the optical display module 100 is completed. The sealant 60 is at least arranged at the connection position between the spring 50 and the fixing bracket 30. Since the spring 50 itself is relatively small in size, the sealant 60 is applied to the entire outer surface 514 of the spring 50 and the sealant 60 is connected between the light engine 10 and the fixing bracket 30. The sealant 60 as a whole is presented as a circle around the light engine 10.

[0047] In addition, the sealant 60 has a certain fluidity before solidification. Due to the arrangement of the spring piece 50 , the flowing sealant 60 cannot reach the through hole 301 , and the opening of the exhaust hole 505 in the spring piece 50 is too small to allow the flowing sealant 60 to pass through.

[0048] The embodiment of the present application also provides an augmented reality glasses, which can superimpose virtual images on real scenes, so that users can see the mixture of virtual reality and the real world. The augmented reality glasses include the above-mentioned optical display module 100. In this way, the light generated by the light engine 10 is projected into the human eye through the conduction of the optical waveguide element 20.

[0049] The optical display module 100 of the embodiment of the present application is provided with a spring sheet 50 fixedly sleeved on the light engine 10 at the periphery of the light engine 10, and the spring sheet 50 is connected to the fixing bracket 30, and the spring sheet 50 covers the through hole 301 of the fixing bracket 30, so that during the application of the sealant 60, the sealant 60 cannot pass through the spring sheet 50 to reach the through hole 301, and thus will not reach the surface of the optical waveguide element 20. In addition, the spring sheet 50 is also provided with an exhaust hole 505, which can effectively exhaust the gas between the spring sheet 50 and the fixing bracket 30, and the opening of the exhaust hole 505 is small so that the sealant 60 will not pass through the exhaust hole 505. By providing the spring sheet 50, the alignment assembly of the light engine 10 and the optical waveguide element 20 is more convenient and faster, thereby improving the assembly efficiency and assembly yield of the optical display module 100.

[0050] It should be noted that the above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; the implementation methods of the present application and the features in the implementation methods can be combined with each other without conflict. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An optical display module, characterized in that: include: A fixed bracket is provided with a through hole; An optical waveguide element is fixed on the fixing bracket, and a part of the optical waveguide element is exposed through the through hole; A light engine is disposed on the fixing bracket, the light engine and the optical waveguide element are respectively located on opposite sides of the fixing bracket, and the light engine faces the through hole; A deformable spring sheet fixedly sleeved on the light engine, the spring sheet connected to the fixing bracket and completely covering the through hole; A sealant is arranged at the connection position between the spring sheet and the fixing bracket so as to fix the spring sheet on the fixing bracket.

2. The optical display module according to claim 1, characterized in that: The spring piece includes a connecting portion and an extension portion surrounding and connected to the connecting portion, the connecting portion is provided with an opening penetrating therethrough for the light engine to pass through, the extension portion extends outwardly from the connecting portion, one end of the extension portion away from the connecting portion overlaps the fixing bracket, the extension portion encloses an accommodating space connected to the opening, and the light engine passes through the opening and extends into the accommodating space.

3. The optical display module according to claim 2, characterized in that: From the direction of the combining portion toward the fixing bracket, the cross-sectional area of ​​the accommodating space gradually increases.

4. The optical display module according to claim 2, characterized in that: The light engine comprises a lens barrel and a lens group arranged in the lens barrel, and the combining part is fixedly sleeved on the lens barrel.

5. The optical display module according to claim 4, characterized in that: The diameter of the opening is equal to the outer diameter of the lens barrel, and the outer diameter of the lens barrel is smaller than the diameter of the through hole.

6. The optical display module according to claim 1, characterized in that: Part of the light engine extends into the through hole.

7. The optical display module according to claim 1, characterized in that: The spring sheet is provided with at least one exhaust hole passing through the spring sheet.

8. The optical display module according to claim 7, characterized in that: The spring sheet is provided with a plurality of exhaust holes which are arranged at intervals.

9. The optical display module according to claim 1, characterized in that: The spring sheet includes an inner surface and an outer surface facing each other, wherein the inner surface is a surface facing the fixing bracket, the sealant is arranged on the outer surface of the spring sheet, and the sealant is connected between the light engine and the fixing bracket.

10. An augmented reality glasses, characterized in that: An optical display module comprising any one of claims 1 to 9.

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