An arrayed waveguide system and an augmented reality display device

Abstract

The present invention relates to an array waveguide system and an augmented reality display device. The system includes: an optical engine for emitting image light beams of N colors; N two-dimensional array waveguide layers, which are stacked in order from near to far from the optical engine. An incident part is provided in the light-incident area of each two-dimensional array waveguide layer and is arranged close to the optical engine, and each two-dimensional array waveguide layer includes a pupil expansion part, which is arranged close to the incident part; where N≥2; the incident part at least includes an incident surface, a reflection surface and an exit surface, and a dichroic mirror is provided on the reflection surface; the pupil expansion part includes a beam splitting film with a 50% splitting ratio embedded inside the two-dimensional array waveguide layer along the middle of the thickness of the two-dimensional array waveguide layer and parallel to the surface of the two-dimensional array waveguide layer; a glue layer is provided between adjacent two-dimensional array waveguide layers, which can effectively balance the overall color, significantly improve the color uniformity of the overall waveguide system, improve the user experience, effectively reduce the difficulty of the coating process, and improve the mass production of waveguides.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to an array waveguide system and an augmented reality display device. Background Art

[0002] Augmented Reality (AR) technology is a technology that cleverly integrates virtual information with the real world. It has important significance in the fields of military, industry, entertainment, medical treatment, transportation, etc. The main technologies currently used for transmissive head-mounted displays for augmented reality include: Birdbath, prism, free-form surface and optical waveguide technology. Compared with other technologies, head-mounted displays using optical waveguide technology are smaller in size and more like a pair of glasses. Optical waveguide technology mainly includes array optical waveguides, surface relief grating waveguides and volume holographic waveguides. Among them, array optical waveguides are superior to diffraction optical waveguides and volume holographic waveguides in color performance and light energy utilization. In particular, array optical waveguides using two-dimensional exit pupil expansion technology also have the advantages of small coupling optical machine size, large exit pupil distance, and large eye box.

[0003] Compared with diffraction waveguides, array waveguides use simple light reflection and refraction to achieve pupil expansion, so color uniformity and light efficiency are better. However, the color uniformity of array waveguides on the market, especially two-dimensional array waveguides, is still far behind the color performance of traditional displays. One of the important reasons is that the reflectivity of optical coatings to different wavelengths of light is different.

[0004] In practice, the image light projected by the optical engine enters the array waveguide through the coupling structure, and then hits the splitter surface after a certain length of total reflection transmission. Part of the light is transmitted and part is reflected. To achieve this effect, optical coating is required on the splitter surface. Optical coating uses the principle of light interference to adjust the splitting ratio of light at the optical interface by stacking dielectric layers of different thicknesses and different materials to achieve the desired effect. According to its basic principle, under the condition of a certain film layer structure, the splitting ratios of different wavelengths at the same incident angle are different, and the splitting ratios of different incident angles at the same wavelength are also different.

[0005] In an array waveguide, in order to display a full-color image with a certain field of view (FOV), the light incident on the beam splitting surface has a certain angular range and also a certain wavelength range. Therefore, when the beam splitting ratio of the beam splitting surface changes with the wavelength to a certain extent, it will cause a change in the color of the finally displayed image. Especially in a two-dimensional optical waveguide, the number of beam splitting surfaces of the turning structure and the coupling-out structure increases. Even if the beam splitting ratio of the beam splitting surface changes slightly with the wavelength, it will still cause relatively serious color non-uniformity. Therefore, in order to achieve color uniformity of the displayed image, coating is a very big challenge and also a problem that is relatively difficult to overcome in current two-dimensional array waveguides. Summary of the Invention

[0006] According to the problems existing in the prior art, the present invention provides an array waveguide system and an augmented reality display device to solve the problem of color non-uniformity existing in the existing two-dimensional array waveguide structure.

[0007] The technical solution of the present invention is as follows:

[0008] This specification provides an array waveguide system, including:

[0009] An optical engine for emitting image light beams of N colors;

[0010] N two-dimensional array waveguide layers, which are stacked in order from near to far from the optical engine. An incident light region of each two-dimensional array waveguide layer is provided with a coupling-in part, which is arranged adjacent to the optical engine, and each two-dimensional array waveguide layer includes an expanding pupil part, which is arranged adjacent to the coupling-in part;

[0011] Wherein, N≥2; the coupling-in part at least includes an incident light surface, a reflection surface and an emergent light surface, and the reflection surface is provided with a dichroic mirror; the expanding pupil part includes a 50% beam splitting film embedded inside the two-dimensional array waveguide layer along the 1 / 2 thickness of the two-dimensional array waveguide layer and parallel to the surface of the two-dimensional array waveguide layer;

[0012] A glue layer, and a glue layer is provided between each two adjacent two-dimensional array waveguide layers.

[0013] As a preferred technical solution, the two-dimensional array waveguide layer includes a turning part and a coupling-out part embedded between a first substrate and a second substrate, and are arranged in sequence along a first direction. The turning part includes a plurality of first beam splitters arranged at equal intervals along a second direction at a first preset angle, and the coupling-out part includes a plurality of second beam splitters arranged at equal intervals along the first direction at a second preset angle. Wherein, the number of first beam splitters in each two-dimensional array waveguide layer is the same or different, and the first preset angle is the same or different; the number of second beam splitters in each two-dimensional array waveguide layer is the same, the second preset angle is the same, and the first direction is perpendicular to the second direction.

[0014] As a preferred technical solution, the pupil expansion part is located between the light coupling part and the turning part, and the beam splitting film with a 50% splitting ratio in each two-dimensional array waveguide layer has a length along the first direction that is 5-6 times the thickness of the corresponding two-dimensional array waveguide layer.

[0015] As a preferred technical solution, the incident light surface and the reflection surface are arranged at an included angle α, where the included angle α = 30° - 40°, and the outgoing light surface is perpendicular to the incident light surface.

[0016] As a preferred technical solution, the light coupling part is a triangular prism, where the included angle α = 35°.

[0017] As a preferred technical solution, the thicknesses of each two-dimensional array waveguide layer are the same or different; the refractive indices of each two-dimensional array waveguide layer are the same or different.

[0018] As a preferred technical solution, the adhesive layer is a first optical adhesive layer, or the adhesive layer includes a first magnesium fluoride coating, a second optical adhesive layer, and a second magnesium fluoride coating, where the second optical adhesive layer is located between the first magnesium fluoride coating and the second magnesium fluoride coating.

[0019] As a preferred technical solution, the thicknesses of the first optical adhesive layer and the second optical adhesive layer are the same or different; the thicknesses of the first magnesium fluoride coating and the second magnesium fluoride coating are the same or different.

[0020] As a preferred technical solution, the thicknesses of both the first optical adhesive layer and the second optical adhesive layer are 0.5 - 5 μm; the thicknesses of both the first magnesium fluoride coating and the second magnesium fluoride coating are 80 - 500 nm.

[0021] This specification also provides an augmented reality display device, including the above-mentioned array waveguide system.

[0022] The beneficial effects achieved by the technical solution adopted in the present invention:

[0023] This specification provides an array waveguide system and an augmented reality display device, including a plurality of two-dimensional array waveguide layers glued together as a whole, and each two-dimensional array waveguide layer includes a light coupling part and a pupil expansion part. A dichroic mirror is arranged in the light coupling part and a semi-transmissive and semi-reflective film is arranged in the pupil expansion part to achieve color separation transmission and display of different colors. With this arrangement, the overall color is effectively balanced, the color uniformity of the overall waveguide system is significantly improved, the user experience is enhanced, the difficulty of the coating process can be effectively reduced, and the mass production of the waveguide can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. These drawings form a part of the present invention, and the schematic embodiments of the present invention and their explanations explain the present invention without unduly limiting the present invention. In the drawings:

[0025] Figure 1 Schematic structural diagram of the array waveguide system disclosed in this embodiment;

[0026] Figure 2 Schematic structural diagram of the array waveguide system disclosed in this embodiment;

[0027] Figure 3 Schematic structural diagram of the array waveguide system disclosed in this embodiment.

[0028] Description of reference numerals:

[0029] Array waveguide system 100; optical machine 101; coupling-in part 102; pupil expansion part 103; turning part 104; coupling-out part 105; first two-dimensional array waveguide layer 110; first coupling-in part 111; first pupil expansion part 112; first dichroic mirror 113; second two-dimensional array waveguide layer 120; second coupling-in part 121; second pupil expansion part 122; second dichroic mirror 123; bonding layer 130. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or", unless otherwise clearly specified in the content.

[0031] In the description of the present invention, it should be understood that terms such as "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In addition, those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0033] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Embodiment

[0035] According to Figures 1 - 3 , an array waveguide system 100 includes:

[0036] An optical engine 101 for emitting image light beams of N colors; in this embodiment, it is not limited to the optical engine 101, and it can also be a multi-color laser, or any other way capable of emitting multi-color light sources, and no specific limitation is made here;

[0037] N two-dimensional array waveguide layers, and the N two-dimensional array waveguide layers are stacked in sequence from near to far from the optical engine 101. An input coupling part 102 is provided in the light input area of each two-dimensional array waveguide layer and is arranged adjacent to the optical engine 101, and each two-dimensional array waveguide layer includes an pupil expansion part 103 and is arranged adjacent to the input coupling part 102;

[0038] Wherein, N≥2 and N is a positive integer; the input coupling part 102 at least includes an incident light surface, a reflection surface and an outgoing light surface, and a dichroic mirror is provided on the reflection surface; the pupil expansion part 103 includes a beam splitting film with a 50% splitting ratio embedded inside the two-dimensional array waveguide layer along the middle of the thickness of the two-dimensional array waveguide layer and parallel to the surface of the two-dimensional array waveguide layer;

[0039] A bonding layer 130 is provided between adjacent two-dimensional array waveguide layers.

[0040] Based on the problem of color unevenness caused by the existing two-dimensional array waveguide dispersion effect, this embodiment provides an array waveguide system 100, which includes a plurality of two-dimensional array waveguide layers glued together as a whole, and each two-dimensional array waveguide layer includes an input coupling part 102 and a pupil expansion part 103. A dichroic mirror is provided on the input coupling part 102 and a beam splitting film with a 50% splitting ratio is provided on the pupil expansion part 103 to realize the color separation transmission and display of different colors. With this setting, the overall color is effectively balanced, the color uniformity of the overall waveguide system is significantly improved, the user experience is enhanced, and the difficulty of the coating process can be effectively reduced, and the mass production of the waveguide can be improved.

[0041] Preferably, the two-dimensional array waveguide layer includes a turning portion 104 and an output portion 105 embedded between a first substrate and a second substrate, and they are arranged in sequence along a first direction; the turning portion 104 includes a plurality of first beam splitters arranged at equal intervals along a second direction at a first preset angle, and the output portion 105 includes a plurality of second beam splitters arranged at equal intervals along the first direction at a second preset angle. Among them, the number of first beam splitters in each two-dimensional array waveguide layer may be the same or different, and the first preset angles may be the same or different; the number of second beam splitters in each two-dimensional array waveguide layer is the same, the second preset angles are the same, and the first direction is perpendicular to the second direction.

[0042] Specifically, each two-dimensional array waveguide layer includes a first substrate and a second substrate, as well as a turning portion 104 and an output portion 105 embedded between the first substrate and the second substrate, and the turning portion 104 and the output portion 105 are arranged in sequence along the first direction. Among them, the turning portion 104 includes a plurality of first beam splitters arranged in sequence along the second direction and set at a first preset angle with respect to the second direction, for expanding the pupil of the light entering the turning portion 104 along the second direction, and after turning, the light is incident on the output portion 105; the output portion 105 includes a plurality of second beam splitters arranged in sequence along the first direction, and the second beam splitters are set at a second preset angle with respect to the first direction, and the plurality of second beam splitters are parallel to the second direction, for expanding the pupil of the light output from the turning portion 104 in the first direction and outputting it to the eye position. The first preset angle is between 30° and 60°, preferably 45°, and the second preset angle is preferably 45°. The first direction is perpendicular to the second direction. For the convenience of clarifying the direction, the second direction can also be set as the X-axis and the first direction as the Y-axis.

[0043] Furthermore, the structures of each two-dimensional array waveguide layer may be the same or different. That is to say, the materials of each two-dimensional array waveguide layer may be the same or different. The materials of the first substrate and the second substrate in each two-dimensional array waveguide layer are the same, preferably glass; the turning portions 104 in each two-dimensional array waveguide layer may be the same or different. Preferably, the turning portions 104 in each two-dimensional array waveguide layer are the same. For example, glass is used in terms of material, the first preset angles are the same, the number of first beam splitters is the same, the sizes of the first beam splitters are the same, the distances between the first beam splitters are the same, etc.; the output portions 105 in each two-dimensional array waveguide layer are the same. For example, glass is used in terms of material, the second preset angles are the same, the number of second beam splitters is the same, the sizes of the second beam splitters are the same, the distances between the second beam splitters are the same, etc. The same structure of each two-dimensional array waveguide layer is more conducive to simplifying the processing difficulty in practice and saving costs.

[0044] In another embodiment, each two-dimensional array waveguide layer has the same material, and the first beam splitter and the second beam splitter have the same size and the same spacing. That is to say, the first beam splitters and the second beam splitters in each layer have the same size. Namely, the multiple first beam splitters have the same spacing from each other, the multiple second beam splitters have the same spacing from each other, the first preset angle is the same, and the second preset angle is the same. In this case, the optical coatings for the embedded first beam splitters and second beam splitters can be different, that is, the film layers with different splitting ratios. For example, the splitting ratio of the first first beam splitter among the multiple first beam splitters is 90%, and the splitting ratio of the first first beam splitter in the next two-dimensional array waveguide layer is 80%, so as to adapt to the actual light of different wavelengths and colors, realize the color separation transmission and display of different colors, effectively balance the overall color, and significantly improve the color uniformity of the overall waveguide system.

[0045] Preferably, the pupil expansion part 103 is located between the light coupling part 102 and the turning part 104, and the length of the beam splitting film with a 50% splitting ratio along the first direction is 5-6 times the thickness of the corresponding two-dimensional array waveguide layer.

[0046] Specifically, each two-dimensional array waveguide layer includes a light coupling part 102 arranged in the light incident area and an embedded pupil expansion part 103. In actual operation, the light coupling part 102, the pupil expansion part 103, the turning part 104 and the light output part 105 can all be restricted within the upper and lower substrates of the two-dimensional array waveguide layer, which is more firm in structure and helps to reduce the process difficulty. Among them, the pupil expansion part 103 is located between the light coupling part 102 and the turning part 104. As seen from the arrangement along the second direction, they are the light coupling part 102, the pupil expansion part 103, and the turning part 104 in sequence, and both the pupil expansion part 103 and the turning part 104 are located in the upper part of the two-dimensional array waveguide layer, and the turning part 104 is located in the lower part of the two-dimensional array waveguide layer; the pupil expansion part 103 is a beam splitting film with a 50% splitting ratio arranged inside the two-dimensional array waveguide layer, preferably a semi-transmissive and semi-reflective film. That is to say, the semi-transmissive and semi-reflective film is arranged between the first substrate and the second substrate and is parallel to the first substrate and the second substrate, so as to expand the pupil of the light entering the pupil expansion part 103 through the light coupling part 102 to fill the entrance pupil of the waveguide.

[0047] Further, see Figure 2 In the front view, the length of the pupil expansion part 103 is 5-6 times the thickness of the corresponding two-dimensional array waveguide layer. For example, the multi-color light emitted by the optical engine 101 enters the light coupling part 102 of the first two-dimensional array waveguide layer. After the first dichroic mirror 113 reflects the red light, the other light will pass through and enter the light coupling part 102 of the next two-dimensional array waveguide layer. The reflected red light will be output after passing through the first pupil expansion part 112, the first turning part 104 and the first light output part 105 in sequence. Then the length of the first pupil expansion part 112 is preferably 5-6 times the thickness of the first two-dimensional array waveguide layer, which can be selected according to the actual manufacturing requirements of the two-dimensional array waveguide layer.

[0048] Since the thickness of the beam-splitting film with a 50% splitting ratio is not in the same order of magnitude as the thickness of the two-dimensional array waveguide layer, or the first substrate, or the second substrate, those skilled in the art can set the specific thickness according to actual needs here, as long as it satisfies that light can penetrate the semi-transmissive and semi-reflective film at least once in the pupil expansion part 103, and it can satisfy filling the entrance pupil of the waveguide.

[0049] Preferably, the incident light surface and the reflection surface are arranged at an included angle α, where the included angle α = 30° - 40°, and the outgoing light surface is perpendicular to the incident light surface.

[0050] Preferably, the light coupling part 102 is a triangular prism, where the included angle α = 35°.

[0051] Specifically, the light coupling part 102 is preferably a triangular prism. The light coupling part 102 includes an incident light surface, an outgoing light surface, and a reflection surface, and a dichroic mirror is arranged on the reflection surface; the incident light surface and the reflection surface are arranged at an included angle α, preferably the included angle α = 35°, the outgoing light surface is perpendicular to the incident light surface, and it is arranged in the incident light area of the two-dimensional array waveguide layer. The light coupling part 102 is used in combination with the dichroic mirror to perform spectral screening on multiple incident light beams and couple the selected color light into the waveguide for total reflection propagation.

[0052] Preferably, the thicknesses of each two-dimensional array waveguide layer are the same or different; the refractive indices of each two-dimensional array waveguide layer are the same or different.

[0053] Specifically, the thickness of each two-dimensional array waveguide layer can be selected by those skilled in the art according to actual needs, and can be the same or different to adjust the color brightness uniformity of different colors, so as to improve the color brightness uniformity of the overall waveguide system, and no specific limitation is made here.

[0054] Preferably, the bonding layer 130 is a first optical adhesive layer, or the bonding layer 130 includes a first magnesium fluoride coating, a second optical adhesive layer, and a second magnesium fluoride coating, where the second optical adhesive layer is located between the first magnesium fluoride coating and the second magnesium fluoride coating.

[0055] Preferably, the thicknesses of the first optical adhesive layer and the second optical adhesive layer are the same or different; the thicknesses of the first magnesium fluoride coating and the second magnesium fluoride coating are the same or different.

[0056] Preferably, the thicknesses of both the first optical adhesive layer and the second optical adhesive layer are 0.5 - 5 μm; the thicknesses of both the first magnesium fluoride coating and the second magnesium fluoride coating are 80 - 500 nm.

[0057] Specifically, the bonding layer 130 has two forms. The first is an optical adhesive layer, and the second is that magnesium fluoride coatings are provided on both sides of the optical adhesive layer. In practice, multiple two-dimensional array waveguide layers may be provided with only the first type of bonding layer 130 between each other, or only the second type of bonding layer 130, or the first and second bonding layers 130 are arranged alternately, or half of the part is the first type of bonding layer 130 and the other half is the second type of bonding layer 130. The thickness of each layer of the bonding layer 130 may be different or the same. Regardless of which form the bonding layer 130 adopts, it is invented to strengthen the structural firmness and avoid light leakage and crosstalk problems during the lateral transmission of light, so as to improve the brightness and uniformity and enhance the total internal reflection transmission efficiency of light.

[0058] In a preferred embodiment, the materials and structures of each two-dimensional array waveguide layer are the same, that is, the refractive indices are the same. Then, a first optical adhesive layer is provided between adjacent two-dimensional array waveguide layers, satisfying the following first formula:

[0059]

[0060] Alternatively, a second optical adhesive layer is provided between adjacent two-dimensional array waveguide layers, and magnesium fluoride coatings are provided on the upper and lower surfaces of the second optical adhesive layer, that is, a first magnesium fluoride coating, a second optical adhesive layer, and a second magnesium fluoride coating, and the second optical adhesive layer is located between the first magnesium fluoride coating and the second magnesium fluoride coating, satisfying the following second formula:

[0061]

[0062] wherein, the second beam splitter forms an angle ω with the first direction; 0 ≤ μ ≤ 40°; the refractive index of each two-dimensional array waveguide layer is n W ; the refractive indices of the first optical adhesive layer and the second optical adhesive layer are n G ; the refractive indices of the first magnesium fluoride coating and the second magnesium fluoride coating are both n C .

[0063] Preferably, the thickness of the optical adhesive layer is 0.5 - 5 μm; the thickness of the magnesium fluoride coating is 80 - 500 nm. The specific thickness is set according to actual requirements. In actual operation, the magnesium fluoride coating can be first coated on the opposite surfaces of adjacent two-dimensional array waveguide layers, and then the second optical adhesive layer is provided between the first magnesium fluoride coating and the second magnesium fluoride coating to complete the bonding of adjacent two-dimensional array waveguide layers. Manual bonding or bonding equipment can be used. The specific bonding process flow and equipment selection can be selected according to actual requirements to achieve the purpose of precise bonding.

[0064] Figure 3The figure shows the optical path diagram after the light from the optical engine 101 enters the waveguide. In each two-dimensional array waveguide layer, the first substrate and the second substrate are parallel to each other. In this embodiment, N = 2 is used for illustration. The optical engine 101 emits a full-color image of red light and blue-green light. Among them, the structures and materials of the first two-dimensional array waveguide layer 110 and the second two-dimensional array waveguide layer 120 are the same; the structures and materials of the light coupling part 102 and the pupil expansion part 103 are also the same. Glass is used for illustration in terms of materials. The light coupling part 102 all uses triangular prisms, and each included angle α = 35°. The first two-dimensional array waveguide layer 110 and the second two-dimensional array waveguide layer 120 are stacked in sequence from near to far from the optical engine 101. Since the light path from the turning part 104 to the light coupling-out part 105 and output to the human eye is the same as that of the traditional two-dimensional waveguide, it will not be elaborated here. In this embodiment, the optical path from the optical engine 101 to the light coupling part 102 and then to the pupil expansion part 103 is introduced.

[0065] The full-color image projected by the optical engine 101 passes through the first light incident surface and enters the first light coupling part 111, and is incident on the first dichroic mirror 113. Then the first dichroic mirror 113 will reflect 100% of the red light in the full-color image. Its wavelength range is 600nm - 640nm, and the specific range depends on the wavelength of all the LED lamp beads of the optical engine 101, and will transmit 100% of the blue-green light. Its wavelength range is 450nm - 540nm, and the specific range depends on the wavelength of all the LED lamp beads of the optical engine. Due to the placement angle α of the dichroic mirror and the existence of the adhesive layer 130, the reflected red light will be restricted to total reflection propagation within the first two-dimensional array waveguide layer 110. When the light encounters a beam splitter film with a 50% splitting ratio each time, sub-rays will be split to fill the entrance pupil of the first two-dimensional array waveguide layer 110. The red light filling the first two-dimensional array waveguide layer 110 will always perform total reflection transmission within the first two-dimensional array waveguide layer 110, and after passing through the first turning part 104 and the first light coupling-out part 105 in sequence and being coupled out, it is incident on the human eye.

[0066] Similarly, the blue-green light transmitted through the first light coupling part 111 will enter the second light coupling part 121 through the second light incident surface and be incident on the second dichroic mirror 123. The second dichroic mirror 123 will reflect 100% of the blue-green light in the full-color image. The wavelength range is 450nm - 540nm, and the specific range depends on the wavelength of all the LED lamp beads of the optical engine. Similar to the red light, after passing through the second pupil expansion part 122, the blue-green light will also fill the entrance pupil of the second two-dimensional array waveguide layer 120, and after passing through the second turning part 104 and the second light coupling-out part 105 in sequence and being coupled out, it is incident on the human eye. Finally, the human eye receives a complete and full-color image.

[0067] In this process, only the first turning portion 104 and the first output portion 105 in the first two-dimensional array waveguide layer 110 need to be coated and processed for red light. Compared with the previous full-color coating design, in this solution, since the wavelength range is greatly reduced, the coating difficulty is extremely reduced, and at the same time, the coating effect and mass production performance are greatly improved. Similarly, since the wavelength ranges of blue and green light are much smaller than the entire waveguide, the coating difficulty is also greatly reduced, and at the same time, the coating effect and mass production performance are greatly improved. In addition, the design of the adhesive layer 130 strengthens the firmness of the structure, improves the brightness and uniformity.

[0068] The solution in this embodiment can also be applied to the design of multiple two-dimensional array waveguide layers. For example, two two-dimensional array waveguide layers can be set, designed for red light and blue-green light, corresponding to the transmission of red and blue-green colors respectively. Three two-dimensional array waveguide layers can also be set, designed for red light, blue light, and green light, corresponding to the transmission of red, green, and blue colors respectively, effectively improving the color uniformity of the waveguide, reducing the coating difficulty, and improving the mass production performance of the waveguide.

[0069] This embodiment also provides an augmented reality display device, including the above-mentioned array waveguide system 100, which effectively realizes the color separation transmission and display of different colors, significantly improves the color uniformity of the overall waveguide system, improves the user experience, and can also effectively reduce the difficulty of the coating process and improve the mass production performance of the waveguide.

[0070] The above has introduced in detail an array waveguide system and an augmented reality display device according to an embodiment of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. An array waveguide system, characterized in that, It includes: An optical machine for emitting image light beams of N colors; N two-dimensional array waveguide layers, which are stacked in sequence from near to far from the optical machine. An optical coupling part is provided in the light incident area of each two-dimensional array waveguide layer and is arranged adjacent to the optical machine, and each two-dimensional array waveguide layer includes a pupil expansion part and is arranged adjacent to the optical coupling part; each two-dimensional array waveguide layer includes an optical coupling out part, and the turning part and the optical coupling out part are arranged in sequence along a first direction; the optical coupling part, the pupil expansion part, and the turning part are arranged in sequence along a second direction, and the first direction is perpendicular to the second direction; Wherein, N≥2; the optical coupling part at least includes a light incident surface, a reflection surface and a light output surface. A dichroic mirror is provided on the reflection surface. The light incident surface and the reflection surface are arranged at an angle α, and the angle α = 30°-40°. The light output surface is perpendicular to the light incident surface; the pupil expansion part includes a beam splitting film with a 50% splitting ratio embedded inside the two-dimensional array waveguide layer along the middle of the thickness of the two-dimensional array waveguide layer and parallel to the surface of the two-dimensional array waveguide layer; the length of the beam splitting film with a 50% splitting ratio is 5-6 times the thickness of the corresponding two-dimensional array waveguide layer, and the thickness of each two-dimensional array waveguide layer is the same or different; the turning parts in each two-dimensional array waveguide layer are different, and the optical coupling out parts in each two-dimensional array waveguide layer are the same; Glue layers are provided between adjacent two-dimensional array waveguide layers.

2. The array waveguide system according to claim 1, characterized in that, The two-dimensional array waveguide layer includes a turning part and an optical coupling out part embedded between the first substrate and the second substrate and arranged in sequence along a first direction. The turning part includes a plurality of first beam splitters arranged at equal intervals along a second direction at a first preset angle, and the optical coupling out part includes a plurality of second beam splitters arranged at equal intervals along the first direction at a second preset angle. Among them, the number of first beam splitters in each two-dimensional array waveguide layer is the same or different, and the first preset angle is the same or different; the number of second beam splitters in each two-dimensional array waveguide layer is the same, and the second preset angle is the same. The first direction is perpendicular to the second direction.

3. The array waveguide system according to claim 2, characterized in that, The pupil expansion part is located between the optical coupling part and the turning part, and the length of the beam splitting film with a 50% splitting ratio in each two-dimensional array waveguide layer along the first direction is 5-6 times the thickness of the corresponding two-dimensional array waveguide layer.

4. The array waveguide system according to claim 1, characterized in that, The optical coupling part is a triangular prism, and the angle α = 35°.

5. The array waveguide system according to claim 1, characterized in that, The refractive index of each two-dimensional array waveguide layer is the same or different.

6. The array waveguide system according to any one of claims 1-5, characterized in that, The adhesive layer is a first optical adhesive layer, or the adhesive layer includes a first magnesium fluoride coating, a second optical adhesive layer, and a second magnesium fluoride coating, wherein the second optical adhesive layer is located between the first magnesium fluoride coating and the second magnesium fluoride coating.

7. The array waveguide system according to claim 6, wherein the first optical adhesive layer and the second optical adhesive layer have the same or different thicknesses; the first magnesium fluoride coating and the second magnesium fluoride coating have the same or different thicknesses.

8. The array waveguide system according to claim 7, wherein the thicknesses of both the first optical adhesive layer and the second optical adhesive layer are 0.5 - 5 μm; the thicknesses of both the first magnesium fluoride coating and the second magnesium fluoride coating are 80 - 500 nm.

9. An augmented reality display device, wherein it includes the array waveguide system according to any one of claims 1 - 8.

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