Two-dimensional pupil-expanding optical waveguide device and binocular display system

Abstract

The embodiment of the invention provides a two-dimensional pupil-expanding optical waveguide device and a binocular display system, and relates to the technical field of optics. The two-dimensional pupil-expanding optical waveguide device provided by the invention comprises a waveguide assembly; the waveguide assembly comprises at least two waveguide sheets, and the waveguide sheets are stacked. Projections of the coupling-in areas of the waveguide sheets in the first direction are overlapped or spliced to form a coupling-in area of the waveguide assembly; projection parts of the coupling-out areas of the waveguide sheets in the first direction are overlapped to form a coupling-out area of the waveguide assembly, pupil expansion directions of the waveguide sheets are different and have included angles, and the pupil expansion areas of the waveguide sheets can be continuously spliced to cover the coupling-out area of the waveguide assembly; the first direction is a direction perpendicular to the surface of the waveguide sheet. The two-dimensional pupil-expanding optical waveguide device and the binocular display system provided by the invention have the advantages of high luminous efficiency, low color cast, high yield, high definition, low cost and capability of realizing no forward light leakage and external stray light reflection in design.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a two-dimensional pupil expansion optical waveguide device and a binocular display system. Background Art

[0002] Augmented reality (AR) technology is a technology that integrates computer-generated virtual information with the real environment. AR optical waveguides are divided into one-dimensional and two-dimensional pupil expansion optical waveguides based on the pupil expansion method. In order to reduce the size and weight of near-eye display devices while ensuring a larger eye movement range, a smaller optical machine is required, which means a smaller optical waveguide coupling aperture is required. Therefore, two-dimensional pupil expansion is the current mainstream solution.

[0003] At present, there are two main solutions for two-dimensional pupil expansion of AR optical waveguides. In one solution, the principle of geometric optics is used, and light is coupled in, expanded, and coupled out through refraction and reflection. The disadvantage of this solution is that the optical waveguide needs to undergo a complex glass cold processing process, resulting in a high yield and low cost. In particular, the turning pupil expansion spectroscopic surface requires many layers, and the lack of parallelism and verticality accuracy will affect the display clarity. In another solution, the principle of diffraction optics is used, and light is coupled in, expanded, and coupled out through diffraction. The disadvantage of this solution is low light efficiency. To achieve a high-quality full-color display with a large field of view, at least two waveguides need to be superimposed, and there is an obvious color deviation, serious forward light leakage, and stray light reflected from external light. Summary of the invention

[0004] The present invention provides a two-dimensional pupil expansion optical waveguide device and a binocular display system, which realize two-dimensional pupil expansion by using a one-dimensional waveguide sheet, so that the two-dimensional pupil expansion optical waveguide device has the advantages of high light efficiency, low color deviation, high yield, high definition, low cost of the one-dimensional waveguide sheet, and can be designed to achieve no forward light leakage and external reflected stray light.

[0005] In a first aspect, the present invention provides a two-dimensional pupil expansion optical waveguide device, comprising: a waveguide component; The waveguide assembly comprises: at least two waveguide sheets, each waveguide sheet is stacked, wherein a transparent interlayer is arranged between adjacent waveguide sheets, and the refractive index of the transparent interlayer is smaller than the refractive index of the adjacent waveguide sheets; Each waveguide sheet includes a coupling-in region and a coupling-out region. The projections of the coupling-in regions of each waveguide sheet in a first direction overlap or are spliced ​​to form the coupling-in region of the waveguide assembly. The projections of the coupling-out regions of each waveguide sheet in the first direction partially overlap to form the coupling-out region of the waveguide assembly. The pupil expansion directions of each waveguide sheet are different and have an angle. The pupil expansion regions of each waveguide sheet can be continuously spliced ​​to cover the coupling-out region of the waveguide assembly. The first direction is a direction perpendicular to the surface of the waveguide sheet.

[0006] Optionally, each waveguide plate is an array optical waveguide or a diffraction optical waveguide.

[0007] Optionally, the light source coupled into the coupling-in region of the waveguide component and the human eye into which the light coupled out of the coupling-out region of the waveguide component enter are located on the same side of the waveguide component.

[0008] Optionally, the light source coupled into the coupling-in region of the waveguide component and the human eye into which the light coupled out of the coupling-out region of the waveguide component enter are located on opposite sides of the waveguide component.

[0009] Optionally, when each waveguide plate is an array optical waveguide, in each waveguide plate, the coupling structure in the coupling-in area has one or more mutually parallel first splitting surfaces, and the coupling-out structure in the coupling-out area has multiple mutually parallel second splitting surfaces, and the first splitting surfaces and the second splitting surfaces are arranged non-parallel.

[0010] Optionally, when each waveguide plate is an array optical waveguide, in each waveguide plate, the coupling structure in the coupling area has one or more mutually parallel first splitting surfaces, and the coupling structure in the coupling area has multiple mutually parallel second splitting surfaces, and the first splitting surfaces are arranged in parallel with the second splitting surfaces.

[0011] Optionally, when each waveguide sheet is an array optical waveguide, in each waveguide sheet, the coupling structure in the coupling region has one or more mutually parallel first splitting surfaces, the coupling structure in the coupling region has a plurality of mutually parallel second splitting surfaces, and the first splitting surfaces are arranged in parallel with the second splitting surfaces; The two-dimensional pupil expansion optical waveguide device also includes: a reflector and a 1 / 4 wave plate, the 1 / 4 wave plate is located on the side surface of the coupling region in the waveguide component away from the light source, the reflector is located on the side surface of the 1 / 4 wave plate away from the waveguide component, and the light source is a linearly polarized light source.

[0012] Optionally, the first angle between the first splitting surface and the two surfaces of the waveguide plate is the same, the second angle between the second splitting surface and the two surfaces of the waveguide plate is the same, and the first angle is the same as the second angle.

[0013] Optionally, when each waveguide plate is a diffractive optical waveguide, in each waveguide plate, the coupling-in structure in the coupling-in region has a first grating, and the coupling-out structure in the coupling-out region has a second grating.

[0014] Optionally, the center of the out-coupling region in the waveguide component corresponds to the position of a human eye, and the center of the in-coupling region in the waveguide component is higher than the position of a human eye.

[0015] In a second aspect, the present invention provides a binocular display system, comprising: a light source module and two groups of two-dimensional pupil expansion optical waveguide devices provided by any embodiment of the present invention.

[0016] Optionally, the light source module includes a first light source, and two groups of two-dimensional pupil expansion optical waveguide devices are spliced ​​to form a binocular display system, wherein the coupling areas of the two groups of two-dimensional pupil expansion optical waveguide devices are spliced ​​to form the same coupling area, and the first light source is used to provide light to the same coupling area.

[0017] A two-dimensional pupil expansion optical waveguide device provided in an embodiment of the present invention realizes two-dimensional pupil expansion by rotating and superimposing multiple one-dimensional waveguide sheets, so that the two-dimensional pupil expansion optical waveguide device inherits the advantages of high optical efficiency, low color deviation, high yield, high definition, low cost and no forward leakage light and external reflected stray light of the one-dimensional waveguide sheet in design. Compared with the two-dimensional optical waveguide in the prior art, the two-dimensional pupil expansion optical waveguide device provided in an embodiment of the present invention has lower process difficulty and manufacturing cost.

[0018] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 is a schematic structural diagram of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 2 is an exploded top view of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 3 is a top view of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 4 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 5 is an exploded top view of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 6 is a top view of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Figure 7 It is a schematic structural diagram of the coupling-in region and the coupling-out region of the waveguide assembly provided in an embodiment of the present invention; Figure 8 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Fig. 9is a schematic structural diagram of a waveguide provided by an embodiment of the present invention; Fig.10 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Fig.11 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Fig.12 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Fig.13 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention; Fig.14 It is a schematic diagram of the positions of the coupling-in region and the coupling-out region of a waveguide component provided by an embodiment of the present invention; Fig.15 It is a structural schematic diagram of a binocular display system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] There are two types of pupil expansion methods for two-dimensional optical waveguides in the prior art. One is diffraction waveguide, which uses a one-dimensional turning grating and a one-dimensional out-coupling grating to expand the pupil in two directions respectively, and another uses a two-dimensional grating to directly achieve two-dimensional pupil expansion. The other is array waveguide, which uses a turning beam splitter and an out-coupling beam splitter to expand the pupil in two directions respectively to achieve two-dimensional pupil expansion. In order to ensure brightness uniformity, these two pupil expansion methods cannot efficiently utilize light in the non-out-coupling pupil expansion direction, resulting in low light efficiency.

[0024] In order to solve the above problems, the present invention provides a two-dimensional pupil expansion optical waveguide device. Figure 1 is a schematic structural diagram of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, Figure 2 is an exploded top view of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, Figure 3 is a top view of a two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, combined with Figure 1 , Figure 2 and Figure 3 As shown, the two-dimensional pupil expansion optical waveguide device includes: a waveguide component 100; wherein the waveguide component 100 includes: at least two waveguide sheets 101, each waveguide sheet 101 is stacked, wherein a transparent interlayer 102 is arranged between adjacent waveguide sheets 101, and the refractive index of the transparent interlayer 102 is less than the refractive index of the adjacent waveguide sheets 101; each waveguide sheet 101 includes a coupling-in region and a coupling-out region, and the coupling-in region (referred to as the first coupling-in region 1011) of each waveguide sheet 101 is overlapped or spliced ​​in the first direction X to form the waveguide component 100. The projections of the out-coupling regions (referred to as the first out-coupling regions 1012) of the waveguide sheets 101 in the first direction X partially overlap to form an out-coupling region (referred to as the second out-coupling region 104) of the waveguide assembly 100. The pupil expansion directions S of the waveguide sheets 101 are different and have an angle. The pupil expansion regions 1015 of the waveguide sheets 101 can be continuously spliced ​​to cover the out-coupling region (referred to as the second out-coupling region 104) of the waveguide assembly 100. The first direction X is a direction perpendicular to the surface of the waveguide sheet 101.

[0025] Each waveguide sheet 101 itself can realize one-dimensional pupil expansion in the pupil expansion direction S, and multiple waveguide sheets 101 are superimposed in the first direction X, and it is ensured that there is an angle between the pupil expansion directions S of each waveguide sheet 101, and a transparent interlayer 102 is provided between adjacent waveguide sheets 101, so as to form a waveguide component 100 capable of two-dimensional pupil expansion. The thickness of the transparent interlayer 102 is generally greater than 1 μm, and the refractive index of the transparent interlayer 102 between adjacent waveguide sheets 101 needs to be small enough so that the light beam can be totally reflected in the waveguide sheet 101. Exemplarily, the transparent interlayer includes but is not limited to air, glass, glue, resin or silicone.

[0026] like Figures 1 to 3 As shown, the waveguide component 100 includes a waveguide sheet A 101a, a waveguide sheet B 101b and a transparent interlayer 102. The waveguide sheet A 101a includes a first coupling-in region A 1011a, a first coupling-out region A 1012a and a pupil dilation region A 1015a, and the waveguide sheet B 101b includes a first coupling-in region B 1011b, a first coupling-out region B 1012b and a pupil dilation region B 1015b. The pupil dilation direction of the waveguide sheet A 101a is S1, and the pupil dilation direction of the waveguide sheet B 101b is S2. Figure 2 The waveguide plate A 101a and the waveguide plate B 101b in the middle state are superimposed to Figure 1 After the shape in the figure, the waveguide component 100 can be obtained as Figure 3 Top view shown.

[0027] In the first direction X, the projections of the first coupling region A 1011a and the first coupling region B 1011b overlap to form the second coupling region 103, which is an example. In other examples, partial overlap is also possible (i.e., the second coupling region 103 is formed by splicing the projections of the first coupling region A 1011a and the first coupling region B 1011b). The projections of the first coupling region A 1012a and the first coupling region B 1012b partially overlap to form the second coupling region 104. The projections of the pupil dilation region A 1015a and the pupil dilation region B 1015b are spliced ​​to form the two-dimensional pupil dilation region of the waveguide component 100, wherein the two-dimensional pupil dilation region after splicing can be used as the user's field of view.

[0028] In other embodiments, three waveguide sheets and two transparent interlayers may be used to form the waveguide assembly 100 .

[0029] Specifically, Figure 4 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, Figure 5 is an exploded top view of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, Figure 6 is a top view of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, combined with Figure 4 , Figure 5 and Figure 6 As shown, Figure 5 The three waveguide sheets 101 in the stack can form Figure 6 The waveguide assembly 100 shown includes three waveguide plates 101 , and the pupil expansion directions S of the three waveguide plates 101 are different.

[0030] like Figures 4 to 6As shown, the waveguide component 100 includes waveguide sheet A 101a, a first transparent interlayer 102a, waveguide sheet C 101c, a second transparent interlayer 102b and waveguide sheet B 101b in sequence along the first direction X. Among them, waveguide sheet A 101a includes first coupling-in region A 1011a, first coupling-out region A 1012a and pupil dilation region A 1015a, waveguide sheet B 101b includes first coupling-in region B 1011b, first coupling-out region B 1012b and pupil dilation region B 1015b, and waveguide sheet C 101c includes first coupling-in region C 1011c, first coupling-out region C 1012c and pupil dilation region C 1015c. The pupil dilation direction of waveguide sheet A 101a is S1, the pupil dilation direction of waveguide sheet B 101b is S2, and the pupil dilation direction of waveguide sheet C 101c is S3. Figure 5 The waveguide plate A 101a, waveguide plate B 101b and waveguide plate C 101c in the middle state are superimposed to Figure 4 After the shape in the figure, the waveguide component 100 can be obtained as Figure 6 Top view shown.

[0031] In the first direction X, the projections of the first coupling region A 1011a, the first coupling region B 1011b, and the first coupling region C 1011c overlap to form the second coupling region 103, which is an example. In other examples, they may also partially overlap (i.e., the second coupling region 103 is formed by splicing the projections of the first coupling region A 1011a, the first coupling region B 1011b, and the first coupling region C 1011c). The projections of the first coupling region A 1012a, the first coupling region B 1012b, and the second coupling region C 1012c partially overlap to form the second coupling region 104. The projections of the pupil dilation region A 1015a, the pupil dilation region B 1015b, and the pupil dilation region C 1015c are spliced ​​to form the two-dimensional pupil dilation region of the waveguide component 100, wherein the two-dimensional pupil dilation region after the three splicing can be used as the user's field of view.

[0032] It should be noted that the number of waveguide plates 101 used in the waveguide assembly 100 can be designed according to the size of the coupling area of ​​the waveguide plate 101, the size of the pupil expansion area, the spacing between the coupling area and the pupil expansion area, and the actual requirements of the eye movement range. When other parameters are the same, the more waveguide plates 101 there are, the denser the rotation and splicing pupil expansion area is, and the larger the eye movement range is. Conversely, when the number of waveguide plates 101 is smaller, the rotation and splicing range is smaller, and the eye movement range is smaller. And for the same number of waveguide plates, other parameters are the same, the smaller the coupling area of ​​the waveguide plate 101, the smaller the pupil expansion area, the smaller the range that can be rotated and spliced, and the smaller the eye movement range. Conversely, the larger the coupling area of ​​the waveguide plate 101, the larger the pupil expansion area, the larger the range that can be rotated and spliced, and the larger the eye movement range.

[0033] Exemplary, combined Figure 4 , Figure 5 and Figure 6 As shown, assuming that the diameter of the coupled beam is 5 mm, the size of the eye movement range of each waveguide plate 101 along the pupil expansion direction S depends on the size of the first coupling-out region 1012, rather than the width of the central field of view light in the pupil expansion direction. If the width of the central field of view light in the pupil expansion direction is consistent with the diameter of the coupled beam, which is 5 mm, assuming that the rotation angle of waveguide plate A 101a relative to waveguide plate C 101c is 7 degrees, and the rotation angle of waveguide plate B 101b relative to waveguide plate C 101c is 7 degrees, then the eye movement range of the central exit pupil position of the waveguide assembly 100 in the second direction Y can be increased to 13 mm. The second direction Y is parallel to the surface of the waveguide plate, perpendicular to the first direction X, and perpendicular to the third direction Z. The third direction Z is the direction in which the first coupling-in region 1011 in the waveguide plate C 101 points vertically to the first coupling-out region 1012.

[0034] Specifically, taking array waveguide as an example, Figure 7 Schematic diagram of the structure of the coupling-in region and the coupling-out region of the waveguide assembly provided in an embodiment of the present invention, with reference to Figure 7 , assuming that the diameter of the coupled light beam is D, the distance from the center of the coupling area to the center of the coupling area is L1, the exit pupil distance is L2, the horizontal and vertical eye movement ranges are Eh and Ev respectively (excluding the pupil diameter of the human eye 4mm), the diagonal field of view is FOV, the horizontal and vertical ratio of the picture is a / b, the refractive index of the waveguide 101 is n, the horizontal and vertical half field of view angles before the light beam enters the waveguide 101 are FOV_H and FOV_V respectively, and the horizontal and vertical half field of view angles after the light refracts into the waveguide 101 are FOV_H_n and FOV_V_n respectively, the acute angle between the beam splitting surface of the array waveguide and the surface of the waveguide 101 is δ, the relative rotation angle between the waveguide A 101a and the waveguide C 101c is θ, the relative rotation angle between the waveguide B 101b and the waveguide C 101c is θ, and the number of waveguide layers is N. In order to make the rotating pupil expansion direction light beam continuous and realize the corresponding eye movement range, it is necessary to meet the following requirements: , , , , , .

[0035] For example, the diameter D of the coupled beam is 4.5 mm, the distance L1 from the center of the second coupling-in region 103 to the center of the second coupling-out region 104 is 32 mm, the pupil distance L2 is 18 mm, the horizontal and vertical eye movement ranges Eh and Ev are 6 mm and 4 mm respectively (excluding the pupil diameter of the human eye of 4 mm), the diagonal field of view FOV is 30°, the horizontal and vertical ratio a / b of the picture is 16 / 9, the refractive index n of the waveguide plate 101 is 1.7, and the acute angle δ formed by the beam splitting surface of the array waveguide and the surface of the waveguide plate 101 is 36°. Then, it can be calculated that the light enters the waveguide plate The horizontal half field of view FOV_H before the light enters the waveguide 101 is 13.15°, the vertical half field of view FOV_V before the light enters the waveguide 101 is 7.48°, the horizontal half field of view FOV_H_n after the light refracts into the waveguide 101 is 7.65°, and the vertical half field of view FOV_V_n after the light refracts into the waveguide 101 is 4.32°. In order to ensure the continuity of the light beam in the direction of rotating pupil expansion, the relative rotation angle θ of the waveguide needs to be 7.2°. To achieve the corresponding eye movement range, the number of waveguide layers N ≥ 3.94, that is, at least 4 layers of waveguides 101 are required.

[0036] Furthermore, increasing the diameter D of the coupled light beam can reduce the minimum number of layers of the required waveguide plate 101. For example, if the diameter D is increased to 5.7 mm, only three layers of waveguide plates 101 are needed to achieve the corresponding eye movement range, and if the diameter D is increased to 8 mm, only two layers of waveguide plates 101 are needed to achieve the corresponding eye movement range. In actual design, a reasonable design can be made according to the requirements of the eye movement range and the relevant parameters of a single waveguide plate.

[0037] A two-dimensional pupil expansion optical waveguide device provided in an embodiment of the present invention realizes two-dimensional pupil expansion by rotating and superimposing multiple one-dimensional waveguide sheets. At the same time, the two-dimensional pupil expansion optical waveguide device inherits the advantages of high optical efficiency, low color deviation, high yield, high definition, low cost and design without forward leakage light and external reflected stray light of the one-dimensional waveguide sheets. Compared with the two-dimensional optical waveguide in the prior art, the two-dimensional pupil expansion optical waveguide device provided in an embodiment of the present invention has lower manufacturing difficulty and cost.

[0038] Optionally, each waveguide sheet 101 is an array optical waveguide or a diffraction optical waveguide. The outcoupling region of the array optical waveguide has multiple splitting surfaces, which reflect part of the light beam out of the array optical waveguide, and the light beam that is not reflected continues to be transmitted to the next splitting surface, thereby realizing the outcoupling of the light beam. The diffraction optical waveguide uses a diffraction grating to couple the light beam into and out of the optical waveguide. When each waveguide sheet 101 is a diffraction optical waveguide, in each waveguide sheet 101, the coupling structure in the coupling region has a first grating, and the coupling structure in the outcoupling region has a second grating. The coupling structure and the coupling structure can also be microprisms or metasurface structures. It can be understood that this article mainly uses the array optical waveguide as an example for explanation, and the diffraction optical waveguide can refer to the principle of rotating and splicing multiple one-dimensional waveguides in the array optical waveguide into a two-dimensional waveguide when designing.

[0039] Figure 8 is a schematic diagram of the structure of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, with reference to Figure 8 Optionally, the light source 200 coupled into the coupling region (second coupling region 103 ) of the waveguide component 100 and the human eye 30 into which the light coupled out of the coupling region (second outcoupling region 104 ) of the waveguide component 100 enter are located on the same side of the waveguide component 100 .

[0040] That is, after the light beam emitted by the light source is coupled into the waveguide component 100 from the second coupling-in region 103, it propagates in the waveguide component 100, and finally the light beam is coupled out from the side of the second coupling-out region 104 close to the light source. The waveguide component 100 designed in this way can adapt to a device with a larger space on the side of the human eye 30, and the larger space can accommodate the light source 200.

[0041] refer to Figure 8 When each waveguide plate 101 is an array optical waveguide, in each waveguide plate 101, the coupling structure in the first coupling region 1011 has one or more mutually parallel first splitting surfaces 1013, and the coupling structure in the first coupling region 1012 has a plurality of mutually parallel second splitting surfaces 1014, and the first splitting surfaces 1013 and the second splitting surfaces 1014 are arranged non-parallel.

[0042] When the first beam splitting surface 1013 and the second beam splitting surface 1014 are arranged non-parallel, in order to enable the coupled light to be transmitted from the first beam splitting surface 1013 to the second beam splitting surface 1014 and coupled out from the second beam splitting surface 1014, the first beam splitting surface 1013 and the second beam splitting surface 1014 are arranged relative to each other (such as Figure 8 as shown).

[0043] Fig. 9 is a schematic diagram of the structure of the waveguide provided by an embodiment of the present invention, with reference to Fig. 9The first angle α between the first beam splitting surface 1013 and the two surfaces of the waveguide plate 101 is the same, and the second angle β between the second beam splitting surface 1014 and the two surfaces of the waveguide plate 101 is the same. The first surface 1016 and the second surface 1017 of the waveguide plate 101 are parallel to each other, α=β.

[0044] By setting the first angle α and the second angle β to be the same, preferably, setting α=β=45°, the light source 200 and the human eye 30 are located on the same side, and the light from the light source 200 is incident on the first beam splitting surface 1013 at an angle of 45° and can be horizontally transmitted to the second beam splitting surface 1014, and can be emitted from the second beam splitting surface 1014 at 45°, thereby simplifying the optical path.

[0045] In this embodiment, when adjacent waveguide plates 101 are attached, parallelism needs to be ensured to avoid ghosting of the out-coupled image.

[0046] Fig.10 is a schematic diagram of the structure of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, with reference to Fig.10 , the coupling structure and the coupling structure of the waveguide plate 101 cannot be made in one piece, so that the light of the same field of view will have an angle deviation after being coupled out of different layers of waveguides, resulting in the problem of ghosting. Therefore, when the human eye 30 and the light source 200 are located on the same side of the waveguide component, the angle tolerance requirements of the coupling and coupling splitting surfaces of the waveguide plate and the parallelism requirements of the multi-layer bonding are very strict, and it is necessary to ensure that Figure 8 The parallelism shown in FIG. 1 is to obtain a waveguide assembly 100 with better imaging quality and avoid Fig.10 The poor parallelism of the two waveguides results in poor imaging quality.

[0047] Optionally, Fig.11 is a schematic diagram of the structure of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, with reference to Fig.11 , the light source 200 coupled in by the coupling region (second coupling region 103) of the waveguide component 100 and the light coupled out by the coupling region (second coupling region 104) of the waveguide component 100 enter the human eye 30, which is located on the opposite side of the waveguide component 100. In this way, the human eye 30 and the light source 200 are located on both sides of the waveguide component 100. The waveguide component 100 designed in this way can adapt to a device with a larger space on the side away from the human eye 30, and the larger space can accommodate the light source 200.

[0048] Continue to refer Fig.11When each waveguide plate 101 is an array optical waveguide, in each waveguide plate 101, the coupling structure in the first coupling region 1011 has one or more first splitting surfaces 1013 parallel to each other, and the coupling structure in the first coupling region 1012 has a plurality of second splitting surfaces 1014 parallel to each other, and the first splitting surfaces 1013 are arranged in parallel with the second splitting surfaces 1014.

[0049] refer to Fig.11 When the first splitting surface 1013 and the second splitting surface 1014 are arranged in parallel, the light beam emitted by the light source 200 is coupled into the waveguide plate 101, propagates in the waveguide plate 101, and finally the light beam is coupled out from the side of the waveguide plate 101 away from the light source 200.

[0050] It should be noted that Fig.12 is a schematic structural diagram of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, such as Fig.12 As shown, when the human eye 30 and the light source 200 are located on the opposite sides of the waveguide assembly, the first splitter surface 1013 and the second splitter surface 1014 are arranged in parallel, and the coupling structure and the coupling structure of the waveguide plate 101 can be made in a single integrated manner, thereby ensuring that the first splitter surface 1013 and the second splitter surface 1014 have the same angle and high precision. In this way, there is no need to control the parallelism of the multi-layer bonding of the waveguide plates. Even if there is a large parallelism error in the bonding of each layer of the waveguide plates, it can be ensured that the angles of the light in the same field of view are consistent after coupling out of different layers of waveguides. It can also avoid the situation where the human eye 30 and the light source 200 are located on the same side of the waveguide assembly (such as Fig.10 In addition, compared with the case where the human eye 30 and the light source 200 are located on the same side of the waveguide assembly, the angle tolerance requirements for the coupling-in and coupling-out splitter surfaces of the waveguide plate and the parallelism requirements for the multi-layer bonding are very strict. Fig.12 The examples in the illustrations reduce the difficulty of the process and ensure clarity.

[0051] Fig.13 is a schematic diagram of the structure of another two-dimensional pupil expansion optical waveguide device provided by an embodiment of the present invention, with reference to Fig.13 When each waveguide plate 101 is an array optical waveguide, in each waveguide plate 101, the coupling structure in the first coupling region 1011 has one or more mutually parallel first splitting surfaces 1013, and the coupling structure in the first coupling region 1012 has multiple mutually parallel second splitting surfaces 1014, and the first splitting surfaces 1013 are arranged in parallel with the second splitting surfaces 1014; the two-dimensional pupil expansion optical waveguide device also includes: a reflector 300 and a 1 / 4 wave plate 400, the 1 / 4 wave plate 400 is located on a side surface of the second coupling region 103 in the waveguide component 100 away from the light source 200, the reflector 300 is located on a side surface of the 1 / 4 wave plate 400 away from the waveguide component 100, and the light source 200 is a linearly polarized light source.

[0052] refer to Fig.13 , the first beam splitter surface 1013 has a higher transmittance for the linearly polarized light beam emitted by the light source 200, and has a higher reflectance for the light beam whose polarization direction is perpendicular to the linearly polarized light beam. Exemplarily, the linearly polarized light source emits P-polarized light, and the first beam splitter surface 1013 has a higher transmittance for the P-polarized light and a higher reflectance for the S-polarized light, so the P-polarized light will be transmitted through the first beam splitter surface 1013, and then the P-polarized light will pass through the 1 / 4 wave plate 400 to become circularly polarized light, and the circularly polarized light will be reflected by the reflector 300 and pass through the 1 / 4 wave plate 400 again to become S-polarized light, and the S-polarized light will be reflected by the first beam splitter surface 1013, and then the S-polarized light will propagate in the waveguide plate 101, and finally be coupled out from the first outcoupling region 1012. Thus, the two-dimensional pupil expansion optical waveguide device can achieve that the coupled-in light and the coupled-out light are located on the same side of the waveguide component 100, the light source 200 and the human eye 30 are located on the same side of the waveguide component 100, while the first splitter surface 1013 and the second splitter surface 1014 are parallel, and the energy loss in the light propagation process can be reduced, so as to meet the application of the waveguide device in different scenarios.

[0053] Fig.14 is a schematic diagram of the positions of the coupling-in region and the coupling-out region of a waveguide component provided by an embodiment of the present invention, combined with Figure 3 , Figure 6 and Fig.14 As shown, the center of the outcoupling region (the second outcoupling region 104 ) in the waveguide component 100 corresponds to the position of the human eye, and the center of the incoupling region (the second incoupling region 103 ) in the waveguide component 100 is higher than the position of the human eye.

[0054] It is understandable that the current waveguide component 100 is generally used in a virtual display device or an enhanced display device. For example, it will be used in AR glasses. If the light source 200 is set on the same side as the human eye 30, then the light source 200 will generally be set on the temple. With this arrangement, the second coupling region 103 of the waveguide component 100 needs to be aligned with the light source 200, and the second coupling region 104 needs to be aligned with the human eye 30. Furthermore, the line connecting the center of the second coupling region 103 with respect to the center of the second coupling region 104 and the line connecting the two eyes has an angle and is not parallel. Since the temple is generally higher than the human eye 30, furthermore, the center of the second coupling region 103 is generally higher than the center of the second coupling region 104. Therefore, in order to conform to the form of AR glasses, the waveguide component 100 can be rotated, and the relative positions of the rotated second coupling region 103 and the second coupling region 104 are as shown in FIG. Fig.14 As shown, the display screen does not rotate with the rotation of the waveguide assembly 100.

[0055] In other embodiments, if it is required that the line connecting the center of the second coupling-in region 103 and the center of the second coupling-out region 104 is not parallel to the binocular line, the actual design requirement can be met by rotating the waveguide component 100 .

[0056] Based on the same inventive concept, an embodiment of the present invention further provides a binocular display system, comprising: a light source module and two sets of two-dimensional pupil expansion optical waveguide devices provided by any embodiment of the present invention. Since the binocular display system includes the two-dimensional pupil expansion optical waveguide device provided by any embodiment of the present invention, the binocular display system has the same or corresponding beneficial effects as the two-dimensional pupil expansion optical waveguide.

[0057] Among them, the two sets of two-dimensional pupil expansion optical waveguide devices can be spliced ​​according to actual needs, such as using two light sources to be placed on the inner side of the temples (the light source is on the same side as the human eye), or on the outer side of the temples (the light source is on the opposite side of the human eye), or using one light source to be placed on the outer side of the middle of the glasses (such as Fig.15 As shown in the figure). Among them, the inner side and the outer side are relative to the space formed by the glasses and the face. The side closer to the face is the inner side of the glasses, and the side farther from the face is the outer side of the glasses.

[0058] Fig.15 is a schematic diagram of a binocular display system provided by an embodiment of the present invention, with reference to Fig.15 The light source module includes a first light source 600, and two groups of two-dimensional pupil expansion optical waveguide devices 500 are spliced ​​to form a binocular display system, wherein the coupling regions of the two groups of two-dimensional pupil expansion optical waveguide devices 500 are spliced ​​to form the same second coupling region 103, and the first light source 600 is used to provide light to the same second coupling region 103. The light is coupled into the two groups of two-dimensional pupil expansion optical waveguide devices 500 from the second coupling region 103, and finally coupled out from the two groups of two-dimensional pupil expansion optical waveguide devices 500, respectively, and the two groups of two-dimensional pupil expansion optical waveguide devices 500 correspond to the left eye and the right eye, respectively. The two coupling regions share a light source module to reduce the cost of the binocular display system. In this embodiment, a light source module is used. Fig.11 The waveguide device shown.

[0059] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A two-dimensional pupil expansion optical waveguide device, characterized in that: include: Waveguide components; The waveguide assembly comprises: at least two waveguide sheets, each of which is stacked, wherein a transparent interlayer is arranged between adjacent waveguide sheets, and the refractive index of the transparent interlayer is smaller than the refractive index of the adjacent waveguide sheets; Each of the waveguide sheets comprises an in-coupling region and an out-coupling region, and the projections of the in-coupling regions of each of the waveguide sheets in a first direction overlap or are spliced ​​to form the in-coupling region of the waveguide assembly; the projections of the out-coupling regions of each of the waveguide sheets in the first direction partially overlap to form the out-coupling region of the waveguide assembly, the pupil expansion directions of each of the waveguide sheets are different and have an angle, and the pupil expansion regions of each of the waveguide sheets can be continuously spliced ​​to cover the out-coupling region of the waveguide assembly; the first direction is a direction perpendicular to the surface of the waveguide sheets.

2. The two-dimensional pupil expansion optical waveguide device according to claim 1, characterized in that: Each of the waveguide plates is an array optical waveguide or a diffraction optical waveguide.

3. The two-dimensional pupil expansion optical waveguide device according to claim 1, characterized in that: The light source coupled into the coupling-in region of the waveguide component and the human eye into which the light coupled out of the coupling-out region of the waveguide component enter are located on the same side of the waveguide component.

4. The two-dimensional pupil expansion optical waveguide device according to claim 1, characterized in that: The light source coupled into the coupling-in region of the waveguide component and the human eye into which the light coupled out of the coupling-out region of the waveguide component enter are located on the opposite side of the waveguide component.

5. The two-dimensional pupil expansion optical waveguide device according to claim 3, characterized in that: When each of the waveguide plates is an array optical waveguide, in each of the waveguide plates, the coupling structure in the coupling-in area has one or more first splitting surfaces parallel to each other, and the coupling-out structure in the coupling-out area has multiple second splitting surfaces parallel to each other, and the first splitting surfaces are non-parallel to the second splitting surfaces.

6. The two-dimensional pupil expansion optical waveguide device according to claim 4, characterized in that: When each of the waveguide plates is an array optical waveguide, in each of the waveguide plates, the coupling structure in the coupling-in area has one or more first splitting surfaces parallel to each other, and the coupling-out structure in the coupling-out area has multiple second splitting surfaces parallel to each other, and the first splitting surfaces are arranged in parallel with the second splitting surfaces.

7. The two-dimensional pupil expansion optical waveguide device according to claim 3, characterized in that: When each of the waveguide sheets is an array optical waveguide, in each of the waveguide sheets, the coupling structure in the coupling region has one or more first beam splitting surfaces parallel to each other, and the outcoupling structure in the outcoupling region has a plurality of second beam splitting surfaces parallel to each other, and the first beam splitting surfaces are arranged in parallel with the second beam splitting surfaces; The two-dimensional pupil expansion optical waveguide device also includes: a reflector and a 1 / 4 wave plate, wherein the 1 / 4 wave plate is located on a side surface of the coupling region in the waveguide component away from the light source, and the reflector is located on a side surface of the 1 / 4 wave plate away from the waveguide component, and the light source is a linearly polarized light source.

8. The two-dimensional pupil expansion optical waveguide device according to any one of claims 5 to 7, characterized in that: The first angle between the first splitting surface and the two surfaces of the waveguide plate is the same, the second angle between the second splitting surface and the two surfaces of the waveguide plate is the same, and the first angle is the same as the second angle.

9. The two-dimensional pupil expansion optical waveguide device according to claim 3, characterized in that: When each of the waveguide plates is a diffractive optical waveguide, in each of the waveguide plates, the coupling-in structure in the coupling-in region has a first grating, and the coupling-out structure in the coupling-out region has a second grating.

10. The two-dimensional pupil expansion optical waveguide device according to claim 1, characterized in that: The center of the out-coupling region in the waveguide component corresponds to the position of the human eye, and the center of the in-coupling region in the waveguide component is higher than the position of the human eye.

11. A binocular display system, characterized in that: include: A light source module and two groups of two-dimensional pupil expansion optical waveguide devices as described in any one of claims 1 to 10.

12. The binocular display system according to claim 11, characterized in that: The light source module includes a first light source, and two groups of the two-dimensional pupil expansion optical waveguide devices are spliced ​​to form the binocular display system, wherein the coupling areas of the two groups of the two-dimensional pupil expansion optical waveguide devices are spliced ​​to form the same coupling area, and the first light source is used to provide light to the same coupling area.

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