Pupil dilation device and AR equipment

Abstract

The present invention discloses a pupil expansion device and an AR device, belonging to the field of optical display technology. The pupil expansion device includes a first pupil expansion unit, a second pupil expansion unit and a third pupil expansion unit. The first pupil expansion unit includes N first beam splitters arranged along a first direction, and the first beam splitter is arranged at a first angle with the first direction; the second pupil expansion unit includes M second beam splitters arranged along a first direction, and the second beam splitter is arranged at a second angle with the first direction, the first pupil expansion unit and the second pupil expansion unit are arranged along the first direction, and the exit pupil is arranged between the first pupil expansion unit and the second pupil expansion unit; the third pupil expansion unit includes P third beam splitters arranged along a second direction, and the third beam splitter is arranged at a third angle with the substrate, and the third pupil expansion unit is arranged on one side of the first pupil expansion unit and the second pupil expansion unit along the second direction. The pupil expansion device and the AR device of the present invention have a simple structure, reduce processing difficulty and cost, and improve light energy utilization.

Description

Technical Field

[0001] The present invention relates to the field of optical display technology, and in particular to a pupil expansion device and an AR device. Background Art

[0002] Augmented Reality (AR) technology is a technology that cleverly integrates virtual information with the real world. This head-mounted display using augmented reality technology allows people to view the surrounding environment while projecting virtual images into the human eye. It has important significance in the fields of military, industry, entertainment, medical care, transportation, etc. At present, the main technologies used in the transmissive head-mounted display for augmented reality include: Birdbath, prism, free-form surface and optical waveguide technology. Compared with other technologies, the head-mounted display using optical waveguide technology is smaller in size.

[0003] In the AR system of the prior art, one is to use one-dimensional pupil expansion technology, such as Figure 1 The one-dimensional array optical waveguide 100' is shown, which often cannot meet the requirements of small coupling optical machine volume, large field of view, large exit pupil distance, and large eye box at the same time, and cannot meet people's daily needs of wearing AR glasses. Another way is to use two-dimensional exit pupil expansion technology, such as Figure 2 and Figure 3 The two-dimensional array optical waveguide 100" is shown, including an upper structure waveguide plate 101" and a lower structure waveguide plate 102". The main difference between the two-dimensional array optical waveguide 100" and the one-dimensional array optical waveguide 100' is the upper structure waveguide plate 101", while the lower structure waveguide plate 102" is similar to the one-dimensional array optical waveguide 100'. Specifically, the upper structure waveguide plate 101" mainly includes two mutually parallel surfaces, and a series of parallel beam splitters 103" are embedded between the two surfaces.

[0004] When using, Figure 4As shown, the exit pupil 200″ of the coupling optical machine is located on one side of the upper structure waveguide 101″, which describes the light path of the parallel light emitted from the exit pupil 200″ entering the human eye. The figure only shows the farthest light 302″ at the edge of the eye box and the closest light 302″ at the edge of the eye box, and the other light rays are between these two light rays; the above process can be equivalent to that the exit pupil 200″ of the coupling optical machine passes through a series of beam splitters 103″ to form a series of virtual images, each of these virtual images is equivalent to a replica of the exit pupil 200″, that is, a replica pupil 303″, and the angle and width of the light emitted by the replica pupil 303″ are exactly the same as those of the exit pupil 200″ of the coupling optical machine. This series of replica pupils 303″ emit light together, which passes through the equivalent lower structure waveguide 102″ and then enters the human eye, thereby realizing horizontal pupil expansion. The main function of this structure is to deflect the light beam emitted by the coupled optical machine, and each beam splitter 103" will form an image of the exit pupil 200". By expanding the pupil twice horizontally and vertically, a larger exit pupil distance and eye box and a smaller volume of the coupled optical machine can be achieved under a large field of view. Through the above analysis, it can be found that the upper structure waveguide 101" uses 11 beam splitters 103" to replicate the exit pupil 200" of the coupled optical machine 11 times, and the 11 replicated pupils 303" emit light at the same time, thereby increasing the range of movement of the human eye.

[0005] In practice, in order to achieve a good imaging effect, this series of beam splitters 103" needs to be optically processed and then glued together, and its parallelism and density have very high requirements, which not only causes energy loss after multiple splitting and glue layers, but also increases the difficulty of processing and makes the cost higher. The structure and processing technology of the two-dimensional array optical waveguide 100" will be more complicated, resulting in increased costs. In addition, if Figure 4 As shown, taking the distal light 302" at the edge of the eye box as an example, it needs to pass through three to four beam splitters 103" when reaching the eye box. The multi-layer beam splitters 103" used in the horizontal pupil expansion will reduce the utilization rate of light energy, thereby reducing the brightness of the system output. Summary of the invention

[0006] An object of the present invention is to provide a pupil expansion device that simplifies the structure, reduces the difficulty and cost of processing, and improves the utilization rate of light energy.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A pupil expansion device comprises two substrates arranged at an interval, wherein:

[0009] A first pupil expansion unit, comprising N first beam splitters arranged along a first direction, wherein the first beam splitters are arranged at a first angle with the first direction, wherein N≥2;

[0010] A second pupil expansion unit, comprising M second beam splitters arranged along the first direction, and the second beam splitters are arranged at a second angle to the first direction, wherein M≥2, the first pupil expansion unit and the second pupil expansion unit are arranged along the first direction, and an exit pupil is arranged between the first pupil expansion unit and the second pupil expansion unit;

[0011] A third pupil expansion unit comprises P third beam splitters arranged along a second direction, and the third beam splitters are arranged at a third angle with the substrate, wherein P≥2, and the third pupil expansion unit is arranged on one side of the first pupil expansion unit and the second pupil expansion unit along the second direction.

[0012] Optionally, N of the first beam splitters are arranged in parallel and spaced apart, M of the second beam splitters are arranged in parallel and spaced apart, and P of the third beam splitters are arranged in parallel and spaced apart.

[0013] Optionally, the first angle is α, and the second angle is β, wherein 0<α<90°, 0<β<90°.

[0014] Optionally, the first angle is equal to the second angle, and the exit pupil is placed along the first direction; or

[0015] The first angle is not equal to the second angle, and the exit pupil is set at a fourth angle with the first direction, the fourth angle is γ, wherein γ=90°-α-β, when the fourth angle is a positive number, the inclination direction of the exit pupil is opposite to that of the first beam splitter, and when the fourth angle is a negative number, the inclination direction of the exit pupil is the same as that of the first beam splitter.

[0016] Optionally, the first pupil expansion unit includes a plurality of first glass blocks bonded in sequence along a first direction, and bonding surfaces of two adjacent first glass blocks form the first beam splitter;

[0017] The second pupil expansion unit includes a plurality of second glass blocks bonded in sequence along a first direction, and bonding surfaces of two adjacent second glass blocks form the second beam splitter;

[0018] The third pupil expansion unit includes a plurality of third glass blocks bonded in sequence along the second direction, and the bonding surfaces of two adjacent third glass blocks form the third beam splitter.

[0019] Optionally, a thickness of the first glass block along the first direction is the same as a thickness of the second glass block along the first direction.

[0020] Optionally, ends of the first glass block and the second glass block are bonded to the third glass block at an end of the third pupil expansion unit along the second direction.

[0021] Optionally, the pupil expansion device further includes a fourth glass block, and the first glass block and the second glass block facing each other are respectively bonded to two sides of the fourth glass block.

[0022] Another object of the present invention is to provide an AR device with a simplified structure, reduced processing difficulty and cost, and improved light energy utilization.

[0023] To achieve this object, the present invention adopts the following technical solutions:

[0024] An AR device, characterized by comprising the above-mentioned pupil expansion device.

[0025] Optionally, the first direction is a horizontal direction, the second direction is a vertical direction, and the third pupil expansion unit is arranged at a lower side of the first pupil expansion unit and the second pupil expansion unit.

[0026] Beneficial effects of the present invention:

[0027] The present invention provides a pupil expansion device, which reduces the total number of first beam splitters and second beam splitters used by setting a first pupil expansion unit, a second pupil expansion unit, a third pupil expansion unit and the positional relationship between the three, as well as the exit pupil position, and can achieve the same or greater number of second copy pupils and third copy pupils. Compared with the prior art, it can achieve the same effect or increase the effect, reduce the manufacturing difficulty, reduce the cost, and reduce the volume at the same time, making it more convenient to use; improve the utilization rate of light energy and reduce unnecessary energy loss.

[0028] The present invention provides an AR device, which adopts the above-mentioned pupil expansion device. The first pupil expansion unit and the second pupil expansion unit increase the number of second replica pupils along the first direction, thereby increasing the viewing angle in the first direction; the third pupil expansion unit increases the number of third replica pupils along the second direction, thereby increasing the viewing angle in the second direction, thereby increasing the viewing angles in both directions; while reducing the total number of first beam splitters and second beam splitters used, the same or more numbers of second replica pupils and third replica pupils can be achieved, that is, the same effect can be achieved or the effect can be increased, the difficulty of production is reduced, the cost is reduced, and the volume is reduced, which is more convenient to use; the utilization rate of light energy is improved, and unnecessary energy loss is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of a one-dimensional array optical waveguide in the prior art;

[0030] Figure 2 It is a schematic diagram of the structure of a two-dimensional array optical waveguide in the prior art;

[0031] Figure 3 is an exploded diagram of a two-dimensional array optical waveguide in the prior art;

[0032] Figure 4 It is a light path diagram of a two-dimensional array optical waveguide in the prior art;

[0033] Figure 5 is a schematic structural diagram of a pupil expansion device provided in a specific embodiment of the present invention;

[0034] Figure 6 is an optical path diagram of a pupil expansion device provided by a specific embodiment of the present invention;

[0035] Figure 7 is a light path diagram of a top view of a first pupil expansion unit provided in a specific embodiment of the present invention;

[0036] Figure 8 It is a light path diagram of the front view of the first pupil expansion unit provided in a specific embodiment of the present invention.

[0037] In the figure:

[0038] 100', one-dimensional array optical waveguide;

[0039] 100", two-dimensional array optical waveguide; 101", upper structure waveguide; 102", lower structure waveguide; 103", beam splitter; 104", glass stack; 200", exit pupil; 301", near-end light at the edge of the eye box; 302", far-end light at the edge of the eye box; 303", replica pupil;

[0040] 100, exit pupil;

[0041] 1. a first pupil expansion unit; 11. a first beam splitter; 12. a first glass stack;

[0042] 2. a second pupil expansion unit; 21. a second beam splitter; 22. a second glass stack;

[0043] 3. a third pupil expansion unit; 31. a third beam splitter; 32. a third glass stack;

[0044] 4. Substrate;

[0045] 5. The fourth glass block;

[0046] 6. Auxiliary glass stacking;

[0047] 71. First duplicate pupil; 72. Second duplicate pupil; 73. Near-end ray at the edge of the eye box; 74. Far-end ray at the edge of the eye box. DETAILED DESCRIPTION

[0048] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] This embodiment provides a pupil expansion device, which includes two substrates 4 arranged at an interval, and a first pupil expansion unit 1, a second pupil expansion unit 2 and a third pupil expansion unit 3 are arranged between the two substrates 4; Figure 5 As shown, the first pupil expansion unit 1 includes N first beam splitters 11 arranged along the first direction, and the first beam splitter 11 is arranged at a first angle with the first direction, wherein N≥2; the second pupil expansion unit 2 includes M second beam splitters 21 arranged along the first direction, and the second beam splitter 21 is arranged at a second angle with the first direction, wherein M≥2, the first pupil expansion unit 1 and the second pupil expansion unit 2 are arranged along the first direction, and the exit pupil 100 is arranged between the first pupil expansion unit 1 and the second pupil expansion unit 2; the third pupil expansion unit 3 includes P third beam splitters 31 arranged along the second direction, and the third beam splitter 31 is arranged at a third angle with the substrate 4, wherein M≥2, and the third pupil expansion unit 3 is arranged on one side of the first pupil expansion unit 1 and the second pupil expansion unit 2 along the second direction. In this embodiment, the first direction is the x direction, and the second direction is the y direction. Preferably, the second direction is perpendicular to the first direction.

[0052] By setting the exit pupil 100 between the first pupil expansion unit 1 and the second pupil expansion unit 2, and setting the positional relationship between the first pupil expansion unit 1, the second pupil expansion unit 2 and the third pupil expansion unit 3, the parallel light emitted from the exit pupil 100 passes through the first pupil expansion unit 1, the second pupil expansion unit 2 and the third pupil expansion unit 3 in sequence, and enters the human eye after completing three pupil expansions. Specifically, the N first beam splitters 11 of the first pupil expansion unit 1 can perform the first pupil expansion on the exit pupil 100 to form N first replica pupils 71, the M second beam splitters 21 of the second pupil expansion unit 2 can perform the second pupil expansion on the light beam of the first pupil expansion to form N×M second replica pupils 72, and the P third beam splitters 31 of the third pupil expansion unit 3 can perform the third pupil expansion on the replica pupil of the second pupil expansion to form N×M×P third replica pupils. The first pupil expansion unit 1 and the second pupil expansion unit 2 increase the number of the second replica pupils 72 along the first direction, thereby increasing the viewing angle in the first direction; the third pupil expansion unit 3 increases the number of the third replica pupils along the second direction, thereby increasing the viewing angle in the second direction.

[0053] In this embodiment, Figure 6 As shown, N=2, M=6 are used as an example for exemplary description. The exit pupil 100 of the coupling optical machine forms two first replica pupils 71 after the first pupil expansion unit, and these two first replica pupils 71 will form 2×6 second replica pupils 72 after the second pupil expansion unit. The total number of first beam splitters 11 and second beam splitters 21 used is 8. Compared with the prior art that uses 11 beam splitters to form 11 replica pupils, the total number of first beam splitters 11 and second beam splitters 21 used is reduced, and the same or more number of second replica pupils 72 can be achieved, that is, the same effect can be achieved or the effect can be increased, the difficulty of production is reduced, the cost is reduced, and the volume is reduced, which is more convenient to use; due to the reduction in the number of first beam splitters 11 and second beam splitters 21, as shown in FIG. Figure 6 As shown, taking the distal light 74 at the edge of the eye box as an example, it needs to pass through two second beam splitters 21 when reaching the eye box. Reducing the use of the second beam splitters 21 reduces the number of light rays passing through the second beam splitters 21, thereby improving the utilization rate of light energy and reducing unnecessary energy loss.

[0054] Specifically, the coupling optical machine can be installed on the pupil expansion device using existing means without limitation.

[0055] Optionally, N first beam splitters 11 are arranged in parallel and spaced apart, M second beam splitters 21 are arranged in parallel and spaced apart, P third beam splitters 31 are arranged in parallel and spaced apart, and the first beam splitter 11, the second beam splitter 21 and the third beam splitter 31 are arranged in parallel to avoid ghost images in the displayed image.

[0056] like Figure 7 and Figure 8FIG. 1 shows the transmission path of light in the first pupil expansion unit 1 . Figure 7 is a light path diagram of light transmitted from one end to the other end in the first pupil expansion unit 1, Figure 8 is a route map of light transmitted from one end to the other end on the surface of the first pupil expansion unit 1, wherein the path length of the light in the first pupil expansion unit 1 is 2L, the path length of the light on the surface of the substrate 4 of the first pupil expansion unit 1 is D, and the incident angle of the light is A. From the geometric relationship in the figure, it can be seen that: D = 2L × sinA; it can be understood that the first pupil expansion unit 1 with a length of D has an equivalent length or expanded length of D / sinA for the light with an incident angle of A, so for the beam splitter 102' with an interval of d, for the light with an incident angle of A, the equivalent interval or expanded interval is d / sinA. According to the above light transmission principle, the first beam splitter 11 is arranged at intervals, which can increase the exit pupil distance; similarly, the second beam splitter 21 and the third beam splitter 31 are arranged at intervals, which can increase the exit pupil distance.

[0057] Specifically, the first angle and the second angle can be set according to the position and angle of the exit pupil. When it is used for AR glasses, the temples and temple positions of corresponding shapes can be set. Optionally, the first angle is α and the second angle is β, wherein 0<α<90°, 0<β<90°, so that the first beam splitter 11 and the second beam splitter are tilted in the same direction, which is convenient for manufacturing. Optionally, the third angle ranges from 20° to 30°.

[0058] Optionally, the first angle and the second angle may be equal or unequal. In this embodiment, the first angle is equal to the second angle, so that the first beam splitter 11 and the second beam splitter 21 are set at the same inclination angle, reducing the manufacturing standards and reducing the manufacturing difficulty; and the exit pupil 100 is placed along the first direction, ensuring that the parallel light emitted by each second replica pupil 72 is consistent with the exit pupil 100, and the parallel light emitted by the second replica pupil 72 enters the human eye after passing through the third pupil expansion unit 3, ensuring that the parallel light emitted by the second replica pupil 72 entering the human eye is consistent with the parallel light emitted by the exit pupil 100.

[0059] In other embodiments, the first angle and the second angle may also be unequal. Specifically, the exit pupil 100 is set at a fourth angle with the first direction, and the fourth angle is γ, wherein γ=90°-α-β. When the fourth angle is a positive number, the exit pupil 100 is tilted in the opposite direction to the first beam splitter 11. When the fourth angle is a negative number, the exit pupil 100 is tilted in the same direction as the first beam splitter 11, thereby ensuring that the parallel light emitted by each second replica pupil 72 is consistent with the exit pupil 100. The parallel light emitted by the second replica pupil 72 enters the human eye after passing through the third pupil expansion unit 3, thereby ensuring that the parallel light emitted by the second replica pupil 72 entering the human eye is consistent with the parallel light emitted by the exit pupil 100.

[0060] Optionally, the first pupil expansion unit 1 includes a plurality of first glass blocks 12 sequentially bonded along a first direction, and the bonding surfaces of two adjacent first glass blocks 12 form a first beam splitter 11; the second pupil expansion unit 2 includes a plurality of second glass blocks 22 sequentially bonded along a first direction, and the bonding surfaces of two adjacent second glass blocks 22 form a second beam splitter 21; the third pupil expansion unit 3 includes a plurality of third glass blocks 32 sequentially bonded along a second direction, and the bonding surfaces of two adjacent third glass blocks 32 form a third beam splitter 31, and the structure is simple. Specifically, the first glass block 12, the second glass block 22, and the third glass block 32 need to be coated before being glued. Reducing the number of beam splitters used will reduce the number of glass blocks used, and reduce the difficulty of production; since the glue layer generated by gluing will also reduce the utilization rate of light energy, reducing the glue layer will improve the utilization rate of light energy. Moreover, in order to obtain good imaging effects, when pursuing an AR display system with a larger field of view, better display effects, and smaller size, the glass stack used in the upper structure waveguide in the prior art is smaller in size, and more beam splitter layers are required. The use of the first beam splitter 11 and the second beam splitter 21 of the present invention will reduce more layers of beam splitters, making the effect more prominent.

[0061] More specifically, the two surfaces of the first glass block 12, the second glass block 22 and the third glass block 32 for gluing are arranged in parallel to ensure that different first beam splitters 11 are parallel to each other, different second beam splitters 21 are parallel to each other and different third beam splitters 31 are parallel to each other to avoid ghost images in the displayed image.

[0062] More specifically, the thicknesses of the first glass blocks 12 are all the same, the thicknesses of the second glass blocks 22 are all the same, and the thicknesses of the third glass blocks 32 are all the same. Optionally, the thickness of the first glass block 12 along the first direction is the same as the thickness of the second glass block 22 along the first direction, and the two can be used interchangeably during production, which is more convenient. Optionally, the thicknesses of the first glass block 12, the second glass block 22, and the third glass block 32 are all the same, and the three can be used interchangeably during production, which is more convenient.

[0063] Optionally, the ends of the first glass block 12 and the second glass block 22 are bonded to the third glass block 32 at the ends of the third pupil expansion unit 3 along the second direction, so that the first pupil expansion unit 1 and the second pupil expansion unit 2 are both connected to the third pupil expansion unit 3, making the structure more stable and reliable.

[0064] Optionally, the pupil expansion device further includes a fourth glass block 5, and the first glass block 12 and the second glass block 22 facing each other are respectively bonded to the two sides of the fourth glass block 5, so that the first pupil expansion unit 1 is connected to the second pupil expansion unit 2, making the structure more stable and reliable. Specifically, the end of the fourth glass block 5 is bonded to the third glass block 32 at the end of the third pupil expansion unit 3 along the second direction, further improving the stability and reliability of the structure.

[0065] Optionally, the pupil expansion device further includes an auxiliary glass stack 6, which is arranged on the periphery of the first pupil expansion unit 1, the second pupil expansion unit 2 and the third pupil expansion unit 3, and is used to assist the pupil expansion device in forming a corresponding shape and improving the aesthetics. In this embodiment, two auxiliary glass stacks 6 are arranged along the first direction on the side of the first pupil expansion unit 1 and the second pupil expansion unit 2 away from each other, so that the cross-sections of the first pupil expansion unit 1 and the second pupil expansion unit 2 are rectangular.

[0066] Optionally, the first glass block 12, the second glass block 22, the third glass block 32, the fourth glass block 5 and the auxiliary glass block 6 can all be made of the same material and bonded by the same method; optionally, the first glass block 12, the second glass block 22, the third glass block 32, the fourth glass block 5 and the auxiliary glass block 6 can also be made of different materials and bonded by different methods; optionally, the first glass block 12, the second glass block 22, the third glass block 32, the fourth glass block 5 and the auxiliary glass block 6 can also be partially made of the same material and another part made of different materials, some of which are bonded by the same method and another part by different methods. The specific manufacturing method can be set according to actual conditions and is not limited.

[0067] The specific comparative examples of the prior art and the present invention are given below.

[0068] like Figure 4 As shown, the upper structure waveguide has 10 glass blocks, the inclination angle of the beam splitter is 45°, the thickness of the substrate 4 is 1.7mm, the glass material is H-BAK5 (n=1.56), the equivalent spacing of the beam splitter in the upper structure waveguide is 5mm, and the diagonal field angle of the image transmitted in the waveguide is 40° (using a 16:9 screen, the horizontal field of view × the vertical field of view is 35.2° × 20.24°). The diameter of the exit pupil 100 L1" is 5.5mm, and after the light is emitted from the upper structure waveguide 101", the equivalent length or the unfolded length L2" in the lower structure waveguide 102" is 18mm, the exit pupil distance L3" is 20mm, the replica pupil diameter L4" is 5.5mm, and the eye box distance L5" is 8.43mm.

[0069] Specifically, Figure 6An equivalent optical path diagram is shown as shown, where the first pupil expansion unit 1 uses one first glass block 12, and the second pupil expansion unit 2 uses five second glass blocks 22, wherein the thickness of the substrate 4 is 1.7 mm, the glass material is H-BAK5 (n=1.56), the inclination angles of the first beam splitter 11 and the second beam splitter 21 are both 45°, the equivalent interval between the first beam splitters 11 is 5 mm, the equivalent interval between the second beam splitters 21 is 10 mm, and the diagonal field of view of the image transmitted in the waveguide is 40° (using a 16:9 screen, the horizontal field of view × the vertical field of view is 35.2°×20.24°). The diameter L1 of the exit pupil 100 is 5.5 mm, after the light is emitted from the second pupil expansion unit 2, the equivalent length or expansion length L2 of the light in the lower structure waveguide is 18 mm, the exit pupil distance L3 is 20 mm, the second replica pupil diameter L4 is 5.5 mm, and the eye box distance L5 is 9.14 mm. Compared with the prior art, this solution reduces the number of glass blocks used, reduces the volume, and increases the eye box distance.

[0070] This embodiment also provides an AR device, which includes the above-mentioned pupil expansion device, wherein the first pupil expansion unit 1 and the second pupil expansion unit 2 increase the number of second replica pupils 72 along the first direction to increase the viewing angle in the first direction; the third pupil expansion unit 3 increases the number of third replica pupils along the second direction to increase the viewing angle in the second direction, thereby increasing the viewing angles in both directions; while reducing the total number of first beam splitters 11 and second beam splitters 21 used, the same or more number of second replica pupils 72 and third replica pupils can be achieved, that is, the same effect can be achieved or the effect can be increased, the manufacturing difficulty is reduced, the cost is reduced, and the volume is reduced, which is more convenient to use; the utilization rate of light energy is improved and unnecessary energy loss is reduced.

[0071] For AR glasses, the horizontal eye box distance is increased to meet more user needs, while the vertical eye box distance can meet user needs when adopting a universal standard. Optionally, the first direction is a horizontal direction, the second direction is a vertical direction, and the third pupil expansion unit 3 is arranged at the lower side of the first pupil expansion unit 1 and the second pupil expansion unit 2. Therefore, the first pupil expansion unit 1 and the second pupil expansion unit 2 are adopted in the horizontal direction, and more replica pupils are obtained with fewer first beam splitters 11 and second beam splitters 21 to meet user needs while reducing the difficulty of production. The third pupil expansion unit 3 can meet the needs by adopting the structure in the prior art, that is, a smaller number of third beam splitters 31, which can meet user needs and reduce the difficulty of production.

[0072] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pupil dilation device, characterized in that: It comprises two substrates (4) arranged at an interval, and between the two substrates (4) is arranged: A first pupil expansion unit (1), comprising N first beam splitters (11) arranged along a first direction, wherein the first beam splitters (11) are arranged at a first angle with the first direction, wherein N≥2; A second pupil expansion unit (2), comprising M second beam splitters (21) arranged along the first direction, and the second beam splitters (21) are arranged at a second angle with the first direction, wherein M≥2, the first pupil expansion unit (1) and the second pupil expansion unit (2) are arranged along the first direction, and an exit pupil (100) is arranged between the first pupil expansion unit (1) and the second pupil expansion unit (2); A third pupil expansion unit (3), comprising P third beam splitters (31) arranged along a second direction, wherein the third beam splitters (31) are arranged at a third angle with the substrate (4), wherein P≥2, and the third pupil expansion unit (3) is arranged on one side of the first pupil expansion unit (1) and the second pupil expansion unit (2) along the second direction, and the second direction is perpendicular to the first direction; The first angle is α, the second angle is β, wherein 0<α<90°, 0<β<90°, and the third angle ranges from 20° to 30°; The first angle is equal to the second angle, and the exit pupil (100) is placed along the first direction; or the first angle is not equal to the second angle, and the exit pupil (100) is arranged at a fourth angle with the first direction, the fourth angle being γ, wherein γ=90°-α-β, and when the fourth angle is a positive number, the exit pupil (100) and the first beam splitter (11) are inclined in opposite directions, and when the fourth angle is a negative number, the exit pupil (100) and the first beam splitter (11) are inclined in the same direction; The parallel light emitted from the exit pupil (100) passes through the first pupil expansion unit (1), the second pupil expansion unit (2) and the third pupil expansion unit (3) in sequence.

2. The pupil expansion device according to claim 1, characterized in that: N of the first beam splitters (11) are arranged in parallel and spaced apart, M of the second beam splitters (21) are arranged in parallel and spaced apart, and P of the third beam splitters (31) are arranged in parallel and spaced apart.

3. The pupil expansion device according to any one of claims 1 to 2, characterized in that: The first pupil expansion unit (1) comprises a plurality of first glass blocks (12) bonded in sequence along a first direction, and the bonding surfaces of two adjacent first glass blocks (12) form the first beam splitter (11); The second pupil expansion unit (2) comprises a plurality of second glass blocks (22) bonded in sequence along a first direction, and the bonding surfaces of two adjacent second glass blocks (22) form the second beam splitter (21); The third pupil expansion unit (3) comprises a plurality of third glass blocks (32) bonded in sequence along a second direction, and the bonding surfaces of two adjacent third glass blocks (32) form the third beam splitter (31).

4. The pupil expansion device according to claim 3, characterized in that: The thickness of the first glass block (12) along the first direction is the same as the thickness of the second glass block (22) along the first direction.

5. The pupil expansion device according to claim 4, characterized in that: The ends of the first glass block (12) and the second glass block (22) are bonded to the third glass block (32) at the end of the third pupil expansion unit (3) along the second direction.

6. The pupil expansion device according to claim 4, characterized in that: The pupil expansion device further comprises a fourth glass block (5), and the first glass block (12) and the second glass block (22) facing each other are respectively bonded to two sides of the fourth glass block (5).

7. An AR device, characterized in that: The invention comprises the pupil dilation device according to any one of claims 1 to 6.

8. The AR device according to claim 7, characterized in that: The first direction is a horizontal direction, the second direction is a vertical direction, and the third pupil expansion unit (3) is arranged at the lower side of the first pupil expansion unit (1) and the second pupil expansion unit (2).

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