Binocular display optical device and display apparatus

Abstract

The invention provides a binocular display optical device and display equipment, and relates to the technical field of waveguides, the binocular display optical device comprises a waveguide plate, the waveguide plate comprises an entrance pupil grating unit, and a left pupil expansion grating unit and a right pupil expansion grating unit which are symmetrically distributed at two sides of the entrance pupil grating unit, the left exit pupil grating unit and the right exit pupil grating unit are symmetrically distributed below the left pupil expanding grating unit and the right pupil expanding grating unit, and the entrance pupil grating unit, the left pupil expanding grating unit, the right pupil expanding grating unit, the left exit pupil grating unit and the right exit pupil grating unit all have only one grating vector; each of the left pupil-expanding grating unit and the right pupil-expanding grating unit comprises a plurality of pupil-expanding sub-areas, and the diffraction efficiency of each pupil-expanding sub-area is gradually increased in the direction away from the entrance pupil grating unit; the waveguide plate has basic flatness, and binocular fusion can be realized by the left eye and the right eye without other extra adjustment. The images of the left eye and the right eye achieve color complementation, and better color uniformity and larger FOV are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waveguide, in particular to a binocular display optical device and a display device. BACKGROUND

[0002] Near-eye display technology is one of the key technologies that must be used in current AR glasses. The near-eye display system is generally composed of an image far and an optical transmission system. The image picture emitted by the image source is transmitted to the human eye through the optical transmission system. The optical transmission system here needs to have a certain transmittance, so that the wearer can see the outside environment while seeing the image picture.

[0003] For the optical transmission system, there are many schemes in the industry, such as free-space optics, free-form optics, and display optical waveguide. Among them, the optical waveguide technology is obviously superior to other optical solutions due to its large eyebox and light and thin characteristics. However, the current optical waveguide can only realize monocular display, and there are problems of high hardware cost and high power consumption to realize binocular display. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a binocular display optical device and a display panel to solve the problem that the current optical waveguide can only realize monocular display.

[0005] In one aspect of the embodiments of the present application, a binocular display optical device is provided, which includes a waveguide plate, the waveguide plate includes an entrance pupil grating unit, left and right pupil expansion grating units symmetrically distributed on both sides of the entrance pupil grating unit, and left and right exit pupil grating units symmetrically distributed below the left and right pupil expansion grating units, wherein the entrance pupil grating unit, the left and right pupil expansion grating units, and the left and right exit pupil grating units each have only one grating vector. Each of the left and right pupil expansion grating units includes a plurality of sub-pupil expansion regions, and the diffraction efficiency of each of the sub-pupil expansion regions gradually increases in a direction away from the entrance pupil grating unit.

[0006] In another aspect of the embodiments of the present application, a binocular display optical device is provided, which includes a waveguide plate, the waveguide plate includes an entrance pupil grating unit, left and right pupil expansion grating units symmetrically distributed on both sides of the entrance pupil grating unit, and left and right exit pupil grating units symmetrically distributed below the left and right pupil expansion grating units, wherein the entrance pupil grating unit, the left and right pupil expansion grating units, and the left and right exit pupil grating units each have only one grating vector. The left pupil grating unit and the right pupil grating unit each include multiple sub-pupil regions, and the boundary lines between adjacent sub-pupil regions have different angles with the horizontal direction.

[0007] In another aspect of this application, a binocular display optical device is provided, the display device including a light engine and the above-described binocular display optical device; the light engine is used to generate a light beam input to the entrance pupil grating unit.

[0008] The binocular display optical device and display equipment provided in this application embodiment have an entrance pupil grating unit formed on a waveguide plate, which diffracts the input light into left and right guided light using positive and negative diffraction orders. Symmetrical pupil expansion grating units and symmetrical exit pupil grating units are also formed on the same waveguide plate, enabling binocular display. Since the waveguide plate is a single unit with basic flatness, binocular fusion can be achieved between the left and right eyes without additional adjustments. Due to the overall left-right symmetry, the images of the left and right eyes achieve color complementarity, resulting in better color uniformity and a larger field of view (FOV). Further improvement in color uniformity is achieved through the partitioning of the left and right pupil expansion units and exit pupil units. Simultaneously, both positive and negative diffraction orders of the entrance pupil unit are utilized, greatly improving the system's light energy utilization. Therefore, the power consumption of the binocular system is far lower than that of conventional binocular display solutions. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of an embodiment of the binocular display optical device provided in this embodiment; Figure 2 This is a schematic diagram of the partitioning of the grating unit in one embodiment of the binocular display optical device provided in this embodiment; Figure 3 This is a schematic diagram of the vector direction of the grating unit in one embodiment of the binocular display optical device provided in this embodiment; Figure 4 This is a side view of an embodiment of the binocular display optical device provided in this embodiment; Figure 5 This is a wave vector diagram of light in one embodiment of the binocular display optical device provided in this embodiment; Figure 6 This is a schematic diagram of another embodiment of the binocular display optical device provided in this embodiment. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application.

[0012] In the description of the present application, it should be noted that the positions or location relationships indicated by the terms "inner", "outer" and the like are based on the positions or location relationships shown in the drawings, or the positions or location relationships in which the products of the present application are usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0013] It should also be noted that, unless otherwise explicitly specified and limited, the terms "provided", "connected" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0014] As shown in FIG. 1, the binocular display optical device EPE1 can include a waveguide plate SUB01, which is a flat plate with good flatness, but the shape of the waveguide plate SUB01 can be a flat plate or a curved plate that fits the face, both of which have good flatness. Figure 1

[0015] The waveguide plate SUB01 is formed with an entrance pupil grating unit DOE1, a left pupil expansion grating unit DOE2a, a right pupil expansion grating unit DOE2b, a left exit pupil grating unit DOE3a, and a right exit pupil grating unit DOE3b.

[0016] The entrance pupil grating unit DOE1 can receive an input light beam IN1, and the left and right exit pupil grating units DOE3a and DOE3b can respectively provide expanded output light beams OUT1 and OUT2, wherein the lengths and widths of the output light beams OUT1 and OUT2 are greater than those of the input light beam IN1 under the action of the left and right pupil expansion grating units DOE2a and DOE2b, and the left and right exit pupil grating units DOE3a and DOE3b, thereby realizing the function of pupil expansion.

[0017] The binocular display optical device EPE1 can expand the light beam IN1 in two dimensions (for example, along the horizontal direction SX and along the vertical direction SY). The expansion process can also be referred to as exit pupil expansion, light ray expansion, etc. The binocular display optical device EPE1 can be referred to as a beam expander or an exit pupil expander, etc. ​

[0018] The entrance pupil grating unit DOE1 can be used as an entrance coupling unit. The entrance pupil grating unit DOE1 can form a first left-guided light B1a and a first right-guided light B1b by diffracting the input beam IN1. The input beam IN1 can be incident from either the front or the back of the binocular display optical device EPE1. The first left-guided light B1a and the first right-guided light B1b can propagate inside the planar waveguide plate SUB01, with the main propagation direction symmetrical left and right. The first left-guided light B1a and the first right-guided light B1b can be confined within the planar waveguide plate SUB01 for total internal reflection.

[0019] The term "conduction" may mean that the light propagates within the planar waveguide plate SUB01, confining the light within the plate by total internal reflection (TIR). The term "waveguide" may be used interchangeably with the term "optical waveguide".

[0020] The left pupil grating unit DOE2a receives the first left-guided light B1a and forms the second left-guided light B2a through diffraction. DOE2a can distribute the second left-guided light B2a nearly uniformly to the left exit pupil grating unit DOE3a. The beamwidth of the second left-guided light B2a is much larger than that of the first left-guided light B1a. The second left-guided light B2a can be confined to propagate within the waveguide plate SUB01 by total internal reflection.

[0021] The right pupil grating unit DOE2b receives the first right-guided light B1b and forms the second right-guided light B2b through diffraction. The right pupil grating unit DOE2b can distribute the second right-guided light B2b nearly uniformly to the right exit pupil grating unit DOE3b. The beamwidth of the second right-guided light B2b is much larger than that of the first right-guided light B1b. The second right-guided light B2b can be confined to propagate within the waveguide plate SUB01 by total internal reflection.

[0022] Among them, the directions of the first left-guided light B1a and the first right-guided light B1b are symmetrical, and the main directions of the second left-guided light B2a and the second right-guided light B2b are the same.

[0023] The left exit pupil grating unit DOE3a diffracts the extended guided light B2a to form the left output light OB1. The left output light OB1 is further broadened in the Y direction while maintaining good uniformity, forming the overall left output beam OUT1. The directions of the left output light OB1 and the left output beam OUT1 are DIR0'.

[0024] The right exit pupil grating unit DOE3b diffracts the extended guided light B2b to form the right output light OB2. The right output light OB2 is further broadened in the Y direction while maintaining good uniformity, forming the overall right output beam OUT2. The directions of the right output light OB2 and the right output beam OUT2 are also DIR0'.

[0025] Specifically, the direction DIR0 of the incident beam IN1 is consistent with the direction DIR0' of the left and right output beams OUT1 and OUT2, and this relationship remains unchanged regardless of how the direction of the incident beam IN1 changes. Because the directions DIR0' of the left and right output beams OUT1 and OUT2 are the same, the virtual image VIMG1 received by the left eye EYE1 and the virtual image VIMG2 received by the right eye EYE2 can be naturally merged together without angular deviation, and the content of the virtual images VIMG1 and VIMG2 is exactly the same.

[0026] SX, SY, and SZ are orthogonal directions. Waveguide plate SUB1 can be parallel to the plane defined by SX and SY.

[0027] like Figure 2 The partitioning and dimensions of different grating regions in the binocular display optical device EPE1 are given. The diameter of the entrance pupil grating unit DOE1 is D1, and the area of ​​D1 ranges from 2.5 mm to 7 mm. The entrance pupil grating unit DOE1 can be a surface grating or a holographic grating. This grating has high diffraction efficiency and can propagate the first left-directing light B1a and the first right-directing light B1a to the left and right sides respectively.

[0028] The left pupil grating unit DOE2a is a quadrilateral with a maximum width of W2 and a maximum height of H2, and is the tallest on the left. The width W2 can be 5-10 times the diameter D1, and the height H2 can be 2-5 times the diameter D1. The angles between the top and bottom sides of the quadrilateral and the horizontal direction are a21 and a22, respectively. The left pupil grating unit DOE2a needs to be further divided into 5-15 sub-pupil regions. Taking 6 regions as an example, the left pupil grating unit DOE2a includes sub-regions L11, L12, L13, L14, L15, and L16. The angle between the boundaries of different sub-regions is a23, which can be set from 20° to 160°. Furthermore, the angles of the boundaries between different adjacent sub-regions can be different to achieve better uniformity. In addition, the grating period can be fixed in different sub-regions, and the shape characteristics, depth, duty cycle, or exposure conditions of the grating can be controlled so that the diffraction efficiency of different sub-regions gradually increases. That is, when i is greater than j, the grating diffraction efficiency of sub-region L1i is greater than that of sub-region L1j. The efficiency setting range of all corresponding sub-region diffraction gratings can be 5%-95%.

[0029] The right pupil grating unit DOE2b is a quadrilateral with a maximum width of W4 and a maximum height of H4, being the tallest on the right. The width W4 can be 5-10 times the diameter D1, and the height H4 can be 2-5 times the diameter D1. The angles between the top and bottom sides of the quadrilateral and the horizontal direction are b21 and b22, respectively. The right pupil grating unit DOE2b needs to be further divided into 5-15 sub-pupil regions. Taking 6 regions as an example, the right pupil grating unit DOE2b includes sub-regions R11, R12, R13, R14, R15, and R16. The angle between the boundaries of different sub-regions is b23, which can be set from 20° to 160°. Furthermore, the angles of the boundaries between different adjacent sub-regions can be different to achieve better uniformity. In addition, the grating period can be fixed in different sub-regions, and the shape characteristics, depth, duty cycle, or exposure conditions of the grating can be controlled so that the diffraction efficiency of different sub-regions gradually increases. That is, when i is greater than j, the grating diffraction efficiency of sub-region R1i is greater than that of sub-region R1j. The efficiency setting range of all corresponding sub-region diffraction gratings can be 5%-95%.

[0030] The left pupil grating unit DOE2a and the right pupil grating unit DOE2b have the same pupil grating structure. Their structural dimensions, grating parameters, and partitioning characteristics must be strictly mirror-symmetrical, and the diffraction efficiency of each sub-region must also be the same, i.e., L1i=R1i.

[0031] The left exit pupil grating unit DOE3a is a rectangle with a length of W3 and a height of H3. The width W3 can be 80%-95% of the width W2, and the height H3 can be 3-6 times the diameter D1. The left exit pupil grating unit DOE3a needs to be further divided into 5-15 sub-exit pupil regions. Taking 7 regions as an example, the left exit pupil grating unit DOE3a includes sub-regions L21, L22, L23, L24, L25, L26, and L27 to achieve better uniformity. In addition, the grating period can be fixed in different sub-regions to control the shape characteristics, depth, duty cycle, or exposure conditions of the grating, so that the diffraction efficiency of different sub-regions gradually increases. That is, when i is greater than j, the grating diffraction efficiency of sub-region L2i is greater than that of sub-region L2j. The efficiency setting range of all corresponding sub-region diffraction gratings can be 5%-95%.

[0032] The right exit pupil grating unit DOE3b is a rectangle with a length of W5 and a height of H5. The width W5 can be 80%-95% of the width W4, and the height H5 can be 3-6 times the diameter D1. The right exit pupil grating unit DOE3b needs to be further divided into 5-15 sub-regions. Taking 7 regions as an example, the right exit pupil grating unit DOE3b includes sub-regions R21, R22, R23, R24, R25, R26, and R27 to achieve better uniformity. In addition, the grating period can be fixed in different sub-regions to control the shape characteristics, depth, duty cycle, or exposure conditions of the grating, so that the diffraction efficiency of different sub-regions gradually increases. That is, when i is greater than j, the grating diffraction efficiency of sub-region R2i is greater than that of sub-region R2j. The efficiency setting range for all corresponding sub-region diffraction gratings can be 5%-95%.

[0033] The left exit pupil grating unit DOE3a and the right exit pupil grating unit DOE3b have the same exit pupil grating structure. Their structural dimensions, grating parameters, and partitioning characteristics must be strictly mirror-symmetrical, and the diffraction efficiency of each sub-region must also be the same, i.e., L2i=R2i.

[0034] The distance between the center of the left exit pupil grating unit DOE3a and the center of the right exit pupil grating unit DOE3b is the interpupillary distance (IPD), set to within the range of 60mm-70mm. The left half of the distance, X1, equals the right half, X2, and X1 + X2 = IPD. The vertical distance between the center of the entrance pupil grating unit DOE1 and the center of the left exit pupil grating unit DOE3a is Y1, set to 8mm-25mm.

[0035] Figure 3 The periods and orientations of different grating regions in the binocular display optical device EPE1 are given. Each unit DOE1, DOE2a, DOE2b, DOE3a, and DOE3b can contain one or more diffraction grating regions. For example, unit DOE1 can contain one grating region. For example, unit DOE2a can contain multiple sub-regions, and the periods and orientations of the gratings in each sub-region are consistent. For example, unit DOE2b can contain multiple sub-regions, and the periods and orientations of the gratings in each sub-region are consistent. For example, unit DOE3a can contain multiple sub-regions, and the periods and orientations of the gratings in each sub-region are consistent. For example, unit DOE3b can contain multiple sub-regions, and the periods and orientations of the gratings in each sub-region are consistent.

[0036] The grating period (d) and orientation (β) of the diffraction features of the diffraction grating can be determined by the grating vector V of the diffraction grating. The diffraction grating contains multiple diffraction features (F) that can serve as diffracted rays. Diffraction features can be, for example, minute ridges or grooves. Diffraction features can also be, for example, microscopic protrusions (or depressions), where adjacent protrusions (or depressions) can serve as diffracted rays. The grating vector V can be defined as a vector having a direction perpendicular to the diffraction ray perpendicular to the diffraction grating and an amplitude given by 2π / d, where d is the grating period. The grating period has the same meaning as the length of the grating period. The grating period can be the length between consecutive diffraction features of the grating. The grating period can be equal to a unit length divided by the number of diffraction features located within that unit length. The grating period d1a of the entrance pupil grating unit DOE1 can be in the range of, for example, 330 nm to 450 nm, with the optimal value depending on the refractive index of SUB1 and the wavelength λ of the diffracted light.

[0037] The entrance pupil grating unit DOE1 can have a grating vector V1. The left expanding pupil grating unit DOE2a can have a grating vector V2a. The right expanding pupil grating unit DOE2b can have a grating vector V2b. The left exit pupil grating unit DOE3a can have a grating vector V3a. The right exit pupil grating unit DOE3b can have a grating vector V3b.

[0038] Raster vector V1 has a direction β1 and a magnitude of 2π / d1. Raster vector V2a has a direction β2a and a magnitude of 2π / d2a. Raster vector V2b has a direction β2b and a magnitude of 2π / d2b. Raster vector V3a has a direction β3a and a magnitude of 2π / d3a. Raster vector V3b has a direction β3b and a magnitude of 2π / d3b. The direction (β) of the grating vector can be defined as the angle between the grating vector and a reference direction (e.g., direction SX).

[0039] The grating period (d) and the orientation (β) of the diffraction grating of the optical units DOE1, DOE2a, and DOE3a can be selected such that the propagation direction DIR0' of the light at the center point of the output beam OUT1 is parallel to the propagation direction DIR0 of the light at the center point of the input beam IN1. The grating period (d) and the orientation (β) of the diffraction grating of the optical units DOE1, DOE2b, and DOE3b can be selected so that the propagation direction DIR0' of the light at the center point of the output beam OUT2 is also parallel to the propagation direction DIR0 of the light at the center point of the input beam IN1.

[0040] The direction β1 of the grating vector V1 in the entrance pupil grating unit DOE1 can be around 0°, for example, -1° to 1°. The direction β2a of the grating vector V2a in the left expanding pupil grating unit DOE2a can be from 30° to 60°. The direction β2b of the grating vector V2b in the right expanding pupil grating unit DOE2b can be from 120° to 150°, and the grating vectors V2a and V2b are mirror-symmetric. The direction β3a of the grating vector V3a in the left exit pupil grating unit DOE3a can be around 90°, for example, 88° to 92°; the direction β3b of the grating vector V3b in the right exit pupil grating unit DOE3b can be around 90°, for example, 88° to 92°; and the grating vectors V3a and V3b are mirror-symmetric.

[0041] For predetermined integers m1, m2a, m2b, m3a, and m3b, the grating period (d) and direction (β) of the grating vector can satisfy the following: the vector sum (m1V1 + m2aV2a + m3aV3a) is zero, and the vector sum (-m1V1 + m2bV2b + m3bV3b) is zero. The values ​​of these predetermined integers are typically +1 or -1. For example, the values ​​of integers m1, m2a, m2b, m3a, and m3b can be +1 or -1. Specifically, if V1 is directed to the left, the sum of V1, V2a, and V3a is zero; if V1 is directed to the right, the sum of V1, V2b, and V3b is zero.

[0042] like Figure 4 As shown, the binocular display optical device EPE1 can form output light OUT1 by diffracting and transmitting the input light IN1 obtained from the light engine ENG1. The display device 500 may include the light engine ENG1 and the binocular display optical device EPE1.

[0043] The input light IN1 can contain multiple beams propagating in different directions. Each beam of input light IN1 can correspond to a different point in the input image IMG0. The output lights OUT1 and OUT2 can contain multiple beams propagating in different directions, entering the left eye EYE1 and right eye EYE2 respectively. Each beam of output lights OUT1 and OUT2 can correspond to a different point in the displayed virtual image VIMG1. The pupil dilator EPE1 can form the left output light OUT1 and the right output light OUT2 from the input light IN1, such that the direction and intensity of the output lights OUT1 and OUT2 correspond to a point in the input image IMG0.

[0044] The input light IN1 can correspond to a single image point of the displayed image. The binocular display optics EPE1 can form a left output beam OB1 and a right output beam OB2 with the same direction from the beam of the input light IN1, such that the direction of the output beam DIR0' is parallel to the direction DIR0 of the corresponding input light IN1 beam.

[0045] Display device 500 may include a light engine ENG1 to form a main image IMG0 and convert the main image IMG0 into multiple beams of input light IN1. The light from the light engine ENG1 can be coupled into the entrance pupil grating unit DOE1 of the binocular display optics device EPE1. The input light IN1 can also be coupled into the entrance pupil grating unit DOE1 of the binocular display optics device EPE1. Display device 500 can be a display device for displaying virtual images. Display device 500 can also be a myopia-correcting optical device.

[0046] The binocular display optics EPE1 can transmit virtual image content from the light engine ENG1 to the user's left eye EYE1 and right eye EYE2. The binocular display optics EPE1 can expand the pupils, thereby enlarging the eyebox.

[0047] The light engine ENG1 may include a microdisplay DISP1 to generate a main image IMG0. The microdisplay DISP1 may contain a two-dimensional array of luminescent pixels. The display DISP1 can generate, for example, the main image IMG0 with a resolution of 1280×720 (HD). The display DISP1 can also generate, for example, the main image IMG0 with a resolution of 1920×1080 (Full HD). The display DISP1 can also generate, for example, the main image IMG0 with a resolution of 3840×2160 (4K UHD). The light engine ENG1 may include a collimating optics LNS1 to form a beam of light different from each image pixel. The light engine ENG1 may include a collimating optics LNS1 to form a substantially collimated beam of light emitted from a particular pixel. Different pixels correspond to different collimation directions.

[0048] The light engine ENG1 can provide multiple light beams corresponding to the generated master image IMG0. One or more light beams provided by the light engine ENG1 can be coupled to the binocular display optics EPE1 and used as input light IN1.

[0049] The light engine ENG1 may include, for example, one or more light-emitting diodes (LEDs). The display DISP1 may include one or more microdisplay imagers, such as liquid crystal on silicon (LCOS), liquid crystal display (LCD), or digital micromirror device (DMD).

[0050] Waveguide plate SUB1 may have a first main surface SRF1 and a second main surface SRF2. Surfaces SRF1 and SRF2 may be substantially parallel to a plane defined by directions SX and SY. Waveguide plate SUB1 may have a thickness t1. The waveguide plate includes a planar waveguide core portion. In embodiments, waveguide plate SUB1 may optionally include, for example, one or more cladding layers, one or more protective layers, and / or one or more mechanical support layers. Thickness t1 may refer to the thickness of the planar waveguide core portion of waveguide plate SUB1.

[0051] The grating structure of the entrance pupil grating unit DOE1 can be disposed on the first main surface SRF1 or the second main surface SRF2 of the waveguide plate SUB1, forming the first left guided light B1a and the first right guided light B1b by diffracting the input beam IN1. The input beam IN1 can be incident from either the front or the back of the binocular display optical device EPE1. The first left guided light B1a and the first right guided light B1b can propagate inside the planar waveguide plate SUB1, with the main propagation direction being symmetrical from left to right. The first left guided light B1a and the first right guided light B1b can be confined within the planar waveguide plate SUB1 for total internal reflection.

[0052] The grating structures of the right pupil grating unit DOE2b and the right pupil grating unit DOE2b can be disposed on the first main surface SRF1 or the second main surface SRF2 of the waveguide plate SUB1. The left pupil grating unit DOE2a receives the first left-guided light B1a and forms the second left-guided light B2a through diffraction. The left pupil grating unit DOE2a can distribute the second left-guided light B2a nearly uniformly to the left exit pupil grating unit DOE3a, and the second left-guided light B2a can be confined to propagation within the waveguide plate SUB1 by total internal reflection. The right pupil grating unit DOE2b receives the first right-guided light B1a and forms the second right-guided light B2b through diffraction. The right pupil grating unit DOE2b can distribute the second right-guided light B2b nearly uniformly to the right exit pupil grating unit DOE3b. The second left-guided light B2a can be confined to propagation within the waveguide plate SUB1 by total internal reflection.

[0053] The grating structures of the left exit pupil grating unit DOE3a and the right exit pupil grating unit DOE3b can be disposed on the first main surface SRF1 or the second main surface SRF2 of the waveguide plate SUB1. The left exit pupil grating unit DOE3a diffracts the extended guided light B2a to form the left output light OB1, which together forms the left output beam OUT1. The directions of the left output light OB1 and the left output beam OUT1 are DIR0'. The right exit pupil grating unit DOE3b diffracts the extended guided light B2b to form the left output light OB2, which together forms the right output beam OUT2. The directions of the right output light OB2 and the right output beam OUT2 are also DIR0'.

[0054] The left output beam OUT1 and the right output beam OUT2 enter the left eye EYE1 and the right eye EYE2 respectively. Because the beams are in the same direction, the left and right eyes can achieve binocular fusion without any additional adjustments. Due to the overall left-right symmetry, the images of the left and right eyes achieve complementary colors, thus achieving better color uniformity and a larger FOV.

[0055] Waveguide plate SUB1 may comprise or be substantially composed of a transparent solid material. Waveguide plate SUB1 may comprise, for example, glass, polycarbonate, or polymethyl methacrylate (PMMA). Diffractive optical units DOE1, DOE2a, DOE2b, DOE3a, and DOE3b may be formed, for example, by molding, embossing, and / or etching. Units DOE1, DOE2a, DOE2b, DOE3a, and DOE3b may be implemented, for example, by one or more surface diffraction gratings or by one or more volume diffraction gratings.

[0056] Figure 5 The wave vector diagram of light is given as an example, showing that light of this wavelength can propagate along the left and right paths within the waveguide plate SUB. The wave vector of the input light IN1 can exist in a region BOX0 of the wave vector space defined by the initial wave vectors kx and ky. Each corner of region BOX0 can represent the wave vector of light at a corner point of an input image IMG0.

[0057] The wave vectors of the first left-guided beam B1a and the first right-guided beam B1b are both within region BOX1a. The wave vectors of the second left-guided beam B2a and the second right-guided beam B2b are both within region BOX2b. The wave vector of the left output beam OUT1 is within region BOX3a, and the wave vector of the right output beam OUT2 is within region BOX3b.

[0058] BND1 represents the minimum boundary for satisfying the total internal reflection (TIR) ​​criterion in waveguide plate SUB1, and BND2 represents the maximum boundary for the TIR criterion in waveguide plate SUB1, which can be determined by the refractive index of the waveguide plate. Light can only waveguide in plate SUB1 if the wave vector of the light is within region ZONE1 between the first boundary BND1 and the second boundary BND2. If the wave vector of the light is outside region ZONE1, the light may leak out of the waveguide plate or not propagate at all.

[0059] The grating period (d) and diffraction grating orientation (β) of optical units DOE1, DOE2a, DOE3a, DOE2b, and DOE3b can be selected so that regions BOX0, BOX3a, and BOX3b in wave vector space almost coincide. Simultaneously, for the wavelengths of the three colors RGB, the wave vectors of regions BOX1a, BOX1b, BOX2a, and BOX2b are all within region ZONE1 defined by boundaries BND1 and BND2. Furthermore, regions BOX2a and BOX2b in wave vector space almost coincide.

[0060] The left path is counterclockwise. For example, the entrance pupil grating unit DOE1 can form the first left-guided light B1a by diffracting the input light IN1. That is, the wave vector of the first left-guided light B1a is represented by adding the grating vector -m1V1 of the entrance pupil grating unit DOE1 to the wave vector of the input light IN1. The wave vector of the second left-guided light B2a can be determined by adding the grating vector m2aV2a to the wave vector of the first guide light B1a. Finally, the wave vector of the outgoing light OUT1 can be determined by adding the grating vector m3aV3a to the wave vector of the second left-guided light B2a.

[0061] The right path is counterclockwise. For example, the entrance pupil grating unit DOE1 can diffract the input light IN1 to form the first right-guided light B1b. That is, the wave vector of the first right-guided light B1b is represented by adding the grating vector m1 V1 of the entrance pupil grating unit DOE1 to the wave vector of the input light IN1. The wave vector of the second right-guided light B2b can be determined by adding the grating vector m2b V2b to the wave vector of the first guide light B1b. Finally, the wave vector of the outgoing light OUT2 can be determined by adding the grating vector m3b V3b to the wave vector of the second right-guided light B2b.

[0062] The grating period (d) and the orientation (β) of the diffraction gratings of the optical units DOE1, DOE2a, DOE3a, DOE2b, and DOE3b can be selected, so that the angle between grating vectors -V1 and V2a can be 30° to 60°, the angle between grating vectors V1 and V2b can be 120° to 150°, the angle between grating vectors V2a and V3a can be 30° to 60°, the angle between grating vectors V2b and V3b can be 30° to 60°, and the left and right paths of light propagation are mirror symmetrical.

[0063] kx represents the direction in wave vector space, where the direction kx is parallel to the direction SX in actual space. ky represents the direction in wave vector space, where the direction ky is parallel to the direction SY in actual space. The symbol kz (not shown in the figure) represents the direction in wave vector space, where the direction kz is parallel to the direction SZ in actual space. The wave vector k can have components in the directions kx, ky, and / or kz.

[0064] Figure 6 The front view of the EPE1 binocular display optical device illustrates that the corners of the grating area can be made curved to better fit the shape of the glasses.

[0065] The second left pupil dilation region DOE2a has an upper left arc of r1, a lower left arc of r2, and a right arc of r5. The second right pupil dilation region DOE2b has an upper right arc of r3, a lower right arc of r4, and a left arc of r6. The four corner arcs of the third left exit pupil region DOE3a can be r7, and the four corner arcs of the third right exit pupil region DOE3b can be r8. The radius of curvature for all arcs ranges from 2mm to 20mm.

[0066] This embodiment of the binocular display optical device directs entrance pupil light to both eyes, requiring only one optical engine and improving the overall efficiency of the diffraction waveguide. Utilizing the waveguide plate's grating setup and employing glass wafer precision to control binocular coupling reduces the difficulty of generating binocular coupling and improves coupling strength. Furthermore, the optical symmetry between the left and right eyes allows for mutual compensation, resulting in better color uniformity. The integrated waveguide design, compatible with curved shapes, is more suitable for human use.

[0067] This application also discloses a display device 500, including a light engine ENG1 and a binocular display optical device EPE1 as described above. The light engine ENG1 is used to generate a light beam, i.e., an input light beam IN1, for the input entrance pupil grating unit DOE1.

[0068] The display device 500 includes the same structure and beneficial effects as the binocular display optical device in the foregoing embodiments. The structure and beneficial effects of the binocular display optical device have been described in detail in the foregoing embodiments and will not be repeated here.

[0069] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A binocular display optical device, characterized in that, The binocular display optical device includes a waveguide plate, which includes an entrance pupil grating unit, a left dilation pupil grating unit and a right dilation pupil grating unit symmetrically distributed on both sides of the entrance pupil grating unit, and a left exit pupil grating unit and a right exit pupil grating unit symmetrically distributed below the left dilation pupil grating unit and the right dilation pupil grating unit. Each of the entrance pupil grating unit, the left dilation pupil grating unit, the right dilation pupil grating unit, the left exit pupil grating unit, and the right exit pupil grating unit has only one grating vector. The left and right pupil grating units each include multiple sub-pupil regions, and the diffraction efficiency of each sub-pupil region gradually increases in the direction away from the entrance pupil grating unit.

2. The binocular display optical device according to claim 1, characterized in that, In the plurality of sub-pupil regions of the left pupil grating unit and the right pupil grating unit, the angle between the boundary line of adjacent sub-pupil regions and the horizontal direction is different.

3. The binocular display optical device according to claim 1 or 2, characterized in that, The multiple sub-pupil regions of the left pupil grating unit and the right pupil grating unit are symmetrically distributed, and the diffraction efficiency of the sub-pupil regions at corresponding positions is the same.

4. The binocular display optical device according to claim 3, characterized in that, Both the left and right pupil grating units are pupil grating structures, which divide the pupil grating structure into 5 to 15 sub-pupil regions. The angle between the boundary line between adjacent sub-pupil regions and the horizontal direction is 20 to 160 degrees. The diffraction efficiency of the sub-pupil regions is 5% to 95%.

5. The binocular display optical device according to claim 1 or 2, characterized in that, The entrance pupil grating unit is a surface grating or a holographic grating. The entrance pupil grating unit is circular with a diameter of 2.5 mm to 7 mm and a grating period of 330 nm to 450 nm. And / or, both the left pupil grating unit and the right pupil grating unit are pupil grating structures. In the direction horizontally away from the entrance pupil grating unit, the height of the pupil grating structure in the vertical direction gradually increases. The maximum height of the pupil grating structure in the vertical direction is 2 to 5 times the diameter of the entrance pupil grating unit, and the width in the horizontal direction is 5 to 10 times the diameter of the entrance pupil grating unit.

6. The binocular display optical device according to claim 1 or 2, characterized in that, Both the left and right pupil grating units are pupil grating structures. The pupil grating structure is quadrilateral with arc-shaped corners and a radius of curvature of 0mm to 20mm.

7. The binocular display optical device according to claim 1 or 2, characterized in that, Both the left exit pupil grating unit and the right exit pupil grating unit are exit pupil grating structures. The exit pupil grating structure is divided into 5 to 15 sub-exit pupil regions in the vertical direction. In the direction that is vertically away from the entrance pupil grating unit, the diffraction efficiency of each sub-exit pupil region gradually increases, and the diffraction efficiency of the sub-exit pupil region is 5% to 95%.

8. The binocular display optical device according to claim 7, characterized in that, The multiple sub-exit pupil regions of the left exit pupil grating unit and the right exit pupil grating unit are symmetrically distributed, and the diffraction efficiency of the sub-exit pupil regions at corresponding positions is the same.

9. The binocular display optical device according to claim 7, characterized in that, Both the left and right pupil grating units are pupil grating structures. The height of the exit pupil grating structure in the vertical direction is 3 to 6 times the diameter of the entrance pupil grating unit, and the width in the horizontal direction is 80% to 95% of the width of the pupil grating structure. And / or, the exit pupil grating structure is quadrilateral, the four corners of the quadrilateral are arc-shaped, and the radius of curvature of the arc is 0mm to 20mm.

10. The binocular display optical device according to claim 1 or 2, characterized in that, The light beam incident through the entrance pupil grating unit is parallel to the light beam exiting through the exit pupil grating unit.

11. The binocular display optical device according to claim 1 or 2, characterized in that, Based on the left-to-right direction, the grating vector direction of the entrance pupil grating unit is -1 degree to 1 degree, the grating vector direction of the left dilator pupil grating unit is 30 degree to 60 degree, the grating vector direction of the right dilator pupil grating unit is 120 degree to 150 degree, and the grating vector directions of the left exit pupil grating unit and the right exit pupil grating unit are both 88 degree to 92 degree.

12. The binocular display optical device according to claim 11, characterized in that, Within the wave vector space, the wave vector regions of the light beam incident through the entrance pupil grating unit coincide with those of the light beams exiting through the left exit pupil grating unit and the right exit pupil grating unit. The wave vector regions of the first left-guided light and the first right-guided light exiting through the entrance pupil grating unit, the second left-guided light exiting through the left dilated pupil grating unit, and the second right-guided light exiting through the right dilated pupil grating unit are between the minimum and maximum total internal reflection wave vectors of the waveguide plate. Furthermore, the wave vector regions of the second left-guided light exiting through the left dilated pupil grating unit and the second right-guided light exiting through the right dilated pupil grating unit coincide.

13. The binocular display optical device according to claim 11, characterized in that, The grating vector of the entrance pupil grating unit is directed to the left, and the sum of the grating vectors of the entrance pupil grating unit, the left dilator pupil grating unit, and the left exit pupil grating unit is zero; the grating vector of the entrance pupil grating unit is directed to the right, and the sum of the grating vectors of the entrance pupil grating unit, the right dilator pupil grating unit, and the right exit pupil grating unit is zero.

14. The binocular display optical device according to claim 1 or 2, characterized in that, The horizontal distance between the centers of the left exit pupil grating unit and the right exit pupil grating unit is the interpupillary distance of the human eye, which is 60mm to 70mm; the vertical distance from the center of the entrance pupil grating unit to the center of the left exit pupil grating unit is 8mm to 25mm.

15. A binocular display optical device, characterized in that, The binocular display optical device includes a waveguide plate, which includes an entrance pupil grating unit, a left dilation pupil grating unit and a right dilation pupil grating unit symmetrically distributed on both sides of the entrance pupil grating unit, and a left exit pupil grating unit and a right exit pupil grating unit symmetrically distributed below the left dilation pupil grating unit and the right dilation pupil grating unit. Each of the entrance pupil grating unit, the left dilation pupil grating unit, the right dilation pupil grating unit, the left exit pupil grating unit, and the right exit pupil grating unit has only one grating vector. The left pupil grating unit and the right pupil grating unit each include multiple sub-pupil regions, and the boundary lines between adjacent sub-pupil regions have different angles with the horizontal direction.

16. The binocular display optical device according to claim 15, characterized in that, The diffraction efficiency of each of the plurality of sub-diopter regions of the left and right diopter grating units gradually increases in the direction away from the entrance pupil grating unit.

17. The binocular display optical device according to claim 15 or 16, characterized in that, The multiple sub-pupil regions of the left pupil grating unit and the right pupil grating unit are symmetrically distributed, and the diffraction efficiency of the sub-pupil regions at corresponding positions is the same.

18. The binocular display optical device according to claim 17, characterized in that, Both the left and right pupil grating units are pupil grating structures, which divide the pupil grating structure into 5 to 15 sub-pupil regions. The angle between the boundary line between adjacent sub-pupil regions and the horizontal direction is 20 to 160 degrees. The diffraction efficiency of the sub-pupil regions is 5% to 95%.

19. The binocular display optical device according to claim 15 or 16, characterized in that, The entrance pupil grating unit is a surface grating or a holographic grating. The entrance pupil grating unit is circular with a diameter of 2.5 mm to 7 mm and a grating period of 330 nm to 450 nm. And / or, both the left pupil grating unit and the right pupil grating unit are pupil grating structures. In the direction horizontally away from the entrance pupil grating unit, the height of the pupil grating structure in the vertical direction gradually increases. The maximum height of the pupil grating structure in the vertical direction is 2 to 5 times the diameter of the entrance pupil grating unit, and the width in the horizontal direction is 5 to 10 times the diameter of the entrance pupil grating unit.

20. The binocular display optical device according to claim 15 or 16, characterized in that, Both the left and right pupil grating units are pupil grating structures. The pupil grating structure is quadrilateral with arc-shaped corners and a radius of curvature of 0mm to 20mm.

21. The binocular display optical device according to claim 15 or 16, characterized in that, Both the left exit pupil grating unit and the right exit pupil grating unit are exit pupil grating structures. The exit pupil grating structure is divided into 5 to 15 sub-exit pupil regions in the vertical direction. In the direction that is vertically away from the entrance pupil grating unit, the diffraction efficiency of each sub-exit pupil region gradually increases, and the diffraction efficiency of the sub-exit pupil region is 5% to 95%.

22. The binocular display optical device according to claim 21, characterized in that, The multiple sub-exit pupil regions of the left exit pupil grating unit and the right exit pupil grating unit are symmetrically distributed, and the diffraction efficiency of the sub-exit pupil regions at corresponding positions is the same.

23. The binocular display optical device according to claim 21, characterized in that, Both the left and right pupil grating units are pupil grating structures. The height of the exit pupil grating structure in the vertical direction is 3 to 6 times the diameter of the entrance pupil grating unit, and the width in the horizontal direction is 80% to 95% of the width of the pupil grating structure. And / or, the exit pupil grating structure is quadrilateral, the four corners of the quadrilateral are arc-shaped, and the radius of curvature of the arc is 0mm to 20mm.

24. The binocular display optical device according to claim 15 or 16, characterized in that, The light beam incident through the entrance pupil grating unit is parallel to the light beam exiting through the exit pupil grating unit.

25. The binocular display optical device according to claim 15 or 16, characterized in that, Based on the left-to-right direction, the grating vector direction of the entrance pupil grating unit is -1 degree to 1 degree, the grating vector direction of the left dilator pupil grating unit is 30 degree to 60 degree, the grating vector direction of the right dilator pupil grating unit is 120 degree to 150 degree, and the grating vector directions of the left exit pupil grating unit and the right exit pupil grating unit are both 88 degree to 92 degree.

26. The binocular display optical device according to claim 25, characterized in that, Within the wave vector space, the wave vector regions of the light beam incident through the entrance pupil grating unit coincide with those of the light beams exiting through the left exit pupil grating unit and the right exit pupil grating unit. The wave vector regions of the first left-guided light and the first right-guided light exiting through the entrance pupil grating unit, the second left-guided light exiting through the left dilated pupil grating unit, and the second right-guided light exiting through the right dilated pupil grating unit are between the minimum and maximum total internal reflection wave vectors of the waveguide plate. Furthermore, the wave vector regions of the second left-guided light exiting through the left dilated pupil grating unit and the second right-guided light exiting through the right dilated pupil grating unit coincide.

27. The binocular display optical device according to claim 25, characterized in that, The grating vector of the entrance pupil grating unit is directed to the left, and the sum of the grating vectors of the entrance pupil grating unit, the left dilator pupil grating unit, and the left exit pupil grating unit is zero; the grating vector of the entrance pupil grating unit is directed to the right, and the sum of the grating vectors of the entrance pupil grating unit, the right dilator pupil grating unit, and the right exit pupil grating unit is zero.

28. The binocular display optical device according to claim 15 or 16, characterized in that, The horizontal distance between the centers of the left exit pupil grating unit and the right exit pupil grating unit is the interpupillary distance of the human eye, which is 60mm to 70mm; the vertical distance from the center of the entrance pupil grating unit to the center of the left exit pupil grating unit is 8mm to 25mm.

29. A display device, characterized in that, The display device includes a light engine and a binocular display optical device as described in any one of claims 1 to 28; the light engine is used to generate a light beam input to the entrance pupil grating unit.

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