Near-to-eye display assembly

Abstract

The utility model provides a near-to-eye display assembly. The near-to-eye display assembly comprises a coupling-in substrate, the coupling-in substrate is provided with a reflecting surface and a light guiding-in surface, and the reflecting surface is used for receiving and reflecting light guided in through the light guiding-in surface; the turning structure is a diffraction structure; the coupling-out substrate and the turning structure are arranged on the surface of the coupling-in substrate or the surface of the coupling-out substrate, the coupling-out substrate and the coupling-in substrate are located on the same plane, the opposite side faces of the coupling-in substrate and the coupling-out substrate are connected, the coupling-out substrate comprises a plurality of coupling-out sub-parts, and the coupling-out sub-parts are connected with the coupling-in substrate and the coupling-out substrate. The plurality of coupling-out sub-parts are sequentially arranged along a first direction and extend along a second direction, the first direction is perpendicular to the second direction, a connecting surface between two adjacent coupling-out sub-parts in the plurality of coupling-out sub-parts is inclined to the first direction, and a functional film is arranged on the connecting surface. According to the utility model, the problems of distortion and difficult improvement of a rainbow effect of a near-to-eye display assembly in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of near-eye display devices, and more particularly, to a near-eye display assembly. Background Art

[0002] With the continuous development of near-eye display technology and the increasing market demand, various display devices have flowed into the market. Near-eye display assemblies have gradually attracted the attention of researchers because they can be widely used in related devices of virtual reality (VR) and augmented reality (AR).

[0003] Current near-eye display assemblies are generally divided into geometric optical waveguides and diffractive optical waveguides. Geometric optical waveguides mainly utilize the law of refraction and reflection of light to confine the light rays carrying information emitted by the light engine within the waveguide sheet through total reflection and propagate forward. After reflection from the surface of the waveguide sheet with a special film layer inside, the light rays exit to the outside of the waveguide sheet and then enter the human eye for display. Its principle is simple, but the processing is complex and the yield is extremely low, which is not conducive to mass production. Diffractive optical waveguides utilize the diffraction effect of light and mainly adopt a grating structure to achieve the modulation of light beams. However, the design process of the grating structure is relatively complex, and problems such as rainbow effect and chromatic dispersion during imaging are relatively serious. Moreover, it is difficult to integrate the advantages of the two types of optical waveguides.

[0004] That is to say, the near-eye display assemblies in the prior art have problems in that it is difficult to improve distortion and rainbow effect. Summary of the Utility Model

[0005] The main purpose of the utility model is to provide a near-eye display assembly to solve the problems in the prior art that it is difficult to improve distortion and rainbow effect in near-eye display assemblies.

[0006] To achieve the above purpose, according to one aspect of the utility model, a near-eye display assembly is provided, including: an input substrate having a reflection surface and a light introduction surface, the reflection surface being used for receiving and reflecting the light rays introduced through the light introduction surface; a turning structure, the turning structure being a diffractive structure; an output substrate, the turning structure being disposed on the surface of the input substrate or on the surface of the output substrate, the output substrate and the input substrate being in the same plane, and the opposite side surfaces of the input substrate and the output substrate being connected to each other, the output substrate including a plurality of sub-output portions, the plurality of sub-output portions being arranged in sequence along a first direction and all extending along a second direction, the first direction being perpendicular to the second direction, the connection surface between two adjacent sub-output portions among the plurality of sub-output portions being inclined with respect to the first direction, and a functional film being disposed on the connection surface.

[0007] Further, the surface of the coupling-in substrate away from the coupling-out substrate is inclined with respect to the first direction, and a reflective film is provided on this surface to form a reflecting surface.

[0008] Further, the coupling-in substrate has a first surface, a second surface, a third surface, and a fourth surface that are sequentially connected in the clockwise direction. The first surface is parallel to the third surface, and both the first surface and the third surface are inclined with respect to the first direction. The second surface is parallel to the fourth surface, and both the second surface and the fourth surface are parallel to the first direction. A reflective film is provided on the first surface, and the fourth surface is a light input surface.

[0009] Further, the thickness d1 of the coupling-in substrate satisfies: 0.5 mm ≤ d1 ≤ 3 mm; and / or the refractive index n1 of the coupling-in substrate satisfies: 1.3 ≤ n1 ≤ 2.2; and / or the included angle θi between the first surface and the fourth surface satisfies: 20° ≤ θi ≤ 35°.

[0010] Further, the diffraction structure includes one of a surface relief grating, a volume holographic grating, a metasurface structure, and a liquid crystal grating.

[0011] Further, the diffraction structure is a surface relief grating. The turning structure is divided into multiple turning regions. The grating shape, grating height, duty cycle, grating period, and aspect ratio of the grating in the same turning region are the same, and at least one of the grating shape, grating height, duty cycle, grating period, and aspect ratio of the grating in different turning regions is different.

[0012] Further, the diffraction structure is a metasurface structure. The metasurface structure includes multiple column structures. The multiple column structures are arranged in an array, and the multiple column structures are divided into multiple array regions. The diameters of the column structures in the same array region are the same, and the diameters of the column structures in different array regions are different.

[0013] Further, when the turning structure is provided on the surface of the coupling-in substrate, the turning structure is provided on the second surface or the fourth surface.

[0014] Further, the surfaces of the coupling-in substrate and the coupling-out substrate that are connected to each other are inclined with respect to the first direction. The thickness of the coupling-in substrate is equal to the thickness of the coupling-out substrate, and the refractive index of the coupling-in substrate is equal to the refractive index of the coupling-out substrate.

[0015] Further, the extending direction of the turning structure is parallel to or at an angle to the extending direction of the sub-coupling-out portion.

[0016] Further, the cross-section of the sub-coupling-out portion along the first direction is a parallelogram, and one interior angle θ of the parallelogram satisfies: 20° ≤ θ ≤ 35°.

[0017] Further, the functional film is a selective permeation film, and the working angle range γ of the selective permeation film satisfies: θ - 1 / 2 FOV ≤ γ ≤ θ + 1 / 2 FOV; where FOV is the field of view angle of the input light, and θ is an interior angle of the cross-sectional shape of the sub-outcoupling portion along the first direction.

[0018] Further, the near-eye display component satisfies:

[0019]

[0020] Wherein, is the light vector of the light-coupling substrate, is the light vector of the turning structure, is the light vector of the light-outcoupling substrate.

[0021] Further, the light-coupling substrate is divided into a first light-coupling portion and a second light-coupling portion along the second direction, and there are two turning structures, and the two turning structures are correspondingly arranged on the first light-coupling portion and the second light-coupling portion respectively.

[0022] Applying the technical solution of the present utility model, the near-eye display component includes a light-coupling substrate, a turning structure, and a light-outcoupling substrate. The light-coupling substrate has a reflecting surface and a light guiding surface, and the reflecting surface is used to receive and reflect the light guided through the light guiding surface; the turning structure is a diffraction structure; the turning structure is arranged on the surface of the light-coupling substrate or on the surface of the light-outcoupling substrate. The light-outcoupling substrate and the light-coupling substrate are located in the same plane, and the opposite side surfaces of the light-coupling substrate and the light-outcoupling substrate are connected to each other. The light-outcoupling substrate includes a plurality of sub-outcoupling portions, and the plurality of sub-outcoupling portions are sequentially arranged along the first direction and all extend along the second direction. The first direction is perpendicular to the second direction. The connecting surface between two adjacent sub-outcoupling portions among the plurality of sub-outcoupling portions is inclined to the first direction, and a functional film is arranged on the connecting surface.

[0023] By setting that the coupling-in substrate has a reflective surface and a light guiding surface, the light guiding surface can smoothly pour the light output by the external light engine into the interior of the coupling-in substrate, and then transmit it to the reflective surface. Through the reflection of the reflective surface, the transmission direction of the light is deflected and the light is transmitted along a zigzag path. By setting a turning structure and planning the turning structure as a diffraction structure, the turning structure can receive the light in the substrate where it is located and diffract the light transmitted to it, and then transmit it to the coupling-out substrate. By planning that the coupling-out substrate and the coupling-in substrate are located on the same plane and the opposite sides of the coupling-in substrate and the coupling-out substrate are connected to each other, it is beneficial to ensure that the coupling-out substrate can stably receive the light of the coupling-in substrate, and at the same time it is beneficial for the two to form an integral body. In addition, by setting that the coupling-out substrate includes a plurality of sub-coupling-out parts, the plurality of sub-coupling-out parts are arranged in sequence along a first direction and the plurality of sub-coupling-out parts all extend along a second direction, the first direction is perpendicular to the second direction, the connecting surface between two adjacent sub-coupling-out parts among the plurality of sub-coupling-out parts is inclined to the first direction, and a functional film is arranged on the connecting surface, so that the connecting surface combined with the functional film can realize the coupling-out of light, and the light transmitted from the coupling-in substrate and the turning structure to the coupling-out substrate can be coupled out by the connecting surface provided with the functional film, ensuring the stability of the light coupling-out.

[0024] In addition, the near-eye display component of the present application can combine the advantages of the diffractive waveguide and the geometric waveguide. Through the mutual cooperation of the geometric structure and the diffractive structure, it is ensured that the display effect of the near-eye display component of the present application has no distortion and no rainbow effect. When light of different wavelengths passes through the same grating, chromatic dispersion will occur, that is, the RGB three colors are separated. However, in the near-eye display component of the present application, after the light passes through the diffractive structure, it enters the interior of the coupling-out substrate again, and the chromatic dispersion direction is opposite, so that the synthesis of chromatic aberration can be realized and the influence of chromatic dispersion on the imaging effect can be eliminated. Description of the Drawings

[0025] The specification drawings forming a part of the present application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0026] Figure 1 A schematic structural diagram of a near-eye display component at an angle of an optional embodiment of the present invention is shown;

[0027] Figure 2 Shown is Figure 1 a schematic structural diagram of the near-eye display component in

[0028] Figure 3 Shown is Figure 1 a schematic structural diagram of the coupling-in substrate in

[0029] Figure 4The schematic diagram shows the turning structure of the near-eye display component in an alternative embodiment of the present utility model as a volume holographic grating;

[0030] Figure 5 The schematic diagram shows the turning structure of the near-eye display component in an alternative embodiment of the present utility model as a one-dimensional relief grating;

[0031] Figure 6 The schematic diagram shows the turning structure of the near-eye display component in an alternative embodiment of the present utility model as a two-dimensional relief grating;

[0032] Figure 7 The schematic diagram shows the turning structure of the near-eye display component in an alternative embodiment of the present utility model as a liquid crystal grating;

[0033] Figure 8 The partition efficiency diagrams of red, green, and blue wavelengths obtained by adjusting grating parameters are shown;

[0034] Figure 9 Shows Figure 1 The schematic diagram of the sub-coupling out part in

[0035] Figure 10 The light vector diagram of the light-coupling-in substrate of the near-eye display component in an alternative embodiment of the present utility model is shown;

[0036] Figure 11 The light vector diagram of the turning structure of the near-eye display component in an alternative embodiment of the present utility model is shown;

[0037] Figure 12 The schematic diagram shows the turning structure of the near-eye display component in an alternative embodiment of the present utility model as a metasurface structure;

[0038] Figure 13 The K-domain diagram of the near-eye display component in an alternative embodiment of the present utility model is shown;

[0039] Figure 14 And Figure 15 Respectively show the two-dimensional K-domain diagram and three-dimensional K-domain diagram of the light propagation under a reference plane in the near-eye display component;

[0040] Figure 16 And Figure 17 Respectively show the two-dimensional K-domain diagram and three-dimensional K-domain diagram of the light propagation under another reference plane in the near-eye display component;

[0041] Figure 18 And Figure 19 Respectively show the two-dimensional K-domain diagram and three-dimensional K-domain diagram of the light propagation under another reference plane in the near-eye display component;

[0042] Figure 20 Shows the K-domain diagram when light travels twice in the x and y directions inside the output substrate;

[0043] Figure 21 Shows the optical path diagram of the near-eye display component of an alternative embodiment of the present invention;

[0044] Figure 22 Shows Figure 21 the K-domain diagram of the near-eye display component in

[0045] Figure 23 Shows the optical path diagram of the near-eye display component of another alternative embodiment of the present invention;

[0046] Figure 24 Shows the optical path diagram of the near-eye display component of another alternative embodiment of the present invention;

[0047] Figure 25 Shows Figure 24 a schematic diagram of another angle of the near-eye display component in

[0048] Figure 26 Shows the optical path diagram of the near-eye display component of another alternative embodiment of the present invention;

[0049] Figure 27 Shows the optical path diagram of the near-eye display component of another alternative embodiment of the present invention;

[0050] Figure 28 Shows the reflectivity curve diagram of the selective transmission film of the near-eye display component of a specific embodiment of the present invention;

[0051] Figure 29 Shows the simulation diagram of the near-eye display component of a specific embodiment of the present invention;

[0052] Figure 30 Shows Figure 29 the optical path simulation diagram of single-ray input of the near-eye display component of

[0053] Figure 31 Shows Figure 29 the optical path simulation diagram of the near-eye display component of when using an optical engine;

[0054] Figure 32 Shows Figure 31 the output spot diagram of the near-eye display component of

[0055] Among them, the above-mentioned drawings include the following reference numerals:

[0056] 10. Coupling substrate; 11. First surface; 12. Second surface; 13. Third surface; 14. Fourth surface; 15. First coupling portion; 16. Second coupling portion; 20. Turning structure; 21. One-dimensional relief grating; 22. Two-dimensional relief grating; 23. Volume holographic grating; 24. Liquid crystal grating; 25. Metasurface structure; 26. First turning portion; 27. Second turning portion; 30. Output coupling substrate; 31. Sub-output portions; 32. Connection surface; 40. First direction; 50. Second direction; 60. Input light ray. Detailed implementation manners

[0057] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0058] It should be pointed out that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0059] In the present invention, unless otherwise stated, the orientation terms such as "upper, lower, top, bottom" are usually relative to the direction shown in the drawings, or relative to the component itself in the vertical, perpendicular or gravitational direction; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contour of each component itself, but the above orientation terms do not limit the present invention.

[0060] In order to solve the problems of distortion and difficult improvement of the rainbow effect in the existing near-eye display components, the present invention provides a near-eye display component.

[0061] As Figures 1 to 21 shown, in an optional embodiment of the present application, the near-eye display component includes a coupling substrate 10, a turning structure 20 and an output coupling substrate 30. The coupling substrate 10 has a reflection surface and a light guiding surface. The reflection surface is used to receive and reflect the light guided through the light guiding surface; the turning structure 20 is a diffraction structure; the turning structure 20 is disposed on the surface of the coupling substrate 10 or on the surface of the output coupling substrate 30. The output coupling substrate 30 and the coupling substrate 10 are in the same plane, and the opposite side surfaces of the coupling substrate 10 and the output coupling substrate 30 are connected. The output coupling substrate 30 includes a plurality of sub-output portions 31. The plurality of sub-output portions 31 are arranged in sequence along the first direction 40 and the plurality of sub-output portions 31 all extend along the second direction 50. The first direction 40 is perpendicular to the second direction 50. The connection surface 32 between two adjacent sub-output portions 31 among the plurality of sub-output portions 31 is inclined with respect to the first direction 40, and a functional film is disposed on the connection surface 32.

[0062] By setting that the light-coupling substrate 10 has a reflective surface and a light-introducing surface, the light-introducing surface can smoothly introduce the light output by the external light engine into the interior of the light-coupling substrate 10, and then transmit it to the reflective surface. Through the reflection of the reflective surface, the transmission direction of the light is deflected and the light is transmitted along a zigzag path. By setting the turning structure 20 and planning the turning structure 20 as a diffraction structure, the turning structure 20 can receive the light in the substrate where it is located and diffract the light transmitted to it, and then transmit it to the light-coupling-out substrate 30. By planning that the light-coupling-out substrate 30 and the light-coupling substrate 10 are located on the same plane, and the opposite side surfaces of the light-coupling substrate 10 and the light-coupling-out substrate 30 are connected to each other, it is beneficial to ensure that the light-coupling-out substrate 30 can stably receive the light of the light-coupling substrate 10, and at the same time it is beneficial for the two to form an integral body. In addition, by setting that the light-coupling-out substrate 30 includes a plurality of sub-light-coupling-out portions 31, the plurality of sub-light-coupling-out portions 31 are arranged in sequence along the first direction 40 and the plurality of sub-light-coupling-out portions 31 all extend along the second direction 50, the first direction 40 is perpendicular to the second direction 50, the connecting surface 32 between two adjacent sub-light-coupling-out portions 31 among the plurality of sub-light-coupling-out portions 31 is inclined to the first direction 40, and a functional film is arranged on the connecting surface 32, so that the connecting surface 32 combined with the functional film can realize the light coupling-out, and the light transmitted from the light-coupling substrate 10 and the turning structure 20 to the light-coupling-out substrate 30 can be coupled out by the connecting surface 32 provided with the functional film, ensuring the stability of the light coupling-out.

[0063] In addition, the near-eye display component of the present application can combine the advantages of the diffractive waveguide and the geometric structure waveguide. Through the mutual cooperation of the geometric structure and the diffraction structure, it is ensured that the display effect of the near-eye display component of the present application has no distortion and no rainbow effect. When light of different wavelengths passes through the same grating, chromatic dispersion will occur, that is, the RGB three colors are separated. However, in the near-eye display component of the present application, after the light passes through the diffraction structure, it enters the interior of the light-coupling-out substrate 30 again, and its chromatic dispersion direction is opposite, so that the synthesis of chromatic aberration can be realized and the influence of chromatic dispersion on the imaging effect can be eliminated. While achieving excellent display effects, the near-eye display component of the present application also greatly reduces the process difficulty and greatly improves its mass production performance.

[0064] In Figure 1 and Figure 2 In an optional embodiment shown in, the light-coupling substrate 10 and the light-coupling-out substrate 30 are connected to form an integral flat plate, and the top view of the flat plate is rectangular. The surfaces of the light-coupling substrate 10 and the light-coupling-out substrate 30 that are connected to each other are both inclined surfaces, and the inclined surfaces are inclined to the first direction 40. The surface of the light-coupling substrate 10 away from the light-coupling-out substrate 30 is inclined to the first direction 40, and a reflective film is plated on this surface to form a reflective surface.

[0065] As Figure 3As shown in the figure, the coupling substrate 10 has a first surface 11, a second surface 12, a third surface 13, and a fourth surface 14 that are sequentially connected in a clockwise direction. The first surface 11 is parallel to the third surface 13, and both the first surface 11 and the third surface 13 are inclined with respect to the first direction 40. The second surface 12 is parallel to the fourth surface 14, and both the second surface 12 and the fourth surface 14 are parallel to the first direction 40. A reflective film is provided on the first surface 11 to form a reflective surface, and the reflective film completely covers the first surface 11. The fourth surface 14 is a light introduction surface. Both the second surface 12 and the fourth surface 14 are polished planes. Through the cooperation of the light introduction surface and the reflective surface, it is beneficial to ensure that the light emitted by the light engine can be poured into the interior of the coupling substrate 10.

[0066] As Figure 3 shown in the figure, the thickness d1 of the coupling substrate 10 satisfies: 0.5 mm ≤ d1 ≤ 3 mm, and the refractive index n1 of the coupling substrate 10 satisfies: 1.3 ≤ n1 ≤ 2.2. By reasonably planning the thickness and refractive index of the coupling substrate 10, it is beneficial to ensure the processability of the coupling substrate 10, and at the same time, it can ensure that the refractive index range of the coupling substrate 10 can meet the transmission of light therein. The included angle θi between the first surface 11 and the fourth surface 14 satisfies: 20° ≤ θi ≤ 35°, and the included angle θo between the second surface 12 and the third surface 13 is θo = θi. The cross-sectional shape of the coupling substrate 10 along the first direction 40 is a parallelogram, and θo and θi are a pair of opposite interior angles of the parallelogram.

[0067] Optionally, the turning structure 20 is a diffraction structure to achieve the diffraction effect on light. The diffraction structure can be a diffraction grating or a metasurface. Specifically, the diffraction structure includes one of a surface relief grating, a volume holographic grating 23, a metasurface structure 25, and a liquid crystal grating 24. The surface relief grating includes a one-dimensional relief grating 21 and a two-dimensional relief grating 22. By setting the turning structure 20 as a diffraction structure, the modulation of light with different wavelengths and different incident angles is achieved.

[0068] The following is an example in combination with the specific selection of the diffraction structure.

[0069] As Figure 4 shown in the figure, when the diffraction grating is a volume holographic grating 23, the grating in the volume holographic grating 23 is a structure with a gradually changing refractive index to achieve the diffraction function.

[0070] In addition, when the diffraction structure is a surface relief grating, the turning structure 20 is divided into multiple turning regions. The grating shape, grating height, duty cycle of the grating, period of the grating, and depth-to-width ratio of the grating in the same turning region are the same, and at least one of the grating shape, grating height, duty cycle of the grating, period of the grating, and depth-to-width ratio in different turning regions is different. Such a setting enables the grating to make specific-order light continue to propagate forward at the expected angle after passing through different turning regions. By setting the regions separately, the diffraction efficiency and uniformity can be improved, which is beneficial to enhancing the display performance of the near-eye display component. The grating shape specifically refers to the cross-sectional shape of the grating along the direction perpendicular to the substrate. The cross-sectional shape includes a rectangle, a parallelogram, and a random shape. Different grating shapes can be set for different turning regions to achieve the purpose of improving the diffraction efficiency.

[0071] Figure 5 FIG. shows a schematic diagram of the diffraction structure being a one-dimensional relief grating 21. The turning structure 20 shown in the figure is divided into three turning regions from left to right. The grating types in different turning regions are different, that is, the shapes are different. The cross-sectional shape of the grating in the first turning region along the direction perpendicular to the substrate is rectangular, the cross-sectional shape of the grating in the second turning region along the direction perpendicular to the substrate is parallelogram-shaped, and the cross-sectional shape of the grating in the third turning region along the direction perpendicular to the substrate is trapezoidal. Only one feasible way is shown in the figure, but it is not limited to this. Figure 6 FIG. shows a schematic diagram of the diffraction structure being a two-dimensional relief grating 22. At this time, the grating shape of the two-dimensional relief grating 22 includes the L shape shown in the figure, but it is not limited to this.

[0072] In Figure 5 , a is the height of a single grating, b is the period of the grating, α1 and α2 are respectively the angles between the two sides of the trapezoid and the substrate when the cross-sectional shape of the grating is trapezoidal. By adjusting the above parameters, the energy of a specific diffraction output angle and diffraction order can be achieved, and the improvement of the output diffraction efficiency and uniformity can be realized through the partition design such as the rectangular structure, parallelogram structure, and special-shaped structure shown in the figure. Figure 8 FIG. is the partition efficiency of red, green, and blue wavelengths at the 0th order and -1st order by adjusting the above parameters, where the abscissa is the grating height a and the ordinate is the diffraction efficiency.

[0073] As Figure 7 shown, when the diffraction structure is a liquid crystal grating 24, the liquid crystal grating 24 utilizes the refractive index and period change of the liquid crystal to achieve the function of diffractive light transmission.

[0074] As Figure 12As shown, when the diffraction structure is the metasurface structure 25, the metasurface structure 25 includes a plurality of column structures. The plurality of column structures are arranged in an array, and the plurality of column structures are divided into a plurality of array regions. The diameters of the column structures in the same array region are the same, and the diameters of the column structures in different array regions are different. In an alternative embodiment of the present application, the plurality of column structures in the same array region are arranged at intervals along a straight line, and the plurality of array regions are arranged at intervals in a direction perpendicular to the straight line. Figure 12 An alternative manner in which the metasurface structure 25 includes a plurality of array regions with sequentially varying diameters is shown in Figure 12 . The diameters of the column structures in three sequentially arranged array regions are 60 nm, 90 nm, and 150 nm in sequence. The metasurface structure 25 can achieve variable efficiency in different regions, and can also improve the output diffraction efficiency and uniformity.

[0075] Moreover, the metasurface structure 25 satisfies the following formula in the reflection state:

[0076]

[0077] where θ r is the incident angle of light in air, θ i is the exit angle after passing through the metasurface structure 25, n i is the refractive index of the incident medium, and λ0 is the working wavelength.

[0078] The metasurface structure 25 satisfies the following formula in the refraction state:

[0079]

[0080] where n t is the refractive index of the refracting medium, and θ t is the refraction angle in the medium.

[0081] In the alternative embodiment shown in Figure 2 , the turning structure 20 is disposed on the surface of the coupling substrate 10, and the turning structure 20 is disposed on the second surface 12, and the turning grating is disposed closer to the reflecting surface relative to the output coupling substrate 30. Of course, in other alternative embodiments, the turning structure 20 may also be disposed on the fourth surface 14.

[0082] As Figure 9 shown, the thickness of the coupling substrate 10 is equal to the thickness of the output coupling substrate 30, and the refractive index of the coupling substrate 10 is equal to the refractive index of the output coupling substrate 30. Specifically, the thickness d2 of the output coupling substrate 30 satisfies: 0.5 mm ≤ d2 ≤ 3 mm, the refractive index n2 of the output coupling substrate 30 satisfies: 1.3 ≤ n2 ≤ 2.2, and the cross-section of each sub-output coupling portion 31 along the first direction 40 is a parallelogram, and an interior angle θ of the parallelogram satisfies: 20° ≤ θ ≤ 35°. The upper and lower surfaces of the sub-output coupling portion 31 are polished.​​

[0083] In addition, a functional film is provided at the connection surface 32 of any two adjacent sub-coupling output portions 31 in the first direction 40. Specifically, the functional film is a selective permeation film, and the working angle range γ of the selective permeation film satisfies: θ - 1 / 2 FOV ≤ γ ≤ θ + 1 / 2 FOV; where FOV is the field of view angle of the input light 60, and θ is an interior angle of the cross-sectional shape of the sub-coupling output portion 31 along the first direction 40. The selective permeation film is a spectral splitting film, and the spectral splitting film and the connection surface 32 cooperate to form a spectral splitting inclined surface.

[0084] Moreover, the selective permeation film needs to satisfy the following formula:

[0085] Ri = 1 / (n - i + 1);

[0086] T = 1 - Ri;

[0087] Where, from near to far from the coupling input end, i is the surface where the i-th selective permeation film is located, n is the total number of surfaces with selective permeation films, Ri is the reflectivity of the i-th surface, T is the transmittance, and l is the total transmittance.

[0088] As Figure 10 shown, for the coupling input substrate 10 and the coupling output substrate 30, since the light rays all follow the law of refraction and reflection, the light ray reflection vector satisfies:

[0089]

[0090]

[0091]

[0092] Where, is the vector propagation direction of the incident light ray, is the direction unit vector, α is the angle between the projection of on the lower surface and β is the angle between and the lower surface.

[0093] When propagating in different media, the reflection vector satisfies:

[0094]

[0095] Where, n1 and n2 are the refractive indices of different materials;

[0096] For the turning structure 20, the grating optical path satisfies:

[0097]

[0098] Among them, n in is the refractive index of the medium before incidence, and n out is the refractive index of the material after incidence. θ in is the incident angle, θ out is the diffraction angle, m is the diffraction order, λ is the wavelength of the incident light, and Λ is the grating period;

[0099] As Figure 11 shown, its grating vector k g satisfies:

[0100]

[0101] Among them,

[0102] n i ·sinφ·sinω = γ;

[0103] Among them, ni is the refractive index of the grating substrate material.

[0104] Specifically, in the near-eye display component of the present application, to enable the light carrying information emitted by the light engine to propagate completely inside the near-eye display component, it is required that the internal light wave vector is closed. Therefore, it is necessary to satisfy:

[0105]

[0106] Among them, is the light vector coupled into the substrate 10, is the light vector of the turning structure 20, is the light vector coupled out of the substrate 30.

[0107] As Figure 13 shown in the K-domain diagram, in the figure, A is the K-domain of the substrate 10 for coupling in, B is the K-domain of the turning structure 20, and C is the K-domain of the substrate 30 for coupling out. Due to the wavelength response of the grating, the light of different wavelengths will be dispersed when passing through the same grating, that is, the RGB three colors are separated. However, in the near-eye display component of the present application, after the light passes through the turning structure 20 and then enters the substrate 30 for coupling out again, its dispersion direction is opposite, so that chromatic aberration synthesis can be achieved.

[0108] Among them, Kmax is the maximum K boundary supported by the substrate material, and Ktir is the small K boundary supported by the substrate material.

[0109]

[0110]

[0111] Among them, n is the refractive index of the substrate material, λ is the response wavelength, and θ max is the maximum incident angle.

[0112] Figure 14 and Figure 15 、 Figure 16 and Figure 17 、 Figure 18 and Figure 19 Three groups of diagrams respectively show two - dimensional and three - dimensional K - domain diagrams of light propagation under different reference planes in a near - eye display component, respectively.

[0113] As Figure 20 shown, when light propagates twice along the x and y directions inside the output substrate 30, the length and width directions of the field of view will rotate by 90°. Under the action of the K - vector of the reflection surface of the light engine, the image light wave vector deflects and satisfies the total reflection condition. The image light enters the input substrate 10. The K - vector of the reflection surface is represented as a circular arc vector centered at the origin in the K - domain. The image light transmits inside the input substrate 10 and hits the turning structure 20. Under the action of the vector of the turning structure 20, the 0 - order continues to transmit, and the + 1 - order diffracted light deviates from the original transmission direction, i.e., the pupil - expansion direction. During the transmission of the + 1 - order diffracted light, it hits the turning structure 20 again and diffracts. The + 1 - order diffracted light has the same transmission direction as the original image light inside the substrate, thus realizing the first - dimension pupil expansion. The image light after the first - dimension pupil expansion transmits along the substrate and reaches the output substrate 30. Under the action of the K - vector of the selective - transmission film, it deflects and breaks the total - reflection condition to exit the output substrate 30. It can be seen from the K - domain diagram that the grating vector and the K - vector of the reflection surface are closed, meeting the requirements of diffractive transmission.

[0114] As Figure 21 shown, it is the optical - path diagram of the near - eye display component in an optional embodiment of the present application. Among them, the turning structure 20 is arranged on the second surface 12, and the extending direction of the turning structure 20 is parallel to the extending direction of the sub - output part 31. The input light ray 60 is deflected by the reflection surface and then contacts the turning structure 20. Among them, the 0 - order continues to propagate to the right and exits after contacting the selective - transmission film of the output substrate 30, and the + 1 - order propagates downward; in the next grating period, the 0 - order continues to propagate to the right and exits after contacting the selective - transmission film of the output substrate 30, and the + 1 - order continues to propagate downward. The subsequent optical path repeats the above process. Figure 22 It is a schematic diagram of light - vector propagation.

[0115] As Figure 23 shown, in another optional implementation manner of the present application, the turning structure 20 is arranged on the surface of the input substrate 10, and the incident direction of the incident light ray on the turning structure 20 is perpendicular to the light - ray direction from the turning structure 20 to the output substrate 30. The specific optical - path transmission process is the same as the above, and will not be elaborated here.

[0116] As Figure 24 and Figure 25As shown, in another alternative embodiment of the present application, the turning structure 20 is disposed on the coupling-in substrate 10, and specifically disposed on the fourth surface 14. The input light ray 60 reaches the turning structure 20 after being reflected by the reflecting surface, where the 0th order continues to propagate to the right and is coupled out after contacting the connecting surface 32 with the selective transmission film of the coupling-out substrate 30, and the +1st order propagates downward; in the next grating period, the 0th order continues to propagate to the right and is coupled out after contacting the connecting surface 32 with the selective transmission film, and the +1st order continues to propagate downward, and the subsequent optical path repeats the above process.

[0117] As Figure 26 shown, in another alternative embodiment of the present application, the coupling-in substrate 10 is divided into a first coupling-in portion 15 and a second coupling-in portion 16 along the second direction 50. The turning structure 20 includes two parts, namely a first turning portion 26 and a second turning portion 27, and the first turning portion 26 and the second turning portion 27 are correspondingly disposed on the first coupling-in portion 15 and the second coupling-in portion 16 respectively. By partitioning the coupling-in substrate 10 and simultaneously disposing two turning structures 20, the field of view angle is -FOV after the coupled-in light ray passes through the first turning portion 26 and then is coupled out through the coupling-out substrate 30, and the field of view angle is +FOV after the coupled-in light ray passes through the second turning portion 27 and then is coupled out through the coupling-out substrate 30. Therefore, the near-eye display component can achieve an output of 2FOV.

[0118] As Figure 27 shown, in another alternative embodiment of the present application, the extending direction of the turning structure 20 is set at an angle with the extending direction of the sub-coupling-out portion 31. The input light ray 60 enters the coupling-in substrate 10 and contacts the turning structure 20, where the 0th order continues to propagate to the right and is coupled out after contacting the corresponding inclined surface of the coupling-out substrate 30, and the +1st order propagates downward; in the next grating period, the 0th order continues to propagate to the right and is coupled out after contacting the corresponding inclined surface of the coupling-out substrate 30, and the +1st order continues to propagate downward, and the subsequent optical path repeats the above process.

[0119] In summary, in the specific embodiments of the present application, as Figures 28 to 32As shown, the near-eye display component supports a field of view angle of 40°, the aspect ratio of the screen is 16:9, the angle between the first surface 11 and the fourth surface 14 of the coupling substrate 10 is 25°, the turning structure 20 is a right-angle grating, the grating period Λ is 0.3 um, the depth a is 0.08 um, the multiple sub-coupling parts 31 of the coupling-out substrate 30 form 6 connection surfaces 32 with selective transmission membranes, the material refractive indices of the coupling substrate 10 and the coupling-out substrate 30 are both 1.64, the thicknesses are both 1.6 mm, the selective transmission membrane and the connection surface 32 cooperate to form a beam-splitting inclined plane, and the ideal reflectivities of the six selective transmission membranes are successively R1 = 16.67%, R2 = 20%, R3 = 25%, R4 = 33.33%, R5 = 50%, R6 = 100%, the working angle is 14° to 36°, and the selected reflectivity curve after uniformity optimization is as Figure 28 shown, where the abscissa is the incident angle, the ordinate is the reflectivity, the different curves in the image are different wavelengths, and the dashed box is the working angle.

[0120] Based on the above parameters, a simulation of the near-eye display component in this embodiment is carried out.

[0121] Among them, Figure 29 shows a modeling schematic diagram of the near-eye display component in this embodiment, Figure 30 is the optical path performance of a single ray entering the near-eye display component. The turning structure 20 realizes one-dimensional pupil expansion of the coupled-in light, and the coupling-out substrate 30 realizes two-dimensional pupil expansion of the light. The specific implementation path is as follows:

[0122] The input light ray 60 of the light engine enters the coupling substrate 10 through the surface of the coupling substrate 10, is reflected by the first surface 11 plated with a reflective film and continues to transmit along a Z shape, transmits to the turning structure 20 and contacts the grating area. Among them, the 0th order continues to propagate to the right and is coupled out after contacting the beam-splitting inclined plane of the coupling-out substrate 30, and the +1st order propagates downward; in the next grating period, the 0th order continues to propagate to the right and is coupled out after contacting the beam-splitting inclined plane in the coupling-out substrate 30, and the +1st order continues to propagate downward, and the subsequent optical path repeats the above process.

[0123] Figure 31 shows the optical path simulation diagram with a light engine added in it, Figure 32 shows Figure 31 the output spot diagram of. From Figure 32 it can be seen that the output image of this embodiment is free of distortion.

[0124] Of course, the present application also provides a near-eye display device. The near-eye display device includes a light engine and the above-mentioned near-eye display component. The light engine is correspondingly arranged with the coupling substrate 10 of the near-eye display component. Specifically, the light engine is correspondingly arranged with the first surface 11 of the coupling substrate 10.

[0125] Obviously, the embodiments described above are only a part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0126] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0127] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0128] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A near-eye display component, characterized in that, Comprising: An input coupling substrate (10), the input coupling substrate (10) having a reflective surface and a light introduction surface, the reflective surface being used for receiving and reflecting light introduced through the light introduction surface; A turning structure (20), the turning structure (20) being a diffraction structure; An output coupling substrate (30), the turning structure (20) being disposed on the surface of the input coupling substrate (10) or on the surface of the output coupling substrate (30), the output coupling substrate (30) and the input coupling substrate (10) being in the same plane, and the opposite side surfaces of the input coupling substrate (10) and the output coupling substrate (30) being connected to each other. The output coupling substrate (30) includes a plurality of sub-output coupling portions (31), the plurality of sub-output coupling portions (31) being arranged in sequence along a first direction (40) and the plurality of sub-output coupling portions (31) all extending along a second direction (50), the first direction (40) being perpendicular to the second direction (50). A connection surface (32) between two adjacent ones of the plurality of sub-output coupling portions (31) is inclined with respect to the first direction (40), and a functional film is disposed on the connection surface (32).

2. The near-eye display component according to claim 1, characterized in that, A surface of the input coupling substrate (10) away from the output coupling substrate (30) is inclined with respect to the first direction (40), and a reflective film is disposed on this surface to form the reflective surface.

3. The near-eye display component according to claim 1, characterized in that, The input coupling substrate (10) has a first surface (11), a second surface (12), a third surface (13), and a fourth surface (14) that are sequentially connected in a clockwise direction. The first surface (11) is parallel to the third surface (13), and both the first surface (11) and the third surface (13) are inclined with respect to the first direction (40). The second surface (12) is parallel to the fourth surface (14), and both the second surface (12) and the fourth surface (14) are parallel to the first direction (40). A reflective film is disposed on the first surface (11), and the fourth surface (14) is the light introduction surface.

4. The near-eye display component according to claim 3, wherein The thickness d1 of the input coupling substrate (10) satisfies: 0.5 mm ≤ d1 ≤ 3 mm; and / or The refractive index n1 of the input coupling substrate (10) satisfies: 1.3 ≤ n1 ≤ 2.2; and / or The included angle θi between the first surface (11) and the fourth surface (14) satisfies: 20° ≤ θi ≤ 35°.

5. The near-eye display component according to claim 1, wherein The diffraction structure includes one of a surface relief grating, a volume holographic grating (23), a metasurface structure (25), and a liquid crystal grating (24).

6. The near-eye display component according to claim 1, wherein The diffraction structure is a surface relief grating. The turning structure (20) is divided into a plurality of turning regions. In the same turning region, the grating shape, grating height, duty cycle of the grating, period of the grating, and aspect ratio of the grating are the same. At least one of the grating shape, grating height, duty cycle of the grating, period of the grating, and aspect ratio of the grating in different turning regions is different.

7. The near-eye display component according to claim 1, wherein The diffraction structure is a metasurface structure (25), and the metasurface structure (25) includes a plurality of column structures. The plurality of column structures are arranged in an array, and the plurality of column structures are divided into a plurality of array regions. The column structures in the same array region have the same diameter, and the column structures in different array regions have different diameters.

8. The near-eye display component according to claim 3, wherein When the turning structure (20) is disposed on the surface of the coupling substrate (10), the turning structure (20) is disposed on the second surface (12) or the fourth surface (14).

9. The near-eye display component according to any one of claims 1 to 8, characterized in that The surfaces of the coupling substrate (10) and the output coupling substrate (30) that are connected to each other are inclined with respect to the first direction (40). The thickness of the coupling substrate (10) is equal to the thickness of the output coupling substrate (30), and the refractive index of the coupling substrate (10) is equal to the refractive index of the output coupling substrate (30).

10. The near-eye display component according to claim 1, characterized in that, The extending direction of the turning structure (20) is parallel or at an angle to the extending direction of the sub-output coupling portion (31).

11. The near-eye display component according to claim 1, characterized in that, The cross-section of the sub-output coupling portion (31) along the first direction (40) is a parallelogram, and an interior angle θ of the parallelogram satisfies: 20° ≤ θ ≤ 35°.

12. The near-eye display component according to any one of claims 1 to 8, characterized in that, The functional film is a selective transmission film, and the operating angle range γ of the selective transmission film satisfies: θ - 1 / 2 FOV ≤ γ ≤ θ + 1 / 2 FOV; wherein, FOV is the field of view angle of the input light, and θ is an interior angle of the cross-sectional shape of the sub-output coupling portion (31) along the first direction (40).

13. The near-eye display component according to any one of claims 1 to 8, characterized in that, The near-eye display assembly satisfies: ； Among them, is the optical vector of the input substrate (10), is the optical vector of the turning structure (20), is the optical vector of the output substrate (30).

14. The near-eye display component according to claim 1, wherein The coupling substrate (10) is divided into a first coupling portion (15) and a second coupling portion (16) along the second direction (50). The turning structure (20) includes two, and the two turning structures (20) are correspondingly disposed on the first coupling portion (15) and the second coupling portion (16).

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