Optical lens and near-to-eye display equipment

Abstract

The invention relates to an optical lens and near-to-eye display equipment, and the optical lens comprises a light guide plate which comprises a first surface and a second surface which are parallel to each other, and parallel substrates which are located between the first surface and the second surface and at least comprise two different refractive index materials, and the parallel substrates of the two different refractive index materials are alternately arranged in parallel, the first surface and the second surface are both not parallel to the first surface and / or the second surface, small-angle high-transmission transmission and large-angle reflection coupling-out are achieved, the problem of ghosting caused by traditional large-angle high reflectivity is solved, the process complexity is simplified, the product performance and reliability are improved, the yield is high, and the cost is low.

Description

Technical Field

[0001] This invention relates to the field of augmented reality technology, and more particularly to an optical lens and a near-eye display device. Background Technology

[0002] Traditional arrayed waveguide coupling structures, see Figure 1 It includes an array of beam splitters, with multiple beam splitters 1 set at an angle θ', where θ' = 25°-35°. During light transmission, for the same beam of light incident from two directions on the beam splitter 1, there will be different incident angles α' and β': called small angle α' incident light and large angle β' incident light. When the small angle α' incident light hits the beam splitter 1, part of the light is reflected and directly emitted, eventually entering the human eye. The other part of the light penetrates the beam splitter 1 and continues to propagate forward. The light transmitted through the beam splitter 1 will be incident on the other side of the beam splitter 1 again at a large angle β'. This part of the light will also be separated: the transmitted light continues to propagate forward, while the reflected light cannot enter the human eye to form an effective image, and eventually becomes a ghost image that affects the display quality.

[0003] To solve the above problems, the design of the single-layer beam splitter needs to strictly control the reflectivity of light at different incident angles. It is required to control the reflectivity of light incident at a small angle α' to about 10%, and the reflectivity of light incident at a large angle β' to be as low as possible. Due to physical and process limitations, this value is usually required to be below 0.5%.

[0004] However, the complexity of the actual spectrophotometer design and coating process has a great influence on the control of reflectivity. For example, the design of the film system needs to match various optical parameters such as the thickness, refractive index, and number of layers of each film, and the parameter coupling is complex. The coating process is affected by the interaction of multiple factors such as material properties, equipment precision, ambient temperature and humidity, and coating uniformity, which makes it difficult to control the reflectivity to be very low. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides an optical lens and a near-eye display device.

[0006] The technical solution of the present invention is as follows:

[0007] An optical lens, comprising:

[0008] A light guide plate includes a first surface and a second surface that are parallel to each other. Between the first surface and the second surface are parallel substrates made of at least two different refractive index materials. The two parallel substrates made of different refractive index materials are alternately arranged in parallel and are not parallel to the first surface and / or the second surface.

[0009] As a preferred technical solution, the light guide plate includes at least a coupling end, through which light is coupled into the light guide plate. The light is transmitted by total internal reflection between the first surface and the second surface. The light includes at least a first-direction light transmitted from the first surface to the second surface and a second-direction light transmitted from the second surface to the first surface.

[0010] As a preferred technical solution, a first-direction light is incident on a parallel substrate at a first incident angle. The first-direction light is reflected and refracted at the interface between the parallel substrates to form a first reflected light and a first transmitted light. A second-direction light is incident on a parallel substrate at a second incident angle. The second-direction light is reflected and refracted at the interface between the parallel substrates to form a second reflected light and a second transmitted light. The first incident angle is smaller than the second incident angle. The first transmitted light and the second transmitted light are transmitted by total internal reflection between the first surface and the second surface. The second reflected light exits the light guide plate.

[0011] As a preferred technical solution, the reflectivity of light rays from the first direction and / or the second direction at the interface between parallel substrates during reflection and refraction satisfies the following Fresnel formula:

[0012] ;

[0013] ;

[0014] in, For s-light reflectance, p-light reflectance, , The refractive indices are those of parallel substrates made of two different refractive index materials. For the first angle of incidence or the second angle of incidence, For the angle of refraction, Conforms to the law of refraction .

[0015] As a preferred technical solution, the parallel substrate is located inside the light guide plate and is set at an angle θ with respect to the first surface, where 45° < θ < 90°.

[0016] As a preferred technical solution, the tilt angle θ = 60°, the first incident angle is 0°, and the second incident angle is 60°.

[0017] As a preferred technical solution, a matte film is provided at the connection between the parallel substrate and the first and second surfaces, or the connection between the parallel substrate and the first and second surfaces is roughened or coated to form a micro-nano rough structure.

[0018] As a preferred technical solution, the first surface and the second surface include two parallel substrates made of different refractive index materials, and the thicknesses of the two parallel substrates made of different refractive index materials are the same or different.

[0019] As a preferred technical solution, the first surface and the second surface include parallel substrates made of two or more materials with different refractive indices. One type of parallel substrate is a primary material, and the remaining parallel substrates are secondary materials. The primary material parallel substrate has a greater thickness than the secondary material parallel substrates. The primary material parallel substrate is used to couple light out, while the secondary material parallel substrates are used to regulate reflectivity and transmit light.

[0020] This application also provides a near-eye display device, including the aforementioned optical lens.

[0021] The beneficial effects achieved by the technical solution adopted in this invention are as follows:

[0022] This application proposes an optical lens and a near-eye display device. The optical lens includes multiple parallel substrates tilted within a light guide plate. These multiple parallel substrates include at least two types of parallel substrates made of different refractive index materials. The two types of parallel substrates are alternately arranged and are not parallel to the surface of the light guide plate. This transforms the traditional beam splitter design from "small-angle reflection coupling and large-angle high-transmission transmission" to the current solution of "small-angle high-transmission transmission and large-angle reflection coupling," solving the ghosting problem caused by high reflectivity at large angles. Furthermore, the light guide plate solution cleverly reverses the reflectivity characteristics through an innovative physical structure rather than a complex beam splitter design, fundamentally solving the process difficulties of traditional array waveguide beam splitters. This breakthrough simplifies the manufacturing process, improves product performance and reliability, achieves high yield, and reduces costs. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of an arrayed optical waveguide coupling structure in the prior art;

[0025] Figure 2 This is a schematic diagram of the optical lens structure disclosed in this embodiment;

[0026] Figure 3 This is a schematic diagram of the optical lens structure disclosed in this embodiment;

[0027] Figure 4 This is a schematic diagram of the optical lens structure disclosed in this embodiment.

[0028] Explanation of reference numerals in the attached figures:

[0029] Light guide plate 10; first surface 11; second surface 12; parallel substrate 20. Detailed Implementation

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

[0031] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through a medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] Furthermore, those skilled in the art should understand that in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this invention.

[0033] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] Example

[0035] according to Figures 2-4 This invention provides an optical lens, comprising:

[0036] The light guide plate 10 includes a first surface 11 and a second surface 12 that are parallel to each other. Between the first surface 11 and the second surface 12, there are parallel substrates 20 made of at least two different refractive index materials. The two parallel substrates 20 made of different refractive index materials are alternately arranged in parallel and are not parallel to the first surface 11 and / or the second surface 12.

[0037] This embodiment proposes an optical lens that abandons the traditional beam-splitting film method and adopts a completely new physical mechanism: multiple parallel substrates 20 are tilted and arranged within the light guide plate 10. These multiple parallel substrates include at least two parallel substrates 20 made of materials with different refractive indices. The two parallel substrates 20 are arranged alternately in parallel and are not parallel to the surface of the light guide plate 10. This changes the traditional beam-splitting film layer design from "small-angle reflection coupling and large-angle high transmission transmission" to the current solution of "small-angle high transmission transmission and large-angle reflection coupling". This solves the ghosting problem caused by high reflectivity at large angles. Moreover, the light guide plate 10 solution cleverly reverses the reflectivity characteristics through innovative physical structure rather than complex beam-splitting film system design, fundamentally solving the process problems of traditional array waveguide beam-splitting films. This breakthrough simplifies the manufacturing process, improves product performance and reliability, has a high yield, and effectively reduces costs.

[0038] As the core optical component of the near-eye display system, the light guide plate 10 includes at least a coupling end, which serves as the only channel for external incident light to enter the light guide plate 10, achieving efficient light coupling. The coupling end can be matched with a corresponding coupling structure according to actual needs, such as a microlens array, a diffraction grating, a wedge prism, or a holographic optical element. The coupling structure is optically bonded to the end face of the coupling end to ensure that light enters the light guide plate 10 efficiently and is transmitted to the entire light guide area without loss through total internal reflection.

[0039] Light is transmitted via total internal reflection along the length of the light guide plate 10 between the first surface 11 and the second surface 12. The light guide plate 10 is designed with two types of tilted parallel substrates 20 with different refractive indices. Specifically, multiple parallel substrates 20 of two different materials are arranged between the first surface 11 and the second surface 12 of the light guide plate 10. Preferably, the two types of parallel substrates 20 are arranged alternately and at equal intervals to form a periodic refractive index interface, ensuring that reflection / refractive effects occur at the interface of adjacent parallel substrates 20. All parallel substrates 20 are not parallel to the first surface 11 and the second surface 12 of the light guide plate 10. It can be understood that all parallel substrates 20 are set at an angle θ between the first surface 11 and the second surface 12, where 0 < θ < 90°. This ensures that the light transmission in the light guide plate 10 includes light rays with at least two propagation directions: one is light rays propagating from the first surface 11 to the second surface 12 in the first direction, and the other is light rays propagating from the second surface 12 to the first surface 11 in the second direction.

[0040] Furthermore, according to Figure 2When the first directional light ray propagates within the light guide plate 10, and it strikes the interface between two adjacent parallel substrates 20 with different refractive indices, due to the refractive index difference between the two materials (meaning total internal reflection is not satisfied), reflection and refraction occur simultaneously. The propagation path of the first directional light ray forms a first angle of incidence with the inclined interface of the parallel substrates 20. This first angle of incidence is the angle between the light ray and the normal to the interface of the parallel substrates 20. Because total internal reflection is not satisfied, some light is reflected to form the first reflected light, and some light passes through the interface to form the first transmitted light. According to... Figure 3 When the second-direction light propagates within the light guide plate 10 and is incident on the interface between two adjacent parallel substrates 20 with different refractive indices, the total internal reflection condition is not met due to the refractive index difference between the two materials. Simultaneous reflection and refraction occur. The propagation path of the second-direction light forms a second angle of incidence with the inclined interface of the parallel substrates 20. That is, the second angle of incidence is the angle between the light ray and the normal to the interface of the parallel substrates 20. Again, because the total internal reflection condition is not met, part of the second-direction light is reflected and emitted, forming second reflected light, while part of the light passes through the interface, becoming second transmitted light. The first angle of incidence is smaller than the second angle of incidence; the first angle of incidence is a small angle, and the second angle of incidence is a large angle. This determines the reflection / refractive energy of the light ray at the interface of the parallel substrates 20. The proportion of light distribution is such that when the first and second transmitted light rays reach the first surface 11 or the second surface 12 of the light guide plate 10, they satisfy the condition of total internal reflection and continue to be stably transmitted through total internal reflection in the light guide plate 10, ensuring that the light can cover the entire light guide area and achieve the pupil expansion effect. Because the first incident angle is small and corresponds to high transmission characteristics, the first reflected light has extremely low reflectivity and weak light intensity, which will not interfere with the display effect of effective imaging. Since the propagation direction of the second reflected light rays formed after reflection is deflected, when they reach the first surface 11 or the second surface 12 of the light guide plate 10, they no longer satisfy the condition of total internal reflection. Therefore, they will penetrate the first surface 11 or the second surface 12 and exit the light guide plate 10, directly coupling into the field of view of the human eye to achieve effective imaging. This can be understood as follows: the first directional light ray is a small-angle light ray that propagates from the first surface 11 to the second surface 12, and its interaction with the parallel substrate 20 follows the principle of "low reflection and high transmission". The second directional light ray is a large-angle light ray that propagates from the second surface 12 to the first surface 11, and its interaction with the parallel substrate 20 follows the principle of "high reflection and low transmission". This is the key to achieving effective light coupling, so that the traditional solution of "large-angle light reflection forming ghost image" is replaced by this solution which directly designs the reflected light of large-angle light as effective coupling light, effectively eliminating ghost image interference.

[0041] Preferably, the relationship between reflectivity and angle follows the Fresnel formula, which quantifies the distribution of reflectivity and transmittance. The Fresnel formula is as follows:

[0042] ;

[0043] ;

[0044] in, For s-light reflectance, p-light reflectance, , The refractive indices of parallel substrates 20 are given by two materials with different refractive indices. For the first angle of incidence or the second angle of incidence, Let be the angle of refraction, according to the law of refraction. Sure.

[0045] Preferably, the reflectivity of the light from the first direction at the interface is less than 1%, and the reflectivity of the light from the second direction at the interface is between 5% and 20%. This ensures that the reflectivity and transmittance reach more ideal target values, that is, it ensures that the light from the first direction has high transmission without interference, and the light from the second direction is efficiently coupled out while retaining an appropriate amount of transmission to expand the pupil. This avoids the uncertainty of the empirical film system design in traditional solutions, and fundamentally improves the purity, brightness uniformity and contrast of the displayed image to meet the performance requirements of mid-to-high-end near-eye display devices.

[0046] Furthermore, the thicknesses of the two parallel substrates 20 made of different refractive index materials can be the same or different. Specifically, the thicknesses of the two parallel substrates 20 made of different refractive index materials can be the same or different, or partially the same or different. Through thickness design, it is possible to effectively avoid local light density or sparseness, thereby further optimizing the uniformity of pupil expansion. For example, a design where the thicknesses of the two parallel substrates 20 made of different refractive index materials are different or partially different results in better optical performance, improving pupil expansion uniformity and adaptability. A design where the thicknesses of the two parallel substrates 20 made of different refractive index materials are the same ensures uniform stress during substrate stacking, avoids tilting deviations, reduces process adjustment steps, and lowers production complexity. In summary, compared to traditional solutions where thin substrates are prone to deformation and damage to optical performance, this solution can guarantee the flatness of each parallel substrate 20 and simplify the process.

[0047] In a preferred embodiment, this embodiment follows Figure 4The parallel substrates 20 are set at an angle θ to the first surface 11, where 45° < θ < 90°. The two parallel substrates 20, made of materials with different refractive indices, have different thicknesses and are alternately set at equal intervals. Specifically, there are two parallel substrates 20, one with a first refractive index and the other with a second refractive index. Preferably, the first parallel substrate 20 is a high-refractive-index substrate 20, and the second parallel substrate 20 is a low-refractive-index substrate 20. For example, the high-refractive-index substrate 20 has a refractive index of 1.62, and the low-refractive-index substrate 20 has a refractive index of 1.51. Both parallel substrates 20 are set at an angle θ to the light guide plate 10, where 45° < θ < 90°. Therefore, light rays in the first direction are incident on the high-refractive-index substrate and the low-refractive-index parallel substrate at a first incident angle. At the interface between the two substrates 20 and 20, reflection and refraction occur simultaneously, forming a first reflected light and a first transmitted light. Following the principle of low reflection and high transmission achieved by small-angle incident light, the first transmitted light undergoes total internal reflection through the second surface 12 of the light guide plate 10 to form a second directional light. The second directional light then enters the interface between the next low-refractive-index parallel substrate 20 and the high-refractive-index parallel substrate 20 at a second incident angle, where reflection and refraction occur simultaneously, forming a second reflected light and a second transmitted light. The second transmitted light continues to be transmitted forward by total internal reflection within the light guide plate 10. The second reflected light is an effective high-reflection light, which is coupled out to the light guide plate 10 and enters the human eye. Following the principle of high reflection and low transmission achieved by large-angle incident light, the light is ensured to be transmitted uniformly within the light guide plate 10, achieving a pupil-expanding effect and more uniform brightness.

[0048] In a preferred embodiment, the first incident angle β and the second incident angle α are set. If θ = 90° - θ', then α = β' and β = α', where θ' is the tilt angle of the beam splitter in the traditional scheme, and the small angle α' incident light and the large angle β' incident light in the traditional scheme are completely interchanged with the two incident angles in the traditional scheme, thus completing the reversal of the reflection / transmission characteristics. This allows the traditional scheme to completely get rid of its dependence on the film system design.

[0049] In a preferred embodiment, the tilt angle θ = 60°, the first incident angle is 0°, the second incident angle is 60°, and the light rays in the first direction are incident perpendicular to the interface. At this time, the reflectivity between the two media is the lowest. Specifically, when the angle between the parallel substrate 20 and the light guide plate 10 is 60°, the first incident angle of the light rays at the interface of the adjacent parallel substrates 20 is 0°, and the reflectivity at the interface of the parallel substrates 20 is the lowest, which is the best choice in terms of angle.

[0050] Preferably, an anti-light coating is provided at the junction of the first surface 11 and the second surface 12 of the parallel substrate 20, in order to eliminate the extra stray light generated by the light on the high refractive index parallel substrate 20, since the high refractive index parallel substrate 20 cannot be made particularly thin in the process, and to further improve the imaging purity. The matting film material can be a light-absorbing optical coating, such as a nano-scale carbon-based light-absorbing film. This absorbs or suppresses extra light, preventing it from entering the main optical path and causing stray light interference. The process can be achieved through vacuum deposition, coating curing, etc., compatible with the processing flow of the parallel substrate 20 without adding complex steps. Alternatively, the surface of the parallel substrate 20 cut by the first surface 11 and the second surface 12 can be roughened or painted. When light undergoes total internal reflection within the light guide plate 10, some light may incident on the cross-section of the parallel substrate 20. Without treatment, this easily leads to transmission or irregular reflection, forming stray light. After roughening or painting, a micro / nano rough structure is formed. This portion of light incident on the micro / nano rough structure is absorbed or scattered and cannot be coupled out. Alternatively, other methods can be used to form a micro / nano rough structure to ensure that effective light is transmitted only according to the designed path. Figures 2-4 The light path shown is essentially formed by physically creating a micro-nano rough structure on the cross-section. The micro-nano rough structure is an irregular geometric pattern, such as stripes, lattices, hexagons, etc. The incident light is diffusely scattered on the rough surface. The scattered light is absorbed by the material after multiple reflections inside the parallel substrate 20 and cannot be coupled out.

[0051] Furthermore, materials with different refractive indices can be transparent optical glass, resin materials, silicon carbide, optical adhesives, or other transparent materials that can transmit light, such as a combination of ZF3 glass and K9 glass, or a combination of silicon carbide and optical glass, or a combination of silicon carbide and high refractive index resin, etc. The specific settings need to be selected in combination with the optical characteristics, mechanical properties and process compatibility of each material, and no strict specific limitations are made here.

[0052] This embodiment also provides an optical lens, which differs from the above in that the light guide plate 10 includes two or more parallel substrates 20 made of different refractive indexes. These parallel substrates 20 are arranged at equal or non-interval intervals. One material is the primary material parallel substrate 20, and the others are secondary material parallel substrates 20. The primary and secondary materials have different refractive indices. Each secondary material parallel substrate 20 can be made of two or more materials with different refractive indices. The thickness of the primary material parallel substrate 20 is greater than the thickness of the secondary material parallel substrates 20. The primary material parallel substrate 20 is responsible for light coupling, while the secondary material parallel substrates 20 are responsible for adjusting reflectivity and transmitting light, achieving "high transmission at small angles and reflection coupling at large angles." For example, the primary material A... The system consists of a secondary material B, a primary material A, and a secondary material C, all of which have different refractive indices. The parallel substrates 20 are parallel to each other and have a preset tilt angle with the surface of the light guide plate 10. Preferably, the thickness of the secondary material parallel substrate 20 is significantly less than that of the primary material parallel substrate 20 to avoid occupying too much space or increasing light transmission loss, ensuring that the light continuously interacts with the primary material in the light transmission path. When light is incident on the interface between adjacent parallel substrates of different materials 20, the large-angle incident light that meets the coupling conditions will be reflected and penetrate the surface of the light guide plate 10 to form an effective image, achieve effective pupil expansion, and effectively improve brightness uniformity. This solution does not require changing the parameters of the primary material; the overall reflectivity and coupling efficiency can be adjusted simply by replacing and / or adding secondary materials, which can meet the product requirements of different brightness and large field of view.

[0053] This embodiment also provides a near-eye display device, including the aforementioned optical lens, which meets the product requirements for a large field of view, has good brightness uniformity, improves product performance and yield, and effectively reduces costs.

[0054] The foregoing has provided a detailed description of an optical lens and a near-eye display device according to embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An optical lens, characterized in that, include: A light guide plate includes a first surface and a second surface that are parallel to each other. Between the first surface and the second surface, there are parallel substrates made of at least two different refractive index materials. The two parallel substrates made of different refractive index materials are alternately arranged in parallel and are not parallel to the first surface and / or the second surface.

2. The optical lens according to claim 1, characterized in that, The light guide plate includes at least an insertion end, through which light is coupled into the light guide plate. The light is transmitted by total internal reflection between the first surface and the second surface. The light includes at least a first-direction light transmitted from the first surface to the second surface and a second-direction light transmitted from the second surface to the first surface.

3. The optical lens according to claim 2, characterized in that, The first directional light is incident on the parallel substrate at a first incident angle. The first directional light is reflected and refracted at the interface between the parallel substrates to form a first reflected light and a first transmitted light. The second directional light is incident on the parallel substrate at a second incident angle. The second directional light is reflected and refracted at the interface between the parallel substrates to form a second reflected light and a second transmitted light. The first incident angle is smaller than the second incident angle. The first transmitted light and the second transmitted light are transmitted by total internal reflection between the first surface and the second surface. The second reflected light exits the light guide plate.

4. The optical lens according to claim 3, characterized in that, The reflectivity of the light rays in the first direction and / or the second direction at the interface between the parallel substrates, when reflected and refracted, satisfies the following Fresnel formula: ； ； in, For s-light reflectance, p-light reflectance, , The refractive indices of the parallel substrates are those of two materials with different refractive indices. For the first incident angle or the second incident angle, For the angle of refraction, Conforms to the law of refraction .

5. The optical lens according to claim 4, characterized in that, The parallel substrate is located within the light guide plate and is set at an angle θ to the first surface, where 45° < θ < 90°.

6. The optical lens according to claim 5, characterized in that, The tilt angle θ = 60°, the first incident angle is 0°, and the second incident angle is 60°.

7. The optical lens according to claim 6, characterized in that, The parallel substrate is provided with a matte film at the connection between it and the first surface and the second surface, or the connection between the parallel substrate and the first surface and the second surface is roughened or coated to form a micro-nano rough structure.

8. The optical lens according to any one of claims 1-7, characterized in that, The first surface and the second surface are separated by parallel substrates made of two different refractive index materials, and the thicknesses of the two parallel substrates made of different refractive index materials are the same or different.

9. The optical lens according to any one of claims 1-7, characterized in that, The first surface and the second surface include parallel substrates made of two or more materials with different refractive indices. One type of parallel substrate is a primary material parallel substrate, and the remaining parallel substrates are secondary material parallel substrates. The thickness of the primary material parallel substrate is greater than the thickness of the secondary material parallel substrates. The primary material parallel substrate is used to perform light coupling, and the secondary material parallel substrates are used to perform the functions of adjusting reflectivity and transmitting light.

10. A near-eye display device, characterized in that, Includes the optical lens as described in any one of claims 1-9.

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