Near-to-eye display system and intelligent head-mounted device

Abstract

The embodiment of the invention provides a near-to-eye display system and intelligent head-mounted equipment. The near-to-eye display system comprises a lens assembly and a prism assembly. The lens assembly comprises a first lens, a second lens, a light splitting element and a phase delayer, the first lens and the second lens are mutually glued along the same optical axis, the light splitting element is arranged between the first lens and the second lens, and the phase delayer is arranged on the side, away from the first lens, of the second lens; the prism assembly comprises a first prism, a second prism and a polarization reflection element, the first prism and the second prism are glued with each other, the polarization reflection element is arranged on the glued surface of the first prism and the second prism, and the phase delayer is located between the light splitting element and the light path of the polarization reflection element; the lens assembly is configured to be capable of moving relative to the prism assembly in the optical axis direction of the lens assembly so that the diopter adjusting function can be achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of optical display devices. More specifically, the embodiments of the present application relate to a near-eye display system and an intelligent head-mounted device. Background Art

[0002] With the advancement of science and technology, AR smart glasses, as an important carrier of AR technology, have gradually entered people's lives. However, as a device that needs to be worn on the eyes, AR smart glasses face many challenges in design and use. On the one hand, in order to ensure the comfort and convenience of wearing, AR smart glasses must be thin and light; on the other hand, in order to improve the user's visual experience, AR glasses need to have a larger field of view (FOV) and higher imaging quality to ensure that users can clearly see the integration of virtual information and the real world.

[0003] Since the vision conditions of different users are different, AR smart glasses also need to have a diopter adjustment function to adapt to the vision needs of different users. However, it is not easy to achieve diopter adjustment while ensuring lightness, large FOV and high imaging quality. This requires that when designing AR smart glasses, various components must be arranged in a limited space and ensure that they can work together. With its large FOV, PWG products provide users with a wide field of view and immersive experience. However, as users' requirements for AR glasses continue to increase, how to achieve the diopter adjustment function while ensuring lightness and large FOV has become an urgent problem to be solved in the design of AR smart glasses. Summary of the invention

[0004] The purpose of this application is to provide a new technical solution for a near-eye display system and an intelligent head-mounted device.

[0005] In a first aspect, the present application provides a near-eye display system. The near-eye display system includes a lens assembly and a prism assembly;

[0006] The lens assembly comprises a first lens and a second lens glued to each other along the same optical axis, a beam splitter and a phase retarder, wherein the beam splitter is arranged between the first lens and the second lens, and the phase retarder is arranged on a side of the second lens away from the first lens;

[0007] The prism assembly includes a first prism and a second prism glued to each other, and a polarized reflective element, wherein the polarized reflective element is arranged on the glued surface of the first prism and the second prism, wherein the phase retarder is located between the light path of the beam splitting element and the polarized reflective element;

[0008] The lens assembly is configured to be movable relative to the prism assembly along its optical axis direction to achieve a diopter adjustment function.

[0009] Optionally, the near-eye display system comprises an image source, and the image source is located on one side of the first prism;

[0010] The image source is used to provide light for imaging display.

[0011] Optionally, the first prism is a right-angle triangular prism, and the second prism is a trapezoidal right-angle quadrangular prism;

[0012] The sharp angles of the first prism and the second prism are both a, and satisfy 25°<a<33°;

[0013] The first right-angled surface of the first prism and the second inclined surface of the second prism are glued to each other, and the upper bottom surface of the second prism is flush with the first inclined surface of the first prism;

[0014] The sharp corners of the first prism and the second prism are respectively located on two sides of the bonding surface of the first prism and the second prism.

[0015] Optionally, the image source is located on one side of a second right-angled surface of the first prism, and the second right-angled surface is a plane or a spherical surface;

[0016] The second lens is located on one side of the first inclined surface of the first prism and is spaced apart from the first prism.

[0017] Optionally, the center of the prism assembly is designed to be located on the optical axis of the lens assembly, and the center thickness of the prism assembly is T1, 5mm<T1<10mm.

[0018] Optionally, the first lens is a plano-concave lens, and the second lens is a plano-convex lens;

[0019] The convex surface of the plano-convex lens is any one of a spherical surface, an aspherical surface and a free-form surface;

[0020] The concave surface shape of the plano-concave lens is the same as the convex surface shape of the plano-convex lens.

[0021] Optionally, the central thickness d of the first lens is 11 0.6mm <d 11 <1mm;

[0022] The second lens meets the following conditions:

[0023] 80mm <f2<120mm;

[0024] 6 <D2 / (d 21 -d22 )<12;

[0025] Where: f2 is the effective focal length of the second lens; D2 is the diameter of the second lens; d 21 is the center thickness of the second lens, and 1 mm <d 21 <4mm;d 22 is the thickness of the non-optical region of the second lens, and 0.4 mm <d 22 <0.8mm.

[0026] Optionally, the effective focal length F of the near-eye display system is: 15 mm <F<25mm。

[0027] Optionally, an average value δ of lens stress of the first lens, the second lens, the first prism, and the second prism is δ<15 nm.

[0028] Optionally, an air gap is provided between the first prism and the second lens, so that a first inclined surface adjacent to the first prism and the second lens is formed as a total reflection surface.

[0029] Optionally, an air gap g is provided between the first prism and the second lens, and the air gap g and the focusing range x of the near-eye display system satisfy the relationship: 0.08mm≤(gx)≤0.2mm; wherein, the focusing range x≤3mm, under this condition, the refractive power adjustment range φ of the lens assembly is 0≤φ≤-6D.

[0030] Optionally, a polarizing element is disposed on the second right-angled surface of the first prism.

[0031] Optionally, the near-eye display system further comprises a third lens, wherein the third lens is located between the image source and the first prism.

[0032] Optionally, the entrance pupil size D and the entrance pupil distance L of the near-eye display system satisfy: 0.15≤D / L<0.34;

[0033] Among them, 12mm≤L≤20mm.

[0034] In a second aspect, the present application provides a smart head-mounted device, the smart head-mounted device comprising:

[0035] casing; and

[0036] A near-eye display system as described in the first aspect.

[0037] The beneficial effects of this application are:

[0038] The embodiment of the present application provides a near-eye display system, which is a PWG optical architecture suitable for the field of AR technology. While ensuring the lightness and large FOV characteristics of the entire optical system, the diopter adjustment function is achieved by moving the glued lens components, and the diopter adjustment range can be 0 to -6D, or even larger. This design enables the near-eye display system to adapt to more users with different vision conditions, improving the versatility and practicality of the product.

[0039] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0041] Figure 1 One of the structural schematic diagrams of the near-eye display system provided in an embodiment of the present application;

[0042] Figure 2 The second structural diagram of the near-eye display system provided in the embodiment of the present application

[0043] Figure 3 for Figure 2 The MTF diagram of the near-eye display system shown is at single green 0D;

[0044] Figure 4 for Figure 2 A vertical axis chromatic aberration diagram of a near-eye display system is shown;

[0045] Figure 5 for Figure 2 A grid distortion diagram of a near-eye display system is shown;

[0046] Figure 6 The third structural diagram of the near-eye display system provided in the embodiment of the present application;

[0047] Figure 7 for Figure 6 The MTF diagram of the near-eye display system shown is at single green 0D;

[0048] Figure 8 for Figure 6 A vertical axis chromatic aberration diagram of a near-eye display system is shown;

[0049] Fig. 9 for Figure 6 A grid distortion diagram of a near-eye display system is shown;

[0050] Fig.10A fourth structural diagram of a near-eye display system provided in an embodiment of the present application;

[0051] Fig.11 for Fig.10 The MTF diagram of the near-eye display system shown is at single green 0D;

[0052] Fig.12 for Fig.10 A vertical axis chromatic aberration diagram of a near-eye display system is shown;

[0053] Fig.13 for Fig.10 Grid distortion diagram of a near-eye display system is shown.

[0054] Description of reference numerals:

[0055] 1. First lens; 2. Second lens; 3. First prism; 31. First right-angled surface; 32. Second right-angled surface; 33. First inclined surface; 4. Second prism; 41. Upper bottom surface; 42. Second inclined surface; 5. Image source; 6. Entrance pupil position; 7. Beam splitter; 8. Phase retarder; 9. Polarization reflection element; 10. Polarization element; 11. Third lens. DETAILED DESCRIPTION

[0056] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0057] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0058] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0059] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0060] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0061] The near-eye display system and the smart head-mounted device provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0062] According to one embodiment of the present application, a near-eye display system is provided. Figure 1 The near-eye display system includes a lens assembly and a prism assembly; the lens assembly includes a first lens 1 and a second lens 2 glued to each other along the same optical axis, a beam splitter 7 and a phase retarder 8, the beam splitter 7 is arranged between the first lens 1 and the second lens 2, and the phase retarder 8 is arranged on the side of the second lens 2 away from the first lens 1; the prism assembly includes a first prism 3 and a second prism 4 glued to each other, and a polarized reflection element 9, the polarized reflection element 9 is arranged on the glued surface of the first prism 3 and the second prism 4, wherein the phase retarder 8 is located between the optical paths of the beam splitter 7 and the polarized reflection element 9; the lens assembly is configured to be movable relative to the prism assembly along its optical axis direction to achieve a diopter adjustment function.

[0063] The near-eye display system provided in the embodiment of the present application is a PWG optical architecture, which is suitable for application in the field of AR optical display technology. In the field of AR optical display technology, the optical architecture provided in the embodiment of the present application can be used to build an AR optical machine system to achieve the fusion of virtual images and the real world, bringing users a good immersive visual experience.

[0064] From the perspective of optical architecture, the near-eye display system of the embodiment of the present application combines the design of a lens assembly and a prism assembly. This combined design not only gives the near-eye display system the ability to flexibly adjust the diopter, but also ensures excellent optical performance. At the same time, the entire near-eye display system maintains a compact size, fully meeting the dual pursuit of lightness and practicality of modern AR optical equipment.

[0065] The near-eye display system of the embodiment of the present application is provided with a lens assembly on the side away from the entrance pupil position 6. Figure 1 As shown, the lens assembly is mainly composed of a first lens 1 and a second lens 2 that are glued together. This glue design not only enhances the overall stability of the lens structure, but also effectively reduces the generation of aberrations, significantly improves the imaging quality, and ensures that users can get a clearer visual experience.

[0066] Furthermore, the lens assembly also introduces two key optical elements, a beam splitter 7 and a phase retarder 8. The beam splitter 7 is arranged between the first lens 1 and the second lens 2, and its function is to split the incident light into two parts, a transmission part and a reflection part, which lays a solid foundation for subsequent polarization conversion and optical path adjustment.

[0067] In the embodiment of the present application, the light splitting element 7 is, for example, a semi-transparent and semi-reflective film, which can allow a part of the light to be transmitted and another part of the light to be reflected.

[0068] It should be noted that the reflectivity and transmittance of the light splitting element 7 can be flexibly adjusted according to specific needs, and this is not limited in the embodiments of the present application.

[0069] The phase retarder 8 introduced in the lens assembly is designed to be located on the surface of the second lens 2 facing away from the first lens 1. Its main function is to change the polarization state of light, for example, to convert linearly polarized light into circularly polarized light, or to convert circularly polarized light into linearly polarized light.

[0070] In the embodiment of the present application, the phase retarder 8 is, for example, a quarter wave plate. The phase retarder 8 can, for example, enable the S light to be transformed into the P light after two reflections. This transformation is crucial for the effective transmission of light and the reduction of loss, and further improves the optical performance of the near-eye display system.

[0071] It should be noted that the phase retarder 8 can be configured as other phase retarder plates as required.

[0072] In the near-eye display system of the present application embodiment, a prism assembly is introduced between the entrance pupil position 6 and the lens assembly, see Figure 1 The prism assembly includes, for example, a first prism 3 and a second prism 4 glued to each other, and also includes a polarized reflective element 9 (such as a transparent P-reflective S film) between the two prisms. This design helps to achieve polarization conversion and reflection of light, thereby controlling the light path.

[0073] The polarized reflective element 9 is a polarized reflector that reflects horizontal linear polarized light and transmits vertical linear polarized light, or a polarized reflector that reflects linear polarized light at any other specific angle and transmits linear polarized light in a direction perpendicular to the angle.

[0074] In the embodiment of the present application, when the S light enters the prism assembly, it is reflected on the polarized reflective element 9 and then enters the lens assembly for further polarization conversion. This design utilizes the polarization characteristics of light to achieve precise control of the light path. At the same time, the P light part of the external light can pass through the polarized reflective element 9 without hindrance and directly enter the human eye, thereby achieving a transparent display function. This design not only ensures the clear presentation of virtual images, but also ensures that users can clearly see the real world, realizing the integration of virtual and reality.

[0075] In the embodiment of the present application, the polarized reflective element 9 is, for example, a polarized reflective film. This film material has good optical properties and stability, and can meet the high requirements of the near-eye display system for optical elements.

[0076] In the embodiment of the present application, the relative movement of the lens assembly and the prism assembly and the diopter adjustment mechanism are specifically described as follows:

[0077] The lens assembly is designed to be movable relative to the prism assembly along its optical axis to be closer to or farther from the prism assembly. This design feature allows the first lens and the second lens to adjust their positions as a whole along their optical axes, and through such position adjustment, the focus position of the light can be effectively changed, thereby achieving flexible adjustment of the diopter of the lens assembly.

[0078] Specifically, by moving the lens assembly, the near-eye display system of the present application can achieve a larger diopter adjustment range, such as 0 to -5D, or even greater than -5D. This adjustment range is wide enough to meet the personalized needs of users with different vision conditions. Whether it is myopia, hyperopia or other vision problems, the system can find a suitable diopter setting.

[0079] In summary, the near-eye display system provided in this embodiment, through the combination and design of the lens assembly and the prism assembly, not only realizes the flexible adjustment of the diopter, but also ensures that the system has good optical performance. At the same time, this design also takes into account the compactness and lightness of the structure, making the product more portable and comfortable while maintaining high performance. The combined effect of these technical effects greatly enhances the user's visual experience and enhances the practicality and market competitiveness of the product.

[0080] In some examples of this application, see Figure 1 The near-eye display system includes an image source 5, which is located on one side of the first prism 3 and is used to provide light for imaging display.

[0081] See also Figure 1 The image source 5 is arranged on one side of the first prism 3, and its main function is to provide light required for imaging display. The image source 5 is, for example, an OLED screen, a Micro-LED screen or an LCD screen.

[0082] In one example, the image source 5 uses a 0.6-inch OLED screen with a resolution of up to 1920*1080. This high-resolution image source can ensure that the near-eye display system outputs clear and detailed images, bringing a more realistic visual experience to the user. At the same time, the OLED screen has excellent color performance and contrast, further improving the image quality.

[0083] From the perspective of the optical architecture provided in this application, the image source 5 is set on one side of the first prism 3. This layout meets the requirements of the optical path design and also helps to improve the compactness and integration of the entire near-eye display system. With the development of AR technology, users have higher and higher requirements for the portability and comfort of the device. By reasonably combining the image source 5 with the prism assembly in the layout position, the embodiment of the present application effectively reduces the volume and weight of the system, allowing users to wear and use it more conveniently.

[0084] The light provided by the image source 5 can efficiently enter the human eye (the human eye is located at Figure 1 The entrance pupil position 6 shown in FIG. 1 is thus obtained, so that the human eye can see the image. In this process, the loss of light is controlled to a minimum, thereby improving the light energy utilization rate of the entire near-eye optical display system.

[0085] Of course, the image source 5 in the present application includes but is not limited to the OLED screen in the above example, and a Micro-LED screen or an LCD screen can also be selected as needed.

[0086] In this example of the present application, by introducing a high-resolution image source 5 and combining the position layout design, multiple technical effects such as clear imaging, compact structure and efficient light utilization are achieved. These optimization measures jointly enhance the user's visual experience and also enhance the market competitiveness of the product.

[0087] In some examples of this application, see Figure 1 The first prism 3 is a right-angle triangular prism, and the second prism 4 is a trapezoidal right-angle quadrangular prism; the sharp angles of the first prism 3 and the second prism 4 are both a, and satisfy 25°<a<33°; the first right-angle surface 31 of the first prism 3 and the second inclined surface 42 of the second prism 4 are glued to each other, and the upper bottom surface 41 of the second prism 4 is flush with the first inclined surface 33 of the first prism 3; the sharp corners of the first prism 3 and the second prism 4 are respectively located on both sides of the glued surface of the first prism 3 and the second prism 4.

[0088] In this example of the present application, see Figure 1, the first prism 3 is a right-angle triangular prism, and the second prism 4 is a trapezoidal right-angle quadrangular prism. This design significantly improves the optical performance of the near-eye display system by optimizing the surface shape and gluing method of the prism. Specifically, the sharp angles of the first prism 3 and the second prism 4 are both a, and satisfy 25°<a<33°. This angle range has been carefully calculated to ensure that the light can be efficiently and accurately transmitted when total reflection occurs inside the prism. At the same time, the first right-angle surface 31 of the first prism 3 and the second inclined surface 42 of the second prism 4 are glued to each other, and the upper bottom surface 41 of the second prism 4 is flush with the first inclined surface 33 of the first prism 3. This surface matching and gluing method not only enhances the structural stability of the prism assembly, but also effectively reduces the volume and weight of the prism assembly, and improves the wearing comfort and portability of the user. In addition, the design also simplifies the assembly process of the prism assembly, reducing the difficulty and cost of assembly.

[0089] According to the first prism 3 and the second prism 4 designed in this example of the present application, at least the following significant technical effects can be achieved:

[0090] (1) Optimize optical performance, which is specifically reflected in the following two aspects:

[0091] The sharp angle a of the first prism 3 and the second prism 4 is designed to meet 25°<a<33°. This range is carefully calculated to optimize the refraction and reflection paths of light. The selection of the sharp angle ensures that when the light is totally reflected inside the prism, it can be efficiently and accurately transmitted, reducing light loss and aberration, thereby improving the imaging quality of the system.

[0092] The first right-angled surface 31 of the first prism 3 and the second inclined surface 42 of the second prism 4 are glued to each other. This surface matching design not only enhances the structural stability of the prism assembly, but also helps to accurately control the propagation direction of light, ensuring that the light can enter the lens assembly along a predetermined path.

[0093] (2) Reduce volume and weight, which is specifically reflected in the following two aspects:

[0094] By gluing the first right-angled surface of the first prism 3 to the second inclined surface of the second prism 4, and making the upper bottom surface 41 of the second prism 4 flush with the first inclined surface 33 of the first prism 3, this design effectively reduces the volume of the prism assembly. While maintaining the optical performance, the near-eye display system is made thinner and lighter, and the wearing comfort and portability of the user are improved.

[0095] The reduction in volume directly leads to a reduction in weight, which is crucial for AR glasses that need to be worn for a long time. The lighter weight reduces the burden on the user's head and improves the product's user experience.

[0096] (3) Improving manufacturing and assembly accuracy: The bonding surface design of the first prism 3 and the second prism 4 enables the two to fit tightly together, which helps to achieve high-precision bonding during the manufacturing process and improves the overall stability and optical performance of the entire near-eye display system.

[0097] In some examples of this application, see Figure 1 , Figure 2 and Figure 6 The image source 5 is located on one side of the second right-angled surface 32 of the first prism 3, and the second right-angled surface 32 is a plane or a spherical surface; the second lens 2 is located on one side of the first inclined surface 33 of the first prism 3, and is spaced apart from the first prism 3.

[0098] The interval between the second lens 2 and the first inclined surface 33 of the first prism 3 enables the first inclined surface 33 of the first prism 3 to form a total reflection surface.

[0099] The three surfaces of the first prism 3 can all be planes, or the surface of the first prism 3 close to the image source 5, namely the second right-angle surface 32, can be set as a spherical surface, while the other surfaces are planes. All surfaces of the second prism 4 can be planes.

[0100] The specific surface shapes of the surfaces of the first prism 3 and the second prism 4 can be adjusted according to actual needs, and this is not limited in the present application.

[0101] In some examples of the present application, the center of the prism assembly is designed to be located on the optical axis of the lens assembly, and the center thickness of the prism assembly is T1, 5mm<T1<10mm.

[0102] In this example of the present application, the center of the prism assembly is located on the optical axis of the lens assembly, and the center thickness T1 thereof is controlled within a range of 5 mm to 10 mm.

[0103] First, the center of the prism assembly is designed to be on the optical axis of the lens assembly, which can ensure that the light can maintain consistency with the optical axis when passing through the prism, thereby avoiding the degradation of imaging quality caused by the light deviating from the optical axis. This design helps to improve the imaging clarity of the system and ensure that users can view high-quality virtual images.

[0104] Secondly, the center thickness T1 of the prism assembly is controlled within the range of 5mm to 10mm. This design is also based on multiple considerations. On the one hand, this thickness can ensure that the prism assembly has sufficient structural strength to withstand external shocks and vibrations, and ensure the stability and durability of the near-eye display system. On the other hand, by controlling the reasonable range of thickness, the refraction and polarization effects of the prism assembly on light can be optimized, further improving the optical performance of the near-eye display system.

[0105] In some examples of the present application, the first lens 1 is a plano-concave lens, and the second lens 2 is a plano-convex lens; the convex surface of the plano-convex lens is any one of a spherical surface, an aspherical surface, and a free-form surface; the concave surface of the plano-concave lens is the same as the convex surface of the plano-convex lens.

[0106] In this example of the present application, the lens assembly in the near-eye display system adopts a specific design, that is, the first lens 1 is a plano-concave lens, the second lens 2 is a plano-convex lens, and the convex surface of the plano-convex lens can be any one of a spherical surface, an aspherical surface or a free-form surface, while the concave surface of the plano-concave lens is consistent with the convex surface of the plano-convex lens. This specific design is based on the following considerations.

[0107] First of all, the combination of plano-concave lens and plano-convex lens helps to correct aberration and improve the imaging quality of the system. The concave surface of the plano-concave lens can compensate for the divergence of light after passing through the display panel, while the convex surface of the plano-convex lens can converge the light. The two work together to make the light more accurately focused in the user's eyes after passing through the lens assembly, thus presenting a clearer and more delicate image.

[0108] Secondly, the diversity of convex surface types of plano-convex lenses (spherical, aspherical, free-form) provides greater flexibility for the design of near-eye display systems. Different surface types can refract and regulate light to different degrees to meet different imaging requirements. For example, the design of aspherical or free-form surfaces can more effectively correct aberrations and improve the resolution and contrast of near-eye display systems; while the design of spherical surfaces may be simpler and less costly, and is suitable for occasions where the requirements for imaging quality are not particularly high.

[0109] Furthermore, the concave surface of the plano-concave lens is consistent with the convex surface of the plano-convex lens. This design helps to simplify the manufacturing and assembly process of the near-eye display system. Because the two lenses have the same surface shape, the same mold or processing equipment can be used for manufacturing, reducing production costs. At the same time, during the assembly process, due to the consistency of the surface shape, it is easier to achieve precise alignment between lenses, improving the assembly accuracy and stability of the system.

[0110] It can be seen that the near-eye display system in the example of this application achieves improved imaging quality, increased design flexibility, reduced manufacturing costs, and improved assembly accuracy and stability by adopting a combination design of a plano-concave lens and a plano-convex lens, as well as a variety of choices for the convex surface of the plano-convex lens. These optimization measures together improve the overall performance of the near-eye display system and the user's visual experience.

[0111] In an example, for the parameter design of the first lens 1, the second lens 2, the first prism 3 and the second prism 4 in the near-eye display system provided in the present application, please refer to the description in the following table.

[0112]

[0113] In some examples of the present application, the central thickness d of the first lens 1 is 11 0.6mm <d 11 <1mm;

[0114] The second lens 2 meets the following conditions:

[0115] 80mm <f2<120mm;

[0116] 6 <D2 / (d 21 -d 22 )<12;

[0117] Where: f2 is the effective focal length of the second lens 2; D2 is the diameter of the second lens 2; d 21 is the center thickness of the second lens 2, and 1 mm <d 21 <4mm;d 22 is the thickness of the non-optical region of the second lens 2, and 0.4 mm <d 22 <0.8mm.

[0118] In this example of the present application, the central thickness d of the first lens 1 is 11 Designed to be in the range of 0.6mm to 1mm, this choice was based on multiple considerations.

[0119] First, this thickness range can ensure that the first lens 1 has appropriate focal length and excellent aberration correction capability, which is crucial to meet the strict requirements of near-eye display systems for high-definition imaging. Appropriate focal length ensures that the first lens 1 can accurately focus light, while good aberration correction capability helps reduce image distortion and blur, thereby improving the overall imaging quality.

[0120] Secondly, the selection of this center thickness range is also based on the balance between manufacturing difficulty and cost. If the first lens 1 is too thin, it may be more susceptible to damage during processing and assembly, increasing the production scrap rate; if it is too thick, it will increase the material and processing costs, which is not conducive to product cost control. The range of 0.6mm to 1mm ensures the strength of the lens and avoids unnecessary cost increases.

[0121] In addition, this thickness range also helps to achieve a lightweight design of the near-eye display system. The thinner first lens 1 can reduce the volume and weight of the entire near-eye display system, which is of great significance for improving the wearing comfort and portability of users.

[0122] It can be seen that the selection of the center thickness of the first lens 1 in this example of the present application not only meets the high requirements of optical performance, but also takes into account the control of manufacturing difficulty and cost, while promoting the lightweight design of the near-eye display system, providing users with a better visual experience.

[0123] In this example of the present application, the second lens 2 is a plano-convex lens, the diameter of the optically effective area of ​​the second lens 2 is greater than 12 mm, and the area outside the optically effective area is a non-optical area.

[0124] First, the effective focal length f2 of the second lens 2 is controlled between 80 mm and 120 mm. This focal length range ensures that the second lens 2 has sufficient convergence ability for light, thereby meeting the high requirements of the near-eye display system for imaging quality. At the same time, it avoids the manufacturing difficulty and increased cost that may be caused by a short focal length. Secondly, the diameter D2 of the second lens is closely related to its aperture, which will affect the field of view (FOV) and imaging quality of the system. The size of D2 is selected according to the overall design and performance requirements of the near-eye display system to ensure sufficient light throughput.

[0125] In terms of the thickness of the second lens 2, its central thickness d 21 The thickness of the second lens 2 is controlled between 1 mm and 4 mm. This design ensures that the second lens 2 has sufficient mechanical strength to resist external impact and vibration, while maintaining the lightness and small size of the second lens 2. 22 It is controlled between 0.4 mm and 0.8 mm. This range ensures the ease of processing of the second lens 2 during the manufacturing process and the tight fit during assembly.

[0126] More importantly, the diameter D2 of the second lens and its center thickness d 21 and edge thickness d 22 The proportional relationship between <D2 / (d 21 -d22 )<12. This ratio not only reflects the shape of the second lens 2, but also has a certain impact on its optical performance and manufacturing difficulty. By accurately controlling this ratio, the optical performance of the lens, such as aberration correction and light convergence, can be optimized to ensure that the system can maintain high imaging quality when adjusting the diopter. At the same time, this design also reduces the manufacturing difficulty and cost of the second lens 2 and improves production efficiency.

[0127] Based on the above design parameters, the near-eye display system of the embodiment of the present application can achieve diopter adjustment from 0D to -6D, and the change in the field of view (FOV) is less than 1.2 degrees during this process. This technical effect is very important for near-eye display systems such as AR smart glasses, because it ensures that users can get a consistent and clear visual experience at different diopters.

[0128] In order to achieve this technical effect, the near-eye display system of the present application is designed by comprehensively considering factors such as the material, surface shape, thickness of the lens and the layout of the entire optical path. Among them, the ratio between the diameter and thickness of the second lens 2 is a key factor, which directly affects the optical performance of the second lens 2 and the stability of the system.

[0129] In summary, by reasonably designing the diameter, thickness and proportional relationship of the second lens 2 (plano-convex lens) and comprehensively considering other relevant factors, the near-eye display system provided in the embodiment of the present application can maintain high imaging quality and field of view angle stability when adjusting the diopter, thereby significantly improving the user experience and system performance.

[0130] Furthermore, when D2 / (d 21 -d 22 ) is less than 6, the shape of the second lens 2 will tend to be flat, or the difference between its center thickness and edge thickness will become too small. This shape design will result in the second lens 2 having insufficient ability to converge or diverge light, thereby affecting the clarity and accuracy of imaging. Specifically, the aberration correction ability of the second lens 2 may be weakened, making the image easily distorted or blurred, thereby reducing the imaging quality.

[0131] In addition, due to the flat shape or small thickness difference, the edge of the second lens 2 may become thinner. This makes the lens more vulnerable to damage during handling and assembly, increasing the risk of damage. At the same time, the mechanical strength of the lens may also be reduced, making it more susceptible to external shocks and vibrations, thereby reducing the stability of the system.

[0132] When D2 / (d 21 -d 22) is greater than 12, the shape of the second lens 2 may be too steep, or the difference between the center thickness and the edge thickness may become too large. This shape design makes it difficult to control the optical performance of the second lens 2, because the propagation path of light inside the lens may become very complicated. In addition, a larger lens diameter and thickness will increase the volume and weight of the entire system, which is an obvious disadvantage for a near-eye display system that pursues lightness and compactness.

[0133] In some examples of the present application, the effective focal length F of the near-eye display system is: 15 mm <F<25mm。

[0134] The effective focal length F is a crucial optical parameter that directly affects the imaging quality of the near-eye display system. In the example of this application, the effective focal length F of the near-eye display system is designed to ensure that the near-eye display system can provide a clear and wide visual effect.

[0135] First, the appropriate focal length ensures that the near-eye display system has the right magnification and field of view (FOV). This not only allows users to enjoy realistic images, but also reduces aberrations such as distortion and chromatic aberration, thereby further improving image clarity and accuracy. This design allows users to experience a more realistic and delicate picture during use.

[0136] Secondly, considering that the near-eye display system needs to work closely with the user's eyes, the selection of the effective focal length F must also fully consider the adaptability of the human eye. Within the focal length range of 15mm to 25mm, the near-eye display system can better adapt to the pupil position and eye distance of different users, providing a more comfortable wearing experience. This wide range of user adaptability enables the near-eye display system to meet the needs of more users.

[0137] In addition, the size of the effective focal length F also has an important impact on the overall size and weight of the near-eye display system. A shorter focal length helps reduce the volume and weight of the system and achieve a more compact design. This is especially important for applications such as AR smart glasses that pursue a thin and light design, making it easier for users to wear and use the device.

[0138] In addition, the need for diopter adjustment is also taken into account. While maintaining the compactness of the near-eye display system, it is ensured that the effective focal length F has a sufficient adjustment range to meet the vision needs of different users.

[0139] In some examples of the present application, an average value δ of lens stress of the first lens 1 , the second lens 2 , the first prism 3 , and the second prism 4 is δ<15 nm.

[0140] In this example of the present application, the influence of lens stress on polarized light imaging is considered. Lens stress, an internal force generated by the physical properties of the lens or during the processing, will cause the lens to produce double refraction when light passes through it, thereby changing the polarization state of the light, posing a threat to the image quality, especially in polarized light imaging.

[0141] In order to meet this challenge, the design in this application strictly controls the average value of the lens stress of the two lenses and two prisms within the range of δ<15nm. This control brings the following significant technical effects:

[0142] By properly reducing the lens stress, the occurrence of birefringence is reduced, ensuring that the polarization state of polarized light can remain stable when passing through the lens, laying a solid foundation for high-quality polarization imaging.

[0143] A stable polarization state helps improve imaging clarity and accuracy.

[0144] Rainbow streaks and similar stray lights are often caused by birefringence caused by refraction, reflection or lens stress. By strictly controlling the average value of lens stress, birefringence is effectively reduced, thereby eliminating rainbow streaks and similar stray lights. This improves the purity and contrast of the image, making the picture clearer. The clear, stray light-free image quality significantly enhances the user's visual experience. In the near-eye display system, the application of this technical detail allows users to enjoy a higher quality picture.

[0145] To sum up, in this example of the present application, by controlling the average value of lens stress, the birefringence phenomenon is effectively reduced, the stable transmission of polarized light is ensured, the imaging quality is improved, rainbow patterns and stray light are eliminated, and the user experience is enhanced.

[0146] In some examples of this application, see Figure 1 There is an air gap between the first prism 3 and the second lens 2, so that the first inclined surface 33 adjacent to the first prism 3 and the second lens 2 is formed as a total reflection surface.

[0147] In this example of the present application, an air gap is designed between the first prism 3 and the second lens 2, which enables the first prism 3 and the second lens 2 adjacent surface, namely the first inclined surface 33, to form a total reflection surface. Total reflection is an optical phenomenon. When light is emitted from a denser medium to a less dense medium, and the incident angle is greater than or equal to the critical angle, the light will be completely reflected back to the original medium without entering the less dense medium.

[0148] By forming such a total reflection surface, the present application effectively reduces the scattering and absorption of light during propagation. This is because total reflection can ensure that light is reflected in the original medium with almost no loss, thereby greatly improving the transmission efficiency of light. This design not only optimizes the performance of the near-eye display system, but also provides a more stable and efficient light foundation for subsequent optical processing.

[0149] In some examples of the present application, an air gap g is provided between the first prism 3 and the second lens 2, and the air gap g and the focusing range x of the near-eye display system satisfy the relationship: 0.08mm≤(gx)≤0.2mm; wherein, the focusing range x≤3mm, under this condition, the diopter adjustment range φ of the lens assembly is 0≤φ≤-6D.

[0150] The presence of the air gap g enables the surface adjacent to the first prism 3 and the second lens 2 to form a total reflection surface. Total reflection is an efficient light transmission method that can reduce the scattering and absorption of light during the propagation process, thereby improving the transmission efficiency of light.

[0151] The size of the air gap g is crucial to the formation of total reflection. If the air gap g is too small, it may cause physical contact between the prism and the lens, destroying the total reflection surface. If the air gap g is too large, it will be detrimental to the lightweight design of the device.

[0152] The focus range x refers to the moving distance of the lens assembly relative to the prism assembly in the direction of its own optical axis, which is used to adjust the diopter. In the present application, the focus range x is constrained to be less than or equal to 3 mm. At this time, the diopter adjustment range φ of the lens assembly can reach 0<φ<-6D. This adjustment range is wide enough to meet the vision adjustment needs of most users.

[0153] The diopter adjustment range φ is 0<φ<-6D, which means that the lens assembly can provide a certain degree of myopia correction capability. This is particularly important for near-eye display devices, because users may need to adjust the focus under different visual needs (such as reading, looking far away), and the design provides this flexibility.

[0154] By controlling the relationship between the air gap g and the focus range x, it is possible to ensure that the optical path length between the lens assembly and the prism assembly is maintained within an optimized range under different focus states, which helps to reduce optical aberrations and improve image clarity and quality.

[0155] In this example of the present application, after the lens assembly is moved, a certain air gap needs to be maintained between the lens assembly and the prism assembly, and the minimum value of this gap is 0.08mm. This design ensures that even when the lens assembly is moved to the extreme position of its focusing range, it will not physically contact the prism assembly.

[0156] For example, at 0° (i.e., when no focusing is required), the lens assembly is closest to the prism assembly, but there is still an air gap of at least 0.08 mm between the two (for forming a total reflection surface). This design ensures a close fit between the optical components and avoids potential problems caused by excessive proximity.

[0157] That is to say, when the lens assembly is at a position corresponding to 0° diopter, it is at a specific initial position, at which time, an optimized air gap g is maintained between the lens assembly and the prism assembly. This air gap g is determined according to the requirements of optical design and mechanical structure, with a minimum value of 0.08 mm and a maximum value of 0.2 mm. Of course, it can be flexibly selected between 0.08 mm and 0.2 mm as needed, such as 0.09 mm, 0.1 mm, 0.15 mm, etc., and this application does not impose specific restrictions on this.

[0158] When the diopter needs to be changed to meet the vision requirements of different users, the lens assembly can be moved along its optical axis in a direction away from the prism assembly by, for example, a driving mechanism. This movement process is performed within a limited range, that is, the moving distance is less than or equal to 3 mm. This limitation avoids degradation of optical performance or mechanical structure problems caused by excessive movement.

[0159] During the movement of the lens assembly, the air gap g will change accordingly, but it always satisfies a specific relationship: 0.08mm<(gx)<0.2mm, where x is the focus range. This relationship ensures that light can be effectively transmitted and reflected between the lens assembly and the prism assembly at different diopters, thereby achieving high-quality imaging effects.

[0160] In some examples of this application, see Figure 1 A polarizing element 10 is disposed on the second right-angle surface 32 of the first prism 3 .

[0161] In this example of the present application, the introduction of the polarization element 10 improves the optical performance of the near-eye display system. This element can selectively transmit or block light of a specific polarization direction, thereby achieving precise control of the polarization state of the light.

[0162] Specifically, the polarizing element 10 is in the form of a polarizing film, for example, and is disposed on a surface of the first prism 3 adjacent to the image source 5 , namely, the second right-angle surface 32 .

[0163] The light emitted from the image source 5 first undergoes polarization control by the polarization element 10 before entering the prism assembly. This step is critical because it ensures that the light entering the near-eye display system has a consistent polarization state. This consistent polarization state provides a stable and reliable basis for subsequent imaging processing, helping to reduce unnecessary reflections, scattering, and interference.

[0164] In addition, the introduction of the polarization element 10 also allows the optical path of the near-eye display system to be adjusted and optimized. By controlling the polarization direction of the light, the transmission path and distribution of the light can be more effectively managed, thereby reducing the loss and distortion in the optical path. This optimization not only improves the overall imaging performance of the near-eye display system, but also brings a clearer and higher contrast visual experience to the user.

[0165] In some examples of this application, see Fig.10 The near-eye display system also includes a third lens 11, and the third lens 11 is located between the image source 5 and the first prism 3.

[0166] In the near-eye display system provided in the embodiment of the present application, the introduction of the third lens 11 brings about optimization of optical performance. This design not only provides the system with additional light adjustment capabilities, but also significantly improves the transmission path and focusing effect of the light.

[0167] First, the third lens 11 can adjust the propagation path of the light, ensuring that the light can be transmitted in the expected direction and angle when passing through the system. This optimization helps to reduce the aberration and distortion that may be generated during the propagation of light, thereby improving the accuracy and clarity of imaging.

[0168] Secondly, the third lens 11 also plays an important role in improving the light focusing effect. By adjusting the curvature and position of the lens, the light can be better focused when it reaches the observer's eyes, forming a clearer image.

[0169] In addition to optimizing the light transmission path and focusing effect, the third lens 11 can also enhance the contrast, brightness and color saturation of the image. This improvement not only makes the image quality better, but also greatly enhances the overall visual experience, allowing users to enjoy a more immersive near-eye display effect.

[0170] It should be noted that, the arrangement between the image source 5 and the first prism 3 is not limited to only one lens, and no lens may be arranged, or the number of lenses may be increased as required.

[0171] See also Figure 1 , the optical transmission path of the near-eye display system provided by the embodiment of the present application is as follows:

[0172] When light is emitted from the image source 5, it first encounters the polarization element 10 attached to the second right-angle surface 32 of the first prism 3. The function of the polarization element 10 is to convert the light into S-polarized light (S light for short). Subsequently, the S light enters the first prism 3 and is totally reflected at the interface between the first prism 3 and the air (i.e., the first inclined surface 33). This total reflection ensures that the light can be efficiently propagated along a predetermined path.

[0173] After total reflection, the S light will be incident on the polarized reflective element 9 (transparent P-reflective S film). Due to the characteristics of the transparent P-reflective S film, it has a reflective effect on the S light, so the S light will be reflected and enter the second lens 2 (plano-convex lens). On the inner surface of the second lens 2 (plano-convex lens), the light is reflected again; in this process, the S light will pass through the phase retarder 8 (1 / 4 wave plate) attached to the plane of the second lens 2 (plano-convex lens) twice; and these two passes cause the polarization state of the light to change, and the S light is converted into P polarized light (P light for short).

[0174] After the above transformation, the P light will pass through the first prism 3 again, then pass through the polarized reflective element 9 (transparent P-reflective S film) and the second prism 4, and finally enter the user's eyes. In this way, the user can see the image formed by the light emitted by the image source.

[0175] In addition, for external light, its optical path is slightly different. The external light will first pass through the first lens 1 (plano-concave lens), and then pass through the beam splitter 7 (a semi-transparent and semi-reflective film that allows part of the light to pass through and part of the light to be reflected). After that, the light will pass through the first lens 1 (plano-concave lens) again, and continue to pass through the phase retarder 8 (1 / 4 wave plate), the first prism 3, the polarized reflective element 9 (transparent P-reflective S film), and finally enter the user's eyes. This design allows the user to perceive the external ambient light while watching the image.

[0176] In general, this optical path design achieves efficient and clear light transmission and image display through precise polarization control and layout of optical components.

[0177] Optionally, the third lens 11 is an aspherical plastic lens.

[0178] The third lens 11 includes two surfaces, a first surface S1 close to the image source 5 and a second surface S2 close to the first prism 3 .

[0179] In some examples of the present application, the entrance pupil size D and the entrance pupil distance L of the near-eye display system satisfy: 0.15≤D / L<0.34; wherein, 12mm≤L≤20mm.

[0180] This design in this example of the present application fully considers the physiological structure of the human eye and wearing comfort, and is of great significance for improving the user's visual experience and wearing comfort.

[0181] The entrance pupil size D may range from 3 mm to 4 mm (including both end values), which satisfies the pupil size of most human eyes.

[0182] The choice of entrance pupil size D has a direct impact on the imaging quality and field of view of the system. A larger entrance pupil size helps improve the resolution and brightness of the system, but it also increases the complexity and cost of the system. Therefore, it is necessary to reasonably control the entrance pupil size while ensuring the imaging quality.

[0183] The pupil distance L mainly considers the length of the eyelashes and brow bones of the human eye, as well as the comfort when wearing glasses. When wearing glasses, in order to ensure that the eyelashes will not be touched, the pupil distance L needs to be set within a reasonable range. In this example of the present application, the pupil distance L is set to 12mm to 20mm. This range not only ensures the comfort of wearing, but also fully considers the differences in facial features of different users.

[0184] The ratio D / L between the entrance pupil size D and the entrance pupil distance L has an important influence on the field of view (FOV) and image quality of the system. A smaller D / L ratio helps to increase the field of view of the system, but may reduce the image quality; a larger D / L ratio may improve the image quality but reduce the field of view.

[0185] In this example of the present application, by setting the range of 0.15≤D / L<0.34, a wider field of view can be obtained while ensuring a certain imaging quality, thereby improving the user's visual experience.

[0186] It can be seen that the present application achieves comprehensive optimization of wearing comfort, field of view, imaging quality and user adaptability by reasonably setting the relationship and range between the entrance pupil size D and the entrance pupil distance L. This design not only improves the user's visual experience, but also enhances the practicality of the near-eye display system.

[0187] The near-eye display system of the present application is described below through Examples 1 to 3.

[0188] Example 1

[0189] The near-eye display system of this embodiment 1, see Figure 2 , including an image source 5, a lens assembly and a prism assembly;

[0190] The lens assembly comprises a first lens 1 and a second lens 2 glued to each other along the same optical axis, a beam splitter 7 and a phase retarder 8, wherein the beam splitter 7 is glued to the glued surface of the first lens 1 and the second lens 2, and the phase retarder 8 is arranged on the surface of the second lens 2 on the side away from the first lens 1;

[0191] The first lens 1 is a plano-concave lens, the second lens 2 is a plano-convex lens, and the concave surface of the plano-concave lens is the same as the convex surface of the plano-convex lens;

[0192] The prism assembly includes a first prism 3 and a second prism 4 glued to each other and a polarized reflective element 9, wherein the polarized reflective element 9 is arranged on the glued surface of the first prism 3 and the second prism 4; the lens assembly is configured to be movable relative to the prism assembly along its optical axis direction to achieve a diopter adjustment function;

[0193] The first prism 3 is a right-angle triangular prism, and the second prism 4 is a trapezoidal right-angle quadrangular prism;

[0194] The sharp angle a of the first prism 3 and the second prism 4 is 25°<a<33°;

[0195] See also Figure 2 , the first right-angled surface 31 of the first prism 3 and the second inclined surface 42 of the second prism 4 are glued to each other, and the surfaces of the first prism 3 and the second prism 4 are all planes; after the first prism 3 and the second prism 4 are glued, the upper bottom surface 41 of the second prism 4 is flush with the first inclined surface 33 of the first prism 3; the sharp corners of the first prism 3 and the second prism 4 are respectively located on both sides of the glued surface of the first prism 3 and the second prism 4;

[0196] The image source 5 is located on one side of the second right-angled surface 32 (a plane) of the first prism 3, and the second lens 2 and the first inclined surface 33 of the first prism 3 are adjacent to and spaced apart from each other;

[0197] The center of the prism assembly is designed to be located on the optical axis of the lens assembly, and the center thickness of the prism assembly is T1, 5mm<T1<10mm;

[0198] The effective focal length F of the near-eye display system is 15 mm <F<25mm;

[0199] The average value δ of the lens stress of the first lens 1, the second lens 2, the first prism 3 and the second prism 4 is δ<15nm;

[0200] There is an air gap between the first prism 3 and the second lens 2, so that the first inclined surface adjacent to the first prism 3 and the second lens 2 is formed as a total reflection surface;

[0201] A polarizing element 10 is disposed on the second right-angle surface 32 of the first prism 3 .

[0202] The near-eye display system of this embodiment 1 has a diagonal FOV of 51° at 0D, which means that without diopter adjustment (i.e. 0D), the diagonal viewing angle range of the virtual image that the user can see through the near-eye display system is 51 degrees. This is a relatively large field of view, which can provide a relatively wide field of view for the user.

[0203] The near-eye display system provided in this embodiment 1 has a diagonal FOV of 50° at -5D. That is, when the diopter of the lens assembly is adjusted to -5D, the diagonal FOV of the near-eye display system is slightly reduced to 50°. By comparison, it can be seen that although it is reduced, the change is not large, such as the change is only 1°, which shows that the near-eye display system can maintain good field of view stability during the diopter adjustment process.

[0204] It can be seen that the near-eye optical system provided in this embodiment 1 can support a diopter adjustment range from 0D to -5D, which can meet the needs of most myopic users. Through adjustment, users can obtain clear virtual images according to their vision conditions.

[0205] In this embodiment 1, the refractive power is adjusted by adjusting the air space between the lens assembly (including the plano-convex lens and the plano-concave lens) and the prism assembly (including the first prism 3 and the second prism 4), and the focusing range x of the lens assembly is 1.3 mm.

[0206] When the diopter is adjusted to -5D, the total thickness of the first lens 1, the second lens 2, the first prism 3 and the second prism 4 in the near-eye display system is 10.8 mm, which is a relatively compact thickness and achieves a better thin and light design.

[0207] The optical parameters involved in this embodiment 1 are shown in Table 1 and Table 2.

[0208] Table 1

[0209]

[0210]

[0211] Table 2

[0212] Surface number Second lens 2 (plano-convex lens) 1 / c -52.305 k 0.279 A4 2.436E-007 A6 -9.247E-009 A8 1.640E-010 A10 -2.367E-012 A12 1.888E-014 A14 -7.215E-017 A16 1.050E-019

[0213] The optical performance of the near-eye display system provided by this embodiment 1 is shown below through the MTF curve diagram, vertical axis chromatic aberration diagram and grid distortion diagram. Figures 3 to 5 .

[0214] See also Figure 3 ,against Figure 2 For the near-eye display system shown, the MTF is >0.05 at 18lp / mm, which indicates that the near-eye display system has certain imaging capabilities, especially at lower spatial frequencies.

[0215] See also Figure 4 ,against Figure 2 The maximum color difference value of the near-eye display system shown is less than 60 μm, which indicates that the color difference generated by the near-eye display system during the imaging process is relatively small, and the color reproduction of the image is high. For the near-eye display system, a smaller color difference value helps to improve the user's visual experience and reduce the discomfort caused by color difference.

[0216] See also Figure 5 ,against Figure 2 The near-eye display system shown in FIG. Figure 5 It can be seen that the grid lines are not completely parallel or vertical, but show a certain degree of curvature and deformation. This distortion will cause errors in image measurement and data processing, so it is necessary to use software to correct it later. This is precisely the characteristic of the PWG optical architecture on which this application is based, that is, grid distortion may occur during use, and post-processing is required to ensure the accuracy of the data. Post-adjustments can usually be made through specialized software to restore the parallelism and verticality of the grid and reduce measurement errors.

[0217] Example 2

[0218] The optical architecture provided in this embodiment 2 is the same as the optical architecture provided in the above-mentioned embodiment 1, see Figure 6 The difference between this embodiment 2 and embodiment 1 is the following:

[0219] The near-eye display system provided in this embodiment 2 has a diagonal FOV of 51° at 0D, which means that without diopter adjustment (i.e. 0D), the diagonal viewing angle range of the virtual image that the user can see through the near-eye display system is 51°. This is a relatively large field of view, which can provide the user with a relatively wide field of view.

[0220] The near-eye display system provided in Example 2 has a diagonal FOV of 49.8° at -6D, that is, when the diopter is adjusted to -6D, the diagonal FOV is slightly reduced to 49.8°. Although it is reduced, the change is not large, only 1.2°, which shows that the near-eye display system can maintain good field angle stability during the diopter adjustment process.

[0221] It can be seen that the near-eye optical system provided in this embodiment 2 supports a diopter adjustment range from 0D to -6D, which can meet the needs of most myopic users. Through adjustment, users can obtain clear virtual images according to their vision conditions.

[0222] In this embodiment 2, the diopter is adjusted by adjusting the air space between the lens assembly (including the plano-convex lens and the plano-concave lens) and the prism assembly (including the first prism 3 and the second prism 4). The focusing range x of the lens assembly is 1.8 mm. When the diopter is adjusted to -6D, the total thickness of the first lens 1, the second lens 2, the first prism 3 and the second prism 4 in the near-eye display system is 10.8 mm. This is a relatively compact thickness, achieving a better thin and light design.

[0223] Table 3

[0224]

[0225]

[0226] Table 4

[0227] Surface number Second lens 2 (plano-convex lens) First prism 3 (spherical) 1 / c -53.974 26.909 k 1.266 - A4 6.811E-008 - A6 4.999E-008 - A8 -9.638E-010 - A10 1.035E-011 - A12 -5.940E-014 - A14 1.737E-016 - A16 -2.026E-019 -

[0228] The optical performance of the near-eye display system provided in this embodiment 2 is demonstrated below through the MTF curve diagram, the vertical axis chromatic aberration diagram and the grid distortion diagram.

[0229] See also Figure 7 ,against Figure 6 The near-eye display system shown has an MTF of >0.3 at 36lp / mm, which means that at a high spatial frequency of 36 line pairs / mm, the MTF value of the near-eye display system still remains above 0.3, which is a relatively high MTF value, indicating that the near-eye display system has high resolution and clear imaging capabilities.

[0230] See also Figure 8 ,against Figure 6 The maximum color difference value of the near-eye display system shown is less than 70 μm, which indicates that the color difference generated by the near-eye display system during imaging is very small and the color reproduction is high. For the near-eye display system, a smaller color difference value can reduce the visual discomfort caused by color difference and improve the user's viewing experience.

[0231] See also Fig. 9 ,against Figure 6 The near-eye display system shown in FIG. Fig. 9It can be seen that the grid lines are not completely parallel or vertical, but show a certain degree of curvature and deformation. This distortion will cause errors in image measurement and data processing, so it is necessary to use software to correct it later. This is precisely the characteristic of the PWG optical architecture on which this application is based, that is, grid distortion may occur during use, and post-processing is required to ensure the accuracy of the data. Post-adjustments can usually be made through specialized software to restore the parallelism and verticality of the grid and reduce measurement errors.

[0232] Example 3

[0233] The optical architecture provided in this embodiment 3 is different from the optical architecture provided in the above-mentioned embodiment 1 in that a third lens 11 is added between the image source 5 and the first prism 3. Fig.10 In addition, the difference between this embodiment 3 and embodiment 1 lies in the following:

[0234] The near-eye display system provided in this embodiment 3 has a diagonal FOV of 51° at 0D, which means that without diopter adjustment (i.e. 0D), the diagonal viewing angle range of the virtual image that the user can see through the near-eye display system is 51°. This is a relatively large field of view, which can provide the user with a relatively wide field of view.

[0235] The near-eye display system provided in this embodiment 3 has a diagonal FOV of 50° at -6D, that is, when the diopter is adjusted to -6D, the diagonal FOV is slightly reduced to 50°. Although it is reduced, the change is not large, and the change is only 1°, which shows that the near-eye display system can maintain good field angle stability during the diopter adjustment process.

[0236] It can be seen that the near-eye optical system provided in this embodiment 3 supports a diopter adjustment range from 0D to -6D, which can meet the needs of most myopic users. Through adjustment, users can obtain clear virtual images according to their own vision conditions.

[0237] In this embodiment 3, the diopter is adjusted by adjusting the air space between the lens assembly (including the plano-convex lens and the plano-concave lens) and the prism assembly (including the first prism 3 and the second prism 4), and the focusing range x of the lens assembly is 1.8 mm. When the diopter is adjusted to -6D, the total thickness of the first lens 1, the second lens 2, the first prism 3 and the second prism 4 in the near-eye display system is 10.8 mm. This is a relatively compact thickness, achieving a better light and thin design.

[0238] Table 5

[0239]

[0240] Table 6

[0241]

[0242]

[0243] The optical performance of the near-eye display system provided in this embodiment 3 is demonstrated below through the MTF curve diagram, the vertical axis chromatic aberration diagram and the grid distortion diagram.

[0244] See also Fig.11 ,against Fig.10 The near-eye display system shown has an MTF of >0.6 at 36lp / mm, which means that at a high spatial frequency of 36 line pairs / mm, the MTF value of the near-eye display system still remains above 0.3, which is a relatively high MTF value, indicating that the near-eye display system has high resolution and clear imaging capabilities.

[0245] See also Fig.12 ,against Fig.10 The maximum color difference value of the near-eye display system shown is less than 70 μm, which indicates that the color difference generated by the near-eye display system during imaging is very small and the color reproduction is high. For the near-eye display system, a smaller color difference value can reduce the visual discomfort caused by color difference and improve the user's viewing experience.

[0246] See also Fig.13 ,against Fig.10 The near-eye display system shown in FIG. Fig.13 It can be seen that the grid lines are not completely parallel or vertical, but show a certain degree of curvature and deformation. This distortion will cause errors in image measurement and data processing, so it is necessary to use software to correct it later. This is precisely the characteristic of the PWG optical architecture on which this application is based, that is, grid distortion may occur during use, and post-processing is required to ensure the accuracy of the data. Post-adjustments can usually be made through specialized software to restore the parallelism and verticality of the grid and reduce measurement errors.

[0247] According to another embodiment of the present application, a smart head-mounted device is provided, wherein the smart head-mounted device includes a housing and the near-eye display system as described above.

[0248] The specific implementation of the intelligent head mounted device of the embodiment of the present application can refer to the various embodiments of the above-mentioned near-eye display system, and therefore at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0249] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0250] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A near-eye display system, characterized in that: It includes a lens assembly and a prism assembly; The lens assembly comprises a first lens (1) and a second lens (2) which are glued together along the same optical axis, a beam splitter (7) and a phase retarder (8), wherein the beam splitter (7) is arranged between the first lens (1) and the second lens (2), and the phase retarder (8) is arranged on a side of the second lens (2) away from the first lens (1); The prism assembly comprises a first prism (3) and a second prism (4) glued to each other, and a polarized reflective element (9), wherein the polarized reflective element (9) is arranged on the glued surface of the first prism (3) and the second prism (4), wherein the phase retarder (8) is located between the optical path of the beam splitting element (7) and the polarized reflective element (9); The lens assembly is configured to be movable relative to the prism assembly along its optical axis direction to achieve a diopter adjustment function.

2. The near-eye display system according to claim 1, characterized in that: The near-eye display system comprises an image source (5), wherein the image source (5) is located on one side of the first prism (3); The image source (5) is used to provide light for imaging display.

3. The near-eye display system according to claim 2, characterized in that: The first prism (3) is a right-angle triangular prism, and the second prism (4) is a trapezoidal right-angle quadrangular prism; The sharp angles of the first prism (3) and the second prism (4) are both a and satisfy 25°<a<33°; The first right-angled surface (31) of the first prism (3) and the second inclined surface (42) of the second prism (4) are glued to each other, and the upper bottom surface (41) of the second prism (4) is flush with the first inclined surface (33) of the first prism (3); The sharp corners of the first prism (3) and the second prism (4) are respectively located on two sides of the bonding surface of the first prism (3) and the second prism (4).

4. The near-eye display system according to claim 3, characterized in that: The image source (5) is located on one side of a second right-angled surface (32) of the first prism (3), and the second right-angled surface (32) is a plane or a spherical surface; The second lens (2) is located on one side of the first inclined surface (33) of the first prism (3), and is spaced apart from the first prism (3).

5. The near-eye display system according to claim 3, characterized in that: The center of the prism assembly is designed to be located on the optical axis of the lens assembly, and the center thickness of the prism assembly is T1, 5mm<T1<10mm.

6. The near-eye display system according to claim 1, characterized in that: The first lens (1) is a plano-concave lens, and the second lens (2) is a plano-convex lens; The convex surface of the plano-convex lens is any one of a spherical surface, an aspherical surface and a free-form surface; The concave surface shape of the plano-concave lens is the same as the convex surface shape of the plano-convex lens.

7. The near-eye display system according to claim 6, characterized in that: The central thickness d of the first lens (1) 11 0.6mm <d 11 <1mm; The second lens (2) meets the following conditions: 80mm <f2<120mm; 6<D2 / (d 21 -d 22 )<12; Wherein: f2 is the effective focal length of the second lens (2); D2 is the diameter of the second lens (2); d 21 is the center thickness of the second lens (2), and 1 mm <d 21 <4mm;d 22 is the thickness of the non-optical region of the second lens (2), and 0.4 mm <d 22 <0.8mm.

8. The near-eye display system according to claim 1, characterized in that: The effective focal length F of the near-eye display system is: 15 mm <F<25mm。 9. The near-eye display system according to claim 1, characterized in that: The average value δ of the lens stress of the first lens (1), the second lens (2), the first prism (3) and the second prism (4) is δ<15 nm.

10. The near-eye display system according to claim 4, characterized in that: An air gap is provided between the first prism (3) and the second lens (2), so that a first inclined surface (33) adjacent to the first prism (3) and the second lens (2) is formed into a total reflection surface.

11. The near-eye display system according to claim 4, characterized in that: An air gap g is provided between the first prism (3) and the second lens (2), and the air gap g and the focusing range x of the near-eye display system satisfy the relationship: 0.08mm≤(gx)≤0.2mm; wherein the focusing range x≤3mm, under which condition, the diopter adjustment range φ of the lens assembly is 0≤φ≤-6D.

12. The near-eye display system according to claim 4, characterized in that: A polarizing element (10) is arranged on the second right-angle surface (32) of the first prism (3).

13. The near-eye display system according to claim 2, characterized in that: The near-eye display system further comprises a third lens (11), wherein the third lens (11) is located between the image source (5) and the first prism (3).

14. The near-eye display system according to claim 1, characterized in that: The entrance pupil size D and the entrance pupil distance L of the near-eye display system satisfy the following: 0.15≤D / L<0.34; Among them, 12mm≤L≤20mm.

15. A smart head mounted device, characterized in that: include: shell; and A near-eye display system as claimed in any one of claims 1 to 14.

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