Near-eye display system and smart head-mounted device

Abstract

Embodiments of the present application provide a near-eye display system and a smart head-mounted device; wherein the near-eye display system comprises a lens assembly and a prism assembly; the lens assembly comprises a first lens and a second lens mutually cemented along the same optical axis, a beam splitting element and a phase retarder, the beam splitting element is arranged between the first lens and the second lens, and the phase retarder is arranged on the side of the second lens away from the first lens; the prism assembly comprises a first prism and a second prism mutually cemented, and a polarization reflection element, the polarization reflection element is arranged on the cemented surface of the first prism and the second prism, wherein the phase retarder is located between the beam splitting element and the light path of the polarization reflection element; the lens assembly is configured to be able to move relative to the prism assembly along the optical axis direction thereof to realize the adjustment function of diopter.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of optical display devices, and more particularly, to a near-eye display system and a smart head-mounted device. BACKGROUND

[0002] With the progress 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 comfort and convenience, 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 large field of view (FOV) and high imaging quality to ensure that users can clearly see the fusion of virtual information and the real world.

[0003] Because of the differences in vision of different users, 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 thinness, large FOV, and high imaging quality. This requires AR smart glasses to arrange various components in a limited space and ensure their coordinated work when designed. The PWG product has the characteristics of a large FOV, providing users with a wide field of view and an immersive experience. However, as users' requirements for AR glasses continue to improve, how to achieve diopter adjustment function while ensuring thinness and large FOV has become a problem that needs to be solved in the design of AR smart glasses. SUMMARY

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

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

[0006] The lens assembly comprises a first lens and a second lens that are cemented along the same optical axis, a light splitting element, and a phase retarder, the light splitting element is arranged between the first lens and the second lens, and the phase retarder is arranged on the side of the second lens away from the first lens;

[0007] The prism assembly comprises a first prism and a second prism that are cemented, and a polarization reflection element, the polarization reflection element is arranged on the cemented surface of the first prism and the second prism, and the phase retarder is located between the light path of the light splitting element and the polarization reflection element;

[0008] The lens assembly is configured to be movable relative to the prism assembly along the optical axis direction thereof to achieve an accommodation function.

[0009] Optionally, the near-eye display system comprises an image source, which is located at one side of the first prism.

[0010] The image source is configured 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 acute angle of the first prism and the second prism is a, and 25° < a < 33° is satisfied.

[0013] The first right-angle face of the first prism and the second inclined face of the second prism are mutually glued, and the upper base face of the second prism is flush with the first inclined face of the first prism.

[0014] The acute angles of the first prism and the second prism are respectively located at two sides of the glued faces of the first prism and the second prism.

[0015] Optionally, the image source is located at one side of the second right-angle face of the first prism, and the second right-angle face is a plane or a spherical face.

[0016] The second lens is located at one side of the first inclined face 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 face of the plano-convex lens is any one of a spherical face, an aspherical face and a free-form face.

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

[0021] Optionally, the center thickness of the first lens is d1, and 0.6mm < d1 < 1mm. 11 11 <1mm.

[0022] The second lens satisfies the following conditions:

[0023] 80mm < f2 < 120mm.

[0024] 6 < D2 / (d 21 -d​22 )<12;

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

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

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

[0028] Optionally, an air gap is arranged 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 arranged between the first prism and the second lens, and the air gap g and a focusing range x of the near-eye display system satisfy the relationship: 0.08mm ≤ (g-x) ≤ 0.2mm; wherein the focusing range x ≤ 3mm, and under this condition, a refractive power adjustment range φ of the lens assembly is: 0 ≤ φ ≤ -6D.

[0030] Optionally, a polarization element is arranged on a second right-angle surface of the first prism.

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

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

[0033] wherein, 12mm ≤ L ≤ 20mm.

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

[0035] a housing; and

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

[0037] The present application has the following beneficial effects:

[0038] The embodiment of the present application provides a near-eye display system, which is a PWG optical architecture, is suitable for the field of AR technology, can realize the refractive power adjusting function by moving the lens assembly bonded together while ensuring the light and thin characteristics and the large FOV characteristics of the whole optical system, and the refractive power adjusting range can be 0 to-6D, or even larger. The design makes the near-eye display system be able to adapt to more users with different vision conditions, and improves the universality and practicability of the product.

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

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

[0041] Figure 1 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application;

[0042] Figure 2 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application

[0043] Figure 3 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application; Figure 2 An MTF diagram of the near-eye display system at single green 0D is shown;

[0044] Figure 4 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application; Figure 2 A sagittal chromatic aberration diagram of the near-eye display system is shown;

[0045] Figure 5 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application; Figure 2 A grid distortion diagram of the near-eye display system is shown;

[0046] Figure 6 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application;

[0047] Figure 7 A structure schematic diagram of a near-eye display system provided by the embodiment of the present application; Figure 6 An MTF diagram of the near-eye display system at single green 0D is shown;

[0048] Figure 8 A sagittal chromatic aberration diagram of the near-eye display system is shown; Figure 6

[0049] A grid distortion diagram of the near-eye display system is shown; Figure 9 Figure 6

[0050] Figure 10 ​​This is a fourth structural diagram of the near-eye display system provided in an embodiment of the present application;

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

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

[0053] Figure 13 for Figure 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 oblique surface; 4. Second prism; 41. Upper base surface; 42. Second oblique 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 arrangements 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 disclosure, 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 like 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 following describes in detail the near-eye display system and smart head-mounted device provided in the embodiments of the present application 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 comprises a lens assembly and a prism assembly; the lens assembly comprises a first lens 1 and a second lens 2 which are cemented along the same optical axis, a beam splitting element 7 and a phase retarder 8, the beam splitting element 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 comprises a first prism 3 and a second prism 4 which are cemented, and a polarization reflection element 9, the polarization reflection element 9 is arranged on the cemented surface of the first prism 3 and the second prism 4, wherein the phase retarder 8 is located between the beam splitting element 7 and the light path of the polarization reflection element 9; the lens assembly is configured to be movable relative to the prism assembly along the optical axis direction thereof to realize the function of adjusting the diopter.

[0063] The near-eye display system provided by 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 by the embodiment of the present application can be used to construct an AR optical system to realize the fusion of virtual images and the real world, thereby bringing good immersive visual experience to users.

[0064] From the aspect of optical architecture, the near-eye display system of the embodiment of the present application combines the combined design of the lens assembly and the prism assembly. This combined design not only endows the near-eye display system with the ability of flexible adjustment of diopter, but also ensures excellent optical performance. At the same time, the entire near-eye display system maintains a compact volume, fully meeting the dual pursuit of portability and practicality of modern AR optical equipment.

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

[0066] Further, two key optical elements, the beam splitting element 7 and the phase retarder 8, are introduced into the lens assembly. The beam splitting element 7 is arranged between the first lens 1 and the second lens 2, which functions to divide the incident light into transmitted and reflected parts, laying a solid foundation for subsequent polarization conversion and optical path adjustment.

[0067] In the embodiment of the present application, the beam splitting element 7 is, for example, a semi-transmissive and semi-reflective film which can transmit part of the light and reflect another part of the light.

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

[0069] The phase retarder 8 introduced in the lens assembly is designed to be located on the side surface of the second lens 2 away from the first lens 1, and 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 embodiments of the present application, the phase retarder 8 is, for example, a 1 / 4 wave plate. The phase retarder 8 can, for example, enable S light to be converted into P light after two reflections. This conversion is crucial for the effective transmission of light and the reduction of loss, further improving the optical performance of the near-eye display system.

[0071] It should be noted that the phase retarder 8 can be set to other phase retarders as needed.

[0072] The near-eye display system of the embodiments of the present application introduces a prism assembly between the entrance pupil position 6 and the lens assembly, as shown in Figure 1 The prism assembly, for example, includes a first prism 3 and a second prism 4 that are bonded to each other, and further includes a polarization reflection element 9 (such as a P-transmission S-reflection film) between the two prisms. This design helps to achieve polarization conversion and reflection of light, thereby controlling the optical path.

[0073] The polarization reflection element 9 is a polarization reflector that reflects horizontally linearly polarized light and transmits vertically linearly polarized light, or any other specific angle linearly polarized light reflector and the polarization reflector that transmits linearly polarized light in the direction perpendicular to the angle.

[0074] In the embodiments of the present application, when S light enters the prism assembly, it is reflected on the polarization reflection element 9 and then enters the lens assembly for further polarization conversion. This design takes advantage of the polarization properties of light to achieve precise control of the optical path. At the same time, the P light part of the external light can be transmitted through the polarization reflection element 9 without obstruction, directly entering the human eye, thereby realizing 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 combination of virtual and reality.

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

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

[0077] The lens assembly is designed to be movable relative to the prism assembly along the optical axis direction thereof to approach or move away from the prism assembly. This design feature allows the first lens and the second lens as a whole to adjust their positions in the optical axis direction, and through such position adjustment, the focal position of light rays can be effectively changed, thereby realizing flexible adjustment of the refractive power of the lens assembly.

[0078] Specifically, by moving the lens assembly, the near-eye display system of the present application can achieve a large refractive power adjustment range, such as 0~ -5D, or even greater than -5D. This adjustment range is wide enough to meet the individual needs of users with different vision conditions, whether nearsighted, farsighted or other vision problems, and the appropriate refractive power settings can be found in the system.

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

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

[0081] Referring to Figure 1 , the image source 5 is arranged on one side of the first prism 3, and its main function is to provide the light required for imaging display. Among them, 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, and its resolution can be as high as 1920*1080. Such a high-resolution image source can ensure that the near-eye display system outputs clear and delicate images, providing users with a more realistic visual experience. At the same time, the OLED screen has excellent color performance and contrast, further improving the imaging 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 increasingly higher requirements for the portability and comfort of the device. By rationally 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, making it more convenient for users to wear and use.

[0084] The light provided by the image source 5 can efficiently enter the human eye (the human eye is located at Figure 1 In this process, the light loss is kept 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 this 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, by introducing a high-resolution image source 5 and combining it with a position layout design, multiple technical effects such as clear imaging, compact structure, and efficient light utilization are achieved. These optimization measures together enhance the user's visual experience and strengthen 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-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 base 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 face type and gluing method of the prisms. Specifically, the acute angle of the first prism 3 and the second prism 4 is a, and satisfies 25° < a < 33°. This angle range is carefully calculated to ensure that the light can be efficiently and accurately conducted when it is totally reflected inside the prism. At the same time, the first right-angle face 31 of the first prism 3 and the second inclined face 42 of the second prism 4 are glued to each other, and the upper base face 41 of the second prism 4 is flush with the first inclined face 33 of the first prism 3. This face type 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, improving the wearing comfort and portability of the user. In addition, this design also simplifies the assembly process of the prism assembly, reduces the assembly difficulty and cost.

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

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

[0091] The acute angle a of the first prism 3 and the second prism 4 is designed to satisfy 25° < a < 33°, which is carefully calculated to optimize the refraction and reflection path of the light. The choice of acute angle ensures that the light can be efficiently and accurately conducted when it is totally reflected inside the prism, reducing light loss and aberration, thereby improving the imaging quality of the system.

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

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

[0094] By gluing the first right-angle face of the first prism 3 and the second inclined face of the second prism 4, and making the upper base face 41 of the second prism 4 flush with the first inclined face 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 thinned, improving the wearing comfort and portability of the user.

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

[0096] (3) Improve the manufacturing and assembly accuracy: the gluing surface design of the first prism 3 and the second prism 4 makes them closely fit, which helps to achieve high-precision gluing in the manufacturing process, and improves the overall stability and optical performance of the entire near-eye display system.

[0097] In some examples of the present application, referring to Figure 1 , Figure 2 and Figure 6 , the image source 5 is located on one side of the second right-angle surface 32 of the first prism 3, and the second right-angle 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 spacing between the second lens 2 and the first inclined surface 33 of the first prism 3 makes the first inclined surface 33 of the first prism 3 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, i.e. the second right-angle surface 32, can be designed as a spherical surface, while the other surfaces are planes. All surfaces of the second prism 4 can be planes.

[0100] The specific surface shape of each surface of the first prism 3 and the second prism 4 can be adjusted according to actual needs, which 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 is controlled in the range of 5mm to 10mm.

[0103] First, the center of the prism assembly is designed on the optical axis of the lens assembly, which can ensure that the light remains consistent with the optical axis when passing through the prism, thereby avoiding the decline of imaging quality caused by the deviation of light from the optical axis. This design helps to improve the imaging clarity of the system and ensures that the user can watch high-quality virtual images.

[0104] Secondly, the central thickness T1 of the prism assembly is controlled within a range of 5mm to 10mm, which 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 impact and vibration, ensuring 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 effect 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 can be any one of a spherical surface, an aspherical surface, and a free-form surface; and the concave surface of the plano-concave lens has the same surface type 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, i.e., the first lens 1 is a plano-concave lens, and 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 has the same surface type as the convex surface of the plano-convex lens. This specific design is based on the following considerations.

[0107] Firstly, the combination of plano-concave and plano-convex lenses helps to correct aberrations 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 eye after passing through the lens assembly, thus presenting a clearer and more detailed image.

[0108] Secondly, the variety of convex surface types of the plano-convex lens (spherical, aspherical, free-form) provides greater flexibility for near-eye display system design. Different surface types can refract and control light to different degrees, thus meeting different imaging needs. For example, the design of aspherical or free-form surface can more effectively correct aberrations, improving the resolution and contrast of the near-eye display system; while the design of spherical surface can be simpler and lower in cost, suitable for occasions where the imaging quality is not particularly high.

[0109] Furthermore, the concave surface of the plano-concave lens has the same surface type as the convex surface of the plano-convex lens, which helps to simplify the manufacturing and assembly process of the near-eye display system. Because the surface types of the two lenses are the same, the same mold or machining equipment can be used for manufacturing, reducing production costs. At the same time, during the assembly process, due to the consistency of the surface types, the precise alignment between the lenses can be achieved more easily, improving the assembly precision and stability of the system.

[0110] Therefore, the near-eye display system in the examples of the present application realizes the improvement of imaging quality, the increase of design flexibility, the reduction of manufacturing cost, and the improvement of assembly precision and stability by adopting the combination design of plano-concave lens and plano-convex lens, and the diversity selection of the convex surface profile of the plano-convex lens. These optimization measures collectively improve the overall performance of the near-eye display system and the visual experience of the user.

[0111] In one example, 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 by the present application is described in the following table.

[0112]

[0113] In some examples of the present application, the central thickness d 11 of the first lens 1 is designed to be in the range of 0.6mm<d 11 <1mm.

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

[0115] 80mm<f2<120mm.

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

[0117] 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 central thickness of the second lens 2, and 1mm<d 21 <4mm; d 22 is the thickness of the non-optical area of the second lens 2, and 0.4mm<d 22 <0.8mm.

[0118] In this example of the present application, the central thickness d 11 of the first lens 1 is designed to be in the range of 0.6mm to 1mm, which is based on the consideration of multiple factors.

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

[0120] Secondly, this center thickness range was chosen to balance 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 material and processing costs, which is not conducive to product cost control. The range of 0.6mm to 1mm ensures lens strength while avoiding 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 user wearing comfort and portability.

[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 80mm and 120mm. This focal length range ensures that the second lens 2 has sufficient light converging ability, 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 too short focal length. Secondly, the diameter D2 of the second lens is closely related to its aperture, which affects 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, the central thickness d 21 The thickness of the second lens 2 is controlled between 1mm and 4mm. This design not only ensures that the second lens 2 has sufficient mechanical strength to resist external impact and vibration, but also maintains the lightness and compact 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 6 <D2 / (d 21 -d22 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 precisely controlling this ratio, the optical performance of the lens such as aberration correction and light convergence can be optimized, ensuring that the system still maintains high imaging quality when adjusting the refractive power. At the same time, this design also reduces the manufacturing difficulty and cost of the second lens 2, improving production efficiency.

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

[0128] In order to achieve this technical effect, the material, face shape, thickness of the lens and the layout of the entire optical path are considered comprehensively when designing the near-eye display system of the present application. Among them, the diameter-to-thickness ratio 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 their ratio of the second lens 2 (plano-convex lens), and comprehensively considering other related factors, the near-eye display system provided by the embodiments of the present application can maintain high imaging quality and field of view stability when adjusting the refractive power, thereby significantly improving user experience and system performance.

[0130] Further, when the value of D2 / (d 21 -d 22 ) is less than 6, the shape of the second lens 2 tends to be flat, or the difference between the center thickness and the edge thickness becomes too small. This shape design will result in insufficient convergence or divergence of light by the second lens 2, which will affect the clarity and accuracy of the image. Specifically, the aberration correction ability of the second lens 2 may be weakened, making the image prone to distortion or blurring, 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 susceptible 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 impact and vibration, which will further lead to a decrease in system stability.

[0132] When the value of D2 / (d 21 -d 22When the value of the ratio of the thickness of the second lens 2 at the center to the thickness of the second lens 2 at the edge is greater than 12, the shape of the second lens 2 can be too steep, or the difference between the center thickness and the edge thickness can become too large. Such a shape design makes it difficult to control the optical performance of the second lens 2, because the propagation path of light inside the lens can become very complex. In addition, a larger lens diameter and thickness increases the volume and weight of the entire system, which is a clear disadvantage for near-eye display systems that pursue lightness and compactness.

[0133] In some examples of the present application, the effective focal length F of the near-eye display system is: 15mm < 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 examples of the present application, the effective focal length F of the near-eye display system is designed to ensure that the near-eye display system can provide clear and wide visual effects.

[0135] Firstly, an appropriate focal length can ensure that the near-eye display system has a suitable magnification and field of view (FOV). This not only allows users to enjoy realistic images, but also reduces aberrations such as distortion, chromatic aberration, etc., thereby further improving the clarity and accuracy of the images. Such a design allows users to experience more realistic and detailed pictures during use.

[0136] Secondly, considering that the near-eye display system needs to closely cooperate 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 eye pupil positions and interpupillary distances of different users, providing a more comfortable wearing experience. This wide user adaptability allows 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 to reduce the volume and weight of the system, achieving a more compact design. This is particularly important for applications such as AR smart glasses that pursue thin and light designs, allowing users to wear and use the device more easily.

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

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

[0140] In this example of the present application, the influence of lens stress on the imaging of polarized light is considered. Lens stress, which is an internal force generated by the physical properties or processing of the lens, can cause birefringence when light passes through the lens, thereby changing the polarization state of the light and threatening the imaging quality, especially in polarized light imaging.

[0141] To address this challenge, the lens stress average of the two lenses and two prisms is strictly controlled in the range of δ < 15 nm in this application. This control brings the following significant technical effects:

[0142] By appropriately reducing the lens stress, the occurrence of birefringence is reduced. The polarization state of the polarized light can be kept stable when it passes through the lens, laying a solid foundation for high-quality polarized imaging.

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

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

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

[0146] In some examples of the present application, referring to Figure 1 , the first prism 3 and the second lens 2 have an air gap therebetween, so that the first inclined surface 33 adjacent to the second lens 2 of the first prism 3 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 allows the surface adjacent to the second lens 2 of the first prism 3, i.e. the first inclined surface 33, to be formed as a total reflection surface. Total reflection is an optical phenomenon in which when light is emitted from a dense medium to a rare medium, and the incident angle is greater than or equal to the critical angle, the light is totally reflected back into the original medium, and does not enter the rare medium.

[0148] By forming such a total reflection surface, the present application effectively reduces the scattering and absorption of light during propagation. Because total reflection can ensure that light is reflected in the original medium with almost no loss, the transmission efficiency of light is greatly improved. This design not only optimizes the performance of the near-eye display system, but also provides a more stable and efficient light basis 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≤(g-x)≤0.2mm; wherein the focusing range x≤3mm, and under this condition, the dioptric adjustment range φ of the lens assembly is 0≤φ≤-6D.

[0150] The presence of the air gap g allows the surface adjacent to the first prism 3 and the second lens 2 to be formed as a total reflection surface. Total reflection is an efficient light transmission method that can reduce scattering and absorption of light during propagation, 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, physical contact between the prism and the lens may occur, damaging the total reflection surface. If the air gap g is too large, it is not conducive to the lightweight design of the device.

[0152] The focusing range x refers to the movement distance of the lens assembly in the direction of its optical axis relative to the prism assembly, used to achieve dioptric adjustment. In the present application, the focusing range x is constrained to be less than or equal to 3mm, and at this time, the dioptric 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 dioptric adjustment range φ is 0<φ<-6D, which means that the lens assembly can provide a certain degree of myopia correction. This is particularly important for near-eye display devices, as users may need to adjust the focal length under different visual needs (such as reading, gazing at a distance), and this design provides such flexibility.

[0154] By controlling the relationship between the air gap g and the focusing range x, the optical path length between the lens assembly and the prism assembly can be kept within an optimized range under different focusing states. This helps to reduce optical aberrations and improve the clarity and quality of images.

[0155] In this example of the application, after moving the lens assembly, an air gap needs to be maintained between the lens assembly and the prism assembly, the minimum value of which is 0.08 mm. This design ensures that physical contact with the prism assembly does not occur even when the lens assembly is moved to the extreme position of its focusing range.

[0156] For example, at 0° (i.e. without focusing), the lens assembly is closest to the prism assembly, but an air gap of at least 0.08 mm (for forming a total reflection surface) is still maintained between the two. This design ensures both close cooperation between optical elements and avoids potential problems caused by excessive proximity.

[0157] That is, when the lens assembly is in the position corresponding to 0° diopter, it is in a specific initial position, at which an optimized air gap g is maintained between the lens assembly and the prism assembly. This air gap g is determined according to optical design and mechanical structure requirements, and its minimum value is 0.08 mm and its maximum value is 0.2 mm. Of course, it can be flexibly selected between 0.08 mm and 0.2 mm, such as 0.09 mm, 0.1 mm, 0.15 mm, etc., which are not specifically limited in the present application.

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

[0159] During the movement of the lens assembly, the air gap g changes accordingly, but it always satisfies a specific relationship: 0.08 mm < (g - x) < 0.2 mm, where x is the focusing 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 the application, referring to Figure 1 , the second right-angle surface 32 of the first prism 3 is provided with a polarization element 10.

[0161] In this example of the application, the introduction of the polarization element 10 brings optical performance improvement to 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 light.

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

[0163] The light emitted from the image source 5 will first pass through the polarization control of the polarization element 10 before entering the prism assembly. This step is crucial as 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 foundation for subsequent imaging processes, helping to reduce unnecessary reflections, scattering, and interference.

[0164] In addition, the introduction of the polarization element 10 also adjusts and optimizes the optical path of the near-eye display system. 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 the present application, referring to Figure 10 , the near-eye display system further comprises a third lens 11 located between the image source 5 and the first prism 3.

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

[0167] Firstly, 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 occur during the propagation of the light, thereby improving the accuracy and clarity of the imaging.

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

[0169] In addition to the optimization of 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 imaging quality better, but also greatly enhances the overall visual experience, allowing the user to enjoy a more immersive near-eye display effect.

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

[0171] Referring to Figure 1 The optical transmission path of the near-eye display system provided by the embodiments of the present application is as follows:

[0172] When the light rays are emitted from the image source 5, they first encounter the polarizing element 10 attached to the second right-angle surface 32 of the first prism 3. The polarizing element 10 converts the light rays into S-polarized light (S light for short). Subsequently, the S light enters the first prism 3 and undergoes total reflection at the interface between the first prism 3 and air (i.e. the first inclined surface 33). This total reflection ensures that the light rays propagate along the predetermined path efficiently.

[0173] After total reflection, the S light is incident on the polarizing reflection element 9 (P-transmitting S-reflecting film). Due to the characteristics of the P-transmitting S-reflecting film, it reflects the S light, which is then incident on the second lens 2 (plano-convex lens). At the inner surface of the second lens 2 (plano-convex lens), the light rays are reflected again. In this process, the S light passes through the phase retarder 8 (1 / 4 wave plate) attached to the plane of the second lens 2 (plano-convex lens) twice. The two passes change the polarization state of the light rays, and the S light is converted into P-polarized light (P light for short).

[0174] After the above conversion, the P light passes through the first prism 3 again, then passes through the polarizing reflection element 9 (P-transmitting S-reflecting film) and the second prism 4, and finally enters the user's eye. In this way, the user can see the image formed by the light rays emitted by the image source.

[0175] In addition, the light path of external light is slightly different. The external light first passes through the first lens 1 (plano-concave lens), and then passes through the light splitting element 7 (half-transmission half-reflection film, which allows part of the light to transmit and part of the light to reflect). Subsequently, the light passes through the first lens 1 (plano-concave lens) again, and continues to pass through the phase retarder 8 (1 / 4 wave plate), the first prism 3, the polarizing reflection element 9 (P-transmitting S-reflecting film), and finally enters the user's eye as well. This design allows the user to perceive the ambient light while viewing the image.

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

[0177] Optionally, the third lens 11 is a non-spherical plastic lens.

[0178] The third lens 11 includes two surfaces, namely 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 to improve the visual experience and wearing comfort of the user.

[0181] The entrance pupil size D can range from 3mm to 4mm (including both end values). This meets the pupil size of most human eyes.

[0182] The selection of the 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 to improve the resolution and brightness of the system, but 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 entrance pupil distance L mainly considers the length of the eyelashes and the brow bone of the human eye, as well as the comfort when wearing glasses. When wearing glasses, in order to ensure that the eyelashes are not touched, the entrance pupil distance L needs to be set within a reasonable range. In this example of the present application, the entrance 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 imaging quality of the system. A smaller D / L ratio helps to increase the field of view of the system, but may reduce the imaging quality; a larger D / L ratio may improve the imaging quality, but will 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 relatively wide field of view can be obtained while ensuring a certain imaging quality, thereby improving the visual experience of the user.

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

[0187] The following describes the near-eye display system of the present application through Examples 1 to 3.

[0188] Example 1

[0189] The near-eye display system of Example 1 of the present application, as shown in Figure 2 , comprises 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 which are glued to each other along the same optical axis, and a light splitting element 7 and a phase retarder 8, the light splitting element 7 is glued on the gluing surface of the first lens 1 and the second lens 2, and the phase retarder 8 is arranged on the side surface of the second lens 2 away from the first lens 1;

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

[0192] The prism assembly comprises a first prism 3 and a second prism 4 which are glued to each other, and a polarized reflection element 9 arranged on the gluing 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 the optical axis direction thereof to realize the function of adjusting the diopter;

[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 acute angle a of the first prism 3 and the second prism 4 is 25°<a<33°;

[0195] Referring to Figure 2 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 each surface of the first prism 3 and the second prism 4 is a plane; after the first prism 3 and the second prism 4 are glued, the upper base surface 41 of the second prism 4 is flush with the first inclined surface 33 of the first prism 3; the acute angles of the first prism 3 and the second prism 4 are respectively located on both sides of the gluing surface of the first prism 3 and the second prism 4;

[0196] The image source 5 is located on the side of the second right-angle 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 and spaced apart;

[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 15mm<F<25mm;

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

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

[0201] The second right-angle surface 32 of the first prism 3 is provided with a polarizing element 10.

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

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

[0204] As can be seen, the near-eye optical system provided by this embodiment 1 can support a diopter adjustment range from 0D to -5D, which can meet the needs of most myopic users. Through adjustment, the user can obtain a clear virtual image according to his own vision condition.

[0205] This embodiment 1 adjusts the diopter by adjusting the air gap 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 1.3mm.

[0206] When the diopter adjustment is -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 10.8mm. This is a relatively compact thickness, which realizes a good thin design.

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

[0208] Table 1

[0209]

[0210]

[0211] Table 2

[0212] Surface No. 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 in this embodiment 1 is shown below through MTF curve, vertical color difference graph and grid distortion graph respectively, please refer to Figures 3 to 5 .

[0214] Referring to Figure 3 , for the near-eye display system shown in Figure 2 , the MTF is >0.05 at 18 lp / mm, which indicates that the near-eye display system has a certain imaging ability, especially at a lower spatial frequency.

[0215] Referring to Figure 4 , for the near-eye display system shown in Figure 2 , the maximum color difference value is less than 60 μm, which indicates that the color difference generated in the imaging process of the near-eye display system is relatively small, and the color restoration degree of the image is relatively 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] Referring to Figure 5 , for the near-eye display system shown in Figure 2 , it can be seen from Figure 5 that the grid lines are not completely parallel or vertical, but exhibit a certain curvature and distortion. This distortion can cause errors in image measurement and data processing, so it needs to be corrected later using software. This is the feature of the PWG optical architecture based on the present application, that is, grid distortion may occur during use, and post-processing is needed to ensure the accuracy of the data. Post-adjustment can usually be performed through special software to restore the parallelism and perpendicularity of the grid and reduce measurement errors.

[0217] Embodiment 2

[0218] The optical architecture provided in this embodiment 2 is the same as the optical architecture provided in the above embodiment 1, please refer to Figure 6 . However, the difference between this embodiment 2 and embodiment 1 is as follows:

[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 user can see a virtual image through the near-eye display system with a diagonal viewing angle range of 51°. This is a relatively large field of view, which can provide a relatively wide field of view for the user.

[0220] The near-eye display system provided in this embodiment 2 has a diagonal FOV of 49.8° at -6D, that is, when the diopter adjustment is -6D, the diagonal FOV slightly decreases to 49.8°. Although there is a decrease, the change is not large, and the change is only 1.2°, which indicates that the near-eye display system can maintain good field of view stability during diopter adjustment.

[0221] Therefore, the near-eye optical system provided in 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 a clear virtual image according to their own vision conditions.

[0222] Embodiment 2 adjusts the diopter by adjusting the air gap 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 good thin design.

[0223] Table 3

[0224]

[0225]

[0226] Table 4

[0227] Surface No. 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 Embodiment 2 is respectively shown by MTF curves, vertical chromatic aberration diagrams, and grid distortion diagrams.

[0229] Referring to Figure 7 , for the near-eye display system shown in Figure 6 , the MTF is >0.3 at 36 lp / mm, which means that the MTF value of the near-eye display system is still maintained above 0.3 at a high spatial frequency of 36 line pairs per millimeter, which is a relatively high MTF value, indicating that the near-eye display system has high resolution and clear imaging capability.

[0230] Referring to Figure 8 , for the near-eye display system shown in Figure 6 , the maximum chromatic aberration value is less than 70 μm, which indicates that the near-eye display system produces very small chromatic aberration during imaging, and has high color restoration. For a near-eye display system, a smaller chromatic aberration value can reduce visual discomfort caused by chromatic aberration and improve user viewing experience.

[0231] Referring to Figure 9 , for the near-eye display system shown in Figure 6 , from Figure 9As can be seen, the grid lines are not completely parallel or perpendicular, but exhibit a certain bending and deformation. Such distortion will cause errors in image measurement and data processing, and therefore needs to be corrected in the later stage using software. This is the feature of the PWG optical architecture based on the present application, i.e. grid distortion may occur during use, and needs to be corrected through post-processing to ensure the accuracy of the data. Post-adjustment can usually be performed through special software to restore the parallelism and perpendicularity of the grid and reduce measurement errors.

[0232] Embodiment 3

[0233] The optical architecture provided in this embodiment 3 differs from the optical architecture provided in the above-described embodiment 1 in that a third lens 11 is added between the image source 5 and the first prism 3, as shown in FIG. 3. Figure 10 In addition, this embodiment 3 differs from embodiment 1 in the following aspects:

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

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

[0236] As can be seen, 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, the user can obtain a clear virtual image according to his own vision condition.

[0237] This embodiment 3 adjusts the diopter by adjusting the air gap 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 adjustment is -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, which realizes a good 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 an MTF curve diagram, a vertical axis chromatic aberration diagram, and a grid distortion diagram.

[0244] See also Figure 11 ,against Figure 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 Figure 12 ,against Figure 10 The near-eye display system shown has a maximum color difference of less than 70μm, indicating that the color difference produced during imaging is very small and the color reproduction is high. For near-eye display systems, smaller color difference can reduce visual discomfort caused by color difference and improve the user's viewing experience.

[0246] See also Figure 13 ,against Figure 10 The near-eye display system shown, from Figure 13 As can be seen in the figure, the grid lines are not completely parallel or perpendicular, but rather exhibit a certain degree of curvature and deformation. This distortion can cause errors in image measurement and data processing, and therefore requires post-processing using software. This is precisely the characteristic of the PWG optical architecture on which this application is based, namely that grid distortion may occur during use, requiring post-processing to ensure data accuracy. Post-processing adjustments can usually be performed using specialized software to restore the parallelism and perpendicularity 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 repeated here one by one.

[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] While certain embodiments of the application have been described in detail as set forth above, modifications and alterations to those embodiments will be apparent to those skilled in the art from this detailed description. It is intended that the scope of the application be limited by nothing other than the appended claims.

Claims

1. A near-eye display system, characterized in that: including a lens assembly and a prism assembly; The lens assembly comprises a first lens (1) and a second lens (2) 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) facing 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 to achieve a diopter adjustment function.

2. The near-eye display system according to claim 1, wherein: 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, wherein: 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 base 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 bonding surface of the first prism (3) and the second prism (4).

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

6. The near-eye display system according to claim 1, wherein: 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, wherein: 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 1mm <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, wherein: The effective focal length F of the near-eye display system is: 15mm <F<25mm。 9. The near-eye display system according to claim 1, wherein: 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, wherein: 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, wherein: 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.

12. The near-eye display system according to claim 4, wherein: A polarizing element (10) is provided on the second right-angled surface (32) of the first prism (3).

13. The near-eye display system according to claim 2, wherein: 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, wherein: 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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