VR eyepiece system

Abstract

The present invention provides a VR eyepiece system, which sequentially comprises a first lens, a connecting assembly, a second lens, a diffractive element, a third lens, a semi-transparent and semi-reflective film and a display screen, wherein the diffractive element is attached to the image side surface of the second lens; the display screen is located on the imaging surface of the VR eyepiece system; the combined focal length F1 of the first lens, the connecting assembly, the second lens and the diffractive element, the effective focal length f3 of the third lens, and the effective focal length f of the VR eyepiece system satisfy: 0.024≤f / (F1-f3)≤0.043; the combined focal length F1 of the first lens, the connecting assembly, the second lens and the diffractive element, and the effective focal length f3 of the third lens satisfy: -2.066≤f3 / F1≤-0.036. The present invention solves the problems of low edge field clarity and large chromatic aberration of VR eyepieces in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of optical lens technology, and in particular to a VR eyepiece system. Background Art

[0002] In the virtual reality head-mounted displays (VRHMDs) currently released on the market, optical design (reentrant system) lenses with short focal length and small size are usually used to reduce the size of VR eyepieces. However, VR eyepieces are still heavy, and the user's wearing comfort is poor. In addition, the field of view of the reentrant system design is small. When the user's eyeballs move at a large angle, the VR eyepiece will have problems such as low image clarity and large color difference, resulting in poor visual experience of the user's peripheral field of view and cannot be worn for a long time.

[0003] That is to say, the VR eyepiece system in the prior art has the problems of poor wearing comfort and poor imaging quality in the edge field of view. Summary of the invention

[0004] The main purpose of the present invention is to provide a VR eyepiece system to solve the problems of poor wearing comfort and poor imaging quality of the edge field of view of the VR eyepiece system in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a VR eyepiece system, which includes, from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system: a first lens; a connecting component, which includes, from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system: a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate and a fourth adhesive layer; a second lens, the first lens and the second lens are glued together by the connecting component, the second lens has positive focal length, and the image side surface of the second lens is a plane; a diffraction element, the diffraction element is attached to the image side surface of the second lens, the diffraction element has a diffraction optical surface, and the diffraction optical surface is a plane structure with a preset thickness; a third lens, the third The lens has negative optical power, the eye side surface of the third lens is convex, the image side surface of the third lens has a semi-transparent and semi-reflective film, and the diffractive optical surface is arranged toward the eye side surface of the third lens; a display screen is located on the imaging surface of the VR eyepiece system; wherein the first lens, the second lens and the third lens are coaxially arranged; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element, the effective focal length f3 of the third lens, and the effective focal length f of the VR eyepiece system satisfy: 0.024≤f / (F1-f3)≤0.043; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element, and the effective focal length f3 of the third lens satisfy: -2.066≤f3 / F1≤-0.036.

[0006] Furthermore, the thickness of the first adhesive layer, the linear polarizer, the second adhesive layer, the polarizing reflective film, the third adhesive layer, the quarter wave plate and the fourth adhesive layer are all greater than 0 mm and less than 0.06 mm.

[0007] Furthermore, the image-side surface of the third lens is a plane.

[0008] Furthermore, an axial distance TTL from the eye side of the first lens to the imaging surface of the VR eyepiece system and an axial distance ED from the human eye to the eye side of the first lens satisfy: 1.155≤ED / TTL≤1.221.

[0009] Furthermore, the entrance pupil diameter EPD of the VR eyepiece system and half the diagonal length of the effective pixel area on the imaging surface of the VR eyepiece system ImgH satisfy the following: 2.715≤ImgH / EPD≤3.062.

[0010] Furthermore, the effective focal length f3 of the third lens and the effective focal length fi of the i-th lens satisfy: |f3|<|fi|, where i is 1 or 2.

[0011] Furthermore, the effective focal length f of the VR eyepiece system and the effective focal length f3 of the third lens satisfy: -15.572≤f3 / f≤-1.471.

[0012] Furthermore, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: -2.829≤f2 / f1≤5.776.

[0013] Furthermore, the effective focal length f of the VR eyepiece system and the on-axis distance TTL from the eye-side surface of the first lens to the imaging surface of the VR eyepiece system satisfy: 0.904≤TTL / f≤1.039.

[0014] Furthermore, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the refractive index N1 of the first lens, and the refractive index N2 of the second lens satisfy: -0.653mm≤(CT2*N2)-(CT1*N1)≤3.756mm.

[0015] Furthermore, an edge thickness ET1 of the first lens, an edge thickness ET2 of the second lens, and an edge thickness ET3 of the third lens satisfy: 2.100≤(ET1+ET2) / ET3≤5.437.

[0016] Furthermore, an axial distance Tr1r4 from the eye side surface of the first lens to the image side surface of the second lens and a center thickness CT3 of the third lens satisfy: 1.483≤Tr1r4 / CT3≤1.703.

[0017] Furthermore, a curvature radius R3 of the eye-side surface of the second lens and a curvature radius R5 of the eye-side surface of the third lens satisfy: -1.283≤R3 / R5≤2.857.

[0018] Further, an axial distance TD from the eye side surface of the first lens to the image side surface of the third lens and an axial distance T23 of an air gap between the second lens and the third lens satisfy: 0.121≤T23 / TD≤0.188.

[0019] By applying the technical solution of the present invention, the VR eyepiece system includes a first lens, a connecting assembly, a second lens, a diffractive element, a third lens and a display screen in sequence from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system, and the connecting assembly includes a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate and a fourth adhesive layer in sequence from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system; the first lens and the second lens are bonded together by the connecting assembly, the second lens has a positive focal length, and the image side surface of the second lens is a plane; the diffractive element is attached to the image side surface of the second lens, the diffractive element has a diffractive optical surface, and the diffractive optical surface is a plane structure with a preset thickness; the third The lens has negative optical power, the eye side surface of the third lens is convex, the image side surface of the third lens has a semi-transparent and semi-reflective film, and the diffractive optical surface is arranged toward the eye side surface of the third lens; the display screen is located on the imaging surface of the VR eyepiece system; wherein the first lens, the second lens and the third lens are coaxially arranged; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element, the effective focal length f3 of the third lens, and the effective focal length f of the VR eyepiece system satisfy: 0.024≤f / (F1-f3)≤0.043; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element, and the effective focal length f3 of the third lens satisfy: -2.066≤f3 / F1≤-0.036.

[0020] The VR eyepiece system of the present application uses three lenses, and the first lens, the second lens and the third lens are coaxially arranged. In order to enhance the user's edge field visual experience, a connecting component is glued between the first lens and the second lens, and the connecting component includes a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate and a fourth adhesive layer in sequence. The linear polarizer, the polarizing reflective film and the quarter wave plate glued between the first lens and the second lens are used to control the polarization state, phase and reflection characteristics of the light path, and realize the refraction of the light path. The second lens has a positive focal length, and the image side of the second lens is set to a plane so that the diffraction element is attached to the image side of the second lens, and the diffraction optical surface is set toward the eye side of the third lens to improve the resolution of the imaging. The third lens of the VR eyepiece system has a negative focal length and the image side of the third lens has a semi-transparent and semi-reflective film, which is conducive to increasing the field of view of the VR eyepiece system, reducing the optical path of the VR eyepiece system, and compressing the thickness and weight of the lens. The display screen is located on the imaging surface of the VR eyepiece system, which is conducive to forming a clear image. Among them, the ratio of the effective focal length f3 of the third lens to the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element is small, which is conducive to controlling the weight of the VR eyepiece system. By controlling the ratio of the effective focal length f of the VR eyepiece system to the difference between the above f3 and F1, the center thickness and edge thickness of the VR eyepiece system under the optical design of the reentrant system are also indirectly controlled, thereby increasing the wearing comfort of the user and reducing the weight of the user's head. At the same time, by reasonably controlling the focal length relationship of the first lens, the connecting component, the second lens, the diffractive element, the third lens and the VR eyepiece system, the imaging performance of the VR eyepiece system can be better improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 A structural schematic diagram of a VR eyepiece system according to a first embodiment of the present invention is shown;

[0023] Figure 2 Shows Figure 1 Axial chromatic aberration curve of the VR eyepiece system;

[0024] Figure 3 Shows Figure 1 Astigmatism curve of the VR eyepiece system;

[0025] Figure 4 Shows Figure 1 Distortion curve of the VR eyepiece system;

[0026] Figure 5 Shows Figure 1MTF curve of the medium VR eyepiece system;

[0027] Figure 6 A structural schematic diagram of a VR eyepiece system according to a second embodiment of the present invention is shown;

[0028] Figure 7 Shows Figure 6 Axial chromatic aberration curve of the VR eyepiece system;

[0029] Figure 8 Shows Figure 6 Astigmatism curve of the VR eyepiece system;

[0030] Fig. 9 Shows Figure 6 Distortion curve of the VR eyepiece system;

[0031] Fig.10 Shows Figure 6 MTF curve of the medium VR eyepiece system;

[0032] Fig.11 A schematic structural diagram of a VR eyepiece system according to a third embodiment of the present invention is shown;

[0033] Fig.12 Shows Fig.11 Axial chromatic aberration curve of the VR eyepiece system;

[0034] Fig.13 Shows Fig.11 Astigmatism curve of the VR eyepiece system;

[0035] Fig.14 Shows Fig.11 Distortion curve of the VR eyepiece system;

[0036] Fig.15 Shows Fig.11 MTF curve of the medium VR eyepiece system;

[0037] Fig.16 A structural schematic diagram of a VR eyepiece system according to a fourth embodiment of the present invention is shown;

[0038] Fig.17 Shows Fig.16 Axial chromatic aberration curve of the VR eyepiece system;

[0039] Fig.18 Shows Fig.16 Astigmatism curve of the VR eyepiece system;

[0040] Fig.19 Shows Fig.16 Distortion curve of the VR eyepiece system;

[0041] Fig. 20 Shows Fig.16 MTF curve of the medium VR eyepiece system;

[0042] Fig.21 A cross-sectional view of a diffractive element of a VR eyepiece system according to an alternative embodiment of the present invention is shown;

[0043] Fig. 22 Shows Fig.21 Front view of the diffractive optical surface.

[0044] The above drawings include the following reference numerals:

[0045] E1, first lens; S1, eye side of the first lens; S2, image side of the first lens (eye side of the first adhesive layer); LP, linear polarizer; S3, image side of the first adhesive layer (eye side of the linear polarizer); S4, image side of the linear polarizer (eye side of the second adhesive layer); RP, polarizing reflective film; S5, image side of the second adhesive layer (eye side of the polarizing reflective film); S6, image side of the polarizing reflective film (eye side of the third adhesive layer); QWP, quarter wave plate; S7, image side of the third adhesive layer (1 / 4 wave plate); S8, image side surface of 1 / 4 wave plate (eye side surface of the fourth adhesive layer); E2, second lens; S9, eye side surface of the second lens (image side surface of the fourth adhesive layer); S10, image side surface of the second lens (eye side surface of the diffraction element); DOE, diffraction element; S11, image side surface of the diffraction element; E3, third lens; S12, eye side surface of the third lens; S13, image side surface of the third lens; BS, semi-transparent and semi-reflective film; IMG, display screen; S14, imaging surface of the VR eyepiece system. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0048] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0049] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0050] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0051] In this article, the paraxial area refers to the area near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial area; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial area. The judgment of the surface shape in the paraxial area can be based on the judgment method of ordinary knowledgeable people in this field, and the positive and negative R value (R refers to the radius of curvature of the paraxial area, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the convexity and concavity. For the eye-side surface, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; for the display-side surface, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface.

[0052] In order to solve the problems in the prior art of poor wearing comfort and poor imaging quality in the edge field of view of a VR eyepiece system, the present invention provides a VR eyepiece system.

[0053] First embodiment

[0054] like Figures 1 to 22As shown, the present invention provides a VR eyepiece system, wherein the VR eyepiece system includes a first lens, a connecting assembly, a second lens, a diffractive element, a third lens and a display screen in sequence from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system, and the connecting assembly includes a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate and a fourth adhesive layer in sequence from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system; the first lens and the second lens are bonded together by the connecting assembly, the second lens has a positive focal length, and the image side surface of the second lens is a plane; the diffractive element is bonded to the image side surface of the second lens, the diffractive element has a diffractive optical surface, and the diffractive optical surface is a plane structure with a preset thickness ; The third lens has negative optical power, the eye side of the third lens is convex, the image side of the third lens has a semi-transparent and semi-reflective film, and the diffraction optical surface is arranged toward the eye side of the third lens; the display screen is located on the imaging surface of the VR eyepiece system; wherein the first lens, the second lens and the third lens are coaxially arranged; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffraction element, the effective focal length f3 of the third lens, and the effective focal length f of the VR eyepiece system satisfy: 0.024≤f / (F1-f3)≤0.043; the combined focal length F1 of the first lens, the connecting component, the second lens and the diffraction element, and the effective focal length f3 of the third lens satisfy: -2.066≤f3 / F1≤-0.036.

[0055] The VR eyepiece system of the present application uses three lenses, and the first lens, the second lens and the third lens are coaxially arranged. In order to enhance the user's edge field visual experience, a connecting component is glued between the first lens and the second lens, and the connecting component includes a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate and a fourth adhesive layer in sequence. The linear polarizer, the polarizing reflective film and the quarter wave plate glued between the first lens and the second lens are used to control the polarization state, phase and reflection characteristics of the light path, and realize the refraction of the light path. The second lens has a positive focal length, and the image side of the second lens is set to a plane so that the diffraction element is attached to the image side of the second lens, and the diffraction optical surface is set toward the eye side of the third lens to improve the resolution of the imaging. The third lens of the VR eyepiece system has a negative focal length and the image side of the third lens has a semi-transparent and semi-reflective film, which is conducive to increasing the field of view of the VR eyepiece system, reducing the optical path of the VR eyepiece system, and compressing the thickness and weight of the lens. The display screen is located on the imaging surface of the VR eyepiece system, which is conducive to forming a clear image. Among them, the ratio of the effective focal length f3 of the third lens to the combined focal length F1 of the first lens, the connecting component, the second lens and the diffractive element is small, which is conducive to controlling the weight of the VR eyepiece system. By controlling the ratio of the effective focal length f of the VR eyepiece system to the difference between the above f3 and F1, the center thickness and edge thickness of the VR eyepiece system under the optical design of the reentrant system are also indirectly controlled, thereby increasing the wearing comfort of the user and reducing the weight of the user's head. At the same time, by reasonably controlling the focal length relationship of the first lens, the connecting component, the second lens, the diffractive element, the third lens and the VR eyepiece system, the imaging performance of the VR eyepiece system can be better improved.

[0056] In this embodiment, the thickness of the first adhesive layer, the linear polarizer, the second adhesive layer, the polarizing reflective film, the third adhesive layer, the quarter wave plate, and the fourth adhesive layer are all greater than 0 mm and less than 0.06 mm. By limiting the thickness of each part of the connection component to a reasonable range, the composite thickness of the connection component can be controlled to be thinner, which can further avoid the weakening of the performance of the connection component due to excessive thickness. In addition, there is only one composite component of the connection component, and the light path transmittance of the VR eyepiece system is high, which effectively improves the light efficiency of the VR eyepiece system.

[0057] In this embodiment, the image side surface of the third lens is a plane. By setting the image side surface of the second lens and the image side surface of the third lens to be planes at the same time, the maximum deviation of the wavefront of the VR eyepiece system can be effectively reduced and the imaging quality of the VR eyepiece system can be improved. At the same time, the sensitivity of single-sided decentration can be reduced, and the performance difference between the theoretical value and the design value caused by the manufacturing process can be effectively reduced.

[0058] In this embodiment, the on-axis distance TTL from the eye side of the first lens to the imaging surface of the VR eyepiece system and the on-axis distance ED from the human eye to the eye side of the first lens satisfy the following conditions: 1.155≤ED / TTL≤1.221. By controlling the on-axis distance from the eye side of the first lens to the imaging surface of the VR eyepiece system, the size and weight of the VR eyepiece system can be effectively controlled, which is conducive to the compact structure of the VR eyepiece system and is easy to integrate. At the same time, controlling the on-axis distance from the human eye to the eye side of the first lens can be applied to a wider range of user groups. In addition, by limiting ED / TTL within a reasonable range, light can be used to the maximum extent to reduce the sense of weight on the head, so that the user's line of sight remains stable and is not affected by external interference or body movement, so as to obtain better visual effects and a comfortable viewing experience.

[0059] In this embodiment, the entrance pupil diameter EPD of the VR eyepiece system and half of the diagonal length of the effective pixel area on the imaging surface of the VR eyepiece system ImgH satisfy the following: 2.715≤ImgH / EPD≤3.062. Setting the entrance pupil diameter of the VR eyepiece system to 4mm allows more light to pass through the VR eyepiece system. The entrance pupil diameter of the VR eyepiece system is larger than the average diameter of the human pupil, so that users with larger eyeballs can have a good visual experience. By controlling the diagonal length of the effective pixel area on the imaging surface of the VR eyepiece system, the size of the display screen can be shortened, thereby reducing the cost of the display screen. At the same time, by limiting ImgH / EPD within a reasonable range, the VR eyepiece system can achieve the goals of high pixels, high resolution, and high definition.

[0060] In this embodiment, the effective focal length f3 of the third lens and the effective focal length fi of the i-th lens satisfy: |f3|<|fi|, where i is 1 or 2. By controlling the effective focal length of the third lens to be smaller than the effective focal lengths of the first lens and the second lens, the light divergence problem caused by the negative optical power of the first lens can be further alleviated. At the same time, under the premise of keeping the thickness of the third lens small, the light emitted from the optical path to the imaging surface of the VR eyepiece system is converged, which is conducive to reducing the image height of the imaging surface of the VR eyepiece system.

[0061] In this embodiment, the effective focal length f of the VR eyepiece system and the effective focal length f3 of the third lens satisfy: -15.572≤f3 / f≤-1.471. By limiting f3 / f within a reasonable range and controlling it to a smaller value, the light-gathering ability of the VR eyepiece system can be mainly focused on the third lens, and the overall flatness of the first lens, the connecting component, the second lens and the diffraction element is relatively high, which effectively reduces the process difficulty of processing the VR eyepiece system, and only the third lens needs to be focused on during design.

[0062] In this embodiment, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: -2.829≤f2 / f1≤5.776. By limiting f2 / f1 within a reasonable range, the light bending effect can be mainly concentrated on the first lens, thereby limiting the propagation range of the light, reducing the scattering and interference of the light in the VR eyepiece system, and further improving the resolution, contrast, color reproducibility and imaging quality of the VR eyepiece system.

[0063] In this embodiment, the effective focal length f of the VR eyepiece system and the on-axis distance TTL from the eye side of the first lens to the imaging surface of the VR eyepiece system satisfy: 0.904≤TTL / f≤1.039. By limiting TTL / f within a reasonable range, the aberration of the VR eyepiece system can be effectively improved, the luminous flux of the VR eyepiece system can be increased, and the imaging quality of the VR eyepiece system can be optimized.

[0064] In this embodiment, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the refractive index N1 of the first lens, and the refractive index N2 of the second lens satisfy: -0.653mm≤(CT2*N2)-(CT1*N1)≤3.756mm. By limiting the optical path difference (CT2*N2)-(CT1*N1) between the second lens and the first lens within a reasonable range and reasonably matching high-refractive index materials and low-refractive index materials, the optical path difference between the second lens and the first lens can be reduced under the premise of effectively correcting chromatic aberration. At the same time, when the first lens increases the field of view angle, the light beam is converged by the second lens and the third lens, which reduces the weight of the VR eyepiece system and greatly improves the user's sense of immersion.

[0065] In this embodiment, the edge thickness ET1 of the first lens, the edge thickness ET2 of the second lens, and the edge thickness ET3 of the third lens satisfy the following relationship: 2.100≤(ET1+ET2) / ET3≤5.437. By limiting (ET1+ET2) / ET3 to a reasonable range, the difference in edge thickness of the first lens, the connecting assembly, the second lens, the diffractive element, and the third lens is small, which can make the propagation path of light in the VR eyepiece system more uniform, thereby correcting the aberrations and distortions of the VR eyepiece system and improving the quality and accuracy of the image. In addition, optical problems such as aberrations, defocusing, and scattering of the VR eyepiece system can also be minimized.

[0066] In this embodiment, the on-axis distance Tr1r4 from the eye side of the first lens to the image side of the second lens and the center thickness CT3 of the third lens satisfy: 1.483≤Tr1r4 / CT3≤1.703. By limiting Tr1r4 / CT3 within a reasonable range, the difference between the on-axis distance from the eye side of the first lens to the image side of the second lens and the center thickness of the third lens is small, so that the weight distribution of the VR eyepiece system is more uniform, and the user's wearing comfort is enhanced. At the same time, the image field flatness and imaging quality of the VR eyepiece system are balanced, and better image clarity and resolution are obtained.

[0067] In this embodiment, the curvature radius R3 of the eye side surface of the second lens and the curvature radius R5 of the eye side surface of the third lens satisfy: -1.283≤R3 / R5≤2.857. By limiting R3 / R5 within a reasonable range, the effective focal length of the VR eyepiece system is effectively controlled, which is conducive to the convergence of light with a large field of view angle and the miniaturization of the VR eyepiece system head-mounted device.

[0068] In this embodiment, the on-axis distance TD from the eye side surface of the first lens to the image side surface of the third lens and the on-axis distance T23 of the air gap between the second lens and the third lens satisfy: 0.121≤T23 / TD≤0.188. By limiting T23 / TD within a reasonable range, the on-axis distance of the air gap between the second lens and the third lens is smaller than the on-axis distance from the eye side surface of the first lens to the image side surface of the third lens, which can further shorten the optical path and the total length of the VR eyepiece system, and facilitate the high integration of the VR eyepiece system.

[0069] This embodiment may also include other parameter formulas in the first embodiment, which will not be described in detail here.

[0070] The VR eyepiece system in this application may use multiple lenses, such as the three lenses mentioned above. By reasonably allocating the effective focal length, surface shape, center thickness of each lens, and axial distance between each lens, etc., the aperture of the VR eyepiece system can be effectively increased, the sensitivity of the lens can be reduced, and the processability of the lens can be improved, making the VR eyepiece system more conducive to production and processing and applicable to portable electronic devices such as smartphones.

[0071] In the present application, at least one lens has an aspherical mirror surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0072] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the VR eyepiece system can be changed to obtain the various results and advantages described in this specification. For example, although three lenses are described as an example in the embodiment, the VR eyepiece system is not limited to including three lenses. If necessary, the VR eyepiece system may also include other numbers of lenses.

[0073] Figure 1 A partial structural schematic diagram of a VR eyepiece system of the present application is shown. Figure 1 The various optical components of the VR eyepiece system are marked in the figure, where the first lens is E1, the linear polarizer is LP, the polarized reflective film is RP, the quarter wave plate is QWP, the second lens is E2, the diffraction element is DOE, the third lens is E3, the semi-transparent and semi-reflective film is BS and the display screen IMG, so as to clearly mark the various optical components.

[0074] Fig.21 and Fig. 22 A schematic diagram of the diffraction element DOE is given. Among them, Fig.21 is a cross-sectional schematic diagram of a diffractive element, in which the right side of the surface facing the third lens E3 is configured as a diffractive optical surface. Fig. 22 A schematic diagram of looking straight at a diffractive optical surface is given.

[0075] The following further describes examples of specific face shapes and parameters of the VR eyepiece system that can be applied to the above-mentioned embodiments with reference to the accompanying drawings.

[0076] It should be noted that any one of the following embodiments 1 to 4 is applicable to all implementation methods of the present application.

[0077] Embodiment 1

[0078] like Figures 1 to 5 As shown, the VR eyepiece system of embodiment 1 of the present application is described.

[0079] like Figure 1As shown, the VR eyepiece system includes a first lens E1, a connecting component, a second lens E2, a diffraction element DOE, a third lens E3, a semi-transparent and semi-reflective film BS and a display screen IMG in sequence from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, wherein the first lens E1 and the second lens E2 are glued together by the connecting component, and from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, the connecting component includes a first glue layer, a linear polarizer LP, a second glue layer, a polarizing reflective film RP, a third glue layer, a 1 / 4 wave plate QWP and a fourth glue layer in sequence, the diffraction element DOE is attached to the image side surface S10 of the second lens, the diffraction optical surface of the diffraction element DOE is arranged toward the eye side surface S12 of the third lens, and the image side surface S13 of the third lens has a semi-transparent and semi-reflective film BS.

[0080] The light from the eye side direction of the VR eyepiece system passes through the first lens E1, the connecting component, the second lens E2, the diffraction element DOE, and the third lens E3 in sequence to reach the semi-transparent and semi-reflective film BS. After being reflected by the semi-transparent and semi-reflective film BS, the light passes through the third lens E3, the diffraction element DOE, and the second lens E2 again to reach the connecting component. The polarized reflective film RP in the connecting component reflects the light, so that the light propagates toward the imaging surface of the VR eyepiece system again, passes through the second lens E2, the diffraction element DOE, and the third lens E3 in sequence, is transmitted by the semi-transparent and semi-reflective film BS, and reaches the imaging surface S14 of the VR eyepiece system.

[0081] It should be noted that since the polarization direction of the light changes by 90° after passing through the quarter wave plate QWP twice during the return process, the light is transmitted when it first reaches the polarizing reflective film RP, and is reflected when it reaches the polarizing reflective film RP for the second time after passing through the quarter wave plate QWP twice.

[0082] In this embodiment, the first lens E1 has negative power, the eye-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave; the second lens E2 has positive power, the eye-side surface S9 of the second lens is convex, and the image-side surface S10 of the second lens is a plane; the third lens E3 has negative power, the eye-side surface S12 of the third lens is convex, and the image-side surface S13 of the third lens is a plane.

[0083] Table 1 shows the basic structural parameter table of the VR eyepiece system of Example 1, wherein the units of the radius of curvature, thickness / distance, and effective focal length are all in millimeters (mm). In Table 1, the arrangement order of the surface numbers is the order in which the light passes, and the refraction / reflection is the refraction or reflection of the light when it passes through the surface this time.

[0084]

[0085] In this embodiment, both side surfaces of the first lens E1, the eye-side surface S9 of the second lens, and both side surfaces of the third lens E3 are aspherical surfaces. The surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0086] Formula (1);

[0087] Wherein, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 below lists the high-order coefficients A2, A4, A6, A8, and A10 that can be used for each aspherical mirror surface in this embodiment.

[0088]

[0089] Table 2

[0090] Figure 2 The axial chromatic aberration curve of the VR eyepiece system of Example 1 is shown, which indicates that light rays of different wavelengths deviate from the focal point after passing through. Figure 3 The astigmatism curve of the VR eyepiece system of Example 1 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 4 The distortion curve of the VR eyepiece system of Example 1 is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles. Figure 5 The MTF curve of the VR eyepiece system of Example 1 is shown. The on-axis MTF value is high, which indicates good imaging quality.

[0091] according to Figures 2 to 5 It can be seen that the VR eyepiece system provided in Example 1 can achieve good imaging quality.

[0092] Embodiment 2

[0093] like Figures 6 to 10 As shown, the VR eyepiece system of the second embodiment of the present application is described. The difference from the first embodiment is that the structural parameters of the VR eyepiece system are different. For the sake of brevity, some descriptions similar to the first embodiment will be omitted.

[0094] like Figure 6As shown, the VR eyepiece system includes a first lens E1, a connecting component, a second lens E2, a diffraction element DOE, a third lens E3, a semi-transparent and semi-reflective film BS and a display screen IMG in sequence from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, wherein the first lens E1 and the second lens E2 are glued together by the connecting component, and from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, the connecting component includes a first glue layer, a linear polarizer LP, a second glue layer, a polarizing reflective film RP, a third glue layer, a 1 / 4 wave plate QWP and a fourth glue layer in sequence, the diffraction element DOE is attached to the image side surface S10 of the second lens, the diffraction optical surface of the diffraction element DOE is arranged toward the eye side surface S12 of the third lens, and the image side surface S13 of the third lens has a semi-transparent and semi-reflective film BS.

[0095] In this embodiment, the first lens E1 has negative power, the eye-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave; the second lens E2 has positive power, the eye-side surface S9 of the second lens is convex, and the image-side surface S10 of the second lens is a plane; the third lens E3 has negative power, the eye-side surface S12 of the third lens is convex, and the image-side surface S13 of the third lens is a plane.

[0096] Table 3 shows the basic structural parameter table of the VR eyepiece system of Example 2, wherein the units of the radius of curvature, thickness / distance, and effective focal length are all in millimeters (mm). In Table 3, the arrangement order of the surface numbers is the order in which the light passes, and the refraction / reflection is the refraction or reflection of the light when it passes through the surface this time.

[0097]

[0098] Table 3

[0099] In this embodiment, both side surfaces of the first lens E1, the eye-side surface S9 of the second lens, and both side surfaces of the third lens E3 are aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, formula (1) in the first embodiment.

[0100] Table 4 below lists the higher-order coefficients that can be used for each aspherical mirror surface in this embodiment.

[0101]

[0102] Table 4

[0103] Figure 7 The axial chromatic aberration curve of the VR eyepiece system of Example 2 is shown, which indicates that light rays of different wavelengths deviate from the focal point after passing through. Figure 8 The astigmatism curve of the VR eyepiece system of Example 2 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig. 9The distortion curve of the VR eyepiece system of Example 2 is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles. Fig.10 The MTF curve of the VR eyepiece system of Example 2 is shown, and the on-axis MTF value is high, which indicates good imaging quality.

[0104] according to Figures 7 to 10 It can be seen that the VR eyepiece system provided in Example 2 can achieve good imaging quality.

[0105] Embodiment 3

[0106] like Figures 11 to 15 As shown, the VR eyepiece system of the third embodiment of the present application is described. The difference from the first embodiment is that the structural parameters are different.

[0107] like Fig.11 As shown, the VR eyepiece system includes a first lens E1, a connecting component, a second lens E2, a diffraction element DOE, a third lens E3, a semi-transparent and semi-reflective film BS and a display screen IMG in sequence from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, wherein the first lens E1 and the second lens E2 are glued together by the connecting component, and from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, the connecting component includes a first glue layer, a linear polarizer LP, a second glue layer, a polarizing reflective film RP, a third glue layer, a 1 / 4 wave plate QWP and a fourth glue layer in sequence, the diffraction element DOE is attached to the image side surface S10 of the second lens, the diffraction optical surface of the diffraction element DOE is arranged toward the eye side surface S12 of the third lens, and the image side surface S13 of the third lens has a semi-transparent and semi-reflective film BS.

[0108] In this embodiment, the first lens E1 has positive power, the eye-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is convex; the second lens E2 has positive power, the eye-side surface S9 of the second lens is concave, and the image-side surface S10 of the second lens is a plane; the third lens E3 has negative power, the eye-side surface S12 of the third lens is convex, and the image-side surface S13 of the third lens is a plane.

[0109] Table 5 shows the basic structural parameter table of the VR eyepiece system of Example 3, wherein the units of the radius of curvature, thickness / distance, and effective focal length are all in millimeters (mm). In Table 5, the arrangement order of the surface numbers is the order in which the light passes, and the refraction / reflection is the refraction or reflection of the light when it passes through the surface this time.

[0110]

[0111] Table 5

[0112] In this embodiment, both side surfaces of the first lens E1, the eye-side surface S9 of the second lens, and both side surfaces of the third lens E3 are aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, formula (1) in the first embodiment.

[0113] Table 6 below lists the high-order coefficients that can be used for each aspherical mirror surface in this embodiment.

[0114]

[0115] Table 6

[0116] Fig.12 The axial chromatic aberration curve of the VR eyepiece system of Example 3 is shown, which indicates that light of different wavelengths deviates from the focal point after passing through. Fig.13 The astigmatism curve of the VR eyepiece system of Example 3 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.14 The distortion curve of the VR eyepiece system of Example 3 is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles. Fig.15 The MTF curve of the VR eyepiece system of Example 3 is shown, and the on-axis MTF value is high, which indicates good imaging quality.

[0117] according to Figures 12 to 15 It can be seen that the VR eyepiece system provided in Example 3 can achieve good imaging quality.

[0118] Embodiment 4

[0119] like Figures 16 to 20 As shown, the VR eyepiece system of the fourth embodiment of the present application is described. The difference from the first embodiment is that the structural parameters are different.

[0120] like Fig.16 As shown, the VR eyepiece system includes a first lens E1, a connecting component, a second lens E2, a diffraction element DOE, a third lens E3, a semi-transparent and semi-reflective film BS and a display screen IMG in sequence from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, wherein the first lens E1 and the second lens E2 are glued together by the connecting component, and from the eye side of the VR eyepiece system to the imaging surface S14 of the VR eyepiece system, the connecting component includes a first glue layer, a linear polarizer LP, a second glue layer, a polarizing reflective film RP, a third glue layer, a 1 / 4 wave plate QWP and a fourth glue layer in sequence, the diffraction element DOE is attached to the image side surface S10 of the second lens, the diffraction optical surface of the diffraction element DOE is arranged toward the eye side surface S12 of the third lens, and the image side surface S13 of the third lens has a semi-transparent and semi-reflective film BS.

[0121] In this embodiment, the first lens E1 has positive power, the eye-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave; the second lens E2 has positive power, the eye-side surface S9 of the second lens is convex, and the image-side surface S10 of the second lens is a plane; the third lens E3 has negative power, the eye-side surface S12 of the third lens is convex, and the image-side surface S13 of the third lens is a plane.

[0122] Table 7 shows the basic structural parameter table of the VR eyepiece system of Example 4, wherein the units of the radius of curvature, thickness / distance, and effective focal length are all in millimeters (mm). In Table 7, the arrangement order of the surface numbers is the order in which the light passes, and the refraction / reflection is the refraction or reflection of the light when it passes through the surface this time.

[0123]

[0124] Table 7

[0125] In this embodiment, both side surfaces of the first lens E1, the eye-side surface S9 of the second lens, and both side surfaces of the third lens E3 are aspherical surfaces. The surface shape of each aspherical lens can be defined by, but not limited to, formula (1) in the first embodiment.

[0126] Table 8 below lists the high-order coefficients that can be used for each aspherical mirror surface in this embodiment.

[0127]

[0128] Table 8

[0129] Fig.17 The axial chromatic aberration curve of the VR eyepiece system of Example 4 is shown, which indicates that light of different wavelengths deviates from the focal point after passing through. Fig.18 The astigmatism curve of the VR eyepiece system of Example 4 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.19 The distortion curve of the VR eyepiece system of Example 4 is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles. Fig. 20 The MTF curve of the VR eyepiece system of Example 4 is shown, and the on-axis MTF value is high, which indicates good imaging quality.

[0130] according to Figures 17 to 20 It can be seen that the VR eyepiece system provided in Example 4 can achieve good imaging quality.

[0131] In summary, the VR eyepiece system of the present application includes the above-mentioned embodiments 1 to 4, and the following Table 9 lists some optical parameters of the four embodiments.

[0132]

[0133] Table 9

[0134] Table 10 shows the conditional values ​​of Examples 1 to 4.

[0135]

[0136] Table 10

[0137] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0138] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0139] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A VR eyepiece system, characterized in that: From the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system, the following are included in sequence: First lens; A connecting component, wherein the connecting component includes, from the eye side of the VR eyepiece system to the imaging surface of the VR eyepiece system, a first adhesive layer, a linear polarizer, a second adhesive layer, a polarizing reflective film, a third adhesive layer, a quarter wave plate, and a fourth adhesive layer in sequence; a second lens, wherein the first lens and the second lens are bonded together by the connecting assembly, the second lens has positive optical power, and the image side surface of the second lens is a plane; A diffraction element, wherein the diffraction element is attached to the image side surface of the second lens, and the diffraction element has a diffraction optical surface, and the diffraction optical surface is a planar structure with a preset thickness; a third lens, wherein the third lens has negative optical power, the eye side surface of the third lens is a convex surface, the image side surface of the third lens has a semi-transparent and semi-reflective film, and the diffractive optical surface is arranged toward the eye side surface of the third lens; A display screen, wherein the display screen is located on an imaging surface of the VR eyepiece system; Wherein, the first lens, the second lens and the third lens are coaxially arranged; The combined focal length F1 of the first lens, the connecting assembly, the second lens and the diffractive element, the effective focal length f3 of the third lens, and the effective focal length f of the VR eyepiece system satisfy: 0.024≤f / (F1-f3)≤0.043; The combined focal length F1 of the first lens, the connecting assembly, the second lens and the diffractive element, and the effective focal length f3 of the third lens satisfy the following: -2.066≤f3 / F1≤-0.

036.

2. The VR eyepiece system according to claim 1, characterized in that: The thickness of the first adhesive layer, the linear polarizer, the second adhesive layer, the polarizing reflective film, the third adhesive layer, the quarter wave plate and the fourth adhesive layer are all greater than 0 mm and less than 0.06 mm.

3. The VR eyepiece system according to claim 1, characterized in that: The image-side surface of the third lens is a plane.

4. The VR eyepiece system according to claim 1, characterized in that: An axial distance TTL from the eye side of the first lens to the imaging surface of the VR eyepiece system and an axial distance ED from the human eye to the eye side of the first lens satisfy the following: 1.155≤ED / TTL≤1.

221.

5. The VR eyepiece system according to claim 1, characterized in that: The entrance pupil diameter EPD of the VR eyepiece system and half the diagonal length ImgH of the effective pixel area on the imaging surface of the VR eyepiece system satisfy the following: 2.715≤ImgH / EPD≤3.

062.

6. The VR eyepiece system according to claim 1, characterized in that: The effective focal length f3 of the third lens and the effective focal length fi of the i-th lens satisfy: |f3|<|fi|, where i is 1 or 2.

7. The VR eyepiece system according to claim 1, characterized in that: The effective focal length f of the VR eyepiece system and the effective focal length f3 of the third lens satisfy the following: -15.572≤f3 / f≤-1.

471.

8. The VR eyepiece system according to claim 1, characterized in that: The effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following: -2.829≤f2 / f1≤5.

776.

9. The VR eyepiece system according to claim 1, characterized in that: The effective focal length f of the VR eyepiece system and the on-axis distance TTL from the eye side surface of the first lens to the imaging surface of the VR eyepiece system satisfy the following: 0.904≤TTL / f≤1.

039.

10. The VR eyepiece system according to claim 1, characterized in that: The center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the refractive index N1 of the first lens, and the refractive index N2 of the second lens satisfy: -0.653mm≤(CT2*N2)-(CT1*N1)≤3.756mm.

11. The VR eyepiece system according to any one of claims 1 to 10, characterized in that: The edge thickness ET1 of the first lens, the edge thickness ET2 of the second lens, and the edge thickness ET3 of the third lens satisfy the following: 2.100≤(ET1+ET2) / ET3≤5.

437.

12. The VR eyepiece system according to any one of claims 1 to 10, characterized in that: An axial distance Tr1r4 from the eye side surface of the first lens to the image side surface of the second lens and a center thickness CT3 of the third lens satisfy the following: 1.483≤Tr1r4 / CT3≤1.

703.

13. The VR eyepiece system according to any one of claims 1 to 10, characterized in that: A curvature radius R3 of the eye-side surface of the second lens and a curvature radius R5 of the eye-side surface of the third lens satisfy: -1.283≤R3 / R5≤2.

857.

14. The VR eyepiece system according to any one of claims 1 to 10, characterized in that: An axial distance TD from the eye side surface of the first lens to the image side surface of the third lens and an axial distance T23 of an air gap between the second lens and the third lens satisfy the following: 0.121≤T23 / TD≤0.188.

Images