Visual lens

Abstract

The application provides a visual lens, which comprises a first lens, a second lens and a third lens arranged in sequence from the human eye side to the display side along the optical axis; a first spacer is at least partially in contact with the surface of the first lens facing the display side; a second spacer is at least partially in contact with the surface of the second lens facing the display side, and the outer ring surface of the first spacer and the second spacer is in abutment with the inner wall surface of the lens barrel; at least one surface of the lens facing the display side or the surface facing the human eye side has a partial reflection layer; a reflective polarizing element; a quarter-wave plate, the reflective polarizing element and the quarter-wave plate are located on the human eye side or the display side of the first lens; the radius of curvature R3 of the surface of the second lens facing the human eye side, the radius of curvature R4 of the surface of the second lens facing the display side and the distance EP12 of the first spacer and the second spacer on the optical axis satisfy: -138<(R3+R4) / EP12< -68.0. The application solves the problem that the miniaturization and high assembly yield of the visual lens in the prior art are difficult to be considered simultaneously.

Description

Technical Field

[0001] This invention relates to the field of optical imaging equipment technology, and more specifically, to a visual lens. Background Technology

[0002] With the advancement of technology, AR / VR lenses have ushered in a second opportunity for development. AR / VR lenses play a crucial role in human-computer interaction, and they offer advantages such as miniaturization and lightweight design. As AR / VR lenses have evolved, users have increasingly higher demands for image quality and smaller size. Miniaturized AR / VR lenses are not only shorter in length but also narrower in width, leading to smaller lens dimensions and increased manufacturing complexity. Furthermore, miniaturized lenses are difficult to assemble into the lens barrel, especially those located in the center of the optical system. The field of view is worst in the center, making it easy for lens assembly to deviate during assembly, thus reducing the lens's assembly yield.

[0003] In other words, existing technologies for visual lenses present a challenge in balancing miniaturization with high assembly yield. Summary of the Invention

[0004] The main objective of this invention is to provide a visual lens to solve the problem in the prior art where miniaturization and high assembly yield are difficult to achieve simultaneously.

[0005] To achieve the above objectives, the present invention provides a viewing lens, comprising: a lens barrel; a first lens, a second lens, and a third lens arranged sequentially from the human eye side to the display side along the optical axis of the viewing lens; a first isolator, the first isolator being in at least partial contact with the surface of the first lens facing the display side; a second isolator, the second isolator being in at least partial contact with the surface of the second lens facing the display side, the outer annular surfaces of the first and second isolators abutting against the inner wall surface of the lens barrel; at least one lens having a partially reflective layer on the surface facing the display side or the surface facing the human eye side; a reflective polarizing element; a quarter-wave plate, the reflective polarizing element and the quarter-wave plate being located on the human eye side or the display side of the first lens; wherein, the radius of curvature R3 of the surface of the second lens facing the human eye side, the radius of curvature R4 of the surface of the second lens facing the display side, and the distance EP12 between the first isolator and the second isolator on the optical axis satisfy: -138 < (R3 + R4) / EP12 < -68.0.

[0006] Furthermore, the reflective polarizing element is positioned closer to the human eye side relative to the quarter-wave plate, and both the reflective polarizing element and the quarter-wave plate have a surface facing the human eye side and a surface facing the display side.

[0007] Furthermore, the distance EP01 between the surface of the lens barrel facing the human eye and the surface of the first isolator facing the human eye on the optical axis, the center thickness CTQ of the quarter-wave plate and the center thickness CTB of the reflective polarizing element satisfy the following condition: EP01 / (CTQ+CTB)<1.5.

[0008] Furthermore, the viewing lens also includes a second auxiliary isolator, which is in at least partial contact with the surface of the second isolator facing the display side.

[0009] Furthermore, the combined focal length f23 of the second and third lenses, the maximum thickness CP2 of the second isolator in the direction of optical axis extension, and the maximum thickness CP2b of the second auxiliary isolator in the direction of optical axis extension satisfy the following condition: 4.0 <f23 / (CP2+CP2b)<11.0。

[0010] Furthermore, the surface of the first lens facing the human eye or the surface of the first lens facing the display is a plane.

[0011] Furthermore, the reflective polarizing element or quarter-wave plate contacts at least a portion of the plane of the first lens.

[0012] Furthermore, the effective focal length f2 of the second lens and the distance EP12 between the first and second isolators on the optical axis satisfy: 125.5 <f2 / EP12<200。

[0013] Furthermore, the inner diameter d0m of the surface of the lens barrel facing the display, the inner diameter d0s of the surface of the lens barrel facing the human eye, the maximum height L of the lens barrel, and the distance TD on the optical axis from the surface of the first lens facing the human eye to the surface of the third lens facing the display satisfy the following condition: 1.5 <d0m / d0s+L / TD<4.0。

[0014] Furthermore, the inner diameter d1s of the surface of the first isolator facing the human eye, the radius of curvature R2 of the surface of the first lens facing the display, the effective focal length f1 of the first lens, and the Abbe number V1 of the first lens satisfy the following relationship: 3.0 <d1s / R2+f1 / V1<5.5。

[0015] Furthermore, the effective focal length f of the visual lens, the effective focal length f1 of the first lens, the center thickness CT1 of the first lens, and the maximum height L of the lens barrel satisfy the following relationship: 7.5 <f1 / f+CT1 / L<11.0。

[0016] Furthermore, the inner diameter d0m of the surface of the lens barrel facing the display side, the outer diameter D2m of the surface of the second isolator facing the display side, and half of the maximum field of view (Semi-FOV) of the viewing lens satisfy the following relationship: 0.8 <d0m / D2m*TAN(Semi-FOV)<2.0。

[0017] Furthermore, the maximum height L of the lens barrel, the maximum thickness CP1 of the first isolator in the direction of extension of the optical axis, the distance EP01 of the surface of the lens barrel facing the human eye to the surface of the first isolator facing the human eye on the optical axis, the distance EP12 of the first isolator and the second isolator on the optical axis, the air gap T23 of the second lens and the third lens on the optical axis, and the center thickness CT3 of the third lens satisfy the following condition: 0.5 < (L - EP01 - CP1 - EP12) / (T23 + CT3) < 4.0.

[0018] Furthermore, the combined focal length F1 of the reflective polarizing element, the quarter-wave plate, and the first lens, and the distance EP01 on the optical axis from the surface of the lens barrel facing the human eye to the surface of the first isolator facing the human eye satisfy the following condition: 29.0. <F1 / EP01<58。

[0019] According to the technical solution of the present invention, the visual lens includes a lens barrel, a first lens, a second lens, and a third lens arranged sequentially from the human eye side to the display side along the optical axis of the visual lens, and also includes a first isolator, a second isolator, a reflective polarizing element, and a quarter-wave plate. The first isolator is at least partially in contact with the surface of the first lens facing the display side; the second isolator is at least partially in contact with the surface of the second lens facing the display side, and the outer ring surfaces of the first and second isolators abut against the inner wall surface of the lens barrel; at least one lens has a partially reflective layer on the surface facing the display side or the surface facing the human eye side; the reflective polarizing element and the quarter-wave plate are located on the human eye side or the display side of the first lens; wherein, the radius of curvature R3 of the surface of the second lens facing the human eye side, the radius of curvature R4 of the surface of the second lens facing the display side, and the distance EP12 between the first and second isolators on the optical axis satisfy: -138 < (R3 + R4) / EP12 < -68.0.

[0020] This application relates to a three-element visual lens. By rationally setting the relationship between the curvature radii of the second lens's surfaces facing the human eye and the display, and the distance between the first and second spacers, the shape of the second lens can be controlled. This reduces the molding difficulty of the second lens while ensuring its miniaturization, and keeps its shape within a reasonable range, facilitating accurate contact between the second lens and the first and second spacers, and promoting rapid and accurate assembly. Simultaneously, controlling the contact between the first and second spacers and the inner wall of the lens barrel, and rationally controlling the vertical dimensions, reduces the contour requirements of the mating parts between the lens barrel and the first and second spacers, facilitating the assembly of the lens and spacers into the lens barrel, reducing the difficulty of the lens assembly process, and improving the lens assembly yield, achieving high yield while ensuring miniaturization. Furthermore, by incorporating a reflective polarizing element, a quarter-wave plate, and a partial reflective layer on the lens, the optical path length of light in the visual lens can be increased, improving the imaging quality of the visual lens while maintaining miniaturization. This gives the visual lens the advantages of miniaturization, high image quality, and high yield simultaneously. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A schematic diagram of the structure of a viewing lens according to an optional embodiment of the present invention is shown;

[0023] Figures 2 to 4 A schematic diagram of the visual lens of Example 1 of the present invention is shown in the first, second and third states.

[0024] Figures 5 to 7 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 1 of the present invention are shown respectively.

[0025] Figures 8 to 10 The diagram shows a structural schematic of the visual lens of Example 2 of the present invention in the first, second and third states;

[0026] Figures 11 to 13 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 2 of the present invention are shown respectively.

[0027] Figures 14 to 16 The diagram shows a structural schematic of the visual lens of Example 3 of the present invention in the first, second and third states;

[0028] Figures 17 to 19The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Example 3 of the present invention are shown respectively;

[0029] Figure 20 A light path diagram of a visual lens according to an optional embodiment of the present invention is shown.

[0030] The above figures include the following reference numerals:

[0031] RP, reflective polarizing element; S1, surface of reflective polarizing element facing the human eye; S2, surface of reflective polarizing element facing the display (surface of quarter-wave plate facing the human eye); QWP, quarter-wave plate; S3, surface of quarter-wave plate facing the display (surface of first lens facing the human eye); E1, first lens; S4, surface of first lens facing the display; E2, second lens; S5, surface of second lens facing the human eye; S6, surface of second lens facing the display; E3, third lens; S7, surface of third lens facing the human eye; S8, surface of third lens facing the display; S9, display. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0034] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0035] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0036] In the accompanying 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 illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0037] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The determination of the surface shape in the paraxial region can be based on the judgment method commonly used by those skilled in the art, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens data in optical software) to determine convexity or concavity. For a surface facing the human eye, a positive R value indicates a convex surface, and a negative R value indicates a concave surface; for a surface facing the display, a positive R value indicates a concave surface, and a negative R value indicates a convex surface.

[0038] To address the challenge of balancing miniaturization and high assembly yield in existing visual lenses, this invention provides a visual lens.

[0039] like Figures 1 to 20 As shown, the viewing lens includes a lens barrel, a first lens, a second lens, and a third lens arranged sequentially along the optical axis of the viewing lens from the human eye side to the display side, and also includes a first isolator, a second isolator, a reflective polarizing element, and a quarter-wave plate. The first isolator is in at least partial contact with the surface of the first lens facing the display side; the second isolator is in at least partial contact with the surface of the second lens facing the display side, and the outer ring surfaces of the first and second isolators abut against the inner wall surface of the lens barrel; at least one lens has a partially reflective layer on the surface facing the display side or the surface facing the human eye side; the reflective polarizing element and the quarter-wave plate are located on the human eye side or the display side of the first lens; wherein, the radius of curvature R3 of the surface of the second lens facing the human eye side, the radius of curvature R4 of the surface of the second lens facing the display side, and the distance EP12 between the first and second isolators on the optical axis satisfy: -138 < (R3 + R4) / EP12 < -68.0.

[0040] This application relates to a three-element visual lens. By rationally setting the relationship between the curvature radii of the second lens's surfaces facing the human eye and the display, and the distance between the first and second spacers, the shape of the second lens can be controlled. This reduces the molding difficulty of the second lens while ensuring its miniaturization, and keeps its shape within a reasonable range, facilitating accurate contact between the second lens and the first and second spacers, and promoting rapid and accurate assembly. Simultaneously, controlling the contact between the first and second spacers and the inner wall of the lens barrel, and rationally controlling the vertical dimensions, reduces the contour requirements of the mating parts between the lens barrel and the first and second spacers, facilitating the assembly of the lens and spacers into the lens barrel, reducing the difficulty of the lens assembly process, and improving the lens assembly yield, achieving high yield while ensuring miniaturization. Furthermore, by incorporating a reflective polarizing element, a quarter-wave plate, and a partial reflective layer on the lens, the optical path length of light in the visual lens can be increased, improving the imaging quality of the visual lens while maintaining miniaturization. This gives the visual lens the advantages of miniaturization, high image quality, and high yield simultaneously.

[0041] Preferably, the radius of curvature R3 of the surface of the second lens facing the human eye, the radius of curvature R4 of the surface of the second lens facing the display, and the distance EP12 between the first and second isolators on the optical axis satisfy the following: -137.5 < (R3 + R4) / EP12 < -68.5.

[0042] In this embodiment, the reflective polarizing element is positioned closer to the user's eye than the quarter-wave plate. Both the reflective polarizing element and the quarter-wave plate have surfaces facing the user's eye and surfaces facing the display. The arrangement of the quarter-wave plate and the reflective polarizing element helps increase the total length of light reflected in the viewing lens, maximizing the field of view while maintaining focus and enhancing the user's visual experience. Furthermore, the inclusion of the reflective polarizing element and the quarter-wave plate in the viewing lens effectively improves image quality without making the viewing lens excessively large, thus contributing to its miniaturization.

[0043] In this embodiment, the distance EP01 between the surface of the lens barrel facing the human eye and the surface of the first isolator facing the human eye on the optical axis, the center thickness CTQ of the quarter-wave plate, and the center thickness CTB of the reflective polarizing element satisfy the following condition: EP01 / (CTQ+CTB)<1.5. By controlling the distance from the surface of the lens barrel facing the human eye to the first isolator, and the relationship between the center thicknesses of the quarter-wave plate and the reflective polarizing element, it is beneficial to control the thickness-to-weight ratio of the edge thickness to the center thickness of the first lens, which facilitates the forming of the first lens, avoids the use of extreme processes in the forming of the first lens, and improves the forming yield of the first lens. Preferably, 0.7 <EP01 / (CTQ+CTB)<1.3。

[0044] In this embodiment, the visual lens further includes a second auxiliary spacer, and the second auxiliary spacer is at least partially in contact with the surface of the second spacer facing the display side. The arrangement of the second auxiliary spacer is beneficial for controlling the maximum thickness of the second spacer and improving the molding process of the second spacer, and meanwhile contributes to increasing the stability of the visual lens.

[0045] In this embodiment, the combined focal length f23 of the second lens and the third lens, the maximum thickness CP2 of the second spacer in the extension direction of the optical axis, and the maximum thickness CP2b of the second auxiliary spacer in the extension direction of the optical axis satisfy: 4.0 < f23 / (CP2+CP2b) < 11.0. By controlling f23 / (CP2+CP2b) within a reasonable range, it is beneficial to limit the thicknesses of the second spacer and the second auxiliary spacer to a reasonable range, which facilitates the molding of the second spacer and the second auxiliary spacer. Meanwhile, the second spacer and the second auxiliary spacer can absorb excess edge light, reduce stray light entering the imaging system, and improve the imaging quality of the visual lens. Preferably, 4.5 < f23 / (CP2+CP2b) < 11.0.

[0046] In this embodiment, the surface of the first lens facing the human eye side or the surface of the first lens facing the display side is a plane. Arranging one side of the first lens as a plane facilitates connection of the reflective polarizing element or the quarter-wave plate thereto, and improves the bonding accuracy.

[0047] In this embodiment, the reflective polarizing element or the quarter-wave plate is in contact with at least a part of the plane of the first lens. The reflective polarizing element or the quarter-wave plate is bonded to the first lens. Wherein, when the surface of the first lens facing the human eye side is a plane, the quarter-wave plate is bonded to the surface of the first lens facing the human eye side, and at this time the reflective polarizing element and the quarter-wave plate are located on the human eye side of the first lens; when the surface of the first lens facing the display side is a plane, the reflective polarizing element is bonded to the surface of the first lens facing the display side, and at this time the reflective polarizing element and the quarter-wave plate are located between the first lens and the second lens.

[0048] In this embodiment, the effective focal length f2 of the second lens and the distance EP12 between the first spacer and the second spacer on the optical axis satisfy: 125.5 < f2 / EP12 < 200. By limiting f2 / EP12 within a reasonable range, the thickness and position of the non-optical effective portion of the second lens can be limited, which is beneficial to improving the processability of the second lens, and meanwhile facilitates controlling the exit angle of the second lens and ensuring the imaging quality of the visual lens. Preferably, 125.8 < f2 / EP12 < 200.

[0049] In this embodiment, among the inner diameter d0m of the surface of the lens barrel facing the display side, the inner diameter d0s of the surface of the lens barrel facing the human eye side, the maximum height L of the lens barrel, and the distance TD on the optical axis from the surface of the first lens facing the human eye side to the surface of the third lens facing the display side, the following relation is satisfied: 1.5<d0m / d0s+L / TD<4.0. By limiting d0m / d0s+L / TD within a reasonable range, the overall size of the visual lens is effectively constrained, which facilitates later matching with other modules, and simultaneously constrains the outer dimension of the lens barrel. On the premise of ensuring the processability of the lens barrel, it is beneficial to reduce the size of the lens barrel, thereby further facilitating the reduction of the size of the visual lens. Preferably, 1.8<d0m / d0s+L / TD<3.5.

[0050] In this embodiment, among the inner diameter d1s of the surface of the first spacer facing the human eye side, the curvature radius R2 of the surface of the first lens facing the display side, the effective focal length f1 of the first lens and the Abbe number V1 of the first lens, the following relation is satisfied: 3.0<d1s / R2+f1 / V1<5.5. By controlling d1s / R2+f1 / V1 within a reasonable range, it is beneficial to control the optical power of the first lens, the curvature radius of the surface facing the display side and the Abbe number of the first lens within reasonable ranges, thereby further facilitating the control of the shape of the first lens. It is conducive to that extra light generated at the edge after being refracted and reflected by the second lens is blocked by the first spacer, so that effective light can obtain the best image quality after being refracted or reflected by the first lens, which is beneficial to improving the imaging quality. Preferably, 3.4<d1s / R2+f1 / V1<5.0.

[0051] In this embodiment, among the effective focal length f of the visual lens, the effective focal length f1 of the first lens, the center thickness CT1 of the first lens and the maximum height L of the lens barrel, the following relation is satisfied: 7.5<f1 / f+CT1 / L<11.0. By controlling f1 / f+CT1 / L within a reasonable range, the optical power of each lens in the visual lens can be reasonably distributed, which is conducive to the mutual cancellation of positive and negative spherical aberration between the front group lens and the rear group lens, facilitating the correction of off-axis aberration and improving the overall image quality of the system. Meanwhile, it is beneficial to the miniaturization of the visual lens and improving the structural compactness. Preferably, 7.8<f1 / f+CT1 / L<10.8.

[0052] In this embodiment, the following relationship is satisfied among the inner diameter d0m of the surface of the lens barrel facing the display side, the outer diameter D2m of the surface of the second spacer facing the display side, and half of the maximum field of view angle Semi-FOV of the visual lens: 0.8<d0m / D2m*TAN(Semi-FOV)<2.0. By controlling d0m / D2m*TAN(Semi-FOV) within a reasonable range, the field of view angle of the visual lens can be constrained. Under the premise that the visual lens has a large field of view angle, the constraints on the inner diameter of the surface facing the display side and the outer diameter of the surface of the second spacer facing the display side are also achieved, which is beneficial to reducing the step structure of the visual lens in the radial direction and improving the assembly yield of the lens. Preferably, 1.1<d0m / D2m*TAN(Semi-FOV)<1.7.

[0053] In this embodiment, the following relationship is satisfied among the maximum height L of the lens barrel, the distance EP01 on the optical axis between the surface of the lens barrel facing the human eye side and the surface of the first spacer facing the human eye side, the distance EP12 on the optical axis between the first spacer and the second spacer, the air interval T23 on the optical axis between the second lens and the third lens, and the central thickness CT3 of the third lens: 0.5<(L-EP01-CP1-EP12) / (T23+CT3)<4.0. By controlling (L-EP01-CP1-EP12) / (T23+CT3) within a reasonable range, it is conducive to the reasonable distribution of the thickness of each component in the lens barrel, ensures the structural strength of each component, and improves the assembly yield of the lens. At the same time, it ensures that the front end of the lens barrel has a certain wall thickness, which is beneficial to improving the reliability of the visual lens. Preferably, 1.0<(L-EP01-CP1-EP12) / (T23+CT3)<3.8.

[0054] In this embodiment, the following relationship is satisfied between the combined focal length F1 of the reflective polarizing element, the quarter-wave plate and the first lens, and the distance EP01 on the optical axis between the surface of the lens barrel facing the human eye side and the surface of the first spacer facing the human eye side: 29.0<F1 / EP01<58. By controlling F1 / EP01 within a reasonable range, it is conducive to reasonably distributing the optical power of the first lens, the reflective polarizing element and the quarter-wave plate, and at the same time ensures the edge thickness of the first lens, which is beneficial to the molding of the first lens, improves the assembly stability of the first lens, and is conducive to improving the assembly yield of the visual lens. Preferably, 29.3<F1 / EP01<57.

[0055] The visual lens in the present application can adopt a plurality of lenses, such as the three lenses described above. By reasonably distributing the effective focal length, surface shape, central thickness of each lens and the on-axis distance between each lens, the image quality of the visual lens can be effectively increased, the sensitivity of the lens can be reduced, and the processability of the lens can be improved, so that the visual lens is more conducive to production and processing and can be applied to portable electronic devices such as smart phones.

[0056] In this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using aspherical lenses, aberrations occurring during image formation can be eliminated as much as possible, thereby improving image quality.

[0057] However, those skilled in the art will understand that the number of lenses constituting the visual lens can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although three lenses are described as an example in the embodiments, the visual lens is not limited to including three lenses. If necessary, the visual lens may also include other numbers of lenses.

[0058] Figure 1 A schematic diagram of the structure of a viewing lens of this application is shown. Figure 1 The diagram also indicates parameters such as d0s and d1s to clearly and intuitively explain their meaning. To facilitate the visual demonstration of the lens structure and specific surface shape, these parameters will not be shown in the accompanying diagrams when explaining specific examples later.

[0059] Where Dis refers to the maximum outer diameter of the surface of the i-th isolator facing the human eye, dis refers to the minimum inner diameter of the surface of the i-th isolator facing the human eye, Dim refers to the maximum outer diameter of the surface of the i-th isolator facing the display, and dim refers to the minimum inner diameter of the surface of the i-th isolator facing the display, where i takes a value from 1 and 2. EP12 is the distance from the surface of the first isolator facing the display to the surface of the second isolator facing the human eye, d0s is the minimum inner diameter of the surface of the lens barrel facing the human eye, and d0m is the minimum inner diameter of the surface of the lens barrel facing the display.

[0060] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of the visual lens applicable to the above embodiments.

[0061] It should be noted that the following examples include a first state, a second state, and a third state. Within the same example, the curvature radius, center thickness, and other parameters of the first to third lenses of the visual lens, as well as the inter-lens spacing and higher-order image coefficients, are the same in all three states. However, the parameters of the lens barrel P0, the thickness of the spacer, the inner and outer diameters of the spacer, and the distance between the spacers differ, as do the shapes of some lenses. In other words, the main structure used for imaging is the same, but the auxiliary structures used for imaging are different.

[0062] It should be noted that any of the examples one through three below are applicable to all embodiments of this application.

[0063] Example 1

[0064] like Figures 2 to 7 As shown, the viewing lens of Example 1 of this application is described. Figure 2 A schematic diagram of the visual lens in Example 1 in its first state is shown. Figure 3 The diagram shows a schematic of the visual lens in Example 1 in the second state. Figure 4 A schematic diagram of the visual lens in Example 1 in the third state is shown.

[0065] like Figure 2 As shown, the viewing lens, from the human eye to the display, includes, in sequence: a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, and a third lens E3.

[0066] exist Figure 2 In the visual lens, there is a first isolation member P1 between the first lens E1 and the second lens, and a second isolation member P2 between the second lens E2 and the third lens E3.

[0067] exist Figure 3 The second state shown is the same as Figure 2 The first state shown is similar, except that the size of the separator is slightly different.

[0068] exist Figure 4 The third state shown is the same as Figure 3 The second state shown is similar, except that the size of the separator is slightly different.

[0069] Table 1 shows the basic structural parameters of the visual lens in Example 1. The units for radius of curvature and thickness / distance are millimeters (mm). In Table 1, the arrangement order of the surface numbers is the order in which the light passes through, and refraction / reflection is the refraction or reflection of the light by that surface during this passage.

[0070] spherical unlimited unlimited refraction STO aperture spherical unlimited 15.0000 refraction S1 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 refraction S2 Quarter-wave plate (QWR) spherical unlimited 0.2000 1.502 57.0 refraction S3 First lens (E1) spherical unlimited 7.7731 1.545 56.0 refraction S4 aspherical -157.3057 2.8870 refraction S5 Second lens (E2) aspherical -154.7712 3.5732 1.545 56.0 refraction S6 Partial reflective layer aspherical -106.0013 -3.5732 1.545 56.0 reflection S5 aspherical -154.7712 -2.8870 refraction S4 aspherical -157.3057 -7.7731 1.545 56.0 refraction S3 Quarter-wave plate (QWR) spherical unlimited -0.2000 1.502 57.0 refraction S2 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 reflection S3 spherical unlimited 7.7731 1.545 56.0 refraction S4 aspherical -157.3057 2.8870 refraction S5 Second lens (E2) aspherical -154.7712 3.5732 1.545 56.0 refraction S6 aspherical -106.0013 0.9677 refraction S7 Third lens (E3) aspherical 47.1735 11.5989 1.545 56.0 refraction S8 aspherical -364.2246 2.9900 refraction S9 monitor spherical unlimited 0.0000

[0071] Table 1

[0072] In Example 1, the surfaces of some of the lenses, from the first lens E1 to the third lens E3, facing the human eye and facing the display are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0073]

[0074] Where x is the distance vector from the vertex of the aspherical surface at a height 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 radius of curvature R in Table 1 above; k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the conic coefficients and higher-order coefficients A4, A6, A8, and A10 that can be used for the aspherical mirrors S4-S8 in Example 1.

[0075] S4 0.0000 -1.12E-02 5.49E-02 -4.04E-03 6.23E-03 S5 0.0000 1.66E-01 -1.74E-01 4.65E-02 1.45E-02 S6 0.0000 1.81E-01 -8.73E-02 1.66E-02 3.63E-03 S7 0.0000 -1.13E+00 1.01E-01 2.33E-02 1.02E-02 S8 0.0000 4.88E-02 -6.33E-02 -4.22E-02 3.36E-02

[0076] Table 2

[0077] Figure 6 The on-axis chromatic aberration curve of the eyepiece in Example 1 is shown, which indicates the deflection of the focal point of light of different wavelengths after passing through the eyepiece. Figure 7 The astigmatism curve of the visual lens in Example 1 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 8 The distortion curve of the visual lens in Example 1 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0078] according to Figures 6 to 8 As can be seen, the visual lens given in Example 1 can achieve good image quality.

[0079] Example 2

[0080] like Figures 8 to 13 As shown, the viewing lens of Example 2 of this application is described. Figure 8 A schematic diagram of the visual lens in Example 2 in its first state is shown. Figure 9 A schematic diagram of the visual lens in Example 2 in the second state is shown. Figure 10 A schematic diagram of the visual lens in Example 2 in the third state is shown. For the sake of brevity, descriptions similar to those in Example 1 are omitted.

[0081] like Figure 8 As shown, the viewing lens, from the human eye to the display, includes, in sequence: a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, and a third lens E3.

[0082] exist Figure 8 In the visual lens, there is a first isolation member P1 between the first lens E1 and the second lens, and a second isolation member P2 between the second lens E2 and the third lens E3.

[0083] exist Figure 9 The second state shown is the same as Figure 8 The difference in the first state shown is that it also includes a second auxiliary isolator P2b, which is located between the second isolator P2 and the third lens E3.

[0084] exist Figure 10 The third state shown is the same as Figure 9 The second state shown is similar, except that the size of the spacer is slightly different.

[0085] Table 3 shows the basic structural parameters of the visual lens in Example 2. The units for radius of curvature and thickness / distance are millimeters (mm). In Table 3, the arrangement order of the surface numbers is the order in which the light passes through, and refraction / reflection is the refraction or reflection of the light by that surface during this passage.

[0086] spherical unlimited unlimited refraction STO aperture spherical unlimited 15.0000 refraction S1 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 refraction S2 Quarter-wave plate (QWR) spherical unlimited 0.2000 1.502 57.0 refraction S3 First lens (E1) spherical unlimited 5.0746 1.545 56.0 refraction S4 aspherical -135.5062 1.6509 refraction S5 Second lens (E2) aspherical -244.3208 3.4593 1.545 56.0 refraction S6 Partial reflective layer aspherical -135.4521 -3.4593 1.545 56.0 reflection S5 aspherical -244.3208 -1.6509 refraction S4 aspherical -135.5062 -5.0746 1.545 56.0 refraction S3 Quarter-wave plate (QWR) spherical unlimited -0.2000 1.502 57.0 refraction S2 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 reflection S3 spherical unlimited 5.0746 1.545 56.0 refraction S4 aspherical -135.5062 1.6509 refraction S5 Second lens (E2) aspherical -244.3208 3.4593 1.545 56.0 refraction S6 aspherical -135.4521 0.9571 refraction S7 Third lens (E3) aspherical 39.8803 4.2841 1.545 56.0 refraction S8 aspherical 57.2991 14.3561 refraction S9 monitor spherical unlimited 0.0000

[0087] Table 3

[0088] Table 4 gives the conic coefficients and higher-order coefficients that can be used for each aspherical lens S4-S8 in Example 2. The surface shape of each aspherical lens can be limited by, but is not limited to, the formula (1) in Example 1.

[0089] S4 0.0000 -3.58E-01 1.47E-01 -1.91E-02 -2.31E-03 S5 0.0000 1.63E-01 -1.54E-01 6.68E-02 -1.24E-02 S6 0.0000 1.03E-01 -9.52E-02 3.61E-02 -3.42E-03 S7 0.0000 -1.11E+00 1.58E-01 4.94E-02 -4.89E-02 S8 0.0000 1.48E+00 -2.30E-01 3.99E-02 -3.19E-02

[0090] Table 4

[0091] Figure 11 The on-axis chromatic aberration curve of the eyepiece in Example 2 is shown, which indicates the deflection of the focal point of light of different wavelengths after passing through the eyepiece. Figure 12 The astigmatism curve of the visual lens in Example 2 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 13 The distortion curve of the visual lens in Example 2 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0092] according to Figures 11 to 13 As can be seen, the visual lens given in Example 2 can achieve good image quality.

[0093] Example 3

[0094] like Figures 14 to 19 As shown, the viewing lens of Example 3 of this application is described. Figure 14 A schematic diagram of the visual lens in Example 3 in its first state is shown. Figure 15 A schematic diagram of the visual lens in Example 3 in the second state is shown. Figure 16 A schematic diagram of the visual lens in Example 3 in its third state is shown. For the sake of brevity, descriptions similar to those in Example 1 are omitted.

[0095] like Figure 14 As shown, the viewing lens, from the human eye to the display, includes, in sequence: a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, and a third lens E3.

[0096] exist Figure 14 In the visual lens, there is a first isolation member P1 between the first lens E1 and the second lens, and a second isolation member P2 between the second lens E2 and the third lens E3.

[0097] exist Figure 15 The second state shown is the same as Figure 14 The difference in the first state shown is that it also includes a second auxiliary isolator P2b, which is located between the second isolator P2 and the third lens E3.

[0098] exist Figure 16 The third state shown is the same as Figure 15 The second state shown is similar, except that the size of the spacer is slightly different.

[0099] Table 5 shows the basic structural parameters of the visual lens in Example 3. The units for radius of curvature and thickness / distance are millimeters (mm). In Table 5, the arrangement order of the surface numbers is the order in which the light passes through, and refraction / reflection is the refraction or reflection of the light by that surface during this passage.

[0100] spherical unlimited unlimited refraction STO aperture spherical unlimited 15.0000 refraction S1 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 refraction S2 Quarter-wave plate (QWR) spherical unlimited 0.2000 1.502 57.0 refraction S3 First lens (E1) spherical unlimited 4.8900 1.545 56.0 refraction S4 aspherical -129.1119 1.7404 refraction S5 Second lens (E2) aspherical -217.1750 3.3539 1.545 56.0 refraction S6 Partial reflective layer aspherical -133.5351 -3.3539 1.545 56.0 reflection S5 aspherical -217.1750 -1.7404 refraction S4 aspherical -129.1119 -4.8900 1.545 56.0 refraction S3 Quarter-wave plate (QWR) spherical unlimited -0.2000 1.502 57.0 refraction S2 Reflective polarizing element (RP) spherical unlimited 0.2000 1.502 57.0 reflection S3 spherical unlimited 4.8900 1.545 56.0 refraction S4 aspherical -129.1119 1.7404 refraction S5 Second lens (E2) aspherical -217.1750 3.3539 1.545 56.0 refraction S6 aspherical -133.5351 2.1430 refraction S7 Third lens (E3) aspherical 41.2768 4.4036 1.545 56.0 refraction S8 aspherical 62.8945 13.2511 refraction S9 monitor spherical unlimited

[0101] Table 5

[0102] Table 6 gives the conic coefficients and higher-order coefficients that can be used for each aspherical lens S4-S8 in Example 3. The surface shape of each aspherical lens can be limited by, but is not limited to, the formula (1) in Example 1.

[0103]

[0104]

[0105] Table 6

[0106] Figure 17 The on-axis chromatic aberration curve of the eyepiece in Example 3 is shown, which indicates the deflection of the focal point of light of different wavelengths after passing through the eyepiece. Figure 18 The astigmatism curve of the visual lens in Example 3 is shown, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 19 The distortion curve of the visual lens in Example 3 is shown, which represents the distortion magnitude corresponding to different field of view angles.

[0107] according to Figures 17 to 19 As can be seen, the visual lens given in Example 3 can achieve good image quality.

[0108] In summary, in Examples 1 to 3, the reflective polarizing element RP, the quarter-wave plate QWP, and the first lens are bonded together. That is, the surface S2 of the reflective polarizing element RP facing the display side and the surface S2 of the quarter-wave plate QWP facing the human eye side are the same surface, and the surface S3 of the quarter-wave plate QWP facing the display side and the surface S3 of the first lens facing the human eye side are the same surface.

[0109] In Examples 1 to 3, a partial reflective layer is disposed on the surface S6 of the second lens facing the display side.

[0110] The following is combined with Figure 20 The trajectory of the light emitted from display S9 is explained as follows: The light emitted from display S9 passes sequentially through the surface S8 of the third lens facing the display side, the surface S7 of the third lens facing the human eye side, the surface S6 of the second lens facing the display side, the surface S5 of the second lens facing the human eye side, and the surface S4 of the first lens facing the display side before entering the surface S3 of the quarter-wave plate facing the display side. The quarter-wave plate QWP converts the light into light with a first polarization state. The first polarization state light enters the surface S2 of the reflective polarizing element facing the display side and is reflected to form the first reflected light. The first reflected light enters the surface S3 of the quarter-wave plate facing the display side, and the quarter-wave plate QWP converts the first reflected light into light with a second polarization state. The light in the third polarization state passes sequentially through the surface S4 of the first lens facing the display side, the surface S5 of the second lens facing the human eye side, and then enters the surface S6 of the second lens facing the display side. It is reflected by a part of the reflective layer on the surface S6 of the second lens facing the display side to form a second reflected light. The second reflected light passes sequentially through the surface S5 of the second lens facing the human eye side, the surface S4 of the first lens facing the display side, and the surface S3 of the quarter-wave plate facing the display side. The quarter-wave plate QWP converts the second reflected light into light in the third polarization state. The light in the third polarization state enters the reflective polarizing element and is transmitted by the surface S2 of the reflective polarizing element facing the display side. The transmitted light passes through the surface S1 of the reflective polarizing element facing the human eye side and exits at the aperture STO.

[0111] It should be noted that during the process of light from the first polarization state becoming light from the third polarization state, it passes through a quarter-wave plate twice, which makes the polarization direction of the light from the first polarization state perpendicular to the polarization direction of the light from the third polarization state. Therefore, the reflective polarizing element reflects the light from the first polarization state and transmits the light from the third polarization state.

[0112] In summary, Examples 1 to 3 satisfy the relationships shown in Table 7.

[0113]

[0114]

[0115] Table 7

[0116] Table 8 provides some parameters of the visual lenses for Examples 1 to 3.

[0117] d1s 60.373 63.503 63.503 60.127 60.126 59.945 59.199 59.199 59.199 D2m 63.781 73.197 72.195 67.416 72.229 72.229 66.485 69.327 68.755 d0s 74.039 67.418 67.418 61.629 61.629 61.629 60.702 60.701 60.702 d0m 63.052 81.651 80.650 74.965 74.961 74.961 74.033 74.037 73.465 EP01 9.711 8.555 8.555 5.453 5.453 4.423 5.453 5.453 5.453 CP1 0.170 0.100 0.100 0.100 0.200 2.726 0.100 0.100 0.100 EP12 3.784 3.608 3.608 3.914 4.359 2.764 3.656 3.656 3.656 CP2 13.974 13.817 13.817 15.057 0.200 0.200 15.500 14.795 14.795 L 32.715 29.612 29.612 28.055 28.055 28.055 28.055 28.055 28.055 CP2b / / / / 14.412 14.412 / 0.200 0.200

[0118] Table 8

[0119] It should be noted that in Tables 7 and 8, 1-1 represents the first state of the visual camera in Example 1, 1-2 represents the second state of the visual camera in Example 1, and 1-3 represents the third state of the visual camera in Example 1. Similarly, 2-1 represents the first state of the visual camera in Example 2, 2-2 represents the second state of the visual camera in Example 2, 2-3 represents the third state of the visual camera in Example 2, 3-1 represents the first state of the visual camera in Example 3, 3-2 represents the second state of the visual camera in Example 3, and 3-3 represents the third state of the visual camera in Example 3.

[0120] Table 9 shows the effective focal lengths of the first lens, second optical element, and third lens of the visual lenses in Examples 1 to 3.

[0121] Semi-FOV (°) 53 53 53 f(mm) 28.292 30.093 29.947 F1 (mm) 287.85 247.96 236.26 f2 (mm) 600.04 550.08 625.62 f3 (mm) 77.19 220.86 205.00 f23(mm) 68.09 156.04 153.23

[0122] Table 9

[0123] This application also provides an imaging device, wherein the electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the viewing lens described above.

[0124] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0125] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0126] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A visual lens, characterized in that, include: Lens tube; The visual lens consists of only three lenses with optical power, namely the first lens, the second lens, and the third lens, which are arranged sequentially from the human eye side to the display side along the optical axis of the visual lens. A first isolator is in at least partial contact with the surface of the first lens facing the display side; The second isolator is in at least partial contact with the surface of the second lens facing the display side, and the outer circumferential surfaces of the first and second isolators abut against the inner wall surface of the lens barrel. The surface of the second lens facing the display has a partial reflective layer; Reflective polarizing element; A quarter-wave plate, wherein the reflective polarizing element and the quarter-wave plate are located on the human eye side of the first lens; Wherein, the radius of curvature R3 of the surface of the second lens facing the human eye, the radius of curvature R4 of the surface of the second lens facing the display, and the distance EP12 between the first isolator and the second isolator on the optical axis satisfy the following: -137.42≤(R3+R4) / EP12≤-68.92; The first lens has positive optical power, the surface of the first lens facing the human eye is flat, and the surface of the first lens facing the display is convex; the second lens has positive optical power, the surface of the second lens facing the human eye is concave, and the surface of the second lens facing the display is convex; the third lens has positive optical power, the surface of the third lens facing the human eye is convex.

2. The visual lens according to claim 1, characterized in that, The reflective polarizing element is located closer to the human eye side relative to the quarter-wave plate, and both the reflective polarizing element and the quarter-wave plate have a surface facing the human eye side and a surface facing the display side.

3. The visual lens according to claim 1, characterized in that, The distance EP01 between the surface of the lens barrel facing the human eye and the surface of the first isolator facing the human eye on the optical axis, the center thickness CTQ of the quarter-wave plate and the center thickness CTB of the reflective polarizing element satisfy the following: 0.81≤EP01 / (CTQ+CTB)≤1.

19.

4. The visual lens according to claim 1, characterized in that, The viewing lens also includes a second auxiliary isolator, which is in at least partial contact with the surface of the second isolator facing the display side.

5. The visual lens according to claim 4, characterized in that, The combined focal length f23 of the second lens and the third lens, the maximum thickness CP2 of the second isolator in the direction of extension of the optical axis, and the maximum thickness CP2b of the second auxiliary isolator in the direction of extension of the optical axis satisfy the following: 4.87≤f23 / (CP2+CP2b)≤10.

68.

6. The visual lens according to claim 1, characterized in that, The reflective polarizing element or the quarter-wave plate is in contact with at least a portion of the plane of the first lens.

7. The visual lens according to any one of claims 1 to 6, characterized in that, The effective focal length f2 of the second lens and the distance EP12 between the first and second isolators on the optical axis satisfy the following condition: 126.19 ≤ f2 / EP12 ≤ 199.

04.

8. The visual lens according to any one of claims 1 to 6, characterized in that, The inner diameter d0m of the surface of the lens barrel facing the display, the inner diameter d0s of the surface of the lens barrel facing the human eye, the maximum height L of the lens barrel, and the distance TD on the optical axis from the surface of the first lens facing the human eye to the surface of the third lens facing the display satisfy the following: 2.07≤d0m / d0s+L / TD≤3.

04.

9. The visual lens according to any one of claims 1 to 6, characterized in that, The inner diameter d1s of the surface of the first isolator facing the human eye, the radius of curvature R2 of the surface of the first lens facing the display, the effective focal length f1 of the first lens, and the Abbe number V1 of the first lens satisfy the following condition: 3.76≤d1s / R2+f1 / V1≤4.

76.

10. The visual lens according to any one of claims 1 to 6, characterized in that, The effective focal length f of the visual lens, the effective focal length f1 of the first lens, the center thickness CT1 of the first lens, and the maximum height L of the lens barrel satisfy the following condition: 8.06≤f1 / f+CT1 / L≤10.

44.

11. The visual lens according to any one of claims 1 to 6, characterized in that, The inner diameter d0m of the surface of the lens barrel facing the display side, the outer diameter D2m of the surface of the second isolator facing the display side, and half of the maximum field of view (Semi-FOV) of the visual lens satisfy the following: 1.31≤d0m / D2m*TAN(Semi-FOV)≤1.

48.

12. The visual lens according to any one of claims 1 to 6, characterized in that, The maximum height L of the lens barrel, the maximum thickness CP1 of the first isolator in the direction of extension of the optical axis, the distance EP01 between the surface of the lens barrel facing the human eye and the surface of the first isolator facing the human eye on the optical axis, the distance EP12 between the first isolator and the second isolator on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, and the center thickness CT3 of the third lens satisfy the following condition: 1.38≤(L-EP01-CP1-EP12) / (T23+CT3)≤3.

55.

13. The visual lens according to any one of claims 1 to 6, characterized in that, The combined focal length F1 of the first lens, the reflective polarizing element and the quarter-wave plate, and the distance EP01 on the optical axis from the surface of the lens barrel facing the human eye to the surface of the first isolator facing the human eye satisfy the following: 29.64≤F1 / EP01≤56.07.

Images