visual system

Abstract

The present invention provides a visual system. The visual system includes a first lens barrel, a second lens barrel, a first optical element group, and a second optical element group. The second optical element group is configured to move along the optical axis of the visual system, approaching or moving away from the first optical element group, to switch the visual system between a first state and a second state. When the visual system switches between the first and second states, the distance ΔL moved along the optical axis by the second optical element group and the minimum inner diameter damin of the first lens barrel satisfy the following relationship: 12.31 ≤ damin / ΔL ≤ 14.15. The minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following relationship: 4.47 ≤ dbmin / CT2 ≤ 7.71. The present invention solves the problem in the prior art that the second lens barrel of the visual system is prone to generating reflected stray light.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging equipment, and in particular to a visual system. Background Art

[0002] With the increasing popularity of AR / VR (Augmented Reality / Virtual Reality) devices, consumers are demanding higher standards for thinness, image quality, and wearable experience. Traditional AR / VR devices based on aspherical and Fresnel technologies are extremely heavy and no longer meet consumer demands. With the advent of reentrant optics, the issue of thinness and lightness in VR devices has been significantly addressed and has become the mainstream solution.

[0003] Among people using AR / VR, everyone's vision conditions are different. There are many users with myopia or hyperopia, and the degree of myopia or hyperopia in different people's eyes is also different. If a fixed-focus reflex module is used, the image quality seen will vary, and the experience obtained will vary greatly. A visual system with adjustable diopter has come into being so that users with different vision can see the image clearly without wearing glasses, thereby improving the VR visual experience. However, existing visual systems generally include a first optical element group located in a first lens barrel and a second optical element group located in a second lens barrel. The diopter is adjusted by changing the position of the second optical element group relative to the first optical element group. When the minimum inner diameter of the first lens barrel is larger than the maximum moving distance of the second optical element group, the first lens barrel has a poor interception effect on stray light, resulting in stray light formed by reflection from the inner wall of the second lens barrel being incident on the human eye, affecting the image quality and clarity. Summary of the Invention

[0004] The main purpose of the present invention is to provide a visual system to solve the problem in the prior art that the second lens barrel of the visual system easily generates reflected stray light.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a visual system, comprising a lens barrel group and an optical element group, wherein the optical element group comprises only two lenses with optical power, and the lens barrel group comprises a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis direction of the visual system; the optical element group comprises a first optical element group and a second optical element group, the first optical element group rests in the first lens barrel, and a part of the second optical element group rests in the second lens barrel; the first optical element group comprises a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate arranged in sequence from the first side to the second side along the optical axis direction, and the second optical element group comprises a second lens, a partial reflective element, and a display arranged in sequence from the first side to the second side along the optical axis direction, wherein the first lens has positive optical power The first side surface of the first lens is convex, the second side surface of the first lens is flat, the second lens has positive optical power, the first side surface of the second lens is convex, the second side surface of the second lens is convex, and the display is located on the second side of the second lens barrel; the second optical element group is configured to be able to move along the optical axis of the visual system to approach or move away from the first optical element group so that the visual system switches between the first state and the second state; when the visual system switches between the first state and the second state, the distance ΔL moved by the second optical element group along the optical axis and the minimum inner diameter damin of the first lens barrel satisfy: 12.31≤damin / ΔL≤14.15; the minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy: 4.47≤dbmin / CT2≤7.71.

[0006] According to another aspect of the present invention, a visual system is provided, comprising a lens barrel group and an optical element group, wherein the optical element group comprises only two lenses with optical power, and the lens barrel group comprises a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis direction of the visual system; the optical element group comprises a first optical element group and a second optical element group, the first optical element group rests in the first lens barrel, and a part of the second optical element group rests in the second lens barrel; the first optical element group comprises a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate arranged in sequence from the first side to the second side along the optical axis direction, and the second optical element group comprises a second lens, a partially reflecting element, and a display arranged in sequence from the first side to the second side along the optical axis direction, wherein the first lens has positive optical power, the first side surface of the first lens is convex, and the second side surface of the second lens is convex. The second side surface of a lens is a plane, the second lens has positive optical power, the first side surface of the second lens is a convex surface, the second side surface of the second lens is a convex surface, and the display is located on the second side of the second lens barrel; the second optical element group is configured to be movable along the optical axis of the visual system to approach or move away from the first optical element group so that the visual system switches between the first state and the second state; the distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel in the optical axis direction, the curvature radius R3 of the first side surface of the second lens, and the curvature radius R4 of the second side surface of the second lens satisfy: 8.69mm≤Lb×|R3 / R4|≤21.53mm; the minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy: 4.47≤dbmin / CT2≤7.71.

[0007] Furthermore, the distance Lb between the first side end face of the second lens barrel and the second side end face of the second lens barrel in the optical axis direction, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 2.72≤Lb / Δf≤5.60.

[0008] Furthermore, a distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel in the optical axis direction and a curvature radius R1 of the first side surface of the first lens satisfy the following relationship: 8.86≤R1 / La≤15.64.

[0009] Furthermore, the effective focal length f2 of the second lens and the minimum inner diameter dbmin of the second lens barrel satisfy the following relationship: 3.58≤f2 / dbmin≤3.94.

[0010] Furthermore, the inner diameter dam of the second side end surface of the first lens barrel, the inner diameter das of the first side end surface of the first lens barrel, and the center thickness CT1 of the first lens on the optical axis satisfy: 1.61≤(dam-das) / CT1≤2.64.

[0011] Furthermore, a distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel in the optical axis direction, a curvature radius R3 of the first side surface of the second lens, and a curvature radius R4 of the second side surface of the second lens satisfy the following relationship: 8.69 mm ≤ Lb × | R3 / R4 | ≤ 21.53 mm.

[0012] Furthermore, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate, and the outer diameter Das of the first side end surface of the first lens barrel satisfy the following relationship: 2.96≤fz / Das≤3.42.

[0013] Furthermore, the outer diameter Dbs of the first side end surface of the second lens barrel, the outer diameter Dbm of the second side end surface of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 1.00≤(Dbs-Dbm) / Δf≤2.27.

[0014] Furthermore, the inner diameter dbs of the first side end surface of the second lens barrel and the distance ΔL that the second optical element group moves along the optical axis when the visual system switches between the first state and the second state satisfy the following relationship: 17.60≤dbs / ΔL≤19.83.

[0015] Furthermore, the minimum inner diameter damin of the first lens barrel and the effective focal length f1 of the first lens satisfy the following relationship: 3.99≤f1 / damin≤4.94.

[0016] Furthermore, an outer diameter Dam of the second side end surface of the first lens barrel and a curvature radius R3 of the first side surface of the second lens satisfy the following relationship: 4.88≤R3 / Dam≤7.57.

[0017] Furthermore, the inner diameter dbm of the second side end surface of the second lens barrel and the distance BFL between the second side surface of the second lens and the display on the optical axis satisfy the following relationship: 36.20≤dbm / BFL≤43.34.

[0018] Furthermore, the minimum inner diameter damin of the first lens barrel and the entrance pupil diameter EPD of the visual system satisfy the following relationship: 7.25≤damin / EPD≤8.10.

[0019] Furthermore, an outer diameter Das of the first side end surface of the first lens barrel and a distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel in the optical axis direction satisfy: 5.34≤Das / La≤8.36.

[0020] According to the technical solution of the present invention, the visual system includes a lens barrel group and an optical element group, the optical element group includes only two lenses with optical power, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis direction of the visual system; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and a part of the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a polarizer, a reflective polarizing element, and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis direction, and the second optical element group includes a second lens, a partially reflecting element, and a display arranged in sequence from the first side to the second side along the optical axis direction, wherein the first lens has positive optical power, and the first of the first lens has a positive optical power. The side surface is convex, the second side surface of the first lens is a plane, the second lens has positive optical power, the first side surface of the second lens is convex, the second side surface of the second lens is convex, and the display is located on the second side of the second lens barrel; the second optical element group is configured to be able to move along the optical axis of the visual system to approach or move away from the first optical element group so that the visual system can switch between the first state and the second state; when the visual system switches between the first state and the second state, the distance ΔL moved by the second optical element group along the optical axis and the minimum inner diameter damin of the first lens barrel satisfy the following conditions: 12.31≤damin / ΔL≤14.15; the minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following conditions: 4.47≤dbmin / CT2≤7.71.

[0021] The visual system in the present application is formed by two lens barrels, two lenses, a polarizer, a reflective polarizing element, a quarter-wave plate and a partial reflective element. Under the premise that 12.31≤damin / ΔL≤14.15 is satisfied, the minimum inner diameter of the first lens barrel is larger than the movement distance of the second optical element group when switching between the two states, resulting in a larger minimum inner diameter of the first lens barrel, and the first lens barrel's interception effect on stray light is reduced, resulting in some stray light reflected by the inner wall of the second lens barrel not being effectively intercepted by the first lens barrel and entering the human eye, affecting the imaging quality. In order to solve the stray light problem caused by the condition of 12.31≤damin / ΔL≤14.15, this application controls dbmin / CT2 within a reasonable range, controls the relationship between the minimum inner diameter of the second lens barrel and the center thickness of the second lens to control the degree of light deflection on the second lens, and then controls the position where the light enters the first optical element group, so that the stray light formed by reflection from the inner wall of the second lens barrel is deflected to the outside of the human eye, reducing the stray light received by the human eye, which is beneficial to improving the clarity of the image and enhancing the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 A parameter-labeled diagram of a visual system according to an alternative embodiment of the present invention is shown;

[0024] Figure 2 and Figure 3 Schematic diagrams showing the structure of the visual system of Example 1-1 of the present invention in a first state and a second state respectively;

[0025] Figure 4 and Figure 5 Schematic diagrams showing the structures of the visual system of embodiments 1-2 of the present invention in a first state and a second state respectively;

[0026] Figure 6 and Figure 7 Schematic diagrams showing the structures of the visual systems of embodiments 1-3 of the present invention in the first state and the second state respectively;

[0027] Figure 8 and Figure 9 Graphs of optical modulation functions of the visual system in a first state and a second state are respectively shown;

[0028] Figure 10 and Figure 11 Schematic diagrams showing the structure of the visual system of Example 2-1 of the present invention in the first state and the second state respectively;

[0029] Figure 12 and Figure 13 Schematic diagrams showing the structure of the visual system of Example 2-2 of the present invention in a first state and a second state respectively;

[0030] Figure 14 and Figure 15 Schematic diagrams showing the structures of the visual systems of embodiments 2-3 of the present invention in the first state and the second state respectively;

[0031] Figure 16 and Figure 17 Graphs of optical modulation functions of the visual system in a first state and a second state are shown respectively;

[0032] Figure 18 and Figure 19 Schematic diagrams showing the structure of the visual system of Example 3-1 of the present invention in a first state and a second state respectively;

[0033] Figure 20 and Figure 21 Schematic diagrams showing the structure of the visual system of Example 3-2 of the present invention in a first state and a second state respectively;

[0034] Figure 22 and Figure 23 Schematic diagrams showing the structure of the visual system of Example 3-3 of the present invention in the first state and the second state respectively;

[0035] Figure 24 and Figure 25 Graphs of optical modulation functions of the visual system in a first state and a second state according to a third embodiment of the present invention are shown respectively;

[0036] Figure 26 A stray light optical path diagram of a visual system according to an optional embodiment of the present invention is shown;

[0037] Figure 27 A stray light path diagram of a visual system in an example is shown;

[0038] Figure 28 Shown Figure 27 stray light spot diagram of the visual system;

[0039] Figure 29 A stray light path diagram of a visual system in another example is shown;

[0040] Figure 30 Shown Figure 29 Stray light spot pattern of the visual system in .

[0041] The above drawings include the following reference numerals:

[0042] E1, first lens; LP, polarizer; RP, reflective polarizer; QWP, quarter-wave plate; E2, second lens; BS, partially reflecting element; Pa, first lens barrel; Pb, second lens barrel; IMG, display. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0044] 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 ordinary technicians in the technical field to which this application belongs.

[0045] 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 direction; 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 directional words are not used to limit the present invention.

[0046] In this document, if a lens surface is convex and the position of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is undefined, it means that the lens surface is concave at least in the paraxial region. The paraxial region refers to the area near the optical axis. The surface of each lens closest to the first side (e.g., the side facing the human eye) is called the first side of the lens, and the surface of each lens closest to the second side (e.g., the side facing the display screen) is called the second side of the lens.

[0047] In order to solve the problem in the prior art that the second lens barrel of a visual system easily generates reflected stray light, the present invention provides a visual system.

[0048] like Figures 1 to 25 As shown, the visual system includes a lens barrel group and an optical element group, the optical element group includes only two lenses with optical power, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis direction of the visual system; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and a part of the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate arranged in sequence from the first side to the second side along the optical axis direction, and the second optical element group includes a second lens, a partial reflective element and a display arranged in sequence from the first side to the second side along the optical axis direction, wherein the first lens has positive optical power, and the first side surface of the first lens is convex The first lens has a first surface, the second side surface of the first lens is a plane, the second lens has positive optical power, the first side surface of the second lens is a convex surface, the second side surface of the second lens is a convex surface, and the display is located on the second side of the second lens barrel; the second optical element group is configured to be able to move along the optical axis of the visual system to approach or move away from the first optical element group so that the visual system can switch between the first state and the second state; when the visual system switches between the first state and the second state, the distance ΔL moved by the second optical element group along the optical axis and the minimum inner diameter damin of the first lens barrel satisfy the following conditions: 12.31≤damin / ΔL≤14.15; the minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following conditions: 4.47≤dbmin / CT2≤7.71.

[0049] The visual system in the present application is formed by two lens barrels, two lenses, a polarizer, a reflective polarizing element, a quarter-wave plate and a partial reflective element. Under the premise that 12.31≤damin / ΔL≤14.15 is satisfied, the minimum inner diameter of the first lens barrel is larger than the movement distance of the second optical element group when switching between the two states, resulting in a larger minimum inner diameter of the first lens barrel, and the first lens barrel's interception effect on stray light is reduced, resulting in some stray light reflected by the inner wall of the second lens barrel not being effectively intercepted by the first lens barrel and entering the human eye, affecting the imaging quality. In order to solve the stray light problem caused by the condition of 12.31≤damin / ΔL≤14.15, this application controls dbmin / CT2 within a reasonable range, controls the relationship between the minimum inner diameter of the second lens barrel and the center thickness of the second lens to control the degree of light deflection on the second lens, and then controls the position where the light enters the first optical element group, so that the stray light formed by reflection from the inner wall of the second lens barrel is deflected to the outside of the human eye, reducing the stray light received by the human eye, which is beneficial to improving the clarity of the image and enhancing the user experience.

[0050] The following stray light spot diagram simulates the geometrical ray spots formed by geometric rays on the imaging surface and shows the energy intensity distribution of the stray light. The X and Y axes represent the spatial position of the imaging surface (unit: mm), showing the peak position of the stray light energy distribution corresponding to the imaging surface. The color depth represents the intensity of the stray light energy. That is, the luminous flux FLUX of the stray light per square millimeter on the imaging surface (unit: lm) is assumed to be 1 lm of the main ray.

[0051] Optionally, the first lens barrel, the second lens barrel, the first optical element group and the second optical element group of the visual system are configured as described above. On the premise that the visual system satisfies 12.31≤damin / ΔL≤14.15, dbmin / CT2 is set to meet different numerical ranges, thereby forming the following three different visual systems.

[0052] Figure 26 FIG. 2 shows the stray light path of a visual system according to an optional embodiment of the present invention. Specifically, Figure 26 The visual system shown satisfies dbmin / CT2=6.2, and this embodiment is hereinafter referred to as Scheme 1. In Scheme 1, dbmin / CT2 is within the range of 4.47≤dbmin / CT2≤7.71. Figure 26 It can be seen that the stray light formed by the second lens barrel falls outside the receiving range of the human eye, which reduces the stray light entering the human eye and ensures the imaging clarity.

[0053] Figure 27 and Figure 28The stray light path and stray light spot diagram of an example visual system are shown respectively. Specifically, in this example, the visual system satisfies dbmin / CT2=3.4, and this example is hereinafter referred to as Example 1. In Example 1, dbmin / CT2 is less than the lower limit value defined by 4.47≤dbmin / CT2≤7.71. Figure 27 and Figure 28 It can be seen that the inner inclined wall surface of the second lens barrel reflects stray light into the receiving range of the human eye, and the intensity of the stray light is relatively high, which has a greater impact on the imaging effect.

[0054] Figure 29 and Figure 30 The stray light path and stray light spot diagram of another example visual system are shown respectively. Specifically, in this example, the visual system satisfies dbmin / CT2=8.5, and this example is hereinafter referred to as Example 2. In Example 2, dbmin / CT2 is greater than the upper limit value defined by 4.47≤dbmin / CT2≤7.71. Figure 29 and Figure 30 It can be seen that the inner inclined wall surface of the second lens barrel reflects stray light into the receiving range of the human eye, and the intensity of the stray light is relatively high, which has a greater impact on the imaging effect.

[0055] In summary, when 4.47≤dbmin / CT2≤7.71 is satisfied, there is no stray light within the receiving range of the human eye, the imaging effect is good, and the stray light problem caused by 12.31≤damin / ΔL≤14.15 can be solved. It should be noted that the present application constrains damin / ΔL and dbmin / CT2 within a reasonable range, which can reduce stray light, and does not depend on the optical focal length and surface shape of other lenses. The optical focal length and surface shape of other lenses are further optimization of the visual system on this basis. The other lenses can be positive or negative according to the actual design requirements of the visual system, and the surface shape of each lens can also be convex or concave according to the design requirements of the visual system. When the visual system meets the following requirements: 12.31≤damin / ΔL≤14.15; 4.47≤dbmin / CT2≤7.71, it can be ensured that the visual system has a low stray light risk.

[0056] For example, in some optional embodiments, the first lens has positive optical power, and the second lens has positive optical power. For another example, in some optional embodiments, the first side surface of the first lens is convex, and the second side surface of the first lens is flat. The first side surface of the second lens is convex, and the second side surface of the second lens is convex. By properly constraining the surface shape of each lens, it is helpful to properly constrain the light path, ensure a smooth light transition, and facilitate correction of aberrations.

[0057] In some optional embodiments, the distance of the first optical element group relative to the display on the second side of the visual system on the optical axis can be adjusted, the distance of the second lens relative to the display on the optical axis can be fixed, and the second optical element group can be configured to be able to move along the optical axis to move closer to or away from the first optical element group so that the visual system can switch between the first state and the second state.

[0058] Specifically, when the second optical element group moves to the position farthest from the first optical element group, the visual system may be in a +2D state, that is, the first state; when the second optical element group moves to the position closest to the first optical element group, the visual system may be in a -5D state, that is, the second state.

[0059] For example, when the visual system is in a first state, the refractive power of the visual system is +2D, which is suitable for users with a +2D refractive power. When the visual system is in a second state, the refractive power of the visual system is -5D, which is suitable for users with a -5D refractive power. A negative sign for the refractive power indicates that the user is myopic; a positive sign indicates that the user is hyperopic. The specific value of the refractive power indicates the user's refractive power. For example, a +1D refractive power indicates that the user's hyperopia is approximately 100 degrees, while a -1D refractive power indicates that the user's myopia is approximately 100 degrees.

[0060] It should be understood that in addition to the first state and the second state, the visual system according to the embodiment of the present application can also have other states, such as between -5D and +2D. The visual system according to the embodiment of the present application can achieve continuous zoom within the range of -5D to +2D, which can meet the needs of users with different vision and enable users to enjoy the VR experience without wearing glasses.

[0061] In an exemplary embodiment, the visual system of the present application may include at least one aperture. The aperture can constrain the optical path and control the light intensity. The aperture can be positioned appropriately within the visual system as needed. For example, the aperture can be located between the first side (e.g., the side facing the human eye) and the first lens.

[0062] In an exemplary embodiment, the virtual image distance VID of the visual system is different in the first state and the second state. The virtual image distance may be, for example, the distance from the virtual image formed by the image light from the display at a predetermined position to the aperture on the optical axis.

[0063] In some optional embodiments, the distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel in the optical axis direction, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy the following relationship: 2.72≤Lb / Δf≤5.60. By constraining Lb / Δf within a reasonable range, the structural strength of the second lens barrel can be ensured while also facilitating miniaturization of the visual system. If Lb / Δf exceeds an upper limit, the visual system may be enlarged, affecting the overall volume of the device. If Lb / Δf is less than a lower limit, the second lens barrel may be insufficiently strong, affecting the mechanical performance of the visual system.

[0064] In some optional embodiments, the distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel along the optical axis and the radius of curvature R1 of the first side surface of the first lens satisfy the following relationship: 8.86 ≤ R1 / La ≤ 15.64. By constraining R1 / La within a reasonable range, the shape of the first lens can be controlled, which helps reduce the sensitivity of the first lens, thereby improving the assembly yield of the visual system.

[0065] In some optional embodiments, the effective focal length f2 of the second lens and the minimum inner diameter dbmin of the second lens barrel satisfy the following relationship: 3.58 ≤ f2 / dbmin ≤ 3.94. By constraining f2 / dbmin within a reasonable range, the minimum inner diameter of the second lens barrel and the degree of light deflection at the second lens are limited, which helps reduce stray light deflected into the second lens barrel and mitigates stray light risks. It also constrains the shape of the second lens and improves its manufacturability.

[0066] In some optional embodiments, the inner diameter dam of the second side end surface of the first lens barrel, the inner diameter das of the first side end surface of the first lens barrel, and the center thickness CT1 of the first lens on the optical axis satisfy the following relationship: 1.61≤(dam-das) / CT1≤2.64. By constraining (dam-das) / CT1 within a reasonable range, the stability of the assembly of the first lens barrel and the first lens is ensured, the shape of the first lens is constrained, and the workability of the first lens is improved.

[0067] In some optional embodiments, the distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel along the optical axis, the radius of curvature R3 of the first side surface of the second lens, and the radius of curvature R4 of the second side surface of the second lens satisfy the following relationship: 8.69 mm ≤ Lb × |R3 / R4| ≤ 21.53 mm. By constraining Lb × |R3 / R4| within a reasonable range, the shape of the second lens can be constrained, which helps reduce the sensitivity of the second lens and improve the assembly yield of the visual system. Furthermore, the length of the second lens barrel can be matched to the refractive properties of the second lens, preventing non-imaging light from being deflected into the human eye's receptive range while avoiding obstruction of imaging light, reducing the risk of stray light while ensuring brightness.

[0068] In some optional embodiments, the combined focal length fz of the first lens, polarizer, reflective polarizer, and quarter-wave plate, and the outer diameter Das of the first side end surface of the first lens barrel satisfy the following relationship: 2.96 ≤ fz / Das ≤ 3.42. Constraining fz / Das within a reasonable range effectively corrects aberrations and improves imaging quality, while also ensuring efficient light beam propagation along a predetermined path and reducing reflections and scattering of light from the walls of the first lens barrel or other non-target surfaces. This effectively manages stray light and enhances the user experience.

[0069] In some optional embodiments, the outer diameter Dbs of the first side end surface of the second lens barrel, the outer diameter Dbm of the second side end surface of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy the following: 1.00 ≤ (Dbs - Dbm) / Δf ≤ 2.27. Constraining (Dbs - Dbm) / Δf within a reasonable range can, on the one hand, control the overall dimensions of the visual system, preventing the visual system from being too large, which would result in a larger overall size and hinder overall miniaturization, and on the other hand, ensure the structural strength of the second lens barrel, preventing low structural strength from affecting the stability of the visual system. If (Dbs - Dbm) / Δf is greater than 2.27, the overall dimensions of the visual system may be too large. If (Dbs - Dbm) / Δf is less than 1, the strength of the second lens barrel may be insufficient. If (Dbs - Dbm) / Δf is within the range of 1 to 2.27, the size of the visual system can be guaranteed while maintaining the structural strength of the second lens barrel.

[0070] In some optional embodiments, the inner diameter dbs of the first side end surface of the second lens barrel and the distance ΔL that the second optical element group moves along the optical axis when the visual system switches between the first state and the second state satisfy the following relationship: 17.60≤dbs / ΔL≤19.83. Constraining dbs / ΔL within a reasonable range is beneficial for controlling the amount of light passing through at different focal lengths, thereby ensuring that the visual system has excellent optical performance at different focal lengths. Constraining the range of dbs / ΔL can, on the one hand, prevent stray light problems caused by a large inner diameter of the first side end surface of the second lens barrel, and on the other hand, avoid problems of low eye brightness caused by a small inner diameter of the first side end surface of the second lens barrel, thereby ensuring the optical performance of the visual system.

[0071] In some optional embodiments, the minimum inner diameter damin of the first lens barrel and the effective focal length f1 of the first lens satisfy the following relationship: 3.99 ≤ f1 / damin ≤ 4.94. Constraining f1 / damin within a reasonable range not only controls the luminous flux and the degree of light deflection by the first lens, thereby reducing stray light entering the human eye while ensuring brightness, but also constrains the shape of the first lens, facilitating its processing.

[0072] In some optional embodiments, the outer diameter Dam of the second side end surface of the first lens barrel and the curvature radius R3 of the first side surface of the second lens satisfy the following relationship: 4.88 ≤ R3 / Dam ≤ 7.57. Constraining R3 / Dam within a reasonable range not only constrains the shape of the second lens, but also helps reduce its sensitivity and thereby improve the assembly yield of the vision system. It also helps the first lens barrel meet molding and miniaturization requirements.

[0073] In some optional embodiments, the inner diameter (dBm) of the second end surface of the second lens barrel and the distance (BFL) between the second side surface of the second lens and the display on the optical axis satisfy the following relationship: 36.20 ≤ dBm / BFL ≤ 43.34. Constraining the dBm / BFL ratio within a reasonable range effectively controls the amount of light passing through the second lens from the display, preventing excessively low brightness while also reducing the risk of stray light.

[0074] In some optional embodiments, the minimum inner diameter (damin) of the first lens barrel and the entrance pupil diameter (EPD) of the visual system satisfy the following relationship: 7.25 ≤ damin / EPD ≤ 8.10. Constraining damin / EPD within a reasonable range can ensure eye brightness while reducing stray light. If damin / EPD is greater than 8.10, the minimum inner diameter of the first lens barrel is larger, which increases the risk of stray light passing through. If damin / EPD is less than 7.25, the minimum inner diameter of the first lens barrel is smaller, which can easily block light, resulting in lower eye brightness and affecting the user experience.

[0075] In some optional embodiments, the outer diameter Das of the first side end surface of the first lens barrel and the distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel in the direction of the optical axis satisfy the following relationship: 5.34≤Das / La≤8.36. Constraining Das / La within a reasonable range is beneficial for controlling the overall shape and size of the first lens barrel, preventing interference between the first lens barrel and the second lens barrel during focusing, and improving the machinability of the first lens barrel.

[0076] On the other hand, in some other optional embodiments, the visual system includes a lens barrel group and an optical element group, the optical element group includes only two lenses with optical focal length, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis direction of the visual system; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and a part of the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a polarizer, a reflective polarizing element, and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis direction, and the second optical element group includes a second lens, a partially reflecting element and a display arranged in sequence from the first side to the second side along the optical axis direction, wherein the first lens has positive optical focal length, the first side surface of the first lens is convex, and the second side surface of the second lens is convex. The second side surface of a lens is a plane, the second lens has positive optical power, the first side surface of the second lens is a convex surface, the second side surface of the second lens is a convex surface, and the display is located on the second side of the second lens barrel; the second optical element group is configured to be movable along the optical axis of the visual system to approach or move away from the first optical element group so that the visual system switches between the first state and the second state; the distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel in the optical axis direction, the curvature radius R3 of the first side surface of the second lens, and the curvature radius R4 of the second side surface of the second lens satisfy: 8.69mm≤Lb×|R3 / R4|≤21.53mm; the minimum inner diameter dbmin of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy: 4.47≤dbmin / CT2≤7.71.

[0077] The visual system in the present application is formed by two lens barrels, two lenses, a polarizer, a reflective polarizing element, a quarter-wave plate and a partial reflective element. When the visual system satisfies 8.69mm≤Lb×|R3 / R4|≤21.53mm and 4.47≤dbmin / CT2≤7.71, it is beneficial to constrain the length and inner diameter of the second lens barrel, and at the same time control the path of light transmitted in the second lens, so as to control the size of the second lens barrel to match the refractive performance of the second lens for light, reduce the reflection of light by the inner diameter surface of the second lens barrel, reduce the generation of stray light, and at the same time control the path of light emitted from the second optical element group, so that the stray light formed by the reflection of the inner wall surface of the second lens barrel is deflected to the outside of the human eye, reducing the stray light received by the human eye, which is beneficial to improving the clarity of the imaging and enhancing the user experience.

[0078] Of course, this embodiment may also include other parameter formulas in the above optional embodiments, which will not be described here one by one.

[0079] In the present application, at least one of the first and second lenses has an aspheric surface. Aspheric lenses are characterized by a continuously varying curvature from the center to the periphery. Unlike spherical lenses, which have a constant curvature from the center to the periphery, aspheric lenses have a more optimized curvature radius, offering advantages such as improved distortion and astigmatism. The use of aspheric lenses minimizes aberrations that occur during imaging, thereby improving image quality.

[0080] However, those skilled in the art will appreciate that the number of lenses comprising the visual system can be varied to achieve the various results and advantages described herein without departing from the technical solutions claimed herein. For example, while two lenses are described as an example in the embodiments, the visual system is not limited to comprising two lenses. If desired, the visual system can also include other numbers of lenses.

[0081] Figure 1 A schematic diagram showing the dimensions of a visual system according to an optional embodiment of the present application is shown. Figure 1 Parameters such as das, dam, Das, Dam, damin, dbs, dbm, Dbs, Dbm, dbmin, La, and Lb are labeled to provide a clear and intuitive understanding of their meaning. To facilitate the description of the visual system and specific lens profiles, these parameters will not be reflected in the accompanying drawings when describing specific embodiments.

[0082] The first side end surface of the first lens barrel in this application refers to the surface of the first lens barrel located closest to the first side and perpendicular to the optical axis, the second side end surface of the first lens barrel refers to the surface of the first lens barrel located closest to the second side and perpendicular to the optical axis, the first side end surface of the second lens barrel refers to the surface of the second lens barrel located closest to the first side and perpendicular to the optical axis, and the second side end surface of the second lens barrel refers to the surface of the second lens barrel located closest to the second side and perpendicular to the optical axis.

[0083] The following further describes examples of specific surface shapes and parameters of the visual system applicable to the above-mentioned embodiment with reference to the accompanying drawings.

[0084] It should be noted that in the following Example 1, there are Examples 1-1, 1-2, and 1-3; in Example 2, there are Examples 2-1, 2-2, and 2-3; and in Example 3, there are Examples 3-1, 3-2, and 3-3. While the parameters such as the radius of curvature and center thickness of the first and second lenses of the visual systems in the three embodiments within the same embodiment are the same, as are the spacing between the lenses and the coefficients of higher-order terms, the thickness, inner diameter, and outer diameter of the first and second lens barrels, as well as the shapes of some lenses, are different. In other words, the main structure for imaging is the same, while the auxiliary structures for imaging are different.

[0085] It should be noted that any one of the following examples 1 to 3 is applicable to this application.

[0086] Example 1

[0087] like Figures 2 to 9 As shown, the visual system of embodiment 1 is described. Figure 2 FIG1 shows a schematic structural diagram of the visual system of Example 1-1 in the first state. Figure 3 FIG1 shows a schematic diagram of the structure of the visual system of Example 1-1 in the second state. Figure 4 Schematic diagram showing the structure of the visual system of embodiment 1-2 in the first state, Figure 5 FIG2 shows a schematic diagram of the structure of the visual system of Example 1-2 in the second state. Figure 6 Schematic diagram showing the structure of the visual system of Embodiments 1-3 in the first state, Figure 7 A schematic structural diagram of the visual system of Examples 1-3 in the second state is shown.

[0088] like Figures 2 to 7As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, arranged sequentially along the optical axis from the first side to the second side. The visual system also includes a first optical element group and a second optical element group. The first optical element group is supported within the first lens barrel Pa and includes a first lens E1, a polarizer LP, a reflective polarizer RP, and a quarter-wave plate QWP, arranged sequentially along the optical axis from the first side to the second side. The second optical element group includes a second lens E2, a partially reflective element BS, and a display IMG, arranged sequentially along the optical axis from the first side to the second side. The second lens E2 and the partially reflective element BS are supported within the second lens barrel Pb, and the display IMG is located on the second side of the second lens barrel Pb. The polarizer LP is positioned on the second side of the first lens, the reflective polarizer RP is positioned on the second side of the polarizer LP, and the quarter-wave plate QWP is positioned on the second side of the reflective polarizer RP. This can be understood as a cemented arrangement of the first lens E1, polarizer LP, reflective polarizer RP, and quarter-wave plate QWP. The partially reflective element BS is positioned on the second side of the second lens E2.

[0089] In this embodiment, light from the display IMG passes through the second lens E2 and the quarter-wave plate QWP in sequence before reaching the reflective polarizer RP. After being reflected by the reflective polarizer RP, the light passes through the quarter-wave plate QWP and the second lens E2 in sequence again before reaching the partially reflective element BS on the second side surface of the second lens. The light is reflected by the partially reflective element BS again before passing through the second lens E2, the quarter-wave plate QWP, the reflective polarizer RP, the polarizer LP, and the first lens E1 to exit.

[0090] In summary, the structural parameters of the visual system of Example 1 in Example 1-1, Example 1-2, and Example 1-3 are shown in Table 11.

[0091] In Example 1, the first lens has positive optical power, a convex first side surface, and a flat second side surface. The second lens has positive optical power, a convex first side surface, and a convex second side surface. The visual system also includes an aperture stop (STO) located on a first side of the first lens.

[0092] Table 1 shows the basic structural parameters of the visual system of Example 1, where the units of curvature radius and thickness / distance are all in millimeters (mm). In Table 1, light from display IMG propagates from surface number 16 to surface number 0, and refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage. The surfaces represented by surface numbers 16 to 0 are, in order: the display, the second side surface of the second lens, the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the second side surface of the quarter-wave plate, the first side surface of the second lens, the second side surface of the second lens (the first side surface of the partially reflective element), the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the first side surface of the reflective polarizer (the second side surface of the polarizer), the first side surface of the polarizer, the second side surface of the first lens, the first side surface of the first lens, the aperture surface, and the virtual image surface.

[0093] Table 1

[0094]

[0095] Parameters D1 to D4 in Table 1 can be understood as follows: D1 can be understood as the value of the virtual image distance of the visual system according to this embodiment, that is, the value along the optical axis from the virtual image plane to the aperture plane. D2 can be understood as the value along the optical axis from the second side surface of the quarter-wave plate QWP to the first side surface of the second lens; D3 can be understood as the value along the optical axis from the first side surface of the second lens to the second side surface of the quarter-wave plate QWP; and D4 can be understood as the value along the optical axis from the second side surface of the quarter-wave plate QWP to the first side surface of the second lens. It should be noted that during the transmission of light in the visual system, due to the presence of the reflective polarizer, quarter-wave plate, and partially reflective element, light is reflected between some surfaces and passes through some lens surfaces multiple times. The distance traveled from the first side to the second side is positive, while the distance traveled from the second side to the first side is negative. As the second optical element group moves along the optical axis to achieve zoom, the values ​​of the above parameters D1 to D4 will change accordingly.

[0096] The values ​​of D1 to D4 of the visual system in the first state and the second state are shown in Table 2 below.

[0097] Table 2

[0098]

[0099] In Example 1, the first side surface of the first lens (i.e., surface number 2), the first side surface of the second lens (i.e., surface numbers 8 and 14), and the second side surface of the second lens (i.e., surface numbers 9 and 15) are aspherical surfaces. The surface shape of each aspherical surface can be defined using, but not limited to, the following aspherical surface formula:

[0100] Formula (1);

[0101] Where x is the distance vector from the vertex of the aspheric surface at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c = 1 / R, i.e., 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 correction coefficient for the i-th order of the aspheric surface. Table 3 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspheric surface in Example 1.

[0102] Table 3

[0103]

[0104] Figure 8 and Figure 9 The optical modulation function (MTF) curves of the visual system of Example 1 in the first state and the second state are shown, wherein Curve 1 is the MTF curve of the 0 field of view in the meridian direction; Curve 2 is the MTF curve of the 0.5 field of view in the meridian direction; Curve 3 is the MTF curve of the 1 field of view in the meridian direction. Figure 8 and Figure 9 It can be seen that the MTF values ​​(optical modulation function values) of light in each field of view at 15 line pairs / mm are all above 0.85, showing good imaging quality.

[0105] Example 2

[0106] like Figures 10 to 17 As shown, the visual system of embodiment 2 is described. Figure 10 FIG2 shows a schematic structural diagram of the visual system of Example 2-1 in the first state. Figure 11 FIG2 shows a schematic diagram of the structure of the visual system of Example 2-1 in the second state. Figure 12 FIG2 shows a schematic structural diagram of the visual system of Example 2-2 in the first state. Figure 13 FIG2 shows a schematic structural diagram of the visual system of Example 2-2 in the second state. Figure 14 FIG2 shows a schematic structural diagram of the visual system of Example 2-3 in the first state. Figure 15 A schematic structural diagram of the visual system of Example 2-3 in the second state is shown.

[0107] like Figures 10 to 15As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, arranged sequentially along the optical axis from the first side to the second side. The visual system also includes a first optical element group and a second optical element group. The first optical element group is supported within the first lens barrel Pa and includes a first lens E1, a polarizer LP, a reflective polarizer RP, and a quarter-wave plate QWP, arranged sequentially along the optical axis from the first side to the second side. The second optical element group includes a second lens E2, a partially reflective element BS, and a display IMG, arranged sequentially along the optical axis from the first side to the second side. The second lens E2 and the partially reflective element BS are supported within the second lens barrel Pb, and the display IMG is located on the second side of the second lens barrel Pb. The polarizer LP is positioned on the second side of the first lens, the reflective polarizer RP is positioned on the second side of the polarizer LP, and the quarter-wave plate QWP is positioned on the second side of the reflective polarizer RP. This can be understood as a cemented arrangement of the first lens E1, polarizer LP, reflective polarizer RP, and quarter-wave plate QWP. The partially reflective element BS is positioned on the second side of the second lens E2.

[0108] In summary, the structural parameters of the visual system of Example 2 in Example 2-1, Example 2-2, and Example 2-3 are shown in Table 11.

[0109] In Example 2, the first lens has positive power, a convex first side surface, and a flat second side surface. The second lens has positive power, a convex first side surface, and a convex second side surface. The visual system also includes a stop (STO) located on a first side of the first lens.

[0110] Table 4 shows the basic structural parameters of the visual system of Example 2, where the units of curvature radius and thickness / distance are all in millimeters (mm). In Table 4, light from display IMG propagates from surface number 16 to surface number 0, and refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage. The surfaces represented by surface numbers 16 to 0 are, in order: the display, the second side surface of the second lens, the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the second side surface of the quarter-wave plate, the first side surface of the second lens, the second side surface of the second lens (the first side surface of the partially reflective element), the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the first side surface of the reflective polarizer (the second side surface of the polarizer), the first side surface of the polarizer, the second side surface of the first lens, the first side surface of the first lens, the aperture surface, and the virtual image surface.

[0111] Table 4

[0112]

[0113] The values ​​of D1 to D4 of the visual system in the first state and the second state are shown in Table 5 below.

[0114] Table 5

[0115]

[0116] Table 6 shows the high-order coefficients of each aspheric surface that can be used in this embodiment, where the surface shape of each aspheric surface can be defined by formula (1) given in the above embodiment 1. In this embodiment, the first side surface of the first lens (i.e., surface number 2), the first side surface of the second lens (i.e., surface number 8, surface number 14), and the second side surface of the second lens (i.e., surface number 9, surface number 15) are aspheric surfaces.

[0117] Table 6

[0118]

[0119] Figure 16 and Figure 17 The optical modulation function (MTF) curves of the visual system of Example 2 in the first state and the second state are shown, wherein Curve 1 is the MTF curve of the 0 field of view in the meridian direction; Curve 2 is the MTF curve of the 0.5 field of view in the meridian direction; Curve 3 is the MTF curve of the 1 field of view in the meridian direction. Figure 16 and Figure 17 It can be seen that the MTF values ​​(optical modulation function values) of light in each field of view at 15 line pairs / mm are all above 0.8, showing good imaging quality.

[0120] Example 3

[0121] like Figures 18 to 25 As shown, the visual system of embodiment 3 is described. Figure 18 FIG3 shows a schematic structural diagram of the visual system of Example 3-1 in the first state. Figure 19 FIG3 shows a schematic diagram of the structure of the visual system of Example 3-1 in the second state. Figure 20 FIG3 shows a schematic structural diagram of the visual system of Example 3-2 in the first state. Figure 21 FIG3 shows a schematic diagram of the structure of the visual system of Example 3-2 in the second state. Figure 22 FIG3 shows a schematic structural diagram of the visual system of Example 3-3 in the first state. Figure 23 A schematic structural diagram of the visual system of Example 3-3 in the second state is shown.

[0122] like Figures 18 to 23As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, arranged sequentially along the optical axis from the first side to the second side. The visual system also includes a first optical element group and a second optical element group. The first optical element group is supported within the first lens barrel Pa and includes a first lens E1, a polarizer LP, a reflective polarizer RP, and a quarter-wave plate QWP, arranged sequentially along the optical axis from the first side to the second side. The second optical element group includes a second lens E2, a partially reflective element BS, and a display IMG, arranged sequentially along the optical axis from the first side to the second side. The second lens E2 and the partially reflective element BS are supported within the second lens barrel Pb, and the display IMG is located on the second side of the second lens barrel Pb. The polarizer LP is positioned on the second side of the first lens, the reflective polarizer RP is positioned on the second side of the polarizer LP, and the quarter-wave plate QWP is positioned on the second side of the reflective polarizer RP. This can be understood as a cemented arrangement of the first lens E1, polarizer LP, reflective polarizer RP, and quarter-wave plate QWP. The partially reflective element BS is positioned on the second side of the second lens E2.

[0123] In summary, the structural parameters of the visual system of Example 3 in Example 3-1, Example 3-2, and Example 3-3 are shown in Table 11.

[0124] In Example 3, the first lens has positive power, a convex first side surface, and a flat second side surface. The second lens has positive power, a convex first side surface, and a convex second side surface. The visual system also includes an aperture stop (STO) located on a first side of the first lens.

[0125] Table 7 shows the basic structural parameters of the visual system of Example 3, where the units of curvature radius and thickness / distance are all in millimeters (mm). In Table 7, light from display IMG propagates from surface number 16 to surface number 0, and refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage. The surfaces represented by surface numbers 16 to 0 are, in order: the display, the second side surface of the second lens, the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the second side surface of the quarter-wave plate, the first side surface of the second lens, the second side surface of the second lens (the first side surface of the partially reflective element), the first side surface of the second lens, the second side surface of the quarter-wave plate, the first side surface of the quarter-wave plate (the second side surface of the reflective polarizer), the first side surface of the reflective polarizer (the second side surface of the polarizer), the first side surface of the polarizer, the second side surface of the first lens, the first side surface of the first lens, the aperture surface, and the virtual image surface.

[0126] Table 7

[0127]

[0128] The values ​​of D1 to D4 of the visual system in the first state and the second state are shown in Table 8 below.

[0129] Table 8

[0130]

[0131] Table 9 shows the high-order coefficients of each aspheric surface that can be used in this embodiment, where the surface shape of each aspheric surface can be defined by formula (1) given in the above embodiment 1. In this embodiment, the first side surface of the first lens (i.e., surface number 2), the first side surface of the second lens (i.e., surface number 8, surface number 14), and the second side surface of the second lens (i.e., surface number 9, surface number 15) are aspheric surfaces.

[0132] Table 9

[0133]

[0134] Figure 24 and Figure 25 The optical modulation function (MTF) curves of the visual system of Example 3 in the first state and the second state are shown, wherein Curve 1 is the MTF curve of the 0 field of view in the meridian direction; Curve 2 is the MTF curve of the 0.5 field of view in the meridian direction; Curve 3 is the MTF curve of the 1 field of view in the meridian direction. Figure 24 and Figure 25 It can be seen that the MTF values ​​(optical modulation function values) of light in each field of view at 15 line pairs / mm are all above 0.85, showing good imaging quality.

[0135] In summary, embodiments 1 to 3 of the visual system respectively satisfy the relationship shown in Table 10. The conditional expressions for the first state and the second state corresponding to each embodiment of the visual system have the same values.

[0136] Table 10

[0137]

[0138] Table 11 gives some parameters of the visual systems of Examples 1 to 3, in units of mm.

[0139] Table 11

[0140]

[0141] This application also provides an imaging device, whose electronic photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device can be a standalone imaging device or an imaging module integrated into a mobile electronic device. The imaging device is equipped with the visual system described above.

[0142] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0143] 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, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0144] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0145] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A visual system, characterized in that: It includes a lens barrel group and an optical element group, wherein the optical element group only includes two lenses with optical power. The lens barrel assembly comprises a first lens barrel and a second lens barrel arranged in sequence from a first side to a second side along the optical axis direction of the visual system; The optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and a part of the second optical element group is supported in the second lens barrel; The first optical element group includes a first lens, a polarizer, a reflective polarizer, and a quarter-wave plate arranged in sequence from the first side to the second side along the optical axis; the second optical element group includes a second lens, a partially reflective element, and a display arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, a first side surface of the first lens is convex, and a second side surface of the first lens is flat; the second lens has positive optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is convex; and the display is located on the second side of the second lens barrel; The second optical element group is configured to be movable along the optical axis of the visual system to be closer to or farther from the first optical element group, so as to switch the visual system between a first state and a second state; When the visual system switches between the first state and the second state, a distance ΔL moved by the second optical element group along the optical axis and a minimum inner diameter damin of the first lens barrel satisfy the following conditions: 12.31≤damin / ΔL≤14.15; A minimum inner diameter dbmin of the second lens barrel and a center thickness CT2 of the second lens on the optical axis satisfy the following: 4.47≤dbmin / CT2≤7.

71.

2. The visual system according to claim 1, characterized in that: The distance Lb between the first side end face of the second lens barrel and the second side end face of the second lens barrel in the direction of the optical axis, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 2.72≤Lb / Δf≤5.

60.

3. The visual system according to claim 1, wherein: A distance La between a first side end surface of the first lens barrel and a second side end surface of the first lens barrel in the optical axis direction and a curvature radius R1 of a first side surface of the first lens satisfy the following relationship: 8.86≤R1 / La≤15.

64.

4. The visual system according to claim 1, wherein: The effective focal length f2 of the second lens and the minimum inner diameter dbmin of the second lens barrel satisfy the following relationship: 3.58≤f2 / dbmin≤3.

94.

5. The visual system according to claim 1, wherein: An inner diameter dam of the second side end surface of the first barrel, an inner diameter das of the first side end surface of the first barrel, and a center thickness CT1 of the first lens on the optical axis satisfy the following relationship: 1.61≤(dam-das) / CT1≤2.

64.

6. The visual system according to claim 1, wherein: The distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel in the optical axis direction, the curvature radius R3 of the first side surface of the second lens, and the curvature radius R4 of the second side surface of the second lens satisfy the following relationship: 8.69 mm ≤ Lb × | R3 / R4 | ≤ 21.53 mm.

7. The visual system according to claim 1, wherein: The combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate, and the outer diameter Das of the first side end surface of the first lens barrel satisfy the following: 2.96≤fz / Das≤3.

42.

8. The visual system according to claim 1, wherein: The outer diameter Dbs of the first side end surface of the second lens barrel, the outer diameter Dbm of the second side end surface of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 1.00≤(Dbs-Dbm) / Δf≤2.

27.

9. The visual system according to claim 1, wherein: An inner diameter dbs of the first side end surface of the second lens barrel and a distance ΔL that the second optical element group moves along the optical axis when the visual system switches between the first state and the second state satisfy the following: 17.60≤dbs / ΔL≤19.

83.

10. The visual system according to any one of claims 1 to 9, characterized in that: The minimum inner diameter damin of the first lens barrel and the effective focal length f1 of the first lens satisfy the following: 3.99≤f1 / damin≤4.

94.

11. The visual system according to any one of claims 1 to 9, characterized in that: An outer diameter Dam of the second side end surface of the first lens barrel and a curvature radius R3 of the first side surface of the second lens satisfy the following relationship: 4.88≤R3 / Dam≤7.

57.

12. The visual system according to any one of claims 1 to 9, characterized in that: An inner diameter dbm of the second side end surface of the second lens barrel and a distance BFL between the second side surface of the second lens and the display on the optical axis satisfy the following: 36.20≤dbm / BFL≤43.

34.

13. The visual system according to any one of claims 1 to 9, characterized in that: The minimum inner diameter damin of the first lens barrel and the entrance pupil diameter EPD of the visual system satisfy the following: 7.25≤damin / EPD≤8.

10.

14. The visual system according to any one of claims 1 to 9, characterized in that: An outer diameter Das of the first side end surface of the first lens barrel and a distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel in the optical axis direction satisfy the following: 5.34≤Das / La≤8.36.

Images