Visual system

Abstract

The invention provides a visual system. The visual system comprises a first lens cone, a second lens cone, a first element group and a second element group, and the first element group sequentially comprises a first lens, a polarizing film, a reflective polarizing element and a quarter-wave plate from the first side to the second side along the optical axis of the visual system; the second element group sequentially comprises a second lens, a reflecting element and a display from the first side to the second side along the optical axis; the second element group is movably arranged along the optical axis; r1 / damin is greater than or equal to 2.07 and less than or equal to 2.70; (La + Lb) / delta L is greater than or equal to 3.99 and less than or equal to 5.99. According to the invention, the problem that a two-piece type visual system in the prior art controls the focal power and the surface type of the first lens, so that the size design of the first lens is limited, the assembling and bearing stability of the first lens becomes poor, and the surface type field curvature variation is large is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging devices, and more particularly, to a visual system. Background Art

[0002] In existing optical systems, a visual system composed of two lenses is widely used in various scenarios, including but not limited to VR devices, AR devices, etc.

[0003] This type of visual system usually matches the actual requirements by setting refractive and reflective elements and controlling the optical power and surface shape of the front lens, that is, the first lens. However, in this case, it is easy to limit the size design of the first lens, especially the design of the central thickness and edge thickness of the first lens. Unreasonable sizes are likely to cause poor assembly and bearing stability of the first lens, making the first lens prone to deformation under pressure during assembly, and then leading to poor surface field curvature of the first lens, affecting the imaging quality.

[0004] That is to say, the two-piece visual system in the prior art has the problems of controlling the optical power and surface shape of the first lens, which limits the size design of the first lens, resulting in poor assembly and bearing stability of the first lens, and then a large change in surface field curvature. Summary of the Invention

[0005] The main object of the present invention is to provide a visual system to solve the problems in the two-piece visual system of the prior art, namely, controlling the optical power and surface shape of the first lens, which limits the size design of the first lens, resulting in poor assembly and bearing stability of the first lens, and then a large change in surface field curvature.

[0006] To achieve the above object, according to one aspect of the present invention, a visual system is provided, which includes a first barrel, a second barrel, a first element group, and a second element group. At least part of the first element group is accommodated in the first barrel, and at least part of the second element group is accommodated in the second barrel. The first element group includes, in sequence along the optical axis of the visual system from the first side to the second side, a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate. The polarizer, the reflective polarizing element, and the quarter-wave plate are sequentially arranged on the second side surface of the first lens along the direction away from the first lens; the first lens has a positive optical power, the first side surface of the first lens is convex, and the second side surface of the first lens is flat; the second element group includes, in sequence along the optical axis from the first side to the second side, a second lens, a reflective element, and a display. The reflective element is arranged on the second side surface of the second lens; the second lens has a positive optical power, the first side surface of the second lens is convex, and the second side surface of the second lens is convex; the second element group is movably arranged along the optical axis; the number of lenses in the visual system is two; the curvature radius R1 of the first side surface of the first lens and the minimum inner diameter damin of the first barrel satisfy: 2.07 ≤ R1 / damin ≤ 2.70; when the visual system moves from the +2D state to the -5D state, the distance La between the first side surface and the second side surface of the first barrel on the optical axis, the distance Lb between the first side surface and the second side surface of the second barrel on the optical axis, and the distance ΔL that the second element group moves along the optical axis satisfy: 3.99 ≤ (La + Lb) / ΔL ≤ 5.99.

[0007] According to another aspect of the present invention, a visual system is further provided, which includes a first barrel, a second barrel, a first element group, and a second element group. At least part of the first element group is accommodated in the first barrel, and at least part of the second element group is accommodated in the second barrel. The first element group sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate along the optical axis of the visual system from the first side to the second side. The polarizer, the reflective polarizing element, and the quarter-wave plate are sequentially arranged on the second side surface of the first lens along the direction away from the first lens; the first lens has a positive optical power, the first side surface of the first lens is a convex surface, and the second side surface of the first lens is a flat surface; the second element group sequentially includes a second lens, a reflective element, and a display along the optical axis from the first side to the second side; the reflective element is arranged on the second side surface of the second lens; the second lens has a positive optical power, the first side surface of the second lens is a convex surface, and the second side surface of the second lens is a convex surface; the second element group is movably arranged along the optical axis; the number of lenses in the visual system is two; the curvature radius R4 of the second side surface of the second lens and the minimum inner diameter dbmin of the second barrel satisfy: -2.91 ≤ R4 / dbmin ≤ -2.59; when the distance La between the first side surface and the second side surface of the first barrel on the optical axis, the distance Lb between the first side surface and the second side surface of the second barrel on the optical axis, and the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis satisfies: 3.99 ≤ (La + Lb) / ΔL ≤ 5.99.

[0008] Further, the outer diameter Das of the first side surface of the first barrel and the central thickness CT1 of the first lens on the optical axis satisfy: 8.51 ≤ Das / CT1 ≤ 10.20.

[0009] Further, the central thickness CT2 of the second lens on the optical axis and the distance Lb between the first side surface and the second side surface of the second barrel on the optical axis satisfy: 0.94 ≤ CT2 / Lb ≤ 1.47.

[0010] Further, the curvature radius R4 of the second side surface of the second lens and the minimum inner diameter dbmin of the second barrel satisfy: -2.91 ≤ R4 / dbmin ≤ -2.59.

[0011] Further, the inner diameter dbs of the first side surface of the second barrel, the inner diameter dbm of the second side surface of the second barrel, and the change amount Δf of the effective focal length of the visual system when the visual system moves from the +2D state to the -5D state satisfy: 2.18 ≤ (dbs - dbm) / Δf ≤ 5.43.

[0012] Further, the distance La between the first side surface and the second side surface of the first barrel on the optical axis, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate, and the effective focal length f2 of the second lens satisfy: 3.31 mm ≤ La × (fz / f2) ≤ 6.50 mm.

[0013] Further, the radius of curvature R3 of the first side surface of the second lens and the outer diameter Dbs of the first side surface of the second barrel satisfy: 4.82 ≤ R3 / Dbs ≤ 7.68.

[0014] Further, the inner diameter dam of the second side surface of the first barrel, the inner diameter das of the first side surface of the first barrel, and the distance ΔL that the second element group moves along the optical axis when the visual system moves from the +2D state to the -5D state satisfy: 2.43 ≤ (dam - das) / ΔL ≤ 5.53.

[0015] Further, the effective focal length f1 of the first lens and the outer diameter Dam of the second side surface of the first barrel satisfy: 2.76 ≤ f1 / Dam ≤ 3.29.

[0016] Further, the minimum inner diameter dbmin of the second barrel, the minimum inner diameter damin of the first barrel, and the distance ΔL that the second element group moves along the optical axis when the visual system moves from the +2D state to the -5D state satisfy: 1.49 ≤ (dbmin - damin) / ΔL ≤ 4.19.

[0017] Further, the outer diameter Dbm of the second side surface of the second barrel, the inner diameter dbm of the second side surface of the second barrel, and the distance BFL between the second side surface of the second lens and the display on the optical axis satisfy: 3.61 ≤ (Dbm - dbm) / BFL ≤ 7.20.

[0018] Further, the minimum inner diameter damin of the first barrel and the distance La between the first side surface and the second side surface of the first barrel on the optical axis satisfy: 3.97 ≤ damin / La ≤ 9.26.

[0019] Further, the minimum inner diameter dbmin of the second barrel and the distance Lb between the first side surface and the second side surface of the second barrel on the optical axis satisfy: 5.35 ≤ dbmin / Lb ≤ 8.89.

[0020] Further, the effective focal length f2 of the second lens, the refractive index N2 of the second lens, and the inner diameter dbs of the first side surface of the second barrel satisfy: 1.94 ≤ (f2 / N2) / dbs ≤ 2.22.

[0021] Applying the technical solution of the present invention, by planning that the first lens has a positive optical power and a convex-plano surface shape, and a polarizer, a reflective polarizing element and a quarter-wave plate are arranged on the second side surface of the first lens, and at the same time planning that the second lens has a positive optical power and a convex-convex surface shape, and a reflective element is arranged on the second side surface of the second lens, it can be seen that the size design of the first lens is restricted. In particular, the central thickness and edge thickness of the first lens are restricted. An unreasonable size of the first lens is likely to cause poor assembly and bearing stability of the first lens, making the first lens prone to deformation under pressure during assembly, and further leading to poor field curvature of the surface shape of the first lens, affecting the imaging quality. This application ensures the rationality of the surface shape and size of the first lens by restricting 2.07≤R1 / damin≤2.70 and 3.99≤(La+Lb) / ΔL≤5.99, so that in the +2D state and -5D state of the visual system, the assembly and bearing stability of the first lens in the first lens barrel are both better, improving the assembly stability of the first lens, reducing the risk of assembly deformation of the first lens, reducing the change amount of the field curvature of the surface shape of the first lens, ensuring the field curvature stability, and further ensuring the imaging quality of the visual system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 A schematic diagram of the size marking of the visual system according to an optional embodiment of the present invention is shown;

[0024] Figure 2 A schematic structural diagram of the visual system of Embodiment 1-1 of the present invention in the +2D state is shown;

[0025] Figure 3 A schematic structural diagram of the visual system of Embodiment 1-1 of the present invention in the -5D state is shown;

[0026] Figure 4 A schematic structural diagram of the visual system of Embodiment 1-2 of the present invention in the +2D state is shown;

[0027] Figure 5 A schematic structural diagram of the visual system of Embodiment 1-2 of the present invention in the -5D state is shown;

[0028] Figure 6 A schematic structural diagram of the visual system of Embodiment 1-3 of the present invention in the +2D state is shown;

[0029] Figure 7 A schematic structural diagram of the visual system of Embodiment 1-3 of the present invention in the -5D state is shown;

[0030] Figure 8 Shows the optical modulation function curve of the visual system of the first embodiment of the present invention in the +2D state;

[0031] Figure 9 Shows the optical modulation function curve of the visual system of the first embodiment of the present invention in the -5D state;

[0032] Figure 10 Shows the structural schematic diagram of the visual system of the 2-1 embodiment of the present invention in the +2D state;

[0033] Figure 11 Shows the structural schematic diagram of the visual system of the 2-1 embodiment of the present invention in the -5D state;

[0034] Figure 12 Shows the structural schematic diagram of the visual system of the 2-2 embodiment of the present invention in the +2D state;

[0035] Figure 13 Shows the structural schematic diagram of the visual system of the 2-2 embodiment of the present invention in the -5D state;

[0036] Figure 14 Shows the structural schematic diagram of the visual system of the 2-3 embodiment of the present invention in the +2D state;

[0037] Figure 15 Shows the structural schematic diagram of the visual system of the 2-3 embodiment of the present invention in the -5D state;

[0038] Figure 16 Shows the optical modulation function curve of the visual system of the second embodiment of the present invention in the +2D state;

[0039] Figure 17 Shows the optical modulation function curve of the visual system of the second embodiment of the present invention in the -5D state;

[0040] Figure 18 Shows the structural schematic diagram of the visual system of the 3-1 embodiment of the present invention in the +2D state;

[0041] Figure 19 Shows the structural schematic diagram of the visual system of the 3-1 embodiment of the present invention in the -5D state;

[0042] Figure 20 Shows the structural schematic diagram of the visual system of the 3-2 embodiment of the present invention in the +2D state;

[0043] Figure 21 Shows the structural schematic diagram of the visual system of the 3-2 embodiment of the present invention in the -5D state;

[0044] Figure 22 Shows the schematic structural diagram of the visual system of Embodiment 3-3 of the present invention in the +2D state;

[0045] Figure 23 Shows the schematic structural diagram of the visual system of Embodiment 3-3 of the present invention in the -5D state;

[0046] Figure 24 Shows the optical modulation function curve of the visual system of Embodiment 3 of the present invention in the +2D state;

[0047] Figure 25 Shows the optical modulation function curve of the visual system of Embodiment 3 of the present invention in the -5D state.

[0048] Among them, the above-mentioned drawings include the following reference numerals:

[0049] Pa, the first lens barrel; Pb, the second lens barrel; E1, the first lens; E2, the second lens; LP, the polarizer; RP, the reflective polarizing element; QWP, the quarter-wave plate; BS, the reflective element; IMG, the image plane. Detailed implementation manners

[0050] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0051] It should be pointed out that unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0052] In the present invention, unless otherwise stated, the orientation words such as "upper, lower, top, bottom" are usually in the direction shown in the drawings, or in the vertical, perpendicular or gravitational direction of the component itself; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contour of each component itself, but the above orientation words do not limit the present invention.

[0053] In the drawings, for the convenience of illustration, the thickness, size and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only for illustration and are not drawn strictly to scale.

[0054] In this text, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The judgment of the surface shape in the paraxial region can be based on the judgment method of those with ordinary knowledge in this field, and the positive or negative of the R value (R refers to the radius of curvature in the paraxial region, usually the R value on the lens database (lens data) in optical software) is used to judge the convexity and concavity. Taking the first side as an example, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; taking the second side as an example, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface. When the R value is infinite, it is judged as a plane.

[0055] In this application, the first side refers to the side of the visual system facing the human eye (not shown in the figure), and the second side refers to the side of the visual system facing the display. The display has an image surface IMG. Hereinafter, the first side of the lens refers to the surface on the side of the lens facing the human eye (not shown in the figure), and the second side of the lens refers to the surface on the side of the lens facing the display. In the structural schematic diagram shown in this application, the left side is the first side and the right side is the second side.

[0056] In order to solve the problem in the prior art that in a two-piece visual system, controlling the optical power and surface shape of the first lens limits the size design of the first lens, resulting in poor assembly and bearing stability of the first lens, and further resulting in a large change in surface field curvature, the present invention provides a visual system.

[0057] As Figures 1 to 25As shown, in an alternative embodiment of the present application, the visual system includes a first barrel, a second barrel, a first element group, and a second element group. At least part of the first element group is accommodated in the first barrel, and at least part of the second element group is accommodated in the second barrel. The first element group includes, in sequence along the optical axis of the visual system from the first side to the second side, a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate. The polarizer, the reflective polarizing element, and the quarter-wave plate are sequentially arranged on the second side surface of the first lens in a direction away from the first lens. The first lens has a positive optical power, the first side surface of the first lens is convex, and the second side surface of the first lens is flat. The second element group includes, in sequence along the optical axis from the first side to the second side, a second lens, a reflective element, and a display. The reflective element is arranged on the second side surface of the second lens. The second lens has a positive optical power, the first side surface of the second lens is convex, and the second side surface of the second lens is convex. The second element group is movably arranged along the optical axis. The number of lenses in the visual system is two. The radius of curvature R1 of the first side surface of the first lens and the minimum inner diameter damin of the first barrel satisfy: 2.07 ≤ R1 / damin ≤ 2.70. When the distance La between the first side surface and the second side surface of the first barrel along the optical axis, the distance Lb between the first side surface and the second side surface of the second barrel along the optical axis, and the distance ΔL that the second element group moves along the optical axis when the visual system moves from the +2D state to the -5D state satisfy: 3.99 ≤ (La + Lb) / ΔL ≤ 5.99.

[0058] By planning that the first lens has a positive optical power and a convex-flat surface type, and arranging a polarizer, a reflective polarizing element, and a quarter-wave plate on the second side surface of the first lens, and at the same time planning that the second lens has a positive optical power and a convex-convex surface type, and arranging a reflective element on the second side surface of the second lens, it can be seen that the size design of the first lens is limited. In particular, the central thickness and edge thickness of the first lens are limited. An unreasonable size of the first lens is likely to cause poor assembly and bearing stability of the first lens, making the first lens prone to deformation under pressure during assembly, and then resulting in poor field curvature of the surface type of the first lens, affecting the imaging quality. By restricting 2.07 ≤ R1 / damin ≤ 2.70 and 3.99 ≤ (La + Lb) / ΔL ≤ 5.99, it is beneficial to ensure the rationality of the surface type and size of the first lens, so that in the +2D state and -5D state of the visual system, the assembly and bearing stability of the first lens in the first barrel are both better, improving the assembly stability of the first lens, reducing the risk of assembly deformation of the first lens, reducing the change amount of the field curvature of the surface type of the first lens, ensuring the field curvature stability, and thus ensuring the imaging quality of the visual system.

[0059] It should be noted that the refractive adjustment ability of the visual system in this application covers a continuous range from hyperopia correction to myopia correction. Specifically, when the visual system is in the +2D state, it can adapt to users with a maximum hyperopia degree of 200 degrees; when the visual system changes to the -5D state, it can adapt to users with a maximum myopia degree of 500 degrees. It is worth noting that the visual system in this application is not limited to these two extreme states. It also has multiple intermediate states, and the diopter in these states can flexibly change between the +2D state and the -5D state to meet the needs of a wide range of users from mild hyperopia to moderate myopia. This broad diopter adjustment range is achieved by precisely adjusting the position of the second element group on the optical axis, ensuring smooth and efficient adjustment of the visual system between the +2D state and the -5D state.

[0060] In addition, as shown in Table 1 below, Table 1 is a comprehensive sensitivity table of the surface field curvature of the first lens during the assembly process. In the following table, the field curvature change amounts of the first side surface and the second side surface of the first lens in the solutions of the present invention, Comparative Example 1, and Comparative Example 2 under different fields of view from 0.1F to 1.0F are shown.

[0061] It can be seen from Table 1 that when the visual system of the solution 1 of the present invention satisfies R1 / damin = 2.45 and (La + Lb) / ΔL = 4.59, the size of the first lens is more reasonable. During assembly, the deformation amount of the first lens is smaller, and the field curvature change amounts of the first side surface and the second side surface of the first lens are smaller, showing better performance. When the visual system of Comparative Example 1 satisfies R1 / damin = 3.1 and (La + Lb) / ΔL = 7.8, during assembly, the deformation amount of the first lens is larger, and the field curvature change amounts of the first side surface and the second side surface of the first lens are larger, showing poorer performance. When the visual system of Comparative Example 2 satisfies R1 / damin = 1.7 and (La + Lb) / ΔL = 2.4, during assembly, the deformation amount of the first lens is larger, and the field curvature change amounts of the first side surface and the second side surface of the first lens are larger, showing poorer performance. From this, it can be known that when the visual system satisfies 2.07 ≤ R1 / damin ≤ 2.70 and 3.99 ≤ (La + Lb) / ΔL ≤ 5.99, the deformation amount generated by the first lens under pressure during assembly is smaller, and the surface field curvature change amounts of the two side surfaces of the first lens are smaller. Therefore, by restricting 2.07 ≤ R1 / damin ≤ 2.70 and 3.99 ≤ (La + Lb) / ΔL ≤ 5.99 in this application, the rationality of the surface shape and size of the first lens is ensured, so that when the visual system is in the +2D state and the -5D state, the assembly and bearing stability of the first lens in the first lens barrel are both better, the assembly stability of the first lens is improved, the risk of assembly deformation of the first lens is reduced, the surface field curvature change amount of the first lens is reduced, the field curvature stability is ensured, and thus the imaging quality of the visual system is ensured.

[0062] Table 1

[0063]

[0064] It should be noted that since the second component group is accommodated in the second lens barrel, when the second component group moves along the optical axis towards or away from the first component group, the second lens barrel moves together with the second component group.

[0065] In this embodiment, the outer diameter Das of the first side surface of the first lens barrel and the central thickness CT1 of the first lens on the optical axis satisfy: 8.51 ≤ Das / CT1 ≤ 10.20. By reasonably controlling the range of this conditional expression, it is beneficial to improve the processability of the first lens on the premise of ensuring the assembly stability of the visual system, thereby ensuring the light deflection effect of the first lens.

[0066] In this embodiment, the central thickness CT2 of the second lens on the optical axis and the interval distance Lb between the first side surface and the second side surface of the second lens barrel on the optical axis satisfy: 0.94 ≤ CT2 / Lb ≤ 1.47. By reasonably controlling the range of this conditional expression, it is beneficial to improve the processability and assembly stability of the second lens, and ensure the light deflection effect of the second lens.

[0067] In this embodiment, the curvature radius R4 of the second side surface of the second lens and the minimum inner diameter dbmin of the second lens barrel satisfy: -2.91 ≤ R4 / dbmin ≤ -2.59. By controlling the proportional relationship between the curvature radius of the second side surface of the second lens and the minimum inner diameter of the second lens barrel, on the one hand, the shape of the second lens is restricted, ensuring the surface shape stability of the second lens, which is beneficial to reducing the sensitivity of the second lens, thereby improving the yield of assembly; on the other hand, it can ensure the matching of the inner diameter of the second lens barrel and the light refraction of the second lens, control the inner diameter of the second lens barrel, prevent blocking the effective light, and at the same time be able to block the ineffective light, which is beneficial to reducing the risk of stray light and ensuring the light efficiency.

[0068] In this embodiment, the inner diameter dbs of the first side surface of the second lens barrel, the inner diameter dbm of the second side surface of the second lens barrel and the change amount Δf of the effective focal length of the visual system when the visual system moves from the +2D state to the -5D state satisfy: 2.18 ≤ (dbs - dbm) / Δf ≤ 5.43. By reasonably controlling the range of this conditional expression, it can not only prevent it from exceeding the upper limit value and causing the increase in the outer shape of the module cooperating with the visual system, thereby affecting the volume of the whole machine, but also prevent it from being less than the lower limit value and causing the insufficient strength of the second lens barrel and the performance of the module cooperating with it.

[0069] In this embodiment, the distance La on the optical axis between the first side surface and the second side surface of the first lens barrel, the combined focal length fz of the first lens, the polarizing plate, the reflective polarizing element, and the quarter-wave plate, and the effective focal length f2 of the second lens satisfy: 3.31 mm ≤ La × (fz / f2) ≤ 6.50 mm. By reasonably controlling the range of this conditional expression, positive spherical aberration can be generated by the first element group and balanced with the negative spherical aberration generated by other lenses of the visual system, so that the imaging quality of the visual system on the axis is good; secondly, by controlling the distance on the optical axis between the first side surface and the second side surface of the first lens barrel, on the basis of ensuring its function of limiting the first lens, it is beneficial to improve the processability of the first lens barrel.

[0070] In this embodiment, the curvature radius R3 of the first side surface of the second lens and the outer diameter Dbs of the first side surface of the second lens barrel satisfy: 4.82 ≤ R3 / Dbs ≤ 7.68. By reasonably controlling the range of this conditional expression, on the one hand, the shape of the second lens is restricted, which is beneficial to reducing the sensitivity of the second lens, thereby improving the yield of assembly; on the other hand, the forming feasibility of the second lens barrel can be ensured.

[0071] In this embodiment, the inner diameter dam of the second side surface of the first lens barrel, the inner diameter das of the first side surface of the first lens barrel, and the distance ΔL that the second element group moves along the optical axis when the visual system moves from the +2D state to the -5D state satisfy: 2.43 ≤ (dam - das) / ΔL ≤ 5.53. By reasonably controlling the range of this conditional expression, it can prevent the situation that the maximum thickness of the first lens barrel is too large due to the unreasonable size of the first lens barrel caused by its value being less than the lower limit, which affects the user experience; and it can also prevent the interference problem of the first lens barrel in the case of a large diopter adjustment caused by its value exceeding the upper limit, avoiding the situation where the function cannot be realized.

[0072] In this embodiment, the effective focal length f1 of the first lens and the outer diameter Dam of the second side surface of the first lens barrel satisfy: 2.76 ≤ f1 / Dam ≤ 3.29. By controlling the above relational expression, the shape of the first lens is restricted, and the processability of the first lens is improved; at the same time, the outer diameter of the first lens barrel is restricted, which is beneficial to reducing the overall size and meeting the miniaturization requirements.

[0073] In this embodiment, when the minimum inner diameter dbmin of the second lens barrel, the minimum inner diameter damin of the first lens barrel, and the visual system move from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis satisfies: 1.49 ≤ (dbmin - damin) / ΔL ≤ 4.19. By controlling the above relational expression, the minimum inner diameters of the first lens and the second lens barrel and the distance that the second element group moves along the optical axis in different focusing states are controlled within a certain range, which is beneficial to controlling the stability of the light passing amount of the visual system in different focusing states, and preventing problems such as increased stray light caused by a large inner diameter and too low brightness of the light entering the eye caused by a small inner diameter.

[0074] In this embodiment, the outer diameter Dbm of the second side surface of the second lens barrel, the inner diameter dbm of the second side surface of the second lens barrel, and the distance BFL from the second side surface of the second lens to the display on the optical axis satisfy: 3.61 ≤ (Dbm - dbm) / BFL ≤ 7.20. By restricting the ratio between the difference between the outer diameter and the inner diameter of the second side surface of the second lens barrel and the distance from the second side surface of the second lens to the display on the optical axis, the light amount of the light emitted by the display passing through the second lens is effectively controlled, preventing the situation of too low brightness of the light entering the eye; and it can also prevent problems such as high risk of stray light caused by too large a light passing aperture.

[0075] In this embodiment, the minimum inner diameter damin of the first lens barrel and the interval distance La on the optical axis from the first side surface of the first lens barrel to the second side surface of the first lens barrel satisfy: 3.97 ≤ damin / La ≤ 9.26. By controlling the above relational expression, on the one hand, it is beneficial to the processing feasibility of the first side end of the first lens barrel, facilitating the dispensing and assembly of the first lens and the first lens barrel. Additionally, it restricts the overall shape and length of the first lens barrel, which is beneficial to the miniaturization of the visual system.

[0076] In this embodiment, the minimum inner diameter dbmin of the second lens barrel and the interval distance Lb on the optical axis from the first side surface of the second lens barrel to the second side surface of the second lens barrel satisfy: 5.35 ≤ dbmin / Lb ≤ 8.89. By controlling the above relational expression, it is beneficial to ensure the processing feasibility of the second lens barrel; additionally, it indirectly restricts the overall shape and length of the second lens barrel, preventing the problem of interference between the second lens barrel and other components during the focusing process.

[0077] In this embodiment, the effective focal length f2 of the second lens, the refractive index N2 of the second lens, and the inner diameter dbs of the first side surface of the second lens barrel satisfy: 1.94 ≤ (f2 / N2) / dbs ≤ 2.22. By controlling the relationship between the effective focal length and the refractive index of the second lens, the aberration can be effectively corrected and the imaging quality can be improved. At the same time, by restricting the inner diameter of the first side surface of the second lens barrel, the problem of stray light can be better considered, enabling the second lens barrel to effectively intercept stray light.

[0078] In addition, in another optional embodiment of the present application, a visual system is further provided, which includes a first barrel, a second barrel, a first element group, and a second element group. At least part of the first element group is accommodated in the first barrel, and at least part of the second element group is accommodated in the second barrel. The first element group sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate along the optical axis of the visual system from the first side to the second side. The polarizer, the reflective polarizing element, and the quarter-wave plate are sequentially arranged on the second side surface of the first lens in a direction away from the first lens; the first lens has a positive optical power, the first side surface of the first lens is convex, and the second side surface of the first lens is flat; the second element group sequentially includes a second lens, a reflective element, and a display along the optical axis from the first side to the second side; the reflective element is arranged on the second side surface of the second lens; the second lens has a positive optical power, the first side surface of the second lens is convex, and the second side surface of the second lens is convex; the second element group is movably arranged along the optical axis; the number of lenses in the visual system is two; the curvature radius R4 of the second side surface of the second lens and the minimum inner diameter dbmin of the second barrel satisfy: -2.91 ≤ R4 / dbmin ≤ -2.59; when the interval distance La on the optical axis from the first side surface to the second side surface of the first barrel and the interval distance Lb on the optical axis from the first side surface to the second side surface of the second barrel and the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis satisfy: 3.99 ≤ (La + Lb) / ΔL ≤ 5.99.

[0079] By planning that the first lens has a positive optical power and a convex-flat surface type, and arranging a polarizer, a reflective polarizing element, and a quarter-wave plate on the second side surface of the first lens, and at the same time planning that the second lens has a positive optical power and a convex-convex surface type, and arranging a reflective element on the second side surface of the second lens, it can be seen that the size design of the first lens and the second lens is limited. If the sizes of the first lens and the second lens are unreasonable, it is easy to cause the assembly and bearing stability of the first lens and the second lens to deteriorate, so that the first lens and the second lens are easily deformed under pressure during assembly, and then the field curvature of the surface types of the first lens and the second lens becomes worse, affecting the imaging quality. By restricting -2.91 ≤ R4 / dbmin ≤ -2.59 and 3.99 ≤ (La + Lb) / ΔL ≤ 5.99, it is beneficial to ensure the rationality of the surface types and sizes of the first lens and the second lens, so that in the +2D state and the -5D state of the visual system, the assembly and bearing stability of the first lens in the first barrel are both better, and the assembly stability of the first lens in the second barrel is also better, improving the assembly stability of the first lens and the second lens, reducing the risk of assembly deformation of the first lens and the second lens, reducing the variation amount of the field curvature of the surface types of the first lens and the second lens, ensuring the field curvature stability, and thus ensuring the imaging quality of the visual system.

[0080] Of course, other parameters in the above embodiments may also be included in this embodiment, which will not be elaborated one by one here.

[0081] In the visual system of this application, multiple lenses can be used, such as the two lenses mentioned above. In this application, at least one of the lens surfaces of each lens is an aspherical surface. The characteristics of an aspherical lens are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0082] However, those skilled in the art should understand that without departing from the technical solution claimed in this application, the number of lenses constituting the visual system can be changed to obtain the various results and advantages described in this specification. For example, although two lenses are described as an example in the embodiment, the visual system is not limited to including two lenses. If necessary, the visual system can also include other numbers of lenses.

[0083] Figure 1 A schematic diagram of the dimension marking of the visual system of an alternative embodiment of the present invention is shown. Figure 1 Parameters such as Dbs, dbs, Das, das, damin, dbmin, dbm, dam, Dbm, Dam, La, and Lb are marked in it to clearly and intuitively understand the meaning of the parameters. For the convenience of describing the surface shape of the visual system and specific lenses, these parameters will no longer be shown in the drawings when specific embodiments are described later.

[0084] Next, with reference to the drawings, specific examples of the surface shape and parameters of the visual system applicable to the above embodiments will be further described.

[0085] It should be noted that in the following Example 1, there are three examples of Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3. In Example 2, there are three examples of Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3. In Example 3, there are three examples of Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3. And the parameters of the optical system in the visual system under the three examples in the same embodiment are the same. Specifically, the curvature radius, center thickness, and other parameters of the first lens and the second lens of the visual system, as well as the spacing distance and higher-order term coefficients between the lenses, are the same, but the size parameters such as the inner diameter and outer diameter of the first lens barrel and the second lens barrel are different.

[0086] It should be noted that any of the examples in the following Example 1 to Example 3 is applicable to all embodiments of this application.

[0087] Example 1

[0088] As Figures 2 to 9 shown, the visual system of Example 1 is described. Figure 2 The schematic structural diagram of the visual system of Example 1-1 in the +2D state is shown, Figure 3 The schematic structural diagram of the visual system of Example 1-1 in the -5D state is shown, Figure 4 The schematic structural diagram of the visual system of Example 1-2 in the +2D state is shown, Figure 5 The schematic structural diagram of the visual system of Example 1-2 in the -5D state is shown, Figure 6 The schematic structural diagram of the visual system of Example 1-3 in the +2D state is shown, Figure 7 The schematic structural diagram of the visual system of Example 1-3 in the -5D state is shown.

[0089] As Figures 2 to 7 shown, the visual system includes a first lens barrel Pa, a second lens barrel Pb, a first element group, and a second element group. The first element group includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP in sequence along the optical axis of the visual system from the first side to the second side. The polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are sequentially arranged on the second side surface of the first lens in a direction away from the first lens E1. The second element group includes a second lens E2, a reflective element BS, and a display in sequence along the optical axis from the first side to the second side. The display has an image plane IMG. The reflective element BS is arranged on the second side surface of the second lens; the second element group is movably arranged along the optical axis.

[0090] In this embodiment, the first lens E1, the polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are accommodated in the first lens barrel Pa, the second lens E2 and the reflective element BS are accommodated in the second lens barrel Pb, and the display is located on the side of the second lens barrel Pb away from the first lens barrel Pa.

[0091] In this embodiment, the light rays emitted from the image plane IMG pass through the second lens E2 and the transmission of the quarter-wave plate QWP in sequence, then enter the reflective polarizing element RP, and after being reflected by the reflective polarizing element RP, are transmitted toward the display side. Then, after passing through the quarter-wave plate QWP and the second lens E2 in sequence, they enter the reflective element BS, and after being reflected by the reflective element BS, are transmitted toward the human eye side. Then, after passing through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 in sequence, they enter the human eye for imaging.

[0092] In summary, the structural parameters of the visual system in the first embodiment under Examples 1-1, 1-2, and 1-3 are shown in Table 2 below (unit: millimeter, mm). It should be noted here that the following parameters of each embodiment are the same in the -5D state and the +2D state.

[0093] Table 2

[0094] Parameter / Embodiment 1-1 1-2 1-3 das 31.330 32.034 30.954 dam 41.366 41.022 40.156 Das 39.804 40.723 40.087 Dam 43.657 43.313 42.447 damin 29.541 30.245 28.988 dbs 41.824 42.377 41.453 dbm 38.514 35.998 38.896 Dbs 44.039 44.592 44.889 Dbm 42.639 41.930 43.289 dbmin 37.657 35.141 37.939 La 7.450 5.331 6.304 Lb 5.345 6.570 5.707

[0095] In the first embodiment, the first lens E1 has a positive optical power. The first side of the first lens is convex, and the second side of the first lens is flat. The second lens E2 has a positive optical power. The first side of the second lens is convex, and the second side of the second lens is convex.

[0096] In the first embodiment, the effective focal length f1 of the first lens is 120.6365 mm, the effective focal length f2 of the second lens is 138.3122 mm, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate is 120.6365 mm, the distance BFL from the second side of the second lens to the display on the optical axis is 0.9944 mm. When the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis is 2.1374 mm. When the visual system moves from the +2D state to the -5D state, the change amount Δf of the effective focal length of the visual system is 1.1740 mm.

[0097] Table 3 shows the basic structural parameter table of the visual system in the first embodiment, where the unit of the radius of curvature and the thickness / distance is millimeter (mm). In the following table, STO (not shown in the figure) is the aperture stop, and the aperture stop is located on the first side of the first lens E1.

[0098] Table 3

[0099]

[0100]

[0101] Table 4 shows the values of D1, D2, D3, and D4 corresponding to the above table in the +2D state and the -5D state of the visual system in the first embodiment. D1 represents the value of the virtual image distance of the visual system in this embodiment. D2, D3, and D4 are all the distances on the optical axis from the second side of the quarter-wave plate QWP to the first side of the second lens. When D1, D2, D3, and D4 are positive, it means the direction is from the first side to the second side. When they are negative, it means the direction is from the second side to the first side. The unit of D1, D2, D3, and D4 is millimeter (mm).

[0102] Table 4

[0103] D1 D2 D3 D4 +2D State 500.0000 6.3681 -6.3681 6.3681 -5D State -200.0000 4.2307 -4.2307 4.2307

[0104] In Embodiment 1, the first side surface of the first lens, the first side surface of the second lens, and the second side surface of the second lens are all aspherical surfaces. The surface profiles of the aspherical surfaces can be defined by, but are not limited to, the following aspherical formula:

[0105]

[0106] where x is the sagitta, the distance from the vertex of the aspherical surface to the position at a height of h along the optical axis direction of the aspherical surface; 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 3 above; k is the conic constant; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 5 below gives the higher-order coefficients A4, A6, A8, A10, A12, A,14, A16, A18, and A20 that can be used for each aspherical surface in Embodiment 1.

[0107] Table 5

[0108]

[0109]

[0110] Figure 8 shows the optical modulation function curve of the visual system in Embodiment 1 in the +2D state. As can be seen from the figure, the optical modulation function values of the curves of the 0 field of view in the meridional direction, the 0.5 field of view in the meridional direction, and the 1.0 field of view in the meridional direction are all relatively high, indicating that the imaging quality at this spatial frequency is relatively good. Figure 9 shows the optical modulation function curve of the visual system in Embodiment 1 in the -5D state. As can be seen from the figure, the optical modulation function values of the curves of the 0 field of view in the meridional direction, the 0.5 field of view in the meridional direction, and the 1.0 field of view in the meridional direction are all relatively high, indicating that the imaging quality at this spatial frequency is relatively good.

[0111] Embodiment 2

[0112] As Figures 10 to 17 shown, the visual system of Embodiment 2 is described. Figure 10 shows the structural schematic diagram of the visual system of Embodiment 2-1 in the +2D state, Figure 11 shows the structural schematic diagram of the visual system of Embodiment 2-1 in the -5D state, Figure 12 shows the structural schematic diagram of the visual system of Embodiment 2-2 in the +2D state, Figure 13 shows the structural schematic diagram of the visual system of Embodiment 2-2 in the -5D state, Figure 14 shows the structural schematic diagram of the visual system of Embodiment 2-3 in the +2D state, Figure 15 shows the structural schematic diagram of the visual system of Embodiment 2-3 in the -5D state.

[0113] As shown Figures 10 to 15 in the figure, the visual system includes a first barrel Pa, a second barrel Pb, a first element group, and a second element group. The first element group includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP in sequence from the first side to the second side along the optical axis of the visual system. The polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are sequentially arranged on the second side surface of the first lens in the direction away from the first lens E1. The second element group includes a second lens E2, a reflective element BS, and a display in sequence from the first side to the second side along the optical axis. The display has an image surface IMG. The reflective element BS is arranged on the second side surface of the second lens; the second element group is movably arranged along the optical axis.

[0114] In this embodiment, the first lens E1, the polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are accommodated in the first barrel Pa, the second lens E2 and the reflective element BS are accommodated in the second barrel Pb, and the display is located on the side of the second barrel Pb away from the first barrel Pa.

[0115] In this embodiment, the light rays emitted from the image surface IMG pass through the second lens E2 and the transmission of the quarter-wave plate QWP in sequence, then enter the reflective polarizing element RP, and after being reflected by the reflective polarizing element RP, are transmitted toward the display side. Then, after passing through the transmission of the quarter-wave plate QWP and the second lens E2 in sequence, they enter the reflective element BS, and after being reflected by the reflective element BS, are transmitted toward the human eye side. Then, after passing through the transmission of the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 in sequence, they enter the human eye for imaging.

[0116] In summary, the structural parameters of the visual system in Embodiment 2 under Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3 are shown in Table 6 (unit: millimeter mm). It should be noted here that the following parameters are the same in the -5D state and the +2D state for each embodiment.

[0117] Table 6

[0118]

[0119]

[0120] In Embodiment 2, the first lens E1 has a positive focal power, the first side surface of the first lens is convex, and the second side surface of the first lens is flat; the second lens E2 has a positive focal power, the first side surface of the second lens is convex, and the second side surface of the second lens is convex.

[0121] In the second embodiment, the effective focal length f1 of the first lens is 143.9799 mm, the effective focal length f2 of the second lens is 132.4296 mm, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate is 143.9799 mm, the distance BFL from the second side surface of the second lens to the display on the optical axis is 0.8944 mm, when the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis is 2.3696 mm, and when the visual system moves from the +2D state to the -5D state, the change amount Δf of the effective focal length of the visual system is 1.3328 mm.

[0122] Table 7 shows the basic structural parameter table of the visual system in the second embodiment. Among them, the unit of the radius of curvature and the thickness / distance is millimeter (mm). In the following table, STO (not shown in the figure) is the aperture stop, and the aperture stop is located on the first side of the first lens E1.

[0123] Table 7

[0124]

[0125] Table 8 shows the values of D1, D2, D3, and D4 corresponding to the above table when the visual system in the second embodiment is in the +2D state and the -5D state. D1 represents the value of the virtual image distance of the visual system in this embodiment, and D2, D3, and D4 are all the distances on the optical axis from the second side surface of the quarter-wave plate QWP to the first side surface of the second lens. When D1, D2, D3, and D4 are positive values, it means the direction is from the first side to the second side, and when they are negative values, it means the direction is from the second side to the first side. The units of D1, D2, D3, and D4 are all millimeters (mm).

[0126] Table 8

[0127] D1 D2 D3 D4 +2D State 500.0000 9.1947 -9.1947 9.1947 -5D State -200.0000 6.8251 -6.8251 6.8251

[0128] The following Table 9 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical surface in the second embodiment.

[0129] Table 9

[0130] Surface 2 14 15 A4 9.0467E-06 -2.3034E-06 3.3955E-07 A6 -3.2844E-08 -4.8862E-09 -9.2771E-10 A8 7.2829E-11 8.3570E-12 0.0000E+00 A10 -7.4355E-14 -4.6692E-14 0.0000E+00 A12 0.0000E+00 9.7425E-17 0.0000E+00 A14 0.0000E+00 -9.1227E-20 0.0000E+00 A16 0.0000E+00 0.0000E+00 0.0000E+00 A18 0.0000E+00 0.0000E+00 0.0000E+00 A20 0.0000E+00 0.0000E+00 0.0000E+00

[0131] Figure 16 shows the optical modulation function curve diagram of the visual system in the second embodiment in the +2D state. It can be seen from the figure that the optical modulation function values of the curves in the meridian direction at the 0 field of view, the 0.5 field of view, and the 1.0 field of view are all relatively high, indicating that the imaging quality at this spatial frequency is relatively good. Figure 17The optical modulation function curve diagram of the visual system in Embodiment 2 in the -5D state is shown. The optical modulation function values of the curves in the meridian direction at the 0 field of view, 0.5 field of view, and 1.0 field of view are all relatively high. A higher curve indicates better imaging quality at that spatial frequency.

[0132] Embodiment 3

[0133] As Figures 18 to 25 shown, the visual system of Embodiment 3 is described. Figure 18 The structural schematic diagram of the visual system in Embodiment 3-1 in the +2D state is shown, Figure 19 The structural schematic diagram of the visual system in Embodiment 3-1 in the -5D state is shown, Figure 20 The structural schematic diagram of the visual system in Embodiment 3-2 in the +2D state is shown, Figure 21 The structural schematic diagram of the visual system in Embodiment 3-2 in the -5D state is shown, Figure 22 The structural schematic diagram of the visual system in Embodiment 3-3 in the +2D state is shown, Figure 23 The structural schematic diagram of the visual system in Embodiment 3-3 in the -5D state is shown.

[0134] As Figures 18 to 23 shown, the visual system includes a first lens barrel Pa, a second lens barrel Pb, a first element group, and a second element group. The first element group sequentially includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP along the optical axis of the visual system from the first side to the second side. The polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are sequentially arranged on the second side surface of the first lens in the direction away from the first lens E1. The second element group sequentially includes a second lens E2, a reflective element BS, and a display, and the display has an image surface IMG. The reflective element BS is arranged on the second side surface of the second lens; the second element group is movably arranged along the optical axis.

[0135] In this embodiment, the first lens E1, the polarizer LP, the reflective polarizing element RP, and the quarter-wave plate QWP are accommodated in the first lens barrel Pa, the second lens E2 and the reflective element BS are accommodated in the second lens barrel Pb, and the display is located on the side of the second lens barrel Pb away from the first lens barrel Pa.

[0136] In this embodiment, the light emitted from the image plane IMG sequentially passes through the second lens E2 and the quarter-wave plate QWP, and then is incident on the reflective polarizing element RP. After being reflected by the reflective polarizing element RP, it is transmitted toward the display side. Then, after passing through the quarter-wave plate QWP and the second lens E2 in sequence, it is incident on the reflective element BS. After being reflected by the reflective element BS, it is transmitted toward the human eye side. Then, after passing through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 in sequence, it is incident on the human eye for imaging.

[0137] In summary, the structural parameters of the visual system in Embodiment 3 under Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3 are shown in Table 10 (unit: mm). It should be noted here that the following parameters of each embodiment are the same in the -5D state and the +2D state.

[0138] Table 10

[0139] Parameter / Embodiment 3-1 3-2 3-3 das 35.112 33.909 34.839 dam 40.922 40.532 40.821 Das 42.846 38.970 40.862 Dam 43.213 42.343 43.074 damin 34.366 33.163 34.237 dbs 44.055 43.665 43.415 dbm 39.856 40.739 38.641 Dbs 46.264 45.886 45.607 Dbm 44.864 43.967 44.208 dbmin 38.999 38.409 37.784 La 4.442 4.198 3.696 Lb 5.643 5.956 6.394

[0140] In Embodiment 3, the first lens E1 has a positive focal power. The first side of the first lens is a convex surface, and the second side of the first lens is a flat surface; the second lens E2 has a positive focal power. The first side of the second lens is a convex surface, and the second side of the second lens is a convex surface.

[0141] In Embodiment 3, the effective focal length f1 of the first lens is 132.4572 mm, the effective focal length f2 of the second lens is 147.8224 mm, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate is 132.4572 mm, the distance BFL from the second side of the second lens to the display on the optical axis is 0.8944 mm. When the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis is 2.3870 mm. When the visual system moves from the +2D state to the -5D state, the change amount Δf of the effective focal length of the visual system is 1.2855 mm.

[0142] Table 11 shows the basic structural parameter table of the visual system in Embodiment 3, where the unit of the radius of curvature and the thickness / distance is millimeter mm. In the following table, STO (not shown in the figure) is the aperture stop, and the aperture stop is located on the first side of the first lens E1.

[0143] Table 11

[0144] Surface Surface Type Radius of Curvature Thickness / Distance Refractive Index Dispersion Coefficient Refraction / Reflection Conic Coefficient 0 Spherical Infinity D1 Refraction 1 Aperture STO Spherical Infinity 12.0000 Refraction 2 First Lens E1 Aspherical 71.1426 4.2000 1.537 55.71 Refraction -1.6197 3 Spherical Infinity 0.0000 Refraction 4 Polarizer LP Spherical Infinity 0.0640 1.533 50.00 Refraction 5 Reflective Polarizing Element RP Spherical Infinity 0.0580 1.623 50.00 Refraction 6 Quarter-Wave Plate QWP Spherical Infinity 0.0510 1.533 50.00 Refraction 7 Spherical Infinity D2 Refraction 8 Second Lens E2 Aspherical 350.4281 7.0000 1.537 55.71 Refraction -100.0000 9 Reflective Element BS Aspherical -101.9363 -7.0000 1.537 55.71 Reflection -28.0714 10 Aspherical 350.4281 D3 Refraction -100.0000 11 Spherical Infinity -0.0510 1.533 50.00 Refraction 12 Reflective Polarizing Element RP Spherical Infinity 0.0510 1.533 50.00 Reflection 13 Spherical Infinity D4 Refraction 14 Second Lens E2 Aspherical 350.4281 7.0000 1.537 55.71 Refraction -100.0000 15 Aspherical -101.9363 0.8944 Refraction -28.0714 16 Image Plane IMG Spherical Infinity 0.0000 Refraction

[0145] Table 12 shows the values of D1, D2, D3, and D4 in the above table for the visual system in Example 3 in the +2D state and -5D state. D1 represents the value of the virtual image distance of the visual system in this embodiment, and D2, D3, and D4 are all the distances on the optical axis from the second side of the quarter-wave plate QWP to the first side of the second lens. When D1, D2, D3, and D4 are positive, it means the direction is from the first side to the second side, and when they are negative, it means the direction is from the second side to the first side. The units of D1, D2, D3, and D4 are all millimeters (mm).

[0146] Table 12

[0147] D1 D2 D3 D4 +2D State 500.0000 7.7326 -7.7326 7.7326 -5D State -200.0000 5.3456 -5.3456 5.3456

[0148] The following Table 13 gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 for each aspheric surface in Example 3.

[0149] Table 13

[0150] Surface 2 14 15 A4 1.0188E-05 4.6598E-06 -9.7263E-07 A6 -3.1447E-08 -1.3777E-08 1.0075E-09 A8 1.5279E-10 -9.7518E-12 -6.9702E-12 A10 -4.6364E-13 1.0531E-14 -3.5101E-16 A12 4.9453E-16 5.7019E-17 3.4244E-17 A14 1.7319E-19 -1.5646E-20 -3.8789E-20 A16 2.5324E-21 -7.9100E-23 -9.6257E-24 A18 -7.7360E-24 -3.1643E-25 -1.5650E-26 A20 0.0000E+00 0.0000E+00 0.0000E+00

[0151] Figure 24 Shows the optical modulation function curve of the visual system in Example 3 in the +2D state. As can be seen from the figure, the optical modulation function values of the curves in the meridional direction at the 0 field of view, 0.5 field of view, and 1.0 field of view are all relatively high, indicating that the imaging quality at this spatial frequency is good. Figure 25 Shows the optical modulation function curve of the visual system in Example 3 in the -5D state. As can be seen from the figure, the optical modulation function values of the curves in the meridional direction at the 0 field of view, 0.5 field of view, and 1.0 field of view are all relatively high, indicating that the imaging quality at this spatial frequency is good.

[0152] In summary, each of Examples 1 to 3 satisfies the relationships shown in Table 14. The values of the following conditional expressions for each example in the -5D state and +2D state are the same.

[0153] Table 14

[0154] Condition / Embodiment 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 R1 / damin 2.23 2.18 2.28 2.49 2.70 2.43 2.07 2.15 2.08 (La + Lb) / ΔL 5.99 5.57 5.62 3.99 4.59 4.09 4.22 4.25 4.23 Das / CT1 8.65 8.85 8.71 8.51 8.90 8.63 10.20 9.28 9.73 CT2 / Lb 1.47 1.20 1.38 1.08 0.94 1.16 1.24 1.18 1.09 R4 / dbmin -2.61 -2.79 -2.59 -2.91 -2.88 -2.89 -2.61 -2.65 -2.70 (dbs - dbm) / Δf 2.82 5.43 2.18 4.79 4.35 3.31 3.27 2.28 3.71 La×(fz / f2)(mm) 6.50 4.65 5.50 5.48 6.28 6.03 3.98 3.76 3.31 R3 / Dbs 7.30 7.21 7.16 4.85 4.82 4.92 7.57 7.64 7.68 (dam - das) / ΔL 4.70 4.21 4.31 3.40 5.53 3.36 2.43 2.77 2.51 f1 / Dam 2.76 2.79 2.84 3.29 3.15 3.24 3.07 3.13 3.08 (dbmin - damin) / ΔL 3.80 2.29 4.19 2.07 3.31 1.92 1.94 2.20 1.49 (Dbm - dbm) / BFL 4.15 5.97 4.42 6.89 7.20 4.68 5.60 3.61 6.22 damin / La 3.97 5.67 4.60 6.28 5.05 5.84 7.74 7.90 9.26 dbmin / Lb 7.05 5.35 6.65 8.25 7.24 8.89 6.91 6.45 5.91 (f2 / N2) / dbs 2.14 2.11 2.16 1.95 1.94 1.99 2.18 2.20 2.22

[0155] Table 15 shows the parameters such as the effective focal length of each lens in each example.

[0156] Table 15

[0157] Parameter / Embodiment 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 f1(mm) 120.6365 120.6365 120.6365 143.9799 143.9799 143.9799 132.4572 132.4572 132.4572 f2(mm) 138.3122 138.3122 138.3122 132.4296 132.4296 132.4296 147.8224 147.8224 147.8224 [[ID= 120.6365 120.6365 120.6365 143.9799 143.9799 143.9799 132.4572 132.4572 132.4572 ​ 0.9944 0.9944 0.9944 0.8944 0.8944 0.8944 0.8944 0.8944 0.8944 ​ 2.1374 2.1374 2.1374 2.3696 2.3696 2.3696 2.3870 2.3870 2.3870 ​ 1.1740 1.1740 1.1740 1.3328 1.3328 1.3328 1.2855 1.2855 1.2855

[0158] The present application also provides an imaging device, and its electronic photosensitive element may be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor device (CMOS). The imaging device may be an independent imaging device such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the visual system described above.

[0159] Optionally, the imaging device may be a VR device or an AR device.

[0160] Obviously, the above-described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0161] 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 specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0162] It should be noted that the terms "first", "second", etc. in the description, claims and drawings of the present 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 under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0163] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A visual system, characterized in that, It includes a first lens barrel, a second lens barrel, a first element group, and a second element group. At least part of the first element group is accommodated in the first lens barrel, and at least part of the second element group is accommodated in the second lens barrel. The first element group sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate along the optical axis of the visual system from the first side to the second side. The polarizer, the reflective polarizing element, and the quarter-wave plate are sequentially arranged on the second side surface of the first lens in a direction away from the first lens. The first lens has a positive optical power. The first side surface of the first lens is a convex surface, and the second side surface of the first lens is a flat surface. The second element group sequentially includes a second lens, a reflecting element, and a display along the optical axis from the first side to the second side. The reflecting element is arranged on the second side surface of the second lens. The second lens has a positive optical power. The first side surface of the second lens is a convex surface, and the second side surface of the second lens is a convex surface. The second element group is movably arranged along the optical axis. The number of lenses in the visual system is two. The curvature radius R1 of the first side surface of the first lens and the minimum inner diameter damin of the first lens barrel satisfy: 2.07 ≤ R1 / damin ≤ 2.

70. When the distance La between the first side surface and the second side surface of the first lens barrel on the optical axis, the distance Lb between the first side surface and the second side surface of the second lens barrel on the optical axis, and the visual system moves from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis satisfy: 3.99 ≤ (La + Lb) / ΔL ≤ 5.

99.

2. The visual system according to claim 1, characterized in that, The outer diameter Das of the first side surface of the first lens barrel and the central thickness CT1 of the first lens on the optical axis satisfy: 8.51 ≤ Das / CT1 ≤ 10.

20.

3. The visual system according to claim 1, characterized in that The central thickness CT2 of the second lens on the optical axis and the distance Lb between the first side surface and the second side surface of the second lens barrel on the optical axis satisfy: 0.94 ≤ CT2 / Lb ≤ 1.

47.

4. The visual system according to claim 1, characterized in that, The curvature radius R4 of the second side surface of the second lens and the minimum inner diameter dbmin of the second lens barrel satisfy: -2.91 ≤ R4 / dbmin ≤ -2.

59.

5. The visual system according to claim 1, wherein The inner diameter dbs of the first side surface of the second lens barrel, the inner diameter dbm of the second side surface of the second lens barrel, and the change amount Δf of the effective focal length of the visual system when the visual system moves from the +2D state to the -5D state satisfy: 2.18 ≤ (dbs - dbm) / Δf ≤ 5.

43.

6. The visual system according to claim 1, wherein The distance La between the first side surface and the second side surface of the first lens barrel on the optical axis, the combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate, and the effective focal length f2 of the second lens satisfy: 3.31 mm ≤ La×(fz / f2) ≤ 6.50 mm.

7. The visual system according to claim 1, characterized in that, The curvature radius R3 of the first side of the second lens and the outer diameter Dbs of the first side of the second lens barrel satisfy: 4.82 ≤ R3 / Dbs ≤ 7.

68.

8. The visual system according to claim 1, wherein When the inner diameter dam of the second side of the first lens barrel, the inner diameter das of the first side of the first lens barrel, and the visual system move from the +2D state to the -5D state, the distance ΔL that the second element group moves along the optical axis satisfies: 2.43 ≤ (dam - das) / ΔL ≤ 5.

53.

9. The visual system according to claim 1, characterized in that, The effective focal length f1 of the first lens and the outer diameter Dam of the second side of the first lens barrel satisfy: 2.76 ≤ f1 / Dam ≤ 3.

29.

10. The visual system according to claim 1, characterized in that, The minimum inner diameter dbmin of the second lens barrel, the minimum inner diameter damin of the first lens barrel, and the distance ΔL that the second element group moves along the optical axis when the visual system moves from the +2D state to the -5D state satisfy: 1.49 ≤ (dbmin - damin) / ΔL ≤ 4.19.

Images