Visual system

Abstract

The application provides a visual system, comprising an optical element group and a lens barrel group: the first element group comprises a first lens, a polarizer, a reflective polarizing element and a quarter-wave plate, the second element group comprises a second lens, a partially reflective element and a display; the lens barrel group comprises a first lens barrel and a second lens barrel; the maximum thickness La from the first side surface of the first lens barrel to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface of the second lens barrel to the second side surface of the second lens barrel, and the change amount Δf of the effective focal length of the visual system when moving from a +2D state to a -5D state satisfy: 3.45 ≤ (La+Lb) / Δf ≤ 7.79; the distance ΔL of the second element group moving along the direction of the optical axis when the visual system moves from the +2D state to the -5D state, the inner diameter dam of the second side surface of the first lens barrel, and the inner diameter dbs of the first side surface of the second lens barrel satisfy: 4.54 mm ≤ ΔL × (dam / dbs) ≤ 5.01 mm. The application solves the problem of serious imaging stray light of the visual system in the prior art.

Description

Technical Field

[0001] This invention relates to the field of wearing devices, and more specifically, to a visual system. Background Technology

[0002] In recent years, with the explosive popularity of AI and the metaverse, people's entertainment options have become increasingly diverse, among which VR devices for human-computer interaction are gaining popularity. However, the visual systems currently integrated into VR devices have limited internal space to achieve diopter adjustment and adapt to miniaturized VR devices. During the light path reflection and transmission process, the space constraints of the lens barrel and different component groups lead to the generation of a large amount of stray light, thus affecting the user's visual experience. Therefore, how to rationally arrange the internal space of the visual system to ensure the range of diopter adjustment while reducing stray light generation is a very important issue. Summary of the Invention

[0003] The main objective of this invention is to provide a visual system to solve the problem of severe stray light in the imaging of existing visual systems.

[0004] To achieve the above objectives, according to one aspect of the present invention, a visual system is provided, comprising: an optical element group including a first element group and a second element group; the first element group, along the optical axis of the visual system, sequentially including a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate from a first side to a second side; the first lens having positive optical power; a first side surface of the first lens being convex; and a second side surface of the first lens being planar; the second element group, sequentially including a second lens, a partially reflective element, and a display from a first side to a second side; the second lens having positive optical power; and a first side surface of the second lens being convex; and a lens barrel group including a first lens barrel and a second lens barrel; the first element group resting on the first lens barrel; and the second element group... At least a portion rests on the second lens barrel; wherein the second element group is movable along the optical axis to approach or move away from the first element group; the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy: 3.45≤(La+Lb) / Δf≤7.79; the distance ΔL that the second element group moves along the optical axis when the visual system moves from +2D state to -5D state, the inner diameter dam of the second side surface of the first lens barrel, and the inner diameter dbs of the first side surface of the second lens barrel satisfy: 4.54mm≤ΔL×(dam / dbs)≤5.01mm.

[0005] According to another aspect of the present invention, a visual system is provided, comprising: an optical element group including a first element group and a second element group; the first element group, along the optical axis of the visual system, sequentially including a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate from a first side to a second side; the first lens having positive optical power; a first side surface of the first lens being convex; and a second side surface of the first lens being planar; the second element group, sequentially including a second lens, a partially reflective element, and a display from the first side to the second side; the second lens having positive optical power; and a first side surface of the second lens being convex; and a lens barrel group including a first lens barrel and a second lens barrel. The first element group rests on the first lens barrel, and at least a portion of the second element group rests on the second lens barrel; wherein the second element group is movable along the optical axis to move closer to or further away from the first element group; the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy: 3.45≤(La+Lb) / Δf≤7.79; 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 lens barrel satisfy: 3.08≤R3 / Dbs≤3.58.

[0006] Furthermore, 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 lens barrel satisfy the following condition: 3.08≤R3 / Dbs≤3.58.

[0007] Furthermore, the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the effective focal length f1 of the first lens, and the radius of curvature R1 of the first side surface of the first lens satisfy the following condition: 2.65mm≤La / (f1 / R1)≤6.57mm.

[0008] Furthermore, the inner diameter das of the first side surface of the first lens barrel and the center thickness CT1 of the first lens on the optical axis satisfy the following condition: 9.04≤das / CT1≤11.49.

[0009] Furthermore, the combined focal length fz of the first lens, polarizer, reflective polarizing element, and quarter-wave plate, the outer diameter Das of the first side surface of the first lens barrel, and the outer diameter Dam of the second side surface of the first lens barrel satisfy the following condition: 1.63≤fz / (Das+Dam)≤1.98.

[0010] Furthermore, the effective focal length f2 of the second lens and the inner diameter dbm of the second side surface of the second lens barrel satisfy the following condition: 3.10≤f2 / dbm≤3.37.

[0011] Furthermore, the outer diameter Dbm of the second side surface of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following condition: 8.98≤Dbm / CT2≤11.44.

[0012] Furthermore, the maximum thickness Lb from the first side surface of the second lens barrel to 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 the following condition: 5.78≤Lb / BFL≤10.67.

[0013] Furthermore, the outer diameter Dbs of the first side surface of the second lens tube, the outer diameter Dbm of the second side surface of the second lens tube, 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 the following condition: 0.45≤(Dbs-Dbm) / ΔL≤1.84.

[0014] Furthermore, the outer diameter Dam of the second side surface of the first lens barrel, the inner diameter dam of the second side surface of the first lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy the following: 1.01≤(Dam-dam) / Δf≤2.15.

[0015] Furthermore, the maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfies the following relationship with the entrance pupil diameter EPD of the visual system: 1.23≤La / EPD≤3.00.

[0016] Furthermore, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, 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: -11.90mm≤Lb×(R3 / R4)≤-6.39mm.

[0017] Furthermore, the outer diameter Das of the first side surface of the first lens barrel and the maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfy the following condition: 4.61≤Das / La≤11.22.

[0018] Furthermore, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel satisfy the following condition: 3.03≤(f1-f2) / Lb≤10.28.

[0019] According to the technical solution of this invention, the visual system includes an optical element group and a lens barrel group. The optical element group includes a first element group and a second element group. Along the optical axis of the visual system, the first element group sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate from the first side to the second side. The first lens has positive optical power, its first side surface is convex, and its second side surface is planar. The second element group sequentially includes a second lens, a partially reflective element, and a display from the first side to the second side. The second lens has positive optical power, its first side surface is convex, and its second side surface is convex. The lens barrel group includes a first lens barrel and a second lens barrel. The first element group rests on the first lens barrel, and at least a portion of the second element group rests on the second lens barrel. On the lens barrel; wherein, the second element group can move along the optical axis to approach or move away from the first element group; the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy: 3.45≤(La+Lb) / Δf≤7.79; the distance ΔL that the second element group moves along the optical axis when the visual system moves from +2D state to -5D state, the inner diameter dam of the second side surface of the first lens barrel, and the inner diameter dbs of the first side surface of the second lens barrel satisfy: 4.54mm≤ΔL×(dam / dbs)≤5.01mm.

[0020] This application achieves diopter adjustment from +2D to -5D by reasonably configuring the visual system and controlling (La+Lb) / Δf and ΔL×(dam / dbs) within a reasonable range. At the same time, it ensures that the total thickness of the first and second lens tubes is large enough to provide space for multiple reflections of the light path, avoids stray light interference and ghosting at the edge of the field of view caused by insufficient lens tube thickness, and prevents the lens tubes from being too thick and heavy, which would limit the size of the visual system and avoid light energy loss and contrast reduction due to excessively long optical path. Attached Figure Description

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

[0022] Figure 1 A schematic diagram showing partial parameters of the visual system according to any optional embodiment of the present invention is shown;

[0023] Figure 2 A schematic diagram of the visual system of Embodiment 1 of the present invention in a first state is shown;

[0024] Figure 3A schematic diagram of the visual system of Embodiment 1 of the present invention in a second state is shown;

[0025] Figure 4 The MTF curve of the visual system of Embodiment 1 of the present invention in the first state is shown;

[0026] Figure 5 The MTF curve of the visual system of Embodiment 1 of the present invention in the second state is shown;

[0027] Figure 6 A schematic diagram of the visual system of Embodiment 2 of the present invention in a first state is shown;

[0028] Figure 7 A schematic diagram of the visual system of Embodiment 2 of the present invention in a second state is shown;

[0029] Figure 8 A schematic diagram of the visual system of Embodiment 3 of the present invention in a first state is shown;

[0030] Figure 9 A schematic diagram of the visual system of Embodiment 3 of the present invention in a second state is shown;

[0031] Figure 10 A schematic diagram of the visual system of Embodiment 4 of the present invention in a first state is shown;

[0032] Figure 11 A schematic diagram of the visual system of Embodiment 4 of the present invention in a second state is shown;

[0033] Figure 12 The MTF curve of the visual system in the first state according to Embodiment 4 of the present invention is shown;

[0034] Figure 13 The MTF curve of the visual system of Embodiment 4 of the present invention in the second state is shown.

[0035] Figure 14 A schematic diagram of the visual system of Embodiment 5 of the present invention in a first state is shown;

[0036] Figure 15 A schematic diagram of the visual system of Embodiment 5 of the present invention in a second state is shown;

[0037] Figure 16 A schematic diagram of the visual system of Embodiment 6 of the present invention in a first state is shown;

[0038] Figure 17 A schematic diagram of the visual system of Embodiment 6 of the present invention in a second state is shown;

[0039] Figure 18 A schematic diagram of the visual system of Embodiment 7 of the present invention in a first state is shown;

[0040] Figure 19 A schematic diagram of the visual system of Embodiment 7 of the present invention in a second state is shown;

[0041] Figure 20 The MTF curve of the visual system of Embodiment 7 of the present invention in the first state is shown;

[0042] Figure 21 The MTF curve of the visual system of Embodiment 7 of the present invention in the second state is shown;

[0043] Figure 22 A schematic diagram of the visual system of Embodiment 8 of the present invention in a first state is shown;

[0044] Figure 23 A schematic diagram of the visual system of Embodiment 8 of the present invention in a second state is shown;

[0045] Figure 24 A schematic diagram of the visual system of Embodiment 9 of the present invention in a first state is shown;

[0046] Figure 25 A schematic diagram of the visual system of Embodiment 9 of the present invention in a second state is shown;

[0047] Figure 26 A schematic diagram of stray light spot is shown for a visual system of optional embodiment 1 of the present invention under the conditions of (La+Lb) / Δf=4.72 and ΔL×(dam / dbs)=4.84mm.

[0048] Figure 27 A schematic diagram of stray light spot of the visual system of Comparative Example 1 is shown under the conditions of (La+Lb) / Δf=8.2 and ΔL×(dam / dbs)=5.5mm;

[0049] Figure 28 A schematic diagram of stray light spots of the visual system in Comparative Example 2 is shown under the conditions of (La+Lb) / Δf=2.9 and ΔL×(dam / dbs)=4.1mm.

[0050] The above figures include the following reference numerals:

[0051] Pa, first lens barrel; Pb, second lens barrel; E1, first lens; LP, polarizer; RP, reflective polarizing element; QWP, quarter-wave plate; E2, second lens; BS, partial reflective element; IMG, image plane. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0054] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0055] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0056] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0057] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of that convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of that concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The determination of the surface shape in the paraxial region can be based on the judgment method commonly used by those knowledgeable in the field, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine convexity or concavity. For the eye-side surface, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the display-side surface, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0058] To address the problem of severe stray light in existing visual systems, this invention provides a visual system.

[0059] First Implementation Method

[0060] like Figures 1 to 26As shown, the visual system includes an optical element group and a lens barrel group. The optical element group includes a first element group and a second element group. Along the optical axis of the visual system, the first element group includes, from the first side to the second side, a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate. 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 element group includes, from the first side to the second side, a second lens, a partially reflective element, and a display. 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. The lens barrel group includes a first lens barrel and a second lens barrel. The first element group rests on the first lens barrel, and at least a portion of the second element group rests on the second lens barrel. The second element group can move along the optical axis to approach or move away from the first element group; the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy: 3.45≤(La+Lb) / Δf≤7.79; the distance ΔL that the second element group moves along the optical axis when the visual system moves from +2D state to -5D state, the inner diameter dam of the second side surface of the first lens barrel, and the inner diameter dbs of the first side surface of the second lens barrel satisfy: 4.54mm≤ΔL×(dam / dbs)≤5.01mm.

[0061] This application achieves diopter adjustment from +2D to -5D by reasonably configuring the visual system and controlling (La+Lb) / Δf and ΔL×(dam / dbs) within a reasonable range. At the same time, it ensures that the total thickness of the first and second lens tubes is large enough to provide space for multiple reflections of the light path, avoids stray light interference and ghosting at the edge of the field of view caused by insufficient lens tube thickness, and prevents the lens tubes from being too thick and heavy, which would limit the size of the visual system and avoid light energy loss and contrast reduction due to excessively long optical path.

[0062] like Figures 26 to 28 The diagram shows the stray light energy of the visual systems in Comparative Example 1, Comparative Example 2, and an alternative embodiment 1 of this application. Figure 27 As shown, when the visual system of Comparative Example 1 satisfies the conditions (La+Lb) / Δf=8.2 and ΔL×(dam / dbs)=5.5mm, the overall volume of the visual system is large, the lens barrel is too thick and the internal optical path is too long, resulting in a higher risk of light leakage and significantly stronger stray light energy. Figure 28As shown, when the visual system of Comparative Example 2 satisfies the conditions (La+Lb) / Δf=2.9 and ΔL×(dam / dbs)=4.1mm, the thickness of the first and second lens tubes is insufficient, resulting in spatial constraints during the optical path refracting process and thus severe stray light interference. In contrast, the visual system of Option 1 of this application... Figure 26 As shown, stray light energy is very low and effectively controlled, allowing users to obtain a good visual experience.

[0063] In this embodiment, 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 lens barrel satisfy the following condition: 3.08 ≤ R3 / Dbs ≤ 3.58. By limiting R3 / Dbs within a reasonable range, the internal focusing mechanism of the second element group can be supported. By moving the second element group to change the light refraction path, the focal length change is synchronized with the user's eye adjustment, thereby alleviating the dizziness caused by a fixed focal length. It also helps to make the structure of the visual system more compact, in line with the trend of VR devices becoming thinner and lighter. In addition, it helps to maintain the mechanical stability of the second element group and prevents the deformation of components due to frequent adjustments.

[0064] In this embodiment, the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the effective focal length f1 of the first lens, and the radius of curvature R1 of the first side surface of the first lens satisfy the following: 2.65mm ≤ La / (f1 / R1) ≤ 6.57mm. By limiting La / (f1 / R1) within a reasonable range, the physical size of the first lens barrel can be limited, allowing it to accommodate the first element group while meeting the requirements for a thinner and lighter VR device. At the same time, it ensures the linearity and accuracy of the spacing adjustment between the first and second element groups, avoiding jamming due to excessively tight mechanical structure or insufficient adjustment stroke to cover the user's refractive power requirements.

[0065] In this embodiment, the inner diameter das of the first side surface of the first lens barrel and the center thickness CT1 of the first lens on the optical axis satisfy the following ratio: 9.04 ≤ das / CT1 ≤ 11.49. By limiting das / CT1 within a reasonable range, when the first lens barrel is made of plastic injection molding, the value of das / CT1 can directly affect the mold tolerance requirements. Satisfying the range of 9.04 ≤ das / CT1 ≤ 11.49 means that an easily moldable parameter combination has been selected, reducing defects such as flash and shrinkage during the molding process and improving the yield of the first lens barrel. At the same time, this ratio range allows for the installation of eye-tracking components by slotting the side wall of the first lens barrel while maintaining optical performance without interference. In addition, it also provides an adjustment margin of ±0.5mm or more for the motor-driven second element group, ensuring linear displacement accuracy.

[0066] In this embodiment, the combined focal length fz of the first lens, polarizer, reflective polarizing element, and quarter-wave plate, and the outer diameters Das and Dam of the first and second side surfaces of the first lens barrel satisfy the following condition: 1.63 ≤ fz / (Das+Dam) ≤ 1.98. By limiting fz / (Das+Dam) within a reasonable range, micron-level ventilation slots can be designed on the side of the first lens barrel. Air convection is used to control the temperature rise of the first lens and OLED screen to less than 5°C, avoiding polarization film aging or liquid crystal layer response delay caused by high temperatures, while also limiting the generation of higher-order dispersion (such as second-order spectral density). For the visible light band (400-700nm), the visual system can avoid color fringing or rainbow effects affecting visual immersion.

[0067] In this embodiment, the effective focal length f2 of the second lens and the inner diameter dbm of the second side surface of the second lens barrel satisfy the following condition: 3.10 ≤ f2 / dbm ≤ 3.37. By limiting f2 / dbm within a reasonable range, an assembly gap of ≥0.1mm can be maintained between the second lens and the second lens barrel wall, avoiding deformation of the second lens curvature or displacement of some reflective elements due to compression, ensuring stable performance of the optical components, and increasing the assembly margin, which can reduce the coating damage rate from 1.5% to below 0.05%.

[0068] In this embodiment, the outer diameter Dbm of the second side surface of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following condition: 8.98 ≤ Dbm / CT2 ≤ 11.44. By limiting Dbm / CT2 within a reasonable range, the contact area between the second lens barrel and the second lens is optimized, absorbing high-frequency vibrations during equipment use, preventing collisions between the second lens barrel and the second lens, and reducing image quality degradation caused by impact. Furthermore, a light-absorbing structure can be designed on the inner wall of the second lens barrel to control stray light intensity to below 0.5% of the total light intensity, preventing halos or ghosting on the screen.

[0069] In this embodiment, the maximum thickness Lb from the first side surface to 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 the following condition: 5.78 ≤ Lb / BFL ≤ 10.67. By limiting Lb / BFL within a reasonable range, edge aberrations can be optimized, distortion can be reduced to less than 0.3%, and field curvature drift at high temperatures can be suppressed. By reserving a BFL adjustment margin, the assembly precision requirements are reduced, allowing imaging requirements to be met even when the cumulative tolerance is greater than 0.15mm, thus improving the production line yield. In addition, it provides a hardware foundation for integrating eye tracking and dynamic zoom algorithms, supports real-time focal length adjustment, and achieves suppression of "visual convergence-accommodation conflict".

[0070] In this embodiment, the outer diameter Dbs of the first side surface of the second lens barrel, the outer diameter Dbm of the second side surface of the second lens barrel, and the distance ΔL that the second element group moves along the optical axis when the viewing system moves from a +2D state to a -5D state satisfy the following condition: 0.45 ≤ (Dbs - Dbm) / ΔL ≤ 1.84. By limiting (Dbs - Dbm) / ΔL to a reasonable range, the matching between the outer diameter difference of the two side surfaces of the second lens barrel and the movement of the second element group is constrained, enhancing the axial rigidity of the second lens barrel and avoiding stress concentration due to excessive taper or deformation due to insufficient taper. Furthermore, it allows for the design of micron-level heat dissipation grooves on the sidewall of the second lens barrel, forming a convection airflow channel in conjunction with the movement space of the second element group, controlling the temperature rise of the OLED screen to less than 5°C and extending the display lifespan.

[0071] In this embodiment, the outer diameter Dam of the second side surface of the first lens barrel, the inner diameter dam of the second side surface of the first lens barrel, and the change in effective focal length Δf of the visual system moving from +2D to -5D satisfy the following condition: 1.01 ≤ (Dam - dam) / Δf ≤ 2.15. By limiting (Dam - dam) / Δf within a reasonable range, space is provided for the lateral mounting of a miniature infrared camera, supporting eye-tracking interaction functions with a tracking accuracy of less than 0.2°, while avoiding optical path obstruction. It can also accommodate injection molding shrinkage, reducing warping and shrinkage issues of the first lens barrel, and is suitable for thin-walled lens barrel structures. Furthermore, it ensures that light is reflected at the optimal incident angle, reducing polarization crosstalk and light intensity loss.

[0072] In this embodiment, the maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfies the following relationship with the entrance pupil diameter EPD of the visual system: 1.23 ≤ La / EPD ≤ 3.00. By limiting La / EPD within a reasonable range, the radius of curvature of the aspherical lens can be optimized, and the wavefront errors of spherical aberration and coma can be controlled to less than 0.05λ (λ = 550nm), adapting to monocular 4K resolution. It can also balance the optical path folding depth and image field flatness, making edge distortion less than 0.3%, while suppressing field curvature drift at temperatures above 45°C.

[0073] In this embodiment, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and 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: -11.90mm ≤ Lb×(R3 / R4) ≤ -6.39mm. By limiting Lb×(R3 / R4) within a reasonable range, the curvature of the second lens barrel and the second lens are designed in a coordinated manner, enhancing the axial rigidity of the second lens barrel, suppressing lens barrel deflection during zoom adjustment, and ensuring optical axis alignment accuracy. Simultaneously, it can reduce optical path escape, keeping light leakage less than 3%, while avoiding volume redundancy caused by an excessively long second lens barrel.

[0074] In this embodiment, the outer diameter Das of the first side surface of the first lens barrel and the maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfy the following condition: 4.61 ≤ Das / La ≤ 11.22. By limiting Das / La to a reasonable range, it is possible to prevent the thickness of the first lens barrel along the optical axis from being too small, which would lead to insufficient internal space, affecting the zoom range or accuracy, and ensuring that the first lens barrel can withstand assembly stress and mechanical impacts during use. In addition, it provides the necessary space for the folded optical path design, ensuring that light propagates efficiently within the compact structure and avoiding stray light interference.

[0075] In this embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel satisfy the following condition: 3.03 ≤ (f1-f2) / Lb ≤ 10.28. By limiting (f1-f2) / Lb within a reasonable range, a wide range of zoom (such as switching from telephoto to near-photo) can be achieved, while avoiding the risk of limited movement or collision of the second element group due to excessively small thickness of the second lens barrel along the optical axis. Simultaneously, it ensures a reasonable load on the drive mechanism, avoiding positioning errors or vibrations due to excessive inertia, reducing system power consumption, and extending battery life.

[0076] Second Implementation Method

[0077] like Figures 1 to 26 As shown, the visual system includes an optical element group and a lens barrel group. The optical element group includes a first element group and a second element group. Along the optical axis of the visual system, the first element group, from the first side to the second side, sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate. The first lens has positive optical power, its first side surface is convex, and its second side surface is flat. The second element group, from the first side to the second side, sequentially includes a second lens, a partially reflective element, and a display. The second lens has positive optical power, its first side surface is convex, and its second side surface is convex. The lens barrel group includes a first lens barrel and a second lens barrel. The first element group rests against the first... On the lens barrel, at least a portion of the second element group rests on the second lens barrel; wherein the second element group is movable along the optical axis to move closer to or further away from the first element group; the maximum thickness La from the first side surface to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy: 3.45≤(La+Lb) / Δf≤7.79; 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 lens barrel satisfy: 3.08≤R3 / Dbs≤3.58.

[0078] This application, through reasonable configuration of the visual system and control of (La+Lb) / Δf and R3 / Dbs within a reasonable range, supports the internal focusing mechanism of the second element group, enabling diopter adjustment from +2D to -5D. By moving the second element group to change the light refraction path, the focal length change is synchronized with the user's eye adjustment, thereby alleviating dizziness caused by a fixed focal length. Furthermore, it ensures that the total thickness of the first and second lens barrels is sufficiently large to provide space for multiple reflections of light, avoiding stray light interference and ghosting at the edges of the field of view due to insufficient lens barrel thickness. Simultaneously, it ensures a relatively compact structure for the visual system, conforming to the trend of thinner and lighter VR devices. In addition, it helps maintain the mechanical stability of the second element group, preventing component deformation due to frequent adjustments.

[0079] This embodiment may also include other parametric expressions from the first embodiment, which will not be elaborated here.

[0080] In this application, at least one of the first and second lenses has an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0081] However, those skilled in the art will understand that the number of lenses constituting the visual system can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although two lenses are described as an example in the embodiments, the visual system is not limited to including two lenses. If necessary, the visual system may also include other numbers of lenses.

[0082] Figure 1 Parameters such as das and Dbm are labeled to clearly and intuitively explain their meaning. To better illustrate the structure of the visual system and specific surface types, these parameters will not be shown in the accompanying drawings when explaining specific examples later.

[0083] It should be noted that in the following embodiments, the visual system of the same embodiment has a first state and a second state. The radius of curvature, center thickness and higher order image coefficient of the first lens and the second lens are the same in these two states, but the spacing distance between the first element group and the second element group, the lens barrel and other parameters are different.

[0084] It should be noted that the movement of the second element group of the visual system closer to the first element group along the optical axis causes a change in refractive power. The refractive power of the visual system is +2D in the first state and -5D in the second state. Specifically, the first state indicates that the visual system is suitable for users with a hyperopia of 200 diopters, and the second state indicates that the visual system is suitable for users with a myopia of 500 diopters. The visual system also has other states besides the first and second states, and the refractive power of the visual system in these other states can be between +2D and -5D.

[0085] It should be noted that the first side refers to the side of the human eye, and the second side refers to the side of the display screen, with the image surface located on the display screen.

[0086] The following describes in further detail, with reference to the accompanying drawings, specific surface features and parameters of the visual system applicable to the above embodiments.

[0087] Example 1

[0088] like Figure 2 and Figure 3 As shown, the structure of the visual system of Embodiment 1 of this application in the first state and the second state are described respectively.

[0089] like Figure 2 and Figure 3 As shown, a first element group rests on a first lens barrel Pa, and at least a portion of a second element group rests on a second lens barrel Pb. The first element group, from the first side to the second side, sequentially includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP. The second element group, from the first side to the second side, sequentially includes a second lens E2, a partially reflective element BS, and a display. It should be noted that in this embodiment, the first side end of the first lens barrel Pa extends towards the optical axis so that the first side surface of the first lens rests on the first lens barrel Pa. Therefore, the first lens E1, polarizer LP, reflective polarizing element RP, and quarter-wave plate QWP are assembled from the second side of the first lens barrel Pa. Simultaneously, the second side end of the second lens barrel Pb extends towards the optical axis so that the second side surface of the second lens rests on the second lens barrel Pb. Therefore, the second lens E2 and the partially reflective element BS are assembled from the first side of the second lens barrel Pb.

[0090] In this embodiment, 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 planar. The second lens also has positive optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is also convex. The visual system further includes an aperture stop STO located between the first side and the first element group. The first side surface of the polarizer is at least partially attached to the second side surface of the first lens. The second side surface of the polarizer is attached to the first side surface of the reflective polarizing element. The second side surface of the reflective polarizing element is attached to the first side surface of the quarter-wave plate. The first side surface of the partially reflective element is at least partially attached to the second side surface of the second lens.

[0091] In this embodiment, light rays from the image plane IMG pass sequentially through the second lens E2 and the quarter-wave plate QWP before reaching the reflective polarizing element RP. After being reflected by the reflective polarizing element RP, the light rays pass sequentially through the quarter-wave plate QWP and the second lens E2 before reaching the partial reflective element BS on the second side of the second lens. After being reflected by the partial reflective element BS, the light rays pass through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 before exiting.

[0092] Table 1 shows the basic structural parameters of the visual system in Embodiment 1, where the units for radius of curvature, thickness / distance, and effective focal length are millimeters (mm). In Table 1, light rays from the image plane IMG propagate from surface number 16 to surface number 0. Refraction / reflection refers to the refraction or reflection of light rays by the surface represented by that surface number. Surfaces 16 to 0 are, in order, the image plane, 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 polarizing element), 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 polarizing element), the first side surface of the reflective polarizing element (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 plane, and the virtual image plane.

[0093] Table 1

[0094] 0 spherical endless D1 refraction 1 Stabilizer (STO) spherical endless 12.0000 refraction 2 First lens (E1) aspherical 120.5394 4.4355 1.537 55.71 refraction 14.6841 3 spherical endless 0.0000 refraction 4 Polarizing filter (LP) spherical endless 0.0500 1.533 50.00 refraction 5 Reflective polarizing element (RP) spherical endless 0.0580 1.623 50.00 refraction 6 Quarter-wave plate (QWP) spherical endless 0.0510 1.533 50.00 refraction 7 spherical endless D2 refraction 8 Second lens (E2) aspherical 210.5945 4.9866 1.547 56.30 refraction 46.3547 9 Partial reflective element (BS) aspherical -167.3860 -4.9866 1.547 56.30 reflection 1.0728 10 aspherical 210.5945 D3 refraction 46.3547 11 spherical endless -0.0510 1.533 50.00 refraction 12 Reflective polarizing element (RP) spherical endless 0.0510 1.533 50.00 reflection 13 spherical endless D4 refraction 14 Second lens (E2) aspherical 210.5945 4.9866 1.547 56.30 refraction 46.3547 15 aspherical -167.3860 0.8944 refraction 1.0728 16 Image View (IMG) spherical endless 0.0000 refraction

[0095] In Embodiment 1, the first side surface of the first lens E1, the first side surface of the second lens E2, and the second side surface of the second lens E2 are aspherical surfaces. The shape of the aspherical surface can be defined using, but is not limited to, the following aspherical surface formula:

[0096]

[0097] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R, that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above; k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for the aspherical surface in Example 1.

[0098] Table 2

[0099] A4 8.5143E-06 2.4791E-06 1.8271E-06 A6 -4.6669E-08 -2.8777E-08 -9.5049E-09 A8 1.7533E-10 5.6786E-11 1.6998E-11 A10 -3.5452E-13 -3.9261E-14 -9.9571E-15 A12 2.8049E-16 1.1162E-18 0.0000E+00 A14 -5.6266E-20 2.3077E-21 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

[0100] In this embodiment, moving the second element group changes the refractive power of the visual system, thereby achieving the desired effect. Figure 1 The first state (+2D state) shown transitions to Figure 2 The second state (-5D state) is shown in Table 3. As shown in Table 3, some structural parameters of the visual system change. D1 represents the virtual image distance of the visual system in this embodiment. D2, D3, and D4 represent the distances on the optical axis from the second side of the quarter-wave plate to the first side of the second lens. When D1, D2, D3, and D4 are positive, the direction is from the first side to the second side. When they are negative, the direction is from the second side to the first side. The units of D1, D2, D3, and D4 are all millimeters (mm).

[0101] Table 3

[0102] +2D state 500.0000 15.5245 -15.5245 15.5245 -5D status -200.0000 10.5667 -10.5667 10.5667

[0103] Figure 4 and Figure 5 The MTF curves of the visual system of Embodiment 1 are shown in the first state (+2D state) and the second state (-5D state). The MTF values ​​under the light of each field of view are all above 0.8, showing good imaging quality.

[0104] Example 2

[0105] like Figure 6 and Figure 7 The image shows a visual system according to Embodiment 2 of this application. Figure 6 and Figure 7 The first and second states of the visual system in Embodiment 2 are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment 1, but different structural parameters. Please refer to the relevant description in Embodiment 1, which will not be repeated here.

[0106] Example 3

[0107] like Figure 8 and Figure 9The image shows a visual system according to Embodiment 3 of this application. Figure 8 and Figure 9 The first and second states of the visual system in Embodiment 3 are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment 1, but different structural parameters. Please refer to the relevant description in Embodiment 1, which will not be repeated here.

[0108] Example 4

[0109] like Figure 10 and Figure 11 As shown, the structure of the visual system of Embodiment 4 of this application in the first state and the second state are described respectively.

[0110] like Figure 10 and Figure 11 As shown, a first element group rests on a first lens barrel Pa, and at least a portion of a second element group rests on a second lens barrel Pb. The first element group, from the first side to the second side, sequentially includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP. The second element group, from the first side to the second side, sequentially includes a second lens E2, a partially reflective element BS, and a display. It should be noted that in this embodiment, the first side end of the first lens barrel Pa extends towards the optical axis so that the first side surface of the first lens rests on the first lens barrel Pa. Therefore, the first lens E1, polarizer LP, reflective polarizing element RP, and quarter-wave plate QWP are assembled from the second side of the first lens barrel Pa. Simultaneously, the second side end of the second lens barrel Pb extends towards the optical axis so that the second side surface of the second lens rests on the second lens barrel Pb. Therefore, the second lens E2 and the partially reflective element BS are assembled from the first side of the second lens barrel Pb.

[0111] In this embodiment, 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 planar. The second lens also has positive optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is also convex. The visual system further includes an aperture stop STO located between the first side and the first element group. The first side surface of the polarizer is at least partially attached to the second side surface of the first lens. The second side surface of the polarizer is attached to the first side surface of the reflective polarizing element. The second side surface of the reflective polarizing element is attached to the first side surface of the quarter-wave plate. The first side surface of the partially reflective element is at least partially attached to the second side surface of the second lens.

[0112] In this embodiment, light rays from the image plane IMG pass sequentially through the second lens E2 and the quarter-wave plate QWP before reaching the reflective polarizing element RP. After being reflected by the reflective polarizing element RP, the light rays pass sequentially through the quarter-wave plate QWP and the second lens E2 before reaching the partial reflective element BS on the second side of the second lens. After being reflected by the partial reflective element BS, the light rays pass through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 before exiting.

[0113] Table 4 shows the basic structural parameters of the visual system in Embodiment 4, where the units for radius of curvature, thickness / distance, and effective focal length are millimeters (mm). In Table 4, light rays from the image plane IMG propagate from surface number 16 to surface number 0. Refraction / reflection refers to the refraction or reflection of light rays by the surface represented by that surface number. Surfaces 16 to 0 are, in order, the image plane, 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 polarizing element), 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 polarizing element), the first side surface of the reflective polarizing element (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 plane.

[0114] Table 4

[0115]

[0116]

[0117] In Embodiment 4, the first side surface of the first lens E1, the first side surface of the second lens E2, and the second side surface of the second lens E2 are aspherical surfaces. The shape of the aspherical surface can be defined using, but is not limited to, the formula (1) in Embodiment 1. Table 5 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surface in Embodiment 4.

[0118] Table 5

[0119] A4 9.4069E-06 -5.7697E-06 -9.4096E-08 A6 -7.6396E-08 9.1957E-09 1.9166E-09 A8 4.0434E-10 -3.2656E-12 9.4631E-13 A10 -1.2892E-12 -6.1694E-15 -1.0142E-15 A12 1.5579E-15 -1.8894E-18 -3.8759E-18 A14 1.7572E-18 -8.7148E-21 1.4701E-23 A16 -5.2893E-21 -4.1942E-24 -1.9017E-24 A18 1.7511E-24 1.9487E-26 5.9373E-27 A20 0.0000E+00 0.0000E+00 0.0000E+00

[0120] In this embodiment, moving the second element group changes the refractive power of the visual system, thereby achieving the desired effect. Figure 1 The first state (+2D state) shown transitions to Figure 2The second state (-5D state) is shown in Table 6. As shown in Table 6, some structural parameters of the visual system change. D1 represents the virtual image distance of the visual system in this embodiment. D2, D3, and D4 represent the distances on the optical axis from the second side of the quarter-wave plate to the first side of the second lens. When D1, D2, D3, and D4 are positive, the direction is from the first side to the second side. When they are negative, the direction is from the second side to the first side. The units of D1, D2, D3, and D4 are all millimeters (mm).

[0121] Table 6

[0122] +2D state 500.0000 13.8768 -13.8768 13.8768 -5D status -200.0000 9.2824 -9.2824 9.2824

[0123] Figure 12 and Figure 13 The MTF curves of the visual system of Embodiment 4 are shown in the first state (+2D state) and the second state (-5D state). The MTF values ​​under the light in each field of view are all above 0.8, showing good imaging quality.

[0124] Example 5

[0125] like Figure 14 and Figure 15 The image shows a visual system according to Embodiment 5 of this application. Figure 14 and Figure 15 The first and second states of the visual system in Embodiment 5 are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment 4, but different structural parameters. Please refer to the relevant description in Embodiment 4, which will not be repeated here.

[0126] Example 6

[0127] like Figure 16 and Figure 17 The image shows a visual system according to Embodiment Six of this application. Figure 16 and Figure 17 The first and second states of the visual system in Embodiment Six are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment Four, but different structural parameters. Please refer to the relevant description in Embodiment Four, which will not be repeated here.

[0128] Example 7

[0129] like Figure 18 and Figure 19 As shown, the structure of the visual system of Embodiment 7 of this application in the first state and the second state are described respectively.

[0130] like Figure 18 and Figure 19As shown, a first element group rests on a first lens barrel Pa, and at least a portion of a second element group rests on a second lens barrel Pb. The first element group, from the first side to the second side, sequentially includes a first lens E1, a polarizer LP, a reflective polarizing element RP, and a quarter-wave plate QWP. The second element group, from the first side to the second side, sequentially includes a second lens E2, a partially reflective element BS, and a display. It should be noted that in this embodiment, the first side end of the first lens barrel Pa extends towards the optical axis so that the first side surface of the first lens rests on the first lens barrel Pa. Therefore, the first lens E1, polarizer LP, reflective polarizing element RP, and quarter-wave plate QWP are assembled from the second side of the first lens barrel Pa. Simultaneously, the second side end of the second lens barrel Pb extends towards the optical axis so that the second side surface of the second lens rests on the second lens barrel Pb. Therefore, the second lens E2 and the partially reflective element BS are assembled from the first side of the second lens barrel Pb.

[0131] In this embodiment, 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 planar. The second lens also has positive optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is also convex. The visual system further includes an aperture stop STO located between the first side and the first element group. The first side surface of the polarizer is at least partially attached to the second side surface of the first lens. The second side surface of the polarizer is attached to the first side surface of the reflective polarizing element. The second side surface of the reflective polarizing element is attached to the first side surface of the quarter-wave plate. The first side surface of the partially reflective element is at least partially attached to the second side surface of the second lens.

[0132] In this embodiment, light rays from the image plane IMG pass sequentially through the second lens E2 and the quarter-wave plate QWP before reaching the reflective polarizing element RP. After being reflected by the reflective polarizing element RP, the light rays pass sequentially through the quarter-wave plate QWP and the second lens E2 before reaching the partial reflective element BS on the second side of the second lens. After being reflected by the partial reflective element BS, the light rays pass through the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the polarizer LP, and the first lens E1 before exiting.

[0133] Table 7 shows the basic structural parameters of the visual system in Embodiment 7, where the units for radius of curvature, thickness / distance, and effective focal length are millimeters (mm). In Table 7, light rays from the image plane IMG propagate from surface number 16 to surface number 0. Refraction / reflection refers to the refraction or reflection of light rays by the surface represented by that surface number. Surfaces 16 to 0 are, in order, the image plane, 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 polarizing element), 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 polarizing element), the first side surface of the reflective polarizing element (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 plane, and the virtual image plane.

[0134] Table 7

[0135] 0 spherical endless D1 refraction 1 Stabilizer (STO) spherical endless 12.0000 refraction 2 First lens (E1) aspherical 114.7076 4.4938 1.547 56.30 refraction 22.2070 3 spherical endless 0.0000 refraction 4 Polarizing filter (LP) spherical endless 0.0500 1.533 50.00 refraction 5 Reflective polarizing element (RP) spherical endless 0.0580 1.623 50.00 refraction 6 Quarter-wave plate (QWP) spherical endless 0.0510 1.533 50.00 refraction 7 spherical endless D2 refraction 8 Second lens (E2) aspherical 187.4054 5.5000 1.537 55.71 refraction 43.2855 9 Partial reflective element (BS) aspherical -171.1993 -5.5000 1.537 55.71 reflection 20.0340 10 aspherical 187.4054 D3 refraction 43.2855 11 spherical endless -0.0510 1.533 50.00 refraction 12 Reflective polarizing element (RP) spherical endless 0.0510 1.533 50.00 reflection 13 spherical endless D4 refraction 14 Second lens (E2) aspherical 187.4054 5.5000 1.537 55.71 refraction 43.2855 15 aspherical -171.1993 0.8944 refraction 20.0340 16 Image View (IMG) spherical endless 0.0000 refraction

[0136] In Embodiment Seven, the first side surface of the first lens E1, the first side surface of the second lens E2, and the second side surface of the second lens E2 are aspherical surfaces. The shape of the aspherical surface can be defined using, but is not limited to, the formula (1) in Embodiment One. Table 8 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surface in Embodiment Seven.

[0137] Table 8

[0138] A4 9.3242E-06 -6.4962E-06 -4.1904E-07 A6 -7.4332E-08 9.0578E-09 1.9971E-09 A8 4.0671E-10 -2.4633E-12 6.6200E-13 A10 -1.3835E-12 -6.7914E-15 -3.9865E-16 A12 1.9181E-15 -1.3212E-18 -3.3045E-18 A14 2.3531E-18 -6.1896E-21 -4.7899E-22 A16 -1.0580E-20 -2.2297E-24 -2.9618E-24 A18 8.4920E-24 6.9969E-27 5.6044E-27 A20 0.0000E+00 0.0000E+00 0.0000E+00

[0139] In this embodiment, moving the second element group changes the refractive power of the visual system, thereby achieving the desired effect. Figure 1 The first state (+2D state) shown transitions to Figure 2 The second state (-5D state) is shown in Table 9. As shown in Table 9, some structural parameters of the visual system change. D1 represents the virtual image distance of the visual system in this embodiment. D2, D3, and D4 represent the distances on the optical axis from the second side of the quarter-wave plate to the first side of the second lens. When D1, D2, D3, and D4 are positive, the direction is from the first side to the second side. When they are negative, the direction is from the second side to the first side. The units of D1, D2, D3, and D4 are all millimeters (mm).

[0140] Table 9

[0141] +2D state 500.0000 14.9529 -14.9529 14.9529 -5D status -200.0000 10.0523 -10.0523 10.0523

[0142] Figure 20 and Figure 21 The MTF curves of the visual system of Embodiment 7 are shown in the first state (+2D state) and the second state (-5D state). The MTF values ​​under the light of each field of view are all above 0.8, showing good imaging quality.

[0143] Example 8

[0144] like Figure 22 and Figure 23 The image shows a visual system according to Embodiment 8 of this application. Figure 22 and Figure 23 The first and second states of the visual system in Embodiment 8 are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment 7, but different structural parameters. Please refer to the relevant description in Embodiment 7, which will not be repeated here.

[0145] Example 9

[0146] like Figure 24 and Figure 25 The image shows a visual system according to Embodiment Nine of this application. Figure 24 and Figure 25 The first and second states of the visual system in Embodiment 9 are described respectively. The visual system in this embodiment has the same optical parameters as that in Embodiment 7, but different structural parameters. Please refer to the relevant description in Embodiment 7, which will not be repeated here.

[0147] In summary, embodiments one through nine of the visual system satisfy the relationships shown in Table 10. Specifically, the conditional expressions for the first and second states corresponding to each embodiment of the visual system have the same values.

[0148] Table 10

[0149] (La+Lb) / Δf 3.45 4.13 3.86 7.79 6.57 6.31 5.36 5.12 4.72 ΔL×(dam / dbs)(mm) 4.92 4.92 4.90 4.54 4.55 4.54 5.01 4.97 4.84 R3 / Dbs 3.58 3.55 3.55 3.24 3.21 3.38 3.10 3.12 3.08 La / (f1 / R1)(mm) 2.65 3.02 2.80 6.57 5.48 4.96 5.51 4.90 4.10 das / CT1 11.47 11.49 11.44 9.04 9.61 9.51 10.97 11.16 10.92 fz / (Das+Dam) 1.98 1.96 1.95 1.65 1.63 1.72 1.74 1.74 1.78 f2 / dbm 3.37 3.36 3.34 3.36 3.34 3.31 3.16 3.12 3.10 Dbm / CT2 11.28 11.44 11.24 8.98 9.05 9.11 10.49 10.41 10.58 Lb / BFL 5.78 7.22 6.82 10.67 9.11 9.38 6.53 6.97 7.28 (Dbs-Dbm) / ΔL 0.52 0.45 0.65 1.80 1.84 1.07 0.58 0.58 0.53 (Dam-dam) / Δf 1.10 1.31 1.02 2.15 2.15 2.15 1.40 1.32 1.01 La / EPD 1.23 1.41 1.30 3.00 2.50 2.27 2.52 2.24 1.87 Lb×(R3 / R4)(mm) -6.51 -8.13 -7.68 -11.90 -10.17 -10.47 -6.39 -6.83 -7.13 Das / La 11.22 9.81 10.84 4.61 5.58 5.89 5.72 6.53 7.65 (f1-f2) / Lb 10.28 8.23 8.71 3.03 3.54 3.44 7.23 6.77 6.48

[0150] Table 11 shows the effective focal length and some structural parameters of each lens and component group of the visual system in Examples 1 to 9, in mm.

[0151] Table 11

[0152] f1(mm) 224.4270 224.4270 224.4270 195.3480 195.3480 195.3480 209.6839 209.6839 209.6839 f2 (mm) 171.2776 171.2776 171.2776 166.4727 166.4727 166.4727 167.4742 167.4742 167.4742 fz(mm) 224.4270 224.4270 224.4270 195.3480 195.3480 195.3480 209.6839 209.6839 209.6839 EPD (mm) 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 BFL (mm) 0.8944 0.8944 0.8944 0.8944 0.8944 0.8944 0.8944 0.8944 0.8944 ΔL(mm) 4.9578 4.9578 4.9578 4.5944 4.5944 4.5944 4.9006 4.9006 4.9006 Δf(mm) 2.9296 2.9296 2.9296 2.7669 2.7669 2.7669 2.9695 2.9695 2.9695

[0153] Table 12 shows some structural parameters of the visual systems of Examples 1 to 9, in mm.

[0154] Table 12

[0155] das 50.861 50.980 50.732 45.192 48.062 47.564 49.307 50.133 49.088 dam 55.105 55.323 55.790 57.146 57.815 54.580 58.817 57.910 57.162 Das 55.254 55.261 56.483 55.411 55.934 53.367 57.614 58.440 57.395 Dam 58.339 59.166 58.764 63.100 63.769 60.533 62.978 61.827 60.173 dbs 55.571 55.802 56.475 57.795 58.410 55.211 57.538 57.080 57.833 dbm 50.831 51.050 51.286 49.478 49.810 50.270 53.032 53.649 54.101 Dbs 58.856 59.239 59.281 62.769 63.384 60.185 60.526 60.067 60.821 Dbm 56.260 57.029 56.046 54.490 54.924 55.282 57.697 57.238 58.210 La 4.925 5.631 5.210 12.013 10.016 9.067 10.080 8.953 7.498 Lb 5.171 6.460 6.102 9.540 8.152 8.388 5.839 6.237 6.514

[0156] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0157] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0158] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0159] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A visual system, characterized in that, The visual system comprises two lenses with optical power, and the visual system includes: An optical element group, comprising a first element group and a second element group, is provided along the optical axis of the visual system. The first element group, from a first side to a second side, sequentially includes a first lens, a polarizer, a reflective polarizing element, and a quarter-wave plate. 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 planar. The second element group, from a first side to a second side, sequentially includes a second lens, a partially reflective element, and a display. 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. The lens barrel assembly includes a first lens barrel and a second lens barrel, wherein the first element group rests on the first lens barrel, and at least a portion of the second element group rests on the second lens barrel; The second element group is capable of moving along the direction of the optical axis to move closer to or further away from the first element group; The maximum thickness La from the first side surface of the first lens barrel to the second side surface of the first lens barrel, the maximum thickness Lb from the first side surface of the second lens barrel to the second side surface of the second lens barrel, and the change in effective focal length Δf of the visual system moving from +2D state to -5D state satisfy the following: 3.45≤(La+Lb) / Δf≤7.79; When the visual system moves from a +2D state to a -5D state, the distance ΔL that the second element group moves along the optical axis, the inner diameter dam of the second side surface of the first lens barrel, and the inner diameter dbs of the first side surface of the second lens barrel satisfy the following condition: 4.54mm ≤ ΔL × (dam / dbs) ≤ 5.01mm; The outer diameter Dbm of the second side surface of the second lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy the following condition: 8.98≤Dbm / CT2≤11.

44.

2. The visual system according to claim 1, characterized in that, 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 lens barrel satisfy the following condition: 3.08≤R3 / Dbs≤3.

58.

3. The visual system according to claim 1, characterized in that, The maximum thickness La from the first side surface to the second side surface of the first lens barrel, the effective focal length f1 of the first lens, and the radius of curvature R1 of the first side surface of the first lens satisfy the following condition: 2.65mm≤La / (f1 / R1)≤6.57mm.

4. The visual system according to claim 1, characterized in that, The inner diameter das of the first side surface of the first lens barrel and the center thickness CT1 of the first lens on the optical axis satisfy the following condition: 9.04≤das / CT1≤11.

49.

5. The visual system according to claim 1, characterized in that, The combined focal length fz of the first lens, the polarizer, the reflective polarizing element, and the quarter-wave plate, the outer diameter Das of the first side surface of the first lens barrel, and the outer diameter Dam of the second side surface of the first lens barrel satisfy the following condition: 1.63≤fz / (Das+Dam)≤1.

98.

6. The visual system according to claim 1, characterized in that, The effective focal length f2 of the second lens and the inner diameter dbm of the second side surface of the second lens barrel satisfy the following condition: 3.10≤f2 / dbm≤3.

37.

7. The visual system according to claim 1, characterized in that, The maximum thickness Lb from the first side surface of the second lens barrel to 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 the following condition: 5.78≤Lb / BFL≤10.

67.

8. The visual system according to claim 1, characterized in that, The outer diameter Dbs of the first side surface of the second lens barrel, the outer diameter Dbm of the second side surface of the second 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 the following condition: 0.45≤(Dbs-Dbm) / ΔL≤1.

84.

9. The visual system according to claim 1, characterized in that, The outer diameter Dam of the second side surface of the first lens barrel, the inner diameter dam of the second side surface of the first lens barrel, and the change in effective focal length Δf of the visual system from +2D state to -5D state satisfy the following: 1.01≤(Dam-dam) / Δf≤2.

15.

10. The visual system according to claim 1, characterized in that, The maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfies the following relationship with the entrance pupil diameter EPD of the visual system: 1.23≤La / EPD≤3.

00.

11. The visual system according to claim 1, characterized in that, The maximum thickness Lb from the first side surface to the second side surface of the second lens barrel, 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: -11.90mm≤Lb×(R3 / R4)≤-6.39mm.

12. 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 maximum thickness La from the first side surface to the second side surface of the first lens barrel satisfy the following condition: 4.61≤Das / La≤11.

22.

13. The visual system according to claim 1, characterized in that, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the maximum thickness Lb from the first side surface to the second side surface of the second lens barrel satisfy the following condition: 3.03≤(f1-f2) / Lb≤10.28.

Images