Visual system

Abstract

The invention discloses a visual system. The visual system comprises a first lens cone and a second lens cone which are sequentially arranged from a first side to a second side along an optical axis, and a first lens group and a second lens group which are respectively supported on the two lens cones, the first lens group sequentially comprises a first lens, a reflective polarizing element and a quarter-wave plate, and the second lens group sequentially comprises a second lens, a partial reflection element and a third lens; the focal power of the first lens and the second lens is positive, the surface types of the first lens and the third lens are convex and concave-convex respectively, and the second side surface of the second lens is a convex surface; the second lens and the third lens are glued; the second lens group can move along the optical axis to be close to or far away from the display on the second side, so that the system is switched between the first state and the second state; the visual system satisfies the following conditional expressions: 0.33 < = (fz / f23) * (La / Lb) < = 1.10 and 0.75 mmlt; (dbs / dam) * [delta] flt; and the thickness is 1.95 mm.

Description

Technical Field

[0001] The present application relates to the field of optical devices, and in particular to a visual system. Background Art

[0002] With the introduction of the concept of the metaverse, virtual reality and augmented reality technologies for human-computer interaction have ushered in a second opportunity for development. As an important entrance to human-computer interaction, the visual system plays a key role in it. Early visual systems mainly used aspherical lenses or Fresnel lenses, which had a long body length and the user's center of gravity was forward when worn, thus affecting the user's experience.

[0003] The catadioptric optical system is a major innovation in the visual system itself. It reserves space for the overall design of virtual reality devices or augmented reality devices and has become a mainstream trend in research and development. The catadioptric optical system shortens the length of the visual system by bending the optical path, thereby moving the center of gravity of the virtual reality device or augmented reality device backward and improving the user experience.

[0004] However, the refractive powers of different individuals vary greatly, and the fixed-focus visual system is usually only suitable for some people, resulting in a poor user experience. At the same time, ghost interference is prone to occur between lenses, resulting in poor image quality. Summary of the invention

[0005] One aspect of the present application provides such a visual system, which may include a lens barrel group and a lens group, wherein the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the lens group includes a first lens group and a second lens group arranged in sequence from the first side to the second side along the optical axis; the first lens group is supported by the first lens barrel, and the second lens group is supported by the second lens barrel. The first lens group includes a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens, a partial reflective element and a third lens arranged in sequence from the first side to the second side along the optical axis; wherein the first lens has positive optical power, and its first side surface is convex, and the second side surface is flat; the second lens has positive optical power, and its second side surface is convex; the third lens has positive optical power or negative optical power, and its first side surface is concave, and the second side surface is convex; and the second lens is glued to the third lens. The second lens group is configured to be able to move along the optical axis to approach or move away from the display located on the second side, and enable the visual system to switch between the first state and the second state. The visual system can satisfy the conditional formula 0.33≤(fz / f23)×(La / Lb)≤1.10 and 0.75mm<(dbs / dam)×Δf<1.95mm, wherein fz is the combined focal length of the first lens, the reflective polarizing element and the quarter wave plate, f23 is the combined focal length of the second lens and the third lens, La is the maximum distance from the first side end face of the first lens barrel to the second side end face of the first lens barrel on the optical axis, Lb is the maximum distance from the first side end face of the second lens barrel to the second side end face of the second lens barrel on the optical axis, dbs is the inner diameter of the first side end face of the second lens barrel, dam is the inner diameter of the second side end face of the first lens barrel, and Δf is the change in the effective focal length of the visual system when it switches from the first state to the second state.

[0006] In one embodiment, the outer diameter Dbs of the first side end surface of the second lens barrel, the effective focal length f2 of the second lens and the center thickness CT2 of the second lens on the optical axis may satisfy: 2.25 mm <Dbs / (f2 / CT2)<3.5mm。

[0007] In one embodiment, the outer diameter Dam of the second side end surface of the first lens barrel, the center thickness CT1 of the first lens on the optical axis, the center thickness CTR of the reflective polarizing element on the optical axis, and the center thickness CTQ of the quarter-wave plate on the optical axis may satisfy: 8.45 <Dam / (CT1+CTR+CTQ)<9.35。

[0008] In one embodiment, the effective focal length f3 of the third lens, the center thickness CT3 of the third lens on the optical axis and the inner diameter dbm of the second side end surface of the second lens barrel may satisfy: 0.85 mm -1 ≤|f3 / CT3| / dbm≤1.92mm -1 .

[0009] In one embodiment, the radius of curvature R1 of the first side surface of the first lens and the maximum distance La from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel on the optical axis may satisfy: 12.39≤R1 / La≤16.77.

[0010] In one embodiment, the maximum distance Lb between the first side end surface of the second lens barrel and the second side end surface of the second lens barrel on the optical axis and the distance ΔL moved by the second lens group along the optical axis during the process of switching the visual system from the first state to the second state can satisfy: 2.95 <Lb / ΔL<3.35。

[0011] In one embodiment, the effective focal length f3 of the third lens and the outer diameter Dbm of the second side end surface of the second lens barrel may satisfy: 1.95<|f3| / Dbm<4.15.

[0012] In one embodiment, the inner diameter dbm of the second side end surface of the second lens barrel and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis may satisfy: 6.05≤dbm / Lb≤6.73.

[0013] In one embodiment, the refractive index N2 of the second lens, the refractive index N3 of the third lens and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis may satisfy: 6.55mm≤(N2 / N3)×Lb≤7.38mm.

[0014] In one embodiment, a maximum distance La from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel on the optical axis and a refractive index N1 of the first lens may satisfy: 2.43 mm≤La / N1≤2.83 mm.

[0015] In one embodiment, the inner diameter dbs of the first side end surface of the second lens barrel and the distance ΔL that the second lens group moves along the optical axis during the process of switching the visual system from the first state to the second state may satisfy: 21.35 <dbs / ΔL<21.7。

[0016] In one embodiment, the inner diameter das of the first side end surface of the first lens barrel, the effective focal length f1 of the first lens and the entrance pupil diameter EPD of the visual system may satisfy: 2.4 mm <das / (f1 / EPD)<3.0mm。

[0017] In one embodiment, the outer diameter Das of the first side end surface of the first lens barrel, the inner diameter das of the first side end surface of the first lens barrel, and the distance ΔL that the second lens group moves along the optical axis when the visual system switches from the first state to the second state may satisfy: 2.0<(Das-das) / ΔL<3.25.

[0018] In one embodiment, the outer diameter Dbm of the second side end surface of the second lens barrel, the outer diameter Das of the first side end surface of the first lens barrel and the change Δf of the effective focal length when the visual system switches from the first state to the second state may satisfy: 3.77≤(Dbm-Das) / Δf≤9.21.

[0019] The visual system disclosed in the present application includes a lens barrel group and a lens group. The lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the lens group includes a first lens group and a second lens group arranged in sequence from the first side to the second side along the optical axis; the first lens group is supported by the first lens barrel, and the second lens group is supported by the second lens barrel. The first lens group includes a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens, a partial reflection element and a third lens arranged in sequence from the first side to the second side along the optical axis; wherein the first lens has positive optical power, and its first side surface is convex and the second side surface is flat; the second lens has positive optical power and its second side surface is convex; the third lens has positive optical power or negative optical power, and its first side surface is concave and the second side surface is convex; and the second lens is glued to the third lens. The second lens group is configured to be able to move along the optical axis to approach or move away from the display located on the second side, and enable the visual system to switch between the first state and the second state. Through the above configuration of the visual system, and controlling the combined focal length fz of the first lens, the reflective polarizing element and the quarter-wave plate, the combined focal length f23 of the second lens and the third lens, the maximum distance La from the first side end face of the first lens barrel to its second side end face on the optical axis, and the maximum distance Lb from the first side end face of the second lens barrel to its second side end face on the optical axis to satisfy the condition 0.33≤(fz / f23)×(La / Lb)≤1.10, the inner diameter dbs of the first side end face of the second lens barrel, the inner diameter dam of the second side end face of the first lens barrel and the change Δf of the effective focal length when the visual system switches from the first state to the second state satisfy the condition 0.75mm<(dbs / dam)×Δf<1.95mm, the visual system can realize the adjustment of the refractive power from the +2D state (first state) to the -5D state (second state), and can also help reduce the stray light interference at the side wall of the first lens barrel, ensuring that users can obtain clear images under different visual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0021] Figure 1 A schematic diagram showing the structure and some parameters of a visual system according to an exemplary embodiment of the present application is shown;

[0022] Figure 2 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 1 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0023] Figure 3 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 2 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0024] Figure 4 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 3 of the present application when it is in the first state (+2D state) and the second state (-5D state);

[0025] Figure 5 The figure shows the MTF (Modulation Transfer Function) diagram when the visual system according to Embodiment 1, Embodiment 2 and Embodiment 3 of the present application is in the first state (+2D state);

[0026] Figure 6 The MTF diagrams when the visual systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of the present application are in the second state (-5D state) are shown;

[0027] Figure 7 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 4 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0028] Figure 8 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 5 of the present application when it is in the first state (+2D state) and the second state (-5D state);

[0029] Fig. 9 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 6 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0030] Fig.10 The MTF diagrams when the visual systems according to Embodiment 4, Embodiment 5 and Embodiment 6 of the present application are in the first state (+2D state) are shown;

[0031] Fig.11 The MTF diagrams when the visual systems according to Embodiment 4, Embodiment 5 and Embodiment 6 of the present application are in the second state (-5D state) are shown;

[0032] Fig.12The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 7 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0033] Fig.13 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 8 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0034] Fig.14 The left figure and the right figure in the figure respectively show the structural schematic diagrams of the visual system according to Example 9 of the present application when they are in the first state (+2D state) and the second state (-5D state);

[0035] Fig.15 The MTF diagrams when the visual systems according to Embodiment 7, Embodiment 8 and Embodiment 9 of the present application are in the first state (+2D state) are shown;

[0036] Fig.16 The MTF diagrams when the visual systems according to Embodiment 7, Embodiment 8 and Embodiment 9 of the present application are in the second state (-5D state) are shown;

[0037] Fig.17 A stray light simulation diagram is shown according to an exemplary visual system of the present application when the conditional formula (fz / f23)×(La / Lb)=0.1 and (dbs / dam)×Δf=0.3mm is satisfied;

[0038] Fig.18 A stray light simulation diagram is shown according to an exemplary visual system of the present application when the conditional formula (fz / f23)×(La / Lb)=1.5 and (dbs / dam)×Δf=2.5mm is satisfied;

[0039] Fig.19 A stray light simulation diagram is shown for an exemplary visual system according to the present application when the conditional formulas (fz / f23)×(La / Lb)=0.81 and (dbs / dam)×Δf=1.57 mm are satisfied. DETAILED DESCRIPTION

[0040] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0042] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0043] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position 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 concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0044] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0045] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0046] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0047] The features, principles and other aspects of the present application are described in detail below.

[0048] The visual system according to the exemplary embodiment of the present application may include a lens barrel group and a lens group, the lens barrel group may include a first lens barrel and a second lens barrel; the lens group may include a first lens group and a second lens group. The first lens barrel and the second lens barrel may be arranged in sequence from the first side to the second side along the optical axis; the first lens group and the second lens group may be arranged in sequence from the first side to the second side along the optical axis.

[0049] In an exemplary embodiment, the first lens group may be supported on or assembled to the first lens barrel; and the second lens group may be supported on or assembled to the second lens barrel.

[0050] In an exemplary embodiment, the first lens group may include a first lens, a reflective polarizing element, and a quarter wave plate. Exemplarily, the first lens, the reflective polarizing element, and the quarter wave plate may be arranged in sequence from the first side to the second side along the optical axis.

[0051] In an exemplary embodiment, the reflective polarizing element may be disposed on or attached to the second side surface of the first lens; the quarter wave plate may be disposed on or attached to the second side surface of the reflective polarizing element. Exemplarily, the first side surface of the reflective polarizing element may at least partially conform to the second side surface of the first lens; the first side surface of the quarter wave plate may at least partially conform to the second side surface of the reflective polarizing element.

[0052] In an exemplary embodiment, the second lens group may include a second lens, a partially reflecting element, and a third lens. Exemplarily, the second lens, the partially reflecting element, and the third lens may be arranged in sequence from the first side to the second side along the optical axis.

[0053] In an exemplary embodiment, the second lens and the third lens may be cemented to form a cemented lens. Specifically, the second lens, the partial reflective element and the third lens may be cemented to form a cemented lens.

[0054] In an exemplary embodiment, the first lens may have positive optical power, its first side surface may be convex, and its second side surface may be flat.

[0055] In an exemplary embodiment, the second lens may have positive power, a first side surface thereof may be convex or concave, and a second side surface thereof may be convex.

[0056] In exemplary embodiments, the third lens may have positive or negative power, a first side surface thereof may be a concave surface, and a second side surface thereof may be a convex surface.

[0057] The light path can be folded back by rationally setting the structure of the visual system, which can effectively shorten the length of the visual system, reduce the volume and weight of the visual system, and make the visual system lighter. The setting of the cemented lens provides the system with a high-quality lens material with the advantages of lightness, good light transmittance, and wear resistance. It is more suitable for the lens manufacturing of VR equipment and can improve the quality and adaptability of the lens.

[0058] It can be understood that, in the direction along the optical axis, the surface of each element or structure in the visual system close to the first side and away from the second side can be the first side of the element or structure, and the surface of each element close to the second side and away from the first side can be the second side of the element or structure. The first side and the second side of the element or structure can be, for example, perpendicular to the optical axis.

[0059] In an exemplary embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. The visual system may be used in, for example, a variety of VR devices or apparatuses.

[0060] In an exemplary embodiment, the distance on the optical axis of the first lens group (or the first lens group and the first lens barrel) relative to the display or image surface on the second side of the visual system can be fixed. The second lens group (or the second lens group and the second lens barrel) can be configured to be able to move along the optical axis to approach or move away from the display or image surface on the second side of the visual system, and enable the visual system to switch between the first state and the second state. Specifically, when the second lens group (or the second lens group and the second lens barrel) moves to the position closest to the display or image surface, the distance between the second lens group and the first lens group on the optical axis is the largest, and the visual system can be in a +2D state, that is, the first state; when the second lens group (or the second lens group and the second lens barrel) moves to the position farthest from the display or image surface, the distance between the second lens group and the first lens group on the optical axis is the smallest, and the visual system can be in a -5D state, that is, the second state.

[0061] Exemplarily, when the visual system is in the first state, the diopter of the visual system is +2D, for example, it is applicable to users with a diopter of +2D; when the visual system is in the second state, the diopter of the visual system is -5D, for example, it is applicable to users with a diopter of -5D. Wherein, when the sign of the diopter is a negative sign, it may indicate that the user is a myopic user; when the sign of the diopter is a positive sign, it may indicate that the user is a hyperopic user; the specific value of the diopter may indicate the diopter of the user. For example, a diopter of +1D may indicate that the user's hyperopia is approximately 100 degrees, and a diopter of -1D may indicate that the user's myopia is approximately 100 degrees.

[0062] It should be understood that, in addition to the first state and the second state, the visual system according to the embodiment of the present application may also have other states, for example, between -5D and +2D. The visual system according to the embodiment of the present application can achieve continuous zooming within the range of -5D to +2D, which can meet the needs of users with different vision, so that users can enjoy the VR experience without wearing glasses.

[0063] In an exemplary embodiment, the visual system of the present application may include at least one aperture. The aperture may constrain the optical path and control the light intensity. The aperture may be set at an appropriate position of the visual system as required, for example, the aperture may be located between the first side (e.g., the human eye side) and the first lens.

[0064] In an exemplary embodiment, the visual system has different virtual image distances VID in the first state and the second state, and the virtual image distance may be, for example, the distance from the virtual image formed by the image light from the second side at a predetermined position to the aperture on the optical axis, wherein VID=1000 / diopter.

[0065] In an exemplary embodiment, the visual system of the present application may satisfy the conditional formula 0.33≤(fz / f23)×(La / Lb)≤1.10, wherein fz is the combined focal length of the first lens, the reflective polarizing element, and the quarter wave plate, f23 is the combined focal length of the second lens and the third lens, La is the maximum distance on the optical axis from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel, and Lb is the maximum distance on the optical axis from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel. It can be understood that the first side end surface of the lens barrel may be the end surface or surface of the lens barrel that is closest to the first side and is perpendicular or approximately perpendicular to the optical axis; the second side end surface of the lens barrel may be the end surface or surface of the lens barrel that is closest to the second side and is perpendicular or approximately perpendicular to the optical axis.

[0066] In an exemplary embodiment, the visual system of the present application can satisfy the condition 0.75mm<(dbs / dam)×Δf<1.95mm, wherein dbs is the inner diameter of the first side end surface of the second lens barrel, dam is the inner diameter of the second side end surface of the first lens barrel, and Δf is the change in the effective focal length of the visual system when it switches from the +2D state to the -5D state.

[0067] The visual system provided according to the exemplary embodiment of the present application includes a lens barrel group and a lens group, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the lens group includes a first lens group and a second lens group arranged in sequence from the first side to the second side along the optical axis; the first lens group is supported by the first lens barrel, and the second lens group is supported by the second lens barrel. The first lens group includes a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens, a partial reflection element and a third lens arranged in sequence from the first side to the second side along the optical axis; wherein the first lens has positive optical power, and its first side is convex and the second side is flat; the second lens has positive optical power and its second side is convex; the third lens has positive optical power or negative optical power, and its first side is concave and the second side is convex; and the second lens is glued to the third lens. The second lens group is configured to be able to move along the optical axis to approach or move away from the display located on the second side, and to switch the visual system between the first state and the second state. Through the above configuration of the visual system, and controlling the combined focal length fz of the first lens, the reflective polarizing element and the quarter-wave plate, the combined focal length f23 of the second lens and the third lens, the maximum distance La from the first side end face of the first lens barrel to its second side end face on the optical axis, and the maximum distance Lb from the first side end face of the second lens barrel to its second side end face on the optical axis to satisfy the condition 0.33≤(fz / f23)×(La / Lb)≤1.10, the inner diameter dbs of the first side end face of the second lens barrel, the inner diameter dam of the second side end face of the first lens barrel and the change Δf of the effective focal length when the visual system switches from the first state to the second state satisfy the condition 0.75mm<(dbs / dam)×Δf<1.95mm, the visual system can realize the adjustment of the refractive power from the +2D state (first state) to the -5D state (second state), and can also help reduce the stray light interference at the side wall of the first lens barrel, ensuring that users can obtain clear images under different visual needs.

[0068] In an exemplary embodiment, the lens group and the lens barrel group of the visual system are configured as described above, and by setting the above two conditional expressions (fz / f23)×(La / Lb) and (dbs / dam)×Δf to satisfy different numerical ranges, the following three different visual system solutions can be formed:

[0069] In the visual system 1 of the first scheme, the above two conditional expressions (fz / f23)×(La / Lb) and (dbs / dam)×Δf respectively satisfy (fz / f23)×(La / Lb)=0.1 and (dbs / dam)×Δf=0.3mm. It can be seen that the values ​​of the two conditional expressions are relatively small, which are respectively smaller than the lower limit values ​​of the range defined by the conditional expressions 0.33≤(fz / f23)×(La / Lb)≤1.10 and 0.75mm<(dbs / dam)×Δf<1.95mm. The stray light diagram of the imaging effect of the visual system 1 is shown in FIG. Fig.17 As shown by Fig.17 It can be seen that this scheme has a lot of stray light. For example, the side wall of the first lens barrel is prone to produce reflected stray light, and the intensity of stray light is relatively high, reaching 1.3E-05, which has a great impact on the imaging effect.

[0070] In the visual system 2 of the second scheme, the above two conditional expressions (fz / f23)×(La / Lb) and (dbs / dam)×Δf respectively satisfy (fz / f23)×(La / Lb)=1.5 and (dbs / dam)×Δf=2.5mm. It can be seen that the values ​​of the two conditional expressions are relatively large, which are respectively greater than the upper limit values ​​of the range limited by the conditional expressions 1.11≤0.33≤(fz / f23)×(La / Lb)≤1.10 and 0.75mm<(dbs / dam)×Δf<1.95mm. The stray light diagram of the imaging effect of the visual system 2 is shown in FIG. Fig.18 As shown by Fig.18 It can be seen that this solution also has a lot of stray light. For example, the side wall of the first lens barrel is prone to generate reflected stray light, and the intensity of the stray light is relatively high, reaching 8.4E-06, which has a greater impact on the imaging effect.

[0071] In the visual system 3 of the third scheme, the above two conditional expressions (fz / f23)×(La / Lb) and (dbs / dam)×Δf respectively satisfy (fz / f23)×(La / Lb)=0.81 and (dbs / dam)×Δf=1.57mm. It can be seen that the values ​​of the two conditional expressions are respectively within the range defined by the conditional expressions 0.33≤(fz / f23)×(La / Lb)≤1.10 and 0.75mm<(dbs / dam)×Δf<1.95mm, and the values ​​are relatively reasonable. The stray light diagram of the imaging effect of the visual system 3 is shown in FIG. Fig.19 As shown by Fig.19 It can be seen that this solution has less system stray light, which can effectively reduce the stray light interference generated at locations such as the side wall of the first lens barrel. The stray light intensity is also significantly reduced to 2.9E-06, which has little impact on the imaging effect of the system and is beneficial to improving the clarity of the image.

[0072] Therefore, the visual system according to the present application, through reasonable configuration and control of the system to meet the conditional expressions 0.33 ≤ (fz / f23) × (La / Lb) ≤ 1.10 and 0.75 mm < (dbs / dam) × Δf < 1.95 mm, can not only enable the visual system to adjust the diopter between the +2D state and the -5D state, but also effectively reduce the interference of stray light at positions such as the side wall of the first lens barrel on the imaging system, which is beneficial to improving the imaging clarity and ensuring that users can obtain clear images under different visual requirements.

[0073] In an exemplary embodiment, the outer diameter Dbs of the first side end face of the second lens barrel, the effective focal length f2 of the second lens, and the central thickness CT2 of the second lens on the optical axis may satisfy: 2.25 mm < Dbs / (f2 / CT2) < 3.5 mm. By controlling this conditional expression, making the value of the conditional expression less than the upper limit can ensure that the overall thickness of the machine does not increase, which is beneficial to ensuring the user experience. At the same time, controlling the value of the conditional expression to be greater than the lower limit can ensure that the second lens has good processability.

[0074] In an exemplary embodiment, the outer diameter Dam of the second side end face of the first lens barrel, the central thickness CT1 of the first lens on the optical axis, the central thickness CTR of the reflective polarizing element on the optical axis, and the central thickness CTQ of the quarter-wave plate on the optical axis may satisfy: 8.45 < Dam / (CT1 + CTR + CTQ) < 9.35. By controlling this conditional expression, making the value of the conditional expression less than the upper limit is beneficial to ensuring the adhesion effect of the reflective polarizing element and the quarter-wave plate on the surface of the first lens, reducing the generation of bubbles, wrinkles, orange peel, etc. At the same time, controlling the value of the conditional expression to be greater than the lower limit can effectively prevent the situation where the light reflection position of the actual module deviates from the theoretical design position, which is beneficial to ensuring and improving the overall performance of the machine.

[0075] In an exemplary embodiment, the effective focal length f3 of the third lens, the central thickness CT3 of the third lens on the optical axis, and the inner diameter dbm of the second side end face of the second lens barrel may satisfy: 0.85 mm -1 ≤ |f3 / CT3| / dbm ≤ 1.92 mm -1 . By controlling this conditional expression, it can ensure that the third lens has good processability and at the same time ensure that the overall thickness of the machine does not increase, thereby ensuring the user experience.

[0076] In an exemplary embodiment, the radius of curvature R1 of the first side surface of the first lens and the maximum distance La on the optical axis from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel may satisfy: 12.39 ≤ R1 / La ≤ 16.77. By controlling this conditional expression, the radius of curvature of the first side surface of the first lens is positive, which can ensure the convergence of light rays; at the same time, controlling the ratio of the conditional expression within the above range can also ensure good machinability of the first lens barrel.

[0077] In an exemplary embodiment, the maximum distance Lb on the optical axis from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel and the distance ΔL that the second lens group moves along the optical axis during the process of the visual system switching from the first state to the second state may satisfy: 2.95 < Lb / ΔL < 3.35. By controlling this conditional expression, it is beneficial to ensure that the visual system can accurately control the gear subdivision from +2D to -5D during the focusing process, and at the same time, it can prevent the module from moving too far during the focusing process, avoid the extension length of the module from being too long, ensure that the maximum thickness of the whole machine will not be too large, and thus is beneficial to ensuring the user experience.

[0078] In an exemplary embodiment, the effective focal length f3 of the third lens and the outer diameter Dbm of the second side end surface of the second lens barrel may satisfy: 1.95 < |f3| / Dbm < 4.15. By controlling this conditional expression, it can ensure that the strength of the second lens barrel meets the requirements, and thus is beneficial to ensuring the mechanical performance of the module.

[0079] In an exemplary embodiment, the inner diameter dbm of the second side end surface of the second lens barrel and the maximum distance Lb on the optical axis from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel may satisfy: 6.05 ≤ dbm / Lb ≤ 6.73. By controlling this conditional expression, it can ensure that the second lens barrel has sufficient wall thickness and strength, which is beneficial to ensuring the mechanical performance of the module; at the same time, it can also avoid the influence of the lens barrel on the light incident system and ensure the incidence of effective light rays of the system.

[0080] In an exemplary embodiment, the refractive index N2 of the second lens, the refractive index N3 of the third lens and the maximum distance Lb on the optical axis from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel may satisfy: 6.55 mm ≤ (N2 / N3)×Lb ≤ 7.38 mm. By controlling this conditional expression, it can not only prevent the increase in the thickness of the whole machine and ensure the user experience, but also ensure that the second lens barrel has sufficient mechanical strength.

[0081] In an exemplary embodiment, the maximum distance La on the optical axis from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel and the refractive index N1 of the first lens may satisfy: 2.43 mm ≤ La / N1 ≤ 2.83 mm. By controlling this conditional expression, the mechanical strength of the first lens barrel can be ensured under the reasonable selection of the first lens material.

[0082] In an exemplary embodiment, the inner diameter dbs of the first side end face of the second lens barrel and the distance ΔL that the second lens group moves along the optical axis during the process of the visual system switching from the first state to the second state may satisfy: 21.35 < dbs / ΔL < 21.7. By controlling this conditional expression, it is beneficial to ensure that the second lens barrel has sufficient wall thickness and strength during the process of the second lens group moving to achieve system focusing, which is beneficial to ensuring the stability of the system.

[0083] In an exemplary embodiment, the inner diameter das of the first side end face of the first lens barrel, the effective focal length f1 of the first lens, and the entrance pupil diameter EPD of the visual system may satisfy: 2.4 mm < das / (f1 / EPD) < 3.0 mm. By controlling this conditional expression, the light entering the system can be reasonably controlled, preventing too much light from entering, avoiding the generation of excessive stray light, and being beneficial to improving the imaging quality of the system.

[0084] In an exemplary embodiment, the outer diameter Das of the first side end face of the first lens barrel, the inner diameter das of the first side end face of the first lens barrel, and the distance ΔL that the second lens group moves along the optical axis during the process of the visual system switching from the first state to the second state may satisfy: 2.0 < (Das - das) / ΔL < 3.25. By controlling this conditional expression, it is beneficial to ensure that the first lens barrel has sufficient strength, which is beneficial to improving the mechanical performance of its module.

[0085] In an exemplary embodiment, the outer diameter Dbm of the second side end face of the second lens barrel, the outer diameter Das of the first side end face of the first lens barrel, and the change amount Δf of the effective focal length during the process of the visual system switching from the first state to the second state may satisfy: 3.77 ≤ (Dbm - Das) / Δf ≤ 9.21. By controlling this conditional expression, it not only ensures that the outer shape of the first lens barrel is smaller than that of the second lens barrel, facilitating assembly; at the same time, it limits the difference in their outer shapes within a reasonable range, which is beneficial to reducing the design difficulty of the diopter adjustment structure of the system.

[0086] The second aspect of the present application provides such a visual system, by setting a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis, and a first lens group and a second lens group arranged in sequence from the first side to the second side along the optical axis, and setting the first lens group to bear on the first lens barrel, and the second lens group to bear on the second lens barrel; and further setting the first lens group to include a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis, and the second lens group to include a second lens, a partial reflection element and a third lens arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, and its first side surface is convex, and the second side surface is flat; the second lens has positive optical power, and its second side surface is convex; the third lens has positive optical power or negative optical power, and its first side surface is concave, and the second side surface is convex; and the second lens and the third lens are mutually glued glued lenses; and the second lens group is configured to be able to move along the optical axis to approach or move away from a display located on the second side, so that the visual system switches between the first state and the second state. At the same time, the combined focal length fz of the first lens, the reflective polarizing element and the quarter-wave plate, the combined focal length f23 of the second lens and the third lens, the maximum distance La from the first side end face of the first lens barrel to the second side end face thereof on the optical axis and the maximum distance Lb from the first side end face of the second lens barrel to the second side end face thereof on the optical axis are controlled to satisfy: 0.33≤(fz / f23)×(La / Lb)≤1.10; the outer diameter Dbm of the second side end face of the second lens barrel, the outer diameter Das of the first side end face of the first lens barrel and the visual system are determined by the first The change Δf of the effective focal length when switching from the first state to the second state satisfies: 3.77≤(Dbm-Das) / Δf≤9.21; the visual system can be adjusted in diopter from +2D state (first state) to -5D state (second state), thereby enabling users to obtain clear images under different visual requirements; it can also ensure that the shape of the first lens barrel is smaller than the second lens barrel for easy assembly, while limiting the difference in shape between the two within a reasonable range, which can help reduce the design difficulty of the diopter adjustment structure of the system.

[0087] According to the visual system of the exemplary embodiment of the present application, a three-piece folding structure is adopted, for example. Through the reasonable setting of the system structure such as the lens barrel and the lens group, and the reasonable configuration of multiple parameters of the system structure and components, not only the total optical length can be reduced, the system weight can be reduced, the system can be miniaturized and lightweight, and the user comfort can be improved; it can also achieve zooming in the range of -5D to +2D through the movement of the second lens group to meet the needs of users with different vision, and users can enjoy the VR experience without wearing glasses; at the same time, it can also effectively reduce the stray light interference generated at the side wall of the first lens barrel and other positions, which is beneficial to improving the imaging quality and ensuring that users can obtain clear images under different visual needs; in addition, the use of cemented lenses in the system has the advantages of lightness, good light transmittance, wear resistance, etc., and is more suitable for the lens manufacturing of VR equipment, improving the quality and adaptability of the lenses.

[0088] In addition, the present application also provides a VR device, which may include the visual system provided by any of the above-mentioned embodiments, wherein the first side may be the human eye side, and the second side may be the display / image surface side. The VR device can achieve continuous zoom in the range of -5D to +2D, allowing users with different vision conditions to clearly enjoy the VR experience without wearing glasses, and at the same time has the characteristics of miniaturization, light weight, high imaging quality and stable performance, thereby improving the user experience.

[0089] Example 1

[0090] The following reference Figure 2 Describe the visual system according to Example 1 of the present application. Figure 2 The middle left figure shows a schematic diagram of the structure of the visual system according to Example 1 of the present application when it is in the first state (+2D state). Figure 2 The middle right figure shows a schematic diagram of the structure of the visual system according to Example 1 of the present application when it is in the second state (-5D state).

[0091] like Figure 2 As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0092] In this embodiment, the first lens E1 has positive focal power, its first side surface S3 is convex, and its second side surface S4 is a plane. The second lens E2 has positive focal power, its first side surface S13 is convex, and its second side surface S14 is convex. The third lens E3 has negative focal power, its first side surface S14 is concave, and its second side surface S15 is convex. The reflective polarizing element RP is disposed on the second side surface of the first lens E1, and the quarter wave plate QWP is disposed on the second side surface of the reflective polarizing element RP. The second lens E2 and the third lens E3 are cemented lenses that are cemented to each other.

[0093] In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Figure 2 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the +2D state. Figure 2 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in a -5D state.

[0094] Table 1 shows the basic parameter table of the visual system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0095]

[0096]

[0097] Table 1

[0098] The parameters D1 to D5 in Table 1 can be understood as follows: D5 can be understood as the value taken along the optical axis from the first side of the filter and / or protective glass IR / CG arranged on the first side of the image plane IMG to the second side of the third lens E3; D4 can be understood as the value taken along the optical axis from the first side of the second lens E2 to the second side of the quarter-wave plate QWP; D3 can be understood as the value taken along the optical axis from the second side of the quarter-wave plate QWP to the first side of the second lens E2; D2 can be understood as the value taken along the optical axis from the first side of the second lens E2 to the second side of the quarter-wave plate QWP; D1 can be understood as the value of the virtual image distance of the visual system according to this embodiment. In the process of realizing zooming by moving the second lens group and the second lens barrel Pb along the optical axis, the values ​​of the above parameters D1 to D5 will change accordingly. The visual system is Figure 2 The +2D state shown in the middle left figure and Figure 2 The values ​​of parameters D1 to D5 in the -5D state shown in the middle right figure are shown in Table 2 below.

[0099] D1 D2 D3 D4 D5 +2D Status 500.0000 2.7097 -2.7097 2.7097 1.0000 -5D state -200.0000 0.5000 -0.5000 0.5000 3.2097

[0100] Table 2

[0101] In this embodiment, the first side surface S3 of the first lens E1, the first side surface S13 and the second side surface S14 of the second lens E2, and the first side surface S14 and the second side surface S15 of the third lens E3 are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0102]

[0103] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 3 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspheric surface S3 and S13-S15 in Example 1.

[0104]

[0105]

[0106] Table 3

[0107] Referring to Table 10, according to the visual system of this embodiment, the values ​​of its multiple structural parameters are respectively shown in the column of 'Example 1' in Table 10, wherein das is the inner diameter of the first side end face of the first lens barrel Pa, dam is the inner diameter of the second side end face of the first lens barrel Pa, Das is the outer diameter of the first side end face of the first lens barrel Pa, Dam is the outer diameter of the second side end face of the first lens barrel Pa, dbs is the inner diameter of the first side end face of the second lens barrel Pb, dbm is the inner diameter of the second side end face of the second lens barrel Pb, Dbs is the outer diameter of the first side end face of the second lens barrel Pb, Dbm is the outer diameter of the second side end face of the second lens barrel Pb, La is the maximum distance from the first side end face of the first lens barrel Pa to its second side end face on the optical axis, and Lb is the maximum distance from the first side end face of the second lens barrel Pb to its second side end face on the optical axis. According to the visual system of this embodiment, the values ​​of the above structural parameters correspond to each other in the two different focal length states of +2D and -5D. The units of the above parameters shown in Table 10 are all millimeters (mm), and the schematic diagram of the above parameters in the visual system structure diagram can be referred to Figure 1 .

[0108] Example 2

[0109] The following reference Figure 3 Describe the visual system according to Example 2 of the present application.

[0110] like Figure 3 As shown, similar to the visual system in Example 1, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0111] Similar to Embodiment 1, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Figure 3The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Figure 3 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0112] The basic parameter table of the visual system of this embodiment is the same as Table 1 in Example 1, the numerical values ​​of parameters D1 to D5 are the same as Table 2 in Example 1, and the high-order coefficient table of the aspheric mirror surface is the same as Table 3 in Example 1.

[0113] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 2' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0114] Example 3

[0115] The following reference Figure 4 Describe the visual system according to Example 3 of the present application.

[0116] like Figure 4 As shown, similar to the visual system in Example 1, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0117] Similar to Embodiment 1, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Figure 4The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Figure 4 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0118] The basic parameter table of the visual system of this embodiment is also the same as Table 1 in Example 1, the values ​​of parameters D1 to D5 are also the same as Table 2 in Example 1, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 3 in Example 1.

[0119] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 3' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0120] Figure 5 The MTF curves of the visual systems of Embodiment 1, Embodiment 2 and Embodiment 3 when they are in the +2D state are shown. Figure 6 The MTF curves of the visual systems of Example 1, Example 2 and Example 3 when they are in the -5D state are shown. The MTF (Modulation Transfer Function) curve can represent the optical modulation function values ​​corresponding to different spatial frequencies. Figure 5 and Figure 6 It can be seen that the visual systems provided in Example 1, Example 2 and Example 3 can achieve good imaging quality in two different focal length states of +2D and -5D.

[0121] Example 4

[0122] The following reference Figure 7 Describe the visual system according to Example 4 of the present application. Figure 7 The middle left figure shows a schematic diagram of the structure of the visual system according to Example 4 of the present application when it is in the first state (+2D state). Figure 7 The middle right figure shows a schematic diagram of the structure of the visual system according to Example 4 of the present application when it is in the second state (-5D state).

[0123] like Figure 7As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0124] In this embodiment, the first lens E1 has positive focal power, its first side surface S3 is convex, and the second side surface S4 is a plane. The second lens E2 has positive focal power, its first side surface S13 is convex, and the second side surface S14 is convex. The third lens E3 has positive focal power, its first side surface S14 is concave, and the second side surface S15 is convex. The reflective polarizing element RP is disposed on the second side surface of the first lens E1, and the quarter wave plate QWP is disposed on the second side surface of the reflective polarizing element RP. The second lens E2 and the third lens E3 are cemented lenses that are cemented to each other.

[0125] In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Figure 7 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the +2D state. Figure 7 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in a -5D state.

[0126] Table 4 shows the basic parameter table of the visual system of Example 4, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0127]

[0128] Table 4

[0129] According to this embodiment, when the visual system is in the +2D state and the -5D state respectively, the values ​​of the parameters D1 to D5 in Table 4 are respectively shown in Table 5 below. The meanings of the parameters D1 to D5 can refer to the description in Example 1.

[0130] D1 D2 D3 D4 D5 +2D Status 500.0000 2.7219 -2.7219 2.7219 1.0000 -5D state -200.0000 0.5006 -0.5006 0.5006 3.2213

[0131] Table 5

[0132] In this embodiment, the first side surface S3 of the first lens E1, the first side surface S13 and the second side surface S14 of the second lens E2, and the first side surface S14 and the second side surface S15 of the third lens E3 are all aspherical surfaces. Table 6 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 of the aspherical surfaces S3 and S13-S15 that can be used in Embodiment 4, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above Embodiment 1.

[0133] Coefficient\Surface S3 S13 S14 S15 A4 -2.9247E-06 1.2102E-05 2.3863E-06 6.3263E-06 A6 1.6227E-08 -3.2768E-08 -1.5857E-09 -6.2153E-08 A8 -4.0928E-11 -2.2534E-12 -1.1040E-11 6.2266E-11 A10 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A12 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A14 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A16 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A18 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A20 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0134] Table 6

[0135] Referring to Table 10, the values ​​of the structural parameters of the visual system of this embodiment are respectively shown in the 'Example 4' column in Table 10, wherein the specific description of the meaning represented by each parameter is the same as that in the above Example 1 and will not be repeated here.

[0136] Example 5

[0137] The following reference Figure 8 Describe the visual system according to Example 5 of the present application.

[0138] like Figure 8 As shown, similar to the visual system in Example 4, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0139] Similar to Embodiment 4, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Figure 8 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Figure 8 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0140] The basic parameter table of the visual system of this embodiment is the same as Table 4 in Example 4, the numerical values ​​of parameters D1 to D5 are the same as Table 5 in Example 4, and the high-order coefficient table of the aspheric mirror surface is the same as Table 6 in Example 4.

[0141] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 5' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0142] Example 6

[0143] The following reference Fig. 9 Describe the visual system according to Example 6 of the present application.

[0144] like Fig. 9 As shown, similar to the visual system in Example 4, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0145] Similar to Embodiment 4, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Fig. 9 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Fig. 9 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0146] The basic parameter table of the visual system of this embodiment is also the same as Table 4 in Example 4, the values ​​of parameters D1 to D5 are also the same as Table 5 in Example 4, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 6 in Example 4.

[0147] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 6' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0148] Fig.10 The MTF curves of the visual systems of Embodiment 4, Embodiment 5 and Embodiment 6 when they are in the +2D state are shown. Fig.11 The MTF curves of the visual systems of Embodiments 4, 5 and 6 when they are in the -5D state are shown. Fig.10 and Fig.11 It can be seen that the visual systems provided in Example 4, Example 5 and Example 6 can achieve good imaging quality in two different focal length states of +2D and -5D.

[0149] Example 7

[0150] The following reference Fig.12 Describe the visual system according to Example 7 of the present application. Fig.12 The middle left figure shows a schematic diagram of the structure of the visual system according to Example 7 of the present application when it is in the first state (+2D state). Fig.12 The middle right figure shows a schematic diagram of the structure of the visual system according to Example 7 of the present application when it is in the second state (-5D state).

[0151] like Fig.12 As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0152] In this embodiment, the first lens E1 has positive focal power, its first side surface S3 is convex, and the second side surface S4 is a plane. The second lens E2 has positive focal power, its first side surface S13 is concave, and the second side surface S14 is convex. The third lens E3 has positive focal power, its first side surface S14 is concave, and the second side surface S15 is convex. The reflective polarizing element RP is disposed on the second side surface of the first lens E1, and the quarter wave plate QWP is disposed on the second side surface of the reflective polarizing element RP. The second lens E2 and the third lens E3 are cemented lenses that are cemented to each other.

[0153] In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Fig.12 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the +2D state. Fig.12 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in a -5D state.

[0154] Table 7 shows the basic parameter table of the visual system of Example 7, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0155]

[0156]

[0157] Table 7

[0158] According to this embodiment, when the visual system is in the +2D state and the -5D state respectively, the values ​​of the parameters D1 to D5 in Table 7 are respectively shown in Table 8 below. The meanings of the parameters D1 to D5 can refer to the description in Example 1.

[0159] D1 D2 D3 D4 D5 +2D Status 500.0000 3.0597 -3.0597 3.0597 1.0000 -5D state -200.0000 0.8400 -0.8400 0.8400 3.2197

[0160] Table 8

[0161] In this embodiment, the first side surface S3 of the first lens E1, the first side surface S13 and the second side surface S14 of the second lens E2, and the first side surface S14 and the second side surface S15 of the third lens E3 are all aspherical surfaces. Table 9 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 of the aspherical surfaces S3 and S13-S15 that can be used in Example 7, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above Example 1.

[0162] Coefficient\Surface S3 S13 S14 S15 A4 -3.0146E-06 1.9696E-05 4.7944E-06 3.9629E-05 A6 2.0191E-08 -4.7456E-08 -4.4489E-09 -1.7519E-07 A8 -4.6596E-11 9.9562E-12 -1.0327E-11 1.9510E-10 A10 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A12 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A14 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A16 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A18 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A20 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0163] Table 9

[0164] Referring to Table 10, the values ​​of the structural parameters of the visual system of this embodiment are respectively shown in the 'Example 7' column in Table 10, wherein the specific description of the meaning represented by each parameter is the same as that in the above Example 1 and will not be repeated here.

[0165] Example 8

[0166] The following reference Fig.13 Describe the visual system according to Example 8 of the present application.

[0167] like Fig.13 As shown, similar to the visual system in Example 7, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0168] Similar to Example 7, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter-wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Fig.13 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Fig.13 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0169] The basic parameter table of the visual system of this embodiment is the same as Table 7 in Example 7, the numerical values ​​of parameters D1 to D5 are the same as Table 8 in Example 7, and the high-order coefficient table of the aspheric mirror surface is the same as Table 9 in Example 7.

[0170] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 8' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0171] Example 9

[0172] The following reference Fig.14 Describe the visual system according to Example 9 of the present application.

[0173] like Fig.14 As shown, similar to the visual system in Example 7, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from the first side to the second side along the optical axis, and also includes a first lens group supported by the first lens barrel Pa and a second lens group supported by the second lens barrel Pb, wherein the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens E2, a partial reflection element BS (not shown in the figure) and a third lens E3 arranged in sequence from the first side to the second side along the optical axis.

[0174] Similar to Example 7, in this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. A display / image surface IMG is provided on the second side of the visual system. The first lens group including the first lens E1, the reflective polarizing element RP and the quarter-wave plate QWP and the first lens barrel Pa are relatively fixed in distance from the display / image surface IMG along the optical axis; the second lens group including the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can move along the optical axis to approach or move away from the display / image surface IMG, and in this process the visual system can achieve zooming in the range of -5D to +2D. Fig.14 The middle left figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position closest to the display / image surface IMG. At this time, the visual system is in the first state (+2D state). Fig.14 The middle right figure shows a schematic diagram of the structure of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the farthest position from the display / image surface IMG. At this time, the visual system is in the second state (-5D state).

[0175] The basic parameter table of the visual system of this embodiment is also the same as Table 7 in Example 7, the numerical values ​​of parameters D1 to D5 are also the same as Table 8 in Example 7, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 9 in Example 7.

[0176] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 9' column in Table 10. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0177] Fig.15 The MTF curves of the visual systems of Embodiment 7, Embodiment 8 and Embodiment 9 when they are in the +2D state are shown. Fig.16 The MTF curves of the visual systems of Example 7, Example 8 and Example 9 when they are in the -5D state are shown. Fig.15 and Fig.16 It can be seen that the visual systems provided in Examples 7, 8 and 9 can achieve good imaging quality in two different focal length states of +2D and -5D.

[0178] Table 10 shows the values ​​of the parameters das, dam, Das, Dam, dbs, dbm, Dbs, Dbm, La and Lb of the visual system according to the above-mentioned embodiments 1-9. At least some of the above-mentioned parameters can be calculated according to Figure 1 The units of the parameters listed in Table 10 are all mm. It should be noted that the values ​​of the above parameters of the visual system of each embodiment in the two different focal length states of +2D and -5D are consistent.

[0179]

[0180]

[0181] Table 10

[0182] In addition, in Examples 1 to 9, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the combined focal length f23 of the second lens and the third lens, the combined focal length fz of the first lens, the reflective polarizing element and the quarter-wave plate, the entrance pupil diameter EPD of the visual system, the distance ΔL that the second lens group moves along the optical axis when the visual system switches from the +2D state to the -5D state, and the change Δf of the effective focal length of the system when the visual system switches from the +2D state to the -5D state are respectively shown in Table 11 below.

[0183] Parameters\Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 f1(mm) 115.14 115.14 115.14 104.23 104.23 104.23 99.12 99.12 99.12 f2(mm) 85.79 85.79 85.79 105.01 105.01 105.01 118.96 118.96 118.96 f3(mm) -149.04 -149.04 -149.04 196.29 196.29 196.29 95.04 95.04 95.04 f23(mm) 199.37 199.37 199.37 69.40 69.40 69.40 53.47 53.47 53.47 fz(mm) 115.14 115.14 115.14 104.23 104.23 104.23 99.12 99.12 99.12 EPD(mm) 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 ΔL(mm) 2.21 2.21 2.21 2.22 2.22 2.22 2.22 2.22 2.22 Δf(mm) 0.67 0.67 0.67 1.36 1.36 1.36 1.66 1.66 1.66

[0184] Table 11

[0185] And, Examples 1 to 9 respectively satisfy the conditions shown in Table 12 below. The visual systems of each embodiment in Examples 1 to 9 correspond to the same values ​​of the conditional expressions in Table 12 below in two different focal length states of +2D and -5D.

[0186] Conditional / Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 (fz / f23)×(La / Lb) 0.34 0.33 0.35 0.84 0.87 0.81 1.04 1.03 1.10 (dbs / dam)×Δf 0.78 0.78 0.77 1.58 1.57 1.57 1.92 1.92 1.92 das / (f1 / EPD) 2.45 2.43 2.52 2.72 2.71 2.79 2.90 2.89 2.97 Dbs / (f2 / CT2) 3.49 3.49 3.46 2.88 2.88 2.86 2.27 2.27 2.27 Dam / (CT1+CTR+CTQ) 9.31 9.29 9.22 8.75 8.73 8.69 8.52 8.49 8.48 (Das-das) / ΔL 2.87 3.23 2.55 2.70 2.97 2.15 2.52 2.70 2.04 |f3 / CT3| / dbm 1.26 1.27 1.25 1.91 1.92 1.89 0.86 0.86 0.85 R1 / La 15.96 16.77 15.07 14.09 13.79 14.40 13.44 13.70 12.39 Lb / ΔL 3.05 2.96 3.15 3.25 3.21 3.32 3.26 3.21 3.32 |f3| / Dbm 3.12 3.10 3.15 4.11 4.08 4.14 1.98 1.98 1.99 dbm / Lb 6.57 6.73 6.42 6.13 6.17 6.05 6.14 6.21 6.08 (Dbm-Das) / Δf 9.21 8.87 8.23 4.64 4.58 4.64 3.83 3.77 3.83 (N2 / N3)×Lb 6.75 6.55 6.95 7.23 7.13 7.38 7.23 7.13 7.36 La / N1 2.55 2.43 2.71 2.62 2.68 2.56 2.61 2.56 2.83 dbs / ΔL 21.64 21.68 21.62 21.38 21.43 21.36 21.41 21.49 21.36

[0187] Table 12

[0188] The present application also provides an imaging device, which is provided with an electronic photosensitive element for imaging, and the electronic photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the visual system described above.

[0189] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of application involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the application. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A visual system, characterized in that: It includes a lens barrel group and a lens group, wherein: The lens barrel assembly comprises a first lens barrel and a second lens barrel which are sequentially arranged from a first side to a second side along the optical axis; The lens group includes a first lens group and a second lens group arranged in sequence from the first side to the second side along the optical axis; the first lens group is supported by the first lens barrel, and the second lens group is supported by the second lens barrel; The first lens group includes a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence from the first side to the second side along the optical axis, and the second lens group includes a second lens, a partial reflective element and a third lens arranged in sequence from the first side to the second side along the optical axis; wherein the first lens has positive optical power, and its first side surface is convex, and its second side surface is flat; the second lens has positive optical power, and its second side surface is convex; the third lens has positive optical power or negative optical power, and its first side surface is concave, and its second side surface is convex; and the second lens is glued to the third lens; The second lens group is configured to be movable along the optical axis to be closer to or farther from the display located at the second side, and to switch the visual system between a first state and a second state; The visual system meets the following requirements: 0.33≤(fz / f23)×(La / Lb)≤1.10, 0.75mm<(dbs / dam)×Δf<1.95mm, Among them, fz is the combined focal length of the first lens, the reflective polarizing element and the quarter-wave plate, f23 is the combined focal length of the second lens and the third lens, La is the maximum distance from the first side end face of the first lens barrel to the second side end face of the first lens barrel on the optical axis, Lb is the maximum distance from the first side end face of the second lens barrel to the second side end face of the second lens barrel on the optical axis, dbs is the inner diameter of the first side end face of the second lens barrel, dam is the inner diameter of the second side end face of the first lens barrel, and Δf is the change in the effective focal length of the visual system when it switches from the first state to the second state.

2. The visual system according to claim 1, characterized in that: The outer diameter Dbs of the first side end surface of the second lens barrel, the effective focal length f2 of the second lens, and the center thickness CT2 of the second lens on the optical axis satisfy: 2.25mm <Dbs / (f2 / CT2)<3.5mm。 3. The visual system according to claim 1, characterized in that: The outer diameter Dam of the second side end surface of the first lens barrel, the center thickness CT1 of the first lens on the optical axis, the center thickness CTR of the reflective polarizing element on the optical axis, and the center thickness CTQ of the quarter-wave plate on the optical axis satisfy: 8.45 <Dam / (CT1+CTR+CTQ)<9.35。 4. The visual system according to claim 1, characterized in that: The effective focal length f3 of the third lens, the center thickness CT3 of the third lens on the optical axis and the inner diameter dbm of the second side end surface of the second lens barrel satisfy: <h2 style=";text-align:left;direction:ltr">0.85mm<h2 style=";text-align:left;direction:ltr"> -1 <h2 style=";text-align:left;direction:ltr"> ≤|f3 / CT3| / dbm≤1.92mm<h2 style=";text-align:left;direction:ltr"> -1 <h2 style=";text-align:left;direction:ltr"> 。 5. The visual system according to claim 1, characterized in that: The curvature radius R1 of the first side surface of the first lens and the maximum distance La from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel on the optical axis satisfy: 12.39≤R1 / La≤16.

77.

6. The visual system according to claim 1, characterized in that: The maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis and the distance ΔL moved by the second lens group along the optical axis during the process of the visual system switching from the first state to the second state satisfy: 2.95 <Lb / ΔL<3.35。 7. The visual system according to claim 1, characterized in that: The effective focal length f3 of the third lens and the outer diameter Dbm of the second side end surface of the second lens barrel satisfy: 1.95<|f3| / Dbm<4.

15.

8. The visual system according to claim 1, characterized in that: The inner diameter dbm of the second side end surface of the second lens barrel and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 6.05≤dbm / Lb≤6.

73.

9. The visual system according to claim 1, characterized in that: The refractive index N2 of the second lens, the refractive index N3 of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 6.55mm≤(N2 / N3)×Lb≤7.38mm.

10. The visual system according to claim 1, characterized in that: The maximum distance La from the first side end surface of the first lens barrel to the second side end surface of the first lens barrel on the optical axis and the refractive index N1 of the first lens satisfy: 2.43mm≤La / N1≤2.83mm.

11. The visual system according to claim 1, characterized in that: The inner diameter dbs of the first side end surface of the second lens barrel and the distance ΔL that the second lens group moves along the optical axis during the process of switching the visual system from the first state to the second state satisfy: 21.35 <dbs / ΔL<21.7。 12. The visual system according to any one of claims 1 to 11, characterized in that: The inner diameter das of the first side end surface of the first lens barrel, the effective focal length f1 of the first lens and the entrance pupil diameter EPD of the visual system satisfy: 2.4mm <das / (f1 / EPD)<3.0mm。 13. The visual system according to any one of claims 1 to 11, characterized in that: The outer diameter Das of the first side end surface of the first lens barrel, the inner diameter das of the first side end surface of the first lens barrel, and the distance ΔL that the second lens group moves along the optical axis during the process of the visual system switching from the first state to the second state satisfy: 2.0<(Das-das) / ΔL<3.

25.

14. The visual system according to any one of claims 1 to 11, characterized in that: The outer diameter Dbm of the second side end surface of the second lens barrel, the outer diameter Das of the first side end surface of the first lens barrel, and the change Δf of the effective focal length of the visual system from the first state to the second state satisfy: 3.77≤(Dbm-Das) / Δf≤9.21.

Images