Visual system

Abstract

The utility model 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, in particular to a visual system. BACKGROUND

[0002] With the proposal of the concept of metaverse, virtual reality technology and augmented reality technology of human-computer interaction ushered in the second development opportunity. The visual system, as an important entrance of human-computer interaction, plays a key role in it. The early visual system mainly adopts aspheric lens or Fresnel lens, and the body length is relatively long, so that the user's center of gravity is forward when wearing, thereby affecting the user's experience.

[0003] Catadioptric optical system is a major innovation of visual system itself, which reserves space for the overall design of virtual reality device or augmented reality device, and has become the mainstream trend of research and development. The catadioptric optical system shortens the body length of the visual system by light path folding, so that the center of gravity of the virtual reality device or augmented reality device moves backward, thereby improving the user's experience.

[0004] However, the diopter of different individuals differs greatly, and the fixed-focus structure of the visual system is usually only suitable for part of the population, and the user experience is poor, and ghost image interference is easy to exist between lenses, and the imaging quality is poor. CONTENT OF THE UTILITY MODEL

[0005] An aspect of the present application provides a visual system, which can 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 order from a first side to a second side along an optical axis; the lens group includes a first lens group and a second lens group arranged in order 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 order from the first side to the second side along the optical axis, and the second lens group includes a second lens, a partially reflective element, and a third lens arranged in order from the first side to the second side along the optical axis; wherein the first lens has positive focal power, the first side of the first lens is convex, and the second side of the first lens is flat; the second lens has positive focal power, and the second side of the second lens is convex; the third lens has positive focal power or negative focal power, the first side of the third lens is concave, and the second side of the third lens is convex; and the second lens and the third lens are cemented. The second lens group is configured to be movable along the optical axis to approach or move away from a display located at the second side, and to switch the visual system between a first state and a second state. The visual system can satisfy the condition 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 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, 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, 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 effective focal length of the visual system when switching from the first state to the second state.

[0006] In an 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 can satisfy: 2.25mm<Dbs / (f2 / CT2)<3.5mm.

[0007] In an 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 can satisfy: 8.45<Dam / (CT1+CTR+CTQ)<9.35.

[0008] In an 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 can satisfy: 0.85mm -1 ≤|f3 / CT3| / dbm≤1.92mm -1 .

[0009] In an 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 can satisfy: 12.39≤R1 / La≤16.77.

[0010] In an 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 AL along the optical axis that the second lens group moves during the switching of the visual system from the first state to the second state can satisfy: 2.95<Lb / AL<3.35.

[0011] In an 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 can satisfy: 1.95<|f3| / Dbm<4.15.

[0012] In an 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 can satisfy: 6.05≤dbm / Lb≤6.73.

[0013] In an 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 can satisfy: 6.55mm≤(N2 / N3)×Lb≤7.38mm.

[0014] In an 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 can satisfy: 2.43mm≤La / N1≤2.83mm.

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

[0016] In an 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 can satisfy: 2.4mm<das / (f1 / EPD)<3.0mm.

[0017] In an 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 AL along the optical axis that the second lens group moves during the switching of the visual system from the first state to the second state can satisfy: 2.0<(Das-das) / AL<3.25.

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

[0019] The visual system disclosed in the present application comprises a barrel group and a lens group. The barrel group comprises a first barrel and a second barrel arranged in sequence from a first side to a second side along an optical axis. The lens group comprises 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 barrel, and the second lens group is supported by the second barrel. The first lens group comprises 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. The second lens group comprises a second lens, a partially reflective element, and a third lens arranged in sequence from the first side to the second side along the optical axis. The first lens has positive focal power, the first side face of the first lens is a convex surface, and the second side face of the first lens is a flat surface. The second lens has positive focal power, and the second side face of the second lens is a convex surface. The third lens has positive focal power or negative focal power, the first side face of the third lens is a concave surface, and the second side face of the third lens is a convex surface. The second lens and the third lens are cemented together. The second lens group is configured to be movable along the optical axis to approach or move away from a display located at the second side, and to switch the visual system between a first state and a second state. By configuring the visual system as described above, and by 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 on the optical axis from the first side end face of the first barrel to the second side end face of the first barrel, and the maximum distance Lb on the optical axis from the first side end face of the second barrel to the second side end face of the second barrel to satisfy the condition formula 0.33≤(fz / f23)×(La / Lb)≤1.10, and by controlling the inner diameter dbs of the first side end face of the second barrel, the inner diameter dam of the second side end face of the first barrel, and the change amount Δf of the effective focal length of the visual system when switching from the first state to the second state to satisfy the condition formula 0.75mm<(dbs / dam)×Δf<1.95mm, the visual system can be adjusted between a diopter of +2D (the first state) to -5D (the second state), while also helping to reduce stray light interference at the side wall of the first barrel, and ensuring that the user can obtain a clear image under different visual requirements. BRIEF DESCRIPTION OF DRAWINGS

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

[0021] Figure 1 The structure and part of the parameters of the visual system according to the exemplary embodiments of the present application are shown in the schematic diagram;

[0022] Figure 2 The left and right graphs in FIG. 1A and FIG. 1B respectively show structural schematic diagrams of the visual system according to Embodiment 1 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0023] Figure 3 The left and right graphs in FIG. 2A and FIG. 2B respectively show structural schematic diagrams of the visual system according to Embodiment 2 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0024] Figure 4 The left and right graphs in FIG. 3A and FIG. 3B respectively show structural schematic diagrams of the visual system according to Embodiment 3 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0025] Figure 5 FIG. 4 shows MTF (Modulation Transfer Function) diagrams of the visual system according to Embodiments 1, 2 and 3 of the present application in the first state (+2D state);

[0026] Figure 6 FIG. 5 shows MTF diagrams of the visual system according to Embodiments 1, 2 and 3 of the present application in the second state (-5D state);

[0027] Figure 7 The left and right graphs in FIG. 6A and FIG. 6B respectively show structural schematic diagrams of the visual system according to Embodiment 4 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0028] Figure 8 The left and right graphs in FIG. 7A and FIG. 7B respectively show structural schematic diagrams of the visual system according to Embodiment 5 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0029] Figure 9 The left and right graphs in FIG. 8A and FIG. 8B respectively show structural schematic diagrams of the visual system according to Embodiment 6 of the present application in the first state (+2D state) and the second state (-5D state) respectively;

[0030] Figure 10 FIG. 9 shows MTF diagrams of the visual system according to Embodiments 4, 5 and 6 of the present application in the first state (+2D state);

[0031] Figure 11 FIG. 10 shows MTF diagrams of the visual system according to Embodiments 4, 5 and 6 of the present application in the second state (-5D state);

[0032] Figure 12The left and right figures in the figure show the structural schematic diagrams of the visual system according to Embodiment 7 of this application when it is in the first state (+2D state) and the second state (-5D state), respectively;

[0033] Figure 13 The left and right figures in the figure show the structural schematic diagrams of the visual system according to Embodiment 8 of this application when it is in the first state (+2D state) and the second state (-5D state), respectively;

[0034] Figure 14 The left and right figures in the figure show the structural schematic diagrams of the visual system according to Embodiment 9 of this application when it is in the first state (+2D state) and the second state (-5D state), respectively;

[0035] Figure 15 The MTF diagrams of the visual system according to Embodiments 7, 8 and 9 of this application in the first state (+2D state) are shown.

[0036] Figure 16 The MTF diagrams of the visual system according to Embodiments 7, 8 and 9 of this application in the second state (-5D state) are shown.

[0037] Figure 17 A stray light simulation diagram of an exemplary visual system according to this application is shown when the conditions (fz / f23)×(La / Lb)=0.1 and (dbs / dam)×Δf=0.3mm are met;

[0038] Figure 18 A stray light simulation diagram of an exemplary visual system according to this application is shown when the conditions (fz / f23)×(La / Lb)=1.5 and (dbs / dam)×Δf=2.5mm are met;

[0039] Figure 19 A stray light simulation diagram of an exemplary visual system according to this application is shown when the conditions (fz / f23)×(La / Lb)=0.81 and (dbs / dam)×Δf=1.57mm are met. Detailed Implementation

[0040] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this 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 the terms first, second, third, etc. in the present specification are used only to distinguish one feature from another, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

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

[0043] In the present specification, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region.

[0044] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the use of "may" means that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0046] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The following embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as limiting the scope of the patent of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. The present application will be described in detail below with reference to the drawings and in combination 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 an example embodiment of the present application can include a lens barrel group and a lens group. The lens barrel group can include a first lens barrel and a second lens barrel. The lens group can include a first lens group and a second lens group. The first lens barrel and the second lens barrel can be arranged in order from a first side to a second side along an optical axis. The first lens group and the second lens group can be arranged in order from the first side to the second side along the optical axis.

[0049] In an example embodiment, the first lens group can be supported by or assembled to the first lens barrel. The second lens group can be supported by or assembled to the second lens barrel.

[0050] In an example embodiment, the first lens group can include a first lens, a reflective polarizing element, and a quarter wave plate. The first lens, the reflective polarizing element, and the quarter wave plate can be arranged in order from a first side to a second side along an optical axis.

[0051] In an example embodiment, the reflective polarizing element can be disposed on or attached to the second side of the first lens. The quarter wave plate can be disposed on or attached to the second side of the reflective polarizing element. The first side of the reflective polarizing element can be at least partially in contact with the second side of the first lens. The first side of the quarter wave plate can be at least partially in contact with the second side of the reflective polarizing element.

[0052] In an example embodiment, the second lens group can include a second lens, a partial reflecting element, and a third lens. The second lens, the partial reflecting element, and the third lens can be arranged in order from a first side to a second side along an optical axis.

[0053] In an example embodiment, the second lens and the third lens can be cemented to each other to form a cemented lens. Specifically, the second lens, the partial reflecting element, and the third lens can be cemented to each other to form a cemented lens.

[0054] In an example embodiment, the first lens can have a positive refractive power. The first side of the first lens can be a convex surface. The second side of the first lens can be a flat surface.

[0055] In an example embodiment, the second lens can have a positive refractive power. The first side of the second lens can be a convex surface or a concave surface. The second side of the second lens can be a convex surface.

[0056] In an example embodiment, the third lens can have a positive refractive power or a negative refractive power. The first side of the third lens can be a concave surface. The second side of the third lens can be a convex surface.

[0057] By reasonably setting the structure of the visual system, the light path can be folded back, the length of the body of the visual system can be effectively shortened, the volume and weight of the visual system can be reduced, and the lightness of the visual system can be achieved. The setting of the cemented lens provides a high-quality lens material for the system, has the advantages of lightness, good light transmission, wear resistance, etc., can be more suitable for lens manufacturing of VR devices, 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 perpendicular to the optical axis, for example.

[0059] In example embodiments, the first side can be the side of the human eye, for example, and the second side can be the side of the display, for example. The visual system can be used in various VR devices or apparatuses, for example.

[0060] In example embodiments, the distance between the first lens group (or the first lens group and the first lens barrel) and the display or image surface on the second side of the visual system along the optical axis can be fixed. The second lens group (or the second lens group and the second lens barrel) can be configured to be movable along the optical axis to approach or move away from the display or image surface on the second side of the visual system, and to switch the visual system 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 along the optical axis is the largest, and the visual system can be in the +2D state, i.e., 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 along the optical axis is the smallest, and the visual system can be in the -5D state, i.e., the second state.

[0061] For example, when the visual system is in the first state, the refractive power of the visual system is +2D, which can be suitable for a user with a refractive power of +2D; when the visual system is in the second state, the refractive power of the visual system is -5D, which can be suitable for a user with a refractive power of -5D. Wherein, the negative sign of the refractive power can represent that the user belongs to myopic user; the positive sign of the refractive power can represent that the user belongs to hypermetropic user; the specific value of the refractive power can represent the refractive power of the user. For example, the refractive power of +1D can represent that the hypermetropic degree of the user is about 100 degrees, and the refractive power of -1D can represent that the myopic degree of the user is about 100 degrees.

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

[0063] In an exemplary embodiment, the visual system of the present application can include at least one diaphragm. The diaphragm can restrict the light path and control the light intensity. The diaphragm can be disposed at a suitable position of the visual system as needed, for example, the diaphragm can be located between the first side (for example, 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. The virtual image distance can be, for example, the distance from the virtual image of the image light from the second side at a predetermined position to the diaphragm on the optical axis. Wherein, VID = 1000 / Diopter.

[0065] In an exemplary embodiment, the visual system of the present application can satisfy the condition 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 face of the first barrel to the second side end face of the first barrel, and Lb is the maximum distance on the optical axis from the first side end face of the second barrel to the second side end face of the second barrel. It can be understood that the first side end face of the barrel can be the end face or surface of the barrel closest to the first side and perpendicular or approximately perpendicular to the optical axis; the second side end face of the barrel can be the end face or surface of the barrel closest to the second side and perpendicular or approximately perpendicular to the optical axis.

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

[0067] The visual system according to the exemplary embodiments of the present application comprises a lens barrel group and a lens group. The lens barrel group comprises a first lens barrel and a second lens barrel arranged in sequence along an optical axis from a first side to a second side. The lens group comprises a first lens group and a second lens group arranged in sequence along the optical axis from the first side to the second side. 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 comprises a first lens, a reflective polarizing element and a quarter wave plate arranged in sequence along the optical axis from the first side to the second side. The second lens group comprises a second lens, a partially reflective element and a third lens arranged in sequence along the optical axis from the first side to the second side. The first lens has positive focal power, and the first side of the first lens is a convex surface and the second side of the first lens is a flat surface. The second lens has positive focal power, and the second side of the second lens is a convex surface. The third lens has positive focal power or negative focal power, and the first side of the third lens is a concave surface and the second side of the third lens is a convex surface. The second lens and the third lens are cemented together. The second lens group is configured to be movable along the optical axis to approach or move away from a display located at the second side, and to switch the visual system between a first state and a second state. By configuring the visual system as described above, and by 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 on the optical axis from the first end surface of the first lens barrel to the second end surface of the first lens barrel, the maximum distance Lb on the optical axis from the first end surface of the second lens barrel to the second end surface of the second lens barrel, the inner diameter dbs of the first end surface of the second lens barrel, the inner diameter dam of the second end surface of the first lens barrel, and the change Δf of the effective focal length of the visual system when switching from the first state to the second state, the condition formula 0.33≤(fz / f23)×(La / Lb)≤1.10 is satisfied, and the condition formula 0.75mm<(dbs / dam)×Δf<1.95mm is satisfied, the visual system can be adjusted from a +2D state (the first state) to a -5D state (the second state) in diopter, and at the same time, the stray light interference at the sidewall of the first lens barrel can be reduced, and the user can obtain a clear image under different visual needs.

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

[0069] In the visual system 1 of the first scheme, the two conditions (fz / f23) x (La / Lb) and (dbs / dam) x Af satisfy (fz / f23) x (La / Lb) = 0.1 and (dbs / dam) x Af = 0.3 mm, respectively. It can be seen that the values of the two conditions are both smaller than the lower limit values of the ranges defined by the conditions 0.33 ≤ (fz / f23) x (La / Lb) ≤ 1.10 and 0.75 mm < (dbs / dam) x Af < 1.95 mm. The stray light diagram of the imaging effect of the visual system 1 is shown in FIG. 2, and the stray light diagram is shown in FIG. 3. Figure 17 It can be seen that the system of this scheme has more stray light, for example, the side wall of the first lens barrel is prone to produce reflected stray light, and the stray light intensity is high, which can reach 1.3E-05, and has a greater impact on the imaging effect. Figure 17

[0070] In the visual system 2 of the second scheme, the two conditions (fz / f23) x (La / Lb) and (dbs / dam) x Af satisfy (fz / f23) x (La / Lb) = 1.5 and (dbs / dam) x Af = 2.5 mm, respectively. It can be seen that the values of the two conditions are both greater than the upper limit values of the ranges defined by the conditions 1.11 ≤ (fz / f23) x (La / Lb) ≤ 1.10 and 0.75 mm < (dbs / dam) x Af < 1.95 mm. The stray light diagram of the imaging effect of the visual system 2 is shown in FIG. 4, and the stray light diagram is shown in FIG. 5. Figure 18 It can be seen that the system of this scheme also has more stray light, for example, the side wall of the first lens barrel is prone to produce reflected stray light, and the stray light intensity is high, which can reach 8.4E-06, and also has a greater impact on the imaging effect. Figure 18

[0071] In the visual system 3 of the third scheme, the two conditions (fz / f23) x (La / Lb) and (dbs / dam) x Af satisfy (fz / f23) x (La / Lb) = 0.81 and (dbs / dam) x Af = 1.57 mm, respectively. It can be seen that the values of the two conditions are both within the ranges defined by the conditions 0.33 ≤ (fz / f23) x (La / Lb) ≤ 1.10 and 0.75 mm < (dbs / dam) x Af < 1.95 mm, and the values are reasonable. The stray light diagram of the imaging effect of the visual system 3 is shown in FIG. 6, and the stray light diagram is shown in FIG. 7. Figure 19 It can be seen that the system of this scheme has less stray light, which can effectively reduce the stray light interference at positions such as the side wall of the first lens barrel, and the stray light intensity is also significantly weakened to 2.9E-06, which has a smaller impact on the imaging effect, and is beneficial to improving the clarity of imaging. Figure 19

[0072] ​​​Therefore, according to the visual system of the present application, by reasonably configuring and controlling the system to meet the condition 0.33≤(fz / f23)×(La / Lb)≤1.10 and 0.75mm<(dbs / dam)×Δf<1.95mm, the visual system can effectively reduce the interference of stray light at positions such as the first lens barrel sidewall on the imaging system while enabling the visual system to adjust the diopter from a +2D state to a -5D state, thereby improving the clarity of the image and ensuring that the user can obtain a clear image under different visual needs.

[0073] In an example 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 can satisfy: 2.25mm<Dbs / (f2 / CT2)<3.5mm. By controlling this condition, the condition value less than the upper limit value can ensure that the overall thickness does not increase, which is conducive to ensuring the user experience, and the condition value greater than the lower limit value can ensure that the second lens has good processability.

[0074] In an example 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 can satisfy: 8.45<Dam / (CT1+CTR+CTQ)<9.35. By controlling this condition, the condition value less than the upper limit value is conducive to ensuring the effect of the reflective polarizing element and the quarter-wave plate attached to the surface of the first lens, reducing the generation of bubbles, wrinkles, orange peel, and the like, and the condition value greater than the lower limit value can effectively prevent the light reflection position of the actual module from deviating from the theoretical design position, which is conducive to ensuring and improving the overall performance of the machine.

[0075] In an example 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 can satisfy: 0.85mm -1 ≤|f3 / CT3| / dbm≤1.92mm -1 . By controlling this condition, the third lens can have good processability, while the overall thickness of the machine does not increase, thereby ensuring the user experience.

[0076] In the example 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 can satisfy 12.39≤R1 / La≤16.77. By controlling the conditional expression, the radius of curvature of the first side surface of the first lens is positive, which can ensure that the light converges; at the same time, controlling the conditional expression ratio in the above range can also ensure that the first lens barrel has good processability.

[0077] In the example 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 of the second lens group along the optical axis during the switching of the visual system from the first state to the second state can satisfy 2.95<Lb / ΔL<3.35. By controlling the conditional expression, it is beneficial to ensure that the visual system can accurately control the gear subdivision from +2D to -5D during focusing, and also prevent the module from moving too much during focusing, avoid the length of the module being too long, ensure that the maximum thickness of the whole machine is not too large, and further ensure the user experience.

[0078] In the example 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 can satisfy 1.95<|f3| / Dbm<4.15. By controlling the conditional expression, the strength of the second lens barrel can be ensured, and further the mechanical properties of the module can be ensured.

[0079] In the example 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 can satisfy 6.05≤dbm / Lb≤6.73. By controlling the conditional expression, the second lens barrel can have sufficient wall thickness and strength, which is beneficial to ensure the mechanical properties 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 of the system.

[0080] In the example 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 can satisfy 6.55mm≤(N2 / N3)×Lb≤7.38mm. By controlling the conditional expression, the thickness of the whole machine can be prevented from increasing, and the user experience can be ensured, and at the same time, the second lens barrel can have sufficient mechanical strength.

[0081] In the example 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 can satisfy 2.43mm≤La / N1≤2.83mm. By controlling the conditional expression, the mechanical strength of the first lens barrel can be ensured under the reasonable selection of the first lens material.

[0082] In the example embodiment, the inner diameter dbs of the first side end face of the second lens barrel and the distance AL of the movement of the second lens group along the optical axis during the switching of the visual system from the first state to the second state can satisfy: 21.35 < dbs / AL < 21.7. By controlling the conditional expression, it is beneficial to ensure that the second lens barrel has sufficient wall thickness and strength during the movement of the second lens group to achieve system focusing, and it is beneficial to ensure the stability of the system.

[0083] In the example 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 can satisfy: 2.4 mm < das / (f1 / EPD) < 3.0 mm. By controlling the conditional expression, the light of the incident system can be reasonably controlled to prevent excessive light from being incident and to avoid generating large stray light, which is beneficial to improve the imaging quality of the system.

[0084] In the example 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 AL of the movement of the second lens group along the optical axis during the switching of the visual system from the first state to the second state can satisfy: 2.0 < (Das-das) / AL < 3.25. By controlling the conditional expression, it is beneficial to ensure that the first lens barrel has sufficient strength and to improve the mechanical performance of the module.

[0085] In the example 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 Af of the effective focal length during the switching of the visual system from the first state to the second state can satisfy: 3.77 ≤ (Dbm-Das) / Af ≤ 9.21. By controlling the conditional expression, it is ensured that the first lens barrel is smaller than the second lens barrel, which is beneficial for assembly, and at the same time, the difference between the two is limited within a reasonable range, which is beneficial to reduce the design difficulty of the refractive adjustment structure of the system.

[0086] The second aspect of the present application provides such a visual system, by arranging a first lens barrel and a second lens barrel in sequence from a first side to a second side along an optical axis, and arranging a first lens group and a second lens group in sequence from the first side to the second side along the optical axis, and arranging the first lens group to abut against the first lens barrel, and the second lens group to abut against the second lens barrel; and further arranging 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 partially 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 focal power, the first side thereof is a convex surface, and the second side thereof is a flat surface; the second lens has positive focal power, and the second side thereof is a convex surface; the third lens has positive focal power or negative focal power, the first side thereof is a concave surface, and the second side thereof is a convex surface; and the second lens and the third lens are cemented together as a cemented lens; and arranging the second lens group to be movable along the optical axis to approach or move away from a display located at the second side, so that the visual system is switched between a first state and a 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 on the optical axis from the first side end surface of the first lens barrel to the second side end surface thereof, 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 thereof satisfy: 0.33≤(fz / f23)×(La / Lb)≤1.10; 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 amount Δf of the effective focal length of the visual system when switched from the first state to the second state satisfy: 3.77≤(Dbm-Das) / Δf≤9.21; so that the visual system can be adjusted from a +2D state (first state) to a -5D state (second state), and the user can obtain a clear image under different visual requirements; and the first lens barrel is smaller than the second lens barrel in shape, facilitating assembly, and limiting the difference between the shapes of the two to a reasonable range, which can be conducive to reducing the design difficulty of the refractive power adjustment structure of the system.

[0087] The visual system according to the exemplary embodiments of the present application adopts a folding architecture of, for example, three pieces. By reasonably arranging the system structure such as the lens barrel and the lens group, and reasonably configuring multiple parameters of the system structure and elements, the total optical length can be reduced, the system weight can be reduced, the system miniaturization and light weight can be realized, and the user comfort can be improved. By moving the second lens group, the zooming in the range of -5D to +2D can be realized, the needs of users with different vision can be met, and the users can enjoy the VR experience without wearing glasses. At the same time, the stray light interference generated at the positions such as the side wall of the first lens barrel can be effectively reduced, which is beneficial to improve the imaging quality and ensure that the user can obtain a clear image under different visual needs. In addition, the use of cemented lenses in the system has the advantages of lightness, good light transmission, wear resistance, and is more suitable for the manufacture of lenses for VR devices, and improves the quality and adaptability of the lenses.

[0088] In addition, the present application also provides a VR device, which can include the visual system provided by any one of the above embodiments. The first side can be the human eye side, and the second side can be the display / image plane side. The VR device can realize continuous zooming in the range of -5D to +2D, so that users with different vision can clearly enjoy the VR experience without wearing glasses. At the same time, the VR device has the characteristics of miniaturization, light weight, high imaging quality, stable performance, and the like, and improves the user experience.

[0089] Embodiment 1

[0090] The following refers to Figure 2 The visual system according to Embodiment 1 of the present application is described. Figure 2 The left diagram in FIG. 1 shows a structural schematic diagram of the visual system according to Embodiment 1 of the present application in a first state (+2D state), Figure 2 The right diagram in FIG. 1 shows a structural schematic diagram of the visual system according to Embodiment 1 of the present application in a second state (-5D state).

[0091] As Figure 2 shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence along the optical axis from the first side to the second side. The visual system also includes a first lens group supported on the first lens barrel Pa and a second lens group supported on the second lens barrel Pb. The first lens group includes a first lens E1, a reflective polarizing element RP, and a quarter-wave plate QWP arranged in sequence along the optical axis from the first side to the second side. 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 along the optical axis from the first side to the second side.

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

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

[0094] Table 1 shows a table of basic parameters of the visual system of Embodiment 1, wherein the units of the radius of curvature and the thickness / distance are 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 along the optical axis from the first side of the filter and / or the first side of the protective glass IR / CG disposed 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 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 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 along the optical axis from the first side of the second lens E2 to the second side of the quarter-wave plate QWP again; and D1 can be understood as the value of the virtual image distance of the visual system according to the present embodiment. The values of the parameters D1 to D5 will change accordingly during the zooming process of the visual system according to the present embodiment by moving along the optical axis through the second lens group and the second lens barrel Pb. The values of the parameters D1 to D5 in the +2D state shown in the left image of Figure 2 and the -5D state shown in the right image of Figure 2 of Table 2.

[0099] D1 D2 D3 D4 D5 +2D state 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 the present embodiment, the first side S3 of the first lens E1, the first side S13 and the second side S14 of the second lens E2, and the first side S14 and the second side 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 sag of the aspherical surface at a position along the optical axis at a height h from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the inverse of the radius of curvature R in Table 1 above); k is the conic coefficient; and Ai is the correction coefficient of the i-th order of the aspherical surface. Table 3 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical surfaces S3 and S13-S15 in Embodiment 1.

[0104]

[0105]

[0106] Table 3

[0107] Referring to Table 10, the visual system according to this embodiment has a plurality of structural parameters, the values of which are shown in the column of 'Embodiment 1' in Table 10, respectively, where das is the inner diameter of the first side end surface of the first lens barrel Pa, dam is the inner diameter of the second side end surface of the first lens barrel Pa, Das is the outer diameter of the first side end surface of the first lens barrel Pa, Dam is the outer diameter of the second side end surface of the first lens barrel Pa, dbs is the inner diameter of the first side end surface of the second lens barrel Pb, dbm is the inner diameter of the second side end surface of the second lens barrel Pb, Dbs is the outer diameter of the first side end surface of the second lens barrel Pb, Dbm is the outer diameter of the second side end surface of the second lens barrel Pb, La is the maximum distance on the optical axis from the first side end surface to the second side end surface of the first lens barrel Pa, and Lb is the maximum distance on the optical axis from the first side end surface to the second side end surface of the second lens barrel Pb. The values of the above-mentioned structural parameters of the visual system according to this embodiment are consistent at two different focal length states of +2D and -5D, respectively. The units of the above-mentioned parameters shown in Table 10 are millimeters (mm), and the schematic of the above-mentioned parameters in the structure diagram of the visual system can be referred to Coefficient \ Surface .

[0108] Embodiment 2

[0109] The visual system according to Embodiment 2 of the present application is described below with reference to Figure 8 .

[0110] As shown in Figure 8 , the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb arranged in order from a first side to a second side along an 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, where the first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged in order from a first side to a 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 order from a first side to a second side along the optical axis.

[0111] Similarly to Embodiment 1, in this embodiment, the first side can be, for example, an eye side, and the second side can be, for example, a display side. The second side of the visual system is provided with a display / image surface IMG. 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 have a relatively fixed distance from the display / image surface IMG in the direction of 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 to approach or move away from the display / image surface IMG in the direction of the optical axis, during which the visual system can realize zooming in a range of -5D to +2D. Figure 8The middle left drawing shows a structural schematic diagram of the vision system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position closest to the display / image plane IMG, at which time the vision system is in the first state (+2D state). Figure 8 The middle right drawing shows a structural schematic diagram of the vision system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position farthest from the display / image plane IMG, at which time the vision system is in the second state (-5D state).

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

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

[0114] Embodiment 3

[0115] The following refers to Figure 9 The vision system according to Embodiment 3 of the present application is described.

[0116] As Figure 9 indicated, the vision system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb arranged in order from a first side to a second side along an optical axis, and also includes a first lens group supported on the first lens barrel Pa and a second lens group supported on 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 order 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 drawing) and a third lens E3 arranged in order from the first side to the second side along the optical axis, which are the same as the vision system in Embodiment 1.

[0117] Similarly to Embodiment 1, in this embodiment, the first side may, for example, be the side of the human eye, and the second side may, for example, be the side of the display. The second side of the vision system is provided with a display / image plane IMG. 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 have a relatively fixed distance from the display / image plane IMG along the optical axis direction; 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 be moved along the optical axis direction to approach or move away from the display / image plane IMG, during which the vision system can realize zooming in the range of -5D to +2D. Figure 9The middle left drawing shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position closest to the display / image plane IMG, at which time the visual system is in the first state (+2D state). Figure 9 The middle right drawing shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position farthest from the display / image plane IMG, at which 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 Embodiment 1, the numerical values of parameters D1 to D5 are also the same as Table 2 in Embodiment 1, and the high-order term coefficient table of the aspherical mirror surface is also the same as Table 3 in Embodiment 1.

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

[0120] Figure 10 The MTF curves of the visual systems of Embodiments 1, 2 and 3 in the +2D state are shown, Figure 11 The MTF curves of the visual systems of Embodiments 1, 2 and 3 in the -5D state are shown, The MTF (Modulation Transfer Function) curve can represent the optical modulation function value corresponding to different spatial frequencies, which is Figure 10 and Figure 11 It can be seen that the visual systems given in Embodiments 1, 2 and 3 can achieve good imaging quality in both +2D and -5D different focal length states.

[0121] Embodiment 4

[0122] The visual system according to Embodiment 4 of the present application is described below with reference to Figure 12 The visual system according to Embodiment 4 of the present application is described below with reference to Figure 12 The middle left drawing shows a structural schematic diagram of the visual system according to Embodiment 4 of the present application in the first state (+2D state), Figure 12 The middle right drawing shows a structural schematic diagram of the visual system according to Embodiment 4 of the present application in the second state (-5D state).

[0123] As Figure 12As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from a first side to a second side along an optical axis, and further includes a first lens group supported on the first lens barrel Pa and a second lens group supported on 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 reflecting 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, the first side S3 thereof is a convex surface, and the second side S4 thereof is a plane. The second lens E2 has positive focal power, the first side S13 thereof is a convex surface, and the second side S14 thereof is a convex surface. The third lens E3 has positive focal power, the first side S14 thereof is a concave surface, and the second side S15 thereof is a convex surface. The reflective polarizing element RP is disposed on the second side of the first lens E1, and the quarter-wave plate QWP is disposed on the second side of the reflective polarizing element RP. The second lens E2 and the third lens E3 are cemented lenses.

[0125] In this embodiment, the first side may, for example, be the side of the human eye, and the second side may, for example, be the side of the display. The second side of the visual system is provided with a display / image plane IMG. 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 have a relatively fixed distance from the display / image plane IMG along the optical axis direction; the second lens group including the second lens E2, the partial reflecting element BS and the third lens E3 and the second lens barrel Pb can be moved along the optical axis direction to approach or move away from the display / image plane IMG, during which the visual system can realize zooming in a range of -5D to +2D. Figure 12 The left diagram in the middle shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved to the position closest to the display / image plane IMG along the optical axis, at which time the visual system is in a +2D state. Figure 12 The right diagram in the middle shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved to the position farthest from the display / image plane IMG along the optical axis, at which time the visual system is in a -5D state.

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

[0127]

[0128] Table 4

[0129] When the visual system according to the present embodiment is in the +2D state and the -5D state respectively, the values of the parameters D1 to D5 in Table 4 are shown in Table 5 below respectively, and the meanings of the parameters D1 to D5 can refer to the description in Embodiment 1.

[0130] D1 D2 D3 D4 D5 +2D state 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 the present 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 high-order term 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 are shown in Table 6, wherein each aspherical surface can be defined by the formula (1) given in Embodiment 1 above.

[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 the present embodiment are shown in the column of ‘Embodiment 4’ in Table 10 respectively, wherein the specific description of the meanings of each parameter is the same as that in Embodiment 1 above, and will not be repeated here.

[0136] Embodiment 5

[0137] The visual system according to Embodiment 5 of the present application is described below with reference to Figure 13

[0138] As shown in Figure 13 the same as the visual system in Embodiment 4, the visual system in the present 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] ​As in Embodiment 4, in this embodiment, the first side can be, for example, the side of the human eye, and the second side can be, for example, the side of the display. The second side of the visual system is provided with a display / image surface IMG. 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 partially reflective element BS, and the third lens E3, and the second lens barrel Pb are movable along the optical axis to approach or move away from the display / image surface IMG, in the process of which the visual system can achieve zooming in a range of -5D to +2D. Figure 13 The left middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position closest to the display / image surface IMG, at which time the visual system is in the first state (+2D state). Figure 13 The right middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position farthest from the display / image surface IMG, at which 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 Embodiment 4, the numerical values of parameters D1 to D5 are the same as Table 5 in Embodiment 4, and the high-order term coefficient table of the aspherical surface is the same as Table 6 in Embodiment 4.

[0141] The numerical values of the structural parameters of the visual system of this embodiment are shown in the ‘Embodiment 5’ column in Table 10. Among them, the specific description of the meaning represented by each parameter is the same as described in Embodiment 1 above, and will not be repeated here.

[0142] Embodiment 6

[0143] The following refers to Figure 14 A visual system according to Embodiment 6 of the present application is described.

[0144] As Figure 14 shown, the visual system in this embodiment also includes the first lens barrel Pa and the second lens barrel Pb, which are arranged in order from the first side to the second side along the optical axis, and also includes the first lens group supported on the first lens barrel Pa and the second lens group supported on the second lens barrel Pb, wherein the first lens group includes the first lens E1, the reflective polarizing element RP, and the quarter-wave plate QWP arranged in order from the first side to the second side along the optical axis, and the second lens group includes the second lens E2, the partially reflective element BS (not shown in the diagram), and the third lens E3 arranged in order from the first side to the second side along the optical axis.

[0145] Similar to Embodiment 4, in this embodiment, the first side can be, for example, the human eye side, and the second side can 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 a first lens E1, a reflective polarizing element RP, and a 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 a second lens E2, a partial reflective element BS, and a 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. During this process, the visual system can achieve zoom within the range of -5D to +2D. Figure 14 The left-middle figure shows a schematic diagram 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 14 The middle right figure shows a schematic diagram of the visual system when the second lens group and the second lens barrel Pb move along the optical axis to the position furthest 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 in this embodiment is the same as Table 4 in Embodiment 4, the values ​​of parameters D1 to D5 are the same as Table 5 in Embodiment 4, and the table of higher-order coefficients of the aspherical mirror is the same as Table 6 in Embodiment 4.

[0147] The numerical values ​​of the structural parameters of the visual system in this embodiment are shown in the 'Embodiment 6' column of Table 10. The specific descriptions of the meanings represented by each parameter are the same as those in Embodiment 1 above, and will not be repeated here.

[0148] Figure 15 The MTF curves of the visual systems in Examples 4, 5, and 6 when they are in +2D mode are shown. Figure 16 The MTF curves of the visual systems of Examples 4, 5, and 6 in the -5D state are shown. Figure 15 and Figure 16 As can be seen, the visual systems given in Examples 4, 5 and 6 can achieve good imaging quality in both +2D and -5D focal length states.

[0149] Example 7

[0150] The following is for reference Figure 1 A visual system according to Embodiment 7 of this application is described. Parameter \ Example The left-middle figure shows a schematic diagram of the visual system according to Embodiment 7 of this application in the first state (+2D state). Example 1 The figure on the right shows a schematic diagram of the visual system according to Embodiment 7 of this application in the second state (-5D state).

[0151] As shown in Example 2 the visual system comprises a first lens barrel Pa and a second lens barrel Pb, which are arranged in sequence from a first side to a second side along an optical axis, and further comprises 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 comprises 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 comprises 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 a positive focal power, the first side S3 thereof is a convex surface, and the second side S4 thereof is a plane. The second lens E2 has a positive focal power, the first side S13 thereof is a concave surface, and the second side S14 thereof is a convex surface. The third lens E3 has a positive focal power, the first side S14 thereof is a concave surface, and the second side S15 thereof is a convex surface. The reflective polarizing element RP is arranged on the second side of the first lens E1, and the quarter-wave plate QWP is arranged on the second side of the reflective polarizing element RP. The second lens E2 and the third lens E3 are cemented lenses.

[0153] In this embodiment, the first side may, for example, be the side of the human eye, and the second side may, for example, be the side of the display. The second side of the visual system is provided with a display / image plane IMG. The first lens group comprising the first lens E1, the reflective polarizing element RP and the quarter-wave plate QWP and the first lens barrel Pa have a relatively fixed distance from the display / image plane IMG along the optical axis direction; the second lens group comprising the second lens E2, the partial reflection element BS and the third lens E3 and the second lens barrel Pb can be moved along the optical axis direction to approach or move away from the display / image plane IMG, during which the visual system can realize zooming in a range of -5D to +2D. Example 3 The left diagram in FIG. 7 shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved to the position closest to the display / image plane IMG along the optical axis, at which time the visual system is in a +2D state. Example 4 The right diagram in FIG. 7 shows a structural schematic diagram of the visual system when the second lens group and the second lens barrel Pb are moved to the position farthest from the display / image plane IMG along the optical axis, at which time the visual system is in a -5D state.

[0154] Table 7 shows a table of basic parameters of the visual system of Example 7, wherein the units of the curvature radius and the thickness / distance are 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, the values ​​of parameters D1 to D5 in Table 7 are shown in Table 8 below. The meanings of parameters D1 to D5 can be referred to the description in Embodiment 1.

[0159] D1 D2 D3 D4 D5 Example 5 500.0000 3.0597 -3.0597 3.0597 1.0000 Example 6 -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 gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical surface S3 and S13-S15 in Embodiment 7. The aspherical surface shape can be defined by the formula (1) given in Embodiment 1 above.

[0162] Example 7 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 each structural parameter of the visual system in this embodiment are shown in the 'Embodiment 7' column of Table 10. The specific description of the meaning of each parameter is the same as that in Embodiment 1 above, and will not be repeated here.

[0165] Example 8

[0166] The following is for reference Example 8 A visual system according to Embodiment 8 of this application is described.

[0167] like Example 9 As shown, similar to the visual system in Embodiment 7, the visual system in this embodiment also includes a first lens barrel Pa and a second lens barrel Pb, which are arranged sequentially from the first side to the second side along the optical axis. It 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. The first lens group includes a first lens E1, a reflective polarizing element RP and a quarter-wave plate QWP arranged sequentially from the first side to the second side along the optical axis. The second lens group includes a second lens E2, a partial reflective element BS (not shown in the figure) and a third lens E3 arranged sequentially from the first side to the second side along the optical axis.

[0168] As in Embodiment 7, in this embodiment, the first side can be, for example, the side of the human eye, and the second side can be, for example, the side of the display. The second side of the visual system is provided with a display / image surface IMG. 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 partially reflective element BS, and the third lens E3, and the second lens barrel Pb are movable along the optical axis to approach or move away from the display / image surface IMG, in the process of which the visual system can achieve zooming in a range of -5D to +2D. f1 (mm) The left middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position closest to the display / image surface IMG, at which time the visual system is in the first state (+2D state). f2 (mm) The right middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position farthest from the display / image surface IMG, at which 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 Embodiment 7, the numerical values of parameters D1 to D5 are the same as Table 8 in Embodiment 7, and the high-order term coefficient table of the aspherical surface is the same as Table 9 in Embodiment 7.

[0170] The numerical values of the structural parameters of the visual system of this embodiment are shown in the ‘Embodiment 8’ column in Table 10. Among them, the specific description of the meaning represented by each parameter is the same as described in Embodiment 1 above, and will not be repeated here.

[0171] Embodiment 9

[0172] The following refers to f3 (mm) A visual system according to Embodiment 9 of the present application is described.

[0173] As f23 (mm) indicated, the visual system in this embodiment also includes the first lens barrel Pa and the second lens barrel Pb, which are arranged in order from the first side to the second side along the optical axis, and also includes the first lens group supported on the first lens barrel Pa and the second lens group supported on the second lens barrel Pb, wherein the first lens group includes the first lens E1, the reflective polarizing element RP, and the quarter-wave plate QWP arranged in order from the first side to the second side along the optical axis, and the second lens group includes the second lens E2, the partially reflective element BS (not shown in the diagram), and the third lens E3 arranged in order from the first side to the second side along the optical axis.

[0174] In this embodiment, the first side can be, for example, the side of the human eye, and the second side can be, for example, the side of the display. The second side of the visual system is provided with a display / image surface IMG. The first lens group comprising 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 comprising the second lens E2, the partially reflective element BS and the third lens E3, and the second lens barrel Pb can be moved along the optical axis to approach or move away from the display / image surface IMG, in the process of which the visual system can achieve zooming in the range of -5D to +2D. fz (mm) The left middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position closest to the display / image surface IMG, at which time the visual system is in the first state (+2D state). EPD (mm) The right middle diagram shows a schematic structural diagram of the visual system when the second lens group and the second lens barrel Pb are moved along the optical axis to the position farthest from the display / image surface IMG, at which 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 Embodiment 7, and the numerical values of parameters D1 to D5 are also the same as Table 8 in Embodiment 7, and the high-order term coefficient table of the aspherical surface is also the same as Table 9 in Embodiment 7.

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

[0177] AL (mm) The MTF curves of the visual systems of Embodiments 7, 8 and 9 in the +2D state are shown in Af (mm) The MTF curves of the visual systems of Embodiments 7, 8 and 9 in the -5D state are shown by Condition / Example and Example 1 It can be seen that the visual systems given in Embodiments 7, 8 and 9 can achieve good imaging quality in both +2D and -5D different focal length states.

[0178] Table 10 shows the values of the das, dam, Das, Dam, dbs, dbm, Dbs, Dbm, La and Lb parameters of the visual systems according to the above-mentioned embodiments 1-9. Among them, at least part of the above-mentioned parameters can be measured according to the marking method shown in Example 2 , and the units of the parameters listed in Table 10 are all mm. It should be noted that the numerical values of the above-mentioned parameters of the visual systems of each embodiment in the +2D and -5D two different focal length states are all consistent respectively.

[0179]

[0180]

[0181] Table 10

[0182] In addition, in Embodiments 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 and the reflective polarizing element and the quarter-wave plate, the entrance pupil diameter EPD of the visual system, the distance AL of the second lens group moving along the optical axis during the switching of the visual system from the +2D state to the -5D state, and the change amount Af of the effective focal length of the visual system during the switching of the visual system from the +2D state to the -5D state are as shown in Table 11 below, respectively.

[0183] Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 (fz / f23) x (La / Lb) (dbs / dam) x Af das / (f1 / EPD) Dbs / (f2 / CT2) 115.14 115.14 115.14 104.23 104.23 104.23 99.12 99.12 99.12 Dam / (CT1+CTR+CTQ) 85.79 85.79 85.79 105.01 105.01 105.01 118.96 118.96 118.96 (Das-das) / AL -149.04 -149.04 -149.04 196.29 196.29 196.29 95.04 95.04 95.04 |f3 / CT3| / dbm 199.37 199.37 199.37 69.40 69.40 69.40 53.47 53.47 53.47 R1 / La 115.14 115.14 115.14 104.23 104.23 104.23 99.12 99.12 99.12 Lb / AL 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 |f3| / Dbm 2.21 2.21 2.21 2.22 2.22 2.22 2.22 2.22 2.22 dbm / Lb 0.67 0.67 0.67 1.36 1.36 1.36 1.66 1.66 1.66

[0184] Table 11

[0185] In addition, Embodiments 1 to 9 respectively satisfy the conditions shown in Table 12 below. The values of the conditions in Table 12 corresponding to the visual system of each of Embodiments 1 to 9 in the two different focal length states of +2D and -5D are respectively consistent.

[0186] (Dbm-Das) / Af (N2 / N3) x Lb La / N1 dbs / AL ​ ​ ​ ​ ​ ​ ​ 0.34 0.33 0.35 0.84 0.87 0.81 1.04 1.03 1.10 ​ 0.78 0.78 0.77 1.58 1.57 1.57 1.92 1.92 1.92 ​ 2.45 2.43 2.52 2.72 2.71 2.79 2.90 2.89 2.97 ​ 3.49 3.49 3.46 2.88 2.88 2.86 2.27 2.27 2.27 ​ 9.31 9.29 9.22 8.75 8.73 8.69 8.52 8.49 8.48 ​ 2.87 3.23 2.55 2.70 2.97 2.15 2.52 2.70 2.04 ​ 1.26 1.27 1.25 1.91 1.92 1.89 0.86 0.86 0.85 ​ 15.96 16.77 15.07 14.09 13.79 14.40 13.44 13.70 12.39 ​ 3.05 2.96 3.15 3.25 3.21 3.32 3.26 3.21 3.32 ​ 3.12 3.10 3.15 4.11 4.08 4.14 1.98 1.98 1.99 ​ 6.57 6.73 6.42 6.13 6.17 6.05 6.14 6.21 6.08 ​ 9.21 8.87 8.23 4.64 4.58 4.64 3.83 3.77 3.83 ​ 6.75 6.55 6.95 7.23 7.13 7.38 7.23 7.13 7.36 ​ 2.55 2.43 2.71 2.62 2.68 2.56 2.61 2.56 2.83 ​ 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 provided with an electronic photosensitive element for imaging, which can be a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS). The imaging device can be a stand-alone imaging apparatus such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the visual system described above.

[0189] The above description is merely preferred embodiments of the present application and a description of the principles of the technology used. Those skilled in the art will understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combinations of the technical features described above, and should also cover other technical solutions formed by any combination of the above technical features or equivalent features without departing from the concept of the application. For example, the above features can be replaced with technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. Vision system, characterized in that The visual system comprises a lens barrel group and a lens group, wherein, the lens barrel group comprises a first lens barrel and a second lens barrel arranged in sequence from a first side to a second side along an optical axis; the lens group comprises a first lens group and a second lens group arranged in sequence from a first side to a 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 comprises a first lens, a reflective polarizing element and a quarter-wave plate arranged in sequence from a first side to a second side along the optical axis, and the second lens group comprises a second lens, a partially reflective element and a third lens arranged in sequence from a first side to a second side along the optical axis; wherein the first lens has positive focal power, the first side surface is convex, and the second side surface is flat; the second lens has positive focal power, and the second side surface is convex; the third lens has positive focal power or negative focal power, the first side surface is concave, and the second side surface is convex; and the second lens and the third lens are cemented together; the second lens group is configured to be movable along the optical axis to approach or move away from a display located at the second side, and to switch the visual system between a first state and a second state; the visual system satisfies: 0.33≤(fz / f23)×(La / Lb)≤1.10, 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 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, 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, 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 effective focal length of the visual system when switching from the first state to the second state.

2. The vision system of claim 1, wherein, 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 central thickness CT2 of the second lens on the optical axis satisfy: 2.25mm<Dbs / (f2 / CT2)<3.5mm.

3. The vision system of claim 1, wherein, the outer diameter Dam of the second side end surface 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 satisfy: 8.45<Dam / (CT1+CTR+CTQ)<9.

35.

4. The vision system of claim 1, wherein, 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 surface of the second lens barrel satisfy: 0.85 mm -1 ≤ |f3 / CT3| / dbm ≤ 1.92 mm -1 .

5. The vision system of claim 1, wherein, 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 satisfy: 12.39≤R1 / La≤16.

77.

6. The vision system of claim 1, wherein, A maximum distance Lb of 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 and a distance ΔL of the second lens group moving along the optical axis during the switching of the visual system from the first state to the second state satisfy: 2.95 < Lb / ΔL < 3.

35.

7. The vision system of claim 1, wherein, An effective focal length f3 of the third lens and an outer diameter Dbm of the second side end face of the second lens barrel satisfy: 1.95 < |f3| / Dbm < 4.

15.

8. The vision system of claim 1, wherein, An inner diameter dbm of the second side end face of the second lens barrel and the maximum distance Lb of 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 satisfy: 6.05 ≤ dbm / Lb ≤ 6.

73.

9. The vision system of claim 1, wherein, A refractive index N2 of the second lens, a refractive index N3 of the third lens and the maximum distance Lb of 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 satisfy: 6.55 mm ≤ (N2 / N3) × Lb ≤ 7.38 mm.

10. The vision system of claim 1, wherein, A maximum distance La of 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 and a refractive index N1 of the first lens satisfy: 2.43 mm ≤ La / N1 ≤ 2.83 mm.

11. The vision system of claim 1, wherein, An inner diameter dbs of the first side end face of the second lens barrel and the distance ΔL of the second lens group moving along the optical axis during the switching of the visual system from the first state to the second state satisfy: 21.35 < dbs / ΔL < 21.

7.

12. The vision system of any one of claims 1 to 11, wherein, An inner diameter das of the first side end face of the first lens barrel, an effective focal length f1 of the first lens and an entrance pupil diameter EPD of the visual system satisfy: 2.4 mm < das / (f1 / EPD) < 3.0 mm.

13. The vision system of any one of claims 1 to 11, wherein, An 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 of the second lens group moving along the optical axis during the switching of the visual system from the first state to the second state satisfy: 2.0 < (Das-das) / ΔL < 3.

25.

14. The vision system of any one of claims 1 to 11, wherein, An outer diameter Dbm of the second side end face of the second lens barrel, an outer diameter Das of the first side end face of the first lens barrel and a change amount Δf of the effective focal length during the switching of the visual system from the first state to the second state satisfy: 3.77 ≤ (Dbm-Das) / Δf ≤ 9.21.

Images