Visual system

Abstract

The invention provides a visual system. The visual system can be switched between a first state and a second state; the curvature radius R5 of the first side surface of the third lens, the curvature radius R6 of the second side surface of the third lens and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis meet the condition that R6 / R5 * Lb is greater than or equal to 0.99 mm and less than or equal to 6.47 mm; the inner diameter dbs of the first side end face of the second lens barrel, the inner diameter dbm of the second side end face of the second lens barrel, and the distance delta L of the second optical element group moving along the optical axis when the visual system is switched between the first state and the second state meet the condition that (dbs-dbm) / delta L is larger than 0.8 and smaller than 2.7. According to the invention, the problem that structural members such as a lens cone of a visual system in the prior art are easy to generate reflection stray light is solved.

Description

Technical Field

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

[0002] With the further popularization of AR / VR (Augmented Reality / Virtual Reality) devices, consumers have put forward higher requirements for the lightness, image quality, and wearing experience of AR / VR. Traditional AR / VR devices based on aspherical and Fresnel technology are very heavy and can no longer meet the needs of consumers. With the introduction of the reentrant optical solution, the problem of VR device lightness has been greatly improved and has become the mainstream solution today.

[0003] Among people who use AR / VR, everyone's vision is different. There are many users with myopia or hyperopia, and the degree of myopia or hyperopia in different people's eyes is also different. If a fixed focal length reentrant module is used, the image quality seen will vary, and the experience effect will vary greatly. Therefore, it is necessary to design and develop a visual system with adjustable diopter so that users with different vision can see the image clearly without wearing glasses, thereby improving the VR visual experience. However, although the existing reentrant optical design based on the folded optical path performs well in shortening the lens length, there is still room for improvement in optical performance. For example, the side walls of the structural parts such as the lens barrel in the system are prone to reflective stray light, which interferes with the imaging and affects the image quality and clarity, which urgently needs to be improved. Summary of the invention

[0004] The main purpose of the present invention is to provide a visual system to solve the problem in the prior art that structural parts such as the lens barrel of the visual system are prone to generate reflected stray light.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present invention, a visual system is provided, comprising a lens barrel group and an optical element group, the optical element group only comprising three lenses with optical power, the lens barrel group comprising a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the optical element group comprising a first optical element group and a second optical element group, the first optical element group resting in the first lens barrel, and the second optical element group resting in the second lens barrel; the first optical element group comprising a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, the second optical element group comprising a third lens and a partial reflecting element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, the first side surface of the first lens is a convex surface, and the second lens has optical power. degrees, the third lens has positive focal power, and the second side surface of the third lens is convex; the second optical element group is configured to be movable along the optical axis to approach or move away from the display located on the second side, so that the visual system can switch between the first state and the second state; the radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the inner diameter dbs of the first side end surface of the second lens barrel, the inner diameter dbm of the second side end surface of the second lens barrel, and the distance ΔL moved by the second optical element group along the optical axis when the visual system switches between the first state and the second state satisfy: 0.8<(dbs-dbm) / ΔL<2.7.

[0006] According to another aspect of the present invention, a visual system is provided, comprising a lens barrel group and an optical element group, wherein the optical element group comprises only three lenses with optical power, 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 optical element group comprises a first optical element group and a second optical element group, the first optical element group rests in the first lens barrel, and the second optical element group rests in the second lens barrel; the first optical element group comprises a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, and the second optical element group comprises a third lens and a partial reflecting element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, and a first side surface of the first lens is a convex surface, The second lens has optical power, the third lens has positive optical power, and the second side surface of the third lens is convex; the second optical element group is configured to be movable along the optical axis to approach or move away from the display located on the second side, so that the visual system can switch between the first state and the second state; the radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel, and the center thickness CT2 of the second lens on the optical axis satisfy: 1.45≤La / CT2≤1.79.

[0007] Furthermore, the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel, the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis, and the entrance pupil diameter EPD of the visual system satisfy: 1.15≤(La+Lb) / EPD≤1.64.

[0008] Further, the inner diameter das of the first side end surface of the first lens barrel, the outer diameter Das of the first side end surface of the first lens barrel, and the center thickness CT1 of the first lens on the optical axis satisfy: 0.9<(Das-das) / CT1<2.85.

[0009] Further, a maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel, and a center thickness CT2 of the second lens on the optical axis satisfy: 1.45≤La / CT2≤1.79.

[0010] Furthermore, the outer diameter Das of the first side end surface of the first lens barrel, the outer diameter Dam of the second side end surface of the first lens barrel, and the effective focal length f1 of the first lens satisfy: 1.20≤f1 / (Das+Dam)≤1.62.

[0011] Further, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter dbs of the first side end surface of the second lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy: 1.15≤|f2 / f3|×(dam / dbs)≤4.05.

[0012] Furthermore, the outer diameter Dbs of the first side end surface of the second lens barrel, the outer diameter Dbm of the second side end surface of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 0.74≤(Dbs-Dbm) / Δf≤3.36.

[0013] Further, the inner diameter dbm of the second side end surface of the second lens barrel and the center thickness CT3 of the third lens on the optical axis satisfy: 6.47≤dbm / CT3≤12.72.

[0014] Further, the refractive index N1 of the first lens, the refractive index N2 of the second lens, and the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy: 5.49 mm≤(N1 / N2)×La≤8.09 mm.

[0015] Furthermore, the combined focal length fz of the first lens, the reflective polarizing element, the quarter wave plate and the second lens, the inner diameter das of the first side end surface of the first lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy: 0.87≤|fz| / (das+dam)≤6.56.

[0016] Furthermore, 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 curvature radius R1 of the first side surface of the first lens satisfy the following relationship: 14.82 mm ≤ das / (f1 / R1) ≤ 20.55 mm.

[0017] Further, the Abbe number V3 of the third lens, the refractive index V3 of the third lens, and the outer diameter Dbs of the first side end surface of the second lens barrel satisfy: 1.05 mm≤Dbs / (V3 / N3)≤2.46 mm.

[0018] Furthermore, the outer diameter Dam of the second side end surface of the first lens barrel, the inner diameter dam of the second side end surface of the first lens barrel, and the distance ΔL moved by the second optical element group along the optical axis when the visual system switches between the first state and the second state satisfy: 0.54≤(Dam-dam) / ΔL≤3.00.

[0019] Further, an outer diameter Das of the first side end surface of the first lens barrel and a maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy: 4.41≤Das / La≤8.47.

[0020] According to the technical solution of the present invention, the visual system includes a lens barrel group and an optical element group, the optical element group includes only three lenses with optical power, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens and a partial reflection element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, the first side surface of the first lens is a convex surface, the second lens has optical power, and the third lens has Positive optical power, the second side surface of the third lens is convex; the second optical element group is configured to be movable along the optical axis to approach or move away from the display located on the second side, so that the visual system can switch between the first state and the second state; the radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the inner diameter dbs of the first side end surface of the second lens barrel, the inner diameter dbm of the second side end surface of the second lens barrel, and the distance ΔL moved by the second optical element group along the optical axis when the visual system switches between the first state and the second state satisfy: 0.8<(dbs-dbm) / ΔL<2.7.

[0021] The visual system in the present application is formed by two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate and a partial reflective element. By reasonably setting the visual system to meet 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, the deflection angle of the light on the first side surface of the third lens and the second side surface of the third lens can be constrained, so that the light can smoothly pass through the inner diameter of the first side end surface of the second lens barrel and the inner diameter of the second side end surface of the second lens barrel, and the light deflected to the first side end surface of the second lens barrel and the second side end surface of the second lens barrel is reduced, thereby reducing the generation of stray light and improving the imaging quality. At the same time, the maximum distance of the second optical element group moving along the optical axis is constrained, so that the visual system can reduce the stray light generated by the reflection of the second lens barrel in different states, thereby ensuring the imaging quality of the visual system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1A parameter annotation diagram of a visual system of an optional embodiment of the present invention is shown;

[0024] Figure 2 and Figure 3 The schematic diagrams of the structure of the visual system of Example 1-1 of the present invention in the first state and the second state are respectively shown;

[0025] Figure 4 and Figure 5 The schematic diagrams of the structures of the visual system of Embodiments 1-2 of the present invention in the first state and the second state are shown respectively;

[0026] Figure 6 and Figure 7 The schematic diagrams of the structures of the visual systems of Embodiments 1 to 3 of the present invention in the first state and the second state are shown respectively;

[0027] Figure 8 and Fig. 9 The MTF curve diagrams of the visual system of the first embodiment of the present invention in the first state and the second state are respectively shown;

[0028] Fig.10 and Fig.11 The schematic diagrams of the structure of the visual system of Example 2-1 of the present invention in the first state and the second state are respectively shown;

[0029] Fig.12 and Fig.13 The schematic diagrams of the structure of the visual system of Example 2-2 of the present invention in the first state and the second state are respectively shown;

[0030] Fig.14 and Fig.15 The schematic diagrams of the structures of the visual system of Embodiments 2-3 of the present invention in the first state and the second state are shown respectively;

[0031] Fig.16 and Fig.17 The MTF curves of the visual system of the second embodiment of the present invention in the first state and the second state are shown respectively;

[0032] Fig.18 and Fig.19 The schematic diagrams of the structure of the visual system of Example 3-1 of the present invention in the first state and the second state are respectively shown;

[0033] Fig. 20 and Fig.21 The schematic diagrams of the structure of the visual system of Example 3-2 of the present invention in the first state and the second state are respectively shown;

[0034] Fig. 22 and Fig.23The schematic diagrams of the structure of the visual system of Example 3-3 of the present invention in the first state and the second state are respectively shown;

[0035] Fig.24 and Fig.25 The MTF curves of the visual system of the third embodiment of the present invention in the first state and the second state are shown respectively;

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

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

[0038] Fig.28 Shows Fig. 27 The stray light spot diagram of the visual system in the image;

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

[0040] Fig.30 Shows Fig.29 The stray light spot diagram of the visual system.

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

[0042] E1, first lens; RP, reflective polarizing element; QWP1, quarter wave plate; E2, second lens; E3, third lens; BS, partial reflection element; Pa, first lens barrel; Pb, second lens barrel; IMG, image plane; IR / CG, filter and / or protective glass. DETAILED DESCRIPTION

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0045] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0046] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0048] In this document, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The paraxial region refers to the region near the optical axis. The surface of each lens closest to the first side (e.g., the human eye side) is called the first side surface of the lens, and the surface of each lens closest to the second side (e.g., the display screen side) is called the second side surface of the lens.

[0049] The visual system of the exemplary embodiment of the present application can be simulated by software and / or tools such as ZEMAX and CODEV. Alternatively, the visual system can be simulated by CODEV software. In the process of simulation using the above software and / or tools, the surface shape of each lens can be appropriately adjusted according to the surface shape model of the software and / or tool used.

[0050] In order to solve the problem that the lens barrel and other structural parts of the visual system in the prior art are prone to generate reflected stray light, the present invention provides a visual system.

[0051] like Figures 1 to 25As shown, the visual system includes a lens barrel group and an optical element group, the optical element group includes only three lenses with optical power, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens and a partial reflection element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, the first side surface of the first lens is a convex surface, the second lens has optical power, and the third lens has positive optical power , the second side surface of the third lens is convex; the second optical element group is configured to be movable along the optical axis to approach or move away from the display located on the second side, so that the visual system switches between the first state and the second state; the radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the inner diameter dbs of the first side end surface of the second lens barrel, the inner diameter dbm of the second side end surface of the second lens barrel, and the distance ΔL moved by the second optical element group along the optical axis when the visual system switches between the first state and the second state satisfy: 0.8<(dbs-dbm) / ΔL<2.7.

[0052] The visual system in the present application is formed by two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate and a partial reflective element. By reasonably setting the visual system to meet 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, the deflection angle of the light on the first side surface of the third lens and the second side surface of the third lens can be constrained, so that the light can smoothly pass through the inner diameter of the first side end surface of the second lens barrel and the inner diameter of the second side end surface of the second lens barrel, and the light deflected to the first side end surface of the second lens barrel and the second side end surface of the second lens barrel is reduced, thereby reducing the generation of stray light and improving the imaging quality. At the same time, the maximum distance of the second optical element group moving along the optical axis is constrained, so that the visual system can reduce the stray light generated by the reflection of the second lens barrel in different states, thereby ensuring the imaging quality of the visual system.

[0053] In an exemplary embodiment, the first lens barrel, the second lens barrel, the first optical element group and the second optical element group of the visual system are configured as described above, and by setting the above two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL to satisfy different numerical ranges, three different visual system solutions can be formed as follows:

[0054] In the visual system of the first scheme, the above two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL respectively satisfy |R6 / R5|×Lb=2.74mm and (dbs-dbm) / ΔL=1.18. It can be seen that the values ​​of the two conditional expressions are respectively within the range of 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7. The stray light path of the visual system is as follows: Fig.26 As shown, the deflection angle of the light in the third lens is changed, and the stray light formed by the second lens barrel falls outside the receiving range of the human eye, which reduces the stray light entering the human eye and ensures the imaging clarity.

[0055] In the visual system of the second scheme, the above two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL respectively satisfy |R6 / R5|×Lb=6.8mm and (dbs-dbm) / ΔL=3.0. It can be seen that the values ​​of the two conditional expressions are respectively greater than the upper limit values ​​defined by 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7. The stray light path of the visual system is as follows: Fig. 27 As shown in the figure, the stray light spot diagram of the visual system is as follows Fig.28 As shown, the visual system has a lot of stray light. For example, the stray light reflected by the first side of the second lens barrel falls into the reception range of the human eye, and the intensity of the stray light is high, which has a great impact on the imaging effect.

[0056] In the visual system of the third scheme, the above two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL respectively satisfy |R6 / R5|×Lb=0.6mm and (dbs-dbm) / ΔL=0.5. It can be seen that the values ​​of the two conditional expressions are respectively less than the lower limits defined by 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7. The stray light path of the visual system is as follows: Fig.29 As shown in the figure, the stray light spot diagram of the visual system is as follows Fig.30 As shown, the visual system has a lot of stray light. For example, the stray light reflected by the minimum inner diameter of the second lens barrel falls within the acceptance range of the human eye, and the intensity of the stray light is high, which has a greater impact on the imaging effect.

[0057] In some optional embodiments, the distance of the first optical element group relative to the display or image surface on the second side of the visual system on the optical axis can be fixed, and the second optical element group can be configured to be able to move along the optical axis to approach or move away from the display or image surface on the second side of the visual system and enable the visual system to switch between the first state and the second state. Specifically, when the second optical element group moves to the position closest to the display or image surface, the distance between the second optical element group and the first optical element group on the optical axis is the largest, and the visual system can be in the +2D state, that is, the first state; when the second optical element group moves to the position farthest from the display or image surface, the distance between the second optical element group and the first optical element group on the optical axis is the smallest, and the visual system can be in the -5D state, that is, the second state.

[0058] Exemplarily, when the visual system is in the first state, the diopter of the visual system is +2D, for example, it is applicable to users with a diopter of +2D; when the visual system is in the second state, the diopter of the visual system is -5D, for example, it is applicable to users with a diopter of -5D. Wherein, when the sign of the diopter is a negative sign, it may indicate that the user is a myopic user; when the sign of the diopter is a positive sign, it may indicate that the user is a hyperopic user; the specific value of the diopter may indicate the diopter of the user. For example, a diopter of +1D may indicate that the user's hyperopia is approximately 100 degrees, and a diopter of -1D may indicate that the user's myopia is approximately 100 degrees.

[0059] It should be understood that, in addition to the first state and the second state, the visual system according to the embodiment of the present application may also have other states, for example, between -5D and +2D. The visual system according to the embodiment of the present application can achieve continuous zooming within the range of -5D to +2D, which can meet the needs of users with different vision, so that users can enjoy the VR experience without wearing glasses.

[0060] In an exemplary embodiment, the visual system of the present application may include at least one aperture. The aperture may constrain the optical path and control the light intensity. The aperture may be set at an appropriate position of the visual system as required, for example, the aperture may be located between the first side (e.g., the human eye side) and the first lens.

[0061] In an exemplary embodiment, the visual system has different virtual image distances VID in the first state and the second state, and the virtual image distance may be, for example, the distance from the virtual image formed by the image light from the second side at a predetermined position to the aperture on the optical axis, wherein VID=1000 / diopter.

[0062] In some optional embodiments, the maximum distance La between the first side end face of the first lens barrel and the second side end face of the first lens barrel, the maximum distance Lb from the first side end face of the second lens barrel to the second side end face of the second lens barrel on the optical axis, and the entrance pupil diameter EPD of the visual system satisfy: 1.15≤(La+Lb) / EPD≤1.64. By constraining (La+Lb) / EPD within a reasonable range, the maximum length of the first lens barrel and the second lens barrel can be constrained, which indirectly constrains the overall length of the visual system, which is conducive to the miniaturized design of the visual system. At the same time, the entrance pupil diameter is increased, which is conducive to improving the performance degradation caused by pupil deviation when the human eye rotates, thereby improving the comfort during visual viewing and further improving the user experience.

[0063] In some optional embodiments, the inner diameter das of the first side end surface of the first lens barrel, the outer diameter Das of the first side end surface of the first lens barrel, and the center thickness CT1 of the first lens on the optical axis satisfy: 0.9<(Das-das) / CT1<2.85. By constraining (Das-das) / CT1 within a reasonable range, the outer dimensions of the first lens barrel and the thickness of the first lens barrel can be constrained. Under the premise of ensuring that the first lens barrel can be processed, the outer dimensions of the first lens barrel are as small as possible, thereby reducing the overall size of the visual system, while ensuring that the front end of the first lens barrel can stably support the first lens, and ensuring the stability of the first lens assembly.

[0064] In some optional embodiments, the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel and the center thickness CT2 of the second lens on the optical axis satisfy: 1.45≤La / CT2≤1.79. By constraining La / CT2 within a reasonable range, the first lens barrel can be made as small as possible while ensuring that the first lens barrel can stably support the first lens and the second lens, thereby reducing the overall size of the visual system. In addition, constraining the center thickness of the second lens can ensure the structural strength of the second lens, and constraining the shape of the second lens can reduce the sensitivity of the second lens, thereby improving the assembly yield.

[0065] In some optional embodiments, the outer diameter Das of the first side end surface of the first lens barrel, the outer diameter Dam of the second side end surface of the first lens barrel, and the effective focal length f1 of the first lens satisfy: 1.20≤f1 / (Das+Dam)≤1.62. By constraining f1 / (Das+Dam) within a reasonable range, the outer diameter of the first lens barrel can be controlled, and then the size of the visual system can be indirectly controlled, while constraining the effective focal length and outer diameter of the first lens, so that the structure can support the lens and ensure the processing feasibility.

[0066] In some optional embodiments, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter dbs of the first side end surface of the second lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy the following relationship: 1.15≤|f2 / f3|×(dam / dbs)≤4.05. By constraining |f2 / f3|×(dam / dbs) within a reasonable range, the inner diameters of the first lens barrel and the second lens barrel can be controlled, which is conducive to miniaturization. At the same time, by constraining the focal lengths of the second lens and the third lens, the deflection angles of the second lens and the third lens can be controlled, which is conducive to the light rays smoothly passing through the inner diameter of the second side end surface of the first lens barrel and the inner diameter of the first side end surface of the second lens barrel while returning between the second lens and the third lens, reducing the reflected stray light formed by the light rays at the first lens barrel and the second lens barrel. At the same time, the reasonable distribution of the optical power of the second lens and the third lens is also conducive to correcting the aberration of the visual system, thereby improving the performance of the visual system.

[0067] In some optional embodiments, the outer diameter Dbs of the first side end face of the second lens barrel, the outer diameter Dbm of the second side end face of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 0.74≤(Dbs-Dbm) / Δf≤3.36. By constraining (Dbs-Dbm) / Δf within a reasonable range, the outer diameter of the second lens barrel can be constrained, and the overall size of the visual system can be indirectly controlled, which is conducive to miniaturization of the visual system. At the same time, constraining the difference Δf can ensure that the visual system can achieve continuous zooming, and clear imaging can be achieved at different diopters, thereby ensuring the optical performance of the visual system. The visual system has the advantages of miniaturization and clear imaging at different diopters.

[0068] In some optional embodiments, the inner diameter dbm of the second side end surface of the second lens barrel and the center thickness CT3 of the third lens on the optical axis satisfy: 6.47≤dbm / CT3≤12.72. By constraining dbm / CT3 within a reasonable range, the assembly stability of the third lens in the lens barrel can be guaranteed, and on the other hand, the relationship between the center thickness of the third lens and its outer diameter is restricted, thereby ensuring the processing feasibility of the third lens.

[0069] In some optional embodiments, the refractive index N1 of the first lens, the refractive index N2 of the second lens, and the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy the following: 5.49 mm ≤ (N1 / N2) × La ≤ 8.09 mm. By constraining (N1 / N2) × La within a reasonable range, the length of the first lens barrel can be constrained, which is conducive to improving the machinability of the lens barrel on the basis of ensuring its limiting lens function. At the same time, the refractive indexes of the first lens and the second lens are constrained so as to constrain the deflection angle of the light in the first lens barrel, so as to avoid the formation of stray light due to the light being emitted to the inner wall of the first lens barrel due to the first lens barrel being too long, and the unstable assembly and light leakage caused by the first lens barrel being too short can also be avoided.

[0070] In some optional embodiments, the combined focal length fz of the first lens, the reflective polarizing element, the quarter wave plate and the second lens, the inner diameter das of the first side end surface of the first lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy: 0.87≤|fz| / (das+dam)≤6.56. By constraining |fz| / (das+dam) within a reasonable range, the spherical aberration generated by other lenses in the visual system can be balanced, so that the imaging quality of the visual system on the optical axis is good, and at the same time, the outer diameter of the first lens barrel is controlled to ensure that the first lens barrel has a limiting effect on the lens, which is conducive to improving the processability of the first lens.

[0071] In some optional embodiments, 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 curvature radius R1 of the first side surface of the first lens satisfy the following: 14.82mm≤das / (f1 / R1)≤20.55mm. By constraining das / (f1 / R1) within a reasonable range and controlling the effective focal length of the first lens and the curvature radius of the first side surface of the first lens, the shape of the first lens can be constrained, which is beneficial to reducing the sensitivity of the first lens, thereby improving the assembly yield, and can also control the deflection angle of the light in the first lens barrel, reducing the risk of reflected stray light generated by the inner wall surface of the first lens barrel, and at the same time constraining the inner diameter of the first side end surface of the first lens barrel, on the basis of ensuring the limiting effect of the first lens barrel on the lens, the feasibility of forming the lens barrel is improved.

[0072] In some optional embodiments, the Abbe number V3 of the third lens, the refractive index V3 of the third lens, and the outer diameter Dbs of the first side end surface of the second lens barrel satisfy the following relationship: 1.05mm≤Dbs / (V3 / N3)≤2.46mm. By constraining Dbs / (V3 / N3) within a reasonable range, it is helpful to control the deflection angle of light passing through the third lens to reduce the incident angle of light on the screen. At the same time, the outer diameter of the second lens barrel is constrained, and the overall size of the visual system is indirectly controlled, which is beneficial to miniaturization of the visual system.

[0073] In some optional embodiments, the outer diameter Dam of the second side end surface of the first lens barrel, the inner diameter dam of the second side end surface of the first lens barrel, and the distance ΔL that the second optical element group moves along the optical axis when the visual system switches between the first state and the second state satisfy: 0.54≤(Dam-dam) / ΔL≤3.00. By constraining (Dam-dam) / ΔL within a reasonable range, the inner and outer diameters of the second side end surface of the first lens barrel and the distance that the second optical element group can move can be constrained, which can indirectly constrain the size of the visual system, which is conducive to the miniaturization of the visual system. At the same time, by constraining the thickness of the second side end surface of the first lens barrel, the structural strength of the first lens barrel can be ensured, which is conducive to improving the stability of the internal structure of the first lens barrel.

[0074] In some optional embodiments, the outer diameter Das of the first side end surface of the first lens barrel and the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy: 4.41≤Das / La≤8.47. By constraining Das / La within a reasonable range, on the one hand, the processing feasibility of the front end of the first lens barrel can be controlled, which is conducive to the assembly of the lens into the first lens barrel and the assembly stability between the lenses is ensured, and at the same time, the overall shape and length of the first lens barrel are limited, which is conducive to the miniaturization of the first lens barrel, and then to the miniaturization of the whole machine.

[0075] On the other hand, an optional embodiment of the present invention, the visual system includes a lens barrel group and an optical element group, the optical element group includes only three lenses with optical power, the lens barrel group includes a first lens barrel and a second lens barrel arranged in sequence from the first side to the second side along the optical axis; the optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and the second optical element group is supported in the second lens barrel; the first optical element group includes a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens and a partial reflection element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, and the first side surface of the first lens is a convex surface , the second lens has optical power, the third lens has positive optical power, and the second side surface of the third lens is convex; the second optical element group is configured to be movable along the optical axis to approach or move away from the display located on the second side, so that the visual system switches between the first state and the second state; the radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel, and the center thickness CT2 of the second lens on the optical axis satisfy: 1.45≤La / CT2≤1.79.

[0076] The visual system in the present application is formed by two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate and a partial reflective element. By reasonably setting the visual system to meet 0.99mm≤|R6 / R5|×Lb≤6.47mm and 1.45≤La / CT2≤1.79, the deflection angle of the light on the first side surface of the third lens and the second side surface of the third lens can be constrained, and the transmission optical path of the light in the second lens can be constrained, thereby changing the transmission path of the stray light, reducing the stray light transmitted to the human eye, and improving the imaging quality. At the same time, the maximum length of the first lens barrel and the maximum length of the second lens barrel are constrained, which can limit the size of the visual system and ensure the miniaturization of the visual system.

[0077] Of course, this implementation may also include other parameter formulas in the above optional embodiments, which will not be described one by one here.

[0078] Optionally, the visual system may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0079] In the present application, the mirror surface of at least one of the first lens to the third lens is an aspherical mirror surface. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0080] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the visual system can be changed to obtain the various results and advantages described in this specification. For example, although three lenses are used as an example in the embodiment, the visual system is not limited to including three lenses. If necessary, the visual system may also include other numbers of lenses.

[0081] Figure 1 A schematic diagram of dimension marking of a visual system of an optional embodiment of the present application is shown. Figure 1Parameters such as das, dam, Das, Dam, dbs, dbm, Dbs, Dbm, La, and Lb are marked in the figure to clearly and intuitively understand the meaning of the parameters. For the convenience of describing the visual system and the surface type of the specific lens, these parameters will no longer be reflected in the accompanying drawings when the specific embodiments are described later. The first side end face of the first lens barrel in the present application refers to the surface on which the first lens barrel is located closest to the first side and perpendicular to the optical axis, the second side end face of the first lens barrel refers to the surface on which the first lens barrel is located closest to the second side and perpendicular to the optical axis, the first side end face of the second lens barrel refers to the surface on which the second lens barrel is located closest to the first side and perpendicular to the optical axis, and the second side end face of the second lens barrel refers to the surface on which the second lens barrel is located closest to the second side and perpendicular to the optical axis.

[0082] The following further describes examples of specific surface shapes and parameters of the visual system applicable to the above-mentioned embodiment with reference to the accompanying drawings.

[0083] It should be noted that in the following embodiment 1, there are three examples of embodiment 1-1, embodiment 1-2, and embodiment 1-3; in embodiment 2, there are three examples of embodiment 2-1, embodiment 2-2, and embodiment 2-3; and in embodiment 3, there are three examples of embodiment 3-1, embodiment 3-2, and embodiment 2-3. In the three examples of the same embodiment, the parameters such as the radius of curvature, center thickness, and the spacing distance between the lenses and the coefficients of high-order terms of the visual system are the same, but the parameters such as the thickness, inner diameter, and outer diameter of the first lens barrel and the second lens barrel, as well as the shapes of some lenses are different. In other words, the main structure for imaging is the same, but the auxiliary structure for imaging is different.

[0084] It should be noted that any one of the following embodiments 1 to 3 is applicable to the present application.

[0085] Embodiment 1

[0086] like Figures 2 to 9 As shown, the visual system of embodiment 1 is described. Figure 2 FIG. 1 shows a schematic diagram of the structure of the visual system of Example 1-1 in the first state, Figure 3 FIG. 1 shows a schematic diagram of the structure of the visual system of Example 1-1 in the second state. Figure 4 shows a schematic structural diagram of the visual system of Embodiment 1-2 in the first state, Figure 5 shows a schematic diagram of the structure of the visual system of Example 1-2 in the second state, Figure 6 shows a schematic diagram of the structure of the visual system of Embodiments 1-3 in the first state, Figure 7 A schematic diagram of the structure of the visual system of Embodiments 1-3 in the second state is shown.

[0087] like Figures 2 to 7 As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first optical element group supported by the first lens barrel Pa and a second optical element group supported by the second lens barrel Pb, the first optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, and a second lens E2 arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens E3 and a partial reflection element BS arranged in sequence from the first side to the second side along the optical axis. The reflective polarizing element RP is arranged on the second side of the first lens, the quarter wave plate QWP is arranged on the second side of the reflective polarizing element RP, and the second lens is arranged on the second side of the quarter wave plate QWP. It can be understood that the first lens E1, the reflective polarizing element RP, the quarter wave plate QWP, and the second lens E2 are glued together. The partial reflection element BS is arranged on the second side of the third lens.

[0088] In summary, the structural parameters of the visual system of Example 1 in Example 1-1, Example 1-2, and Example 1-3 are shown in Table 11.

[0089] In the first embodiment, the first lens has positive power, the first side surface of the first lens is convex, and the second side surface of the first lens is flat; the second lens has positive power, the first side surface of the second lens is flat, and the second side surface of the second lens is convex; the third lens has positive power, the first side surface of the third lens is concave, and the second side surface of the third lens is convex. The visual system also includes a stop, which is located on the first side of the first lens.

[0090] Table 1 shows the basic structural parameters of the visual system of the first embodiment, wherein the units of the radius of curvature and thickness / distance are all in millimeters. In Table 1, the light from the image surface IMG propagates from the surface number 20 to the side of the surface number 1, and the refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage.

[0091]

[0092]

[0093] Table 1

[0094] The parameters D1 to D5 in Table 1 can be understood as follows: D1 can be understood as the value of the virtual image distance of the visual system according to this embodiment. D2 can be understood as the value from the second side surface of the second lens to the first side surface of the third lens along the optical axis; D3 can be understood as the value from the first side surface of the third lens to the second side surface of the second lens along the optical axis; D4 can be understood as the value from the second side surface of the second lens to the first side surface of the third lens along the optical axis; D5 can be understood as the value from the second side surface of the third lens to the first side surface of the filter and / or protective glass IR / CG located on the first side of the image surface IMG along the optical axis. It should be noted that during the transmission of light in the visual system, due to the presence of the reflective polarizing element, the quarter-wave plate, and the partial reflection element, the light will be folded back between some surfaces and will pass through the surface of some lenses many times. The distance of the light transmitted from the first side to the second side is positive, and the distance of the light transmitted from the second side to the first side is negative. In the process of the second optical element group moving along the optical axis to achieve zooming, the values ​​of the above parameters D1 to D5 will change accordingly.

[0095] The values ​​of D1 to D5 of the visual system in the first state and the second state are shown in Table 2 below.

[0096] D1 D2 D3 D4 D5 First state (+2D state) 500.0000 2.4964 -2.4964 2.4964 1.0000 Second state (-5D state) -200.0000 0.5000 -0.5000 0.5000 2.9964

[0097] Table 2

[0098] In the first embodiment, the first side surface of the first lens, the second side surface of the second lens, the first side surface of the third lens, and the second side surface of the third lens are aspherical surfaces, and the surface shape of each aspherical surface can be defined by but not limited to the following aspherical surface formula:

[0099]

[0100] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 3 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for the aspheric surface in Example 1.

[0101] Face number 3 7 16 17 A4 1.0169E-06 -3.9431E-06 -5.9739E-06 -2.1109E-07 A6 -4.2055E-09 5.7408E-09 2.4408E-09 -2.7191E-10 A8 8.4694E-12 -3.2742E-12 -3.9160E-13 1.0511E-12 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

[0102] Table 3

[0103] Figure 8 and Fig. 9 The MTF curves of the visual system of Example 1 in the first state and the second state are shown. The MTF values ​​under the light of each field of view are all above 0.7, showing good imaging quality.

[0104] Embodiment 2

[0105] like Figures 10 to 17 As shown, the visual system of embodiment 2 is described. Fig.10 FIG. 2 shows a schematic diagram of the structure of the visual system of Example 2-1 in the first state. Fig.11 FIG. 2 shows a schematic diagram of the structure of the visual system of Example 2-1 in the second state. Fig.12 FIG. 2 shows a schematic diagram of the structure of the visual system of Example 2-2 in the first state. Fig.13 FIG. 2 shows a schematic diagram of the structure of the visual system of Example 2-2 in the second state. Fig.14 shows a schematic structural diagram of the visual system of Example 2-3 in the first state, Fig.15 A schematic diagram of the structure of the visual system of Example 2-3 in the second state is shown.

[0106] like Figures 10 to 15 As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first optical element group supported by the first lens barrel Pa and a second optical element group supported by the second lens barrel Pb, the first optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, and a second lens E2 arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens E3 and a partial reflection element BS arranged in sequence from the first side to the second side along the optical axis. The reflective polarizing element RP is arranged on the second side of the first lens, the quarter wave plate QWP is arranged on the second side of the reflective polarizing element RP, and the second lens is arranged on the second side of the quarter wave plate QWP. It can be understood that the first lens E1, the reflective polarizing element RP, the quarter wave plate QWP, and the second lens E2 are glued together. The partial reflection element BS is arranged on the second side of the third lens.

[0107] In summary, the structural parameters of the visual system of Example 2 in Example 2-1, Example 2-2, and Example 2-3 are shown in Table 11.

[0108] In the second embodiment, the first lens has positive focal power, the first side surface of the first lens is convex, and the second side surface of the first lens is concave; the second lens has negative focal power, the first side surface of the second lens is convex, and the second side surface of the second lens is concave; the third lens has positive focal power, the first side surface of the third lens is convex, and the second side surface of the third lens is convex. The visual system also includes a stop, which is located on the first side of the first lens.

[0109] Table 4 shows the basic structural parameters of the visual system of Example 2, where the units of the radius of curvature and thickness / distance are all in millimeters. In Table 4, the light from the image surface IMG propagates from the surface number 21 to the side of the surface number 1, and the refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage.

[0110]

[0111]

[0112] Table 4

[0113] The values ​​of D1 to D5 of the visual system in the first state and the second state are shown in Table 5 below.

[0114] D1 D2 D3 D4 D5 First state (+2D state) 500.0000 1.3378 -1.3378 1.3378 0.1276 Second state (-5D state) -200.0000 0.1000 -0.1000 0.1000 0.2632

[0115] Table 5

[0116] Table 6 shows the coefficients of the higher order terms that can be used for each aspherical mirror surface in this embodiment, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. In this embodiment, the first side surface of the first lens, the second side surface of the second lens, the first side surface of the third lens, and the second side surface of the third lens are aspherical surfaces.

[0117] Face number 3 7 16 17 A4 1.3824E-06 -4.5944E-06 -7.1887E-06 -1.6732E-07 A6 -1.2784E-09 -1.9725E-09 1.5743E-09 -1.2878E-09 A8 2.4030E-12 2.6015E-13 -1.2408E-11 -2.8083E-13 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

[0118] Table 6

[0119] Fig.16 and Fig.17 The MTF curves of the visual system of Example 2 in the first state and the second state are shown. The MTF values ​​under the light of each field of view are all above 0.7, showing good imaging quality.

[0120] Embodiment 3

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

[0122] like Figures 18 to 23 As shown, the visual system includes a first lens barrel Pa and a second lens barrel Pb arranged in sequence from the first side to the second side along the optical axis. The visual system also includes a first optical element group supported by the first lens barrel Pa and a second optical element group supported by the second lens barrel Pb, the first optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, and a second lens E2 arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens E3 and a partial reflection element BS arranged in sequence from the first side to the second side along the optical axis. The reflective polarizing element RP is arranged on the second side of the first lens, the quarter wave plate QWP is arranged on the second side of the reflective polarizing element RP, and the second lens is arranged on the second side of the quarter wave plate QWP. It can be understood that the first lens E1, the reflective polarizing element RP, the quarter wave plate QWP, and the second lens E2 are glued together. The partial reflection element BS is arranged on the second side of the third lens.

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

[0124] In the third embodiment, the first lens has positive focal power, the first side surface of the first lens is convex, and the second side surface of the first lens is concave; the second lens has positive focal power, the first side surface of the second lens is convex, and the second side surface of the second lens is convex; the third lens has positive focal power, the first side surface of the third lens is convex, and the second side surface of the third lens is convex. The visual system also includes an aperture, which is located on the first side of the first lens.

[0125] Table 7 shows the basic structural parameters of the visual system of Example 3, where the units of the radius of curvature and thickness / distance are all in millimeters. In Table 7, the light from the image surface IMG propagates from the surface number 21 to the side of the surface number 1, and the refraction / reflection refers to the refraction or reflection effect of the surface on the light during this passage.

[0126] Face number Surface type Radius of curvature thickness Refractive Index Dispersion coefficient Refraction / Reflection Cone coefficient Spherical endless D1 refraction 1 Spherical endless 0.0000 refraction 2 Aperture (STO) Spherical endless 12.0000 refraction 3 First lens (E1) Aspheric 64.5487 3.5000 1.490 70.40 refraction 1.3701 4 Reflective polarizer (RP) Spherical 527.9075 0.1180 1.487 57.47 refraction 5 Quarter Wave Plate (QWP) Spherical 527.9075 0.1340 1.487 57.47 refraction 6 Second lens (E2) Spherical 527.9075 3.7765 1.490 70.40 refraction 7 Aspheric -500.0000 D2 refraction 4.3746 8 Third lens (E3) Aspheric 151.7201 3.7477 1.490 70.40 refraction -5.6027 9 Partially reflective element (BS) Aspheric -105.3251 -3.7477 1.490 70.40 reflection 1.5612 10 Aspheric 151.7201 D3 refraction -5.6027 11 Aspheric -500.0000 -3.7765 1.490 70.40 refraction 4.3746 12 Spherical 527.9075 -0.1340 1.487 57.47 refraction 13 Reflective polarizer (RP) Spherical 527.9075 0.1340 1.487 57.47 reflection 14 Second lens (E2) Spherical 527.9075 3.7765 1.490 70.40 refraction 15 Aspheric -500.0000 D4 refraction 4.3746 16 Third lens (E3) Aspheric 151.7201 3.7477 1.490 70.40 refraction -5.6027 17 Aspheric -105.3251 D5 refraction 1.5612 18 Spherical endless 0.2000 refraction 19 Spherical endless 0.7000 1.519 64.17 refraction 20 Spherical endless 0.0000 refraction 21 Image surface (IMG) Spherical endless 0.0000 refraction

[0127] Table 7

[0128] The values ​​of D1 to D5 of the visual system in the first state and the second state are shown in Table 8 below.

[0129] D1 D2 D3 D4 D5 First state (+2D state) 500.0000 5.8715 -5.8715 5.8715 0.1000 Second state (-5D state) -200.0000 2.6460 -2.6460 2.6460 2.4206

[0130] Table 8

[0131] Table 9 shows the coefficients of the higher order terms that can be used for each aspherical mirror surface in this embodiment, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. In this embodiment, the first side surface of the first lens, the second side surface of the second lens, the first side surface of the third lens, and the second side surface of the third lens are aspherical surfaces.

[0132] Face number 3 7 16 17 A4 3.1529E-06 -4.7305E-06 -9.8957E-06 -7.1448E-07 A6 -3.5374E-09 -4.3884E-09 1.3914E-09 1.6825E-10 A8 6.1799E-12 7.7723E-12 -8.7757E-13 1.9656E-12 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

[0133] Table 9

[0134] Fig.24 and Fig.25 The MTF curves of the visual system of Example 3 in the first state and the second state are shown. The MTF values ​​under the light of each field of view are all above 0.7, showing good imaging quality.

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

[0136] Conditional / Example 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 |R6 / R5|×Lb(mm) 0.99 1.05 1.13 6.47 6.34 5.85 2.74 2.94 2.60 (dbs-dbm) / ΔL 1.60 1.91 1.27 2.67 1.77 2.34 1.18 1.10 0.82 (La+Lb) / EPD 1.32 1.26 1.31 1.64 1.59 1.57 1.34 1.29 1.15 (Das-das) / CT1 1.18 1.00 0.91 2.47 1.60 1.51 2.84 2.28 2.84 La / CT2 1.76 1.58 1.61 1.73 1.68 1.69 1.79 1.61 1.45 f1 / (Das+Dam) 1.21 1.20 1.20 1.59 1.61 1.62 1.54 1.58 1.58 |f2 / f3|×(dam / dbs) 1.16 1.15 1.17 2.22 2.26 2.25 4.05 3.97 4.03 (Dbs-Dbm) / Δf 1.27 2.19 1.15 3.36 1.42 1.91 0.75 0.74 0.75 dbm / CT3 12.59 12.48 12.72 6.47 6.59 6.52 11.95 12.13 12.03 (N1 / N2)×La(mm) 7.14 6.40 6.51 8.09 7.84 7.89 6.78 6.09 5.49 |fz| / (das+dam) 0.89 0.87 0.87 6.56 6.41 6.46 1.38 1.37 1.41 das / (f1 / R1)(mm) 19.56 20.55 20.30 14.82 15.40 15.17 16.09 16.39 15.76 Dbs / (V3 / N3)(mm) 1.30 1.29 1.30 2.46 2.41 2.43 1.07 1.08 1.05 (Dam-dam) / ΔL 1.15 0.92 1.27 2.77 2.90 3.00 0.71 0.54 0.54 Das / La 5.77 6.58 6.33 4.53 4.53 4.41 6.97 7.55 8.47

[0137] Table 10

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

[0139] Parameters / Examples 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 das 35.484 37.295 36.840 35.683 37.067 36.520 37.325 38.020 36.569 dam 42.739 42.654 43.041 43.776 44.187 44.170 47.810 47.261 46.712 Das 41.179 42.137 41.241 43.431 42.080 41.246 47.269 45.989 46.514 Dam 45.030 44.489 45.573 47.202 47.776 47.889 50.101 49.003 48.466 dbs 44.843 45.095 44.600 46.391 46.082 46.327 48.585 49.017 47.729 dbm 41.658 41.281 42.072 43.082 43.891 43.430 44.784 45.469 45.072 Dbs 47.058 46.711 47.322 48.606 47.535 47.885 50.465 51.093 49.419 Dbm 45.659 44.305 46.058 46.535 46.662 46.710 48.909 49.559 47.864 La 7.138 6.403 6.510 9.583 9.285 9.349 6.779 6.092 5.489 Lb 3.439 3.639 3.931 3.532 3.461 3.193 3.950 4.239 3.741 f1 104.06 104.06 104.06 144.40 144.40 144.40 149.78 149.78 149.78 f2 197.26 197.26 197.26 -107.95 -107.95 -107.95 524.92 524.92 524.92 f3 162.38 162.38 162.38 45.83 45.83 45.83 127.54 127.54 127.54 fz 69.48 69.48 69.48 -521.09 -521.09 -521.09 117.23 117.23 117.23 EPD 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 ΔL 1.9964 1.9964 1.9964 1.2378 1.2378 1.2378 3.2254 3.2254 3.2254 Δf 1.1011 1.1011 1.1011 0.6165 0.6165 0.6165 2.0729 2.0729 2.0729

[0140] Table 11

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

[0142] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0143] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0144] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0145] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A visual system, characterized in that: The optical device comprises a lens barrel group and an optical element group, wherein the optical element group comprises only three lenses having optical power. The lens barrel assembly comprises a first lens barrel and a second lens barrel arranged in sequence from a first side to a second side along the optical axis; The optical element group includes a first optical element group and a second optical element group, the first optical element group is supported in the first lens barrel, and the second optical element group is supported in the second lens barrel; The first optical element group includes a first lens, a reflective polarizing element, a quarter wave plate, and a second lens arranged in sequence from the first side to the second side along the optical axis, and the second optical element group includes a third lens and a partial reflective element arranged in sequence from the first side to the second side along the optical axis, wherein the first lens has positive optical power, a first side surface of the first lens is a convex surface, the second lens has optical power, the third lens has positive optical power, and a second side surface of the third lens is a convex surface; The second optical element group is configured to be movable along the optical axis to be closer to or farther from the display located at the second side, so that the visual system switches between the first state and the second state; The radius of curvature R5 of the first side surface of the third lens, the radius of curvature R6 of the second side surface of the third lens, and the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis satisfy the following conditions: 0.99 mm ≤ |R6 / R5|×Lb ≤ 6.47 mm; The inner diameter dbs of the first side end surface of the second lens barrel, the inner diameter dbm of the second side end surface of the second lens barrel, and the distance ΔL that the second optical element group moves along the optical axis when the visual system switches between the first state and the second state satisfy: 0.8<(dbs-dbm) / ΔL<2.

7.

2. The visual system according to claim 1, characterized in that: The maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel, the maximum distance Lb from the first side end surface of the second lens barrel to the second side end surface of the second lens barrel on the optical axis, and the entrance pupil diameter EPD of the visual system satisfy the following: 1.15≤(La+Lb) / EPD≤1.

64.

3. The visual system according to claim 1, characterized in that: An inner diameter das of the first side end surface of the first barrel, an outer diameter Das of the first side end surface of the first barrel, and a center thickness CT1 of the first lens on the optical axis satisfy the following: 0.9<(Das-das) / CT1<2.

85.

4. The visual system according to claim 1, characterized in that: A maximum distance La between a first side end surface of the first lens barrel and a second side end surface of the first lens barrel and a center thickness CT2 of the second lens on the optical axis satisfy the following: 1.45≤La / CT2≤1.

79.

5. The visual system according to claim 1, characterized in that: An outer diameter Das of a first side end surface of the first lens barrel, an outer diameter Dam of a second side end surface of the first lens barrel, and an effective focal length f1 of the first lens satisfy the following: 1.20≤f1 / (Das+Dam)≤1.

62.

6. The visual system according to claim 1, characterized in that: The effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter dbs of the first side end surface of the second lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy: 1.15≤|f2 / f3|×(dam / dbs)≤4.

05.

7. The visual system according to claim 1, characterized in that: The outer diameter Dbs of the first side end surface of the second lens barrel, the outer diameter Dbm of the second side end surface of the second lens barrel, and the difference Δf between the effective focal length of the visual system in the first state and the effective focal length of the visual system in the second state satisfy: 0.74≤(Dbs-Dbm) / Δf≤3.

36.

8. The visual system according to claim 1, characterized in that: An inner diameter dbm of the second side end surface of the second lens barrel and a center thickness CT3 of the third lens on the optical axis satisfy the following: 6.47≤dbm / CT3≤12.

72.

9. The visual system according to claim 1, characterized in that: The refractive index N1 of the first lens, the refractive index N2 of the second lens, and the maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy: 5.49 mm≤(N1 / N2)×La≤8.09 mm.

10. The visual system according to any one of claims 1 to 9, characterized in that: The combined focal length fz of the first lens, the reflective polarizing element, the quarter-wave plate and the second lens, the inner diameter das of the first side end surface of the first lens barrel, and the inner diameter dam of the second side end surface of the first lens barrel satisfy: 0.87≤|fz| / (das+dam)≤6.

56.

11. The visual system according to any one of claims 1 to 9, characterized in that: The inner diameter das of the first side end surface of the first lens barrel, the effective focal length f1 of the first lens, and the curvature radius R1 of the first side surface of the first lens satisfy the following relationship: 14.82 mm ≤ das / (f1 / R1) ≤ 20.55 mm.

12. The visual system according to any one of claims 1 to 9, characterized in that: The Abbe number V3 of the third lens, the refractive index V3 of the third lens, and the outer diameter Dbs of the first side end surface of the second lens barrel satisfy the following relationship: 1.05 mm ≤ Dbs / (V3 / N3) ≤ 2.46 mm.

13. The visual system according to any one of claims 1 to 9, characterized in that: The outer diameter Dam of the second side end surface of the first lens barrel, the inner diameter dam of the second side end surface of the first lens barrel, and the distance ΔL moved by the second optical element group along the optical axis when the visual system switches between the first state and the second state satisfy the following: 0.54≤(Dam-dam) / ΔL≤3.

00.

14. The visual system according to any one of claims 1 to 9, characterized in that: An outer diameter Das of the first side end surface of the first lens barrel and a maximum distance La between the first side end surface of the first lens barrel and the second side end surface of the first lens barrel satisfy the following: 4.41≤Das / La≤8.47.

Images