Visual system

Abstract

The utility model 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 utility model, 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] This utility model relates to the field of optical imaging equipment technology, and more specifically, to a visual system. Background Technology

[0002] With the increasing popularity of AR / VR (Augmented Reality / Virtual Reality) devices, consumers have placed higher demands on their thinness, image quality, and wearing experience. Traditional AR / VR devices based on aspherical and Fresnel technologies are too bulky and can no longer meet consumer needs. With the advent of the folding optical solution, the problem of making VR devices thinner and lighter has been greatly improved, and it has now become the mainstream solution.

[0003] Among AR / VR users, visual acuity varies greatly, with many being nearsighted or farsighted, and the degree of nearsightedness or farsightedness differs among individuals. Using a fixed-focal-length folding optical module results in inconsistent image quality and significantly different user experiences. Therefore, it is necessary to design and develop a diopter-adjustable visual system so that users with varying vision can see images clearly without glasses, thus improving the VR visual experience. However, while existing folding optical path-based folding optical designs excel in shortening lens length, there is still room for improvement in optical performance. For example, the sidewalls of structural components such as the lens barrel can easily generate stray light reflections, interfering with imaging and affecting image quality and clarity, which urgently needs to be addressed. Utility Model Content

[0004] The main objective of this invention is to provide a visual system that solves the problem of stray light reflection easily generated by structural components such as the lens barrel in existing visual systems.

[0005] To achieve the above objectives, according to one aspect of the present invention, a visual system is provided, comprising a lens barrel assembly and an optical element assembly. The optical element assembly comprises only three lenses with optical power. The lens barrel assembly includes a first lens barrel and a second lens barrel arranged sequentially from a first side to a second side along the optical axis. The optical element assembly includes a first optical element assembly and a second optical element assembly, the first optical element assembly resting within the first lens barrel and the second optical element assembly resting within the second lens barrel. The first optical element assembly includes a first lens, a reflective polarizing element, a quarter-wave plate, and a second lens arranged sequentially from a first side to a second side along the optical axis. The second optical element assembly includes a third lens and a partially reflective element arranged sequentially from a first side to a second side along the optical axis. The first lens has positive optical power, and its first side surface is convex. The second lens has optical... The third lens has positive optical power, and the second side of the third lens is convex. The second optical element group is configured to move 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 of the third lens, the radius of curvature R6 of the second side of the third lens, and the maximum distance Lb on the optical axis from the first end face of the second lens barrel to the second end face of the second lens barrel satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm. The inner diameter dbs of the first end face of the second lens barrel, the inner diameter dbm of the second end face 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.

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

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

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

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

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

[0011] Furthermore, 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 face of the second lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 1.15≤|f2 / f3|×(dam / dbs)≤4.05.

[0012] Furthermore, the outer diameter Dbs of the first side end face of the second lens tube, the outer diameter Dbm of the second side end face of the second lens tube, 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 the following condition: 0.74≤(Dbs-Dbm) / Δf≤3.36.

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

[0014] Furthermore, 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 face and the second side end face of the first lens barrel satisfy the following condition: 5.49mm≤(N1 / N2)×La≤8.09mm.

[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 face of the first lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 0.87≤|fz| / (das+dam)≤6.56.

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

[0017] Furthermore, 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 face of the second lens tube satisfy the following condition: 1.05mm≤Dbs / (V3 / N3)≤2.46mm.

[0018] Furthermore, the outer diameter Dam of the second side end face of the first lens tube, the inner diameter dam of the second side end face of the first lens tube, 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 the following condition: 0.54≤(Dam-dam) / ΔL≤3.00.

[0019] Furthermore, the outer diameter Das of the first side end face of the first lens tube and the maximum distance La between the first side end face and the second side end face of the first lens tube satisfy the following condition: 4.41≤Das / La≤8.47.

[0020] The visual system, applying the technical solution of this utility model, includes a lens barrel assembly and an optical element assembly. The optical element assembly includes only three lenses with optical power. The lens barrel assembly includes a first lens barrel and a second lens barrel arranged sequentially from the first side to the second side along the optical axis. The optical element assembly includes a first optical element assembly and a second optical element assembly. The first optical element assembly rests within the first lens barrel, and the second optical element assembly rests within the second lens barrel. The first optical element assembly includes a first lens, a reflective polarizing element, a quarter-wave plate, and a second lens arranged sequentially from the first side to the second side along the optical axis. The second optical element assembly includes a third lens and a partially reflective element arranged sequentially from the first side to the second side along the optical axis. The first lens has positive optical power, and its first side surface is convex. The second lens has optical power, and the third lens has... The third lens has positive optical power and its second side surface is convex. The second optical element group is configured to move 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 on the optical axis from the first end face of the second lens barrel to the second end face of the second lens barrel satisfy the following: 0.99mm≤|R6 / R5|×Lb≤6.47mm. The inner diameter dbs of the first end face of the second lens barrel, the inner diameter dbm of the second end face 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 the following: 0.8<(dbs-dbm) / ΔL<2.7.

[0021] The visual system in this application consists of two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate, and some reflective elements. By reasonably setting the visual system to satisfy 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, the deflection angle of light on the first and second sides of the third lens can be constrained. This allows light to pass smoothly through the inner diameter of the first and second side ends of the second lens barrel, reducing the light deflected to the first and second side ends of the second lens barrel, thereby reducing stray light generation and improving image quality. At the same time, the maximum distance the second optical element group moves along the optical axis is constrained, so that the visual system can reduce stray light generated by reflection from the second lens barrel under different conditions, ensuring the image quality of the visual system. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

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

[0024] Figure 2 and Figure 3 The diagrams show the structural schematics of the visual system of Embodiment 1-1 of this utility model in the first and second states, respectively.

[0025] Figure 4 and Figure 5 The diagrams show the structural schematics of the visual system in embodiments 1-2 of this utility model in the first and second states, respectively.

[0026] Figure 6 and Figure 7 The diagrams show the structural schematics of the visual systems of embodiments 1-3 of this utility model in the first and second states, respectively.

[0027] Figure 8 and Figure 9 The MTF curves of the visual system of Embodiment 1 of this utility model in the first state and the second state are shown respectively.

[0028] Figure 10 and Figure 11 The diagrams show the structural schematics of the visual system of Embodiment 2-1 of this utility model in the first and second states, respectively.

[0029] Figure 12 and Figure 13 The diagrams show the structural schematics of the visual system of Embodiment 2-2 of this utility model in the first and second states, respectively.

[0030] Figure 14 and Figure 15 The diagrams show the structural schematics of the visual system in embodiments 2-3 of this utility model in the first and second states, respectively.

[0031] Figure 16 and Figure 17 The MTF curves of the visual system of Embodiment 2 of this utility model in the first state and the second state are shown respectively;

[0032] Figure 18 and Figure 19 The diagrams show the structural schematics of the visual system of Embodiment 3-1 of this utility model in the first and second states, respectively.

[0033] Figure 20 and Figure 21 The diagrams show the structural schematics of the visual system of Embodiment 3-2 of this utility model in the first and second states, respectively.

[0034] Figure 22 and Figure 23 The diagrams show the structural schematics of the visual system of Embodiments 3-3 of this utility model in the first and second states, respectively.

[0035] Figure 24 and Figure 25 The MTF curves of the visual system of Embodiment 3 of this utility model in the first state and the second state are shown respectively;

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

[0037] Figure 27 A stray light path diagram of an example visual system is shown;

[0038] Figure 28 It shows Figure 27 The stray light spot pattern of the visual system in the image;

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

[0040] Figure 30 It shows Figure 29 A stray light spot pattern of the visual system in the image.

[0041] The above figures 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 reflective element; Pa, First lens barrel; Pb, Second lens barrel; IMG, Image plane; IR / CG, Filter and / or protective glass. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0045] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

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

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

[0048] In this document, if a lens surface is convex and its location is not defined, it means that the lens surface is convex at least in the paraxial region; if a lens surface is concave and its location 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 embodiments of this application can be simulated using software and / or tools such as ZEMAX and CODEV. Optionally, the visual system can be simulated using CODEV software. During the simulation process using software and / or tools as described above, the surface profile of each lens can be appropriately adjusted according to the built-in surface profile model of the software and / or tool used.

[0050] To address the problem of stray light reflection easily generated by structural components such as the lens barrel in existing visual systems, this invention provides a visual system.

[0051] like Figures 1 to 25As shown, the visual system includes a lens barrel assembly and an optical element assembly. The optical element assembly includes only three lenses with optical power. The lens barrel assembly includes a first lens barrel and a second lens barrel arranged sequentially from the first side to the second side along the optical axis. The optical element assembly includes a first optical element assembly and a second optical element assembly. The first optical element assembly rests within the first lens barrel, and the second optical element assembly rests within the second lens barrel. The first optical element assembly includes a first lens, a reflective polarizing element, a quarter-wave plate, and a second lens arranged sequentially from the first side to the second side along the optical axis. The second optical element assembly includes a third lens and a partially reflective element arranged sequentially from the first side to the second side along the optical axis. The first lens has positive optical power, and its first side surface is convex. 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 move 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 on the optical axis from the first end face of the second lens barrel to the second end face of the second lens barrel satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm; the inner diameter dbs of the first end face of the second lens barrel, the inner diameter dbm of the second end face 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.

[0052] The visual system in this application consists of two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate, and some reflective elements. By reasonably setting the visual system to satisfy 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, the deflection angle of light on the first and second sides of the third lens can be constrained. This allows light to pass smoothly through the inner diameter of the first and second side ends of the second lens barrel, reducing the light deflected to the first and second side ends of the second lens barrel, thereby reducing stray light generation and improving image quality. At the same time, the maximum distance the second optical element group moves along the optical axis is constrained, so that the visual system can reduce stray light generated by reflection from the second lens barrel under different conditions, ensuring the image 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. Simultaneously, by setting the two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL to satisfy different numerical ranges, three different visual system schemes can be achieved:

[0054] In the visual system of the first scheme, the two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL satisfy |R6 / R5|×Lb=2.74mm and (dbs-dbm) / ΔL=1.18, respectively. It can be seen that the values ​​of the two conditional expressions are both within the ranges of 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, respectively. The stray light path of this visual system is as follows: Figure 26 As shown, by changing the deflection angle of light in the third lens, the stray light generated by the second lens tube falls outside the range of human eye reception, reducing the stray light entering the human eye and ensuring image clarity.

[0055] In the second visual system, the two conditional expressions |R6 / R5|×Lb and (dbs-dbm) / ΔL satisfy |R6 / R5|×Lb=6.8mm and (dbs-dbm) / ΔL=3.0, respectively. It is evident that the values ​​of the two conditional expressions are greater than the upper limits defined by 0.99mm≤|R6 / R5|×Lb≤6.47mm and 0.8<(dbs-dbm) / ΔL<2.7, respectively. The stray light path of this visual system is as follows: Figure 27 As shown, the stray light pattern of this visual system is as follows: Figure 28 As shown, this visual system has a lot of stray light. For example, stray light reflected from the first side of the second lens tube falls into the range of human eye reception, and the intensity of the stray light is high, which has a significant impact on the imaging effect.

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

[0057] In some alternative embodiments, the distance on the optical axis between the first optical element group and the display or image surface on the second side of the viewing system can be fixed. The second optical element group can be configured to move along the optical axis to approach or move away from the display or image surface on the second side of the viewing system, allowing the viewing system to switch between a first state and a second state. Specifically, when the second optical element group moves to the position closest to the display or image surface, the distance on the optical axis between the second optical element group and the first optical element group is at its maximum, and the viewing system can be in a +2D state, i.e., the first state. When the second optical element group moves to the position farthest from the display or image surface, the distance on the optical axis between the second optical element group and the first optical element group is at its minimum, and the viewing system can be in a -5D state, i.e., the second state.

[0058] For example, when the visual system is in the first state, its diopter is +2D, which is suitable for users with a diopter of +2D. When the visual system is in the second state, its diopter is -5D, which is suitable for users with a diopter of -5D. A negative sign for diopter indicates that the user is myopic; a positive sign indicates that the user is hyperopic. The specific value of diopter represents the user's refractive error. For example, +1D diopter indicates that the user's hyperopia is approximately 100 degrees, and -1D diopter indicates that the user's myopia is approximately 100 degrees.

[0059] It should be understood that, in addition to the first and second states, the visual system according to the embodiments of this application may also have other states, for example, between -5D and +2D. The visual system according to the embodiments of this application can achieve continuous zoom within the range of -5D to +2D, meeting the needs of users with different visual acuity, allowing users to enjoy VR experiences without wearing glasses.

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

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

[0062] In some optional embodiments, the maximum distance La between the first and second side faces of the first lens barrel, the maximum distance Lb between the first and second side faces 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. By constraining (La + Lb) / EPD within a reasonable range, the maximum length of the first and second lens barrels can be constrained, indirectly constraining the overall length of the visual system. This is beneficial for the miniaturization design of the visual system. At the same time, increasing the entrance pupil diameter helps to mitigate the performance degradation caused by pupil deflection when the human eye rotates, thereby improving comfort during visual observation and further enhancing the user experience.

[0063] In some optional embodiments, the inner diameter das of the first side end face of the first lens barrel, the outer diameter Das of the first side end face of the first lens barrel, and the center thickness CT1 of the first lens on the optical axis satisfy the following condition: 0.9 < (Das-das) / CT1 < 2.85. By constraining (Das-das) / CT1 within a reasonable range, the external dimensions and wall thickness of the first lens barrel can be constrained. While ensuring that the first lens barrel is machinable, the external dimensions of the first lens barrel are minimized, thereby reducing the overall size of the visual system. At the same time, it ensures that the front end of the first lens barrel can stably support the first lens, ensuring the stability of the first lens assembly.

[0064] In some optional embodiments, the maximum distance La between the first side end face and the second side end face of the first lens barrel, and the center thickness CT2 of the second lens on the optical axis, satisfy the following condition: 1.45 ≤ La / CT2 ≤ 1.79. By constraining La / CT2 within a reasonable range, the first lens barrel can stably support the first and second lenses while minimizing its overall size, thereby reducing the overall size of the visual system. Furthermore, constraining the center thickness of the second lens can ensure its structural strength, and constraining its shape can reduce its sensitivity, thereby improving the assembly yield.

[0065] In some alternative embodiments, the outer diameter Das of the first side end face of the first lens barrel, the outer diameter Dam of the second side end face of the first lens barrel, and the effective focal length f1 of the first lens satisfy the following condition: 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, thereby indirectly controlling the size of the visual system. At the same time, constraining the effective focal length and outer diameter of the first lens satisfies the structural support for the lens while ensuring fabrication 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 face of the second lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 1.15 ≤ |f2 / f3|×(dam / dbs) ≤ 4.05. By constraining |f2 / f3|×(dam / dbs) within a reasonable range, the inner diameter dimensions of the first and second lens barrels can be controlled, which is beneficial for miniaturization. At the same time, constraining the focal lengths of the second and third lenses can control their deflection angles, which is beneficial for light to pass smoothly through the inner diameters of the second and first side end faces of the first lens barrel while being reflected between the second and third lenses. This reduces stray light reflections at the first and second lens barrels. Furthermore, the reasonable allocation of the optical power of the second and third lenses is also beneficial for correcting aberrations in the visual system, thus 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 the following condition: 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, indirectly controlling the overall size of the visual system, which is beneficial for miniaturization of the visual system. At the same time, constraining the difference Δf ensures that the visual system can achieve continuous zoom and clear imaging at different diopters, 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 alternative embodiments, the inner diameter (dbm) of the second side end face of the second lens barrel and the center thickness (CT3) of the third lens on the optical axis satisfy the following condition: 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. On the other hand, it restricts the relationship between the center thickness of the third lens and its outer diameter, ensuring the feasibility of manufacturing 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 face and the second side end face of the first lens barrel satisfy the following condition: 5.49mm ≤ (N1 / N2)×La ≤ 8.09mm. By constraining (N1 / N2)×La within a reasonable range, the length of the first lens barrel can be constrained. While ensuring its function as a limiting lens, this improves the manufacturability of the lens barrel. At the same time, constraining the refractive indices of the first and second lenses helps to constrain the deflection angle of light within the first lens barrel, preventing the first lens barrel from being too long and causing stray light to be incident on the inner wall of the first lens barrel. It also avoids assembly instability and light leakage caused by the first lens barrel being too short.

[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 face of the first lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 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, thereby ensuring good imaging quality of the visual system on the optical axis. At the same time, controlling the outer diameter of the first lens barrel, while ensuring the limiting effect of the first lens barrel on the lens, is beneficial to improving the manufacturability of the first lens.

[0071] In some optional embodiments, 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 radius of curvature R1 of the first side surface of the first lens satisfy the following condition: 14.82mm ≤ das / (f1 / R1) ≤ 20.55mm. By constraining das / (f1 / R1) within a reasonable range, and by controlling the effective focal length and the radius of curvature of the first side surface of the first lens, the shape of the first lens can be constrained. This helps to reduce the sensitivity of the first lens, thereby improving the assembly yield. It also controls the deflection angle of light within the first lens barrel, reducing the risk of stray light reflected from the inner wall surface of the first lens barrel. At the same time, constraining the inner diameter of the first side end face of the first lens barrel ensures that the first lens barrel provides a limiting effect on the lens while improving the feasibility of lens barrel molding.

[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 face of the second lens barrel satisfy the following condition: 1.05mm ≤ Dbs / (V3 / N3) ≤ 2.46mm. By constraining Dbs / (V3 / N3) within a reasonable range, it is beneficial to control the deflection angle of light passing through the third lens, thereby reducing the incident angle of light on the screen. Simultaneously, constraining the outer diameter of the second lens barrel indirectly controls the overall size of the visual system, facilitating miniaturization of the visual system.

[0073] In some optional embodiments, the outer diameter Dam of the second side end face of the first lens barrel, the inner diameter dam of the second side end face 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 the following condition: 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 face 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 beneficial to the miniaturization of the visual system. At the same time, constraining the wall thickness of the second side end face of the first lens barrel can ensure the structural strength of the first lens barrel and help improve the stability of the internal structure assembly of the first lens barrel.

[0074] In some optional embodiments, the outer diameter Das of the first side end face of the first lens barrel and the maximum distance La between the first side end face and the second side end face of the first lens barrel satisfy the following condition: 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 beneficial for assembling the lens into the first lens barrel and ensuring the assembly stability between the lenses. On the other hand, the overall shape and length of the first lens barrel are limited, which is beneficial for the miniaturization of the first lens barrel and thus for the miniaturization of the entire machine.

[0075] In another aspect, in an optional embodiment of this utility model, the visual system includes a lens barrel assembly and an optical element assembly. The optical element assembly includes only three lenses with optical power. The lens barrel assembly includes a first lens barrel and a second lens barrel arranged sequentially from the first side to the second side along the optical axis. The optical element assembly includes a first optical element assembly and a second optical element assembly, with the first optical element assembly resting inside the first lens barrel and the second optical element assembly resting inside the second lens barrel. The first optical element assembly includes a first lens, a reflective polarizing element, a quarter-wave plate, and a second lens arranged sequentially from the first side to the second side along the optical axis. The second optical element assembly includes a third lens and a partially reflective element arranged sequentially from the first side to the second side along the optical axis. The first lens has positive optical power, and the first side of the first lens is convex. 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 move along the optical axis to approach or move away from the display located on the second side, so that the visual system switches between a first state and a 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 end face of the second lens barrel to the second end face of the second lens barrel on the optical axis satisfy: 0.99mm≤|R6 / R5|×Lb≤6.47mm. The maximum distance La between the first end face of the first lens barrel and the second end face 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 this application consists of two lens barrels, three lenses, a reflective polarizing element, a quarter-wave plate, and some reflective elements. By reasonably setting the visual system to satisfy 0.99mm≤|R6 / R5|×Lb≤6.47mm and 1.45≤La / CT2≤1.79, the deflection angle of light on the first and second sides of the third lens can be constrained, and the optical path of light in the second lens can be constrained. This changes the transmission path of stray light, reduces stray light transmitted to the human eye, and improves image quality. At the same time, by constraining the maximum length of the first and second lens barrels, the size of the visual system can be limited, thereby ensuring the miniaturization of the visual system.

[0077] Of course, this embodiment may also include other parametric expressions from the optional embodiments described above, which will not be elaborated here.

[0078] Optionally, the above-described visual system may also include protective glass for protecting the photosensitive element located on the imaging surface.

[0079] In this application, at least one of the first to third lenses has an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0080] However, those skilled in the art will understand that the number of lenses constituting the visual system can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although three lenses have been described as an example in the embodiments, 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 showing the dimensions of a visual system according to an alternative embodiment of this application is illustrated. Figure 1The parameters das, dam, Das, Dam, dbs, dbm, Dbs, Dbm, La, and Lb are clearly and intuitively illustrated to provide a clear understanding of their meaning. To facilitate the description of the visual system and the surface shape of specific lenses, these parameters will not be shown in the accompanying drawings when describing specific embodiments. In this application, the first side end face of the first lens barrel refers to the surface of the first lens barrel 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 of the first lens barrel 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 of the second lens barrel 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 of the second lens barrel closest to the second side and perpendicular to the optical axis.

[0082] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters applicable to the visual system described above.

[0083] It should be noted that in the following Embodiment 1, there are three examples: Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3; in Embodiment 2, there are three examples: Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3; and in Embodiment 3, there are three examples: Embodiment 3-1, Embodiment 3-2, and Embodiment 2-3. In the three examples within the same embodiment, the curvature radius, center thickness, and other parameters of the first to third lenses of the visual system, as well as the spacing between the lenses and the higher-order coefficients, are the same. However, the thickness, inner diameter, and outer diameter of the first and second lens barrels, and the shape of some lenses, are different. In other words, the main structure used for imaging is the same, but the auxiliary structures used for imaging are different.

[0084] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to this application.

[0085] Example 1

[0086] like Figures 2 to 9 As shown, the visual system of Embodiment 1 is described. Figure 2 A schematic diagram of the visual system of Embodiment 1-1 in its first state is shown. Figure 3 A schematic diagram of the visual system of Embodiment 1-1 in the second state is shown. Figure 4 A schematic diagram of the visual system of Embodiments 1-2 in the first state is shown. Figure 5 A schematic diagram of the visual system of Embodiments 1-2 in the second state is shown. Figure 6 The diagram shows the structural schematics of the visual systems of Embodiments 1-3 in the first state. Figure 7 A schematic diagram 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 sequentially 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 sequentially from the first side to the second side along the optical axis. The second optical element group includes a third lens E3 and a partially reflective element BS arranged sequentially from the first side to the second side along the optical axis. The reflective polarizing element RP is disposed on the second side of the first lens, the quarter-wave plate QWP is disposed on the second side of the reflective polarizing element RP, and the second lens is disposed on the second side of the quarter-wave plate QWP. This can be understood as the first lens E1, the reflective polarizing element RP, the quarter-wave plate QWP, and the second lens E2 being cemented together. The partially reflective element BS is disposed on the second side of the third lens.

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

[0089] In Embodiment 1, the first lens has positive optical power, a first side surface of the first lens is convex, and a second side surface of the first lens is planar; the second lens has positive optical power, a first side surface of the second lens is planar, and a second side surface of the second lens is convex; the third lens has positive optical power, a first side surface of the third lens is concave, and a second side surface of the third lens is convex. The visual system also includes an aperture stop located on the first side of the first lens.

[0090] Table 1 shows the basic structural parameters of the visual system in Embodiment 1, where the units for radius of curvature and thickness / distance are millimeters (mm). In Table 1, light from the image plane IMG propagates from plane number 20 to the side of plane number 1, and refraction / reflection refers to the refraction or reflection of light by that plane 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 along the optical axis from the second side of the second lens to the first side of the third lens; D3 can be understood as the value along the optical axis from the first side of the third lens to the second side of the second lens; D4 can be understood as the value along the optical axis again from the second side of the second lens to the first side of the third lens; D5 can be understood as the value along the optical axis from the second side of the third lens to the first side of the filter and / or protective glass IR / CG located on the first side of the image plane IMG. It should be noted that during the transmission of light in the visual system, due to the presence of reflective polarizing elements, quarter-wave plates, and partial reflective elements, the light is reflected between some surfaces and will pass through the surface of some lenses multiple times. The distance of light transmission from the first side to the second side is positive, while the distance of light transmission from the second side to the first side is negative. During the zooming process of the second optical element group moving along the optical axis, the values ​​of the above parameters D1 to D5 will change accordingly.

[0095] The values ​​of D1 to D5 for the visual system in the first and second states 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 Embodiment 1, 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. The shape of each aspherical surface can be defined using, but is not limited to, the following aspherical formula:

[0099]

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

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

[0104] Example 2

[0105] like Figures 10 to 17 As shown, the visual system of Embodiment 2 is described. Figure 10 A schematic diagram of the visual system of Embodiment 2-1 in its first state is shown. Figure 11 A schematic diagram of the visual system of Embodiment 2-1 in the second state is shown. Figure 12 A schematic diagram of the visual system of Embodiment 2-2 in its first state is shown. Figure 13 A schematic diagram of the visual system of Embodiment 2-2 in the second state is shown. Figure 14 A schematic diagram of the visual system of Embodiments 2-3 in the first state is shown. Figure 15 A schematic diagram of the visual system of Embodiments 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 sequentially 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 sequentially from the first side to the second side along the optical axis. The second optical element group includes a third lens E3 and a partially reflective element BS arranged sequentially from the first side to the second side along the optical axis. The reflective polarizing element RP is disposed on the second side of the first lens, the quarter-wave plate QWP is disposed on the second side of the reflective polarizing element RP, and the second lens is disposed on the second side of the quarter-wave plate QWP. This can be understood as the first lens E1, the reflective polarizing element RP, the quarter-wave plate QWP, and the second lens E2 being cemented together. The partially reflective element BS is disposed on the second side of the third lens.

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

[0108] In Embodiment 2, the first lens has positive optical power, a first side surface of the first lens is convex, and a second side surface of the first lens is concave; the second lens has negative optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is concave; the third lens has positive optical power, a first side surface of the third lens is convex, and a second side surface of the third lens is convex. The visual system also includes an aperture stop located on the first side of the first lens.

[0109] Table 4 shows the basic structural parameters of the visual system in Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm). In Table 4, light from the image surface IMG propagates from surface 21 to surface 1, and refraction / reflection refers to the refraction or reflection of light by that surface during this passage.

[0110]

[0111]

[0112] Table 4

[0113] The values ​​of D1 to D5 for the visual system in the first and second states 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 higher-order coefficients that can be used for each aspherical mirror in this embodiment, wherein the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. 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] Figure 16 and Figure 17 The MTF curves of the visual system of Embodiment 2 are shown in the first and second states, respectively. The MTF values ​​under the light of each field of view are all above 0.7, showing good imaging quality.

[0120] Example 3

[0121] like Figures 18 to 25 As shown, the visual system of Embodiment 3 is described. Figure 18 A schematic diagram of the visual system of Embodiment 3-1 in its first state is shown. Figure 19 A schematic diagram of the visual system of Embodiment 3-1 in the second state is shown. Figure 20 A schematic diagram of the visual system of Embodiment 3-2 in its first state is shown. Figure 21 A schematic diagram of the visual system of Embodiment 3-2 in the second state is shown. Figure 22 A schematic diagram of the visual system of Embodiment 3-3 in the first state is shown. Figure 23 A schematic diagram of the visual system of Embodiment 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 sequentially 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 sequentially from the first side to the second side along the optical axis. The second optical element group includes a third lens E3 and a partially reflective element BS arranged sequentially from the first side to the second side along the optical axis. The reflective polarizing element RP is disposed on the second side of the first lens, the quarter-wave plate QWP is disposed on the second side of the reflective polarizing element RP, and the second lens is disposed on the second side of the quarter-wave plate QWP. This can be understood as the first lens E1, the reflective polarizing element RP, the quarter-wave plate QWP, and the second lens E2 being cemented together. The partially reflective element BS is disposed on the second side of the third lens.

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

[0124] In Embodiment 3, the first lens has positive optical power, a first side surface of the first lens is convex, and a second side surface of the first lens is concave; the second lens has positive optical power, a first side surface of the second lens is convex, and a second side surface of the second lens is convex; the third lens has positive optical power, a first side surface of the third lens is convex, and a second side surface of the third lens is convex. The visual system also includes an aperture stop located on the first side of the first lens.

[0125] Table 7 shows the basic structural parameters of the visual system in Embodiment 3, where the units for radius of curvature and thickness / distance are millimeters (mm). In Table 7, light from the image plane IMG propagates from plane 21 to the side of plane 1, and refraction / reflection refers to the refraction or reflection of light by that plane during this passage.

[0126] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection Conic coefficient spherical endless D1 refraction 1 spherical endless 0.0000 refraction 2 Stabilizer (STO) spherical endless 12.0000 refraction 3 First lens (E1) aspherical 64.5487 3.5000 1.490 70.40 refraction 1.3701 4 Reflective polarizing element (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 aspherical -500.0000 D2 refraction 4.3746 8 Third lens (E3) aspherical 151.7201 3.7477 1.490 70.40 refraction -5.6027 9 Partial reflective element (BS) aspherical -105.3251 -3.7477 1.490 70.40 reflection 1.5612 10 aspherical 151.7201 D3 refraction -5.6027 11 aspherical -500.0000 -3.7765 1.490 70.40 refraction 4.3746 12 spherical 527.9075 -0.1340 1.487 57.47 refraction 13 Reflective polarizing element (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 aspherical -500.0000 D4 refraction 4.3746 16 Third lens (E3) aspherical 151.7201 3.7477 1.490 70.40 refraction -5.6027 17 aspherical -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 View (IMG) spherical endless 0.0000 refraction

[0127] Table 7

[0128] The values ​​of D1 to D5 for the visual system in the first and second states 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 higher-order coefficients that can be used for each aspherical mirror in this embodiment, wherein the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. 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] Figure 24 and Figure 25 The MTF curves of the visual system of Embodiment 3 are shown in the first and second states, respectively. The MTF values ​​under the light of each field of view are all above 0.7, showing good imaging quality.

[0135] In summary, embodiments one through three of the visual system satisfy the relationships shown in Table 10. Specifically, the conditional values ​​for the first and second states corresponding to each embodiment of the visual system are identical.

[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 provides some parameters of the visual systems in Examples 1 to 3, in 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] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device or an imaging module integrated into a mobile electronic device. The imaging device is equipped with the visual system described above.

[0142] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0143] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

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

[0145] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A visual system, characterized in that, It includes a lens barrel assembly and an optical element assembly, wherein the optical element assembly consists of only three lenses with optical power. The lens barrel assembly includes a first lens barrel and a second lens barrel arranged sequentially 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, wherein the first optical element group is supported inside the first lens barrel and the second optical element group is supported inside 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 sequentially along the optical axis from the first side to the second side. The second optical element group includes a third lens and a partially reflective element arranged sequentially along the optical axis from the first side to the second side. The first lens has positive optical power and its first side surface is convex. The second lens has optical power, and the third lens has positive optical power and its second side surface is convex. The second optical element group is configured to move along the optical axis to approach or move away from the display located on the second side, so that the visual system switches between a first state and a 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 end face of the second lens barrel to the second end face of the second lens barrel on the optical axis satisfy the following: 0.99mm≤|R6 / R5|×Lb≤6.47mm; 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 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 the following condition: 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 face of the first lens barrel and the second side end face of the first lens barrel, the maximum distance Lb between the first side end face of the second lens barrel and 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 the following: 1.15≤(La+Lb) / EPD≤1.

64.

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

85.

4. The visual system according to claim 1, characterized in that, 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, and the center thickness CT2 of the second lens on the optical axis satisfy the following condition: 1.45≤La / CT2≤1.

79.

5. The visual system according to claim 1, characterized in that, The outer diameter Das of the first side end face of the first lens barrel, the outer diameter Dam of the second side end face of the first lens barrel, and the effective focal length f1 of the first lens satisfy the following condition: 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 face of the second lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 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 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 the following condition: 0.74≤(Dbs-Dbm) / Δf≤3.

36.

8. The visual system according to claim 1, characterized in that, The inner diameter dbm of the second side end face of the second lens barrel and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 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 face and the second side end face of the first lens barrel satisfy the following condition: 5.49mm≤(N1 / N2)×La≤8.09mm.

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 face of the first lens barrel, and the inner diameter dam of the second side end face of the first lens barrel satisfy the following condition: 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 face of the first lens barrel, the effective focal length f1 of the first lens, and the radius of curvature R1 of the first side face of the first lens satisfy the following condition: 14.82mm≤das / (f1 / R1)≤20.55mm.

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 face of the second lens barrel satisfy the following condition: 1.05mm≤Dbs / (V3 / N3)≤2.46mm.

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 face of the first lens barrel, the inner diameter dam of the second side end face 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 the following condition: 0.54≤(Dam-dam) / ΔL≤3.

00.

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

Images