CN220671727U

CN220671727U - Visual optical system

Info

Publication number: CN220671727U
Application number: CN202322105659.0U
Authority: CN
Inventors: 赵世一; 张晓彬; 游金兴; 金银芳; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2023-08-07
Filing date: 2023-08-07
Publication date: 2024-03-26
Anticipated expiration: 2033-08-07

Abstract

The application discloses a visual optical system, which sequentially comprises a first lens group and a second lens group along an optical axis from a screen far side to a screen near side, wherein the first lens group comprises a first lens, a reflective polarizing element and a quarter wave plate; the second lens group comprises a second lens and a partial reflecting layer; the side surface of the first lens far away from the screen or the side surface of the second lens far away from the screen is a Fresnel surface; the visual optical system also comprises a lens barrel and a first bearing piece arranged on the side, close to the screen, of the first lens, wherein the first bearing piece is at least partially contacted with the side, close to the screen, of the first lens or the side, far from the screen, of the second lens; the first lens group, the second lens group and the first bearing piece are all accommodated in the lens barrel, wherein the inner diameters of the first bearing piece, which is far away from the screen side, and is close to the screen side are both larger than 50mm, and the inner diameter d1m of the first bearing piece, which is close to the screen side, the curvature radius R3 of the second lens, which is far away from the screen side, and the curvature radius R4 of the second lens, which is close to the screen side, satisfy the following conditions: -19.0< d1 m/(r3+r4) <9.5.

Description

Visual optical system

Technical Field

The present application relates to the field of optical imaging, and in particular to a visual optical system comprising a two-piece lens.

Background

In recent years, as the concept of "meta universe" is proposed, ways of entertainment for people are increasingly abundant, and devices such as augmented Reality (Augmented Reality, AR) and Virtual Reality (VR) of man-machine interaction are increasingly favored by people. However, the VR lens at present has the common defects of large volume, heavy weight and dizziness. Thus, miniaturization, weight saving, and imaging quality of the lens become the most important factors for improving the feeling of experience of consumers.

Based on the above-described requirements, a fresnel scheme and a light path turning-back scheme are proposed. The Fresnel scheme reduces the lens thickness by removing the straight propagation portion and only retaining the curved surface where refraction occurs, thereby realizing the reduction of the lens length and weight. The optical path turning-back scheme is to enable the length of the body of the lens to be compressed to be half of the original length through optical path turning-back, so that the gravity center of the head-mounted device is moved backwards, and the experience of consumers is improved. However, some current devices adopting the fresnel scheme and the optical path folding scheme still need to be perfect in terms of weight and thickness from the user experience, and meanwhile, the imaging quality cannot well meet the user requirements due to chromatic aberration, aberration and various stray light problems.

In view of this, there is a need for a visual optical system that can satisfy a high user experience, can ensure external field performance and improve imaging quality while reducing the volume and weight.

Disclosure of Invention

According to an aspect of the present application, there is provided a visual optical system including, in order from a screen-far side to a screen-near side along an optical axis, a first lens group including a first lens, a reflective polarizing element, and a quarter-wave plate; the second lens group comprises a second lens and a partial reflecting layer; the side surface of the first lens far away from the screen or the side surface of the second lens far away from the screen is a Fresnel surface; the visual optical system also comprises a lens barrel and a first bearing piece arranged on the side, close to the screen, of the first lens, wherein the first bearing piece is at least partially contacted with the side, close to the screen, of the first lens or the side, far from the screen, of the second lens; the first lens group, the second lens group and the first bearing piece are all accommodated in the lens barrel, wherein the inner diameters of the first bearing piece, which is far away from the screen side, and is close to the screen side are both larger than 50mm, and the inner diameter d1m of the first bearing piece, which is close to the screen side, the curvature radius R3 of the second lens, which is far away from the screen side, and the curvature radius R4 of the second lens, which is close to the screen side, satisfy the following conditions: -19.0< d1 m/(r3+r4) <9.5.

According to another aspect of the present application, there is provided a visual optical system including, in order from a screen-far side to a screen-near side along an optical axis, a first lens group including a first lens, a reflective polarizing element, and a quarter-wave plate; the second lens group comprises a second lens and a partial reflecting layer; the side surface of the first lens far away from the screen or the side surface of the second lens far away from the screen is a Fresnel surface; the visual optical system also comprises a lens barrel and a first bearing piece arranged on the side, close to the screen, of the first lens, wherein the first bearing piece is at least partially contacted with the side, close to the screen, of the first lens or the side, far from the screen, of the second lens; the first lens group, the second lens group and the first leaning piece are all accommodated in the lens barrel, wherein the first leaning piece is far away from the screen side and the inner diameter close to the screen side is larger than 50mm, and the effective focal length F1 of the first lens group, the curvature radius R1 of the first lens far away from the screen side, the outer diameter D1s of the first leaning piece far away from the screen side and the inner diameter D1s of the first leaning piece far away from the screen side meet the following conditions: 0.8< F1/R1+D1s/d1s <3.5.

In some embodiments, the visual optical system further comprises a first auxiliary bearing located on the first lens away from the screen side and in at least partial contact with the screen-away side of the first lens, or on the second lens away from the screen side and in at least partial contact with the screen-away side of the second lens.

In some embodiments, the reflective polarizing element and the quarter-wave plate are sequentially attached to the side of the first lens near the screen; the partial reflecting layer is attached to the side surface of the second lens, which is close to the screen.

In some embodiments, the effective focal length F1 of the first lens group, the radius of curvature R1 of the first lens away from the screen side, the outer diameter D1s of the first bearing away from the screen side, and the inner diameter D1s of the first bearing away from the screen side satisfy: 0.8< F1/R1+D1s/d1s <3.5.

In some embodiments, a distance EP01 on the optical axis from a surface of the barrel away from the screen side to a surface of the first bearing away from the screen side satisfies a central thickness CT1 of the first lens: 1.0< EP01/CT1<2.5.

In some embodiments, the outer diameter D1s of the first bearing member away from the screen side, the effective focal length F1 of the first lens group, and the effective focal length F2 of the second lens group satisfy: 0mm < D1 s/(F1/F2) <7.0mm.

In some embodiments, the spacing distance between the first lens group and the second lens group is less than 1.0mm, and the maximum thickness CP1 of the first bearing member, the inner diameter d1m of the first bearing member near the screen side, and the inner diameter d1s of the first bearing member far from the screen side satisfy: 0mm < CP1/(d 1m/d1 s) <4.0mm.

In some embodiments, the outer diameter D0m of the lens barrel on the screen side, the outer diameter D0s of the lens barrel on the screen side, and the distance TD on the optical axis from the screen side of the first lens to the screen side of the second lens satisfy: 6.0< (d0m+d0s)/TD <8.5.

In some embodiments, the inner diameter d0s of the lens barrel on the side away from the screen, the inner diameter d1bs of the first auxiliary bearing on the side away from the screen, and the f-number Fno of the visual optical system satisfy: 7.5< d0s/d1bs < FNo <10.5.

In some embodiments, the outer diameter D0m of the barrel near the screen side and the inner diameter D0m of the barrel near the screen side satisfy: 309.5mm ² <π(D0m ² -d0m ² )<393.0mm ² Where pi is the circumference ratio.

In some implementations, the distance from the screen-approaching side of the second lens to the screen is less than 20.0mm, and the inner diameter d0m of the barrel on the screen-approaching side and the radius of curvature R4 of the second lens on the screen-approaching side satisfy: d0m/R4 <0.8.

In some embodiments, the maximum height L of the lens barrel, the distance EP01 on the optical axis from the surface of the lens barrel away from the screen side to the surface of the first bearing member away from the screen side, the maximum thickness CP1 of the first bearing member, and the center thickness CT2 of the second lens satisfy: (L-EP 01-CP 1)/CT 2<1.0.

In some embodiments, the radius of curvature R2 of the first lens near the screen side, the radius of curvature R3 of the second lens far the screen side, and the inner diameter d1s of the first bearing member far the screen side satisfy: -38.0< (r2+r3)/d 1s < -8.5.

In some embodiments, the effective focal length F of the visual optical system and the maximum height L of the barrel satisfy: 1.5< F/L <2.5.

In some embodiments, the base curvature of the Fresnel surface is less than 10 ^-6 。

In some embodiments, the maximum thickness of the first bearing is greater than 0.2mm, and the first bearing is at least partially in contact with the inner wall of the barrel.

According to the visual optical system provided by one aspect of the application, the visual optical system comprises the lens barrel, the first lens group, the second lens group and the first bearing piece, and the thickness of the aspheric surface is reduced by changing the aspheric surface into the Fresnel surface, so that the visual optical system can be effectively combined with the plane or the curved surface of the rear surface, the thickness increase caused by rise is reduced, the length of the optical system is reduced, and the length and the performance of the foldback optical system are well balanced; through the reasonable design of the relevant parameters and structural forms of the lens, the bearing piece, the lens barrel and other optical elements, the inner diameter of the first bearing piece is controlled to be larger than 50mm, so that the inner diameter of the bearing piece arranged after the light passes through the foldback and Fresnel surface can ensure that imaging is complete and simultaneously block superfluous light at the edge, meanwhile, the curvature radius of the second lens far away from the screen side is limited, the curvature radius of the two surfaces of the second lens can be effectively controlled to be in a certain range, the focal power value of the second lens can be limited, the light trend of the second lens is better, the shape of the aspherical lens of the second lens can be limited, and the processability of the lens is ensured.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings, in which:

FIG. 1 illustrates a schematic view of the structure and partial parameters of a visual optical system according to an embodiment of the present application;

fig. 2A and 2B respectively show schematic structural views of a visual optical system having a fresnel surface according to an embodiment of the present application;

FIG. 3 illustrates a schematic view of optical path reversal of a visual optical system according to an embodiment of the present application;

FIG. 4 shows a schematic structural diagram of a visual optical system according to embodiment 1 of the present application;

FIG. 5 shows a schematic structural diagram of a visual optical system according to embodiment 2 of the present application;

FIGS. 6A and 6B show on-axis chromatic aberration curves and astigmatism curves, respectively, of visual optical systems according to examples 1 and 2 of the present application;

FIG. 7 is a schematic view showing the structure of a visual optical system according to embodiment 3 of the present application;

FIG. 8 is a schematic view showing the structure of a visual optical system according to embodiment 4 of the present application;

fig. 9A and 9B show on-axis chromatic aberration curves and astigmatism curves of the visual optical systems according to examples 3 and 4, respectively, of the present application;

Fig. 10 shows a schematic structural diagram of a visual optical system according to embodiment 5 of the present application;

fig. 11 shows a schematic structural view of a visual optical system according to embodiment 6 of the present application;

FIGS. 12A and 12B show on-axis chromatic aberration curves and astigmatism curves, respectively, for visual optical systems according to examples 5 and 6 of the present application;

fig. 13 shows a schematic structural view of a visual optical system according to embodiment 7 of the present application;

fig. 14 shows a schematic structural view of a visual optical system according to embodiment 8 of the present application;

fig. 15A and 15B show on-axis chromatic aberration curves and astigmatism curves of the visual optical systems according to examples 7 and 8 of the present application, respectively;

fig. 16 shows a schematic structural view of a visual optical system according to embodiment 9 of the present application;

FIG. 17 is a schematic view showing the structure of a visual optical system according to embodiment 10 of the present application; and

fig. 18A and 18B show on-axis chromatic aberration curves and astigmatism curves of the visual optical systems according to embodiment 9 and embodiment 10 of the present application, respectively.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed description are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present 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 feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present application.

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

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, then the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side of the lens.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the present application, use of "may" means "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

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

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The following examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements may be made without departing from the concept of the present application, which are all within the scope of protection of the present application, for example, the lens group (i.e., the first lens to the sixth lens) in each embodiment of the present application, the lens barrel structure, and the spacer element may be arbitrarily combined, and the lens group in one embodiment is not limited to be combined with the lens barrel structure, the spacer element, and the like of the embodiment.

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

Referring to fig. 1, a visual optical system according to an embodiment of the present application may include a first lens group and a second lens group disposed in order from a screen side to a near screen side along an optical axis. The first lens group may include a first lens E1, a reflective polarizing element RP, and a quarter wave plate QWP; the second lens group may include a second lens E2 and a partially reflective layer BS. The first lens E1 and the second lens E2 have an incident surface near the screen side and an emergent surface far from the screen side, respectively. Wherein the first lens E1 and the second lens E2 may have a separation distance therebetween.

According to the visual optical system provided by the embodiment of the application, the lens structure comprising two pieces is adopted, so that the lens structure is more compact and lighter, meanwhile, the structural design is optimized on the aspects of eliminating chromatic aberration, phase difference and various stray light problems, and the molding quality is improved.

In an exemplary embodiment, a screen-far side (light-emitting surface) of the first lens E1 or a screen-far side (light-emitting surface) of the second lens E2 is a fresnel surface. By replacing the aspherical lens with the Fresnel surface, the thickness of the Fresnel surface is reduced, the Fresnel lens can be effectively combined with the plane or the curved surface of the rear surface, the thickness increase caused by rise is reduced, the length of the optical system is reduced, and the length and the performance of the foldback optical system are well balanced.

In an exemplary embodiment, the first lens group may have positive optical power. A reflective polarizing element RP and a quarter-wave plate QWP are sequentially attached to the side (light incident surface) of the first lens E1 close to the screen.

As an exemplary embodiment, the reflective polarizing element RP and the quarter-wave plate QWP are designed on the same side of the first lens E1, and can be combined together to achieve one-time attachment, thereby improving production efficiency and reducing cost; meanwhile, the two components are combined together, so that the angle deviation between the optical axis of the reflective polarizing element and the optical axis of the quarter-wave plate caused by the attaching process can be avoided, and the imaging effect is improved; in addition, through the arrangement, the folded light rays can be controlled to be in the range of the second lens and the gap between the second lens and the first lens, so that only the lens stress of the second lens is required to be controlled, and the material and the molding requirements of the first lens are reduced.

In an exemplary embodiment, the second lens group may have positive optical power. The partial reflection layer BS is attached to the side (light incident surface) of the second lens E2 close to the screen.

In an exemplary embodiment, the visual optical system may further include a first bearing member P1 located between the first lens E1 and the second lens E2, where the first bearing member P1 may be disposed on a screen-close side of the first lens E1 and at least partially contact with the screen-close side of the first lens E1 or a screen-far side of the second lens E2, for example, the first bearing member P1 may abut against a light incident surface of the first lens E1 or abut against a light emergent surface of the second lens E2.

In an exemplary embodiment, the visual optical system may further include a lens barrel P0, and the first lens group, the second lens group and the first bearing member P1 are all accommodated inside the lens barrel P0.

As shown in fig. 2A and 2B, according to the visual optical system with fresnel surfaces of the embodiment of the present application, the light-emitting surface of the first lens E1 is a fresnel surface, or the light-emitting surface of the second lens E2 is a fresnel surface.

According to the visual optical system of the present exemplary embodiment, the inner diameters of the first bearing member P1 on the screen-far side and the screen-near side are both greater than 50mm, and the visual optical system can satisfy: -19.0< d1 m/(r3+r4) <9.5, wherein d1m is the inner diameter of the first bearing member P1 near the screen side, R3 is the radius of curvature of the light exit surface of the second lens E2, and R4 is the radius of curvature of the light entrance surface of the second lens. According to the visual optical system of the embodiment of the application, the inner diameter of the first bearing part is larger than 50mm, so that the inner diameter of the bearing part arranged after the light passes through the foldback and Fresnel surface is used for guaranteeing that imaging is complete and simultaneously blocking redundant light at the edge, meanwhile, the curvature radius of the second lens away from the screen side is limited, the curvature radius of the two surfaces of the second lens can be effectively controlled in a certain range, the focal power value of the second lens can be limited, the trend of the light is better, the shape of the aspheric lens of the second lens can be limited, and the processability of the lens is guaranteed. Meanwhile, when the surface (namely the light-emitting surface) of the second lens, which is far away from the screen side, is a Fresnel surface, the curvature radius of the second lens is limited, so that the height of the Fresnel teeth can be effectively controlled within a certain range, and the phenomena of high processing difficulty, difficult demoulding and low imaging quality can be prevented; on the other hand, the Fresnel teeth can be ensured to be at a certain height, and the reduction of the thickness and the weight of the lens is avoided, so that the optimization quantity is too small.

According to the visual optical system of the exemplary embodiment of the present application, the inner diameters of the first bearing member P1 on the screen-far side and the screen-near side are both greater than 50mm, and the visual optical system may satisfy the following conditional expression: 0.8< F1/R1+D1s/d1s <3.5, wherein F1 is the effective focal length of the first lens group, R1 is the curvature radius of the light-emitting surface of the first lens, D1s is the outer diameter of the first bearing part far away from the screen side, and D1s is the inner diameter of the first bearing part far away from the screen side. By limiting the effective focal length of the first lens group and the shape of the first lens, not only the trend angle of light rays can be restrained, the light rays are prevented from being steeper, but also the processability of the first lens can be ensured; and meanwhile, the inner diameter and the outer diameter of the first bearing piece far away from the screen side are limited, the bearing supporting area of the first bearing piece is ensured, and the structural support of the first bearing piece is ensured.

The visual optical system provided by some embodiments of the present application can be used for a virtual reality device, and the fresnel scheme is combined with the optical path turn-back scheme, and only the curved surface where refraction occurs is reserved by removing the linear propagation part through the fresnel scheme, so that the thickness of the lens is reduced, and the length and weight of the lens are reduced; the optical path turning-back scheme is to enable the length of the body of the lens to be compressed to be half of the original length through optical path turning-back, so that the gravity center of the head-mounted device is moved backwards, and the experience of consumers is improved.

In an exemplary embodiment, the light incident surface of the first lens E1 may be a spherical surface or an aspherical surface, so that a better light deflection can be ensured when the light passes through the first lens E1.

In an exemplary embodiment, both the light incident surface and the light emergent surface of the second lens E2 may be convex.

In the exemplary embodiment, the light incident surface of the second lens E2 is aspheric, and a partially reflective layer BS is attached to the light incident surface of the second lens E2, so as to achieve the purpose of turning back the light beam at the second lens E2 and reduce the height of the optical system.

Referring to fig. 3, according to the visual optical system of the embodiment of the present application, image light from a screen is reflected and refracted multiple times in the second lens E2 and the first lens E1 by using polarization characteristics of light, and the length of the optical system is shortened by increasing the number of times of turning back the image light, and at the same time, the number of optical lenses used can be reduced, thereby realizing advantages of small volume, light weight and high resolution.

Referring to fig. 1, in an exemplary embodiment, the visual optical system may further include a first auxiliary supporting member P1b, where the first auxiliary supporting member P1b may be located on a side of the first lens E1 away from the screen and may be at least partially in contact with the light emitting surface of the first lens E1, for example, may abut against the light emitting surface of the first lens E1. Alternatively, the first auxiliary supporting member P1b may be located at a side of the second lens element E2 away from the screen, and may be at least partially in contact with the light-emitting surface of the second lens element E2, for example, may be abutted against the light-emitting surface of the second lens element E2. Because the thickness specification of the first auxiliary bearing piece P1b is easier to control, through selecting the first auxiliary bearing pieces with different thicknesses, the air gaps with reasonable ranges can be obtained between lenses with different thicknesses, and the produced lens field curves are ensured to be in a certain range, so that the tolerance requirement of the lens thickness is reduced, and the utilization rate of the lenses is improved.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: 1.0< EP01/CT1<2.5, wherein EP01 is a distance on the optical axis from a surface of the lens barrel away from the screen side to a surface of the first bearing member away from the screen side, and CT1 is a center thickness of the first lens. By limiting the thickness of the lens barrel ceiling and the thickness of the center of the first lens within a certain range, the structural strength of the lens barrel ceiling and the center of the first lens can be ensured, and certain workability of the first lens can be ensured.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: 0mm < D1 s/(F1/F2) <7.0mm, wherein D1s is the outer diameter of the first bearing member away from the screen side, F1 is the effective focal length of the first lens group, and F2 is the effective focal length of the second lens group. By controlling the effective focal lengths of the first lens group and the second lens group within a certain range, the focal power of the system is reasonably distributed, the aberration of the system is corrected on the premise of meeting the focal length of the system, and the imaging quality of the system is improved.

In an exemplary embodiment, a separation distance between the first lens group and the second lens group is less than 1.0mm, and the visual optical system may satisfy the following conditional expression: 0mm < CP1/(d 1m/d1 s) <4.0mm, wherein CP1 is the maximum thickness of the first bearing member, d1m is the inner diameter of the first bearing member on the side close to the screen, and d1s is the inner diameter of the first bearing member on the side far from the screen. The appearance that satisfies this conditional expression can control first bearing spare, both can restrict the bearing area that first bearing spare is close to the screen side, guarantees its support nature to the second lens, can restrict the diameter thick ratio of first bearing spare again, ensures its workability.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: 6.0< (d0m+d0s)/TD <8.5, where D0m is the outer diameter of the barrel on the side close to the screen, D0s is the outer diameter of the barrel on the side far away from the screen, and TD is the distance on the optical axis from the surface of the first lens on the side far away from the screen to the surface of the second lens on the side close to the screen. By limiting the structural appearance of the lens barrel and controlling the diameter-thickness ratio of the lens barrel, on one hand, the outer diameter of the lens barrel is prevented from being too large to influence the assembly space of the whole machine design; on the other hand, the outer diameter of the lens barrel is prevented from being too small, and the processing and forming difficulty is too high.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: fno <10.5, where d0s is the inner diameter of the barrel away from the screen side, d1bs is the inner diameter of the first auxiliary bearing member away from the screen side, and Fno is the f-number of the visual optical system. The system light inlet aperture can be controlled to absorb redundant light from the screen side by meeting the condition, so that the system light inlet aperture can be prevented from being too large to generate redundant stray light, and the system light inlet aperture can be prevented from being too small, so that the image is smaller, and the user experience effect is affected.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: 309.5mm ² <π(D0m ² -d0m ² )<393.0mm ² Wherein D0m is the outer diameter of the lens barrel close to the screen side, D0m is the inner diameter of the lens barrel close to the screen side, and pi is the circumference ratio. By limiting the appearance of the lens barrel, the inner diameter of the lens barrel, which is close to the screen, is not only prevented from being too small, so that the effective display range of the screen is limited, but also the inner diameter of the lens barrel, which is close to the screen, is prevented from being too large, and extra parasitic light is generated; meanwhile, the inner diameter and the outer diameter of the lens barrel, which are close to the screen side, are limited, so that the reasonable bearing support area of the lens barrel can be ensured, the characteristics of the support structure of the lens barrel can be met, and the processability of the lens barrel can be met.

In an exemplary embodiment, the distance from the light incident surface of the second lens to the screen is less than 20.0mm, and the visual optical system may satisfy the following conditional expression: d0m/R4 <0.8, wherein d0m is the inner diameter of the lens barrel near the screen side, and R4 is the radius of curvature of the light incident surface of the second lens. Through limiting the structural appearance of the second lens, and the second lens is a core lens of a folding light path, the structural appearance of the second lens is more reasonable, and the second lens is beneficial to the processability of the second lens and the overall performance of the lens.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: (L-EP 01-CP 1)/CT 2<1.0, wherein L is the maximum height of the lens barrel, EP01 is the distance on the optical axis between the surface of the lens barrel away from the screen side and the surface of the first bearing member away from the screen side, and CP1 is the maximum thickness of the first bearing member. The lens barrel length can be prevented from being overlong by meeting the condition, the TTL of the whole lens can be prevented from being influenced, the thicknesses of the lens constituent elements can be reasonably distributed, and the workability of the elements is ensured.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: -38.0< (r2+r3)/d 1s < -8.5, wherein R2 is the radius of curvature of the light incident surface of the first lens, R3 is the radius of curvature of the light emergent surface of the second lens, and d1s is the inner diameter of the first bearing member away from the screen side. The condition is satisfied, so that the trend of light rays between the first lens and the second lens can be limited, and as the reflective polarizing element and the quarter-wave plate are attached to the light incident surface of the first lens, which is close to the screen side, the light ray between the first lens and the second lens is prevented from being excessively large in refraction and reflection angle, and the polarization characteristics of the reflective polarizing element and the quarter-wave plate are prevented from being influenced; meanwhile, the first bearing piece is combined with the limitation of the inner diameter of the side far away from the screen, so that stray light between the first lens and the second lens can be controlled, and the imaging quality is improved.

In an exemplary embodiment, the visual optical system may satisfy the following conditional expression: 1.5< F/L <2.5, wherein F is the effective focal length of the visual optical system, and L is the maximum height of the lens barrel. The focal length of the optical imaging system can be controlled by meeting the conditional expression, and the view angle of the system is effectively restrained, so that the system meets the characteristic of large view field of the VR lens, meanwhile, the maximum height of the lens barrel is limited, the length of the whole lens barrel is shortened, and the experience of a user is ensured.

In an exemplary embodiment, the fresnel surface of the visual optical system has a base curvature of less than 10 ^-6 . By limiting the basic curvature of the Fresnel surface to less than 10 ^-6 The height of the Fresnel teeth can be prevented from being too large, the good processability of the Fresnel surface can be ensured, and the too large degree of ghost distortion caused by the Fresnel surface can be prevented, so that the experience effect is influenced.

In an exemplary embodiment, the maximum thickness of the first bearing member of the visual optical system is greater than 0.2mm, and the first bearing member is at least partially in contact with the inner wall of the barrel. When the gap between the first lens and the second lens is larger, the edge thickness cannot be greatly increased to ensure the molding of the lens, and then a bearing element is needed to form an assembly support. Meanwhile, in order to ensure that the inner side of the bearing diameter plays a role in shielding stray light, the outer diameter of the bearing diameter is required to be in partial contact fit with the inner wall of the lens barrel.

According to the visual optical system of the embodiment of the application, two lenses can be adopted, and by reasonably distributing the focal length, the surface thickness, the center thickness and the axial spacing among the lenses, etc. of each lens, incident light rays can be effectively converged, the total optical length can be reduced, and the processability can be improved, so that the visual optical system is more beneficial to production and processing.

In an embodiment of the present application, at least one of the optical surfaces of each of the first lens and the second lens is an aspherical mirror surface. The aspherical lens is characterized in that: the curvature varies 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 radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens, aberration occurring during imaging can be eliminated as much as possible, thereby improving imaging quality.

Examples 1 to 10 applicable to the visual optical system of the above-described exemplary embodiment will be further described below with reference to the drawings in combination with examples.

Example 1

Fig. 4 shows a schematic structural diagram of a visual optical system according to embodiment 1 of the present application. As shown in fig. 4, the visual optical system includes a lens barrel P0 and a lens assembly accommodated in the lens barrel P0, which are sequentially arranged along an optical axis from a screen-far side to a screen-near side: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2 and a screen. The first lens E1 has a light-exiting surface S1 far from the screen side and a light-entering surface S2 near the screen side. The second lens E2 has a light-exiting surface S5 far from the screen side and a light-entering surface S6 near the screen side.

In this embodiment, the first lens E1, the reflective polarizing element RP, and the quarter-wave plate QWP may constitute a first lens group. Specifically, the light incident surface S2 of the first lens E1 is attached with a reflective polarizing element RP and a quarter wave plate QWP in order, and the reflective polarizing element RP and the quarter wave plate QWP have optical surfaces S3 and S4, respectively. When the light passes through the reflective polarizing element RP, the reflective polarizing element may reflect light in a certain direction and may transmit light orthogonal to the reflected light. The quarter wave plate QWP can be used for converting between circularly polarized light and linearly polarized light, so that the light path is turned back, and the length of a visual optical system is shortened.

In this embodiment, the second lens E2 and the partially reflective layer BS constitute a second lens group. Specifically, the partially reflecting layer BS is attached to the light incident surface S6 of the second lens E2. The partially reflective layer BS has a transflective effect on light. By providing the partial reflection layer BS on the light incident surface S6 of the second lens E2 and combining the reflective polarizing element RP and the quarter-wave plate QWP, the light can be folded back multiple times, thereby effectively reducing the body length of the visual optical system.

In this embodiment, the light exit surface S1 of the first lens E1 is a thin fresnel surface. The thickness of the Fresnel surface is reduced, the Fresnel surface can be effectively combined with the plane or the curved surface of the rear surface, and the thickness increase caused by rise is reduced.

In this embodiment, the visual optical system may further include a first bearing member P1 located between the first lens E1 and the second lens E2, where the first bearing member P1 may be at least partially contacted with the screen-far side of the second lens E2, for example, may be abutted on the light-emitting surface S5 of the second lens E2 and at least partially contacted with the inner wall of the lens barrel P0; and a first auxiliary bearing member P1b positioned on the side of the first lens E1 away from the screen, wherein the first auxiliary bearing member P1b can be at least partially contacted with the inner wall of the lens barrel P0 and the side of the first lens E1 away from the screen.

In this embodiment, the first lens E1 has positive power, and the light-emitting surface S1 of the first lens E1 may be convex.

In this embodiment, the second lens E2 has positive power, and both the light incident surface S6 and the light emergent surface S5 of the second lens E2 may be convex.

In this example, as an exemplary embodiment, the light incident surface S2 of the first lens E1 may be a plane so as to attach the reflective polarizing element RP and the quarter-wave plate QWP.

As an exemplary embodiment, the reflective polarizing element RP and the quarter wave plate QWP are combined together, so that the reflective polarizing element RP and the quarter wave plate QWP are prevented from being attached separately, and the attaching efficiency is improved.

As an exemplary embodiment, the light incident surface S6 of the second lens E2 may be an aspherical surface. The light exit surface S1 of the first lens E1 is aspheric, and the light entrance surface S2 may be spherical or aspheric. The aspheric lens has better curvature radius characteristic and has the advantages of improving distortion aberration and astigmatism aberration. The use of the aspherical lens can eliminate aberrations occurring at the time of imaging as much as possible, thereby improving imaging quality.

In this embodiment, the visual optical system may further include a stop STO disposed on the screen-distant side. The image light emitted from the screen is refracted and reflected for many times by the second lens E2 and the first lens E1, and then enters the aperture stop STO, and further enters the human eye. Specifically, the image light from the display screen sequentially passes through the second lens E2 and the quarter wave plate QWP to the reflective polarizing element RP, then is reflected at the reflective polarizing element RP, and again passes through the quarter wave plate QWP and the second lens E2 to the partially reflective layer BS, after which the light beam is reflected at the partially reflective layer BS and sequentially passes through the second lens E2, the quarter wave plate QWP, the reflective polarizing element RP, and the first lens E1, and then is incident on the stop STO, and then exits toward the human eye side. According to the visual optical system provided by the application, the required optical path is folded by means of light reflection and refraction combination on the premise of not affecting imaging quality, so that the length of the body of the visual optical system is effectively shortened.

Example 2

Fig. 5 shows a schematic structural diagram of a visual optical system according to embodiment 2 of the present application. In this embodiment 2 and the following embodiments, a description of portions similar to that of embodiment 1 will be omitted for brevity.

As shown in fig. 5, the visual optical system barrel P0 of the present embodiment, and the first lens E1, the reflective polarizing element RP, the quarter-wave plate QWP, the second lens E2, the partially reflective layer BS, and the screen, which are arranged in this order from the screen side to the near-screen side. The light-emitting surface S1 of the first lens E1 is a thin fresnel surface.

Table 1 below shows basic parameter tables of the visual optical systems of examples 1 and 2, in which the unit of curvature radius, thickness/distance is millimeter (mm).

TABLE 1

In embodiments 1 and 2, the light exit surface S1 of the first lens E1 and the light entrance surface S6 of the second lens E2 are aspheric, and the surface shape x of each aspheric lens can be defined by, but not limited to, the following aspheric formula:

wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the aspherical i-th order.

Table 2 shows the higher order coefficients A that can be used for each of the aspherical surfaces S1, S6 in example 1 and example 2 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

Face number	A4	A6	A8	A10	A12
						S1	1.04E-06	-9.87E-11	0.00E+00	0.00E+00	0.00E+00
S6	1.49E-07	3.55E-11	0.00E+00	0.00E+00	0.00E+00
						Face number	A14	A16	A18	A20
S1	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	0.00E+00	0.00E+00	0.00E+00	0.00E+00

TABLE 2

Fig. 6A shows on-axis chromatic aberration curves of the visual optical systems of example 1 and example 2, which represent the convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 6B shows astigmatism curves of the visual optical systems of example 1 and example 2, which represent meridional image plane curvature and sagittal image plane curvature. As can be seen from fig. 6A and 6B, the visual optical systems given in example 1 and example 2 can achieve good imaging quality.

Example 3

Fig. 7 shows a schematic structural diagram of a visual optical system according to embodiment 3 of the present application. As shown in fig. 7, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side. In this embodiment, the light exit surface S5 of the second lens E2 is a thin fresnel surface.

As an exemplary embodiment, the light exit surface S5 and the light entrance surface S6 of the second lens E2 may be aspherical surfaces. The light exit surface S1 of the first lens E1 is aspheric, and the light entrance surface S2 may be spherical or aspheric. The aspheric lens has better curvature radius characteristic and has the advantages of improving distortion aberration and astigmatism aberration. The use of the aspherical lens can eliminate aberrations occurring at the time of imaging as much as possible, thereby improving imaging quality.

Example 4

Fig. 8 shows a schematic structural diagram of a visual optical system according to embodiment 4 of the present application. As shown in fig. 8, the visual optical system of the present embodiment includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side. In this embodiment, the light exit surface S5 of the second lens E2 is a thin fresnel surface.

Table 3 shows basic parameter tables of the visual optical systems of example 3 and example 4, in which the unit of curvature radius, thickness/distance is millimeter (mm).

TABLE 3 Table 3

In embodiments 3 and 4, the light-emitting surface S1 of the first lens E1, the light-emitting surface S5 of the second lens E2, and the light-entering surface S6 are all aspheric, and the surface shape x of each aspheric lens can be defined by, but not limited to, the above formula (1).

Table 4 shows the higher order coefficients A that can be used for each of the aspherical surfaces S1, S5, S6 in example 3 and example 4 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

Face number	A4	A6	A8	A10	A12
						S1	1.09E-06	-1.81E-09	5.28E-12	-9.36E-15	0.00E+00
S5	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	5.34E-08	4.93E-10	0.00E+00	0.00E+00	0.00E+00
Face number	A14	A16	A18	A20
						S1	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S5	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	0.00E+00	0.00E+00	0.00E+00	0.00E+00

TABLE 4 Table 4

Fig. 9A shows on-axis chromatic aberration curves of the visual optical systems of example 3 and example 4, which represent the convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 9B shows astigmatism curves of the visual optical systems of example 3 and example 4, which represent meridional image plane curvature and sagittal image plane curvature. As can be seen from fig. 9A and 9B, the visual optical systems given in example 3 and example 4 can achieve good imaging quality.

Example 5

Fig. 10 shows a schematic structural diagram of a visual optical system according to embodiment 5 of the present application. As shown in fig. 10, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side. In this embodiment, the light exit surface S1 of the first lens E1 is a thin fresnel surface. The thickness of the Fresnel surface is reduced, the Fresnel surface can be effectively combined with the plane or the curved surface of the rear surface, and the thickness increase caused by rise is reduced.

In this embodiment, the reflective polarizing element RP and the quarter wave plate QWP are combined together, so that the reflective polarizing element RP and the quarter wave plate QWP are prevented from being attached separately, and the attaching efficiency is improved.

In this embodiment, the light incident surface S6 of the second lens E2 may be an aspheric surface. The light-emitting surface S1 and the light-entering surface S2 of the first lens E1 are aspheric. The aspheric lens has better curvature radius characteristic and has the advantages of improving distortion aberration and astigmatism aberration. The use of the aspherical lens can eliminate aberrations occurring at the time of imaging as much as possible, thereby improving imaging quality.

Example 6

Fig. 11 shows a schematic structural diagram of a visual optical system according to embodiment 6 of the present application. As shown in fig. 11, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side.

In this embodiment, the light exit surface S1 of the first lens E1 is a thin fresnel surface.

In this embodiment, the visual optical system may further include a first bearing member P1 located between the first lens E1 and the second lens E2, where the first bearing member P1 may be at least partially contacted with the screen side of the first lens E1, for example, may be abutted against the light incident surface S2 of the first lens E1 and may be at least partially contacted with the inner wall of the lens barrel P0; and a first auxiliary bearing member P1b positioned on the side of the second lens E2 away from the screen, wherein the first auxiliary bearing member P1b can be at least partially contacted with the inner wall of the lens barrel P0 and the side of the second lens E2 away from the screen.

Table 5 shows basic parameter tables of the visual optical systems of example 5 and example 6, in which the unit of curvature radius, thickness/distance is millimeter (mm).

TABLE 5

In embodiments 5 and 6, the light exit surface S1 and the light entrance surface S2 of the first lens E1 and the light entrance surface S6 of the second lens E2 are both aspheric, and the surface shape x of each aspheric lens can be defined by, but not limited to, the above formula (1).

Table 6 shows the higher order coefficients A that can be used for each of the aspherical surfaces S1, S2, S3, S4, S6 in example 5 and example 6 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

Face number	A4	A6	A8	A10	A12
						S1	5.31E-06	-8.82E-10	0.00E+00	0.00E+00	0.00E+00
S2	5.90E-07	6.10E-10	-1.15E-13	0.00E+00	0.00E+00
						S3	5.90E-07	6.10E-10	-1.15E-13	0.00E+00	0.00E+00
S4	5.90E-07	6.10E-10	-1.15E-13	0.00E+00	0.00E+00
						S6	5.08E-07	4.24E-10	0.00E+00	0.00E+00	0.00E+00
Face number	A14	A16	A18	A20
						S1	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S2	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S3	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S4	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	0.00E+00	0.00E+00	0.00E+00	0.00E+00

TABLE 6

Fig. 12A shows on-axis chromatic aberration curves of the visual optical systems of example 5 and example 6, which represent the convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 12B shows astigmatism curves of the visual optical systems of example 5 and example 6, which represent meridional image plane curvature and sagittal image plane curvature. As can be seen from fig. 12A and 12B, the visual optical systems given in example 5 and example 6 can achieve good imaging quality.

Example 7

Fig. 13 shows a schematic structural diagram of a visual optical system according to embodiment 7 of the present application. As shown in fig. 13, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side.

In this embodiment, the visual optical system may further include a first bearing member P1 located between the first lens E1 and the second lens E2, where the first bearing member P1 may be at least partially contacted with the screen-far side of the second lens E2, for example, may be abutted on the light-emitting surface S5 of the second lens E2 and may be at least partially contacted with the inner wall of the lens barrel P0; and a first auxiliary bearing member P1b positioned on the side of the first lens E1 away from the screen, wherein the first auxiliary bearing member P1b can be at least partially contacted with the inner wall of the lens barrel P0 and the side of the first lens E1 away from the screen.

In this embodiment, the first lens E1 has positive power, and the light exit surface S1 and the light entrance surface S2 of the first lens E1 may be convex.

In this embodiment, the light incident surface S6 of the second lens E2 may be an aspheric surface. The light-emitting surface S1 and the light-entering surface S2 of the first lens E1 are aspheric.

Example 8

Fig. 14 shows a schematic structural diagram of a visual optical system according to embodiment 8 of the present application. As shown in fig. 14, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side.

Table 7 shows basic parameter tables of the visual optical systems of examples 7 and 8, in which the unit of curvature radius, thickness/distance is millimeter (mm).

TABLE 7

In embodiments 7 and 8, the light exit surface S1 and the light entrance surface S2 of the first lens E1 and the light entrance surface S6 of the second lens E2 are both aspheric, and the surface shape x of each aspheric lens can be defined by, but not limited to, the above formula (1).

Table 8 shows the higher order coefficients A that can be used for each of the aspherical surfaces S1, S2, S3, S4, S6 in example 7 and example 8 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

Face number	A4	A6	A8	A10	A12
						S1	6.33E-06	-1.30E-09	0.00E+00	0.00E+00	0.00E+00
S2	6.51E-07	7.18E-10	-1.61E-13	0.00E+00	0.00E+00
						S3	6.92E-07	7.22E-10	-1.51E-13	0.00E+00	0.00E+00
S4	6.50E-07	7.51E-10	-1.58E-13	0.00E+00	0.00E+00
						S6	6.80E-07	4.67E-10	0.00E+00	0.00E+00	0.00E+00
Face number	A14	A16	A18	A20
						S1	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S2	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S3	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S4	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	0.00E+00	0.00E+00	0.00E+00	0.00E+00

TABLE 8

Fig. 15A shows on-axis chromatic aberration curves of the visual optical systems of example 7 and example 8, which represent the convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 15B shows astigmatism curves of the visual optical systems of examples 7 and 8, which represent meridional image plane curvature and sagittal image plane curvature. As can be seen from fig. 15A and 15B, the visual optical systems given in example 7 and example 8 can achieve good imaging quality.

Example 9

Fig. 16 shows a schematic structural diagram of a visual optical system according to embodiment 9 of the present application. As shown in fig. 16, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side.

In this embodiment, the light exit surface S5 of the second lens E2 is a thin fresnel surface.

In this embodiment, the light incident surface S6 of the second lens E2 may be an aspheric surface. The light-emitting surface S1 of the first lens E1 is aspheric, and the light-entering surface S2 may be spherical.

Example 10

Fig. 17 shows a schematic structural diagram of a visual optical system according to embodiment 10 of the present application. As shown in fig. 17, the visual optical system includes a lens barrel P0, and a first lens E1, a reflective polarizing element RP, a quarter-wave plate QWP, a second lens E2, a partially reflective layer BS, and a screen, which are arranged in this order from the screen side to the near-screen side.

Table 9 shows basic parameter tables of the visual optical systems of example 9 and example 10, in which the unit of curvature radius, thickness/distance is millimeter (mm).

TABLE 9

In embodiments 9 and 10, the light-emitting surface S1 of the first lens E1, the light-emitting surface S5 of the second lens E2, and the light-entering surface S6 are all aspheric, and the surface shape x of each aspheric lens can be defined by, but not limited to, the above formula (1).

Table 10 shows the higher order coefficients A that can be used for each of the aspherical surfaces S1, S5, S6 in example 9 and example 10 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

Face number	A4	A6	A8	A10	A12
						S1	1.82E-06	3.30E-09	-9.06E-12	6.13E-15	0.00E+00
S5	0.00E+00	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	3.80E-07	4.16E-10	0.00E+00	0.00E+00	0.00E+00
Face number	A14	A16	A18	A20
						S1	0.00E+00	0.00E+00	0.00E+00	0.00E+00
S5	0.00E+00	0.00E+00	0.00E+00	0.00E+00
						S6	0.00E+00	0.00E+00	0.00E+00	0.00E+00

Table 10

Fig. 18A shows on-axis chromatic aberration curves of the visual optical systems of example 9 and example 10, which represent the convergent focus deviation after light rays of different wavelengths pass through the lens. Fig. 18B shows astigmatism curves of the visual optical systems of example 9 and example 10, which represent meridional image plane curvature and sagittal image plane curvature. As can be seen from fig. 18A and 18B, the visual optical systems given in example 9 and example 10 can achieve good imaging quality.

Tables 11-1 and 11-2 below show data such as optical parameters of the visual optical systems of examples 1 to 10 and the pitches of the respective optical elements, for example, the effective focal length F, F-number FNO, half of the maximum field angle Semi-FOV of the visual optical system, focal length values of the respective lens groups, and relevant parameters of the first bearing member and the lens barrel, respectively. Wherein, the units of the distance and the focal length value are millimeter (mm).

Parameters/embodiments	1	2	3	4	5
						Semi-FOV(°)	47.97	47.97	47.97	47.97	47.97
F	33.62	33.62	29.55	29.55	33.02
						F1	115638.30	115638.30	68765.42	68765.42	3535.17
F2	159.72	159.72	121.05	121.05	147.13
						FNO	8.41	8.41	7.39	7.39	6.60
d1bs	38.181	38.181	38.621	38.621	37.897
						d1s	57.043	58.408	53.678	53.112	61.259
d1m	56.841	58.408	52.845	53.112	60.262
						D1s	59.719	63.779	57.024	58.483	64.236
d0s	45.641	45.641	46.082	46.082	46.262
						d0m	63.783	65.779	60.189	60.189	68.290
D0s	55.305	55.305	55.746	55.746	55.926
						D0m	67.479	69.475	63.385	63.385	71.486
CP1	3.522	0.100	1.150	0.100	3.544
						L	16.989	16.989	16.453	16.453	20.073
EP01	7.585	11.007	8.697	8.697	9.747

TABLE 11-1

Parameters/embodiments	6	7	8	9	10
						Semi-FOV(°)	47.97	50.00	50.00	47.97	47.97
F	33.02	33.56	33.56	33.62	33.62
						F1	3535.17	4378.59	4378.59	115638.30	115638.30
F2	147.13	152.43	152.43	159.72	159.72
						FNO	6.60	8.39	8.39	8.46	8.46
d1bs	60.070	40.011	62.008	40.065	38.841
						d1s	60.588	61.607	61.020	54.802	54.830
d1m	60.588	61.023	61.020	54.838	54.830
						D1s	64.710	64.665	65.972	60.033	60.577
d0s	66.248	48.358	67.952	46.982	45.759
						d0m	67.022	67.973	67.973	63.107	64.004
D0s	69.444	58.022	71.148	56.867	55.644
						D0m	70.218	71.168	71.168	66.303	67.200
CP1	0.100	3.235	0.100	1.792	0.100
						L	16.064	19.044	15.814	16.668	17.077
EP01	9.372	9.241	9.121	6.233	6.769

TABLE 11-2

In summary, in examples 1 to 10, the visual optical system satisfies the following conditional expressions shown in table 12.

Table 12

The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the utility model referred to in this application is not limited to the specific combinations of features described above, but also covers other technical solutions which may be formed by any combination of the features described above or their equivalents without departing from the inventive concept. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims

1. A visual optical system comprising a first lens group and a second lens group in this order from a screen-far side to a screen-near side along an optical axis, characterized in that,

the first lens group comprises a first lens, a reflective polarizing element and a quarter-wave plate;

the second lens group comprises a second lens and a partial reflecting layer;

wherein the side surface of the first lens far away from the screen or the side surface of the second lens far away from the screen is a Fresnel surface;

the visual optical system further comprises a lens barrel and a first bearing piece arranged on the side, close to the screen, of the first lens, wherein the first bearing piece is at least partially contacted with the side, close to the screen, of the first lens or the side, away from the screen, of the second lens; the first lens group, the second lens group and the first bearing part are all accommodated in the lens barrel, wherein

The first bearing piece is far away from the screen side and the inner diameter close to the screen side is larger than 50mm, and the inner diameter d1m of the first bearing piece close to the screen side, the curvature radius R3 of the second lens far away from the screen side and the curvature radius R4 of the second lens close to the screen side meet the following conditions: -19.0< d1 m/(r3+r4) <9.5.

2. The visual optical system of claim 1, wherein the visual optical system further comprises a first auxiliary bearing located on a screen-facing side of the first lens and in at least partial contact with a screen-facing side of the first lens, or on a screen-facing side of the second lens and in at least partial contact with a screen-facing side of the second lens.

3. The visual optical system according to claim 1, wherein the reflective polarizing element and the quarter-wave plate are sequentially attached to a screen-approaching side face of the first lens; the partial reflecting layer is attached to the side surface, close to the screen, of the second lens.

4. The visual optical system according to claim 1, wherein an effective focal length F1 of the first lens group, a radius of curvature R1 of the first lens on a screen-side-away side, an outer diameter D1s of the first bearing on a screen-side-away side, and an inner diameter D1s of the first bearing on a screen-side-away side satisfy: 0.8< F1/R1+D1s/d1s <3.5.

5. The visual optical system according to claim 1, wherein a distance EP01 on the optical axis from a surface of the barrel away from the screen side to a surface of the first bearing away from the screen side satisfies a central thickness CT1 of the first lens: 1.0< EP01/CT1<2.5.

6. The visual optical system according to claim 1, wherein an outer diameter D1s of the first bearing member on a screen-side, an effective focal length F1 of the first lens group, and an effective focal length F2 of the second lens group satisfy: 0mm < D1 s/(F1/F2) <7.0mm.

7. The visual optical system according to claim 1, wherein a separation distance between the first lens group and the second lens group is less than 1.0mm, and a maximum thickness CP1 of the first bearing, an inner diameter d1m of the first bearing on a screen side, and an inner diameter d1s of the first bearing on a screen side satisfy: 0mm < CP1/(d 1m/d1 s) <4.0mm.

8. The visual optical system according to claim 1, wherein an outer diameter D0m of the barrel on the screen side, an outer diameter D0s of the barrel on the screen side, and a distance TD on the optical axis from the screen side of the first lens to the screen side of the second lens satisfy: 6.0< (d0m+d0s)/TD <8.5.

9. The visual optical system according to claim 2, wherein an inner diameter d0s of the lens barrel on a screen side, an inner diameter d1bs of the first auxiliary bearing on a screen side, and an f-number Fno of the visual optical system satisfy: 7.5< d0s/d1bs < FNo <10.5.

10. The visual optical system according to claim 1, wherein an outer diameter D0m of the barrel on the screen side and an inner diameter D0m of the barrel on the screen side satisfy: 309.5mm ² <π(D0m ² -d0m ² )<393.0mm ² Where pi is the circumference ratio.

11. The visual optical system according to claim 1, wherein a screen-side-to-screen distance of the second lens is less than 20.0mm, and an inner diameter d0m of the barrel on the screen side and a radius of curvature R4 of the second lens on the screen side satisfy: d0m/R4 <0.8.

12. The visual optical system according to claim 1, wherein a maximum height L of the lens barrel, a distance EP01 on the optical axis from a side of the lens barrel away from the screen to a side of the first bearing away from the screen, a maximum thickness CP1 of the first bearing, and a center thickness CT2 of the second lens satisfy: (L-EP 01-CP 1)/CT 2<1.0.

13. The visual optical system according to any one of claims 1 to 12, wherein a radius of curvature R2 of the first lens on a screen-side surface, a radius of curvature R3 of the second lens on a screen-side surface, and an inner diameter d1s of the first bearing on the screen-side surface satisfy: -38.0< (r2+r3)/d 1s < -8.5.

14. The visual optical system according to any one of claims 1 to 12, wherein an effective focal length F of the visual optical system and a maximum height L of the lens barrel satisfy: 1.5< F/L <2.5.

15. The visual optical system of any of claims 1-12, wherein the fresnel surface has a base curvature of less than 10 ^-6 。

16. The visual optical system of any of claims 1-12, wherein the first bearing has a maximum thickness greater than 0.2mm and is in at least partial contact with an inner wall of the barrel.