CN220232096U

CN220232096U - Optical system and optical apparatus including the same

Info

Publication number: CN220232096U
Application number: CN202321005240.1U
Authority: CN
Inventors: 李开荣; 冯梦怡; 游金兴; 张晓彬; 金银芳; 戴付建; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2023-04-27
Filing date: 2023-04-27
Publication date: 2023-12-22
Anticipated expiration: 2033-04-27

Abstract

The application discloses optical system and optical equipment including this optical system, this optical system lens group includes in proper order from first side to second side along the optical axis: the first lens group, the second lens and the third lens, wherein the first lens group has positive focal power, and sequentially comprises from a first side to a second side: a reflective polarizing element, a quarter wave plate, and a first lens; at least one bearing element comprising a second bearing element arranged on and in contact with the second side of the second lens; and a lens barrel for accommodating the lens group and at least one bearing member; wherein the optical system further comprises a partially reflective layer; the dispersion coefficient VRP of the reflective polarizing element, the effective focal length F1 of the first lens group, and the outer diameter D0s of the first side end face of the barrel satisfy: 20< VRP x F1/D0s <210; and the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2s of the first side surface of the second bearing element and the inner diameter d0m of the second side end surface of the lens barrel satisfy the following conditions: 0< |f2+f3|/(d2s+d0m) <5.

Description

Optical system and optical apparatus including the same

Technical Field

The present application relates to the field of optical elements, and more particularly, to an optical system and an optical apparatus including the same.

Background

The refraction and reflection type optical system scheme realizes the refraction of light rays in different optical elements in a mode of sticking films and coating films on the lenses, and finally achieves the aim of shortening the length of the whole optical system. Compared with the prior scheme of an aspheric lens and a Fresnel lens, the catadioptric optical system scheme has better development prospect.

The refractive-reflective optical devices commonly used in the market at present pay attention to the imaging quality of a central field of view, especially on-axis position chromatic aberration and spherical aberration, and ignore the problem of poor imaging quality of an outer field of view. Meanwhile, the common two-piece type refraction and reflection optical system has less optimized space, so that the experience effect of a user is improved, the length of the body of the optical equipment is ensured not to be prolonged due to the increase of the number of lenses, and the development trend of the refraction and reflection optical equipment is realized. How to overcome the problem of the imaging quality of the external field under the conditions of ensuring stable assembly and controllable stray light of the catadioptric optical system becomes one of the current research hot spots.

Disclosure of Invention

A first aspect of the present application provides an optical system comprising: the lens group sequentially comprises from a first side to a second side along an optical axis: the first lens group, the second lens and the third lens, wherein the first lens group has positive focal power, and sequentially comprises from a first side to a second side: the second side surface of the reflective polarizing element is attached to the first side surface of the quarter wave plate, and the second side surface of the quarter wave plate is attached to the first side surface of the first lens; at least one bearing element comprising a second bearing element arranged on and in contact with the second side of the second lens; and a lens barrel for accommodating the lens group and at least one bearing member; wherein the optical system further comprises a partially reflective layer disposed on the second side of the first lens or the first side of the second lens; the dispersion coefficient VRP of the reflective polarizing element, the effective focal length F1 of the first lens group, and the outer diameter D0s of the first side end face of the barrel satisfy: 20< VRP x F1/D0s <210; and the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2s of the first side surface of the second bearing element and the inner diameter d0m of the second side end surface of the lens barrel satisfy the following conditions: 0< |f2+f3|/(d2s+d0m) <5.

In one embodiment, the inner diameter d0m of the second side end surface of the lens barrel, the inner diameter d0s of the first side end surface of the lens barrel, and the radius of curvature R1 of the first side surface of the first lens satisfy: -5.1< (d0m+d0s)/R1 < -1.

In one embodiment, the first side of the first lens is concave and the second side of the second lens is convex; and the radius of curvature R1 of the first side of the first lens and the radius of curvature R4 of the second side of the second lens satisfy: 1.5 XR 1> R4.

In one embodiment, the radius of curvature of the first side and the second side of the reflective polarizing element is the same; the radius of curvature RRP of the second side surface of the reflective polarizing element, the radius of curvature R4 of the second side surface of the second lens, the inner diameter d2m of the second side surface of the second bearing element and the inner diameter d0s of the first side end surface of the lens barrel satisfy the following conditions: -10< (rrp1+r4)/(d2m+d0s) <0.

In one embodiment, the outer diameter D0m of the second side end surface of the lens barrel, the maximum height L of the lens barrel in the optical axis direction, the effective focal length f of the optical system, and the sum Σct of the center thicknesses of the first lens, the second lens, and the third lens on the optical axis satisfy: 2< D0 m/Lxf/ΣCT <4.

In one embodiment, the abbe number V2 of the second lens, the abbe number V3 of the third lens, the abbe number V1 of the first lens, the inner diameter D2s of the first side surface of the second bearing element, the inner diameter D2m of the second side surface of the second bearing element, and the outer diameter D0s of the first side end surface of the lens barrel satisfy: 0< (V2+V3)/V1× (d2s+d2m)/D0 s <4.

In one embodiment, the outer diameter D2s of the first side of the second bearing element, the maximum field angle FOV of the optical system, the on-axis distance TrRPrBS of the first side of the reflective polarizing element to the surface of the lens where the partially reflective layer is located satisfy: 6< D2s×tan (FOV/2)/TrRPrBS <20.

In one embodiment, the maximum thickness CP2 of the second bearing element in the optical axis direction, the f-number Fno of the optical system, and the air space T12 of the first lens to the second lens on the optical axis satisfy: 6< CP2×FNo/T12<100.

In one embodiment, the refractive index NRP of the reflective polarizing element, the refractive index NQWP of the quarter wave plate, the effective focal length F1 of the first lens group, and the outer diameter D0s of the first side end face of the barrel satisfy: 1< (NRP+NQWP). Times.F1/D0 s <11.

In one embodiment, the maximum height L of the lens barrel in the optical axis direction, the f-number Fno of the optical system, the outer diameter D0s of the first side end surface of the lens barrel, and the outer diameter D0m of the second side end surface of the lens barrel satisfy: 20< LXFNo/|D0s-D0m| <110.

In one embodiment, a distance TD between the first side surface of the first lens and the second side surface of the third lens on the optical axis, a center thickness CTRP of the reflective polarizing element in the optical axis direction, a center thickness CTQWP of the quarter wave plate in the optical axis direction, an effective focal length f of the optical system, a maximum field angle FOV of the optical system, and an outer diameter D0m of the second side end surface of the lens barrel satisfy: 4< (TD+CTRP+CTQWP)/(f×tan (FOV/2) -D0 m/2) <35.

In one embodiment, the radius of curvature of the first side and the second side of the quarter wave plate is the same; and the distance SAG11 between the intersection point of the first side surface of the first lens on the optical axis and the maximum effective radius vertex of the first side surface of the first lens on the optical axis, the radius RQWP of curvature of the second side surface of the quarter wave plate, the outer diameter D0s of the first side end surface of the lens barrel and the central thickness CT1 of the first lens on the optical axis satisfy the following conditions: 0< SAG11/RQWP x D0s/CT1<4.

In one embodiment, the at least one bearing element further comprises a first bearing element disposed on and in contact with the second side of the first lens; the outer diameter D0m of the second side end surface of the lens barrel, the inner diameter D1m of the second side surface of the first bearing element, the center thickness CT2 of the second lens on the optical axis, the air interval T23 of the second lens to the third lens on the optical axis and the center thickness CT3 of the third lens on the optical axis meet the following conditions: 0< (D0 m-D1 m)/(Ct2+T23+Ct3) <2.

In one embodiment, the radius of curvature R1 of the first side surface of the first lens, the distance EP01 between the first side end surface of the lens barrel and the first side surface of the first bearing element in the optical axis direction, the radius of curvature R4 of the second side surface of the second lens, and the distance EP12 between the second side surface of the first bearing element and the first side surface of the second bearing element in the optical axis direction satisfy: 500< R1/EP01+R4/EP12< -20.

The second aspect of the present application also provides an optical system comprising: the lens group sequentially comprises from a first side to a second side along an optical axis: the first lens group, the second lens and the third lens, wherein the first lens group sequentially comprises from a first side to a second side: the second side surface of the reflective polarizing element is attached to the first side surface of the quarter wave plate, and the second side surface of the quarter wave plate is attached to the first side surface of the first lens; at least one bearing element comprising a second bearing element arranged on and in contact with the second side of the second lens; a lens barrel for accommodating the lens group and at least one bearing element; the first side surface of the first lens is a concave surface, and the second side surface of the first lens is a convex surface; at least one of the second lens and the third lens is a biconvex lens; the focal power sign of the second lens is positive and negative opposite to that of the third lens; the optical system satisfies: -2< f2/f3<0 and-4 < (f2+f3)/(d2s+d2m) <0.5, wherein f2 is the effective focal length of the third lens, f3 is the effective focal length of the third lens, d2s is the inner diameter of the first side of the second bearing element, and d2m is the inner diameter of the second side of the second bearing element.

A third aspect of the present application also provides an optical apparatus including the optical system provided by at least one of the above embodiments.

The optical system that this application provided is three formula reflection-back optical system, through the structural arrangement that rationally sets up three lenses, reflective polarizing element, quarter wave plate, partial reflection layer, bearing element and lens cone to satisfy 20< VRP x F1/D0s <210 and 0< |f2+f3|/(d2s+d0m) <5, can make the optical system that this application provided have projection quality good, total length is less and characteristics such as machinability are good. In general, the three-plate type folded optical system has the problem of poor imaging quality of an external view field, and by controlling the dispersion coefficient of the reflective polarizing element and the effective focal length of the first lens group, the outer diameter of the first side end surface of the lens barrel, the inner diameter of the first side surface of the second bearing element and the inner diameter of the second side end surface of the lens barrel, the second bearing element and the lens barrel are beneficial to reducing stray light between the first lens and the second lens, restraining flocculent stray light and feather stray light, restraining chromatic aberration of the system, especially chromatic aberration of the optical system within 53 degrees of the view field, and reducing spherical aberration, and improving the imaging effect of the optical system on the axis on the basis of ensuring the functional effect and strong processability.

Drawings

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

FIG. 1 shows a schematic diagram of a structural layout and some parameters of an optical system according to the present application;

fig. 2A to 2C show schematic structural views of an optical system according to embodiment 1 of the present application;

fig. 3A to 3C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve, respectively, of the optical system according to embodiment 1 of the present application;

fig. 4A to 4C show schematic structural views of an optical system according to embodiment 2 of the present application;

fig. 5A to 5C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the optical system according to embodiment 2 of the present application, respectively;

fig. 6A to 6C show schematic structural views of an optical system according to embodiment 3 of the present application; and

fig. 7A to 7C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the optical system according to embodiment 3 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 this specification, the expressions first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation of the feature. Accordingly, a first lens discussed below may also be referred to as a second lens, and a second lens may also be referred to as a first 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.

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 present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The features, principles and other aspects of the present application are described in detail below with reference to the accompanying drawings and in connection with the embodiments.

An optical system according to an exemplary embodiment of the present application may include three lenses having optical power, a first lens, a second lens, and a third lens, respectively. The three lenses are arranged in sequence along the optical axis from the first side to the second side. Any two adjacent lenses in the first lens to the third lens can have a spacing distance.

The optical system according to exemplary embodiments of the present application may include at least one bearing element, and illustratively, the at least one bearing element may include a second bearing element disposed at and in contact with the second side of the second lens. The at least one bearing element may further comprise a first bearing element arranged at and in contact with the second side of the first lens. It should be understood that the present application is not particularly limited to the number of bearing elements, any number of bearing elements may be included between any two lenses, and the entire optical system may include any number of bearing elements. The bearing element is helpful for the optical system to intercept redundant refraction and reflection light paths and reduce the generation of stray light and ghost images. The auxiliary bearing is added between the bearing element and the lens barrel, so that the problems of poor assembly stability, low performance yield and the like caused by large-level difference between lenses are solved. The number, thickness, inner diameter and outer diameter of the bearing elements are reasonably arranged, so that the assembly of the optical system is improved, stray light is shielded, and the projection quality of the optical system is improved.

An optical system according to an exemplary embodiment of the present application may include a lens barrel accommodating a lens group and at least one bearing member. Illustratively, the lens barrel may be an integral lens barrel.

An optical system according to an exemplary embodiment of the present application includes a lens group, at least one bearing member, and a lens barrel, the lens group including, in order from a first side to a second side along an optical axis: the first lens group, the second lens and the third lens, wherein the first lens group has positive focal power, and sequentially comprises from a first side to a second side: the second side surface of the reflective polarizing element is attached to the first side surface of the quarter wave plate, and the second side surface of the quarter wave plate is attached to the first side surface of the first lens.

Fig. 1 shows a schematic diagram of a structural layout and part of parameters of an optical system according to the present application. It will be appreciated by those skilled in the art that some parameters of the lens such as the central thickness CT1 of the first lens on the optical axis are often used in the art, are not shown in fig. 1, and fig. 1 only illustrates part of the parameters of the barrel and the bearing element of one optical system of the present application for a better understanding of the present invention. As shown in fig. 1, L represents the maximum height of the lens barrel in the optical axis direction, EP01 represents the distance between the first side end surface of the lens barrel and the first side surface of the first bearing member in the optical axis direction, EP12 represents the distance between the second side surface of the first bearing member and the first side surface of the second bearing member in the optical axis direction, CP2 represents the maximum thickness of the second bearing member in the optical axis direction, D0s represents the outer diameter of the first side end surface of the lens barrel, D0s represents the inner diameter of the first side end surface of the lens barrel, D1m represents the inner diameter of the second side surface of the first bearing member, D2s represents the inner diameter of the second side surface of the second bearing member, D2s represents the outer diameter of the first side surface of the second bearing member, D0m represents the inner diameter of the second side end surface of the lens barrel, and D0m represents the outer diameter of the second side end surface of the lens barrel.

In an exemplary embodiment, the optical system further includes a display disposed on a second side of the third lens, where the optical system is applicable to, for example, a VR device, and the first side may be, for example, a human eye side, and the second side may be, for example, a display side, and image light on a display screen is finally projected to an eye of a user after being refracted and reflected multiple times by the third lens, the second lens, the first lens, the quarter wave plate, the reflective polarizing element, and the like.

In an exemplary embodiment, the optical system further includes a partially reflective layer disposed on the second side of the first lens or the first side of the second lens. The partial reflection layer has a semi-transmission and semi-reflection function. In some embodiments, as shown in fig. 2A and 4A, a partially reflective layer is disposed on the second side of the first lens, and light emitted from the display screen sequentially passes through the third lens, the second lens, the first lens, the quarter wave plate QWP, reaches the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter wave plate QWP and the first lens again, and then the light beam is reflected again at the partially reflective layer on the second side of the first lens and sequentially passes through the first lens, the quarter wave plate QWP, the reflective polarizing element RP, passes through the stop STO, and finally exits toward the eye side. In other embodiments, as shown in fig. 6A, a partially reflective layer is disposed on the first side of the second lens, and light emitted from the display screen sequentially passes through the third lens, the second lens, the first lens, and the quarter wave plate QWP to reach the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter wave plate QWP again, and the first lens reaches the first side of the second lens, and then the light beam is reflected again at the partially reflective layer on the first side of the second lens and passes through the first lens, the quarter wave plate QWP, and the reflective polarizing element RP in order, passes through the aperture stop and finally exits toward the human eye side.

In an exemplary embodiment, the reflective polarizing element and the quarter wave plate are combined, and a required structure can be obtained through one-time attaching procedure operation instead of two-time attaching, so that the angle position error caused by attaching is reduced, and the imaging quality is improved.

The optical system according to the exemplary embodiment of the present application can reflect light of a certain polarization direction while transmitting light orthogonal to the polarization direction by providing the reflective polarizing element; the polarization state of the light can be changed by arranging a quarter wave plate; reflection and transmission can be realized through a partial reflection layer on the second side surface of the first lens or the first side surface of the second lens, so that the system light path can be folded back, and the length of the optical system can be shortened.

In an exemplary embodiment, the optical system of the present application may satisfy: 20< VRP x F1/D0s <210, wherein VRP is the dispersion coefficient of the reflective polarizing element, F1 is the effective focal length of the first lens group, and D0s is the outer diameter of the first side end face of the lens barrel. Satisfying 20< VRP x F1/D0s <210, being favorable to restricting the chromatic aberration of the system by controlling the dispersion coefficient of the reflective polarizing element and the effective focal length of the first lens group, and being favorable to restricting the outer diameter of the lens barrel to keep a proper size by controlling the outer diameter of the first side end face of the lens barrel.

In an exemplary embodiment, the optical system of the present application may satisfy: 0< |f2+f3|/(d2s+d0m) <5, wherein f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, d2s is the inner diameter of the first side surface of the second bearing element, and d0m is the inner diameter of the second side end surface of the lens barrel. Satisfies 0< |f2+f3|/(d2s+d0m) <5, and the effective focal lengths of the second lens and the third lens are controlled within a certain range, so that the imaging effect of the system on the axis is good; secondly, by controlling the inner diameter of the first side face of the second bearing element and the inner diameter of the second side end face of the lens barrel, the processability of the second bearing element and the lens barrel is improved on the basis of ensuring the realization of functional effects, stray light between the first lens and the second lens can be reduced, flocculent stray light and feather-like stray light are restrained, chromatic aberration of a system, particularly chromatic aberration of an optical system in a field of view of 53 degrees is restrained, spherical aberration is reduced, and an imaging effect of the optical system on an axis is improved.

In an exemplary embodiment, the optical system of the present application may satisfy: -5.1< (d0m+d0s)/R1 < -1, wherein d0m is the inner diameter of the second side end face of the barrel, d0s is the inner diameter of the first side end face of the barrel, R1 is the radius of curvature of the first side face of the first lens. Satisfying-5.1 < (d0m+d0s)/R1 < -1, by limiting the inner diameters of the first side end face and the second side end face of the lens barrel, on one hand, the light quantity is favorably controlled, and the light imaging is utilized more efficiently, on the other hand, the radiation of redundant light is favorably improved, the generation of stray light is reduced as much as possible, and the imaging definition is improved; by limiting the radius of curvature of the first side of the first lens, the dimensions of the second and third lenses can be better laid out.

In an exemplary embodiment, the first side of the first lens of the optical system of the present application is concave and the second side of the second lens is convex.

In an exemplary embodiment, the optical system of the present application may satisfy the conditional expression 1.5×r1> R4, where R1 is a radius of curvature of the first side of the first lens and R4 is a radius of curvature of the second side of the second lens. Satisfying 1.5×r1> R4, the shapes of the first lens and the second lens are constrained by controlling the relationship between the radius of curvature of the first side of the first lens and the radius of curvature of the second side of the second lens, so that the two lenses are properly matched, and the stability of the assembly of the two lenses is promoted.

In an exemplary embodiment, the radii of curvature of the first side and the second side of the reflective polarizing element are the same, and the optical system of the present application may satisfy: -10< (rrp1+r4)/(d2m+d0s) <0, wherein RRP is a radius of curvature of the second side surface of the reflective polarizing element, R4 is a radius of curvature of the second side surface of the second lens, d2m is an inner diameter of the second side surface of the second bearing element, and d0s is an inner diameter of the first side end surface of the lens barrel. The curvature radius of the first side surface and the second side surface of the reflective polarizing element is the same, so that the difficulty of attaching the reflective polarizing element to the first lens can be reduced; satisfying-10 < (RRP1+R4)/(d2m+d0s) <0, the sensitivity of the first lens and the second lens is reduced by controlling the curvature radius of the second side surface of the reflective polarizing element and the curvature radius of the second side surface of the second lens, and the assembly yield is improved; and secondly, limiting the inner diameter of the second side surface of the second bearing element and the inner diameter of the first side end surface of the lens barrel, so as to ensure the processability of the lens barrel.

In an exemplary embodiment, the optical system of the present application may satisfy: 2< D0 m/Lxf/ΣCT <4, wherein D0m is the outer diameter of the second side end face of the lens barrel, L is the maximum height of the lens barrel in the optical axis direction, f is the effective focal length of the optical system, ΣCT is the sum of the central thicknesses of the first lens, the second lens and the third lens on the optical axis. The method meets 2< D0 m/Lxf/ΣCT <4, and the effective focal length of the optical system is controlled to effectively restrict the angle of view of the optical system so that the system meets the characteristic of large field of view; the outer diameter of the second side end surface of the lens barrel, the maximum height of the lens barrel along the optical axis direction and the sum of the center thicknesses of all lenses are controlled, so that the assembling stability of the lenses is indirectly ensured.

In an exemplary embodiment, the optical system of the present application may satisfy: 0< (v2+v3)/v1× (d2s+d2m)/D0 s <4, wherein V2 is the abbe number of the second lens, V3 is the abbe number of the third lens, V1 is the abbe number of the first lens, D2s is the inner diameter of the first side surface of the second bearing element, D2m is the inner diameter of the second side surface of the second bearing element, and D0s is the outer diameter of the first side end surface of the lens barrel. Satisfying 0< (v2+v3)/v1× (d2s+d2m)/D0 s <4, and by controlling abbe numbers of the first lens, the second lens and the third lens, chromatic aberration of the constraint system is facilitated, so that imaging quality of the optical system is improved; the inner diameters of the first side surface and the second side surface of the second bearing element and the outer diameter of the first side end surface of the lens barrel are controlled to meet the supportability and the processability of the second bearing element on the lens, and the lens barrel is ensured to have proper wall thickness.

In an exemplary embodiment, the lens group further includes a partially reflective layer disposed on the second side of the first lens or the first side of the second lens, and the optical system of the present application may satisfy: 6< D2s×tan (FOV/2)/TrRPrBS <20, wherein D2s is the outer diameter of the first side of the second bearing element, FOV is the maximum field angle of the optical system, trRPrBS is the axial distance from the first side of the reflective polarizing element to the surface of the lens where the partially reflective layer is located. Satisfying 6< D2s×tan (FOV/2)/TrRPrBS <20, by controlling the outer diameter of the first side of the second bearing element and the axial distance from the first side of the reflective polarizing element to the surface of the lens where the partial reflective layer is located, the size of the whole system can be compressed under the condition that the maximum field angle of the system is unchanged, and the purpose of compact equipment can be achieved.

In an exemplary embodiment, the optical system of the present application may satisfy: 6< CP2×FNo/T12<100, wherein CP2 is the maximum thickness of the second bearing element along the optical axis direction, FNo is the f-number of the optical system, and T12 is the air space between the first lens and the second lens on the optical axis. The lens satisfies 6< CP2 x FNo/T12<100, and the focal length of the system is controlled indirectly by controlling the axial distance between the first lens and the second lens, the maximum thickness of the second bearing element and the aperture number of the optical system under the condition that the diameter of the entrance pupil is unchanged, so that the system satisfies the characteristic of a large field of view.

In an exemplary embodiment, the optical system of the present application may satisfy: 1< (NRP+NQWP) ×F1/D0s <11, wherein NRP is refractive index of the reflective polarizing element, NQWP is refractive index of the quarter wave plate, F1 is effective focal length of the first lens group, and D0s is outer diameter of the first side end face of the lens barrel. The ratio of the refractive index of the reflective polarizing element and the quarter wave plate to the effective focal length of the first lens group is controlled to be 1< (NRP+NQWP) x F1/D0s <11, so that the influence on a system when the thicknesses of the reflective polarizing element and the quarter wave plate are changed can be effectively reduced; and secondly, the outer diameter of the first side end face of the lens barrel is controlled, so that the outer diameter of the lens barrel can be controlled to keep proper size, and the processability of the lens barrel is improved.

In an exemplary embodiment, the optical system of the present application may satisfy: 20< L x FNo/|D0s-D0m| <110, wherein L is the maximum height of the lens barrel in the optical axis direction, FNo is the f-number of the optical system, D0s is the outer diameter of the first side end surface of the lens barrel, and D0m is the outer diameter of the second side end surface of the lens barrel. The lens satisfies 20< L multiplied by FNo/|D0s-D0m| <110, and the focal length of the system is indirectly controlled by controlling the f-number of the optical system, the maximum height of the lens barrel along the optical axis direction and the outer diameters of the first side end face and the second side end face of the lens barrel, so that the lens satisfies the characteristic of a large visual field, and the processability of the lens barrel can be ensured.

In an exemplary embodiment, the optical system of the present application may satisfy: 4< (TD+CTWP+CTQWP)/(f×tan (FOV/2) -D0 m/2) <35, wherein TD is the distance between the first side surface of the first lens and the second side surface of the third lens on the optical axis, CTRP is the center thickness of the reflective polarizing element along the optical axis direction, CTQWP is the center thickness of the quarter wave plate along the optical axis direction, f is the effective focal length of the optical system, FOV is the maximum field angle of the optical system, and D0m is the outer diameter of the second side end surface of the lens barrel. Satisfying 4< (td+ctrp+ctqwp)/(f×tan (FOV/2) -D0 m/2) <35, by controlling the on-axis pitch of the first side of the first lens to the second side of the third lens, the sum of the center thicknesses of the reflective polarizing element and the quarter wave plate, the effective focal length of the optical system, the maximum angle of view of the optical system, and the outer diameter of the second side end face of the barrel, on the one hand, the image height of the system can be controlled, the size of the screen can be limited, and on the other hand, the size of the entire optical system can be limited.

In an exemplary embodiment, the radii of curvature of the first side and the second side of the quarter wave plate are the same, and the optical system of the present application may satisfy: 0< SAG11/RQWP x D0s/CT1<4, wherein SAG11 is the distance on the optical axis between the intersection point of the first side surface of the first lens on the optical axis and the maximum effective radius vertex of the first side surface of the first lens, RQWP is the radius of curvature of the second side surface of the quarter wave plate, D0s is the outer diameter of the first side end surface of the lens barrel, and CT1 is the center thickness of the first lens on the optical axis. The curvature radius of the first side surface and the second side surface of the quarter wave plate is reasonably controlled to meet 0< SAG11/RQWP x D0s/CT1<4, so that manufacturability of the quarter wave plate attached to the first lens is improved, and processability of the first lens and the lens barrel is improved on the basis of ensuring system assembly.

In an exemplary embodiment, the optical system of the present application may satisfy: 0< (D0 m-D1 m)/(CT2+T23+CT3) <2, wherein D0m is the outer diameter of the second side end surface of the lens barrel, D1m is the inner diameter of the second side surface of the first bearing element, CT2 is the center thickness of the second lens on the optical axis, T23 is the air interval of the second lens to the third lens on the optical axis, and CT3 is the center thickness of the third lens on the optical axis. Satisfies 0< (D0 m-D1 m)/(CT2+T23+CT3) <2, and by controlling the above parameters, the structural rationalization of the whole lens space can be promoted, the stability of the lens structure can be increased, and the workability of the lens barrel and the bearing element can be ensured.

In an exemplary embodiment, the optical system of the present application may satisfy: 500< R1/EP01+R4/EP12< -20, wherein R1 is the radius of curvature of the first side surface of the first lens, EP01 is the distance between the first side end surface of the lens barrel and the first side surface of the first bearing element along the optical axis direction, R4 is the radius of curvature of the second side surface of the second lens, and EP12 is the distance between the second side surface of the first bearing element and the first side surface of the second bearing element along the optical axis direction. The optical power values of the first lens and the second lens are controlled by controlling the parameters so that the light rays strike better, and the first lens and the second lens have good processing manufacturability so as to ensure the reliability of the whole lens group.

In an exemplary embodiment, the first lens group may have positive optical power, the second lens may have positive optical power or negative optical power, and the third lens may have positive optical power or negative optical power. The optical power of each lens is reasonably matched, so that the aberration of the system can be corrected.

In an exemplary embodiment, at least one of the second lens and the third lens is a biconvex lens.

In an exemplary embodiment, the power sign of the second lens is positive and negative opposite to the power sign of the third lens.

In an exemplary embodiment, the optical system of the present application may satisfy: -2< f2/f3<0 and-4 < (f2+f3)/(d2s+d2m) <0.5, wherein f2 is the effective focal length of the third lens, f3 is the effective focal length of the third lens, d2s is the inner diameter of the first side of the second bearing element, and d2m is the inner diameter of the second side of the second bearing element. By controlling the focal power of the second lens and the third lens and the inner diameters of the first side face and the second side face of the second bearing element, the aberration of the system can be corrected, the imaging quality is improved, the processability of the second bearing element is improved, and the effective supporting function of the lens can be improved.

In an exemplary embodiment, the optical system of the present application may include at least one aperture. The diaphragm can restrict the light path and control the intensity of light. The aperture may be arranged in a suitable position of the optical system, for example the aperture may be located on the first side of the first lens.

In an exemplary embodiment, the effective focal length F of the optical system may be, for example, in the range of 26.0mm to 33.0mm, the effective focal length F1 of the first lens group may be, for example, in the range of 27.0mm to 245.0mm, the effective focal length F2 of the second lens may be, for example, in the range of-136.0 mm to 256.0mm, and the effective focal length F3 of the third lens may be, for example, in the range of-670.0 mm to 75.0 mm.

According to some embodiments of the present application, the optical system according to the present application is a low-volume optical system of high definition imaging quality, and in application, the optical system according to the exemplary embodiments of the present application may be suitable for VR devices. By reasonably setting the effective focal length, the maximum field angle, the entrance pupil diameter, the center thickness of the lens, the refractive index, the Abbe number, the curvature radius and other parameters of the optical system, and by reasonably setting the diaphragm parameters, the purpose of wide angle of the VR device can be met, the chromatic aberration of the system can be corrected, and the imaging quality of the system can be improved. The bearing elements are arranged between the lenses, so that the processing and forming performances of the lenses can be facilitated, the sensitivity of the lenses can be reduced, the assembly yield can be improved, and the VR equipment miniaturization target can be met on the premise of ensuring the performances of the optical system.

Specific examples of the optical system applicable to the above-described embodiments are further described below with reference to the drawings.

Example 1

An optical system according to embodiment 1 of the present application is described below with reference to fig. 2A to 3C. Fig. 2A to 2C show schematic structural views of an optical system according to three embodiments in example 1 of the present application.

As shown in fig. 2A to 2C, the optical system sequentially includes, along the optical axis from a first side to a second side: stop STO, reflective polarizer RP, quarter wave plate QWP, first lens E1, partially reflective layer BS, second lens E2, third lens E3, and display E4. Wherein the diaphragm STO and the display E4 are only schematically shown in fig. 2A.

In the present embodiment, the reflective polarizing element RP has a first side surface S1 and a second side surface S2, the quarter wave plate QWP has a first side surface S2 and a second side surface S3, and the first lens E1 has a first side surface S3 and a second side surface S4. S2 is a common surface of the second side surface of the reflective polarizing element RP and the first side surface of the quarter wave plate QWP, and the second side surface of the reflective polarizing element RP is attached to the first side surface of the quarter wave plate QWP; s3 is a common surface of the second side surface of the quarter wave plate QWP and the first side surface of the first lens E1, and the second side surface of the quarter wave plate QWP is attached to the first side surface of the first lens E1. The second lens E2 has a first side surface S5 and a second side surface S6. The third lens E3 has a first side S7 and a second side S8.

The partially reflective layer BS is disposed on the second side S4 of the first lens E1. In an exemplary embodiment, the partially reflective layer may be a semi-transparent and semi-reflective film layer plated on the second side of the first lens E1. In an example, the partially reflective layer may be plated at a region of the second side of the first lens E1 away from the optical axis.

In an exemplary embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. Referring to fig. 2A, light emitted from the screen of the display E4 sequentially passes through the third lens E3, the second lens E2, the first lens E1, and the quarter wave plate QWP to the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter wave plate QWP and the first lens E1 again, and then the light beam is reflected again at the partial reflection layer BS on the second side of the first lens E1 and passes through the first lens E1, the quarter wave plate QWP, and the reflective polarizing element RP in order, passes through the aperture stop STO, and finally exits toward the human eye side.

Table 1 shows basic parameters of the optical system of example 1, in which the unit of radius of curvature and thickness are both millimeters (mm). Table 1 only exemplifies the correspondence between the surface numbers of the partial surfaces and the partial elements, and the positions of the common surfaces in table 1 are inconvenient to mark all the elements due to the problem of the common surfaces of the adjacent elements.

TABLE 1

In embodiment 1, the reflective polarizing element RP, the quarter wave plate QWP, the first lens E1, the second lens E2, and the first and second sides of the third lens E3 are all aspheric, and the surface profile x of each aspheric lens can be defined by, but not limited to, the following aspheric formula:

wherein z is the depth of the aspheric surface (the point on the aspheric surface at a distance y from the optical axis, and the tangential plane tangential to the vertex on the optical axis of the aspheric surface, the perpendicular distance between the two); c is the curvature of the apex of the aspheric surface; k is the coefficient of the conical surface,is the radial distance; r is (r) _n Is normalized radius; u is r/r _n ；a _m Is the mth order Q ^con Coefficients; q (Q) _m ^con Is the mth order Q ^con A polynomial. Table 2 below shows the higher order coefficients a that can be used for each of the aspherical mirrors in example 1 ₀ 、a ₁ 、a ₂ And a ₃ 。

Face number	a ₀	a ₁	a ₂	a ₃
					S1	9.0707E-02	5.0091E-02	-1.9326E-02	-4.2720E-03
S2	9.0707E-02	5.0091E-02	-1.9326E-02	-4.2720E-03
					S3	9.0707E-02	5.0091E-02	-1.9326E-02	-4.2720E-03
S4	8.2077E-02	3.0319E-02	-1.8254E-02	7.9232E-04
					S5	-3.3474E-01	-2.3464E-03	6.1916E-02	1.2839E-01
S6	3.1941E-01	9.4953E-02	-8.3416E-02	2.9775E-02
					S7	-3.3290E-01	-8.6600E-02	7.0522E-02	-7.1153E-02
S8	2.9386E-01	1.2579E-01	-6.2367E-02	1.5146E-01

TABLE 2

Table 3 shows the values of the maximum field angle FOV, F-stop F no, effective focal length F of the optical system, effective focal length F1 of the first lens group (including the reflective polarizing element RP, the quarter wave plate QWP, the first lens E1, and the partially reflective layer BS), effective focal length F2 of the second lens E2, and effective focal length F3 of the third lens E3, and structural parameters of the lens barrel, the bearing element, and the like of the optical system in the three embodiments of example 1.

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TABLE 3 Table 3

Fig. 2A shows an on-axis chromatic aberration curve of the optical system of embodiment 1, which represents the focus deviation of light rays of different wavelengths after passing through the lens. Fig. 2B shows an astigmatism curve of the optical system of embodiment 1, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 2C shows a distortion curve of the optical system of embodiment 1, which represents distortion magnitude values corresponding to different half angles of view. As can be seen from fig. 2A to 2C, the optical system of embodiment 1 can achieve good imaging quality.

Example 2

An optical system according to embodiment 2 of the present application is described below with reference to fig. 4A to 5C. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 4A to 4C show schematic structural views of an optical system according to three embodiments in example 2 of the present application.

As shown in fig. 4A to 4C, the optical system includes, in order from a first side to a second side along an optical axis: stop STO, reflective polarizer RP, quarter wave plate QWP, first lens E1, partially reflective layer BS, second lens E2, third lens E3, and display E4. Wherein the diaphragm STO and the display E4 are only schematically shown in fig. 4A.

In an exemplary embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. Referring to fig. 4A, light emitted from the screen of the display E4 sequentially passes through the third lens E3, the second lens E2, the first lens E1, and the quarter wave plate QWP to the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter wave plate QWP and the first lens E1 again, and then the light beam is reflected again at the partial reflection layer BS on the second side of the first lens E1 and passes through the first lens E1, the quarter wave plate QWP, and the reflective polarizing element RP in order, passes through the aperture stop STO, and finally exits toward the human eye side.

Table 4 shows basic parameters of the optical system of example 2, in which the unit of radius of curvature and thickness are both millimeters (mm). Table 4 only exemplifies the correspondence between the surface numbers of the partial surfaces and the partial elements, and the positions of the common surfaces in table 4 are inconvenient to mark all the elements due to the problem of the common surfaces of the bonding between the adjacent elements. Table 5 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 2, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

Face number	Element name	Surface type	Radius of curvature	Thickness of (L)	Refractive index	Abbe number	Refraction/reflection
										Spherical surface	Infinity is provided	Infinity is provided
STO	Diaphragm (STO)	Spherical surface	Infinity is provided	15.0000			Refraction by refraction
								S1	Reflective polarizing element (RP)	Aspherical surface	-26.9152	0.2000	1.50	57.00	Refraction by refraction
S2	Quarter Wave Plate (QWP)	Aspherical surface	-26.9152	0.2000	1.50	57.00	Refraction by refraction
								S3	First optical lens (E1)	Aspherical surface	-26.9152	4.7072	1.52	101.09	Refraction by refraction
S4	Partial reflecting member (BS)	Aspherical surface	-26.4877	-4.7072	1.52	101.09	Reflection of
								S3	Quarter Wave Plate (QWP)	Aspherical surface	-26.9152	-0.2000	1.50	57.00	Refraction by refraction
S2		Aspherical surface	-26.9152	0.2000	1.50	57.00	Reflection of
								S3		Aspherical surface	-26.9152	4.7072	1.52	101.09	Refraction by refraction
S4		Aspherical surface	-26.4877	0.1000			Refraction by refraction
								S5	Second optical lens (E2)	Aspherical surface	92.9950	12.0362	1.50	47.60	Refraction by refraction
S6		Aspherical surface	-49.5404	0.1000			Refraction by refraction
								S7	Third optical lens (E3)	Aspherical surface	-48.2066	1.9727	1.67	19.04	Refraction by refraction
S8		Aspherical surface	471.9089	9.1768			Refraction by refraction
								S9	Display (E4)	Spherical surface	Infinity is provided

TABLE 4 Table 4

Face number	a ₀	a ₁	a ₂	a ₃
					S1	-1.9980E-01	2.5055E-03	6.3828E-03	-1.0605E-03
S2	-1.9980E-01	2.5055E-03	6.3828E-03	-1.0605E-03
					S3	-1.9980E-01	2.5055E-03	6.3828E-03	-1.0605E-03
S4	-2.3435E-01	2.1324E-02	5.3922E-03	-8.9875E-04
					S5	-3.4499E-01	-2.7406E-01	5.5219E-02	1.0854E-01
S6	4.8859E-01	1.2283E-01	-2.4694E-02	5.0082E-02
					S7	-4.1882E-01	-5.4365E-02	1.4223E-01	-2.0491E-01
S8	-6.8477E-01	-3.6569E-02	2.0075E-01	-1.5008E-01

TABLE 5

Table 6 shows the values of the maximum field angle FOV, F-stop F no, effective focal length F of the optical system, effective focal length F1 of the first lens group (including the reflective polarizing element RP, the quarter wave plate QWP, the first lens E1, and the partially reflective layer BS), effective focal length F2 of the second lens E2, and effective focal length F3 of the third lens E3, and structural parameters of the barrel, the rest element, and the like of the optical system in the three embodiments of example 2.

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TABLE 6

Fig. 5A shows an on-axis chromatic aberration curve of the optical system of embodiment 2, which represents the focus deviation of light rays of different wavelengths after passing through the lens. Fig. 5B shows an astigmatism curve of the optical system of embodiment 2, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 5C shows a distortion curve of the optical system of embodiment 2, which represents distortion magnitude values corresponding to different half angles of view. As can be seen from fig. 5A to 5C, the optical system according to embodiment 2 can achieve good imaging quality.

Example 3

An optical system according to embodiment 3 of the present application is described below with reference to fig. 6A to 7C. Fig. 6A to 6C show schematic structural views of an optical system according to three embodiments in example 3 of the present application.

As shown in fig. 6A to 6C, the optical system includes, in order from a first side to a second side along an optical axis: stop STO, reflective polarizer RP, quarter wave plate QWP, first lens E1, partially reflective layer BS, second lens E2, third lens E3, and display S9. Wherein the diaphragm STO and the display E4 are only schematically shown in fig. 6A.

The partially reflective layer BS is disposed on the first side S5 of the second lens E2. In an exemplary embodiment, the partially reflective layer may be a semi-transparent and semi-reflective film layer plated on the first side of the second lens E2. In an example, the partially reflective layer may be plated at a region of the first side of the second lens E2 away from the optical axis.

In an exemplary embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. Referring to fig. 6A, light emitted from the screen of the display E4 sequentially passes through the third lens E3, the second lens E2, the first lens E1, and the quarter wave plate QWP to the reflective polarizing element RP, is reflected at the reflective polarizing element RP and passes through the quarter wave plate QWP and the first lens E1 again to the first side of the second lens E2, and then the light beam is reflected again at the partially reflective layer BS on the first side of the second lens E2 and passes through the first lens E1, the quarter wave plate QWP, and the reflective polarizing element RP in order, passes through the stop STO, and finally exits toward the eye side.

Table 7 shows basic parameters of the optical system of example 3, in which the unit of radius of curvature and thickness are both millimeters (mm). Table 7 only exemplifies the correspondence between the surface numbers of the partial surfaces and the partial elements, and the positions of the common surfaces in table 7 are inconvenient to mark all the elements due to the problem of the common surfaces of the bonding between the adjacent elements. Table 8 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 3, wherein each of the aspherical surface types can be defined by the formula (1) given in example 1 above.

Face number

Element name

Surface type

Radius of curvature

Thickness of (L)

Refractive index

Abbe number

Refraction/reflection

Spherical surface

Infinity is provided

STO

Diaphragm (STO)

Spherical surface

Infinity is provided

20.0461

Refraction by refraction

S1

Reflective polarizing element (RP)

Aspherical surface

-65.4535

0.2000

1.50

57.00

Refraction by refraction

S2

Quarter Wave Plate (QWP)

Aspherical surface

-65.4535

0.2000

1.50

57.00

Refraction by refraction

S3

First optical lens (E1)

Aspherical surface

-65.4535

8.1673

1.48

60.00

Refraction by refraction

S4

Aspherical surface

-43.8562

0.5002

Refraction by refraction

S5

Partial reflecting member (BS)

Aspherical surface

-49.7848

-0.5002

Reflection of

S4

Aspherical surface

-43.8562

-8.1673

1.48

60.00

Refraction by refraction

S3

Quarter Wave Plate (QWP)

Aspherical surface

-65.4535

-0.2000

1.50

57.00

Refraction by refraction

S2

Aspherical surface

-65.4535

0.2000

1.50

57.00

Reflection of

S3

Aspherical surface

-65.4535

8.1673

Refraction by refraction

S4

Aspherical surface

-43.8562

0.5002

Refraction by refraction

S5

Second optical lens (E2)

Aspherical surface

-49.7848

0.6000

1.68

19.00

Refraction by refraction

S6

Aspherical surface

-109.4636

0.1000

Refraction by refraction

S7

Third optical lens (E3)

Aspherical surface

85.7409

17.5544

1.52

41.42

Refraction by refraction

S8

Aspherical surface

-66.7595

2.2056

Refraction by refraction

S9

Display (E4)

Spherical surface

Infinity is provided

TABLE 7

Sequence number	a ₀	a ₁	a ₂	a ₃
					S1	-3.3044E-01	4.1575E-02	-9.0531E-03	4.0696E-03
S2	-3.3044E-01	4.1575E-02	-9.0531E-03	4.0696E-03
					S3	-3.3044E-01	4.1575E-02	-9.0531E-03	4.0696E-03
S4	-1.3029E-01	-7.7634E-02	1.4606E-01	-4.6677E-02
					S5	-9.6928E-02	1.0769E-01	-8.8496E-02	2.6431E-02
S6	-1.5446E+00	-5.7178E-03	-1.3545E-02	4.0895E-02
					S7	-4.1101E-01	-2.7284E-01	1.3823E-02	6.1793E-02
S8	3.1523E-01	3.0858E-01	-8.3960E-02	2.5258E-02

TABLE 8

Table 9 shows the values of the maximum field angle FOV, F-stop F no, effective focal length F of the optical system, effective focal length F1 of the first lens group (including the reflective polarizing element RP, the quarter wave plate QWP, and the first lens E1), effective focal length F2 of the second lens E2, and effective focal length F3 of the third lens E3, and structural parameters of the lens barrel, the bearing element, and the like of the optical system in the three embodiments of example 3.

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TABLE 9

Fig. 7A shows an on-axis chromatic aberration curve of the optical system of embodiment 3, which indicates the focus deviation of light rays of different wavelengths after passing through the lens. Fig. 7B shows an astigmatism curve of the optical system of embodiment 3, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 7C shows a distortion curve of the optical system of example 3, which represents distortion magnitude values corresponding to different half angles of view. As can be seen from fig. 7A to 7C, the optical system provided in embodiment 3 can achieve good imaging quality.

In summary, the relationships shown in the optical system table 10 of examples 1 to 4.

Table 10

The present application also provides an optical device that may be a stand-alone projection device, such as a projector, or may be a projection module integrated on a mobile electronic device, such as a VR. The optical apparatus is equipped with the optical system described above.

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 should be understood by those skilled in the art that the scope of protection referred to in this application is not limited to the specific combination of the above technical features, but also encompasses other technical solutions formed by any combination of the above technical features or their equivalents without departing from the spirit of the application. 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. An optical system, comprising:

the lens group sequentially comprises from a first side to a second side along an optical axis: the lens assembly comprises a first lens group, a second lens and a third lens, wherein the first lens group has positive focal power and sequentially comprises the following components from a first side to a second side: the device comprises a reflective polarizing element, a quarter wave plate and a first lens, wherein a second side surface of the reflective polarizing element is attached to a first side surface of the quarter wave plate, and a second side surface of the quarter wave plate is attached to a first side surface of the first lens;

At least one bearing element comprising a second bearing element arranged on and in contact with the second side of the second lens; and

a lens barrel for accommodating the lens group and the at least one bearing member; wherein,

the optical system further includes a partially reflective layer disposed on the second side of the first lens or the first side of the second lens;

the dispersion coefficient VRP of the reflective polarizing element, the effective focal length F1 of the first lens group, and the outer diameter D0s of the first side end face of the lens barrel satisfy: 20< VRP x F1/D0s <210; and

the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the inner diameter d2s of the first side surface of the second bearing element and the inner diameter d0m of the second side end surface of the lens barrel satisfy the following conditions: 0< |f2+f3|/(d2s+d0m) <5.

2. The optical system according to claim 1, wherein an inner diameter d0m of the second side end surface of the lens barrel, an inner diameter d0s of the first side end surface of the lens barrel, and a radius of curvature R1 of the first side surface of the first lens satisfy: -5.1< (d0m+d0s)/R1 < -1.

3. The optical system of claim 1, wherein the first side of the first lens is concave and the second side of the second lens is convex; and

The radius of curvature R1 of the first side of the first lens and the radius of curvature R4 of the second side of the second lens satisfy: 1.5 XR 1> R4.

4. The optical system of claim 1, wherein the radius of curvature of the first side and the second side of the reflective polarizing element are the same; and

the radius of curvature RRP of the second side surface of the reflective polarizing element, the radius of curvature R4 of the second side surface of the second lens, the inner diameter d2m of the second side surface of the second bearing element, and the inner diameter d0s of the first side end surface of the lens barrel satisfy: -10< (rrp1+r4)/(d2m+d0s) <0.

5. The optical system according to claim 1, wherein an outer diameter D0m of the second side end surface of the lens barrel, a maximum height L of the lens barrel in the optical axis direction, an effective focal length f of the optical system, a sum Σct of center thicknesses of the first lens, the second lens, and the third lens on the optical axis satisfy:

2<D0m/L×f/ΣCT<4。

6. the optical system according to claim 1, wherein an abbe number V2 of the second lens, an abbe number V3 of the third lens, an abbe number V1 of the first lens, an inner diameter D2s of the first side surface of the second bearing member, an inner diameter D2m of the second side surface of the second bearing member, and an outer diameter D0s of the first side end surface of the lens barrel satisfy: 0< (V2+V3)/V1× (d2s+d2m)/D0 s <4.

7. The optical system of claim 1, wherein an outer diameter D2s of the first side of the second bearing element, a maximum field angle FOV of the optical system, and an on-axis distance TrRPrBS from the first side of the reflective polarizing element to a surface of the lens on which the partially reflective layer is located satisfy: 6< D2s×tan (FOV/2)/TrRPrBS <20.

8. The optical system according to claim 1, wherein a maximum thickness CP2 of the second bearing member in the optical axis direction, an f-number Fno of the optical system, and an air interval T12 of the first lens to the second lens on the optical axis satisfy: 6< CP2×FNo/T12<100.

9. The optical system according to any one of claims 1 to 8, wherein a refractive index NRP of the reflective polarizing element, a refractive index NQWP of the quarter wave plate, an effective focal length F1 of the first lens group, and an outer diameter D0s of the first side end face of the lens barrel satisfy: 1< (NRP+NQWP). Times.F1/D0 s <11.

10. The optical system according to any one of claims 1 to 8, wherein a maximum height L of the lens barrel in the optical axis direction, an f-number Fno of the optical system, an outer diameter D0s of a first side end surface of the lens barrel, and an outer diameter D0m of a second side end surface of the lens barrel satisfy: 20< LXFNo/|D0s-D0m| <110.

11. The optical system according to any one of claims 1 to 8, wherein a distance TD on the optical axis from the first side surface of the first lens to the second side surface of the third lens, a center thickness CTRP of the reflective polarizing element in the optical axis direction, a center thickness CTQWP of the quarter wave plate in the optical axis direction, an effective focal length f of the optical system, a maximum field angle FOV of the optical system, and an outer diameter D0m of the second side end surface of the lens barrel satisfy: 4< (TD+CTRP+CTQWP)/(f×tan (FOV/2) -D0 m/2) <35.

12. The optical system of any one of claims 1 to 8, wherein the radius of curvature of the first and second sides of the quarter wave plate is the same; and

the distance SAG11 between the intersection point of the first side surface of the first lens on the optical axis and the vertex of the maximum effective radius of the first side surface of the first lens on the optical axis, the radius of curvature RQWP of the second side surface of the quarter wave plate, the outer diameter D0s of the first side end surface of the lens barrel, and the central thickness CT1 of the first lens on the optical axis satisfy: 0< SAG11/RQWP x D0s/CT1<4.

13. The optical system of claim 1, wherein the at least one bearing element further comprises a first bearing element disposed on and in contact with the second side of the first lens; and

An outer diameter D0m of the second side end surface of the lens barrel, an inner diameter D1m of the second side surface of the first bearing element, a center thickness CT2 of the second lens on the optical axis, an air interval T23 from the second lens to the third lens on the optical axis, and a center thickness CT3 of the third lens on the optical axis satisfy:

0<(D0m-d1m)/(CT2+T23+CT3)<2。

14. the optical system according to claim 13, wherein a radius of curvature R1 of the first side surface of the first lens, a distance EP01 between the first side end surface of the lens barrel and the first side surface of the first bearing member in the optical axis direction, a radius of curvature R4 of the second side surface of the second lens, and a distance EP12 between the second side surface of the first bearing member and the first side surface of the second bearing member in the optical axis direction satisfy: 500< R1/EP01+R4/EP12< -20.

15. An optical system, comprising:

the lens group sequentially comprises from a first side to a second side along an optical axis: the lens assembly comprises a first lens group, a second lens and a third lens, wherein the first lens group sequentially comprises from a first side to a second side: the device comprises a reflective polarizing element, a quarter wave plate and a first lens, wherein a second side surface of the reflective polarizing element is attached to a first side surface of the quarter wave plate, and a second side surface of the quarter wave plate is attached to a first side surface of the first lens;

At least one bearing element comprising a second bearing element arranged on and in contact with the second side of the second lens;

the first side surface of the first lens is a concave surface, and the second side surface of the first lens is a convex surface;

at least one lens in the second lens and the third lens is a biconvex lens;

the focal power sign of the second lens is opposite to that of the third lens; and

the optical system satisfies: -2< f2/f3<0 and-4 < (f2+f3)/(d2s+d2m) <0.5, wherein f2 is the effective focal length of the third lens, f3 is the effective focal length of the third lens, d2s is the inner diameter of the first side of the second bearing element, d2m is the inner diameter of the second side of the second bearing element.

16. An optical device comprising an optical system as claimed in any one of claims 1 to 15.