CN220438639U - Optical system and optical apparatus including the same - Google Patents

Abstract

The application discloses optical system and optical equipment including this optical system, this optical system includes: the lens barrel, and lens component, reflection component and interval component that set up in the lens barrel, wherein, lens component includes in proper order from first side to second side along the optical axis: a first lens, a second lens and a third lens; the spacer assembly comprises at least one spacer arranged between two adjacent lenses in the lens assembly; the lens barrel is provided with a front end face facing the first side and a rear end face facing the second side, and the maximum outer diameter of the front end face of the lens barrel is smaller than that of the rear end face of the lens barrel; and an inner diameter d0m of a rear end surface of the lens barrel, a maximum half field angle HFOV of the optical system, and a maximum height L of the lens barrel in the optical axis direction satisfy: 1.0 < tan (HFOV). Times.d0m/L < 1.5.

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 VR process optimization space at the present stage is still larger, future development is needed, and the following four problems mainly exist at present:

First, the optical path loss is high: in the folded light path design mode, light needs to pass through the semi-transparent semi-reflective film twice, 50% of the intensity is lost each time, so that the theoretical highest optical efficiency of the VR scheme is only 25%, the reflective polarizing film is also lost by 10%, the overall optical utilization rate is only 10-20%, and the VR scheme is required to be provided with a high-brightness display screen, such as a Micro OLED, a Micro LED and the like.

Second, there are artifacts: under the double refraction effect, the light is easy to generate artifacts when being folded back in the lens, the influence is eliminated by the polarizing film, and the accurate polarizing film has high requirements on materials, heat resistance, precision machining and the like.

Thirdly, the production difficulty and the cost are high: the core optical film in VR design has higher requirements on materials and the lamination process of a plurality of lenses, only a few enterprises in the world can meet the requirements, the production yield is lower, the cost is high, and the cost of the optical film of a group of lenses (monocular) is close to 100 Yuan people's bank of coins.

Fourth, the actual effect is not ideal: the resolution and angular field performance have not yet reached the desired level due to factors such as the lens diameter being compressed.

Therefore, in order to improve the experience effect of use, the body length of the optical device is further shortened and the imaging quality is improved, and a 3-piece type catadioptric optical device scheme becomes one of the current research hotspots.

Disclosure of Invention

A first aspect of the present application provides an optical system comprising: the lens barrel, and lens component, reflection component and interval component that set up in the lens barrel, wherein, lens component includes in proper order from first side to second side along the optical axis: a first lens, a second lens and a third lens; the spacer assembly comprises at least one spacer arranged between two adjacent lenses in the lens assembly; the lens barrel is provided with a front end face facing the first side and a rear end face facing the second side, and the maximum outer diameter of the front end face of the lens barrel is smaller than that of the rear end face of the lens barrel; and an inner diameter d0m of a rear end surface of the lens barrel, a maximum half field angle HFOV of the optical system, and a maximum height L of the lens barrel in the optical axis direction satisfy: 1.0 < tan (HFOV). Times.d0m/L < 1.5.

In one embodiment, the spacer assembly includes a first spacer disposed between and in contact with the first lens and the second lens; wherein the radius of curvature R2 of the second side surface of the first lens, the outer diameter D1s of the first side surface of the first spacer, and the inner diameter D1s of the first side surface of the first spacer satisfy: 3.0 < |R2|/(D1 s-D1 s) < 18.0.

In one embodiment, the spacer assembly includes a first spacer disposed between and in contact with the first lens and the second lens; wherein the radius of curvature R3 of the first side surface of the second lens, the outer diameter D1m of the second side surface of the first spacer, and the inner diameter D1m of the second side surface of the first spacer satisfy: -5.0 < R3/(D1 m-D1 m) < -2.0.

In one embodiment, the spacer assembly includes: a first spacer disposed between and in contact with the first lens and the second lens; and a second spacer disposed between and in contact with the second lens and the third lens; the combined focal length f12 of the first lens and the second lens, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the spacing distance EP12 of the first spacer and the second spacer along the optical axis direction satisfy: 17.0 < f 12/(CT1+CT2+EP 12) < 335.0.

In one embodiment, the spacer assembly includes a second spacer disposed between and in contact with the second lens and the third lens; wherein the outer diameter D2s of the first side surface of the second spacer, the inner diameter D2s of the first side surface of the second spacer and the radius of curvature R4 of the second side surface of the second lens satisfy: 0.5 < (d2s+d2s)/|r4| < 4.0.

In one embodiment, the spacer assembly includes a second spacer disposed between and in contact with the second lens and the third lens; wherein the effective focal length f3 of the third lens, the maximum thickness CP2 of the second spacer in the optical axis direction, and the air interval T23 of the second lens and the third lens on the optical axis satisfy: 17.0 < |f3|/(CP2+T23) < 92.0.

In one embodiment, the spacer assembly includes a second spacer disposed between and in contact with the second lens and the third lens; wherein, the external diameter D2s of the first side of the second spacer, the external diameter D2m of the second side of the second spacer, the radius of curvature R5 of the first side of the third lens satisfy: 0.3 < (D2s+D2m)/|R5| < 4.5.

In one embodiment, the spacer assembly includes a second spacer disposed between and in contact with the second lens and the third lens; wherein, the curvature radius R6 of the second side surface of the third lens, the maximum thickness CP2 of the second spacer along the optical axis direction, and the center thickness CT3 of the third lens on the optical axis satisfy: 2.5 < |R6|/(EP 12+CP2+CT3) < 4.0.

In one embodiment, the spacer assembly includes a first spacer disposed between and in contact with the first lens and the second lens; wherein, the radius of curvature R1 of the first side surface of the first lens, the radius of curvature R2 of the second side surface of the first lens, the distance EP01 between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis direction, and the center thickness CT1 of the first lens on the optical axis satisfy: 3.0 < |R1+R2|/(EP 01+CT1)) < 19.0.

In one embodiment, the radius of curvature R1 of the first side surface of the first lens and the inner diameter d0s of the front end surface of the lens barrel satisfy: 1.0 < |R1|/d0s < 4.0.

In one embodiment, the spacer assembly includes: a first spacer disposed between and in contact with the first lens and the second lens; and a second spacer disposed between and in contact with the second lens and the third lens; the maximum thickness CP1 of the first spacer along the optical axis direction, the maximum thickness CP2 of the second spacer along the optical axis direction, the effective focal length f1 of the first lens, and the effective focal length f2 of the second lens satisfy: 1.5 < |CP2×f2/(CP1×f1) | < 7500.0.

In one embodiment, the outer diameter D0m of the rear end surface of the lens barrel and the radius of curvature R6 of the second side surface of the third lens satisfy: 1.0 < D0m/|R6| < 2.5.

In one embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy: 0.01 < (f1+f3)/|f2| < 2.5.

In one embodiment, the maximum height L of the lens barrel in the optical axis direction, the sum Σct of the center thicknesses of the first to third lenses on the optical axis, and the sum Σat of the air intervals between any adjacent two lenses of the first to third lenses on the optical axis satisfy: 3.5 < L/ΣCT+L/ΣAT < 7.5.

In one embodiment, the reflective assembly includes a reflective polarizing element, a quarter wave plate, and a partially reflective layer, wherein the reflective polarizing element and the quarter wave plate are disposed on the second side of the second lens, and the partially reflective layer is disposed on the second side of the third lens.

The second 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 provided by the application is a three-piece type refraction-reflection optical system, has the characteristics of good projection quality, smaller total length, good processability and the like, can meet the requirement of 1.0 < tan (HFOV) multiplied by d0m/L < 1.5, and effectively restricts the angle of view of the optical system, so that the system meets the characteristic of large field of view; meanwhile, the inner diameter size of the rear end face of the lens barrel is restrained, the step difference structure of the system in the radial direction is reduced, and the assembly yield of the lens is improved. In addition, the overall dimension of the lens barrel is restrained, so that the overall dimension of the lens barrel is as small as possible on the premise of ensuring the processability of the lens barrel, and the overall dimension is reduced, so that the artifact phenomenon is avoided.

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 illustrates a structural layout of an optical system according to the present application;

FIG. 2 shows a schematic diagram of a portion of parameters of an optical system according to the present application;

fig. 3A to 3D show schematic structural views of an optical system according to embodiment 1 of the present application;

fig. 4A to 4C 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. 5A and 5B show a schematic structural view of an optical system according to embodiment 2 of the present application;

fig. 6A to 6C show an on-axis chromatic aberration curve, an astigmatic curve, and a distortion curve of the optical system according to embodiment 2 of the present application, respectively;

fig. 7A and 7B show a schematic structural view of an optical system according to embodiment 3 of the present application; and

fig. 8A to 8C 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 includes: the lens barrel, and the lens assembly, the reflection assembly and the interval assembly which are arranged in the lens barrel. The lens component has a refraction function, the reflection component has a reflection function, and the spacer component has a bearing and shading function.

In an exemplary embodiment, the lens barrel has a front end surface facing the first side and a rear end surface facing the second side, the front end surface of the lens barrel having a maximum outer diameter smaller than the rear end surface of the lens barrel. Illustratively, the lens barrel may be an integral lens barrel.

The lens assembly of the optical system according to the 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 spacer assembly of the optical system according to the exemplary embodiment of the present application may include at least one spacer disposed between two adjacent lenses in the lens assembly, and the spacer assembly may include a first spacer disposed between and in contact with the first lens and the second lens, for example. Illustratively, the spacer assembly may include a second spacer disposed between and in contact with the second lens and the third lens. It should be understood that the present application is not specifically limited to the number of spacers, and any number of spacers may be included between any two lenses, and the entire optical system may also include any number of spacers. The spacer 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 spacing piece and the lens barrel, so that the problems of poor assembly stability, low performance yield and the like caused by large step difference between lenses are solved. Through reasonable setting of the number, thickness, inner diameter and outer diameter of the spacers, the assembly of the optical system is improved, stray light is shielded, and the projection quality of the optical system is improved.

The reflection assembly of the optical system according to the exemplary embodiment of the present application includes at least one reflection element, and illustratively, the reflection assembly may include a reflection type polarization element, a quarter wave plate, and a partial reflection layer. The partial reflection layer has a semi-transmission and semi-reflection function. In an exemplary embodiment, the reflective polarizing element and the quarter wave plate may be disposed at the second side of the second lens, and the partially reflective layer may be disposed at the second side of the third lens.

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.

In an exemplary embodiment, the optical system may further include an emission part disposed at the second side of the third lens. The optical system provided by the application can be applied to VR devices, for example, the first side can be a human eye side, for example, and the second side can be a display side or an image source side, for example. Accordingly, the emitting part may be a display screen.

Fig. 1 shows a structural layout of an optical system according to the present application, the optical system shown in fig. 1 sequentially including, along an optical axis, from a first side to a second side: stop STO, lens assemblies E1-E3, reflective assembly W, spacer assembly (not shown), and emitter F. The reflection assembly W includes a reflection type polarizing element and a quarter wave plate disposed at the second side of the second lens, and a partial reflection layer disposed at the second side of the third lens. The receiving portion J in fig. 1 may be, for example, a human eye.

In an exemplary embodiment, the light emitted from the emitting part passes through the third lens to reach the reflective polarizing element disposed on the second side of the second lens, is reflected by the reflective polarizing element and passes through the third lens again, and then the light beam is reflected again at the partially reflective layer on the second side of the third lens and passes through the third lens, the reflective polarizing element, the second lens, and the first lens in this order, passes through the diaphragm, and is finally received by the receiving part (e.g., human eye).

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; the reflection and transmission can be realized through the partial reflection layer, the refraction and reflection of the system light path can be realized, and the length of the optical system can be shortened.

Fig. 2 shows a schematic diagram of 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 and are not shown in fig. 1, fig. 1 only schematically showing part of the parameters of the barrel and the spacers of one optical system of the present application in order to better understand 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 front end surface of the lens barrel and the first side surface of the first spacer in the optical axis direction, EP12 represents the distance between the first spacer and the second spacer in the optical axis direction, CP1 represents the maximum thickness of the first spacer in the optical axis direction, CP2 represents the maximum thickness of the second spacer in the optical axis direction, D0s represents the outer diameter of the front end surface of the lens barrel, D0s represents the inner diameter of the front end surface of the lens barrel, D1s represents the outer diameter of the first side surface of the first spacer, D1s represents the inner diameter of the first side surface of the first spacer, D2s represents the inner diameter of the first side surface of the second spacer, D2m represents the inner diameter of the second side surface of the second spacer, D2s represents the outer diameter of the second side surface of the second spacer, D0m represents the inner diameter of the rear end surface of the lens barrel, and D0m represents the outer diameter of the rear end surface of the lens barrel.

In an exemplary embodiment, the optical system of the present application may satisfy: 1.0 < tan (HFOV). Times.d0m/L < 1.5, wherein d0m is the inner diameter of the rear end surface of the lens barrel, HFOV is the maximum half field angle of the optical system, and L is the maximum height of the lens barrel in the optical axis direction. Satisfies the conditions of tan (HFOV) multiplied by d0m/L less than 1.0 and 1.5, effectively constrains the angle of view of the optical system, thereby enabling the system to satisfy the characteristic of large field of view; meanwhile, the inner diameter size of the rear end face of the lens barrel is restrained, the step difference structure of the system in the radial direction is reduced, and the assembly yield of the lens is improved. In addition, the overall dimension of the lens barrel is restrained, so that the overall dimension of the lens barrel is as small as possible on the premise of ensuring the processability of the lens barrel, and the overall dimension is reduced, so that the artifact phenomenon is avoided.

In an exemplary embodiment, the optical system of the present application may satisfy: 3.0 < |R2|/(D1 s-D1 s) < 18.0, where R2 is the radius of curvature of the second side of the first lens, D1s is the outer diameter of the first side of the first spacer, and D1s is the inner diameter of the first side of the first spacer. Satisfies 3.0 < |R2|/(D1 s-D1 s) < 18.0, limits the curvature radius of the second side surface of the first lens, and is favorable for reducing the sensitivity of the first lens, thereby improving the assembly yield; and secondly, the inner diameter and the outer diameter of the first side face of the first spacer between the first lens and the second lens and in contact with the first lens are limited, so that the processability of the spacer is ensured.

In an exemplary embodiment, the optical system of the present application may satisfy: -5.0 < R3/(D1 m-D1 m) < -2.0, wherein R3 is the radius of curvature of the first side of the second lens, D1m is the outer diameter of the second side of the first spacer, and D1m is the inner diameter of the second side of the first spacer. R < 3/(D1 m-D1 m) < -2.0 is satisfied, and the sensitivity of the second lens is reduced by controlling the curvature radius of the first side surface of the second lens, so that the imaging quality of the system on the axis is good; and secondly, controlling the inner diameter and the outer diameter of the second side surface of the first spacer between the first lens and the second lens and contacting with the first lens, so that the processability of the spacer can be ensured.

In an exemplary embodiment, the optical system of the present application may satisfy: 17.0 < f 12/(Ct1+Ct2+Ep12) < 335.0, wherein f12 is the combined focal length of the first lens and the second lens, CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, and EP12 is the spacing distance between the first spacer and the second spacer along the optical axis direction. Satisfies 17.0 < f 12/(CT1+CT2+EP 12) < 335.0, reasonably distributes the optical power of the first lens and the second lens, is favorable for controlling the contribution quantity of the aberration of the two lenses, balances the aberration generated by other optical elements, ensures that the aberration of the system is in a reasonable horizontal state, controls CT1, CT2 and EP12, is favorable for controlling the edge thickness of the first lens and the second lens and the distance between the two spacers, and ensures that the optical system achieves optimal forming structure and assembly stability.

In an exemplary embodiment, the optical system of the present application may satisfy: 0.5 < (d2s+d2s)/|r4| < 4.0, where D2s is the outer diameter of the first side of the second spacer, D2s is the inner diameter of the first side of the second spacer, and R4 is the radius of curvature of the second side of the second lens. Satisfying 0.5 < (d2s+d2s)/|R4| < 4.0, the on-axis chromatic aberration can be reduced through the curvature radius of the second side surface of the second lens, but the position is sensitive and stray light is easy to appear, the sensitivity of the position is further reduced through controlling the outer diameter and the inner diameter of the first side surface of the second spacer, and the imaging quality is improved; and secondly, the outer diameter and the inner diameter of the first side face of the second spacer are controlled, so that the processability of the second spacer is improved on the basis of guaranteeing the bearing function of the second spacer, and the miniaturization of an optical system is realized.

In an exemplary embodiment, the optical system of the present application may satisfy: 17.0 < |f3|/(CP2+T23) < 92.0, wherein f3 is the effective focal length of the third lens, CP2 is the maximum thickness of the second spacer in the direction of the optical axis, and T23 is the air gap of the second and third lenses on the optical axis. The thickness of the second spacer and the air interval between the second lens and the third lens are reasonably set so as to meet the requirement that 17.0 < |f3|/(CP2+T23) < 92.0, and the method is favorable for effectively absorbing the marginal excessive light rays refracted by the third lens without entering a subsequent optical system, so that the imaging quality of the system is improved; by controlling the conditional expression, the thicknesses of all parts in the lens barrel are reasonably distributed, and the lens assembly is facilitated.

In an exemplary embodiment, the optical system of the present application may satisfy: 0.3 < (d2s+d2m)/|r5| < 4.5, where D2s is the outer diameter of the first side of the second spacer, D2m is the outer diameter of the second side of the second spacer, and R5 is the radius of curvature of the first side of the third lens. The curvature radius of the third lens is controlled to be less than 4.5 and 0.3 < (D2s+D2m)/|R5| is satisfied, so that light convergence is facilitated, and the screen size is reduced; by controlling the outer diameters of the first side surface and the second side surface of the second spacer, on one hand, the improvement of stray light of the lens is facilitated, and on the other hand, the optimization of the bearing relation of the second lens, the second spacer and the third lens is facilitated, and the assembly stability is improved.

In an exemplary embodiment, the optical system of the present application may satisfy: 2.5 < |R6|/(EP 12+CP2+CT3) < 4.0, wherein R6 is the radius of curvature of the second side surface of the third lens, CP2 is the maximum thickness of the second spacer in the direction of the optical axis, and CT3 is the center thickness of the third lens on the optical axis. Satisfies 2.5 < |R6|/(EP 12+CP2+CT3) < 4.0, and reasonably distributes the thickness of each part in the lens barrel, thereby facilitating the assembly of the lens and improving the reliability of the lens. And the curvature radius of the third lens is beneficial to control, and the light emergent angle of the third lens is controlled.

In an exemplary embodiment, the optical system of the present application may satisfy: 3.0 < |R1+R2|/(EP 01+CT1)) < 19.0, wherein R1 is a radius of curvature of the first side surface of the first lens, R2 is a radius of curvature of the second side surface of the first lens, EP01 is a distance between the front end surface of the lens barrel and the first side surface of the first spacer in the optical axis direction, and CT1 is a center thickness of the first lens on the optical axis. Satisfies that 3.0 < |R1+R2|/(EP 01+CT1)) < 19.0, is favorable for controlling the curvature radius of the first lens, ensures the thickness ratio of the first lens, and is more favorable for the forming stability of the first lens.

In an exemplary embodiment, the optical system of the present application may satisfy: 1.0 < |R1|/d0s < 4.0, wherein R1 is the radius of curvature of the first side surface of the first lens, and d0s is the inner diameter of the front end surface of the lens barrel. Satisfies 1.0 < |R1|/d0s < 4.0, can limit the maximum appearance of the lens barrel, is favorable for realizing the compactness of the lens structure, and simultaneously controls the curvature radius of the first side surface of the first lens, is favorable for correcting off-axis aberration and improving the overall image quality of the system.

In an exemplary embodiment, the optical system of the present application may satisfy: 1.5 < |CP2×f2/(CP1×f1) | < 7500.0, wherein CP1 is the maximum thickness of the first spacer in the optical axis direction, CP2 is the maximum thickness of the second spacer in the optical axis direction, f1 is the effective focal length of the first lens, and f2 is the effective focal length of the second lens. Satisfying 1.5 < |CP2 xf2/(CP1 xf1) | < 7500.0, correction of system aberrations is facilitated by controlling the effective focal lengths of the first lens and the second lens; and meanwhile, the thickness of the first spacer and the thickness of the second spacer are controlled, so that the assembly of the first lens and the second lens is facilitated, and the deformation of the assembled lens and spacer is reduced.

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: 1.0 < D0m/|R6| < 2.5, wherein D0m is the outer diameter of the rear end face of the lens barrel, and R6 is the curvature radius of the second side face of the third lens. Satisfies 1.0 < D0m/|R6| < 2.5, and effectively constrains the angle of view of the system by controlling the radius of curvature of the optical system, so that the system satisfies the characteristic of a large field of view; meanwhile, the outer diameter of the rear end face of the lens barrel is limited, the external dimension of the lens barrel is restrained, and the external dimension of the lens barrel is made to be as small as possible on the premise of ensuring the processability of the lens barrel, so that the overall dimension of the lens barrel is reduced.

In an exemplary embodiment, the optical system of the present application may satisfy: 0.01 < (f1+f3)/|f2| < 2.5, wherein f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens. Satisfies 0.01 < (f1+f3)/|f2| < 2.5, and the focal lengths of the first lens, the second lens and the third lens are controlled to enable the second lens to be flatter, the first lens and the third lens to be bent, so that the influence of the structural part of the first lens on the total length of the whole optical system is reduced, and meanwhile, the control of the light emergent angle of the third lens is facilitated; the effective focal lengths of the three lenses are controlled, so that the focal power can be reasonably distributed, the light path is folded back, and the length of the optical system is shortened; meanwhile, the aberration of the system is corrected, and the performance of the system is improved.

In an exemplary embodiment, the optical system of the present application may satisfy: 3.5 < L/ΣCT+L/ΣAT < 7.5, wherein L is the maximum height of the lens barrel along the optical axis direction, ΣCT is the sum of the thicknesses of the centers of the first lens and the third lens on the optical axis, and ΣAT is the sum of the air intervals between any two adjacent lenses in the first lens and the third lens on the optical axis. The method satisfies the condition that the L/sigma CT+L/sigma AT is less than 3.5 and less than 7.5, is beneficial to realizing miniaturization and ensures the appearance of the whole optical system.

In an exemplary embodiment, the first lens 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, 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 f1 of the first lens may be, for example, in the range of 56.0mm to 2308.0mm, the effective focal length f2 of the second lens may be, for example, in the range of-85.0 mm to 290000.0mm, and the effective focal length f3 of the third lens may be, for example, in the range of-400.0 mm to 125.0 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. Through setting up the spacer between the lens, can also be favorable to the processability of lens, reduce the sensitivity of lens, improve the assemblage yield to can satisfy VR and equip miniaturized target under the prerequisite of guaranteeing optical system performance.

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. 3A to 4C. Fig. 3A to 3D show schematic structural views of an optical system according to four embodiments in example 1 of the present application.

As shown in fig. 3A to 3D, the optical system sequentially includes, along the optical axis from a first side to a second side: the lens assembly comprises a first lens E1, a second lens E2 and a third lens E3. The reflection assembly may include a reflective polarizing element (not shown) disposed on the second side of the second lens, a quarter wave plate (not shown), and a partially reflective layer (not shown) disposed on the second side of the third lens. For example, the reflective polarizing element and the quarter wave plate may be attached to the second side of the second lens after being combined.

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. For example, S4 is the second side of the second lens and is also the first side of the reflective polarizing element; s6 is the second side of the third lens, which is also the first side of the partially reflective layer. For simplicity, the thicknesses of the reflective polarizing element, the quarter wave plate, and the partially reflective layer are not specifically shown in table 1.

TABLE 1

Referring to table 1, the optical system may further include an emission part disposed at the second side of the third lens. The light emitted from the emitting part passes through the third lens E3 to reach the reflective polarizing element provided on the second side surface S4 of the second lens E2, is reflected by the reflective polarizing element and passes through the third lens E3 again, and then the light beam is reflected again at the partially reflective layer on the second side surface S6 of the third lens E3 and passes through the third lens E3, the reflective polarizing element, the second lens E2 and the first lens E1 in this order, passes through the stop STO and is finally received by the receiving part, which may be, for example, a human eye.

In embodiment 1, the first side surface and the second side surface of any one of the first lens E1 to the third lens E3 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the following aspherical 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 cone coefficients and higher order coefficients A for each of the aspherical mirror surfaces S1 to S6 usable in example 1 ₄ 、A ₆ 、A ₈ And A ₁₀ 。

Face number	Coefficient of taper	A4	A6	A8	A10
						S1	0.0000	2.97E-01	-6.33E-02	-1.49E-02	3.58E-02
S2	0.0000	-5.33E-01	4.12E-02	-1.69E-02	2.49E-03
						S3	0.0000	-1.12E+00	2.83E-01	-8.92E-02	1.23E-02
S4	0.0000	-4.36E-01	1.04E-01	-3.58E-02	1.48E-02
						S5	0.0000	-1.28E-01	-4.76E-02	-8.96E-03	6.12E-03
S6	0.0000	5.26E-02	6.79E-02	-1.53E-02	1.83E-03

TABLE 2

In this example, the maximum half field angle HFOV of the optical system is 30.0, the effective focal length of the first lens is 71.65mm, the effective focal length of the second lens is-84.70 mm, and the effective focal length of the third lens is 124.37mm.

The spacer assembly of the optical system shown in fig. 3A and 3C includes a first spacer P1 and a second spacer P2, and the spacer assembly of the optical system shown in fig. 3B and 3D includes the first spacer P1. The first spacer P1 is disposed between and in contact with the first lens, and the second spacer P2 is disposed between and in contact with the second lens.

Table 3 shows basic parameters of the lens barrel and the spacer of the optical system in the four embodiments of example 1, and each parameter in table 3 is in millimeters (mm).

Parameter name	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4
					D1s	35.521	35.579	28.849	28.849
d1s	25.740	25.951	22.639	22.639
					EP01	5.374	5.374	6.410	6.410
D1m	35.521	35.579	29.926	29.926
					d1m	25.740	25.951	24.100	24.100
EP12	4.600	/	5.051	/
					CP2	4.248	/	2.565	/
D2s	36.224	/	33.335	/
					d2s	32.015	/	28.125	/
D2m	37.518	/	34.412	/
					d2m	34.693	/	29.586	/
d0m	44.118	44.118	42.244	42.244
					d0s	26.962	26.962	21.304	21.304
CP1	0.050	0.050	1.757	1.757
					D0m	49.118	49.118	46.244	46.244
L	19.740	19.740	22.400	22.400

TABLE 3 Table 3

Fig. 4A shows an on-axis chromatic aberration curve of the optical system of embodiment 1, which indicates the focus deviation of light rays of different wavelengths after passing through the lens. Fig. 4B shows an astigmatism curve of the optical system of embodiment 1, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 4C 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. 4A to 4C, 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. 5A to 6C. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 5A and 5B show schematic structural views of an optical system according to two implementations in example 2 of the present application.

As shown in fig. 5A and 5B, the optical system includes, in order from a first side to a second side along an optical axis: the lens assembly comprises a first lens E1, a second lens E2 and a third lens E3. The reflection assembly may include a reflective polarizing element (not shown) disposed on the second side of the second lens, a quarter wave plate (not shown), and a partially reflective layer (not shown) disposed on the second side of the third lens. For example, the reflective polarizing element and the quarter wave plate may be attached to the second side of the second lens after being combined.

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. For example, S4 is the second side of the second lens and is also the first side of the reflective polarizing element; s6 is the second side of the third lens, which is also the first side of the partially reflective layer. For simplicity, the thicknesses of the reflective polarizing element, the quarter wave plate, and the partially reflective layer are not specifically shown in table 4. Table 5 shows cone coefficients and higher order coefficients that can be used for each aspherical mirror surface in example 2, wherein each aspherical surface profile can be defined by the formula (1) given in example 1 above.

TABLE 4 Table 4

Face number	Coefficient of taper	A4	A6	A8	A10
						S1	0.0000	-1.67E+00	-1.78E-01	-4.30E-02	-1.30E-03
S2	0.0000	-2.29E+00	-2.27E-01	-6.64E-02	-1.37E-03
						S3	0.0000	-1.64E+00	-2.92E-01	-1.50E-01	-1.02E-02
S4	0.0000	-9.10E-01	-3.10E-01	-1.01E-01	8.55E-03
						S5	0.0000	7.47E-01	-6.59E-02	1.26E-02	1.49E-02
S6	0.0000	4.83E-03	-4.03E-02	-2.54E-02	-1.77E-03

TABLE 5

Referring to table 4, the optical system may further include an emission part disposed at the second side of the third lens. The light emitted from the emitting part passes through the third lens E3 to reach the reflective polarizing element provided on the second side surface S4 of the second lens E2, is reflected by the reflective polarizing element and passes through the third lens E3 again, and then the light beam is reflected again at the partially reflective layer on the second side surface S6 of the third lens E3 and passes through the third lens E3, the reflective polarizing element, the second lens E2 and the first lens E1 in this order, passes through the stop STO and is finally received by the receiving part, which may be, for example, a human eye.

In this example, the maximum half field angle HFOV of the optical system is 30.0, the effective focal length of the first lens is 2307.29mm, the effective focal length of the second lens is 280748.65mm, and the effective focal length of the third lens is-399.58 mm.

The spacer assembly of the optical system as shown in fig. 5A and 5B includes a first spacer P1 and a second spacer P2, the first spacer P1 is disposed between and in contact with the first lens, and the second spacer P2 is disposed between and in contact with the second lens.

Table 6 shows basic parameters of the lens barrel and the spacer of the optical system in both embodiments of example 2, and each parameter in table 6 is in millimeters (mm).

Parameter name	Embodiment 1	Embodiment 2
			D1s	35.495	35.495
d1s	27.574	27.574
			EP01	10.232	10.232
D1m	35.495	35.495
			d1m	27.574	27.574
EP12	5.017	2.178
			CP2	0.050	2.939
D2s	42.419	36.123
			d2s	34.310	31.913
D2m	42.419	38.111
			d2m	34.310	35.088
d0m	46.831	46.831
			d0s	19.481	19.481
CP1	0.050	0.050
			D0m	50.831	50.831
L	22.720	22.720

TABLE 6

Fig. 6A 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. 6B shows an astigmatism curve of the optical system of embodiment 2, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 6C 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. 6A to 6C, 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. 7A to 8C. Fig. 7A and 7B show schematic structural views of an optical system according to two embodiments in example 3 of the present application.

As shown in fig. 7A and 7B, the optical system includes, in order from a first side to a second side along an optical axis: the lens assembly comprises a first lens E1, a second lens E2 and a third lens E3. The reflection assembly may include a reflective polarizing element (not shown) disposed on the second side of the second lens, a quarter wave plate (not shown), and a partially reflective layer (not shown) disposed on the second side of the third lens. For example, the reflective polarizing element and the quarter wave plate may be attached to the second side of the second lens after being combined.

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. For example, S4 is the second side of the second lens and is also the first side of the reflective polarizing element; s6 is the second side of the third lens, which is also the first side of the partially reflective layer. For simplicity, the thicknesses of the reflective polarizing element, the quarter wave plate, and the partially reflective layer are not specifically shown in table 8. Table 8 shows cone coefficients and higher order coefficients that can be used for each aspherical mirror surface in example 3, where each aspherical surface profile can be defined by the formula (1) given in example 1 above.

TABLE 7

Face number	Coefficient of taper	A4	A6	A8	A10
						S1	0.0000	-9.68E-01	7.26E-02	5.54E-02	-1.34E-02
S2	0.0000	-1.27E+00	2.27E-01	-1.23E-02	1.01E-02
						S3	0.0000	-1.01E+00	2.51E-01	-1.49E-01	6.31E-02
S4	0.0000	-5.00E-01	5.41E-02	-9.34E-03	2.49E-02
						S5	0.0000	-6.93E-01	2.07E-02	2.60E-02	1.60E-02
S6	0.0000	-3.14E-01	2.26E-03	-1.65E-02	1.31E-02

TABLE 8

Referring to table 7, the optical system may further include an emission part disposed at the second side of the third lens. The light emitted from the emitting part passes through the third lens E3 to reach the reflective polarizing element provided on the second side surface S4 of the second lens E2, is reflected by the reflective polarizing element and passes through the third lens E3 again, and then the light beam is reflected again at the partially reflective layer on the second side surface S6 of the third lens E3 and passes through the third lens E3, the reflective polarizing element, the second lens E2 and the first lens E1 in this order, passes through the stop STO and is finally received by the receiving part, which may be, for example, a human eye.

In this example, the maximum half field angle HFOV of the optical system is 30.0, the effective focal length of the first lens is 56.48mm, the effective focal length of the second lens is-75.99 mm, and the effective focal length of the third lens is 102.22mm.

The spacer assembly of the optical system shown in fig. 7A includes a first spacer P1 and a second spacer P2, and the spacer assembly of the optical system shown in fig. 7B includes a first spacer P1 disposed between and in contact with the first lens and a second lens, and a second spacer P2 disposed between and in contact with the second lens and the third lens.

Table 9 shows basic parameters of the lens barrel and the spacer of the optical system in both embodiments of example 3, and each parameter in table 9 is in millimeters (mm).

Parameter name	Embodiment 1	Embodiment 2
			D1s	33.464	33.464
d1s	24.162	24.162
			EP01	5.382	5.382
D1m	33.464	33.464
			d1m	24.162	24.162
EP12	4.452	/
			CP2	2.869	/
D2s	33.085	/
			d2s	28.876	/
D2m	35.921	/
			d2m	33.096	/
d0m	41.888	41.888
			d0s	23.752	23.752
CP1	0.050	0.050
			D0m	45.888	45.888
L	19.176	19.176

TABLE 9

Fig. 8A 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. 8B shows an astigmatism curve of the optical system of embodiment 3, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 8C shows a distortion curve of the optical system of embodiment 3, which represents distortion magnitude values corresponding to different half angles of view. As can be seen from fig. 8A to 8C, 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 3.

/>

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 (16)

1. An optical system, comprising: the lens cone, the lens component, the reflecting component and the spacing component are arranged in the lens cone, wherein,

the lens assembly sequentially comprises from a first side to a second side along an optical axis: a first lens, a second lens and a third lens;

the spacer assembly includes at least one spacer disposed between two adjacent lenses in the lens assembly;

the lens barrel has a front end face facing the first side and a rear end face facing the second side, a maximum outer diameter of the front end face of the lens barrel being smaller than a maximum outer diameter of the rear end face of the lens barrel; and

an inner diameter d0m of a rear end surface of the lens barrel, a maximum half field angle HFOV of the optical system, and a maximum height L of the lens barrel in the optical axis direction satisfy: 1.0 < tan (HFOV). Times.d0m/L < 1.5.

2. The optical system of claim 1, wherein the spacer assembly comprises a first spacer disposed between and in contact with the first lens and the second lens; wherein,

the radius of curvature R2 of the second side of the first lens, the outer diameter D1s of the first side of the first spacer, and the inner diameter D1s of the first side of the first spacer satisfy: 3.0 < |R2|/(D1 s-D1 s) < 18.0.

3. The optical system of claim 1, wherein the spacer assembly comprises a first spacer disposed between and in contact with the first lens and the second lens; wherein,

the radius of curvature R3 of the first side surface of the second lens, the outer diameter D1m of the second side surface of the first spacer, and the inner diameter D1m of the second side surface of the first spacer satisfy: -5.0 < R3/(D1 m-D1 m) < -2.0.

4. The optical system of claim 1, wherein the spacer assembly comprises:

a first spacer disposed between and in contact with the first lens and the second lens; and

a second spacer disposed between and in contact with the second lens and the third lens; wherein,

the combined focal length f12 of the first lens and the second lens, the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the spacing distance EP12 of the first spacer and the second spacer along the optical axis direction satisfy: 17.0 < f 12/(CT1+CT2+EP 12) < 335.0.

5. The optical system of claim 1, wherein the spacer assembly comprises a second spacer disposed between and in contact with the second lens and the third lens; wherein,

an outer diameter D2s of the first side surface of the second spacer, an inner diameter D2s of the first side surface of the second spacer, and a radius of curvature R4 of the second side surface of the second lens satisfy: 0.5 < (d2s+d2s)/|r4| < 4.0.

6. The optical system of claim 1, wherein the spacer assembly comprises a second spacer disposed between and in contact with the second lens and the third lens; wherein,

the effective focal length f3 of the third lens, the maximum thickness CP2 of the second spacer in the optical axis direction, and the air interval T23 of the second lens and the third lens on the optical axis satisfy: 17.0 < |f3|/(CP2+T23) < 92.0.

7. The optical system of claim 1, wherein the spacer assembly comprises a second spacer disposed between and in contact with the second lens and the third lens; wherein,

an outer diameter D2s of the first side surface of the second spacer, an outer diameter D2m of the second side surface of the second spacer, and a radius of curvature R5 of the first side surface of the third lens satisfy: 0.3 < (D2s+D2m)/|R5| < 4.5.

8. The optical system of claim 1, wherein the spacer assembly comprises a second spacer disposed between and in contact with the second lens and the third lens; wherein,

the radius of curvature R6 of the second side surface of the third lens, the maximum thickness CP2 of the second spacer along the optical axis direction, and the center thickness CT3 of the third lens on the optical axis satisfy: 2.5 < |R6|/(EP 12+CP2+CT3) < 4.0.

9. The optical system of claim 1, wherein the spacer assembly comprises a first spacer disposed between and in contact with the first lens and the second lens; wherein,

the radius of curvature R1 of the first side surface of the first lens, the radius of curvature R2 of the second side surface of the first lens, the distance EP01 between the front end surface of the lens barrel and the first side surface of the first spacer along the optical axis direction, and the center thickness CT1 of the first lens on the optical axis satisfy: 3.0 < |R1+R2|/(EP 01+CT1)) < 19.0.

10. The optical system according to any one of claims 1 to 9, wherein a radius of curvature R1 of the first side surface of the first lens and an inner diameter d0s of the front end surface of the lens barrel satisfy: 1.0 < |R1|/d0s < 4.0.

11. The optical system of claim 1, wherein the spacer assembly comprises:

a first spacer disposed between and in contact with the first lens and the second lens; and

a second spacer disposed between and in contact with the second lens and the third lens; wherein,

the maximum thickness CP1 of the first spacer along the optical axis direction, the maximum thickness CP2 of the second spacer along the optical axis direction, the effective focal length f1 of the first lens, and the effective focal length f2 of the second lens satisfy:

1.5＜|CP2×f2/(CP1×f1)|＜7500.0。

12. the optical system according to any one of claims 1 to 9, wherein an outer diameter D0m of a rear end surface of the lens barrel and a radius of curvature R6 of the second side surface of the third lens satisfy: 1.0 < D0m/|R6| < 2.5.

13. The optical system according to any one of claims 1 to 9, wherein an effective focal length f1 of the first lens, an effective focal length f2 of the second lens, and an effective focal length f3 of the third lens satisfy: 0.01 < (f1+f3)/|f2| < 2.5.

14. The optical system according to any one of claims 1 to 9, wherein a maximum height L of the lens barrel in the optical axis direction, a sum Σct of center thicknesses of the first lens to the third lens on the optical axis, a sum Σat of air intervals between any adjacent two lenses of the first lens to the third lens on the optical axis satisfy: 3.5 < L/ΣCT+L/ΣAT < 7.5.

15. The optical system of any one of claims 1 to 9, wherein the reflective assembly comprises a reflective polarizing element, a quarter wave plate, and a partially reflective layer, wherein,

the reflective polarizing element and the quarter wave plate are arranged on the second side surface of the second lens, and the partial reflecting layer is arranged on the second side surface of the third lens.

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