CN115047592A

CN115047592A - Optical lens

Info

Publication number: CN115047592A
Application number: CN202210643190.3A
Authority: CN
Inventors: 戴付建; 宋立通; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2022-09-13

Abstract

The application discloses optical lens, it includes along the optical axis in proper order from people's eye side to image source side: the first lens with focal power, the side near the image source of the first lens is convex; the side surface of the second lens close to the image source is a concave surface; the third lens with positive focal power has a convex surface on the side close to an image source; a fourth lens having a focal power, a near-imaging side of which is convex; and the side surface of the fifth lens close to the image source is concave. The optical lens satisfies: 0.3 < (CT4+ T45+ CT5)/Tr1R6 < 0.7 and-1.3 < R6/f < -0.9, wherein Tr1R6 is a distance on the optical axis from the near-image-source-side surface of the first lens to the near-image-source-side surface of the third lens, CT4 is a center thickness of the fourth lens, T45 is a distance on the optical axis from the near-image-source-side surface of the fourth lens to the near-image-side surface of the fifth lens, CT5 is a center thickness of the fifth lens, R6 is a radius of curvature of the near-image-source-side surface of the third lens, and f is a total effective focal length of the optical lens.

Description

Optical lens

Technical Field

The present application relates to the field of optical elements, and in particular, to an optical lens.

Background

Virtual Reality technology (VR) is a visual Virtual environment that is generated by a computer, interactive, and immersive, and can generate various Virtual environments as required, and is widely applied to the fields of city planning, driving training, indoor design, and the like. In recent years, with the development of computer computing capability and various types of sensors, various types of virtual reality helmets have appeared on the market, which are basically composed of a display screen or a mobile phone and a pair of display eyepieces (i.e., optical lenses) through which a human eye can see an enlarged image on a screen on the image source side, and the sensors adjust images in left and right screens in response to changes in the human head so that the human eye can see a stereoscopic, interactive visual image.

With the rapid development of the virtual reality technology, the display eyepiece (i.e. an optical lens, such as a projection lens) is used as a core optical component of the VR headset, and key indexes such as the imaging quality, the weight and the size of the display eyepiece directly relate to the experience and the comfort level of a user wearing the VR helmet. Although the eyepiece mounted on a virtual reality helmet in the market at present has a short focal length, a large visual range and compact equipment due to simple lens arrangement, and can bring a user a good immersion feeling, the problems of blurred edge images, increased dispersion degree, serious image deformation and the like are also brought.

Therefore, how to design an optical lens that can be mounted on a portable electronic device such as a VR headset and has a small size and a small weight and still has a good imaging quality has become one of the problems to be solved by many lens designers.

Disclosure of Invention

The present application provides an optical lens, which sequentially includes from a human eye side to an image source side along an optical axis: the first lens with focal power, the side near the image source of the first lens is a convex surface; the side surface of the second lens close to the image source is a concave surface; the third lens with positive focal power has a convex surface on the near-image side and a convex surface on the near-image source side; a fourth lens having a focal power, a near-imaging side of which is convex; and the side surface of the fifth lens close to the image source is concave. The optical lens can satisfy: 0.3 < (CT4+ T45+ CT5)/Tr1R6 < 0.7 and-1.3 < R6/f < -0.9, wherein Tr1R6 is a distance on the optical axis from the near-image-source-side surface of the first lens to the near-image-source-side surface of the third lens, CT4 is a center thickness of the fourth lens, T45 is a distance on the optical axis from the near-image-source-side surface of the fourth lens to the near-image-side surface of the fifth lens, CT5 is a center thickness of the fifth lens, R6 is a radius of curvature of the near-image-source-side surface of the third lens, and f is a total effective focal length of the optical lens.

In one embodiment, at least one of the near image side of the first lens to the near image source side of the fifth lens is an aspheric mirror.

In one embodiment, the optical lens may satisfy: ET3/ET2 < 0.5, where ET3 is the edge thickness of the third lens at the maximum effective radius and ET2 is the edge thickness of the second lens at the maximum effective radius.

In one embodiment, the optical lens may satisfy: 1.2 < (CT4+ CT5)/(ET4+ ET5) < 2.0, wherein CT4 is the center thickness of the fourth lens, CT5 is the center thickness of the fifth lens, ET4 is the edge thickness of the fourth lens at the maximum effective radius, and ET5 is the edge thickness of the fifth lens at the maximum effective radius.

In one embodiment, the optical lens may satisfy: 1 < DT32/DT41 < 1.5, where DT32 is the maximum effective radius of the near-image source side of the third lens and DT41 is the maximum effective radius of the near-image side of the fourth lens.

In one embodiment, the optical lens may satisfy: 0.8 < DT12/DT21 < 1.1, where DT12 is the maximum effective radius of the near-image source side of the first lens and DT21 is the maximum effective radius of the near-image side of the second lens.

In one embodiment, the optical lens may satisfy: -1.1 < SAG32/SAG41 < -0.7, wherein SAG32 is the distance on the optical axis from the intersection of the near-image source side of the third lens and the optical axis to the effective radius vertex of the near-image source side of the third lens, and SAG41 is the distance on the optical axis from the intersection of the near-imaging side of the fourth lens and the optical axis to the effective radius vertex of the near-imaging side of the fourth lens.

In one embodiment, the optical lens may satisfy: 0.6 < (DT32-DT41)/(DT41-DT52) < 1.3, wherein DT32 is the maximum effective radius of the near-image source side of the third lens, DT41 is the maximum effective radius of the near-image source side of the fourth lens, and DT52 is the maximum effective radius of the near-image source side of the fifth lens.

In one embodiment, the optical lens may satisfy: 2 < | SAG21/CT2| + | SAG22/CT2| < 5.5, wherein SAG21 is the distance on the optical axis from the intersection point of the near imaging side surface of the second lens and the optical axis to the effective radius vertex of the near imaging side surface of the second lens, SAG22 is the distance on the optical axis from the intersection point of the near image source side surface of the second lens and the optical axis to the effective radius vertex of the near image source side surface of the second lens, and CT2 is the central thickness of the second lens on the optical axis.

In one embodiment, the optical lens may satisfy: 0.6 < (T12+ T23)/. SIGMA AT < 1, wherein T12 is a distance on an optical axis from a near-image source side surface of the first lens to a near-image side surface of the second lens, T23 is a distance on an optical axis from a near-image source side surface of the second lens to a near-image side surface of the third lens, and SIGMA AT is a sum of air spaces on an optical axis between any adjacent two lenses of the first lens to the fifth lens.

In one embodiment, the optical lens may satisfy: -1 < f2/f1 < -0.3, wherein f2 is the effective focal length of the second lens and f1 is the effective focal length of the first lens.

In one embodiment, the optical lens may satisfy: 0.4 < DTmax/TD < 0.7, where DTmax is the maximum value of the maximum effective radius in the near image-forming side of the first lens to the near source side of the fifth lens, and TD is the distance on the optical axis from the near image-forming side of the first lens to the near source side of the fifth lens.

In one embodiment, the optical lens may satisfy: 3 < TD/ImgH < 4.5, wherein TD is the distance on the optical axis from the near imaging side surface of the first lens to the near image source side surface of the fifth lens, and ImgH is half of the diagonal length of the image source surface of the optical lens.

In one embodiment, the optical lens may satisfy: 0.6 < ∑ ET/Σ CT < 1, where Σ ET is the sum of the edge thicknesses of the first lens to the fifth lens at the maximum effective diameter, and Σ CT is the sum of the center thicknesses of the first lens to the fifth lens on the optical axis.

In one embodiment, the optical lens may satisfy: tan (FOV/2) × f/EPD < 1, where FOV is the maximum field angle of the optical lens, EPD is the entrance pupil diameter of the optical lens, and f is the total effective focal length of the optical lens.

In one embodiment, the optical lens may satisfy: 1 < f123/f < 2, where f123 is the combined focal length of the first lens, the second lens, and the third lens, and f is the total effective focal length of the optical lens.

Another aspect of the present application provides an optical lens. The optical lens sequentially comprises the following components from the human eye side to the image source side along the optical axis: a first lens group having positive optical power, including a first lens, a second lens, and a third lens having optical power; and a second lens group having a power, including a fourth lens having a positive power and a fifth lens having a power. Focal power of the first lens

And the focal power of the second lens

Can satisfy the following conditions:

the side surface of at least one of the first lens, the second lens and the third lens close to an image source is a convex surface; the side surface of the fifth lens close to the image source is a concave surface; and the optical lens may satisfy: f × tan (FOV/4) > 6mm, where f is the total effective focal length of the optical lens and FOV is the maximum field angle of the optical lens.

In one embodiment, the optical lens may satisfy: 0 < (N1max-N1_2)/N1_2 < 0.5, where N1max is the maximum value of the refractive indexes in the first to third lenses, and N1_2 is the refractive index of the second lens.

The optical lens satisfies: ET3/ET2 < 0.5, wherein ET3 is the edge thickness of the third lens at the maximum effective radius, and ET2 is the edge thickness of the second lens at the maximum effective radius.

In one embodiment of the present application, the image pickup lens is manufactured by disposing the near-image-source side surface of the first lens to be convex; the second lens is set to have negative focal power, and the side surface close to the image source is a concave surface; the third lens is set to have positive focal power, the near imaging side surface is a convex surface, and the near image source side surface is a convex surface; the near imaging side surface of the fourth lens is set to be a convex surface; and the side surface of the fifth lens close to the image source is set to be a concave surface, so that the imaging quality of the optical lens is improved and the weight of the optical lens is reduced by reasonably setting the number of the lenses, the focal power and the surface type of the lenses. Illustratively, by setting 0.3 < Tr1R6/(CT4+ T45+ CT5 < 0.7 and-1.3 < R6/f < 0.9, the compactness of the optical lens is favorably realized, and the optical lens has the advantages of good imaging quality and small external dimension.

Drawings

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

fig. 1 shows a schematic structural diagram of an optical lens according to embodiment 1 of the present application;

fig. 2A to 2D respectively show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a relative illuminance curve of the optical lens of embodiment 1;

fig. 3 shows a schematic structural diagram of an optical lens according to embodiment 2 of the present application;

fig. 4A to 4D show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a relative illuminance curve, respectively, of the optical lens of embodiment 2;

fig. 5 is a schematic structural view showing an optical lens according to embodiment 3 of the present application;

fig. 6A to 6D show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a relative illuminance curve, respectively, of the optical lens of embodiment 3;

fig. 7 is a schematic structural view showing an optical lens according to embodiment 4 of the present application;

fig. 8A to 8D show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a relative illuminance curve, respectively, of the optical lens of embodiment 4;

fig. 9 is a schematic structural view showing an optical lens according to embodiment 5 of the present application; and

fig. 10A to 10D show an axial chromatic aberration curve, an astigmatism curve, a distortion curve, and a relative illuminance curve, respectively, of the optical lens of example 5.

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 the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present 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, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and 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, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the eye side (i.e., the image side) of the person is referred to as the near image side of the lens, and the surface of each lens closest to the image source side is referred to as the near image source side of the lens.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" 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. Moreover, when a statement such as "at least one of" appears after a list of listed features, the entirety of the listed features is modified rather than modifying individual elements in the list. Furthermore, when describing embodiments of the present application, the use of "may" mean "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 the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

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

The optical lens according to the exemplary embodiment of the present application may be used as a projection lens, which may include five lenses having optical powers, i.e., a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The five lenses are arranged in order from the EYE side EYE (i.e., the image side) to the image source side along the optical axis. Any adjacent two lenses of the first lens to the fifth lens can have a spacing distance therebetween.

In an exemplary embodiment, the first lens may have a positive or negative power, and its near-image-source side may be convex, e.g., its paraxial region near the image-source side may be convex; the second lens can have negative focal power, and the side surface close to the image source can be a concave surface; the third lens can have positive focal power, the near imaging side surface of the third lens can be a convex surface, and the near image source side surface of the third lens can be a convex surface; the fourth lens can have positive focal power or negative focal power, and the near imaging side surface of the fourth lens can be a convex surface; the fifth lens can have positive power or negative power, and the side surface close to the image source can be concave. Illustratively, a paraxial region of the near image source side of the first lens can be convex.

In another exemplary embodiment of the present application, an optical lens may include, in order from a human EYE side EYE (i.e., an image side) to an image source side along an optical axis, a first lens group having positive optical power and a second lens group having optical power. The first lens group may include a first lens, a second lens, and a third lens having power. The second lens group may include a fourth lens having positive optical power and a fifth lens having optical power. The near-image-source side of the fifth lens element can be concave. Focal power of the first lens

And the focal power of the second lens

Can satisfy the following conditions:

for example, when the first lens has a positive optical power, the second lens may have a negative optical power. The near image side surface of at least one of the first lens, the second lens and the third lens is a convex surface, and the near image source side surface is a convex surface.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.3 < (CT4+ T45+ CT5)/Tr1r6 < 0.7, wherein Tr1r6 is the distance on the optical axis from the near-image-side surface of the first lens to the near-image-source-side surface of the third lens, CT4 is the center thickness of the fourth lens, T45 is the distance on the optical axis from the near-image-source-side surface of the fourth lens to the near-image-side surface of the fifth lens, and CT5 is the center thickness of the fifth lens. More specifically, Tr1r6, CT4, T45 and CT5 may further satisfy: 0.2 < (CT4+ T45+ CT5)/Tr1r6 < 0.5. Satisfy 0.3 < (CT4+ T45+ CT5)/Tr1r6 < 0.7, be favorable to realizing the compactness of optical lens, be favorable to making optical lens have the advantage of small overall dimension simultaneously when having better projection quality.

In an exemplary embodiment, an optical lens according to the present application may satisfy: -1.3 < R6/f < -0.9, wherein R6 is the radius of curvature of the near-image source side of the third lens, and f is the total effective focal length of the optical lens. The optical lens meets the condition that R6/f is more than-1.3 and less than-0.9, is favorable for realizing the compactness of the optical lens, and is favorable for ensuring that the optical lens has the advantages of better projection quality and small overall dimension.

In an exemplary embodiment, an optical lens according to the present application may satisfy: ET3/ET2 < 0.5, where ET3 is the edge thickness of the third lens at the maximum effective radius, and ET2 is the edge thickness of the second lens at the maximum effective radius. More specifically, ET3 and ET2 further satisfy: 0.1 < ET3/ET2 < 0.5. Satisfying ET3/ET2 < 0.5 is beneficial to correcting chromatic aberration of the lens and simultaneously beneficial to ensuring the manufacturability of the second lens and the third lens.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 1.2 < (CT4+ CT5)/(ET4+ ET5) < 2.0, wherein CT4 is the center thickness of the fourth lens, CT5 is the center thickness of the fifth lens, ET4 is the edge thickness of the fourth lens at the maximum effective radius, and ET5 is the edge thickness of the fifth lens at the maximum effective radius. Satisfying 1.2 < (CT4+ CT5)/(ET4+ ET5) < 2.0 is beneficial to correcting chromatic aberration of the lens and simultaneously beneficial to ensuring the manufacturability of the fourth lens and the fifth lens.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 1 < DT32/DT41 < 1.5, where DT32 is the maximum effective radius of the near-image source side of the third lens and DT41 is the maximum effective radius of the near-image side of the fourth lens. The visual field correction method meets the requirement that DT32/DT41 is more than 1.5, can better correct coma aberration of an off-axis visual field, and reduces the phenomenon of edge picture tailing in visual experience.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.8 < DT12/DT21 < 1.1, where DT12 is the maximum effective radius of the near-image source side of the first lens and DT21 is the maximum effective radius of the near-image side of the second lens. The requirements of DT12/DT21 of 0.8 and 1.1 are met, astigmatic aberration can be eliminated well, projection quality is improved, and the assembly of the lens can be improved.

In an exemplary embodiment, an optical lens according to the present application may satisfy: -1.1 < SAG32/SAG41 < -0.7, wherein SAG32 is the distance on the optical axis from the intersection of the near-image source side of the third lens and the optical axis to the effective radius vertex of the near-image source side of the third lens, and SAG41 is the distance on the optical axis from the intersection of the near-imaging side of the fourth lens and the optical axis to the effective radius vertex of the near-imaging side of the fourth lens. The requirement of-1.1 < SAG32/SAG41 < 0.7 is met, coma aberration can be corrected, and the resolution of the edge field of view can be improved.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.6 < (DT32-DT41)/(DT41-DT52) < 1.3, wherein DT32 is the maximum effective radius of the near-image source side of the third lens, DT41 is the maximum effective radius of the near-image source side of the fourth lens, and DT52 is the maximum effective radius of the near-image source side of the fifth lens. Satisfy 0.6 < (DT32-DT41)/(DT41-DT52) < 1.3, can correct coma of off-axis field of view better, when this optical lens is mounted on wearing equipment such as VR, can reduce the edge picture trailing phenomenon that appears in the visual experience.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 2 < | SAG21/CT2| + | SAG22/CT2| < 5.5, wherein SAG21 is the distance on the optical axis from the intersection point of the near imaging side surface of the second lens and the optical axis to the effective radius vertex of the near imaging side surface of the second lens, SAG22 is the distance on the optical axis from the intersection point of the near image source side surface of the second lens and the optical axis to the effective radius vertex of the near image source side surface of the second lens, and CT2 is the central thickness of the second lens on the optical axis. The lens meets the condition that 2 < | SAG21/CT2| + | SAG22/CT2| < 5.5, is beneficial to reducing the spherical aberration and chromatic aberration of the lens, enables the lens to obtain better projection quality and reduces the color fringing phenomenon in visual experience.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.6 < (T12+ T23)/. SIGMA AT < 1, wherein T12 is a distance on an optical axis from a near-image source side surface of the first lens to a near-image side surface of the second lens, T23 is a distance on an optical axis from a near-image source side surface of the second lens to a near-image side surface of the third lens, and SIGMA AT is a sum of air spaces on an optical axis between any adjacent two lenses of the first lens to the fifth lens. Satisfying 0.6 < (T12+ T23)/. SIGMA AT < 1 is beneficial to correcting the field curvature aberration of the off-axis field of view and simultaneously beneficial to enabling the optical lens to have smaller total length.

In an exemplary embodiment, an optical lens according to the present application may satisfy: -1 < f2/f1 < -0.3, wherein f2 is the effective focal length of the second lens and f1 is the effective focal length of the first lens. More specifically, f2 and f1 may further satisfy: -0.9 < f2/f1 < -0.5. Satisfy-1 < f2/f1 < -0.3, be favorable to correcting on-axis chromatic aberration, improve the image quality sharpness of the central region on the image source surface.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.4 < DTmax/TD < 0.7, where DTmax is the maximum value of the maximum effective radius in the near image-forming side of the first lens to the near source side of the fifth lens, and TD is the distance on the optical axis from the near image-forming side of the first lens to the near source side of the fifth lens. The requirement that DTmax/TD is more than 0.4 and less than 0.7 is met, the wide eye movement range can be realized in the use scene of the ocular lens, and the comfortable experience is realized.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 3 < TD/ImgH < 4.5, wherein TD is the distance on the optical axis from the near imaging side surface of the first lens to the near image source side surface of the fifth lens, and ImgH is half of the diagonal length of the image source surface of the optical lens. The optical lens meets the requirements that TD/ImgH is more than 3 and less than 4.5, and the optical lens has shorter total length so as to meet the requirement of miniaturization of the lens.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0.6 < ∑ ET/Σ CT < 1, where Σ ET is the sum of the edge thicknesses of the first lens to the fifth lens at the maximum effective diameter, and Σ CT is the sum of the center thicknesses of the first lens to the fifth lens on the optical axis. Satisfies the requirement that 0.6 < SigmaET/Sigma CT < 1, is beneficial to reasonably distributing the focal power of each lens and better corrects spherical aberration and aberration.

In an exemplary embodiment, an optical lens according to the present application may satisfy: tan (FOV/2) × f/EPD < 1, where FOV is the maximum field angle of the optical lens, EPD is the entrance pupil diameter of the optical lens, and f is the total effective focal length of the optical lens. The lens meets tan (FOV/2) multiplied by f/EPD < 1, can obtain a wider eye movement range in an eyepiece use scene on the premise of ensuring that the lens has a larger field angle, and improves the wearing convenience of a user.

In an exemplary embodiment, an optical lens according to the present application may satisfy: f × tan (FOV/4) > 6mm, where f is the total effective focal length of the optical lens and FOV is the maximum field angle of the optical lens. More specifically, f and FOV further satisfy: f × tan (FOV/4) > 4 mm. Satisfying f × tan (FOV/4) > 6mm can better correct various aberrations, and is beneficial to enabling the imaging lens to obtain a larger field angle so as to provide a better immersion feeling for the user.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 0 < (N1max-N1_2)/N1_2 < 0.5, where N1max is the maximum value of the refractive indexes in the first to third lenses, and N1_2 is the refractive index of the second lens. More specifically, N1max and N1_2 further satisfy: 0 < (N1max-N1_2)/N1_2 < 0.2. The optical lens meets the requirement that 0 < (N1max-N1_2)/N1_2 < 0.5, and when the optical lens is mounted on wearing equipment such as VR and the like, the optical lens is beneficial to correcting the vertical axis chromatic aberration of the eye movement range of a wearer and ensures smooth pictures in the visual experience process.

In an exemplary embodiment, an optical lens according to the present application may satisfy: 1 < f123/f < 2, wherein f123 is a combined focal length of the first lens, the second lens and the third lens, and f is a total effective focal length of the optical lens. Satisfying 1 < f123/f < 2, which is beneficial to correcting the spherical aberration of the lens.

In an exemplary embodiment, the total effective focal length f of the optical lens may be in a range of 13mm to 15 mm; the effective focal length f1 of the first lens can be in the range of 12.5 mm-19.0 mm; the effective focal length f2 of the second lens can be in the range of-15.5 mm to-7.5 mm; and the effective focal length f3 of the third lens may be in the range of 13.0mm to 16.0 mm.

In an exemplary embodiment, a distance TTL on an optical axis from a near imaging side surface of the first lens to an image source surface of the optical lens may be in a range of 29mm to 35 mm; the ImgH of the half of the diagonal length of the image source surface of the optical lens can be in the range of 6.0 mm-9.0 mm; the maximum field angle FOV of the optical lens can be in the range of 53.5-58.5 degrees; and the aperture value Fno of the optical lens can be within the range of 1.4-1.8.

In an exemplary embodiment, an optical lens according to the present application further includes a stop (not shown) disposed between the imaging side and the first lens, and the stop may be disposed, for example, in the vicinity of EYE observation of a human EYE. Optionally, the optical lens may further include a filter for correcting color deviation and/or a protective glass for protecting a photosensitive element located on the image source surface.

The optical lens according to the above-described embodiment of the present application may employ a plurality of lenses, for example, five lenses as described above. By reasonably distributing the focal power, the surface type, the central thickness of each lens, the on-axis distance between each lens and the like, the volume of the optical lens can be effectively reduced, the processability of the optical lens can be improved, and the optical lens is more favorable for production and processing and can be suitable for portable electronic products. The optical lens has the advantages of being small in size, light in weight, good in imaging quality and the like, and can well meet the use requirements of various portable electronic products such as VR head-mounted equipment in a projection scene.

In the embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the near-image-side surface of the first lens to the near-image-source-side surface of the fifth lens is an aspherical mirror surface. The aspheric lens is characterized in that: the curvature varies continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics, and has advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, the aberration generated in the projection process can be eliminated as much as possible, and the projection quality is further improved. Optionally, at least one of the near image side and the near source side of each of the first, second, third, fourth, and fifth lenses is an aspheric mirror. Optionally, each of the first, second, third, fourth, and fifth lenses has a near-image side and a near-image source side that are aspheric mirror surfaces.

However, it will be understood by those skilled in the art that the number of lenses constituting the optical lens may be varied to obtain the respective results and advantages described in the present specification without departing from the technical solutions claimed in the present application. For example, although five lenses are exemplified in the embodiment, the optical lens is not limited to include five lenses. The optical lens may also include other numbers of lenses, if desired.

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

Example 1

An optical lens according to embodiment 1 of the present application is described below with reference to fig. 1 to 2D. Fig. 1 shows a schematic structural diagram of an optical lens according to embodiment 1 of the present application.

As shown in fig. 1, the optical lens system sequentially includes, from an image forming side to an image source side: the lens comprises a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6 and an image source surface S13.

The first lens element E1 has positive power, and has a concave near-image side surface S1 and a convex near-image source side surface S2. The second lens element E2 has negative power, and its near image side S3 is convex and its near image source side S4 is concave. The third lens element E3 has positive power, and has a convex near-image side surface S5 and a convex near-image source side surface S6. The fourth lens element E4 has positive power, and has a convex near-image side surface S7 and a convex near-image source side surface S8. The fifth lens element E5 has negative power, and its near image side S9 is concave and its near image source side S10 is concave. The filter E6 has a near image side S11 and a near image source side S12. The light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected onto a target object (not shown) in space. For example, when the optical lens is mounted on a wearing device such as a VR, light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected into the EYE of the wearer.

Table 1 shows a basic parameter table of the optical lens of embodiment 1, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm).

TABLE 1

In this example, the total effective focal length f of the optical lens is 13.12mm, the total length TTL of the optical lens (i.e., the distance on the optical axis from the near-imaging side surface S1 of the first lens E1 to the image source surface S13 of the optical lens) is 30.28mm, the half ImgH of the diagonal length of the image source surface S13 of the optical lens is 6.45mm, the maximum field angle FOV of the optical lens is 54.31 °, and the aperture value Fno of the optical lens is 1.46.

In embodiment 1, the near-image-side surface and the near-image-source-side surface of any one of the first lens E1 to the third lens E3 are both aspheric, and the profile x of each aspheric lens can be defined by, but is not limited to, the following aspheric formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, and c is 1/R (i.e., paraxial curvature c is the reciprocal of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 below shows the high-order coefficient A of each of the aspherical mirror surfaces S1 to S6 used in example 1 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ And A ₁₆ 。

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

7.1887E-04

-8.0965E-06

2.2810E-08

-1.0405E-10

6.9340E-13

0.0000E+00

S2

8.0761E-04

-4.8456E-06

-6.3366E-08

7.4948E-10

-2.3805E-12

0.0000E+00

S3

-5.5602E-05

3.5220E-07

1.5178E-09

8.5788E-13

-8.6035E-14

1.8406E-16

-4.7853E-19

S4

6.4932E-05

-9.9452E-07

4.1768E-09

1.8976E-11

-1.2244E-13

-8.3001E-17

2.8642E-19

S5

1.3168E-04

-4.9811E-07

-4.0984E-09

3.9677E-11

-1.0141E-13

0.0000E+00

S6

1.1599E-04

-1.2676E-06

1.7357E-08

-1.0926E-10

2.3960E-13

0.0000E+00

TABLE 2

Fig. 2A shows an on-axis chromatic aberration curve of the optical lens of embodiment 1, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 2B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 1. Fig. 2C shows a distortion curve of the optical lens of embodiment 1, which represents distortion magnitude values corresponding to different image heights. Fig. 2D shows a relative illuminance curve of the optical lens of embodiment 1, which represents relative illuminance magnitude values corresponding to different image heights. As can be seen from fig. 2A to 2D, the optical lens system of embodiment 1 can achieve good image quality.

Example 2

An optical lens according to embodiment 2 of the present application is described below with reference to fig. 3 to 4D. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity. Fig. 3 shows a schematic structural diagram of an optical lens according to embodiment 2 of the present application.

As shown in fig. 3, the optical lens assembly includes, in order from an image forming side to an image source side: the lens comprises a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6 and an image source surface S13.

The first lens element E1 has positive power, and has a concave near-image side surface S1 and a convex near-image source side surface S2. The second lens element E2 has negative power, and its near image-side surface S3 is convex and its near image-source side surface S4 is concave. The third lens element E3 has positive power, and has a convex near-image side surface S5 and a convex near-image source side surface S6. The fourth lens element E4 has positive power, and has a convex near-image side surface S7 and a convex near-image source side surface S8. The fifth lens element E5 has negative power, and its near image side S9 is concave and its near image source side S10 is concave. The filter E6 has a near image side S11 and a near image source side S12. The light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected onto a target object (not shown) in space. For example, when the optical lens is mounted on a wearing device such as a VR, light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected into the EYE of the wearer.

In this example, the total effective focal length f of the optical lens is 13.47mm, the total length TTL of the optical lens is 30.01mm, the half ImgH of the diagonal length of the image source surface S13 of the optical lens is 6.45mm, the maximum field angle FOV of the optical lens is 53.93 °, and the aperture value Fno of the optical lens is 1.49.

Table 3 shows a basic parameter table of the optical lens of embodiment 2, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 4 shows high-order term coefficients that can be used for each aspherical mirror surface in example 2, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 3

Flour mark

A4

A6

A8

A10

A12

A14

A16

A18

A20

S1

1.0084E-03

-3.3118E-05

1.1013E-06

-2.8982E-08

5.2500E-10

-6.3373E-12

4.7417E-14

-1.9517E-16

3.3566E-19

S2

1.1941E-03

-3.4090E-05

9.4888E-07

-1.9955E-08

2.8855E-10

-2.9764E-12

2.0969E-14

-8.7866E-17

1.6163E-19

S3

4.9173E-05

-4.3338E-06

9.9702E-08

-1.1683E-09

7.8204E-12

-2.7743E-14

3.9494E-17

0.0000E+00

S4

1.2812E-04

-4.0647E-06

6.9005E-08

-7.3436E-10

4.9277E-12

-1.8195E-14

2.7059E-17

0.0000E+00

S5

8.5081E-05

3.6862E-07

-1.1458E-08

7.6426E-11

-1.7391E-13

0.0000E+00

S6

7.8008E-05

-5.7375E-07

8.6186E-09

-4.6068E-11

8.0777E-14

0.0000E+00

TABLE 4

Fig. 4A shows an on-axis chromatic aberration curve of the optical lens of embodiment 2, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 4B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 2. Fig. 4C shows a distortion curve of the optical lens of embodiment 2, which represents distortion magnitude values corresponding to different image heights. Fig. 4D shows a relative illuminance curve of the optical lens of embodiment 2, which represents relative illuminance magnitude values corresponding to different image heights. As can be seen from fig. 4A to 4D, the optical lens system of embodiment 2 can achieve good imaging quality.

Example 3

An optical lens according to embodiment 3 of the present application is described below with reference to fig. 5 to 6D. Fig. 5 shows a schematic structural diagram of an optical lens according to embodiment 3 of the present application.

As shown in fig. 5, the optical lens assembly includes, in order from an image forming side to an image source side: the lens comprises a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6 and an image source surface S13.

The first lens element E1 has positive power, and has a convex near-image side surface S1 and a convex near-image source side surface S2. The second lens E2 has negative power and has a concave near-image side S3 and a concave near-image source side S4. The third lens element E3 has positive power, and has a convex near-image side surface S5 and a convex near-image source side surface S6. The fourth lens element E4 has positive power, and has a convex near-image side surface S7 and a concave near-image source side surface S8. The fifth lens element E5 has negative power, and its near image side S9 is concave and its near image source side S10 is concave. The filter E6 has a near image side S11 and a near image source side S12. The light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected onto a target object (not shown) in space. For example, when the optical lens is mounted on a wearing device such as a VR, light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected into the EYE of the wearer.

In this example, the total effective focal length f of the optical lens is 13.50mm, the total length TTL of the optical lens is 29.14mm, the half ImgH of the diagonal length of the image source surface S13 of the optical lens is 6.45mm, the maximum field angle FOV of the optical lens is 53.86 °, and the aperture value Fno of the optical lens is 1.69.

Table 5 shows a basic parameter table of the optical lens of example 3, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 6 shows high-order term coefficients that can be used for each aspherical mirror surface in example 3, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 5

Flour mark

A4

A6

A8

A10

A12

A14

A16

S1

-1.4558E-05

-2.7828E-07

-1.8944E-09

3.1374E-12

0.0000E+00

S2

3.0056E-04

-3.0620E-06

6.4991E-09

1.0007E-11

0.0000E+00

S3

4.9264E-04

-6.5319E-06

6.4194E-08

-4.1978E-10

1.1855E-12

0.0000E+00

S4

-2.3249E-04

5.8870E-06

-1.2820E-07

1.3805E-09

-7.9078E-12

1.8966E-14

0.0000E+00

S5

-9.4376E-05

7.0520E-06

-1.3848E-07

9.2789E-10

6.3445E-14

-2.3552E-14

6.7796E-17

S6

1.9409E-04

2.7705E-06

-6.0457E-08

3.4626E-10

1.5067E-12

-1.8488E-14

4.0822E-17

S9

2.0585E-03

-8.1362E-05

1.2836E-06

-3.0931E-09

-1.7213E-10

2.1723E-12

-8.1134E-15

S10

2.2295E-03

-6.7113E-05

-1.0317E-06

9.4296E-08

-2.1830E-09

2.2898E-11

-9.2557E-14

TABLE 6

Fig. 6A shows an on-axis chromatic aberration curve of the optical lens of embodiment 3, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 6B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 3. Fig. 6C shows a distortion curve of the optical lens of embodiment 3, which represents distortion magnitude values corresponding to different image heights. Fig. 6D shows a relative illuminance curve of the optical lens of embodiment 3, which represents relative illuminance magnitude values corresponding to different image heights. As can be seen from fig. 6A to 6D, the optical lens system of embodiment 3 can achieve good imaging quality.

Example 4

An optical lens according to embodiment 4 of the present application is described below with reference to fig. 7 to 8D. Fig. 7 shows a schematic structural diagram of an optical lens according to embodiment 4 of the present application.

As shown in fig. 7, the optical lens system sequentially includes from the image forming side to the image source side: the lens comprises a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6 and an image source surface S13.

The first lens element E1 has positive power, and has a convex near-image side surface S1 and a convex near-image source side surface S2. The second lens E2 has negative power and has a concave near-image side S3 and a concave near-image source side S4. The third lens element E3 has positive power, and has a convex near-image side surface S5 and a convex near-image source side surface S6. The fourth lens element E4 has positive power, and has a convex near-image side surface S7 and a concave near-image source side surface S8. The fifth lens element E5 has positive power, and its near image side S9 is convex and its near image source side S10 is concave. The filter E6 has a near image side S11 and a near image source side S12. The light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected onto a target object (not shown) in space. For example, when the optical lens is mounted on a wearing device such as a VR, light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected into the EYE of the wearer.

In this example, the total effective focal length f of the optical lens is 14.82mm, the total length TTL of the optical lens is 34.73mm, the half ImgH of the diagonal length of the image source surface S13 of the optical lens is 7.52mm, the maximum field angle FOV of the optical lens is 57.14 °, and the aperture value Fno of the optical lens is 1.65.

Table 7 shows a basic parameter table of the optical lens of example 4, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 8 shows high-order term coefficients that can be used for each aspherical mirror surface in example 4, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 7

Flour mark	A4	A6
			S1	0.0000E+00	0.0000E+00
S2	3.3596E-05	0.0000E+00
			S3	2.8772E-05	7.9498E-09
S4	1.7139E-06	-2.1691E-08
			S5	1.0516E-06	0.0000E+00
S6	-6.6952E-06	0.0000E+00

TABLE 8

Fig. 8A shows an on-axis chromatic aberration curve of the optical lens of embodiment 4, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 8B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of embodiment 4. Fig. 8C shows a distortion curve of the optical lens of embodiment 4, which represents distortion magnitude values corresponding to different image heights. Fig. 8D shows a relative illuminance curve of the optical lens of example 4, which represents relative illuminance magnitude values corresponding to different image heights. As can be seen from fig. 8A to 8D, the optical lens system of embodiment 4 can achieve good imaging quality.

Example 5

An optical lens according to embodiment 5 of the present application is described below with reference to fig. 9 to 10D. Fig. 9 shows a schematic structural diagram of an optical lens according to embodiment 5 of the present application.

As shown in fig. 9, the optical lens system sequentially includes, from an image forming side to an image source side: the lens comprises a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6 and an image source surface S13.

The first lens element E1 has positive power, and has a convex near-image side surface S1 and a convex near-image source side surface S2. The second lens E2 has negative power and has a concave near-image side S3 and a concave near-image source side S4. The third lens element E3 has positive power, and has a convex near-image side surface S5 and a convex near-image source side surface S6. The fourth lens element E4 has positive power, and has a convex near-image side surface S7 and a concave near-image source side surface S8. The fifth lens element E5 has negative power, and its near image side S9 is convex and its near image source side S10 is concave. The filter E6 has a near image side S11 and a near image source side S12. The light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected onto a target object (not shown) in space. For example, when the optical lens is mounted on a wearing device such as a VR, light from the image source surface S13 passes through the respective surfaces S12 to S1 in order and is finally projected into the EYE of the wearer.

In this example, the total effective focal length f of the optical lens is 13.57mm, the total length TTL of the optical lens is 32.25mm, the half ImgH of the diagonal length of the image source surface S13 of the optical lens is 8.87mm, the maximum field angle FOV of the optical lens is 58.34 °, and the aperture value Fno of the optical lens is 1.51.

Table 9 shows a basic parameter table of the optical lens of example 5, in which the units of the radius of curvature, the thickness/distance, and the focal length are all millimeters (mm). Table 10 shows high-order term coefficients that can be used for each aspherical mirror surface in example 5, wherein each aspherical mirror surface type can be defined by formula (1) given in example 1 above.

TABLE 9

Watch 10

Fig. 10A shows an on-axis chromatic aberration curve of the optical lens of embodiment 5, which represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 10B shows astigmatism curves representing meridional field curvature and sagittal field curvature of the optical lens of example 5. Fig. 10C shows a distortion curve of the optical lens of embodiment 5, which represents distortion magnitude values corresponding to different image heights. Fig. 10D shows a relative illuminance curve of the optical lens of example 5, which represents relative illuminance magnitude values corresponding to different image heights. As can be seen from fig. 10A to 10D, the optical lens system of embodiment 5 can achieve good imaging quality.

In summary, examples 1 to 5 satisfy the relationships shown in table 11, respectively.

TABLE 11

The present application further provides a projection device, wherein the electronic photosensitive element can be a photosensitive coupling element (CCD) or a Complementary Metal Oxide Semiconductor (CMOS). The projection means may be a separate projection device, such as a projector, or may be a projection module integrated on a mobile electronic device, such as a VR. The projection device is equipped with the optical lens described above.

The foregoing description is only exemplary of the preferred embodiments of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. An optical lens, comprising, in order from a human eye side to an image source side along an optical axis:

the first lens with focal power, the side near the image source of the first lens is convex;

the side surface of the second lens close to the image source is a concave surface;

the third lens with positive focal power has a convex side surface close to an image source;

a fourth lens having a focal power, a near-imaging side of which is convex;

the fifth lens with focal power has a concave surface on the side close to the image source;

the optical lens satisfies: 0.3 < (CT4+ T45+ CT5)/Tr1R6 < 0.7 and-1.3 < R6/f < -0.9, wherein Tr1R6 is a distance on the optical axis from a near-image-source-side surface of the first lens to a near-image-source-side surface of the third lens, CT4 is a center thickness of the fourth lens, T45 is a distance on the optical axis from a near-image-source-side surface of the fourth lens to a near-image-side surface of the fifth lens, CT5 is a center thickness of the fifth lens, R6 is a radius of curvature of a near-image-source-side surface of the third lens, and f is a total effective focal length of the optical lens.

2. An optical lens according to claim 1, characterized in that the optical lens satisfies: ET3/ET2 < 0.5, wherein ET3 is the edge thickness of the third lens at the maximum effective radius, and ET2 is the edge thickness of the second lens at the maximum effective radius.

3. An optical lens according to claim 1, characterized in that the optical lens satisfies: 1.2 < (CT4+ CT5)/(ET4+ ET5) < 2.0, wherein ET4 is the edge thickness of the fourth lens at the maximum effective radius and ET5 is the edge thickness of the fifth lens at the maximum effective radius.

4. An optical lens according to claim 1, characterized in that the optical lens satisfies: 1 < DT32/DT41 < 1.5, wherein DT32 is the maximum effective radius of the near-image source side of the third lens and DT41 is the maximum effective radius of the near-image side of the fourth lens.

5. An optical lens according to claim 1, characterized in that the optical lens satisfies: 0.8 < DT12/DT21 < 1.1, wherein DT12 is the maximum effective radius of the near-image source side of the first lens and DT21 is the maximum effective radius of the near-image side of the second lens.

6. An optical lens according to claim 1, characterized in that the optical lens satisfies: -1.1 < SAG32/SAG41 < -0.7, wherein SAG32 is the distance on the optical axis from the intersection of the near-image source side of the third lens and the optical axis to the effective radius vertex of the near-image source side of the third lens, and SAG41 is the distance on the optical axis from the intersection of the near-imaging side of the fourth lens and the optical axis to the effective radius vertex of the near-imaging side of the fourth lens.

7. An optical lens according to claim 1, characterized in that the optical lens satisfies: 0.6 < (DT32-DT41)/(DT41-DT52) < 1.3, wherein DT32 is the maximum effective radius of the near-image source side of the third lens, DT41 is the maximum effective radius of the near-image source side of the fourth lens, and DT52 is the maximum effective radius of the near-image source side of the fifth lens.

8. An optical lens according to claim 1, characterized in that the optical lens satisfies: 2 < | SAG21/CT2| + | SAG22/CT2| < 5.5, wherein SAG21 is a distance on the optical axis from an intersection point of a near imaging side surface of the second lens and the optical axis to an effective radius vertex of the near imaging side surface of the second lens, SAG22 is a distance on the optical axis from an intersection point of a near image source side surface of the second lens and the optical axis to an effective radius vertex of the near image source side surface of the second lens, and CT2 is a center thickness of the second lens on the optical axis.

9. An optical lens according to claim 1, characterized in that the optical lens satisfies: 0.6 < (T12+ T23)/. SIGMA AT < 1, wherein T12 is a distance on the optical axis from a near-image source side surface of the first lens to a near-image side surface of the second lens, T23 is a distance on the optical axis from a near-image source side surface of the second lens to a near-image side surface of the third lens, and SIGMA AT is a sum of air intervals on the optical axis between any adjacent two lenses of the first lens to the fifth lens.

10. An optical lens, comprising, in order from a human eye side to an image source side along an optical axis:

a first lens group having positive refractive power, including a first lens, a second lens, and a third lens having refractive power;

a second lens group having a focal power, including a fourth lens having a positive focal power and a fifth lens having a focal power;

the focal power of the first lens

And the power of the second lens

Satisfies the following conditions:

the near imaging side surface of at least one of the first lens, the second lens and the third lens is a convex surface, and the near image source side surface is a convex surface;

the side surface of the fifth lens close to the image source is a concave surface; and

the optical lens satisfies: f × tan (FOV/4) > 6mm, where f is the total effective focal length of the optical lens and FOV is the maximum field angle of the optical lens.