CN117872569A

CN117872569A - Optical lens

Info

Publication number: CN117872569A
Application number: CN202410286159.8A
Authority: CN
Inventors: 肖国亮; 章彬炜
Original assignee: Jiangxi Lianyi Optics Co Ltd
Current assignee: Jiangxi Lianyi Optics Co Ltd
Priority date: 2024-03-13
Filing date: 2024-03-13
Publication date: 2024-04-12

Abstract

The invention discloses an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a first lens having negative optical power, the image side surface of which is concave; a diaphragm; a second lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface; wherein the maximum field angle FOV of the optics and the entrance pupil diameter EPD of the optical lens satisfy: 180 DEG/mm < FOV/EPD < 220 DEG/mm. According to the optical lens provided by the invention, three lenses with specific focal power are adopted, and the specific focal power combination and the surface type collocation are used, so that the optical lens has the advantages of large aperture, large field of view, small distortion, miniaturization and high pixel, and can meet the shooting requirement and development trend of a TOF lens.

Description

Optical lens

Technical Field

The invention relates to the technical field of imaging lenses, in particular to an optical lens.

Background

With the development of mobile phone photographing technology, the requirements on mobile phone lenses are also increasing. In recent years, many different types of lenses such as a wide-angle lens, a telephoto lens, a periscopic telephoto lens, a 3D lens, a portrait lens, a TOF lens and the like are appeared on the market, and the choices of people are greatly enriched. The TOF lens is an imaging technology for obtaining a stereoscopic 3D model by calculating the time difference between infrared light emitted from the infrared light emitting device and reflected back to the camera and collecting the data to form a group of distance depth data. However, the TOF lens industry is not full at present, and there is a great room for optimization and improvement.

Disclosure of Invention

The invention aims to provide an optical lens, which has at least the advantages of large aperture, large field of view, miniaturization and high pixel.

To this end, the present invention discloses an optical lens comprising, in order from an object side to an imaging surface along an optical axis: a first lens having negative optical power, the image side surface of which is concave; a diaphragm; a second lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface; wherein the maximum field angle FOV of the optics and the entrance pupil diameter EPD of the optical lens satisfy: 180 DEG/mm < FOV/EPD < 220 DEG/mm.

Compared with the prior art, the optical lens provided by the invention has the advantages of large aperture, large field of view, small distortion, miniaturization and high pixel by adopting three lenses with specific focal power and using specific focal power combination and surface type collocation, and can meet the shooting requirement and development trend of the TOF lens.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic structural diagram of an optical lens according to a first embodiment of the present invention.

Fig. 2 is a graph showing a field curvature of an optical lens according to a first embodiment of the present invention.

Fig. 3 is a distortion graph of an optical lens according to a first embodiment of the present invention.

Fig. 4 is an axial chromatic aberration diagram of an optical lens according to a first embodiment of the present invention.

Fig. 5 is a vertical axis chromatic aberration diagram of an optical lens according to a first embodiment of the present invention.

Fig. 6 is a schematic structural diagram of an optical lens according to a second embodiment of the present invention.

Fig. 7 is a field curvature chart of an optical lens according to a second embodiment of the present invention.

Fig. 8 is a distortion graph of an optical lens according to a second embodiment of the present invention.

Fig. 9 is an axial chromatic aberration diagram of an optical lens according to a second embodiment of the present invention.

Fig. 10 is a vertical axis chromatic aberration diagram of an optical lens according to a second embodiment of the present invention.

Fig. 11 is a schematic structural diagram of an optical lens according to a third embodiment of the present invention.

Fig. 12 is a field curve diagram of an optical lens according to a third embodiment of the present invention.

Fig. 13 is a distortion graph of an optical lens according to a third embodiment of the present invention.

Fig. 14 is an axial chromatic aberration diagram of an optical lens according to a third embodiment of the present invention.

Fig. 15 is a vertical axis chromatic aberration diagram of an optical lens according to a third embodiment of the present invention.

Fig. 16 is a schematic structural view of an optical lens according to a fourth embodiment of the present invention.

Fig. 17 is a field curvature graph of an optical lens according to a fourth embodiment of the present invention.

Fig. 18 is a distortion graph of an optical lens according to a fourth embodiment of the present invention.

Fig. 19 is an axial chromatic aberration diagram of an optical lens according to a fourth embodiment of the present invention.

Fig. 20 is a vertical axis chromatic aberration diagram of an optical lens according to a fourth embodiment of the present invention.

Detailed Description

In order that the objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Several embodiments of the invention are presented in the figures. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Like reference numerals refer to like elements throughout the specification.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present invention.

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

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

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

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 invention provides an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: the optical centers of the first lens, the diaphragm, the second lens, the third lens and the optical filter are positioned on the same straight line.

The first lens has negative focal power, the object side surface of the first lens is a convex surface or a concave surface at a paraxial region, and the image side surface of the first lens is a concave surface; the second lens has positive focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the third lens has positive focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface.

In some embodiments, the incidence angle CRA of the maximum field angle chief ray of the optical lens on the image plane satisfies: CRA < 10 deg.. The light-sensitive area of the chip can be well matched with the incident angle of the chief ray of the chip by the CRA of the optical lens, thereby being beneficial to improving the light efficiency received by the light-sensitive area of the chip and achieving the best imaging effect.

In some implementations, the maximum field angle FOV of the optical lens satisfies: the FOV is less than 100 DEG and less than 140 deg. The wide-angle characteristic can be realized by meeting the range, so that more scene information can be acquired, and the requirement of large-range detection is met.

In some embodiments, the maximum field angle FOV of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 180 DEG/mm < FOV/EPD < 220 DEG/mm. The above range is satisfied, which is advantageous to expand the angle of view of the optical lens and increase the aperture of the optical lens, realizing the characteristics of wide angle and large aperture. The realization of the wide-angle characteristic is favorable for the optical lens to acquire more scene information, meets the requirement of large-range detection, and is favorable for improving the problem of rapid decrease of the relative brightness of the edge view field caused by the wide angle, thereby being favorable for acquiring more scene information.

In some embodiments, the optical total length TTL of the optical lens and the effective focal length f of the optical lens satisfy: TTL/f is less than 4.5 and less than 5.5. The ratio of the total length of the optical lens to the focal length can be reasonably set to meet the range, which is favorable for controlling the total length and the volume of the optical lens and realizing the miniaturization of the optical lens.

In some embodiments, the effective focal length f of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: f/EPD < 1.0. The range is met, the optical lens can be guaranteed to have a large aperture characteristic, the optical lens is facilitated to obtain enough luminous flux, the imaging surface is guaranteed to have higher illumination, and further the optical lens is guaranteed to have good imaging quality in a darker environment, so that shooting requirements of the TOF lens can be met.

In some embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.0 < f1/f < -1.0; the radius of curvature R11 of the object side surface of the first lens and the radius of curvature R12 of the image side surface of the first lens satisfy: -1.0 < (R11+R12)/(R11-R12) < 2.0. The optical lens has the advantages that the focal length and the surface shape of the first lens can be reasonably controlled, the change of the refraction angle of incident light rays is mild, excessive aberration caused by excessively strong refraction change is avoided, more light rays enter the rear lens, the relative illuminance of the optical lens is improved, the field angle of the optical lens is increased, and the balance of a large field angle and high pixels is realized.

In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: f2/f is more than 1.5 and less than 2.5; the radius of curvature R21 of the object side surface of the second lens and the radius of curvature R22 of the image side surface of the second lens satisfy: -2.0 < R21/R22 < -1.0. The optical lens has the advantages that the range is met, the focal length and the surface shape of the second lens can be reasonably controlled, smooth transition of light rays is facilitated, meanwhile, aberration generated by excessive deflection of the light rays through the first lens can be corrected, and the imaging quality of the optical lens is improved.

In some embodiments, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f of the optical lens satisfy: 3.5 < (f2+f3)/f < 4.5. The optical lens has the advantages that the range is met, the optical power of the second lens and the optical power of the third lens are reasonably configured, so that the coma correction of the off-axis visual field is enhanced, and meanwhile, the curvature and the aberration are well converged, and the optical lens has higher resolving power.

In some embodiments, the optical aperture DM1 of the first lens and the optical aperture DM3 of the third lens satisfy: DM1/DM3 is more than 0.8 and less than 1.2. The optical aperture ratio of the first lens and the third lens can be reasonably controlled to meet the range, and the miniaturization of the optical lens is facilitated to be maintained.

In some embodiments, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the air spacing AT12 between the first lens and the second lens on the optical axis satisfy: 0.4 < (CT1+AT12)/CT 2 < 0.8. The thickness of the first lens and the second lens and the distance between the first lens and the second lens can be reasonably adjusted to meet the range, miniaturization of the optical lens is facilitated to be maintained, smooth transition of light is facilitated, correction difficulty of aberration and distortion is reduced, and imaging quality of the optical lens is improved.

In some embodiments, the radius of curvature R31 of the object side surface of the third lens, the radius of curvature R32 of the image side surface of the third lens, and the center thickness CT3 of the third lens satisfy: -1.0 < (R31-CT 3)/R32 < 0. The shape of the third lens can be reasonably controlled to be beneficial to correcting spherical aberration, field curvature, distortion and the like of the optical lens so as to enable imaging of the optical lens to be clearer, and the center thickness of the third lens can be properly restrained so as to enable the third lens to be easy to process and assemble.

In some embodiments, the center thickness CT1 of the first lens, the edge thickness ET1 of the first lens, the center thickness CT2 of the second lens, the edge thickness ET2 of the second lens, the center thickness CT3 of the third lens, and the edge thickness ET3 of the third lens satisfy: 1.2 < (CT1+CT2+CT3)/(ET 1+ET2+ET 3) < 1.8. The lens has the advantages that the shapes of the first lens, the second lens and the third lens can be reasonably controlled, lens processing is facilitated, cost and processing sensitivity of the optical lens are reduced, meanwhile, convergence curvature and aberration of the optical lens can be well reduced, distortion of the optical lens is reduced, imaging quality of the optical lens is improved, and competitiveness of the optical lens in the market is enhanced.

In some embodiments, the optical back focal length BFL of the optical lens and the optical total length TTL of the optical lens satisfy: BFL/TTL is more than 0.2 and less than 0.35. The ratio of the optical back focus to the total optical length of the optical lens can be reasonably adjusted to meet the range, so that the miniaturization of the optical lens is maintained, and meanwhile, the matching of the optical lens and the chip module is ensured.

In some embodiments, the sagittal height SAG21 of the object side of the second lens and the sagittal height SAG22 of the image side of the second lens satisfy: 0 < SAG21/SAG22 < 0.25. The range is satisfied, the surface type of the second lens can be reasonably adjusted, the ghost image energy level of the object surface of the second lens reflected by the image side surface of the second lens can be reduced, and the imaging quality of the optical lens is improved.

In some embodiments, at least one of the object-side or image-side surfaces of each lens is aspheric, i.e., the object of the first lens

At least one of the side surfaces to the image side surface of the third lens is aspheric. The aspherical lens is characterized in that: from the center of the lens to the periphery of the lens

Side, curvature is continuously variable, unlike a spherical lens which has a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens

The lens has better curvature radius characteristic and has the advantages of improving distortion aberration and astigmatism aberration. After the aspheric lens is adopted, the lens is arranged,

aberrations occurring at the time of imaging can be eliminated as much as possible, thereby improving imaging quality. Preferably, the first lens, the second lens

The lens and the third lens are plastic aspherical lenses. The application optimizes the aspheric lens by reasonably distributing the focal power of each lens

The surface shape can realize the characteristics of large field angle, large aperture, small distortion, small volume and high pixel.

The invention is further illustrated in the following examples. In various embodiments, the thickness, radius of curvature, and material selection portion of each lens in the optical lens may vary, and for specific differences, reference may be made to the parameter tables of the various embodiments. The following examples are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and any other changes, substitutions, combinations or simplifications that do not depart from the gist of the present invention are intended to be equivalent substitutes within the scope of the present invention.

In various embodiments of the present invention, the aspherical profile of each lens satisfies the following equation:

；

where z is the distance sagittal height from the aspherical surface vertex when the aspherical surface is at a position of height h in the optical axis direction, c is the paraxial curvature of the surface, k is the quadric coefficient, A _2i The aspherical surface profile coefficient of the 2 i-th order.

First embodiment

Referring to fig. 1, a schematic structural diagram of an optical lens 100 according to a first embodiment of the present invention is shown, where the optical lens 100 includes, in order from an object side to an imaging surface S9 along an optical axis: a first lens L1, a stop ST, a second lens L2, a third lens L3, and a filter G1.

The first lens element L1 is a plastic aspheric lens with negative refractive power, wherein an object-side surface S1 of the first lens element is concave at a paraxial region, and an image-side surface S2 of the first lens element is concave; the second lens element L2 is a plastic aspheric lens with positive refractive power, wherein an object-side surface S3 of the second lens element is a convex surface, and an image-side surface S4 of the second lens element is a convex surface; the third lens element L3 is a plastic aspheric lens with positive refractive power, wherein an object-side surface S5 of the third lens element is a convex surface, and an image-side surface S6 of the third lens element is a convex surface; the object side surface of the filter G1 is S7, and the image side surface is S8.

The relevant parameters of each lens in the optical lens 100 provided in this embodiment are shown in table 1.

TABLE 1

The aspherical surface coefficients of the optical lens 100 in this embodiment are shown in table 2.

TABLE 2

In the present embodiment, graphs of curvature of field, distortion, axial chromatic aberration, and vertical chromatic aberration of the optical lens 100 are shown in fig. 2, 3, 4, and 5, respectively.

In fig. 2, a field Qu Quxian indicates a field curvature of different image heights in a meridian direction and a sagittal direction at an image plane, and an abscissa indicates an offset (unit: mm) and an ordinate indicates a half field angle (unit: °). As can be seen from fig. 2, the curvature of field offset in the meridian direction and the sagittal direction at the image plane are controlled within ±0.1mm, which indicates that the curvature of field of the optical lens 100 is well corrected.

In fig. 3, the optical distortion curve represents distortion corresponding to different image heights on an image plane, the abscissa represents the magnitude of distortion (unit:%) and the ordinate represents the half field angle (unit: °). As can be seen from fig. 3, the distortion of the optical lens is controlled within ±4.0% in the full field of view, which means that the distortion of the optical lens 100 is well corrected.

The axial chromatic aberration curve in fig. 4 represents aberration on the optical axis at the imaging plane, and the abscissa in the figure represents the amount of shift (unit: mm), and the ordinate represents the normalized pupil radius. As can be seen from fig. 4, the axial chromatic aberration of the shortest wavelength and the maximum wavelength is controlled within ±0.03mm, which indicates that the axial chromatic aberration of the optical lens 100 is well corrected.

The vertical axis color difference curve in fig. 5 shows the color difference of each wavelength at different image heights on the image plane, and the abscissa in the figure shows the offset (unit: μm) and the ordinate shows the normalized angle of view. As can be seen from fig. 5, the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1 μm, which means that the optical lens 100 can excellently correct chromatic aberration of the fringe field of view and the secondary spectrum of the entire image plane.

Second embodiment

Referring to fig. 6, a schematic diagram of an optical lens 200 according to a second embodiment of the present invention is shown, and the optical lens 200 in the present embodiment is substantially the same as the optical lens 100 in the first embodiment in structure, and the main differences are that: parameters such as radius of curvature and thickness of each lens are different.

Specifically, the relevant parameters of each lens in the optical lens 200 provided in this embodiment are shown in table 3.

TABLE 3 Table 3

The aspherical surface coefficients of the optical lens 200 in this embodiment are shown in table 4.

TABLE 4 Table 4

In the present embodiment, graphs of curvature of field, distortion, axial chromatic aberration, and vertical chromatic aberration of the optical lens 200 are shown in fig. 7, 8, 9, and 10, respectively. As can be seen from fig. 7 to 10, the curvature of field is controlled within ±0.1mm, the distortion is controlled within ±4%, the axial chromatic aberration is controlled within ±0.02mm, and the vertical chromatic aberration of each wavelength with respect to the center wavelength in different fields of view is controlled within ±1 μm, indicating that the curvature of field, distortion and chromatic aberration of the optical lens 200 are well corrected.

Third embodiment

Referring to fig. 11, a schematic diagram of an optical lens 300 according to a third embodiment of the present invention is shown, and the structure of the optical lens 300 in the present embodiment is substantially the same as that of the optical lens 100 in the first embodiment, and the main differences are that: the object side surface of the first lens is a convex surface, and parameters such as curvature radius, thickness and the like of each lens are different.

Specifically, the relevant parameters of each lens in the optical lens 300 provided in this embodiment are shown in table 5.

TABLE 5

The aspherical surface coefficients of the optical lens 300 in this embodiment are shown in table 6.

TABLE 6

In the present embodiment, graphs of curvature of field, distortion, axial chromatic aberration, and vertical chromatic aberration of the optical lens 300 are shown in fig. 12, 13, 14, and 15, respectively. As can be seen from fig. 12 to 15, the curvature of field is controlled within ±0.1mm, the distortion is controlled within ±2%, the axial chromatic aberration is controlled within ±0.025mm, and the vertical chromatic aberration of each wavelength with respect to the center wavelength in different fields of view is controlled within ±1 μm, indicating that the curvature of field, distortion and chromatic aberration of the optical lens 300 are well corrected.

Fourth embodiment

Referring to fig. 16, a schematic diagram of an optical lens 400 according to a fourth embodiment of the present invention is shown, wherein the optical lens 400 in the present embodiment has substantially the same structure as the optical lens 100 in the first embodiment, and the main differences are that: the object side surface of the first lens is a convex surface, and parameters such as curvature radius, thickness and the like of each lens are different.

Specifically, the relevant parameters of each lens in the optical lens 400 in this embodiment are shown in table 7.

TABLE 7

The aspherical surface coefficients of the optical lens 400 in this embodiment are shown in table 8.

TABLE 8

In the present embodiment, graphs of curvature of field, distortion, axial chromatic aberration, and vertical chromatic aberration of the optical lens 400 are shown in fig. 17, 18, 19, and 20, respectively. As can be seen from fig. 17 to 20, the curvature of field is controlled within ±0.1mm, the distortion is controlled within ±2%, the axial chromatic aberration is controlled within ±0.02mm, and the vertical chromatic aberration of each wavelength with respect to the center wavelength in different fields of view is controlled within ±1 μm, indicating that the curvature of field, distortion and chromatic aberration of the optical lens 400 are well corrected.

Table 9 is an optical characteristic corresponding to the above four embodiments, and mainly includes an effective focal length f, an optical total length TTL, a maximum field angle FOV, an image height IH corresponding to the maximum field angle, an entrance pupil diameter EPD, and a numerical value corresponding to each of the above conditional expressions.

TABLE 9

In summary, the optical lens provided by the embodiment of the invention adopts three plastic aspherical lenses with specific focal power, and uses specific focal power combination and surface type collocation, so that the optical lens has the advantages of large aperture, large field of view, small distortion, miniaturization and high pixel, and can meet the shooting requirement and development trend of the current TOF lens.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. An optical lens comprising three lenses in order from an object side to an imaging surface along an optical axis, comprising:

a first lens having negative optical power, an image side surface of the first lens being a concave surface;

a diaphragm;

a second lens with positive focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface;

a third lens with positive focal power, wherein the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface;

wherein, the maximum field angle FOV of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 180 DEG/mm < FOV/EPD < 220 DEG/mm.

2. The optical lens of claim 1, wherein an optical total length TTL of the optical lens and an effective focal length f of the optical lens satisfy: TTL/f is less than 4.5 and less than 5.5.

3. The optical lens according to claim 1, wherein an effective focal length f of the optical lens and an entrance pupil diameter EPD of the optical lens satisfy: f/EPD < 1.0.

4. The optical lens of claim 1, wherein an effective focal length f1 of the first lens and an effective focal length f of the optical lens satisfy: -2.0 < f1/f < -1.0.

5. The optical lens of claim 1, wherein an effective focal length f2 of the second lens and an effective focal length f of the optical lens satisfy: 1.5 < f2/f < 2.5.

6. The optical lens of claim 1, wherein an effective focal length f2 of the second lens, an effective focal length f3 of the third lens, and an effective focal length f of the optical lens satisfy: 3.5 < (f2+f3)/f < 4.5.

7. The optical lens of claim 1, wherein an optical aperture DM1 of the first lens and an optical aperture DM3 of the third lens satisfy: DM1/DM3 is more than 0.8 and less than 1.2.

8. The optical lens of claim 1, wherein a center thickness CT1 of the first lens, a center thickness CT2 of the second lens, and an air space AT12 between the first lens and the second lens on an optical axis satisfy: 0.4 < (CT1+AT12)/CT 2 < 0.8.

9. The optical lens of claim 1, wherein a radius of curvature R31 of an object side surface of the third lens, a radius of curvature R32 of an image side surface of the third lens, and a center thickness CT3 of the third lens satisfy: -1.0 < (R31-CT 3)/R32 < 0.

10. The optical lens of claim 1, wherein a center thickness CT1 of the first lens, an edge thickness ET1 of the first lens, a center thickness CT2 of the second lens, an edge thickness ET2 of the second lens, a center thickness CT3 of the third lens, and an edge thickness ET3 of the third lens satisfy: 1.2 < (CT1+CT2+CT3)/(ET 1+ET2+ET 3) < 1.8.