CN116224542A

CN116224542A - Optical lens

Info

Publication number: CN116224542A
Application number: CN202310053037.XA
Authority: CN
Inventors: 章彬炜; 谢先国; 曾昊杰
Original assignee: Jiangxi Lianyi Optics Co Ltd
Current assignee: Jiangxi Lianyi Optics Co Ltd
Priority date: 2023-02-03
Filing date: 2023-02-03
Publication date: 2023-06-06

Abstract

The invention discloses an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm; the first lens with positive focal power has a convex object side surface and a concave image side surface; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a third lens having positive optical power; a fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a fifth lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a sixth lens with negative focal power, the object side surface of which is a concave surface; a seventh lens having negative optical power, the object-side surface of which is concave at a paraxial region; wherein, at least one plastic lens and one glass lens are contained in the optical lens. The optical lens adopts glass-plastic mixed lens collocation, and the lens has the advantages of long focal length, large aperture, large target surface imaging and high pixel through specific surface collocation and focal power combination.

Description

Optical lens

Technical Field

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

Background

With the continuous upgrading and updating of smart phones, consumers have higher and higher requirements on the shooting function of the mobile phones, and ultra-high pixel, large aperture and long focus shooting become main development trend of mobile phone lenses. In order to pursue high-quality imaging, currently, all plastic lenses are mostly adopted in the main-stream mobile phone lens, and the number of lenses is increased from 5-6 lenses to 7-8 lenses for correcting the light path, but the number of plastic lenses is difficult to further increase due to the limitations of the light and thin mobile phone, the light transmittance of the plastic lenses, the assembly precision and other factors, and the all plastic lenses meet the bottleneck period. The glass lens has better light transmittance and smaller chromatic dispersion, can effectively correct chromatic aberration and shorten the total length of the system, so that the glass-plastic mixed lens combining the advantages of the glass lens and the plastic lens can effectively reduce the total length of the lens and correct the chromatic aberration of the system, and improve the light inlet quantity and imaging definition of the optical lens, is widely applied to equipment such as security monitoring, digital cameras, single-lens reflex cameras and the like, and is hopeful to be applied to high-end flagship type main shooting.

Compared with a full plastic lens, the glass-plastic mixed lens has higher light transmittance and more stable performance, can improve imaging effects under different shades, and is a development trend of future mobile phone lenses. However, how to better realize the long focal length, large aperture, high pixel and small size performance of the glass-plastic hybrid lens is still an urgent problem to be solved.

Disclosure of Invention

Therefore, the invention aims to provide an optical lens which has the advantages of long focal length, large aperture, large target surface imaging and high pixel.

The embodiment of the invention realizes the aim through the following technical scheme.

The invention provides an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm; a first lens with positive focal power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative 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 concave surface; a third lens having positive optical power; a fourth lens element with positive refractive power, wherein the object-side surface of the fourth lens element is convex, and the image-side surface of the fourth lens element is concave; a fifth lens with positive focal power, wherein an object side surface of the fifth lens is a concave surface, and an image side surface of the fifth lens is a convex surface; a sixth lens with negative focal power, wherein the object side surface of the sixth lens is a concave surface; a seventh lens having negative optical power, an object-side surface of the seventh lens being concave at a paraxial region; wherein, at least one plastic lens and one glass lens are contained in the optical lens.

Compared with the prior art, the optical lens provided by the invention adopts the glass-plastic mixed lens for matching, and through specific surface shape arrangement and reasonable focal power distribution, particularly the second lens and the sixth lens are both of negative focal power, so that the optical lens has a compact structure, has a larger aperture and higher imaging quality, and can be matched with a large target chip to realize high-definition imaging; through reasonably selecting the glass material of the first lens and adding the use of the aspheric surface, the aberration of the system can be reasonably corrected, so that the lens has high pixels, the overall length of the system is effectively shortened, and the use requirements of miniaturization, high image quality and long-focus shooting of electronic equipment are better met.

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 graph showing distortion curves of an optical lens according to a first embodiment of the present invention;

FIG. 4 is a graph showing axial chromatic aberration of an optical lens according to a first embodiment of the present invention;

FIG. 5 is a graph showing a vertical axis chromatic aberration curve of an optical lens according to a first embodiment of the present invention;

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

FIG. 7 is a graph showing a field curvature of an optical lens according to a second embodiment of the present invention;

FIG. 8 is a graph showing distortion curves of an optical lens according to a second embodiment of the present invention;

FIG. 9 is a graph showing axial chromatic aberration of an optical lens according to a second embodiment of the present invention;

FIG. 10 is a graph of a vertical axis chromatic aberration curve of an optical lens according to a second embodiment of the present invention;

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

FIG. 12 is a graph showing a field curvature of an optical lens according to a third embodiment of the present invention;

FIG. 13 is a graph showing distortion curves of an optical lens according to a third embodiment of the present invention;

FIG. 14 is a graph showing axial chromatic aberration 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.

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.

The invention provides an optical lens, which sequentially comprises from an object side to an imaging surface along an optical axis: a diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an optical filter.

The first lens has positive focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

the second lens has negative 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 concave surface;

the third lens has positive focal power;

the fourth lens has positive focal power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface;

the fifth lens has positive focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface;

the sixth lens has negative focal power, and the object side surface of the sixth lens is a concave surface;

the seventh lens has negative focal power, and the object side surface of the seventh lens is concave at a paraxial region;

wherein, at least one plastic lens and one glass lens are contained in the optical lens. Compared with a plastic lens, the glass lens has the advantages of smaller dispersion coefficient, better light transmittance, stronger stability and the like, and can greatly reduce the problems of glare, ghosting and the like, and the glass plastic lens combines the advantages of the glass lens and the plastic lens, can reduce the thickness and the distortion rate of the lens, and improves the imaging definition and the aperture size.

According to the invention, through the mixing and collocation of glass and plastic lenses and the reasonable constraint of the surface and focal power of each lens, the structure is compact, and the lens has high imaging quality and large aperture, so that the miniaturization of the lens and the reasonable balance of high pixels are better realized.

In some embodiments, the optical lens satisfies the following conditional expression:

0.6<f1/f<1.05；

27mm<(Vd1/Vd2)×f<32mm；

wherein f1 represents a focal length of the first lens, vd1 represents an abbe number of the first lens, vd2 represents an abbe number of the second lens, and f represents an effective focal length of the optical lens. The focal length ratio of the first lens is reasonably set, so that negative spherical aberration generated by the first lens (positive lens) is balanced by positive spherical aberration generated by the second lens (negative lens), meanwhile, the positive lens has low dispersion, the negative lens has high dispersion, axial chromatic aberration generated by the negative lens can be mutually offset, a better balance effect is finally achieved, and the overall imaging quality is improved.

5<f4/f<30；

0.2<R41/R42<1；

wherein f4 denotes a focal length of the fourth lens, f denotes an effective focal length of the optical lens, R41 denotes a radius of curvature of an object side surface of the fourth lens, and R42 denotes a radius of curvature of an image side surface of the fourth lens. The aberration of the system can be better corrected by reasonably setting the focal length and the surface shape of the fourth lens, long-focal-length imaging of the lens is facilitated, and the portrait shooting effect with small depth of field is better realized.

-2<f6/f<-0.5；

0.3<R61/f<3；

where f6 denotes a focal length of the sixth lens, f denotes an effective focal length of the optical lens, and R61 denotes a radius of curvature of an object side surface of the sixth lens. The above conditions are met, and the shape change of the sixth lens can be slowed down by reasonably adjusting the focal length and the shape of the sixth lens, so that the stray light is reduced, meanwhile, the aberration of the marginal view field is effectively improved, and the overall imaging quality is improved.

-20<f4/f6<-5；

where f4 denotes a focal length of the fourth lens, and f6 denotes a focal length of the sixth lens. The focal length relation of the fourth lens and the sixth lens is reasonably set, so that the aberration of the system can be balanced better, the imaging quality of the whole lens is improved, and better resolving power is obtained.

0.3<f7/f6<1；

where f6 denotes a focal length of the sixth lens, and f7 denotes a focal length of the seventh lens. The focal length ratio of the sixth lens and the seventh lens is reasonably distributed, so that the aberration of the whole system is balanced, the imaging quality is improved, meanwhile, the light trend can be reasonably controlled, and the problem of over-high lens sensitivity caused by over-large light deflection degree is avoided.

0.2<CT1/TTL<0.3；

CT1/CT2>3.5；

wherein CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, and TTL represents the total optical length of the optical lens. The first lens has proper thickness, so that the problem that the lens is cracked due to the fact that the thickness of the lens is too thin in the forming process and the lens is clamped by the equipment manipulator in the assembling process is avoided; meanwhile, the thickness difference of the first lens and the second lens is reasonably controlled, so that uneven filling of lens molding plastic materials caused by too thin thickness of the second lens is avoided, the overall imaging quality is influenced, and the production yield is improved.

1.5<TTL/IH<1.8；

1<TTL/f<1.2；

wherein TTL represents the total optical length of the optical lens, IH represents half of the diagonal length of an effective pixel area on an imaging surface of the optical lens, and f represents the effective focal length of the optical lens. The large target surface imaging of the optical lens can be realized by meeting the conditions, the pixel point size can be increased under the same pixel, and the energy receiving efficiency of the chip to the light collected by the lens can be improved, so that the imaging quality is improved; meanwhile, miniaturization of the lens and reasonable balance of long focal length can be better achieved.

1.5<f/IH<1.6；

wherein IH represents half of the diagonal length of an effective pixel area on an imaging surface of the optical lens, and f represents the effective focal length of the optical lens. The long focal length of the lens and the large target surface imaging can be balanced better by meeting the conditions, and the high-definition shooting effect of the virtual background and the prominent main body can be realized.

1.5<f/EPD<1.8；

8mm<f<9mm；

where f represents the effective focal length of the optical lens and EPD represents the entrance pupil diameter of the optical lens. The above conditions are met, which shows that the optical lens has the characteristic of a large aperture, the luminous flux entering the lens is increased to a certain extent while the lens has a longer focal length, and the influence of noise generated when light is insufficient on an imaging picture is reduced, so that the lens still has an excellent imaging effect in a dark environment at night, and the imaging requirement of a bright and dark environment can be met.

5mm<f×tanθ<6mm；

where f represents the effective focal length of the optical lens, and θ represents the maximum half field angle of the optical lens. The lens can be well matched with a large target surface chip to realize high-definition imaging.

-12<f2/f<-1；

2<(R21+R22)/(R21-R22)<20；

wherein f2 represents a focal length of the second lens, f represents an effective focal length of the optical lens, R21 represents a radius of curvature of an object side surface of the second lens, and R22 represents a radius of curvature of an image side surface of the second lens. The focal length and the surface shape of the second negative lens are reasonably set, so that the total optical length is reduced, meanwhile, the aberration of the system is better corrected, and the imaging quality is improved.

0.5<ET6/CT6<3；

0<CT6/TTL<0.08；

wherein ET6 represents the edge thickness of the sixth lens, CT6 represents the center thickness of the sixth lens, and TTL represents the total optical length of the optical lens. The thickness ratio of the sixth lens is reasonably controlled to meet the conditions, so that the lens forming is facilitated, the production yield is improved, the total optical length of the system is shortened, and the miniaturization of the lens is realized.

-2<(R61+R62)/(R61-R62)<-0.6；

-3<(f6+f7)/f<-1；

wherein R61 represents a radius of curvature of an object side surface of the sixth lens element, R62 represents a radius of curvature of an image side surface of the sixth lens element, f6 represents a focal length of the sixth lens element, f7 represents a focal length of the seventh lens element, and f represents an effective focal length of the optical lens element, thereby effectively controlling a plane shape of the sixth lens element, effectively improving aberration of an edge field of view, and improving imaging quality.

0.06<(CT5+CT56)/TTL<0.25；

0.2<(R51-R52)/(R51+R52)<0.7；

wherein CT5 represents the center thickness of the fifth lens element, R51 represents the radius of curvature of the object-side surface of the fifth lens element, R52 represents the radius of curvature of the image-side surface of the fifth lens element, CT56 represents the air gap between the fifth lens element and the sixth lens element on the optical axis, and TTL represents the total optical length of the optical lens element. The center thickness and the surface shape of the fifth lens are effectively controlled by meeting the conditions, so that the spherical aberration of the system is effectively corrected, the image quality is improved, and the imaging quality is improved.

10<(f3+f4)/f<30；

0.1<(CT3+CT4+CT34)/TTL<0.16；

wherein f3 denotes a focal length of the third lens, f4 denotes a focal length of the fourth lens, f denotes an effective focal length of the optical lens, CT3 denotes a center thickness of the third lens, CT4 denotes a center thickness of the fourth lens, CT34 denotes an air gap between the third lens and the fourth lens on the optical axis, and TTL denotes an optical total length of the optical lens. The lens structure is compact, and the emergent light can be transmitted to the following optical system more smoothly by reasonably setting the focal lengths of the third lens and the fourth lens, so that the aberration is further improved, and the imaging quality is improved.

-8<(R41+R42)/(R41-R42)<-1；

wherein R41 represents a radius of curvature of an object side surface of the fourth lens, and R42 represents a radius of curvature of an image side surface of the fourth lens. The conditions are met, the chromatic aberration can be effectively corrected, and the imaging quality is improved.

-1.5<f5/f6<-0.1；

1.5<(R51+R52)/(R51-R52)<3；

where f5 denotes an effective focal length of the fifth lens, f6 denotes an effective focal length of the sixth lens, R51 denotes a radius of curvature of an object-side surface of the fifth lens, and R52 denotes a radius of curvature of an image-side surface of the fifth lens. The eccentric distribution of the fifth lens to the sixth lens can be realized by meeting the above conditions, which is favorable for improving the overall optimization space of the lens, thereby further improving the optical performance and realizing high-definition imaging.

As an implementation mode, the glass-plastic mixed matching structure of one glass lens and six plastic lenses is adopted, so that the lens can be better matched with a large target surface chip to realize high-definition imaging, and meanwhile, the reasonable balance of large aperture, miniaturization and long focal length of the lens can be realized. Because the first lens is made of glass aspheric surface materials, the geometrical chromatic aberration of the optical lens is effectively corrected through the characteristic of low chromatic dispersion of the glass. The first lens is a glass aspheric lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are plastic aspheric lenses, and the aspheric lenses are adopted, so that the cost can be effectively reduced, the aberration can be corrected, and an optical performance product with higher cost performance can be provided. It should be noted that other matching combinations of the glass-plastic mixed lenses can also meet the requirements, and the selection can be specifically made according to the requirements.

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, when an aspherical lens is used as the lens, the surface shape of the aspherical 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 S17 along an optical axis: stop ST, first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, and filter G1.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 of the first lens element is convex, and an image-side surface S2 of the first lens element is concave;

the second lens L2 has negative focal power, the object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a concave surface;

the third lens element L3 has positive refractive power, wherein an object-side surface S5 of the third lens element is convex, and an image-side surface S6 of the third lens element is concave at a paraxial region;

the fourth lens element L4 has positive refractive power, wherein an object-side surface S7 of the fourth lens element is convex at a paraxial region thereof, and an image-side surface S8 of the fourth lens element is concave at a paraxial region thereof;

the fifth lens element L5 has positive refractive power, wherein an object-side surface S9 of the fifth lens element is concave, and an image-side surface S10 of the fifth lens element is convex;

the sixth lens element L6 with negative focal power has a concave object-side surface S11 and a concave image-side surface S12 at a paraxial region;

the seventh lens L7 has negative focal power, the object side surface S13 of the seventh lens is a concave surface, and the image side surface S14 of the seventh lens is a convex surface;

the object side surface of the filter G1 is S15, and the image side surface is S16.

The first lens L1 is a glass aspheric lens, and the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are plastic aspheric lenses.

Specifically, the design parameters of each lens of the optical lens 100 provided in this embodiment are shown in table 1.

TABLE 1

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

TABLE 2

Referring to fig. 2, 3, 4 and 5, a field curvature curve, a distortion curve, an axial chromatic aberration curve and a vertical chromatic aberration curve of the optical lens 100 are shown. As can be seen from fig. 2, the curvature of field is controlled to be within 0.03mm, which indicates that the curvature of field of the optical lens 100 is well corrected; as can be seen from fig. 3, the distortion is controlled within ±2%, which indicates that the distortion correction of the optical lens 100 is better; as can be seen from fig. 4, the offset of the axial chromatic aberration is within ±0.035mm, which indicates that the axial chromatic aberration of the optical lens 100 is well corrected; as can be seen from fig. 5, the vertical chromatic aberration of the shortest wave and the longest wave is controlled within ±1.5μm, which indicates that the vertical chromatic aberration of the optical lens 100 is well corrected; as can be seen from fig. 2, 3, 4 and 5, the aberration of the optical lens 100 is well balanced, and has good optical imaging quality.

Second embodiment

As shown in fig. 6, a schematic structural diagram of an optical lens 200 according to the present embodiment is provided, and the optical lens 200 according to the present embodiment is substantially the same as the first embodiment described above, and is different in that an object-side surface of the third lens element is a concave surface, and an image-side surface of the third lens element is a convex surface; the seventh lens element has a concave image-side surface, and the curvature radius, aspherical surface coefficient, fifth lens element and sixth lens element are different from each other.

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

TABLE 3 Table 3

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

TABLE 4 Table 4

Referring to fig. 7, 8, 9 and 10, a field curvature curve, a distortion curve, an axial chromatic aberration curve and a vertical chromatic aberration curve of the optical lens 200 are shown. From fig. 7, it can be seen that the curvature of field is controlled within 0.05mm, which indicates that the curvature of field of the optical lens 200 is well corrected; as can be seen from fig. 8, the distortion is controlled within 2%, which indicates that the distortion correction of the optical lens 200 is good; as can be seen from fig. 9, the offset of the axial chromatic aberration is within ±0.025mm, which indicates that the axial chromatic aberration of the optical lens 200 is well corrected; as can be seen from fig. 10, the vertical chromatic aberration of the shortest wave and the longest wave is controlled within ±1.5μm, which means that the vertical chromatic aberration of the optical lens 200 is well corrected; as can be seen from fig. 7, 8, 9 and 10, the aberration of the optical lens 200 is well balanced, and has good optical imaging quality.

Third embodiment

As shown in fig. 11, a schematic structural diagram of an optical lens 300 according to the present embodiment is provided, and the optical lens 300 according to the present embodiment is substantially the same as the first embodiment described above, and is mainly different in that the image side surface of the sixth lens element is a convex surface, the image side surface of the seventh lens element is a concave surface, and the curvature radius, the aspheric coefficient, and the thickness of each lens element are different.

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

TABLE 5

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

TABLE 6

Referring to fig. 12, 13, 14 and 15, a field curvature curve, a distortion curve, an axial chromatic aberration curve and a vertical chromatic aberration curve of the optical lens 300 are shown. From fig. 12, it can be seen that the curvature of field is controlled within 0.05mm, which indicates that the curvature of field of the optical lens 300 is well corrected; as can be seen from fig. 13, the distortion is controlled to be within 1.5%, which indicates that the optical lens 300 has better distortion correction; as can be seen from fig. 14, the axial chromatic aberration is within ±0.035mm, which indicates that the axial chromatic aberration of the optical lens 300 is well corrected; as can be seen from fig. 15, the vertical chromatic aberration of the shortest wave and the longest wave is controlled within ±4μm, which means that the vertical chromatic aberration of the optical lens 300 is well corrected; as can be seen from fig. 12, 13, 14 and 15, the aberrations of the optical lens 300 are well balanced, with good optical imaging quality.

Referring to table 7, the optical characteristics of the optical lens provided in the above three embodiments, respectively, include the field angle FOV, the total optical length TTL, the actual half-image height IH, the effective focal length f, and the correlation value corresponding to each of the above conditions.

TABLE 7

Compared with the prior art, the glass-plastic mixed optical lens provided by the invention has at least the following advantages:

(1) The balance between high pixel and miniaturization can be realized. Because the glass has better light transmittance and lower dispersion coefficient, the optical lens provided by the invention adopts one glass lens and six plastic lenses, the optical quality of the optical lens is basically consistent with that of the currently mainstream 8 plastic lenses, the light transmittance and the optical performance are more excellent, and the balance of high pixels and miniaturization of the lens is realized.

(2) More layers of coating optimization can be realized. At present, a high-temperature process is mostly adopted for coating the plastic lens, and the plastic lens is more likely to deform under the process, so that the yield is lower, and the coating is usually not more than 5 layers; the glass lens has strong high temperature resistance, can realize that more layers of coating films are used for controlling reflection and dazzling light, and further improves the optical imaging quality.

(3) Large aperture performance can be achieved. Because each lens face type and focal power setting are reasonable to the diaphragm sets up before first lens, can make the camera lens have the characteristic of super large light ring, increases the luminous flux that gets into the camera lens to a certain extent, reduces the noise that produces when light is not enough and influences the image picture, makes the camera lens still have good imaging effect under dark environment night, thereby can satisfy the imaging demand of bright and dark environment.

In summary, the seven glass-plastic mixed lenses are adopted, and through specific surface shape arrangement and reasonable focal power distribution, the optical lens provided by the invention has a compact structure, a longer focal length, a larger aperture and higher imaging quality, and can be matched with a 50M high-pixel chip to realize high-definition imaging; meanwhile, through reasonably selecting the glass material of the first lens and adding the use of the aspheric surface, the aberration of the system can be reasonably corrected, so that the lens has high pixels, the overall length of the system is effectively shortened, and the use requirements of miniaturization and high image quality of electronic equipment are better met.

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 above examples merely represent a few embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the present 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 the invention should be assessed as that of the appended claims.

Claims

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

a diaphragm;

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

a second lens with negative 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 concave surface;

a third lens having positive optical power;

a fourth lens element with positive refractive power, wherein the object-side surface of the fourth lens element is convex, and the image-side surface of the fourth lens element is concave;

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

a sixth lens with negative focal power, wherein the object side surface of the sixth lens is a concave surface;

a seventh lens having negative optical power, an object-side surface of the seventh lens being concave at a paraxial region;

wherein, at least one plastic lens and one glass lens are contained in the optical lens.

2. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

0.6<f1/f<1.05；

27mm<(Vd1/Vd2)×f<32mm；

wherein f1 represents a focal length of the first lens, f represents an effective focal length of the optical lens, vd1 represents an abbe number of the first lens, and Vd2 represents an abbe number of the second lens.

3. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

5<f4/f<30；

0.2<R41/R42<1；

wherein f4 denotes a focal length of the fourth lens, f denotes an effective focal length of the optical lens, R41 denotes a radius of curvature of an object side surface of the fourth lens, and R42 denotes a radius of curvature of an image side surface of the fourth lens.

4. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-2<f6/f<-0.5；

0.3<R61/f<3；

where f6 denotes a focal length of the sixth lens, f denotes an effective focal length of the optical lens, and R61 denotes a radius of curvature of an object side surface of the sixth lens.

5. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

-20<f4/f6<-5；

where f4 denotes a focal length of the fourth lens, and f6 denotes a focal length of the sixth lens.

6. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

0.3<f7/f6<1；

where f6 denotes a focal length of the sixth lens, and f7 denotes a focal length of the seventh lens.

7. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

0.2<CT1/TTL<0.3；

CT1/CT2>3.5；

wherein CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, and TTL represents the total optical length of the optical lens.

8. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

1.5<TTL/IH<1.8；

1<TTL/f<1.2；

wherein TTL represents the total optical length of the optical lens, IH represents half of the diagonal length of an effective pixel area on an imaging surface of the optical lens, and f represents the effective focal length of the optical lens.

9. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

1.5<f/IH<1.6；

wherein IH represents half of the diagonal length of an effective pixel area on an imaging surface of the optical lens, and f represents the effective focal length of the optical lens.

10. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional expression:

1.5<f/EPD<1.8；

8mm<f<9mm；

where f represents the effective focal length of the optical lens and EPD represents the entrance pupil diameter of the optical lens.

11. The optical lens of claim 1, wherein the first lens is a glass aspheric lens, and the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are plastic aspheric lenses.