CN114637100B

CN114637100B - Optical lens

Info

Publication number: CN114637100B
Application number: CN202210546341.3A
Authority: CN
Inventors: 章彬炜; 张力瑶; 曾昊杰
Original assignee: Jiangxi Lianyi Optics Co Ltd
Current assignee: Jiangxi Lianyi Optics Co Ltd
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-10-25
Anticipated expiration: 2042-05-20
Also published as: CN114637100A

Abstract

The invention discloses an optical lens, which comprises the following components in sequence from an object side to an imaging surface along an optical axis: a diaphragm; a first lens having a positive optical power, an object side surface of the first lens being convex; a second lens having a negative optical power, an image-side surface of the second lens being concave at a paraxial region; the lens comprises a third lens with 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 concave surface; a fourth lens having a focal power, an object side surface of the fourth lens being convex; a fifth lens having a power, an object-side surface of the fifth lens being concave at a paraxial region, an image-side surface of the fifth lens being convex at a paraxial region; a sixth lens having a power, an image-side surface of the sixth lens being concave at the paraxial region. The optical lens has the advantages of large aperture and clear imaging, and has a good portrait imaging effect in a dark environment.

Description

Optical lens

Technical Field

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

Background

At present, with the rapid development of networks, more people are actively on the networks, and less people can share photos on a social platform, so that the requirements of people on camera equipment are higher and higher, people need abundant shooting modes to meet various shooting requirements of the people, the abundant shooting modes are naturally less than the human image modes, and the human image lens is generally a telephoto lens and has the characteristics of long focal length and small visual angle, so that the telephoto lens has shorter depth of field and larger magnification, and can effectively blur the background and highlight a focusing main body.

However, with the increasing requirements of people on image shooting, the Fno (Fno = effective focal length/entrance pupil diameter) of a general telephoto lens is about 3.0, when a distant object is shot, because the depth of field of the telephoto lens is too large, the focusing subject cannot be obviously reflected, the Fno is too large, the aperture is too small, and a good portrait effect cannot be presented in a dark image shooting environment.

Disclosure of Invention

Therefore, the invention aims to provide the optical lens which has the advantages of large aperture and clear imaging and has a good portrait imaging effect in a dark environment.

The embodiment of the invention implements the above object by the following technical scheme.

The invention provides an optical lens, which sequentially comprises the following components from an object side to an imaging surface along an optical axis: a diaphragm; a first lens having a positive optical power, an object side surface of the first lens being convex; a second lens having a negative optical power, an image-side surface of the second lens being concave at a paraxial region; the lens comprises a third lens with 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 concave surface; a fourth lens having a focal power, an object side surface of the fourth lens being convex; a fifth lens having a power, an object-side surface of the fifth lens being concave at a paraxial region, an image-side surface of the fifth lens being convex at a paraxial region; a sixth lens having a power, an image-side surface of the sixth lens being concave at a paraxial region; wherein, the optical lens satisfies the following conditional expression: 1.2< f/D <1.5; wherein f represents an effective focal length of the optical lens, and D represents an entrance pupil diameter of the optical lens.

Compared with the prior art, the optical lens provided by the invention adopts six aspheric lenses with specific materials and surface shapes, and the distribution of the positions and focal powers of the diaphragms is reasonable, so that the aberration is well modified, the imaging of the optical lens is clearer, the high-definition pixel requirement of the portrait lens is better met, and the user shooting experience is improved.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of 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 field curvature graph of an optical lens according to a first embodiment of the present invention;

FIG. 3 is a graph showing the f-tan θ distortion of the optical lens according to the first embodiment of the present invention;

FIG. 4 is a graph of on-axis spherical aberration curves of an optical lens according to a first embodiment of the present invention;

FIG. 5 is a lateral chromatic aberration diagram of an optical lens according to a first embodiment of the present invention;

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

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

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

FIG. 9 is a graph of on-axis spherical aberration of an optical lens according to a second embodiment of the present invention;

FIG. 10 is a lateral 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 assembly according to a third embodiment of the present invention;

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

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

FIG. 14 is a graph of on-axis spherical aberration of an optical lens according to a third embodiment of the present invention;

FIG. 15 is a lateral chromatic aberration diagram of an optical lens according to a third embodiment of the present invention;

FIG. 16 is a schematic structural diagram of an optical lens assembly 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 graph showing the f-tan θ distortion of an optical lens according to a fourth embodiment of the present invention;

FIG. 19 is a graph showing an on-axis spherical aberration of an optical lens according to a fourth embodiment of the present invention;

fig. 20 is a lateral chromatic aberration diagram of an optical lens according to a fourth embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. Several embodiments of the invention are presented in the drawings. 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 present invention provides an optical lens, sequentially including, from an object side to an image plane along an optical axis: the lens comprises a diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth 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 or a convex surface at a paraxial region;

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

the third lens has 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 concave surface;

the fourth lens has 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 or a convex surface at a paraxial region;

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

the sixth lens element has a power, an object-side surface of the sixth lens element being convex or concave at a paraxial region, and an image-side surface of the sixth lens element being concave at the paraxial region.

As an embodiment, the optical lens satisfies the following conditional expression:

1.2<f/D<1.5；（1）

wherein f represents an effective focal length of the optical lens, and D represents an entrance pupil diameter of the optical lens.

When the condition formula (1) is satisfied, the light inlet quantity of the lens can be enlarged, and the lens can have a good imaging effect in a dark environment.

3.0 mm<IH<3.5 mm；（2）

2.7<f/IH<3.4；（3）

wherein f represents an effective focal length of the optical lens, and IH represents a half-image height of the optical lens.

When the conditional expressions (2) and (3) are met, the lens can be controlled to have a longer focal length, the main body can be shot well in a protruding mode when shooting is guaranteed, the background is blurred, and portrait shooting is better carried out.

0.8<R31/R32<1.2；（4）

wherein R31 denotes a radius of curvature of an object-side surface of the third lens, and R32 denotes a radius of curvature of an image-side surface of the third lens.

When the conditional expression (4) is satisfied, the bending degree of the third lens can be effectively controlled, the thickness ratio of the lens of the third lens is uniform, the spherical aberration of the optical lens is improved, the optical performance of the lens is improved, meanwhile, the risk of ghost image generation can be effectively reduced, and the image resolving capability of the lens is improved.

1.2<(SAG51+SAG52)/SAG51<2.1；（5）

wherein SAG51 represents a sagged height of an object side effective diameter edge of the fifth lens, and SAG52 represents a sagged height of an image side effective diameter edge of the fifth lens.

When the conditional expression (5) is met, the surface type of the fifth lens can be well controlled by controlling the ratio of the height loss of the edge of the object side surface and the image side surface of the fifth lens, so that the light deflection angle of the edge is smaller, the light can be smoothly transited at the edge, the aberration of the edge field can be well corrected, and the resolving power of the lens is improved.

1<SAG31/CT3<5；（6）

wherein SAG31 represents a rise of an object side effective diameter edge of the third lens, and CT3 represents a center thickness of the third lens.

When the conditional expression (6) is satisfied, the shape of the third lens can be reasonably controlled, the lens forming requirement is satisfied, meanwhile, the lens edge aberration and the on-axis spherical aberration can be better reduced, and the imaging quality of the optical lens is improved.

1.7<f/R31<5；（7）

where f denotes an effective focal length of the optical lens, and R31 denotes a radius of curvature of an object side surface of the third lens.

When the conditional expression (7) is satisfied, the chromatic aberration of the light entering the lens can be reasonably modified, and the chromatic aberration of the light entering the lens can be well modified by reasonably controlling the curvature of the lens.

0.17<(CT4+CT5+CT6)/TTL <0.26；（8）

0.07＜CT4/TTL＜0.13；（9）

wherein CT4 denotes a center thickness of the fourth lens, CT5 denotes a center thickness of the fifth lens, CT6 denotes a center thickness of the sixth lens, and TTL denotes an optical total length of the optical lens.

When the conditional expressions (8) and (9) are satisfied, the central thicknesses of the fourth lens, the fifth lens and the sixth lens can be reasonably configured, so that the structure of the optical lens is more compact, the total length of the optical lens is favorably shortened, and the miniaturization of the lens is realized.

-4<（Φ31-Φ21）/（Φ32+Φ22）<13；(10)

where Φ 21 denotes an optical power of an object-side surface of the second lens, Φ 22 denotes an optical power of an image-side surface of the second lens, Φ 31 denotes an optical power of an object-side surface of the third lens, and Φ 32 denotes an optical power of an image-side surface of the third lens.

When conditional expression (10) is satisfied, the length of control camera lens that can be fine does benefit to structural design, and each visual field defocusing curve dispersion of control that simultaneously can be fine promotes the imaging quality of camera lens.

0.1<|f34/f3|<0.9；（11）

where f3 denotes an effective focal length of the third lens, and f34 denotes a combined focal length of the third lens and the fourth lens.

When the conditional expression (11) is satisfied, the focal lengths of the third lens and the fourth lens are controlled, so that the focal powers of the third lens and the fourth lens can be reasonably distributed, the spherical aberration and the axial chromatic aberration of the lens can be effectively reduced, and the imaging quality of the lens is improved.

In one embodiment, the optical lens satisfies the following conditional expression:

0.40 mm ² <AT12*TTL<0.61 mm ² ；（12）

wherein AT12 denotes an air space between the first lens and the second lens on an optical axis, and TTL denotes an optical total length of the optical lens.

When the conditional expression (12) is satisfied, the air interval between the first lens and the second lens can be reasonably controlled, the total length can be shortened under the same image height, and the miniaturization of the optical lens is favorably realized.

0<AT45/TTL<0.2；（13）

0<ET45/TTL<0.2；（14）

wherein AT45 denotes an air space between the fourth lens and the fifth lens on an optical axis, ET45 denotes an air space between the fourth lens and the fifth lens on an edge, and TTL denotes an optical total length of the optical lens.

When the conditional expressions (13) and (14) are met, the distance between the fourth lens and the fifth lens can be reasonably matched, the chromatic aberration of the lens and the chromatic aberration of spherical aberration on an axis are modified, the lens is more compact, and the miniaturization of the lens is realized.

In one embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are aspheric lenses. The aspheric lens can effectively reduce the number of the lenses, correct aberration and provide better optical performance.

The invention is further illustrated below in the following examples. In various embodiments, the thickness, the curvature radius, and the material selection of each lens in the optical lens are different, and the specific differences can be referred to in the parameter tables of the various embodiments. The following examples are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following examples, and any other changes, substitutions, combinations or simplifications which do not depart from the innovative points of the present invention should be construed as being equivalent substitutions and shall be included within the scope of the present invention.

In each embodiment of the present invention, when the lens is an aspherical lens, the surface shape of the aspherical lens satisfies the following equation:

wherein z is the distance rise from the aspheric surface vertex when the aspheric surface is at the position of height h along the optical axis direction, c is the paraxial curvature of the surface, k is conic coefficient, A _2i Is the aspheric surface type coefficient of 2i 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 sequentially includes, from an object side to an image side S15 along an optical axis: the stop ST, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter G1.

Wherein the first lens element L1 has positive refractive power, the object-side surface S1 of the first lens element is convex, and the image-side surface S2 of the first lens element is concave at a paraxial region;

the second lens element L2 has a negative optical power, the object-side surface S3 of the second lens element is convex at the paraxial region, and the image-side surface S4 of the second lens element is concave at the paraxial region;

the third lens L3 has positive focal power, the object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a concave surface;

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

the fifth lens element L5 has a negative optical power, the fifth lens element has a concave object-side surface S9 at the paraxial region and a convex image-side surface S10 at the paraxial region;

the sixth lens element L6 has positive optical power, and has a convex object-side surface S11 and a concave image-side surface S12 at the paraxial region;

the object side surface of the filter G1 is S13, and the image side surface is S14;

the first lens element L1, the second lens element L2, the third lens element L3, the fourth lens element L4, the fifth lens element L5 and the sixth lens element L6 are all plastic aspheric lenses.

Specifically, the design parameters of each lens in the optical lens 100 provided by the present embodiment are shown in table 1, where R represents a curvature radius (unit: mm), d represents an optical surface distance (unit: mm), and n represents _d D-line refractive index, V, of the representative material _d Represents the abbe number of the material.

TABLE 1

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

TABLE 2

In the present embodiment, graphs of curvature of field, f-tan θ distortion, chromatic aberration of point-on-axis spherical aberration, and lateral chromatic aberration of the optical lens 100 are shown in fig. 2, 3, 4, and 5, respectively.

In fig. 2, the curves show field curves at different image heights on the image plane in the meridional direction and the sagittal direction. The abscissa represents the offset and the ordinate represents the field angle, and it can be seen from the figure that the field curvature offset at the image plane in both the meridional direction and the arc loss direction is controlled within ± 0.1mm, indicating that the field curvature correction is good.

The curves in fig. 3 represent f-tan θ distortions at the image plane for different image heights. The abscissa represents the magnitude of distortion and the ordinate represents the field angle, and it can be seen from the figure that distortion is controlled within 2% in the imaging field required by the lens, indicating that distortion is well corrected.

As can be seen from the graph in FIG. 4, the curve shows the on-axis spherochromatism, the abscissa shows the offset, and the ordinate shows the normalized pupil coordinate, the chromatism offset of the dominant wavelength (0.550 μm) is controlled within + -0.02 mm, and the axial chromatism of the shortest wavelength and the maximum wavelength is controlled within + -0.025 mm, which indicates that the on-axis spherochromatism is well corrected.

In fig. 5, the curves indicate the chromatic aberrations of the respective wavelengths at different image heights on the image plane with respect to the main wavelength, the abscissa indicates the chromatic aberration value, and the ordinate indicates the normalized field angle. As can be seen from the figure, the chromatic aberration of each wavelength relative to the central wavelength is controlled within +/-2 μm in different fields of view, and the lateral chromatic aberration of the visible optical lens is well corrected.

Second embodiment

Referring to fig. 6, a schematic structural diagram of an optical lens 200 according to a second embodiment of the present invention is shown, where the optical lens 200 sequentially includes, from an object side to an image side S15 along an optical axis: the stop ST, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter G1.

Wherein the first lens L1 has positive optical power, the object side surface S1 of the first lens is convex, and the image side surface S2 of the first lens is concave at a paraxial region;

the second lens L2 has a negative optical power, the second lens 'object side surface S3 is convex at the paraxial region, and the second lens' image side surface S4 is concave at the paraxial region;

the third lens L3 has negative focal power, the object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a concave surface;

the fourth lens L4 has negative optical power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is concave at the paraxial region;

the fifth lens L5 has positive optical power, an object-side surface S9 of the fifth lens is concave at a paraxial region, and an image-side surface S10 of the fifth lens is convex at a paraxial region;

the sixth lens element L6 has a negative optical power, and has an object-side surface S11 that is convex at a paraxial region and an image-side surface S12 that is concave at a paraxial region;

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

TABLE 3

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

TABLE 4

In the present embodiment, graphs of field curvature, f-tan θ distortion, on-axis spherical aberration and lateral chromatic aberration of the optical lens 200 are shown in fig. 7, 8, 9 and 10, respectively.

Fig. 7 shows the field curvature of different image heights at the image plane in the tangential direction and the sagittal direction, and it can be seen from the figure that the field curvature in both the tangential direction and the sagittal direction is controlled within ± 0.1mm, which indicates that the lens field curvature correction is good.

Fig. 8 shows the f-tan θ distortion of different image heights on the image plane, and it can be seen that the distortion of different image heights on the image plane is controlled to be within 1%, which shows that the lens distortion correction is good.

FIG. 9 shows the on-axis chromatic aberration of point, and it can be seen that the aberration of the dominant wavelength (0.550 μm) is controlled within. + -. 0.03mm, and the chromatic aberration of all wavelengths is controlled within. + -. 0.07mm, which shows that the axial chromatic aberration of point of the lens is also corrected well.

FIG. 10 shows chromatic aberration of each wavelength with respect to the dominant wavelength for different fields of view, and it can be seen from the figure that the chromatic aberration with respect to the dominant wavelength is controlled within + -2 μm within the range of the imaging field of view, which illustrates that the optical lens can well correct the fringe field aberration and the chromatic aberration of each field of view.

Third embodiment

Referring to fig. 11, which is a schematic structural diagram of an optical lens 300 according to a first embodiment of the present invention, the optical lens 300 sequentially includes, from an object side to an image side S15 along an optical axis: the stop ST, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter G1.

The first lens L1 has positive focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is convex at the paraxial region;

the second lens L2 has a negative optical power, the second lens 'object side surface S3 is concave at the paraxial region, and the second lens' image side surface S4 is concave at the paraxial region;

the fourth lens L4 has positive optical power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex at the paraxial region;

the fifth lens L5 has positive optical power, the object-side surface S9 of the fifth lens is concave at the paraxial region, and the image-side surface S10 of the fifth lens is convex at the paraxial region;

the sixth lens L6 has a negative optical power, the object-side surface S11 of the sixth lens is concave, and the image-side surface S12 of the sixth lens is concave at the paraxial region;

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

TABLE 5

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

TABLE 6

In the present embodiment, graphs of curvature of field, f-tan θ distortion, chromatic aberration of point-on-axis spherical aberration, and lateral chromatic aberration of the optical lens 300 are shown in fig. 12, 13, 14, and 15, respectively.

Fig. 12 shows the field curvature of different image heights at the image plane in the tangential direction and the sagittal direction, and it can be seen from the figure that the field curvature in both the tangential direction and the sagittal direction is controlled within ± 0.05mm, which indicates that the lens field curvature correction is good.

Fig. 13 shows the f-tan θ distortion of different image heights on the image plane, and it can be seen from the figure that the distortion of different image heights on the image plane is controlled within ± 1.0%, which indicates that the lens distortion correction is good.

FIG. 14 shows the on-axis chromatic aberration of point, and it can be seen that the aberration of the dominant wavelength (0.550 μm) is controlled within. + -. 0.02mm, and the chromatic aberration of all wavelengths is controlled within. + -. 0.03mm, indicating that the axial chromatic aberration of point of the lens is also corrected well.

FIG. 15 shows the chromatic aberration of each wavelength with respect to the main wavelength for different fields, and it can be seen from the graph that the chromatic aberration with respect to the main wavelength is controlled within + -2 μm in the range of the imaging field, which illustrates that the optical lens can correct the fringe field aberration and the chromatic aberration of each field well.

Fourth embodiment

Referring to fig. 16, a schematic structural diagram of an optical lens 400 according to a first embodiment of the present invention is shown, where the optical lens 400 includes, in order from an object side to an image side S15 along an optical axis: the stop ST, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the filter G1.

The first lens L1 has positive focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave at the paraxial region;

the fourth lens L4 has positive optical power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is concave at the paraxial region;

the fifth lens element L5 has a negative optical power, the fifth lens element having an object-side surface S9 that is concave at the paraxial region and an image-side surface S10 that is convex at the paraxial region;

the sixth lens L6 has positive optical power, an object-side surface S11 of the sixth lens being convex at a paraxial region, and an image-side surface S12 of the sixth lens being concave at a paraxial region;

Specifically, the design parameters of each lens in the optical lens 100 provided in this embodiment are shown in table 7.

TABLE 7

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

TABLE 8

In the present embodiment, graphs of curvature of field, f-tan θ distortion, chromatic aberration of point-on-axis spherical aberration, and lateral chromatic aberration of the optical lens 400 are shown in fig. 17, 18, 19, and 20, respectively.

Fig. 17 shows the field curvature of different image heights at the image plane in the tangential direction and the sagittal direction, and it can be seen from the figure that the field curvature in both the tangential direction and the sagittal direction is controlled within ± 0.05mm, which indicates that the lens field curvature correction is good.

Fig. 18 shows the f-tan θ distortion of different image heights on the image plane, and it is understood that the distortion of different image heights on the image plane is controlled to be within 2%, which indicates that the lens distortion correction is good.

FIG. 19 shows the on-axis chromatic aberration of point, and it can be seen that the aberration of the dominant wavelength (0.550 μm) is controlled within. + -. 0.02mm, and the chromatic aberration of all wavelengths is controlled within. + -. 0.04mm, indicating that the axial chromatic aberration of point of the lens is also corrected well.

FIG. 20 shows the chromatic aberration of each wavelength with respect to the main wavelength for different fields, and it can be seen from the graph that the chromatic aberration with respect to the main wavelength is controlled within + -2 μm in the range of the imaging field, which illustrates that the optical lens can correct the fringe field aberration and the chromatic aberration of each field well.

Table 9 shows the optical characteristics corresponding to the four embodiments, which mainly include the half height IH, the effective focal length f, the total optical length TLL, and the viewing angle 2 θ of the optical lens, and the values corresponding to each of the above conditional expressions.

TABLE 9

In summary, the optical lens provided by the invention has at least the following advantages:

(1) Because the FNO (f/D) of the optical lens is small and the shapes of the diaphragm and other lenses are reasonably set, the optical lens can have a good imaging effect in a dark environment, and can better blur the background and highlight the shooting main body.

(2) Six aspheric lenses with specific focal power and specific surface types are adopted for matching, so that the optical lens has the characteristic of imaging quality of long-focus ultra-high-definition pixels, and can better meet the development trend of the current lens.

(3) Compared with the expensive long Jiao Gaoqing portrait lens, the invention has mature manufacturing process on the premise of ensuring high pixel and long focus, greatly reduces the manufacturing cost and is more beneficial to market popularization.

In the description of the specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like 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 invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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 are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An optical lens assembly, comprising six lenses, in order from an object side to an image plane along an optical axis:

a diaphragm;

a first lens having a positive optical power, an object side surface of the first lens being convex;

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

the lens comprises a third lens with 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 concave surface;

a fourth lens having a focal power, an object side surface of the fourth lens being convex;

a fifth lens having a power, an object-side surface of the fifth lens being concave at a paraxial region, an image-side surface of the fifth lens being convex at a paraxial region;

a sixth lens having a power, an image-side surface of the sixth lens being concave at a paraxial region;

wherein, the optical lens satisfies the following conditional expression:

1.2< f/D<1.5；

0.1<|f34/f3|<0.9；

3.0 mm＜IH＜3.5 mm；

2.7<f/IH<3.4；

wherein f denotes an effective focal length of the optical lens, D denotes an entrance pupil diameter of the optical lens, f3 denotes an effective focal length of the third lens, f34 denotes a combined focal length of the third lens and the fourth lens, and IH denotes a half-image height of the optical lens.

2. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

0.8<R31/R32<1.2；

3. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

1.2<(SAG51+SAG52)/SAG51<2.1；

4. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

1<SAG31/CT3<5；

wherein SAG31 represents the height of the object side effective diameter edge of the third lens, and CT3 represents the central thickness of the third lens.

5. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

1.7<f/R31<5；

6. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

0.17<(CT4+CT5+CT6)/TTL <0.26；

0.07＜CT4/TTL＜0.13；

7. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

-4<（Φ31-Φ21）/（Φ32+Φ22）<13；

wherein Φ 21 represents an optical power of an object-side surface of the second lens, Φ 22 represents an optical power of an image-side surface of the second lens, Φ 31 represents an optical power of an object-side surface of the third lens, and Φ 32 represents an optical power of an image-side surface of the third lens.

8. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

0.40mm ² <AT12*TTL<0.61mm ² ；

wherein AT12 represents an air space on an optical axis between the first lens and the second lens, and TTL represents an optical total length of the optical lens.

9. An optical lens according to claim 1, characterized in that the optical lens satisfies the following conditional expression:

0<AT45/TTL<0.2；

0<ET45/TTL<0.2；