WO2022089344A1 - Optical lens and imaging device - Google Patents

Abstract

An optical lens (100) and an imaging device (400). The optical lens (100) sequentially comprises, along the optical axis, from the object side to an imaging surface (S15), a first lens (L1), a second lens (L2), a third lens (L3), a diaphragm (ST), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), and a seventh lens (L7). The first lens (L1) has negative focal power, an object side surface (S1) is convex, and an image side surface (S2) is concave; the second lens (L2) has focal power, and an object side surface (S3) is concave; the third lens (L3) has positive focal power, and an image side surface (S6) is convex; the fourth lens (L4) has positive focal power, and both an object side surface (S7) and an image side surface (S8) are convex; the fifth lens (L5) has positive focal power, an object side surface (S9) is concave, and an image side surface (S10) is convex; the sixth lens (L6) has negative focal power, and both an object side surface (S11) and an image side surface (S12) are concave; the seventh lens (L7) has positive focal power, an object side surface (S13) is convex near the optical axis and has an inflection point, and an image side surface (S14) is concave near the optical axis and has an inflection point. The optical lens (100) has an ultra-wide angle, a compact structure, and extremely small optical distortion, and thus achieves the ultra-wide angle, lens miniaturization, and high pixel equalization.

Description

Optical Lenses and Imaging Equipment

cross reference

This application claims the priority of an earlier application with the title of invention: "Optical Lens and Imaging Device" filed on October 26, 2020, with application number 2020111588116, the contents of which are incorporated into this text by reference.

technical field

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

Background technique

In recent years, camera lenses have been widely used in various fields, especially wide-angle lenses including ultra-wide-angle lenses and fisheye lenses are playing an important role in more and more occasions. In terms of photography, wide-angle lenses have the characteristics of short focus and large field of view, which can produce large barrel distortion to create special effects and bring strong visual impact to the observer. In terms of measurement, the wide-angle lens uses the large field of view to obtain more data in a single imaging to capture more scene information. At the same time, the market's requirements for the miniaturization of lenses are getting higher and higher. However, the reduction in lens size has a great impact on the imaging quality of the lens, especially for wide-angle lenses with a large field of view. Therefore, there is a need for a high-quality imaging lens that combines a large field of view and miniaturization.

SUMMARY OF THE INVENTION

Based on this, the purpose of the present invention is to provide an optical lens and an imaging device to improve the above problems.

The embodiments of the present invention achieve the above objectives through the following technical solutions.

In a first aspect, an embodiment of the present invention provides an optical lens, which is composed of seven lenses, and includes a first lens, a second lens, a third lens, a diaphragm, and a fourth lens in sequence from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a diaphragm, and a fourth lens. , the fifth lens, the sixth lens and the seventh lens. The first lens has negative refractive power, its object side is convex, and its image side is concave; the second lens has refractive power, and its object side is concave; the third lens has positive power, and its image side is convex; The lens has positive refractive power, and its object side and image side are convex; the fifth lens has positive power, and its object side is concave and its image side is convex; the sixth lens has negative power, and its object side and image side are convex. are concave; the seventh lens has a positive refractive power, its object side is convex at the near optical axis, its image side is concave at the near optical axis, and the seventh lens has at least one inflection on the object side and the image side point. Among them, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspherical lenses; the optical lens satisfies the following conditional formula: 6<TTL/EPD<7 ; Among them, TTL represents the total optical length of the optical lens, and EPD represents the entrance pupil diameter of the optical lens.

In a second aspect, an embodiment of the present invention further provides an imaging device, including an imaging element and the optical lens provided in the first aspect, where the imaging element is used to convert an optical image formed by the optical lens into an electrical signal.

Compared with the prior art, the optical lens and imaging device provided by the embodiments of the present application can meet the requirements of large and wide-angle while reasonably matching the lens shape and the reasonable combination of refractive power among the seven lenses with specific refractive power. The structure is more compact, thereby better realizing the miniaturization of the optical lens and the balance of high pixels, which can effectively improve the camera experience of the user.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings are only some embodiments of the present invention, and therefore should not be It is regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic structural diagram of an optical lens provided by a first embodiment of the application;

FIG. 2 is a field curvature diagram of the optical lens provided by the first embodiment of the present application;

FIG. 3 is a distortion curve diagram of the optical lens provided by the first embodiment of the present application;

4 is a vertical-axis chromatic aberration curve diagram of an optical lens provided by the first embodiment of the present application;

5 is an axial chromatic aberration curve diagram of the optical lens provided by the first embodiment of the present application;

6 is a schematic structural diagram of an optical lens provided by a second embodiment of the present application;

7 is a field curvature diagram of an optical lens provided by the second embodiment of the present application;

FIG. 8 is a distortion curve diagram of an optical lens provided by the second embodiment of the present application;

9 is a vertical-axis chromatic aberration curve diagram of an optical lens provided by the second embodiment of the present application;

10 is an axial chromatic aberration curve diagram of the optical lens provided by the second embodiment of the application;

11 is a schematic structural diagram of an optical lens provided by a third embodiment of the application;

12 is a field curvature diagram of an optical lens provided by a third embodiment of the application;

13 is a distortion curve diagram of an optical lens provided by the third embodiment of the application;

14 is a vertical-axis chromatic aberration curve diagram of an optical lens provided by the third embodiment of the application;

15 is an axial chromatic aberration curve diagram of the optical lens provided by the third embodiment of the application;

FIG. 16 is a schematic structural diagram of an imaging device provided by a fourth embodiment of the present application.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the related drawings. The drawings show several embodiments of the invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

An embodiment of the present application provides an optical lens. The optical lens includes in sequence from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens For the lens, the seventh lens and the filter, the image side here refers to the side where the imaging plane is located, and the object side refers to the side opposite to the image side.

The first lens has negative refractive power, the object side of the first lens is convex, and the image side of the first lens is concave.

The second lens has optical power, the object side of the second lens is concave, and the image side of the second lens is concave or convex.

The third lens has positive refractive power, the object side of the third lens is concave or convex, and the image side of the third lens is convex.

The fourth lens has positive refractive power, and both the object side of the fourth lens and the image side of the fourth lens are convex.

The fifth lens has positive refractive power, the object side of the fifth lens is concave, and the image side of the fifth lens is convex.

The sixth lens has negative refractive power, and both the object side of the sixth lens and the image side of the sixth lens are concave.

The seventh lens has positive refractive power, the object side of the seventh lens is convex at the near optical axis and has at least one inflection point, and the image side of the seventh lens is concave at the near optical axis and has at least one inflection point ( inflection point).

In some optional embodiments, the optical lens satisfies the following conditional formula:

6<TTL/EPD<7; (1)

Among them, TTL represents the optical total length of the optical lens, and EPD represents the entrance pupil diameter of the optical lens.

When the conditional formula (1) is satisfied, the light transmission amount and the total optical length of the optical lens can be reasonably controlled, which is beneficial to increase the light transmission amount on the optical lens, while shortening the optical total length of the optical lens and realizing the miniaturization of the lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

1<f/DM1<1.5; (2)

Among them, f represents the focal length of the optical lens, and DM1 represents the effective semi-diameter of the first lens.

When the conditional formula (2) is satisfied, the effective aperture of the first lens can be reasonably controlled, the head size of the optical lens can be reduced, the screen opening area of the portable electronic device can be reduced, the head can be miniaturized, and the portable electronic product can be improved. screen ratio.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

0.5<R1/f<1.5; (3)

Among them, f represents the focal length of the optical lens, and R1 represents the curvature radius of the object side surface of the first lens.

When the conditional formula (3) is satisfied, by controlling the surface shape and focal length of the first lens, the imaging space depth and effective focal length of the optical lens can be reasonably controlled, which is beneficial to realize the ultra-wide-angle characteristic of the optical lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

0.5mm<R2/tan(θ2)<1.2mm; (4)

Wherein, R2 represents the curvature radius of the image side surface of the first lens, and θ2 represents the maximum inclination angle of the image side surface of the first lens.

When the conditional formula (4) is satisfied, the curvature of the image side surface of the first lens can be reasonably controlled, and the optical power of the first lens can be enhanced, so that the lens can also correct aberrations well under a large aperture, and at the same time, it is beneficial to reduce the subsequent The diameter of the lens and the overall length of the lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

-1<f1/f2<2; (5)

-1<R3/R2<0; (6)

Wherein, f1 represents the focal length of the first lens, f2 represents the focal length of the second lens, R2 represents the radius of curvature of the image side of the first lens, and R3 represents the radius of curvature of the object side of the second lens.

When the conditional expressions (5) and (6) are satisfied, the focal lengths of the first lens and the second lens can be reasonably balanced, so that the focal lengths of the first lens and the second lens can be matched with positive and negative, which is conducive to the correction of chromatic aberration, and can reasonably control the light entering The incident angle of the object side of the second lens reduces the sensitivity of the optical lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

-1<(R3+R4)/(R3-R4)<30; (7)

-30<(R5+R6)/(R5-R6)<1; (8)

Wherein, R3 represents the radius of curvature of the object side of the second lens, R4 represents the radius of curvature of the image side of the second lens, R4 represents the radius of curvature of the object side of the third lens, and R5 represents the radius of curvature of the image side of the third lens.

When the conditional expressions (7) and (8) are satisfied, the surface shapes of the second lens and the third lens can be reasonably controlled, the condensing intensity of the off-axis field of view can be eased, and the aberration of the edge field of view and the center field of view can be reduced. Good for correcting spherical aberration and distortion.

In some optional embodiments, the optical lens 100 may also satisfy the following conditional formula:

0.05<CT2/TTL<0.1; (9)

0.04<CT3/TTL<0.1; (10)

Among them, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, and TTL represents the total optical length of the optical lens.

When the conditional expressions (9) and (10) are satisfied, the central thickness of the second lens and the third lens can be reasonably controlled, and the design of the lens miniaturization and thinning lens can be satisfied, which is conducive to the correction of aberration and f-θ distortion. It can maintain the amount of light, which is conducive to the improvement of relative illuminance.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

1<f ₄₅₆ /f<1.5; (11)

0<f4/f5<0.5; (12)

-6<f5/f6<-3; (13)

Wherein, f ₄₅₆ represents the combined focal length of the fourth lens, the fifth lens and the sixth lens, f4 represents the focal length of the fourth lens, f5 represents the focal length of the fifth lens, and f6 represents the focal length of the sixth lens.

When the conditional expressions (11), (12) and (13) are satisfied, the balanced distribution of the power of the fourth lens, the fifth lens and the sixth lens can be achieved, and the fourth lens to the sixth lens have a positive combination The optical power is beneficial to correct the aberration of the optical lens and improve the resolution of the optical lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

0.2<(CT4+CT5+CT6)/TTL<0.4; (14)

Among them, CT4 represents the center thickness of the fourth lens, CT5 represents the center thickness of the fifth lens, CT6 represents the center thickness of the sixth lens, and TTL represents the total optical length of the optical lens.

When the conditional formula (14) is satisfied, the center thickness of the fourth lens to the sixth lens after the diaphragm can be reasonably allocated, the total length of the lens can be reduced, and at the same time, the collocation of each lens can be reasonably controlled to reduce the sensitivity of the optical lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

-50<(R13+R14)/(R13-R14)<-10; (15)

2mm<R14/tan(θ14)<3mm; (16)

Wherein, R13 represents the curvature radius of the object side of the seventh lens, R14 represents the curvature radius of the image side of the seventh lens, and θ14 represents the maximum inclination angle of the image side of the seventh lens.

When the conditional expressions (15) and (16) are satisfied, by reasonably controlling the curvature radius of the object side and the image side of the seventh lens, the distribution of the incident angle of light can be effectively controlled, the matching degree of the optical lens and the imaging chip can be improved, and the optical lens can be improved. At the same time, the curvature of the image side surface of the seventh lens can be reasonably controlled to reduce the generation of ghost images of the optical lens.

In some optional embodiments, the optical lens may also satisfy the following conditional formula:

CRA<33°; (17)

0.1<BFL/TTL<0.2; (18)

Among them, CRA represents the chief ray incident angle of the optical lens, BFL represents the distance between the image side of the seventh lens and the imaging surface on the optical axis, also called the optical back focus, and TTL represents the total optical length of the optical lens.

When the conditional expressions (17) and (18) are satisfied, the incident angle of the chief ray and the optical back focus of the optical lens can be reasonably controlled, the imaging quality of the lens can be improved, and at the same time, the overall length can be shortened and the miniaturization of the optical lens can be realized.

As an embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens may be aspherical lenses. Optionally, the above lenses are all made of plastic aspherical lenses. . The use of aspherical lenses can effectively reduce the number of lenses, correct aberrations, and provide better optical performance.

As an embodiment, when each lens in the optical lens 100 is an aspherical lens, each aspherical surface type of the optical lens may satisfy the following equation:

Among them, z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position of height h along the optical axis, c is the paraxial curvature radius of the surface, k is the quadratic surface coefficient conic, and A _2i is the 2i order Aspheric surface shape coefficient.

The optical lens provided by the embodiment of the present invention adopts seven lenses with a specific refractive power to reasonably match the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens The combination of the best lens shape and focal power can make the structure of the optical lens more compact under the premise that the lens has a large wide angle, better realize the balance of the miniaturization of the lens and the high pixel, and can effectively improve the user's camera experience.

The present invention will be further described below with a plurality of embodiments. In each of the following embodiments, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For details, please refer to the parameter table of each embodiment.

first embodiment

Please refer to FIG. 1 , which is a schematic structural diagram of an optical lens 100 according to a first embodiment of the present invention. The optical lens 100 includes in sequence from the object side to the imaging surface S15 along the optical axis: a first lens L1 , a second lens L2 , a first lens Three lenses L3, diaphragm ST, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7.

The first lens L1 has negative refractive power, the object side S1 of the first lens L1 is convex, and the image side S2 of the first lens L1 is concave.

The second lens L2 has positive refractive power, the object side S3 of the second lens L2 is concave, and the image side S4 of the second lens L2 is convex.

The third lens L3 has positive refractive power, the object side S5 of the third lens L3 is concave, and the image side S6 of the third lens L3 is convex.

The fourth lens L4 has positive refractive power, and both the object side S7 of the fourth lens L4 and the image side S8 of the fourth lens L4 are convex surfaces.

The fifth lens L5 has positive refractive power, the object side S9 of the fifth lens L5 is concave, and the image side S10 of the fifth lens L5 is convex.

The sixth lens L6 has negative refractive power, and both the object side S11 of the sixth lens L6 and the image side S12 of the sixth lens L6 are concave.

The seventh lens L7 has positive refractive power, the object side S13 of the seventh lens L7 is convex at the near optical axis, and the image side S14 of the seventh lens L7 is concave at the near optical axis; in this embodiment, the seventh lens The vertical distance between the inflection point of the object side S13 of L7 and the optical axis is 1.13 mm, and the vertical distance of the inflection point of the image side S14 of the seventh lens L7 and the optical axis is 1.19 mm.

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 seventh lens L7 are all plastic aspherical lenses.

Referring to Table 1, the relevant parameters of each lens in the optical lens 100 provided by the first embodiment of the present invention are shown in Table 1.

Table 1

Please refer to Table 2, the surface coefficients of each aspherical surface of the optical lens 100 provided by the first embodiment of the present invention are shown in Table 2:

Table 2

face number	k	A 4	A 6	A 8	A 10	A 12	A 14	A 16
S1	-3.50936	-0.01157	-0.00812	-0.00087	-0.00044	0.00043	0.00011	-3.9999E-05
S2	-1.04551	0.02290	0.01664	-0.01105	0.00711	-0.04356	-0.02914	0.04644
S3	-0.05392	0.04030	0.03995	0.01397	-0.03160	-0.01132	-0.00508	-0.00218
S4	-0.52747	0.04262	-0.02004	0.16189	0.23367	-0.39063	-0.72453	1.11937
S5	-1.05356	0.08762	0.03178	0.18230	0.16752	-0.43960	-0.65016	1.23255
S6	-4.36914	0.03719	0.02610	0.13868	0.23282	-0.50760	-0.81147	1.35794
S7	2.90888	-0.01832	-0.24935	-0.39610	-0.15327	0.09535	0.17640	-6.80034
S8	-0.51168	0.01597	0.05087	0.08660	-0.21764	0.17406	-1.25914	-0.97933
S9	-0.05086	0.02604	-0.14522	-0.19556	0.41511	1.73772	1.69614	-7.38269
S10	1.33599	-0.01231	-0.16919	0.17306	0.80872	0.82255	0.57571	-3.23107
S11	77.96614	-0.28960	0.25302	-0.15742	0.16034	0.49692	0.11826	-3.03137
S12	-28.51506	0.07966	0.13871	-0.09568	-0.09040	-0.01424	0.08828	-0.02211
S13	-7.01354	-0.11892	0.01788	0.00774	-0.00085	-0.00085	0.00023	-1.61116E-05
S14	-5.29427	-0.10535	0.01439	0.00266	-0.00208	0.00023	2.54278E-05	-8.5944E-07

Please refer to FIG. 2 , FIG. 3 , FIG. 4 and FIG. 5 , which are respectively a field curvature graph, a distortion graph, a vertical chromatic aberration graph, and an axial chromatic aberration graph of the optical lens 100 .

The field curvature curve of FIG. 2 represents the degree of curvature of the meridional image plane and the sagittal image plane. Here, in FIG. 2 , the horizontal axis represents the offset (unit: mm), and the vertical axis represents the field angle (unit: degree). It can be seen from FIG. 2 that the curvature of field of the meridional image plane and the sagittal image plane is controlled within ±0.5mm, indicating that the field curvature of the optical lens 100 is well corrected.

The distortion curve of FIG. 3 represents the distortion at different image heights on the imaging plane S17. Among them, in FIG. 3 , the horizontal axis represents the f-θ distortion percentage, and the vertical axis represents the field angle (unit: degree). It can be seen from FIG. 3 that the f-θ distortion at different image heights on the imaging surface S17 is controlled within ±5%, which indicates that the distortion of the optical lens 100 has been well corrected.

The vertical-axis chromatic aberration curve in FIG. 4 represents the chromatic aberration of the longest wavelength and the shortest wavelength at different image heights on the imaging plane S17. The horizontal axis in FIG. 4 represents the vertical axis chromatic aberration value (unit: um) of each wavelength relative to the central wavelength, and the vertical axis represents the normalized viewing angle. It can be seen from FIG. 4 that the vertical chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2um, which indicates that the vertical chromatic aberration of the optical lens 100 is well corrected.

The axial chromatic aberration curve of FIG. 5 represents the aberration on the optical axis at the imaging plane S17. The vertical axis in FIG. 5 represents the spherical value (unit: mm), and the horizontal axis represents the normalized pupil radius (unit: mm). It can be seen from FIG. 5 that the offset of the axial chromatic aberration is controlled within ±0.02mm, indicating that the optical lens 100 can effectively correct the aberration of the fringe field of view and the secondary spectrum of the entire image plane.

Second Embodiment

Please refer to FIG. 6 , which is a schematic structural diagram of an optical lens 200 provided by a second embodiment of the present invention. The optical lens 200 in this embodiment has substantially the same structure as the optical lens 100 provided by the first embodiment, and the main differences are The second lens L2 in the optical lens 200 has negative refractive power, the image side S4 of the second lens L2 is concave, the object side S5 of the third lens L3 is convex, and the curvature radius and material selection of each lens are different.

In the second embodiment of the present invention, the vertical distance between the inflection point of the object side S13 of the seventh lens L7 and the optical axis is 1.08 mm, and the vertical distance between the inflection point of the image side S14 of the seventh lens L7 and the optical axis is 1.16mm.

Referring to Table 3, the relevant parameters of each lens in the optical lens 200 provided by the second embodiment of the present invention are shown in Table 3.

table 3

Please refer to Table 4, the surface shape coefficients of each aspherical surface of the optical lens 200 provided by the second embodiment of the present invention are shown in Table 4:

Table 4

face number	k	A 4	A 6	A 8	A 10	A 12	A 14	A 16
S1	-3.27941	-0.01004	-0.00684	-0.00107	-0.00058	0.00037	0.00011	-3.3573E-05
S2	-1.05433	0.02060	0.00381	-0.00344	0.00401	-0.06415	-0.03836	0.05894
S3	0.38438	0.02628	0.02104	0.00160	-0.02297	0.02476	0.04017	-0.04140

S4	-99.98458	-0.00415	0.00815	-0.02221	0.02423	0.08561	-0.02300	-0.24837
S5	27.93201	0.00718	-0.00143	0.03234	-0.01445	-0.13381	-0.17255	-0.09795
S6	-11.60247	0.03915	-0.00236	0.14124	0.17079	-0.63221	-1.06260	1.55204
S7	3.06910	-0.04195	-0.30762	-0.43197	0.00490	0.47671	-0.06739	-15.77346
S8	-0.54385	0.02437	0.04345	0.11402	-0.18784	-0.07132	-1.41934	0.24805
S9	-0.48409	0.04182	-0.08701	-0.17900	0.42890	1.68646	2.00888	-6.53124
S10	1.64861	-0.02470	-0.17956	0.25914	0.84897	0.89632	0.38706	-3.43763
S11	71.26034	-0.28631	0.21930	-0.11170	0.17368	0.40699	-0.12100	-3.84511
S12	-26.38508	0.11060	0.13455	-0.08576	-0.12624	-0.02660	0.08707	0.01345
S13	-6.07785	-0.12708	0.01772	0.00911	-0.00077	-0.00104	0.00023	-8.22436E-06
S14	-4.64106	-0.11501	0.01649	0.00265	-0.00213	0.00028	1.77232E-05	-1.70244E-06

Please refer to FIG. 7 , FIG. 8 , FIG. 9 and FIG. 10 , which are respectively a field curvature graph, a distortion graph, a vertical chromatic aberration graph, and an axial chromatic aberration graph of the optical lens 200 .

FIG. 7 shows the degree of curvature of the meridional image plane and the sagittal image plane. It can be seen from FIG. 7 that the curvature of field of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the field curvature of the optical lens 200 is well corrected.

FIG. 8 shows the distortion at different image heights on the imaging plane S17. As can be seen from FIG. 8 , the f-θ distortion at different image heights on the imaging surface S17 is controlled within ±5%, indicating that the distortion of the optical lens 200 is well corrected.

FIG. 9 shows the chromatic aberration of the longest wavelength and the shortest wavelength at different image heights on the imaging plane S17. It can be seen from FIG. 9 that the vertical chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2um, which indicates that the vertical chromatic aberration of the optical lens 200 is well corrected.

FIG. 10 shows aberrations on the optical axis at the imaging plane S17. It can be seen from FIG. 10 that the offset of the axial chromatic aberration is controlled within ±0.03mm, indicating that the optical lens 200 can effectively correct the aberration of the fringe field of view and the secondary spectrum of the entire image plane.

Third Embodiment

Please refer to FIG. 11 , which is a schematic structural diagram of an optical lens 300 provided by a third embodiment of the present invention. The optical lens 300 in this embodiment has substantially the same structure as the optical lens 100 provided by the first embodiment, and the main differences are The second lens L2 in the optical lens 300 has negative refractive power, the image side S4 of the second lens L2 is concave, the object side S5 of the third lens L3 is convex, and the curvature radius and material selection of each lens are different.

In the third embodiment of the present invention, the vertical distance between the inflection point of the object side S13 of the seventh lens L7 and the optical axis is 1.15 mm, and the vertical distance between the inflection point of the image side S14 of the seventh lens L7 and the optical axis is 1.21mm.

Referring to Table 5, the relevant parameters of each lens in the optical lens 300 provided by the third embodiment of the present invention are shown in Table 5.

table 5

Please refer to Table 6, the surface shape coefficients of each aspherical surface of the optical lens 300 in the third embodiment of the present invention are shown in Table 6:

Table 6

face number	k	A 4	A 6	A 8	A 10	A 12	A 14	A 16
S1	-3.06626	-0.01052	-0.00718	-0.00114	-0.00060	0.00037	0.00011	-3.29634E-05
S2	-1.10328	0.01361	0.00092	-0.01025	-0.00151	-0.06666	-0.03880	0.06042
S3	0.33816	0.02751	0.02522	-0.00261	-0.02933	0.02149	0.04247	-0.03070
S4	50.58251	-0.01298	0.02175	-0.03366	-0.01100	0.06933	0.07641	0.23866
S5	17.89255	0.01018	-0.03045	0.02014	0.00007	-0.14594	-0.33766	-0.67047
S6	-23.90262	0.07037	0.01497	0.12757	0.07416	-0.91243	-1.73195	0.11374
S7	3.06722	-0.05011	-0.31039	-0.44318	-0.02301	0.42298	-0.16510	-15.89582
S8	-0.32910	0.00819	0.08597	0.22332	-0.07597	-0.09580	-1.77101	-0.67307
S9	-0.42566	0.03989	-0.07261	-0.15967	0.47267	1.73623	1.93091	-7.15822
S10	1.71768	-0.03272	-0.22387	0.22457	0.78746	0.77871	0.19455	-3.39040
S11	72.97474	-0.30052	0.24090	-0.20337	0.06217	0.48871	0.16664	-4.28600
S12	-33.85426	0.11265	0.14071	-0.08597	-0.12298	-0.01471	0.09720	-0.02091

S13	-5.71786	-0.12478	0.01752	0.00892	-0.00081	-0.00103	0.00024	-9.12865E-06
S14	-3.21474	-0.11818	0.01547	0.00270	-0.00210	0.00029	1.82824E-05	-2.17561E-06

Please refer to FIG. 12 , FIG. 13 , FIG. 14 and FIG. 15 , which are the field curvature graph, the distortion graph, the vertical chromatic aberration graph and the axial chromatic aberration graph of the optical lens 300 , respectively.

FIG. 12 shows the degree of curvature of the meridional image plane and the sagittal image plane. It can be seen from FIG. 12 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the field curvature of the optical lens 300 is well corrected.

FIG. 13 shows the distortion at different image heights on the imaging plane S17. As can be seen from FIG. 13 , the f-θ distortion at different image heights on the imaging surface S17 is controlled within ±5%, indicating that the distortion of the optical lens 300 has been well corrected.

FIG. 14 shows the chromatic aberration at different image heights on the imaging plane between the longest wavelength and the shortest wavelength. It can be seen from FIG. 14 that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2.0um, indicating that the vertical axis chromatic aberration of the optical lens 300 is well corrected.

FIG. 15 shows aberrations on the optical axis at the imaging plane S17. It can be seen from FIG. 15 that the offset of the axial chromatic aberration at the imaging plane S17 is controlled within ±0.01 mm, indicating that the optical lens 300 can effectively correct the aberration of the fringe field of view and the secondary spectrum of the entire image plane.

Please refer to Table 7, which shows the optical characteristics corresponding to the optical lenses provided by the above three embodiments respectively. Among them, the optical characteristics mainly include the focal length f of the optical lens, the aperture number F#, the entrance pupil diameter EPD, the optical total length TTL and the field of view angle FOV, as well as the relevant values corresponding to each of the aforementioned conditional expressions.

Table 7

	first embodiment	Second Embodiment	Third Embodiment	Remark
f(mm)	1.837	1.830	1.834
F#	2.2	2.2	2.2
TTL(mm)	5.47	5.684	5.646
FOV(°)	150	150	150
EPD(mm)	0.820	0.817	0.819
IH(mm)	2.299	2.299	2.298
TTL/EPD	6.672	6.956	6.897	Condition (1)
f/DM1	1.134	1.086	1.056	Condition (2)
R1/f	1.007	1.003	0.939	Condition (3)
R2/tan(θ2)	0.806	0.883	1.024	Condition (4)
f1/f2	-0.141	1.101	1.422	Condition (5)
R3/R2	-0.482	-0.479	-0.437	Condition (6)
(R3+R4)/(R3-R4)	28.367	-0.903	-0.457	Condition (7)
(R5+R6)/(R5-R6)	-29.125	0.662	0.198	Condition (8)
CT2/TTL	0.061	0.081	0.077	Condition (9)

CT3/TTL	0.048	0.063	0.069	Condition (10)
f456 /f	1.219	1.308	1.210	Condition (11)
f4/f5	0.193	0.106	0.123	Condition (12)
f5/f6	-3.270	-5.811	-4.817	Condition (13)
(CT4+CT5+CT6)/TTL	0.235	0.216	0.207	Condition (14)
(R13+R14)/(R13-R14)	-31.780	-41.959	-12.844	Condition (15)
R14/tan(θ14)	2.202	2.286	2.557	Conditional Expression (16)
CRA(°)	32.45	32.62	32.71	Condition (17)
BFL/TTL	0.157	0.151	0.152	Condition (18)

To sum up, the optical lens 100 provided by the embodiment of the present invention has the following advantages:

(1) Due to the reasonable setting of the diaphragm and the shape of each lens, on the one hand, the optical lens 100 has a smaller entrance pupil diameter (EPD<0.84mm), so that the outer diameter of the head of the lens can be made smaller to meet the requirements of high screen On the other hand, the overall length of the optical lens 100 is shorter (TTL<5.7mm) and the volume is reduced, which can better meet the development trend of portable smart electronic products, such as mobile phones.

(2) Seven plastic aspherical lenses with a specific refractive power are used, and each lens is matched with a specific surface shape, so that the optical lens 100 has an imaging quality of ultra-high pixels.

(3) The field of view of the optical lens 100 can reach 150°, which can effectively correct optical distortion, control the f-θ distortion to be less than ±5%, and can meet the needs of large field of view and high-definition imaging.

Fourth Embodiment

Embodiments of the present application further provide an imaging device 400. Referring to FIG. 16, the imaging device 400 includes an imaging element 410 and an optical lens (eg, the optical lens 100) in any of the foregoing embodiments. The imaging element 410 may be a CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) image sensor, or may be a CCD (Charge Coupled Device, charge coupled device) image sensor.

The imaging device 400 may be a camera, a mobile terminal, or any other electronic device loaded with the optical lens 100 , and the mobile terminal may be a terminal device such as a smart phone, a smart tablet, and a smart reader.

The imaging device 400 provided by the embodiment of the present application includes the optical lens 100. Since the optical lens 100 has the advantages of a small outer diameter of the head, a wide viewing angle, and high imaging quality, the imaging device 400 with the optical lens 100 also has a small size and a wide viewing angle. , the advantages of high imaging quality.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims (12)

1. An optical lens, which is composed of seven lenses, is characterized in that, along the optical axis from the object side to the imaging plane, it sequentially includes:

   A first lens with negative refractive power, the object side of the first lens is convex, and the image side of the first lens is concave;

   A second lens with optical power, the object side of the second lens is concave, and the image side of the second lens is concave or convex;

   a third lens with positive refractive power, the object side of the third lens is concave or convex, and the image side of the third lens is convex;

   aperture;

   a fourth lens with positive refractive power, the object side of the fourth lens and the image side of the fourth lens are both convex;

   a fifth lens with positive refractive power, the object side of the fifth lens is concave, and the image side of the fifth lens is convex;

   a sixth lens having negative refractive power, the object side of the sixth lens and the image side of the sixth lens are both concave; and

   The seventh lens with positive refractive power, the object side of the seventh lens is convex at the near optical axis, the image side of the seventh lens is concave at the near optical axis, and the object side of the seventh lens and The image sides have at least one inflection point;

   Wherein, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspherical lenses;

   The optical lens satisfies the following conditional formula:

   6<TTL/EPD<7;

   Wherein, TTL represents the total optical length of the optical lens, and EPD represents the entrance pupil diameter of the optical lens.
2. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   1<f/DM1<1.5;

   Wherein, f represents the focal length of the optical lens, and DM1 represents the effective semi-diameter of the first lens.
3. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   0.5<R1/f<1.5;

   Wherein, f represents the focal length of the optical lens, and R1 represents the curvature radius of the object side surface of the first lens.
4. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   0.5mm<R2/tan(θ2)<1.2mm;

   Wherein, R2 represents the curvature radius of the image side surface of the first lens, and θ2 represents the maximum inclination angle of the image side surface of the first lens.
5. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   -1<f1/f2<2;

   -1<R3/R2<0;

   Wherein, f1 represents the focal length of the first lens, f2 represents the focal length of the second lens, R2 represents the radius of curvature of the image side of the first lens, and R3 represents the radius of curvature of the object side of the second lens.
6. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   -1<(R3+R4)/(R3-R4)<30;

   -30<(R5+R6)/(R5-R6)<1;

   Wherein, R3 represents the radius of curvature of the object side of the second lens, R4 represents the radius of curvature of the image side of the second lens, R5 represents the radius of curvature of the object side of the third lens, and R6 represents the third lens. The radius of curvature of the image side of the lens.
7. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   0.05<CT2/TTL<0.1;

   0.04<CT3/TTL<0.1;

   Wherein, CT2 represents the central thickness of the second lens, CT3 represents the central thickness of the third 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 formula:

   1<f ₄₅₆ /f<1.5;

   0<f4/f5<0.5;

   -6<f5/f6<-3;

   Wherein, f ₄₅₆ represents the combined focal length of the fourth lens, the fifth lens and the sixth lens, f4 represents the focal length of the fourth lens, f5 represents the focal length of the fifth lens, and f6 represents the focal length of the The focal length of the sixth lens.
9. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

   0.2<(CT4+CT5+CT6)/TTL<0.4;

   Wherein, CT4 represents the center thickness of the fourth lens, CT5 represents the center thickness of the fifth lens, CT6 represents the center thickness of the sixth lens, and TTL represents the total optical length of the optical lens.
10. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

    -50<(R13+R14)/(R13-R14)<-10;

    2mm<R14/tan(θ14)<3mm;

    Wherein, R13 represents the curvature radius of the object side of the seventh lens, R14 represents the curvature radius of the image side of the seventh lens, and θ14 represents the maximum inclination angle of the image side of the seventh lens.
11. The optical lens according to claim 1, wherein the optical lens satisfies the following conditional formula:

    CRA<33°;

    0.1<BFL/TTL<0.2;

    Wherein, CRA represents the chief ray incident angle of the optical lens, BFL represents the distance between the image side surface of the seventh lens and the imaging surface on the optical axis, and TTL represents the optical total length of the optical lens.
12. An imaging device, characterized by comprising an imaging element and the optical lens according to any one of claims 1-11, wherein the imaging element is used for converting an optical image formed by the optical lens into an electrical signal.

Images