CN217425808U - Wide-angle optical lens - Google Patents

Abstract

The utility model relates to an optical lens technical field specifically is a wide angle optical lens. Which comprises, in order from an object side to an image side along an optical axis: the lens comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens and a sixth lens; the first lens element is an aspheric plastic lens with negative refractive power, and has a convex or concave object-side surface at the paraxial region and a concave image-side surface; the second lens is a spherical glass lens with positive refractive power; the third lens is an aspheric plastic lens with negative refractive power; the fourth lens element is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface; the fifth lens is an aspheric plastic lens with positive refractive power; the sixth lens element is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface. The utility model can accommodate more scenery due to the wide-angle shooting characteristic, and increase the sense of space; and the device has the characteristics of large aperture and high resolution, and can improve the imaging quality.

Description

Wide-angle optical lens

Technical Field

The utility model relates to an optical lens technical field especially relates to a wide angle optical lens.

Background

With the progress of human society and the improvement of living standard of people, scientific technology enters the era of rapid development. In order to meet more diverse and severe market demands, conventional lenses are gradually limited in terms of their angle, lens material, assembly method, etc., and thus cannot meet new application requirements.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcoming, the deficiency of prior art, the utility model provides a big light ring optical lens, it is little that it has solved light flux among the prior art, and the depth of field scope is short, the not high problem of analytic power.

In order to achieve the above object, the utility model discloses a main technical scheme include:

an embodiment of the present invention provides a wide-angle optical lens, which includes, along an optical axis, from an object side to an image side in sequence: the lens comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens and a sixth lens;

the first lens element is an aspheric plastic lens with negative refractive power, and has a convex or concave object-side surface at the paraxial region and a concave image-side surface;

the second lens is a spherical glass lens with positive refractive power;

the third lens is an aspheric plastic lens with negative refractive power;

the fourth lens element is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface;

the fifth lens element is an aspheric plastic lens with positive refractive power;

the sixth lens element is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface;

the optical lens satisfies the following conditions:

1.1<f1/f6<2

0.5<(R1-R8)/(R1+R8)<1.4

wherein f1 is the focal length of the first lens, and f6 is the focal length of the sixth lens; r1 is a radius of curvature of the object-side surface of the first lens element, and R8 is a radius of curvature of the image-side surface of the fourth lens element.

Further, the optical lens satisfies the following relation:

CT1 _max /CT1<2.5

among them, CT1 _max CT1 is the thickness of the first lens on the optical axis, which is the maximum edge thickness of the first lens.

Further, the optical lens satisfies the following relation:

BFL/f>0.6

and BFL is the distance from the outermost point of the image side surface of the sixth lens to the imaging surface, and f is the focal length of the optical lens.

Further, the optical lens satisfies the following relation:

0.4<EPD/ImgH<2

the EPD is the entrance pupil diameter of the optical lens, and the ImgH is the maximum image height of the optical lens. Further, the optical lens satisfies the following relation:

0.2<∑CT/TTL<0.4

sigma CT is the sum of the distances between two adjacent lenses in the optical lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface.

The utility model has the advantages that: the wide-angle optical lens provided by the utility model can accommodate more scenery due to the wide-angle shooting characteristic, and increase the sense of space; the lens has the characteristics of large aperture and high resolution, and can improve the imaging quality; the mode of combining the aspheric plastic lens and the spherical glass lens can better improve the distortion problem caused by overhigh or overlow temperature.

Drawings

Fig. 1 is a schematic structural view of a wide-angle optical lens according to embodiment 1 of the present application;

FIG. 2A is a graph showing axial chromatic aberration in example 1 of the present application;

fig. 2B is an astigmatism graph of embodiment 1 of the present application;

FIG. 2C is a distortion plot of example 1 of the present application;

fig. 3 is a schematic structural view of a wide-angle optical lens according to embodiment 2 of the present application;

FIG. 4A is a graph of axial chromatic aberration in example 2 of the present application;

fig. 4B is an astigmatism graph of example 2 of the present application;

FIG. 4C is a distortion plot of example 2 of the present application;

fig. 5 is a schematic structural view of a wide-angle optical lens according to embodiment 3 of the present application;

FIG. 6A is a graph of axial chromatic aberration in example 3 of the present application;

fig. 6B is an astigmatism graph of embodiment 3 of the present application;

fig. 6C is a distortion curve diagram of embodiment 3 of the present invention;

fig. 7 is a schematic structural view of a wide-angle optical lens according to embodiment 4 of the present application;

FIG. 8A is a graph of axial chromatic aberration in example 4 of the present application;

fig. 8B is an astigmatism graph of embodiment 4 of the present application;

fig. 8C is a distortion graph of embodiment 4 of the present application.

In the figure: 1. a first lens; 2. a second lens; 3. a third lens; 4. a fourth lens; 5. a fifth lens; 6. a sixth lens; 7. an optical filter; 8. and (4) a diaphragm.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention, examples of which are illustrated in the accompanying drawings.

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

In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for the convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

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

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

The utility model provides a wide angle optical lens, this optical lens include by the thing side to picture side along the optical axis in proper order: a first lens 1; a second lens 2; a diaphragm 8; a third lens 3; a fourth lens 4; a fifth lens 5 and a sixth lens 6. The first lens element 1 with negative refractive power has an object-side surface which can be convex or concave at a paraxial region thereof and an image-side surface which can be concave. The second lens element 2 is a spherical glass lens element with positive refractive power. The third lens element 3 is an aspheric plastic lens with negative refractive power. The fourth lens element 4 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface. The fifth lens element 5 is an aspheric plastic lens element with positive refractive power. The sixth lens element 6 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface.

Wherein the focal length of the first lens 1 is f1, the focal length of the sixth lens 6 is f6, and the following conditions are satisfied: 1.1< f1/f6< 2. The focal length of each lens can reach a balanced state by satisfying the formula, and the miniaturization of the lens is ensured while the wide angle is realized; further, light rays are better converged, and the imaging quality of the optical lens is improved.

Wherein, the curvature radius of the object side surface of the first lens 1 is R1, the curvature radius of the image side surface of the fourth lens 4 is R8, and the following requirements are met: 0.5< (R1-R8)/(R1+ R8) < 1.4. The formula is satisfied, the incidence of light rays with large visual angle can be adjusted by adjusting the surface type change of the object side surface of the first lens and the image side surface of the fourth lens, the generation of aberration is inhibited, and the requirements of wide angle and high imaging quality are met; and has better effect of eliminating chromatic aberration.

Wherein the maximum edge thickness of the first lens 1 is CT1 _max The thickness of the first lens 1 on the optical axis is CT1, and satisfies: CT1max/CT1<2.5. The thickness ratio of the first lens is adjusted to make the shape of the lens more uniform; the sensitivity is reduced, the processing and the assembly molding are facilitated, and the qualification rate is improved.

The distance from the outermost point of the image side surface of the sixth lens element 6 to the imaging surface is BFL, the focal length of the optical lens is f, and the following conditions are met: BFL/f > 0.6. Satisfy above-mentioned formula, through the lens distribution of adjustment optical lens head image side to gain the back focal length of suitable length, make the lens arrange compacter, do benefit to structural design.

Wherein, the entrance pupil diameter of optical lens is EPD, and optical lens's maximum image height is imgH to satisfy: 0.4< EPD/ImgH <2. The illumination control method meets the formula, and the near light quantity of the system is increased by adjusting the diameter of the entrance pupil so as to achieve the purpose of improving the illumination of the system.

The optical lens may further include a filter 7 for correcting color deviation and/or a protective glass for protecting a photosensitive element on an image forming surface, as required in the specific case of the embodiment, and the filter or the protective glass may not be used in the case of no specific requirement.

Example 1

Fig. 1 and fig. 2A to 2C are given below of an optical lens according to embodiment 1 of the present application, and fig. 1 is a schematic structural view of the optical lens according to embodiment 1.

The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1; a second lens 2; a diaphragm 8; a third lens 3; a fourth lens 4; a fifth lens 5 and a sixth lens 6. The first lens element 1 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface at the paraxial region and a concave image-side surface. The second lens element 2 is a spherical glass lens element with positive refractive power, and has a convex object-side surface at the paraxial region and a convex image-side surface at the paraxial region. The third lens element 3 is an aspheric plastic lens with negative refractive power, and has a convex object-side surface at the paraxial region and a concave image-side surface. The fourth lens element 4 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface. The fifth lens element 5 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens element 6 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface.

Table 1 shows the surface type, radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each lens of the optical lens of example 1, wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

TABLE 1

Surface numbering	Surface name	Surface type	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									S0	Article surface	Spherical surface	INF	INF
S1	First lens	Aspherical surface	-6212.1385	0.6951	Plastic material	1.5445	55.987	-3.17
									S2		Aspherical surface	1.7323	0.9
S3	Second lens	Spherical surface	10.2776	1.4711	Glass	1.728426	46.118	3.28
									S4		Spherical surface	-2.9454	0.05
S5	Diaphragm	Spherical surface	INF	0.1145
									S6	Third lens	Aspherical surface	3.1133	0.4247	Plastic material	1.6397	23.5289	-3.95
S7		Aspherical surface	1.3264	0.1026
									S8	Fourth lens	Aspherical surface	2.2529	0.9329	Plastic material	1.5352	56.115	5.52
S9		Aspherical surface	8.0363	0.1975
									S10	Fifth lens element	Aspherical surface	1.1487	0.7514	Plastic material	1.5352	56.115	1.64
S11		Aspherical surface	-2.89	0.2867
									S12	Sixth lens element	Aspherical surface	-0.9832	0.6005	Plastic material	1.6397	23.5289	-2.44
S13		Aspherical surface	-3.2398	0.6672
									S14	Optical filter	Spherical surface	INF	0.21	Glass	-	-	-
S15		Spherical surface	INF	0.5847
									S16	Image plane	Spherical surface	INF	-

Table 2 below gives the cone coefficient k, the higher order term coefficients a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 1.

TABLE 2

Surface numbering	S1	S2	S6	S7	S8	S9	S10	S11	S12	S13
											k	13.264	0.000	1.495	0.000	-32.860	25.171	-4.616	1.395	-1.537	1.128
A4	0.004	0.034	-0.179	-0.317	0.180	-0.638	-0.108	0.327	0.721	0.459
											A6	-0.009	-0.046	0.084	0.541	-0.482	0.971	0.160	-0.377	-1.705	-0.871
A8	0.007	0.138	-0.037	-2.019	1.342	-1.907	-0.650	-0.597	2.549	1.264
											A10	-0.003	-0.248	-2.145	5.077	-3.804	3.661	1.435	2.401	-2.317	-1.207
A12	0.001	0.311	12.592	-8.518	7.438	-5.356	-1.930	-3.357	1.289	0.759
											A14	0.000	-0.240	-34.878	9.750	-8.628	5.274	1.651	2.543	-0.496	-0.317
A16	0.000	0.000	53.138	-7.359	5.742	-3.178	-0.857	-1.097	0.168	0.087

Any surfaces of the first lens 1, the third lens 3, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are aspheric surfaces, wherein Z is a point on the aspheric surface which is away from the optical axis by h and a relative distance between the point and a tangent plane tangent to an intersection point on the aspheric optical axis; h is the distance between a point on the aspheric curve and the optical axis; c being paraxial to aspheric surfaceCurvature, c ═ 1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; a. the ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ High-order term coefficients of the aspheric lens surface; and satisfies the following formula:

the optical lens in embodiment 1 satisfies:

1. in the optical lens, the focal length of the first lens is f1, the focal length of the sixth lens is f6, and f1/f6 is 1.3, which satisfies the following conditions: 1.1< f1/f6< 2.

2. A radius of curvature of the object-side surface of the first lens is R1, a radius of curvature of the image-side surface of the fourth lens is R8, (R1-R8)/(R1+ R8) is 1.003, and satisfies: 0.5< (R1-R8)/(R1+ R8) < 1.4.

3. The maximum edge thickness of the first lens in the optical lens is CT1max, the thickness of the first lens on the optical axis is CT1, and CT1max/CT1 is 2.41, and the optical lens meets the following conditions: CT1max/CT1< 2.5.

4. The distance from the outermost point of the image side surface of the sixth lens to the imaging surface in the optical lens is BFL, the focal length is f, and the BFL/f is 0.614, which satisfies the following conditions: BFL/f > 0.6.

5. The entrance pupil diameter of the optical lens is EPD, the maximum image height is imgH, and the EPD/imgH is 0.43, which satisfies the following conditions: 0.4< EPD/ImgH <2.

6. In the optical lens, the sum of the distance between two adjacent lenses on the optical axis is Σ CT, the distance from the object side surface of the first lens to the imaging surface is TTL, and Σ CT/TTL is 0.21, which satisfies: 0.2< ∑ CT/TTL < 0.4.

In addition, fig. 2A shows an axial chromatic aberration curve of the optical lens of embodiment 1, which shows how the converging focal points of light rays with different wavelengths deviate after passing through the lens. Fig. 2B shows astigmatism curves of the optical lens of example 1, which represent meridional field curvature and sagittal field curvature. Fig. 2C shows distortion curves of the optical lens of example 1, which indicate values of distortion magnitudes for different angles of view. As can be seen from fig. 2A to 2C, the optical lens system of embodiment 1 has the characteristics of wide-angle shooting, small astigmatism, and the like, and can achieve good imaging quality.

Example 2

Fig. 3 and fig. 4A to 4C are given below of an optical lens according to embodiment 2 of the present application, and fig. 3 is a schematic structural view of the optical lens according to embodiment 2.

The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1; a second lens 2; a diaphragm 8; a third lens 3; a fourth lens 4; a fifth lens 5 and a sixth lens 6. The first lens element 1 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface at the paraxial region and a concave image-side surface. The second lens element 2 is a spherical glass lens element with positive refractive power, and has a convex object-side surface at the paraxial region and a convex image-side surface at the paraxial region. The third lens element 3 is an aspheric plastic lens with negative refractive power, and has a convex object-side surface at the paraxial region and a concave image-side surface. The fourth lens element 4 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface. The fifth lens element 5 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens element 6 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface.

Table 3 shows the surface type, radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each lens of the optical lens of example 2, wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

TABLE 3

Surface numbering	Surface name	Surface type	Radius of curvature	Thickness of	Material of	Refractive index	Coefficient of dispersion	Focal length
									S0	Article surface	Spherical surface	INF	INF
S1	First lens	Aspherical surface	-6408.6209	0.6950	Plastic material	1.5445	55.9870	-3.17
									S2		Aspherical surface	1.7322	0.8500
S3	Second lens	Spherical surface	10.2777	1.4711	Glass	1.7284	46.1180	3.28
									S4		Spherical surface	-2.9454	0.0500
S5	Diaphragm	Spherical surface	INF	0.1145
									S6	Third lens	Aspherical surface	3.1133	0.4247	Plastic material	1.6397	23.5289	-3.95
S7		Aspherical surface	1.3264	0.1026
									S8	Fourth lens	Aspherical surface	2.2529	0.6029	Plastic material	1.5352	56.1150	5.63
S9		Aspherical surface	8.0363	0.1975
									S10	Fifth lens element	Aspherical surface	1.1487	0.7514	Plastic material	1.5352	56.1150	1.64
S11		Aspherical surface	-2.8900	0.2866
									S12	Sixth lens element	Aspherical surface	-0.9832	0.4050	Plastic material	1.6397	23.5289	-2.36
S13		Aspherical surface	-3.2405	0.6673
									S14	Optical filter	Spherical surface	INF	0.2100	Glass	-	-	-
S15		Spherical surface	INF	0.6833
									S16	Image plane	Spherical surface	INF	-

Table 4 below gives the cone coefficient k, and the higher order term coefficients a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 2.

TABLE 4

Surface numbering	S1	S2	S6	S7	S8	S9	S10	S11	S12	S13
											k	13.264	-0.020	1.494	0	0	25.171	-4.616	1.395	-1.537	0
A4	0.004	0.034	-0.179	-0.317	0.180	-0.638	-0.108	0.327	0.721	0.459
											A6	-0.009	-0.046	0.082	0.542	-0.482	0.972	0.160	-0.376	-1.706	-0.871
A8	0.007	0.139	-0.017	-2.021	1.343	-1.908	-0.650	-0.598	2.551	1.264
											A10	-0.003	-0.250	-2.259	5.084	-3.805	3.663	1.435	2.402	-2.319	-1.206
A12	0.001	0.313	12.968	-8.531	7.440	-5.358	-1.930	-3.358	1.291	0.758
											A14	0.000	-0.241	-35.622	9.764	-8.630	5.275	1.650	2.544	-0.497	-0.317
A16	0.000	0.110	54.006	-7.369	5.742	-3.179	-0.857	-1.097	0.168	0.087

Any surfaces of the first lens 1, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are aspheric. Wherein each aspherical surface type can be defined by the formula given in the above embodiment 1. The optical lens in embodiment 2 satisfies:

1. in the optical lens, the focal length of the first lens is f1, the focal length of the sixth lens is f6, and f1/f6 is 1.34, which satisfies the following conditions: 1.1< f1/f6< 2.

2. A radius of curvature of the object-side surface of the first lens is R1, a radius of curvature of the image-side surface of the fourth lens is R8, (R1-R8)/(R1+ R8) is 1.003, and satisfies: 0.5< (R1-R8)/(R1+ R8) < 1.4.

3. The maximum edge thickness of the first lens in the optical lens is CT1max, the thickness of the first lens on the optical axis is CT1, and CT1max/CT1 is 2.13, which satisfies the following conditions: CT1max/CT1< 2.5.

4. The distance from the outermost point of the image side surface of the sixth lens element to the imaging surface in the optical lens is BFL, the focal length is f, and the BFL/f is 0.678, which satisfies the following conditions: BFL/f > 0.6.

5. The entrance pupil diameter of the optical lens is EPD, the maximum image height is ImgH, and EPD/ImgH is 0.41, and the optical lens meets the following requirements: 0.4< EPD/ImgH <2.

6. In the optical lens, the sum of the distance between two adjacent lenses on the optical axis is Σ CT, the distance from the object side surface of the first lens to the imaging surface is TTL, and Σ CT/TTL is 0.213, which satisfies: 0.2< ∑ CT/TTL < 0.4.

In addition, fig. 4A shows an axial chromatic aberration curve of the optical lens of embodiment 2, which shows the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens. Fig. 4B shows astigmatism curves of the optical lens of example 2, which represent meridional field curvature and sagittal field curvature. Fig. 4C shows a distortion curve of the optical lens of example 2, which represents the distortion magnitude values in the case of different viewing angles. As can be seen from fig. 4A to 4C, the optical lens provided in embodiment 2 has the characteristics of wide-angle shooting, small chromatic aberration, and the like, and can achieve good imaging quality.

Example 3

Fig. 5 and fig. 6A to 6C are given below of an optical lens according to embodiment 3 of the present application, and fig. 5 is a schematic structural view of the optical lens according to embodiment 3.

The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1; a second lens 2; a diaphragm 8; a third lens 3; a fourth lens 4; a fifth lens 5 and a sixth lens 6. The first lens element 1 is an aspheric plastic lens with negative refractive power, and has a convex object-side surface at the paraxial region and a concave image-side surface. The second lens element 2 is a spherical glass lens element with positive refractive power, and has a convex object-side surface at the paraxial region and a convex image-side surface at the paraxial region. The third lens element 3 is an aspheric plastic lens with negative refractive power, and has a convex object-side surface at the paraxial region and a concave image-side surface. The fourth lens element 4 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface. The fifth lens element 5 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens element 6 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface.

Table 5 shows the surface type, radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each lens of the optical lens of example 3, wherein the units of the radius of curvature and the thickness are millimeters (mm).

TABLE 5

Table 6 below gives the cone coefficient k, and the coefficients of the higher order terms a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 3.

TABLE 6

Surface numbering	S1	S2	S6	S7	S8	S9	S10	S11	S12	S13
											k	13.264	0.000	1.519	0.000	-32.860	25.171	-4.621	1.426	-1.536	1.208
A4	0.006	0.037	-0.244	-0.432	0.250	-0.875	-0.150	0.452	1.011	0.626
											A6	-0.015	-0.031	0.159	0.863	-0.861	1.657	0.259	-0.772	-3.076	-1.472
A8	0.015	0.173	-0.675	-3.656	3.129	-3.970	-1.213	-0.519	6.108	2.631
											A10	-0.009	-0.473	0.815	10.292	-10.955	9.183	3.214	4.273	-7.801	-3.068
A12	0.003	0.837	7.092	-19.308	25.916	-16.338	-5.316	-7.801	6.654	2.330
											A14	-0.001	-0.851	-42.608	25.488	-36.469	19.773	5.677	7.396	-4.126	-1.166
A16	0.000	0.494	106.157	-23.390	29.564	-14.727	-3.694	-3.934	1.928	0.380

Any surfaces of the first lens 1, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are aspheric. Wherein each aspherical surface type can be defined by the formula given in the above embodiment 1. The optical lens in embodiment 3 satisfies:

1. in the optical lens, the focal length of the first lens is f1, the focal length of the sixth lens is f6, and f1/f6 is 1.3, which satisfies the following conditions: 1.1< f1/f6< 2.

2. A radius of curvature of the object-side surface of the first lens is R1, a radius of curvature of the image-side surface of the fourth lens is R8, (R1-R8)/(R1+ R8) is 0.94, and satisfies: 0.5< (R1-R8)/(R1+ R8) < 1.4.

3. The maximum edge thickness of the first lens in the optical lens is CT1max, the thickness of the first lens on the optical axis is CT1, and CT1max/CT1 is 2.1, which satisfies the following conditions: CT1max/CT1< 2.5.

4. The distance from the outermost point of the image side surface of the sixth lens to the imaging surface in the optical lens is BFL, the focal length is f, and the BFL/f is 0.706, so that the following requirements are met: BFL/f > 0.6.

5. The entrance pupil diameter of the optical lens is EPD, the maximum image height is imgH, and the EPD/imgH is 0.46, which satisfies the following conditions: 0.4< EPD/ImgH <2.

6. In the optical lens, the sum of the distance between each two adjacent lenses on the optical axis is sigma CT, the distance from the object side surface of the first lens to the imaging surface is TTL, and sigma CT/TTL is 0.27, which satisfies the following conditions: 0.2< ∑ CT/TTL < 0.4.

In addition, fig. 6A shows a chromatic aberration curve on the axis of the optical lens of embodiment 3, which shows the case where the converging focal points of the light rays with different wavelengths are deviated after passing through the lens. Fig. 6B shows astigmatism curves of the optical lens of embodiment 3, which represent meridional field curvature and sagittal field curvature. Fig. 6C shows a distortion curve of the optical lens of embodiment 3, which represents the distortion magnitude values in the case of different viewing angles. As can be seen from fig. 6A to 6C, the optical lens system according to embodiment 3 has the characteristics of wide-angle shooting, small astigmatism, small chromatic aberration, and the like, and can achieve good imaging quality.

Example 4

Fig. 7 and fig. 8A to 8C are given below of an optical lens according to embodiment 4 of the present application, and fig. 7 is a schematic structural view of the optical lens of embodiment 4.

The optical lens sequentially comprises from an object side to an image side along an optical axis: a first lens 1; a second lens 2; a diaphragm 8; a third lens 3; a fourth lens 4; a fifth lens 5 and a sixth lens 6. The first lens element 1 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface at the paraxial region and a concave image-side surface. The second lens element 2 is a spherical glass lens element with positive refractive power, and has a convex object-side surface at the paraxial region and a convex image-side surface at the paraxial region. The third lens element 3 is an aspheric plastic lens with negative refractive power, and has a convex object-side surface at the paraxial region and a concave image-side surface. The fourth lens element 4 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface. The fifth lens element 5 is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens element 6 is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface.

Table 7 shows the surface type, radius of curvature, thickness, material, refractive index, dispersion coefficient, and focal length of each lens of the optical lens of example 4, wherein the unit of the radius of curvature and the thickness are both millimeters (mm).

TABLE 7

Table 8 below gives the cone coefficient k, and the higher order term coefficients a4, a6, A8, a10, a12, a14, and a16 that can be used for each aspherical mirror in example 4.

TABLE 8

Surface numbering	S1	S2	S6	S7	S8	S9	S10	S11	S12	S13
											k	13.264	-0.177	1.022	-0.222	-32.860	25.171	-4.477	1.510	-1.608	1.028
A4	0.003	0.031	-0.156	-0.282	0.213	-0.651	-0.148	0.298	0.753	0.464
											A6	-0.006	-0.046	-0.280	0.277	-0.640	1.231	0.345	-0.457	-1.821	-0.768
A8	0.004	0.157	2.735	-0.836	1.728	-2.883	-1.057	0.151	3.161	0.957
											A10	-0.002	-0.291	-13.854	1.746	-3.932	5.608	1.923	0.328	-4.110	-0.778
A12	0.000	0.333	41.192	-2.332	6.217	-7.616	-2.184	-0.405	4.009	0.394
											A14	0.000	-0.228	-74.337	2.151	-6.171	6.777	1.614	0.158	-2.814	-0.119
A16	0.000	0.091	80.201	-1.432	3.669	-3.714	-0.751	0.006	1.300	0.020

Any surfaces of the first lens 1, the third lens 3, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are aspheric. Wherein each aspherical surface type can be defined by the formula given in the above embodiment 1. The optical lens in embodiment 4 satisfies:

1. in the optical lens, the focal length of the first lens is f1, the focal length of the sixth lens is f6, and f1/f6 is 1.24, which satisfies the following conditions: 1.1< f1/f6< 2.

2. A radius of curvature of the object-side surface of the first lens is R1, a radius of curvature of the image-side surface of the fourth lens is R8, (R1-R8)/(R1+ R8) is 1.19, and satisfies: 0.5< (R1-R8)/(R1+ R8) < 1.4.

3. The maximum edge thickness of the first lens in the optical lens is CT1max, the thickness of the first lens on the optical axis is CT1, and CT1max/CT1 is 2, which satisfies the following conditions: CT1max/CT1< 2.5.

4. The distance from the outermost point of the image side surface of the sixth lens to the imaging surface in the optical lens is BFL, the focal length is f, and the BFL/f is 0.66, which satisfies the following conditions: BFL/f > 0.6.

5. The entrance pupil diameter of the optical lens is EPD, the maximum image height is imgH, and the EPD/imgH is 0.5, which satisfies the following conditions: 0.4< EPD/ImgH <2.

6. In the optical lens, the sum of the distance between each two adjacent lenses on the optical axis is sigma CT, the distance from the object side surface of the first lens to the imaging surface is TTL, and sigma CT/TTL is 0.28, which satisfies the following conditions: 0.2< ∑ CT/TTL < 0.4.

In addition, fig. 8A shows a chromatic aberration curve on the axis of the optical lens of example 4, which shows how the converging focal points of the light rays with different wavelengths are deviated after passing through the lens. Fig. 8B shows astigmatism curves of the optical lens of example 4, which represent meridional field curvature and sagittal field curvature. Fig. 8C shows a distortion curve of the optical lens of example 4, which represents the distortion magnitude values in the case of different viewing angles. As can be seen from fig. 8A to 8C, the optical lens system according to embodiment 4 has the characteristics of wide-angle shooting, small astigmatism, small chromatic aberration, and the like, and can achieve good imaging quality.

Claims (5)

1. A wide-angle optical lens, in order from an object side to an image side along an optical axis, comprising: the lens comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens and a sixth lens;

the first lens element is an aspheric plastic lens with negative refractive power, and has a convex or concave object-side surface at the paraxial region and a concave image-side surface;

the second lens is a spherical glass lens with positive refractive power;

the third lens is an aspheric plastic lens with negative refractive power;

the fourth lens element is an aspheric plastic lens with positive refractive power, and has a convex object-side surface and a concave image-side surface;

the fifth lens element is an aspheric plastic lens with positive refractive power;

the sixth lens element is an aspheric plastic lens with negative refractive power, and has a concave object-side surface and a convex image-side surface;

the optical lens satisfies the following conditions:

1.1<f1/f6<2

0.5<(R1-R8)/(R1+R8)<1.4

wherein f1 is the focal length of the first lens, and f6 is the focal length of the sixth lens; r1 is a radius of curvature of the object-side surface of the first lens element, and R8 is a radius of curvature of the image-side surface of the fourth lens element.

2. A wide-angle optical lens as claimed in claim 1, wherein the optical lens satisfies the following relation:

CT1 _max /CT1<2.5

among them, CT1 _max CT1 is the thickness of the first lens on the optical axis, which is the maximum edge thickness of the first lens.

3. A wide-angle optical lens as claimed in claim 1, wherein the optical lens satisfies the following relation:

BFL/f>0.6

and BFL is the distance from the outermost point of the image side surface of the sixth lens to the imaging surface, and f is the focal length of the optical lens.

4. A wide-angle optical lens as claimed in claim 1, wherein the optical lens satisfies the following relation:

0.4<EPD/ImgH<2

the EPD is the entrance pupil diameter of the optical lens, and the ImgH is the maximum image height of the optical lens.

5. A wide-angle optical lens as claimed in claim 1, wherein the optical lens satisfies the following relationship:

0.2<∑CT/TTL<0.4

sigma CT is the sum of the distances between two adjacent lenses in the optical lens on the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface.

Images