CN212255849U

CN212255849U - Miniaturized athermal prime lens with six lenses

Info

Publication number: CN212255849U
Application number: CN202021309003.0U
Authority: CN
Inventors: 王锦平
Original assignee: Dongguan Changyi Photoelectric Co ltd
Current assignee: Dongguan Changyi photoelectric Co.,Ltd.
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2020-12-29
Anticipated expiration: 2030-07-07

Abstract

The utility model discloses a six lens's miniaturized no thermalization tight shot includes first lens, second lens, third lens, fourth lens, fifth lens and sixth lens from the object side to the image plane in proper order, wherein first lens are negative meniscus negative refractive power lens, and second lens and fifth lens are biconcave negative refractive power lens, and third lens, fourth lens and sixth lens are biconvex positive refractive power lens, are the grating face between third lens and the fourth lens. The utility model discloses a focus of each lens of rational configuration realizes big wide angle, big light ring, does not have the thermalization, has advantages such as resistant ambient temperature stability.

Description

Miniaturized athermal prime lens with six lenses

Technical Field

The utility model relates to a camera lens technical field, especially a miniaturized athermal prime lens of six lenses.

Background

With the development of security lenses, the requirements on imaging quality are higher and higher while the products are further miniaturized. The requirements for image quality in a night vision environment are becoming more and more strict, and therefore a lens capable of realizing full-color photographing under a low-light condition is required.

However, the existing products obviously cannot meet the technical requirements of large wide angle, large aperture, no heat and the like while achieving miniaturization, and therefore further technical research and development are needed.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is not enough to above-mentioned prior art, provide a miniaturized no thermalization prime lens of six lenses, realized the miniaturization of product, realized not thermalization when satisfying big wide angle, big light ring.

In order to solve the technical problem, the utility model discloses the technical scheme who takes is: the zoom lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image plane, wherein the first lens is a negative meniscus negative refractive power lens, the second lens and the fifth lens are biconcave negative refractive power lenses, the third lens, the fourth lens and the sixth lens are double convex positive refractive power lenses, and a grating surface is arranged between the third lens and the fourth lens.

In the above technical solution, an optical filter is further disposed between the sixth lens and the imaging side.

In the above technical solution, at least one or two surfaces of the second lens, the fourth lens, the fifth lens and the sixth lens are aspheric surfaces, and the third lens is a spherical surface or an aspheric surface.

In the above technical solution, the focal length f1 of the first lens satisfies the following condition: -2.2< f1/f < -1.8; where f is the focal length of the lens.

In the above technical solution, the focal length f2 of the second lens satisfies the following condition: -2.8< f2/f < -2.25; where f is the focal length of the lens.

In the above technical solution, the focal length f3 of the third lens satisfies the following condition: 2.1< f3/f < 2.3; where f is the focal length of the lens.

In the above technical solution, the focal length f4 of the fourth lens satisfies the following condition: 1.4< f4/f < 1.8; where f is the focal length of the lens.

In the above technical solution, the focal length f5 of the fifth lens satisfies the following condition: -1.6< f5/f < -1.05; where f is the focal length of the lens.

In the above technical solution, the focal length f6 of the sixth lens meets the following condition: 1.6< f6/f < 2.2; where f is the focal length of the lens.

The utility model has the advantages that: the miniaturized athermal prime lens with six lenses sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an imaging surface, wherein the first lens is a negative meniscus negative refractive power lens, the second lens and the fifth lens are double-concave negative refractive power lenses, the third lens, the fourth lens and the sixth lens are double-convex positive refractive power lenses, and a grating surface is arranged between the third lens and the fourth lens. And the large wide angle, the large aperture and the athermalization are realized by reasonably configuring the focal length of each lens, and the lens has the advantages of environmental temperature stability resistance and the like.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the optical path of the present invention;

fig. 3 is a graph of field curvature/distortion characteristics of an embodiment of the present invention;

fig. 4 is a graph of axial tolerance of an embodiment of the present invention.

In the figure, the first to sixth lenses L1 to L6, the filter IRCF, the lens surfaces s1 to s12, the grating surface STO and the imaging surface IMA.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, a six-lens small-sized athermalized prime lens includes, in order from an object side to an image plane IMA, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6, wherein the first lens L1 is a negative meniscus negative refractive power lens, the second lens L2 and the fifth lens L5 are biconcave negative refractive power lenses, the third lens L3, the fourth lens L4, and the sixth lens L5 are biconvex positive refractive power lenses, and a grating plane STO is located between the third lens L3 and the fourth lens L4. An optical filter IRCF is further arranged between the sixth lens L6 and the imaging side. At least one or two surfaces of the second lens L2, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are aspheric surfaces, and the third lens L3 is a spherical surface or an aspheric surface. The focal length f1 of the first lens L1 satisfies the following condition: -2.2< f1/f < -1.8; where f is the focal length of the lens. The focal length f2 of the second lens L2 satisfies the following condition: -2.8< f2/f < -2.25; where f is the focal length of the lens. A focal length f3 of the third lens L3 satisfies the following condition: 2.1< f3/f < 2.3; where f is the focal length of the lens. A focal length f4 of the fourth lens L4 satisfies the following condition: 1.4< f4/f < 1.8; where f is the focal length of the lens. A focal length f5 of the fifth lens L5 satisfies the following condition: -1.6< f5/f < -1.05; where f is the focal length of the lens. A focal length f6 of the sixth lens L6 satisfies the following condition: 1.6< f6/f < 2.2; where f is the focal length of the lens. Further description will be made below by way of specific examples.

The following is a specific embodiment of the optical system, the aspheric coefficients in the embodiment being defined as follows:

when the optical axis is located in the Z direction, Z (r) is the sag value calculated from the vertex of the surface, C is the reciprocal of the paraxial radius of curvature, r is the height from the optical axis, K is a conic constant, and A2i is an aspheric coefficient.

Parameters of the examples

Focal length of entire system: f =3.00mm

F-number=1.6

FOV=142°

f1=-6.222mm,f2=-7.361mm,f3=6.511mm,f4=5.014mm,f5=-3.743mm,

f6=5.619mm

f1/f=-2.06

f2/f=-2.44

f3/f=2.16

f4/f=1.66

f5/f=-1.24

f6/f=-1.86 。

The lens in the embodiment has the following conditions (table 1) that the radius of curvature R of each lens, the thickness d of each lens, the distance between lenses, the refractive index nd of each lens, and the abbe number vd of each lens satisfy the following conditions:

table 1: physical parameters of each lens

	Flour mark	Radius of curvature R	Thickness d	Effective diameter	Refractive index nd	Abbe number vd
								Article surface	Infinite number of elements	Infinite number of elements	---	---	---
L1	s1	24.068	0.600	13.50	1.62	56.73
								s2	3.303	3.057	6.29
L2	s3	-6.711	1.000	6.15	1.54	55.78
								s4	10.032	0.493	6.15
L3	s5	11.968	4.500	6.50
								s6	-7.460	2.164	6.30	1.79	44.21
STO	s7	Infinite number of elements	-0.050	4.75
							L4	s8	4.955	2.622	5.20	1.54	55.78
	s9	-4.773	0.100	4.60
							L5	s10	-4.804	0.700	4.30	1.64	23.97
	s11	4.979	0.382	5.00
							L6	s12	Infinite number of elements	2.257	5.85	1.54	55.78
	s13	Infinite number of elements	0.100	6.27
							IRCF	s14	Infinite number of elements	0.700	5.73	1.52	64.21
	s15	Infinite number of elements	3.873	5.82

As can be seen from Table 1, the focal powers of the first lens element to the sixth lens elements L1-L6 are distributed reasonably, so that the focal power of each lens element is in a reasonable interval, the tolerance sensitivity is reduced to the greatest extent, and the best performance is achieved.

The aspheric coefficients of the object planes s3, s4, s8, s9, s10, s11, s12 and s13 are as follows (table 2):

table 2:

K

A4

A6

A8

A10

A12

A14

A16

S3

2.16

6.09E-04

2.08E-04

-1.53E-05

6.26E-07

1.89E-08

0.00E+00

S4

7.96

7.53E-05

2.15E-04

-4.35E-05

4.01E-06

-2.24E-07

0.00E+00

S8

-0.65

2.05E-04

2.52E-04

-3.34E-05

6.74E-06

-1.62E-07

0.00E+00

S9

2.58

3.64E-03

2.01E-03

-4.23E-04

8.88E-05

-5.41E-06

0.00E+00

s10

-11.54

-7.96E-03

2.37E-03

-6.99E-04

1.41E-04

-1.30E-05

0.00E+00

s11

-4.93

2.58E-03

-1.28E-04

9.81E-05

-1.20E-05

-1.41E-07

0.00E+00

s12

-2.74

-8.71E-03

1.54E-03

-2.24E-04

2.79E-05

-1.40E-06

0.00E+00

s13

-19.03

-7.22E-03

4.13E-04

-8.65E-06

-3.56E-06

4.60E-07

0.00E+00

as can be seen from table 2, the aspheric coefficients of the second lens L2, the fourth lens L4, the fifth lens L5 and the sixth lens L6 provide advantages.

The field curvature/distortion characteristic graph of the present embodiment can be seen from fig. 3, and the axial convergence graph of the present embodiment can be seen from fig. 4. Fig. 3 and 4 can reflect the main parameter level that the lens of the embodiment can reach in the optical design, which is superior to the existing lens products of the same type.

The above embodiments are merely illustrative and not restrictive, and all equivalent changes and modifications made by the methods described in the claims are intended to be included within the scope of the present invention.

Claims

1. A miniaturized athermal prime lens with six lenses is characterized in that: the zoom lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image plane, wherein the first lens is a negative meniscus negative refractive power lens, the second lens and the fifth lens are biconcave negative refractive power lenses, the third lens, the fourth lens and the sixth lens are double convex positive refractive power lenses, and a grating surface is arranged between the third lens and the fourth lens.

2. The six-lens miniature athermal prime lens of claim 1, wherein: and an optical filter is arranged between the sixth lens and the imaging side.

3. The six-lens miniature athermal prime lens of claim 1, wherein: at least one surface or two surfaces of the second lens, the fourth lens, the fifth lens and the sixth lens are aspheric surfaces, and the third lens is a spherical surface or an aspheric surface.

4. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f1 of the first lens satisfies the following condition: -2.2< f1/f < -1.8; where f is the focal length of the lens.

5. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f2 of the second lens satisfies the following condition: -2.8< f2/f < -2.25; where f is the focal length of the lens.

6. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f3 of the third lens satisfies the following condition: 2.1< f3/f < 2.3; where f is the focal length of the lens.

7. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f4 of the fourth lens satisfies the following condition: 1.4< f4/f < 1.8; where f is the focal length of the lens.

8. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f5 of the fifth lens satisfies the following condition: -1.6< f5/f < -1.05; where f is the focal length of the lens.

9. The six-lens miniature athermal prime lens of claim 1, wherein: the focal length f6 of the sixth lens satisfies the following condition: 1.6< f6/f < 2.2; where f is the focal length of the lens.