CN213399035U

CN213399035U - Low-distortion fixed-focus lens with five lenses

Info

Publication number: CN213399035U
Application number: CN202022489941.XU
Authority: CN
Inventors: 王锦平
Original assignee: Dongguan Changyi Photoelectric Co ltd
Current assignee: Dongguan Changyi photoelectric Co.,Ltd.
Priority date: 2020-11-02
Filing date: 2020-11-02
Publication date: 2021-06-08
Anticipated expiration: 2030-11-02

Abstract

The utility model discloses a low distortion prime lens of five lenses, it includes first lens, second lens, third lens, fourth lens and fifth lens from the object side to the imaging surface in proper order, and wherein first lens are negative meniscus negative refractive power lens, and the second lens are biconvex positive refractive power lens, and the third lens are negative meniscus positive refractive power lens, and fourth lens and fifth lens are positive meniscus positive refractive power lens, and the convex surface towards the object side in the second lens is the grating face. And through the focal length of each lens of rational configuration, realize big wide angle, big light ring, low distortion, have advantages such as resistant ambient temperature stability.

Description

Low-distortion fixed-focus lens with five lenses

Technical Field

The utility model relates to a camera lens technical field, especially a low distortion prime lens of five lenses.

Background

Along with the popularization of intelligent electrical equipment, the miniaturization and performance requirements for the lens are higher and higher, so that the original existing lens module cannot completely meet the market requirements.

The current products obviously cannot meet the technical requirements of miniaturization (such as 1/2.7 inch lens chip) and the requirements of large wide angle, large aperture, low distortion and the like, 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 low distortion tight shot of five lenses, realized the miniaturization of product, realized low distortion 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: a low-distortion prime lens of a five-lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an imaging surface, wherein the first lens is a negative meniscus negative refractive power lens, the second lens is a double-convex positive refractive power lens, the third lens is a negative meniscus positive refractive power lens, the fourth lens and the fifth lens are positive meniscus positive refractive power lenses, and a convex surface facing the object side in the second lens is a grating surface.

In the above technical scheme, an optical filter is further disposed between the fifth lens and the imaging surface.

In the above technical solution, at least one surface or two surfaces of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element are aspheric surfaces.

In the above technical solution, the focal length f1 of the first lens satisfies the following condition: -1.9< f1/f < -1.3; 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: 0.6< f2/f < 0.95; 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< f3/f < -1.4; 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: 2.2< f4/f < 2.6; 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: 8.5< f5/f < 12; where f is the focal length of the lens.

The utility model has the advantages that: the low-distortion prime lens of the five lenses sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an imaging surface, wherein the first lens is a negative meniscus negative refractive power lens, the second lens is a double-convex positive refractive power lens, the third lens is a negative meniscus positive refractive power lens, the fourth lens and the fifth lens are positive meniscus positive refractive power lenses, and a convex surface facing the object side in the second lens is a grating surface. And through the focal length of each lens of rational configuration, realize big wide angle, big light ring, low distortion, have advantages such as resistant ambient temperature stability.

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 and 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 fifth lenses L1-L5, the filter IRCF, the lens surfaces s 1-s 12, 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. 1-2, a low-distortion fixed-focus lens with five lenses 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, and a fifth lens L5, wherein the first lens L1 is a negative meniscus negative refractive power lens, the second lens L2 is a biconvex positive refractive power lens, the third lens L3 is a negative meniscus positive refractive power lens, the fourth lens L4 and the fifth lens L5 are positive meniscus positive refractive power lenses, and a convex surface of the second lens L2 facing the object side is a grating plane STO. An optical filter IRCF is further disposed between the fifth lens L5 and the imaging plane IMA. At least one surface or both surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are aspheric. The focal length f1 of the first lens L1 satisfies the following condition: -1.9< f1/f < -1.3; where f is the focal length of the lens. The focal length f2 of the second lens L2 satisfies the following condition: 0.6< f2/f < 0.95; where f is the focal length of the lens. The focal length f3 of the third lens L3 satisfies the following condition: -2< f3/f < -1.4; where f is the focal length of the lens. The focal length f4 of the fourth lens L4 satisfies the following condition: 2.2< f4/f < 2.6; where f is the focal length of the lens. The focal length f5 of the fifth lens L5 satisfies the following condition: 8.5< f5/f < 12; 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.

The parameters in the examples are as follows:

focal length of entire system: f =3.15mm

F-number=2.3

FOV=97°

f1=-5.52mm,f2=2.71mm,f3=5.04mm,f4=8.14mm,f5=30.54mm,

f1/f=-1.75

f2/f=0.86

f3/f=-1.60

f4/f=2.58

f5/f=9.66 。

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	-17.030	0.480	4.46	1.54	55.95
								s2	3.683	1.795	3.22
STO	s3	Infinite number of elements	-0.053	1.83
							L2	s4	3.933	1.528	1.89	1.54	55.95
	s5	-2.039	0.401	2.66
							L3	s6	3.684	0.320	2.78	1.66	20.37
	s7	1.690	0.824	3.14
							L4	s8	-2.546	0.800	3.95	1.54	55.95
	s9	-1.796	0.064	4.27
							L5	s10	1.784	0.870	5.51	1.54	55.95
	s11	1.656	0.935	5.73
							IRCF	s12	Infinite number of elements	0.700	6.23	1.52	64.17
	s13	Infinite number of elements	0.705	6.33

As can be seen from table 1, the focal powers of the first lens element to the fifth lens element L1 to L5 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 exhibited.

Wherein, aspheric coefficients of surfaces of surface numbers s1, s2, s4, s5, s6, s7, s8, s9, s10 and s11 are as follows (tables 2-1 and 2-2):

table 2-1:

	K	A4	A6	A8	A10
						s1	25.51	8.42E-02	-4.15E-02	1.85E-02	-6.27E-03
s2	-11.94	1.38E-01	-3.34E-02	-1.69E-02	4.52E-02
						s4	-8.04	-5.78E-03	2.83E-03	-7.61E-02	1.57E-01
s5	-2.71	-6.50E-02	4.73E-03	3.89E-04	-8.55E-04
						s6	-60.00	-4.40E-02	-2.52E-01	4.25E-01	-4.24E-01
s7	-6.28	-5.55E-03	-1.45E-01	2.24E-01	-1.94E-01
						s8	-16.39	7.21E-02	-4.45E-02	3.87E-02	-2.24E-02
s9	-0.45	3.86E-03	5.49E-02	-4.97E-02	3.30E-02
						s10	-6.71	-2.31E-02	-1.16E-02	1.02E-02	-3.51E-03
s11	-3.69	-6.49E-02	2.15E-02	-5.80E-03	1.21E-03

tables 2 to 2:

	A12	A14	A16	A18
					s1	1.44E-03	-2.11E-04	1.75E-05	-6.31E-07
s2	-3.71E-02	1.59E-02	-3.52E-03	3.14E-04
					s4	-2.19E-01	1.65E-01	-5.46E-02
s5	-4.95E-03	3.82E-03	-9.75E-04
					s6	2.79E-01	-1.15E-01	2.66E-02	-2.66E-03
s7	1.05E-01	-3.45E-02	6.36E-03	-5.02E-04
					s8	8.05E-03	-1.78E-03	2.22E-04	-1.21E-05
s9	-1.18E-02	2.27E-03	-2.24E-04	9.01E-06
					s10	6.75E-04	-7.56E-05	4.64E-06	-1.22E-07
s11	-1.90E-04	2.01E-05	-1.24E-06	3.39E-08

as can be seen from tables 2-1 and 2-2, the advantages are brought about by the aspheric coefficients of the surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5.

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. The utility model provides a five low distortion prime lens of lens which characterized in that: the zoom lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an imaging surface, wherein the first lens is a negative meniscus negative refractive power lens, the second lens is a double convex positive refractive power lens, the third lens is a negative meniscus positive refractive power lens, the fourth lens and the fifth lens are positive meniscus positive refractive power lenses, and a convex surface facing the object side in the second lens is a grating surface.

2. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: and an optical filter is arranged between the fifth lens and the imaging surface.

3. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: at least one surface or two surfaces of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are aspheric surfaces.

4. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: the focal length f1 of the first lens satisfies the following condition: -1.9< f1/f < -1.3; where f is the focal length of the lens.

5. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: the focal length f2 of the second lens satisfies the following condition: 0.6< f2/f < 0.95; where f is the focal length of the lens.

6. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: the focal length f3 of the third lens satisfies the following condition: -2< f3/f < -1.4; where f is the focal length of the lens.

7. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: the focal length f4 of the fourth lens satisfies the following condition: 2.2< f4/f < 2.6; where f is the focal length of the lens.

8. The five-lens low-distortion fixed-focus lens according to claim 1, characterized in that: the focal length f5 of the fifth lens satisfies the following condition: 8.5< f5/f < 12; where f is the focal length of the lens.