CN216595709U

CN216595709U - Security lens

Info

Publication number: CN216595709U
Application number: CN202122880533.1U
Authority: CN
Inventors: 陈永欢
Original assignee: Jiangxi Yongwei Photoelectric Technology Co ltd
Current assignee: Jiangxi Yongwei Photoelectric Technology Co ltd
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2022-05-24
Anticipated expiration: 2031-11-23

Abstract

The utility model provides a security lens, which comprises an optical system, wherein the optical system sequentially comprises a first lens P1 with a positive refractive index and a meniscus structure, a second lens P2 with a negative refractive index and a meniscus structure, a third lens G3 with a negative refractive index and a biconvex structure, a fourth lens P4 with a positive refractive index and a biconcave structure, and a biconvex structure with a positive refractive index from an object space to an image spaceThe first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 are all aspheric lenses, the third lens G3 is a spherical lens, and the refractive index of the first lens P1 is n₁The refractive index of the third lens G3 is n_3，The refractive index of the fifth lens P5 is n₅Which satisfies the relation: 1.5 < n₁＜1.75，1.55＜n₃＜1.85，1.5＜n₅Less than 1.8, the utility model can effectively improve the imaging definition of a 4mm lens, and the highest pixel of the lens can reach 5 MP.

Description

Security lens

Technical Field

The utility model relates to the technical field of lens manufacturing, in particular to a security lens.

Background

In the field of security monitoring, a security lens is an important component of the whole security monitoring system, and is used for presenting an image of a target on a sensor for subsequent processing. The performance of the security monitoring system is directly related to whether the picture of the camera is clear or not, and the performance of the whole security monitoring system is directly influenced. With the continuous development of the technology in the field of security monitoring, the requirements for the 4mm lens are more and more stringent, the highest pixel in the conventional market is 3MP, which cannot meet the market requirements, and therefore, the development of a 4mm security lens with a higher pixel is more and more urgent.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

The utility model aims to provide a security lens, which can effectively improve the imaging definition of a 4mm lens and enable the highest pixel of the lens to reach 5 MP. In order to achieve the purpose, the utility model adopts the following technical scheme:

(II) technical scheme

The utility model provides a security protection camera lens, includes optical system, optical system is by object space to image space in proper order including first lens P1 that has positive refracting power and meniscus structure, second lens P2 that has negative refracting power and meniscus structure, third lens G3 that has negative refracting power and biconvex structure, fourth lens P4 that has positive refracting power and biconcave surface structure, fifth lens P5 that has positive refracting power and biconvex structure, first lens P1, second lens P2, fourth lens P4 and fifth lens P5 are aspheric lens, third lens G3 is spherical lens, wherein, the refracting power of first lens P1 is n₁It satisfies the relation: n is more than 1.5₁< 1.75, the refractive index of the third lens G3 is n₃It satisfies the relation: 1.55 < n₃< 1.85, the refractive index of the fifth lens P5 is n₅It satisfies the relation: n is more than 1.5₅＜1.8。

Furthermore, a plastic spacer is disposed between the first lens P1 and the second lens P2.

Further, the first lens P1, the second lens P2, the fourth lens P4, and the fifth lens P5 are all resin lenses, and the third lens G3 is a glass lens.

Further, still include the diaphragm, the diaphragm set up in between third lens G3 and fourth lens P4, the hole of diaphragm is the round hole, and the diaphragm of diaphragm sets up to F1.6.

(III) advantageous effects

Compared with the prior art, the four-lens-array optical lens has obvious advantages and beneficial effects, and particularly, the problem of imaging definition of a 4mm lens can be effectively improved through the combination of four aspheric lenses and one spherical lens in order arrangement, so that the highest pixel of the lens can reach 5 MP.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a light path diagram of an optical system in an embodiment of the present invention.

10-diaphragm 20-plastic spacer ring 30-optical filter

Optical back intercept of BFL-optical system

L-distance from vertex of front surface of first lens to vertex of rear surface of fifth lens

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the utility model and are not to be construed as limiting the utility model.

The utility model is further described with reference to the following detailed description and accompanying drawings.

Referring to fig. 1 and 2, a security lens includes an optical system, which includes, in order from an object side to an image side, a first lens P1 having a positive refractive index and a meniscus structure, a second lens P2 having a negative refractive index and a meniscus structure, a third lens G3 having a negative refractive index and a biconvex structure, a fourth lens P4 having a positive refractive index and a biconcave structure, and a biconvex junction having a positive refractive index and a biconvex junctionThe fifth lens P5 is composed of a filter 30 on one side, the light rays of the fifth lens P5 form an image, the first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 are all aspheric lenses, the third lens G3 is a spherical lens, wherein the refractive index of the first lens P1 is n₁It satisfies the relation: n is more than 1.5₁< 1.75, the refractive index of the third lens G3 is n₃It satisfies the relation: 1.55 < n₃< 1.85, the refractive index of the fifth lens P5 is n₅It satisfies the relation: n is more than 1.5₅＜1.8。

Preferably, a plastic spacer 20 is disposed between the first lens P1 and the second lens P2, and the plastic spacer 20 replaces a conventional metal spacer, so that stray light can be effectively reduced, because the plastic spacer 20 can maintain effective consistency, and the metal spacer is easy to generate stray light due to different surface treatments.

Preferably, the first lens P1, the second lens P2, the fourth lens P4, and the fifth lens P5 are all resin lenses, and the third lens G3 is a glass lens, and is lightweight and highly portable.

Preferably, the optical disc further comprises a diaphragm 10, wherein the diaphragm 10 is arranged between the third lens G3 and the fourth lens P4, the hole of the diaphragm 10 is a circular hole, and the aperture of the diaphragm 10 is F1.6.

The first embodiment is as follows:

in this embodiment, the first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 are all resin lenses, and are light and portable, the third lens G3 is a glass lens, and in this embodiment, the optical data are as follows:

surface of	Radius (mm)	Thickness (mm)	Refractive index
				G3 front curve	11.5	0.6	1.6
G3 back curve	-7.0	1.1

The aspherical cone coefficient values and the respective-order aspherical coefficient values of the first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 may be set to appropriate values. The aspheric conic coefficient values and aspheric coefficients of each order in the examples of the present invention are shown in the following table, wherein K is an aspheric conic coefficient, and a1, a2, A3, a4 correspond to aspheric coefficients of 2, 4, 6, 8 orders, respectively.

Flour mark

K

A1

A2

A3

A4

R value

S1

-4.47E-01

0

-4.18E-03

3.44E-06

4.16E-06

4.96

S2

-6.63E-01

0

-5.95E-03

-1.76E-04

-3.63E-05

1.93

S3

1.91E+00

0

5.35E-04

-2.48E-04

5.70E-05

-6.94

S4

-3.69E+00

0

-1.99E-03

-2.04E-07

-1.74E-06

-5.16

S7

6.96E+00

0

-9.79E-03

1.39E-03

-3.09E-04

35.47

S8

-4.93E+00

0

6.52E-03

-1.47E-03

1.20E-04

2.92

S9

1.31E-01

0

-5.72E-03

1.20E-03

-5.05E-04

3.94

S10

-8.49E+00

0

-3.70E-03

3.84E-04

-9.82E-06

-6.71

In the present embodiment, the effective focal length of the lens is 22.3mm, the distance L from the front surface vertex of the first lens G1 to the rear surface vertex of the fifth lens G5 is 11.50mm, the optical back-focal length BFL is 2.81mm, and the focal length f of the first lens P1 is_P1Focal length f of second lens P2 ═ 8.23mm_P2Focal length f of the third lens G3, 8.73mm_G3Focal length f of the fourth lens P4, 8.62mm_P4Focal length f of-6.1 mm, fifth lens P5_P5＝4.33mm。

The embodiment is tested to obtain fig. 2, fig. 2 is a light path diagram of the optical system in the embodiment, and the highest pixel can reach 5mp by testing.

According to the utility model, the imaging definition of the 4mm lens can be effectively improved by combining four aspheric lenses with one spherical lens in order arrangement, so that the highest pixel can reach 5MP, the security monitoring quality can be well improved, and compared with the traditional 2 glass spherical lenses and 3 plastic lenses, the highest pixel can be improved from 3MP to 5 MP.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any minor modifications, equivalent changes and modifications made to the above embodiment according to the technical spirit of the present invention are within the technical scope of the present invention.

Claims

1. The utility model provides a security protection camera lens, includes optical system, its characterized in that: the optical system comprises a first lens P1 with a positive refractive index and a meniscus structure, a second lens P2 with a negative refractive index and a meniscus structure, a third lens G3 with a negative refractive index and a biconvex structure, a fourth lens P4 with a positive refractive index and a biconcave structure, and a fifth lens P5 with a positive refractive index and a biconvex structure in sequence from an object side to an image side, wherein the first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 are all aspheric lenses, the third lens G3 is a spherical lens, and the refractive index of the first lens P1 is n₁It satisfies the relation: n is more than 1.5₁< 1.75, the refractive index of the third lens G3 is n₃It satisfies the relation: 1.55 < n₃< 1.85, the refractive index of the fifth lens P5 is n₅It satisfies the relation: n is more than 1.5₅＜1.8。

2. The security lens of claim 1, wherein: a plastic spacer is arranged between the first lens P1 and the second lens P2.

3. The security lens of claim 1, wherein: the first lens P1, the second lens P2, the fourth lens P4 and the fifth lens P5 are all resin lenses, and the third lens G3 is a glass lens.

4. The security lens of claim 1, wherein: still include the diaphragm, the diaphragm set up in between third lens G3 and the fourth lens P4, the hole of diaphragm is the round hole, and the diaphragm of diaphragm sets up to F1.6.