CN104749743B

CN104749743B - Object lens of large relative aperture monitoring camera

Info

Publication number: CN104749743B
Application number: CN201310751768.8A
Authority: CN
Inventors: 蔡宏; 杨坤; 王威; 何品将; 刘超
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2013-12-30
Filing date: 2013-12-30
Publication date: 2017-11-14
Anticipated expiration: 2033-12-30
Also published as: CN104749743A

Abstract

The invention provides a kind of object lens of large relative aperture monitoring camera, including the first to the 7th lens and aperture diaphragm sequentially configured from object plane side to image planes side, wherein, the first lens are slightly convex surface to be formed in the object plane side and with the meniscus lens of negative refracting power；Second lens omit convex surface and with the meniscus lens of positive refracting power for the meniscus with positive refracting power or to be formed in object plane side；3rd lens are that slightly concave face and the meniscus lens with positive refracting power are formed in object plane side；Aperture diaphragm is arranged between the 3rd lens and the 4th lens；4th lens are the meniscus with positive refracting power；5th lens are slightly concave face to be formed in object plane side and with the meniscus lens of negative refracting power, and the 4th lens and the 5th lens are cemented doublet；6th lens are parallel lens；7th lens are parallel lens.The present invention can make monitoring camera have larger relative aperture and structure it is compacter, processing and assembly cost it is lower, be easy to volume production.

Description

Object lens of large relative aperture monitoring camera

Technical field

The present invention relates to a kind of object lens of large relative aperture monitoring camera.

Background technology

The optical system of large aperture high quality monitoring camera is even included using 7 or 8 sheet glass eyeglasses mostly at present The eyeglass of Glass aspheric, it is sheet glass number is more and cost is higher the shortcomings that this optical system, and difficulty of processing Height, the assembling of optical system is relatively difficult, is not suitable for volume production.Therefore, a kind of economy using simple glass eyeglass is needed badly at present Type wide-aperture lens optical system.

The content of the invention

It is an object of the invention to provide a kind of object lens of large relative aperture monitoring camera, it can make monitoring camera that there is larger phase To aperture and structure is compacter, processing and assembly cost are lower, is easy to volume production.

To solve the above problems, the present invention provides a kind of object lens of large relative aperture monitoring camera, including from object plane side to image planes side First sequentially configured to the 7th lens and aperture diaphragm, wherein,

First lens are slightly convex surface to be formed in the object plane side and with the meniscus lens of negative refracting power；

Second lens omit convex surface simultaneously for the biconvex lens with positive refracting power or to be formed in the object plane side Meniscus lens with positive refracting power；

3rd lens are that slightly concave face and the meniscus lens with positive refracting power are formed in the object plane side；

4th lens are the biconvex lens with positive refracting power；

The aperture diaphragm is arranged between the 3rd lens and the 4th lens；

5th lens are slightly concave face to be formed in the object plane side and with the meniscus lens of negative refracting power；

6th lens are parallel lens, for simulating optical filter；

7th lens are parallel lens, the protective glass for analog chip.

Further, in object lens of large relative aperture monitoring camera, the aperture of lens of the first lens to the 5th lens is gradual Reduce.

Further, in object lens of large relative aperture monitoring camera, radius D and the object lens of large relative aperture monitoring mirror of the aperture diaphragm Capitiform into the focal length f of whole optical system meet following condition：

f/D≤1.78；

The f-number FNO of the aperture diaphragm meets following condition：

FNO≤1.5。

Further, in object lens of large relative aperture monitoring camera, curvature of the 3rd lens in the concave surface of the object plane side Radius R1 meets following condition with radius of curvature R 2 of the 3rd lens in the concave surface of the image planes side：

1.35 ＜ R1/R2 ＜ 1.45.

Further, in object lens of large relative aperture monitoring camera, the refractive index Nd of the 3rd lens meets following condition：

1.75 ＜ Nd ＜ 1.82.

Further, in object lens of large relative aperture monitoring camera, the Abbe number Vd1 of the 4th lens and the 5th lens Ah Shellfish number Vd2 meets following condition respectively：

The ＜ Vd2 ＜ 25 of 50 ＜ Vd1 ＜ 58,22.

Further, in object lens of large relative aperture monitoring camera, the convex surface of the 4th lens and the concave surface phase of the 5th lens It is glued.

Compared with prior art, the present invention passes through the first to the 7th lens sequentially configured from object plane side to image planes side and hole Footpath diaphragm, it can make monitoring camera that there is larger relative aperture, FNO can reach 1.49, and lens group is common only with five The lens of sphere are formed so that monitoring camera structure is compacter, process and assembly cost is lower and is easy to volume production, image planes size Reach 6.18, have the larger angle of visual field and can compatible current main flow sensitive chip, effectively save production cost, monitor simultaneously Camera lens overall length is less than 26mm, can very easily be fitted into small-sized CCTV camera, realize the miniaturization of monitoring device.

Brief description of the drawings

Fig. 1 is the structure chart of the object lens of large relative aperture monitoring camera of one embodiment of the invention.

Fig. 2 is the modulation transfer function figure of the system of monitoring camera of the present invention；

Fig. 3 is the axial chromatic aberration figure of the system of monitoring camera of the present invention；

Fig. 4 is the chromatic longitudiinal aberration of the system of monitoring camera of the present invention.

Embodiment

In order to facilitate the understanding of the purposes, features and advantages of the present invention, it is below in conjunction with the accompanying drawings and specific real Applying mode, the present invention is further detailed explanation.

As shown in figure 1, being object plane side close to the side of object plane 10, the side close to image planes 9 is image planes side, and the present invention provides A kind of object lens of large relative aperture monitoring camera, including the first lens 1, the second lens the 2, the 3rd sequentially configured from object plane side to image planes side Lens 3, the 4th lens 5, the 5th lens 6, the 6th lens 7 and the 7th lens 8 and aperture diaphragm 4.Specifically, to object point light on axle The diaphragm that the bore of beam limits at most is referred to as aperture diaphragm 4,

First lens 1 are slightly convex surface 11 to be formed in the object plane side and with the meniscus lens of negative refracting power；

Second lens 2 are for the biconvex lens with positive refracting power or to form slightly convex surface 21 in the object plane side And the meniscus lens with positive refracting power；Specifically, second lens 2 can be to form convex surface 21, image planes in object plane side Side forms convex surface 22 and the biconvex lens with positive refracting power, and second lens 2 are alternatively and formed in the object plane side Slightly convex surface 21 and the meniscus lens with positive refracting power.

3rd lens 3 are that slightly concave face 31 and the meniscus lens with positive refracting power are formed in the object plane side；

4th lens 5 are the biconvex lens with positive refracting power；Specifically, the 4th lens 5 are in thing Surface side forms convex surface and the biconvex lens with positive refracting power；

The aperture diaphragm 4 is arranged between the 3rd lens 3 and the 4th lens 5；

5th lens 6 are slightly concave face 61 to be formed in the object plane side and with the meniscus lens of negative refracting power；

6th lens 7 are parallel lens, for simulating optical filter；

7th lens 8 are parallel lens, the protective glass for analog chip.Specifically, the big phase of the present embodiment The whole optical system formed to aperture monitoring camera can require ± 56 ° of visual fields, have and be less than compared with object lens of large relative aperture, camera lens overall length 26mm, in 0.458 μm of -0.6563 mu m waveband optical imagery.6th and the 7th lens are parallel lens, simulate optical filter and chip Influence of the protective glass to whole optical system imaging quality.

Preferably, the aperture of lens of first lens to the 5th lens 1,2,3,5,6 is gradually reduced.It is specifically, described The reduction aperture of lens of first to the 5th lens classification.

Preferably, Jiao for the whole optical system that the radius D of the aperture diaphragm 4 is formed with object lens of large relative aperture monitoring camera Meet following condition away from f：

f/D≤1.78；

The f-number FNO of the aperture diaphragm 4 meets following condition：

FNO≤1.5.Specifically, f-number FNO is the ratio of lens focus and entrance pupil, the thang-kng ability of camera lens is represented.Phase Ratio to aperture for FNO inverse, i.e. entrance pupil and lens focus, represent the thang-kng ability of camera lens.F/D≤1.78 and FNO≤ 1.5 conditions define the refracting power of the first lens 1, the second lens 2 and the 3rd lens 3, and the position of aperture diaphragm, pass through Meet the condition, can increase optical system while optical system total length is not increased passes through aperture.

Preferably, radius of curvature of the 3rd lens 3 in the concave surface 31 of the object plane side is R1 and the 3rd lens 3 Radius of curvature R 2 on the convex surface 32 of the image planes side meets following condition：

1.35 ＜ R1/R2 ＜ 1.45.

The refractive index Nd of 3rd lens 3 meets following condition：

1.75 ＜ Nd ＜ 1.82.Specifically, the wide-aperture optical system that the object lens of large relative aperture monitoring camera of the present invention is formed Spherical aberration and coma on larger axle can be produced, in order to correct spherical aberration and coma on axle, by the 3rd lens 3 in the side shape of object 10 Into bigger concave surface 31, smaller convex surface 32 is formed in image planes side, and be formed as falcate has the curved of negative refracting power Month lens.Wherein, radius of curvature of the 3rd lens 3 in the concave surface 31 of the object plane side is R1, and it is on the convex surface of the image planes side 32 radius of curvature is R2, need to meet following condition：That is the ＜ Nd ＜ 1.82 of 1.35 ＜ R1/R2 ＜ 1.45,1.75；Such as R1/R2 ＜ 1.35, then it is difficult to realize in optical manufacturing, is then difficult spherical aberration and coma on correction axle such as R1/R2 ＞ 1.45.What table 1 was listed Be lensed relationship type, the radius of curvature of lens face and diameter, the center thicknesses of also each lens, airspace, from thing Side to image space successively order optical glass use material, as can be seen from Table 1 the present embodiment meet above-mentioned condition.

Face sequence number	Surface type	Radius of curvature	Center thickness	Glass material	Thang-kng radius
						OBJ (object)	STANDARD (standard sphere)	Infinity (unlimited)	Infinity (unlimited)	AIR (air)	Infinity
Convex surface 11	STANDARD (standard sphere)	23.69114	1.24	H-ZK4	5.04
						Concave surface 12	STANDARD (standard sphere)	4.280648	2.118803	AIR (air)	3.55
Convex surface 21	STANDARD (standard sphere)	11.507504	1.73	S-LAH63	4.72
						Convex surface 22	STANDARD (standard sphere)	-145.40506	2.524189	AIR (air)	4.72
Concave surface 31	STANDARD (standard sphere)	-10.649212	5.9	LAH65	4.09
						Convex surface 32	STANDARD (standard sphere)	-7.601469	0.097296	AIR	4.62
STO (aperture diaphragm)	STANDARD (standard sphere)	Infinity	0.083346	AIR	3.47
						Convex surface 51	STANDARD (standard sphere)	9.775644	2.46	H-LAK8A	3.8
The concave surface 61 of convex surface 52/	STANDARD (standard sphere)	-6.397389	1.57	SF57	3.8
						Convex surface 62	STANDARD (standard sphere)	-93.449675	1.664906	AIR (air)	4.4
Parallel surface 71	STANDARD (standard sphere)	Infinity (unlimited)	0.55	K9	3.42
						Parallel surface 72	STANDARD (standard sphere)	Infinity (unlimited)	3.613283	AIR (air)	3.4
Parallel surface 81	STANDARD (standard sphere)	Infinity (unlimited)	0.55	K9	3.2
						Parallel surface 82	STANDARD (standard sphere)	Infinity (unlimited)	1.645786	AIR (air)	3.18
IMA (image planes)	STANDARD (standard sphere)	Infinity (unlimited)	0	AIR (air)	3.09

Table 1

Preferably, the Abbe number Vd1 of the 4th lens 5 and the Abbe number Vd2 of the 5th lens meet following condition respectively： The ＜ Vd2 ＜ 25 of 50 ＜ Vd1 ＜ 58,22.The lens 6 of convex surface 52 and the 5th in the object plane side of 4th lens 5 in institute The phase of concave surface 61 for stating object plane side is glued.Specifically, in the optical system that the object lens of large relative aperture monitoring camera of the present invention is formed, use The optical system of 5 simple glasses can produce the Abbe of aberration and chromatic longitudiinal aberration on very big axle, the 4th lens and the 4th lens Number Vd1 and Vd2 need to meet following condition：That is the ＜ Vd2 ＜ 25 of 50 ＜ Vd1 ＜ 58,22, and by the 4th lens and the 5th Lens Design For balsaming lens, as long as meeting above-mentioned condition, aberration and chromatic longitudiinal aberration on axle can be reduced.

For example, the various numerical value for the optical system correlation that the object lens of large relative aperture monitoring camera of the present invention is formed can be following number According to：

The focal length f=6.0 of whole optical system；

The radius D=3.47 of aperture diaphragm；

FNO=1.49；

R1=-10.65；

R2=-7.6；

Nd=1.80；

Vd1=50.3；

Vd2=23.8.

The main specifications coefficient of the object lens of large relative aperture monitoring camera of the present invention is as follows：

Focal length (EFL)	5.9998
		Relative aperture (1：FNO)	1：1.49
The angle of visual field (FOV)	54.5
		Camera lens overall length (TTL)	25.7

In summary, the present invention has larger relative aperture, and FNO reaches 1.49, and lens group is common only with five The lens of sphere are formed so that structure is compacter, and processing and assembly cost are lower and are easy to volume production, and image planes size reaches 6.18, there is the larger angle of visual field, image quality is excellent as shown in Fig. 2 axial chromatic aberration and chromatic longitudiinal aberration are effectively corrected, such as Fig. 3 and Fig. 4, can compatible main flow sensitive chip, effectively save production cost, while camera lens overall length is less than 26mm at present, can be with Very easily it is fitted into small-sized CCTV camera, realizes the miniaturization of monitoring device.

Each embodiment is described by the way of progressive in this specification, what each embodiment stressed be and other The difference of embodiment, between each embodiment identical similar portion mutually referring to.For system disclosed in embodiment For, due to corresponding to the method disclosed in Example, so description is fairly simple, related part is referring to method part illustration .

Professional further appreciates that, with reference to the unit of each example of the embodiments described herein description And algorithm steps, can be realized with electronic hardware, computer software or the combination of the two, in order to clearly demonstrate hardware and The interchangeability of software, the composition and step of each example are generally described according to function in the above description.These Function is performed with hardware or software mode actually, application-specific and design constraint depending on technical scheme.Specialty Technical staff can realize described function using distinct methods to each specific application, but this realization should not Think beyond the scope of this invention.

Obviously, those skilled in the art can carry out the spirit of various changes and modification without departing from the present invention to invention And scope.So, if these modifications and variations of the present invention belong to the claims in the present invention and its equivalent technologies scope it Interior, then the present invention is also intended to including these changes and modification.

Claims

A kind of 1. object lens of large relative aperture monitoring camera, it is characterised in that including sequentially configured from object plane side to image planes side first to 7th lens and aperture diaphragm, wherein,

First lens are slightly convex surface to be formed in the object plane side and with the meniscus lens of negative refracting power；

Second lens for positive refracting power biconvex lens or for the object plane side formed slightly convex surface and with The meniscus lens of positive refracting power；

3rd lens are that slightly concave face and the meniscus lens with positive refracting power are formed in the object plane side；

4th lens are the biconvex lens with positive refracting power；

The aperture diaphragm is arranged between the 3rd lens and the 4th lens；

5th lens are slightly concave face to be formed in the object plane side and with the meniscus lens of negative refracting power；

6th lens are parallel lens, for simulating optical filter；

7th lens are parallel lens, the protective glass for analog chip；

Wherein, the focal length f for the whole optical system that the radius D of the aperture diaphragm is formed with object lens of large relative aperture monitoring camera meets Following condition：

f/D≤1.78；

The f-number FNO of the aperture diaphragm meets following condition：

FNO≤1.5。
2. object lens of large relative aperture monitoring camera as claimed in claim 1, it is characterised in that first lens to the 5th lens Aperture of lens is gradually reduced.
3. object lens of large relative aperture monitoring camera as claimed in claim 1, it is characterised in that the 3rd lens are in the object plane side Radius of curvature R 1 and radius of curvature R 2 of the 3rd lens in the concave surface of the image planes side of concave surface meet following condition：

1.35 ＜ R1/R2 ＜ 1.45.
4. object lens of large relative aperture monitoring camera as claimed in claim 1, it is characterised in that the refractive index Nd of the 3rd lens expires Foot row condition：

1.75 ＜ Nd ＜ 1.82.
5. object lens of large relative aperture monitoring camera as claimed in claim 1, it is characterised in that the Abbe number Vd1 of the 4th lens Meet following condition respectively with the Abbe number Vd2 of the 5th lens：

The ＜ Vd2 ＜ 25 of 50 ＜ Vd1 ＜ 58,22.
6. object lens of large relative aperture monitoring camera as claimed in claim 1, it is characterised in that the convex surface and the 5th of the 4th lens The concave surface of lens is mutually glued.