CN105137574A - Pinhole optical lens - Google Patents

Abstract

The invention discloses a pinhole optical lens. The lens successively comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side. The five-lens structure is adopted, so that the minimized design of the integral size of the lens is facilitated; for all the lenses, plastic lenses are combined with glass lenses, and spherical lenses are combined with aspherical lenses; in addition, the focal length and distribution of each lens is optimized, the frame analysis degree of the lens provided by the invention reaches millions of pixels, an aperture F# is no more than 2.5 mm, and the requirements of 1/2.7 inch image height and temperature drifting compensation are met, so that the lens provided by the invention has the advantages that the outline dimension is small, the production and manufacturing cost is low, the image quality is high, and the usage environment range is widened.

Description

A kind of pin hole optical lens

[technical field]

The present invention relates to optical lens, especially a kind of pin hole optical lens.

[background technology]

Pinhole lens is easy to hiding feature because it is small and exquisite, is widely used in some special monitoring occasion, and as reporter investigates secretly, public security organ investigates into a case evidence obtaining, bank counter or automatic drawing machine monitoring etc.So when designing, eyeglass front end bore be made little, the total length of camera lens, and camera lens overall weight is light as far as possible.As patent documentation CN201464692U discloses a kind of pinhole lens of mega pixel, it use 5 glass mirror, wherein there are two groups of cemented doublet, adopt its overall weight of the camera lens of this structure larger, cost is also higher, and rear cut-off distance only has 2.33mm, is unfavorable for installation and the focusing of filter plate, clear aperture is large, is 4.5mm.

Namely the present invention researchs and proposes for the deficiencies in the prior art.

[summary of the invention]

The technical problem to be solved in the present invention is to provide a kind of pin hole optical lens, five lens arrangements are adopted in camera lens, and adopt plastic lens to combine with non-spherical lens with glass lens and spherical lens, by distributing focal length and the distribution of each lens rationally, camera lens picture of the present invention power of resolving is made to reach mega pixel, clear aperture F#≤2.5mm, and the image height of 1/2.7 inch and the requirement of temperature drift compensation can be met.Therefore, camera lens of the present invention has that physical dimension is little, manufacturing cost is low, image quality is clear and add environment for use scope.

For solving the problems of the technologies described above, a kind of pin hole optical lens of the present invention, is provided with the first lens, the second lens, the 3rd lens, the 4th lens, the 5th lens, optical filter and sensitive film successively from object plane to image planes.

Described first lens, the second lens and the 3rd lens are plastic aspheric lenes.

Described 4th lens and the 5th lens bonding be balsaming lens.

Described first lens, the second lens, the 3rd lens are meniscus shaped lens, and the concave surface of described first lens and the second lens is all towards image planes, and described 3rd concave lens surface is towards object plane.

Described first lens are negative focal length lens, and described second lens and the 3rd lens are positive focal length lens, described first lens, the second lens, the 3rd lens, focal length be respectively f1, f2, f3, meet:

-2.8<f2/f1<-2.45，-1.8<f3/f1<-1.5。

The curvature corresponding to aspheric surface radius of described first lens (1), the second lens (2) and the 3rd lens (3) is c, distance a bit to optical axis on lens surface is r, the quadric surface constant of lens surface is K, the asphericity coefficient on the quadravalence of described first lens (1), the second lens (2) and the 3rd lens (3), six rank, eight rank, ten rank, ten second orders, ten quadravalences and 16 rank is respectively A, B, C, D, E, F, G, in aspherical lens surface a bit

Rise along optical axis direction is z, meets:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-(1+k)c^2{r}^2}}+{\mathrm{Ar}}^4+{\mathrm{Br}}^6+{\mathrm{Cr}}^8+{\mathrm{Dr}}^{10}+{\mathrm{Er}}^{12}+{\mathrm{Fr}}^{14}+{\mathrm{Gr}}^{16}.$

Described 4th lens (4) are biconvex spherical lens, described 5th lens (5) concave surface facing object plane, 5th lens (5) are meniscus shaped lens, described 4th lens are positive focal length lens, described 5th lens are negative focal length lens, and the focal length of described 4th lens (4) and the 5th lens (5) is respectively f4 and f5, and lens optical back focal length is BFL, lens optical overall length is TTL, meets:

-0.6<f4/f5<-0.53，BFL＞5mm，0.45<BFL/TTL<0.48。

Described 4th lens (4) and the 5th lens (5) are glass lens.

Camera lens clear aperture of the present invention is F#, and visual field is FOV, meets:

F#≦2.5mm，FOV≥96°。

Compared with prior art, tool of the present invention has the following advantages:

1, camera lens of the present invention only adopts five lens, is beneficial to camera lens overall volume miniaturized design, meets the environment request for utilization of this camera lens at special occasions.

2, five lens in camera lens of the present invention, plastic lens is adopted to combine with non-spherical lens with glass lens and spherical lens, alleviate the overall weight of camera lens and reduce its manufacturing cost, simultaneously, effectively overcome and in high temperature or low temperature environment, be used alone plastic lens cause camera lens focus drifting amount large, be difficult to ensure to resolve the problem of quality, such that lens performance of the present invention is stable, image quality is good, and meet the requirement of the image height of 1/2.7 inch.

3, camera lens clear aperture F#≤2.5mm of the present invention, is beneficial to the installation and focusing that increase back focal length and optical filter, and still can ensures that enough light passes through, and effectively ensure that picture brightness.

4, camera lens visual field 2w > 96 ° of the present invention, aberration control, within 30%, has wide-angle lens feature, and monitoring visual field scope is wide.

[accompanying drawing explanation]

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail, wherein:

Fig. 1 is the distribution schematic diagram of each lens in invention camera lens.

Fig. 2 is the analysis diagram of the first embodiment of invention.

Fig. 3 is the hot spot figure of the first embodiment of invention.

Fig. 4 be invention the first embodiment axle on chromaticity difference diagram.

Fig. 5 is the chromatic longitudiinal aberration figure of the first embodiment of invention.

Fig. 6 is the analysis diagram of invention the second embodiment.

Fig. 7 is the hot spot figure of invention the second embodiment.

Fig. 8 be invention the second embodiment axle on chromaticity difference diagram.

Fig. 9 is the chromatic longitudiinal aberration figure of invention the second embodiment.

Figure 10 is the analysis diagram of the third embodiment of invention.

Figure 11 is the hot spot figure of the third embodiment of invention.

Figure 12 be invention the third embodiment axle on chromaticity difference diagram.

Figure 13 is the chromatic longitudiinal aberration figure of the third embodiment of invention.

[embodiment]

Below in conjunction with accompanying drawing, embodiments of the present invention are elaborated.

As shown in the figure, a kind of pin hole optical lens of the present invention, is provided with the first lens 1, second lens 2, the 3rd lens 3, the 4th lens 4, the 5th lens 5, optical filter 6 and sensitive film 7 successively from object plane to image planes.Only adopt five lens, be beneficial to camera lens overall volume miniaturized design, meet the environment request for utilization of this camera lens at special occasions.

Described first lens 1, second lens 2 and the 3rd lens 3 are plastic aspheric lenes, and described 4th lens 4 and the 5th lens 5 are glass lens.Plastic lens is adopted to combine with non-spherical lens with glass lens and spherical lens, alleviate the overall weight of camera lens and reduce its manufacturing cost, simultaneously, effectively overcome and in high temperature or low temperature environment, be used alone plastic lens cause camera lens focus drifting amount large, be difficult to the problem ensureing to resolve quality, make that lens performance of the present invention is stable, image quality good, and meet the requirement of the image height of 1/2.7 inch.

Described 4th lens 4 and the 5th lens 5 bonding be balsaming lens.

The concave surface of described first lens 1 and the second lens 2 is all towards image planes, the concave surface facing object plane of described 3rd lens 3, described 4th lens 4 are biconvex spherical lens, the concave surface facing object plane of described 5th lens 5, described first lens 1, second lens 2, the 3rd lens 3 and the 5th lens 5 are meniscus shaped lens.

Described first lens 1 and the 5th lens 5 are negative focal length lens, described second lens 2, the 3rd lens 3 and the 4th lens 4 are positive focal length lens, the focal length of described first lens 1, second lens 2, the 3rd lens 3, the 4th lens 4 and the 5th lens 5 is respectively f1, f2, f3, f4 and f5, lens optical overall length is BFL, lens optical overall length is TTL, meets:

-2.8<f2/f1<-2.45，-1.8<f3/f1<-1.5，-0.6<f4/f5<-0.53，BFL＞5mm，0.45<BFL/TTL<0.48。

The curvature corresponding to aspheric surface radius of described first lens (1), the second lens (2) and the 3rd lens (3) is c, distance a bit to optical axis on lens surface is r, the quadric surface constant of lens surface is K, the asphericity coefficient on the quadravalence of described first lens (1), the second lens (2) and the 3rd lens (3), six rank, eight rank, ten rank, ten second orders, ten quadravalences and 16 rank is respectively A, B, C, D, E, F, G, rise a bit along optical axis direction in aspherical lens surface is z, meets:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-(1+k)c^2{r}^2}}+{\mathrm{Ar}}^4+{\mathrm{Br}}^6+{\mathrm{Cr}}^8+{\mathrm{Dr}}^{10}+{\mathrm{Er}}^{12}+{\mathrm{Fr}}^{14}+{\mathrm{Gr}}^{16}.$

Camera lens clear aperture of the present invention is F#, F#≤2.5mm, is beneficial to the installation and focusing that increase back focal length BFL and optical filter 6, and still can ensures that enough light passes through, and effectively ensure that picture brightness.Visual field is FOV, and through distributing rationally, visual field FOV > 96 °, aberration control, within 30%, has the advantages that monitoring visual field scope is wide.

It is below the parameter of 3 embodiments of camera lens of the present invention, wherein f is the focal length of camera lens of the present invention, from object plane to image planes, S1 is first surface of the first lens 1, S2 is second surface of the first lens 1, S3 is first surface of the second lens 2, S4 is second surface of the second lens 2, S5 is first surface of the 3rd lens 3, S6 is second surface of the 3rd lens 3, S7 is the surfaces of the 4th lens 4 towards object plane, S8 is the 4th lens 4 and the 5th lens 5 glued surfaces, S9 is the surfaces of the 5th lens 5 towards image planes, S10 is first surface of optical filter 6, S11 is second surface of optical filter 6.

Embodiment one

As shown in Figures 2 to 5, f=4.3mm, F#=2.5, FOV=110 °, BFL=5.6942, TTL=12.278, the focal length of each lens is as shown in the table:

f1	f2	f3	f4	f5	f2/f1	f3/f1	f4/f5	BFL/TTL
									-5.8197	15.3051	9.3	3.38	-6.027	-2.6299	-1.598	-0.5608	0.4637

In the first embodiment, each lens surface, R value, thickness and material thereof are as follows:

In the first embodiment, each Lens Surface Parameters is as follows:

K

A

B

C

D

E

S1

-2.4452

-5.62E-03

8.20E-03

-2.21E-03

4.66E-04

7.98E-05

S2

-3.9095

0.1864

-0.1044

0.1007

-0.0604

0.0277

S3

-0.5878

-7.86E-03

5.24E-03

5.89E-04

-4.14E-04

9.09E-05

S4

-2.0732

-5.20E-03

1.40E-03

6.49E-04

2.39E-03

-9.81E-04

S5

-4.0179

-4.48E-03

0.0181

-0.0136

0.0117

-3.22E-03

S6

0.3071

5.07E-03

7.52E-04

4.18E-04

-2.64E-05

3.73E-05

Embodiment two

As shown in Figures 6 to 9, f=4.3mm, F#=2.45, FOV=105 °, BFL=5.3142, TTL=11.89, the focal length of each lens is as shown in the table:

f1	f2	f3	f4	f5	f2/f1	f3/f1	f4/f5	BFL/TTL
									-6.2873	15.713	9.6	3.33	-5.63	-2.4992	-1.5269	-0.5915	0.4469

In the second embodiment, each lens surface, R value, thickness and material thereof are as follows:

In the second embodiment, each Lens Surface Parameters is as follows:

K

A

B

C

D

E

S1

-2.4452

-5.62E-03

8.20E-03

-2.21E-03

4.66E-04

7.98E-05

S2

-3.9095

0.1864

-0.1044

0.1007

-0.0604

0.0277

S3

-0.5878

-7.86E-03

5.24E-03

5.89E-04

-4.14E-04

9.09E-05

S4

-2.0732

-5.20E-03

1.40E-03

6.49E-04

2.39E-03

-9.81E-04

S5

-4.0179

-4.48E-03

0.0181

-0.0136

0.0117

-3.22E-03

S6

0.3071

5.07E-03

7.52E-04

4.18E-04

-2.64E-05

3.73E-05

Embodiment three

As shown in Figure 10 to Figure 13, f=4.3mm, F#=2.4, FOV=96 °, BFL=5.842, TTL=12.41, the focal length of each lens is as shown in the table:

f1	f2	f3	f4	f5	f2/f1	f3/f1	f4/f5	BFL/TTL
									-5.8	15.71	9.89	3.41	-6.34	-2.7086	-1.7052	-0.5379	0.47

In the third embodiment, each lens surface, R value, thickness and material thereof are as follows:

In the third embodiment, each Lens Surface Parameters is as follows:

K

A

B

C

D

E

S1

-2.4452

-5.62E-03

8.20E-03

-2.21E-03

4.66E-04

7.98E-05

S2

-3.9095

0.1864

-0.1044

0.1007

-0.0604

0.0277

S3

-0.5878

-7.49E-03

6.75E-03

-1.52E-03

1.42E-04

2.47E-04

S4

-2.0732

-3.22E-03

2.34E-03

2.29E-03

3.29E-03

-1.05E-03

S5

-4.0179

-3.26E-03

0.0193e

-0.0115

0.0124

-2.94E-03

S6

0.3071

5.13E-03

6.85E-04

4.34E-04

-2.25E-05

3.57E-05

Claims (5)

1. a pin hole optical lens, is characterized in that from object plane to image planes, be provided with the first lens (1), the second lens (2), the 3rd lens (3), the 4th lens (4), the 5th lens (5), optical filter (6) and sensitive film (7) successively;

Described first lens (1), the second lens (2) and the 3rd lens (3) are plastic aspheric lenes;

Described 4th lens (4) and the 5th lens (5) bonding be balsaming lens;

Described first lens (1), the second lens (2), the 3rd lens (3) are meniscus shaped lens, the concave surface of described first lens (1) and the second lens (2) all towards image planes, described 3rd lens (3) concave surface facing object plane;

Described first lens (1) are negative focal length lens, described second lens (2) and the 3rd lens (3) are positive focal length lens, the focal length of described first lens (1), the second lens (2), the 3rd lens (3) is respectively f1, f2, f3, meets:

-2.8<f2/f1<-2.45，-1.8<f3/f1<-1.5。

2. a kind of pin hole optical lens according to claim 1, it is characterized in that described 4th lens (4) are biconvex spherical lens, described 5th lens (5) are meniscus shaped lens, and described 5th lens (5) concave surface facing object plane, described 4th lens (4) are positive focal length lens, described 5th lens (5) are negative focal length, described in lens, the focal length of the 4th lens (4) and the 5th lens (5) is respectively f4 and f5, lens optical back focal length is BFL, lens optical overall length is TTL, meets:

-0.6<f4/f5<-0.53，BFL＞5mm，0.45<BFL/TTL<0.48。

3. a kind of pin hole optical lens according to claim 2, is characterized in that described 4th lens (4) and the 5th lens (5) are glass lens.

4. a kind of pin hole optical lens according to claim 3, it is characterized in that described first lens (1), the curvature corresponding to aspheric surface radius of the second lens (2) and the 3rd lens (3) is c, distance a bit to optical axis on lens surface is r, the quadric surface constant of lens surface is K, described first lens (1), the quadravalence of the second lens (2) and the 3rd lens (3), six rank, eight rank, ten rank, ten second orders, the asphericity coefficient on ten quadravalences and 16 rank is respectively A, B, C, D, E, F, G, rise a bit along optical axis direction in aspherical lens surface is z, meet:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1+k\right)c^2{r}^2}}+{\mathrm{Ar}}^4+{\mathrm{Br}}^6+{\mathrm{Cr}}^8+{\mathrm{Dr}}^{10}+{\mathrm{Er}}^{12}+{\mathrm{Fr}}^{14}+{\mathrm{Gr}}^{16}.$

5. by a kind of pin hole optical lens described in claim 1 or 2 or 3 or 4, it is characterized in that clear aperture is F#, visual field is FOV, meets: F#≤2.5mm, FOV >=96 °.