CN214225566U - Lens barrel - Google Patents

Abstract

The utility model relates to a lens, which comprises a first lens (1) with negative focal power, a second lens (2) with negative focal power, a third lens (3) with positive focal power, a fourth lens (4) with negative focal power, a fifth lens (5) with positive focal power, a sixth lens (6) with positive focal power, a seventh lens (7) with negative focal power and an eighth lens (8) with positive focal power in sequence along the direction of an optical axis from an object side to an image side; the first lens (1), the second lens (2), the seventh lens (7) and the eighth lens (8) are plastic lenses, and at least three lenses of the third lens (3), the fourth lens (4), the fifth lens (5) and the sixth lens (6) are glass lenses. The utility model discloses a camera lens has big light ring, the confocal characteristic of day night.

Description

Lens barrel

Technical Field

The utility model relates to an optical system and device design technical field especially relate to a camera lens.

Background

With the rapid development of science and technology, various industries have put higher demands on optical lenses in aspects such as resolution, day and night confocal, high and low temperature confocal and the like. The general camera does not have day-night confocal function, only is suitable for places with good lighting conditions, but has poor imaging effect at night with low brightness and under low-light conditions such as low light and the like or needs to be added with auxiliary light sources such as an infrared light supplement lamp and a flash lamp to cause the structure of an optical system to be complex and large, and meanwhile, the imaging effect cannot be effectively guaranteed. Under the circumstances, a large aperture lens which can ensure an imaging effect under a low-light condition and has a simple structure has been developed to become one of the current hot spots.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to solve above-mentioned problem, provide a camera lens with big light ring.

To achieve the above object, the present invention provides a lens barrel, which comprises, in order from an object side to an image side along an optical axis, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, a sixth lens having positive refractive power, a seventh lens having negative refractive power, and an eighth lens having positive refractive power;

the first lens, the second lens, the seventh lens and the eighth lens are plastic lenses, and at least three of the third lens, the fourth lens, the fifth lens and the sixth lens are glass lenses.

According to the utility model discloses an embodiment, the camera lens still includes the diaphragm, the diaphragm is located on the image side face of third lens, or is located third lens with between the fourth lens or be located on the object side face of fourth lens.

According to an embodiment of the present invention, the fourth lens and the fifth lens constitute a cemented lens group having positive optical power.

According to an aspect of the present invention, in a direction from the object side to the image side, the first lens is a convex-concave lens, the second lens is a concave-concave lens or a concave-convex lens, the third lens is a convex-convex lens or a concave-convex lens, the fourth lens is a concave-concave lens or a convex-concave lens, the seventh lens is a concave-concave lens or a convex-concave lens, and the fifth lens, the sixth lens, and the eighth lens are convex-convex lenses.

According to an aspect of the present invention, at least one of the third lens, the fourth lens, the fifth lens and the sixth lens is a low dispersion glass lens, and the abbe number Vd thereof is not less than 60.

According to an aspect of the present invention, the refractive index Nd of at least two lenses among the first lens, the second lens, the third lens, the seventh lens and the eighth lens is not less than 1.6.

According to an aspect of the present invention, the first lens to the effective focal length of the third lens is f1, the effective focal length of the lens is f, satisfying the relation: f1/f is not less than-11 and not more than-1.

According to an aspect of the present invention, the fourth lens element is to the effective focal length of the eighth lens element is f2, the effective focal length of the lens element is f, and the following relation is satisfied: f2/f is more than or equal to 1.6 and less than or equal to 2.

According to the utility model discloses an aspect, eighth lens image side center extremely the distance of camera lens image plane is D, first lens object side arrives the distance of camera lens image plane is D, satisfies the relational expression: D/D is more than or equal to 0.18.

According to an aspect of the present invention, abbe numbers of the fourth lens and the fifth lens are v4 and v5, respectively, and satisfy the following relations: and | v4-v5| ≧ 30.

According to an aspect of the utility model, the relative aperture FNO of camera lens is less than or equal to 1.2.

The utility model discloses a camera lens through the positive and negative focal power of optimizing each lens of configuration, makes the aberration obtain effectual correction, and the mixed structure collocation is moulded to the glass that deuterogamies is reducing into manufacturing cost and is making the utility model discloses the infrared out-of-focus volume of camera lens can realize the confocality of day and night (visible light and infrared light are confocal), realizes the F1.0 big light ring of camera lens, and the power of resolving image simultaneously reaches 5M lens requirement, guarantees the high resolution under big light ring. Meanwhile, the lens of the utility model can realize no virtual focus within the temperature range of-40 ℃ to 80 ℃, and overcomes the difficulty that the focus drift is easily caused in the high and low temperature environment due to the large expansion coefficient of the plastic aspheric lens; furthermore, the utility model discloses a camera lens contains 8 lens altogether, and is small, and the camera lens overall length is within 22.2mm, simultaneously the utility model discloses camera lens unit article and equipment tolerance are better, have good manufacturability.

Drawings

Fig. 1 schematically shows a schematic structural view of a lens barrel according to embodiment 1 of the present invention;

fig. 2 schematically shows an MTF chart of the lens of embodiment 1;

FIG. 3 is a Through-Focus-MTF graph schematically showing a lens frequency of 120lp/mm in accordance with example 1;

FIG. 4 is a Through-Focus-MTF graph schematically showing the infrared frequency of 120lp/mm in the lens of example 1;

fig. 5 schematically shows a ray fan diagram of the lens of embodiment 1;

fig. 6 is a schematic structural view of a lens barrel according to embodiment 2 of the present invention;

fig. 7 schematically shows an MTF chart of the lens of embodiment 2;

FIG. 8 is a Through-Focus-MTF graph schematically showing a lens frequency of 120lp/mm in example 2;

FIG. 9 is a Through-Focus-MTF graph showing an infrared frequency of 120lp/mm in the lens of example 2;

fig. 10 schematically shows a ray fan diagram of a lens of embodiment 2;

fig. 11 is a schematic structural view of a lens barrel according to embodiment 3 of the present invention;

fig. 12 schematically shows an MTF chart of the lens of embodiment 3;

FIG. 13 is a Through-Focus-MTF graph schematically showing a lens frequency of 120lp/mm in example 3;

FIG. 14 is a Through-Focus-MTF graph showing an infrared frequency of 120lp/mm in the lens according to example 3;

fig. 15 schematically shows a ray fan diagram of a lens of embodiment 3;

fig. 16 is a schematic structural view of a lens barrel according to embodiment 4 of the present invention;

fig. 17 schematically shows an MTF chart of the lens of embodiment 4;

FIG. 18 is a Through-Focus-MTF graph showing a lens frequency of 120lp/mm in accordance with example 4;

FIG. 19 is a Through-Focus-MTF plot showing the infrared frequency of the lens of embodiment 4 at 120 lp/mm;

fig. 20 is a ray fan diagram schematically showing a lens of embodiment 4;

fig. 21 is a schematic structural view of a lens barrel according to embodiment 5 of the present invention;

fig. 22 schematically shows an MTF chart of the lens of embodiment 5;

FIG. 23 is a Through-Focus-MTF plot schematically showing a lens frequency of 120lp/mm in accordance with example 5;

FIG. 24 is a Through-Focus-MTF plot showing the infrared frequency of 120lp/mm for the lens of example 5;

fig. 25 schematically shows a ray fan diagram of the lens of example 5.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

The present invention will be described in detail with reference to the accompanying drawings and specific embodiments, which are not repeated herein, but the present invention is not limited to the following embodiments.

As shown in fig. 1, the present invention provides a lens barrel, which includes, in order from an object side to an image side along an optical axis, a first lens 1 having negative refractive power, a second lens 2 having negative refractive power, a third lens 3 having positive refractive power, a fourth lens 4 having negative refractive power, a fifth lens 5 having positive refractive power, a sixth lens 6 having positive refractive power, a seventh lens 7 having negative refractive power, and an eighth lens 8 having positive refractive power. The first lens 1, the second lens 2, the seventh lens 7 and the eighth lens 8 are plastic lenses, and at least three of the third lens 3, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are glass lenses.

The utility model discloses a camera lens includes 8 lens altogether, and is small, through the scheme of rational arrangement each lens focal power and adoption plastic lens and the use of glass lens collocation, feasible the utility model discloses a confocal function of day night can be realized to the camera lens, realizes big light ring simultaneously, and the resolution power reaches 5M lens requirement, and the use of collocation of plastic lens and glass lens still is favorable to reduction in production cost in addition, guarantees not virtual burnt at high low temperature within range.

The utility model discloses a camera lens still includes diaphragm S, and diaphragm S is located the image side face of third lens 3, or is located between third lens 3 and the fourth lens 4 or is located the object side face of fourth lens 4.

In the present invention, the fourth lens 4 and the fifth lens 5 constitute a cemented lens group having positive power.

According to an embodiment of the present invention, the first lens 1 is a convex-concave lens, the second lens 2 is a concave-concave lens or a concave-convex lens, the third lens 3 is a convex-convex lens or a concave-convex lens, the fourth lens 4 is a concave-concave lens or a convex-concave lens, the seventh lens 7 is a concave-concave lens or a convex-concave lens, and the fifth lens 5, the sixth lens 6 and the eighth lens 8 are all convex-convex lenses in the object-side to image-side directions.

At least one of the third lens 3, the fourth lens 4, the fifth lens 5 and the sixth lens 6 is a low dispersion glass lens, and the Abbe number Vd of the low dispersion glass lens is more than or equal to 60. The refractive index Nd of at least two of the first lens 1, the second lens 2, the third lens 3, the seventh lens 7 and the eighth lens 8 is larger than or equal to 1.6.

The utility model discloses a camera lens, first lens 1 is f1 to the effective focal length of third lens 3, and the effective focal length of camera lens is f, satisfies the relational expression: f1/f is not less than-11 and not more than-1. The effective focal lengths of the fourth lens 4 to the eighth lens 8 are f2, and satisfy the relation: f2/f is more than or equal to 1.6 and less than or equal to 2.

The utility model discloses a camera lens, 8 image side centers of eighth lens extremely the distance of camera lens image planes is D, and 1 object side of first lens is D to the distance of camera lens image planes, satisfies the relational expression: D/D is more than or equal to 0.18. Abbe numbers of the fourth lens 4 and the fifth lens 5 are v4 and v5, respectively, and satisfy the following relations: and | v4-v5| ≧ 30.

The utility model discloses the relative aperture FNO of camera lens is less than or equal to 1.2.

The utility model discloses a plastic lens is aspheric lens promptly, the utility model discloses the camera lens, all aspheres satisfy:

in the formula, z is the axial distance from the curved surface to the vertex at the position which is along the direction of the optical axis and is vertical to the optical axis by the height h; c represents the curvature at the apex of the aspherical surface; k is a conic coefficient; a4, A6, A8, A10, A12, A14 and A16. the aspheric coefficients of the fourth, sixth, eighth, tenth, twelfth, fourteenth and sixteenth orders, respectively.

To sum up, the utility model discloses a camera lens is injectd according to above and is set up, through the positive and negative focal power of optimizing each lens of configuration, makes the aberration obtain effectual correction, and the mixed structure collocation is being reduced into manufacturing cost and is making to the glass of deuterogamying the utility model discloses the infrared out-of-focus volume of camera lens can realize the confocality of day and night (visible light and infrared light are confocal), realizes the F1.0 big light ring of camera lens, and the power of resolving image reaches 5M lens requirement simultaneously, guarantees the high resolution under big light ring. Meanwhile, the lens of the utility model can realize no virtual focus within the temperature range of-40 ℃ to 80 ℃, and overcomes the difficulty that the focus drift is easily caused in the high and low temperature environment due to the large expansion coefficient of the plastic aspheric lens; furthermore, the utility model discloses a camera lens contains 8 lens altogether, and is small, and the camera lens overall length is within 22.2mm, simultaneously the utility model discloses camera lens unit article and equipment tolerance are better, have good manufacturability.

The lens barrel according to the present invention will be specifically described below by giving 5 sets of specific embodiments according to the above-described arrangement of the present invention. The utility model discloses a camera lens contains 8 lens altogether, and wherein fourth lens 4 and fifth lens 5 constitute the veneer lens group, and including light filter and imaging surface, 18 optical surfaces altogether, when diaphragm S is located between third lens 3 and the fourth lens 4, increase a diaphragm face, consequently, the utility model discloses a prime lens includes 19 optical surfaces at most, for the ease of narration, numbers 19 optical surfaces as required S1-S19.

Five sets of embodiment data are as in table 1 below:

conditional formula (II)	Example 1	Example 2	Embodiment 3	Example 4	Example 5
						-11≤f1/f≤-1	-10.95	-1.46	-2.39	-4.42	-3.2
1.6≤f2/f≤2	1.93	1.65	1.93	1.81	1.85
						d/D≥0.18	0.21	0.23	0.18	0.24	0.21
|v4-v5|≥30	30.2	42.5	66.62	35.8	69.6

TABLE 1

The first implementation mode comprises the following steps:

fig. 1 is a schematic diagram illustrating a lens structure according to a first embodiment of the present invention.

In the present embodiment, the total lens length TTL is 22.2mm, the FN0 is 1.0, the stop S is located between the third lens 3 and the fourth lens 4, the third lens 3 is a plastic lens, the fourth lens 4 is a glass lens, the fifth lens 5 and the sixth lens 6 are low dispersion glass lenses, and the refractive indices Nd of the third lens 3 and the seventh lens 7 are not less than 1.6.

Table 2 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

TABLE 2

Table 3 shows the aspheric coefficients of the aspheric lenses of the present embodiment, K is the conic constant of the surface, and A, B, C, D, E, F are the aspheric coefficients of fourth, sixth, eighth, tenth, and twelfth, fourteen orders, respectively.

Number of noodles

K

A

B

C

D

E

S1

6.915E+00

-3.992E-04

0.000E+00

0.000E+00

0.000E+00

0.000E+00

S2

-8.996E-01

-1.356E-04

1.997E-04

-2.904E-05

1.932E-06

6.0414E-8

S3

-8.116E-01

1.132E-02

-4.609E-04

2.410E-05

-5.411E-07

1.7939E-08

S4

3.364E-01

8.392E-03

-9.941E-06

2.561E-06

-8.044E-09

-3.0668E-10

S5

-3.686E-02

-2.720E-03

1.979E-04

-1.273E-05

3.254E-07

-1.1087E-08

S6

-1.521E+00

-2.565E-03

1.772E-04

-1.035E-05

2.199E-07

1.1245E-08

S13

4.759E-01

-4.752E-03

2.280E-04

-7.637E-06

9.158E-08

2.7486E-09

S14

-1.307E-02

-6.073E-03

2.338E-04

-9.156E-06

1.096E-07

-2.9152E-08

S15

1.476E+00

-1.200E-03

-6.095E-05

1.088E-06

-2.608E-09

-8.0993E-09

S16

1.583E-01

9.726E-04

-2.997E-05

3.319E-07

1.847E-10

3.8623E-10

TABLE 3

FIGS. 2 to 5 schematically show an MTF chart, a Through-Focus-MTF chart at a frequency of 120lp/mm, a Through-Focus-MTF chart at an outer frequency of 120lp/mm, and a ray fan of the lens of example 1, respectively. Can learn in combination with the attached drawing, according to the utility model discloses the camera lens that embodiment 1 obtained, the diaphragm number can reach F1.0, and the infrared defocusing amount of camera lens is within 0.006mm simultaneously, can realize confocal day and night, does not virtually focus at-40 ℃ -80 ℃ temperature range simultaneously.

The second embodiment:

fig. 6 is a schematic view showing a lens structure according to a second embodiment of the present invention.

In the present embodiment, the total lens length TTL is 20.8mm, the FN0 is 1.2, the stop S is located between the third lens 3 and the fourth lens 4, the third lens 3, the fourth lens 4, and the fifth lens 5 are glass lenses, the sixth lens 6 is a plastic lens, the third lens 3 and the fifth lens are low dispersion glass lenses, and the refractive index Nd of the third lens 3 and the seventh lens 7 is not less than 1.6.

Table 4 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

number of noodles	Surface type	R value	Thickness of	Refractive index	Abbe number
						S1	Aspherical surface	16.255	1.17	1.52	56.1
S2	Aspherical surface	2.178	3.74
						S3	Aspherical surface	-3.978	0.74	1.53	56.5
S4	Aspherical surface	29.489	0.24
						S5	Spherical surface	9.062	1.28	1.61	68.6
S6	Spherical surface	101.911	0.66
						S7(STO)	Spherical surface	Infinity	0.1
S8	Spherical surface	19.232	1.42	1.92	20.9
						S9	Spherical surface	11.411	1.79	1.62	63.4
S10	Spherical surface	-5.922	0.1
						S11	Aspherical surface	5.548	1.87	1.53	56.5
S12	Aspherical surface	-34.945	0.14
						S13	Aspherical surface	-56.907	0.59	1.64	23.5
S14	Aspherical surface	5.914	0.1
						S15	Aspherical surface	4.443	2	1.53	56.0
S16	Aspherical surface	-5.958	3.76
						S17	Spherical surface	Infinity	0.8	1.52	64.2
S18	Spherical surface	Infinity	0.2
						S19(IMA)	Spherical surface	Infinity

TABLE 4

Table 5 shows the aspherical surface coefficients of the aspherical lenses in the present embodiment, K is a conic constant of the surface, and A, B, C, D, E, F are aspherical surface coefficients of fourth order, sixth order, eighth order, tenth order, and twelfth and fourteenth orders, respectively.

Number of noodles

K

A

B

C

D

E

S1

0.0000E+00

1.3253E-03

-3.3478E-05

4.0058E-07

-5.2709E-10

-1.1245E-11

S2

0.0000E+00

-1.7862E-03

-1.3237E-04

7.1352E-06

2.6398E-06

-2.7486E-07

S3

-5.5614E-01

9.5534E-03

-9.4782E-04

-5.8180E-05

-2.0223E-06

2.9152E-08

S4

8.6906E+00

-1.1670E-02

-5.5974E-04

1.1557E-05

1.9681E-06

-8.9993E-08

S11

-2.4803E-01

-1.2252E-03

-2.6473E-05

-6.1043E-06

2.6688E-07

-1.8623E-09

S12

-7.2526E+00

3.5416E-03

5.5438E-05

3.0964E-06

-2.9056E-07

1.0441E-08

S13

-1.8828E+01

-1.8240E-03

-1.7410E-04

-9.9725E-06

1.2650E-07

-9.0414E-10

S14

-4.5645E-01

5.3961E-03

4.5219E-04

-1.6513E-05

-9.3842E-09

-1.7939E-08

S15

-4.3720E-01

-5.7458E-03

-3.9654E-04

3.4543E-06

-5.1092E-07

-2.0668E-08

S16

-2.6887E+00

1.9492E-03

-1.0917E-04

1.4904E-05

-8.7973E-07

1.1087E-08

TABLE 5

FIGS. 7 to 10 schematically show an MTF chart, a Through-Focus-MTF chart at a frequency of 120lp/mm, a Through-Focus-MTF chart at an outer frequency of 120lp/mm, and a ray fan of a lens according to example 2, respectively. Can learn in combination with the attached drawing, according to the utility model discloses the camera lens that embodiment 2 obtained, the diaphragm number can reach F1.0, and the infrared defocusing amount of camera lens is within 0.006mm simultaneously, can realize confocal day and night, does not virtually focus at-40 ℃ -80 ℃ temperature range simultaneously.

The third embodiment is as follows:

fig. 11 is a schematic view showing a lens structure according to a third embodiment of the present invention.

In the present embodiment, the total lens length TTL is 22.2mm, the FN0 is 1.0, the stop S is located on the image-side surface of the third lens 3, the fourth lens 4, and the fifth lens 5 are glass lenses, the sixth lens 6 is a plastic lens, the third lens 3 and the fifth lens 5 are low-dispersion glass lenses, and the refractive index Nd of the third lens 3 and the seventh lens 7 is not less than 1.6.

Table 6 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

number of noodles	Surface type	R value	Thickness of	Refractive index	Abbe number
						S1	Aspherical surface	200.498	0.6	1.53	56.1
S2	Aspherical surface	3.75	2.04
						S3	Aspherical surface	-19.001	0.6	1.52	54.2
S4	Aspherical surface	21.11	1.22
						S5	Spherical surface	-7.194	3.19	1.62	63.4
S6(STO)	Spherical surface	-6.181	0.6
						S7	Spherical surface	8.7	3.5	1.92	24.0
S8	Spherical surface	6.451	1.73	1.46	90.62
						S9	Spherical surface	-16.719	0.1
S10	Aspherical surface	5.629	2.02	1.53	56.1
						S11	Aspherical surface	-75.174	0.16
S12	Aspherical surface	-9.03	0.6	1.63	23.5
						S13	Aspherical surface	7.374	0.23
S14	Aspherical surface	3.583	1.61	1.53	56.1
						S15	Aspherical surface	-20.349	3
S16	Spherical surface	Infinity	0.8	1.52	64.2
						S17	Spherical surface	Infinity	0.2
S18(IMA)	Spherical surface	Infinity

TABLE 6

Table 7 shows the aspherical surface coefficients of the aspherical lenses in the present embodiment, K is a conic constant of the surface, and A, B, C, D, E, F are aspherical surface coefficients of fourth order, sixth order, eighth order, tenth order, and twelfth and fourteenth orders, respectively.

TABLE 7

FIGS. 12 to 15 schematically show an MTF chart, a Through-Focus-MTF chart at a frequency of 120lp/mm, a Through-Focus-MTF chart at an outer frequency of 120lp/mm, and a ray fan of a lens according to example 3, respectively. Can learn in combination with the attached drawing, according to the utility model discloses the camera lens that obtains according to the embodiment 3, the diaphragm number can reach F1.0, and the infrared defocusing amount of camera lens is within 0.006mm simultaneously, can realize confocal day and night, does not virtually focus at-40 ℃ -80 ℃ temperature range simultaneously.

The fourth embodiment:

fig. 16 is a schematic view showing a lens structure according to a fourth embodiment of the present invention.

In the present embodiment, the total lens length TTL is 22.2mm, the FN0 is 1.0, the stop S is located on the object-side surface of the fourth lens 4, the third lens 3 is a plastic lens, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are glass lenses, the fifth lens 5 and the sixth lens 6 are low dispersion glass lenses, and the refractive index Nd of the third lens 3 and the seventh lens 7 is not less than 1.6.

Table 8 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

TABLE 8

Table 9 shows the aspherical surface coefficients of the aspherical lenses in the present embodiment, K is a conic constant of the surface, and A, B, C, D, E, F are aspherical surface coefficients of fourth order, sixth order, eighth order, tenth order, and twelfth and fourteenth orders, respectively.

Number of noodles

K

A

B

C

D

E

S1

0.0000E+00

2.3692E-04

3.0607E-06

-5.1584E-10

-1.1245E-11

-5.2709E-11

S2

0.0000E+00

-1.3408E-04

-8.3404E-05

2.9147E-06

1.6576E-06

4.5722E-08

S3

-1.5298E+01

-1.0483E-03

-6.0721E-05

-2.0514E-06

-5.1194E-07

-2.5634E-09

S4

-6.7423E-01

-1.4519E-04

-5.9789E-06

2.0581E-06

-9.8037E-08

1.9601E-09

S5

0.0000E+00

-1.2355E-03

9.9494E-06

2.6502E-07

3.2726E-07

5.9228E-08

S6

-3.2148E-01

-4.1490E-03

-8.7129E-06

-3.0100E-07

2.3035E-07

-7.0648E-08

S12

3.6513E-01

-3.4459E-03

-6.7679E-06

1.2560E-07

9.2484E-08

2.1808E-09

S13

-8.5142E+00

-1.1599E-03

-2.1059E-05

2.7324E-08

9.1696E-08

1.1902E-10

S14

-6.7289E+00

-2.8463E-03

3.7495E-04

-4.9025E-07

-2.3276E-08

-5.1353E-10

S15

5.0000E+01

-8.7957E-04

-2.9256E-04

-8.9082E-07

1.1272E-08

-8.7955E-10

TABLE 9

FIGS. 17 to 20 schematically show an MTF chart, a Through-Focus-MTF chart at a frequency of 120lp/mm, a Through-Focus-MTF chart at an outer frequency of 120lp/mm, and a ray fan of a lens according to example 4, respectively. Can learn in combining the attached drawing, according to the utility model discloses the camera lens that obtains of embodiment 4, the diaphragm number can reach F1.0, and the infrared defocusing amount of camera lens is within 0.006mm simultaneously, can realize confocal day and night, does not virtually focus at-40 ℃ -80 ℃ temperature range simultaneously.

Example five:

fig. 21 is a schematic view showing a lens structure according to a fifth embodiment of the present invention.

In the present embodiment, the total lens length TTL is 22.2mm, the FN0 is 1.0, the stop S is located between the third lens 3 and the fourth lens 4, the third lens 3 is a plastic lens, the fourth lens 4, the fifth lens 5, and the sixth lens 6 are glass lenses, the fifth lens 5 and the sixth lens 6 are low dispersion glass lenses, and the refractive index Nd of the third lens 3 and the seventh lens 7 is not less than 1.6.

Table 10 below lists relevant parameters of each lens of the present embodiment, including surface type, radius of curvature, thickness, refractive index of material, abbe number:

number of noodles	Surface type	R value	Thickness of	Refractive index	Abbe number
						S1	Aspherical surface	10.757	0.73	1.55	55.7
S2	Aspherical surface	2.786	3.42
						S3	Aspherical surface	-2.874	1.52	1.52	56.1
S4	Aspherical surface	-5.487	0.1
						S5	Aspherical surface	13.743	1.3	1.64	23.5
S6	Aspherical surface	-15.643	0.6
						S7(STO)	Spherical surface	Infinity	0.3
S8	Spherical surface	11.185	0.6	1.81	25.5
						S9	Spherical surface	5.566	3.23	1.44	95.1
S10	Spherical surface	-7.799	0.07
						S11	Spherical surface	16.698	1.94	1.46	90.2
S12	Spherical surface	-15.459	0.1
						S13	Aspherical surface	7.974	0.6	1.63	23.5
S14	Aspherical surface	4.137	0.11
						S15	Aspherical surface	6.7	3.02	1.50	56.1
S16	Aspherical surface	-10.194	3.56
						S17	Spherical surface	Infinity	0.8	1.52	64.2
S18	Spherical surface	Infinity	0.2
						S19(IMA)	Spherical surface	Infinity

Watch 10

Table 11 shows the aspherical surface coefficients of the aspherical lenses in the present embodiment, K is a conic constant of the surface, and A, B, C, D, E, F are aspherical surface coefficients of fourth order, sixth order, eighth order, tenth order, and twelfth and fourteenth orders, respectively.

Number of noodles

K

A

B

C

D

E

S1

-2.5851E+01

-7.9013E-04

4.5134E-05

-1.2980E-06

1.8830E-08

9.4149E-10

S2

-3.8443E-01

-2.9300E-03

-9.4775E-05

1.9493E-05

-2.0219E-06

-1.0109E-07

S3

-2.0288E+00

-9.6133E-04

2.2139E-05

0.0000E+00

0.0000E+00

0.0000E+00

S4

-1.1032E+00

4.1411E-03

-1.0009E-04

1.2900E-05

-1.7653E-07

-8.8266E-09

S5

3.0658E+01

-1.0082E-03

5.6836E-05

-9.4815E-07

-1.2732E-07

-6.3658E-09

S6

7.5393E+00

-2.8145E-04

3.5594E-05

-6.8417E-07

-9.0029E-08

-4.5014E-09

S13

2.4306E+00

-2.1930E-03

1.2970E-04

-8.0836E-06

1.5715E-07

7.8575E-09

S14

-2.7363E-01

-2.2812E-03

4.0937E-05

-4.7335E-06

-1.3582E-07

-6.7909E-09

S15

-5.8977E-01

3.2580E-04

-8.8243E-05

1.9353E-06

-1.4068E-07

-7.0338E-09

S16

-1.2603E+01

1.0384E-03

-4.7128E-05

-8.7143E-07

1.1979E-07

5.9897E-09

TABLE 11

FIGS. 22 to 25 schematically show an MTF chart, a Through-Focus-MTF chart at a frequency of 120lp/mm, a Through-Focus-MTF chart at an outer frequency of 120lp/mm, and a ray fan of a lens according to example 5, respectively. Can learn in combination with the attached drawing, according to the utility model discloses the camera lens that embodiment 5 obtained, the diaphragm number can reach F1.0, and the infrared defocusing amount of camera lens is within 0.006mm simultaneously, can realize confocal day and night, does not virtually focus at-40 ℃ -80 ℃ temperature range simultaneously.

The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (11)

1. A lens barrel includes, in order from an object side to an image side along an optical axis, a first lens (1) having negative power, a second lens (2) having negative power, a third lens (3) having positive power, a fourth lens (4) having negative power, a fifth lens (5) having positive power, a sixth lens (6) having positive power, a seventh lens (7) having negative power, and an eighth lens (8) having positive power;

the lens is characterized in that the first lens (1), the second lens (2), the seventh lens (7) and the eighth lens (8) are plastic lenses, and at least three lenses of the third lens (3), the fourth lens (4), the fifth lens (5) and the sixth lens (6) are glass lenses.

2. A lens barrel according to claim 1, characterized in that it further comprises a diaphragm (S) located on the image side of the third lens (3), or between the third lens (3) and the fourth lens (4), or on the object side of the fourth lens (4).

3. A lens barrel according to claim 2, characterized in that the fourth lens (4) and the fifth lens (5) constitute a cemented lens group having positive optical power.

4. The lens barrel according to claim 1, wherein the first lens (1) is a convex-concave lens, the second lens (2) is a concave-concave lens or a concave-convex lens, the third lens (3) is a convex-convex lens or a concave-convex lens, the fourth lens (4) is a concave-concave lens or a convex-concave lens, the seventh lens (7) is a concave-concave lens or a convex-concave lens, and the fifth lens (5), the sixth lens (6), and the eighth lens (8) are each a convex-convex lens in an object-side to image-side direction.

5. A lens barrel according to any one of claims 1 to 4, wherein at least one of the third lens (3), the fourth lens (4), the fifth lens (5) and the sixth lens (6) is a low dispersion glass lens having an Abbe number Vd of 60 or more.

6. A lens barrel according to any one of claims 1 to 4, wherein at least two of the first lens element (1), the second lens element (2), the third lens element (3), the seventh lens element (7) and the eighth lens element (8) have a refractive index Nd ≧ 1.6.

7. A lens barrel according to any one of claims 1 to 4, wherein the effective focal length of the first lens (1) to the third lens (3) is f1, and the effective focal length of the lens barrel is f, satisfying the relation: f1/f is not less than-11 and not more than-1.

8. A lens barrel according to any one of claims 1 to 4, wherein an effective focal length of the fourth lens (4) to the eighth lens (8) is f2, and the effective focal length of the lens barrel is f, satisfying the relation: f2/f is more than or equal to 1.6 and less than or equal to 2.

9. A lens barrel according to any one of claims 1 to 4, wherein a distance D from the center of the image side surface of the eighth lens element (8) to the image plane of the lens barrel, and a distance D from the object side surface of the first lens element (1) to the image plane of the lens barrel satisfy the relation: D/D is more than or equal to 0.18.

10. A lens barrel according to any one of claims 1 to 4, wherein the Abbe numbers of the fourth lens (4) and the fifth lens (5) are v4 and v5, respectively, satisfying the relation: and | v4-v5| ≧ 30.

11. A lens barrel according to any one of claims 1 to 4, wherein the relative aperture FNO of the lens barrel is not more than 1.2.

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