CN218158566U - Eyepiece lens - Google Patents

Abstract

The utility model relates to an eyepiece camera lens, along the direction of optical axis from mesh side to demonstration side, include diaphragm, first lens, second lens, third lens and plate glass in proper order, first lens is the paraxial region convex-convex lens that has positive focal power, the second lens is paraxial region convex-concave lens or paraxial region meniscus lens that has positive focal power, the third lens is paraxial region meniscus lens that has negative focal power; the effective focal length f of the eyepiece lens and the effective focal length f2 of the second lens meet the following conditions: f2/f is more than or equal to 0.00 and less than or equal to 3.68. By reasonably distributing the focal power and the shape of the lens, light rays passing through the optical system smoothly enter the image plane, the chromatic aberration correction of the optical system is facilitated, the higher image quality is facilitated, the number of required optical elements is reduced, the overall dimension of the optical system is reduced, and the weight of the optical system is reduced.

Description

Eyepiece lens

Technical Field

The utility model relates to an optical lens field, concretely relates to eyepiece camera lens.

Background

The human eye is a high-precision optical system, but the human eye has a small spectral sensitivity range and limited resolving power. As the light intensity is continuously weakened, the recognition capability of human eyes is gradually deteriorated, and finally, the object cannot be recognized. At night, two factors of spectral range and light intensity limit the resolving power of human eyes, and the low-light level night vision device breaks through the limit and helps people to observe objects under the low-light level condition at night.

The low-light night vision technology is a mature high-new technology, and the low-light night vision device is a night vision device with the largest production and equipment quantity in developed countries. With the increasing demand of low-light night vision, the corresponding demand is strengthened. In order to meet the requirements of overall miniaturization and light weight of the device, the optimal scheme is to increase the observation magnification of the eyepiece. The observation magnification of the ocular is directly related to the focal length of the lens group, and the ocular is required to have higher focal power when the observation magnification of the ocular is increased. The eyepiece is formed by only using a standard spherical positive lens, and the aberration is difficult to correct.

In addition, the person wearing the glasses needs a relatively long visual gap to see the complete field of vision through the eyepiece, usually more than 15mm is appropriate; many military visual optics require an extended pupillary distance. For a military aiming and telescopic system, in order to prevent the head from being impacted during shooting, an eyeshade and a forehead protector are required to be arranged to ensure the personal safety of a shooter; in order to avoid damage to a shooter caused by shell smoke, toxic gas and the like, the gas mask needs to be worn, the requirements can be met only by ensuring that the eye piece has a long exit pupil distance, and the exit pupil distance of the existing eye piece is generally about 15 mm.

The eyepiece system proposed in the prior art is difficult to correct aberrations while keeping a large field angle, and is also difficult to have higher sensitivity and resolution when the exit pupil distance is long.

SUMMERY OF THE UTILITY MODEL

In view of this, embodiments of the present invention provide an eyepiece lens capable of correcting chromatic aberration of an optical system and achieving higher image quality.

An embodiment of the present invention provides an eyepiece lens, which sequentially includes a diaphragm, a first lens, a second lens, and a third lens along an optical axis from an eye side to a display side, wherein the first lens is a paraxial region convex lens having positive focal power, the second lens is a paraxial region convex lens or paraxial region convex lens having positive focal power, and the third lens is a paraxial region convex lens having negative focal power; the effective focal length f of the eyepiece lens and the effective focal length f2 of the second lens meet the following conditions: f2/f is more than or equal to 0.00 and less than or equal to 3.68.

Preferably, the first lens, the second lens and the third lens are all plastic aspheric lenses.

Preferably, the effective focal length f of the eyepiece lens and the effective focal length f1 of the first lens satisfy: f1/f is more than or equal to 0.63 and less than or equal to 0.88.

Preferably, the effective focal length f of the eyepiece lens and the effective focal length f3 of the third lens satisfy: f3/f is more than or equal to-0.98 and less than or equal to-0.54.

Preferably, the effective focal length f of the eyepiece lens and the combined focal length f12 of the first lens and the second lens satisfy: f/f12 is more than or equal to 1.68 and less than or equal to 2.43.

Preferably, an effective focal length f of the eyepiece lens and a combined focal length f23 of the second lens and the third lens satisfy: f/f23 is more than or equal to-0.93 and less than or equal to 0.00.

Preferably, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: f1/f2 is more than or equal to 0.00 and less than or equal to 1.77.

Preferably, the effective focal length f1 of the first lens and the effective focal length f3 of the third lens satisfy: f1/f3 is more than or equal to-1.48 and less than or equal to-0.59.

Preferably, a thickness CT1 of the first lens on the optical axis and a thickness CT3 of the third lens on the optical axis satisfy: CT1/CT3 is more than or equal to 1.58 and less than or equal to 2.35.

Preferably, the effective focal length f of the eyepiece lens and the object-side-to-image-side distance TTL of the first lens satisfy: TTL/f is more than or equal to 1.08 and less than or equal to 1.29.

The embodiment of the utility model provides a through rational distribution lens focal power and shape, make the light through optical system gently get into image plane, be favorable to optical system to rectify the colour difference, be favorable to realizing higher image quality to reduce required optical element's quantity, reduce optical system's overall dimension, alleviate optical system's weight.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of an optical structure of an eyepiece lens according to a first embodiment of the present invention;

fig. 2 is a schematic view of an optical structure of an eyepiece lens according to a second embodiment of the present invention;

fig. 3 is a schematic view of an optical structure of an eyepiece lens according to a third embodiment of the present invention.

Detailed Description

The description of the embodiments of this specification is intended to be taken in conjunction with the accompanying drawings, which are to be considered part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and simplified for convenience. Further, the components of the structures in the drawings are described separately, and it should be noted that the components not shown or described in the drawings are well known to those skilled in the art.

Any reference to directions and orientations to the description of the embodiments herein is merely for convenience of description and should not be construed as limiting the scope of the present invention in any way. The following description of the preferred embodiments refers to combinations of features which may be present independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

As shown in fig. 1-3, which are schematic diagrams of the optical structure of the eyepiece lens according to the embodiment of the present invention. The eyepiece lens is used for enabling imaging light to enter eyes of an observer through an eyepiece optical system from a display picture to form an image, the direction facing the eyes is a target side, the direction facing the display picture is a display side, and the eyepiece lens sequentially comprises a diaphragm STO, a first lens L1, a second lens L2 and a third lens L3 along the direction from the target side to the display side along an optical axis, wherein the first lens L1 is a paraxial region convex lens with positive focal power, the second lens L2 is a paraxial region convex-concave lens or a paraxial region concave-convex lens with positive focal power, and the third lens L3 is a paraxial region concave-convex lens with negative focal power. By reasonably distributing the focal power and the shape of the lens, light rays passing through the optical system smoothly enter the image plane, the chromatic aberration correction of the optical system is facilitated, the higher image quality is facilitated, the number of required optical elements is reduced, the overall dimension of the optical system is reduced, and the weight of the optical system is reduced. And the effective focal length f of the eyepiece lens and the effective focal length f2 of the second lens L2 meet: f2/f is more than or equal to 0.00 and less than or equal to 3.68. The ratio of the focal length of the single lens to the focal length of the system is reasonably distributed, so that light passing through the single lens is smoothly transmitted, single parts and assembly tolerance are good, and the optical system has good manufacturability and is favorable for improving the resolving power of the optical system.

In some embodiments, the first lens L1, the second lens L2, and the third lens L3 are plastic aspheric lenses. The plastic material can reduce the cost of the optical system, and the aspheric surface is favorable for correcting various aberrations of the optical system and improving the image quality of the optical system.

In some embodiments, the effective focal length f of the eyepiece lens and the effective focal length f1 of the first lens L1 satisfy: f1/f is more than or equal to 0.63 and less than or equal to 0.88. The ratio of the focal length of the single lens to the focal length of the system is reasonably distributed, so that light passing through the single lens is smoothly transmitted, single parts and assembly tolerance are good, and the optical system has good manufacturability and is favorable for improving the resolving power of the optical system.

In some embodiments, the effective focal length f of the eyepiece lens and the effective focal length f3 of the third lens L3 satisfy: f3/f is more than or equal to-0.98 and less than or equal to-0.54. The ratio of the focal length of the single lens to the focal length of the system is reasonably distributed, so that light passing through the single lens is smoothly transited, single parts and assembly tolerance are good, the manufacturability is good, and the resolution power of an optical system is favorably improved.

In some embodiments, the effective focal length f of the eyepiece lens and the combined focal length f12 of the first lens L1 and the second lens L2 satisfy: f/f12 is more than or equal to 1.68 and less than or equal to 2.43. Therefore, various aberrations of the optical system can be balanced, and the resolving power can be improved remarkably.

In some embodiments, the effective focal length f of the eyepiece lens and the combined focal length f23 of the second lens L2 and the third lens L3 satisfy: -0.93-f 23-0.00. Therefore, the optical system is beneficial to balancing various aberrations of the optical system, and the resolving power is greatly improved.

In some embodiments, the effective focal length f1 of the first lens L1 and the effective focal length f2 of the second lens L2 satisfy: f1/f2 is more than or equal to 0.00 and less than or equal to 1.77. Therefore, the refractive power configurations of the first lens element L1 and the second lens element L2 are suitable, which is beneficial to reducing the excessive increase of the system aberration.

In some embodiments, the effective focal length f1 of the first lens L1 and the effective focal length f3 of the third lens L3 satisfy: f1/f3 is more than or equal to-1.48 and less than or equal to-0.59. Therefore, the refractive power configurations of the first lens element L1 and the third lens element L3 are suitable, and the single lens element assembling sensitivity can be reduced.

In some embodiments, the thickness CT1 of the first lens L1 on the optical axis and the thickness CT3 of the third lens L3 on the optical axis satisfy: CT1/CT3 is more than or equal to 1.58 and less than or equal to 2.35. This contributes to the moldability and homogeneity of the lens.

In some embodiments, the effective focal length f of the eyepiece lens and the object-side-to-image-side distance TTL of the first lens L1 satisfy: TTL/f is more than or equal to 1.08 and less than or equal to 1.29. Therefore, the method is beneficial to realizing higher image quality and ensuring smaller volume.

The embodiment of the utility model provides a through rational distribution lens focal power and shape, make the light through optical system gently get into image planes, be favorable to optical system to rectify the colour difference, be favorable to realizing higher image quality to reduce required optical element's quantity, reduce optical system's overall dimension, alleviate optical system's weight. The utility model discloses effective focal length with lightweight eyepiece of long exit pupil distance is 18mm, exit pupil distance (diaphragm to first lens object side distance) is 20mm, and consequently this eyepiece belongs to the eyepiece of long exit pupil distance, and the eyepiece of long exit pupil distance is applicable to the observer who wears glasses, and many military visual optical instrument also require long exit pupil distance. The utility model discloses the eyepiece has long, the small-size, the light, the simple structure of exit pupil distance and the lower characteristics of cost of quality.

The zoom lens of the present invention is specifically described below with reference to three embodiments in conjunction with the drawings and tables. In each embodiment below, the embodiment of the present invention records the stop STO as one surface and records the IMAGE plane IMAGE as one surface.

The parameters of each example specifically satisfying the above conditional expressions are shown in table 1 below:

conditional formula (VII)	Example one	Example two	EXAMPLE III
				0.63≤f1/f≤0.88	0.684	0.818	0.824
0.00≤f2/f≤3.68	2.903	0.618	0.595
				-0.98≤f3/f≤-0.54	-0.882	-0.627	-0.646
1.68≤f/f12≤2.43	1.830	2.235	2.277
				-0.93≤f/f23≤0.00	-0.718	-0.149	-0.085
0.00≤f1/f2≤1.77	0.236	1.323	1.386
				-1.48≤f1/f3≤-0.59	-0.775	-1.304	-1.275
1.58≤CT1/CT3≤2.35	2.194	1.995	1.735
				1.08≤TTL/f≤1.29	1.124	1.225	1.247

TABLE 1

In an embodiment of the present invention, the aspheric lens of the zoom lens satisfies the following formula:

in the above formula, z is a height perpendicular to the optical axis in the direction of the optical axisThe axial distance from the curved surface to the vertex at the position with the degree of y; c represents the curvature at the apex of the aspherical surface; k is a conic coefficient; a. The ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ The values of the aspheric coefficients represent fourth, sixth, eighth, tenth, twelfth, fourteenth and sixteenth orders.

Example one

As shown in fig. 1, in the first embodiment, the curvature radius R, the thickness d, the refractive index Nd, and the abbe number Vd of each surface of the zoom lens are shown in the following table (table 2):

noodle sequence number	Surface type	Radius of curvature R	Thickness d	Refractive index Nd	Abbe number Vd
						S0(OBJ)	STANDARD	Infinity	Infinity
S1(STO)	STANDARD	Infinity	20.00
						S2	EVENASPH	36.61	3.40	1.54	56
S3	EVENASPH	-7.87	0.07
						S4	EVENASPH	18.49	3.53	1.54	56
S5	EVENASPH	49.97	1.82
						S6	EVENASPH	-2.93	1.55	1.66	20.4
S7	EVENASPH	-4.90	4.26
						S8	STANDARD	Infinity	0.70	1.52	64.2
S9	STANDARD	Infinity	4.96
						S10(IMA)	STANDARD	Infinity

TABLE 2

In the first embodiment, the K value and aspheric coefficient of the zoom lens are as follows (table 3):

number of noodles

Value of K

A4

A6

A8

A10

A12

A14

A16

A18

A20

S2

-8.38

-1.50E-04

3.53E-05

-9.43E-07

6.22E-09

1.42E-10

-2.64E-12

-2.53E-15

4.70E-16

-4.88E-18

S3

-8.96

8.44E-04

-8.86E-06

2.90E-08

-5.74E-09

6.49E-11

2.09E-12

-1.59E-14

-7.09E-16

7.32E-18

S4

5.55

2.64E-03

-7.57E-05

9.43E-07

6.29E-09

-2.01E-10

-1.27E-11

2.90E-13

1.68E-16

-2.58E-17

S5

54.92

1.56E-03

-1.83E-05

-8.60E-07

-2.39E-09

6.06E-10

-5.86E-12

3.73E-15

-3.12E-16

-1.24E-18

S6

-3.68

4.53E-03

-1.93E-04

4.61E-06

-1.84E-08

-1.54E-09

2.38E-11

-2.59E-14

2.50E-15

-6.96E-17

S7

-5.21

4.52E-03

-1.16E-04

1.38E-06

-3.52E-08

7.31E-09

-2.43E-10

2.68E-14

9.25E-14

-1.14E-15

TABLE 3

As shown in fig. 1 and tables 1 to 3, in this embodiment, by reasonably distributing the focal power and the shape of the lens, the light passing through the optical system smoothly enters the image plane, which is beneficial to the optical system to correct chromatic aberration, and is beneficial to achieve higher image quality, and reduces the number of required optical elements, the overall size of the optical system, and the weight of the optical system.

Example two

As shown in fig. 2, in the second embodiment, the curvature radius R, the thickness d, the refractive index Nd, and the abbe number Vd of each surface of the zoom lens are shown in the following table (table 4):

number of noodles	Surface type	Radius of curvature R	Thickness d	Refractive index Nd	Abbe number Vd
						S0(OBJ)	STANDARD	Infinity	Infinity
S1(STO)	STANDARD	Infinity	20.00
						S2	EVENASPH	9.86	4.37	1.54	55.7
S3	EVENASPH	-34.16	0.16
						S4	EVENASPH	-14.31	3.62	1.54	55.7
S5	EVENASPH	-4.60	1.92
						S6	EVENASPH	-2.28	2.19	1.64	23.5
S7	EVENASPH	-4.55	0.14
						S8	STANDARD	Infinity	0.70	1.52	64.2
S9	STANDARD	Infinity	8.99
						S10(IMA)	STANDARD	Infinity

TABLE 4

In the second embodiment, the K value and the aspheric coefficient of the zoom lens are as follows (table 5):

number of noodles

Value of K

A4

A6

A8

A10

A12

S2

-0.11

-4.12E-04

-6.67E-06

1.76E-07

-2.58E-09

1.89E-11

S3

13.56

-1.10E-04

1.31E-06

-4.99E-08

5.08E-10

6.68E-12

S4

-4.37

1.47E-03

-1.36E-05

1.02E-07

-1.56E-11

-8.73E-12

S5

-3.69

1.18E-03

-5.68E-06

4.33E-08

-1.78E-09

1.49E-13

S6

-2.38

1.17E-03

-2.17E-05

4.03E-07

-2.32E-09

-1.47E-11

S7

-3.75

9.51E-04

-9.96E-07

-1.53E-07

5.99E-09

-1.82E-11

TABLE 5

With reference to fig. 2 and tables 1 and 4-5, in this embodiment, by reasonably distributing the focal power and shape of the lens, the light passing through the optical system smoothly enters the image plane, which is beneficial to the optical system to correct chromatic aberration, and is beneficial to achieve higher image quality, and reduces the number of required optical elements, the overall size of the optical system, and the weight of the optical system.

EXAMPLE III

As shown in fig. 3, in the third embodiment, the radius of curvature R, the thickness d, the refractive index Nd, and the abbe number Vd of each surface of the zoom lens are as follows (table 6):

number of noodles	Surface type	Radius of curvature R	Thickness d	Refractive index Nd	Abbe number Vd
						S0(OBJ)	STANDARD	Infinity	Infinity
S1(STO)	STANDARD	Infinity	20.00
						S2	EVENASPH	9.97	4.25	1.54	55.7
S3	EVENASPH	-34.27	0.18
						S4	EVENASPH	-13.60	3.62	1.54	55.7
S5	EVENASPH	-4.42	1.88
						S6	EVENASPH	-2.28	2.45	1.64	23.5
S7	EVENASPH	-4.65	0.28
						S8	STANDARD	Infinity	0.70	1.52	64.2
S9	STANDARD	Infinity	9.14
						S10(IMA)	STANDARD	Infinity

TABLE 6

In embodiment three, the K value and aspheric coefficient of the zoom lens are as follows (table 7):

number of noodles

Value of K

A4

A6

A8

A10

A12

S2

-0.07

-4.09E-04

-6.43E-06

1.79E-07

-2.58E-09

1.87E-11

S3

13.37

-9.40E-05

1.50E-06

-4.90E-08

5.25E-10

6.86E-12

S4

-3.24

1.47E-03

-1.38E-05

9.80E-08

-5.18E-11

-8.70E-12

S5

-3.51

1.16E-03

-6.28E-06

4.28E-08

-1.69E-09

7.50E-13

S6

-2.33

1.14E-03

-2.20E-05

4.04E-07

-2.29E-09

-1.35E-11

S7

-3.40

8.80E-04

-1.21E-06

-1.72E-07

6.02E-09

-2.76E-11

TABLE 7

With reference to fig. 3 and tables 1 and 6-7, in this embodiment, by reasonably distributing the focal power and the shape of the lens, the light passing through the optical system smoothly enters the image plane, which is beneficial to the optical system to correct chromatic aberration, and is beneficial to achieve higher image quality, and the number of required optical elements is reduced, the overall size of the optical system is reduced, and the weight of the optical system is reduced.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An eyepiece lens comprising, in order along an optical axis from an object side to a display side, a Stop (STO), a first lens (L1), a second lens (L2), a third lens (L3), and a plate glass (CG),

the first lens (L1) is a paraxial region convex-convex lens having positive optical power, the second lens (L2) is a paraxial region convex-concave lens or a paraxial region convex-concave lens having positive optical power, and the third lens (L3) is a paraxial region convex-concave lens having negative optical power;

the effective focal length f of the eyepiece lens and the effective focal length f2 of the second lens (L2) satisfy: f2/f is more than or equal to 0.00 and less than or equal to 3.68.

2. Eyepiece lens according to claim 1, wherein the first lens (L1), the second lens (L2) and the third lens (L3) are all plastic aspheric lenses.

3. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f of the eyepiece lens and the effective focal length f1 of the first lens (L1) satisfy: f1/f is more than or equal to 0.63 and less than or equal to 0.88.

4. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f of the eyepiece lens and the effective focal length f3 of the third lens (L3) satisfy: f3/f is more than or equal to-0.98 and less than or equal to-0.54.

5. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f of the eyepiece lens and the combined focal length f12 of the first lens (L1) and the second lens (L2) satisfy: f/f12 is more than or equal to 1.68 and less than or equal to 2.43.

6. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f of the eyepiece lens and the combined focal length f23 of the second lens (L2) and the third lens (L3) satisfy: f/f23 is more than or equal to-0.93 and less than or equal to 0.00.

7. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f1 of the first lens (L1) and the effective focal length f2 of the second lens (L2) satisfy: f1/f2 is more than or equal to 0.00 and less than or equal to 1.77.

8. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f1 of the first lens (L1) and the effective focal length f3 of the third lens (L3) satisfy: f1/f3 is more than or equal to-1.48 and less than or equal to-0.59.

9. Eyepiece lens according to claim 1 or 2, wherein the thickness CT1 of the first lens (L1) on the optical axis and the thickness CT3 of the third lens (L3) on the optical axis satisfy: CT1/CT3 is more than or equal to 1.58 and less than or equal to 2.35.

10. Eyepiece lens according to claim 1 or 2, wherein the effective focal length f of the eyepiece lens and the object side to image side distance TTL of the first lens (L1) are such that: TTL/f is more than or equal to 1.08 and less than or equal to 1.29.

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