阅读说明：本技术 一种20mm手动调焦红外镜头及装配方法 (20mm manual focusing infrared lens and assembling method ) 是由 霍亚敏 刘自强 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种20mm手动调焦红外镜头及装配方法,20mm手动调焦红外镜头包括镜筒和与镜筒的外周面螺纹连接的固定筒；镜筒内沿光线入射方向依次设有第一正透镜、第二正透镜和第三正透镜,且第一正透镜与第二正透镜之间的距离为17.91mm,第二正透镜与第三正透镜之间的距离为0.5mm；固定筒用于与探测器的机体相固定,且能够通过旋转镜筒调节镜筒与探测器的成像面的距离。上述20mm手动调焦红外镜头包括镜筒和固定筒,第一正透镜与第二正透镜之间的距离为17.91mm,第二正透镜与第三正透镜之间的距离为0.5mm,镜头长度短,体积小；且结构设计简单,能够通过旋转镜筒实现焦距的手动调节,操作方便,进而补偿温度变化造成的成像面偏移。(The invention discloses a 20mm manual focusing infrared lens and an assembly method, wherein the 20mm manual focusing infrared lens comprises a lens barrel and a fixed barrel in threaded connection with the peripheral surface of the lens barrel; a first positive lens, a second positive lens and a third positive lens are sequentially arranged in the lens barrel along the light incidence direction, the distance between the first positive lens and the second positive lens is 17.91mm, and the distance between the second positive lens and the third positive lens is 0.5 mm; the fixed cylinder is used for being fixed with the body of the detector, and can adjust the distance between the lens cone and the imaging surface of the detector through rotating the lens cone. The 20mm manual focusing infrared lens comprises a lens barrel and a fixed barrel, wherein the distance between the first positive lens and the second positive lens is 17.91mm, the distance between the second positive lens and the third positive lens is 0.5mm, the length of the lens is short, and the size is small; and structural design is simple, can realize the manual regulation of focus through rotatory lens section of thick bamboo, convenient operation, and then the imaging plane skew that the compensation temperature change caused.)

1. A20 mm manual focusing infrared lens is characterized by comprising a lens barrel (1) and a fixed barrel (2) in threaded connection with the peripheral surface of the lens barrel (1);

a first positive lens (3), a second positive lens (4) and a third positive lens (5) are sequentially arranged in the lens barrel (1) along the light incidence direction, the distance between the first positive lens (3) and the second positive lens (4) is 17.91mm, and the distance between the second positive lens (4) and the third positive lens (5) is 0.5 mm;

the fixed cylinder (2) is used for being fixed with a body of the detector, and the distance between the lens barrel (1) and an imaging surface (6) of the detector can be adjusted by rotating the lens barrel (1).

2. A 20mm manual focusing infrared lens according to claim 1, characterized in that the center thickness of the first positive lens (3) is 1.8 mm.

3. The 20mm manual focusing infrared lens according to claim 1, wherein the curvature fitting radius of the light incident side of the first positive lens (3) is 65mm, and the curvature fitting radius of the light exiting side is 54.85 mm.

4. A 20mm manual focusing infrared lens according to claim 1, characterized in that the center thickness of the second positive lens (4) is 2.7 mm.

5. The 20mm manual focusing infrared lens according to claim 1, wherein the curvature fitting radius of the light incident side of the second positive lens (4) is 31.35mm, and the curvature fitting radius of the light exiting side is 26.12 mm.

6. A 20mm manual focusing infrared lens according to claim 1, characterized in that the center thickness of the third positive lens (5) is 2.7 mm.

7. The 20mm manual focusing infrared lens according to claim 1, wherein the curvature fitting radius of the light incidence side of the third positive lens (5) is 20.36mm, and the curvature fitting radius of the light emergence side is 21.23 mm.

8. The 20mm manual focusing infrared lens according to claim 1, wherein a limiting ring (7) is arranged on the outer peripheral surface of the lens barrel (1), a limiting screw (8) is arranged on the inner peripheral surface of the fixed barrel (2), and the limiting screw (8) is matched with the limiting ring (7) to limit the separation of the lens barrel (1) and the fixed barrel (2).

9. The 20mm manual focusing infrared lens according to claim 1, wherein a first seal ring (9) is provided between the outer peripheral surface of the lens barrel (1) and the inner wall of the fixed cylinder (2).

10. The 20mm manual focusing infrared lens according to claim 1, wherein a second sealing ring (10) is arranged between the first positive lens (3) and the lens barrel (1); and a space ring (11) attached to the inner wall of the lens barrel (1) is arranged between the second positive lens (4) and the third positive lens (5).

11. The 20mm manual focusing infrared lens according to claim 1, wherein the light emitting side of the first positive lens (3) and the third positive lens (5) is aspheric, and the following expression is satisfied:

in the formula:

z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position of the height r along the optical axis direction;

c is 1/R; r is the paraxial curvature fitting radius of the mirror surface; k is the cone coefficient;

a, B, C, D and E are high-order aspheric coefficients.

12. An assembling method applied to the 20mm manual focusing infrared lens according to any one of claims 1 to 11, comprising the steps of:

step one, connecting a lens cone (1) with a fixed cylinder (2) through threads;

step two, sequentially assembling a first positive lens (3), a second positive lens (4) and a third positive lens (5) in the lens barrel (1) along the incident direction of light;

and step three, fixing the fixed cylinder (2) and the body of the detector.

Technical Field

The invention relates to an infrared focusing lens, in particular to a 20mm manual focusing infrared lens and an assembly method thereof.

Background

With the development of science and technology, infrared imaging technology has been widely applied in the fields of national defense, industry, medical treatment and the like. The infrared detection has certain capabilities of penetrating smoke, fog, haze, snow and the like and recognizing camouflage, is not interfered by battlefield strong light and flash light to cause blindness, can realize remote and all-weather observation, and is particularly suitable for target detection at night and under adverse weather conditions. The infrared focusing lens can adjust the focal length to meet the imaging requirement of the detector, so that the application is wide.

Under a complex environment, the focal length is influenced by various factors, so that the imaging is not clear, and the normal work of the detector is influenced. For example, the temperature not only affects the refractive index of the optical material, but also expands with heat and contracts with cold on the lens barrel material, so that the power change and the optimal image plane shift, the optical imaging quality is reduced, the image is blurred, the contrast is reduced, and the imaging performance of the lens is finally affected.

Therefore, how to conveniently adjust the focal length to compensate the influence of external factors is a difficult problem to be solved urgently in the field at the present stage.

Disclosure of Invention

In view of this, an object of the present invention is to provide a 20mm manually focusing infrared lens, which can conveniently adjust a focal length to compensate for the influence of external factors, and solve the problem in the field at the present stage. The invention also aims to provide an assembly method, which is applied to the 20mm manual focusing infrared lens, so that the focal length can be conveniently adjusted to compensate the influence of external factors.

A20 mm manual focusing infrared lens comprises a lens barrel and a fixed barrel in threaded connection with the peripheral surface of the lens barrel;

a first positive lens, a second positive lens and a third positive lens are sequentially arranged in the lens barrel along the light incidence direction, the distance between the first positive lens and the second positive lens is 17.91mm, and the distance between the second positive lens and the third positive lens is 0.5 mm;

the fixed cylinder is used for being fixed with a body of the detector, and the distance between the lens barrel and an imaging surface of the detector can be adjusted by rotating the lens barrel.

Preferably, the 20mm manual focusing infrared lens has a center thickness of 1.8 mm.

Preferably, in the 20mm manually focusing infrared lens, the curvature fitting radius of the light incident side of the first positive lens is 65mm, and the curvature fitting radius of the light emergent side of the first positive lens is 54.85 mm.

Preferably, the 20mm manual focusing infrared lens has a center thickness of 2.7 mm.

Preferably, in the 20mm manually-focusing infrared lens, the curvature fitting radius of the light incident side of the second positive lens is 31.35mm, and the curvature fitting radius of the light emergent side of the second positive lens is 26.12 mm.

Preferably, the center thickness of the 20mm manual focusing infrared lens is 2.7 mm.

Preferably, in the 20mm manually-focusing infrared lens, the curvature fitting radius of the light incident side of the third positive lens is 20.36mm, and the curvature fitting radius of the light emergent side of the third positive lens is 21.23 mm.

Preferably, the 20mm manual focusing infrared lens is characterized in that a limiting ring is arranged on the outer peripheral surface of the lens barrel, a limiting screw is arranged on the inner peripheral surface of the fixed barrel, and the limiting screw is matched with the limiting ring to limit the separation of the lens barrel and the fixed barrel.

Preferably, a first sealing ring is arranged between the outer peripheral surface of the lens barrel and the inner wall of the fixed barrel of the 20mm manual focusing infrared lens.

Preferably, a second sealing ring is arranged between the first positive lens and the lens barrel of the 20mm manually-focused infrared lens; and a space ring which is attached to the inner wall of the lens barrel is arranged between the second positive lens and the third positive lens.

Preferably, in the 20mm manually focusing infrared lens, the light emitting sides of the first positive lens and the third positive lens are aspheric surfaces, and the following expressions are satisfied:

in the formula:

z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position of the height r along the optical axis direction;

c is 1/R; r is the paraxial curvature fitting radius of the mirror surface; k is the cone coefficient;

a, B, C, D and E are high-order aspheric coefficients.

An assembling method applied to the 20mm manual focusing infrared lens comprises the following steps:

step one, connecting a lens cone with a fixed cylinder through threads;

step two, sequentially assembling a first positive lens, a second positive lens and a third positive lens in the lens cone along the light incidence direction;

and step three, fixing the fixed cylinder and the body of the detector.

The invention provides a 20mm manual focusing infrared lens, which comprises a lens barrel and a fixed barrel in threaded connection with the peripheral surface of the lens barrel; a first positive lens, a second positive lens and a third positive lens are sequentially arranged in the lens barrel along the light incidence direction, the distance between the first positive lens and the second positive lens is 17.91mm, and the distance between the second positive lens and the third positive lens is 0.5 mm; the fixed cylinder is used for being fixed with the body of the detector, and can adjust the distance between the lens cone and the imaging surface of the detector through rotating the lens cone. The 20mm manual focusing infrared lens comprises a lens barrel and a fixed barrel, wherein the distance between the first positive lens and the second positive lens is 17.91mm, the distance between the second positive lens and the third positive lens is 0.5mm, the length of the lens is short, and the size is small; and structural design is simple, can realize the manual regulation of focus through rotatory lens section of thick bamboo, convenient operation, and then the imaging plane skew that the compensation temperature change caused. Therefore, the 20mm manual focusing infrared lens provided by the invention can conveniently adjust the focal length, and solves the problem in the field at the present stage.

Drawings

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 description of the embodiments or the prior art will be briefly described below, 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 the drawings without creative efforts.

FIG. 1 is a side cross-sectional view of a 20mm manually focused infrared lens in accordance with an embodiment of the present invention;

FIG. 2 is a side view of a 20mm manually focused IR lens according to an embodiment of the present invention;

fig. 3 is a dimension labeled diagram of a 20mm manual focusing infrared lens according to an embodiment of the present invention.

In fig. 1-3:

a lens barrel-1; a fixed cylinder-2; a first positive lens-3; a second positive lens-4; a third positive lens-5; an image plane-6; a limiting ring-7; a limit screw-8; a first seal ring-9; a second seal ring-10; spacer ring-11.

Detailed Description

The core of the specific embodiment is to provide a 20mm manual focusing infrared lens, and the focus of the 20mm manual focusing infrared lens can be conveniently adjusted to compensate the influence of external factors, so that the problem in the field at the present stage is solved.

Hereinafter, embodiments will be described with reference to the drawings. The embodiments described below do not limit the contents of the invention described in the claims. The entire contents of the configurations shown in the following embodiments are not limited to those required as solutions of the inventions described in the claims.

The 20mm manual focusing infrared lens provided by the embodiment comprises a lens barrel 1 and a fixed barrel 2 in threaded connection with the peripheral surface of the lens barrel 1; a first positive lens 3, a second positive lens 4 and a third positive lens 5 are sequentially arranged in the lens barrel 1 along the light incidence direction, the distance between the first positive lens 3 and the second positive lens 4 is 17.91mm, and the distance between the second positive lens 4 and the third positive lens 5 is 0.5 mm; the fixed cylinder 2 is used for being fixed with the body of the detector, and the distance between the lens barrel 1 and the imaging surface 6 of the detector can be adjusted by rotating the lens barrel 1. The 20mm manual focusing infrared lens comprises a lens barrel 1 and a fixed barrel 2, the distance between a first positive lens 3 and a second positive lens 4 is 17.91mm, the distance between the second positive lens 4 and a third positive lens 5 is 0.5mm, the length of the lens is short, and the size is small; and structural design is simple, can realize the manual regulation of focus through rotatory lens section of thick bamboo 1, convenient operation, and then the imaging plane 6 skew that the compensation temperature change caused. Therefore, the 20mm manual focusing infrared lens provided by the invention can conveniently adjust the focal length, and solves the problem in the field at the present stage. Please refer to fig. 1-3.

In the 20mm manual focusing infrared lens provided by the embodiment, the center thickness of the first positive lens 3 may be 1.8 mm; the radius of curvature of the light incident side of the first positive lens 3 may be 65mm, and the radius of curvature of the light exiting side may be 54.85mm, as shown in fig. 3.

Preferably, the center thickness of the second positive lens 4 may be 2.7 mm; the radius of curvature of the light incident side of the second positive lens 4 may be 31.35mm, and the radius of curvature of the light exiting side may be 26.12 mm.

Preferably, the center thickness of the third positive lens 5 may be 2.7 mm; the radius of curvature of the light incident side of the third positive lens 5 may be 20.36mm, and the radius of curvature of the light exiting side may be 21.23 mm.

The thicknesses and curvatures of the two sides of the first positive lens 3, the second positive lens 4 and the third positive lens 5 can also be designed into other parameters capable of playing an equivalent role according to actual needs.

In the 20mm manual focusing infrared lens provided by the embodiment, the outer peripheral surface of the lens barrel 1 can be provided with the limiting ring 7, the inner peripheral surface of the fixed barrel 2 is provided with the limiting screw 8, and further, under the matching of the limiting screw 8 and the limiting ring 7, the lens barrel 1 can be prevented from being separated from the fixed barrel 2 during the rotation movement, and the normal use of the infrared focusing lens is influenced.

Further, in the above 20mm manual focusing infrared lens, the first sealing ring 9 may be disposed between the outer peripheral surface of the lens barrel 1 and the inner wall of the fixed cylinder 2, so that when focusing and relative movement occurs between the lens barrel 1 and the fixed cylinder 2, tightness of connection between the two can be ensured.

Similarly, a second sealing ring 10 may be disposed between the first positive lens 3 and the lens barrel 1; a spacer 11 attached to the inner wall of the lens barrel 1 may be provided between the second positive lens 4 and the third positive lens 5.

An assembly method is applied to the 20mm manual focusing infrared lens, and comprises the following steps: step one, connecting a lens barrel 1 with a fixed barrel 2 through threads; step two, sequentially assembling a first positive lens 3, a second positive lens 4 and a third positive lens 5 in the lens barrel 1 along the light incidence direction; and step three, fixing the fixed cylinder 2 and the body of the detector. Meanwhile, during assembly, a pressing ring, a sealing ring and the like which are correspondingly matched with the first positive lens 3, the second positive lens 4 and the third positive lens 5 need to be installed.

In more detail, the diameter of the lens barrel 1 may be 41mm, and the fixed cylinder 2 may be M34 × 0.75. The detector can be of a long-wave infrared non-refrigeration type 640 multiplied by 480, 17 mu m; the working temperature range is-40 ℃ to 60 ℃; the working wave band ranges from 8 um to 12 um; the vertical field angle is 23.1 degrees, the horizontal field angle is 30.4 degrees, the aperture is 1.0 degree, and the focal length is 20 mm. See table 3 below for details.

In the 20mm manual focusing infrared lens provided by the present embodiment, the light emitting sides of the first positive lens 3 and the third positive lens 3 are aspheric surfaces, and the following expressions are satisfied:

in the formula:

z is the distance rise from the vertex of the aspheric surface when the aspheric surface is at the position of the height r along the optical axis direction;

c is 1/R; r is the paraxial curvature fitting radius of the mirror surface; k is the cone coefficient;

a, B, C, D and E are high-order aspheric coefficients.

TABLE 1 first Positive lens aspherical coefficients A, B, C, D, E data

K	A	B	C	D	E
						0	5.8968913E-06	-2.0356241E-09	3.6432875e-10	-2.527119e-12	9.3815164e-15

TABLE 2 aspherical coefficients A, B, C, D, E of the third positive lens

K	A	B	C	D	E
						0	1.9667485e-06	-1.1567463e-08	1.1175673e-11	8.8142491e-14	0.00000E+00

Table 320 mm manual focusing infrared lens parameter table

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.