阅读说明：本技术 一种镜头 (Lens ) 是由 林法官 刘凯 许端霞 叶蔡龙 丁洪兴 于 2019-11-27 设计创作，主要内容包括：本发明公开了一种镜头,所述镜头包括由物侧至像侧依次排列的第一透镜组、第二透镜组、光栏、第三透镜组、第四透镜组、第五透镜组、滤光片和像面；所述第一透镜组、第三透镜组和第五透镜组的位置固定,第二透镜组和第四透镜组可沿光轴进行移动；透镜组满足以下条件：0.2<|f3/(f2*f4)|<0.4；其中,f2为第二透镜组的焦距,f3为第三透镜组的焦距,f4为第四透镜组的焦距。所述第一透镜组、第三透镜组和第五透镜组的位置固定,第二透镜组和第四透镜组可沿光轴进行移动实现镜头变焦,并且镜头中的透镜组满足：0.2<|f3/(f2*f4)|<0.4,实现了一种星光级变焦镜头。(The invention discloses a lens, which comprises a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group, an optical filter and an image surface, wherein the first lens group, the second lens group, the diaphragm, the third lens group, the fourth lens group, the fifth lens group, the optical filter and the image surface are sequentially arranged from an object side to an image side; the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis; the lens group satisfies the following conditions: 0.2< | f3/(f2 f4) | < 0.4; where f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group. The positions of the first lens group, the third lens group and the fifth lens group are fixed, the second lens group and the fourth lens group can move along an optical axis to realize lens zooming, and the lens groups in the lens meet the following requirements: 0.2< | f3/(f2 f4) | <0.4, a starlight level zoom lens is realized.)

1. The lens is characterized by comprising a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group, an optical filter and an image plane which are sequentially arranged from an object side to an image side;

the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis;

the lens group satisfies the following conditions:

0.2<|f3/(f2*f4)|<0.4；

where f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group.

2. The lens barrel according to claim 1, wherein the first lens group includes a first sub-lens group and a second positive power lens arranged in order from an object side to an image side.

3. The lens barrel according to claim 2, wherein the first sub-lens group includes a first negative power lens and a first positive power lens arranged in order from an object side to an image side;

the curvature radius of one surface of the first negative focal power lens facing the image side is the same as that of one surface of the first positive focal power lens facing the object side;

the first negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the first positive power lens comprises a biconvex lens;

the second positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface.

4. The lens barrel according to claim 1, wherein the second lens group includes a second negative power lens, a third negative power lens, and a second sub-lens group arranged in order from the object side to the image side;

the second sub-lens group comprises a fourth negative focal power lens, a third positive focal power lens and a fifth negative focal power lens which are sequentially arranged from the object side to the image side;

the curvature radius of one surface of the fourth negative focal power lens facing the image side is the same as that of one surface of the third positive focal power lens facing the object side;

the curvature radius of one surface of the third positive focal power lens facing the image side is the same as that of one surface of the fifth negative focal power lens facing the object side;

the second negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the third negative power lens comprises a biconcave lens;

the fourth negative power lens comprises a biconcave lens;

the third positive power lens comprises a biconvex lens;

the fifth negative power lens includes a biconcave lens.

5. The lens barrel according to claim 3, wherein the third lens group includes a third sub-lens group, a sixth positive power lens, a fourth sub-lens group, and an eighth negative power lens, which are arranged in order from the object side to the image side.

6. The lens barrel according to claim 5, wherein the third sub-lens group includes a fourth positive power lens, a sixth negative power lens, and a fifth positive power lens arranged in order from the object side to the image side; the curvature radius of one surface of the fourth positive focal power lens facing the image side is the same as that of one surface of the sixth negative focal power lens facing the object side; the curvature radius of one surface of the sixth negative focal power lens facing the image side is the same as that of one surface of the fifth positive focal power lens facing the object side;

the fourth sub-lens group comprises a seventh negative focal power lens and a seventh positive focal power lens which are arranged in sequence from the object side to the image side; the curvature radius of one surface of the seventh negative focal power lens facing the image side is the same as that of one surface of the seventh positive focal power lens facing the object side;

the fourth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth negative-power lens comprises a concave lens, and one surface of the concave lens facing the object side is a concave surface;

the fifth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the seventh negative power lens comprises a biconcave lens;

the seventh positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the eighth negative power lens includes a biconcave lens.

7. The lens barrel according to claim 6, wherein the fourth lens group includes an eighth positive power lens and a fifth sub-lens group arranged in order from the object side to the image side.

8. The lens barrel according to claim 7, wherein the fifth sub-lens group includes a ninth positive power lens and a ninth negative power lens arranged in order from the object side to the image side;

the curvature radius of one surface of the ninth positive focal power lens facing the image side is the same as that of one surface of the ninth negative focal power lens facing the object side;

the eighth positive power lens includes a biconvex lens;

the ninth positive power lens includes a biconvex lens;

the ninth negative power lens includes a biconcave lens.

9. The lens barrel according to claim 1, wherein the fifth lens group includes a tenth positive power lens and a tenth negative power lens arranged in order from the object side to the image side;

the curvature radius of one surface of the tenth positive focal power lens facing the image side is the same as that of one surface of the tenth negative focal power lens facing the object side;

the tenth positive power lens includes a biconvex lens;

the tenth negative power lens includes a concave lens, and a surface thereof facing the object side is concave.

10. The lens barrel as claimed in claim 8, wherein the refractive index of each of the sixth positive power lens and the eighth positive power lens is greater than 1.85;

the abbe numbers of the first positive focal power lens, the fourth positive focal power lens and the ninth positive focal power lens are all more than 65.

Technical Field

The invention relates to the technical field of optical imaging, in particular to a lens.

Background

In the intelligent transportation industry, because of the perfect industry standard in China, standard 1-inch fixed-focus lenses of 12mm, 16mm, 20mm, 25mm, 30mm, 35mm and the like are often used in actual construction, the actual aperture value is 1.4-1.6, when a certain focal length lens is installed improperly, the lens needs to be replaced, and the use is not very convenient. In addition, for foreign countries, the road standard specification is different from that of China, or some countries have no corresponding standard specification, and the road scene cannot be well matched by using the fixed-focus lens. Since there is no starlight level zoom lens that can satisfy 3 indexes such as aperture value, focal length range and 1.1 inch target surface, it is necessary to develop a zoom lens that can satisfy the three specifications, and it is convenient to use in the intelligent traffic video camera at home and abroad, and reduces the construction cost at home and abroad. Therefore, it becomes important to provide a starlight level zoom lens.

Disclosure of Invention

The embodiment of the invention provides a lens, which is used for providing a starlight level zoom lens.

The embodiment of the invention provides a lens, which comprises a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group, an optical filter and an image plane, wherein the first lens group, the second lens group, the diaphragm, the third lens group, the fourth lens group, the fifth lens group, the optical filter and the image plane are sequentially arranged from an object side to an image side;

the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis;

the lens group satisfies the following conditions:

0.2<|f3/(f2*f4)|<0.4；

where f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group.

Further, the first lens group includes a first sub-lens group and a second positive power lens arranged in order from the object side to the image side.

Further, the first sub-lens group includes a first negative power lens and a first positive power lens arranged in order from the object side to the image side;

the curvature radius of one surface of the first negative focal power lens facing the image side is the same as that of one surface of the first positive focal power lens facing the object side;

the first negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the first positive power lens comprises a biconvex lens;

the second positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface.

Further, the second lens group includes a second negative power lens, a third negative power lens and a second sub-lens group arranged in order from the object side to the image side;

the second sub-lens group comprises a fourth negative focal power lens, a third positive focal power lens and a fifth negative focal power lens which are sequentially arranged from the object side to the image side;

the curvature radius of one surface of the fourth negative focal power lens facing the image side is the same as that of one surface of the third positive focal power lens facing the object side;

the curvature radius of one surface of the third positive focal power lens facing the image side is the same as that of one surface of the fifth negative focal power lens facing the object side;

the second negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the third negative power lens comprises a biconcave lens;

the fourth negative power lens comprises a biconcave lens;

the third positive power lens comprises a biconvex lens;

the fifth negative power lens includes a biconcave lens.

Further, the third lens group includes a third sub-lens group, a sixth positive power lens, a fourth sub-lens group, and an eighth negative power lens arranged in order from the object side to the image side.

Further, the third sub-lens group includes a fourth positive power lens, a sixth negative power lens and a fifth positive power lens arranged in order from the object side to the image side; the curvature radius of one surface of the fourth positive focal power lens facing the image side is the same as that of one surface of the sixth negative focal power lens facing the object side; the curvature radius of one surface of the sixth negative focal power lens facing the image side is the same as that of one surface of the fifth positive focal power lens facing the object side;

the fourth sub-lens group comprises a seventh negative focal power lens and a seventh positive focal power lens which are arranged in sequence from the object side to the image side; the curvature radius of one surface of the seventh negative focal power lens facing the image side is the same as that of one surface of the seventh positive focal power lens facing the object side;

the fourth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth negative-power lens comprises a concave lens, and one surface of the concave lens facing the object side is a concave surface;

the fifth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the seventh negative power lens comprises a biconcave lens;

the seventh positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the eighth negative power lens includes a biconcave lens.

Further, the fourth lens group includes an eighth positive power lens and a fifth sub-lens group arranged in order from the object side to the image side.

Further, the fifth sub-lens group includes a ninth positive power lens and a ninth negative power lens arranged in order from the object side to the image side;

the curvature radius of one surface of the ninth positive focal power lens facing the image side is the same as that of one surface of the ninth negative focal power lens facing the object side;

the eighth positive power lens includes a biconvex lens;

the ninth positive power lens includes a biconvex lens;

the ninth negative power lens includes a biconcave lens.

Further, the fifth lens group includes a tenth positive power lens and a tenth negative power lens arranged in order from the object side to the image side;

the curvature radius of one surface of the tenth positive focal power lens facing the image side is the same as that of one surface of the tenth negative focal power lens facing the object side;

the tenth positive power lens includes a biconvex lens;

the tenth negative power lens includes a concave lens, and a surface thereof facing the object side is concave.

Further, the refractive indexes of the sixth positive power lens and the eighth positive power lens are both greater than 1.85;

the abbe numbers of the first positive focal power lens, the fourth positive focal power lens and the ninth positive focal power lens are all more than 65.

The embodiment of the invention provides a lens, which comprises a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group, an optical filter and an image plane, wherein the first lens group, the second lens group, the diaphragm, the third lens group, the fourth lens group, the fifth lens group, the optical filter and the image plane are sequentially arranged from an object side to an image side; the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis; the lens group satisfies the following conditions: 0.2< | f3/(f2 f4) | < 0.4; where f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group. Since in the embodiment of the present invention, five lens groups are arranged in order from the object side to the image side in a lens barrel in a specific order, the positions of the first lens group, the third lens group, and the fifth lens group are fixed, the second lens group and the fourth lens group are movable along the optical axis to achieve lens zooming, and the lens groups in the lens barrel satisfy: 0.2< | f3/(f2 f4) | <0.4, a starlight level zoom lens is realized.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

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

fig. 2 is a graph of a transfer function (MTF) of a lens provided in embodiment 1 of the present invention at a focal length end of 13 mm;

fig. 3 is a graph of a transfer function (MTF) of a lens provided in embodiment 1 of the present invention at a focal length end of 33 mm;

fig. 4 is a graph of transfer function (MTF) of the lens provided in embodiment 2 of the present invention at the focal length end of 13 mm;

fig. 5 is a graph of transfer function (MTF) of the lens provided in embodiment 2 of the present invention at the focal length end of 33 mm.

Detailed Description

The present invention will be described in further detail with reference to the attached drawings, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a schematic view of a lens barrel according to embodiment 1 of the present disclosure, where the lens barrel includes a first lens group G1, a second lens group G2, a stop P, a third lens group G3, a fourth lens group G4, a fifth lens group G5, an optical filter N, and an image plane M, which are arranged in this order from an object side to an image side;

the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis;

the lens group satisfies the following conditions:

0.2<|f3/(f2*f4)|<0.4；

where f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group.

The lens barrel can realize zooming by changing the positions of lens groups, wherein the positions of the first lens group, the third lens group and the fifth lens group are fixed, and the second lens group and the fourth lens group can move along the optical axis to realize zooming. That is, the second lens group can be moved in position between the first lens group and the diaphragm. The second lens group can be close to the first lens group and far away from the diaphragm; or far away from the first lens group and close to the diaphragm. The fourth lens group may be moved in a position between the third lens group and the fifth lens group. The fourth lens group may be close to the third lens group, distant from the fifth lens group; it may be further from the third lens group and closer to the fifth lens group. The second lens group moves in the optical axis direction to perform zooming, and is called a zoom group or a magnification-varying group. In addition, compensation is performed by moving the fourth lens group in the direction of the optical axis so that the image point variation caused by the second lens group at the image plane is zero, thereby realizing zooming without moving the image plane, which is called a compensation group. In addition, when the object of interest moves, the image is focused sharply by finely adjusting the fourth lens group. In general, in the lens system, the fourth lens group functions as a compensation group and a focusing group.

Because five lens groups are arranged in the lens from the object side to the image side in sequence according to a specific sequence, the positions of the first lens group, the third lens group and the fifth lens group are fixed, the second lens group and the fourth lens group can move along the optical axis to realize the zooming of the lens, and the lens groups in the lens meet the following conditions: 0.2< | f3/(f2 f4) | <0.4, a starlight level zoom lens is realized.

In order to further improve the imaging quality of the lens barrel, in the embodiment of the invention, the first lens group comprises a first sub-lens group and a second positive power lens 3 which are arranged in sequence from the object side to the image side.

The first sub-lens group comprises a first negative focal power lens 1 and a first positive focal power lens 2 which are arranged in sequence from the object side to the image side;

the curvature radius of one surface of the first negative focal power lens facing the image side is the same as that of one surface of the first positive focal power lens facing the object side;

the first negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the first positive power lens comprises a biconvex lens;

the second positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface.

To further enable the system to be compact, the first negative power lens 1 and the first positive power lens 2 may be cemented or cemented.

In order to further improve the imaging quality of the lens, in the embodiment of the invention, the second lens group comprises a second negative power lens 4, a third negative power lens 5 and a second sub-lens group which are arranged in sequence from the object side to the image side;

the second sub-lens group comprises a fourth negative focal power lens 6, a third positive focal power lens 7 and a fifth negative focal power lens 8 which are arranged in sequence from the object side to the image side;

the curvature radius of one surface of the fourth negative focal power lens facing the image side is the same as that of one surface of the third positive focal power lens facing the object side;

the curvature radius of one surface of the third positive focal power lens facing the image side is the same as that of one surface of the fifth negative focal power lens facing the object side;

the second negative-power lens comprises a meniscus concave lens, and one surface of the meniscus concave lens facing the object side is a convex surface;

the third negative power lens comprises a biconcave lens;

the fourth negative power lens comprises a biconcave lens;

the third positive power lens comprises a biconvex lens;

the fifth negative power lens includes a biconcave lens.

To further enable the system to be compact, the fourth negative power lens, the third positive power lens and the fifth negative power lens may be cemented or otherwise snugly connected.

In order to further improve the imaging quality of the lens barrel, in the embodiment of the invention, the third lens group includes a third sub-lens group, a sixth positive power lens 12, a fourth sub-lens group and an eighth negative power lens 15 which are arranged in order from the object side to the image side.

The third sub-lens group comprises a fourth positive focal power lens 9, a sixth negative focal power lens 10 and a fifth positive focal power lens 11 which are arranged in sequence from the object side to the image side; the curvature radius of one surface of the fourth positive focal power lens facing the image side is the same as that of one surface of the sixth negative focal power lens facing the object side; the curvature radius of one surface of the sixth negative focal power lens facing the image side is the same as that of one surface of the fifth positive focal power lens facing the object side;

the fourth sub-lens group includes a seventh negative power lens 13 and a seventh positive power lens 14 arranged in order from the object side to the image side; the curvature radius of one surface of the seventh negative focal power lens facing the image side is the same as that of one surface of the seventh positive focal power lens facing the object side;

the fourth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth negative-power lens comprises a concave lens, and one surface of the concave lens facing the object side is a concave surface;

the fifth positive focal power lens comprises a convex lens, and one surface of the convex lens facing the image side is a convex surface;

the sixth positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the seventh negative power lens comprises a biconcave lens;

the seventh positive power lens comprises a meniscus convex lens, and one surface of the meniscus convex lens facing the object side is a convex surface;

the eighth negative power lens includes a biconcave lens.

To further enable the system to be compact, the fourth positive power lens, the sixth negative power lens and the fifth positive power lens may be cemented or otherwise snugly connected. The seventh negative power lens and the seventh positive power lens may be cemented or adhesively connected.

In order to further improve the imaging quality of the lens barrel, in the embodiment of the invention, the fourth lens group comprises an eighth positive power lens 16 and a fifth sub-lens group which are arranged in sequence from the object side to the image side.

The fifth sub-lens group includes a ninth positive power lens 17 and a ninth negative power lens 18 arranged in order from the object side to the image side;

the curvature radius of one surface of the ninth positive focal power lens facing the image side is the same as that of one surface of the ninth negative focal power lens facing the object side;

the eighth positive power lens includes a biconvex lens;

the ninth positive power lens includes a biconvex lens;

the ninth negative power lens includes a biconcave lens.

To further enable the system to be compact, the ninth positive power lens and the ninth negative power lens may be cemented or cemented.

In order to further improve the imaging quality of the lens barrel, in the embodiment of the present invention, the fifth lens group includes a tenth positive power lens 19 and a tenth negative power lens 20 arranged in order from the object side to the image side;

the curvature radius of one surface of the tenth positive focal power lens facing the image side is the same as that of one surface of the tenth negative focal power lens facing the object side;

the tenth positive power lens includes a biconvex lens;

the tenth negative power lens includes a concave lens, and a surface thereof facing the object side is concave.

To further enable the system to be compact, the tenth positive power lens and the tenth negative power lens may be cemented or cemented.

In the embodiment of the invention, in order to realize clear imaging at the lens from-40 ℃ to 80 ℃, the abbe numbers of the first positive power lens, the fourth positive power lens and the ninth positive power lens are all more than 65. In addition, the abbe numbers of the first positive focal power lens, the fourth positive focal power lens and the ninth positive focal power lens are all larger than 65, and the chromatic aberration of the image can be reduced, so that the imaging quality is improved. The abbe numbers of the first positive power lens, the fourth positive power lens and the ninth positive power lens may be the same or different.

In order to improve the imaging quality of the lens and reduce the total length of the lens, in the embodiment of the invention, the refractive indexes of the sixth positive focal power lens and the eighth positive focal power lens are both greater than 1.85. And the refractive indexes of the sixth positive focal power lens and the eighth positive focal power lens are both larger than 1.85, so that the spherical aberration can be reduced, and the imaging quality is improved. The refractive indexes of the sixth positive power lens and the eighth positive power lens can be the same or different.

In the embodiment of the invention, a diaphragm P is arranged between the second lens group and the third lens group.

The diaphragm comprises an aperture diaphragm, the aperture size of the aperture diaphragm determines the aperture value of the system and the depth of field during shooting, the aperture size can be fixed, or the aperture diaphragm with adjustable aperture can be placed according to requirements to realize the adjustment of the clear aperture, namely the purposes of changing the aperture value of the system and changing the depth of field are achieved.

And an optical filter N is arranged between the fifth lens group and the image surface, and the optical filter is an optical device for selecting a required radiation waveband.

The optical performance of the lens provided by the embodiment of the invention is as follows: focal length is about 13-33mm, aperture Fno1.3, field angle 2 omega range is about 72 degrees to 32 degrees, and image plane size 2 y' is

The embodiment of the invention realizes the technical requirements of high resolution, starlight, no thermalization, large target surface and the like, uses one lens to replace several fixed focus lenses of 12mm, 16mm, 20mm, 25mm, 30mm, 35mm and the like commonly used by intelligent transportation, and is convenient to install and use in engineering.

The following exemplifies the lens parameters provided by the embodiment of the present invention.