CN115185072A

CN115185072A - Aspheric wide-angle long-flange video lens

Info

Publication number: CN115185072A
Application number: CN202210619442.9A
Authority: CN
Inventors: 黄国山; 江健熹; 郑忠亮
Original assignee: Guangdong Beichuang Optoelectronics Technology Co ltd
Current assignee: Guangdong Beichuang Optoelectronics Technology Co ltd
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-10-14
Anticipated expiration: 2042-06-01
Also published as: CN115185072B

Abstract

The invention discloses an aspheric wide-angle long-flange video lens which sequentially comprises a first lens group, an iris diaphragm and a second lens group along the light incidence direction, wherein the first lens group and the second lens group are both provided with positive focal power, the first lens group is a fixed group, and the second lens group is a focusing group capable of moving along an optical axis; the first lens group and the second lens group satisfy the following relationship: 1.6-woven fabric f1/f2<2.1; wherein f1 represents the focal length value of the first lens group, f2 represents the focal length value of the second lens group, can realize large aperture, high resolution, small distortion and long flange back focus, close range focusing, meet the camera module matching the long flange back focus at the same time, but the wide application in the optical lens trade.

Description

Aspheric wide-angle long-flange video lens

Technical Field

The invention relates to the field of optical lenses, in particular to an aspheric wide-angle long-flange video lens.

Background

With the development of society, the market demand of video shooting is increased, and the index parameters of video shots are improved in the development. Important indexes of the short-focus video lens are high definition, large aperture, good chromatic aberration effect and small distortion, the defects of low resolution, large distortion, small aperture, too short focus behind a flange and the like of the short-focus video lens generally exist in the market at present, and the high requirement of the requirement of a video shooting view field cannot be met.

Disclosure of Invention

The present invention is directed to an aspheric wide-angle long-flange video lens, which solves one or more of the problems of the prior art and provides at least one of the advantages of the present invention.

The technical scheme adopted for solving the technical problems is as follows:

the invention provides an aspheric wide-angle long-flange video lens which sequentially comprises a first lens group, an iris diaphragm and a second lens group along the light incidence direction, wherein the first lens group and the second lens group are both provided with positive focal power, the first lens group is a fixed group, and the second lens group is a focusing group capable of moving along an optical axis;

the first lens group and the second lens group satisfy the following relationship:

1.6<f1/f2<2.1；

wherein f1 represents the focal length value of the first lens group, and f2 represents the focal length value of the second lens group.

As a further improvement of the above technical solution, the first lens group includes six lenses arranged in sequence along the optical axis, and the second lens group includes nine lenses arranged in sequence along the optical axis.

As a further improvement of the technical scheme, the refractive index of at least three lenses of the first lens group is larger than 1.7 and smaller than 1.8.

As a further improvement of the above technical solution, the refractive index of at least one lens in the first lens group is greater than 1.9 and smaller than 2.

As a further improvement of the technical scheme, the Abbe number of at least three lenses of the second lens group is larger than 60 and smaller than 70.

As a further improvement of the above technical solution, the aspheric wide-angle long-flange video lens includes three doublet lenses and one triplet lens. Therefore, the chromatic aberration can be effectively optimized, a good real shooting effect is achieved, the tolerance is remarkably improved, and the improvement of the yield of the assembly process is greatly facilitated.

As a further improvement of the above technical solution, in the lens, the third lens from the light incidence direction is a glass aspheric lens, and the rest is a spherical lens.

As a further improvement of the technical scheme, the refractive index of at least three lenses in the second lens group is more than 1.9 and less than 2.

As a further improvement of the above technical solution, a total length between the first mirror surface of the first lens group and the last mirror surface of the second lens group is less than 145.5 mm and greater than 144.5 mm.

The beneficial effects of the invention are: focal power of the first lens group and the second lens group is under the condition that relational expression 1.6 & lt f1/f2 & lt 2.1 is satisfied, the aspheric wide-angle long-flange video lens can realize large aperture, high resolution, small distortion, long flange back focus and close range focusing, and simultaneously satisfies the camera module matched with long flange back focus.

Drawings

The invention is further described with reference to the accompanying drawings and examples;

FIG. 1 is a schematic diagram of an optical structure of an embodiment of an aspheric wide-angle long-flange video lens according to the present invention;

FIG. 2 is a schematic diagram of longitudinal chromatic aberration of an embodiment of an aspheric wide-angle long-flange video lens provided in the present invention;

FIG. 3 is a schematic diagram of lateral chromatic aberration of an embodiment of an aspheric wide-angle long-flange video lens provided in the present invention;

FIG. 4 is a schematic view of field curvature and distortion of an embodiment of an aspheric wide-angle long-flange video lens according to the present invention;

FIG. 5 is a schematic diagram of relative illumination of an embodiment of an aspheric wide-angle long-flange video lens according to the present invention;

FIG. 6 is a schematic MTF diagram of an embodiment of an aspheric wide-angle long-flange video lens according to the present invention;

fig. 7 is a schematic diagram of an MTF defocus curve of an embodiment of an aspheric wide-angle long-flange video lens provided in the present invention.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, if words such as "a", "an", etc. are used, the meaning is one or more, the meaning of a plurality is two or more, less, more, etc. are understood as excluding the present number, and more, less, more, etc. are understood as including the present number.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Referring to fig. 1 to 7, the aspheric wide-angle long-flange video lens of the present invention is made as follows:

as shown in fig. 1, the aspheric wide-angle long-flange video lens of this embodiment includes a first lens group G1, an iris 100, and a second lens group G2, wherein the first lens group G1, the iris 100, and the second lens group G2 are sequentially disposed along a light incident direction.

The first lens group G1 is a fixed group, and has positive focal power, the first lens group G1 includes six lenses, and the six lenses include a first lens body L1, a second lens body L2, a third lens body L3, a fourth lens body L4, a fifth lens body L5, and a sixth lens body L6, which are sequentially arranged along an optical axis.

The second lens group G2 is a focusing group and has positive focal power, and the second lens group G2 includes nine lenses including a seventh lens body L7, an eighth lens body L8, a ninth lens body L9, a tenth lens body L10, an eleventh lens body L11, a twelfth lens body L12, a thirteenth lens body L13, a fourteenth lens body L14, and a fifteenth lens body L15, which are arranged in order along the optical axis.

The first lens group G1 and the second lens group G2 need to satisfy the following relationship:

1.6<f1/f2<2.1；

f1 represents a focal length value of the first lens group G1, and f2 represents a focal length value of the second lens group G2.

After the limitation of the relation 1.6-Ap f1/f2<2.1, the long rear working distance of the lens can be ensured, and the camera module matched with the long flange rear focus can be satisfied.

The definition of the first lens group G1 requires the following:

at least three of the first lens body L1, the second lens body L2, the third lens body L3, the fourth lens body L4, the fifth lens body L5 and the sixth lens body L6 have refractive indexes larger than 1.7 and smaller than 1.8.

And the refractive index of at least one lens body among the first lens body L1, the second lens body L2, the third lens body L3, the fourth lens body L4, the fifth lens body L5 and the sixth lens body L6 is larger than 1.9 and smaller than 2.

Further, the third lens body L3 is a glass aspheric lens, and the first lens body L1, the second lens body L2, the fourth lens body L4, the fifth lens body L5, the sixth lens body L6, the seventh lens body L7, the eighth lens body L8, the ninth lens body L9, the tenth lens body L10, the eleventh lens body L11, the twelfth lens body L12, the thirteenth lens body L13, the fourteenth lens body L14, and the fifteenth lens body L15 are all spherical lenses.

And, taking three meniscus lenses in the first lens group G1, the effect can be to increase the angle of field while improving MTF and improving relative illuminance.

The definition of the second lens group G2 requires the following:

in the seventh lens element L7, the eighth lens element L8, the ninth lens element L9, the tenth lens element L10, the eleventh lens element L11, the twelfth lens element L12, the thirteenth lens element L13, the fourteenth lens element L14, and the fifteenth lens element L15, at least three lens elements have refractive indices greater than 1.9 and smaller than 2.

In an aspheric wide-angle long-flange video lens, there are three doublet lenses and one triplet lens, specifically: the first cemented doublet is formed by gluing the fourth lens body L4 and the fifth lens body L5, the second cemented doublet is formed by gluing the tenth lens body L10 and the eleventh lens body L11, and the third cemented doublet is formed by gluing the thirteenth lens body L13 and the fourteenth lens body L14. And the third cemented lens is formed by a seventh lens body L7, an eighth lens body L8 and a ninth lens body L9 cemented together. Therefore, the chromatic aberration can be effectively optimized, a good real shooting effect is achieved, the tolerance is remarkably improved, and the improvement of the yield of the assembly process is greatly facilitated.

In addition, the total length between the front end mirror surface of the first lens body L1 and the rear end mirror surface of the fifteenth lens body L15 of the present embodiment is less than 145.5 mm and greater than 144.5 mm.

The specific parameters of the aspheric wide-angle long-flange video lens in this embodiment are as follows:

Surf	Type	Radius	Thickness	Index	ABB
						OBJ	STANDARD	INFINITY	INFINITY
1	STANDARD	41.936023	9	1.72916	54.673508
						2	STANDARD	81.612	0.6
3	STANDARD	30.624	2.12	1.7725	49.624286
						4	STANDARD	14.690984	9.65
5	EVENASPH	44.737976	1.29	1.693847	53.151009
						6	EVENASPH	16.217	6.89
7	STANDARD	-36.976	5.39	1.92286	20.880382
						8	STANDARD	23.099	7.17	1.71736	29.5005
9	STANDARD	-37.863	7.280442
						10	STANDARD	42.427021	4.15	1.846663	23.784819
11	STANDARD	-89.54	5.509089
						STO	STANDARD	INFINITY	4.324263
13	STANDARD	62.432	1.93	1.910822	35.250008
						14	STANDARD	13.583	9.58	1.846663	23.784819
15	STANDARD	-21.893	1	1.883001	39.225276
						16	STANDARD	31.36	1.33
17	STANDARD	INFINITY	5.09	1.592824	68.624378
						18	STANDARD	-13.722	0.97	1.92286	20.880382
19	STANDARD	357.484	0.1
						20	STANDARD	51.519	5.22	1.592824	68.624378
21	STANDARD	-24.77198	0.1
						22	STANDARD	-58.442	1	1.846663	23.784819
23	STANDARD	26.348968	7.07	1.592824	68.624378
						24	STANDARD	-32.751	0.1
25	STANDARD	71.096	6.369513	1.92286	20.880382
						26	STANDARD	-66.897	37.984224
27	STANDARD	INFINITY	2.25	1.516798	64.198266
						28	STANDARD	INFINITY	1.442745
IMA	STANDARD	INFINITY	-

where Surf denotes the number of the corresponding surface in the optical system, type denotes the Type of the surface, radius denotes the Radius of curvature, thickness denotes the Thickness, index denotes the refractive Index, and ABB denotes the ABB number.

Further, the aspherical lens parameters in the present embodiment are as follows:

it can be determined from fig. 2 to 7 that the optical system of the present invention has good aberration correction, small distortion and high resolution.

According to the embodiment, the invention realizes 18mm focal length, large aperture, small distortion, high resolution and long flange back focus.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the present invention is not limited to the details of the embodiments shown and described, but is capable of numerous equivalents and substitutions without departing from the spirit of the invention as set forth in the claims appended hereto.

Claims

1. An aspheric wide-angle long-flange video lens is characterized by sequentially comprising a first lens group, an iris diaphragm and a second lens group along a light incidence direction, wherein the first lens group and the second lens group both have positive focal power, the first lens group is a fixed group, and the second lens group is a focusing group capable of moving along an optical axis;

1.6<f1/f2<2.1；

2. An aspheric wide-angle long-flange video lens as claimed in claim 1, characterized in that:

the first lens group comprises six lenses which are sequentially arranged along an optical axis, and the second lens group comprises nine lenses which are sequentially arranged along the optical axis.

3. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the refractive index of at least three lenses of the first lens group is larger than 1.7 and smaller than 1.8.

4. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the refractive index of at least one lens in the first lens group is larger than 1.9 and smaller than 2.

5. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the abbe number of at least three lenses in the second lens group is more than 60 and less than 70.

6. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the aspheric wide-angle long-flange video lens comprises three double-cemented lenses and one triple-cemented lens.

7. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

in the lens, the third lens in the incident direction of light rays is a glass aspheric lens, and the rest are spherical lenses.

8. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the refractive index of at least three lenses in the second lens group is larger than 1.9 and smaller than 2.

9. An aspheric wide-angle long-flange video lens as claimed in claim 2, characterized in that:

the total length between the first mirror surface of the first lens group and the last mirror surface of the second lens group is less than 145.5 mm and greater than 144.5 mm.