CN212808765U - Five million pixel glass-plastic mixed wide-angle lens - Google Patents

Abstract

The utility model discloses a five-megapixel glass-plastic mixed wide-angle lens, which comprises a first lens, a diaphragm, a second lens and a fourth lens from an object side to an image side along an optical axis in sequence; the first lens L1 is a plastic aspheric lens with negative focal power, the second lens L2 is a double-convex glass spherical lens with positive focal power, the third lens L3 is a double-convex glass spherical lens with positive focal power, and the fourth lens L4 is a plastic aspheric lens with negative focal power; the lens has the advantages of simple and reasonable structure, short total length, large target surface size and field angle of 80 degrees, can meet the resolution of five million pixels, and simultaneously has the requirements of day and night confocal property and high and low temperature.

Description

Five million pixel glass-plastic mixed wide-angle lens

Technical Field

The utility model relates to an optical lens technical field specifically relates to a mixed wide-angle lens is moulded to five megapixel glass.

Background

The lens is used as an important component of a security monitoring system, and the performance of the lens is extremely critical. With the development of the security monitoring industry and the progress of the optical lens technology, the requirements of the market on the resolving power, the aperture, the high and low temperature performance, the day and night confocal performance and the like of the security monitoring lens are higher and higher.

In the current market, the lens with a large field angle cannot meet the requirements of size miniaturization and light weight. In addition, for high resolution and chromatic aberration correction, a plurality of glass lenses or cemented lenses are mostly adopted, and the product has the defects of high cost and large volume.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a mixed wide-angle camera lens is moulded to glass is used for solving the technical problem that above-mentioned exists.

In order to achieve the above object, the utility model adopts the following technical scheme: the optical lens assembly comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens and a lens base in sequence from an object side to an image side along an optical axis.

The first lens L1 is a plastic aspheric lens with negative focal power, the second lens L2 is a double-convex glass spherical lens with positive focal power, the third lens L3 is a double-convex glass spherical lens with positive focal power, and the fourth lens L4 is an aspheric lens with negative focal power.

Preferably, the focal lengths of the lenses of the lens respectively satisfy: -2< f1/f < -1.2; 1< f2/f < 2; 0.5< f3/f < 1; -0.4< f4/f < -0.1.

Preferably, the effective focal length f and the optical back focal length BFL of the lens satisfy the following condition 0.8< f/BFL < 1.

Preferably, the full field angle FOV of the lens is more than or equal to 80 degrees.

Preferably, the lens image plane

Preferably, the total lens length TTL is less than or equal to 22.2 mm.

Preferably, the lens aperture FNo is less than or equal to 2.0.

Preferably, a filter is disposed between the last lens and the image plane.

The utility model has the advantages of: the utility model discloses a 3 plastic lens, 1 glass lens totally 4, focal power, the selection lens material through rational distribution lens, and adjust the diaphragm position, full visual field resolution can reach 200lp/mm >0.3, whole image quality is even, and day night is confocal, infrared mode out of focus <0.008mm, operating temperature is-40 ℃ -80 ℃.

Drawings

FIG. 1 is a two-dimensional outline diagram of a five-megapixel glass-plastic hybrid wide-angle lens according to the present embodiment;

FIG. 2 is a dot array diagram of 0.435-0.656 μm of visible light of a five-megapixel glass-plastic hybrid wide-angle lens according to the present embodiment;

FIG. 3 is a graph of MTF of 0.435-0.656 μm in visible light of a five-megapixel glass-plastic hybrid wide-angle lens according to the present embodiment;

FIG. 4 is a defocus graph of 0.435-0.656 μm for visible light of a five-megapixel glass-plastic hybrid wide-angle lens according to the present embodiment;

FIG. 5 is a defocus graph of 0.850nm in the infrared of a five-megapixel glass-plastic hybrid wide-angle lens in this embodiment;

FIG. 6 is a defocused MTF curve at-40 ℃ of the five-megapixel glass-plastic hybrid wide-angle lens of the present embodiment;

FIG. 7 is a through-focus MTF curve of the five-megapixel glass-plastic hybrid wide-angle lens of the present embodiment at 80 ℃;

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, 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 application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

As shown in fig. 1, the embodiment provides a five-megapixel glass-plastic hybrid wide-angle lens, which comprises, in order along an optical axis from an object side to an image side, a first lens L1, a stop, and second to fourth lenses L2 to L4.

The first lens L1 is a plastic aspheric lens with negative focal power, the second lens L2 is a double-convex glass spherical lens with positive focal power, the third lens L3 is a double-convex glass spherical lens with positive focal power, and the fourth lens L4 is an aspheric lens with negative focal power.

In this embodiment, the focal lengths of the lenses of the lens respectively satisfy: -2< f1/f < -1.2; 1< f2/f < 2; 0.5< f3/f < 1; -0.4< f4/f < -0.1.

In this embodiment, the effective focal length f and the optical back focal length BFL of the lens satisfy the following condition 0.8< f/BFL < 1.

In this embodiment, the full field angle FOV is 80 °.

In this embodiment, the image plane

In this embodiment, the aperture FNo is 2.0.

In this embodiment, a filter is disposed between the last lens and the image plane.

The first lens, the third lens and the fourth lens are all even-order aspheric plastic lenses, and aspheric coefficients meet the following equation:

wherein z is an aspheric sagittal height, c is an aspheric paraxial curvature, y is a lens aperture, k is a conic coefficient, a4 is a 4-th aspheric coefficient, a6 is a 6-th aspheric coefficient, A8 is an 8-th aspheric coefficient, a10 is a 10-th aspheric coefficient, a12 is a 12-th aspheric coefficient, and a14 is a 14-th aspheric coefficient.

Specifically, the radius values, thicknesses and materials of the lens surfaces in this embodiment are shown in table 1, and the parameters of the plastic aspheric surface type are shown in table 2.

TABLE 1 radius value, thickness and Material Properties of the surface of each lens

TABLE 2 aspherical parameters

Surface number

1

2

5

6

7

8

K

1.094

-0.818

-11.235

1.022

-0.296

-44.611

A4

-3.66E-4

9.200E-3

8.808E-3

3.057E-3

0.011

4.788E-3

A6

3.547E-4

-5.776E-4

-1.565E-3

7.915E-4

-1.072E-3

2.331E-4

A8

2.210E-5

-2.112E-4

2.305E-4

-2.642E-4

1.070E-4

-5.583E-5

A10

3.351E-7

1.052E-4

-3.148E-5

1.795E-5

-1.471E-5

3.876E-6

A12

7.711E-8

-1.053E-5

2.530E-6

5.070E-7

2.075E-6

1.412E-7

A14

-1.843E-9

6.897E-7

-1.487E-7

-8.110E-8

-1.064E-8

-7.273E-9

FIG. 1 is a 2D diagram of an optical system, in which the lenses of the lens are symmetrical and reasonable in shape, so that the lens is convenient to mold and produce, and the lenses are reasonable in spacing, so that the later structural design is convenient;

FIG. 2 is a dot arrangement diagram of an optical system, in which the image spot size obtained for each field of view is uniform and aberration correction is sufficient;

FIG. 3 is a graph of the MTF for an optical system with full field resolution of 200lp/mm >0.3 up to 500 ten thousand pixels.

Fig. 4 and 5 are graphs of visible light and infrared defocusing MTF curves respectively, and the maximum defocusing amount of the embodiment in an infrared 850mm waveband is less than 0.01mm, so that day and night confocal can be realized.

Fig. 6 and 7 are graphs of defocus mtf at-40 c and 80 c, respectively, over which this embodiment can operate.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (9)

1. A five-megapixel glass-plastic hybrid wide-angle lens is characterized by comprising a first lens, a diaphragm, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis in sequence;

the first lens is a plastic aspheric lens with negative focal power, the second lens is a double-convex glass spherical lens with positive focal power, the third lens is a double-convex glass spherical lens with positive focal power, and the fourth lens is a plastic aspheric lens with negative focal power.

2. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein focal lengths of the lenses respectively satisfy: -2< f1/f < -1.2; 1< f2/f < 2; 0.5< f3/f < 1; -0.4< f4/f < -0.1.

3. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein a full field angle FOV of the wide-angle lens is equal to or greater than 80 °.

4. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein the target surface of the wide-angle lens

5. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein the total length TTL of the wide-angle lens is less than or equal to 22.2 mm.

6. The five-megapixel glass-plastic hybrid wide-angle lens according to claim 1, wherein an aperture FNo of the wide-angle lens is less than or equal to 2.0.

7. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein an effective focal length f and an optical back focal length BFL of the five-megapixel glass-plastic hybrid wide-angle lens satisfy the following condition 0.8< f/BFL < 1.

8. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein an optical filter is arranged between the last lens of the wide-angle lens and an image plane.

9. The five-megapixel glass-plastic hybrid wide-angle lens of claim 1, wherein the first lens, the third lens and the fourth lens are all even-order aspheric plastic lenses, and aspheric coefficients satisfy the following equation:

wherein z is an aspheric sagittal height, c is an aspheric paraxial curvature, y is a lens aperture, k is a conic coefficient, a4 is a 4-th aspheric coefficient, a6 is a 6-th aspheric coefficient, A8 is an 8-th aspheric coefficient, a10 is a 10-th aspheric coefficient, a12 is a 12-th aspheric coefficient, and a14 is a 14-th aspheric coefficient.

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