CN112558271B

CN112558271B - High-definition long-focus optical lens for security and vehicle-mounted fields

Info

Publication number: CN112558271B
Application number: CN202011285851.7A
Authority: CN
Inventors: 何玉林; 陈胜利; 刘维娜; 张许娜; 黄雷; 李智超; 杨方元
Original assignee: Nanyang Lida Photoelectric Co ltd
Current assignee: Nanyang Lida Photoelectric Co ltd
Priority date: 2020-05-22
Filing date: 2020-11-17
Publication date: 2022-09-16
Anticipated expiration: 2040-11-17
Also published as: CN112558271A

Abstract

The invention discloses a high-definition long-focus optical lens used in the fields of security and vehicle-mounted, which comprises a front lens group and a rear lens group which are sequentially arranged from an object space to an image surface, wherein a diaphragm is arranged between the front lens group and the rear lens group, and an optical filter is arranged between the rear lens group and the image surface; the front lens group comprises a first lens with positive focal power, a second lens with negative focal power and a third lens with negative focal power; the rear lens group comprises a fourth lens with positive focal power, a fifth lens with positive focal power and a sixth lens with negative focal power, wherein the fifth lens and the sixth lens form a cemented lens group. Compared with the prior art, the high-definition camera has high resolution, has a very good imaging effect within minus 40-80 ℃, can meet the requirement of a 4K ultrahigh-definition camera on a high-definition lens, and is very suitable for high-definition security monitoring and vehicle-mounted systems.

Description

High-definition long-focus optical lens for security and vehicle-mounted fields

Technical Field

The invention relates to the technical field of optical imaging equipment, in particular to a high-definition long-focus optical lens used in the fields of security and vehicle-mounted.

Background

In recent years, with the rapid development of the ultra-high definition 4K video technology, a 4K high definition camera is also developed, an ultra-high definition image sensor is mounted at the rear end of the 4K camera, and the front end of the 4K camera is required to be matched with an ultra-high definition optical lens.

Disclosure of Invention

The invention aims to provide a high-definition telephoto optical lens used in the fields of security and vehicle-mounted, which can realize the high-definition monitoring function in the fields of security monitoring and intelligent driving so as to improve the safety and early warning capability of security monitoring and intelligent driving.

In order to achieve the purpose, the invention adopts the following technical scheme: a high-definition long-focus optical lens used in the fields of security protection and vehicle-mounted comprises a front lens group and a rear lens group which are sequentially arranged from an object space to an image surface, wherein a diaphragm is arranged between the front lens group and the rear lens group, and an optical filter is arranged between the rear lens group and the image surface; the front lens group comprises a first lens with positive focal power, a second lens with negative focal power and a third lens with negative focal power; the rear lens group comprises a fourth lens with positive focal power, a fifth lens with positive focal power and a sixth lens with negative focal power, wherein the fifth lens and the sixth lens form a cemented lens group.

Preferably, the first lens, the third lens, the fifth lens and the sixth lens are meniscus lenses.

The second lens is a biconcave lens.

The diaphragm is located between the third lens and the fourth lens.

The fourth lens is a biconvex lens.

The optical filter is flat glass with a surface coated with a filter film.

The optical filter is positioned between the seventh lens and the image plane.

Further, the lens parameters of the present invention are as follows:

compared with the prior art, the invention has the beneficial effects that: the invention has high resolution ratio which can reach eight million pixels, has full image distortion within 1.2 percent, compact structure and good shockproof effect, has very good imaging effect within minus 40 to 80 ℃, can meet the requirement of a 4K ultra-high definition camera on a high definition lens, and is very suitable for high definition security monitoring and vehicle-mounted systems.

Drawings

The structure and features of the present invention will be further described with reference to the accompanying drawings and examples.

Fig. 1 is a structural view of an optical system according to an embodiment of the present invention.

FIG. 2 is a graph showing MTF (modulation transfer function) under normal temperature (20 ℃ C.) conditions according to the embodiment of the present invention.

FIG. 3 is a graph of MTF (modulation transfer function) under low temperature (-40 ℃ C.) conditions in accordance with an embodiment of the present invention.

FIG. 4 is a graph of MTF (modulation transfer function) under high temperature (80 ℃ C.) conditions according to an embodiment of the present invention.

FIG. 5 is a distortion diagram of an embodiment of the present invention.

FIG. 6 is a graph of color difference for an embodiment of the present invention.

FIG. 7 is a graph of relative illumination according to an embodiment of the present invention.

In FIG. 1, A01-front lens group, A02-rear lens group, B01-cemented lens group, STOP-diaphragm, F-filter, P-image plane, L1-first lens, L2-second lens, L3-third lens, L4-fourth lens, L5-fifth lens, and L6-sixth lens.

Detailed Description

Referring to the drawings of the present application, a detailed description will be given of an embodiment of the present application, as shown in fig. 1, in which the telephoto optical lens includes, in order from an object side to an image side, a front lens group a01 having positive power, a rear lens group a02 having positive power, a STOP, and a filter.

A long burnt optical lens system embodiment for security protection control and on-vehicle field:

the front lens group a01 includes a first lens L1 having positive power, a second lens L2 having negative power, and a third lens L3 having negative power;

the rear lens group a02 includes a fourth lens L4 having positive power, a fifth lens L5 having positive power, and a sixth lens L6 having negative power. Wherein the fifth lens L5 and the sixth lens L6 constitute a cemented lens group B01.

The STOP is located between the third lens L3 and the fourth lens L4, and the optical filter is located between the cemented lens group B01 and the image plane.

Preferred values of the relevant parameters for each lens are shown in the following table:

the distance from the vertex of the rear surface of the first lens L1 to the vertex of the front surface of the second lens L2 of the front lens group A01 is 0.95-1.05 mm, and preferably 1.07 mm.

The distance from the vertex of the rear surface of the second lens L2 of the front lens group A01 to the vertex of the front surface of the third lens L3 is 0.15-0.25 mm, preferably 0.2 mm.

The distance from the vertex of the rear surface of the third lens L3 of the front lens group A01 to the vertex of the front surface of the fourth lens L4 of the rear lens group A02 is 1.4-1.5 mm, preferably 1.45 mm.

The distance from the vertex of the rear surface of the fourth lens L4 of the rear lens group A02 to the vertex of the front surface of the gluing lens group B01 is 2.1-2.2 mm, preferably 2.17 mm.

FIG. 1 is a diagram showing the structure of an optical system according to an embodiment of the present invention, in which the overall length of the system is 22mm, and it can be seen that the embodiment is compact.

FIG. 2 is a graph of MTF (modulation transfer function) for an embodiment of the present invention, with the abscissa representing spatial frequency in units: line pair/millimeter (lp/mm), the ordinate represents the MTF value. As can be seen from fig. 2, the concentration ratio of the MTF curve in this embodiment is relatively high, which indicates that the imaging uniformity of the whole image plane is excellent, and a high-definition image can be obtained on the whole image plane, and at 200lp/mm, the MTF values of all fields reach about 50%.

FIGS. 3 and 4 are graphs of MTF (modulation transfer function) at low temperatures (-40 ℃) and high temperatures (80 ℃) in which the abscissa indicates spatial frequency in units of: line pair/millimeter (lp/mm), the ordinate represents the MTF value. As can be seen from comparison with FIG. 2, the MTF of the example of the present invention is reduced to some extent under the conditions of low temperature (-40 ℃) and high temperature (80 ℃), but the overall MTF value is still kept above 35%, which is within the acceptable range.

Fig. 5 is a distortion diagram of an embodiment of the present invention, as can be seen from fig. 5, the distortion of the whole image plane of the embodiment is below 1.2%, and the image distortion of the whole image plane is relatively small.

Fig. 6 is a color difference graph of an embodiment of the present invention, and it can be seen that the axial color difference and the longitudinal color difference of the embodiment are relatively small.

Fig. 7 is a graph of relative illuminance for an embodiment of the present invention, where the abscissa represents the field range and the ordinate represents the relative illuminance value, and it can be seen from fig. 7 that the relative illuminance is as high as 85% for the peripheral field relative to the central field.

The above-described embodiments are only some of the embodiments of the present invention, and the concept and scope of the present invention are not limited to the details of the above-described exemplary embodiments. Therefore, various changes and modifications of the present invention can be made by those skilled in the art without departing from the design concept of the present invention, and all the contents of the claims are included in the present invention.

Claims

1. The utility model provides a high definition telephoto optical lens for security protection and on-vehicle field which characterized in that: the lens group comprises a front lens group and a rear lens group which are sequentially arranged from an object space to an image surface, a diaphragm is arranged between the front lens group and the rear lens group, and an optical filter is arranged between the rear lens group and the image surface; the front lens group consists of a first lens with positive focal power, a second lens with negative focal power and a third lens with negative focal power; the rear lens group consists of a fourth lens with positive focal power, a fifth lens with positive focal power and a sixth lens with negative focal power, wherein the fifth lens and the sixth lens form a cemented lens group; the first lens, the third lens, the fifth lens and the sixth lens are meniscus lenses; the second lens is a biconcave lens; the diaphragm is positioned between the third lens and the fourth lens; the fourth lens is a biconvex lens; the optical filter is plate glass with a surface coated with a filter film; the optical filter is positioned between the sixth lens and the image plane; the parameters of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the optical filter are as follows:

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