CN217034390U

CN217034390U - Vehicle-mounted camera lens for monitoring fatigue driving

Info

Publication number: CN217034390U
Application number: CN202123374363.6U
Authority: CN
Inventors: 万里; 吴刘森; 陈艺敏; 连伟
Original assignee: Suzhou Lightins Optical Co ltd
Current assignee: Suzhou Lightins Optical Co ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2022-07-22
Anticipated expiration: 2031-12-29

Abstract

The application discloses on-vehicle driver fatigue is camera lens for control, including the lens cone, have set gradually first lens, diaphragm, second lens, third lens group, protection glass and sensitization chip along the optical axis from the thing side to image side in the lens cone, first lens is concave-convex type negative lens, the second lens is the positive lens of biconvex type, the third lens group is the positive cemented lens of biconvex type, first lens group is constituteed to first lens and second lens, the focus of first lens group is-3.458 ~ 0.5mm, the focus of third lens group is 1-27.725 mm. The vehicle-mounted fatigue driving monitoring lens is small in structure, high in resolution, high in color reduction degree, large in aperture, infrared confocal and low in cost; under the condition of meeting the vehicle gauge, a larger image plane is realized, high resolution and miniaturization of the structure volume are facilitated, and meanwhile, high reliability and infrared confocal are achieved.

Description

Vehicle-mounted camera lens for monitoring fatigue driving

Technical Field

The application relates to the technical field of optical lenses, in particular to a vehicle-mounted lens for monitoring fatigue driving.

Background

In order to meet the requirement of a vehicle driver monitoring lens on working in a complex illumination environment, the imaging requirement of infrared confocal application under the corresponding complex illumination condition is provided in the industry at present. The existing fixed focus lens is difficult to meet the requirements of visible light and infrared confocal, cannot meet the imaging requirement of high imaging definition in a complex illumination environment, has serious purple boundary phenomenon in a visible mode, seriously reduces the definition in a high-low temperature environment, has large temperature drift, has insufficient peripheral brightness of an imaging picture and low relative illumination, and generally has the problems of complex structure and large volume and is difficult to meet the requirement of miniaturization.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a vehicle-mounted lens for monitoring fatigue driving, which overcomes the defects in the prior art.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides a vehicle-mounted camera lens for driver fatigue monitoring, includes the lens cone, has set gradually first lens, diaphragm, second lens, third lens group, protective glass and sensitization chip along the optical axis from the thing side to the image side in the lens cone, first lens is concave-convex type negative lens, the second lens is biconvex type positive lens, the third lens group is biconvex type positive cemented lens, first lens and second lens constitution first lens group, the focus of first lens group is-3.458 ~ 0.5mm, the focus of third lens group is 1-27.725 mm.

Preferably, the first lens, the second lens, and the third lens group satisfy:

-5≤f1/f2≤5

4≤f2/f3≤30

25≤f3/f1≤-3

wherein: f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f3 is the focal length of the third lens group.

Preferably, the first lens, the second lens, and the third lens group satisfy:

1.5≤Nd1≤1.7，1.65≤Nd2≤1.75，1.60≤Nd3≤1.66；

50≤Vd1≤70，35≤Vd2≤40，50≤Vd3≤60；

wherein: nd1 is the refractive index of the first lens, Nd2 is the refractive index of the second lens, Nd3 is the refractive index of the third lens group, Vd1 is the optical Abbe coefficient of the first lens, Vd2 is the optical Abbe coefficient of the second lens, and Vd3 is the optical Abbe coefficient of the third lens group.

Preferably, the first lens, the second lens and the third lens group are all spherical glass lenses.

Preferably, the lens meets the requirements that TTL is less than or equal to 16.65mm, image height is greater than or equal to 6.9mm, and distortion is 0 to up to

34.20 percent below zero, more than or equal to 50 percent of relative illumination, more than or equal to 1.6 and less than or equal to 3.9 percent of F/NO.

Compared with the prior art, the utility model has the beneficial effects that: the vehicle-mounted lens for monitoring the fatigue driving is small in structure, high in resolution, high in color reduction degree, large in aperture, infrared confocal and low in cost; under the condition of meeting the vehicle gauge, a larger image plane is realized, high resolution and miniaturization of the structure volume are facilitated, and meanwhile, high reliability and infrared confocal are achieved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be 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 described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a vehicle-mounted lens for monitoring fatigue driving according to an embodiment of the present invention;

fig. 2 is a graph illustrating an optical transfer function solution of a vehicle-mounted lens for monitoring fatigue driving according to an embodiment of the present invention;

fig. 3 is a distortion diagram and a field curvature diagram of a vehicle-mounted lens for monitoring fatigue driving according to an embodiment of the present invention;

fig. 4 is a relative illuminance diagram of a vehicle-mounted lens for monitoring fatigue driving according to an embodiment of the present invention;

in the figure: 1. a first lens group; 11. a first lens; 12. a second lens; 2. a second lens group 5, a diaphragm; 21. a third lens group; 3. protecting glass; 4. and (7) a photosensitive chip.

Detailed Description

The technical solutions in the embodiments of the present invention will be described in detail below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, a lens assembly for monitoring vehicle-mounted fatigue driving of the present application includes a lens barrel 4, and a first lens group, a diaphragm, a second lens group, a protective glass, and a photosensitive chip, which are sequentially arranged along an optical axis from an object side to an image side, where the first lens group 1 includes a first lens 11 and a second lens 12, which are sequentially arranged along the optical axis from the object side to the image side; the second lens group 2 includes a third lens group 21 arranged in order from the object side to the image side along the optical axis; the diaphragm 5 is located between the first lens 11 and the second lens 12, the first lens 11 is a concave-convex lens, the second lens 12 is a biconvex lens, and the third lens group 21 is a biconvex cemented lens group. The focal length range of the first lens assembly 1 is-3.458 c

0.5mm, and the focal length of the third lens group 21 is in the range of 1-27.725 mm.

The concave-convex first lens 11 has negative focal power, and the biconvex second lens 12 has positive focal power. The concave-convex first lens 11, the biconvex second lens 12 and the biconvex third lens group 21 are all spherical glass lenses. The image height of the lens is more than or equal to 6.9 mm.

Wherein 17< TTL/EFL <4, and under the above conditions, the related parameters have the following meanings:

TTL: the total optical length of the lens group; EFL: is the focal length of the lens group.

The focal length of the first lens 11 is f1, the focal length of the second lens 12 is f2, the focal length of the third lens group 21 is f3, the f1 and the f2 are in a relation that-5 is not less than f1/f2 is not less than 5, the f2 and the f3 are in a relation that 4 is not less than f2/f3 is not less than 30, and the f3 and the f1 are in a relation that 25 is not less than f3/f1 is not more than-3.

The Nd1, Nd2 and Nd3 respectively represent the refractive indexes of the light d of the first lens 11, the second lens 12 and the third lens group 21, and the Nd1, the Nd2 and the Nd3 have the relations of 1.5-1.7 of the Nd1, 1.65-1.75 of the Nd2 and 1.60-1.66 of the Nd 3.

Vd1, Vd2 and Vd3 respectively represent d-optical Abbe numbers of the first lens 11, the second lens 12 and the third lens group 21, and the Vd1, Vd2 and Vd3 are in the relations of 50-70 Vd1, 35-40 Vd2 and 50-60 Vd 3; the aperture value of the vehicle-mounted lens group for monitoring fatigue driving is represented by F/NO, and the F/NO is more than or equal to 1.6 and less than or equal to 3.9; the total optical length of the lens is represented by TTL (transistor-transistor logic), wherein the TTL is not more than 16.65 mm; the height of the lens image is more than or equal to 6.9 mm.

The aperture value F/NO of the utility model satisfies the following conditions: F/NO is more than or equal to 1.6 and less than or equal to 3.9, and the total optical length TTL meets the following conditions: TTL is less than or equal to 17.0mm, image height is more than or equal to 6.9mm, distortion is 0 to minus 34.20 percent, and relative illumination is more than or equal to 50 percent.

Where fig. 2 is a schematic diagram of an optical transfer function, where the abscissa is the line logarithm and the ordinate is the modulation value. The linear logarithm is 100lp/mm, and the modulation value is more than 50% when the full field of view is 103 degrees.

FIG. 3 (right) is a schematic diagram of lens distortion performance, which can be seen, where the abscissa is distortion value and the ordinate is image height value; the distortion is between 0% and-34.2% at all fields of view.

FIG. 3 (left) is a schematic diagram of lens curvature of field with field values on the abscissa and image height values on the ordinate; within the full field of view, the field curvature is within ± 0.12 mm. High resolution, small distortion and high contrast.

Fig. 4 is a relative illuminance diagram of a vehicle-mounted lens for monitoring fatigue driving according to an embodiment of the present invention.

The working principle of the utility model is as follows:

the vehicle-mounted lens group for monitoring fatigue driving comprises a convex-concave first lens 11, a convex-concave second lens 12 and a biconvex third lens 21 which are all spherical glass lenses. The requirements of the lens on imaging definition and good color performance are met, and meanwhile, the processing difficulty is low, and the manufacturing is easy; the lens is made of a professional optical material with a low expansion coefficient, can work normally in a severe environment of-40 to +105 ℃, and the temperature drift is minimum by reasonably setting the curvature radius and the center thickness of the lens, so that the temperature change basically has no influence on the imaging pixel of an imaging system.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely a detailed description of the present application and it should be noted that modifications and embellishments could be made by those skilled in the art without departing from the principle of the present application and should also be considered as within the scope of the present application.

Claims

1. The utility model provides a vehicle-mounted camera lens for monitoring fatigue driving, includes the lens cone, its characterized in that: the lens barrel is internally provided with a first lens, a diaphragm, a second lens, a third lens group, protective glass and a photosensitive chip in sequence from the object side to the image side along an optical axis, wherein the first lens is a concave-convex negative lens, the second lens is a biconvex positive lens, the third lens group is a biconvex positive cemented lens, the first lens and the second lens form a first lens group, the focal length of the first lens group is-3.458-0.5 mm, and the focal length of the third lens group is 1-27.725 mm.

2. The lens for monitoring vehicle-mounted fatigue driving according to claim 1, characterized in that: the first lens, the second lens and the third lens group satisfy:

-5≤f1/f2≤5

4≤f2/f3≤30

25≤f3/f1≤-3

3. The lens for monitoring vehicle-mounted fatigue driving according to claim 1, characterized in that: the first lens, the second lens and the third lens group satisfy:

1.5≤Nd1≤1.7，1.65≤Nd2≤1.75，1.60≤Nd3≤1.66；

50≤Vd1≤70，35≤Vd2≤40，50≤Vd3≤60；

4. The lens for monitoring vehicle-mounted fatigue driving according to claim 1, characterized in that: the first lens, the second lens and the third lens group are all spherical glass lenses.

5. The lens for monitoring vehicle-mounted fatigue driving according to claim 1, characterized in that: the lens meets the requirements that TTL is less than or equal to 16.65mm, image height is more than or equal to 6.9mm, distortion is 0-34.20%, relative illumination is more than or equal to 50%, and F/NO is more than or equal to 1.6 and less than or equal to 3.9.