CN116027523A

CN116027523A - Ultra-wide angle in-car monitoring lens

Info

Publication number: CN116027523A
Application number: CN202211709662.7A
Authority: CN
Inventors: 洪坚; 吴喆明; 罗艳波; 孙振中; 杨井留; 徐辉; 崔海波
Original assignee: Sirtec International Suzhou Co ltd
Current assignee: Sirtec International Suzhou Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-04-28

Abstract

The invention provides an ultra-wide-angle in-vehicle monitoring lens, which is sequentially provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a first parallel flat plate, a second parallel flat plate and an image plane IMA along the incidence direction of an optical axis; the first lens has negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative optical power; the second lens, the fourth lens, the fifth lens and the sixth lens are aspheric lenses, so that the visible light near infrared confocal function of the in-vehicle monitoring lens is met, the view field angle of the in-vehicle monitoring lens is increased, the in-vehicle monitoring range is wider, driving accidents are effectively avoided, clear imaging is achieved within the range of-40 ℃ to 85 ℃ at the same time, and the use environment temperature of the ultra-wide-angle in-vehicle monitoring lens is widened.

Description

Ultra-wide angle in-car monitoring lens

Technical Field

The invention relates to the technical field of optical imaging, in particular to an ultra-wide-angle in-vehicle monitoring lens.

Background

In recent years, with the development of vehicle-mounted technology, the technical requirements of in-vehicle cameras, driver monitoring, automobile data recorders and vehicle-mounted cameras are increasing. The existing vehicle-mounted camera has the following technical problems:

1) The traditional in-vehicle monitoring lens cannot meet the visible light near infrared confocal function, so that the imaging of the lens is unclear, and the imaging quality is poor;

2) The diagonal angle of the traditional in-vehicle monitoring lens is generally within the range of 110-120 degrees, the in-vehicle monitoring range is limited, passengers cannot be monitored in the vehicle, meanwhile, dangerous behaviors such as sleepiness and smoking in the driving process of a driver can be monitored, driving accidents are frequent, and therefore the in-vehicle monitoring lens with the view angle increased is required to be proposed;

3) The traditional in-vehicle monitoring lens cannot be used in severe environments, particularly cannot be normally used in extremely cold conditions (the ambient temperature is less than or equal to 30 ℃), and the use ambient temperature of the in-vehicle monitoring lens is greatly limited.

Disclosure of Invention

In order to solve the technical problems, the invention provides the ultra-wide-angle in-vehicle monitoring lens, which not only meets the visible light near-infrared confocal function of the in-vehicle monitoring lens, but also increases the view field angle of the in-vehicle monitoring lens, has wider monitoring range, effectively avoids frequent driving accidents, realizes clear imaging in the range of-40 ℃ to 85 ℃ at the same time, and widens the use environment temperature of the ultra-wide-angle in-vehicle monitoring lens.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

the ultra-wide angle in-vehicle monitoring lens is sequentially provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a first parallel flat plate, a second parallel flat plate and an image plane I MA along the incidence direction of an optical axis;

the first lens has negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative optical power; and the second lens, the fourth lens, the fifth lens and the sixth lens are all aspheric lenses.

The ultra-wide-angle in-vehicle monitoring lens provided by the invention not only meets the visible light near infrared confocal function of the in-vehicle monitoring lens, but also increases the view field angle of the in-vehicle monitoring lens, has a wider in-vehicle monitoring range, avoids frequent driving accidents, realizes clear imaging within the range of-40 ℃ to 85 ℃ at the same time, and widens the use environment temperature of the ultra-wide-angle in-vehicle monitoring lens.

As a preferable technical scheme, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

As a preferable technical scheme, the object side surface of the second lens is a convex surface, and the image side surface is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens and the fifth lens form an achromatic cemented lens group, the fourth lens has positive focal power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

As a preferable technical scheme, the object side surface of the second lens is a concave surface, the image side surface of the second lens is a concave surface, the object side surface of the third lens is a convex surface, the image side surface of the third lens is a convex surface, the fourth lens and the fifth lens form an achromatic cemented lens group, the fourth lens has positive focal power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

As a preferable technical scheme, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, the image side surface of the third lens is a convex surface, the fourth lens and the fifth lens form an achromatic cemented lens group, the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface; the fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

As a preferable technical scheme, the first lens Nd1 is more than 1.80, and vd1 is more than 25, wherein Nd1 refers to the refractive index of the first lens, and Vd1 refers to the abbe number of the first lens; the second lens Nd2 is more than 1.53, vd2 is less than 57, wherein Nd2 refers to the refractive index of the second lens, vd2 refers to the Abbe number of the second lens; the third lens Nd3 is more than 1.80, vd3 is more than 25, wherein Nd3 refers to the refractive index of the third lens, vd3 refers to the Abbe number of the third lens; the lens Nd with positive focal power in the fourth lens and the fifth lens is more than 1.53, vd is less than 57, wherein Nd refers to the refractive index of the fourth lens or the fifth lens, vd refers to the Abbe number of the fourth lens or the fifth lens; nd < 1.65, vd > 23, wherein Nd is the refractive index of the fourth lens or the fifth lens, vd is the Abbe number of the fourth lens or the fifth lens; the sixth lens Nd6 is more than 1.53, vd6 is less than 57, wherein Nd6 refers to the refractive index of the sixth lens, and Vd6 refers to the Abbe number of the sixth lens.

As an optimal technical scheme, the ultra-wide angle in-vehicle monitoring lens meets the following conditional expression: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens, the second lens, the third lens and the sixth lens in sequence, and f is a focal length of the whole lens.

As an optimal technical scheme, the ultra-wide angle in-vehicle monitoring lens meets the following conditions:

1.61≤h/FOV≤2.3，

wherein, FOV is the radian value of the horizontal half field angle of the optical lens;

h is the image height corresponding to the optical lens level.

TTL/2H≤3.4，

wherein TTL is a distance between an object side surface center of the first lens and an imaging surface of the optical lens on the optical axis;

h is the maximum image height of the optical lens.

As a preferable technical scheme, a diaphragm is arranged between the third lens and the fourth lens, the first lens and the third lens are glass spherical lenses, the second lens, the fourth lens, the fifth lens and the sixth lens are plastic aspherical lenses, and the second lens, the fourth lens, the fifth lens and the sixth lens all satisfy the following equations:

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wherein z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction, and c is the curvature of the paraxial of the aspheric surface; c=1/R, where R is the radius of curvature, c is the inverse of the radius of curvature, and k is the conic coefficient; a2 is an aspherical second-order coefficient, A4 is an aspherical fourth-order coefficient, A6 is an aspherical sixth-order coefficient, A8 is an aspherical eighth-order coefficient, a10 is an aspherical tenth-order coefficient, a12 is an aspherical twelfth-order coefficient, a14 is an aspherical fourteenth-order coefficient, a16 is an aspherical sixteenth-order coefficient, a18 is an aspherical eighteenth-order coefficient, and a20 is an aspherical twentieth-order coefficient.

The ultra-wide angle in-vehicle monitoring lens provided by the invention has the following beneficial effects:

1) The ultra-wide-angle in-vehicle monitoring lens provided by the invention not only meets the visible light near-infrared confocal function of the in-vehicle monitoring lens, but also increases the view field angle of the in-vehicle monitoring lens, has a wider in-vehicle monitoring range, effectively avoids frequent driving accidents, simultaneously realizes clear imaging within the range of-40 ℃ to 85 ℃, and widens the use environment temperature of the ultra-wide-angle in-vehicle monitoring lens;

2) According to the ultra-wide-angle in-vehicle monitoring lens, the focal length of the lens is reasonably matched, so that the assembly sensitivity is reduced, the lens is controlled in a very small range after being subjected to high and low temperature Jiao Piaoyi, and clear imaging is achieved;

3) The ultra-wide-angle in-vehicle monitoring lens provided by the invention is not only beneficial to the fact that the lens does not deviate from the expected distortion and focal length range, but also beneficial to the miniaturization of the lens;

4) The ultra-wide-angle in-vehicle monitoring lens provided by the invention has the advantages that the first lens is in a meniscus shape, the first lens with negative focal power and the second lens with negative focal power are mutually matched, so that light rays can be collected, the view field angle of the lens is increased, the view field angle of the lens is further increased, the control cost is further increased, the second lens is provided with the plastic aspherical lens, the view field angle is further increased, meanwhile, the received and converted light rays are smoother, the aberration is reduced, the head size of the lens is reduced, the first lens and the second lens both have negative focal power, and the technical problem that the view field angle of the traditional in-vehicle monitoring lens is smaller is solved by mutually matching the plastic aspherical lens.

Drawings

Fig. 1 is a structural combination diagram of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 1 (the object side is at the leftmost position, and the image side is at the rightmost position);

fig. 2 is a graph of visible light and near infrared defocus of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 1;

fig. 3 is a structural combination diagram of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 2 (the object side is at the leftmost position, and the image side is at the rightmost position);

fig. 4 is a graph of visible and near infrared defocus curves of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 2;

fig. 5 is a structural combination diagram of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 3 (the object side is at the leftmost position, and the image side is at the rightmost position);

fig. 6 is a graph of visible and near infrared defocus curves of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 3;

fig. 7 is a structural combination diagram of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 4 (the object side is at the leftmost position, and the image side is at the rightmost position);

fig. 8 is a graph of visible and near infrared defocus curves of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 4;

wherein 1-a first lens; 2-a second lens; 3-a third lens; 4-a fourth lens; 5-a fifth lens; 6-a sixth lens; 7-diaphragm; 8-a first parallel plate; 9-a second parallel plate; 10-image plane I MA.

Detailed Description

It should be noted that, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used to define the components only for convenience in distinguishing between corresponding components, and the terms are not to be construed as limiting the scope of the present invention, unless otherwise specified.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

It will be appreciated that the present invention achieves the objects of the invention by some embodiments.

Example 1

As shown in fig. 1, the present invention provides an ultra-wide angle in-vehicle monitoring lens, which is sequentially provided with a first lens 1, a second lens 2, a third lens 3, a diaphragm 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a first parallel flat plate 8, a second parallel flat plate 9 and an image plane ima 10 along an optical axis incidence direction;

the first lens element 1 has a negative refractive power, a convex object-side surface and a concave image-side surface; the second lens 2 has negative focal power, and the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 all adopt aspherical lenses;

the object side surface of the second lens element 2 is a concave surface, and the image side surface thereof is a concave surface; the object side surface of the third lens element 3 is convex, and the image side surface thereof is convex; the object side surface of the fourth lens element 4 is convex, and the image side surface thereof is convex; the object side surface of the fifth lens element 5 is concave, and the image side surface thereof is concave; the object side surface of the sixth lens element 6 is convex, the image side surface thereof is convex, and a stop 7 is disposed between the third lens element 3 and the fourth lens element 4;

The first lens 1 is in a meniscus shape, the first lens 1 with negative focal power and the second lens 2 with negative focal power are matched with each other, so that light is collected, the view field angle of the lens is increased, the view field angle of the lens is further increased, the cost is controlled, the second lens 2 is provided with a plastic aspheric lens, the view field angle is further increased, meanwhile, the received converted light is smoother, the aberration is reduced, the size of the head of the lens is reduced, the first lens 1 and the second lens 2 both have negative focal power and the lens in the ultra-wide-angle in-vehicle monitoring lens adopts the plastic aspheric lens to match with each other, the technical problem that the view field angle of the traditional in-vehicle monitoring lens is smaller is solved, the ultra-wide-angle in-vehicle monitoring lens has the ultra-wide-angle function, and the in-vehicle monitoring range is wider; the optical parameters of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 1 are as shown in table 1:

table 1 optical parameters of ultra-wide-angle in-vehicle monitoring lens provided in example 1

From table 1, we can observe that the first lens 1Nd1 is 2.00, the first lens 1Vd1 is 28.3, and the first lens 1Nd1 > 1.80, and vd1 > 25 are satisfied, wherein Nd1 refers to the refractive index of the first lens 1, and Vd1 refers to the abbe number of the first lens 1;

The second lens 2Nd2 is 1.54, the second lens 2Vd2 is 56.0, and the second lens 2Nd2 is more than 1.53, and vd2 is less than 57, wherein Nd2 refers to the refractive index of the second lens 2, and Vd2 refers to the abbe number of the second lens 2;

the third lens 3Nd3 is 1.81, the third lens 3Vd3 is 25.5, and the third lens 3Nd3 > 1.80 and the vd3 > 25 are satisfied, wherein Nd3 refers to the refractive index of the third lens 3, and Vd3 refers to the abbe number of the third lens 3;

the fourth lens 4 has positive focal power, nd of the fourth lens 4 is 1.66, vd of the fourth lens 4 is 20.4, nd is more than 1.53, vd is less than 57, wherein Nd is the refractive index of the fourth lens 4, vd is the Abbe number of the fourth lens 4;

the fifth lens 5 has negative focal power, the fifth lens 5Nd is 1.54, the fifth lens 5Vd is 56.0, nd < 1.65, vd > 23 are satisfied, wherein Nd refers to the refractive index of the fifth lens 5, and Vd refers to the abbe number of the fifth lens 5;

the sixth lens 6Nd6 is 1.52, the sixth lens 6Vd6 is 54.2, the requirement that the sixth lens 6Nd6 is greater than 1.53, and the requirement that vd6 is less than 57, wherein Nd6 refers to the refractive index of the sixth lens 6, and Vd6 refers to the abbe number of the sixth lens 6; the specification summary table of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 1 is shown in table 2:

Table 2 the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in example 1

	f1	f2	f3	f6	f	TTL	FOV	h	H
										Example 1	-4.978	-3.369	4.377	3.033	1.789	18.88	1.22	2.4	3.08

According to the specification summary of the ultra-wide angle in-vehicle monitoring lens provided in table 2, we can calculate that f1/f= -2.783, f2/f= -1.883, f3/f=2.447, f6/f=1.695, and the following conditional expression is satisfied: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens 1, the second lens 2, the third lens 3 and the sixth lens 6 in sequence, and f is a focal length of the whole lens group; the reasonable matching of the focal length of the lens is beneficial to reducing the assembly sensitivity, so that Jiao Piaoyi of the lens after high and low temperature is controlled in a very small range, and clear imaging is satisfied;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 2, we can calculate that h/fov=1.967, satisfies the following conditions: h/FOV is more than or equal to 1.61 and less than or equal to 2.3, so that the lens is not deviated from the expected distortion and focal length range; wherein, FOV is the radian value of the horizontal half field angle of the optical lens; h is the image height corresponding to the optical lens level;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 2, we can calculate that TTL/2h= 3.065 satisfies the following conditions: TTL/2H is less than or equal to 3.4, so that miniaturization of the lens is facilitated; wherein TTL is the distance between the center of the object side surface of the first lens 1 and the imaging surface of the optical lens on the optical axis; h is the maximum image height of the optical lens;

The first lens 1 and the third lens 3 are glass spherical lenses, the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are plastic aspherical lenses, and the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 satisfy the following equations:

wherein z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction, and c is the curvature of the paraxial of the aspheric surface; c=1/R, where R is the radius of curvature, c is the inverse of the radius of curvature, and k is the conic coefficient; a2 is an aspherical second-order coefficient, A4 is an aspherical fourth-order coefficient, A6 is an aspherical sixth-order coefficient, A8 is an aspherical eighth-order coefficient, a10 is an aspherical tenth-order coefficient, a12 is an aspherical twelfth-order coefficient, a14 is an aspherical fourteenth-order coefficient, a16 is an aspherical sixteenth-order coefficient, a18 is an aspherical eighteenth-order coefficient, and a20 is an aspherical twentieth-order coefficient; the coefficients of the facets of the provided plastic aspherical lenses of example 1 are shown in table 3 below:

TABLE 3 coefficients of surface area of Plastic aspherical lenses provided in example 1

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As shown in fig. 2, the left graph is a visible light defocus graph, the ordinate of the defocus graph is an MTF value, and the abscissa is a distance from a focal plane; the right graph is a near-infrared defocusing graph, the ordinate of the defocusing graph is an MTF value, the abscissa is a distance away from a focal plane, the defocusing curve can reflect the MTF condition of a lens image in a space defocusing state, and when the defocusing distance of a visible light center of the optical lens is 0 and the center is focused, the defocusing distance of a peak value of the near-infrared defocusing curve is not more than 10um, so that the visible light and the near infrared are regarded as confocal.

The embodiment provides a super wide angle in-car monitoring lens, not only satisfies the confocal function of in-car monitoring lens visible light near infrared, increases in-car monitoring lens's visual field angle moreover, and is wider to in-car monitoring scope, avoids driving accident to take frequently, realizes simultaneously that the clear formation of image when ambient temperature is-40 ℃, has guaranteed the normal use of super wide angle in-car monitoring lens under extremely cold ambient temperature, has widened the service environment temperature of super wide angle in-car monitoring lens.

Example 2

As shown in fig. 3, the present invention provides an ultra-wide angle in-vehicle monitoring lens, which is sequentially provided with a first lens 1, a second lens 2, a third lens 3, a diaphragm 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a first parallel flat plate 8, a second parallel flat plate 9 and an image plane ima 10 along an optical axis incidence direction;

the object side surface of the second lens element 2 is convex, and the image side surface thereof is concave; the object side surface of the third lens element 3 is convex, and the image side surface thereof is convex; the fourth lens 4 and the fifth lens 5 form an achromatic cemented lens group, and the fourth lens 4 has positive optical power, a convex object-side surface and a convex image-side surface; the fifth lens element 5 has negative refractive power, wherein an object-side surface thereof is concave, and an image-side surface thereof is concave; the object side surface of the sixth lens element 6 is convex, and the image side surface thereof is convex; a diaphragm 7 is arranged between the third lens 3 and the fourth lens 4;

The first lens 1 is in a meniscus shape, the first lens 1 with negative focal power and the second lens 2 with negative focal power are matched with each other, so that light is collected, the view field angle of the lens is increased, the view field angle of the lens is further increased, the cost is controlled, the second lens 2 is provided with a plastic aspheric lens, the view field angle is further increased, meanwhile, the received converted light is smoother, the aberration is reduced, the size of the head of the lens is reduced, the first lens 1 and the second lens 2 both have negative focal power and the lens in the ultra-wide-angle in-vehicle monitoring lens adopts the plastic aspheric lens to match with each other, the technical problem that the view field angle of the traditional in-vehicle monitoring lens is smaller is solved, the ultra-wide-angle in-vehicle monitoring lens has the ultra-wide-angle function, and the in-vehicle monitoring range is wider; the optical parameters of the ultra-wide angle in-vehicle monitoring lens provided in example 2 are shown in table 4:

table 4 optical parameters of ultra-wide-angle in-vehicle monitoring lens provided in example 2

From table 4, we can observe that the first lens 1Nd1 is 1.83, the first lens 1Vd1 is 28.3, and the first lens 1Nd1 > 1.80, and vd1 > 25 are satisfied, wherein Nd1 refers to the refractive index of the first lens 1, and Vd1 refers to the abbe number of the first lens 1;

the third lens 3Nd3 is 1.82, the third lens 3Vd3 is 25.6, and the third lens 3Nd3 > 1.80 and the vd3 > 25 are satisfied, wherein Nd3 refers to the refractive index of the third lens 3, and Vd3 refers to the abbe number of the third lens 3;

the fourth lens 4 has positive focal power, nd of the fourth lens 4 is 1.54, vd of the fourth lens 4 is 56.0, nd is more than 1.53, vd is less than 57, wherein Nd is the refractive index of the fourth lens 4, vd is the Abbe number of the fourth lens 4;

the fifth lens 5 has negative focal power, the fifth lens 5Nd is 1.64, the fifth lens 5Vd is 23.5, nd is less than 1.65, vd is more than 23, wherein Nd is the refractive index of the fifth lens 5, vd is the Abbe number of the fifth lens 5;

the sixth lens 6Nd6 is 1.54, the sixth lens 6Vd6 is 56.0, the requirement that the sixth lens 6Nd6 is greater than 1.53, and the requirement that vd6 is less than 57 is met, wherein Nd6 refers to the refractive index of the sixth lens 6, and Vd6 refers to the abbe number of the sixth lens 6; the specification summary table of the ultra-wide angle in-vehicle monitoring lens provided in example 2 is shown in table 5:

Table 5A summary of the specifications of the ultra-wide-angle in-vehicle monitoring lens provided in example 2

	f1	f2	f3	f6	f	TTL	FOV	h	H
										Example 2	-9.393	-3.746	4.676	3.627	1.75	20.82	1.22	2.5	3.08

According to the specification summary of the ultra-wide angle in-vehicle monitoring lens provided in table 5, we can calculate that f1/f= -5.367, f2/f= -2.141, f3/f= 2.672, f6/f= 2.073, and the following conditional expression is satisfied: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens 1, the second lens 2, the third lens 3 and the sixth lens 6 in sequence, and f is a focal length of the whole lens group; the reasonable matching of the focal length of the lens is beneficial to reducing the assembly sensitivity, so that Jiao Piaoyi of the lens after high and low temperature is controlled in a very small range, and clear imaging is satisfied;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 5, we can calculate that h/fov=2.049, satisfies the following conditions: h/FOV is more than or equal to 1.61 and less than or equal to 2.3, so that the lens is not deviated from the expected distortion and focal length range; wherein, FOV is the radian value of the horizontal half field angle of the optical lens; h is the image height corresponding to the optical lens level;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 5, we can calculate that TTL/2h= 3.380 satisfies the following conditions: TTL/2H is less than or equal to 3.4, so that miniaturization of the lens is facilitated; wherein TTL is the distance between the center of the object side surface of the first lens 1 and the imaging surface of the optical lens on the optical axis; h is the maximum image height of the optical lens;

wherein z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction, and c is the curvature of the paraxial of the aspheric surface; c=1/R, where R is the radius of curvature, c is the inverse of the radius of curvature, and k is the conic coefficient; a2 is an aspherical second-order coefficient, A4 is an aspherical fourth-order coefficient, A6 is an aspherical sixth-order coefficient, A8 is an aspherical eighth-order coefficient, a10 is an aspherical tenth-order coefficient, a12 is an aspherical twelfth-order coefficient, a14 is an aspherical fourteenth-order coefficient, a16 is an aspherical sixteenth-order coefficient, a18 is an aspherical eighteenth-order coefficient, and a20 is an aspherical twentieth-order coefficient; the coefficients of the facets of the provided plastic aspherical lenses of example 2 are shown in table 6 below:

TABLE 6 coefficients of the surface profile of the Plastic aspherical lens provided in example 2

As shown in fig. 4, the left graph is a visible light defocus graph, the ordinate of the defocus graph is an MTF value, and the abscissa is a distance from the focal plane; the right graph is a near-infrared defocusing graph, the ordinate of the defocusing graph is an MTF value, the abscissa is a distance away from a focal plane, the defocusing curve can reflect the MTF condition of a lens image in a space defocusing state, and when the defocusing distance of a visible light center of the optical lens is 0 and the center is focused, the defocusing distance of a peak value of the near-infrared defocusing curve is not more than 10um, so that the visible light and the near infrared are regarded as confocal.

The embodiment provides a monitoring lens in super wide angle car, not only satisfies the confocal function of monitoring lens visible light near infrared in the car, increases the visual field angle of monitoring lens in the car moreover, and monitoring range is wider in the car, avoids driving accident to frequently take place, realizes simultaneously that the clear formation of image when ambient temperature is 85 ℃, has widened the service environment temperature of monitoring lens in the super wide angle car.

Example 3

As shown in fig. 5, the present invention provides an ultra-wide angle in-vehicle monitoring lens, which is sequentially provided with a first lens 1, a second lens 2, a third lens 3, a diaphragm 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a first parallel flat plate 8, a second parallel flat plate 9 and an image plane ima 10 along an optical axis incidence direction;

the object side surface of the second lens element 2 is concave, the image side surface thereof is convex, the object side surface of the third lens element 3 is convex, the image side surface thereof is convex, the fourth lens element 4 and the fifth lens element 5 form an achromatic cemented lens assembly, the fourth lens element 4 has positive focal power, the object side surface thereof is convex, and the image side surface thereof is convex; the fifth lens element 5 has negative refractive power, wherein an object-side surface thereof is concave, and an image-side surface thereof is concave; the object side surface of the sixth lens element 6 is convex, and the image side surface thereof is convex; a diaphragm 7 is arranged between the third lens 3 and the fourth lens 4;

The first lens 1 is in a meniscus shape, the first lens 1 with negative focal power and the second lens 2 with negative focal power are matched with each other, so that light is collected, the view field angle of the lens is increased, the view field angle of the lens is further increased, the cost is controlled, the second lens 2 is provided with a plastic aspheric lens, the view field angle is further increased, meanwhile, the received converted light is smoother, the aberration is reduced, the size of the head of the lens is reduced, the first lens 1 and the second lens 2 both have negative focal power and the lens in the ultra-wide-angle in-vehicle monitoring lens adopts the plastic aspheric lens to be matched with each other, the technical problem that the view field angle of the traditional in-vehicle monitoring lens is smaller is solved, the ultra-wide-angle in-vehicle monitoring lens has an ultra-wide-angle function, and the monitoring range is wider; the optical parameters of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 3 are as shown in table 7:

table 7 example 3 provides optical parameters of ultra-wide-angle in-vehicle monitoring lens

From table 7, we can observe that the first lens 1Nd1 is 1.88, the first lens 1Vd1 is 39.2, and the first lens 1Nd1 > 1.80, and vd1 > 25 are satisfied, wherein Nd1 refers to the refractive index of the first lens 1, and Vd1 refers to the abbe number of the first lens 1;

The second lens 2Nd2 is 1.55, the second lens 2Vd2 is 56.5, and the second lens 2Nd2 is more than 1.53, and vd2 is less than 57, wherein Nd2 refers to the refractive index of the second lens 2, and Vd2 refers to the abbe number of the second lens 2;

the third lens 3Nd3 is 1.82, the third lens 3Vd3 is 25.7, and the third lens 3Nd3 > 1.80 and the vd3 > 25 are satisfied, wherein Nd3 refers to the refractive index of the third lens 3, and Vd3 refers to the abbe number of the third lens 3;

the sixth lens 6Nd6 is 1.54, the sixth lens 6Vd6 is 56.0, the requirement that the sixth lens 6Nd6 is greater than 1.53, and the requirement that vd6 is less than 57 is met, wherein Nd6 refers to the refractive index of the sixth lens 6, and Vd6 refers to the abbe number of the sixth lens 6; the specification summary table of the ultra-wide angle in-vehicle monitoring lens provided in embodiment 3 is shown in table 8:

Table 8A specification summary of ultra-wide-angle in-vehicle monitoring lenses provided in example 3

According to the specification summary of the ultra-wide angle in-vehicle monitoring lens provided in table 8, we can calculate that f1/f= -2.454, f2/f= -1.538, f3/f=1.972, f6/f= 2.109, and the following conditional expression is satisfied: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens 1, the second lens 2, the third lens 3 and the sixth lens 6 in sequence, and f is a focal length of the whole lens group; the reasonable matching of the focal length of the lens is beneficial to reducing the assembly sensitivity, so that Jiao Piaoyi of the lens after high and low temperature is controlled in a very small range, and clear imaging is satisfied;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 8, we can calculate that h/fov= 1.951, satisfies the following conditions: h/FOV is more than or equal to 1.61 and less than or equal to 2.3, so that the lens is not deviated from the expected distortion and focal length range; wherein, FOV is the radian value of the horizontal half field angle of the optical lens; h is the image height corresponding to the optical lens level;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 8, we can calculate that TTL/2h=3.005 satisfies the following conditions: TTL/2H is less than or equal to 3.4, so that miniaturization of the lens is facilitated; wherein TTL is the distance between the center of the object side surface of the first lens 1 and the imaging surface of the optical lens on the optical axis; h is the maximum image height of the optical lens;

The first lens 1 and the third lens 3 are glass spherical lenses, the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 are plastic aspherical lenses, and the second lens 2, the fourth lens 4, the fifth lens 5 and the sixth lens 6 all satisfy the following equations:

wherein z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction, and c is the curvature of the paraxial of the aspheric surface; c=1/R, where R is the radius of curvature, c is the inverse of the radius of curvature, and k is the conic coefficient; a2 is an aspherical second-order coefficient, A4 is an aspherical fourth-order coefficient, A6 is an aspherical sixth-order coefficient, A8 is an aspherical eighth-order coefficient, a10 is an aspherical tenth-order coefficient, a12 is an aspherical twelfth-order coefficient, a14 is an aspherical fourteenth-order coefficient, a16 is an aspherical sixteenth-order coefficient, a18 is an aspherical eighteenth-order coefficient, and a20 is an aspherical twentieth-order coefficient; the coefficients of the facets of the provided plastic aspherical lenses of example 3 are shown in table 9 below:

TABLE 9 coefficients of the surface profile of the Plastic aspherical lens provided in example 3

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As shown in fig. 6, the left graph is a visible light defocus graph, the ordinate of the defocus graph is an MTF value, and the abscissa is a distance from the focal plane; the right graph is a near-infrared defocusing graph, the ordinate of the defocusing graph is an MTF value, the abscissa is a distance away from a focal plane, the defocusing curve can reflect the MTF condition of a lens image in a space defocusing state, and when the defocusing distance of a visible light center of the optical lens is 0 and the center is focused, the defocusing distance of a peak value of the near-infrared defocusing curve is not more than 10um, so that the visible light and the near infrared are regarded as confocal.

The embodiment provides a super wide angle in-car monitoring lens, not only satisfies the confocal function of in-car monitoring lens visible light near infrared, increases in-car monitoring lens's visual field angle moreover, and is wider to in-car monitoring scope, avoids driving accident to take frequently, realizes simultaneously that the clear formation of image when ambient temperature is-30 ℃, has guaranteed the normal use of super wide angle in-car monitoring lens under extremely cold ambient temperature, has widened the service environment temperature of super wide angle in-car monitoring lens.

Example 4

As shown in fig. 7, the present invention provides an ultra-wide angle in-vehicle monitoring lens, which is sequentially provided with a first lens 1, a second lens 2, a third lens 3, a diaphragm 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a first parallel flat plate 8, a second parallel flat plate 9 and an image plane ima 10 along an optical axis incidence direction;

the object side surface of the second lens element 2 is a concave surface, and the image side surface thereof is a concave surface; the object side surface of the third lens element 3 is convex, the image side surface thereof is convex, the fourth lens element 4 and the fifth lens element 5 form an achromatic cemented lens assembly, the fourth lens element 4 has negative focal power, the object side surface thereof is concave, and the image side surface thereof is concave; the fifth lens element 5 has positive refractive power, wherein an object-side surface thereof is convex, and an image-side surface thereof is convex; the object side surface of the sixth lens element 6 is convex, and the image side surface thereof is convex; a diaphragm 7 is arranged between the third lens 3 and the fourth lens 4;

The first lens 1 is in a meniscus shape, the first lens 1 with negative focal power and the second lens 2 with negative focal power are matched with each other, so that light is collected, the view field angle of the lens is increased, the view field angle of the lens is further increased, the cost is controlled, the second lens 2 is provided with a plastic aspheric lens, the view field angle is further increased, meanwhile, the received converted light is smoother, the aberration is reduced, the size of the head of the lens is reduced, the first lens 1 and the second lens 2 both have negative focal power and the lens in the ultra-wide-angle in-vehicle monitoring lens adopts the plastic aspheric lens to be matched with each other, the technical problem that the view field angle of the traditional in-vehicle monitoring lens is smaller is solved, the ultra-wide-angle in-vehicle monitoring lens has an ultra-wide-angle function, and the monitoring range is wider; the optical parameters of the ultra-wide angle in-vehicle monitoring lens provided in example 4 are shown in table 10:

table 10 optical parameters of ultra-wide-angle in-vehicle monitoring lens provided in example 4

From table 10, we can observe that the first lens 1Nd1 is 1.89, the first lens 1Vd1 is 39.1, and the first lens 1Nd1 > 1.80, and vd1 > 25 are satisfied, wherein Nd1 refers to the refractive index of the first lens 1, and Vd1 refers to the abbe number of the first lens 1;

the third lens 3Nd3 is 1.83, the third lens 3Vd3 is 25.6, and the third lens 3Nd3 > 1.80 and the vd3 > 25 are satisfied, wherein Nd3 refers to the refractive index of the third lens 3, and Vd3 refers to the abbe number of the third lens 3;

the fourth lens 4 has negative focal power, nd of the fourth lens 4 is 1.64, vd of the fourth lens 4 is 23.5, nd is less than 1.65, vd is more than 23, wherein Nd is the refractive index of the fourth lens 4, vd is the Abbe number of the fourth lens 4;

the fifth lens 5 has positive focal power, the fifth lens 5Nd is 1.54, the fifth lens 5Vd is 56.0, nd is more than 1.53, vd is less than 57, wherein Nd is the refractive index of the fifth lens 5, vd is the Abbe number of the fifth lens 5;

the sixth lens 6Nd6 is 1.54, the sixth lens 6Vd6 is 56.1, the requirement that the sixth lens 6Nd6 is greater than 1.53, and the requirement that vd6 is less than 57 is met, wherein Nd6 refers to the refractive index of the sixth lens 6, and Vd6 refers to the abbe number of the sixth lens 6; the specification summary table of the ultra-wide angle in-vehicle monitoring lens provided in example 4 is shown in table 11:

Table 11A summary of the specifications of the ultra-wide-angle in-vehicle monitoring lens provided in example 4

	f1	f2	f3	f6	f	TTL	FOV	h	H
										Example 4	-5.993	-3.71	3.804	5.207	1.94	17.39	1.20	2.4	3.08

According to the specification summary of the ultra-wide angle in-vehicle monitoring lens provided in table 11, we can calculate that f1/f= -3.089, f2/f= -1.912, f3/f=1.961, f6/f= 2.684, and the following conditional expression is satisfied: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens 1, the second lens 2, the third lens 3 and the sixth lens 6 in sequence, and f is a focal length of the whole lens group; the reasonable matching of the focal length of the lens is beneficial to reducing the assembly sensitivity, so that Jiao Piaoyi of the lens after high and low temperature is controlled in a very small range, and clear imaging is satisfied;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 11, we can calculate that h/fov=2.000, satisfying the following conditions: h/FOV is more than or equal to 1.61 and less than or equal to 2.3, so that the lens is not deviated from the expected distortion and focal length range; wherein, FOV is the radian value of the horizontal half field angle of the optical lens; h is the image height corresponding to the optical lens level;

according to the specification summary of the ultra-wide-angle in-vehicle monitoring lens provided in table 11, we can calculate that TTL/2h= 2.823 satisfies the following conditions: TTL/2H is less than or equal to 3.4, so that miniaturization of the lens is facilitated; wherein TTL is the distance between the center of the object side surface of the first lens 1 and the imaging surface of the optical lens on the optical axis; h is the maximum image height of the optical lens;

wherein z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the optical axis direction, and c is the curvature of the paraxial of the aspheric surface; c=1/R, where R is the radius of curvature, c is the inverse of the radius of curvature, and k is the conic coefficient; a2 is an aspherical second-order coefficient, A4 is an aspherical fourth-order coefficient, A6 is an aspherical sixth-order coefficient, A8 is an aspherical eighth-order coefficient, a10 is an aspherical tenth-order coefficient, a12 is an aspherical twelfth-order coefficient, a14 is an aspherical fourteenth-order coefficient, a16 is an aspherical sixteenth-order coefficient, a18 is an aspherical eighteenth-order coefficient, and a20 is an aspherical twentieth-order coefficient; the coefficients of the facets of the provided plastic aspherical lenses of example 4 are shown in table 12 below:

table 12 coefficients of the provided plastic aspherical lens facets of example 4

As shown in fig. 8, the left graph is a visible light defocus graph, the ordinate of the defocus graph is an MTF value, and the abscissa is a distance from the focal plane; the right graph is a near-infrared defocusing graph, the ordinate of the defocusing graph is an MTF value, the abscissa is a distance away from a focal plane, the defocusing curve can reflect the MTF condition of a lens image in a space defocusing state, and when the defocusing distance of a visible light center of the optical lens is 0 and the center is focused, the defocusing distance of a peak value of the near-infrared defocusing curve is not more than 10um, so that the visible light and the near infrared are regarded as confocal.

The embodiment provides the ultra-wide-angle in-vehicle monitoring lens, which not only meets the visible light near infrared confocal function of the in-vehicle monitoring lens, but also increases the view field angle of the in-vehicle monitoring lens, has wider monitoring range in the vehicle, effectively avoids frequent driving accidents, simultaneously realizes clear imaging when the environmental temperature is-20 ℃, and widens the use environmental temperature of the ultra-wide-angle in-vehicle monitoring lens.

It will be understood that the invention has been described in terms of several embodiments, and that various changes and equivalents may be made to these features and embodiments by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all modifications and equivalents falling within the scope of the claims of the present application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. The ultra-wide angle in-vehicle monitoring lens is characterized in that a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a first parallel flat plate, a second parallel flat plate and an image plane IMA are sequentially arranged along the incidence direction of an optical axis;

the first lens has negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens has negative focal power, and the second lens, the fourth lens, the fifth lens and the sixth lens all adopt aspherical lenses.

2. The ultra-wide-angle in-vehicle monitoring lens of claim 1, wherein the object-side surface of the second lens element is concave and the image-side surface thereof is concave; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

3. The ultra-wide-angle in-vehicle monitoring lens of claim 1, wherein the object-side surface of the second lens element is convex and the image-side surface thereof is concave; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens and the fifth lens form an achromatic cemented lens group, the fourth lens has positive focal power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

4. The ultra-wide-angle in-vehicle monitoring lens system according to claim 1, wherein the object-side surface of the second lens element is concave, the image-side surface thereof is concave, the object-side surface of the third lens element is convex, the image-side surface thereof is convex, the fourth lens element and the fifth lens element form an achromatic cemented lens assembly, the fourth lens element has positive optical power, the object-side surface thereof is convex, and the image-side surface thereof is convex; the fifth lens has negative focal power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

5. The ultra-wide-angle in-vehicle monitoring lens of claim 1, wherein the object-side surface of the second lens element is concave and the image-side surface thereof is concave; the object side surface of the third lens is a convex surface, the image side surface of the third lens is a convex surface, the fourth lens and the fifth lens form an achromatic cemented lens group, the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface; the fifth lens has positive focal power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

6. The ultra-wide angle in-vehicle monitoring lens according to claim 1, wherein Nd1 is > 1.80 and Vd1 is > 25, wherein Nd1 is the refractive index of the first lens, and Vd1 is the abbe number of the first lens; the second lens Nd2 is more than 1.53, vd2 is less than 57, wherein Nd2 refers to the refractive index of the second lens, vd2 refers to the Abbe number of the second lens; the third lens Nd3 is more than 1.80, vd3 is more than 25, wherein Nd3 refers to the refractive index of the third lens, vd3 refers to the Abbe number of the third lens; the lens Nd with positive focal power in the fourth lens and the fifth lens is more than 1.53, vd is less than 57, wherein Nd refers to the refractive index of the fourth lens or the fifth lens, vd refers to the Abbe number of the fourth lens or the fifth lens; nd < 1.65, vd > 23, wherein Nd is the refractive index of the fourth lens or the fifth lens, vd is the Abbe number of the fourth lens or the fifth lens; the sixth lens Nd6 is more than 1.53, vd6 is less than 57, wherein Nd6 refers to the refractive index of the sixth lens, and Vd6 refers to the Abbe number of the sixth lens.

7. The ultra-wide-angle in-vehicle monitoring lens according to claim 1, wherein the ultra-wide-angle in-vehicle monitoring lens satisfies the following conditional expression: -6.ltoreq.f1/f.ltoreq.2, -2.5.ltoreq.f2/f.ltoreq.1, 1.5.ltoreq.f3/f.ltoreq. 3,1.5.ltoreq.f6/f.ltoreq.3.0; wherein f1, f2, f3 and f6 are focal lengths of the first lens, the second lens, the third lens and the sixth lens in sequence, and f is a focal length of the whole lens.

8. The ultra-wide-angle in-vehicle monitoring lens according to claim 1, wherein the ultra-wide-angle in-vehicle monitoring lens satisfies the following condition:

1.61≤h/FOV≤2.3，

h is the image height corresponding to the optical lens level.

9. The ultra-wide-angle in-vehicle monitoring lens according to claim 1, wherein the ultra-wide-angle in-vehicle monitoring lens satisfies the following condition:

TTL/2H≤3.4，

h is the maximum image height of the optical lens.

10. The ultra-wide-angle in-vehicle monitoring lens according to claim 1, wherein a diaphragm is arranged between the third lens and the fourth lens, the first lens and the third lens are glass spherical lenses, the second lens, the fourth lens, the fifth lens and the sixth lens are plastic aspherical lenses, and the second lens, the fourth lens, the fifth lens and the sixth lens all satisfy the following equations: