CN111538144A

CN111538144A - Ultrathin vehicle-mounted lens

Info

Publication number: CN111538144A
Application number: CN202010474624.2A
Authority: CN
Inventors: 孙仲辉; 孙杰克; 罗争
Original assignee: Ningbo Jinhui Optical Technology Co ltd
Current assignee: Ningbo Jinhui Optical Technology Co ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2020-08-14

Abstract

The invention discloses an ultrathin vehicle-mounted lens, which comprises a lens shell and an optical lens group, wherein the optical lens group sequentially comprises: the lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens, wherein 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, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces; the fourth lens has negative focal power, and the object side surface and the image side surface of the fourth lens are both concave surfaces; 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 convex surface; the optical lens group satisfies the following conditional expression: Tmax/Tmin ≧ 3.0. The invention has the following advantages and effects: the whole is thin, and the effects of high resolution, low cost and large aperture are achieved.

Description

Ultrathin vehicle-mounted lens

Technical Field

The invention relates to the technical field of vehicle-mounted lenses, in particular to an ultrathin vehicle-mounted lens.

Background

At present, vehicle-mounted driving record monitoring plays an important role in driving safety and traffic disputes, the horizontal field of view of such vehicle-mounted lenses in the market is generally between 90 and 120 degrees, and the imaging performance is poor; in addition, the difficulty of the lens process is increased due to the overlarge angle of the lens field, the cost of the lens is high, and the problem of thick integral thickness exists. The existing multilane monitoring has higher requirements on a horizontal view field, objects such as license plates and the like which are farther away are identified, the higher requirements on pixels are provided, the improvement of the night vision effect is met by a larger aperture, and the industry trend is to have higher performance and reduce the cost.

In recent years, driving safety is more and more emphasized, and various driving-assisted imaging devices are developed, wherein attention is paid to 360-degree panoramic detection devices, the surrounding environment of a vehicle is detected from all directions, and the driving safety of the vehicle is ensured.

Disclosure of Invention

The invention aims to provide an ultrathin vehicle-mounted lens which has the effects of being thin as a whole, high in resolution, low in cost and large in aperture.

The technical purpose of the invention is realized by the following technical scheme: an ultra-thin vehicle-mounted lens comprises a lens shell and an optical lens group arranged in the lens shell, wherein the optical lens group sequentially comprises from an object side to an image side along an optical axis: the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element each have an object-side surface facing the object side and passing the image light, and an image-side surface facing the image side and passing the image light,

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, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

the third lens has positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces;

the fourth lens has negative focal power, and the object side surface and the image side surface of the fourth lens are both concave surfaces;

the fifth lens has positive 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 convex surface;

any two lenses of the first lens to the fifth lens are separated from each other;

the optical lens group satisfies the following conditional expression:

Tmax/Tmin≧3.0；

wherein Tmax represents a thickness of a lens with the largest refractive index and thickness in the optical imaging lens on the optical axis, and Tmin represents a thickness of a lens with the smallest refractive index and thickness in the optical imaging lens on the optical axis.

The invention is further provided with: the first lens is a spherical lens, and the second lens, the third lens, the fourth lens and the fifth lens are aspheric lenses.

The invention is further provided with: a shading mylar film is arranged between the second lens and the third lens, between the third lens and the fourth lens and between the fourth lens and the fifth lens, and the center of the shading mylar film is provided with a light through hole for light to pass through; a space ring is arranged between the second lens and the third lens, and a light guide angle is arranged on the inner wall of the space ring.

The invention is further provided with: the optical back focus BFL of the optical lens group and the optical total length TTL of the optical lens group satisfy the conditional expression: BFL/TTL is more than or equal to 0.13 and less than or equal to 0.15.

The invention is further provided with: the optical lens group satisfies the following conditional expression: D/H/FOV is more than or equal to 0.032 and less than or equal to 0.036;

d is the maximum clear aperture of the object side surface of the first lens corresponding to the maximum field angle of the optical lens group;

h is the image height corresponding to the maximum field angle of the optical lens group.

The invention is further provided with: the total optical length TTL of the optical lens group and the effective focal length of the optical lens group satisfy the following conditional expression: TTL/EFL is less than or equal to 10.0.

The invention is further provided with: the optical lens group satisfies the following conditional expression: TTL/H/FOV is more than or equal to 0.031 and less than or equal to 0.035.

The invention is further provided with: the optical lens group satisfies the following conditional expression: (R1+ R2)/(R1-R2) is not more than 1.20 and not more than 1.63; (R3+ R4)/(R3-R4) is not more than 1.39 and not more than 2.16; (R5+ R6)/(R5-R6) is not more than 0.473 and not more than 0.475; (R7+ R8)/(R7-R8) is not more than 0.55 and not more than 0.57; not less than 1.03 (R9+ R10)/(R9-R10) not more than 1.18;

wherein R1 is the radius of curvature of the object-side surface of the first lens; r2 is the radius of curvature of the image-side surface of the first lens; r3 is the radius of curvature of the object-side surface of the second lens; r4 is the radius of curvature of the image-side surface of the second lens; r5 is the radius of curvature of the object-side surface of the third lens; r6 is the radius of curvature of the image-side surface of the third lens; r7 is the radius of curvature of the object-side surface of the fourth lens; r8 is the radius of curvature of the image-side surface of the fourth lens element; r9 is the radius of curvature of the object-side surface of the fifth lens; r10 is the radius of curvature of the image-side surface of the fifth lens.

The invention is further provided with: the optical lens group satisfies the following conditional expression: (G12+ G23)/T2 of more than or equal to 10.0 and less than or equal to 20.0; (G23+ G34)/T3 of not more than 1.8 and not more than 2.2; (G34+ G45)/T4 is more than or equal to 0.7 and less than or equal to 1.2;

wherein G12 denotes a spatial gap width on the optical axis between the first lens and the second lens;

g23 denotes a spatial gap width on the optical axis between the second lens and the third lens;

g34 denotes a spatial gap width on the optical axis between the third lens and the fourth lens;

g45 denotes a spatial gap width on the optical axis between the fourth lens and the fifth lens;

t2 denotes the thickness of the second lens on the optical axis;

t3 denotes the thickness of the third lens on the optical axis;

t4 denotes the thickness of the fourth lens on the optical axis.

The invention is further provided with: the refractive indexes of the second lens, the third lens and the fifth lens are the same, and are set to be 1.5-1.6.

In conclusion, the invention has the following beneficial effects:

the optical lens assembly of the present invention adopts the concave-convex curved surface arrangement of each lens and controls the related parameters in the related condition mode, thereby maintaining the higher imaging quality, having shorter total length of the lens, thinner overall structure, and having the effects of high resolution, low cost and large aperture.

Drawings

Fig. 1 is an overall structural sectional view of the first embodiment, the second embodiment, and the third embodiment.

Fig. 2 is a schematic structural relationship diagram of the optical lens sets of the first, second, and third embodiments.

Fig. 3 is a schematic view of the structural relationship of the curved surfaces of the optical lens sets according to the first, second, and third embodiments.

Fig. 4 is an optical path diagram of the optical lens assembly according to the first embodiment, the second embodiment and the third embodiment.

Fig. 5 is MTF graphs of the first, second, and third embodiments.

Fig. 6 is a relative illuminance diagram of the first embodiment, the second embodiment, and the third embodiment.

In the figure: 1. a lens housing; 2. an optical lens group; 21. a first lens; 22. a second lens; 23. a third lens; 24. a fourth lens; 25. a fifth lens; 3. a space ring; 31. a light through hole; 32. a light guide angle; 4. a light-shielding Mylar film; 5. and (3) a filter.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in this specification, the expressions first, second, third, etc. are used only to distinguish one feature from another, and do not represent any limitation on the features. Thus, the first lens discussed below may also be referred to as the second lens or the third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lens have been slightly exaggerated for convenience of explanation. In particular, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The figures are purely diagrammatic and not drawn to scale.

It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including 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. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The features, principles, and other aspects of the present application are described in detail below.

The ultra-thin vehicular lens of the exemplary embodiment of the present application includes a lens housing 1 and an optical lens assembly 2 disposed in the lens housing 1, wherein the optical lens assembly 2 sequentially includes, from left to right along an optical axis from an object side to an image side: the optical lens assembly comprises a first lens 21, a second lens 22, a third lens 23, a fourth lens 24 and a fifth lens 25, wherein each lens is provided with an object side surface facing to the object side and allowing imaging light rays to pass through and an image side surface facing to the image side and allowing imaging light rays to pass through, and any two lenses of the first lens 21 to the fifth lens 25 are separated from each other; and may further include a filter 5 disposed between the imaging surface and the fifth lens 25.

The first lens element 21 has negative power, and has a convex object-side surface S1 and a concave image-side surface S2; the first lens 21 is provided in a meniscus shape convex toward the object side so as to collect as much light rays of a large field as possible, increasing the amount of light flux. Since the first lens 21 is disposed on the outermost side, it is formed in a meniscus shape, which is advantageous for water droplets to slide down, and reduces the influence on the image formation. The first lens 21 is made of plastic, Nd1 is larger than or equal to 1.4 and smaller than or equal to 1.6, the first lens 21 is a spherical lens, and imaging quality is improved.

The second lens element 22 has negative power, and has a convex object-side surface S3 and a concave image-side surface S4; the object side S3 has a concavity smaller than the image side S4, and the second lens element 22 disperses the light rays to make the light rays smoothly transition to the image plane. The second lens 22 is made of plastic, Nd1 is larger than or equal to 1.4, the second lens 22 is an aspheric lens, and the effect of light weight and low cost is achieved.

The third lens 23 has positive power, and both the object-side surface S5 and the image-side surface S6 are convex; the third lens 23 can converge the light, so that the divergent light can smoothly enter the image plane. In addition, the third lens 23 is set to positive power, so that spherical aberration introduced by the first two lenses can be compensated. The third lens 23 is made of plastic, the refractive index of the third lens 23 is the same as that of the first lens 21, the third lens 23 is an aspheric lens, and the third lens 23 is the lens most sensitive to yield.

The fourth lens 24 has a negative power, and both the object-side surface S7 and the image-side surface S8 are concave; the fourth lens 24 may act to diverge the light. The fourth lens 24 is made of a material with a relatively high refractive index and made of plastic, Nd1 is larger than or equal to 1.6, the fourth lens 24 is an aspheric lens, the resolution ratio is improved, and the fourth lens 24 is an aspheric lens.

The fifth lens element 25 has positive refractive power, the object-side surface S9 is a concave surface, the image-side surface S10 is a convex surface, and corrects light passing through the front lenses, the fifth lens element 25 is made of plastic and has the same refractive index as the second lens element 22 and the third lens element 23, and the fifth lens element 25 is an aspheric lens element.

The field angle range of the optical lens group 2 is set to be more than or equal to 156 degrees and less than or equal to 166 degrees.

A light shading mylar film 4 is arranged between the second lens 22 and the third lens 23, between the third lens 23 and the fourth lens 24, and between the fourth lens 24 and the fifth lens 25, and a light through hole 31 for light to pass through is formed in the center of the light shading mylar film 4; a space ring 3 is arranged between the second lens 22 and the third lens 23, and a light guide angle 32 is arranged on the inner wall of the space ring 3. The arrangement of the shading mylar film 4 and the space ring 3 can play a role in eliminating stray light to a certain extent, and restrain light, and the light guide angle 32 can play a light guide role in the light entering the space ring 33, so that the imaging effect is improved, and the effect of high resolution is achieved.

In order to reduce the total length of the lens and ensure high-quality imaging, the air gap between the lenses can be reduced or the thickness of the lens can be reduced properly, but the difficulty of manufacturing is considered, so that the imaging effect can be high if the numerical limitation of the following conditional expression is satisfied:

conditional formula (1): Tmax/Tmin ≧ 3.0, and the preferred range is 3.9-6.4; wherein Tmax represents a thickness of a lens with the largest refractive index and thickness in the optical imaging lens on the optical axis, and Tmin represents a thickness of a lens with the smallest refractive index and thickness in the optical imaging lens on the optical axis.

The optical back focus BFL of the optical lens group 22 and the total optical length TTL of the optical lens group satisfy the conditional expression (2): BFL/TTL is more than or equal to 0.13 and less than or equal to 0.15, and the preferable range is between 0.140 and 0.146.

Conditional formula (3): D/H/FOV is more than or equal to 0.032 and less than or equal to 0.035; wherein D is the maximum clear aperture of the object-side surface of the first lens element 21 corresponding to the maximum field angle of the optical lens group; h is the image height corresponding to the maximum field angle of the optical lens set 2, and the preferred range is between 0.033 and 0.035.

The total optical length TTL of the optical lens assembly 2 and the effective focal length EFL of the optical lens assembly 2 satisfy the following conditional expression (4): TTL/EFL is less than or equal to 10.0, and the preferable range is between 9.25 and 9.60.

The optical lens group 2 satisfies the following conditional expression (5): 0.031 TTL/H/FOV is less than or equal to 0.036, and the preferable range is 0.031-0.032.

The optical lens group 2 satisfies the following conditional expression (6): (R1+ R2)/(R1-R2) is not more than 1.20 and not more than 1.63; (R3+ R4)/(R3-R4) is not more than 1.39 and not more than 2.16; (R5+ R6)/(R5-R6) is not more than 0.473 and not more than 0.475; (R7+ R8)/(R7-R8) is not more than 0.55 and not more than 0.57; not less than 1.03 (R9+ R10)/(R9-R10) not more than 1.18;

wherein R1 is the radius of curvature of the object-side surface of the first lens 21; r2 is the radius of curvature of the image-side surface of the first lens element 21; r3 is the radius of curvature of the object-side surface of the second lens 22; r4 is the radius of curvature of the image-side surface of the second lens 22; r5 is the radius of curvature of the object-side surface of the third lens 23; r6 is the radius of curvature of the image-side surface of the third lens element 23; r7 is the radius of curvature of the object-side surface of the fourth lens 24; r8 is the radius of curvature of the image-side surface of the fourth lens element 24; r9 is the radius of curvature of the object-side surface of the fifth lens 25; r10 is the radius of curvature of the image-side surface of the fifth lens element 25.

The optical lens group 2 satisfies the following conditional expression (7): (G12+ G23)/T2 of more than or equal to 10.0 and less than or equal to 20.0; (G23+ G34)/T3 of not more than 1.8 and not more than 2.2; (G34+ G45)/T4 is more than or equal to 0.7 and less than or equal to 1.2; (G45+ G56)/T5 is not more than 0.25 and not more than 1.70;

where G12 denotes a spatial gap width on the optical axis between the first lens 21 and the second lens 22;

g23 denotes a spatial gap width on the optical axis between the second lens 22 and the third lens 23;

g34 denotes a spatial gap width on the optical axis between the third lens 23 and the fourth lens 24;

g45 denotes a spatial gap width on the optical axis between the fourth lens 24 and the fifth lens 25;

g56 represents a spatial gap width on the optical axis between the fifth lens 25 and the filter 5;

t2 denotes the thickness of the second lens 22 on the optical axis;

t3 denotes the thickness of the third lens 23 on the optical axis;

t4 denotes the thickness of the fourth lens 24 on the optical axis;

t5 denotes the thickness of the fifth lens 25 on the optical axis.

The ratio of the focal lengths of two adjacent lenses satisfies the following conditional expression (8): F1/F2 is more than or equal to 2.4 and less than or equal to 3.4; f2 of-3 is more than or equal to the ratio of F3 to-1; F3/F4 is more than or equal to-1 and less than or equal to-0.8; F4/F5 of more than or equal to-0.8 and less than or equal to-0.6;

wherein F1 is the focal length of the first lens 21, F2 is the focal length of the second lens 22, F3 is the focal length of the third lens 23, and F4 is the focal length of the fourth lens 24; f5 is the focal length of the fifth lens 25.

The refractive indices of the second lens 22, the third lens 23, and the fifth lens 25 are the same, and the refractive index Nd is set to 1.5 to 1.6.

According to the ultrathin optical lens group of the above embodiment of the application, the lens shape is optimally set, the focal power is reasonably distributed, the lens material is reasonably selected, and the ultrathin optical lens group adopts the all-plastic lens, so that the ultrathin optical lens group has a light effect. The five-separation framework is adopted, so that the lens has more degrees of freedom, and high resolution of the wide-angle lens can be realized; meanwhile, the effects of miniaturization of the lens, low sensitivity, high production yield, low cost, large aperture and large field angle can be considered.

Specific examples suitable for the above-described embodiments are further described below with reference to the drawings.

Example 1

An ultra-thin vehicular lens system as shown in fig. 1-3 includes a lens housing 1 and an optical lens assembly 2 disposed in the lens housing 1, wherein the optical lens assembly 2 sequentially includes, from an object side to an image side along an optical axis: the first lens element 21, the second lens element 22, the third lens element 23, the fourth lens element 24 and the fifth lens element 25 each having an object-side surface facing the object side and passing the image light and an image-side surface facing the image side and passing the image light; the first lens 21 has negative focal power, and is a spherical lens with a convex object-side surface and a concave image-side surface; the second lens element 22 has a negative focal power, and is a non-spherical lens element with a convex object-side surface and a concave image-side surface; the third lens 23 has positive focal power, and both the object-side surface and the image-side surface are convex surfaces and are aspheric lenses; the fourth lens element 24 has negative focal power, and both the object-side surface and the image-side surface thereof are concave and are aspheric lenses; the fifth lens element 25 has a positive focal power, and is an aspheric lens element having a concave object-side surface and a convex image-side surface; any two lenses of the first lens 21 to the fifth lens 25 are separated from each other.

The field angle range of the optical lens group 2 is set to 156 °.

A light shading mylar film 4 is arranged between the second lens 22 and the third lens 23, between the third lens 23 and the fourth lens 24, and between the fourth lens 24 and the fifth lens 25, and a light through hole 31 for light to pass through is formed in the center of the light shading mylar film 4; a space ring 3 is arranged between the second lens 22 and the third lens 23, a light guide angle 32 is arranged on the inner wall of the space ring 3, and the light guide angle 32 is set to be 45 degrees.

Table 1 shows the radius of curvature R, thickness T, gap G, refractive index Nd, abbe number Vd, focal length F, and material of each lens element of the optical lens group 2 of example 1, where the radius of curvature R, thickness T, gap G, and focal length F are all in millimeters (mm).

TABLE 1

The even-order aspheric rise formula for each mirror is defined as follows:

wherein Z is the distance vector from the aspheric surface to the fixed point when the aspheric surface is at the position of h along the optical axis direction, c is the paraxial curvature of the aspheric surface, c is 1/R, k is the conic coefficient, R is the distance from the optical axis to the point on the optical surface, α₁、α₂、α₃、α₄Are all high-order term coefficients.

Table 2 shows the conic coefficients k and the respective high-order term coefficients used for the aspherical lens surfaces S3 to S10 in the present embodiment.

TABLE 2

Table 3 below shows the optical back focus BFL (i.e., the on-axis distance from the center of the image-side surface S10 of the fifth lens element 25 to the imaging surface IMA), the total length TTL (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens element 21 to the imaging surface IMA) of the optical lens group 2, the maximum aperture diameter D of the object-side surface S1 of the first lens element 21 corresponding to the maximum field angle of the optical lens group 2, the image height H corresponding to the maximum field angle of the optical lens group, the effective focal length EFL of the optical lens group 2, and the optical focus FNO of the optical lens group 2 according to the present embodiment.

TABLE 3

EFL(mm)	1.21	D(mm)	12.16
				BFL(mm)	1.63	FOV(°)	156
TTL(mm)	11.20	FNO	2.0
				H(mm)	2.24

In this embodiment, Tmax/Tmin is 4.19, and the conditional expression is satisfied between the optical back focus BFL of the optical lens group 2 and the optical total length TTL of the optical lens group: BFL/TTL is 0.146; the maximum clear aperture D of the object-side surface S1 of the first lens 21 corresponding to the maximum field angle and the image height H corresponding to the maximum field angle satisfy D/H/FOV of 0.035; the total optical length TTL and the effective focal length EFL of the optical lens assembly 2 satisfy the following conditional expressions: TTL/EFL 9.256; the total optical length TTL, the maximum field angle FOV of the optical lens group and the image height H corresponding to the maximum field angle of the optical lens group satisfy that TTL/H/FOV is 0.032.

The radius of curvature R1 of the object-side surface of the first lens 21 and the radius of curvature R2 of the image-side surface of the first lens 21 satisfy (R1+ R2)/(R1-R2) 1.582; the radius of curvature R3 of the object-side surface of the second lens 22 and the radius of curvature R4 of the image-side surface of the second lens 22 satisfy (R3+ R4)/(R3-R4) ═ 2.159; the radius of curvature R5 of the object-side surface of the third lens 23 and the radius of curvature R6 of the image-side surface of the third lens 23 satisfy (R5+ R6)/(R5-R6) ═ 0.474; the radius of curvature R7 of the object-side surface of the fourth lens 24 and the radius of curvature R8 of the image-side surface of the fourth lens 24 satisfy (R7+ R8)/(R7-R8) ═ 0.559; the radius of curvature R9 of the object-side surface of the fifth lens 25 and the radius of curvature R10 of the image-side surface of the fifth lens 25 satisfy (R9+ R10)/(R9-R10) ═ 1.179.

A front-rear space gap width of the second lens 22 on the optical axis and a thickness T2 of the second lens 22 on the optical axis satisfy (G12+ G23)/T2 of 10.51; a front-rear space gap width of the third lens 23 on the optical axis and a thickness T3 of the third lens 23 on the optical axis satisfy (G23+ G34)/T3 equal to 1.99; a front-rear space gap width of the fourth lens 24 on the optical axis and a thickness T4 of the fourth lens 24 on the optical axis satisfy (G34+ G45)/T4 equal to 1.1; the front-rear space gap width of the fifth lens 25 on the optical axis and the thickness T5 of the fifth lens 25 on the optical axis satisfy (G45+ G56)/T5 equal to 1.69.

The ratio of the focal lengths of the two adjacent lenses is: F1/F2 ═ 2.482; F2/F3 ═ 2.531; F3/F4 ═ 0.912; F4/F5 ═ 0.654.

Example 2

As shown in fig. 1-3, the optical lens assembly 2, in order from an object side to an image side along an optical axis, comprises: the first lens element 21, the second lens element 22, the third lens element 23, the fourth lens element 24 and the fifth lens element 25 each having an object-side surface facing the object side and passing the image light and an image-side surface facing the image side and passing the image light; the first lens 21 has negative focal power, and is a spherical lens with a convex object-side surface and a concave image-side surface; the second lens element 22 has a negative focal power, and is a non-spherical lens element with a convex object-side surface and a concave image-side surface; the third lens 23 has positive focal power, and both the object-side surface and the image-side surface are convex surfaces and are aspheric lenses; the fourth lens element 24 has negative focal power, and both the object-side surface and the image-side surface thereof are concave and are aspheric lenses; the fifth lens element 25 has a positive focal power, and is an aspheric lens element having a concave object-side surface and a convex image-side surface; any two lenses of the first lens 21 to the fifth lens 25 are separated from each other.

The field angle range of the optical lens group 2 is set to 163 °.

Table 4 shows the radius of curvature R, thickness T, gap G, refractive index Nd, abbe number Vd, focal length F, and material of each lens element of the optical lens group 2 of example 2, wherein the radius of curvature R, thickness T, gap G, and focal length F are all in millimeters (mm).

TABLE 4

The even-order aspheric rise formula for each mirror is defined as follows:

Table 5 shows the conic coefficients k and the respective high-order term coefficients used for the aspherical lens surfaces S3 to S10 in the present embodiment.

TABLE 5

Table 6 below shows the optical back focus BFL (i.e., the on-axis distance from the center of the image-side surface S10 of the fifth lens element 25 to the imaging surface IMA), the total length TTL (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens element 21 to the imaging surface IMA) of the optical lens group 2, the maximum aperture diameter D of the object-side surface S1 of the first lens element 21 corresponding to the maximum field angle of the optical lens group 2, the image height H corresponding to the maximum field angle of the optical lens group 2, the maximum field angle of the optical lens group, the effective focal length EFL of the optical lens group 2, and the optical focus FNO of the optical lens group 2 according to the present embodiment.

TABLE 6

EFL(mm)	1.21	D(mm)	12.16
				BFL(mm)	1.63	FOV(°)	163
TTL(mm)	11.60	FNO	2.0
				H(mm)	2.24

In this embodiment, Tmax/Tmin is 3.91, and the conditional expression is satisfied between the optical back focus BFL of the optical lens group 2 and the total optical length TTL of the optical lens group 2: BFL/TTL is 0.141; the maximum light transmission aperture D of the object-side surface S1 of the first lens element 21 corresponding to the maximum field angle and the image height H corresponding to the maximum field angle satisfy a D/H/FOV of 0.033; the total optical length TTL and the effective focal length EFL of the optical lens assembly 2 satisfy the following conditional expressions: TTL/EFL 9.587; the total optical length TTL, the maximum field angle FOV of the optical lens group 2, and the image height H corresponding to the maximum field angle of the optical lens group 2 satisfy TTL/H/FOV equal to 0.032.

The radius of curvature R1 of the object-side surface of the first lens 21 and the radius of curvature R2 of the image-side surface of the first lens 21 satisfy (R1+ R2)/(R1-R2) 1.623; the radius of curvature R3 of the object-side surface of the second lens 22 and the radius of curvature R4 of the image-side surface of the second lens 22 satisfy (R3+ R4)/(R3-R4) ═ 2.121; the radius of curvature R5 of the object-side surface of the third lens 23 and the radius of curvature R6 of the image-side surface of the third lens 23 satisfy (R5+ R6)/(R5-R6) ═ 0.474; the radius of curvature R7 of the object-side surface of the fourth lens 24 and the radius of curvature R8 of the image-side surface of the fourth lens 24 satisfy (R7+ R8)/(R7-R8) ═ 0.559; the radius of curvature R9 of the object-side surface of the fifth lens 25 and the radius of curvature R10 of the image-side surface of the fifth lens 25 satisfy (R9+ R10)/(R9-R10) ═ 1.178.

The width of the front-back space gap of the second lens 22 on the optical axis and the thickness T2 of the second lens 22 on the optical axis satisfy (G12+ G23)/T2-10.689; a front-rear space gap width of the third lens 23 on the optical axis and a thickness T3 of the third lens 23 on the optical axis satisfy (G23+ G34)/T3 equal to 1.98; a front-rear space gap width of the fourth lens 24 on the optical axis and a thickness T4 of the fourth lens 24 on the optical axis satisfy (G34+ G45)/T4 equal to 1.08; the front-rear space gap width of the fifth lens 25 on the optical axis and the thickness T5 of the fifth lens 25 on the optical axis satisfy (G45+ G56)/T5 of 0.356.

The ratio of the focal lengths of the two adjacent lenses is: F1/F2 ═ 2.584; F2/F3 ═ -2.489; F3/F4 ═ 0.913; F4/F5 ═ 0.654.

Example 3

The field angle range of the optical lens group 2 is set to 166 °.

Table 7 shows the radius of curvature R, thickness T, gap G, refractive index Nd, abbe number Vd, focal length F, and material of each lens element of the optical lens group 2 of example 3, wherein the radius of curvature R, thickness T, gap G, and focal length F are all in millimeters (mm).

TABLE 7

The even-order aspheric rise formula for each mirror is defined as follows:

Table 8 shows the conic coefficients k and the respective high-order term coefficients used for the aspherical lens surfaces S3 to S10 in the present embodiment.

TABLE 8

Table 9 below shows the optical back focus BFL (i.e., the on-axis distance from the center of the image-side surface S10 of the fifth lens element 25 to the imaging surface IMA), the total length TTL (i.e., the on-axis distance from the center of the object-side surface S1 of the first lens element 21 to the imaging surface IMA) of the optical lens group 2, the maximum aperture diameter D of the object-side surface S1 of the first lens element 21 corresponding to the maximum field angle of the optical lens group 2, the image height H corresponding to the maximum field angle of the optical lens group 2, the maximum field angle FOV of the optical lens group 2, the effective focal length EFL and the optical focus FNO of the optical lens group 2 according to the present embodiment.

TABLE 9

EFL(mm)	1.21	D(mm)	12.16
				BFL(mm)	1.63	FOV(°)	166
TTL(mm)	11.40	FNO	2.0
				H(mm)	2.24

In this embodiment, Tmax/Tmin is 6.32, and the conditional expression is satisfied between the optical back focus BFL of the optical lens group 2 and the total optical length TTL of the optical lens group 2: BFL/TTL is 0.143; the maximum light transmission aperture D of the object-side surface S1 of the first lens element 21 corresponding to the maximum field angle and the image height H corresponding to the maximum field angle satisfy a D/H/FOV of 0.033; the total optical length TTL and the effective focal length of the optical lens assembly 2 satisfy the following conditional expressions: TTL/EFL 9.421; the total optical length TTL, the maximum field angle FOV of the optical lens group 2, and the image height H corresponding to the maximum field angle of the optical lens group 2 satisfy TTL/H/FOV equal to 0.031.

The radius of curvature R1 of the object-side surface of the first lens 21 and the radius of curvature R2 of the image-side surface of the first lens 21 satisfy (R1+ R2)/(R1-R2) 1.216; the radius of curvature R3 of the object-side surface of the second lens 22 and the radius of curvature R4 of the image-side surface of the second lens 22 satisfy (R3+ R4)/(R3-R4) ═ 1.401; the radius of curvature R5 of the object-side surface of the third lens 23 and the radius of curvature R6 of the image-side surface of the third lens 23 satisfy (R5+ R6)/(R5-R6) ═ 0.473; the radius of curvature R7 of the object-side surface of the fourth lens 24 and the radius of curvature R8 of the image-side surface of the fourth lens 24 satisfy (R7+ R8)/(R7-R8) ═ 0.563; the radius of curvature R9 of the object-side surface of the fifth lens 25 and the radius of curvature R10 of the image-side surface of the fifth lens 25 satisfy (R9+ R10)/(R9-R10) ═ 1.04.

The width of the front-back space gap of the second lens 22 on the optical axis and the thickness T2 of the second lens 22 on the optical axis satisfy (G12+ G23)/T2-19.902; a front-rear space gap width of the third lens 23 on the optical axis and a thickness T3 of the third lens 23 on the optical axis satisfy (G23+ G34)/T3 of 2.103; the front-rear space gap width of the fourth lens 24 on the optical axis and the thickness T4 of the fourth lens 24 on the optical axis satisfy (G34+ G45)/T4 ═ 0.771; the front-rear space gap width of the fifth lens 25 on the optical axis and the thickness T5 of the fifth lens 25 on the optical axis satisfy (G45+ G56)/T5 of 0.257.

The ratio of the focal lengths of the two adjacent lenses is: F1/F2 ═ 3.305; F2/F3 ═ -1.560; F3/F4 ═ -0.874; F4/F5 ═ 0.776.

In summary, examples 1 to 3 each satisfy the relationship shown in table 10 below.

Watch 10

Fig. 4 is an optical path diagram of the optical lens assembly 2. FIG. 5 shows MTF (tuned to optical transfer function) values for evaluating the imaging clarity of the lens, where the MTF values range from 0 to 1, and the MTF curves represent the imaging clarity and image restoration ability of the lens. As can be seen from fig. 5, MTF curves of the fields of view are dense, which indicates that the on-vehicle lens has good consistency on the whole imaging plane IMA, imaging chromatic aberration is relatively uniform, chromatic aberration is well corrected, and the full-field-angle image quality is relatively uniform, so that high-quality and clear imaging can be performed on the whole imaging plane.

FIG. 6 is a relative illumination chart of the present invention, in which the abscissa represents the field range of the lens, and the ordinate represents the illumination value of the lens, and the value range is 0-1. It can be seen from the figure that the illumination values of the middle field and the edge field are very high and the difference value is small, which indicates that the vehicle-mounted lens has very high brightness on the whole imaging plane IMA and the brightness consistency of the central range and the edge range is good.

The above description is only a preferred embodiment of the present invention, and all equivalent changes or modifications of the structure, characteristics and principles described in the present invention are included in the scope of the present invention.

Claims

1. The utility model provides an ultra-thin vehicle-mounted camera lens, includes camera lens casing (1) and locates optical lens group (2) in camera lens casing (1), optical lens group (2) include along the optical axis from the thing side to the image side in proper order: a first lens element (21), a second lens element (22), a third lens element (23), a fourth lens element (24), and a fifth lens element (25), each having an object-side surface facing the object side and passing the image light, and an image-side surface facing the image side and passing the image light, wherein:

the first lens (21) 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 (22) has negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface;

the third lens (23) has positive focal power, and both the object side surface and the image side surface of the third lens are convex surfaces;

the fourth lens (24) has negative focal power, and both the object-side surface and the image-side surface of the fourth lens are concave;

the fifth lens (25) has positive 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 convex surface;

any two of the first lens (21) to the fifth lens (25) are separated from each other;

the optical lens group (2) satisfies the following conditional expression:

Tmax/Tmin≧3.0；

2. The ultra-thin vehicular lens according to claim 1, characterized in that: the first lens (21) is a spherical lens, and the second lens (22), the third lens (23), the fourth lens (24) and the fifth lens (25) are aspheric lenses.

3. The ultra-thin vehicular lens according to claim 1, characterized in that: a light shading mylar piece (4) is arranged between the second lens (22) and the third lens (23), between the third lens (23) and the fourth lens (24) and between the fourth lens (24) and the fifth lens (25), and a light through hole (31) for light to pass through is formed in the center of the light shading mylar piece (4); a space ring (3) is arranged between the second lens (22) and the third lens (23), and a light guide angle (32) is arranged on the inner wall of the space ring (3).

4. The ultra-thin vehicular lens according to claim 1, characterized in that: the optical back focus BFL of the optical lens group (2) and the optical total length TTL of the optical lens group satisfy the conditional expression: BFL/TTL is more than or equal to 0.13 and less than or equal to 0.15.

5. The ultra-thin vehicular lens according to claim 1, characterized in that: the optical lens group (2) satisfies the following conditional expression: D/H/FOV is more than or equal to 0.032 and less than or equal to 0.036;

d is the maximum clear aperture of the object side surface of the first lens (21) corresponding to the maximum field angle of the optical lens group (2);

h is the image height corresponding to the maximum field angle of the optical lens group (2).

6. The ultra-thin vehicular lens according to claim 1, characterized in that: the total optical length TTL of the optical lens group (2) and the effective focal length of the optical lens group (2) satisfy the following conditional expression: TTL/EFL is less than or equal to 10.0.

7. The ultra-thin vehicular lens according to claim 1, characterized in that: the optical lens group (2) satisfies the following conditional expression: TTL/H/FOV is more than or equal to 0.031 and less than or equal to 0.035.

8. The ultra-thin vehicular lens according to claim 1, characterized in that: the optical lens group (2) satisfies the following conditional expression: (R1+ R2)/(R1-R2) is not more than 1.20 and not more than 1.63; (R3+ R4)/(R3-R4) is not more than 1.39 and not more than 2.16; (R5+ R6)/(R5-R6) is not more than 0.473 and not more than 0.475; (R7+ R8)/(R7-R8) is not more than 0.55 and not more than 0.57; not less than 1.03 (R9+ R10)/(R9-R10) not more than 1.18;

wherein R1 is the curvature radius of the object side surface of the first lens (21); r2 is the curvature radius of the image side surface of the first lens (21); r3 is the curvature radius of the object side of the second lens (22); r4 is the curvature radius of the image side surface of the second lens (22); r5 is the curvature radius of the object side of the third lens (23); r6 is the curvature radius of the image side surface of the third lens (23); r7 is the curvature radius of the object side of the fourth lens (24); r8 is the curvature radius of the image side surface of the fourth lens (24); r9 is the curvature radius of the object side surface of the fifth lens (25); r10 is the curvature radius of the image side surface of the fifth lens (25).

9. The ultra-thin vehicular lens according to claim 1, characterized in that: the optical lens group (2) satisfies the following conditional expression: (G12+ G23)/T2 of more than or equal to 10.0 and less than or equal to 20.0; (G23+ G34)/T3 of not more than 1.8 and not more than 2.2; (G34+ G45)/T4 is more than or equal to 0.7 and less than or equal to 1.2;

wherein G12 denotes a spatial gap width on the optical axis between the first lens (21) and the second lens (22);

g23 denotes a space gap width on the optical axis between the second lens (22) and the third lens (23);

g34 represents a space gap width on the optical axis between the third lens (23) and the fourth lens (24);

g45 represents a space gap width on the optical axis between the fourth lens (24) and the fifth lens (25);

t2 represents the thickness of the second lens (22) on the optical axis;

t3 represents the thickness of the third lens (23) on the optical axis;

t4 represents the thickness of the fourth lens (24) on the optical axis.

10. The ultra-thin vehicular lens according to claim 1, characterized in that: the refractive indexes of the second lens (22), the third lens (23) and the fifth lens (25) are the same, and the refractive index is set to be 1.5-1.6.