All-weather wide-angle cabin camera lens

Abstract

This invention relates to an all-weather wide-angle in-cabin camera lens. The lens's optical system comprises a first lens, a second lens, an aperture stop, a third lens, a fourth lens, and a fifth lens arranged sequentially from left to right along the incident light path. The first lens is a meniscus negative lens, the second lens is a meniscus positive lens, the third lens is a biconvex positive lens, the fourth lens is a meniscus negative lens, and the fifth lens is a biconvex positive lens. The first and third lenses are both glass spherical lenses, while the second, fourth, and fifth lenses are all plastic aspherical lenses. This invention features a rational design, employing a hybrid glass-plastic optical structure consisting of two glass spherical lenses and three plastic aspherical lenses. This fully utilizes the aberration correction advantages of aspherical lenses, achieving high-definition imaging while maintaining a smaller lens outer diameter and shorter overall optical length, thus ensuring lens miniaturization.

Description

Technical fields:

[0001] This invention belongs to the field of lens technology, and in particular relates to an all-weather wide-angle cabin camera lens. Background technology:

[0002] OMS, or Passenger Monitoring System, uses cameras to recognize passengers' faces and provides a user-friendly, intelligent experience. After facial recognition, passengers can personalize their settings using their current facial account, such as seat position, angle, and ventilation. It can also monitor passenger behavior and gaze in real time, and control the sunroof, air conditioning, side windows, and seat movement using eye-tracking control. When leaving the vehicle and closing the door, it can detect if any children or pets are left inside and send a notification to the owner. It also enables remote monitoring and other functions.

[0003] The camera lens of this type of system is mainly installed in the position of the inner rearview mirror. Since the inner rearview mirror has a very compact structure, the optical lens used in the OMS system not only needs to have high image quality, high and low temperature stability, day and night confocal and wide-angle characteristics, but also needs to meet the characteristics of miniaturization. Summary of the Invention:

[0004] The present invention addresses the problems existing in the prior art, namely, the technical problem to be solved by the present invention is to provide an all-weather wide-angle cabin camera lens.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an all-weather wide-angle cabin camera lens, the optical system of which consists of a first lens, a second lens, an aperture stop, a third lens, a fourth lens, and a fifth lens arranged sequentially from left to right along the incident light path. The first lens is a meniscus negative lens, the second lens is a meniscus positive lens, the third lens is a biconvex positive lens, the fourth lens is a meniscus negative lens, and the fifth lens is a biconvex positive lens. The first and third lenses are both glass spherical lenses, and the second, fourth, and fifth lenses are all plastic aspherical lenses.

[0006] Furthermore, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the second lens is concave, and the image-side surface is convex; the object-side surface of the fourth lens is convex near the optical axis, and the image-side surface is concave near the optical axis.

[0007] Furthermore, the air gap between the first lens and the second lens is 1.45–1.7 mm; the air gap between the second lens and the third lens is 0.1–0.3 mm; the air gap between the third lens and the fourth lens is 0.01–0.1 mm; and the air gap between the fourth lens and the fifth lens is 0.2–0.45 mm.

[0008] Furthermore, the focal length of the optical system is f, and the focal lengths of the first lens, second lens, third lens, fourth lens, and fifth lens are f1, f2, f3, f4, and f5, respectively, where f1, f2, f3, f4, and f5 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,5.0<f2 / f<6.0,1.0<f3 / f<2.0,-2.0<f4 / f<-1.0,1.0<f5 / f<2.0。

[0009] Furthermore, the first lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The second lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The third lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; The fourth lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The fifth lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; where N d V is the refractive index. d Let be Abbe's constant.

[0010] Furthermore, the equations for the aspherical curves of the second, fourth, and fifth lenses are as follows:

[0011]

[0012] Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0013] Furthermore, the total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 6.0.

[0014] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f ≥ 2.0.

[0015] Furthermore, the refractive index temperature coefficients dn / dt of the first and third lenses are <0.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed. The lens adopts a design of 2 glass lenses and 3 plastic lenses, which gives full play to the advantages of aspherical lenses in correcting aberrations. It meets the optical performance requirements such as high resolution and high and low temperature stability, while also meeting the requirements of wide angle of view and day and night confocal focus. The overall length of the lens is also smaller. Attached image description:

[0017] Figure 1 This is a schematic diagram of the optical structure according to an embodiment of the present invention;

[0018] Figure 2 This is an axial chromatic aberration diagram of the entire working band of this invention.

[0019] Figure 3 This is a cross-axis chromatic aberration diagram of the entire working band of this invention.

[0020] Figure 4 This is a field curvature distortion diagram of the entire working band according to an embodiment of the present invention.

[0021] In the picture:

[0022] L1 - First lens; L2 - Second lens; STO - Aperture stop; L3 - Third lens; L4 - Fourth lens; L5 - Fifth lens; L6 - Equivalent glass plate; IMA - Imaging surface. Detailed implementation method:

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, this invention discloses an all-weather wide-angle in-cabin camera lens. The optical system of the lens consists of a first lens L1, a second lens L2, an aperture stop STO, a third lens L3, a fourth lens L4, and a fifth lens L5 arranged sequentially from left to right along the incident light path. The first lens is a meniscus negative lens with a convex object-side surface and a concave image-side surface. The second lens is a meniscus positive lens with a concave object-side surface and a convex image-side surface. The third lens is a biconvex positive lens. The fourth lens is a meniscus negative lens with a convex object-side surface near the optical axis and a concave image-side surface near the optical axis. The fifth lens is a biconvex positive lens. The lenses are made of glass and plastic materials, wherein the first and third lenses are glass spherical lenses, and the second, fourth, and fifth lenses are plastic aspherical lenses. The optical structure employs a hybrid glass-plastic structure consisting of two glass spherical lenses and three plastic aspherical lenses. This achieves high image quality, high and low temperature stability, day and night co-focus, and wide-angle characteristics, while also satisfying the advantages of a small size and taking into account the aesthetics of the lens.

[0025] In this embodiment, the air gap between the first lens and the second lens is 1.45–1.7 mm; the air gap between the second lens and the third lens is 0.1–0.3 mm; the air gap between the third lens and the fourth lens is 0.01–0.1 mm; and the air gap between the fourth lens and the fifth lens is 0.2–0.45 mm.

[0026] In this embodiment, the focal length of the optical system is f, and the focal lengths of the first lens, second lens, third lens, fourth lens, and fifth lens are f1, f2, f3, f4, and f5, respectively, wherein f1, f2, f3, f4, and f5 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,5.0<f2 / f<6.0,1.0<f3 / f<2.0,-2.0<f4 / f<-1.0,1.0<f5 / f<2.0。

[0027] In this embodiment, the first lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The second lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The third lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; The fourth lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The fifth lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; where N d V is the refractive index. d Let be Abbe's constant.

[0028] In this embodiment, the equations for the aspherical curves of the second lens, the fourth lens, and the fifth lens are as follows:

[0029]

[0030] Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0031] In this embodiment, the aspherical coefficients of each aspherical lens in the optical system are shown in the following table:

[0032]

[0033] In this embodiment, the total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 6.0.

[0034] In this embodiment, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f≥2.0.

[0035] In this embodiment, the refractive index temperature coefficients dn / dt of the first lens and the third lens are <0.

[0036] In this embodiment, the aperture of the optical system is located between the second lens and the third lens, and an equivalent glass plate L6 is provided on the rear side of the fifth lens.

[0037] In this embodiment, the technical specifications achieved by the optical system are as follows:

[0038] (1) Focal length: 3.0≤EFFL≤4.0mm;

[0039] (2) Aperture F≤2.4;

[0040] (3) Field of view: 2w ≥ 120°;

[0041] (4) Operating bands: visible light band and 940nm band.

[0042] To achieve the above design parameters, the specific design of the optical system adopted in this embodiment is shown in the table below:

[0043]

[0044] In this embodiment, the optical system achieves high image quality, high and low temperature stability, day and night confocality, and wide-angle characteristics, while also satisfying the advantages of small size and taking into account the aesthetics of the lens.

[0045] In this embodiment, as Figures 2 to 4 As shown, the lens fully utilizes the advantages of aspherical lenses in correcting aberrations, achieving high-definition imaging while having a smaller lens outer diameter and a shorter overall optical length, ensuring the miniaturization of the lens.

[0046] The advantages of this invention are:

[0047] (1) The optical structure of glass-plastic hybrid is adopted, which consists of two glass spherical lenses and three plastic aspherical lenses. This fully utilizes the advantages of aspherical lenses in correcting aberrations, meets the requirements of high-definition imaging, and has a smaller lens outer diameter and shorter optical length, thus ensuring the miniaturization of the lens.

[0048] (2) Adjusting the surface shape of the aspherical plastic lens allows for clear imaging under infrared light conditions without refocusing when visible light imaging is clear, achieving confocal functionality day and night. Combined with a 4MP, 1 / 2.7-inch chip, it can meet the requirement of relative illumination of over 60% at the edge of the field of view;

[0049] (3) While meeting all optical performance indicators, based on the relationship between the refractive index of the material and temperature, the first and third lenses adopt a negative temperature coefficient of refractive index. At the same time, considering the back focus compensation function of the rear lens mount, it is ensured that the back focus shift is minimal at working temperatures from -40℃ to 80℃, and high-definition imaging is still possible.

[0050] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0051] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0052] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An all-weather wide-angle cabin camera lens, characterized in that: The optical system of the lens consists of a first lens, a second lens, an aperture, a third lens, a fourth lens, and a fifth lens arranged in sequence from left to right along the light incident optical path. The first lens is a meniscus negative lens, the second lens is a meniscus positive lens, the third lens is a biconvex positive lens, the fourth lens is a meniscus negative lens, and the fifth lens is a biconvex positive lens. Both the first lens and the third lens are glass spherical lenses, while the second lens, the fourth lens, and the fifth lens are plastic aspherical lenses. The air gap between the first lens and the second lens is 1.45 mm to 1.7 mm; the air gap between the second lens and the third lens is 0.1 mm to 0.3 mm; the air gap between the third lens and the fourth lens is 0.01 mm to 0.1 mm; the air gap between the fourth lens and the fifth lens is 0.2 mm to 0.45 mm. The focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are f1, f2, f3, f4, and f5 respectively, where f1, f2, f3, f4, and f5 satisfy the following ratios with f: -2.0 < f1 / f < -1.0, 5.0 < f2 / f < 6.0, 1.0 < f3 / f < 2.0, -2.0 < f4 / f < -1.0, 1.0 < f5 / f < 2.

0. The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 6.

0.

2. The all-weather wide-angle cabin camera lens according to claim 1, characterized in that: The object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is concave, and the image side surface is convex; the object side surface of the fourth lens in the region near the optical axis is convex, and the image side surface in the region near the optical axis is concave.

3. The all-weather wide-angle cabin camera lens according to claim 1, characterized in that: The first lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The second lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The third lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; The fourth lens satisfies the following relationship: N d ≥1.5, V d ≤50.0; The fifth lens satisfies the following relationship: N d ≥1.5, V d ≥50.0; where N d V is the refractive index. d Let be Abbe's constant.

4. The all-weather wide-angle cabin camera lens according to claim 1, characterized in that: The expressions of the aspheric curve equations of the second lens, the fourth lens, and the fifth lens are: Where z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, r=1 / c; k is the conic constant; a1, a2, a3, a4, a5, a6, a7, and a8 are all higher-order coefficients.

5. The all-weather wide-angle cabin camera lens according to claim 1, characterized in that: The image height H of the optical system and the focal length f of the optical system satisfy: H / f ≥ 2.

0.

6. The all-weather wide-angle cabin camera lens according to claim 1, characterized in that: The refractive index temperature coefficients dn / dt of the first lens and the third lens are less than 0.

Images