An ultra-wide-angle camera lens suitable for vehicle-mounted OMS system

Abstract

The utility model relates to a kind of ultra-wide-angle camera lens suitable for vehicle-mounted OMS system, the optical system of lens is sequentially arranged by first lens, second lens, diaphragm, third lens, fourth lens and fifth lens from left to right along light incident path, first lens is meniscus concave negative lens, second lens is meniscus concave negative lens, third lens is double convex positive lens, fourth lens is double convex positive lens, fifth lens is meniscus concave negative lens, fourth lens and fifth lens form achromatic double cemented lens, first lens and third lens are made of glass material and are spherical lens, second lens, fourth lens and fifth lens are plastic aspherical lens. The optical structure of two glass spherical lenses plus three plastic aspherical lenses of glass-plastic hybrid is adopted, the advantage of aspherical lens correction aberration is fully exerted, high-definition imaging is satisfied, smaller lens outer diameter and shorter optical total length are had, the miniaturization of lens is guaranteed.

Description

Technical Field

[0001] This utility model belongs to the field of lens technology, and in particular relates to an ultra-wide-angle camera lens suitable for vehicle OMS systems. Background Technology

[0002] In recent years, with the continuous development of artificial intelligence technology and the iterative updates of visual hardware sensors, solutions for automotive occupant monitoring systems have emerged. Automotive occupant monitoring systems have high research value for passenger safety and experience, and their development prospects are bright. They are one of the main research routes for the transition of intelligent driving from Level 3 to Level 4. The intelligent cockpit, also known as an intelligent vehicle occupant monitoring system (OMS), not only incorporates some technologies of ADAS (Advanced Driver Assistance Systems) but also proposes several key new technologies for passengers, such as emotion recognition, lost object detection, posture recognition, and gesture recognition. Driving a car requires not only ensuring driver safety but also the safety and riding experience of passengers. Currently, the cameras used in OMS systems generally employ wide-angle lenses with a field of view of less than 120°. Considering the characteristics of OMS systems, the market needs optical lenses with a larger field of view to maximize the acquisition of in-vehicle image information. This often leads to an increase in the number of lenses and the use of more glass elements, thus cost is one of the factors affecting its widespread adoption. Utility Model Content

[0003] This utility model addresses the problems existing in the prior art by providing an ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems. The lens is reasonably designed and achieves clear imaging while having a larger field of view and lower cost.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: an ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems. The optical system of the lens 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 negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, and the fifth lens is a meniscus negative lens. The fourth and fifth lenses form an achromatic cemented doublet lens. The first and third lenses are both made of glass and are spherical lenses, while the second, fourth, and fifth lenses are all plastic aspherical lenses.

[0005] 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 third lens is convex, and the image-side surface is convex; the object-side surface of the fourth lens is convex, and the image-side surface is convex; and the object-side surface of the fifth lens is concave, and the image-side surface is convex.

[0006] Furthermore, the on-axis distances between the lenses satisfy the following relationships: the air gap between the first and second lenses is 4.0–4.5 mm; the air gap between the second lens and the aperture stop is 0.0–0.5 mm; the air gap between the aperture stop and the third lens is 0.0–0.5 mm; the air gap between the third and fourth lenses is 0.0–0.5 mm; and the fourth and fifth lenses are cemented sheets with a 0 mm air gap. Reducing the distance between the lenses while meeting imaging requirements is beneficial to the overall optical length of the lens.

[0007] Furthermore, the focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, and fifth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 ,in f 1 , f 2 , f 3 , f 4 , f 5 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -4.0< f 2 / f <-3.0, 2.0< f 3 / f <3.0, 1.0< f 4 / f <2.0, -2.0< f 5 / f <-1.0.

[0008] Furthermore, the first lens satisfies the relation: 1.7 ≤ N d ≤2.0, V d ≤50.0; The second lens satisfies the relationship: 1.5≤ N d ≤1.8, Vd ≤50.0; The third lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fourth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≤50.0; where N d For refractive index, V d Let be Abbe's constant.

[0009] Furthermore, the equations for the aspherical curves of the second, fourth, and fifth lenses are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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.

[0010] 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 ≤ 7.0.

[0011] Furthermore, the F-number of the optical system is ≤2.0.

[0012] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f ≥ 1.3.

[0013] Furthermore, an equivalent glass plate is provided on the right side of the fifth lens.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed and adopts a glass-plastic hybrid optical structure consisting of two glass spherical lenses and three plastic aspherical lenses. It fully utilizes the advantages of aspherical lenses in correcting aberrations, meets the requirements of high-definition imaging, has a smaller lens outer diameter and a shorter overall optical length, ensures lens miniaturization, and achieves clear imaging while having a larger field of view and lower cost. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the optical structure of an embodiment of the present invention; Figure 2 This is the axial chromatic aberration diagram of the entire working band of this utility model embodiment; Figure 3 This is a cross-axis chromatic aberration diagram of the entire working band of this utility model embodiment; Figure 4 This is a field curvature distortion diagram of the entire working band of this utility model embodiment.

[0016] In the picture: STO - Aperture stop; L1 - First lens; L2 - Second lens; L3 - Third lens; L4 - Fourth lens; L5 - Fifth lens; L6 - Equivalent glass plate; IMA - Imaging surface. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] like Figure 1 As shown, this utility model discloses an ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems. The optical system of the lens 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. Without considering the curvature caused by aspherical coefficients, 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 negative lens with a concave object-side surface and a convex image-side surface; the third lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fourth lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; and the fifth lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface. The fourth and fifth lenses form a cemented lens. The first and third lenses are both made of glass and are spherical lenses, while the second, fourth, and fifth lenses are all plastic aspherical lenses.

[0020] In this embodiment, the first and third lenses are spherical lenses with negative optical power, which adjust large-angle light while reducing optical system distortion. The fourth and fifth lenses form an achromatic cemented doublet. This reasonable lens combination enables the optical system to achieve ultra-wide-angle, low-cost, large-aperture, day-night confocal, and low-temperature drift design, while also providing good correction for on-axis and off-axis aberrations, resulting in good image quality. Figures 2 to 4 As shown.

[0021] In this embodiment, the on-axis distances between the lenses satisfy the following relationships: the air gap between the first and second lenses is 4.0–4.5 mm; the air gap between the second lens and the aperture stop is 0.0–0.5 mm; the air gap between the aperture stop and the third lens is 0.0–0.5 mm; the air gap between the third and fourth lenses is 0.0–0.5 mm; and the fourth and fifth lenses are cemented sheets with a 0 mm air gap. Reducing the distance between the lenses while meeting imaging requirements is beneficial to the overall optical length of the lens.

[0022] In this embodiment, the focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, and fifth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 ,in f 1 , f 2 , f 3 , f 4 , f 5 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -4.0< f 2 / f <-3.0, 2.0< f 3 / f <3.0, 1.0< f 4 / f <2.0, -2.0< f 5 / f <-1.0.

[0023] In this embodiment, the first lens satisfies the relationship: 1.7 ≤ N d ≤2.0, V d ≤50.0; The second lens satisfies the relationship: 1.5≤ N d ≤1.8, Vd ≤50.0; The third lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fourth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≤50.0; where N d For refractive index, V d Let be Abbe's constant.

[0024] In this embodiment, the equations for the aspherical curves of the second lens, the fourth lens, and the fifth lens are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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.

[0025] 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 ≤ 7.0.

[0026] In this embodiment, the F-number of the optical system is ≤2.0.

[0027] 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≥1.3.

[0028] In this embodiment, an equivalent glass plate is provided on the right side of the fifth lens.

[0029] In this embodiment, the technical specifications achieved by the lens's optical system are as follows: (1) Effective focal length: 2.0≤EFFL≤3.0mm; (2) Aperture F≤2.0; (3) Field of view: 2w ≥ 160°; (4) Operating bands: visible light band and 850nm short infrared band.

[0030] To achieve the above technical specifications, the specific design of the optical system in this embodiment is shown in the table below: .

[0031] The aspherical coefficients of the aspherical lenses in the optical system of this embodiment are shown in the table below: .

[0032] In this embodiment, the optical system, by rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis distance between each lens, expands the field of view of the lens while meeting the lens imaging performance requirements, thus satisfying the requirements of ultra-wide angle and low cost, and making it suitable for automotive OMS systems.

[0033] The advantages of this utility model are: 1. This lens has an imaging angle of more than 160 degrees, and also has the advantages of high imaging clarity, large light aperture, low tolerance sensitivity and good high and low temperature stability. At the same time, it can monitor the scene inside the vehicle more comprehensively. 2. By rationally matching the various optical lenses, the system structure is compact and reasonable, easy to assemble, has low tolerance sensitivity, and is more suitable for large-scale high-yield production; 3. It adopts a glass-plastic hybrid optical structure consisting of two glass spherical lenses and three plastic aspherical lenses, which fully utilizes the aberration correction advantages of aspherical lenses to meet high-definition imaging requirements while having a smaller lens outer diameter and a shorter overall optical length, thus ensuring lens miniaturization. 4. Corrected chromatic aberration along each axis, transverse chromatic aberration, and higher-order chromatic aberrations to ensure high imaging quality even at large angles; 5. By introducing plastic aspherical surfaces, costs are greatly reduced while ensuring high and low temperature stability.

[0034] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0035] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0036] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model 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 this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. An ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems, characterized in that: The optical system of the lens 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 negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, and the fifth lens is a meniscus negative lens. The fourth and fifth lenses form an achromatic cemented doublet lens. The first and third lenses are both made of glass and are spherical lenses, while the second, fourth, and fifth lenses are all plastic aspherical lenses.

2. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The first lens has a convex object-side surface and a concave image-side surface; the second lens has a concave object-side surface and a convex image-side surface; the third lens has a convex object-side surface and a convex image-side surface; the fourth lens has a convex object-side surface and a convex image-side surface; and the fifth lens has a concave object-side surface and a convex image-side surface.

3. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 2, characterized in that: The on-axis distances between the lenses satisfy the following relationships: the air gap between the first and second lenses is 4.0–4.5 mm; the air gap between the second lens and the aperture stop is 0.0–0.5 mm; the air gap between the aperture stop and the third lens is 0.0–0.5 mm; the air gap between the third and fourth lenses is 0.0–0.5 mm; and the fourth and fifth lenses are cemented sheets with an air gap of 0 mm.

4. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, and fifth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 ,in f 1 , f 2 , f 3 , f 4 , f 5 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -4.0< f 2 / f <-3.0, 2.0< f 3 / f <3.0, 1.0< f 4 / f <2.0, -2.0< f 5 / f <-1.

0.

5. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The first lens satisfies the relation: 1.7 ≤ N d ≤2.0, V d ≤50.0; The second lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≤50.0; The third lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fourth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≤50.0; where N d For refractive index, V d Let be Abbe's constant.

6. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The equations for the aspherical curves of the second, fourth, and fifth lenses are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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.

7. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The total optical length (TTL) of an optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 7.

0.

8. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: The F-number of the optical system is ≤2.

0.

9. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems 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 the following condition: H / f≥1.

3.

10. The ultra-wide-angle camera lens suitable for vehicle-mounted OMS systems according to claim 1, characterized in that: An equivalent glass plate is provided on the right side of the fifth lens.

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