Ultra-wide-angle camera lens suitable for vehicle-mounted OMS system

Abstract

The utility model relates to an ultra wide angle pick-up lens suitable for a vehicle-mounted OMS system, an optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens, the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a meniscus convex positive lens, the fourth lens is a meniscus convex positive lens, and the seventh lens is a meniscus convex positive lens. The fourth lens is a meniscus concave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconcave negative lens, the seventh lens is a biconvex positive lens, the sixth lens and the seventh lens form a cemented lens group, the first lens and the fifth lens are made of glass materials, and the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are plastic aspheric lenses. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the field angle of the lens is enlarged while the imaging performance requirement of the lens is met, so that the low-cost ultra-wide-angle camera lens suitable for a vehicle-mounted OMS system is realized.

Description

Technical field:

[0001] The utility model belongs to the technical field of lenses, and in particular relates to an ultra-wide-angle camera lens suitable for a vehicle-mounted OMS system. Background technology:

[0002] In recent years, with the continuous development of artificial intelligence technology and the iterative update of visual hardware sensors, solutions for automobile occupant monitoring systems have continued to emerge. The automobile occupant monitoring system has a high research value for the safety and experience of passengers, and has a bright development prospect. It is one of the main research routes for the transformation of intelligent driving from level L3 to level L4. The intelligent cockpit is also called the intelligent automobile occupant monitoring system (OMS). It not only includes some technologies of ADAS assisted driving, but also proposes a number of key new technologies for passengers, such as emotion recognition, forgotten object monitoring, posture recognition and gesture recognition. In addition to ensuring the safety of the driver, driving a car must also ensure the safety of the passengers in the car and the riding experience. At present, the camera lenses used in the OMS system generally use wide-angle lenses with a field of view of less than 120°. Considering the characteristics of the OMS system, the market needs an optical lens with a larger field of view to achieve the maximum acquisition of image information in the car, which often increases the number of lenses and uses more glass sheets. Therefore, cost has become one of the reasons that affect the popularity. Utility model content:

[0003] The present invention aims to improve upon the problems existing in the prior art, that is, to provide an ultra-wide-angle camera lens suitable for an on-board OMS system, which has a reasonable design, a larger field of view and a lower cost while achieving clear imaging.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an ultra-wide-angle camera lens suitable for a vehicle-mounted OMS system, the optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens arranged in sequence from left to right along the incident light path of the light, the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a meniscus convex positive lens, the fourth lens is a meniscus concave negative lens, the fifth lens is a double convex positive lens, the sixth lens is a double concave negative lens, the seventh lens is a double convex positive lens, the sixth lens and the seventh lens are glued together to form a glued lens group, the first lens and the fifth lens are both made of glass material, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are all made of plastic material and are 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 convex, and the image side surface is concave; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is concave, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is convex; the object side surface of the sixth lens is concave, and the image side surface is concave; the object side surface of the seventh lens is convex, and the image side surface is convex.

[0006] Furthermore, the axial distances between the lenses satisfy the following relationship: the air gap between the first lens and the second lens is: 1.0~1.5mm; the air gap between the second lens and the third lens is: 0.0~0.5mm; the air gap between the third lens and the fourth lens is: 0.0~0.5mm; the air gap between the fourth lens and the aperture is: 0.0~0.5mm; the air gap between the aperture and the fifth lens is: 0.0~0.5mm; the air gap between the fifth lens and the sixth lens is: 0.0~0.5mm.

[0007] Furthermore, 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, the fifth lens, the sixth lens, and the seventh lens are f1, f2, f3, f4, f5, f6, and f7, respectively, wherein f1, f2, f3, f4, f5, f6, and f7 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,-14.0<f2 / f<-13.0,2.0<f3 / f<3.0,-10.0<f4 / f<-9.0,1.0<f5 / f<2.0,-1.0<f6 / f<0.0,1.0<f7 / f<2.0。

[0008] Furthermore, the first lens satisfies the relationship: 2.0≤N d ≤2.5, 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: 1.7≤N d ≤2.0, V d ≥50.0; the sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d is the refractive index, Vd is the Abbe constant.

[0009] Furthermore, the aspheric curve equations of the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are expressed as follows:

[0010]

[0011] Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

[0012] Furthermore, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤6.

[0013] Furthermore, the F number of the optical system is ≤2.0.

[0014] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0015] Compared with the prior art, the utility model has the following effects: the utility model expands the field of view of the lens while meeting the imaging performance requirements of the lens by reasonably allocating the optical focal length, surface shape, center thickness of each lens and axial distance between each lens, so as to realize a low-cost ultra-wide-angle camera lens suitable for the vehicle-mounted OMS system; the imaging angle of the lens to the object is greater than 144 degrees, and it has the advantages of high imaging clarity, large light aperture, low tolerance sensitivity and good high and low temperature stability, and can monitor the scene inside the vehicle more comprehensively. Description of the drawings:

[0016] Figure 1 It is a schematic diagram of the optical structure of an embodiment of the utility model;

[0017] Figure 2 This is a full-band axial chromatic aberration diagram of an embodiment of the utility model;

[0018] Figure 3 This is a vertical axis chromatic aberration diagram of the full working band of an embodiment of the utility model;

[0019] Figure 4 This is a field curvature distortion diagram for the entire working band of an embodiment of the utility model.

[0020] In the figure:

[0021] L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; STO-aperture; L5-fifth lens; L6-sixth lens; L7-seventh lens; L8-filter; L9-protective effect glass; IMA-imaging surface. Specific implementation method:

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] like Figure 1 As shown, the utility model is an ultra-wide-angle camera lens suitable for a vehicle-mounted OMS system, the optical system of the lens consists of a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along the incident light path of the light, without considering the backcurvature caused by the aspheric coefficient, the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a meniscus convex positive lens, the fourth lens is a meniscus concave negative lens, the fifth lens is a double convex positive lens, the sixth lens is a double concave negative lens, and the seventh lens is a double convex positive lens, wherein the sixth lens and the seventh lens are glued together to form a glued lens group, wherein the first lens and the fifth lens are both made of glass material, and the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are all made of plastic material and are aspheric lenses.

[0024] In this embodiment, 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 convex, and the image side surface is concave; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is concave, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is convex; the object side surface of the sixth lens is concave, and the image side surface is concave; the object side surface of the seventh lens is convex, and the image side surface is convex.

[0025] In this embodiment, the axial distances between the lenses satisfy the following relationship: the air gap between the first lens and the second lens is: 1.0~1.5mm; the air gap between the second lens and the third lens is: 0.0~0.5mm; the air gap between the third lens and the fourth lens is: 0.0~0.5mm; the air gap between the fourth lens and the aperture is: 0.0~0.5mm; the air gap between the aperture and the fifth lens is: 0.0~0.5mm; the air gap between the fifth lens and the sixth lens is: 0.0~0.5mm.

[0026] In this embodiment, 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, the fifth lens, the sixth lens, and the seventh lens are f1, f2, f3, f4, f5, f6, and f7, respectively, wherein f1, f2, f3, f4, f5, f6, and f7 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,-14.0<f2 / f<-13.0,2.0<f3 / f<3.0,-10.0<f4 / f<-9.0,1.0<f5 / f<2.0,-1.0<f6 / f<0.0,1.0<f7 / f<2.0。

[0027] In this embodiment, the first lens satisfies the relationship: 2.0≤N d ≤2.5, 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: 1.7≤N d ≤2.0, V d ≥50.0; the sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

[0028] In this embodiment, the aspheric curve equations of the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are expressed as follows:

[0029]

[0030] Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

[0031] Specifically, the aspheric coefficients of each aspheric lens of the optical system are as follows:

[0032]

[0033] In this embodiment, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤6.

[0034] In this embodiment, the F number of the optical system is ≤2.0.

[0035] In this embodiment, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0036] The optical system of this embodiment satisfies the requirements of ultra-wide angle and low cost while meeting the requirements of lens imaging performance by reasonably allocating the optical power, surface shape, center thickness of each lens and axial distance between lenses.

[0037] In this embodiment, the first lens and the second lens are both glass spherical lenses with negative focal length, which can reduce the distortion of the optical system while adjusting the light at a large angle. And because they are made of glass materials, they can better adapt to complex conditions. The sixth lens and the seventh lens form an achromatic doublet. Reasonable lens matching enables the optical system to achieve ultra-wide angle, low cost, large aperture, day and night confocal, and low temperature drift design. At the same time, the on-axis and off-axis aberrations are well corrected, and the imaging quality is good. Figures 2 to 4 shown.

[0038] The technical indicators achieved by the optical system of this embodiment are as follows:

[0039] (1) Focal length: 2.0 ≤ EFFL ≤ 3.0 mm;

[0040] (2) Aperture F ≤ 2.0;

[0041] (3) Field of view: 2w ≥ 144°;

[0042] (4) Working band: visible light band and 850nm short infrared band.

[0043] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0044]

[0045] In this embodiment, when the ultra-wide-angle camera lens suitable for the vehicle-mounted OMS system forms an image: the light path sequentially enters the first lens, the second lens, the third lens, the fourth lens, the aperture, the fifth lens, the sixth lens, the seventh lens, the filter and the protective glass to form an image.

[0046] The advantages of the utility model are:

[0047] 1. The imaging angle of the lens to the object is greater than 144 degrees. It has the advantages of high imaging clarity, large aperture, low tolerance sensitivity and good high and low temperature stability. At the same time, it can monitor the scene inside the car more comprehensively.

[0048] 2. Through the reasonable matching of optical lenses, the system structure is compact and reasonable, easy to assemble, with low tolerance sensitivity, and more suitable for large-scale high-yield production;

[0049] 3. The optical structure of glass-plastic hybrid, which is composed of two glass spherical lenses and five plastic aspherical lenses, gives full play to the advantages of aspherical lenses in correcting aberrations. While meeting the requirements of high-definition imaging, it has a smaller lens outer diameter and a shorter total optical length, ensuring the miniaturization of the lens.

[0050] 4. Corrected various axial chromatic aberrations, vertical chromatic aberrations and high-order chromatic aberrations to ensure that the imaging system can have high imaging quality even at large angles;

[0051] 5. By introducing plastic aspheric surfaces, the cost is greatly reduced while ensuring high and low temperature stability.

[0052] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except where it is obviously impossible to use an one-piece molding process).

[0053] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the above utility model include states or shapes that are approximate, similar or close thereto.

[0054] Any component provided by the utility model can be assembled from multiple separate components, or can be a separate component manufactured by an integrated molding process.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the utility model, which should be included in the scope of the technical solution for protection of the utility model.

Claims

1. An ultra-wide-angle camera lens suitable for an in-vehicle OMS system, characterized in that: The optical system of the lens consists of a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along the incident light path of the light; the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a meniscus convex positive lens, the fourth lens is a meniscus concave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconcave negative lens, the seventh lens is a biconvex positive lens, the sixth lens and the seventh lens are cemented to form a cemented lens group, the first lens and the fifth lens are both made of glass material, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are all made of plastic material and are aspherical lenses.

2. The ultra-wide-angle camera lens suitable for an in-vehicle OMS system 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 convex, and the image side surface is concave; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is concave, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is convex; the object side surface of the sixth lens is concave, and the image side surface is concave; the object side surface of the seventh lens is convex, and the image side surface is convex.

3. The ultra-wide-angle camera lens suitable for an on-vehicle OMS system according to claim 2, characterized in that: The axial distances between the lenses satisfy the following relationship: the air gap between the first lens and the second lens is 1.0 to 1.5 mm; the air gap between the second lens and the third lens is 0.0 to 0.5 mm; the air gap between the third lens and the fourth lens is 0.0 to 0.5 mm; the air gap between the fourth lens and the aperture is 0.0 to 0.5 mm; the air gap between the aperture and the fifth lens is 0.0 to 0.5 mm; the air gap between the fifth lens and the sixth lens is 0.0 to 0.5 mm.

4. The ultra-wide-angle camera lens suitable for an on-vehicle OMS system according to claim 2, characterized in that: 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, the fifth lens, the sixth lens, and the seventh lens are f1, f2, f3, f4, f5, f6, and f7, respectively, where f1, f2, f3, f4, f5, f6, and f7 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,-14.0<f2 / f<-13.0,2.0<f3 / f<3.0,-10.0<f4 / f<-9.0,1.0<f5 / f<2.0,-1.0<f6 / f<0.0,1.0<f7 / f<2.0。 5. The ultra-wide-angle camera lens suitable for an in-vehicle OMS system according to claim 1, characterized in that: The first lens satisfies the relationship: 2.0≤N d ≤2.5, 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: 1.7≤N d ≤2.0, V d ≥50.0; the sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

6. The ultra-wide-angle camera lens suitable for an in-vehicle OMS system according to claim 1, characterized in that: The aspheric curve equations of the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are as follows: Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

7. The ultra-wide-angle camera lens suitable for an in-vehicle OMS system according to claim 1, characterized in that: The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤6.

8. The ultra-wide-angle camera lens suitable for an in-vehicle OMS system 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 an in-vehicle OMS system 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≥1.0.

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