Rear view lens and camera module

Abstract

The invention discloses a rear-view lens and a camera module. The rear-view lens adopts nine glass lenses. Through the reasonable matching of the surface shape and the optical focal length of each lens, and the matching of spherical and aspherical lenses, the direction of light in different fields of view is controlled. The rear-view lens has the effects of a large field of view angle (half field of view angle of 95°), high resolution (the central area transfer function MTF is between 0.2 and 0.7 when the spatial frequency is 160lp / mm), and the magnification of the central area is greater than that of the peripheral area. In addition, the rear-view lens has a large image plane (half image height of 4.9mm), a large amount of light entering the lens (F#=1.8), and good temperature stability (all-glass lens), thereby meeting the use requirements of vehicle-mounted products.

Description

Technical Field

[0001] The invention relates to an optical lens, and in particular to a rear-view lens and a camera module. Background Art

[0002] With the development of assisted driving technology, consumers and car manufacturers have put forward higher and higher requirements for the performance of electronic rearview mirrors. For example, in order to solve the problem of blind spots, designers usually use wide-angle lenses to obtain road information within a larger field of view, but the resolution is low and the details are recorded less; using a telephoto lens can obtain more distant details, but the field of view is small; the combination of a wide-angle lens and a telephoto lens can achieve both a large field of view and high resolution, but each lens needs to be equipped with a separate image sensor, which will increase costs and is not conducive to the practical application of electronic rearview mirrors.

[0003] For example, the Chinese invention patent with announcement number CN107728293B provides a high-pixel ultra-wide-angle optical system, which achieves a wide viewing angle (half field angle of 100°) and high pixels (MTF of the full field of view is between 0.2 and 0.7 at a spatial frequency of 120lp / mm) through a combination of eight lenses, but has a large F number (F#=2), a small aperture, and weak night vision. The invention patent with international application publication number WO2024151088A provides four eight-piece rearview optical systems, which have the characteristics of a large field of view (half field angle of 90°) and high resolution, but a small image height (half image height of 4.32mm), and the edge distortion of the last aspherical lens is too large, which is not conducive to lens manufacturing.

[0004] In actual use, it is not necessary to maintain a high imaging resolution in the entire field of view. Usually, different scenes are displayed in different areas according to the actual surrounding conditions of the vehicle when it is driving, such as the wide-angle field of view behind the vehicle and the main field of view behind the vehicle. Different requirements are set for different areas, which can ensure the image quality while controlling the cost. The relevant standards stipulate the field of view of the electronic rearview mirror, requiring that the rearview mirror device should be able to see specific areas on the horizontal road surface, provide road signs and vehicle conditions on the road, and provide protection for safe driving.

[0005] The field of view requirements of electronic rearview mirrors are described in the relevant national standard "GB 15084-2022". For example, a Class II device with a main external field of view should be able to see an area 5 meters wide on the horizontal road surface on the driver's side, extending from 30 meters behind the driver's eye point to the horizon, and an area 4 meters behind the driver's eye point and 1 meter wide extending to the rear; a Class IV device with a wide-angle field of view should be able to see an area 15 meters wide on the horizontal road surface on the driver's side, extending to at least 10 to 25 meters behind the driver's eye point, and an area 1.5 meters behind the driver's eye point and 4.5 meters wide extending to the rear.

[0006] At the same time, many patents have expanded the application of the field of view of electronic rearview mirrors. For example, the Chinese invention patent with the announcement number CN113401059B proposes a method for cutting and splicing multiple camera images to solve the problem of blind spots when the vehicle turns or reverses, and defines the proportion of the vehicle body in the display image; the Chinese invention patent with the announcement number CN110228414B further proposes a camera view segmentation method based on the vehicle body line and the center line of the view, and the ratio of dividing the ground area and the ground area in the vertical direction is 3:1 to 1:1, and the ratio of dividing the vehicle exterior area and the vehicle body area in the horizontal direction is 5:1 to 2:1; the Chinese invention patent with the announcement number CN109353275B proposes a transparent film attached to the display screen based on the above-mentioned partition concept, the horizontal marking line on the film divides the ground area and the ground area, and the vertical marking line divides the vehicle body area and the vehicle exterior area. The user adjusts the camera angle to make the display image correspond to the marking line, which solves the problem that the camera angle calibration can only be completed by professionals based on experience and cannot be adjusted at any time. The Chinese invention patent application with publication number CN108725323A proposes an imaging scheme that uses a distortion curve and its first-order derivative and second-order derivative to describe the characteristics of the image plane, thereby obtaining an imaging result that combines high resolution and wide angle.

[0007] In order to meet the current field of view requirements, the electronic rearview mirror must meet the above two main characteristics, that is, the rearview mirror has both a large field of view and high resolution, and different imaging characteristics at different viewing angles.

[0008] In the Chinese invention patent application with publication number CN118264926A, two imaging schemes for vehicle-mounted cameras are proposed based on the characteristic that the resolution varies with the viewing angle. In the rear-view system, the resolution of the central area of ​​the image sensor is set to be higher than the resolution of the peripheral area, and in the side-view system, the resolution of the central area of ​​the image sensor is set to be lower than the resolution of the peripheral area. In the Chinese invention patent application with publication number CN114815142A and the Chinese invention patent application with publication number CN118311740A, the former designs a rear-view optical system with a large viewing angle (half field of view angle of 90°) and a central area resolution greater than the peripheral area, which improves the detection accuracy of the vehicle, but the F number is large (F#=2.8), the amount of light entering the optical system is reduced, which affects the imaging effect and night vision effect, and the maximum image height (4.361mm) still has room for improvement; the latter designs an 8-piece side-view optical system with a large viewing angle (half field of view angle of 90°), but the central area resolution is lower than the peripheral area, which is more suitable for side-view systems rather than rear-view systems. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a rear-view lens and a camera module with a large field of view, high resolution, a large image plane, a large amount of light entering the lens and good temperature stability.

[0010] The technical solution adopted by the present invention to solve the above technical problems is: a rearview lens, which includes, from the object side to the image side, a first lens with negative optical power, a second lens, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens and a ninth lens with positive optical power, which are made of glass materials, wherein 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, at least one of the object side surface and the image side surface of the fourth lens is convex, and the object side surface of the fifth lens is concave. The side surface is convex, and the image side surface is convex. The object side surface of the sixth lens is convex, and the image side surface is convex. The object side surface of the seventh lens is concave, and the image side surface is concave. The object side surface of the eighth lens is convex. The object side surface of the ninth lens is convex, and the image side surface is concave. The second lens, the eighth lens, and the ninth lens are aspherical lenses. The focal length efl of the rearview lens satisfies: 4mm<efl<6mm, the working F number F# satisfies: 1.7<F#<1.9, the entrance pupil diameter ENPD satisfies: 2.3mm<ENPD<2.6mm, and the total optical length TTL satisfies: 30mm<TTL<40mm.

[0011] Compared with the prior art, the advantages of the present invention are that it uses nine glass lenses, and through the reasonable matching of the surface shape and optical focal length of each lens, and the coordination of spherical and aspherical lenses, the direction of light in different fields of view is controlled, and it has a large field of view angle (half field of view angle 95°), high resolution (the central area transfer function MTF is between 0.2 and 0.7 when the spatial frequency is 160lp / mm), and the magnification of the central area is greater than that of the peripheral area. In addition, the image surface is large (half image height 4.9mm), the lens light input is large (F#=1.8), and the temperature stability is good (all-glass lens), which meets the use requirements of vehicle-mounted products.

[0012] Preferably, the sixth lens and the seventh lens can be glued to each other.

[0013] Preferably, the third lens may be an aspherical lens or a spherical lens.

[0014] Preferably, a filter and a protective glass are sequentially arranged on the image side of the ninth lens.

[0015] Preferably, the dispersion coefficient of the first lens is VD1, the dispersion coefficient of the second lens is VD2, the dispersion coefficient of the third lens is VD3, the dispersion coefficient of the fourth lens is VD4, the dispersion coefficient of the fifth lens is VD5, the dispersion coefficient of the sixth lens is VD6, the dispersion coefficient of the seventh lens is VD7, the dispersion coefficient of the eighth lens is VD8, and the dispersion coefficient of the ninth lens is VD9, and the relationship thereof satisfies: 50<VD1<80, 50<VD2<80, 15<VD3<50, 15<VD4<50, 50<VD5<80, 50<VD6<80, 15<VD7<50, 50<VD8<80, 50<VD9<80.

[0016] Preferably, the imaging surface of the rearview lens includes two areas, a central area and an edge area, and its imaging characteristics are: in the central area, 0.04mm / deg<∆h<0.075mm / deg, in the edge area, 0.03mm / deg<∆h<0.05mm / deg, and 35°<θx<45°, 45°<θm≤95°, wherein ∆h is the angular resolution, θx is the half field angle of the dividing line between the central area and the edge area, and θm is the maximum half field angle of the imaging surface of the rearview lens.

[0017] The present invention provides a camera module, comprising an optical lens and an image sensor. The optical lens is equipped with the above-mentioned rearview lens. The image sensor is located on the imaging surface of the rearview lens to capture images of objects.

[0018] Preferably, the photosensitive surface of the image sensor is composed of a first field of view area and a third field of view area located in the central area of ​​the imaging surface of the rearview lens, and the first field of view area satisfies the condition: 8° < ≤θx<45°, e ≤ r , a < b ,in, e is the field of view angle at the upper edge of the first field of view, r is the viewing angle at the lower edge of the first visual field, a is the field of view angle at the left edge of the first field of view, b is the viewing angle at the right edge of the first visual field area, and the third visual field area satisfies the condition: 35°< b + c ≤95°, where: b + c It is the field angle at the right edge of the third field of view.

[0019] Preferably, the photosensitive surface of the image sensor includes a second field of view area, wherein the second field of view area is partially located in the first field of view area and partially located in the third field of view area, and the second field of view area satisfies the condition: 35°<θx< ≤θm≤95°, where r + g is the viewing angle at the lower edge of the second field of view, b It is also used as the field angle at the right edge of the second field of view. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of an optical system of Example 1 in an embodiment of the present invention;

[0021] Figure 2 This is a transfer function curve diagram of Example 1 in the central area and high line pair in an embodiment of the present invention;

[0022] Figure 3 This is a transfer function curve diagram of Example 1 in the edge area and low line pair in an embodiment of the present invention;

[0023] Figure 4 Graphs of various aberration curves of Example 1 in the embodiment of the present invention;

[0024] Figure 5 is an imaging characteristic curve diagram of Example 1 in an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of an optical system of Example 2 in an embodiment of the present invention;

[0026] Figure 7 It is a transfer function curve diagram of Example 2 in the central area and high line pair in the embodiment of the present invention;

[0027] Figure 8 It is a transfer function curve diagram of Example 2 in the edge area and low line pair according to the embodiment of the present invention;

[0028] Fig. 9 Graphs of various aberration curves in Example 2 of the embodiment of the present invention;

[0029] Fig.10 is an imaging characteristic curve diagram of Example 2 in an embodiment of the present invention;

[0030] Fig.11 Schematic diagram of an optical system of Example 3 in an embodiment of the present invention;

[0031] Fig.12 This is a transfer function curve diagram of Example 3 in the central area and high line pair in the embodiment of the present invention;

[0032] Fig.13This is a transfer function curve diagram of Example 3 in the edge area and low line pair according to the embodiment of the present invention;

[0033] Fig.14 Graphs of various aberration curves of Example 3 in the embodiment of the present invention;

[0034] Fig.15 is an imaging characteristic curve diagram of Example 3 in an embodiment of the present invention;

[0035] Fig.16 Schematic diagram of an optical system of Example 4 in an embodiment of the present invention;

[0036] Fig.17 This is a transfer function curve diagram of Example 4 in the central area and high line pair according to the embodiment of the present invention;

[0037] Fig.18 It is a transfer function curve diagram of Example 4 in the edge area and low line pair according to the embodiment of the present invention;

[0038] Fig.19 Graphs of various aberration curves of Example 4 in the embodiment of the present invention;

[0039] Fig. 20 is an imaging characteristic curve diagram of Example 4 in an embodiment of the present invention;

[0040] Fig.21 It is a schematic diagram of the imaging surface of the rearview lens and the photosensitive area of ​​the camera module of the present invention. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to the accompanying drawings.

[0042] Example:

[0043] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of illustration. The drawings are only examples and are not drawn strictly to scale.

[0044] In the aberration diagrams of the accompanying drawings, aberrations at 656 nm (C line), 546 nm (e line) and 436 nm (g line) as well as T (meridian direction) and S (sagittal direction) are represented by curves and labels of different shapes, respectively.

[0045] In an exemplary embodiment, in order to improve the imaging quality of the lens and reduce the aberration in the imaging system, an aspherical lens is used, and its surface shape satisfies the following equation:

[0046] ,in, y Represents the radial coordinate value of the lens perpendicular to the optical axis, Z is the sagittal height of the aspheric lens from the vertex of the aspheric surface when the aspheric lens is at a height y along the optical axis direction,c =1 / R, R represents the central curvature radius of the corresponding aspherical lens surface. k represents the cone coefficient, parameter A , B , C , D , E , F , G , H These are the coefficients of the 2nd, 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the high-order aspheric polynomial.

[0047] In an exemplary embodiment, the material of the aspheric lens is glass. Compared with a plastic aspheric lens, a glass aspheric lens can not only achieve the aberration reduction function of an aspheric lens, but also have the thermal stability of glass.

[0048] In an exemplary embodiment, the material of the spherical lens is glass, which is less affected by temperature and has good thermal stability.

[0049] like Figure 1 As shown, a rear view lens has nine lenses, which are: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9 from the object side to the image side.

[0050] The first lens L1 has a negative focal length, a convex object side, and a concave image side, which collects light from a larger field of view, achieves a large field of view, and brings distortion, which can reduce water droplets and avoid blurred images when used outdoors. The material of the first lens L1 is high-hardness glass to avoid wear and scratches, meeting the high requirements of automotive products.

[0051] The object side of the second lens L2 is convex, and the image side is concave. Both the object side and the image side of the second lens L2 are aspherical, which can control the direction of light in different fields of view, increase the image height near the center area, improve resolution, and further collect light in a larger field of view, bringing distortion while suppressing other aberrations. At the same time, the shape of the second lens L2 is close to concentric circles, and the use of aspherical molding technology can reduce the difficulty of lens processing and save costs.

[0052] The third lens L3 has a negative focal power, a concave object side surface, and a convex image side surface. The third lens L3 has a negative focal power and diverges the light beam, which is convenient for subsequent light beam propagation and imaging. The two surfaces of the third lens L3 can be spherical or aspherical. The spherical surface can reduce the process difficulty and save manufacturing costs, while the aspherical surface can suppress aberrations and improve imaging quality.

[0053] The fourth lens L4 has a positive optical power, and at least one of the object side and image side is convex. The optical power of the fourth lens L4 accounts for a relatively small proportion of the optical power of the lens, and plays a role in smoothing the light turning and reducing the sensitivity of the lens.

[0054] The fifth lens L5 has a positive optical power, a convex object side surface, and a convex image side surface. The fifth lens L5 has a positive optical power, which suppresses the divergence angle of the light beam, facilitating subsequent light beam propagation and imaging.

[0055] The sixth lens L6 has positive refractive power, a convex object-side surface, and a convex image-side surface. The seventh lens L7 has negative refractive power, a concave object-side surface, and a concave image-side surface.

[0056] The sixth lens L6 and the seventh lens L7 are glued together, and the materials of high and low dispersion coefficients are selected respectively to correct aberrations including chromatic aberration and distortion.

[0057] The eighth lens L8 has a positive optical power and a convex object side surface. Both the object side and the image side of the eighth lens L8 are aspherical surfaces, which control the direction of light in different fields of view and achieve the requirements of large field of view and high resolution.

[0058] The object side surface of the ninth lens L9 is convex, and the image side surface is concave. Both the object side and the image side of the ninth lens L9 are aspherical surfaces, which control the direction of light in different fields of view, suppress aberrations including distortion, and achieve the requirements of large field of view and high resolution.

[0059] The filter G1 is placed on the image side of the ninth lens L9 to filter out stray light in other bands and avoid the blue shift of the filter, thereby improving the imaging quality.

[0060] The protective glass G2 is placed on the image side of the filter G1 and in front of the imaging surface IMA to protect the lens and the image sensor from being bumped.

[0061] like Fig.21 As shown, in order to achieve a large field of view in the wide-angle field of view area and a high resolution in the main field of view area, and to make the imaging magnification of the central area greater than that of the peripheral area, the imaging image plane IMA is divided into two areas, a central area A1 and an edge area A2, according to the boundary half field of view angle θx and the maximum half field of view angle θm. The circular area with a field of view angle less than θx is the central area A1, and the annular area with a field of view angle between θx and θm is the edge area A2, satisfying the conditional formula: 35°<θx<45°, 45°<θm≤95°,

[0062] Its imaging characteristics are: in the central area A1, 0.04mm / deg<∆h<0.075mm / deg, in the edge area A2, 0.03mm / deg<∆h<0.05mm / deg, where ∆h is the angular resolution, that is, the change in image height when the field of view angle increases by 1°.

[0063] The maximum field of view of the rearview lens is FOV = 190°, corresponding to a maximum image height of h = 9.8mm. The larger the field of view, the wider the range that can be observed by the rearview mirror, which is conducive to reducing the blind spots of driving vision; the larger the image surface, the more flexible the selection of different application areas, and the matching image sensor has a larger photosensitive surface, which is conducive to forming high-resolution images, improving the imaging accuracy of road conditions and driving experience.

[0064] When the magnification is the same in the whole field of view, the angular resolution ∆h should be 0.052mm / deg. When the angular resolution ∆h of the central area A1 is greater than 0.052mm / deg, the imaging magnification of the central area A1 is higher than the average value; when the angular resolution ∆h of the edge area A2 is less than 0.052mm / deg, the imaging magnification of the edge area A2 is lower than the average value; at this time, wide-angle field of view observation of the rearview lens and high-resolution detail observation of the main field of view can be achieved. The central area A1 and the edge area A2 are located on the same image plane and are directly connected. In order to make the image planes of the two have a transition zone and leave a margin for the use of the image detector, the central area A1 and the edge area A2 are set to meet the above conditional formula.

[0065] The focal length efl of the rearview lens satisfies: 4mm<efl<6mm, the entrance pupil diameter ENPD satisfies: 2.3mm<ENPD<2.6mm, and the total optical length TTL satisfies: 30mm<TTL<40mm.

[0066] The working F# of the rearview lens satisfies: 1.7<F#<1.9. From the formula F#=efl / ENPD, it can be seen that when the focal length efl is fixed, the smaller the F# and the larger the entrance pupil diameter ENPD, the more light enters the optical system, which can improve the imaging effect and night vision effect. At the same time, the resolution diffraction limit of the lens is also improved, which is conducive to achieving high-resolution imaging.

[0067] The dispersion coefficient of the first lens L1 is VD1, the dispersion coefficient of the second lens L2 is VD2, the dispersion coefficient of the third lens L3 is VD3, the dispersion coefficient of the fourth lens L4 is VD4, the dispersion coefficient of the fifth lens L5 is VD5, the dispersion coefficient of the sixth lens L6 is VD6, the dispersion coefficient of the seventh lens L7 is VD7, the dispersion coefficient of the eighth lens L8 is VD8, and the dispersion coefficient of the ninth lens L9 is VD9, and the relationship thereof satisfies: 50<VD1<80, 50<VD2<80, 15<VD3<50, 15<VD4<50, 50<VD5<80, 50<VD6<80, 15<VD7<50, 50<VD8<80, 50<VD9<80.

[0068] An image sensor is provided at the imaging surface IMA to record the imaging image. The relative position of the photosensitive surface S of the image sensor and the imaging surface IMA is as follows: Fig.21As shown, the photosensitive surface S of the image sensor consists of two areas: the first field of view area S1 and the third field of view area S3: the first field of view area S1 is located in the central area A1, and the field of view angle e at the upper edge, the field of view angle r at the lower edge, the field of view angle a at the left edge, and the field of view angle b at the right edge meet the condition: 8° < ≤θx<45°, e ≤ r , a < b , control the field of view area S1 to fall within the central area A1 with high imaging resolution, without placing too much field of view on the vehicle body and the sky, so as to observe the details of road conditions and improve driving experience and safety.

[0069] The third field of view S3 is the area of ​​the image sensor's photosensitive surface S except the first field of view S1. Most of it falls within the edge area A2. The field of view angle at the upper edge is d + e , Field of view at the lower edge r + g + h , Field of view at the left edge a , Field of view at the right edge b + c Satisfying the condition: 35°< b + c ≤95°, with a wide field of view, it can provide a more comprehensive road condition, fill in the blind spots when the vehicle turns, and improve driving safety.

[0070] The photosensitive surface S of the image sensor includes a second field of view area S2. Most of the second field of view area S2 falls within the central area A1. Part of the area of ​​the second field of view area S2 is located in the first field of view area S1, and another part of the area is located in the third field of view area S3. At the position where the photosensitive surface S of the image sensor deviates from the center, the upper edge falls at the central field of view and the lower edge falls at the field of view angle r + g , Field of view at the left edge a , Field of view at the right edge b Satisfy the condition: 35°<θx< ≤θm≤95°, the field of vision is biased downward, so you can focus on observing the road conditions, provide functions such as reversing assistance, and improve the driving experience.

[0071] The following are four specific examples of the rearview lens of this embodiment, and the main design parameters are shown in Table 1:

[0072] Table 1

[0073] parameter Example 1 Example 2 Example 3 Example 4 Focal length efl 4.33 4.38 4.47 4.55 Working F# 1.80 1.80 1.80 1.80 Entrance pupil diameter ENPD 2.41 2.43 2.48 2.53 Optical total length TTL 33.95 33.71 35.31 39.72 Maximum field of view FOV / ° 190 190 190 190 Maximum image height h / mm 9.8 9.8 9.8 9.8 Angular resolution ∆h (mm / deg@θ=40°) 0.0420 0.0423 0.0424 0.0421 Angular resolution ∆h (mm / deg@θ=80°) 0.0390 0.0388 0.0390 0.0385

[0074] Example 1:

[0075] The structure of this example is as follows Figure 1 As shown,

[0076] A rearview lens and a camera module, wherein there are nine lenses with optical power, which are arranged in sequence from the object side to the image side: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9,

[0077] The first lens L1 has a negative refractive power, a convex object-side surface, and a concave image-side surface;

[0078] The second lens L2 has a negative refractive power, a convex object-side surface, and a concave image-side surface;

[0079] The third lens L3 has a negative refractive power, a concave object-side surface, and a convex image-side surface;

[0080] The fourth lens L4 has a positive refractive power, a flat object-side surface, and a convex image-side surface;

[0081] The fifth lens L5 has a positive refractive power, a convex object-side surface, and a convex image-side surface;

[0082] The sixth lens L6 has a positive refractive power, a convex object-side surface, and a convex image-side surface;

[0083] The seventh lens L7 has a negative refractive power, a concave object-side surface, and a concave image-side surface;

[0084] The eighth lens L8 has a positive refractive power, a convex object-side surface, and a concave image-side surface;

[0085] The ninth lens L9 has a positive refractive power, a convex object-side surface, and a concave image-side surface;

[0086] The sixth lens L6 and the seventh lens L7 are cemented together;

[0087] The second lens L2, the third lens L3, the eighth lens L8 and the ninth lens L9 are aspherical lenses.

[0088] The physical optical parameters of this example 1 are shown in Table 2:

[0089] Table 2

[0090]

[0091] In Example 1, the surface parameters of the aspheric lenses L2, L3, L8, and L9 are shown in Table 3:

[0092] Table 3

[0093] surface k B C D E F G H L2 side -0.94 2.44E-05 -5.94E-06 -1.37E-09 1.10E-09 1.24E-11 1.47E-13 -7.33E-15 L2 side view -0.07 -5.87E-04 -2.29E-05 8.90E-07 -4.04E-08 -9.25E-12 -3.08E-10 1.43E-11 L3 side 2.67 3.33E-04 8.02E-05 -1.50E-05 1.61E-06 -3.62E-08 -4.48E-09 2.37E-10 L3 side view -34.40 -2.53E-05 -5.66E-06 2.22E-06 -3.67E-08 -1.41E-08 -3.35E-10 9.27E-11 L8 side -1.33 -5.58E-04 1.84E-05 -3.20E-06 3.52E-08 1.41E-08 3.52E-10 -1.46E-11 L8 side view 11.82 -1.69E-03 -6.14E-05 1.84E-06 8.91E-08 4.66E-09 6.62E-10 3.18E-11 L9 side -25.22 -1.28E-03 -1.33E-04 6.99E-06 2.60E-07 2.85E-09 -3.10E-10 -8.33E-12 L9 side view 27.28 -4.98E-03 2.16E-06 1.66E-05 -3.25E-07 -1.44E-08 7.24E-10 -1.53E-11

[0094] In this example 1, the transfer function curves of the lens under high line pair and low line pair are as follows: Figure 2 , Figure 3 As shown, the aberration is Figure 4 As shown, the imaging characteristics are Figure 5 shown.

[0095] Figure 2 The transfer function curve shown shows that the transfer function value of Example 1 in the central area A1 at a high line pair of 160lp / mm is between 0.2 and 0.7, which has the characteristic of relatively high resolution.

[0096] Figure 3 The transfer function curve shown in the figure shows that the transfer function value of Example 1 in the edge area A2 at a low line pair of 60lp / mm is greater than 0.2, which has the characteristic of a large field of view.

[0097] Figure 4 The aberration diagram shows the spherical aberration, field curvature and distortion of Example 1 from left to right. The spherical aberration (within ±0.021mm) and field curvature (within ±0.021mm) in the central area A1 are small, and the distortion of the entire field of view is larger due to usage requirements.

[0098] Figure 5 The imaging characteristic curve diagram shown shows the angular resolution of the first example, which meets the use requirement that the angular resolution of the central area A1 is greater than that of the edge area A2.

[0099] Example 2:

[0100] The structure of Example 2 is as follows Figure 6 As shown,

[0101] Compared with Example 1, in Example 2, the surface shape of the eighth lens L8 changes from convex-concave to biconvex, the optical power of the ninth lens L9 changes from positive to negative, and the optical power values ​​of the second lens L2 and the ninth lens L9 become smaller, which eases the degree of deflection of light in the lens, reduces the sensitivity of the lens, and improves the imaging quality.

[0102] The physical optical parameters of Example 2 are shown in Table 4:

[0103] Table 4

[0104]

[0105] In Example 2, the surface parameters of the aspheric lenses L2, L3, L8, and L9 are shown in Table 5:

[0106] Table 5

[0107] surface k B C D E F G H L2 side -1.05 1.11E-05 -5.71E-06 2.59E-08 9.90E-10 2.48E-11 2.99E-13 -1.33E-14 L2 side view -0.10 -1.31E-03 -2.45E-05 -3.78E-07 1.87E-08 6.92E-09 -4.69E-10 7.81E-13 L3 side 2.07 1.84E-04 1.03E-04 -1.38E-05 1.34E-06 -2.67E-08 -3.68E-09 2.16E-10 L3 side view -100.46 -5.24E-05 1.04E-05 6.32E-06 -7.45E-07 -3.34E-08 1.06E-08 -4.40E-10 L8 side -23.54 -2.55E-04 -3.54E-05 2.78E-06 4.78E-08 -9.02E-09 3.48E-10 2.86E-12 L8 side view 6.86 -5.86E-04 5.97E-05 4.02E-08 -1.47E-07 9.69E-09 1.43E-09 -1.13E-10 L9 side -472.84 -2.65E-04 -5.66E-05 -1.17E-08 8.37E-08 3.02E-09 3.26E-10 -4.13E-11 L9 side view -258.06 -2.66E-03 1.75E-05 2.03E-06 3.80E-08 3.55E-09 -7.32E-11 -2.47E-12

[0108] In this example 2, the transfer function curves of the lens under high line pair and low line pair are as follows: Figure 7 , Figure 8 As shown, the aberration is Fig. 9 As shown, the imaging characteristics are Fig.10 shown.

[0109] Figure 7 The transfer function curve shown shows that the transfer function value of Example 2 in the central area A1 at a high line pair of 160lp / mm is between 0.3 and 0.7, and the resolution is improved compared with Example 1.

[0110] Figure 8 The transfer function curve shown shows that the transfer function value of Example 2 in the edge area A2 at a low line pair of 60lp / mm is greater than 0.2, which is close to that of Example 1.

[0111] Fig. 9 The aberration diagrams show the spherical aberration, field curvature and distortion of Example 2 from left to right. The spherical aberration (within ±0.025mm) and field curvature (within ±0.025mm) in the central area A1 are small, which is larger than that in Example 1. The distortion of the full field of view is larger due to usage requirements.

[0112] Fig.10 The imaging characteristic curve diagram shown shows the angular resolution of the second example, which meets the use requirement that the angular resolution of the central area A1 is greater than that of the edge area A2.

[0113] Example 3:

[0114] The structure of Example 3 is as follows Fig.11 As shown,

[0115] Compared with Example 1, in Example 3, the optical power of the second lens L2 changes from negative to positive, the surface shape of the fourth lens L4 changes from plano-convex to convex-planar, the surface shape of the eighth lens L8 changes from convex-concave to convex-convex, and the turning degree of light from the fourth lens L4 to the fifth lens L5 and from the seventh lens L7 to the eighth lens L8 is eased, thereby reducing the sensitivity of the lens and improving the imaging quality.

[0116] In addition, one aspherical lens is reduced, and the third lens L3 is changed from an aspherical lens to a spherical lens, which can reduce the manufacturing cost.

[0117] The physical optical parameters of this example 3 are shown in Table 6:

[0118] Table 6

[0119]

[0120] In Example 3, the surface parameters of the aspheric lenses L2, L8, and L9 are shown in Table 7:

[0121] Table 7

[0122] surface k B C D E F G H L2 side -1.02 9.21E-05 -1.19E-05 -9.46E-09 1.91E-09 4.61E-11 4.63E-13 -2.84E-14 L2 side view -0.65 -9.41E-04 -5.73E-06 6.00E-07 -1.69E-08 4.73E-09 -2.71E-10 6.88E-12 L8 side -10.89 1.39E-04 -3.60E-05 3.25E-06 1.86E-07 2.31E-10 5.51E-10 -3.64E-11 L8 side view 8.97 -9.91E-04 7.94E-05 1.52E-06 -8.25E-08 1.34E-08 1.82E-09 -6.55E-11 L9 side -26.36 -3.63E-04 -6.88E-05 -1.78E-07 1.18E-07 5.38E-09 5.26E-10 -2.79E-11 L9 side view -60.11 -2.52E-03 1.68E-05 7.37E-07 -5.92E-09 3.42E-09 3.12E-11 2.50E-12

[0123] In this example 3, the transfer function curves of the lens under high line pair and low line pair are as follows: Fig.12 , Fig.13 As shown, the aberration is Fig.14 As shown, the imaging characteristics are Fig.15 shown.

[0124] Fig.12 The transfer function curve shown shows that the transfer function value of Example 3 in the central area A1 at a high line pair of 160lp / mm is between 0.2 and 0.7, which is close to that of Example 1.

[0125] Fig.13 The transfer function curve shown shows that the transfer function value of Example 3 in the edge area A2 at a low line pair of 60lp / mm is greater than 0.2, which is close to that of Example 1.

[0126] Fig.14 The aberration diagrams show the spherical aberration, field curvature and distortion of Example 3 from left to right. The spherical aberration (within ±0.021mm) and field curvature (within ±0.021mm) in the central area A1 are small, close to Example 1. The distortion of the full field of view is larger due to usage requirements.

[0127] Fig.15 The imaging characteristic curve shown shows the angular resolution of Example 3, which meets the use requirement that the angular resolution of the central area A1 is greater than that of the edge area A2.

[0128] Example 4:

[0129] The structure of Example 4 is as follows Fig.16 As shown,

[0130] Compared with Example 3, in Example 4, the surface shape of the fourth lens L4 changes from convex-flat to biconvex, the total optical length of the lens increases, the turning degree of light from the third lens L3 to the fourth lens L4 is eased, the lens sensitivity is reduced, and the resolution is improved.

[0131] The physical optical parameters of Example 4 are shown in Table 8:

[0132] Table 8

[0133]

[0134] In Example 4, the surface parameters of the aspheric lenses L2, L8, and L9 are shown in Table 9:

[0135] Table 9

[0136] surface k B C D E F G H L2 side -1.18 7.36E-04 -1.25E-05 -2.49E-07 -1.91E-09 3.36E-11 1.04E-12 -1.84E-14 L2 side view -0.65 -3.27E-04 -6.50E-05 1.24E-06 -1.83E-08 -3.98E-10 -2.38E-10 6.16E-12 L8 side -4.96 1.24E-05 -5.12E-05 4.29E-06 3.05E-07 1.49E-08 -3.02E-10 -4.97E-11 L8 side view 51.42 -2.37E-03 9.94E-05 3.74E-06 6.71E-08 5.83E-09 1.75E-09 -2.16E-11 L9 side -6.59 2.69E-04 -5.60E-05 1.42E-07 -2.30E-08 -1.60E-09 4.80E-10 -1.58E-11 L9 side view -14.53 -1.46E-04 -1.26E-05 -2.72E-06 -5.94E-08 5.59E-09 2.18E-10 -1.08E-11

[0137] In Example 4, the transfer function curves of the lens under high line pair and low line pair are as follows: Fig.17 , Fig.18As shown, the aberration is Fig.19 As shown, the imaging characteristics are Fig. 20 shown.

[0138] Fig.17 The transfer function curve shown shows that the transfer function value of Example 4 in the central area A1 at a high line pair of 160lp / mm is between 0.3 and 0.7, and the resolution is improved compared with Example 3.

[0139] Fig.18 The transfer function curve shown shows that the transfer function value of Example 4 in the edge area A2 and at a low line pair of 60lp / mm is greater than 0.3, and the resolution is improved compared with Example 3.

[0140] Fig.19 The aberration diagram shows the spherical aberration, field curvature and distortion of Example 1 from left to right. The spherical aberration (within ±0.017mm) and field curvature (within ±0.017mm) in the central area A1 are small, which is smaller than that in Example 3. The distortion of the entire field of view is larger due to usage requirements.

[0141] Fig. 20 The imaging characteristic curve shown shows the angular resolution of Example 4, which meets the use requirement that the angular resolution of the central area A1 is greater than that of the edge area A2.

[0142] The above are only individual examples of the present invention and cannot limit the scope of protection of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A rearview lens, characterized in that From the object side to the image side, a first lens with negative optical power, a second lens, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with positive optical power and a ninth lens made of glass materials are used. 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. At least one of the object side surface and the image side surface of the fourth lens 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 convex, and the image side surface is convex, the object side surface of the seventh lens is concave, and the image side surface is concave, the object side surface of the eighth lens is convex, the object side surface of the ninth lens is convex, and the image side surface is concave, the second lens, the eighth lens and the ninth lens are aspherical lenses, the focal length efl of the rearview lens satisfies: 4mm<efl<6mm, the working F number F# satisfies: 1.7<F#<1.9, the entrance pupil diameter ENPD satisfies: 2.3mm<ENPD<2.6mm, and the total optical length TTL satisfies: 30mm<TTL<40mm.

2. A rearview lens as claimed in claim 1, characterized in that The sixth lens and the seventh lens are glued to each other.

3. A rearview lens as claimed in claim 1, characterized in that The third lens is an aspherical lens.

4. A rearview lens as claimed in claim 1, characterized in that The image side of the ninth lens is provided with a filter and a protective glass in sequence.

5. A rearview lens as claimed in claim 1, characterized in that The dispersion coefficient of the first lens is VD1, the dispersion coefficient of the second lens is VD2, the dispersion coefficient of the third lens is VD3, the dispersion coefficient of the fourth lens is VD4, the dispersion coefficient of the fifth lens is VD5, the dispersion coefficient of the sixth lens is VD6, the dispersion coefficient of the seventh lens is VD7, the dispersion coefficient of the eighth lens is VD8, and the dispersion coefficient of the ninth lens is VD9, and the relationship thereof satisfies: 50<VD1<80, 50<VD2<80, 15<VD3<50, 15<VD4<50, 50<VD5<80, 50<VD6<80, 15<VD7<50, 50<VD8<80, 50<VD9<80.

6. A rearview lens as claimed in claim 1, characterized in that The imaging surface of the rearview lens includes a central area and an edge area, and its imaging characteristics are: in the central area, 0.04mm / deg<∆h<0.075mm / deg, in the edge area, 0.03mm / deg<∆h<0.05mm / deg, and 35°<θx<45°, 45°<θm≤95°, wherein ∆h is the angular resolution, θx is the half field angle of the boundary line between the central area and the edge area, and θm is the maximum half field angle of the imaging surface of the rearview lens.

7. A camera module, comprising an optical lens and an image sensor, characterized in that The rear-view lens according to any one of claims 1 to 6 is installed in the optical lens, and the image sensor is located on the imaging surface of the rear-view lens to photograph the object.

8. The camera module as claimed in claim 7, characterized in that The photosensitive surface of the image sensor is composed of a first field of view area and a third field of view area, and the first field of view area satisfies the condition: 8°< ≤θx<45°, e≤r, a<b, wherein e is the field angle at the upper edge of the first field of view, r is the field angle at the lower edge of the first field of view, a is the field angle at the left edge of the first field of view, and b is the field angle at the right edge of the first field of view. The third field of view satisfies the condition: 35°<b+c≤95°, wherein b+c is the field angle at the right edge of the third field of view.

9. The camera module as claimed in claim 8, characterized in that The photosensitive surface of the image sensor includes a second field of view area, wherein the second field of view area is partially located in the first field of view area and partially located in the third field of view area, and the second field of view area satisfies the condition: 35°<θx< ≤θm≤95°, where r+g is the viewing angle at the lower edge of the second field of view, and b is the viewing angle at the right edge of the second field of view.

Images