A vehicle-mounted imaging lens and electronic device

Abstract

This invention discloses a vehicle-mounted imaging lens, comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The first lens has negative optical power, with a convex object side and a concave image side. The second lens has positive optical power, with a convex object side and either a convex or concave image side. The third lens has a convex object side and either a concave or convex image side. The fourth lens has positive optical power, and so on. The lens employs a five-lens structure. By optimizing the lens position, shape, and optical power, and by rationally controlling the positive and negative combinations of the optical power of each lens, lower-order aberrations can be effectively balanced, while reducing the lens's tolerance sensitivity, maintaining miniaturization while ensuring image quality.

Description

Technical Field

[0001] This invention relates to the field of vehicle imaging lens technology, and more particularly to a vehicle imaging lens and electronic device. Background Technology

[0002] Vehicle-mounted imaging cameras are primarily installed on the B-pillars of the vehicle cabin. They identify palm veins and then interact with the vehicle to complete commands such as unlocking and automatic door opening. However, most existing vehicle-mounted imaging cameras suffer from one or more of the following defects:

[0003] Firstly, typical automotive lenses have low light transmission, resulting in poor image quality in low-light environments and failing to meet the resolution requirements of automotive lenses.

[0004] Secondly, automotive lenses generally use more expensive optical materials, resulting in higher production costs.

[0005] Thirdly, the optical composition of general automotive lenses is complex, the manufacturing process is complex, the production cost of lenses is high, and the yield rate is low.

[0006] Fourth, the reliability requirements of general automotive lenses cannot be met, such as dustproofing to IP6KX, waterproofing to IPX7, and stone impact resistance to IP9K.

[0007] Fifth, lenses generally use more lens elements, resulting in lower optical assembly yield and longer lens length;

[0008] Sixth, general lenses are prone to focus loss at high and low temperatures, and cannot meet the requirements of maintaining clear imaging under the actual operating temperature environment of automotive lenses.

[0009] Seventh, when dealing with stray light and ghosting issues, the ratio of stray light illuminance to light source illuminance in a typical lens is greater than 10. -5 This typically fails to meet the stringent requirements of automotive lenses. Especially during use, automotive lenses may be exposed to direct sunlight or strong reflected light from highly reflective surfaces. This excessive sunlight can degrade image quality, producing noticeable stray light and ghosting, thus affecting driving safety. Summary of the Invention

[0010] In view of this, the object of the present invention is to provide an in-vehicle imaging lens and electronic device. This lens can at least solve one of the technical shortcomings mentioned in the background art.

[0011] According to one aspect of the present invention, a vehicle-mounted imaging lens is provided, comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along an optical axis from the object side to the image side, wherein: the first lens has negative optical power, the object side of the first lens is convex, and the image side of the first lens is concave; the second lens has positive optical power, the object side of the second lens is convex, and the image side of the second lens is either convex or concave; the object side of the third lens is convex, and the image side of the third lens is either concave or convex; the fourth lens has positive optical power, the object side of the fourth lens is convex, and the image side of the fourth lens is convex; the fifth lens has positive optical power, the object side of the fifth lens is convex, and the image side of the fifth lens is either convex or concave. The lens of this invention adopts a five-lens structure design. By optimizing the lens position, shape, and optical power, and by reasonably controlling the positive and negative combinations of the optical power of each lens, the low-order aberrations of the lens can be effectively balanced. At the same time, the tolerance sensitivity of the lens can be reduced, and the image quality of the lens can be guaranteed while maintaining its miniaturization.

[0012] According to another aspect of the present invention, an electronic device is provided, comprising a vehicle-mounted imaging lens as described above; and an image sensor configured to receive an image formed by the vehicle-mounted imaging lens. In this technical solution, the advantages of the electronic device depend on the vehicle-mounted imaging lens, which will not be elaborated upon here. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a structural diagram of the optical system of the lens in Example 1.

[0015] Figure 2 The image shows the MTF (Mean Transformer Format) of the lens in Example 1 at 850nm in the near-infrared band.

[0016] Figure 3 This is a distortion diagram of the lens in Example 1 at 850nm in the near-infrared band.

[0017] Figure 4 The relative illumination of the lens in Example 1 at 850nm in the near-infrared band.

[0018] Figure 5 This is a structural diagram of the optical system of the lens in Example 2.

[0019] Figure 6 The image shows the MTF (Mean Transformer Format) of the lens in Example 2 at 850nm in the near-infrared band.

[0020] Figure 7 This is a distortion diagram of the lens in Example 2 at 850nm in the near-infrared band.

[0021] Figure 8 The relative illumination of the lens in Example 2 at 850nm in the near-infrared band.

[0022] Figure 9 This is a structural diagram of the optical system of the lens in Example 3.

[0023] Figure 10 The image shows the MTF (Mean Transformer Format) of the lens in Example 3 at 850nm in the near-infrared band.

[0024] Figure 11 This is a distortion diagram of the lens in Example 3 at 850nm in the near-infrared band.

[0025] Figure 12 The relative illumination of the lens in Example 3 at 850nm in the near-infrared band.

[0026] Figure 13 This is a schematic diagram of the structure of the electronic device of the present invention.

[0027] L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; ST, aperture stop; CG, filter; G, protective glass; IMA, imaging plane. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a vehicle-mounted imaging lens, comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side, wherein:

[0030] The first lens has negative optical power, the object side of the first lens is convex, and the image side of the first lens is concave.

[0031] The second lens has positive optical power, the object side of the second lens is convex, and the image side of the second lens is either convex or concave.

[0032] The object-side surface of the third lens is convex, and the image-side surface of the third lens is either concave or convex.

[0033] The fourth lens has positive optical power, and the object side of the fourth lens is convex, and the image side of the fourth lens is convex.

[0034] The fifth lens has positive optical power, the object side of the fifth lens is convex, and the image side of the fifth lens is either convex or concave.

[0035] The lens of this invention adopts a five-lens structure design. By optimizing the lens position, shape, and optical power, and by reasonably controlling the positive and negative combinations of the optical power of each lens, the low-order aberrations of the lens can be effectively balanced. At the same time, the tolerance sensitivity of the lens can be reduced, and the image quality of the lens can be guaranteed while maintaining its miniaturization.

[0036] Among them, reference Figure 1 , Figure 5 , Figure 9 As shown in the figure. The first lens is labeled L1, the second lens is labeled L2, the third lens is labeled L3, the fourth lens is labeled L4, the fifth lens is labeled L5, the aperture is labeled ST, the filter is labeled G, the protective glass is labeled G, and the imaging plane is labeled I MA.

[0037] As one embodiment, the lens satisfies the following relationship: Nd1 > 1.9; Vd1 < 40; where Nd1 is the refractive index of the first lens and Vd1 is the Abbe coefficient of the first lens. The beneficial effect of this embodiment is that by satisfying the above relationship, a large optical aperture ratio can be guaranteed, which is beneficial for compressing the front aperture of the lens optical system, thereby achieving lens miniaturization.

[0038] As one embodiment, the lens satisfies the following relationship: the impact strength of the first lens is greater than 2.5 KJ / m^2, and the Knoop hardness is greater than 650 HK. The beneficial effect of this embodiment is that, since the first lens, as the first glass lens of the lens, is mounted on the B-pillar of the vehicle cabin and is exposed to the air, the design stage must also consider improving the automotive-grade reliability and dependability of the lens to meet automotive-grade drop ball and gravel drop tests. Therefore, the design stage must also consider glass materials with excellent mechanical properties and chemical stability, preferably H-ZLAF4LB (with an impact strength of 2.72 J / m^2 and a Knoop hardness of 707 HK) or H-ZLAF72 (with an impact strength of 2.82 J / m^2 and a Knoop hardness of 663 HK) as the material for the first lens.

[0039] As one embodiment, the lens satisfies the following relationship: Nd2 > 1.9; Vd2 < 40; where Nd2 is the refractive index of the second lens and Vd2 is the Abbe coefficient of the second lens. The beneficial effect of this embodiment is that the second lens is a positive refractive index lens with a prism-like deflection effect, used to receive large-angle light rays passing through the first lens and converge them towards the aperture stop. By satisfying the above relationship, the second lens can reduce the incident angle of edge field rays on subsequent optical elements, achieving a large field of view imaging range. This makes the optical system structure compact and smaller in size, greatly reducing the space occupied by the entire optical system.

[0040] As one embodiment, the lens satisfies the following relationships: 1.55 < Nd4 < 1.65; Vd4 < 69; dn / dT < -6*10E-6 within the temperature range of -40℃ to 105℃; where Nd4 is the refractive index of the fourth lens, Vd4 is the Abbe coefficient of the fourth lens, and dn / dT is the temperature coefficient of refractive index of the fourth lens. The beneficial effects of this embodiment are: the fourth lens uses a material with a special temperature coefficient of refractive index, and satisfies the above relationships, which can effectively reduce the image plane shift caused by thermal expansion and contraction, so that the lens does not require additional focusing at different temperatures, increasing the consistency of image clarity at different temperatures, balancing temperature drift, and achieving the goal of a heat-free lens.

[0041] As one embodiment, the lens satisfies the following relationship: Nd5 > 1.9; Vd5 < 30; where Nd5 is the refractive index of the fifth lens and Vd5 is the Abbe coefficient of the fifth lens. The beneficial effects of this embodiment are: by satisfying the above relationship, the optical performance of the lens is optimized, the imaging resolution is improved, and the outer diameter of the lens's rear end is effectively reduced. Through this design, the lens meets the specifications of the M8 threaded interface, thereby enhancing its versatility in various imaging systems. The application of high-refractive-index materials allows the lens to achieve a more compact size design while maintaining high optical performance, which is significant for improving system integration and portability. Furthermore, the compatibility of the M8 threaded interface allows the lens to easily adapt to various standard cameras and imaging devices, thus broadening its applicability in different optical systems.

[0042] This invention provides three embodiments. In embodiments 1 and 2, the first lens, the second lens, and the third lens form a first combined lens, and the fourth lens and the fifth lens form a second combined lens, with an aperture stop provided between the first combined lens and the second combined lens. In embodiment 3, the first lens and the second lens form a first combined lens, and the third lens, the fourth lens, and the fifth lens form a second combined lens, with an aperture stop provided between the first combined lens and the second combined lens.

[0043] The lens satisfies the following relationship: -1.5 < f1 / f2 < -1; where f1 is the focal length of the first combined lens and f2 is the focal length of the second combined lens. The beneficial effect of this embodiment is that by satisfying the above relationship, the optical power distribution between the first and second combined lenses is well-balanced, the tolerance of the entire optical system is large, and the lens yield is improved.

[0044] The lens satisfies the following relationship: -2 < f1 / f < -1; where f1 is the focal length of the first combined lens and f is the total focal length of the lens. The beneficial effect of this embodiment is that by satisfying the above relationship, light can pass through the aperture at a gentle angle, reducing tolerance sensitivity and improving the stability of the optical system. Simultaneously, it achieves miniaturization of the entire optical lens. The above conditions limit the first combined lens to having negative optical power, which has a diverging effect on light, mainly used to receive light incident from the wide-angle lens and correct some aberrations of the optical system.

[0045] The lens satisfies the following relationship: 1 < f2 / f < 1.5; where f2 is the focal length of the second combined lens and f is the total focal length of the lens. The beneficial effect of this embodiment is that by satisfying the above relationship, the second combined lens can effectively handle the optical power distribution of the optical lens, which not only helps balance aberrations between the first and second combined lenses, thus reducing the length of the optical lens, but also achieves miniaturization of the entire optical lens.

[0046] The lens satisfies the following relationship: 0.35 < H / TTL < 0.4, where H is the lens image height and TTL is the total optical length of the lens. The beneficial effect of this embodiment is that by satisfying the above relationship, it is advantageous for the optical lens to achieve both miniaturization and improved image quality.

[0047] The lens satisfies the following relationship: 0.2 < BFL / TTL < 0.4, where BFL is the rear optical focal length of the lens and TTL is the total optical length of the lens. The beneficial effect of this embodiment is that by satisfying the above relationship, it is advantageous to balance improving the relative illumination of the lens optical system with miniaturization.

[0048] In summary, the beneficial effects of the present invention are as follows:

[0049] Firstly, the lens of this invention has an aperture of FNO of 2.0. Theoretically, the larger the FNO value (the reciprocal of the aperture), the lower the system brightness, meaning less light enters the system, making the image appear darker and affecting the recognition of small objects. Therefore, this invention, with its excellent low-light processing capabilities brought by the large aperture and its fast palm print recognition capabilities brought by the shallow depth of field, reduces the waiting time of the vehicle's infotainment system.

[0050] Secondly, the lens of this invention consists of 5 global surface glass lenses, which has a simple structure and is suitable for modern automated optical assembly conditions. At the same time, it takes into account the tolerance limits of the entire optical system and has a high mass production yield.

[0051] Thirdly, in the optical design stage, the lens of this invention can meet the extremely high reliability requirements of automotive optical lenses through reasonable power distribution and lens shape selection.

[0052] Fourth, the first lens of this invention uses optical lens materials with excellent mechanical properties and chemical stability. Combined with reasonable center and edge thicknesses, it can meet the requirements of optical lenses for resisting stone impacts, as well as dustproof and waterproof requirements.

[0053] Fifth, by rationally allocating the refractive index, temperature coefficient, and positive and negative focal length of the lens, this invention meets the temperature drift requirement from -40℃ to 85℃, thus achieving a heat-free design for the optical lens.

[0054] Sixth, the lens of this invention performs excellently in ghost image control, with low ghost image energy and a small pixel and target area occupied.

[0055] The present invention will now be described in more detail with reference to the following tables. It should be noted that the following tables are merely specific embodiments of the present invention and not limiting examples.

[0056] Please refer to the optical structure of Example 1. Figure 1 The specific parameters of this embodiment 1 are shown in Table 1 below. In this embodiment 1, the lens focal length f = 2.37 mm, the light transmission FNO = 2.0, the field of view FOV = 130°, the target surface size I MH = 4.62 mm, and the total length TTL = 12 mm.

[0057] Table 1 - Lens Parameter Table for Example 1

[0058] Face number type radius of curvature thickness Refractive index Abbe coefficient lens focal length 1 First lens 35.715 1.00 1.9108 35.282 -2.21 2 1.839 0.66 3 Second lens 5.349 1.40 1.9108 35.282 5.59 4 Infinity 0.08 5 Third lens 7.661 1.08 1.6223 53.171 -16.25 6 4.098 0.18 7 Aperture Infinity 0.08 8 Fourth lens 27.227 1.83 1.5928 68.342 4.83 9 -3.080 0.08 10 Fifth lens 11.673 1.30 2.0007 25.426 5.60 11 -9.631 0.50 12 Filter Infinity 0.30 1.5168 64.199 13 Infinity 2.69 14 Protective glass Infinity 0.40 1.5168 64.199 15 Infinity 0.42 16 Imaging surface Infinity -

[0059] For ease of description, in Table 1: surface number 1 and surface number 2 are the object-side and image-side surfaces of the first lens, respectively; surface number 3 and surface number 4 are the object-side and image-side surfaces of the second lens, respectively; surface number 5 and surface number 6 are the object-side and image-side surfaces of the third lens, respectively; surface number 7 is the surface of the aperture stop; surface number 8 and surface number 9 are the object-side and image-side surfaces of the fourth lens, respectively; surface number 10 and surface number 11 are the object-side and image-side surfaces of the fifth lens, respectively; surface number 12 and surface number 13 are the object-side and image-side surfaces of the filter, respectively; surface number 14 and surface number 15 are the object-side and image-side surfaces of the protective glass; and surface number 16 is the surface of the imaging plane.

[0060] According to Table 1, the conditional expression of Embodiment 1 of the present invention can be read as follows:

[0061] (1) The refractive index of the first lens is Nd1 = 1.9108; the Abbe coefficient of the first lens is Vd1 = 35.282;

[0062] (2) The refractive index of the second lens is Nd2 = 1.9108; the Abbe coefficient of the second lens is Vd2 = 35.282;

[0063] (3) The refractive index of the fourth lens is Nd4 = 1.5928; the Abbe coefficient of the fourth lens is Vd4 = 68.342;

[0064] (4) The refractive index of the fifth lens is Nd5 = 2.0007; the Abbe coefficient of the fifth lens is Vd5 = 25.426.

[0065] Please refer to the optical structure of Example 2. Figure 5 The specific parameters of this embodiment 2 are shown in Table 2 below. In this embodiment 2, the lens focal length f = 2.37mm, the light transmission FNO = 2.0, the field of view FOV = 125°, the target surface size I MH = 4.62mm, and the total length TTL = 12mm.

[0066] Table 2 - Lens Parameter Table for Example 2

[0067]

[0068]

[0069] For ease of description, in Table 2: surface number 1 and surface number 2 are the object-side and image-side surfaces of the first lens, respectively; surface number 3 and surface number 4 are the object-side and image-side surfaces of the second lens, respectively; surface number 5 and surface number 6 are the object-side and image-side surfaces of the third lens, respectively; surface number 7 is the surface of the aperture stop; surface number 8 and surface number 9 are the object-side and image-side surfaces of the fourth lens, respectively; surface number 10 and surface number 11 are the object-side and image-side surfaces of the fifth lens, respectively; surface number 12 and surface number 13 are the object-side and image-side surfaces of the filter, respectively; surface number 14 and surface number 15 are the object-side and image-side surfaces of the protective glass; and surface number 16 is the surface of the imaging plane.

[0070] According to Table 2, the conditional expression of Embodiment 2 of the present invention can be read as follows:

[0071] (1) The refractive index of the first lens is Nd1 = 1.9108; the Abbe coefficient of the first lens is Vd1 = 35.282;

[0072] (2) The refractive index of the second lens is Nd2 = 1.9037; the Abbe coefficient of the second lens is Vd2 = 31.315;

[0073] (3) The refractive index of the fourth lens is Nd4 = 1.5928; the Abbe coefficient of the fourth lens is Vd4 = 68.342;

[0074] (4) The refractive index of the fifth lens is Nd5 = 2.0007; the Abbe coefficient of the fifth lens is Vd5 = 25.426.

[0075] Please refer to the optical structure of Example 3. Figure 9 The specific parameters of this embodiment 3 are shown in Table 3 below. In this embodiment 3, the lens focal length f = 2.37 mm, the light transmission FNO = 2.0, the field of view FOV = 129°, the target surface size I MH = 4.32 mm, and the total length TTL = 12 mm.

[0076] Table 3 - Lens Parameter Table for Example 3

[0077]

[0078]

[0079] For ease of description, in Table 3: surface number 1 and surface number 2 are the object-side and image-side surfaces of the first lens, respectively; surface number 3 and surface number 4 are the object-side and image-side surfaces of the second lens, respectively; surface number 5 is the surface of the aperture stop; surface number 6 and surface number 7 are the object-side and image-side surfaces of the third lens, respectively; surface number 8 and surface number 9 are the object-side and image-side surfaces of the fourth lens, respectively; surface number 10 and surface number 11 are the object-side and image-side surfaces of the fifth lens, respectively; surface number 12 and surface number 13 are the object-side and image-side surfaces of the filter, respectively; surface number 14 and surface number 15 are the object-side and image-side surfaces of the protective glass; and surface number 16 is the surface of the imaging plane.

[0080] According to Table 3, the conditional expression of Embodiment 3 of the present invention can be read as follows:

[0081] (1) The refractive index of the first lens is Nd1 = 1.9108; the Abbe coefficient of the first lens is Vd1 = 35.282;

[0082] (2) The refractive index of the second lens is Nd2 = 2.0007; the Abbe coefficient of the second lens is Vd2 = 25.426;

[0083] (3) The refractive index of the fourth lens is Nd4 = 1.5928; the Abbe coefficient of the fourth lens is Vd4 = 68.342;

[0084] (4) The refractive index of the fifth lens is Nd5 = 2.0007; the Abbe coefficient of the fifth lens is Vd5 = 25.426.

[0085] Table 4 - Lens Parameters

[0086]

[0087]

[0088] In Example 1, due to the low yield and difficulty in ensuring eccentricity accuracy during the cold-working and grinding stage of concentric circular lenses, the performance of lenses is affected by various factors in the field of optical design. For quasi-concentric circular lenses, the yield of their optical characteristics is low during the cold-working and grinding stage, and the eccentricity accuracy is difficult to guarantee, which is mainly affected by the lens geometry and manufacturing tolerances. To overcome these limitations, the application proposes to set the third lens to satisfy the following relationship: |L3R1-L3R2|>3.

[0089] The following is an explanation of the various figures in Examples 1 to 3:

[0090] Figure 1 This is a structural diagram of the optical system of the lens in Embodiment 1. As can be seen from the diagram: the first lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the second lens has positive optical power, its object-side surface is convex, and its image-side surface is convex; the third lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the fourth lens has positive optical power, its object-side surface is convex, and its image-side surface is convex; the fifth lens has positive optical power, its object-side surface is convex, and its image-side surface is convex.

[0091] Figure 2 The image shows the MTF (Mean Transmission Format) of the lens in Example 1 at 850 nm in the near-infrared band. As can be seen from the image, the field of view (FOV) is 130°, the target size (IMH) is 4.62 mm, the MTF value is greater than 0.3 at 200 lp / mm, and greater than 0.45 at 125 lp / mm. The high MTF values ​​at both mid- and high-frequency frequencies indeed demonstrate that this example possesses high resolution and good imaging quality.

[0092] Figure 3 The image shows the distortion of the lens in Example 1 at 850nm in the near-infrared band. As can be seen from the image, the edge field-of-view distortion values ​​are all less than ±55%, indicating relatively low optical distortion in a short focal length wide-angle lens, resulting in excellent imaging performance and high image fidelity.

[0093] Figure 4 The figure shows the relative illumination of the lens in Example 1 at 850nm in the near-infrared band. As can be seen from the figure, the relative illumination of the lens is greater than 70% at a half field of view (HFOV) of 65°, indicating that the lens can still maintain high illumination at a large field of view. The illumination of the lens decreases less in the edge areas, and it can better maintain the overall brightness and color uniformity of the image.

[0094] Figure 5 This is a structural diagram of the optical system of the lens in Embodiment 2. As can be seen from the diagram: the first lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the second lens has positive optical power, its object-side surface is convex, and its image-side surface is convex; the third lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the fourth lens has positive optical power, its object-side surface is convex, and its image-side surface is convex; the fifth lens has positive optical power, its object-side surface is convex, and its image-side surface is concave.

[0095] Figure 6 The image shows the MTF (Mean Transmission Format) of the lens in Example 2 at 850 nm in the near-infrared band. As can be seen from the image, the field of view (FOV) is 125°, the target size (IMH) is 4.62 mm, the MTF value is greater than 0.15 at 200 lp / mm, and greater than 0.3 at 125 lp / mm. The high MTF values ​​at both mid- and high-frequency frequencies indeed demonstrate that this example possesses high resolution and good imaging quality.

[0096] Figure 7 This is a distortion diagram of the lens in Example 2 at 850nm in the near-infrared band. As can be seen from the figure, the edge field-of-view distortion values ​​are all less than ±50%, indicating relatively low optical distortion in a short focal length wide-angle lens, resulting in excellent imaging performance and high image fidelity. It is worth noting that the distortion control in Example 2 is better than that in Example 1.

[0097] Figure 8 The figure shows the relative illuminance of the lens in Example 2 at 850nm in the near-infrared band. As can be seen from the figure, the relative illuminance of the lens is greater than 70% at a half field of view (HFOV) of 62.5°, indicating that the lens can maintain high illuminance even at a large field of view. The illuminance of the lens decreases less in the edge areas, and it can maintain the overall brightness and color uniformity of the image well.

[0098] Figure 9This is a structural diagram of the optical system of the lens in Embodiment 3. As can be seen from the diagram: the first lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the second lens has positive optical power, its object-side surface is convex, and its image-side surface is concave; the third lens has positive optical power, its object-side surface is convex, and its image-side surface is concave; the fourth lens has positive optical power, its object-side surface is convex, and its image-side surface is convex; the fifth lens has positive optical power, its object-side surface is convex, and its image-side surface is concave.

[0099] Figure 10 The image shows the MTF (Mean Transmission Format) of the lens in Example 3 at 850 nm in the near-infrared band. As can be seen from the image, the field of view (FOV) is 129°, the target size (IMH) is 4.62 mm, the MTF value is greater than 0.2 at 200 lp / mm, and greater than 0.3 at 125 lp / mm. The high MTF values ​​at both mid- and high-frequency frequencies indeed demonstrate that this example possesses high resolution and good imaging quality.

[0100] Figure 11 The image shows the distortion of the lens in Example 3 at 850nm in the near-infrared band. As can be seen from the image, the edge field-of-view distortion values ​​are all less than ±55%, indicating relatively low optical distortion in a short focal length wide-angle lens, resulting in excellent imaging performance and high image fidelity. It is worth noting that the distortion control in Example 2 is better than that in Example 1.

[0101] Figure 12 The figure shows the relative illuminance of the lens in Example 3 at 850nm in the near-infrared band. As can be seen from the figure, the relative illuminance of the lens is greater than 70% at a half field of view (HFOV) of 65°, indicating that the lens can maintain high illuminance even at a large field of view. The illuminance of the lens decreases less in the edge areas, and it can maintain the overall brightness and color uniformity of the image well.

[0102] On the other hand, now refer to Figure 13 A schematic diagram of the structure of the electronic device A according to the present invention will be given. Figure 10 This is a schematic diagram of an electronic device (camera) for a camera optical system, one of the vehicle-mounted imaging lenses according to Embodiments 1 to 3.

[0103] exist Figure 13In the figures, reference numeral A2 indicates the main body of the electronic device, and reference numeral A1 indicates any of the imaging optical systems (interchangeable lenses) included in the vehicle-mounted imaging lenses according to Examples 1 to 3. Reference numeral A3 indicates an image sensor (photoelectric conversion element) such as a CMOS image sensor or a CCD image sensor, which is built into the camera body A2 and receives light (the optical image formed by the imaging optical system A1) from the imaging optical system A1 and performs photoelectric conversion.

[0104] By using the vehicle-mounted imaging lens according to any one of Embodiments 1 to 3 in electronic devices such as digital still cameras, electronic devices with high optical performance can be obtained.

[0105] Each example can provide electronic devices with high optical performance.

[0106] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims will be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A vehicle-mounted imaging lens, characterized in that, The lens has five elements, including a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side, wherein: The first lens has negative optical power, the object side of the first lens is convex, and the image side of the first lens is concave. The second lens has positive optical power, the object side of the second lens is convex, and the image side of the second lens is either convex or concave. The object-side surface of the third lens is convex, and the image-side surface of the third lens is either concave or convex. The fourth lens has positive optical power, and the object side of the fourth lens is convex, and the image side of the fourth lens is convex. The fifth lens has positive optical power, the object side of the fifth lens is convex, and the image side of the fifth lens is either convex or concave. The lens satisfies the following relationship: Nd5 > 1.9; Vd5 < 30; Wherein, Nd5 is the refractive index of the fifth lens, and Vd5 is the Abbe coefficient of the fifth lens.

2. The vehicle-mounted imaging lens as described in claim 1, characterized in that, The lens satisfies the following relationship: Nd1 > 1.9; Vd1 < 40; Wherein, Nd1 is the refractive index of the first lens, and Vd1 is the Abbe coefficient of the first lens.

3. The vehicle-mounted imaging lens as described in claim 1, characterized in that, The lens satisfies the following relationship: Nd2 > 1.9; Vd2 < 40; Wherein, Nd2 is the refractive index of the second lens, and Vd2 is the Abbe coefficient of the second lens.

4. The vehicle-mounted imaging lens as described in claim 1, characterized in that, The lens satisfies the following relationship: the impact resistance of the first lens is greater than 2.5 KJ / m^2, and the Knoop hardness is greater than 650 HK.

5. A vehicle-mounted imaging lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.55 < Nd⁴ < 1.65; Vd⁴ < 69; dn / dT < -6 * 10E⁻⁶ in the temperature range of -40℃ to 105℃. Wherein, Nd4 is the refractive index of the fourth lens, Vd4 is the Abbe coefficient of the fourth lens, and dn / dT is the temperature coefficient of the refractive index of the fourth lens.

6. A vehicle-mounted imaging lens as described in claim 1, characterized in that, The first lens, the second lens, and the third lens form a first combined lens, and the fourth lens and the fifth lens form a second combined lens. An aperture stop is provided between the first combined lens and the second combined lens.

7. A vehicle-mounted imaging lens as described in claim 1, characterized in that, The first lens and the second lens form a first combined lens, and the third lens, the fourth lens and the fifth lens form a second combined lens. An aperture stop is provided between the first combined lens and the second combined lens.

8. A vehicle-mounted imaging lens as described in claim 6 or 7, characterized in that, The lens satisfies the following relationship: -1.5<f1 / f2<-1; -2<f1 / f<-1; 1<f2 / f<1.5; Where f1 is the focal length of the first combined lens, f2 is the focal length of the second combined lens, and f is the total focal length of the lens.

9. An electronic device, characterized in that, A vehicle-mounted imaging lens according to any one of claims 1-8; and An image sensor is configured to receive images formed by the vehicle-mounted imaging lens.

Images