An optical lens

Abstract

The present invention discloses an optical lens, comprising a front lens group and a rear lens group, wherein the front lens group comprises a first lens L1 and a second lens L2 which are arranged in sequence, wherein the first lens L1 is a double concave negative lens; the second lens L2 is a double convex positive lens; the rear lens group comprises a third lens L3, a fourth lens L4 and a fifth lens L5, wherein the third lens L3 is a double concave negative lens or a positive meniscus lens with a convex object side surface; the fourth lens L4 is a positive meniscus lens with a convex object side surface; and the fifth lens L5 is a double convex positive lens or a positive meniscus lens with a convex object side surface. The present invention enables the entire optical system to have the performance of miniaturization, low distortion and high resolution by reasonably allocating the positions of the lenses in the optical system, controlling the refractive index of the lenses and reasonably allocating the positions of the lenses with different optical powers.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical lenses, and in particular relates to an optical lens having the advantages of miniaturization, low distortion, large light transmission, high relative illumination, large target surface and high resolution. Background Art

[0002] The on-board camera is an important component for autonomous driving equipment to obtain real-time data on the environment. It plays the role of "eyes" in the intelligent driving system and determines the accuracy of the information obtained.

[0003] Due to the particularity of the use environment, the performance of automotive lenses often needs to be much higher than that of ordinary lenses, such as lower imaging distortion, higher relative illumination, larger imaging target area and smaller size.

[0004] Existing vehicle-mounted lenses have certain deficiencies and defects. The market demand for vehicle-mounted lenses with lower imaging distortion, higher relative illumination, larger imaging target area and smaller volume is far from being met.

[0005] Therefore, an automotive lens that meets the above requirements has become an urgent need in the current market. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides an optical lens, which is mainly used for vehicle-mounted lenses.

[0007] To achieve the above object, the present invention provides the following technical solution: an optical lens, comprising:

[0008] A front lens group disposed on the object side, the front lens group comprising a first lens L1 and a second lens L2 disposed in sequence, the first lens L1 being a biconcave negative lens; the second lens L2 being a biconvex positive lens; and

[0009] A rear lens group is arranged on the image side of the front lens group, and the rear lens group includes a third lens L3, a fourth lens L4 and a fifth lens L5, wherein the third lens L3 is a biconcave negative lens or a positive meniscus lens with a convex object side surface; the fourth lens L4 is a positive meniscus lens with a convex object side surface; and the fifth lens L5 is a biconvex positive lens or a positive meniscus lens with a convex object side surface.

[0010] The optical lens meets the following conditions: 2≤FOV / CRA≤2.2; |f u1 / f|≤1.9;|f u2 / f|≥1.5, wherein FOV represents the maximum field of view of the optical lens; CRA represents the chief ray angle of the optical lens; f represents the effective focal length of the optical lens; f u1 Indicates the effective focal length of the front lens group; f u2 Indicates the effective focal length of the rear lens group.

[0011] As a specific implementation method, the aperture of the largest lens in the optical lens is SD max , the total optical length of the optical lens is TTL, SD max With TTL, the following conditions are met: SD max / TTL≤0.24.

[0012] As a specific implementation, the maximum image plane height of the optical lens is IH, the aperture value of the optical lens is FNO, and IH and FNO satisfy the following condition: IH / FNO≥1.4.

[0013] As a specific implementation, the refractive index of the second lens L2 is N d2 , N d2 Meet the following conditions: N d2 ≥2.

[0014] As a specific implementation, the refractive index of the fifth lens L5 is N d5 , Abbe number is V D5 , N d2 、V D5 The following conditions are met: N d5 ≤1.8;V D5 ≥54.

[0015] As a specific implementation, when the third lens L3 is a meniscus positive lens with a convex object side surface, and the fifth lens L5 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 0.0600 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; the air distance from the aperture C to the third lens L3 is 0.5100 mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1212 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.0633 mm; and the air distance from the fifth lens L5 to the image plane IMG is 5.6038 mm.

[0016] As a specific implementation, when the third lens L3 is a double concave negative lens and the fifth lens L5 is a meniscus positive lens with a convex object side surface, the air distance from the first lens L1 to the second lens L2 is 0.0848 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; the air distance from the aperture C to the third lens L3 is 0.5100 mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1708 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1268 mm; and the air distance from the fifth lens L5 to the image plane IMG is 5.6072 mm.

[0017] As a specific implementation, when the third lens L3 is a double concave negative lens and the fifth lens L5 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 0.0881 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; the air distance from the aperture C to the third lens L3 is 0.6300 mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1735 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.2300 mm; and the air distance from the fifth lens L5 to the image plane IMG is 5.6842 mm.

[0018] Compared with the prior art, the present invention provides an optical lens for vehicle, which has the following beneficial effects:

[0019] 1) The present invention controls the focal length of different optical systems by reasonably allocating the positions of the lenses in the optical system, thereby achieving the purpose of low distortion;

[0020] 2) By reasonably allocating the proportion of the optical power of the front and rear lens groups to the optical power of the entire lens, the system's high relative illumination and high resolution requirements can be achieved;

[0021] 3) By controlling the focal length of the second lens L2, TTL ≤ 11.2 mm, and its refractive index satisfies N d2 ≥2, to meet the demand for miniaturization of lenses;

[0022] 4) By controlling the refractive index of the lens in the imaging system, the miniaturization of the lens is achieved; by adjusting the aperture of the largest lens in the optical lens to control the incident light, the requirement of high relative illumination is met. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the optical structure of the optical lens proposed by the present invention;

[0024] Figure 2 is a light path diagram of the optical lens in Example 1;

[0025] Figure 3 is an MTF resolution curve diagram of the optical lens in Example 1;

[0026] Figure 4 is a field curvature distortion diagram of the optical lens in Example 1;

[0027] Figure 5 is a schematic diagram of a relative illumination curve of the optical lens in Example 1;

[0028] Figure 6 is a light path diagram of the optical lens in Example 2;

[0029] Figure 7is an MTF resolution curve diagram of the optical lens in Example 2;

[0030] Figure 8 is a field curvature distortion diagram of the optical lens in Example 2;

[0031] Fig. 9 is a schematic diagram of a relative illumination curve of the optical lens in Example 2;

[0032] Fig.10 is a light path diagram of the optical lens in Example 3;

[0033] Fig.11 is an MTF resolution curve diagram of the optical lens in Example 3;

[0034] Fig.12 is a field curvature distortion diagram of the optical lens in Example 3;

[0035] Fig.13 Schematic diagram of the relative illumination curve of the optical lens in Example 3. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the following embodiments, the lens materials in the optical system are all glass materials with a conventional refractive index. Example 1

[0038] In this example, an optical lens is provided as a vehicle-mounted lens, which is arranged in sequence from the object side to the image side along the optical axis: a front lens group, an aperture, and a rear lens group.

[0039] The front lens group includes a first lens L1 and a second lens L2. The first lens L1 is a double concave negative lens; the second lens L2 is a double convex positive lens.

[0040] The rear lens group includes a third lens L3, a fourth lens L4 and a fifth lens L5. The third lens L3 is a positive meniscus lens with a convex object side surface; the fourth lens L4 is a positive meniscus lens with a convex object side surface; and the fifth lens L5 is a double convex positive lens.

[0041] The optical structure of the lens described in this example is shown in Figure 1 As shown, the optical path diagram is shown in Figure 2 shown.

[0042] See Table 1, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0043] Table 1

[0044]

[0045] Infinity means infinity. Among them, the air distance from the first lens L1 to the second lens L2 is 0.0600mm; the air distance from the second lens L2 to the aperture C is 0.0400mm; the air distance from the aperture C to the third lens L3 is 0.5100mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1212mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.0633mm; the air distance from the fifth lens L5 to the image plane IMG is 5.6038mm.

[0046] The technical indicators achieved by the optical system in this example are as follows:

[0047] 1) Maximum field of view FOV of the optical lens: FOV = 36.0000°;

[0048] 2) Effective focal length f of the front lens u1 :f u1 =9.2644mm;

[0049] 3) The effective focal length f of the rear lens u2 :f u2 =8.1847mm;

[0050] 4) Abbe number V of the fifth lens L5 D5 :V D5 =54.68;

[0051] 5) The refractive index N of the second lens L2 d2 :N d2 =2.00;

[0052] 6) Refractive index N of the fifth lens L5 d5 :N d5 =1.73;

[0053] 7) Effective focal length of optical lens: f=5.0777mm;

[0054] 8) Total optical length TTL of the optical lens: TTL = 11.0153 mm;

[0055] 9) Chief ray angle CRA of optical lens: CRA = 17.0926°;

[0056] 10) The clear aperture SD of the largest lens in the optical lens max:SD max =2.2929mm;

[0057] 11) Maximum image plane height IH of the optical lens: IH = 3.0900mm;

[0058] 12) Aperture value FNO of optical lens: FNO=2.0668.

[0059] In addition, it is calculated that:

[0060] FOV / CRA=2.1062;f u1 / f=1.8245;f u2 / f=1.6119;SD max / TTL=0.2082;IH / FNO=1.4951.

[0061] Here, the proportion of the front and rear group focal lengths to the focal length of the entire lens is reasonably allocated, that is, |f u1 / f|≤1.9,|f u2 / f|≥1.5, to achieve the system's high relative illumination and high resolution requirements; by reasonably allocating the positions of each lens in the optical system, that is, 2≤FOV / CRA≤2.2, to achieve the low distortion requirements.

[0062] In addition, through SD max / TTL≤0.24, the refractive index N of the second lens L2 d2 ≥2, the miniaturization of the optical lens is realized; IH / FNO≥1.4, the large target surface of the optical lens is realized; when the refractive index and Abbe number of the fifth lens L5 meet N d5 ≤1.8;V D5 When ≥54, the stability of the lens group can be effectively improved.

[0063] Here, the first lens L1 adopts a double concave negative lens to calibrate the light entering the lens, which is beneficial to obtaining higher imaging quality; the second lens L2 adopts a double convex positive lens to compress the light collected by the first lens L1 and reduce the diameter of the incident light, which is beneficial to controlling the volume of the lens, and the aperture is placed between the second lens L2 and the third lens L3 to control the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam; the third lens L3 has a larger radius of curvature facing the image side, which is beneficial to the smooth transition of light to the rear imaging system; the fourth lens L4 adopts a meniscus positive lens, whose object side surface is convex, which is used to focus the light collected by the third lens L3, which is beneficial to controlling the volume of the lens; the fifth lens L5 focuses the light collected by the fourth lens L4 and corrects the aberrations to optimize the imaging performance of the lens group.

[0064] Figure 3This is the MTF curve of the optical lens. It can be seen from the figure that at the spatial frequency of 83pl / mm, its MTF value is greater than 0.45, indicating that the optical system has good imaging quality;

[0065] Figure 4 is the field curvature distortion diagram of the optical lens, from Figure 4 It can be seen that the distortion control of this lens is good, meeting the distortion requirements of vehicle-mounted lenses; Figure 5 This is the relative illumination curve of the optical lens. It can be seen that under the maximum field of view, the relative illumination value of the lens is greater than 65%. Example 2

[0066] In this example, a vehicle-mounted optical lens is provided, which is arranged in sequence from the object side to the image side along the optical axis: a front lens group, an aperture, and a rear lens group.

[0067] The front lens group includes a first lens L1 and a second lens L2. The first lens L1 is a double concave negative lens; the second lens L2 is a double convex positive lens.

[0068] The rear lens group includes a third lens L3, a fourth lens L4 and a fifth lens L5. The third lens L3 is a double concave negative lens; the fourth lens L4 is a positive meniscus lens, whose object side surface is convex; and the fifth lens L5 is a positive meniscus lens, whose object side surface is convex.

[0069] The optical path diagram of the lens described in this example is shown in Figure 6 shown.

[0070] See Table 2, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0071] Table 2

[0072]

[0073] Among them, the air distance from the first lens L1 to the second lens L2 is 0.0848mm; the air distance from the second lens L2 to the aperture C is 0.0400mm; the air distance from the aperture C to the third lens L3 is 0.5100mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1708mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1268mm; the air distance from the fifth lens L5 to the image plane IMG is 5.6072mm.

[0074] The technical indicators achieved by the optical system in this example are as follows:

[0075] 1) Maximum field of view FOV of the optical lens: FOV = 36.0000°;

[0076] 2) Effective focal length f of the front lensu1 :f u1 =9.2639mm;

[0077] 3) The effective focal length f of the rear lens u2 :f u2 =8.1350mm;

[0078] 4) Abbe number V of the fifth lens L5 D5 :V D5 =54.68;

[0079] 5) The refractive index N of the second lens L2 d2 :N d2 =2.00;

[0080] 6) Refractive index N of the fifth lens L5 d5 :N d5 =1.73;

[0081] 7) Effective focal length of optical lens: f=5.0797mm;

[0082] 8) Total optical length TTL of the optical lens: TTL = 11.0563 mm;

[0083] 9) Chief ray angle CRA of the optical lens: CRA = 16.7564°;

[0084] 10) The clear aperture SD of the largest lens in the optical lens max :SD max =2.5500mm;

[0085] 11) Maximum image plane height IH of the optical lens: IH = 3.0900mm;

[0086] 12) Aperture value FNO of optical lens: FNO=2.0716.

[0087] In addition, it is calculated that:

[0088] FOV / CRA=2.1484;f u1 / f=1.8237;f u2 / f=1.6015;SD max / TTL=0.2306;IH / FNO=1.4916.

[0089] Figure 7 , Figure 8 , Fig. 9 is the optical performance curve of this embodiment, wherein Figure 7 This is the MTF curve of the optical lens. It can be seen from the figure that at the spatial frequency of 83pl / mm, its MTF value is greater than 0.46; Figure 8is the field curvature distortion diagram of the optical lens, from Figure 8 It can be seen that the distortion control of this lens is good, meeting the distortion requirements of vehicle-mounted lenses; Fig. 9 This is the relative illumination curve of the optical lens. It can be seen that under the maximum field of view, the relative illumination value of the lens is greater than 60%. Example 3

[0090] In this example, a vehicle-mounted optical lens is provided, which is arranged in sequence from the object side to the image side along the optical axis: a front lens group, an aperture, and a rear lens group.

[0091] The front lens group includes a first lens L1 and a second lens L2. The first lens L1 is a double concave negative lens; the second lens L2 is a double convex positive lens.

[0092] The rear lens group includes a third lens L3, a fourth lens L4 and a fifth lens L5. The third lens L3 is a double concave negative lens; the fourth lens L4 is a meniscus positive lens, whose object side surface is convex; and the fifth lens L5 is a double convex positive lens.

[0093] The optical path diagram of the lens described in this example is shown in Fig.10 shown.

[0094] See Table 3, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0095] Table 3

[0096]

[0097] Among them, the air distance from the first lens L1 to the second lens L2 is 0.0881mm; the air distance from the second lens L2 to the aperture C is 0.0400mm; the air distance from the aperture C to the third lens L3 is 0.6300mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1735mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.2300mm; the air distance from the fifth lens L5 to the image plane IMG is 5.6842mm.

[0098] The technical indicators achieved by the optical system in this example are as follows:

[0099] 1) Maximum field of view FOV of the optical lens: FOV = 36.0000°;

[0100] 2) Effective focal length f of the front lens u1 :f u1 =9.5411mm;

[0101] 3) The effective focal length f of the rear lens u2 :f u2=7.9094mm;

[0102] 4) Abbe number V of the fifth lens L5 D5 :V D5 =54.68;

[0103] 5) The refractive index N of the second lens L2 d2 :N d2 =2.00;

[0104] 6) Refractive index N of the fifth lens L5 d5 :N d5 =1.73;

[0105] 7) Effective focal length of optical lens: f=5.0793mm;

[0106] 8) Total optical length TTL of the optical lens: TTL = 11.0419 mm;

[0107] 9) Chief ray angle CRA of the optical lens: CRA = 16.4802°;

[0108] 10) The clear aperture SD of the largest lens in the optical lens max :SD max =2.5500mm;

[0109] 11) Maximum image plane height IH of the optical lens: IH = 3.0900mm;

[0110] 12) Aperture value FNO of optical lens: FNO=2.0631.

[0111] In addition, it is calculated that:

[0112] FOV / CRA=2.1844;f u1 / f=1.8784;f u2 / f=1.5572;SD max / TTL=0.2309;IH / FNO=1.4978.

[0113] Fig.11 , Fig.12 , Fig.13 is the optical performance curve of this embodiment, wherein Fig.11 This is the MTF curve of the optical lens. It can be seen from the figure that at the spatial frequency of 83pl / mm, its MTF value is greater than 0.48; Fig.12 is the field curvature distortion diagram of the optical lens, from Fig.12 It can be seen that the distortion control of this lens is good, meeting the distortion requirements of vehicle-mounted lenses; Fig.13This is the relative illumination curve of the optical lens. It can be seen that under the maximum field of view, the relative illumination value of the lens is greater than 60%.

[0114] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical lens, characterized in that: include: The optical lens has a total of 5 lenses, specifically: A front lens group disposed on the object side, the front lens group includes a first lens L1 and a second lens L2 disposed in sequence, the first lens L1 is a biconcave negative lens; the second lens L2 is a biconvex positive lens; as well as A rear lens group disposed on the image side of the front lens group, the rear lens group includes a third lens L3, a fourth lens L4 and a fifth lens L5, wherein the third lens L3 is a biconcave negative lens or a positive meniscus lens with a concave object side surface; the fourth lens L4 is a positive meniscus lens with a concave object side surface; and the fifth lens L5 is a biconvex positive lens or a positive meniscus lens with a convex image side surface. The optical lens meets the following conditions: 2≤FOV / CRA≤2.2; |f u1 / f|≤1.9;1.5≤|f u2 / f|≤1.6119, wherein FOV represents the maximum field of view of the optical lens; CRA represents the chief ray angle of the optical lens; f represents the effective focal length of the optical lens; f u1 Indicates the effective focal length of the front lens group; f u2 Indicates the effective focal length of the rear lens group; The maximum aperture of the optical lens is SD max , the total optical length of the optical lens is TTL, SD max With TTL, the following conditions are met: SD max / TTL≤0.

24.

2. An optical lens according to claim 1, characterized in that: The maximum image plane height of the optical lens is IH, the aperture value of the optical lens is FNO, and IH and FNO satisfy the following conditions: 1.4≤IH / FNO≤1.4978.

3. An optical lens according to claim 1, characterized in that: The refractive index of the second lens L2 is N d2 , N d2 Meet the following conditions: N d2 ≥2.

4. The optical lens according to claim 1, characterized in that: The refractive index of the fifth lens L5 is N d5 , Abbe number is V D5 , N d2 、V D5 The following conditions are met: N d5 ≤1.8;V D5 ≥54.

5. The optical lens according to claim 1, characterized in that: When the third lens L3 is a meniscus positive lens with a concave object side surface, and the fifth lens L5 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 0.0600 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; and the air distance from the aperture C to the third lens L3 is 0.5100 mm; The air distance from the third lens L3 to the fourth lens L4 is 0.1212 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.0633 mm; and the air distance from the fifth lens L5 to the image plane IMG is 5.6038 mm.

6. The optical lens according to claim 1, characterized in that: When the third lens L3 is a double concave negative lens, and the fifth lens L5 is a positive meniscus lens with a convex image side surface, the air distance from the first lens L1 to the second lens L2 is 0.0848 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; and the air distance from the aperture C to the third lens L3 is 0.5100 mm; The air distance from the third lens L3 to the fourth lens L4 is 0.1708 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1268 mm; and the air distance from the fifth lens L5 to the image plane IMG is 5.6072 mm.

7. The optical lens according to claim 1, characterized in that: When the third lens L3 is a double concave negative lens and the fifth lens L5 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 0.0881 mm; the air distance from the second lens L2 to the aperture C is 0.0400 mm; the air distance from the aperture C to the third lens L3 is 0.6300 mm; the air distance from the third lens L3 to the fourth lens L4 is 0.1735 mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.2300 mm; The air distance from the fifth lens L5 to the image plane IMG is 5.6842 mm.

Images