Wide-angle lens

Abstract

The wide-angle lens comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object plane to an image plane along an optical axis, the first lens is a glass spherical lens with negative focal power, the object side face of the first lens is a convex face, and the image side face of the first lens is a concave face. The second lens is a plastic aspheric lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface. The third lens is a plastic aspheric lens with positive focal power, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface. The fourth lens is a plastic aspheric lens with positive focal power, the object side surface of the fourth lens is a convex surface or a concave surface, and the image side surface of the fourth lens is a convex surface. The glass spherical surface and the plastic aspheric surface are matched and combined, the resolution is improved, the total axis length is smaller than 10.5 mm, the aperture F can reach 1.6, the field angle FOV can reach 183 degrees, the relative illumination can reach 50%, and the lens has the advantages of being large in aperture, ultra-large in field angle, small in size and high in illumination.

Description

Technical Field

[0001] The present invention relates to the field of optical device technology, and in particular to a wide-angle lens. Background Technology

[0002] With the increasing penetration rate of intelligent cockpits and Advanced Driver-Assistance Systems (ADAS), automobiles are increasingly demanding more environmental perception and human-machine interaction capabilities. Time-of-Flight (TOF) lenses can quickly acquire high-precision depth information and can be used in scenarios such as Driver Monitoring Systems (DMS), Occupant Monitoring Systems (OMS), and gesture interaction, meeting the high-performance sensor requirements of the intelligent development of automobiles.

[0003] TOF stands for Time of Flight, which calculates the time it takes for light to travel. TOF technology is widely used due to its advantages, including fast response, high depth accuracy, small size, and resistance to ambient light interference.

[0004] In the automotive field, traditional automotive TOF lenses are generally over 13mm in total length, large in size, and have a small field of view, which is not conducive to lens integration and interior aesthetics, and is not suitable for installation on cars.

[0005] Therefore, there is an urgent need to provide a new type of automotive TOF lens that combines small size, wide field of view, short focal length, integrability, and aesthetic appeal to interior decoration, making it a perfect fit for automobiles. Summary of the Invention

[0006] Based on this, the present invention provides a wide-angle lens that uses a combination of glass spherical and plastic aspherical surfaces to improve resolution. The total axis length is less than 10.5mm, the aperture can reach F1.6, the field of view (FOV) can reach 183°, and the relative illumination can reach 50%. It has the advantages of large aperture, ultra-large field of view, miniaturization, and high illumination.

[0007] This application provides a wide-angle lens, including a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along the optical axis from the object plane to the image plane;

[0008] The first lens is a glass spherical lens with negative optical power, its object side is convex and its image side is concave;

[0009] The second lens is a plastic aspherical lens with negative optical power, its object side is convex and its image side is concave.

[0010] The third lens is a plastic aspherical lens with positive optical power, its object side is concave and its image side is convex.

[0011] The fourth lens is a plastic aspherical lens with positive optical power, the object side of which is convex or concave, and the image side of which is convex.

[0012] Optionally, the optical power of the first lens to the fourth lens satisfies the following condition:

[0013] -0.38 ≤ Φ1 / Φ ≤ -0.27; -0.30 ≤ Φ2 / Φ ≤ -0.25;

[0014] 0.12 ≤ Φ3 / Φ ≤ 0.38; 0.42 ≤ Φ4 / Φ ≤ 0.45;

[0015] Wherein, Φ is the optical power of the entire wide-angle lens, and Φ1, Φ2, Φ3, and Φ4 are the optical powers of the first lens, the second lens, the third lens, and the fourth lens, respectively.

[0016] Optionally, the refractive index and Abbe number of the first lens to the fourth lens satisfy the following condition:

[0017] 1.67 ≤ n1 ≤ 1.92; 18.90 ≤ v1 ≤ 50.00;

[0018] 1.54 ≤ n2 ≤ 1.64; 23.40 ≤ v2 ≤ 56.00;

[0019] 1.64 ≤ n3 ≤ 1.67; 23.40 ≤ v3 ≤ 27.60;

[0020] 1.54 ≤ n4 ≤ 1.64; 23.40 ≤ v4 ≤ 56.00;

[0021] Wherein, n1, n2, n3, and n4 are the refractive indices of the first lens, the second lens, the third lens, and the fourth lens, respectively, and v1, v2, v3, and v4 are the Abbe numbers of the first lens, the second lens, the third lens, and the fourth lens, respectively.

[0022] Optionally, the optical back focal length (BFL) of the wide-angle lens and the total axial length (TTL) of the wide-angle lens satisfy the following condition: BFL / TTL > 0.2.

[0023] Optionally, the true image height IH corresponding to the maximum field of view of the wide-angle lens and the entrance pupil diameter EPD of the wide-angle lens satisfy the following condition: 4.7 < IH / EPD < 5.7.

[0024] Optionally, the central radius of curvature R1 of the first lens object side and the total focal length EFFL of the wide-angle lens satisfy the following condition: 10 ≤ R1 / EFFL ≤ 15.4.

[0025] Optionally, the wide-angle lens further includes an aperture stop disposed between the third lens and the fourth lens.

[0026] Optionally, the optical total axis length (TTL) of the wide-angle lens is less than 10.5 mm.

[0027] Optionally, the aperture number F of the wide-angle lens satisfies: F≤1.63.

[0028] Optionally, the maximum field of view (FOV) of the wide-angle lens is greater than or equal to 182°.

[0029] This invention discloses a wide-angle lens, comprising a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along the optical axis from the object plane to the image plane. The first lens is a glass spherical lens with negative optical power, its object-side surface being convex and its image-side surface being concave. The second lens is a plastic aspherical lens with negative optical power, its object-side surface being convex and its image-side surface being concave. The third lens is a plastic aspherical lens with positive optical power, its object-side surface being concave and its image-side surface being convex. The fourth lens is a plastic aspherical lens with positive optical power, its object-side surface being either convex or concave, and its image-side surface being convex. The combination of glass spherical and plastic aspherical lenses improves resolution, achieving a total axial length of less than 10.5 mm, an aperture of up to f / 1.6, a field of view (FOV) of up to 183°, and a relative illumination of up to 50%. It offers advantages such as a large aperture, a very wide field of view, miniaturization, and high illumination. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 1 of this application;

[0031] Figure 2 A relative illumination diagram of a wide-angle lens provided in Embodiment 1 of this application;

[0032] Figure 3 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 2 of this application;

[0033] Figure 4 A relative illumination diagram of a wide-angle lens provided in Embodiment 2 of this application;

[0034] Figure 5 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 3 of this application;

[0035] Figure 6This is a relative illumination diagram of a wide-angle lens provided in Embodiment 3 of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] L1, first lens; L2, second lens; L3, third lens; L4, fourth lens. Detailed Implementation

[0038] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the present application and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present application are shown in the drawings, not the entire structure. Various modifications and variations can be made to the present application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, the present application is intended to cover modifications and variations of the present application that fall within the scope of the technical solutions claimed in the corresponding claims and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0039] Figure 1 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 1 of this application, with reference to... Figure 1 This invention provides a wide-angle lens 100, comprising a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged sequentially along the optical axis from the object plane to the image plane. The first lens L1 is a glass spherical lens with negative optical power, its object-side surface being convex and its image-side surface being concave. The second lens L2 is a plastic aspherical lens with negative optical power, its object-side surface being convex and its image-side surface being concave. The third lens L3 is a plastic aspherical lens with positive optical power, its object-side surface being concave and its image-side surface being convex. The fourth lens L4 is a plastic aspherical lens with positive optical power, its object-side surface being either convex or concave, and its image-side surface being convex.

[0040] Optical power is equal to the difference between the image-side convergence and the object-side convergence of the light beam, and its value is the reciprocal of the focal length. It characterizes the ability of a wide-angle lens to deflect light. The larger the absolute value of the optical power, the stronger the ability to bend light; the smaller the absolute value of the optical power, the weaker the ability to bend light. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a lens group formed by multiple lenses.

[0041] refer to Figure 1The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are arranged sequentially along the optical axis from the object plane to the image plane. It should be noted that... Figure 1 The structural diagrams in the subsequent embodiments are for illustrative purposes only, and shapes such as aspherical surfaces are not represented in accordance with actual conditions.

[0042] The optical power combination of the first lens L1 to the fourth lens L4 satisfies negative, negative, positive, and positive. The first lens L1 is a meniscus lens with a convex object-side surface and a concave image-side surface. The second lens L2 is also a meniscus lens with a convex object-side surface and a concave image-side surface. Concave lenses diverge transmitted light, while convex lenses converge transmitted light. This application, by rationally setting the surface shapes of the first lens L1 and the second lens L2, can better allow light to enter the optical system, enabling smooth light propagation, avoiding excessive refraction, and preventing the introduction of aberrations.

[0043] The first lens L1 and the second lens L2, both with negative optical power, diverge the incident light rays, thus increasing the entrance pupil. The third lens L3, with positive optical power, converges the light rays and adjusts the beam. The fourth lens L4, with positive optical power, converges the light rays and forms an image on the image plane M.

[0044] Based on the above embodiment, an aperture stop STO is also provided between the third lens L3 and the fourth lens L4. The first lens L1, the second lens L2, and the third lens L3 form the front optical system of the wide-angle lens, and the fourth lens L4 is the rear optical system of the wide-angle lens. By adjusting the size of the aperture stop STO, stray light from the edges can be limited from entering the system, thereby improving image quality.

[0045] Among them, the aperture stop STO includes the aperture stop and the field stop. The aperture stop refers to the stop that restricts the beam the most, and the field stop refers to the stop that restricts the field of view (size) the most.

[0046] Considering that glass is more stable than plastic in high and low temperature environments, and that glass lenses have stronger light-reflecting capabilities, the first lens L1 of this application uses a glass spherical lens as the entrance pupil. This helps reduce the number of lenses, decrease lens size, reduce focus drift caused by thermal effects, and improve lens stability. Given that aspherical lenses have excellent control over optical aberrations and higher-order optical aberrations, the second lens L2, third lens L3, and fourth lens L4 all use plastic aspherical lenses. This reduces lens costs while simultaneously controlling optical aberrations and higher-order optical aberrations.

[0047] It should be noted that the materials of the glass spherical lens and the plastic aspherical lens are various types of glass and plastic known to those skilled in the art, and this application embodiment will not elaborate on or limit them.

[0048] In this embodiment of the application, the aspherical lens of the wide-angle lens satisfies the following formula:

[0049] .

[0050] Where z represents the axial sagitta in the Z direction of the aspherical surface; r represents the distance from a point on the aspherical surface to the optical axis; c represents the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k represents the fitted conic coefficients; A, B, C, D, E, F, and G represent the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial, respectively.

[0051] Based on the above embodiments, the optical power of the first lens L1 to the fourth lens L4 satisfies the following condition:

[0052] -0.38 ≤ Φ1 / Φ ≤ -0.27; -0.30 ≤ Φ2 / Φ ≤ -0.25.

[0053] 0.12 ≤ Φ3 / Φ ≤ 0.38; 0.42 ≤ Φ4 / Φ ≤ 0.45.

[0054] Where Φ is the optical power of the entire wide-angle lens, and Φ1, Φ2, Φ3, and Φ4 are the optical powers of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, respectively.

[0055] Specifically, the first lens L1 provided in this embodiment is a convex-concave glass spherical lens. When the optical power of the first lens L1 is within the above-mentioned range, it can further reduce the angle of light deflection, allowing the light to enter the optical system smoothly and without excessive refraction during propagation, thus avoiding the introduction of greater aberrations. When the optical powers of the second lens L2 and the third lens L3 both meet the above-mentioned range, and plastic aspherical lenses are used, the lens cost can be reduced while correcting system optical aberrations.

[0056] The fourth lens L4 is a biconvex or concave-convex plastic aspherical lens with positive optical power. When its optical power meets the above range, it is beneficial to correct system aberrations and control the angle of the system principal rays to match the imaging detector (Sensor) paired with the lens and improve illumination.

[0057] Among them, the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium, mainly used to describe the refraction ability of the material. Different materials have different refractive indices. The higher the refractive index, the slower the speed of light in the material. The Abbe number is an index used to represent the dispersion ability of a transparent medium, also known as the dispersion coefficient. The more severe the medium dispersion, the smaller the Abbe number; conversely, the milder the medium dispersion, the larger the Abbe number. Generally speaking, the refractive index and the Abbe number are inversely proportional. This means that materials with higher refractive indices tend to have lower Abbe numbers, and vice versa.

[0058] Based on the above embodiments, the refractive indices and Abbe numbers of the first lens L1 to the fourth lens L4 satisfy the following conditions:

[0059] 1.67 ≤ n1 ≤ 1.96; 18.90 ≤ v1 ≤ 50.00.

[0060] 1.54 ≤ n2 ≤ 1.64; 23.40 ≤ v2 ≤ 56.00.

[0061] 1.64 ≤ n3 ≤ 1.67; 23.40 ≤ v3 ≤ 27.60.

[0062] 1.54 ≤ n4 ≤ 1.64; 23.40 ≤ v4 ≤ 56.00.

[0063] Among them, n1, n2, n3, and n4 are the refractive indices of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 respectively, and v1, v2, v3, and v4 are the Abbe numbers of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 respectively.

[0064] Specifically, the first lens L1 is a glass spherical lens, whose refractive index range is 1.67 < n1 < 1.96, and whose Abbe number range is 18.9 < v1 < 50. When the refractive index and Abbe number of the first lens L1 are within this range, it can better converge light, reduce the ratio of the entrance pupil diameter to the curvature radius of the lens, and achieve the purpose of miniaturization. The third lens L3 is an aspherical lens, whose refractive index range is 1.64 < n3 < 1.67, and whose Abbe number range is 23.4 < v3 < 27.6. This lens can play a role in correcting aberration, making the light more smooth, and ensuring that the light is transmitted to the fourth lens efficiently.

[0065] In summary, by reasonably matching the optical power parameters and Abbe numbers of the first lens L1 to the fourth lens L4, this application can achieve the characteristics of large aperture, ultra-large field angle, miniaturization, and high illumination.

[0066] Based on the above embodiments, the optical axis length (TTL) of the wide-angle lens 100 is less than 10.5mm, achieving small size and miniaturization.

[0067] Based on the above embodiments, the aperture number F of the wide-angle lens 100 satisfies: F≤1.63, achieving a large aperture that allows more light to enter the lens, with a relative illuminance of up to 50%. Here, the lens illuminance refers to the total amount of light passing through the lens and reaching the camera sensor (or film) per unit time when the lens is at its maximum aperture.

[0068] Based on the above embodiments, the maximum field of view (FOV) of the wide-angle lens 100 is greater than or equal to 182°. The field of view refers to the angular size of the area of ​​the image that the lens can capture. The wide-angle lens 100 provided in this application achieves a maximum field of view (FOV) of 182°, enabling shooting with a wide viewing angle.

[0069] Based on the above embodiments, the optical rear focal length (BFL) of the wide-angle lens 100 and the total axial length (TTL) of the wide-angle lens 100 satisfy the condition: BFL / TTL > 0.2. This allows for a more compact lens structure and miniaturization, while the larger optical rear focal length (BFL) of the wide-angle lens 100 facilitates module assembly.

[0070] Based on the above embodiments, the true image height IH corresponding to the maximum field of view of the wide-angle lens 100 and the entrance pupil diameter EPD of the wide-angle lens 100 satisfy the following condition: 4.7 < IH / EPD < 5.7. This range setting helps to increase the width of the light beam entering the wide-angle lens and improve the brightness of the image plane.

[0071] Based on the above embodiments, the central radius of curvature R1 of the object side of the first lens L1 and the overall focal length EFFL of the wide-angle lens 100 satisfy the following: 10 ≤ R1 / EFFL ≤ 15.4. This range setting allows the wide-angle lens to effectively control the curvature of the first lens L1 while ensuring appropriate optical power distribution, reducing the generation of spherical aberration and coma, and improving the imaging sharpness and image quality uniformity of the wide-angle lens.

[0072] Based on the above embodiments, the wide-angle lens 100 may further include a filter CG disposed in the optical path between the fourth lens L4 and the image plane M. The filter CG serves to filter light and protect the photosensitive chip in the imaging sensor. The photosensitive chip is used to convert the light signals collected by the wide-angle lens into electrical signals, thereby ensuring the imaging effect of the wide-angle lens.

[0073] In summary, the wide-angle lens provided in this application improves resolution by using a combination of glass spherical and plastic aspherical surfaces. It has a total axial length of less than 10.5mm, an aperture of up to f / 1.6, a field of view of up to 183°, and a relative illumination of up to 50%. It meets the requirements of large aperture, ultra-wide field of view, miniaturization, and high illumination, and can be applied to automotive lenses.

[0074] The following describes in further detail, with reference to the accompanying drawings, specific embodiments of the wide-angle lens applicable to the above-described embodiments.

[0075] Example 1

[0076] Continue to refer to Figure 1 The wide-angle lens 100 provided in Embodiment 1 of the present invention includes a first lens L1, a second lens L2, a third lens L3, an aperture stop STO, a fourth lens L4, and a filter CG arranged sequentially along the optical axis from the object plane to the image plane. The first lens L1 is a glass spherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The second lens L2 is a plastic aspherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The third lens L3 is a plastic aspherical lens with positive optical power, its object-side surface is concave, and its image-side surface is convex. The fourth lens L4 is a plastic aspherical lens with positive optical power, its object-side surface is convex, and its image-side surface is convex.

[0077] refer to Figure 1 The wide-angle lens 100 has a total axis length (TTL) of 10.03732 mm, a total focal length (EFFL) of 0.77 mm, a field of view (FOV) of 190°, and an aperture (F) of 1.6. Table 1 details the specific optical physical parameters of each lens in the wide-angle lens provided in Embodiment 1 of the present invention.

[0078] Table 1 Design values ​​of optical physical parameters for wide-angle lenses

[0079] Face number S face shape Radius of curvature (mm) Thickness (mm) Refractive index (Nd) Abbe number (Vd) 1 spherical 10.517 0.900 1.92 18.90 2 spherical 1.818 0.979 3 aspherical 4.634 0.660 1.54 56.00 4 aspherical 1.367 1.001 5 aspherical -10.335 1.692 1.64 23.40 6 aspherical -3.394 -0.121 STO flat 0.324 8 aspherical 2.721 2.175 1.54 56.00 9 aspherical -1.512 0.500 10 flat PL 0.700 1.52 64.20 13 flat PL 1.227 14 Image PL

[0080] In Table 1, the surface number S is assigned according to the surface sequence of each lens; "STO" represents the aperture stop of a wide-angle lens; M represents the image plane; the radius of curvature R represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane; "PL" indicates that the surface is flat with an infinite radius of curvature; the thickness represents the central axial distance between the current surface and the next surface; the refractive index Nd represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1. The Abbe number Vd represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current position is air; the more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion of the medium, the larger the Abbe number. The k value represents the magnitude of the conic coefficient of the aspherical surface.

[0081] In this embodiment of the application, the plastic aspherical lens of the wide-angle lens satisfies the following formula:

[0082] .

[0083] Where z represents the axial sagitta in the Z direction of the aspherical surface; r represents the distance from a point on the aspherical surface to the optical axis; c represents the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k represents the fitted conic coefficients; A, B, C, D, E, F, and G represent the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial, respectively.

[0084] For example, Table 2 details the aspherical coefficients of each lens in this embodiment one of feasible implementations.

[0085] Table 2 Design values ​​of aspherical coefficients for various lenses in wide-angle lenses

[0086] Face number S k A B C D E F G 3 3.79E+00 1.18E-01 -3.42E-02 4.35E-03 1.92E-03 -1.03E-03 -2.10E-04 2.3E-05 4 4.03E-01 1.50E-01 4.14E-02 -1.22E-01 4.33E-02 3.61E-02 -6.21E-02 -3.5E-04 5 -3.43E+02 -6.87E-03 -4.70E-02 1.30E-01 -6.88E-02 -3.12E-02 3.53E-02 -6.4E-03 6 4.31E+00 -3.58E-02 8.70E-02 -1.15E-02 -8.68E-02 1.03E-01 -2.50E-02 -1.3E-02 9 -3.20E+01 1.03E-01 -1.19E-01 9.25E-02 -1.71E-03 -3.91E-02 1.54E-02 4.4E-04 10 -1.29E+00 3.13E-02 -3.10E-02 2.61E-02 -8.16E-03 9.60E-05 1.19E-04 1.2E-04

[0087] Wherein, 1.18E-01 represents the coefficient of surface number S3. 1.18*10 -1 And so on.

[0088] Furthermore, several performance tests were conducted on the wide-angle lens provided in Embodiment 1, and the specific test results are as follows:

[0089] Figure 2 This is a relative illumination diagram of a wide-angle lens provided in Embodiment 1 of this application, with reference to... Figure 2 The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating lens image quality, especially crucial for large-format, wide-angle lenses. The wide-angle lens provided in Embodiment 1 of this application has a relative illuminance of 0.5 or higher within a field of view of 0–96°, indicating that the wide-angle lens has excellent uniformity of illumination across the entire image area and strong adaptability to the field of view; even in wide-angle models, edge light can be effectively transmitted.

[0090] Example 2

[0091] Figure 3 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 2 of this application. (Continue referring to...) Figure 3The wide-angle lens 200 provided in Embodiment 2 of the present invention includes a first lens L1, a second lens L2, a third lens L3, an aperture stop STO, a fourth lens L4, and a filter CG arranged sequentially along the optical axis from the object plane to the image plane. The first lens L1 is a glass spherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The second lens L2 is a plastic aspherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The third lens L3 is a plastic aspherical lens with positive optical power, its object-side surface is concave, and its image-side surface is convex. The fourth lens L4 is a plastic aspherical lens with positive optical power, its object-side surface is concave, and its image-side surface is convex.

[0092] refer to Figure 3 The wide-angle lens 200 has a total axis length (TTL) of 9.0061 mm, a total focal length (EFFL) of 0.70 mm, a field of view (FOV) of 182°, and an aperture (F) of 1.63. Table 3 details the specific optical physical parameters of each lens in the wide-angle lens provided in Embodiment 2 of the present invention.

[0093] Table 3 Design values ​​of optical physical parameters for wide-angle lenses

[0094] Face number S face shape Radius of curvature (mm) Thickness (mm) Refractive index (Nd) Abbe number (Vd) 1 spherical 7.087 0.904 1.96 37.80 2 spherical 1.949 1.014 3 aspherical 6.529 0.509 1.64 23.40 4 aspherical 1.501 0.792 5 aspherical -11.971 2.144 1.67 27.60 6 aspherical -1.705 0.011 STO flat 0.114 8 aspherical -6.408 1.945 1.64 23.40 9 aspherical -1.311 0.500 10 flat PL 0.700 1.52 64.20 13 flat PL 1.069 14 Image PL

[0095] In Table 3, the surface number S is assigned according to the surface sequence of each lens; "STO" represents the aperture stop of a wide-angle lens; M represents the image plane; the radius of curvature R represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane; "PL" indicates that the surface is flat with an infinite radius of curvature; the thickness represents the central axial distance between the current surface and the next surface; the refractive index Nd represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1. The Abbe number Vd represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current position is air; the more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion of the medium, the larger the Abbe number. The k value represents the magnitude of the conic coefficient of the aspherical surface.

[0096] In this embodiment of the application, the plastic aspherical lens of the wide-angle lens satisfies the following formula:

[0097] .

[0098] Where z represents the axial sagitta in the Z direction of the aspherical surface; r represents the distance from a point on the aspherical surface to the optical axis; c represents the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k represents the fitted conic coefficients; A, B, C, D, E, F, and G represent the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial, respectively.

[0099] For example, Table 4 details the aspherical coefficients of each lens in this embodiment two according to a feasible implementation.

[0100] Table 4 Design values ​​of aspherical coefficients for various lenses in wide-angle lenses

[0101] Face number S k A B C D E F G 3 1.28E+01 9.00E-02 -2.19E-02 1.68E-03 1.87E-04 -4.36E-04 -2.77E-05 8.9E-07 4 3.38E-01 9.88E-02 4.16E-02 -3.06E-02 8.76E-03 -5.58E-03 1.57E-03 -7.0E-04 5 -1.14E+03 -8.60E-02 1.24E-01 -1.37E-02 -1.12E-01 8.46E-02 2.03E-02 -2.1E-02 6 -7.41E+00 1.95E-02 -3.54E-02 -1.98E-02 1.08E-01 1.83E-01 -2.37E-01 -1.4E-01 9 5.75E+01 1.65E-01 -9.51E-02 -4.07E-02 2.58E-02 2.60E-01 2.82E-01 -5.7E-01 10 -1.17E+00 2.68E-02 -4.13E-02 2.67E-02 -8.73E-03 5.97E-04 -3.06E-04 1.8E-04

[0102] Wherein, 9.00E-02 represents the coefficient of surface number S3. 9.00*10 -2 And so on.

[0103] Furthermore, several performance tests were conducted on the wide-angle lens provided in Embodiment 2, and the specific test results are as follows:

[0104] Figure 4 This is a relative illumination diagram of a wide-angle lens provided in Embodiment 2 of this application, for reference. Figure 4 The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating lens image quality, especially crucial for large-format, wide-angle lenses. The wide-angle lens provided in Embodiment 2 of this application has a relative illuminance of over 0.55 within a field of view of 0–92°, indicating that the wide-angle lens has excellent uniformity of illumination across the entire image area and strong adaptability to the field of view; even in wide-angle models, edge light can be effectively transmitted.

[0105] Example 3

[0106] Figure 5 This is a schematic diagram of the structure of a wide-angle lens provided in Embodiment 3 of this application. (Continue referring to...) Figure 5 The wide-angle lens 300 provided in Embodiment 3 of the present invention includes a first lens L1, a second lens L2, a third lens L3, an aperture stop STO, a fourth lens L4, and a filter CG arranged sequentially along the optical axis from the object plane to the image plane. The first lens L1 is a glass spherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The second lens L2 is a plastic aspherical lens with negative optical power, its object-side surface is convex, and its image-side surface is concave. The third lens L3 is a plastic aspherical lens with positive optical power, its object-side surface is concave, and its image-side surface is convex. The fourth lens L4 is a plastic aspherical lens with positive optical power, its object-side surface is convex, and its image-side surface is convex.

[0107] refer to Figure 5The wide-angle lens 300 has a total axis length (TTL) of 10.00434 mm, a total focal length (EFFL) of 0.70 mm, a field of view (FOV) of 182°, and an aperture (F) of 1.63. Table 5 details the specific optical and physical parameters of each lens in the wide-angle lens provided in Embodiment 3 of the present invention.

[0108] Table 5 Design values ​​of optical physical parameters for wide-angle lenses

[0109] Face number S face shape Radius of curvature (mm) Thickness (mm) Refractive index (Nd) Abbe number (Vd) 1 spherical 13.265 1.002 1.67 50.00 2 spherical 2.023 1.040 3 aspherical 4.842 0.663 1.64 23.40 4 aspherical 1.386 1.032 5 aspherical -7.155 1.719 1.64 23.40 6 aspherical -3.166 -0.121 STO flat 0.272 8 aspherical 2.620 1.958 1.54 56.00 9 aspherical -1.583 0.500 10 flat PL 0.700 1.52 64.20 13 flat PL 1.240 14 Image PL

[0110] In Table 5, the surface number S is assigned according to the surface sequence of each lens; "STO" represents the aperture stop of a wide-angle lens; M represents the image plane; the radius of curvature R represents the curvature of the lens surface, with a positive value indicating that the surface bends towards the image plane and a negative value indicating that the surface bends towards the object plane; "PL" indicates that the surface is flat with an infinite radius of curvature; the thickness represents the central axial distance between the current surface and the next surface; the refractive index Nd represents the ability of the material between the current surface and the next surface to deflect light, with a blank space indicating that the current position is air and the refractive index is 1. The Abbe number Vd represents the dispersion characteristics of the material between the current surface and the next surface; a blank space indicates that the current position is air; the more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less severe the dispersion of the medium, the larger the Abbe number. The k value represents the magnitude of the conic coefficient of the aspherical surface.

[0111] In this embodiment of the application, the plastic aspherical lens of the wide-angle lens satisfies the following formula:

[0112] .

[0113] Where z represents the axial sagitta in the Z direction of the aspherical surface; r represents the distance from a point on the aspherical surface to the optical axis; c represents the curvature of the fitted sphere, which is numerically the reciprocal of the radius of curvature; k represents the fitted conic coefficients; A, B, C, D, E, F, and G represent the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial, respectively.

[0114] For example, Table 4 details the aspherical coefficients of each lens in this embodiment three according to a feasible implementation.

[0115] Table 6 Design values ​​of aspherical coefficients for various lenses in wide-angle lenses

[0116] Face number S k A B C D E F G 3 1.13E+00 1.08E-01 -3.52E-02 3.92E-03 1.77E-03 -1.05E-03 -1.81E-04 8.3E-05 4 5.03E-01 2.00E-01 3.65E-02 -1.13E-01 5.84E-02 4.74E-02 -6.59E-02 -1.2E-02 5 -9.13E+01 9.62E-03 -4.17E-02 1.20E-01 -6.94E-02 -1.78E-02 4.26E-02 -1.5E-02 6 4.11E+00 -3.48E-02 8.97E-02 -1.71E-02 -8.88E-02 1.13E-01 -1.47E-02 -2.9E-02 9 -3.08E+01 9.93E-02 -1.19E-01 9.04E-02 -3.56E-03 -3.88E-02 1.66E-02 1.9E-04 10 -1.15E+00 2.79E-02 -2.84E-02 2.40E-02 -8.83E-03 3.51E-04 2.86E-04 4.9E-05

[0117] Where 1.08E-01 represents the coefficient of surface number S3. 1.08*10 -1 And so on.

[0118] Furthermore, several performance tests were conducted on the wide-angle lens provided in Embodiment 3, and the specific test results are as follows:

[0119] Figure 6 This is a relative illumination diagram of a wide-angle lens provided in Embodiment 3 of this application, for reference. Figure 6 The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating lens image quality, especially crucial for large-format, wide-angle lenses. The wide-angle lens provided in Embodiment 3 of this application has a relative illuminance of 0.5 or higher within a field of view of 0–95°, indicating that the wide-angle lens has excellent uniformity of illumination across the entire image area and strong adaptability to the field of view; even in wide-angle models, edge light can be effectively transmitted.

[0120] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Features of various embodiments of the present invention can be partially or wholly coupled or combined with each other, and can cooperate and be technically driven in various ways. Various obvious changes, readjustments, combinations, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wide-angle lens, characterized in that, It includes a first lens, a second lens, a third lens, and a fourth lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens is a glass spherical lens with negative optical power, its object side is convex and its image side is concave; The second lens is a plastic aspherical lens with negative optical power, its object side is convex and its image side is concave. The third lens is a plastic aspherical lens with positive optical power, its object side is concave and its image side is convex. The fourth lens is a plastic aspherical lens with positive optical power, the object side of which is convex or concave, and the image side of which is convex.

2. The wide-angle lens according to claim 1, characterized in that, The optical power of the first lens to the fourth lens satisfies the following condition: -0.38 ≤ Φ1 / Φ ≤ -0.27; -0.30 ≤ Φ2 / Φ ≤ -0.25; 0.12 ≤ Φ3 / Φ ≤ 0.38; 0.42 ≤ Φ4 / Φ ≤ 0.45; Wherein, Φ is the optical power of the entire wide-angle lens, and Φ1, Φ2, Φ3, and Φ4 are the optical powers of the first lens, the second lens, the third lens, and the fourth lens, respectively.

3. The wide-angle lens according to claim 1, characterized in that, The refractive indices and Abbe numbers of the first to the fourth lenses satisfy the following conditions: 1.67 ≤ n1 ≤ 1.92; 18.90 ≤ v1 ≤ 50.00; 1.54 ≤ n2 ≤ 1.64; 23.40 ≤ v2 ≤ 56.00; 1.64 ≤ n3 ≤ 1.67; 23.40 ≤ v3 ≤ 27.60; 1.54 ≤ n4 ≤ 1.64; 23.40 ≤ v4 ≤ 56.00; Wherein, n1, n2, n3, and n4 are the refractive indices of the first lens, the second lens, the third lens, and the fourth lens, respectively, and v1, v2, v3, and v4 are the Abbe numbers of the first lens, the second lens, the third lens, and the fourth lens, respectively.

4. The wide-angle lens according to claim 1, characterized in that, The optical back focal length (BFL) of the wide-angle lens and the total axial length (TTL) of the wide-angle lens satisfy the following condition: BFL / TTL > 0.

2.

5. The wide-angle lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field of view of the wide-angle lens and the entrance pupil diameter EPD of the wide-angle lens satisfy the following condition: 4.7 < IH / EPD < 5.

7.

6. The wide-angle lens according to claim 1, characterized in that, The central radius of curvature R1 of the first lens object side and the overall focal length EFFL of the wide-angle lens satisfy the following condition: 10 ≤ R1 / EFFL ≤ 15.

4.

7. The wide-angle lens according to any one of claims 1-6, characterized in that, It also includes an aperture stop, which is disposed between the third lens and the fourth lens.

8. The wide-angle lens according to any one of claims 1-6, characterized in that, The optical total axis length (TTL) of the wide-angle lens is less than 10.5 mm.

9. The wide-angle lens according to any one of claims 1-6, characterized in that, The aperture number F of the wide-angle lens satisfies: F≤1.

63.

10. The wide-angle lens according to any one of claims 1-6, characterized in that, The maximum field of view (FOV) of the wide-angle lens is greater than or equal to 182°.

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