A high-pixel wide-angle lens

Abstract

The application discloses a high-pixel wide-angle lens, which is sequentially arranged from an object side to an image side along a lens optical axis as follows: a first lens, which is a glass spherical lens with negative focal power; a second lens, which is a non-spherical plastic lens with negative focal power; a third lens, which is a spherical glass lens with positive focal power or a non-spherical plastic lens with negative focal power; a diaphragm plate; a fourth lens, which is a non-spherical plastic lens with negative focal power or a spherical glass lens with positive focal power; a fifth lens, which is a non-spherical plastic lens with positive focal power; a sixth lens, which is a non-spherical plastic lens with negative focal power; a filter plate, a protective glass and an image acquisition element. The lens is combined by two spherical glass lenses and four non-spherical plastic lenses, can be matched with a 5MP, 1 / 2.4 inch chip, can provide high-definition image quality under a large field angle condition, is not sensitive to each lens in manufacturing, is easy to be formed and manufactured, and has a high cost performance.

Description

Technical Field

[0001] This invention relates to the field of optical lenses, and more particularly to a high-pixel wide-angle lens. Background Technology

[0002] As society continues to progress, people have an increasing demand for visual and intelligent products. Lenses, as the carrier of visualization and the eyes of machine vision, have been widely used in fields such as smart homes, law enforcement recorders, and drone aerial photography. However, mainstream products used in fields such as smart homes, law enforcement recorders, and drone aerial photography suffer from problems such as low pixel count, low sensitivity, and high cost. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-pixel wide-angle lens. This lens uses a hybrid combination of two spherical glass elements and four aspherical plastic elements, and can be paired with a 5MP, 1 / 2.4-inch chip. It can provide high-definition image quality under wide field of view conditions. In terms of manufacturability, each lens is insensitive, easy to mold and manufacture, and has a high cost-performance ratio.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A high-resolution wide-angle lens comprises, along its optical axis from the object side to the image side, a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, a sixth lens, a filter, a protective glass, and an image acquisition element, arranged sequentially. The lens satisfies the following relationship:

[0006] -1.8≤f1 / f≤-1.3,

[0007] -53.5≤f² / f≤5.7,

[0008] -16.4≤f³ / f≤1.6,

[0009] -2.2≤f4 / f≤1.5,

[0010] 0.9≤f5 / f≤1.6,

[0011] -2.6≤f6 / f≤1.7,

[0012] In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens.

[0013] Preferably, the focal length, refractive index, and radius of curvature of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens respectively satisfy the following conditions:

[0014] f1 -5.4～-4.2 ND1 1.50～1.56 R11 +15.11～+200.21 R12 +2.01～+2.52 f2 -161～+17.9 ND2 1.53～1.68 R21 -13.60～-3.61 R22 -6.42～-4.09 f3 -49.5～+4.9 ND3 1.53～1.59 R31 -4.05～-19.37 R32 -5.07～-3.31 f4 -6.9～+5.8 ND4 1.45～1.65 R41 +3.53～+13.47 R42 -3.11～+1.85 f5 +3.0～+4.6 ND5 1.53～1.59 R51 +5.51～+6.79 R52 -3.37～-1.85 f6 -8.0～-5.3 ND6 1.60～1.68 R61 -3.36～-1.85 R62 -2.13～+12.52

[0015] Where f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the object-side radius of curvature of the first lens, and R12 is the image-side radius of curvature of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the object-side radius of curvature of the second lens, and R22 is the image-side radius of curvature of the second lens; f is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the object-side radius of curvature of the third lens, and R32 is the image-side radius of curvature of the third lens; f4 is the fourth lens. The focal length of the fourth lens is f5, where ND4 is the refractive index of the fourth lens, R41 is the object-side radius of curvature of the fourth lens, and R42 is the image-side radius of curvature of the fourth lens. The focal length of the fifth lens is f6, where ND5 is the refractive index of the fifth lens, R51 is the object-side radius of curvature of the fifth lens, and R52 is the image-side radius of curvature of the fifth lens. The focal length of the sixth lens is f6, where ND6 is the refractive index of the sixth lens, R61 is the object-side radius of curvature of the sixth lens, and R62 is the image-side radius of curvature of the sixth lens. The "-" sign indicates that the surface bends towards the object side.

[0016] Preferably, the lens also satisfies the following relationship:

[0017] f≤3.1, TTL≤16.5mm, IC / TTL≥0.47, TTL / f≤5.4, OBFL / TTL≥0.24,

[0018] In the formula, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, and IC is the full-image height of the 1 / 2.4” chip paired with the lens system.

[0019] The aperture of the lens is F#, which satisfies F#≤2.0.

[0020] Preferably, the aperture is disposed between the third lens and the fourth lens; the filter is disposed on the image side of the sixth lens; the protective glass is disposed on the image side of the filter, the image acquisition element is disposed on the image side of the protective glass, and the protective glass is integrated on the image sensor; the filter is made of H-K9L glass.

[0021] Preferably, in the lens: the first lens is a spherical glass lens with negative optical power, the object side of the first lens is convex, and its image side is concave; the second lens is an aspherical plastic lens with negative optical power, the object side of the second lens is concave, and its image side is convex; the third lens is an aspherical plastic lens with negative optical power, the object side of the third lens is concave, and its image side is convex; the fourth lens is a spherical glass lens with positive optical power, the object side of the fourth lens is convex, and its image side is convex; the fifth lens is an aspherical plastic lens with positive optical power, the object side of the fifth lens is convex, and its image side is convex; the sixth lens is an aspherical plastic lens with negative optical power, the object side of the sixth lens is concave, and its image side is either convex or concave.

[0022] Furthermore, in the lens: the image-side surface of the second lens is a convex surface with curvature; the object-side surface of the third lens is a concave surface with curvature, and its image-side surface is a convex surface with curvature; the Abbe number of the fourth lens is greater than 90; the aspherical surfaces of the second, third, fifth, and sixth lenses can all be defined by the following equation for even-order aspherical surfaces:

[0023]

[0024] Where: Z is the sag of the lens along the optical axis, k is the conic coefficient of the surface, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0025] Preferably, in the lens: the first lens is a spherical glass lens with negative optical power, the object side of the first lens is convex, and its image side is concave; the second lens is an aspherical plastic lens with negative optical power, the object side of the second lens is concave, and its image side is convex; the third lens is a spherical glass lens with positive optical power, the object side of the third lens is convex, and its image side is convex; the fourth lens is an aspherical plastic lens with negative optical power, the object side of the fourth lens is convex, and its image side is concave; the fifth lens is an aspherical plastic lens with positive optical power, the object side of the fifth lens is convex, and its image side is convex; the sixth lens is an aspherical plastic lens with negative optical power, the object side of the sixth lens is concave, and its image side is either convex or concave.

[0026] Furthermore, in the lens: the object-side surface of the fourth lens is a convex surface with curvature; the aspherical surfaces of the second, fourth, fifth, and sixth lenses can all be defined by the following equation for even-order aspherical surfaces:

[0027]

[0028] Where: Z is the sag of the lens along the optical axis, k is the conic coefficient of the surface, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0029] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention's high-pixel wide-angle lens has a total focal length f≤3.1mm and an aperture F# ≤2.0, providing high-definition image quality under wide field-of-view conditions. In terms of manufacturability, the lens uses a hybrid combination of two spherical glass elements and four aspherical plastic elements. Each lens is insensitive, making molding and manufacturing easy, resulting in a compact structure. This achieves the characteristics of small size, light weight, good performance, and low cost, offering high cost-effectiveness. Through reasonable lens material selection, optical power allocation, and optical design optimization, this invention can be paired with a 5MP, 1 / 2.4-inch chip to achieve 24 / 7 all-weather high-definition monitoring with day and night confocal focus, exhibiting excellent reliability and stability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the optical structure of Embodiment 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the optical path structure of Embodiment 1 of the present invention;

[0032] Figure 3 This is a chromatic aberration curve for visible light (0.435-0.656 μm) in Embodiment 1 of the present invention.

[0033] Figure 4 This is a field curvature curve of visible light (0.435-0.656 μm) for Embodiment 1 of the present invention;

[0034] Figure 5 The distortion curve of visible light (0.435-0.656µm) is shown in Embodiment 1 of the present invention.

[0035] Figure 6 This is a schematic diagram of the optical structure of Embodiment 2 of the present invention;

[0036] Figure 7 This is a schematic diagram of the optical path structure of Embodiment 2 of the present invention;

[0037] Figure 8 This is a chromatic aberration curve for visible light (0.435-0.656 μm) in Embodiment 2 of the present invention.

[0038] Figure 9 This is a field curvature curve of visible light (0.435-0.656 μm) for Embodiment 2 of the present invention;

[0039] Figure 10 This is a distortion curve of visible light (0.435-0.656µm) in Embodiment 2 of the present invention.

[0040] Reference numerals: 1-First lens, 2-Second lens, 3-Third lens, 4-Fourth lens, 5-Fifth lens, 6-Sixth lens, 7-Aperture, 8-Filter, 9-Protective glass, 10-Image acquisition element. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In this specification, the expressions "first," "second," "third," etc., are only used to distinguish one feature from another, and do not indicate any limitation on the features. The shape of a spherical or aspherical surface is not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not strictly drawn to scale.

[0042] In this invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region; if the lens surface is not defined as convex, concave, or flat, it means that the lens surface can be convex, concave, or flat. The surface of each lens closest to the object being photographed is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0043] Unless otherwise specified, all terms used in this invention (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the same meaning as they have in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so defined in this invention.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. For better understanding and implementation, the invention will be described in detail below with reference to the accompanying drawings.

[0045] This invention provides a high-pixel wide-angle lens. The surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface. Along the lens optical axis from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, an aperture stop 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a filter 8, a protective glass 9, and an image acquisition element 10 are arranged sequentially. The aperture stop 7 is located between the third lens 3 and the fourth lens 4. The filter 8 is disposed on the image-side surface of the sixth lens 6 and is made of H-K9L glass. The protective glass 9 is disposed on the image-side surface of the filter 8, and the image acquisition element 10 is disposed on the image-side surface of the protective glass 9. The protective glass 9 is integrated into the image sensor.

[0046] In this invention, to achieve better performance of the optical system, we need to rationally select lens materials, rationally allocate the focal length of each lens, and rationally optimize the optical system during the design process. Ultimately, we aim to optimize the performance of the optical system. The presence of aberrations in the optical system usually affects the imaging quality. Correcting aberrations is the key to optimizing the optical system. There are many methods for correcting aberrations. For example, using lenses with different refractive indices and significantly different Abbe numbers can eliminate chromatic aberration and spherical aberration to a certain extent. Rationally allocating and optimizing the focal length and shape of each lens can also correct the aberrations of the system.

[0047] In this invention, the focal length of the first lens 11 is f1, the focal length of the second lens 22 is f2, the focal length of the third lens 33 is f3, the focal length of the fourth lens 44 is f4, the focal length of the fifth lens 55 is f5, the focal length of the sixth lens 6 is f6, and the total focal length of the entire lens is f. The ratio of the focal length of each lens to the total focal length of the lens satisfies the following condition:

[0048] -1.8≤f1 / f≤-1.3,

[0049] -53.5≤f² / f≤5.7,

[0050] -16.4≤f³ / f≤1.6,

[0051] -2.2≤f4 / f≤1.5,

[0052] 0.9≤f5 / f≤1.6,

[0053] -2.6≤f6 / f≤1.7.

[0054] In this invention, considering the aberrations and temperature drift of the optical system, the focal length, refractive index, and radius of curvature of each lens satisfy the following conditions:

[0055]

[0056]

[0057] Where f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the object-side radius of curvature of the first lens, and R12 is the image-side radius of curvature of the first lens; f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the object-side radius of curvature of the second lens, and R22 is the image-side radius of curvature of the second lens; f is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the object-side radius of curvature of the third lens, and R32 is the image-side radius of curvature of the third lens; f4 is the fourth lens. The focal length of the fourth lens is f5, where ND4 is the refractive index of the fourth lens, R41 is the object-side radius of curvature of the fourth lens, and R42 is the image-side radius of curvature of the fourth lens. The focal length of the fifth lens is f6, where ND5 is the refractive index of the fifth lens, R51 is the object-side radius of curvature of the fifth lens, and R52 is the image-side radius of curvature of the fifth lens. The focal length of the sixth lens is f6, where ND6 is the refractive index of the sixth lens, R61 is the object-side radius of curvature of the sixth lens, and R62 is the image-side radius of curvature of the sixth lens. The "-" sign indicates that the surface bends towards the object side.

[0058] In this invention, f is the total focal length of the lens; TTL is the total optical length of the lens; OBFL is the optical back focal length of the lens, which is the distance from the point on the image side of the sixth lens 6 closest to the image plane to the image plane; IC is the full image height of the 1 / 2.4” chip paired with the lens system; they satisfy the following conditions: f≤3.1, TTL≤16.5mm, IC / TTL≥0.45, TTL / f≤5.4, OBFL / TTL≥0.22.

[0059] In this invention, the aperture of the lens is F#, which satisfies F#≤2.0.

[0060] The following describes a specific embodiment of the high-pixel wide-angle lens according to the above-described configuration of the present invention.

[0061] The specific implementation data is summarized in Table 1 below:

[0062] Table 1

[0063]

[0064]

[0065] The main element symbols in the specific embodiments of the present invention are explained in Table 2.

[0066] Table 2

[0067] S1 First lens object side S10 Fifth lens object side S2 The image side of the first lens S11 The image side of the fifth lens S3 Second lens object side S12 The sixth lens object side S4 The image side of the second lens S13 The image side of the sixth lens S5 The third lens object side S14 Filter side S6 The image of the third lens is on the side. S15 Filter image from the side S7 Aperture S16 Protect the sides of glass objects S8 Fourth lens object side S17 Protective glass like the side S9 The image side of the fourth lens S18 Image

[0068] Example 1

[0069] refer to Figure 1 , Figure 2 As shown, these are schematic diagrams of the optical structure and optical path structure of Embodiment 1, respectively.

[0070] In this embodiment, the field of view (DFOV) is 155° and the principal ray angle of the lens is CRA, which satisfies CRA≤21°. By rationally selecting lens materials and rationally allocating the focal length and optical power of each lens, the optical system is optimized to achieve insensitivity of each lens and facilitate large-scale mass production.

[0071] In this embodiment, the high-pixel wide-angle lens comprises, in sequence along the lens optical axis from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, an aperture 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a filter 8, a protective glass 9, and an image acquisition element 10, wherein:

[0072] The first lens 1 is a spherical glass lens with negative optical power. The object side of the first lens 1 is convex, and its image side is concave.

[0073] The second lens 2 is an aspherical plastic lens with negative optical power. The object side of the second lens 2 is concave, and its image side is a convex surface with recurve.

[0074] The third lens 3 is an aspherical plastic lens with negative optical power. The object side of the third lens 3 is a concave surface with recurve, and its image side is a convex surface with recurve.

[0075] The fourth lens 4 is a spherical glass lens with positive optical power. The object side of the fourth lens 4 is convex, and its image side is also convex.

[0076] The fifth lens 5 is an aspherical plastic lens with positive optical power. The object side of the fifth lens 5 is convex, and its image side is also convex.

[0077] The sixth lens 6 is an aspherical plastic lens with negative optical power. The object side of the sixth lens 6 is concave, and its image side is also concave.

[0078] In this embodiment, the first lens 1 is a glass spherical lens with negative optical power, its object side is convex and its image side is concave, forming a meniscus lens with negative optical power, which is used to quickly converge light. The fourth lens 4 has an Abbe number greater than 90. This combination can reduce the chromatic aberration of the system and thus achieve day and night confocality. The second lens 2, the third lens 3, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses, whose main function is to correct various optical aberrations and ultimately optimize the performance of the optical system.

[0079] Considering the aberrations and temperature drift of the optical system, the curvature radius, center thickness, refractive index, Abbe constant, and aspherical K value of each lens are designed as shown in Table 3.

[0080] Table 3 provides the radius of curvature R (in mm), center thickness d (in mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) for each lens.

[0081] Table 3

[0082]

[0083]

[0084] In Table 3, the radius of curvature represents the degree of curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is flat. The thickness represents the central axial distance from the current surface to the next surface. The refractive index represents the ability of the current lens material to deflect light. The Abbe number represents the dispersion characteristics of the current lens material. The K value represents the magnitude of the best-fit conic coefficient of the aspherical surface.

[0085] In this embodiment, the aspherical surfaces of the second lens 2, the third lens 3, the fifth lens 5, and the sixth lens 6 can all be defined by the following equation for even-order aspherical surfaces:

[0086]

[0087] In the formula, Z is the sag of the lens along the optical axis, k is the surface conic coefficient, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0088] Table 4 gives the coefficients of the aspherical surfaces of the six optical surfaces of the second lens 2, the third lens 3, the fifth lens 5, and the sixth lens.

[0089] Table 4

[0090]

[0091]

[0092] refer to Figure 3The figure shows the chromatic aberration curves for the lens in this embodiment, specifically for the visible light spectrum (0.435-0.656 μm). The graph displays the longitudinal spherical aberration values ​​for five different color spectra. Here, LONGITUDINAL SPHERICAL ABER represents different fields of view, and FOCUS (MILLIMETERS) represents the longitudinal spherical aberration value. This graph can, to a certain extent, reflect that the aberrations of the wide-angle lens have been well corrected.

[0093] refer to Figure 4 The figure shows the field curvature curves of the lens in this embodiment for visible light (0.435-0.656µm). The vertical axis, ASTIGMATIC FIELD CURVES, represents different fields of view, and the horizontal axis, FOCUS (MILLIMETERS), represents the field area (mm). This figure can, to a certain extent, reflect that the aberrations of the wide-angle lens have been well corrected.

[0094] refer to Figure 5 The figure shows the distortion curve of the lens in the visible light range of 0.435-0.656um in this embodiment. The horizontal axis represents the F-tan(Theta) distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the tan(Theta) distortion of the lens is small and less than -70%, which indicates that the distortion of the lens is well corrected and the actual shooting image will not be too distorted from the real scene.

[0095] Depend on Figure 3 , 4 As can be seen from Figures 5 and 6, field curvature, distortion, and chromatic aberration can all be well corrected in this embodiment.

[0096] In this embodiment 1, the total focal length of the lens system is f = 3.0 mm, the aperture value is F# = 2.0, the total length of the lens is TTL = 16.4 mm, the optical back focal length of the lens is OBFL = 3.6 mm, and the field of view (DFOV) of the 1 / 2.5” chip matched with the lens is 155°.

[0097] Example 2

[0098] refer to Figure 6 , Figure 7 The figures shown are schematic diagrams of the optical structure and optical path structure of Embodiment 2, respectively. In this embodiment, the field of view (DFOV) is 152°, and the principal ray angle of the lens is CRA, which satisfies CRA≤21°. By rationally selecting lens materials and rationally allocating the focal length and optical power of each lens, the optical system is optimized, achieving insensitivity of each lens and facilitating large-scale mass production.

[0099] In this embodiment, the high-pixel wide-angle lens comprises, in sequence along the lens optical axis from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, an aperture 7, a fourth lens 4, a fifth lens 5, a sixth lens 6, a filter 8, a protective glass 9, and an image acquisition element 10, wherein:

[0100] The first lens 1 is a spherical glass lens with negative optical power. The object side of the first lens 1 is convex, and its image side is concave.

[0101] The second lens 2 is an aspherical plastic lens with negative optical power, and the object side of the second lens 2 is concave.

[0102] The third lens 3 is a spherical glass lens with positive optical power. The object side of the third lens 3 is convex, and its image side is also convex.

[0103] The fourth lens 4 is an aspherical plastic lens with negative optical power. The object side of the fourth lens 4 is a convex surface with recurve, and its image side is a concave surface.

[0104] The fifth lens 5 is an aspherical plastic lens with positive optical power. The object side of the fifth lens 5 is convex, and its image side is also convex.

[0105] The sixth lens 6 is an aspherical plastic lens with negative optical power. The object side of the sixth lens 6 is concave, and its image side is convex.

[0106] In this embodiment, the first lens 1 is a glass spherical lens with negative optical power, its object side is convex and its image side is concave, forming a meniscus lens with negative optical power, which is used to quickly converge light. The third lens 3 has an Abbe number greater than 68. This combination can reduce the chromatic aberration of the system and thus achieve day and night confocality. The second lens 2, the third lens 3, the fifth lens 5, and the sixth lens 6 are all plastic aspherical lenses, which are mainly used to correct various optical aberrations and ultimately optimize the performance of the optical system.

[0107] Considering the aberrations and temperature drift of the optical system, the curvature radius, center thickness, refractive index, Abbe constant, and aspherical K value of each lens are designed as shown in Table 5.

[0108] Table 5 provides the radius of curvature R (in mm), center thickness d (in mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) for each lens.

[0109] Table 5

[0110]

[0111]

[0112] In Table 5, the radius of curvature represents the degree of curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is flat. The thickness represents the central axial distance from the current surface to the next surface. The refractive index represents the ability of the current lens material to deflect light. The Abbe number represents the dispersion characteristics of the current lens material. The K value represents the magnitude of the best-fit conic coefficient of the aspherical surface.

[0113] In this embodiment, the aspherical surfaces of the second lens 2, the fourth lens 3, the fifth lens 5, and the sixth lens 6 can all be defined by the following equation for even-order aspherical surfaces:

[0114]

[0115] In the formula, Z is the sag of the lens along the optical axis, k is the surface conic coefficient, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0116] Table 6 gives the coefficients of the aspherical surfaces of the second lens 2, the fourth lens 4, the fifth lens 5, and the sixth lens 6.

[0117] Table 6

[0118]

[0119]

[0120] refer to Figure 8 The figure shows the chromatic aberration curves for the lens in this embodiment, specifically for the visible light spectrum (0.435-0.656 μm). The graph displays the longitudinal spherical aberration values ​​for five different color spectra. Here, LONGITUDINAL SPHERICAL ABER represents different fields of view, and FOCUS (MILLIMETERS) represents the longitudinal spherical aberration value. This graph can, to a certain extent, reflect that the aberrations of the wide-angle lens have been well corrected.

[0121] refer to Figure 9 The figure shows the field curvature curves for the visible light range of 0.435-0.656 μm for this lens in this embodiment. The vertical axis, ASTIGMATIC FIELD CURVES, represents different fields of view, and the horizontal axis, FOCUS (MILLIMETERS), represents the field area (mm). This figure can, to a certain extent, reflect that the aberrations of the wide-angle lens have been well corrected.

[0122] refer to Figure 10The figure shows the distortion curve of the lens in the visible light range of 0.435-0.656um in this embodiment. The horizontal axis represents F-tan(Theta) distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the tan(Theta) distortion of the lens is small and less than -68%, which indicates that the distortion of the lens is well corrected and the actual shooting image will not be too distorted from the real scene.

[0123] Depend on Figure 8 , 9 As can be seen from 10, in this embodiment, field curvature, distortion, and chromatic aberration can all be corrected very well.

[0124] In this embodiment 2, the total focal length of the lens system is f = 3.1mm, the aperture value is F# = 1.9, the total length of the lens is TTL = 15.6mm, the optical back focal length of the lens is OBFL = 3.7mm, and the field of view (DFOV) of the 1 / 2.4” chip matched with the lens is 152°.

[0125] The above embodiments illustrate that the high-pixel wide-angle lens of the present invention has a total focal length f ≤ 3.1mm and an aperture F# ≤ F# 2.0, providing high-definition image quality under wide field-of-view conditions. In terms of manufacturability, the lens uses a hybrid combination of two spherical glass elements and four aspherical plastic elements. Each lens is insensitive, making molding and manufacturing easy, achieving small size, light weight, good performance, and low cost, resulting in high cost-effectiveness. Through reasonable lens material selection, optical power distribution, and optical design optimization, the present invention can be paired with a 5MP, 1 / 2.4-inch chip to achieve 24 / 7 all-weather high-definition monitoring with day and night confocal focus, exhibiting excellent reliability and stability.

[0126] The above description merely illustrates several embodiments of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A high-pixel wide-angle lens, characterized in that: Along the optical axis of the lens, from the object side to the image side, the first lens, the second lens, the third lens, the aperture, the fourth lens, the fifth lens, the sixth lens, the filter, the protective glass, and the image acquisition element are arranged in sequence. The first lens has negative optical power, the second lens has negative optical power, the fifth lens has positive optical power, and the sixth lens has negative optical power; The lens satisfies the following relationship: -1.8≤f1 / f≤-1.3, -53.5≤f² / f≤5.7, -16.4≤f³ / f≤1.6, -2.2≤f4 / f≤1.5, 0.9≤f5 / f≤1.6, -2.6≤f6 / f≤1.7, In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, and f6 is the focal length of the sixth lens.

2. The high-pixel wide-angle lens according to claim 1, characterized in that: The focal length ranges corresponding to the first lens, second lens, third lens, fourth lens, fifth lens and sixth lens are -5.4 to -4.2, -161 to +17.9, -49.5 to +4.9, -6.9 to +5.8, +3.0 to +4.6 and -8.0 to -5.3, respectively. The refractive index ranges of the first lens, second lens, third lens, fourth lens, fifth lens and sixth lens are 1.50~1.56, 1.53~1.68, 1.53~1.59, 1.45~1.65, 1.53~1.59 and 1.60~1.68 respectively. The ranges of the object surface radii of curvature for the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are +15.11 to +200.21, -13.60 to -3.61, -4.05 to -19.37, +3.53 to +13.47, +5.51 to +6.79, and -3.36 to -1.85, respectively. The ranges of the image-side surface curvature radii for the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are +2.01 to +2.52, -6.42 to -4.09, -5.07 to -3.31, -3.11 to +1.85, -3.37 to -1.85, and -2.13 to +12.52, respectively. The "-" sign indicates that the surface bends toward the object surface, the focal length is in mm, and the radius of curvature is in mm.

3. A high-pixel wide-angle lens according to claim 1, characterized in that: The lens also satisfies the following relationship: f≤3.1mm, TTL≤16.5mm, IC / TTL≥0.47, TTL / f≤5.4, OBFL / TTL≥0.22, In the formula, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, and IC is the full-image height of the 1 / 2.4” chip paired with the lens system.

4. A high-pixel wide-angle lens according to claim 1, characterized in that: The aperture of the lens is F#, which satisfies F#≤2.

0.

5. A high-pixel wide-angle lens according to claim 1, characterized in that: The filter is disposed on the image side of the sixth lens; the protective glass is disposed on the image side of the filter, the image acquisition element is disposed on the image side of the protective glass, and the protective glass is integrated on the image sensor; the filter is made of H-K9L glass.

6. A high-pixel wide-angle lens according to any one of claims 1 to 5, characterized in that: The first lens is a spherical glass lens with negative optical power. The object side of the first lens is convex, and its image side is concave. The second lens is an aspherical plastic lens with negative optical power. The object side of the second lens is concave, and its image side is convex. The third lens is an aspherical plastic lens with negative optical power. The object side of the third lens is concave, and its image side is convex. The fourth lens is a spherical glass lens with positive optical power. The object side of the fourth lens is convex, and its image side is also convex. The fifth lens is an aspherical plastic lens with positive optical power. The object side of the fifth lens is convex, and its image side is also convex. The sixth lens is an aspherical plastic lens with negative optical power. The object side of the sixth lens is concave, and its image side is also concave.

7. A high-pixel wide-angle lens according to claim 6, characterized in that: The image-side surface of the second lens is a convex surface with curvature; the object-side surface of the third lens is a concave surface with curvature, and its image-side surface is a convex surface with curvature; the Abbe number of the fourth lens is greater than 90.

8. A high-pixel wide-angle lens according to any one of claims 1 to 5, characterized in that: The first lens is a spherical glass lens with negative optical power. The object side of the first lens is convex, and its image side is concave. The second lens is an aspherical plastic lens with negative optical power. The object side of the second lens is concave, and its image side is convex. The third lens is a spherical glass lens with positive optical power. The object side of the third lens is convex, and its image side is also convex. The fourth lens is an aspherical plastic lens with negative optical power. The object side of the fourth lens is convex, and its image side is concave. The fifth lens is an aspherical plastic lens with positive optical power. The object side of the fifth lens is convex, and its image side is also convex. The sixth lens is an aspherical plastic lens with negative optical power. The object side of the sixth lens is concave, and its image side is convex.

9. A high-pixel wide-angle lens according to claim 8, characterized in that: The object-side surface of the fourth lens is a convex surface with a recurve.

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