A high definition wide angle lens

Abstract

The application discloses a high-definition wide-angle lens, which comprises, in sequence along an optical axis from an object side to an image side, a first lens with negative optical power, the object side being a concave surface and the image side being a concave surface; a second lens with positive optical power, the object side being a convex surface and the image side being a convex surface; a third lens with positive optical power, the object side being a concave surface and the image side being a convex surface; a fourth lens with positive optical power, the object side being a convex surface and the image side being a convex surface; a fifth lens with negative optical power, the object side being a concave surface and the image side being a convex surface; and an infrared filter between the fifth lens and an imaging surface; the third lens is a glass spherical lens, the first lens, the second lens, the fourth lens and the fifth lens are plastic aspherical lenses, and a diaphragm is arranged between the second lens and the third lens. Through reasonable optical power distribution, the performance of 140-150 degrees of large field of view, optical total length of less than 13.6 mm and full-field MTF of 100 lp / mm being greater than or equal to 50% is realized, and the high-definition wide-angle lens is suitable for fields of vehicle-mounted surround view, intelligent security and the like.

Description

Technical Field

[0001] This invention relates to the field of optical lens structure, and more specifically to a high-definition wide-angle lens. Background Technology

[0002] With the continuous development of optical imaging technology, applications such as security monitoring and vehicle surround view are placing higher demands on the comprehensive performance of wide-angle lenses. Current market demands for lenses not only include a large field of view and high resolution, but also emphasize miniaturization, low distortion, and good environmental adaptability. However, existing technologies have significant shortcomings in achieving this synergy, making it difficult to meet the stringent requirements of practical applications.

[0003] Currently, wide-angle lenses on the market generally suffer from two main problems: one type uses a multi-glass lens structure, which, while offering relatively stable image quality, results in large size and high cost, failing to meet the installation requirements of miniaturized devices; the other type uses an all-plastic lens structure, achieving lightweight and low cost, but performing poorly in terms of sharpness, temperature resistance, and distortion control, especially under wide field-of-view conditions, where image distortion is severe and edge resolution is insufficient. Existing wide-angle lenses generally struggle to simultaneously meet the comprehensive requirements of a wide field of view, miniaturization, and low distortion. Furthermore, constrained by miniaturized structures, their environmental adaptability is generally insufficient, failing to maintain stable imaging performance over a wide temperature range, further limiting their application in complex scenarios such as automotive and outdoor security applications.

[0004] Among existing related patents, such as the small wide-angle lens disclosed in Chinese Patent No. CN114019656B, although it achieves a certain degree of miniaturization and wide-angle characteristics, its distortion control capability under ultra-wide field of view is limited, and its high and low temperature resistance is insufficient, failing to meet the long-term stable operation requirements of complex environments such as vehicle-mounted and outdoor security applications. Another Chinese Patent No. CN108061960B discloses a vehicle-mounted wide-angle lens, which optimizes the field of view and sharpness, but under the constraint of extreme miniaturization, it is difficult to balance low distortion and high resolution, resulting in significant degradation in edge imaging quality.

[0005] Therefore, achieving miniaturization, low distortion, high definition, and good environmental adaptability while ensuring a wide field of view has become a pressing technical challenge in the field of wide-angle lenses. This patent addresses the shortcomings of existing technologies by proposing a high-definition wide-angle lens. Through rational optical design, it effectively resolves the contradictions between a wide field of view and low distortion, and between miniaturization and high definition, thereby improving the lens's overall performance and application range, and meeting the industry's urgent demand for high-performance wide-angle lenses. Summary of the Invention

[0006] The object of the present invention is to provide a high-definition wide-angle lens to solve the above problems, which realizes miniaturization, low distortion, high definition and good environmental adaptability on the premise of ensuring a large viewing angle.

[0007] To achieve the above object, the present invention provides the following technical solutions: A high-definition wide-angle lens, which sequentially includes along the optical axis from the object side to the image side: A first lens with negative optical power, the object side is concave, and the image side is concave; A second lens with positive optical power, the object side is convex, and the image side is convex; A third lens with positive optical power, the object side is concave, and the image side is convex; A fourth lens with positive optical power, the object side is convex, and the image side is convex; A fifth lens with negative optical power, the object side is concave, and the image side is convex; and An infrared filter, located between the fifth lens and the imaging surface; The third lens is a glass spherical lens, the first lens, the second lens, the fourth lens and the fifth lens are plastic aspherical lenses, and an aperture stop is arranged between the second lens and the third lens. Arranging the aperture stop is easy to achieve high image quality and reduce the head size of the lens. The modulation transfer function MTF of the full field is greater than 50% at 100 lp / mm, the maximum viewing angle 140° < FOV < 150°, the total optical length TTL < 13.6 mm, and the working wavelength range is 400 - 700 nm.

[0008] Preferably, the high-definition wide-angle lens satisfies: 0.4 < h / TTL < 0.9, where TTL is the total length of the high-definition wide-angle lens, and h is the semi-image height corresponding to the maximum viewing angle of the high-definition wide-angle lens. Controlling this ratio, when the image height is the same, the smaller the ratio, the smaller the total length, which can effectively limit the length of the lens and is beneficial to shortening the lens size.

[0009] Preferably, the high-definition wide-angle lens satisfies: -0.8 < R1 / rad1 < -0.4, where R1 is the curvature radius of the object side of the first lens, and rad1 is the anti-curve inclination angle of the object side of the first lens. Controlling this ratio can adjust the surface shape of the inner and outer fields of the S1 surface of the lens. The edge is convex and the center is concave, which is convenient for collecting large-aperture object-side light and realizing an ultra-wide-angle field of view.

[0010] Preferably, the high-definition wide-angle lens satisfies: -0.7 < R3 / rad3 < -0.2, where R3 is the curvature radius of the object side of the second lens, and rad3 is the anti-curve inclination angle of the object side of the second lens. Controlling this ratio makes the S3 surface show a trend of convex in the center and concave at the edge, which is beneficial to reducing the deflection angle of the edge light rays, reducing the generation of large-aperture off-axis aberrations, and improving the overall performance of the wide-angle lens.

[0011] Preferably, the high-definition wide-angle lens satisfies: -1.3 < R8 / rad8 < -0.9, where R8 is the radius of curvature of the object side surface of the fourth lens, and rad8 is the reverse curvature inclination angle of the object side surface of the fourth lens. By controlling this ratio, the S8 surface shows a trend of being convex in the center and concave at the edges, which is beneficial to controlling the incident angle of marginal rays, reducing the deflection deformation of marginal rays, and reducing distortion.

[0012] Preferably, the high-definition wide-angle lens satisfies: -1.8 < R11 / rad11 < -1.2, where R11 is the radius of curvature of the image side surface of the fifth lens, and rad11 is the reverse curvature inclination angle of the image side surface of the fifth lens. By controlling this ratio, the S11 surface itself shows a trend of being convex in the center and concave at the edges, which can control the exit angle of the outer field of view, flexibly match the target surface with a large CRA, improve the light transmission, and at the same time, can effectively control the exit angle of the inner field of view, correct the paraxial spherical aberration, reduce the astigmatism field curvature at the periphery, and improve the resolution.

[0013] Preferably, the high-definition wide-angle lens satisfies: 0.7 < h / BFL < 1.1, where BFL is the back focal length of the optical system, and h is the semi-image height corresponding to the maximum field angle of the high-definition wide-angle lens. By controlling this ratio, the back focal length can be adjusted, leaving space for the installation and debugging of optical elements to avoid mechanical interference.

[0014] Preferably, the high-definition wide-angle lens satisfies: -1.8 < f4*Vd4 / f5*Vd5 < -0.9, where f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, Vd4 is the Abbe number of the fourth lens, and Vd5 is the Abbe number of the fifth lens. By controlling this ratio, the fourth lens and the fifth lens are approximated to a doublet lens, which can effectively correct chromatic aberration and improve the color reproduction of the lens.

[0015] Preferably, the high-definition wide-angle lens satisfies: -1.4 < |TCE1 / f1 + TCE5 / f5| / (TCE2 / f2 + TCE3 / f3 + TCE4 / f4) < -0.8, where f1 is the focal length of the first lens, TCE1 is the thermal expansion coefficient of the first lens, f2 is the focal length of the second lens, TCE2 is the thermal expansion coefficient of the second lens, f3 is the focal length of the third lens, TCE3 is the thermal expansion coefficient of the third lens, f4 is the focal length of the fourth lens, TCE4 is the thermal expansion coefficient of the fourth lens, f5 is the focal length of the fifth lens, and TCE5 is the thermal expansion coefficient of the fifth lens. By controlling this ratio, the optical power and the thermal expansion coefficient can be reasonably distributed to achieve imaging stability in different temperature environments.

[0016] Preferably, the high-definition wide-angle lens satisfies: -1.4 < f1 / f < -1.3, 6.8 < f2 / f < 6.9, 2.2 < f3 / f < 2.3, 1.3 < f4 / f < 1.4, -2.2 < f5 / f < -2.1, where f is the effective focal length of the high-definition wide-angle 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, and f5 is the focal length of the fifth lens. By controlling their ratios, the optical power of each lens can be reasonably distributed, the light path can be better controlled, the imaging performance is good, the light path is compressed, and the total length of the optical lens is shortened.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The wide-angle lens of the present invention has the advantages of miniaturization, high resolution, athermalization, low distortion, etc. This characteristic helps to improve the performance of the optical system while reducing the volume and size of the optical system, making it have broad application prospects in the fields of intelligent security, action cameras, handheld cameras, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 2 It is a distortion curve diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 3 It is an MTF curve diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 4 It is a normal temperature defocus curve diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 5 It is a -30°C defocus curve diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 6 It is an 80°C defocus curve diagram of the high-definition wide-angle lens of Embodiment 1 of the present invention; Figure 7 It is a schematic structural diagram of the high-definition wide-angle lens of Embodiment 2 of the present invention; Figure 8 It is a distortion curve diagram of the high-definition wide-angle lens of Embodiment 2 of the present invention; Figure 9 It is an MTF curve diagram of the high-definition wide-angle lens of Embodiment 2 of the present invention; Figure 10 This is a defocus curve of the high-definition wide-angle lens at room temperature according to Embodiment 2 of the present invention; Figure 11 This is a -30℃ defocus curve diagram of the high-definition wide-angle lens in Embodiment 2 of the present invention; Figure 12 This is a defocus curve diagram at 80°C for the high-definition wide-angle lens of Embodiment 2 of the present invention; Figure 13 This is a schematic diagram of the structure of the high-definition wide-angle lens in Embodiment 3 of the present invention; Figure 14 This is a distortion curve diagram of the high-definition wide-angle lens in Embodiment 3 of the present invention; Figure 15 This is the MTF curve of the high-definition wide-angle lens in Embodiment 3 of the present invention; Figure 16 This is a defocus curve of the high-definition wide-angle lens at room temperature in Embodiment 3 of the present invention; Figure 17 This is a -30℃ defocus curve diagram of the high-definition wide-angle lens in Embodiment 3 of the present invention; Figure 18 This is a defocus curve at 80°C for the high-definition wide-angle lens in Embodiment 3 of the present invention.

[0020] Reference numerals: L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; ST0, aperture stop; IR&CG, infrared filter. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] It should be noted that the object side of a lens refers to the side of the lens facing the subject, while the image side refers to the side of the lens facing the imaging plane. When a cross-section is made at any point on the object side surface of the lens, if the object side surface is always on the image side of the cross-section and its radius of curvature is positive, then the object side surface of the lens is convex; otherwise, it is concave. When a cross-section is made at any point on the image side surface of the lens, if the image side surface is always on the object side of the cross-section and its radius of curvature is negative, then the image side surface of the lens is convex; otherwise, it is concave. If a cross-section is made at any point on either the object side surface or the cross-section of the image side surface, and the object side surface or image side surface is partially on the image side and partially on the object side of the cross-section, then the surface has a point of inflection. The above method still applies to determining the convexity or concavity of the object side and image side surfaces near the optical axis.

[0023] Furthermore, the equations for the aspherical curves of each aspherical lens are expressed as follows: ; Where Z is the distance vector from the origin of the aspherical surface at a position of height r along the optical axis; c is the paraxial curvature of the aspherical surface (radius of curvature R = 1 / c, which is the reciprocal of the curvature); k is the conic coefficient; Ai is the i-th order coefficient of the aspherical surface, and the higher order coefficients used in this invention are A4, A6, A8, and A... 10 A 12 A 14 A 16 .

[0024] The imaging lens of this invention mainly comprises lenses of optical power fixed sequentially along the optical axis from the object side to the image side, namely, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. An infrared filter is disposed between the fifth lens and the imaging plane.

[0025] The first lens L1 has negative optical power and is a biconcave lens. The concave design of the object side is not conducive to the collection of edge light. By adjusting the curvature of its edge, the object side itself presents a trend of concave center and convex edge, which helps to increase the light transmission of the edge field of view and improve its light collection ability. At the same time, the biconcave design has a superimposed effect on the divergence of light, which diffuses the light of the large field of view to the rear system.

[0026] The second lens, L2, has positive optical power and is a biconvex lens. Since L1 uses a biconcave lens to collect light from a wide field of view, its divergence is significant. The use of a biconvex lens here, with its double-sided converging effect, helps to smoothly converge the large-aperture light transmitted in front of L1. The convex design of the object-side surface itself can cause excessive deflection of edge light, introducing large-aperture off-axis aberrations. Here, by adjusting the curvature of its edges, the object-side surface itself exhibits a central convex and edge concave trend, which helps to reduce the deflection angle of edge light, decrease the generation of large-aperture off-axis aberrations, and improve the overall performance of the wide-angle lens.

[0027] The third lens, L3, has positive optical power and is shaped like a concave-convex glass lens. This glass lens design helps reduce the impact of temperature on the aperture stop position, improving temperature reliability. The object-side surface is concave, receiving diverging rays from L2 and reducing the light deflection angle. The image-side surface is convex, shaped like a meniscus lens, which helps converge light to some extent onto the L4 lens. L3 acts as a connector between the front and rear systems in the entire system. It deflects light entering from the front optical system at a smaller angle, better correcting aberrations while maintaining low system sensitivity and improving resolution.

[0028] The fourth lens L4 has a positive optical power. L3 is a concave-convex lens that converges light for the first time, but the exit angle of the marginal rays is still relatively large. The object side S8 of L4 is convex. By adjusting the reverse curvature of its edge, the object side itself shows a trend of being convex in the center and concave at the edges, which is beneficial for collecting large-aperture marginal light. The image side S9 is convex. L4 receives the converging light from L3, converges the light again to the L5 lens, increases the optical path difference, and makes the light transition smoothly, which is beneficial for correcting aberration and improving the resolution.

[0029] The fifth lens L5 has a negative optical power. The object side S10 is concave, closely receiving the converging light from L4, greatly reducing the light deflection angle and reducing the generation of off-axis aberration. The image side S11 is convex. Since the target surface CRA is relatively large, the convex design cannot obtain a large exit angle and cannot match a large CRA. To meet the requirements of a large CRA, the reverse curvature of its edge is adjusted so that the image side itself shows a trend of being convex in the center and concave at the edges. Such a setting can increase the exit angle of the marginal field of view, match a large CRA, and at the same time, can effectively control the exit angle of the inner field of view, correct the positive paraxial spherical aberration, reduce the peripheral astigmatism field curvature, and improve the resolution.

[0030] The five lenses do not contact each other or only contact at the edges, are immovable relative to each other, and the third lens L3 is a glass spherical lens. The object sides and image surfaces of the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are all aspherical surfaces.

[0031] In some embodiments, an aperture is provided between the second lens L2 and the third lens L3. Providing an aperture is easy to achieve high image quality and reduce the head size of the lens.

[0032] The modulation transfer function MTF of the imaging lens of the present invention is greater than 50% at 100 lp / mm, the maximum field angle 140° < FOV < 150°, the total optical length TTL < 13.6 mm, and the working wavelength range is 400 - 700 nm.

[0033] In some embodiments, the high-definition wide-angle lens satisfies: 0.4 < h / TTL < 0.9, where TTL is the total length of the high-definition wide-angle lens, and h is the semi-image height corresponding to the maximum field angle of the high-definition wide-angle lens. By controlling this ratio, when the image height is the same, the smaller the ratio, the smaller the total length, which can effectively limit the length of the lens and is beneficial for shortening the lens size.

[0034] In some embodiments, the high-definition wide-angle lens satisfies: -0.8 < R1 / rad1 < -0.4, where R1 is the curvature radius of the object side of the first lens, and rad1 is the reverse curvature inclination angle of the object side of the first lens. By controlling this ratio, the surface shape of the inner and outer fields of view of the lens S1 surface can be adjusted. The convex edge and concave center are convenient for collecting large-aperture object-side light and achieving an ultra-wide-angle field of view.

[0035] In some embodiments, the high-definition wide-angle lens satisfies: -0.7 < R3 / rad3 < -0.2, where R3 is the curvature radius of the object side surface of the second lens, and rad3 is the anaclastic inclination angle of the object side surface of the second lens. Controlling this ratio makes the S3 surface convex in the center and concave at the edges, which helps reduce the deflection angle of marginal rays, decreases the generation of off-axis aberration for a large aperture, and improves the overall performance of the wide-angle lens.

[0036] In some embodiments, the high-definition wide-angle lens satisfies: -1.3 < R8 / rad8 < -0.9, where R8 is the curvature radius of the object side surface of the fourth lens, and rad8 is the anaclastic inclination angle of the object side surface of the fourth lens. Controlling this ratio makes the S8 surface convex in the center and concave at the edges, which helps control the incident angle of marginal rays, reduces the deflection deformation of marginal rays, and decreases distortion.

[0037] In some embodiments, the high-definition wide-angle lens satisfies: -1.8 < R11 / rad11 < -1.2, where R11 is the curvature radius of the image side surface of the fifth lens, and rad11 is the anaclastic inclination angle of the image side surface of the fifth lens. Controlling this ratio makes the S11 surface itself convex in the center and concave at the edges, which can control the exit angle of the outer field of view, flexibly match the target surface with a large CRA, increase the light transmittance. At the same time, it can effectively control the exit angle of the inner field of view, correct paraxial spherical aberration, reduce peripheral astigmatism field curvature, and improve the resolution.

[0038] In some embodiments, the high-definition wide-angle lens satisfies: 0.7 < h / BFL < 1.1, where BFL is the back focal length of the optical system, and h is the semi-image height corresponding to the maximum field angle of the high-definition wide-angle lens. Controlling this ratio can adjust the size of the back focal length, reserve space for the installation and debugging of optical elements, and avoid mechanical interference.

[0039] In some embodiments, the high-definition wide-angle lens satisfies: -1.8 < f4*Vd4 / f5*Vd5 < -0.9, where f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, Vd4 is the Abbe number of the fourth lens, and Vd5 is the Abbe number of the fifth lens. Controlling this ratio makes the fourth lens and the fifth lens approximate to a doublet lens, which can effectively correct chromatic aberration and improve the color reproducibility of the lens.

[0040] In some embodiments, the high-definition wide-angle lens satisfies: -1.4 < |TCE1 / f1 + TCE5 / f5| / (TCE2 / f2 + TCE3 / f3 + TCE4 / f4) < -0.8, where f1 is the focal length of the first lens, TCE1 is the thermal expansion coefficient of the first lens, f2 is the focal length of the second lens, TCE2 is the thermal expansion coefficient of the second lens, f3 is the focal length of the third lens, TCE3 is the thermal expansion coefficient of the third lens, f4 is the focal length of the fourth lens, TCE4 is the thermal expansion coefficient of the fourth lens, f5 is the focal length of the fifth lens, and TCE5 is the thermal expansion coefficient of the fifth lens. By controlling the ratio, the optical power and the thermal expansion coefficient can be reasonably distributed to achieve imaging stability in different temperature environments.

[0041] In some embodiments, the high-definition wide-angle lens satisfies: -1.4 < f1 / f < -1.3, 6.8 < f2 / f < 6.9, 2.2 < f3 / f < 2.3, 1.3 < f4 / f < 1.4, -2.2 < f5 / f < -2.1, where f is the effective focal length of the high-definition wide-angle 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, and f5 is the focal length of the fifth lens. By controlling the ratio, the optical power of each lens can be reasonably distributed, better controlling the light path, resulting in better high and low temperature performance, good imaging performance, compressing the light path, and shortening the total length of the optical lens.

[0042] Next, for a high-definition wide-angle lens, embodiments will be listed and described in detail with reference to the accompanying drawings.

[0043] Embodiment 1

[0044] The structure of the imaging lens in this embodiment is as Figure 1 shown, and the design parameters are as shown in the following table:

[0045] The remaining detailed aspherical-related parameters are as shown in the following table:

[0046] Figure 2 This is the distortion diagram of the wide-angle lens provided in Embodiment 1 of the present invention. Among them, the distortion diagram can represent the deformation degree of the imaging picture of the wide-angle lens. The smaller the distortion value, the smaller the deformation of the imaging picture. As Figure 2 shown, the horizontal coordinate represents the distortion value, without unit; the vertical coordinate represents the field angle.

[0047] Figure 3 This is the MTF diagram of the wide-angle lens provided in Embodiment 1 of the present invention. Among them, the MTF diagram can represent the comprehensive imaging quality of the wide-angle lens. The higher the MTF value, the clearer the imaging. As Figure 3 As shown, the horizontal axis represents spatial frequency in lp / mm; the vertical axis represents normalized MTF (OTF coefficient), which has no unit; where T represents metropolis and S represents arc; different lines represent different fields of view. The wide-angle lens has an MTF value greater than 50% across the entire field of view at 100 lp / mm, indicating that the wide-angle lens provided in this embodiment 1 has excellent imaging quality over a large field of view.

[0048] Figure 4 This is the MTF defocus curve of the wide-angle lens provided in Embodiment 1 of the present invention, as shown in the figure. The horizontal axis represents the defocus offset in mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit; T represents meridion, and S represents arc; different lines represent different fields of view. Figure 4 As shown, the MTF defocus offset of the wide-angle lens at 100 lp / mm is within ±0.01 mm, indicating that the wide-angle lens provided in this embodiment has a high concentration of defocus curves within the field of view and good control over field curvature.

[0049] Figure 5 This is a -30℃ defocus curve diagram of the wide-angle lens provided in Embodiment 1 of the present invention. Figure 6 This is a defocus curve diagram at 80℃ for a wide-angle lens provided in Embodiment 1 of the present invention. The horizontal axis represents the defocus offset in mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit. The wide-angle lens exhibits defocus offset within ±3μm at both high and low temperature MTF at 100lp / mm, indicating that the high and low temperature performance of this wide-angle lens is well controlled and can meet consumer needs.

[0050] Example 2

[0051] The structure of the imaging lens in this embodiment is as follows: Figure 6 As shown in the table below:

[0052] The remaining detailed parameters related to aspherical surfaces are shown in the table below:

[0053] Figure 8 This is a distortion diagram of a wide-angle lens provided in Embodiment 2 of the present invention. The distortion diagram represents the degree of image distortion in the wide-angle lens image; the smaller the distortion value, the smaller the image distortion. Figure 8 As shown, the horizontal coordinates represent the distortion values ​​and have no units; the vertical coordinates represent the field of view angles.

[0054] Figure 9This is an MTF chart of a wide-angle lens provided in Embodiment 2 of the present invention. The MTF chart represents the overall imaging quality of the wide-angle lens; a higher MTF value indicates a clearer image. Figure 9 As shown, the horizontal axis represents spatial frequency in lp / mm; the vertical axis represents normalized MTF (OTF coefficient), which has no unit; where T represents metropolis and S represents arc; different lines represent different fields of view. The wide-angle lens has an MTF value greater than 50% across the entire field of view at 100 lp / mm, indicating that the wide-angle lens provided in this embodiment 2 has excellent imaging quality over a large field of view.

[0055] Figure 10 The figure shows the MTF defocus curve of the wide-angle lens provided in Embodiment 2 of the present invention. The horizontal axis represents the defocus offset in mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit; T represents meridion, and S represents arc deflection; different lines represent different fields of view. The MTF defocus offset of the wide-angle lens at 100 lp / mm is within ±0.008 mm, indicating that the wide-angle lens provided in Embodiment 2 has a high concentration of defocus curves within its field of view, demonstrating good control over field curvature.

[0056] Figure 11 This is a -30℃ defocus curve diagram of the wide-angle lens provided in Embodiment 2 of the present invention. Figure 12 This is a defocus curve diagram at 80℃ for the wide-angle lens provided in Embodiment 2 of the present invention. The horizontal axis represents the defocus offset in mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit. The wide-angle lens exhibits high and low temperature MTF defocus offsets within ±3μm at 100lp / mm, indicating that the high and low temperature performance of this wide-angle lens is well controlled and can meet consumer needs.

[0057] Example 3

[0058] The structure of the imaging lens in this embodiment is as follows: Figure 11 As shown in the table below:

[0059] The remaining detailed parameters related to aspherical surfaces are shown in the table below:

[0060] Figure 14 This is a distortion diagram of a wide-angle lens provided in Embodiment 2 of the present invention. The distortion diagram represents the degree of image distortion in the wide-angle lens image; the smaller the distortion value, the smaller the image distortion. Figure 14 As shown, the horizontal coordinates represent the distortion values ​​and have no units; the vertical coordinates represent the field of view angles.

[0061] Figure 15 This is an MTF chart of a wide-angle lens provided in Embodiment 3 of the present invention. The MTF chart represents the overall imaging quality of the wide-angle lens; a higher MTF value indicates a clearer image. Figure 15 As shown, the horizontal axis represents spatial frequency in lp / mm; the vertical axis represents normalized MTF (OTF coefficient); where T represents metropolis and S represents arc; different lines represent different fields of view. The wide-angle lens has an MTF value greater than 50% across the entire field of view at 100 lp / mm, indicating that the wide-angle lens provided in this embodiment 3 has excellent imaging quality over a large field of view.

[0062] Figure 16 This is the MTF defocus curve of the wide-angle lens provided in Embodiment 3 of the present invention, as shown in the figure. The horizontal axis represents the defocus offset in mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit; T represents meridion, and S represents arc; different lines represent different fields of view. Figure 16 As shown, the MTF defocus offset of the wide-angle lens at 100 lp / mm is within ±0.009 mm, indicating that the wide-angle lens provided in this embodiment has a high concentration of defocus curves within the field of view and good control over field curvature.

[0063] Figure 17 This is a -30℃ defocus curve diagram of the wide-angle lens provided in Embodiment 3 of the present invention. Figure 18 This is a defocus curve diagram at 80℃ for the wide-angle lens provided in Embodiment 3 of the present invention. The horizontal axis represents the defocus offset in mm, and the vertical axis represents the normalized MTF (OTF coefficient). The defocus offset of the wide-angle lens at 100 lp / mm is within ±3 μm at both high and low temperatures, indicating that the high and low temperature performance of the wide-angle lens is well controlled and can meet the needs of consumers.

[0064] This invention provides a high-definition wide-angle lens that, through rational optical design, effectively resolves the contradiction between a large field of view and miniaturization and high definition, improving the lens's overall performance and application range, and meeting the industry's urgent demand for high-performance wide-angle lenses. This makes it widely applicable in fields with increasingly high-performance and integrated requirements, such as intelligent security and handheld cameras.

[0065] Within the technical scope disclosed in this invention, any variations or substitutions that can be easily conceived should be included within the protection scope of this invention. Therefore, the protection scope of this invention should be determined by the scope of the claims.

Claims

1. A high definition wide angle lens characterized by, From the object side to the image side along the optical axis, it successively includes: A first lens with negative optical power, the object side being concave and the image side being concave; A second lens with positive optical power, the object side being convex and the image side being convex; A third lens with positive optical power, the object side being concave and the image side being convex; A fourth lens with positive optical power, the object side being convex and the image side being convex; A fifth lens with negative optical power, the object side being concave and the image side being convex; and An infrared filter, located between the fifth lens and the imaging surface; The third lens is a glass spherical lens, and the first lens, the second lens, the fourth lens and the fifth lens are plastic aspherical lenses. An aperture stop is arranged between the second lens and the third lens.

2. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: 0.4 < h / TTL < 0.9, where TTL is the total length of the high-definition wide-angle lens, and h is the semi-image height corresponding to the maximum field angle of the high-definition wide-angle lens.

3. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -0.8 < R1 / rad1 < -0.4, where R1 is the curvature radius of the object side of the first lens, and rad1 is the reverse tilt angle of the object side of the first lens.

4. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -0.7 < R3 / rad3 < -0.2, where R3 is the curvature radius of the object side of the second lens, and rad3 is the reverse tilt angle of the object side of the second lens.

5. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -1.3 < R8 / rad8 < -0.9, where R8 is the curvature radius of the object side of the fourth lens, and rad8 is the reverse tilt angle of the object side of the fourth lens.

6. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -1.8 < R11 / rad11 < -1.2, where R11 is the curvature radius of the image side of the fifth lens, and rad11 is the reverse tilt angle of the image side of the fifth lens.

7. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: 0.7 < h / BFL < 1.1, where BFL is the back focal length of the optical system, and h is the semi-image height corresponding to the maximum field angle of the high-definition wide-angle lens.

8. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -1.8 < f4*Vd4 / f5*Vd5 < -0.9, where f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, Vd4 is the Abbe number of the fourth lens, and Vd5 is the Abbe number of the fifth lens.

9. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -1.4 < (TCE1 / f1 + TCE5 / f5) / (TCE2 / f2 + TCE3 / f3 + TCE4 / f4) < -0.8, where f1 is the focal length of the first lens, TCE1 is the thermal expansion coefficient of the first lens, f2 is the focal length of the second lens, TCE2 is the thermal expansion coefficient of the second lens, f3 is the focal length of the third lens, TCE3 is the thermal expansion coefficient of the third lens, f4 is the focal length of the fourth lens, TCE4 is the thermal expansion coefficient of the fourth lens, f5 is the focal length of the fifth lens, and TCE5 is the thermal expansion coefficient of the fifth lens.

10. The high-definition wide-angle lens according to claim 1, characterized in that: The high-definition wide-angle lens satisfies: -1.4 < f1 / f < -1.3, 6.8 < f2 / f < 6.9, 2.2 < f3 / f < 2.3, 1.3 < f4 / f < 1.4, -2.2 < f5 / f < -2.1, where f is the effective focal length of the high-definition wide-angle 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, and f5 is the focal length of the fifth lens.

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