Compact athermal high-definition wide-angle optical system

Abstract

The application discloses a compact athermal high-definition wide-angle optical system, which comprises, in sequence from an object side to an image side along an optical axis, a first lens with negative focal power, the object side of which is a convex surface and the image side of which is a concave surface; a second lens with positive focal power, the object side of which is a concave surface and the image side of which is a convex surface; a third lens with positive focal power, the object side of which is a convex surface and the image side of which is a convex surface; a fourth lens with positive focal power, the object side of which is a convex surface and the image side of which is a convex surface; a fifth lens with negative focal power, the object side of which is a concave surface and the image side of which is a convex surface; and an infrared filter, which is located 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. The full field modulation transfer function (MTF) is greater than 50% at 100 lp / mm, the maximum field of view is 140°<FOV<156°, the total optical length (TTL) is less than 15.1 mm, and the working waveband is 400-700 nm.

Description

Technical Field

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

[0002] The rapid upgrades in security monitoring, vehicle surround view, and action cameras are placing comprehensive demands on wide-angle imaging systems, requiring ultra-wide-angle, high-resolution, and stable performance across a wide temperature range. Existing wide-angle lenses generally struggle to achieve these performance characteristics, becoming a pain point in the industry.

[0003] The mainstream solutions fall into two categories: multi-glass lens structures offer stable imaging but are bulky and expensive, failing to meet the demands for high resolution; all-plastic solutions, while lightweight, low-cost, and high-resolution, suffer from poor temperature resistance. Among the publicly available technologies, some lenses achieve ultra-wide-angle views, but their large field of view makes them prone to focus drift at high and low temperatures, unsuitable for complex scenes; some optimize center sharpness, but in their compact structures, it's difficult to achieve both poor edge image quality and high resolution.

[0004] Therefore, achieving high resolution and wide-temperature stability simultaneously under the premise of ultra-wide-angle viewing is a key problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a compact, calorimetric, high-definition wide-angle optical system that solves the above problems, achieving high definition and good thermal stability while ensuring a large field of view.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a compact, pyrolysis-free, high-definition wide-angle optical system, comprising, from the object side to the image side along the optical axis, the following components: The first lens with negative optical power has a convex object side and a concave image side. The second lens has positive optical power, with a concave object side and a convex image side; A third lens with positive optical power, the object side is convex, and the image side is convex; The fourth lens has positive optical power, with both the object-side and image-side surfaces being convex. A fifth lens with negative optical power has a concave object-side surface and a convex image-side surface; and An infrared filter is located between the fifth lens and the imaging plane; The five lenses are not in contact with each other or only contact at edges, and cannot move relative to each other. 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. Arranging the diaphragm is easy to achieve high image quality and reduce the head size of the lens. The full-field modulation transfer function (MTF) is greater than 50% at 100 lp / mm, the maximum field of angle satisfies 140°<FOV<156°, the total optical length TTL<15.1 mm, and the operating wavelength band is 400-700 nm.

[0007] Preferably, the optical system satisfies: 0.06<TTL / FOV / H<0.08, wherein TTL is the total length of the optical system, FOV is the maximum field of angle of the optical system, and H is the image height corresponding to the maximum field of angle of the optical system. Controlling the ratio can effectively limit the length of the lens under the condition of the same image height and field of view proportion, which is beneficial to realizing miniaturization of the lens.

[0008] Preferably, the optical system satisfies: 1.9<|f12 / f|<2.2, wherein f is the effective focal length of the optical system, and f12 is the combined effective focal length of the first lens and the second lens.

[0009] Preferably, the optical system satisfies: 1.4<f345 / f<1.6, wherein f is the effective focal length of the optical system, and f345 is the combined effective focal length of the third lens, the fourth lens and the fifth lens.

[0010] Controlling the above focal length ratio can reasonably distribute optical power, reduce the deflection angle of light during propagation, reduce the generation of off-axis aberrations, and improve the overall performance of the lens. The first lens and the second lens form a front lens group, which can compress large-aperture light, increase the amount of transmitted light, gradually converge the large-aperture light transmitted from the front, and reduce the aperture of the system. The third lens, the fourth lens and the fifth lens form a rear lens group, which receives the large-aperture light from the front end and gently transitions it to the image plane, shortens the optical path difference between the central and edge fields of view, can effectively correct off-axis spherical aberration, reduce distortion of the optical system, and improve resolving power.

[0011] Preferably, the optical system satisfies: 0.6<D / H / f<0.8, wherein D is the maximum clear aperture of the object side surface of the first lens corresponding to the maximum field of angle of the optical system, H is the image height corresponding to the maximum field of angle of the optical system, and f is the effective focal length of the optical system. Controlling the ratio enables the lens to have the characteristics of large image surface and small aperture by controlling the maximum clear aperture of the object side surface of the first lens and the image height under the condition of a fixed focal length.

[0012] Preferably, the optical system satisfies: 0.2 < BFL / TTL < 0.3, wherein BFL is the back focal length of the optical system, and TTL is the total optical length of the optical system. Controlling said ratio can reserve space for the installation and adjustment of optical elements on the basis of realizing miniaturization, and avoid mechanical interference.

[0013] Preferably, the optical system satisfies: 0.9 < f3 / (dn / dt(3)) < 1.1, wherein f3 is the focal length of the third lens, and dn / dt(3) is the expansion coefficient of the third lens. By controlling said ratio, the third lens is made of a material with a reasonable expansion coefficient, which helps the lens maintain good resolving power at high and low temperatures and improves the thermal stability of the system.

[0014] Preferably, the optical system satisfies: 1.3 < R9 / R10 < 1.7, wherein R9 is the curvature radius of the image side surface of the fourth lens, and R10 is the curvature radius of the object side surface of the fifth lens. By controlling said ratio, the shape of the object side surface of the fifth lens and the shape of the image side surface of the fourth lens can be similar, which facilitates a gentle transition of the light traveling trend and reduces the deformation degree of edge light, and reduces distortion.

[0015] Preferably, the optical system satisfies: 0.2 < R10 / R11 < 0.4, wherein R10 is the curvature radius of the object side surface of the fifth lens, and R11 is the curvature radius of the image side surface of the fifth lens. Controlling said ratio can make the shapes of the two surfaces of the fifth lens similar, gently transition peripheral light, which helps reduce lens sensitivity.

[0016] Preferably, the optical system satisfies: 1.5 < |f1 / f| < 1.8, 18 < f2 / f < 30, 1.9 < f3 / f < 2.1, 1.4 < f4 / f < 1.6, 1.8 < |f5 / f| < 2.1, wherein f is the effective focal length of the optical system, 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. Controlling said ratios can reasonably distribute the optical power of each lens, better control the traveling trend of light, enable good high and low temperature performance, good imaging performance, compress the traveling trend of light, and shorten the total length of the optical lens.

[0017] Compared with the prior art, the beneficial effects of the present invention are: The wide-angle lens described in the present invention has the advantages of ultra-wide angle, high resolving power, athermalization and the like. This characteristic helps improve the applicability of the optical system in complex environments, so that it has broad application prospects in the fields of intelligent security, sports cameras, handheld cameras and other fields. Description of Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the compact, anechoic, high-definition wide-angle optical system according to Embodiment 1 of the present invention; Figure 2 This is the MTF curve of the compact, anechoic, high-definition wide-angle optical system of Embodiment 1 of the present invention; Figure 3 This is a room-temperature defocusing curve diagram of the compact, anechoic, high-definition wide-angle optical system of Embodiment 1 of the present invention; Figure 4 This is a -30℃ defocus curve diagram of the compact, anechoic, high-definition wide-angle optical system of Embodiment 1 of the present invention; Figure 5 This is a defocusing curve at 80°C for the compact, anechoic, high-definition wide-angle optical system of Embodiment 1 of the present invention. Figure 6 This is a schematic diagram of the structure of the compact, anechoic, high-definition wide-angle optical system of Embodiment 2 of the present invention; Figure 7 This is the MTF curve of the compact, anechoic, high-definition wide-angle optical system of Embodiment 2 of the present invention; Figure 8 This is a room-temperature defocusing curve diagram of the compact, anechoic, high-definition wide-angle optical system of Embodiment 2 of the present invention; Figure 9 This is a -30℃ defocus curve diagram of the compact, anechoic, high-definition wide-angle optical system of Embodiment 2 of the present invention; Figure 10 This is a defocusing curve at 80°C for the compact, anechoic, high-definition wide-angle optical system of Embodiment 2 of the present invention. Figure 11 This is a schematic diagram of the structure of the compact, anechoic, high-definition wide-angle optical system of Embodiment 3 of the present invention; Figure 12 This is the MTF curve of the compact, anechoic, high-definition wide-angle optical system of Embodiment 3 of the present invention; Figure 13 This is a room-temperature defocusing curve of the compact, anechoic, high-definition wide-angle optical system of Embodiment 3 of the present invention; Figure 14 This is a -30℃ defocus curve diagram of the compact, anechoic, high-definition wide-angle optical system of Embodiment 3 of the present invention; Figure 15 This is a defocusing curve at 80°C for the compact, anechoic, high-definition wide-angle optical system of 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 IR&CG is disposed between the fifth lens L5 and the imaging plane IMA.

[0025] The first lens L1 has negative optical power. Its object-side surface S1 is convex near the optical axis to maximize the reception of large-aperture light rays transmitted from the object side into the rear optical system. Its image-side surface S2 is concave near the optical axis to quickly diffuse light into the rear optical system. The configuration of the first lens L1 can reduce light loss and improve illumination.

[0026] The second lens L2 has a smaller positive optical power, with the object side S3 being concave and the image side S4 being convex. This configuration helps to smoothly converge the large-aperture light transmitted in front of the lens, reduce the introduction of higher-order aberrations, compress the light aperture, achieve smooth light transmission inside the wide-angle lens, reduce the generation of higher-order aberrations, and improve the overall performance of the wide-angle lens.

[0027] The third lens L3 has positive optical power, with the object side S6 being convex and the image side S7 being convex. This arrangement allows for the smooth reception and transmission of light from the front to the rear, with a small light deflection angle, preventing excessive curvature of the image plane and reducing field curvature.

[0028] The fourth lens L4 has positive optical power, and the object side S8 and the image side S9 are convex. This arrangement is conducive to light convergence, which increases the physical aperture of the aperture, achieves greater light transmission, and helps to increase the illumination of the image, so that the emitted light is smoothly incident to the rear.

[0029] The fifth lens L5 has negative optical power, with the object-side surface S10 being concave and the image-side surface S11 being convex. This configuration allows it to receive large-aperture light from the front and smoothly transition it to the rear, shortening the optical path difference between the center and edge fields of view, reducing distortion, and increasing illumination. At the same time, it can effectively correct paraxial spherical aberration, reduce peripheral astigmatism curvature, and improve resolution.

[0030] The five lenses do not touch each other or only touch at their edges, and cannot move from one another. The third lens L3 is a spherical glass lens, and the object surface and image surface of the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are all aspherical.

[0031] In some embodiments, an aperture stop is provided between the second lens L2 and the third lens L3. The aperture stop facilitates high image quality and reduces the head size of the lens.

[0032] The imaging lens of this invention has a full-field modulation transfer function (MTF) greater than 50% at 100 lp / mm, a maximum field of view of 140° < FOV < 156°, a total optical length (TTL) of < 15.1 mm, and an operating wavelength of 400-700 nm.

[0033] In some embodiments, the optical system satisfies: 0.06<TTL / FOV / H<0.08, wherein TTL is the total length of the optical system, FOV is the maximum field of view of the optical system, and H is the image height corresponding to the maximum field of view of the optical system. Controlling the ratio can effectively limit the length of the lens under the same image height and field of view ratio, which is beneficial to realizing the miniaturization of the lens.

[0034] In some embodiments, the optical system satisfies: 1.9<|f12 / f|<2.2, 1.4 <f345 / f<1.6, wherein f is the effective focal length of the optical system, f12 is the combined effective focal length of the first lens and the second lens, and f345 is the combined effective focal length of the third lens, the fourth lens and the fifth lens. Controlling the ratio can reasonably allocate the optical power, reduce the deflection angle of light during propagation, reduce the generation of off-axis aberrations, and improve the overall performance of the lens. The first lens and the second lens form a front lens group, which can compress large-aperture light, increase the light flux, slowly converge the large-aperture light transmitted from the front, and reduce the aperture of the system. The third lens, the fourth lens and the fifth lens form a rear lens group, which receives the large-aperture light from the front end and smoothly transitions it to the image plane, shortens the optical path difference between the central and edge fields of view, can effectively correct off-axis spherical aberration, reduce the distortion of the optical system, and improve the resolution.

[0035] In some embodiments, the optical system satisfies: 0.6< D / H / f <0.8, wherein D is the maximum clear aperture of the object-side surface of the first lens corresponding to the maximum field of view of the optical system, H is the image height corresponding to the maximum field of view of the optical system, and f is the effective focal length of the optical system. Controlling the ratio enables the lens to have the characteristics of large image surface and small aperture by controlling the maximum clear aperture of the object-side surface of the first lens and the image height under the condition of a certain focal length.

[0036] In some embodiments, the compact athermalized high-definition wide-angle optical system satisfies: 0.2<BFL / TTL<0.3, wherein BFL is the back focal length of the optical system, and TTL is the total optical length of the compact athermalized high-definition wide-angle optical system. Controlling the ratio can reserve space for the installation and debugging of optical elements on the basis of realizing miniaturization and avoid mechanical interference.

[0037] In some embodiments, the compact athermalized high-definition wide-angle optical system satisfies: 0.9<f3 / (dn / dt(3)) <1.1, wherein f3 is the focal length of the third lens, and dn / dt(3) is the expansion coefficient of the third lens. Controlling the ratio enables the third lens to be made of a material with a reasonable expansion coefficient, which helps the lens maintain good resolution at high and low temperatures and improves the thermal stability of the system.

[0038] In some embodiments, the compact athermalized high-definition wide-angle optical system satisfies: 1.3<R9 / R10<1.7, wherein R9 is the radius of curvature of the image-side surface of the fourth lens, and R10 is the radius of curvature of the object-side surface of the fifth lens. By controlling the ratio, the shape of the object-side surface of the fifth lens and the shape of the image-side surface of the fourth lens can be made similar, which facilitates smooth transition of the light propagation trend, reduces the deformation degree of marginal light, and reduces distortion.

[0039] In some embodiments, the compact athermalized high-definition wide-angle optical system satisfies: 0.2<R10 / R11<0.4, wherein R10 is the radius of curvature of the object-side surface of the fifth lens, and R11 is the radius of curvature of the image-side surface of the fifth lens. Controlling the ratio can make the shapes of the two surfaces of the fifth lens similar, enabling smooth transition of peripheral light, which is beneficial to reducing lens sensitivity.

[0040] In some embodiments, the compact athermalized high-definition wide-angle optical system satisfies: 1.5<|f1 / f|<1.8, 18<|f2 / f|<30, 1.9<f3 / f<2.1, 1.4<f4 / f<1.6, 1.8<|f5 / f|<2.1, wherein f is the effective focal length of the compact athermalized high-definition wide-angle optical system, 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. Controlling the ratios can reasonably distribute the optical power of each lens, better control the light propagation trend, achieve good high and low temperature performance and good imaging performance, compress the light propagation path, and shorten the total length of the optical lens.

[0041] Hereinafter, for a compact athermalized high-definition wide-angle optical system, embodiments are listed and described in detail with reference to the accompanying drawings.

[0042] Embodiment 1: The structure of the imaging lens of this embodiment is as Figure 1 shown, and the design parameters are as shown in the following table:

[0043] Other detailed aspheric-related parameters are as shown in the following table:

[0044] Figure 2 is the MTF diagram of the optical system provided in Embodiment 1 of the present invention, wherein the MTF diagram can represent the comprehensive imaging quality of the wide-angle lens, the higher the MTF value, the clearer the imaging, as shown in Figure 2 the horizontal coordinate represents the spatial frequency, with the unit of lp / mm; the vertical coordinate represents the normalized MTF (OTF coefficient), which has no unit; wherein T represents tangential, S represents sagittal; different lines represent different fields of view. As shown in Figure 2As shown, the MTF value of the wide-angle lens at 100 lp / mm is greater than 50% across the entire field of view, indicating that the wide-angle optical system provided in this embodiment 1 has excellent imaging quality over a large field of view.

[0045] Figure 3 The figure shows the MTF defocus curve of the optical system 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; T represents meridion, and S represents arc deflection; different lines represent different fields of view. Figure 3 As shown, the MTF defocus offset of the wide-angle lens at 100 lp / mm is within ±0.004 mm, indicating that the wide-angle optical system provided in this embodiment 1 has a high concentration of defocus curves within the field of view and good control over field curvature.

[0046] Figure 4 This is a -30℃ defocus curve diagram of the optical system provided in Embodiment 1 of the present invention. Figure 5 The diagram shows the 80℃ defocus curve of the optical system provided in Embodiment 1 of this invention. The horizontal axis represents the defocus offset in mm, and the vertical axis represents the normalized MTF (OTF coefficient), which has no unit. The wide-angle optical system exhibits high and low temperature MTF defocus offsets within ±2.5 μm at 100 lp / mm, indicating that the high and low temperature performance of this wide-angle optical system is well controlled and can meet consumer needs.

[0047] Example 2: The structure of the imaging lens in this example is as follows Figure 6 As shown in the table below:

[0048] The remaining detailed parameters related to aspherical surfaces are shown in the table below:

[0049] Figure 7 The figure shows the MTF (Mean Transmission Factor) of the optical system provided in Embodiment 2 of the present invention. The MTF represents the overall imaging quality of the optical system; a higher MTF value indicates a clearer image. As shown in the figure, the horizontal axis represents spatial frequency in lp / mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit; T represents metropolitanity, and S represents arc distance; different lines represent different fields of view. The wide-angle optical system exhibits an MTF value greater than 50% across the entire field of view at 100 lp / mm, indicating that the wide-angle optical system provided in Embodiment 2 has excellent imaging quality over a large field of view.

[0050] Figure 8The figure shows the MTF defocus curve of the optical system 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 wide-angle lens shows an MTF defocus offset within ±0.003 mm at 100 lp / mm, indicating that the wide-angle optical system provided in Embodiment 2 has a high concentration of defocus curves within the field of view, demonstrating good control over field curvature.

[0051] Figure 9 This is a -30℃ defocus curve diagram of the optical system provided in Embodiment 2 of the present invention. Figure 10 The diagram shows the 80℃ defocus curve of the optical system provided in Embodiment 2 of the present invention. The horizontal axis represents the defocus offset in mm, and the vertical axis represents the normalized MTF (OTF coefficient), which has no unit. The wide-angle optical system 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 optical system is well controlled and can meet consumer needs.

[0052] Example 3: The structure of the imaging lens in this example is as follows Figure 11 As shown in the table below:

[0053] The remaining detailed parameters related to aspherical surfaces are shown in the table below:

[0054] Figure 12 The figure shows the MTF (Mean Transmission Factor) of the optical system provided in Embodiment 3 of the present invention. The MTF represents the overall imaging quality of the optical system; a higher MTF value indicates a clearer image. As shown in the figure, the horizontal axis represents spatial frequency in lp / mm; the vertical axis represents the normalized MTF (OTF coefficient), which has no unit; T represents metropolitanity, and S represents arc distance; different lines represent different fields of view. The wide-angle optical system exhibits an MTF value greater than 50% across the entire field of view at 100 lp / mm, indicating that the wide-angle optical system provided in Embodiment 3 has excellent imaging quality over a large field of view.

[0055] Figure 13The figure shows the MTF defocus curve of the optical system provided in Embodiment 3 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. As shown in the figure, the MTF defocus offset of the optical system at 100 lp / mm is within ±0.003 mm, indicating that the wide-angle optical system provided in Embodiment 3 has a high concentration of defocus curves within the field of view, demonstrating good control over field curvature.

[0056] Figure 14 This is a -30℃ defocus curve diagram of the optical system provided in Embodiment 3 of the present invention. Figure 15 This is a defocus curve diagram at 80℃ for the optical system 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 ±2 μm at both high and low temperatures, indicating that the high and low temperature performance of the wide-angle optical system is well controlled and can meet the needs of consumers.

[0057] This invention discloses a compact, pyrotechnic, high-definition wide-angle optical system. Through rational optical design, it effectively resolves the contradictions between ultra-wide field of view, high definition, and high / low temperature stability, thereby improving the overall performance and application range of the lens 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.

[0058] 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 compact, calorimetric, high-definition wide-angle optical system, characterized in that, It sequentially comprises the following components along the optical axis from the object side to the image side: a first lens having negative refractive power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; a second lens having positive refractive power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; a third lens having positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a fourth lens having positive refractive power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; a fifth lens having negative refractive power, the object side surface of which is a concave surface and the image side surface of which is a convex surface; and an infrared filter located 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 aspheric lenses, and a diaphragm is arranged between the second lens and the third lens.

2. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 0.06<TTL / FOV / H<0.08, wherein TTL is the total length of the optical system, FOV is the maximum field of view angle of the optical system, and H is the image height corresponding to the maximum field of view angle of the optical system.

3. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 1.9<|f12 / f|<2.2, wherein f is the effective focal length of the optical system, and f12 is the combined effective focal length of the first lens and the second lens.

4. The compact, calorimetric, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 1.4<f345 / f<1.6, f is the effective focal length of the optical system, and f345 is the combined effective focal length of the third lens, the fourth lens and the fifth lens.

5. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 0.6<D / H / f<0.8, wherein D is the maximum clear aperture of the object side surface of the first lens corresponding to the maximum field of view of the optical system, H is the image height corresponding to the maximum field of view of the optical system, and f is the effective focal length of the optical system.

6. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 0.2<BFL / TTL<0.3, wherein BFL is the optical back focal length of the optical system, and TTL is the total optical length of the optical system.

7. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 0.9<f3 / (dn / dt(3))<1.1, wherein f3 is the focal length of the third lens, and dn / dt(3) is the expansion coefficient of the third lens.

8. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 1.3<R9 / R10<1.7, wherein R9 is the radius of curvature of the image side surface of the fourth lens, and R10 is the radius of curvature of the object side surface of the fifth lens.

9. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 0.2<R10 / R11<0.4, wherein R10 is the radius of curvature of the object side surface of the fifth lens, and R11 is the radius of curvature of the image side surface of the fifth lens.

10. The compact, athermalized, high-definition wide-angle optical system according to claim 1, characterized in that: the optical system satisfies: 1.5<|f1 / f|<1.8, 18<f2 / f<30, 1.9<f3 / f<2.1, 1.4<f4 / f<1.6, 1.8<|f5 / f|<2.1, wherein f is the effective focal length of the optical system, 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.

Images