High-image-quality wide-angle lens optical system

Abstract

The invention relates to a high-image-quality wide-angle lens optical system, and the system sequentially comprises a first lens which has negative focal power along an optical axis from an object side to an image side, and the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a concave surface; the second lens has positive focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the third lens has positive focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the first lens, the second lens, the third lens and the fourth lens are all made of plastic materials. The high-image-quality wide-angle lens optical system meets the following conditional expressions: 1.2 lt; f1 / f234lt; f1 is the effective focal length of the first lens, and f234 is the combined focal length of the second lens, the third lens and the fourth lens. The invention has the advantages of day and night use, reduced cost and high imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging, and particularly to a high-image-quality wide-angle lens optical system. Background Art

[0002] The wide-angle lens can reduce blind spots when applied in the automotive industry, helping drivers more intuitively understand the environment around the vehicle, reducing the risk of collision between the vehicle and other objects, and improving driving safety; when applied in the security field, it can monitor large areas or open spaces, and is usually used in monitoring scenarios such as parking lots, warehouses, and outdoor perimeter monitoring to improve security; when applied in the field of smart phones, it can help users capture magnificent scenes and capture a wider range of images in narrow spaces. When applied in the field of AR glasses, it can provide users with a broad spatial interaction experience.

[0003] In recent years, with the increasing number of application fields of wide-angle lenses, high-image-quality wide-angle lenses that are compatible with various day and night scenarios have received more and more attention. Therefore, it is particularly important to design a wide-angle lens that can ensure high imaging quality and can be used day and night. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-image-quality wide-angle lens optical system that can be used day and night, reduce costs, and ensure high imaging quality.

[0005] A high-image-quality wide-angle lens optical system sequentially includes, along the optical axis from the object side to the image side: a first lens having a negative optical power, the object side surface of the first lens being concave and the image side surface being concave; a second lens having a positive optical power, the object side surface of the second lens being convex and the image side surface being convex; a third lens having a positive optical power, the object side surface of the third lens being convex and the image side surface being convex; a fourth lens having a negative optical power, the object side surface of the fourth lens being concave and the image side surface being convex; the first lens, the second lens, the third lens, and the fourth lens are all made of plastic material, and the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 1.2 < |f1 / f 234 | < 1.4, where f1 is the effective focal length of the first lens, and f 234 is the combined focal length of the second lens, the third lens, and the fourth lens.

[0006] In the above solution, the four lenses do not contact each other or only contact at the edges, are not movable relative to each other, and the object side surface and the image surface of each lens are both plastic aspherical surfaces, which greatly reduces the manufacturing cost, can effectively reduce the lens thickness and weight, and the optical lens satisfies 1.2 < |f1 / f 234|<1.4, reasonably distribute the optical power, effectively control the light path, reduce the deflection angle during light propagation, reduce the aberration caused by large-angle light entering through L1, reduce the generation of off-axis aberration, improve the overall resolution of the lens, have excellent performance in visible light and infrared light environments, can meet high imaging quality, can achieve the standard of day and night use, and at the same time make the lens structure compact, which is conducive to miniaturization.

[0007] The first lens, the second lens, the third lens and the fourth lens are all aspherical lenses. The degree of freedom of the aspherical surface type is large, so the ability of the aspherical lens to deflect light and correct aberration is significantly stronger than that of the spherical surface. The first lens, the second lens, the third lens and the fourth lens of the aspherical lens are beneficial to improving the lens resolution and correcting lens distortion. At the same time, it is also beneficial to correct the exit light angle of the lens, so as to better match the photosensitive element.

[0008] Furthermore, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 2.5 < |f3 * Vd3 / f4 * Vd4| < 2.8, where f3 is the effective focal length of the third lens of the optical lens, f4 is the effective focal length of the fourth lens of the optical lens, Vd3 is the Abbe number of the material of the third lens of the optical lens, and Vd4 is the Abbe number of the material of the fourth lens of the optical lens.

[0009] In the above solution, by controlling the above ratio, the optical power and Abbe number of the third and fourth lenses can be reasonably matched, the lateral chromatic aberration and higher-order chromatic aberration generated by the front optical system can be corrected, the convergence positions of the image points of each field of view with different wavelengths are close to each other, and better visible light and infrared confocal can be achieved.

[0010] Furthermore, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 1.2 < |f1 * f4 / f2 * f3| < 1.4, where f1 is the effective focal length of the first lens of the optical lens, f2 is the effective focal length of the second lens of the optical lens, f3 is the effective focal length of the third lens of the optical lens, and f4 is the effective focal length of the fourth lens of the optical lens.

[0011] In the above solution, by controlling the ratio between f1 * f4 and f2 * f3, the optical power can be reasonably distributed, the optical lens can achieve a "negative-positive-negative-positive" symmetric architecture matching, realize the smooth transmission of light in the optical lens, reduce the generation of higher-order aberrations, and improve the overall performance of the optical lens.

[0012] Further, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 3.7 < |f3 / R6| + |f3 / R7| < 4.1, where f3 is the focal length of the third lens, R6 is the surface curvature radius of the image side of the third lens, f3 is the focal length of the fourth lens, and R7 is the surface curvature radius of the object side of the fourth lens.

[0013] In the above solution, by controlling the curvature of the image side of the third lens and the curvature of the object side of the fourth lens, it is possible to effectively avoid the ghosting caused by the reflected light of the lens in the front optical system on the object side of the third lens, reduce the generation of ghosting on the imaging surface, and effectively improve the imaging quality of the lens.

[0014] Further, the high-image-quality wide-angle lens optical system satisfies the following conditional formulas: 1.9 < |f1 / f| < 2.5, 1.7 < |f2 / f| < 2.1, 1.1 < |f3 / f| < 2.1, 1.2 < |f4 / f| < 1.7, where 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 f is the focal length of the high-image-quality wide-angle lens optical system.

[0015] In the above solution, the optical powers of the first lens, the second lens, the third lens, and the fourth lens that satisfy the above conditional formulas have a reasonable distribution ratio. The first lens is beneficial to reducing the angle between the light beam and the optical axis after passing through the system, quickly reducing the height of the light, and incident on the second lens at a reasonable height, preparing for further aberration correction of the rear group to improve the lens resolution, and at the same time is beneficial to increasing the field of view angle to achieve wide-angle imaging.

[0016] Further, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 0.34 < CT 12 / TTL < 0.42, where CT 12 is the air gap between the first lens and the second lens, and TTL is the on-axis distance from the object side of the first lens to the imaging surface.

[0017] In the above solution, the air gap between the first lens and the second lens is relatively large, which is beneficial to reducing the reflection of the lens, reducing the risk of ghost images. At the same time, this large distance is beneficial to reducing the rear port diameter, smooth transition of light, and controlling the ratio between CT 12 and TTL can effectively suppress the introduction of ghosting and improve the resolution.

[0018] Further, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 0.11 < R3 / R4 < 0.13, where R3 is the surface curvature radius of the object side of the second lens, and R4 is the surface curvature radius of the image side of the second lens.

[0019] In the above solution, the shape of the second lens is set to facilitate a smooth transition of the light path and reduce the sensitivity of the second lens.

[0020] Further, the high-image-quality wide-angle lens optical system satisfies the conditional formula: 0.95 < f G / f R <1.05, where f G is the focal length of the high-image-quality wide-angle lens optical system in the visible light band, and f R is the focal length of the high-image-quality wide-angle lens optical system in the 850nm infrared band.

[0021] In the above solution, by controlling the ratio of f G and f R , the focal lengths are made similar in the usage environments of visible light and near-infrared, achieving confocal imaging in the visible light band and the near-infrared band.

[0022] Further, the high-image-quality wide-angle lens optical system satisfies the conditional formula: DFOV > 120°, TTL < 3.26mm, where DFOV is the full field of view of the high-image-quality wide-angle lens optical system, and TTL is the axial distance from the object side of the first lens to the imaging plane.

[0023] Further, it also includes a diaphragm and a filter combination. The diaphragm is arranged between the first lens and the second lens, and the filter combination is arranged between the fourth lens and the imaging plane.

[0024] In the above solution, a diaphragm STO with an aperture of F2.2 is configured between the first lens L1 and the second lens L2. By setting it like this, the beam intensity can be adjusted with a simple structure, and it is beneficial to increase the field of view angle of the high-image-quality wide-angle lens optical system, which can better balance the exit angle of the optical system, and further facilitate matching with the corresponding image sensor. The filter combination can be an IR and a CG film.

[0025] A high-image-quality wide-angle lens optical system of the present invention has the beneficial effects of being able to be used day and night, reducing costs, and ensuring high imaging quality. The four lenses do not touch each other or only touch at the edges, are immovable relative to each other, and the object side and image surface of each lens are plastic aspherical surfaces, greatly reducing the manufacturing cost, effectively reducing the lens thickness and weight. The optical lens satisfies 1.2 < |f1 / f 234|<1.4, rationally distribute the optical power, effectively control the light path, reduce the deflection angle during light propagation, reduce the aberration caused by large-angle light entering through L1, reduce the generation of off-axis aberration, improve the overall resolution of the lens, have excellent performance in visible light and infrared light environments, can meet high imaging quality, can achieve the standard of day and night use, and at the same time make the lens structure compact, which is beneficial to miniaturization. Description of the Drawings

[0026] Figure 1 It is the lens cross-section and optical path diagram of the high-image-quality wide-angle lens optical system of Example 1.

[0027] Figure 2 It is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system of Example 1.

[0028] Figure 3 It is a schematic diagram of the MTF curve of infrared light of the high-image-quality wide-angle lens optical system of Example 1.

[0029] Figure 4 It is the lens cross-section and optical path diagram of the high-image-quality wide-angle lens optical system of Example 2.

[0030] Figure 5 It is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system of Example 2.

[0031] Figure 6 It is a schematic diagram of the MTF curve of infrared light of the high-image-quality wide-angle lens optical system of Example 2.

[0032] Figure 7 It is the lens cross-section and optical path diagram of the high-image-quality wide-angle lens optical system of Example 3.

[0033] Figure 8 It is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system of Example 3.

[0034] Figure 9 It is a schematic diagram of the MTF curve of infrared light of the high-image-quality wide-angle lens optical system of Example 3.

[0035] Explanation of the reference numerals in the drawings: L1, the first lens; L2, the second lens; L3, the third lens; L4, the fourth lens; STO, the aperture stop; IR&CG, the IR and CG films; IMA, the imaging surface. Detailed Embodiments

[0036] The following will further describe in detail a high-image-quality wide-angle lens optical system of the present invention in conjunction with specific embodiments and the drawings.

[0037] AsFigures 1 to 9 As shown, in a preferred embodiment, a high-quality wide-angle lens optical system includes, from the object side to the image side along the optical axis: a first lens having a negative optical power, the object side surface of the first lens is a concave surface, and the image side surface is a concave surface; a second lens having a positive optical power, the object side surface of the second lens is a convex surface, and the image side surface is a convex surface; a third lens having a positive optical power, the object side surface of the third lens is a convex surface, and the image side surface is a convex surface; a fourth lens having a negative optical power, the object side surface of the fourth lens is a concave surface, and the image side surface is a convex surface; the first lens, the second lens, the third lens and the fourth lens are all made of plastic material, and the high-quality wide-angle lens optical system meets the following conditional formula: 1.2<|f1 / f 234 |<1.4, where f1 is the effective focal length of the first lens, f 234 is the combined focal length of the second lens, the third lens and the fourth lens.

[0038] The first lens has negative refractive power, and its object side surface is concave near the optical axis, and its image side surface is concave near the optical axis, which is beneficial to collecting light of a large field of view, increasing the luminous flux, and diffusing the light to the rear.

[0039] The second lens has positive refractive power, and its object-side surface is convex at the near optical axis, which can collect as much light as possible into the rear optical system. The image-side surface is convex at the near optical axis, which can quickly transition the light to the rear optical system and reduce the system aperture.

[0040] The third lens has positive refractive power, and its object side surface is convex near the optical axis, and its image side surface is convex near the optical axis. It receives the large-diameter light from the front end and smoothly transitions it to the back end, shortening the optical path difference between the center and the edge of the field of view, reducing distortion, and improving illumination. At the same time, it can effectively correct the paraxial spherical aberration, reduce the peripheral astigmatism field curvature, and improve the resolution.

[0041] The fourth lens has negative refractive power, and its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis. This configuration helps to keep the principal point of the optical photography system away from the image side end, thereby effectively shortening the overall length of the optical imaging system, effectively correcting the paraxial spherical aberration, and reducing the peripheral astigmatism field curvature.

[0042] The four lenses do not touch each other or only touch at the edges, and cannot move relative to each other. The object side and image surface of each lens are plastic aspherical surfaces, which greatly reduces the manufacturing cost and can effectively reduce the thickness and weight of the lens. The optical lens meets 1.2<|f1 / f 234|<1.4, reasonably distribute the optical power, effectively control the trend of light, reduce the deflection angle during light propagation, reduce the aberration caused by large-angle light entering through L1, reduce the generation of off-axis aberration, improve the overall resolution of the lens, have excellent performance in visible light and infrared light environments, can meet higher imaging quality, can achieve the standard of day and night use, and at the same time make the lens structure compact, which is beneficial to miniaturization.

[0043] The present invention takes into account the advantages of high definition, wide angle, infrared confocal, miniaturization, etc. of imaging, meets the urgent needs of the market for high-performance wide-angle lenses, and is applicable to consumer electronics fields such as vehicle-mounted, security, and mobile phones.

[0044] The first lens, the second lens, the third lens, and the fourth lens are all aspherical lenses. The degree of freedom of the aspherical surface shape is large. Therefore, the ability of the aspherical lens to deflect light and correct aberration is significantly stronger than that of the spherical surface. The first lens, the second lens, the third lens, and the fourth lens of the aspherical lens are beneficial to improving the lens resolution and correcting lens distortion. At the same time, it is also beneficial to correct the exit light angle of the lens, so as to better match the photosensitive element.

[0045] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 2.5 < |f3 * Vd3 / f4 * Vd4| < 2.8, where f3 is the effective focal length of the third lens of the optical lens, f4 is the effective focal length of the fourth lens of the optical lens, Vd3 is the Abbe number of the material of the third lens of the optical lens, and Vd4 is the Abbe number of the material of the fourth lens of the optical lens. By controlling the above ratio, the optical power and Abbe number of the third and fourth lenses can be reasonably matched, the lateral chromatic aberration and higher-order chromatic aberration generated by the front optical system can be corrected, and the convergence positions of the image points of each field of view with different wavelengths are close to each other, and visible light and infrared confocal can be better realized.

[0046] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 1.2 < |f1 * f4 / f2 * f 3| <1.4, where f1 is the effective focal length of the first lens of the optical lens, f2 is the effective focal length of the second lens of the optical lens, f3 is the effective focal length of the third lens of the optical lens, and f4 is the effective focal length of the fourth lens of the optical lens. By controlling the ratio between f1 * f4 and f2 * f3, the optical power can be reasonably distributed, the optical lens can achieve a "negative-positive-negative-positive" symmetric architecture matching, realize the smooth transmission of light inside the optical lens, reduce the generation of higher-order aberrations, and improve the overall performance of the optical lens.

[0047] As Figures 1 to 9As shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 3.7 < |f3 / R6| + |f3 / R7| < 4.1, where f3 is the focal length of the third lens, R6 is the surface curvature radius of the image side of the third lens, f3 is the focal length of the fourth lens, and R7 is the surface curvature radius of the object side of the fourth lens. By controlling the curvature of the image side of the third lens and the curvature of the object side of the fourth lens, it is possible to effectively avoid ghost images generated by the reflected light of the lenses in the front optical system on the object side of the third lens, reduce the generation of ghost images on the imaging surface, and effectively improve the imaging quality of the lens.

[0048] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formulas: 1.9 < |f1 / f| < 2.5, 1.7 < |f2 / f| < 2.1, 1.1 < |f3 / f| < 2.1, 1.2 < |f4 / f| < 1.7, where 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 f is the focal length of the high-image-quality wide-angle lens optical system. The optical powers of the first lens, second lens, third lens, and fourth lens that satisfy the above conditional formulas have a reasonable distribution ratio. The first lens is beneficial for reducing the angle between the light beam and the optical axis after passing through the system, quickly reducing the height of the light, and entering the second lens at a reasonable height, preparing for further aberration correction of the rear group to improve the lens resolution, and at the same time being beneficial for increasing the field of view angle to achieve wide-angle imaging.

[0049] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 0.34 < CT 12 / TTL < 0.42, where CT 12 is the air gap between the first lens and the second lens, and TTL is the on-axis distance from the object side of the first lens to the imaging surface. The relatively large air gap between the first lens and the second lens is beneficial for reducing the reflection of the lens, reducing the risk of ghost images. At the same time, this large distance is beneficial for reducing the rear port diameter, smooth transition of light, and controlling the ratio between CT 12 and TTL can effectively suppress the introduction of ghost images and improve the resolution.

[0050] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the following conditional formula: 0.11 < R3 / R4 < 0.13, where R3 is the surface curvature radius of the object side of the second lens, and R4 is the surface curvature radius of the image side of the second lens. The shape setting of the second lens is beneficial for the smooth transition of the light path and at the same time reduces the sensitivity of the second lens.

[0051] AsFigures 1 to 9 As shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the conditional formula: 0.95 < fG / fR < 1.05, where fG is the focal length of the high-image-quality wide-angle lens optical system in the visible light band, and fR is the focal length of the high-image-quality wide-angle lens optical system in the 850 nm infrared band. By controlling the ratio of fG to fR, the focal lengths are similar in the usage environments of visible light and near-infrared, achieving confocal in the visible light band and the near-infrared band.

[0052] As Figures 1 to 9 shown, in some embodiments, the high-image-quality wide-angle lens optical system satisfies the conditional formula: DFOV > 120°, TTL < 3.26 mm, where DFOV is the full field of view of the high-image-quality wide-angle lens optical system, and TTL is the on-axis distance from the object side surface of the first lens to the imaging surface.

[0053] As Figures 1 to 9 shown, in some embodiments, it further includes a diaphragm and a filter combination. The diaphragm is disposed between the first lens and the second lens, and the filter combination is disposed between the fourth lens and the imaging surface. A diaphragm STO is configured between the first lens L1 and the second lens L2, and the aperture is F2.2. By setting it like this, the beam intensity can be adjusted with a simple structure, and at the same time, it is beneficial to increase the field of view angle of the high-image-quality wide-angle lens optical system, which can better balance the exit angle of the optical system, and thus is beneficial to matching the corresponding image sensor. The filter combination can be an IR and a CG film.

[0054] In the description of the present invention, the object side of the lens refers to the side of the lens facing the object to be photographed, and the image side refers to the side of the lens facing the imaging surface. When making a tangent plane at any point on the surface passing through the object side surface of the lens, the object side surface is always located on the image side of the tangent plane, and its radius of curvature is positive, then the object side surface of the lens is a convex surface; otherwise, the object side surface of the lens is a concave surface. When making a tangent plane at any point on the surface passing through the image side surface of the lens, the image side surface is always on the object side of the tangent plane, and its radius of curvature is negative, then the image side surface of the lens is a convex surface; otherwise, the image side surface of the lens is a concave surface. If a tangent plane is made at any point on the surface passing through the object side surface or the image side surface of the lens, and the object side surface or the image side surface has parts both on the image side and on the object side of the tangent plane, then there are inflection points on this surface. The judgment of the convexity and concavity of the object side and the image side surfaces near the optical axis still applies the above method.

[0055] In addition, the aspheric curve equations of each aspheric lens are expressed as follows:

[0056]

[0057] Where, Z is the distance sagitta from the origin of the aspheric surface when the aspheric surface is at a position with a height of r along the optical axis direction, c is the paraxial curvature of the aspheric surface (the curvature radius R = 1 / c, which is the reciprocal of the curvature); k is the conic coefficient; Ai is the i-th order coefficient of the aspheric surface, and the high-order coefficients applied in the present invention are A4, A6, A8, A 10 、A 12 、A 14 、A 16 。

[0058] Next, specific embodiments of the imaging device applicable to the above embodiments will be further described with reference to the accompanying drawings.

[0059] Embodiment 1

[0060] The design parameters of the high-image-quality wide-angle lens optical system of this embodiment can be shown in the following table:

[0061]

[0062] In the above table, the units of the surface radius and thickness are both millimeters; the surface marked with "*" represents an aspheric surface, and the surface shape of the aspheric lens satisfies the following relationship:

[0063] In Equation (1), the parameter c is the curvature corresponding to the lens radius, y is the radial coordinate, and the unit of the radial coordinate is the same as the unit of the lens length. k is the conic quadratic curve coefficient; when the k coefficient is less than -1, the surface shape curve of the lens is a hyperbola; when the k coefficient is equal to -1, the surface shape curve of the lens is a parabola; when the k coefficient is between -1 and 0, the surface shape curve of the lens is an ellipse; when the k coefficient is equal to 0, the surface shape curve of the lens is a circle; when the k coefficient is greater than 0, the surface shape curve of the lens is a flattened ellipse; A4, A6, A8, A10, A12, A14, A16 are the surface coefficients corresponding to the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order radial coordinates respectively. The value of the conic coefficient k is as shown in the above table.

[0064] The remaining detailed aspheric-related parameters are shown in the following table:

[0065]

[0066] Such as Figure 2 is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system 1 of this embodiment; Figure 3 is a schematic diagram of the modulation transfer function MTF curve of infrared light of the high-image-quality wide-angle lens optical system 1 of this embodiment.

[0067] According to the high-image-quality wide-angle lens optical system 1 of this embodiment, by adopting the above-optimized design of the first lens to the fourth lens, the full field of view angle of the optical system reaches more than 120°. Due to the reasonable matching of the lens parameters in the system, the system aberration is well corrected, enabling high-definition imaging, and the total length of the optical system is less than 3.26 mm, with a small volume, which is conducive to the miniaturization of the lens.

[0068] In addition, according to Figure 2 and 3 As shown in the MTF curve graph, it can be seen that the high-image-quality wide-angle lens optical system 1 of the embodiment of the present invention has excellent performance in visible light and infrared light environments, can meet relatively high imaging quality, and can achieve the standard of day and night use. Since all plastic design solutions are adopted, the weight is reduced while the cost is also reduced.

[0069] Embodiment 2

[0070] The design parameters of the high-image-quality wide-angle lens optical system of this embodiment can be shown in the following table:

[0071]

[0072]

[0073] The remaining detailed aspherical-related parameters are shown in the following table:

[0074]

[0075] As Figure 5 is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system 2 of this embodiment; Figure 6 is a schematic diagram of the modulation transfer function MTF curve of infrared light of the high-image-quality wide-angle lens optical system 2 of this embodiment.

[0076] According to the high-image-quality wide-angle lens optical system 2 of this embodiment, by adopting the above-optimized design of the first lens to the fourth lens, the full field of view angle of the optical system reaches more than 120°. Due to the reasonable matching of the lens parameters in the system, the system aberration is well corrected, enabling high-definition imaging, and the total length of the optical system is less than 3.26 mm, with a small volume, which is conducive to the miniaturization of the lens.

[0077] In addition, according to Figure 2 and 3 As shown in the MTF curve graph, it can be seen that the high-image-quality wide-angle lens optical system 2 of the embodiment of the present invention has excellent performance in visible light and infrared light environments, can meet relatively high imaging quality, and can achieve the standard of day and night use. Since all plastic design solutions are adopted, the weight is reduced while the cost is also reduced.

[0078] Embodiment 3

[0079] The design parameters of the high-image-quality wide-angle lens optical system of this embodiment can be shown in the following table:

[0080]

[0081] The remaining detailed aspherical-related parameters are shown in the following table:

[0082]

[0083]

[0084] As Figure 8 is a schematic diagram of the modulation transfer function MTF curve of visible light of the high-image-quality wide-angle lens optical system 3 of this embodiment; Figure 9 is a schematic diagram of the modulation transfer function MTF curve of infrared light of the high-image-quality wide-angle lens optical system 3 of this embodiment.

[0085] According to the high-image-quality wide-angle lens optical system 3 of this embodiment, by adopting the above-optimized design of the first lens to the fourth lens, the full field of view angle of the optical system reaches more than 120°. Due to the reasonable matching of the lens parameters in the system, the system aberrations are well corrected, enabling high-definition imaging, and the total length of the optical system is less than 3.26 mm, with a small volume, which is conducive to realizing the miniaturization of the lens.

[0086] In addition, according to Figure 2 and 3 shown in the MTF curve graph, it can be seen that the high-image-quality wide-angle lens optical system 3 of the embodiment of the present invention has excellent performance in the visible light and infrared light environments, can meet higher imaging quality, and can achieve the standard of day and night use. Since all plastic design schemes are adopted, the weight is reduced and the cost is also reduced.

[0087] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0088] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0089] In the present invention, unless otherwise clearly specified and defined, the terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0090] Although the description of the present invention is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and variations based on the above content. Therefore, all such substitutions, improvements and variations are included within the spirit and scope of the appended claims.

Claims

1. A high-image-quality wide-angle lens optical system, characterized in that It includes, in order along the optical axis from the object side to the image side: A first lens with a negative optical power, the object side of the first lens being concave and the image side being concave; A second lens with a positive optical power, the object side of the second lens being convex and the image side being convex; A third lens with a positive optical power, the object side of the third lens being convex and the image side being convex; A fourth lens with a negative optical power, the object side of the fourth lens being concave and the image side being convex; The first lens, the second lens, the third lens, and the fourth lens are all made of plastic material, and the high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 1.2 < |f1 / f 234 | < 1.4, where f1 is the effective focal length of the first lens, and f 234 is the combined focal length of the second, third, and fourth lenses.

2. The high-image-quality wide-angle lens optical system according to claim 1, wherein The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 2.5 < |f3 * Vd3 / f4 * Vd4| < 2.8, where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, Vd3 is the Abbe number of the material of the third lens, and Vd4 is the Abbe number of the material of the fourth lens.

3. The high-image-quality wide-angle lens optical system according to claim 1, wherein The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 1.2 < |f1 * f4 / f2 * f3| < 1.4, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens.

4. The high-image-quality wide-angle lens optical system according to claim 1, characterized in that, The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 3.7 < |f3 / R6| + |f3 / R7| < 4.1, where f3 is the focal length of the third lens, R6 is the curvature radius of the image side of the third lens, f3 is the focal length of the fourth lens, and R7 is the curvature radius of the object side of the fourth lens.

5. The high-image-quality wide-angle lens optical system according to claim 1, characterized in that, The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 1.9 < |f1 / f| < 2.5, 1.7 < |f2 / f| < 2.1, 1.1 < |f3 / f| < 2.1, 1.2 < |f4 / f| < 1.7, where 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 f is the focal length of the high-image-quality wide-angle lens optical system.

6. The high-image-quality wide-angle lens optical system according to claim 1, wherein, The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 0.34 < CT 12 / TTL < 0.42, wherein, CT 12 is the air gap between the first lens and the second lens, and TTL is the on-axis distance from the object side surface of the first lens to the imaging surface.

7. The high-image-quality wide-angle lens optical system according to claim 1, characterized in that, The high-image-quality wide-angle lens optical system satisfies the following conditional expressions: 0.11 < R3 / R4 < 0.13, where R3 is the curvature radius of the object side of the second lens and R4 is the curvature radius of the image side of the second lens.

8. The high-image-quality wide-angle lens optical system according to claim 1, wherein The high-image-quality wide-angle lens optical system satisfies the conditional expression: 0.95 < f G / f R < 1.05, Among them, f G is the focal length of the visible light band of the high-image-quality wide-angle lens optical system, and f R is the focal length of the 850nm infrared band of the high-image-quality wide-angle lens optical system.

9. The high-image-quality wide-angle lens optical system according to claim 1, characterized in that, The high-image-quality wide-angle lens optical system satisfies the conditional expression: DFOV > 120°, TTL < 3.26 mm, where DFOV is the full field of view of the high-image-quality wide-angle lens optical system and TTL is the on-axis distance from the object side of the first lens to the imaging plane.

10. The high-image-quality wide-angle lens optical system according to claim 1, characterized in that, It further includes a diaphragm and a filter combination. The diaphragm is disposed between the first lens and the second lens, and the filter combination is disposed between the fourth lens and the imaging plane.

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