An ultra-wide angle low-distortion optical imaging system

Abstract

The application discloses an ultra-wide-angle low-distortion optical imaging system in the technical field of optical lenses, which comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the same optical axis from the object side to the image side, and the object side and the image side of each lens are aspherical surfaces; the first lens has negative refractive power, and the object side thereof is a concave surface at the near axis; the second lens has positive refractive power, and the object side thereof is a convex surface; the third lens has negative refractive power, and the image side thereof is a concave surface; the fourth lens has positive refractive power, and the object side thereof is a concave surface at the near axis, and the image side thereof is a convex surface at the near axis; the fifth lens has negative refractive power, and the object side thereof is a convex surface at the near axis; and the sixth lens has negative refractive power, and the image side thereof is a concave surface at the near axis.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and more specifically to an ultra-wide-angle low-distortion optical imaging system. Background Technology

[0002] With the development of technology, people have higher and higher requirements for lens imaging. Miniaturization, high performance and high resolution have become the trend of modern electronic products such as mobile phones.

[0003] As the pixel size of electronic imaging sensors shrinks, the requirements for angle and image quality become increasingly stringent. Traditional optical imaging systems cannot simultaneously meet the demands for ultra-wide-angle and low-distortion imaging. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-wide-angle, low-distortion optical imaging system to solve the technical problem that existing optical imaging systems cannot simultaneously meet the requirements of ultra-wide-angle and low distortion.

[0005] To solve the above-mentioned technical problems, the present invention specifically provides an ultra-wide-angle low-distortion optical imaging system, including a first lens, an aperture, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the same optical axis, wherein the object side and the image side of each lens are aspherical.

[0006] The first lens has negative refractive power, and its object-side surface is concave near the axis.

[0007] The second lens has positive refractive power, and its object-side surface is convex.

[0008] The third lens has negative refractive power, and its image-side surface is concave.

[0009] The fourth lens has positive refractive power; its object side is concave near the axis, and its image side is convex near the axis.

[0010] The fifth lens has negative refractive power, and its object measuring surface is convex near the axis.

[0011] The sixth lens has negative refractive power, and its image-side surface is concave near the axis.

[0012] The ultra-wide-angle low-distortion optical imaging system satisfies the following relationship:

[0013] -0.21 <F / R4<-0.18,111.4<V2+V6<111.5;

[0014] f is the focal length of the high-definition optical imaging lens, R4 is the radius of curvature of the object side of the fourth lens, V2 is the Abbe number of the second lens, and V6 is the Abbe number of the sixth lens.

[0015] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0016] 0.58 <YC52 / f<0.63;

[0017] YC52 is the vertical distance between the inflection point on the image side of the fifth lens and the optical axis.

[0018] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0019] 0.37 <f / TL<0.40;

[0020] TL is the distance between the object-side vertex of the first lens and the imaging plane.

[0021] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0022] -21.63 <SAG45 / T45<-21.33;

[0023] SAG45 is the sag of the image-side surface of the fourth lens at its maximum effective radius, and T45 is the on-axis air gap between the fourth and fifth lenses.

[0024] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0025] 1.98 <TTL / f<2.04;

[0026] TTL is the total optical length of the camera lens;

[0027] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0028] 0.26 <T34 / AAT<0.30;

[0029] T34 is the air gap on the optical axis between the image side of the third lens and the object side of the fourth lens, and AAT is the sum of the air gaps between each adjacent lens from the first lens to the fifth lens.

[0030] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0031] -0.45 <f / (f1+f4)<-0.36;

[0032] f1 is the focal length of the first lens, and f4 is the focal length of the fourth lens;

[0033] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0034] 0.85 <f / f123<0.91;

[0035] f123 is the combined focal length of the first lens, the second lens, and the third lens;

[0036] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0037] 1.71 <f4 / CT4<1.74;

[0038] CT4 is the thickness of the fourth lens on the optical axis.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] The ultra-wide-angle, low-distortion, high-definition imaging lens of this invention is a six-lens type. The surface structure of each lens is combined with the optimized range of optical parameters. It can effectively shorten the overall size of the imaging lens and improve its lens angle while maintaining ultra-wide-angle imaging and reducing imaging distortion. It has high resolution brought by high pixel count. It is an optical imaging lens technology that integrates ultra-wide-angle and low distortion, thus providing it for use in small or thin portable devices that need to be equipped with high imaging quality equipment. Attached Figure Description

[0041] To more clearly illustrate the embodiments of the present invention or the technical solutions in 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 merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the ultra-wide-angle low-distortion optical imaging system in Embodiment 1 of the present invention;

[0043] Figure 2 This is a field curvature and distortion curve diagram of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 1 of the present invention;

[0044] Figure 3 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 1 of the present invention;

[0045] Figure 4 This is a schematic diagram of the ultra-wide-angle low-distortion optical imaging system in Embodiment 2 of the present invention;

[0046] Figure 5This is a field curvature and distortion curve diagram of the ultra-wide-angle low-distortion optical imaging system of Embodiment 2 of the present invention;

[0047] Figure 6 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 2 of the present invention;

[0048] Figure 7 This is a schematic diagram of the ultra-wide-angle low-distortion optical imaging system in Embodiment 3 of the present invention;

[0049] Figure 8 This is a field curvature and distortion curve diagram of the ultra-wide-angle low-distortion optical imaging system of Embodiment 3 of the present invention;

[0050] Figure 9 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system of Embodiment 3 of the present invention;

[0051] Figure 10 This is a schematic diagram of the ultra-wide-angle low-distortion optical imaging system in Embodiment 4 of the present invention;

[0052] Figure 11 This is a field curvature and distortion curve diagram of the ultra-wide-angle low-distortion optical imaging system of Embodiment 4 of the present invention;

[0053] Figure 12 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system of Embodiment 4 of the present invention;

[0054] Figure 13 This is a schematic diagram of the ultra-wide-angle low-distortion optical imaging system in Embodiment 5 of the present invention;

[0055] Figure 14 This is a field curvature and distortion curve diagram of the ultra-wide-angle low-distortion optical imaging system of Embodiment 5 of the present invention;

[0056] Figure 15 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system of Embodiment 5 of the present invention.

[0057] The labels in the diagram represent the following:

[0058] First lens: 101, 201, 301, 401, 501;

[0059] Apertures: 102, 202, 302, 402, 502;

[0060] Second lens: 103, 203, 303, 403, 503;

[0061] Third lens: 104, 204, 304, 404, 504;

[0062] Fourth lens: 105, 205, 305, 405, 505;

[0063] Fifth lens: 106, 206, 306, 406, 506;

[0064] Sixth lens: 107, 207, 307, 407, 507;

[0065] Infrared filters: 108, 208, 308, 408, 508. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] Specifically, this invention provides an ultra-wide-angle low-distortion optical imaging system, including a first lens, an aperture, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the same optical axis, wherein the object side and image side of each lens are aspherical.

[0068] The first lens has negative refractive power, and its object-side surface is concave near the axis.

[0069] The second lens has positive refractive power, and its object-side surface is convex.

[0070] The third lens has negative refractive power, and its image-side surface is concave.

[0071] The fourth lens has positive refractive power; its object side is concave near the axis, and its image side is convex near the axis.

[0072] The fifth lens has negative refractive power, and its object measuring surface is convex near the axis.

[0073] The sixth lens has negative refractive power, and its image-side surface is concave near the axis.

[0074] The ultra-wide-angle low-distortion optical imaging system satisfies the following relationship:

[0075] -0.21 <F / R4<-0.18,111.4<V2+V6<111.5;

[0076] f is the focal length of the high-definition optical imaging lens, R4 is the radius of curvature of the object side of the fourth lens, V2 is the Abbe number of the second lens, and V6 is the Abbe number of the sixth lens.

[0077] The ultra-wide-angle, low-distortion, high-definition imaging lens of this invention is a six-element lens. The optimal range of the surface shape and optical parameters of each lens, combined with the reduced image distortion during ultra-wide-angle imaging, effectively shortens the overall size of the imaging lens and increases its angle of view, while maintaining high resolution due to high pixel count. This is an optical imaging lens technology that integrates ultra-wide-angle and low-distortion capabilities, thus providing a solution for small or thin portable devices requiring high-quality imaging equipment.

[0078] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0079] 0.58 <YC52 / f<0.63;

[0080] YC52 is the vertical distance between the inflection point on the image side of the fifth lens and the optical axis.

[0081] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0082] 0.37 <f / TL<0.40;

[0083] TL is the distance between the object-side vertex of the first lens and the imaging plane.

[0084] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0085] -21.63 <SAG45 / T45<-21.33;

[0086] SAG45 is the sag of the image-side surface of the fourth lens at its maximum effective radius, and T45 is the on-axis air gap between the fourth and fifth lenses.

[0087] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0088] 1.98 <TTL / f<2.04;

[0089] TTL is the total optical length of the camera lens;

[0090] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0091] 0.26 <T34 / AAT<0.30;

[0092] T34 is the air gap on the optical axis from the image side of the third lens to the object side of the fourth lens, and AAT is the sum of the air gaps between each adjacent lens from the first lens to the fifth lens.

[0093] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0094] -0.45 <f / (f1+f4)<-0.36;

[0095] f1 is the focal length of the first lens, and f4 is the focal length of the fourth lens;

[0096] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0097] 0.85 <f / f123<0.91;

[0098] f123 is the combined focal length of the first lens, the second lens, and the third lens;

[0099] As a preferred embodiment of the present invention, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship:

[0100] 1.71 <f4 / CT4<1.74;

[0101] CT4 is the thickness of the fourth lens on the optical axis.

[0102] Example 1

[0103] Please refer to the reference. Figures 1 to 3 , Figure 1 A schematic diagram of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 1 of the present invention is shown. Figure 2 The diagrams shown, from left to right, depict the field curvature and distortion curves of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 1 of the present invention. Figure 3 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system of Example 1.

[0104] The ultra-wide-angle low-distortion optical imaging system in Embodiment 1 includes a first lens 101, an aperture 102, a second lens 103, a third lens 104, a fourth lens 105, a fifth lens 106, and a sixth lens 107 arranged sequentially from the object side to the image side along the same optical axis.

[0105] The surface shapes of each lens are as follows:

[0106] The first lens 101 has negative refractive power, and its object side is concave at the near-axis.

[0107] The second lens 103 has positive refractive power and its object-side surface is convex.

[0108] The third lens 104 has negative refractive power and its image-side surface is concave.

[0109] The fourth lens 105 has positive refractive power, with its object side being concave near the axis and its image side being convex near the axis.

[0110] The fifth lens 106 has negative refractive power, and its object measuring surface is convex near the axis;

[0111] The sixth lens 107 has negative refractive power, and its image-side surface is concave near the axis.

[0112] In this optical imaging lens group, the aperture stop 102 is located between the first lens 101 and the second lens 103, which helps to reduce the front port diameter, thereby achieving the effect of reducing the size of the optical imaging system.

[0113] This ultra-wide-angle low-distortion optical imaging system also includes an infrared filter 108, which is placed between the sixth lens 107 and the imaging plane. The infrared filter 108 filters out infrared light entering the lens, preventing infrared light from shining onto the image sensor and causing noise. Specifically, the infrared filter 108 can be made of glass to avoid affecting the focal length.

[0114] Please refer to Tables 1-1 and 1-2 below for further information.

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] Table 1-1 shows the detailed structural data for Example 1, where the units for radius of curvature, thickness, and focal length are millimeters, f is the focal length of the optical imaging lens group, Fno is the aperture value, and FOV is the maximum field of view of the optical imaging lens group.

[0121] Surfaces 0 to 16 sequentially represent the surfaces from the object side to the image side, wherein surfaces 1-16 sequentially represent the object surface of the first lens 101, the image surface of the first lens 101, the aperture 102, the object surface of the second lens 103, the image surface of the second lens 103, the object surface of the third lens 104, the image surface of the third lens 104, the object surface of the fourth lens 105, the image surface of the fourth lens 105, the object surface of the fifth lens 106, the image surface of the fifth lens 106, the object surface of the sixth lens 107, the image surface of the sixth lens 107, the object surface of the infrared filter, the image surface of the infrared filter, and the imaging plane.

[0122] Table 1-2 shows the aspheric coefficient data in Example 1, where k represents the conical coefficient in the aspheric curve equation, and A4, A6, A8, A10, A12, A14, and A16 represent the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order aspheric coefficients of each surface.

[0123] Example 2

[0124] Please refer to the reference. Figures 4 to 6 , Figure 4 A schematic diagram of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 2 of the present invention is shown. Figure 5 The diagrams shown, from left to right, depict the field curvature and distortion curves of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 2 of the present invention. Figure 6 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system in Example 2.

[0125] The ultra-wide-angle low-distortion optical imaging system in Embodiment 2 includes a first lens 201, an aperture 202, a second lens 203, a third lens 204, a fourth lens 205, a fifth lens 206, and a sixth lens 207 arranged sequentially from the object side to the image side along the same optical axis;

[0126] The surface shapes of each lens are as follows:

[0127] The first lens 201 has negative refractive power, and its object side is concave near the axis.

[0128] The second lens 203 has positive refractive power and its object-side surface is convex.

[0129] The third lens 204 has negative refractive power and its image-side surface is concave.

[0130] The fourth lens 205 has positive refractive power, its object side is concave near the axis, and its image side is convex near the axis;

[0131] The fifth lens 206 has negative refractive power, and its object measuring surface is convex near the axis;

[0132] The sixth lens 207 has negative refractive power, and its image-side surface is concave near the axis.

[0133] In this optical imaging lens group, the aperture stop 202 is located between the first lens 201 and the second lens 203, which helps to reduce the front port diameter, thereby achieving the effect of reducing the size of the optical imaging system.

[0134] This ultra-wide-angle low-distortion optical imaging system also includes an infrared filter 208, which is placed between the sixth lens 207 and the imaging plane. The infrared filter 208 filters out infrared light entering the lens, preventing infrared light from shining onto the image sensor and causing noise. Specifically, the infrared filter 208 can be made of glass to avoid affecting the focal length.

[0135] Please refer to Tables 2-1 and 2-2 below for details.

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] Example 3

[0142] Please refer to the reference. Figures 7 to 9 , Figure 7 A schematic diagram of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 3 of the present invention is shown. Figure 8 The diagrams shown are, from left to right, the field curvature and distortion curves of the ultra-wide-angle low-distortion optical imaging system of Embodiment 3 of the present invention. Figure 9 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system in Example 3.

[0143] The ultra-wide-angle low-distortion optical imaging system in Embodiment 3 includes a first lens 301, an aperture 302, a second lens 303, a third lens 304, a fourth lens 305, a fifth lens 306, and a sixth lens 307 arranged sequentially from the object side to the image side along the same optical axis;

[0144] The surface shapes of each lens are as follows:

[0145] The first lens 301 has negative refractive power, and its object side is concave near the axis.

[0146] The second lens 303 has positive refractive power and its object-side surface is convex.

[0147] The third lens 304 has negative refractive power, and its image-side surface is concave.

[0148] The fourth lens 305 has positive refractive power, with its object side being concave near the axis and its image side being convex near the axis.

[0149] The fifth lens 306 has negative refractive power, and its object measuring surface is convex near the axis.

[0150] The sixth lens 307 has negative refractive power, and its image-side surface is concave near the axis.

[0151] In this optical imaging lens group, the aperture stop 302 is located between the first lens 301 and the second lens 303, which helps to reduce the front port diameter, thereby achieving the effect of reducing the size of the optical imaging system.

[0152] This ultra-wide-angle low-distortion optical imaging system also includes an infrared filter 308, which is placed between the sixth lens 307 and the imaging plane. The infrared filter 308 filters out infrared light entering the lens, preventing infrared light from shining onto the image sensor and causing noise. Specifically, the infrared filter 308 can be made of glass to avoid affecting the focal length.

[0153] Please refer to Tables 3-1 and 3-2 below for further information.

[0154]

[0155]

[0156]

[0157]

[0158] Example 4

[0159] Please refer to the reference. Figures 10 to 12 , Figure 10 A schematic diagram of the ultra-wide-angle low-distortion optical imaging system according to Embodiment 4 of the present invention is shown. Figure 11 The diagrams shown, from left to right, depict the field curvature and distortion curves of the ultra-wide-angle low-distortion optical imaging system of Embodiment 4 of the present invention. Figure 12 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system in Example 4.

[0160] The ultra-wide-angle low-distortion optical imaging system in Embodiment 4 includes a first lens 401, an aperture 402, a second lens 403, a third lens 404, a fourth lens 405, a fifth lens 406, and a sixth lens 407 arranged sequentially from the object side to the image side along the same optical axis;

[0161] The surface shapes of each lens are as follows:

[0162] The first lens 401 has negative refractive power, and its object side is concave at the near-axis.

[0163] The second lens 403 has positive refractive power and its object-side surface is convex.

[0164] The third lens 404 has negative refractive power, and its image side is concave.

[0165] The fourth lens 405 has positive refractive power, with its object side being concave near the axis and its image side being convex near the axis.

[0166] The fifth lens 406 has negative refractive power, and its object measuring surface is convex near the axis.

[0167] The sixth lens 407 has negative refractive power, and its image-side surface is concave near the axis.

[0168] In this optical imaging lens group, the aperture stop 402 is located between the first lens 401 and the second lens 403, which helps to reduce the front port diameter, thereby achieving the effect of reducing the size of the optical imaging system.

[0169] This ultra-wide-angle low-distortion optical imaging system also includes an infrared filter 408, which is placed between the sixth lens 407 and the imaging plane. The infrared filter 408 filters out infrared light entering the lens, preventing infrared light from shining onto the image sensor and causing noise. Specifically, the infrared filter 408 can be made of glass to avoid affecting the focal length.

[0170] Please refer to Tables 4-1 and 4-2 below for further information.

[0171]

[0172]

[0173]

[0174]

[0175]

[0176] Example 5

[0177] Please refer to the reference. Figures 13 to 15 , Figure 13 A schematic diagram of the ultra-wide-angle low-distortion optical imaging system of Embodiment 5 of the present invention is shown. Figure 14 The diagrams shown are, from left to right, the field curvature and distortion curves of the ultra-wide-angle low-distortion optical imaging system of Embodiment 5 of the present invention. Figure 15 This is an axial aberration curve of the ultra-wide-angle low-distortion optical imaging system in Example 5.

[0178] The ultra-wide-angle low-distortion optical imaging system in Embodiment 5 includes a first lens 501, an aperture 502, a second lens 503, a third lens 504, a fourth lens 505, a fifth lens 506, and a sixth lens 507 arranged sequentially from the object side to the image side along the same optical axis.

[0179] The surface shapes of each lens are as follows:

[0180] The first lens 501 has negative refractive power, and its object side is concave near the axis.

[0181] The second lens 503 has positive refractive power and its object-side surface is convex.

[0182] The third lens 504 has negative refractive power and its image-side surface is concave.

[0183] The fourth lens 505 has positive refractive power, with its object side being concave near the axis and its image side being convex near the axis.

[0184] The fifth lens 506 has negative refractive power, and its object measuring surface is convex near the axis.

[0185] The sixth lens 507 has negative refractive power, and its image-side surface is concave near the axis.

[0186] In this optical imaging lens group, the aperture stop 502 is located between the first lens 501 and the second lens 503, which helps to reduce the front port diameter, thereby achieving the effect of reducing the size of the optical imaging system.

[0187] This ultra-wide-angle low-distortion optical imaging system also includes an infrared filter 508, which is placed between the sixth lens 507 and the imaging plane. The infrared filter 508 filters out infrared light entering the lens, preventing infrared light from shining onto the image sensor and causing noise. Specifically, the infrared filter 508 can be made of glass to avoid affecting the focal length.

[0188] Please refer to Tables 5-1 and 5-2 below for further information.

[0189]

[0190]

[0191]

[0192]

[0193] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. An ultra-wide-angle low-distortion optical imaging system, characterized in that, it is composed of a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side along the same optical axis, and the object side and the image side of each lens are aspherical surfaces; the first lens has negative refractive power, and the object side surface is concave at the near-axis; the second lens has positive refractive power, and the object side surface is convex; the third lens has negative refractive power, and the image side surface is concave; the fourth lens has positive refractive power, and the object side surface is concave at the near-axis, and the image side surface is convex at the near-axis; the fifth lens has negative refractive power, and the object side surface is convex at the near-axis; the sixth lens has negative refractive power, and the image side surface is concave at the near-axis; the ultra-wide-angle low-distortion optical imaging system satisfies the following relationship: ； f is the focal length of the ultra-wide-angle low-distortion optical imaging system, R4 is the radius of curvature of the object side surface of the fourth lens, V2 is the Abbe number of the second lens, and V6 is the Abbe number of the sixth lens; the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ； YC52 is the vertical distance between the inflection point of the image side surface of the fifth lens and the optical axis; the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: SAG45 is the sag of the image side surface of the fourth lens at the maximum effective radius, and T45 is the on-axis air separation between the fourth and fifth lenses. the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ; f1 is the focal length of the first lens and f4 is the focal length of the fourth lens.

2. The ultra-wide-angle low-distortion optical imaging system according to claim 1, characterized in that, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ; TL is the distance between the first lens paraxial vertex and the imaging plane.

3. The ultra-wide-angle low-distortion optical imaging system according to claim 1, characterized in that, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ; TTL is the total optical length of the super-wide-angle low-distortion optical imaging system.

4. The ultra-wide-angle low-distortion optical imaging system according to claim 1, characterized in that, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ； T34 is the air gap on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens, and AAT is the sum of the air gaps between each adjacent lens from the first lens to the fifth lens.

5. The ultra-wide-angle low-distortion optical imaging system according to claim 1, characterized in that, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: ; f123 is the combined focal length of the first, second, and third lenses.

6. The ultra-wide-angle low-distortion optical imaging system according to claim 1, characterized in that, the ultra-wide-angle low-distortion optical imaging system also satisfies the following relationship: CT4 is the thickness of the fourth lens on the optical axis.

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