Miniaturized 3P large-aperture infrared lens

Abstract

The invention provides a miniaturized 3P large-aperture infrared lens. The miniaturized 3P large-aperture infrared lens comprises a first lens, an aperture diaphragm, a second lens and a third lens which are sequentially arranged from an object side to an image side along an optical axis, the first lens is a negative lens of which the object-side surface is convex in a paraxial region and the image-side surface is concave in a paraxial region; the second lens is a positive lens of which the object-side surface is concave in a paraxial region and the image-side surface is convex in a paraxial region; the third lens is a positive lens having an object-side surface being convex in a paraxial region and an image-side surface being convex in a paraxial region. The lens can meet the performance requirements of large aperture, high relative illumination and small distortion, the total length of the lens is shortened, miniaturization is realized, the production efficiency is improved, a new design architecture and a brand new film system are matched, the size is light, and the mass production performance is excellent.

Description

Technical Field

[0001] The present invention relates to the field of optical equipment, and more particularly to a miniaturized 3P large-aperture infrared lens. Background Art

[0002] In today's infrared imaging field, optical system design plays a crucial role in image quality. Large-aperture infrared lenses, as a specialized optical system, have attracted significant attention for their large apertures. These lenses significantly improve imaging in low-light conditions and are widely used in a variety of fields, including military, security, surveillance, and thermal imaging, meeting the needs of observing and photographing targets at night or in low-light environments. The core of their design lies in increasing the aperture to allow more light to enter, effectively improving image brightness and clarity, which is crucial for image quality in low-light conditions.

[0003] However, existing large-aperture infrared lenses still face numerous technical challenges in practical application. On the one hand, optimizing the optical design to reduce aberrations and improve image quality while maintaining a large aperture remains a pressing issue. On the other hand, the increasing diversification of application scenarios is placing higher demands on lens size, weight, and cost control.

[0004] In addition, how to ensure the stability and reliability of the lens under extreme environmental conditions is also a difficult problem that needs to be overcome in current technological development. Based on this, the present invention provides a new miniaturized 3P large aperture infrared lens. Summary of the Invention

[0005] In response to the technical problems existing in the prior art, the present invention proposes a miniaturized 3P large aperture infrared lens to supplement the types of infrared lenses and obtain an infrared lens that meets the requirements of large aperture, high relative illumination, small distortion, and good stability and reliability.

[0006] The technical solutions provided by the present invention are as follows:

[0007] A miniaturized 3P large aperture infrared lens, comprising a first lens, an aperture stop, a second lens, and a third lens arranged in sequence from the object side along the optical axis to the image side;

[0008] The first lens is a negative lens with a convex surface on the object side near the optical axis and a concave surface on the image side near the optical axis;

[0009] The second lens is a positive lens with a concave surface on the object side near the optical axis and a convex surface on the image side near the optical axis;

[0010] The third lens is a positive lens with a convex surface near the optical axis on the object side surface and a convex surface near the optical axis on the image side surface.

[0011] On the basis of the above technical solution, the present invention can also make the following improvements.

[0012] Optionally, the radius of the object surface of the first lens is R(L1S1), the core thickness of the first lens is T1, the focal length of the first lens is f1, and the focal length of the lens is f, and the following conditions are met:

[0013] 7.3033 <R(L1S1)<7.3395;

[0014] -0.1714 <T1 / f1<-0.1570;

[0015] -2.6037 <f1 / f<-2.4291。

[0016] Optionally, the air gap between the first lens and the second lens is T(L1-L2), and the total optical length of the lens optical system is TTL, which satisfies the following conditions:

[0017] 0.1325 <T(L1-L2) / TTL<0.1436。

[0018] Optionally, the focal length of the second lens is f2, the focal length of the lens is f, and the following conditions are met:

[0019] 5.7282 <f2 / f<6.6241。

[0020] Optionally, the focal length of the combined lens of the second lens and the third lens is f23, and the focal length of the second lens is f2, satisfying the following conditions:

[0021] 0.1855 <f23 / f2<0.2124。

[0022] Optionally, the radius of the object surface of the third lens is R(L3S1), the focal length of the third lens is f3, and the focal length of the lens is f, and the following conditions are met:

[0023] 1.0563 <R(L3S1)<1.0757;

[0024] 1.5356 <f3 / f<1.6120。

[0025] The miniaturized 3P large aperture infrared lens provided by the present invention has the following beneficial effects by matching the aperture stop and three lenses according to specific surface shapes and reasonable optical power distribution:

[0026] This miniaturized 3P large aperture infrared lens complements the types of infrared lenses on the market. The aperture size of conventional infrared lenses is usually expressed by the F-number, which is the ratio of the focal length of the lens to the aperture diameter. The smaller the F-number, the larger the aperture and the more light entering. In infrared lenses, the common F-number range may be from F1.0 to F5.6 or even higher. The infrared lens provided by the present invention has an F-number between 0.9-0.96, a MAX FOV of 110°, and an F-θ distortion of <5.5, while meeting the requirements of shortening the total length of the lens and miniaturizing it. In short, this lens can meet the performance requirements of large aperture, high relative illumination, and small distortion, and shorten the total length of the lens, achieve miniaturization, and improve production efficiency. With the new design architecture and the new film system, it is lightweight and has excellent mass production performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 1 of the present invention;

[0028] Figure 2 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 1 of the present invention;

[0029] Figure 3 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 1 of the present invention;

[0030] Figure 4 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 1 of the present invention;

[0031] Figure 5 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 1 of the present invention;

[0032] Figure 6 This is a schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 2 of the present invention;

[0033] Figure 7 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 2 of the present invention;

[0034] Figure 8 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 2 of the present invention;

[0035] Figure 9 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 2 of the present invention;

[0036] Figure 10This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 2 of the present invention;

[0037] Figure 11 This is a schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 3 of the present invention;

[0038] Figure 12 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 3 of the present invention;

[0039] Figure 13 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 3 of the present invention;

[0040] Figure 14 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 3 of the present invention;

[0041] Figure 15 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 3 of the present invention;

[0042] Figure 16 This is a schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 4 of the present invention;

[0043] Figure 17 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 4 of the present invention;

[0044] Figure 18 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 4 of the present invention;

[0045] Figure 19 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 4 of the present invention;

[0046] Figure 20 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 4 of the present invention;

[0047] Figure 21 A schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 5 of the present invention;

[0048] Figure 22 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 5 of the present invention;

[0049] Figure 23 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 5 of the present invention;

[0050] Figure 24 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 5 of the present invention;

[0051] Figure 25 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 5 of the present invention;

[0052] Figure 26 A schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 6 of the present invention;

[0053] Figure 27 A schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 6 of the present invention;

[0054] Figure 28 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 6 of the present invention;

[0055] Figure 29 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 6 of the present invention;

[0056] Figure 30 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 6 of the present invention;

[0057] Figure 31 A schematic structural diagram of a miniaturized 3P large aperture infrared lens provided in Example 7 of the present invention;

[0058] Figure 32 Schematic diagram of the MFT performance of the miniaturized 3P large aperture infrared lens provided in Example 7 of the present invention;

[0059] Figure 33 A schematic diagram of relative illumination of a miniaturized 3P large aperture infrared lens provided in Example 7 of the present invention;

[0060] Figure 34 Schematic diagram of light distortion and field curvature at any pupil of the miniaturized 3P large aperture infrared lens provided in Example 7 of the present invention;

[0061] Figure 35 This is a TV distortion diagram of the miniaturized 3P large aperture infrared lens provided in Example 7 of the present invention;

[0062] Figure 36 A schematic diagram of the structure of an infrared lens provided for comparative example;

[0063] Figure 37 Schematic diagram of the MFT performance of the infrared lens provided for comparative example;

[0064] Figure 38A schematic diagram of relative illumination of an infrared lens provided for comparative example;

[0065] Figure 39 Schematic diagram of light distortion and field curvature at any pupil of an infrared lens provided for comparative example;

[0066] Figure 40 TV distortion diagram of the infrared lens provided for comparison;

[0067] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0068] STO, aperture stop, L1, first lens, L2, second lens, L3, third lens. DETAILED DESCRIPTION

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0070] Description of relevant characteristic parameters in the present invention:

[0071] R(L1S1) is the radius of the object surface L1S1 of the first lens element;

[0072] R(L1S2) is the radius of curvature of the image-side surface L1S2 of the first lens element;

[0073] R(L3S1) is the radius of curvature of the object surface L3S1 of the third lens element;

[0074] T(L1) is the core thickness of the first lens (the distance from the center point of the L1S1 surface to the center point of the L1S2 surface on the central optical axis);

[0075] T(L1-L2) is the air gap between the first lens and the second lens (the distance from the center point of the L1S2 surface to the center point of the L2S1 surface on the central optical axis);

[0076] TTL is the total optical length of the lens optical system (the distance from the center point of the L1S1 surface to the center point of the image plane on the central optical axis);

[0077] f1 is the focal length of the first lens;

[0078] f2 is the focal length of the second lens;

[0079] f3 is the focal length of the third lens;

[0080] f23 is the focal length of the combined lens of the second and third lenses;

[0081] f is the focal length of the lens (focal length is a measure of the convergence or divergence of light in an optical system, and refers to the distance from the optical center of the lens to the focus of light when parallel light is incident).

[0082] MAX FOV is the field of view angle (in optical instruments, the angle formed by the two edges of the maximum range of the object image that can pass through the lens of the optical instrument is called the field of view angle).

[0083] FNO is the value obtained by dividing the focal length by the entrance pupil diameter (FNO limits the amount of light entering the lens. The larger the FNO value, the less light entering and the darker the image; the smaller the FNO value, the more light entering and the brighter the image).

[0084] RI relative illumination is the ratio of the image edge brightness to the center brightness.

[0085] (f-θ)DIS is the (f-θ) optical distortion value. Optical distortion refers to the ratio of the difference between the ideal image height ((f-θ) minus the actual image height) in optical theory to the actual image height.

[0086] TV DIS is the TV distortion value. TV distortion is the ratio of the maximum difference in imaging height of objects of equal height in the object space to the maximum imaging height in the image space.

[0087] The present invention provides a miniaturized 3P large aperture infrared lens, such as Figure 1 As shown, the perspective lens includes three lenses, and the components are arranged in the following order from the object side along the optical axis to the image side: the first lens L1, the aperture stop STO, the second lens L2 and the third lens L3.

[0088] The first lens L1 is a negative lens with a convex surface on the object side near the optical axis and a concave surface on the image side near the optical axis;

[0089] The second lens L2 is a positive lens with a concave surface on the object side near the optical axis and a convex surface on the image side near the optical axis;

[0090] The third lens L3 is a positive lens with a convex surface near the optical axis on the object side surface and a convex surface near the optical axis on the image side surface.

[0091] The radius of curvature of the object side surface of the first lens L1 is R(L1S1), the core thickness of the first lens L1 is T1, the focal length of the first lens L1 is f1, and the focal length of the lens is f, satisfying the following conditions:

[0092] 7.3033 <R(L1S1)<7.3395;

[0093] -0.1714 <T1 / f1<-0.1570;

[0094] -2.6037 <f1 / f<-2.4291。

[0095] The air gap between the first lens L1 and the second lens L2 is T(L1-L2), and the total optical length of the lens optical system is TTL, which meets the following conditions:

[0096] 0.1325 <T(L1-L2) / TTL<0.1436。

[0097] The focal length of the second lens L2 is f2, and the focal length of the lens is f, which satisfies the following conditions:

[0098] 5.7282 <f2 / f<6.6241。

[0099] The focal length of the combined lens of the second lens L2 and the third lens L3 is f23, and the focal length of the second lens L2 is f2, satisfying the following conditions:

[0100] 0.1855 <f23 / f2<0.2124。

[0101] The radius of the object-side surface of the third lens L3 is R(L3S1), the focal length of the third lens L3 is f3, and the focal length of the lens is f, satisfying the following conditions:

[0102] 1.0563 <R(L3S1)<1.0757;

[0103] 1.5356 <f3 / f<1.6120。

[0104] Example 1

[0105] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 1 As shown, the lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0106]

[0107]

[0108] The aspheric formula is as follows:

[0109]

[0110] Where z represents the point on the aspheric surface that is h away from the optical axis, and its relative distance from the vertex tangent plane on the optical axis of the aspheric surface, R represents the radius of curvature, h represents the distance between the point on the aspheric surface and the optical axis, k represents the cone coefficient, and Ai represents the i-th order aspheric coefficient.

[0111] The aspheric coefficients are as follows:

[0112]

[0113]

[0114] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0115] R(L1S1) 7.3034 R(L3S1) 1.0563 T1＝ 0.2345 f1＝ -1.4084 T1 / f1= -0.16648 T(L1-L2)= 0.3905 TTL= 2.8615 T(L1-L2) / TTL= 0.13645 f23＝ 0.6914 f2＝ 3.7092 f23 / f2= 0.18640 f1＝ -1.4084 f＝ 0.55996 f1 / f= -2.51519 f2＝ 3.7092 f＝ 0.55996 f2 / f= 6.62408 f3＝ 0.9027 f＝ 0.55996 f3 / f= 1.61203 (f-θ)DIS= 3.250％ TV DIS= -8.790％ MAX FOV= 110.00 RI (FOV 100°) 65.850％ RI (FOV 110°) 60.960％ FNO= 0.944

[0116] The above characteristic parameters are all within the following parameter ranges:

[0117] 7.3033 <R(L1S1)<7.3395;

[0118] -0.1714 <T1 / f1<-0.1570;

[0119] -2.6037 <f1 / f<-2.4291;

[0120] 0.1325 <T(L1-L2) / TTL<0.1436;

[0121] 5.7282 <f2 / f<6.6241;

[0122] 0.1855 <f23 / f2<0.2124;

[0123] 1.0563 <R(L3S1)<1.0757;

[0124] 1.5356 <f3 / f<1.6120。

[0125] It can be seen that RI (FOV100°) is 65.850% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0126] It should be noted that MTF (Modulation Transfer Function) comprehensively reflects the contrast and resolution characteristics of a lens. It is measured instrumentally and can completely eliminate the influence of objective factors such as film and the subjective influence of human interpretation.

[0127] MTF is one of the best tools for quantifying a system's overall imaging performance in terms of resolution and contrast. Higher MTF values ​​indicate a system with higher resolution, capable of delivering even smaller details. MTF is a method of combining resolution and contrast into a single specification or rule. An MTF curve displays both resolution and contrast information, making it suitable for evaluating lenses based on the needs of a specific application and allowing for comparison of the performance of multiple lenses.

[0128] Figure 2This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 1. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis represents the lens performance percentage (0 to 100). Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0129] The solid and dashed lines represent the MTF curve parallel to the diameter, known as the sagittal curve; the dashed line represents the MTF curve perpendicular to the diameter, known as the meridional curve. The closer the solid and dashed lines are, the closer the lens's MTF performance in the meridional and sagittal directions is, and the better the lens performance.

[0130] Different groups of solid / dashed lines represent fields of view at different image heights. An image height value of 0 represents the center of the lens. A larger image height value indicates that the field of view is farther from the center, and the MTF performance of each line is closer, indicating good consistency between the center and edges of the lens.

[0131] Figure 3 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 1. The higher the value, the better the relative illumination.

[0132] Figure 4 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 1. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane varies with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0133] Figure 5 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 1. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0134] Example 2

[0135] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 6 As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0136] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0137]

[0138] The aspheric coefficients are as follows:

[0139]

[0140] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0141] R(L1S1) 7.3395 R(L3S1) 1.0753 T1＝ 0.2352 f1＝ -1.3808 T1 / f1= -0.17034 T(L1-L2)= 0.3788 TTL= 2.8584 T(L1-L2) / TTL= 0.13254 f23＝ 0.6910 f2＝ 3.5366 f23 / f2= 0.19539 f1＝ -1.3808 f＝ 0.56120 f1 / f= -2.46044 f2＝ 3.5366 f＝ 0.56120 f2 / f= 6.30185 f3＝ 0.9003 f＝ 0.56120 f3 / f= 1.60424 (f-θ)DIS= 3.000％ TV DIS= -9.116％ MAX FOV= 110.00 RI (FOV 100°) 68.200％ RI (FOV 110°) 65.500％ FNO= 0.949

[0142] The above characteristic parameters are all within the parameter ranges described above.

[0143] It can be seen that RI (FOV100°) is 68.20% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0144] Figure 7 This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 2. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis, from 0 to 100, represents the lens performance percentage. Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0145] Figure 8 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 2. The higher the value, the better the relative illumination.

[0146] Figure 9 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 2. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane varies with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0147] Figure 10 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 2. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0148] Example 3

[0149] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 11As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0150] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0151]

[0152]

[0153] The aspheric coefficients are as follows:

[0154]

[0155] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0156] R(L1S1) 7.3281 R(L3S1) 1.0581 T1＝ 0.2340 f1＝ -1.3654 T1 / f1= -0.17137 T(L1-L2)= 0.3986 TTL= 2.7944 T(L1-L2) / TTL= 0.14265 f23＝ 0.6862 f2＝ 3.2564 f23 / f2= 0.21072 f1＝ -1.3654 f＝ 0.56210 f1 / f= -2.42911 f2＝ 3.2564 f＝ 0.56210 f2 / f= 5.79328 f3＝ 0.9028 f＝ 0.56210 f3 / f= 1.60612 (f-θ)DIS= 2.920％ TV DIS= -9.530％ MAX FOV= 110.00 RI (FOV 100°) 69.700％ RI (FOV 110°) 64.100％ FNO= 0.960

[0157] The above characteristic parameters are all within the parameter ranges described above.

[0158] It can be seen that RI (FOV100°) is 69.700% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0159] Figure 12 This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 3. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis represents the lens performance percentage (0 to 100). Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0160] Figure 13 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 3. The higher the value, the better the relative illumination.

[0161] Figure 14 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 3. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane changes with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0162] Figure 15This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 3. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0163] Example 4

[0164] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 16 As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0165] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0166]

[0167] The aspheric coefficients are as follows:

[0168]

[0169]

[0170] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0171] R(L1S1) 7.3269 R(L3S1) 1.0588 T1＝ 0.2340 f1＝ -1.3665 T1 / f1= -0.17125 T(L1-L2)= 0.3966 TTL= 2.7802 T(L1-L2) / TTL= 0.14264 f23＝ 0.6840 f2＝ 3.2210 f23 / f2= 0.21236 f1＝ -1.3665 f＝ 0.56230 f1 / f= -2.43020 f2＝ 3.2210 f＝ 0.56230 f2 / f= 5.72826 f3＝ 0.9010 f＝ 0.56230 f3 / f= 1.60235 (f-θ)DIS= 2.912％ TV DIS= -9.560％ MAX FOV= 110.00 RI (FOV 100°) 71.528％ RI (FOV 110°) 65.270％ FNO= 0.960

[0172] The above characteristic parameters are all within the parameter ranges described above.

[0173] It can be seen that RI (FOV100°) is 71.528% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0174] Figure 17 This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 4. The X and Y coordinates represent: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis, from 0 to 100, represents the lens performance percentage. Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0175] Figure 18 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 4. The higher the value, the better the relative illumination.

[0176] Figure 19Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 4. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane changes with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0177] Figure 20 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 4. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0178] Example 5

[0179] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 21 As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0180] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0181]

[0182]

[0183] The aspheric coefficients are as follows:

[0184] Surface serial number 1 2 4 5 6 7 Surface name L1s1 L1s2 L2s1 L2s2 L3s1 L3s2 k＝ 1.2332E+02 1.2674E+00 -4.6323E+01 8.2067E-01 -3.3695E+00 -9.0247E+00 A4＝ 1.3172E+00 2.8716E+00 -2.9901E+00 -1.2058E-01 -1.4848E-01 -7.7527E-01 A6＝ -8.5762E-01 7.8460E+00 1.1551E+01 -2.1245E-01 1.9826E+00 1.3455E+00 A8＝ -2.5678E+00 -1.8299E+01 -2.3652E+01 2.7797E+00 -1.0869E+01 4.3892E+00 A10＝ -5.7507E+00 1.2209E+01 -1.8366E+02 -1.7183E+00 3.2455E+01 -1.4336E+01 A12＝ 1.9901E+01 1.6838E+03 1.3393E+03 -2.3524E+02 -3.3385E+01 1.0238E+01 A14＝ 3.2784E+01 -1.0314E+04 -1.0385E+03 1.3771E+03 -2.3342E+01 -1.5271E-01 A16＝ -1.0134E+02 -1.8691E+04 -6.2879E+04 -2.4547E+03 4.3552E+01 1.3162E-01

[0185] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0186]

[0187]

[0188] The above characteristic parameters are all within the parameter ranges described above.

[0189] It can be seen that RI (FOV100°) is 70.220% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0190] Figure 22This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 5. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis, from 0 to 100, represents the lens performance percentage. Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0191] Figure 23 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 5. The higher the value, the better the relative illumination.

[0192] Figure 24 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 5. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane changes with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0193] Figure 25 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 5. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0194] Example 6

[0195] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 26 As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0196] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0197]

[0198] The aspheric coefficients are as follows:

[0199]

[0200]

[0201] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0202] The above characteristic parameters are all within the parameter ranges described above.

[0203] R(L1S1) 7.3280 R(L3S1) 1.0737 T1＝ 0.2247 f1＝ -1.4249 T1 / f1= -0.15770 T(L1-L2)= 0.3877 TTL= 2.6997 T(L1-L2) / TTL= 0.14360 f23＝ 0.6747 f2＝ 3.2747 f23 / f2= 0.20603 f1＝ -1.4249 f＝ 0.56120 f1 / f= -2.53902 f2＝ 3.2747 f＝ 0.56120 f2 / f= 5.83517 f3＝ 0.8706 f＝ 0.56120 f3 / f= 1.55132 (f-θ)DIS= 2.990％ TV DIS= -10.360％ MAX FOV= 110.00 RI (FOV 100°) 70.920％ RI (FOV 110°) 66.740％ FNO= 0.949

[0204] It can be seen that the RI (FOV100°) is 70.920% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0205] Figure 27 This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 6. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis, from 0 to 100, represents the lens performance percentage. Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0206] Figure 28 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 6. The higher the value, the better the relative illumination.

[0207] Figure 29 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 6. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane changes with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0208] Figure 30 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 6. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0209] Example 7

[0210] This embodiment provides a structure of a miniaturized 3P large aperture infrared lens. Figure 31 As shown, the specific structure is generally consistent with the above-mentioned embodiment 1. The same contents as those in embodiment 1 will not be repeated below. The lens parameters, aspheric coefficients, characteristic parameters and corresponding technical effects are further introduced.

[0211] The lens data of the miniaturized 3P large aperture infrared lens in this embodiment are shown in the following table:

[0212]

[0213]

[0214] The aspheric coefficients are as follows:

[0215] Surface serial number 1 2 4 5 6 7 Surface name L1s1 L1s2 L2s1 L2s2 L3s1 L3s2 k＝ 1.2388E+02 1.3079E+00 -6.5007E+01 8.1470E-01 -2.7802E+00 -8.5116E+00 A4＝ 1.3287E+00 2.8747E+00 -2.8907E+00 3.9806E-02 -1.8605E-01 -8.5695E-01 A6＝ -8.5853E-01 7.8604E+00 1.2023E+01 -9.7589E-01 1.9014E+00 1.3280E+00 A8＝ -2.5761E+00 -1.7956E+01 -1.6115E+01 2.9962E+00 -1.0880E+01 4.4670E+00 A10＝ -5.7995E+00 1.2292E+01 -2.1387E+02 1.2602E+00 3.3076E+01 -1.3938E+01 A12＝ 1.9834E+01 1.6878E+03 9.4280E+02 -2.4898E+02 -3.3804E+01 1.0060E+01 A14＝ 3.2867E+01 -9.9833E+03 -1.1518E+03 1.4854E+03 -2.4738E+01 -5.1423E-01 A16＝ -1.0115E+02 -1.8759E+04 -3.7603E+04 -2.8023E+03 4.4834E+01 -1.3471E-01

[0216] The characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens in this embodiment are as follows:

[0217] R(L1S1) 7.3331 R(L3S1) 1.0757 T1＝ 0.2249 f1＝ -1.4315 T1 / f1= -0.15708 T(L1-L2)= 0.3811 TTL= 2.6863 T(L1-L2) / TTL= 0.14185 f23＝ 0.6659 f2＝ 3.5884 f23 / f2= 0.18557 f1＝ -1.4315 f＝ 0.54980 f1 / f= -2.60367 f2＝ 3.5884 f＝ 0.54980 f2 / f= 6.52674 f3＝ 0.8442 f＝ 0.54980 f3 / f= 1.53547 (f-θ)DIS= 5.139％ TV DIS= -10.770％ MAX FOV= 110.00 RI (FOV 100°) 70.700％ RI (FOV 110°) 68.100％ FNO= 0.930

[0218] The above characteristic parameters are all within the parameter ranges described above.

[0219] It can be seen that RI (FOV100°) is 70.700% (above 60%), indicating high relative illumination, uniform overall brightness, and excellent image quality.

[0220] Figure 32 This is the MTF performance graph of the miniaturized 3P large-aperture infrared lens of Example 7. The X and Y coordinates represent the following: the horizontal axis represents different density levels (0-90 lp / mm); the vertical axis, from 0 to 100, represents the lens performance percentage. Higher MTF curves indicate higher MTF scores and better performance. Higher scores in the high-density (90 lp / mm) MTF curve indicate a greater ability to observe small objects.

[0221] Figure 33 This is a relative illumination diagram of the miniaturized 3P large aperture infrared lens of Example 7. The higher the value, the better the relative illumination.

[0222] Figure 34 Schematic diagram of the distortion and field curvature of light at any pupil in the miniaturized 3P large-aperture infrared lens of Example 7. The distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave are shown. The field curvature graph on the left shows how the distance from the image plane to the paraxial image plane changes with the field of view coordinates; the distortion graph on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect.

[0223] Figure 35 This is the TV distortion plot for the miniaturized 3P large-aperture infrared lens from Example 7. The points are evenly distributed at the center and edges of the image, with no noticeable clustering or sparseness. This indicates that the lens has uniform imaging quality across the entire field of view and well-controlled distortion.

[0224] Comparative Example

[0225] The structure of the miniaturized 3P large aperture infrared lens provided in this comparative example is as follows: Figure 36 shown.

[0226] In this comparative example, the lens data of the miniaturized 3P large aperture infrared lens are shown in the following table:

[0227]

[0228]

[0229] The aspheric coefficients are as follows:

[0230] Surface serial number 1 2 4 5 6 7 Surface name L1s1 L1s2 L2s1 L2s2 L3s1 L3s2 k＝ 2.4688E-01 -7.2775E+00 2.6014E+01 -8.0191E+01 -4.3379E-01 0.0000E+00 A4＝ 1.8535E+00 1.5326E+00 -6.1941E+00 -7.6861E+00 -4.2420E+00 1.0709E+01 A6＝ -3.4989E+00 1.1317E+02 6.3114E+01 1.8062E+01 1.0902E+01 -7.4038E+01 A8＝ 3.9288E+00 -2.3182E+03 3.3253E+01 -5.1705E+01 -1.1017E+02 3.1656E+02 A10＝ -9.4433E-01 5.6987E+03 -1.7871E+04 2.1967E+03 4.4750E+02 -7.9127E+02 A12＝ -1.5746E+00 1.2429E+05 -9.5495E+05 -1.9364E+04 2.2879E+03 2.7919E+01 A14＝ 1.0826E+00 8.1725E+05 -1.0852E+07 6.0735E+04 -1.2283E+04 2.5847E+03 A16＝ 2.1837E-01 -1.7415E+07 -5.6746E+08 -6.1756E+04 -1.6060E+04 -3.9647E+02

[0231] In this comparative example, the characteristic parameter values ​​of the miniaturized 3P large aperture infrared lens are as follows:

[0232] R(L1S1) -1.0200 R(L3S1) 0.4981 T1＝ 0.9593 f1＝ -0.3996 T1 / f1= -2.40067 T(L1-L2)= 0.3035 TTL= 3.4145 T(L1-L2) / TTL= 0.08887 f23＝ 0.6399 f2＝ 1.5921 f23 / f2= 0.40192 f1＝ -0.3996 f＝ 0.28660 f1 / f= -1.39428 f2＝ 1.5921 f＝ 0.28660 f2 / f= 5.55513 f3＝ 0.6864 f＝ 0.28660 f3 / f= 2.39498 (f-θ)DIS= 98.450％ TV DIS= -21.770％ MAX FOV= 110.00 RI (FOV 100°) 27.700％ RI (FOV 110°) 27.200％ FNO= 2.000

[0233] The above characteristic parameters are not within the following parameter ranges:

[0234] 7.3033 <R(L1S1)<7.3395;

[0235] -0.1714 <T1 / f1<-0.1570;

[0236] -2.6037 <f1 / f<-2.4291;

[0237] 0.1325 <T(L1-L2) / TTL<0.1436;

[0238] 5.7282 <f2 / f<6.6241;

[0239] 0.1855 <f23 / f2<0.2124;

[0240] 1.0563 <R(L3S1)<1.0757;

[0241] 1.5356 <f3 / f<1.6120。

[0242] It can be seen that the RI (FOV 100°) is 27.700%, which is relatively low (below 60%), indicating that compared with the above embodiment, the relative illumination is low, the overall brightness is poor, and the image quality is poor.

[0243] Figure 37 This is a graph of the MTF performance of an infrared lens for a comparative example. The X and Y coordinates represent the lens performance percentages, with the horizontal axis representing different density levels (0-90 lp / mm) and the vertical axis (0 to 100). Higher MTF curves indicate higher MTF scores and better performance. Higher scores for high-density (90 lp / mm) MTF curves indicate a greater ability to observe small objects. Compared to the above-mentioned examples, the MTF performance of this comparative example is inferior to that of the examples.

[0244] Figure 38The relative illumination diagram of the infrared lens provided for the comparative example shows that the higher the value, the better the relative illumination. Compared with the above embodiment, the value of this comparative example is lower, and the relative illumination is worse.

[0245] Figure 39 Schematic diagram of the distortion and field curvature of light at any pupil of an infrared lens provided for comparison. This diagram shows the distortion and field curvature of light at any pupil in any field of view at a wavelength defined by Wave. The field curvature diagram on the left shows the distance from the image plane to the paraxial image plane as a function of the field of view coordinates; the distortion diagram on the right shows the difference between the actual image height and the ideal image height for each field of view. The closer to the center, the better the imaging effect. However, compared to the previous example, this comparison shows a larger deviation from the center.

[0246] Figure 40 The TV distortion diagram of the infrared lens provided as a comparative example shows that the points are sparsely distributed and scattered to the outside. Compared with the above embodiment, the imaging quality of this comparative lens is average across the entire field of view and the distortion control is poor.

[0247] In summary, the miniaturized 3P large aperture infrared lens provided by the embodiment of the present invention complements the types of infrared lenses on the market. The aperture size of a conventional infrared lens is usually expressed by the F-number, which is the ratio of the focal length of the lens to the aperture diameter. The smaller the F-number, the larger the aperture and the more light entering. In infrared lenses, the common F-number range may be from F1.0 to F5.6 or even higher. The infrared lens provided by the present invention has an F-number between 0.9-0.96, a MAXFOV of 110°, and an F-θ distortion of <5.5, while meeting the requirements of shortening the total length of the lens and miniaturizing it. In short, the lens can meet the performance requirements of large aperture, high relative illumination, and small distortion, and shorten the total length of the lens, achieve miniaturization, and improve production efficiency. With a new design architecture and a new film system, it is lightweight and has excellent mass production performance.

[0248] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0249] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A miniaturized 3P large aperture infrared lens, characterized in that: It includes a first lens, an aperture stop, a second lens, and a third lens arranged in sequence from the object side along the optical axis to the image side; The first lens is a negative lens with a convex surface on the object side near the optical axis and a concave surface on the image side near the optical axis; The second lens is a positive lens with a concave surface on the object side near the optical axis and a convex surface on the image side near the optical axis; The third lens is a positive lens with a convex surface near the optical axis on the object side surface and a convex surface near the optical axis on the image side surface.

2. The miniaturized 3P large aperture infrared lens according to claim 1, characterized in that: The radius of curvature of the object side surface of the first lens is R(L1S1), the core thickness of the first lens is T1, the focal length of the first lens is f1, and the focal length of the lens is f, satisfying the following conditions: 7.3033 <R(L1S1)<7.3395; -0.1714 <T1 / f1<-0.1570; -2.6037 <f1 / f<-2.4291。 3. The miniaturized 3P large aperture infrared lens according to claim 1, characterized in that: The air gap between the first lens and the second lens is T(L1-L2), and the total optical length of the lens optical system is TTL, which satisfies the following conditions: 0.1325 <T(L1-L2) / TTL<0.1436。 4. The miniaturized 3P large aperture infrared lens according to claim 1, characterized in that: The focal length of the second lens is f2, and the focal length of the lens is f, which satisfies the following conditions: 5.7282 <f2 / f<6.6241。 5. The miniaturized 3P large aperture infrared lens according to claim 1, characterized in that: The focal length of the combined lens of the second lens and the third lens is f23, and the focal length of the second lens is f2, which satisfies the following conditions: 0.1855 <f23 / f2<0.2124。 6. The miniaturized 3P large aperture infrared lens according to claim 1, characterized in that: The radius of the object side surface of the third lens is R(L3S1), the focal length of the third lens is f3, and the focal length of the lens is f, satisfying the following conditions: 1.0563 <R(L3S1)<1.0757; 1.5356 <f3 / f<1.6120。

Images