Super-large-aperture super-wide-angle infrared lens and electronic equipment

Abstract

The invention discloses an ultra-large-aperture ultra-wide-angle infrared lens and electronic equipment. The ultra-large-aperture ultra-wide-angle infrared lens sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis, each of the first to fourth lenses comprises an object side surface which faces the object side and enables imaging light to pass through and an image side surface which faces the image side and enables the imaging light to pass through; the aperture F #, the field angle FOV and the focal length f'of the ultra-large aperture ultra-wide angle infrared lens meet the condition that F # * TAN (FOV / 2) * SQRT (f ' / 100) is greater than or equal to 0.24. According to the ultra-large-aperture ultra-wide-angle infrared lens and the electronic equipment, ultra-large-aperture and ultra-wide-angle performance can be realized, and the ultra-large-aperture ultra-wide-angle infrared lens and the electronic equipment have excellent resolution and meet the requirements of various use scenes.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to an ultra-large aperture ultra-wide angle infrared lens and electronic equipment. Background Art

[0002] With the development of science and technology, infrared lenses can be used for face recognition, thermal imaging and infrared monitoring, and are widely used in mobile phones, drones, smart homes and other fields. However, the usage scenarios are complex, and an infrared lens with a large aperture and a large field of view is needed to meet the stringent requirements of complex usage environments. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide an ultra-large aperture and ultra-wide angle infrared lens and electronic equipment, which can be used in complex scenes and meet the stringent requirements of complex usage environments. The present invention provides an ultra-large aperture ultra-wide-angle infrared lens, which comprises a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side along the optical axis; the first lens to the fourth lens each comprise an object side surface facing the object side and allowing imaging light to pass through, and an image side surface facing the image side and allowing imaging light to pass through; the aperture F#, field of view FOV and focal length f′ of the ultra-large aperture ultra-wide-angle infrared lens satisfy the following conditions: F#*TAN(FOV / 2)*SQRT(f′ / 100)≥0.24.

[0004] Optionally, the first lens has negative optical power, and the second lens, the third lens and the fourth lens have positive optical power.

[0005] Optionally, the image-side sag height S2 of the first lens and the center thickness H1 of the first lens satisfy: 0.4≤S2 / H1≤0.55.

[0006] Optionally, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: ABS(f2-f3)≤0.5.

[0007] Optionally, the focal length f′ of the ultra-large aperture ultra-wide-angle infrared lens and the focal length f1 of the first lens satisfy: 1.6≤f1 / f′≤2.

[0008] Optionally, the maximum values ​​of the absolute values ​​of the object-side sag heights and the image-side sag heights of the second lens to the fourth lens satisfy: MAX(ABS(S3), ABS(S4), ...ABS(S8))≤0.35.

[0009] Optionally, a sag height S1 of the object side surface of the first lens satisfies: 0.3≤S1≤0.55.

[0010] Optionally, a focal length f2 of the second lens satisfies: 1.5≤f2≤3.

[0011] Optionally, the object side sag S3 of the second lens satisfies: ABS(S3)≤0.05.

[0012] The present invention also provides an electronic device, comprising the above-mentioned ultra-large aperture and ultra-wide angle infrared lens.

[0013] The ultra-large aperture ultra-wide-angle infrared lens and electronic device provided by the present invention have an aperture F#, a field of view FOV and a focal length f′ that satisfy: F#*TAN(FOV / 2)*SQRT(f′ / 100)≥0.24, which can help balance the aperture, field of view and focal length, thereby preventing a certain parameter from deviating from a normal range, and setting the aperture F# to be smaller than that of an existing lens, and the field of view FOV to be larger than that of an existing lens, for example, F#<1.4 and FOV=124°, thereby achieving an ultra-large aperture and an ultra-wide angle, and can be used in complex scenes to meet the demanding requirements of complex usage environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 A schematic diagram of the optical structure of an ultra-large aperture and ultra-wide-angle infrared lens according to Example 1 of the present application is shown.

[0016] Figures 2 to 4 The distortion diagram, MTF curve diagram, and relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 1 are respectively shown.

[0017] Figure 5 A schematic diagram of the optical structure of an ultra-large aperture and ultra-wide-angle infrared lens according to Example 2 of the present application is shown.

[0018] Figures 6 to 8 The distortion diagram, MTF curve diagram, and relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 2 are respectively shown.

[0019] Fig. 9 A schematic diagram of the optical structure of an ultra-large aperture and ultra-wide-angle infrared lens according to Example 3 of the present application is shown.

[0020] Figures 10 to 12 The distortion diagram, MTF curve diagram, and relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 3 are respectively shown. DETAILED DESCRIPTION

[0021] The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Through the description of the specific implementation methods, the technical means and effects adopted by the present invention to achieve the intended purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and illustration purposes, and are not used to limit the present invention. Some well-known parts may not be shown. In each of the drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not necessarily drawn strictly in accordance with the actual proportions.

[0022] It should be understood that the terms "first", "second", "third", "fourth", etc. are only used to distinguish components or circuits with similar properties, rather than indicating or implying relative importance or a specific order. The terms "include", "comprises", or any other variation thereof, are intended to cover non-exclusive inclusion, and may include other elements not explicitly listed in addition to those listed elements.

[0023] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0024] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] The features, principles and other aspects of the present application are described in detail below.

[0027] According to the ultra-large aperture ultra-wide-angle infrared lens of the exemplary embodiment of the present application, from the object side to the image side, it includes a first lens P1, a second lens P2, a third lens P3 and a fourth lens P4; the first lens P1 to the fourth lens P4 each include an object-side surface facing the object side and allowing imaging light to pass through, and an image-side surface facing the image side and allowing imaging light to pass through; the aperture F#, field of view FOV and focal length f′ of the ultra-large aperture ultra-wide-angle infrared lens satisfy: F#*TAN(FOV / 2)*SQRT(f′ / 100)≥0.24. The ultra-large aperture ultra-wide angle infrared lens of this embodiment includes four lenses. By reasonably allocating the focal length and spacing of each lens, and by controlling the aperture F#, field of view FOV and focal length f′ of the ultra-large aperture ultra-wide angle infrared lens, it can help balance the aperture, field of view and focal length, thereby avoiding a certain parameter from deviating from the normal range, and setting the aperture F# smaller than the existing lens, and the field of view FOV larger than the existing lens, such as F#<1.4 and FOV=124°, thereby achieving an ultra-large aperture ultra-wide angle, and can be used in complex scenes to meet the demanding requirements of complex use environments. Among them, setting the aperture F# to be smaller, such as F#<1.4, can achieve an ultra-large aperture to meet the needs of fast photography in low light conditions; setting the field of view to be larger, such as 124°, can achieve an ultra-wide angle, allowing the device to have a wider field of view.

[0028] In an exemplary embodiment, according to the ultra-large aperture ultra-wide-angle infrared lens of the present application, the first lens P1 has a negative optical power, and the second lens P2, the third lens P3 and the fourth lens P4 have positive optical power. Through the negative-positive focal length setting of the first lens P1 to the fourth lens P4, the imaging quality can be improved, the astigmatism and distortion can be corrected, and a larger optical path length and system correction capability can be provided, which helps to achieve high-quality image capture and imaging effects. At the same time, the number of lenses used is small, suitable for processing, and low cost; the total optical length can be less than 3.8 mm, which can meet the miniaturization requirements of the camera module.

[0029] In an exemplary embodiment, the ultra-large aperture ultra-wide-angle infrared lens according to the present application further includes an IR filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface 61.

[0030] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application may satisfy 0.4≤S2 / H1≤0.55, wherein the image side sag height of the first lens P1 is S2, and the center thickness of the first lens P1 is H1. Satisfying 0.4≤S2 / H1≤0.55, by controlling the image side sag height S2 and the center thickness H1 of the first lens P1 within a suitable range, the processability may be improved.

[0031] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application can satisfy ABS(f2-f3)≤0.5, wherein the focal length of the second lens P2 is f2, and the focal length of the third lens P3 is f3. Satisfying ABS(f2-f3)≤0.5, by controlling the focal length difference between the second lens P2 and the third lens P3, it is possible to avoid serious primary aberrations caused by excessive light deflection angles, which is beneficial to improving resolution.

[0032] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application may satisfy 1.6≤f1 / f′≤2; wherein, the focal length f′ of the ultra-large aperture ultra-wide angle infrared lens and the focal length f1 of the first lens P1 satisfy 1.6≤f1 / f′≤2, and by controlling the ratio of the focal length f1 of the first lens P1 to the focal length f′ of the ultra-large aperture ultra-wide angle infrared lens within a reasonable range, it is beneficial to converge large-angle light and achieve an ultra-wide angle.

[0033] In an exemplary embodiment, the ultra-large aperture ultra-wide-angle infrared lens according to the present application may satisfy MAX(ABS(S3), ABS(S4), ...ABS(S8))≤0.35; wherein MAX(ABS(S3), ABS(S4), ...ABS(S8)) represents the maximum value of the absolute values ​​of the object side sag and the image side sag of the second lens P2 to the fourth lens P4, wherein the object side sag of the second lens P2 is S3, the image side sag of the second lens P2 is S4, ..., the object side sag of the fourth lens P4 is S7, and the image side sag of the fourth lens P4 is S8. By satisfying MAX(ABS(S3), ABS(S4), ...ABS(S8))≤0.35, the manufacturability of the lens may be enhanced by controlling the sags of the second lens P2 to the fourth lens P4 to be less than a certain value.

[0034] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application may satisfy 0.3≤S1≤0.55, wherein the object side sag of the first lens P1 is S1. Satisfying 0.3≤S1≤0.55 and controlling the object side sag S1 of the first lens P1 to be less than a certain value may help converge large angle light and achieve an ultra-wide angle.

[0035] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application may satisfy 1.5≤f2≤3, wherein the focal length of the second lens P2 is f2. Satisfying 1.5≤f2≤3, by controlling the focal length f2 of the second lens P2 to be less than a certain value, it is beneficial to converge the rear group of light and reduce the height of the lens.

[0036] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application can satisfy ABS(S3)≤0.05, wherein the object side sag height of the second lens P2 is S3. Satisfying ABS(S3)≤0.05 and controlling the object side sag height S3 of the second lens P2 to be less than a certain value can avoid excessive incident angles when the front group of light enters the rear group, resulting in serious primary aberrations, which is beneficial to improving resolution.

[0037] In an exemplary embodiment, the ultra-large aperture ultra-wide angle infrared lens according to the present application further includes a stop STO, which is disposed between the first lens P1 and the second lens P2 to further improve the overall performance. In other exemplary embodiments, the stop STO may be disposed between other lenses.

[0038] Based on the same inventive concept, according to the electronic device of the exemplary embodiment of the present application, the electronic device includes the above-mentioned ultra-large aperture ultra-wide angle infrared lens. The electronic device includes but is not limited to a smart phone, a tablet computer, a laptop computer, a PTZ shooting device, a surveillance camera, and other imaging devices. The implementation of the electronic device can refer to the embodiment of the ultra-large aperture ultra-wide angle infrared lens, and the repetitions will not be repeated.

[0039] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging lens can be changed to obtain the various results and advantages described in this specification. For example, although four lenses are described as an example in the embodiments, the optical imaging lens is not limited to including four lenses. If necessary, the optical imaging lens may also include other numbers of lenses.

[0040] The following further describes a specific embodiment of the ultra-large aperture ultra-wide angle infrared lens applicable to the above-mentioned implementation mode with reference to the accompanying drawings.

[0041] Example 1 The following reference Figure 1 The ultra-large aperture ultra-wide-angle infrared lens according to Example 1 of the present application is described. Figure 1 A schematic diagram of the optical structure of an ultra-large aperture and ultra-wide-angle infrared lens according to Example 1 of the present application is shown.

[0042] like Figure 1 As shown, the ultra-large aperture ultra-wide angle infrared lens includes, from the object side to the image side, a first lens P1, a stop STO, a second lens P2, a third lens P3, a fourth lens P4, a filter IR and an imaging surface 61.

[0043] The first lens P1 has negative power, and its object side surface 11 is convex, and its image side surface 12 is concave. The second lens P2 has positive power, and its object side surface 21 is concave, and its image side surface 22 is convex. The third lens P3 has positive power, and its object side surface 31 is convex, and its image side surface 32 is convex. The fourth lens P4 has positive power, and its object side surface 41 is convex, and its image side surface 42 is concave. The filter IR has an object side surface 51 and an image side surface 52. Light from an object passes through the object side surfaces and image side surfaces of the first lens P1 to the fourth lens P4 and the filter IR in sequence, and is finally imaged on an imaging surface 61.

[0044] Table 1 shows the basic parameters of the ultra-large aperture ultra-wide angle infrared lens of Example 1, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0045] Table 1:

[0046] In Embodiment 1, the object side surface and the image side surface of any lens of the first lens P1 to the fourth lens P4 are both even-order aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the following aspherical formula: (1) Wherein, z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; A2, A4, A6, A8, A 10 , A 12 , A 14 and A 16 They are the correction coefficients for the second, fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders of aspheric surfaces.

[0047] Table 2 shows the high-order coefficients A2, A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A3 10 , A 12 , A 14 and A 16 .

[0048] Table 2:

[0049] In this embodiment, according to the focal power distribution of the first lens P1 to the fourth lens P4 in the above table, the focal power, spacing and refractive index of each lens are reasonably allocated and set, an ultra-large aperture ultra-wide angle can be achieved, wherein the aperture of the ultra-large aperture ultra-wide angle infrared lens is 1.35, and the field of view angle is 124°. The total optical length of existing mobile phone lenses is usually between 3mm and 5mm. The total optical length of the ultra-large aperture ultra-wide angle infrared lens in this embodiment is 3.6mm, which realizes the miniaturization of the ultra-large aperture ultra-wide angle infrared lens. In addition, the focal length of the ultra-large aperture ultra-wide angle infrared lens of this embodiment is 0.92mm. The working band of the ultra-large aperture ultra-wide angle infrared lens is 920-960nm, and the imaging circle diameter of the ultra-large aperture ultra-wide angle infrared lens is 2.36mm. The relationship between the aperture F#, field of view FOV and focal length f' of the ultra-large aperture ultra-wide angle infrared lens is F#*TAN(FOV / 2)*SQRT(f' / 100)=0.243; the relationship between the image side sag S2 and the center thickness H1 of the first lens P1 is: S2 / H1=0.522; the relationship between the focal length f2 of the second lens P2 and the focal length f3 of the third lens P3 is: ABS(f2-f3)=0.03; the focal length f' of the ultra-large aperture ultra-wide angle infrared lens and the focal length of the first lens P1 The relationship between f1 is: f1 / f′=1.79; the relationship between the maximum values ​​of the absolute values ​​of the object side sag height and the image side sag height of the second lens P2 to the fourth lens P4 is: MAX(ABS(S3), ABS(S4), …ABS(S8))=0.30; the object side sag height S1 of the first lens P1 has the relationship: S1=0.44; the focal length f2 of the second lens P2 has the relationship: f2=2.07; the object side sag height S3 of the second lens P2 has the relationship: ABS(S3)=0.02.

[0050] Figure 2 The distortion diagram of the ultra-large aperture ultra-wide-angle infrared lens of Example 1 is shown, and the distortion is less than 35%, which is very small. Figure 3 The MTF curve of the ultra-large aperture ultra-wide-angle infrared lens of Example 1 is shown. The MTF (Modulation Transfer Function) curve is the variation of the degree to which the lens reproduces the details of the subject on the image plane as the spatial frequency changes. When the spatial frequency is 50lp / mm, the minimum MTF is greater than 0.2, and the resolution is good. Figure 4 The relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 1 is shown. The relative illumination is greater than 0.4, and the illumination of the picture is uniform. Figures 2 to 4 It can be seen that the ultra-large aperture and ultra-wide-angle infrared lens provided in Example 1 can achieve good imaging quality, can achieve ultra-large aperture and ultra-wide-angle performance, and has excellent resolution, meeting the needs of various usage scenarios.

[0051] Example 2 The following reference Figure 5 The ultra-large aperture ultra-wide-angle infrared lens according to Example 2 of the present application is described. Figure 5 The optical structure diagram of the ultra-large aperture ultra-wide angle infrared lens according to Embodiment 2 of the present application is shown. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted.

[0052] like Figure 5 As shown, the ultra-large aperture ultra-wide angle infrared lens includes, from the object side to the image side, a first lens P1, a stop STO, a second lens P2, a third lens P3, a fourth lens P4, a filter IR and an imaging surface 61.

[0053] The first lens P1 has negative power, and its object side surface 11 is convex, and its image side surface 12 is concave. The second lens P2 has positive power, and its object side surface 21 is convex, and its image side surface 22 is convex. The third lens P3 has positive power, and its object side surface 31 is convex, and its image side surface 32 is convex. The fourth lens P4 has positive power, and its object side surface 41 is convex, and its image side surface 42 is concave. The filter IR has an object side surface 51 and an image side surface 52. Light from an object passes through the object side surfaces and image side surfaces of the first lens P1 to the fourth lens P4 and the filter IR in sequence, and is finally imaged on an imaging surface 61.

[0054] Table 3 shows the basic parameters of the ultra-large aperture ultra-wide angle infrared lens of Example 2, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0055] Table 3:

[0056] Table 4 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 2, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0057] Table 4:

[0058] In this embodiment, according to the focal power distribution of the first lens P1 to the fourth lens P4 in the above table, the focal power, spacing and refractive index of each lens are reasonably allocated and set, an ultra-large aperture ultra-wide angle can be achieved, wherein the aperture of the ultra-large aperture ultra-wide angle infrared lens is 1.34, and the field of view angle is 124°. The total optical length of existing mobile phone lenses is usually between 3mm and 5mm. The total optical length of the ultra-large aperture ultra-wide angle infrared lens in this embodiment is 3.7mm, which realizes the miniaturization of the ultra-large aperture ultra-wide angle infrared lens. In addition, the focal length of the ultra-large aperture ultra-wide angle infrared lens of this embodiment is 0.93mm. The working band of the ultra-large aperture ultra-wide angle infrared lens is 920-960nm, and the imaging circle diameter of the ultra-large aperture ultra-wide angle infrared lens is 2.5mm. The relationship between the aperture F#, field of view FOV and focal length f' of the ultra-large aperture ultra-wide angle infrared lens is F#*TAN(FOV / 2)*SQRT(f' / 100)=0.243; the relationship between the image side sag S2 and the center thickness H1 of the first lens P1 is: S2 / H1=0.549; the relationship between the focal length f2 of the second lens P2 and the focal length f3 of the third lens P3 is: ABS(f2-f3)=0.03; the focal length f' of the ultra-large aperture ultra-wide angle infrared lens and the focal length of the first lens P1 The relationship between f1 is: f1 / f′=1.76; the relationship between the maximum values ​​of the absolute values ​​of the object side sag height and the image side sag height of the second lens P2 to the fourth lens P4 is: MAX(ABS(S3), ABS(S4), …ABS(S8))=0.29; the object side sag height S1 of the first lens P1 has the relationship: S1=0.37; the focal length f2 of the second lens P2 has the relationship: f2=2.00; the object side sag height S3 of the second lens P2 has the relationship: ABS(S3)=0.01.

[0059] Figure 6 The distortion diagram of the ultra-large aperture ultra-wide-angle infrared lens of Example 2 is shown, and the distortion is less than 30%, which is very small. Figure 7 The MTF curve of the ultra-large aperture ultra-wide-angle infrared lens of Example 2 is shown. The MTF (Modulation Transfer Function) curve is the degree to which the lens reproduces the details of the subject on the image plane as the spatial frequency changes. When the spatial frequency is 50lp / mm, the minimum MTF is greater than 0.2, and the resolution is good. Figure 8 The relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 2 is shown. The relative illumination is greater than 0.39, and the illumination of the picture is uniform. Figures 6 to 8 It can be seen that the ultra-large aperture and ultra-wide-angle infrared lens provided in Example 2 can achieve good imaging quality, can achieve ultra-large aperture and ultra-wide-angle performance, and has excellent resolution, meeting the needs of various usage scenarios.

[0060] Example 3 The following reference Fig. 9 The ultra-large aperture ultra-wide-angle infrared lens according to Example 3 of the present application is described. Fig. 9 The optical structure diagram of the ultra-large aperture ultra-wide angle infrared lens according to Embodiment 3 of the present application is shown. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted.

[0061] like Fig. 9 As shown, the ultra-large aperture ultra-wide angle infrared lens includes, from the object side to the image side, a first lens P1, a stop STO, a second lens P2, a third lens P3, a fourth lens P4, a filter IR and an imaging surface 61.

[0062] The first lens P1 has negative power, and its object side surface 11 is convex, and its image side surface 12 is concave. The second lens P2 has positive power, and its object side surface 21 is convex, and its image side surface 22 is convex. The third lens P3 has positive power, and its object side surface 31 is convex, and its image side surface 32 is convex. The fourth lens P4 has positive power, and its object side surface 41 is convex, and its image side surface 42 is concave. The filter IR has an object side surface 51 and an image side surface 52. Light from an object passes through the object side surfaces and image side surfaces of the first lens P1 to the fourth lens P4 and the filter IR in sequence, and is finally imaged on an imaging surface 61.

[0063] Table 5 shows the basic parameters of the ultra-large aperture ultra-wide angle infrared lens of Example 3, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0064] Table 5:

[0065] Table 6 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0066] Table 6:

[0067] In this embodiment, according to the focal power distribution of the first lens P1 to the fourth lens P4 in the above table, the focal power, spacing and refractive index of each lens are reasonably allocated and set, an ultra-large aperture ultra-wide angle can be achieved, wherein the aperture of the ultra-large aperture ultra-wide angle infrared lens is 1.35, and the field of view angle is 124°. The total optical length of existing mobile phone lenses is usually between 3mm and 5mm. The total optical length of the ultra-large aperture ultra-wide angle infrared lens in this embodiment is 3.65mm, which realizes the miniaturization of the ultra-large aperture ultra-wide angle infrared lens. In addition, the focal length of the ultra-large aperture ultra-wide angle infrared lens of this embodiment is 0.92mm. The working band of the ultra-large aperture ultra-wide angle infrared lens is 920-960nm, and the imaging circle diameter of the ultra-large aperture ultra-wide angle infrared lens is 2.4mm. The relationship between the aperture F#, field of view FOV and focal length f' of the ultra-large aperture ultra-wide angle infrared lens is F#*TAN(FOV / 2)*SQRT(f' / 100)=0.243; the relationship between the image side sag S2 and the center thickness H1 of the first lens P1 is: S2 / H1=0.515; the relationship between the focal length f2 of the second lens P2 and the focal length f3 of the third lens P3 is: ABS(f2-f3)=0.18; the focal length f' of the ultra-large aperture ultra-wide angle infrared lens and the focal length of the first lens P1 The relationship between f1 is: f1 / f′=1.76; the relationship between the maximum values ​​of the absolute values ​​of the object side sag height and the image side sag height of the second lens P2 to the fourth lens P4 is: MAX(ABS(S3), ABS(S4), …ABS(S8))=0.24; the object side sag height S1 of the first lens P1 has the relationship: S1=0.40; the focal length f2 of the second lens P2 has the relationship: f2=1.97; the object side sag height S3 of the second lens P2 has the relationship: ABS(S3)=0.03.

[0068] Fig.10 The distortion diagram of the ultra-large aperture ultra-wide-angle infrared lens of Example 3 is shown, and the distortion is less than 32%, which is very small. Fig.11 The MTF curve of the ultra-large aperture ultra-wide-angle infrared lens of Example 3 is shown. The MTF (Modulation Transfer Function) curve is the degree to which the lens reproduces the details of the subject on the image plane as the spatial frequency changes. When the spatial frequency is 50lp / mm, the minimum MTF is greater than 0.2, and the resolution is good. Fig.12 The relative illumination and Y field angle diagram of the ultra-large aperture ultra-wide angle infrared lens of Example 3 is shown. The relative illumination is greater than 0.3, and the illumination of the picture is uniform. Figures 10 to 12 It can be seen that the ultra-large aperture and ultra-wide-angle infrared lens provided in Example 3 can achieve good imaging quality, can achieve ultra-large aperture and ultra-wide-angle performance, and has excellent resolution, meeting the needs of various usage scenarios.

[0069] In summary, Example 1, Example 2 and Example 3 respectively satisfy the relationship shown in Table 7.

[0070] Table 7:

[0071] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. An ultra-large aperture ultra-wide angle infrared lens, characterized in that: The optical axis includes a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side; the first lens to the fourth lens each include an object-side surface facing the object side and allowing imaging light to pass through, and an image-side surface facing the image side and allowing imaging light to pass through; The aperture F#, field of view FOV and focal length f′ of the ultra-large aperture ultra-wide angle infrared lens satisfy: F#*TAN(FOV / 2)*SQRT(f′ / 100)≥0.

24.

2. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The first lens has negative refractive power, and the second lens, the third lens and the fourth lens have positive refractive power.

3. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The image-side sag height of the first lens is S2, and the center thickness H1 of the first lens satisfies: 0.4≤S2 / H1≤0.

55.

4. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The focal length f2 of the second lens and the focal length f3 of the third lens satisfy: ABS(f2-f3)≤0.

5.

5. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The focal length f′ of the ultra-large aperture ultra-wide angle infrared lens and the focal length f1 of the first lens satisfy: 1.6≤f1 / f′≤2.

6. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The maximum values ​​of the absolute values ​​of the object-side sag heights and the image-side sag heights of the second lens to the fourth lens satisfy: MAX(ABS(S3), ABS(S4), ...ABS(S8))≤0.

35.

7. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The object side sag S1 of the first lens satisfies: 0.3≤S1≤0.

55.

8. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The focal length f2 of the second lens satisfies: 1.5≤f2≤3.

9. The ultra-large aperture ultra-wide angle infrared lens according to claim 1, characterized in that: The object side sag S3 of the second lens satisfies: ABS(S3)≤0.

05.

10. An electronic device, characterized in that: It comprises the ultra-large aperture ultra-wide-angle infrared lens as described in any one of claims 1 to 9.

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