A small high-definition optical imaging lens

Abstract

The present invention relates to the field of lens technology. The present invention discloses a small high-definition optical imaging lens, which includes a first lens to a fifth lens in sequence along an optical axis from the object side to the image side; the first lens is a convex-concave lens with a negative refractive power; the second lens has a positive refractive power and the image side is a convex surface; the third lens and the fifth lens are convex-convex lenses with positive refractive power; the fourth lens is a concave-concave lens with a negative refractive power; the second lens, the fourth lens and the fifth lens are all plastic aspheric lenses, and the first lens and the third lens are both made of glass materials. The present invention has the advantages of small temperature drift; small high and low temperature field curvature, ensuring the consistency of center-to-edge clarity, improving and avoiding stray light; small chromatic aberration; good day and night confocality; and high imaging quality.

Description

Technical Field

[0001] The invention belongs to the technical field of lenses, and in particular relates to a small high-definition optical imaging lens. Background Art

[0002] With the continuous advancement of science and technology and the continuous development of society, optical imaging lenses have also developed rapidly in recent years. Optical imaging lenses are widely used in various fields such as smart phones, tablet computers, video conferencing, vehicle monitoring, security monitoring, drone aerial photography, etc. Therefore, the requirements for optical imaging lenses are getting higher and higher.

[0003] However, the existing conventional glass-plastic hybrid optical imaging lenses still have many shortcomings, such as the difficulty in controlling temperature drift, serious focus deviation in harsh working environments such as high and low temperatures, which deteriorates image quality; field curvature is prone to occur under high and low temperature conditions, so that even if the center of the lens is clear in a high and low temperature working environment, the edges will appear blurred, resulting in loss of clarity; stray light is more obvious under strong light, affecting the imaging effect and picture purity; purple fringing and color cast are prone to occur; when the day and night confocality is good, the chromatic aberration is large, and when the chromatic aberration is good, the day and night confocality performance is poor, and the two are contradictory, etc. Therefore, it is necessary to improve it to meet the increasing demands of consumers. Summary of the invention

[0004] The purpose of the present invention is to provide a small high-definition optical imaging lens to solve the above-mentioned technical problems.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a small high-definition optical imaging lens, which includes a first lens to a fifth lens in sequence along an optical axis from the object side to the image side; the first lens to the fifth 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;

[0006] The first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface;

[0007] The second lens has a positive refractive power, and the image side surface of the second lens is a convex surface;

[0008] The third lens has a positive refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface;

[0009] The fourth lens element has a negative refractive power, the object side surface of the fourth lens element is a concave surface, and the image side surface of the fourth lens element is a concave surface;

[0010] The fifth lens element has a positive refractive power, the object side surface of the fifth lens element is a convex surface, and the image side surface of the fifth lens element is a convex surface;

[0011] The second lens, the fourth lens and the fifth lens are all plastic aspherical lenses, and the first lens and the third lens are both made of glass materials;

[0012] The optical imaging lens has only the first to fifth lenses with refractive power.

[0013] Furthermore, the optical imaging lens also satisfies: |f1 / f|<1.5, wherein f1 is the focal length of the first lens, and f is the focal length of the optical imaging lens.

[0014] Furthermore, the optical imaging lens also satisfies: 0.8<|f3 / f5|<1.2, wherein f3 is the focal length of the third lens, and f5 is the focal length of the fifth lens.

[0015] Furthermore, the optical imaging lens also satisfies: |f4 / f5|<1, wherein f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens.

[0016] Furthermore, the optical imaging lens also satisfies: vd3>50, wherein vd3 is the dispersion coefficient of the third lens.

[0017] Furthermore, the object side surface of the fourth lens is a concave surface, and |R41| is less than 60 mm, wherein R41 is the radius of curvature of the object side surface of the fourth lens.

[0018] Furthermore, the optical imaging lens also satisfies: vd5>50, vd4<30, wherein vd4 is the dispersion coefficient of the fourth lens, and vd5 is the dispersion coefficient of the fifth lens.

[0019] Furthermore, the fourth lens and the fifth lens are directly supported or glued to each other.

[0020] Furthermore, it also includes an infrared cut-off filter for the visible light mode and a white film for the infrared light mode, and the thicknesses of the infrared cut-off filter and the white film are not equal.

[0021] Furthermore, the thickness difference between the infrared cutoff filter and the white film is 0.09 mm.

[0022] Beneficial technical effects of the present invention:

[0023] The present invention adopts five lenses, which are a mixture of glass and plastic, and designs each lens accordingly, so as to have the advantages of no focus deviation at high and low temperatures, obtaining high-definition image quality output; reducing the field curvature at high and low temperatures, ensuring the consistency of clarity from the center to the edge; improving and avoiding stray light; low chromatic aberration, good confocality during the day and at night; and miniaturization and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0026] Figure 2 This is the MTF diagram of visible light 435-656nm of the first embodiment of the present invention;

[0027] Figure 3 This is the MTF diagram of infrared light at 850nm according to the first embodiment of the present invention;

[0028] Figure 4 Schematic diagram of color difference curve of embodiment 1 of the present invention;

[0029] Figure 5 This is a defocus curve diagram of visible light 435-656nm at 60lp / mm at room temperature (20°C) according to Example 1 of the present invention;

[0030] Figure 6 This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at low temperature (-30°C) of Example 1 of the present invention;

[0031] Figure 7 This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at high temperature (85°C) of Example 1 of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0033] Fig. 9 This is the MTF diagram of visible light 435-656nm of the second embodiment of the present invention;

[0034] Fig.10 This is the MTF diagram of infrared light at 850nm according to the second embodiment of the present invention;

[0035] Fig.11 Schematic diagram of color difference curve of the second embodiment of the present invention;

[0036] Fig.12 This is a defocus curve of visible light 435-656nm at 60lp / mm at room temperature (20°C) according to Example 2 of the present invention;

[0037] Fig.13This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at low temperature (-30°C) of Example 2 of the present invention;

[0038] Fig.14 This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at high temperature (85°C) of Example 2 of the present invention;

[0039] Fig.15 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0040] Fig.16 This is the MTF diagram of visible light 435-656nm of Example 3 of the present invention;

[0041] Fig.17 This is the MTF diagram of infrared light at 850nm according to the third embodiment of the present invention;

[0042] Fig.18 Schematic diagram of color difference curve of embodiment 3 of the present invention;

[0043] Fig.19 This is a defocus curve of visible light 435-656nm at 60lp / mm at room temperature (20°C) according to Example 3 of the present invention;

[0044] Fig. 20 This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at low temperature (-30°C) of Example 3 of the present invention;

[0045] Fig.21 This is a defocus curve of visible light 435-650nm at 60lp / mm at high temperature (85°C) of Example 3 of the present invention;

[0046] Fig. 22 This is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0047] Fig.23 This is the MTF diagram of visible light 435-656nm of the fourth embodiment of the present invention;

[0048] Fig.24 This is the MTF diagram of infrared light at 850nm according to the fourth embodiment of the present invention;

[0049] Fig.25 Schematic diagram of color difference curve of the fourth embodiment of the present invention;

[0050] Fig.26 This is a defocus curve of visible light 435-656nm at 60lp / mm at room temperature (20°C) according to Example 4 of the present invention;

[0051] Fig. 27This is a defocus curve diagram of visible light 435-650nm at 60lp / mm at low temperature (-30°C) of Example 4 of the present invention; Fig.28 This is a defocus curve of visible light 435-650nm at 60lp / mm at high temperature (85°C) of Example 4 of the present invention; DETAILED DESCRIPTION

[0052] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0053] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0054] The term "a lens having a positive refractive power (or a negative refractive power)" means that the paraxial refractive power of the lens calculated by Gaussian optical theory is positive (or negative). The term "object side (or image side) of the lens" is defined as a specific range of the lens surface through which the imaging light passes. The concave and convex shape of the lens can be determined by the judgment method of the general knowledgeable person in this field, that is, the concave and convex shape of the lens surface can be determined by the positive and negative signs of the radius of curvature (abbreviated as R value). R value can be commonly used in optical design software, such as Zemax or CodeV. R value is also commonly found in the lens data sheet of optical design software. For the object side, when the R value is positive, the object side is determined to be convex; when the R value is negative, the object side is determined to be concave. Conversely, for the image side, when the R value is positive, the image side is determined to be concave; when the R value is negative, the image side is determined to be convex.

[0055] The present invention discloses a small high-definition optical imaging lens, which comprises a first lens to a fifth lens in sequence along an optical axis from an object side to an image side; the first lens to the fifth lens each comprises 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.

[0056] The first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface.

[0057] The second lens element has a positive refractive power, and the image side surface of the second lens element is a convex surface.

[0058] The third lens element has a positive refractive power, the object side surface of the third lens element is a convex surface, and the image side surface of the third lens element is a convex surface.

[0059] The fourth lens element has a negative refractive power, the object side surface of the fourth lens element is a concave surface, and the image side surface of the fourth lens element is a concave surface.

[0060] The fifth lens element has a positive refractive power, an object-side surface of the fifth lens element is a convex surface, and an image-side surface of the fifth lens element is a convex surface.

[0061] The second lens, the fourth lens and the fifth lens are all plastic aspherical lenses. The first lens and the third lens are both made of glass material, using 2 glass lenses and 3 plastic lenses. The first lens is a glass lens with greater hardness, which can protect the lens, thereby ensuring high optical performance and greatly controlling costs.

[0062] The optical imaging lens has only the first to fifth lenses with refractive power.

[0063] The present invention adopts five lenses, which are a mixture of glass and plastic, and designs each lens accordingly, so as to have the advantages of no focus deviation at high and low temperatures, obtaining high-definition image quality output; reducing the field curvature at high and low temperatures, ensuring the consistency of clarity from the center to the edge; improving and avoiding stray light; low chromatic aberration, good confocality during the day and at night; and miniaturization and low cost.

[0064] Preferably, the optical imaging lens further satisfies: |f1 / f|<1.5, wherein f1 is the focal length of the first lens, and f is the focal length of the optical imaging lens, so as to further control the back focus offset at high and low temperatures.

[0065] Preferably, the optical imaging lens also satisfies: 0.8<|f3 / f5|<1.2, wherein f3 is the focal length of the third lens, and f5 is the focal length of the fifth lens, so as to further control the back focus offset at high and low temperatures.

[0066] Preferably, the optical imaging lens further satisfies: |f4 / f5|<1, wherein f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens, so as to further control the back focus offset at high and low temperatures.

[0067] Preferably, the optical imaging lens also satisfies: vd3>50, wherein vd3 is the dispersion coefficient of the third lens, further eliminating chromatic aberration.

[0068] Preferably, the object side surface of the fourth lens is concave, and |R41| is less than 60 mm, wherein R41 is the radius of curvature of the object side surface of the fourth lens, so as to control reflection between lenses and avoid the occurrence of serious ghost images.

[0069] Preferably, the optical imaging lens also satisfies: vd5>50, vd4<30, wherein vd4 is the dispersion coefficient of the fourth lens, and vd5 is the dispersion coefficient of the fifth lens, so as to further optimize the chromatic aberration.

[0070] Preferably, the fourth lens and the fifth lens are directly supported or glued to each other, which can greatly reduce the tolerance sensitivity of the lens and facilitate mass production.

[0071] Preferably, it also includes an infrared cutoff filter for the visible light mode and a white film for the infrared light mode. The thicknesses of the infrared cutoff filter and the white film are not equal, which compensates for the back focus offset of the infrared, so that both visible light and infrared can achieve high-definition image quality.

[0072] More preferably, the thickness difference between the infrared cutoff filter and the white film is 0.09 mm, which better compensates for the back focus offset of the infrared, so that both visible light and infrared can achieve high-definition image quality.

[0073] The small-sized high-definition optical imaging lens of the present invention will be described in detail with reference to specific embodiments below.

[0074] Embodiment 1

[0075] like Figure 1 As shown, a small high-definition optical imaging lens comprises a first lens 1, a second lens 2, an aperture 6, a third lens 3, a fourth lens 4, a fifth lens 5, a switching plate 7 and an imaging surface 8 in sequence from the object side A1 to the image side A2 along an optical axis I; the first lens 1 to the fifth lens 5 each include an object side surface facing the object side A1 and allowing the imaging light to pass through, and an image side surface facing the image side A2 and allowing the imaging light to pass through.

[0076] The first lens 1 has a negative refractive power, an object-side surface 11 of the first lens 1 is a convex surface, and an image-side surface 12 of the first lens 1 is a concave surface.

[0077] The second lens 2 has a positive refractive power, the object-side surface 21 of the second lens 2 is a convex surface, and the image-side surface 22 of the second lens 2 is a convex surface. Of course, in other embodiments, the object-side surface 21 of the second lens 2 may also be a plane or a concave surface; both the object-side surface 21 and the image-side surface 22 of the second lens 2 are aspherical surfaces.

[0078] The third lens element 3 has a positive refractive power, an object-side surface 31 of the third lens element 3 is a convex surface, and an image-side surface 32 of the third lens element 3 is a convex surface.

[0079] The fourth lens element 4 has a negative refractive power. The object-side surface 41 of the fourth lens element 4 is a concave surface. The image-side surface 42 of the fourth lens element 4 is a concave surface. Both the object-side surface 41 and the image-side surface 42 of the fourth lens element 4 are aspherical surfaces.

[0080] The fifth lens element 5 has a positive refractive power, an object-side surface 51 of the fifth lens element 5 is a convex surface, an image-side surface 52 of the fifth lens element 5 is a convex surface, and both the object-side surface 51 and the image-side surface 52 of the fifth lens element 5 are aspherical surfaces.

[0081] The second lens 2 , the fourth lens 4 and the fifth lens 5 are all made of plastic material, and the first lens 1 and the third lens 3 are all made of glass material.

[0082] In this specific embodiment, the aperture 6 is disposed between the second lens 2 and the third lens 3 to improve the overall performance. Of course, in other embodiments, the aperture 6 may also be disposed at other appropriate positions.

[0083] In this specific embodiment, the switching sheet 7 includes an infrared cutoff filter for the visible light mode and a white sheet for the infrared light mode, which are switched to each other, that is, during the day, the switching sheet 7 is switched to the infrared cutoff filter, and at night, the switching sheet 7 is switched to the white sheet. The thickness of the infrared cutoff filter is 0.3 mm, the thickness of the white sheet is 0.21 mm, and the difference in thickness between the infrared cutoff filter and the white sheet is 0.09 mm, but it is not limited thereto.

[0084] In this specific embodiment, the fourth lens 4 and the fifth lens 5 are directly supported and arranged.

[0085] The detailed optical data of this specific embodiment are shown in Table 1-1.

[0086] Table 1-1 Detailed optical data of Example 1

[0087]

[0088] In this specific embodiment, the object side surface 21, the object side surface 41, the object side surface 51, the image side surface 22, the image side surface 42 and the image side surface 52 are defined according to the following aspheric curve formula:

[0089]

[0090] in:

[0091] z: the depth of the aspherical surface (the vertical distance between the point on the aspherical surface that is y away from the optical axis and the tangent plane that is tangent to the vertex on the optical axis of the aspherical surface);

[0092] c: the curvature of the vertex of the aspherical surface (the vertex curvature);

[0093] K: Conic Constant;

[0094] radial distance;

[0095] r n : Normalization radius (NRADIUS);

[0096] u:r / r n ;

[0097] a m : mth order Q con Coefficient (is the m th Q con coefficient);

[0098] Q m con : mth order Q con Polynomial th Q con polynomial);

[0099] Please refer to the following table for detailed parameter data of each aspheric surface:

[0100] surface 21 22 41 42 51 52 K＝ 0 2.6E+00 0 -3.9E+00 2.4E+00 0 <![CDATA[a4=]]> -2.98E-04 1.37E-03 -3.20E-02 -2.46E-02 -1.46E-02 4.60E-04 <![CDATA[a6=]]> 2.85E-04 2.39E-04 1.63E-02 1.91E-02 7.80E-03 -5.59E-04 <![CDATA[a8=]]> 5.59E-06 -3.16E-06 -7.36E-03 -7.15E-03 -1.31E-03 3.09E-04 <![CDATA[a 10 =]]> 1.49E-05 1.46E-05 2.04E-03 1.84E-03 2.29E-04 -6.15E-05 <![CDATA[a 12 =]]> 0 0 -3.04E-04 -2.90E-04 -5.96E-05 6.69E-06 <![CDATA[a 14 =]]> 0 0 1.81E-05 1.89E-05 5.93E-06 0

[0101] The MTF curve diagram of this specific embodiment is shown in Figure 2 and 3 As you can see, high pixels are achieved under both visible and infrared light, and the confocal quality is good day and night; please refer to the color difference diagram Figure 4 , it can be seen that the chromatic aberration has been corrected very well, and purple fringing is not easy to appear; please refer to the defocus curve Figure 5-7 It can be seen that at different temperatures, the back focus offset is small, all within the range of 10μm, and there will be no serious field curvature under high and low temperatures, which can ensure stable image quality output under high and low temperatures when used with the camera.

[0102] In this specific embodiment, the focal length of the optical imaging lens is f=2.9 mm; the aperture value FNO=2.3; the field of view FOV=140; the distance TTL from the object side surface 11 of the first lens 1 to the imaging surface 8 on the optical axis I is TTL=16.4 mm, |f1 / f|=1.06; |f3 / f5|=0.94, |f4 / f5|=0.82.

[0103] Embodiment 2

[0104] like Figure 8 As shown, the surface concave-convex and refractive power of each lens in this embodiment and the first embodiment are substantially the same, and only the object side surface 21 of the second lens 2 is a concave surface. In addition, the optical parameters such as the curvature radius of each lens surface and the lens thickness are also different.

[0105] The detailed optical data of this specific embodiment are shown in Table 2-1.

[0106] Table 2-1 Detailed optical data of Example 2

[0107]

[0108]

[0109] For detailed parameter data of each aspheric surface in this specific embodiment, please refer to the following table:

[0110] surface 21 22 41 42 51 52 K＝ 0 -9.4E-01 0 -4.3E+00 5.5E+00 0 <![CDATA[a4=]]> -5.78E-03 -1.32E-03 -2.60E-02 -1.51E-02 -1.14E-03 6.42E-03 <![CDATA[a6=]]> -1.98E-04 -1.51E-04 1.64E-02 2.39E-02 1.27E-02 -2.14E-04 <![CDATA[a8=]]> 1.60E-05 5.94E-05 -7.51E-03 -1.04E-02 -4.55E-03 7.50E-04 <![CDATA[a 10 =]]> -2.94E-06 -5.50E-06 2.12E-03 1.96E-03 3.07E-04 -2.80E-04 <![CDATA[a 12 =]]> 0 0 -3.07E-04 -8.01E-05 1.35E-04 3.78E-05 <![CDATA[a 14 =]]> 0 0 1.41E-05 -1.49E-05 0 0

[0111] The MTF curve diagram of this specific embodiment is shown in Fig. 9 and 10 As you can see, high pixels are achieved under both visible and infrared light, and the confocal quality is good day and night; please refer to the color difference diagram Fig.11 , it can be seen that the chromatic aberration has been corrected very well, and purple fringing is not easy to appear; please refer to the defocus curve Figure 12-14 It can be seen that at different temperatures, the back focus offset is small, all within the range of 10μm, and there will be no serious field curvature under high and low temperatures, which can ensure stable image quality output under high and low temperatures when used with the camera.

[0112] In this specific embodiment, the focal length of the optical imaging lens is f=2.98 mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL from the object side surface 11 of the first lens 1 to the imaging surface 8 on the optical axis I is TTL=16.1 mm, |f1 / f|=1.31; |f3 / f5|=0.98, |f4 / f5|=0.71.

[0113] Embodiment 3

[0114] like Fig.15 As shown, the surface profile and refractive power of each lens in this embodiment are the same as those in the first embodiment, and only the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0115] The detailed optical data of this specific embodiment are shown in Table 3-1.

[0116] Table 3-1 Detailed optical data of Example 3

[0117]

[0118]

[0119] For detailed parameter data of each aspheric surface in this specific embodiment, please refer to the following table:

[0120] surface 21 22 41 42 51 52 K＝ 8.0E-02 -3.6E+00 -3.6E+00 <![CDATA[a4=]]> -1.77E-04 3.17E-03 -3.02E-02 -2.31E-02 -1.18E-02 -1.23E-03 <![CDATA[a6=]]> 5.70E-04 7.77E-04 1.49E-02 1.84E-02 7.53E-03 -1.59E-04 <![CDATA[a8=]]> -3.79E-05 -1.33E-04 -7.02E-03 -7.14E-03 -1.43E-03 1.32E-04 <![CDATA[a 10 =]]> 2.39E-05 6.41E-05 2.02E-03 1.83E-03 2.25E-04 -1.97E-05 <![CDATA[a 12 =]]> 0 0 -3.21E-04 -2.94E-04 -5.53E-05 2.34E-06 <![CDATA[a 14 =]]> 0 0.00E+00 2.11E-05 2.05E-05 6.01E-06 0

[0121] The MTF curve diagram of this specific embodiment is shown in Fig.16 and 17 As you can see, high pixels are achieved under both visible and infrared light, and the confocal quality is good day and night; please refer to the color difference diagram Fig.18 , it can be seen that the chromatic aberration has been corrected very well, and purple fringing is not easy to appear; please refer to the defocus curve Figure 19-21 It can be seen that at different temperatures, the back focus offset is small, all within the range of 10μm, and there will be no serious field curvature under high and low temperatures, which can ensure stable image quality output under high and low temperatures when used with the camera.

[0122] In this specific embodiment, the focal length of the optical imaging lens is f=2.93 mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL from the object side surface 11 of the first lens 1 to the imaging surface 8 on the optical axis I is TTL=16.1 mm, |f1 / f|=1.05; |f3 / f5|=0.89, |f4 / f5|=0.79.

[0123] Embodiment 4

[0124] like Fig. 22 As shown, the surface concave-convex and refractive power of each lens in this embodiment and the first embodiment are substantially the same, and only the object side surface 21 of the second lens 2 is a concave surface. In addition, the optical parameters such as the curvature radius of each lens surface and the lens thickness are also different.

[0125] In this specific embodiment, the fourth lens 4 and the fifth lens 5 are glued together.

[0126] The detailed optical data of this specific embodiment are shown in Table 4-1.

[0127] Table 4-1 Detailed optical data of Example 4

[0128]

[0129]

[0130] For detailed parameter data of each aspheric surface in this specific embodiment, please refer to the following table:

[0131] surface 21 22 41 42 51 52 K＝ 7.8E+00 -3.3E+00 1.2E+01 -1.0E+00 -4.4E-01 7.8E+00 <![CDATA[a4=]]> -5.40E-03 5.38E-04 -6.95E-03 -2.53E-02 -2.06E-03 -5.40E-03 <![CDATA[a6=]]> 1.25E-03 1.31E-03 -1.01E-02 8.78E-03 -6.13E-04 1.25E-03 <![CDATA[a8=]]> -3.39E-04 5.16E-04 8.93E-03 -4.89E-03 2.11E-04 -3.39E-04 <![CDATA[a 10 =]]> 9.06E-05 -1.59E-04 -4.28E-03 2.32E-03 -6.49E-05 9.06E-05 <![CDATA[a 12 =]]> 2.43E-06 5.15E-05 1.10E-03 -6.39E-04 1.23E-05 2.43E-06 <![CDATA[a 14 =]]> -4.40E-06 -6.33E-06 -1.36E-04 9.06E-05 -1.38E-06 -4.40E-06 <![CDATA[a 16 =]]> 0 0 5.80E-06 -5.18E-06 6.70E-08 0

[0132] The MTF curve diagram of this specific embodiment is shown in Fig.23 and 24 As you can see, high pixels are achieved under both visible and infrared light, and the confocal quality is good day and night; please refer to the color difference diagram Fig.25 , it can be seen that the chromatic aberration has been corrected very well, and purple fringing is not easy to appear; please refer to the defocus curve Figure 26-28 It can be seen that at different temperatures, the back focus offset is small, all within the range of 10μm, and there will be no serious field curvature under high and low temperatures, which can ensure stable image quality output under high and low temperatures when used with the camera.

[0133] In this specific embodiment, the focal length of the optical imaging lens is f=2.90 mm; the aperture value FNO=2.3; the field of view FOV=140; the distance TTL from the object side surface 11 of the first lens 1 to the imaging surface 8 on the optical axis I is TTL=16.1 mm, |f1 / f|=1.12; |f3 / f5|=1.08, |f4 / f5|=0.96.

[0134] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A small high-definition optical imaging lens, characterized in that: The lens system includes a first lens to a fifth lens in sequence along an optical axis from the object side to the image side; each of the first lens to the fifth lens includes an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing imaging light to pass therethrough; The first lens has a negative refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; The second lens has a positive refractive power, and the image side surface of the second lens is a convex surface; The third lens has a positive refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; The fourth lens element has a negative refractive power, the object side surface of the fourth lens element is a concave surface, and the image side surface of the fourth lens element is a concave surface; The fifth lens element has a positive refractive power, the object side surface of the fifth lens element is a convex surface, and the image side surface of the fifth lens element is a convex surface; The second lens, the fourth lens and the fifth lens are all plastic aspherical lenses, and the first lens and the third lens are both made of glass materials; The optical imaging lens has only the first to fifth lenses with refractive power; The optical imaging lens satisfies: |f1 / f|<1.5, 0.8<|f3 / f5|<1.2, |f4 / f5|<1, wherein f1 is the focal length of the first lens, f is the focal length of the optical imaging lens, f3 is the focal length of the third lens, f5 is the focal length of the fifth lens, and f4 is the focal length of the fourth lens.

2. The small high-definition optical imaging lens according to claim 1, characterized in that: The optical imaging lens also satisfies: vd3>50, where vd3 is the dispersion coefficient of the third lens.

3. The small-sized high-definition optical imaging lens according to claim 1, characterized in that: The object side surface of the fourth lens is a concave surface, and |R41| is less than 60 mm, where R41 is the curvature radius of the object side surface of the fourth lens.

4. The small-sized high-definition optical imaging lens according to claim 1, characterized in that: The optical imaging lens also satisfies: vd5>50, vd4<30, wherein vd4 is the dispersion coefficient of the fourth lens, and vd5 is the dispersion coefficient of the fifth lens.

5. The small-sized high-definition optical imaging lens according to claim 1, characterized in that: The fourth lens and the fifth lens are directly supported or glued to each other.

6. The small-sized high-definition optical imaging lens according to claim 1, characterized in that: It also includes an infrared cut-off filter for the visible light mode and a white film for the infrared light mode, and the thicknesses of the infrared cut-off filter and the white film are not equal.

7. The small-sized high-definition optical imaging lens according to claim 6, characterized in that: The thickness difference between the infrared cutoff filter and the white film is 0.09 mm.

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