CN111367054A - Small high-definition optical imaging lens - Google Patents

Abstract

The present invention relates to the technical field of lenses. The invention discloses a small and high-definition optical imaging lens, which comprises a first lens to a fifth lens along an optical axis from the object side to the image side; the first lens is a convex-concave lens with negative refractive index; the second lens has a The positive refractive index and the image side are convex; the third lens and the fifth lens are convex-convex lenses with positive refractive index; the fourth lens is a concave-concave lens with negative refractive index; the second lens, the fourth lens and the fifth lens Both are plastic aspherical lenses, and both the first lens and the third lens are made of glass material. The invention has the advantages of small temperature drift, small field curvature at high and low temperature, ensuring consistency of sharpness from center to edge, improving and avoiding stray light, small chromatic aberration, good day and night confocality, and high imaging quality.

Description

A small high-definition optical imaging lens

technical field

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

Background technique

With the continuous progress of science and technology and the continuous development of society, in recent years, optical imaging lenses have also developed rapidly. Optical imaging lenses are widely used in smartphones, tablet computers, video conferencing, vehicle monitoring, security monitoring, unmanned Therefore, the requirements for optical imaging lenses are getting higher and higher.

However, the existing conventional glass-plastic hybrid optical imaging lenses still have many shortcomings, such as difficulty in controlling temperature drift, serious defocusing in harsh working environments such as high and low temperature, which makes the image quality worse; Live music makes the lens in high and low temperature working environment, even if the center is clear, the edge will be blurred, resulting in loss of clarity; stray light is more obvious under strong light, affecting the imaging effect and picture purity; it is prone to purple fringing, partial When the chromatic aberration is good, the chromatic aberration is large, and when the chromatic aberration is good, the day and night confocal performance is poor, and the two contradict each other. Therefore, it is necessary to improve it to meet the increasing demands of consumers. Require.

SUMMARY OF THE INVENTION

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

In order to achieve the above object, the technical solution adopted in 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 are respectively Including an object side facing the object side and allowing the imaging light to pass through and an image side facing the image side and allowing the imaging light to pass;

The first lens has a negative refractive index, the object side of the first lens is convex, and the image side of the first lens is concave;

The second lens has a positive refractive index, and the image side surface of the second lens is convex;

The third lens has a positive refractive index, the object side of the third lens is convex, and the image side of the third lens is convex;

The fourth lens has a negative refractive index, the object side of the fourth lens is concave, and the image side of the fourth lens is concave;

The fifth lens has a positive refractive index, the object side of the fifth lens is convex, and the image side of the fifth lens is convex;

The second lens, the fourth lens and the fifth lens are all plastic aspherical lenses, and the first lens and the third lens are made of glass material;

The optical imaging lens has only the first lens to the fifth lens mentioned above.

Further, the optical imaging lens also satisfies: ∣f1/f∣<1.5, where f1 is the focal length of the first lens, and f is the focal length of the optical imaging lens.

Further, the optical imaging lens also satisfies: 0.8<∣f3/f5∣<1.2, where f3 is the focal length of the third lens, and f5 is the focal length of the fifth lens.

Further, the optical imaging lens also satisfies: ∣f4/f5∣<1, where f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens.

Further, the optical imaging lens also satisfies: vd3>50, where vd3 is the dispersion coefficient of the third lens.

Further, the object side of the fourth lens is concave, and ∣R41∣<60mm, where R41 is the radius of curvature of the object side of the fourth lens.

Further, 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.

Further, the fourth lens and the fifth lens are directly supported or cemented with each other.

Further, it also includes an infrared cut filter used in the visible light mode and a white film used in the infrared light mode, and the thickness of the infrared cut filter and the white film are not equal.

Furthermore, the thickness difference between the infrared cut filter and the white film is 0.09mm.

Beneficial technical effects of the present invention:

The invention adopts five lenses, which are mixed with glass and plastic, and through the corresponding design of each lens, it has high and low temperature without defocusing, and obtains high-definition image quality output; reduces the amount of field curvature at high and low temperature, and ensures the consistency of sharpness from the center to the edge ; Improve and avoid stray light; low chromatic aberration, good day and night confocal; miniaturization, low cost advantages.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of Embodiment 1 of the present invention;

Fig. 2 is the MTF diagram of visible light 435-656nm according to the first embodiment of the present invention;

Fig. 3 is the MTF diagram of the infrared light 850nm of the first embodiment of the present invention;

4 is a schematic diagram of a color difference curve according to Embodiment 1 of the present invention;

5 is a defocus curve diagram of visible light 435-656 nm at 60 lp/mm under normal temperature (20° C.) according to Embodiment 1 of the present invention;

6 is a defocus curve diagram of visible light 435-650 nm at 60 lp/mm at low temperature (-30° C.) according to Embodiment 1 of the present invention;

7 is a defocus curve diagram of visible light 435-650 nm at 60 lp/mm under high temperature (85° C.) according to Embodiment 1 of the present invention;

8 is a schematic structural diagram of Embodiment 2 of the present invention;

Fig. 9 is the MTF diagram of visible light 435-656nm according to the second embodiment of the present invention;

Fig. 10 is the MTF diagram of infrared light 850nm of the second embodiment of the present invention;

11 is a schematic diagram of a color difference curve in Embodiment 2 of the present invention;

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

13 is a defocus curve diagram of visible light 435-650nm at 60lp/mm at low temperature (-30°C) according to Embodiment 2 of the present invention;

14 is a defocus curve diagram of visible light 435-650nm at 60lp/mm under high temperature (85°C) according to the second embodiment of the present invention;

15 is a schematic structural diagram of Embodiment 3 of the present invention;

Fig. 16 is the MTF diagram of visible light 435-656nm according to the third embodiment of the present invention;

Fig. 17 is the MTF diagram of infrared light 850nm according to the third embodiment of the present invention;

18 is a schematic diagram of a color difference curve in Embodiment 3 of the present invention;

19 is a defocus curve diagram of visible light 435-656nm at 60lp/mm at room temperature (20°C) according to Embodiment 3 of the present invention;

20 is a defocus curve diagram of visible light 435-650nm at 60lp/mm at low temperature (-30°C) according to Embodiment 3 of the present invention;

21 is a defocus curve diagram of visible light 435-650nm at 60lp/mm under high temperature (85°C) in Example 3 of the present invention;

22 is a schematic structural diagram of Embodiment 4 of the present invention;

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

Fig. 24 is the MTF diagram of the infrared light 850nm of the fourth embodiment of the present invention;

FIG. 25 is a schematic diagram of a color difference curve according to Embodiment 4 of the present invention;

26 is a defocus curve diagram of visible light 435-656nm at 60lp/mm at room temperature (20°C) according to Embodiment 4 of the present invention;

Fig. 27 is the defocus curve of visible light 435-650nm at 60lp/mm at low temperature (-30°C) according to the fourth embodiment of the present invention; Fig. 28 is the visible light 435-650nm at high temperature (85°C) according to the fourth embodiment of the present invention. Defocus curve of 650nm at 60lp/mm;

Detailed ways

To further illustrate the various embodiments, the present invention is provided with the accompanying drawings. These drawings are a 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 description of the specification to explain the operation principles of the embodiments. With reference to these contents, one of ordinary skill in the art will understand other possible embodiments and advantages of the present invention. Components in the figures are not drawn to scale, and similar component symbols are often used to represent similar components.

The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

The "a lens has a positive refractive power (or a negative refractive power)" means that the paraxial refractive power of the lens calculated by the Gaussian optical theory is positive (or negative). The so-called "object side (or image side) of the lens" is defined as the specific range of the imaging light passing through the surface of the lens. The surface concavity and convexity of the lens can be judged according to the judgment method of ordinary knowledge in the field, that is, the convexity and concavity of the lens surface shape can be judged by the sign of the radius of curvature (abbreviated as R value). R-values are commonly used in optical design software such as Zemax or CodeV. R-values are also commonly found in lens data sheets of optical design software. For the side of the object, when the value of R is positive, it is determined that the side of the object is convex; when the value of R is negative, the side of the object 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.

The 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 the object side to the image side; The passing object side and an image side facing the image side and allowing the imaging light to pass through.

The first lens has a negative refractive index, the object side of the first lens is convex, and the image side of the first lens is concave.

The second lens has a positive refractive index, and the image side surface of the second lens is convex.

The third lens has a positive refractive index, the object side of the third lens is convex, and the image side of the third lens is convex.

The fourth lens has a negative refractive index, the object side of the fourth lens is concave, and the image side of the fourth lens is concave.

The fifth lens has a positive refractive index, the object side of the fifth lens is convex, and the image side of the fifth lens is convex.

The second lens, the fourth lens and the fifth lens are all plastic aspherical lenses, the first lens and the third lens are made of glass material, two glass lenses and three plastic lenses are used, and the first lens is a glass lens , The hardness is larger, which can protect the lens, which not only ensures high optical performance but also greatly controls the cost.

The optical imaging lens has only the first lens to the fifth lens mentioned above.

The invention adopts five lenses, which are mixed with glass and plastic, and through the corresponding design of each lens, it has high and low temperature without defocusing, and obtains high-definition image quality output; reduces the amount of field curvature at high and low temperature, and ensures the consistency of sharpness from the center to the edge ; Improve and avoid stray light; low chromatic aberration, good day and night confocal; miniaturization, low cost advantages.

Preferably, the optical imaging lens also satisfies: ∣f1/f∣<1.5, where f1 is the focal length of the first lens, and f is the focal length of the optical imaging lens, further controlling the back focus shift at high and low temperatures.

Preferably, the optical imaging lens also satisfies: 0.8<∣f3/f5∣<1.2, where f3 is the focal length of the third lens, and f5 is the focal length of the fifth lens, further controlling the back focus shift at high and low temperatures.

Preferably, the optical imaging lens also satisfies: ∣f4/f5∣<1, where f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens, further controlling the back focus shift at high and low temperatures.

Preferably, the optical imaging lens also satisfies: vd3>50, where vd3 is the dispersion coefficient of the third lens, which is further achromatic.

Preferably, the object side surface of the fourth lens is concave, and ∣R41∣<60mm, where R41 is the curvature radius of the object side surface of the fourth lens, which controls the reflection between the lenses and avoids serious ghost images.

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

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.

Preferably, it also includes an infrared cut filter for visible light mode and a white film for infrared light mode. The thickness of the infrared cut filter and the white film are not equal to compensate for the infrared back focus shift, so that Visible light and infrared at the same time to achieve high-definition picture quality.

More preferably, the thickness difference between the infrared cut filter and the white film is 0.09mm, which better compensates the infrared back focus shift, so that both visible light and infrared can achieve high-definition image quality.

The small high-definition optical imaging lens of the present invention will be described in detail below with specific embodiments.

Example 1

As shown in FIG. 1, a small high-definition optical imaging lens includes a first lens 1, a second lens 2, a diaphragm 6, a third lens 3, a first lens 1, a second lens 2, a diaphragm 6, a third lens 3, The four lenses 4, the fifth lens 5, the switching plate 7 and the imaging surface 8; the first lens 1 to the fifth lens 5 each include an object side facing the object side A1 and allowing the imaging light to pass through, and an object side facing the image side A2 and allowing the imaging light to pass through. The side of the image through which the imaging light passes.

The first lens 1 has a negative refractive index, the object side 11 of the first lens 1 is convex, and the image side 12 of the first lens 1 is concave.

The second lens 2 has a positive refractive index, the object side 21 of the second lens 2 is convex, and the image side 22 of the second lens 2 is convex. Of course, in other embodiments, the object side 21 of the second lens 2 can also be It is a plane or concave surface; both the object side 21 and the image side 22 of the second lens 2 are aspherical.

The third lens 3 has a positive refractive index, the object side 31 of the third lens 3 is convex, and the image side 32 of the third lens 3 is convex.

The fourth lens 4 has a negative refractive index, the object side 41 of the fourth lens 4 is concave, the image side 42 of the fourth lens 4 is concave, and both the object side 41 and the image side 42 of the fourth lens 4 are aspherical.

The fifth lens 5 has a positive refractive index, the object side 51 of the fifth lens 5 is convex, the image side 52 of the fifth lens 5 is convex, and both the object side 51 and the image side 52 of the fifth lens 5 are aspherical.

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.

In this specific embodiment, the diaphragm 6 is arranged between the second lens 2 and the third lens 3 to improve the overall performance. Of course, in other embodiments, the diaphragm 6 can also be arranged at other suitable positions.

In this specific embodiment, the switching sheet 7 includes an infrared cut-off filter for visible light mode and a white sheet for infrared light mode that are switched with each other, that is, during the day, the switching sheet 7 is switched to an infrared cut-off filter, At night, the switching film 7 is switched to a white film. The thickness of the infrared cut filter is 0.3 mm, the thickness of the white sheet is 0.21 mm, and the thickness difference between the infrared cut filter and the white sheet is 0.09 mm, but not limited thereto.

In this specific embodiment, the fourth lens 4 and the fifth lens 5 are directly supported on each other.

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

Table 1-1 Detailed optical data of Example 1

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

in:

z: the depth of the aspheric surface (the point on the aspheric surface that is y away from the optical axis, and the tangent plane tangent to the vertex on the optical axis of the aspheric surface, the vertical distance between the two);

c: the vertex curvature of the aspherical vertex;

K: Conic Constant;

径向距离(radial distance)；

radial distance;

r _n : normalization radius (NRADIUS);

u: r/r _n ;

a _m : the mth order Q ^con coefficient (is the m ^th Q ^con coefficient);

Q _m ^con : the m th order Q ^con polynomial (the m ^th Q ^con polynomial);

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

surface twenty one twenty two 41 42 51 52 K= 0 2.6E+00 0 -3.9E+00 2.4E+00 0 a₄= -2.98E-04 1.37E-03 -3.20E-02 -2.46E-02 -1.46E-02 4.60E-04 a₆= 2.85E-04 2.39E-04 1.63E-02 1.91E-02 7.80E-03 -5.59E-04 a₈= 5.59E-06 -3.16E-06 -7.36E-03 -7.15E-03 -1.31E-03 3.09E-04 a₁₀= 1.49E-05 1.46E-05 2.04E-03 1.84E-03 2.29E-04 -6.15E-05 a₁₂= 0 0 -3.04E-04 -2.90E-04 -5.96E-05 6.69E-06 a₁₄= 0 0 1.81E-05 1.89E-05 5.93E-06 0

The MTF curves of this specific embodiment are shown in Figures 2 and 3. It can be seen that under visible light and infrared light, high pixels are achieved, and the day and night confocality is good; the chromatic aberration diagram is shown in Figure 4, it can be seen that the chromatic aberration has been corrected. It is very good, and it is not easy to appear purple fringing; please refer to Figure 5-7 for the defocus curve. It can be seen that at different temperatures, the back focus shift is small, all within the range of 10μm, and it does not appear at high and low temperatures. Severe field curvature can ensure stable image quality output under high and low temperature in the use of the camera.

In this specific embodiment, the focal length of the optical imaging lens is f=2.9mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL= 16.4mm, ∣f1/f∣=1.06; ∣f3/f5∣=0.94, ∣f4/f5∣=0.82.

Embodiment 2

As shown in FIG. 8 , the surface concavo-convex and refractive index of each lens in this embodiment and the first embodiment are approximately the same, only the object side surface 21 of the second lens 2 is concave. In addition, the curvature radius of each lens surface and the lens thickness and other optical parameters are also different.

The detailed optical data of this specific example is shown in Table 2-1.

Table 2-1 Detailed optical data of Example 2

Please refer to the following table for the detailed data of the parameters of each aspheric surface in this specific embodiment:

surface twenty one twenty two 41 42 51 52 K= 0 -9.4E-01 0 -4.3E+00 5.5E+00 0 a₄= -5.78E-03 -1.32E-03 -2.60E-02 -1.51E-02 -1.14E-03 6.42E-03 a₆= -1.98E-04 -1.51E-04 1.64E-02 2.39E-02 1.27E-02 -2.14E-04 a₈= 1.60E-05 5.94E-05 -7.51E-03 -1.04E-02 -4.55E-03 7.50E-04 a₁₀= -2.94E-06 -5.50E-06 2.12E-03 1.96E-03 3.07E-04 -2.80E-04 a₁₂= 0 0 -3.07E-04 -8.01E-05 1.35E-04 3.78E-05 a₁₄= 0 0 1.41E-05 -1.49E-05 0 0

See Figures 9 and 10 for the MTF curves of this specific embodiment. It can be seen that under visible light and infrared light, high pixels are achieved, and day and night confocality is good; It is very good, and it is not easy to appear purple fringing; please refer to Figure 12-14 for the defocus curve. It can be seen that at different temperatures, the back focus shift is small, all within the range of 10μm, and it does not appear at high and low temperatures. Severe field curvature can ensure stable image quality output under high and low temperature in the use of the camera.

In this specific embodiment, the focal length of the optical imaging lens is f=2.98mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL= 16.1mm, ∣f1/f∣=1.31; ∣f3/f5∣=0.98, ∣f4/f5∣=0.71.

Embodiment 3

As shown in FIG. 15 , the surface concavo-convex and refractive index of each lens in this embodiment and the first embodiment are the same, and only the optical parameters such as the radius of curvature of the surface of each lens and the thickness of the lens are different.

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

Table 3-1 Detailed optical data of Example 3

Please refer to the following table for the detailed data of the parameters of each aspheric surface in this specific embodiment:

surface twenty one twenty two 41 42 51 52 K= 8.0E-02 -3.6E+00 -3.6E+00 a₄= -1.77E-04 3.17E-03 -3.02E-02 -2.31E-02 -1.18E-02 -1.23E-03 a₆= 5.70E-04 7.77E-04 1.49E-02 1.84E-02 7.53E-03 -1.59E-04 a₈= -3.79E-05 -1.33E-04 -7.02E-03 -7.14E-03 -1.43E-03 1.32E-04 a₁₀= 2.39E-05 6.41E-05 2.02E-03 1.83E-03 2.25E-04 -1.97E-05 a₁₂= 0 0 -3.21E-04 -2.94E-04 -5.53E-05 2.34E-06 a₁₄= 0 0.00E+00 2.11E-05 2.05E-05 6.01E-06 0

See Figures 16 and 17 for the MTF curves of this specific embodiment. It can be seen that under both visible light and infrared light, high pixels are achieved, and day and night confocality is good; It is very good, and it is not easy to appear purple fringing; please refer to Figure 19-21 for the defocus curve. It can be seen that at different temperatures, the back focus shift is small, all within the range of 10μm, and it does not appear at high and low temperatures. Severe field curvature can ensure stable image quality output under high and low temperature in the use of the camera.

In this specific embodiment, the focal length of the optical imaging lens is f=2.93mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL= 16.1mm, ∣f1/f∣=1.05; ∣f3/f5∣=0.89, ∣f4/f5∣=0.79.

Embodiment 4

As shown in FIG. 22 , the surface concavo-convex and refractive index of each lens in this embodiment and the first embodiment are approximately the same, only the object side surface 21 of the second lens 2 is concave. In addition, the curvature radius of each lens surface and the lens thickness and other optical parameters are also different.

In this specific embodiment, the fourth lens 4 and the fifth lens 5 are cemented with each other.

The detailed optical data of this specific example is shown in Table 4-1.

Table 4-1 Detailed optical data of Example 4

Please refer to the following table for the detailed data of the parameters of each aspheric surface in this specific embodiment:

surface twenty one twenty two 41 42 51 52 K= 7.8E+00 -3.3E+00 1.2E+01 -1.0E+00 -4.4E-01 7.8E+00 a₄= -5.40E-03 5.38E-04 -6.95E-03 -2.53E-02 -2.06E-03 -5.40E-03 a₆= 1.25E-03 1.31E-03 -1.01E-02 8.78E-03 -6.13E-04 1.25E-03 a₈= -3.39E-04 5.16E-04 8.93E-03 -4.89E-03 2.11E-04 -3.39E-04 a₁₀= 9.06E-05 -1.59E-04 -4.28E-03 2.32E-03 -6.49E-05 9.06E-05 a₁₂= 2.43E-06 5.15E-05 1.10E-03 -6.39E-04 1.23E-05 2.43E-06 a₁₄= -4.40E-06 -6.33E-06 -1.36E-04 9.06E-05 -1.38E-06 -4.40E-06 a₁₆= 0 0 5.80E-06 -5.18E-06 6.70E-08 0

See Figures 23 and 24 for the MTF curves of this specific embodiment. It can be seen that under both visible light and infrared light, high pixels are achieved, and day and night confocality is good; It is very good, and purple fringing is not easy to appear; please refer to Figure 26-28 for the defocus curve. It can be seen that at different temperatures, the back focus shift is small, all within the range of 10μm, and it does not appear at high and low temperatures. Severe field curvature can ensure stable image quality output under high and low temperature in the use of the camera.

In this specific embodiment, the focal length of the optical imaging lens is f=2.90mm; the aperture value FNO=2.3; the field of view angle FOV=140; the distance TTL= 16.1mm, ∣f1/f∣=1.12; ∣f3/f5∣=1.08, ∣f4/f5∣=0.96.

Although the present invention has been particularly shown and described in connection with preferred embodiments, it will be understood by those skilled in the art that changes in form and detail may be made to the present invention without departing from the spirit and scope of the invention as defined by the appended claims. Various changes are made within the protection scope of the present invention.

Claims (10)

1. The utility model provides an optical imaging lens of small-size high definition which characterized in that: the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a fourth lens, wherein the first lens, the second lens and the fifth lens are arranged in sequence from the object side to the image side along an optical axis; the first lens, the second lens, the third lens and the fourth lens are respectively arranged on the object side and the image side, and the object side faces towards the object side and enables the imaging light rays to pass through;

the first lens element with negative refractive index has a convex object-side surface and a concave image-side surface;

the second lens element with positive refractive index has a convex image-side surface;

the third lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the fourth lens element with negative refractive index has a concave object-side surface and a concave image-side surface;

the fifth lens element with positive refractive index has a convex object-side surface and a convex image-side surface;

the second lens, the fourth lens and the fifth lens are all plastic aspheric lenses, and the first lens and the third lens are all made of glass materials;

the optical imaging lens has only the first lens to the fifth lens with the refractive index.

2. The small high-definition optical imaging lens according to claim 1, further satisfies the following conditions: | f1/f | <1.5, wherein f1 is the focal length of the first lens element, and f is the focal length of the optical imaging lens.

3. The small high-definition optical imaging lens according to claim 1, further satisfies the following conditions: 0.8< | f3/f5 | <1.2, wherein f3 is the focal length of the third lens element, and f5 is the focal length of the fifth lens element.

4. The small high-definition optical imaging lens according to claim 1, further satisfies the following conditions: | f4/f5 | <1, wherein f4 is the focal length of the fourth lens element, and f5 is the focal length of the fifth lens element.

5. The small high-definition optical imaging lens according to claim 1, further satisfies the following conditions: vd3 > 50, where vd3 is the abbe number of the third lens.

6. The small high-definition optical imaging lens according to claim 1, characterized in that: the object-side surface of the fourth lens element is concave, and | R41 | < 60mm, wherein R41 is the radius of curvature of the object-side surface of the fourth lens element.

7. The small high-definition optical imaging lens according to claim 1, further satisfies the following conditions: vd5 is more than 50, vd4 is less than 30, wherein vd4 is the abbe number of the fourth lens, and vd5 is the abbe number of the fifth lens.

8. The small high-definition optical imaging lens according to claim 1, characterized in that: the fourth lens and the fifth lens bear directly or are mutually glued.

9. The small high-definition optical imaging lens according to claim 1, characterized in that: the infrared ray detector also comprises an infrared cut-off filter used in a visible light mode and a white sheet used in an infrared light mode, wherein the thicknesses of the infrared cut-off filter and the white sheet are unequal.

10. The small high-definition optical imaging lens according to claim 9, characterized in that: the difference in thickness between the infrared cut filter and the white piece was 0.09 mm.

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