CN105301740B - Optical imaging lens and electronic device using same - Google Patents

Abstract

The present invention provides an optical imaging lens and an electronic device using the optical imaging lens, comprising a first lens, an aperture and a second lens which are sequentially arranged from an object side to an image side along the same optical axis; the first lens has a positive focal length, and its object side surface is a convex surface; the second lens has a negative focal length, and its image side surface is a convex surface; the optical imaging lens satisfies the following relationship: 0.91<f/TTL<1.3;‑3.2<f1*f2/f<‑1.5;|d3‑d2|<0.2, so that the volume of the optical imaging lens can be reduced and the imaging clarity of the optical imaging lens can be improved by reasonably setting the parameters of the lenses, the positional relationship between the lenses, and the positional relationship between the lenses and the aperture.

Description

Optical imaging lens and electronic equipment using the optical imaging lens

technical field

The invention relates to the technical field of optical lenses, and more specifically, to an optical imaging lens and electronic equipment using the optical imaging lens.

Background technique

Iris recognition technology is a technology based on the iris in the eye for identification. Since the iris of each eye is unique like a fingerprint, iris recognition technology can be applied to places and equipment with strict confidentiality requirements.

The existing iris recognition system first collects the eye image of the person to be verified through a digital camera, then segments and extracts the iris image, then extracts and encodes the features of the iris image, and finally compares the code with the iris code stored in the database , if the two are consistent, the verification is passed, and the person to be verified can enter the site or log in to the device, otherwise, the person to be verified is not allowed to enter the site or log in to the device.

With the continuous advancement of technology, iris recognition systems are gradually applied to small, light, and portable devices such as mobile phones, tablets, and notebooks. Therefore, when designing optical lenses for capturing eye images, it is usually necessary to control the optical imaging lens as much as possible to reduce the overall size of the device.

Moreover, while keeping the size of the device compact, it is also necessary to ensure the spherical aberration of the imaging system to obtain iris images with clear details. Therefore, how to reasonably design the structure of the optical imaging lens and the parameters of the inner lens of the optical imaging lens to meet the needs of the equipment The miniaturization requirements and high-definition imaging have become one of the technical problems to be solved urgently by those skilled in the art.

Contents of the invention

In view of this, the present invention provides an optical imaging lens and electronic equipment using the optical imaging lens to solve the problems of low definition and large volume of the optical imaging lens in the prior art.

To achieve the above object, the present invention provides the following technical solutions:

An optical imaging lens, comprising a first lens, a diaphragm, and a second lens arranged sequentially along the same optical axis from the object side to the image side;

The first lens has positive refractive power, and its object side is convex;

The second lens has negative refractive power, and its image side is convex;

The optical imaging lens satisfies the following relationship:

0.91<f/TTL<1.3; -3.2<f1*f2/f<-1.5; |d3-d2|<0.2;

Wherein, TTL is the total length of the optical imaging lens, f is the effective focal length of the optical imaging lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and d2 is the focal length of the first lens The distance from the vertex of the mirror side surface to the center point of the diaphragm, d3 is the distance from the center point of the diaphragm to the vertex of the object-side surface of the second lens.

Preferably, the optical imaging lens also satisfies the relationship: -0.41<c12*c21/c11<-0.15;

Wherein, c11 is the curvature of the object-side surface of the first lens, c12 is the curvature of the image-side surface of the first lens, and c21 is the curvature of the object-side surface of the second lens.

Preferably, the optical imaging lens also satisfies the relational formula: 1.83<(Nd1+Nd2)/Nd2<2.03;

Wherein, Nd1 is the refractive index of the material of the first lens, and Nd2 is the refractive index of the material of the second lens.

Preferably, the optical imaging lens also satisfies the relationship: 0.8<(d1+d4)/(d2+d3)<2.1;

Wherein, d1 is the thickness of the first lens on the optical axis, and d4 is the thickness of the second lens on the optical axis.

Preferably, the optical imaging lens also satisfies the relational formula: Fno<2.5;

Wherein, Fno is the aperture value of the optical imaging lens.

Preferably, the optical imaging lens also satisfies the relationship: 26°<FOV<36°;

Wherein, FOV is the field angle of the optical imaging lens.

Preferably, the optical imaging lens also satisfies the relational expression: TTL<3.85mm.

Preferably, the optical imaging lens further includes a filter located on the image side of the second lens.

An electronic device includes an optical imaging lens and an image sensing chip, the optical imaging lens is the optical imaging lens described in any one of the above items, and the imaging surface of the image sensing chip is located on the image side of the optical imaging lens.

Compared with the prior art, the technical solution provided by the present invention has the following advantages:

The optical imaging lens provided by the present invention and the electronic equipment using the optical imaging lens include a first lens, a diaphragm and a second lens arranged in sequence along the same optical axis from the object side to the image side, and the optical imaging lens satisfies Relational formula: 0.91<f/TTL<1.3, -3.2<f1*f2/f<-1.5, |d3-d2|<0.2, so that the parameters of the lens, the positional relationship between the lenses and the relationship between the lens and the The positional relationship between the apertures is used to reduce the volume of the optical imaging lens, improve the imaging clarity of the optical imaging lens, and ensure that iris images with clear details can be obtained.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

FIG. 1 is a schematic structural view of an optical imaging lens disclosed in an embodiment of the present invention;

2 is a schematic structural diagram of an optical imaging lens disclosed in Embodiment 1 of the present invention;

FIG. 3 is a graph of field curvature and distortion curves of an optical imaging lens disclosed in Embodiment 1 of the present invention;

FIG. 4 is a graph of spherical aberration of the optical imaging lens disclosed in Embodiment 1 of the present invention;

5 is a schematic structural diagram of an optical imaging lens disclosed in Embodiment 2 of the present invention;

6 is a graph of field curvature and distortion curves of the optical imaging lens disclosed in Embodiment 2 of the present invention;

FIG. 7 is a graph of spherical aberration of the optical imaging lens disclosed in Embodiment 2 of the present invention;

FIG. 8 is a schematic structural diagram of an optical imaging lens disclosed in Embodiment 3 of the present invention;

9 is a graph of field curvature and distortion curves of the optical imaging lens disclosed in Embodiment 3 of the present invention;

FIG. 10 is a graph of spherical aberration of the optical imaging lens disclosed in Embodiment 3 of the present invention;

FIG. 11 is a schematic structural diagram of an optical imaging lens disclosed in Embodiment 4 of the present invention;

FIG. 12 is a graph of field curvature and distortion curves of the optical imaging lens disclosed in Embodiment 4 of the present invention;

FIG. 13 is a graph of spherical aberration of the optical imaging lens disclosed in Embodiment 4 of the present invention;

14 is a schematic structural diagram of an optical imaging lens disclosed in Embodiment 5 of the present invention;

FIG. 15 is a graph of field curvature and distortion curves of the optical imaging lens disclosed in Embodiment 5 of the present invention;

FIG. 16 is a graph of spherical aberration of the optical imaging lens disclosed in Embodiment 5 of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

An embodiment of the present application discloses an optical imaging lens. Preferably, the optical imaging lens is applied to an iris recognition camera module.

Referring to Fig. 1, Fig. 1 is a structural schematic view of the optical imaging lens provided by this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, and a second lens 30 arranged in sequence along the same optical axis from the object side to the image side And the optical filter 40, of course, also has an imaging surface 50 on the image side of the optical filter 40, and the imaging surface 50 is the imaging surface of the image sensing chip, which is used to convert the optical signal into an electrical signal, and then form and be photographed The image corresponding to the object.

Specifically, the first lens 10 has positive refractive power, and its object side is convex; the second lens 30 has negative refractive power, and its image side is convex; the diaphragm 20 is an aperture diaphragm, and the diaphragm 20 is located in the first lens 10 and the second lens 30. It should be further noted that the material of the first lens 10 and the second lens 30 in this embodiment is plastic, which can realize the mass production of the lenses, thereby greatly reducing the processing cost of optical elements such as lenses and the cost of optical imaging lenses. , which is more convenient for large-scale promotion of optical imaging lenses.

In this embodiment, the optical imaging lens satisfies the following relationship:

0.91<f/TTL<1.3; -3.2<f1*f2/f<-1.5;

|d3-d2|<0.2; 0.8<(d1+d4)/(d2+d3)<2.1;

Wherein, TTL is the total length of the optical imaging lens, f is the effective focal length of the optical imaging lens, f1 is the focal length of the first lens 10, f2 is the focal length of the second lens 30, and d1 is the focal length of the second lens 30. The thickness of a lens 10 on the optical axis, d2 is the distance from the apex of the image side surface of the first lens 10 to the center point of the diaphragm 20, and d3 is the distance from the center point of the diaphragm 20 to the object side surface of the second lens 30 The distance between the vertices, d4 is the thickness of the second lens 30 on the optical axis.

In order to further improve the performance of the optical imaging lens, the optical imaging lens also needs to satisfy the following relationship:

-0.41<c12*c21/c11<-0.15; 1.83<(Nd1+Nd2)/Nd2<2.03;

Wherein, c11 is the curvature of the object-side surface of the first lens 10, c12 is the curvature of the image-side surface of the first lens 10, c21 is the curvature of the object-side surface of the second lens 30, and Nd1 is the first The refractive index of the material of the lens 10 , Nd2 is the refractive index of the material of the second lens 30 .

Based on this, this embodiment can reasonably set the parameters of the first lens 10 and the second lens 30 , the positional relationship between the first lens 10 and the second lens 30 and the relationship between the first lens 10 and the second lens 30 and the diaphragm 20 The positional relationship between them realizes an optical imaging lens with high imaging definition, small volume and small field of view.

It should be further noted that in this embodiment, the use of structural components of the optical imaging lens can be reduced by reasonably setting the outer diameters of the two lenses and the gap between the lens and the diaphragm, making the assembly of the optical imaging lens simpler and more cost-effective. lower.

Optionally, the total length TTL of the optical imaging lens in this embodiment satisfies the relational expression: TTL<3.85 mm. And in some cases, the minimum total length of the optical imaging lens can reach 3.55mm, that is, 3.55mm<TTL<3.85mm, which makes the optical imaging lens smaller in size and better suitable for mobile phones, tablet computers, Portable electronic devices such as laptop computers.

In this embodiment, the curvature of the convex surface of the first lens 10 and the second lens 30 can affect the field of view angle of the optical imaging lens, based on this, in the case of setting the curvature of the first lens 10 and the second lens 30 reasonably, The field of view FOV of the optical imaging lens in this embodiment satisfies the relational expression: 26°<FOV<36°. Due to the small field of view of the optical imaging lens, it can meet the technical feature requirements of the single-eye or double-eye iris recognition pixel acquisition algorithm, and can also meet the working distance of portable electronic devices, bringing a more comfortable experience to users.

Moreover, in this embodiment, a large aperture can be set to ensure that enough light in the near-infrared band enters the optical imaging lens. Optionally, the optical imaging lens in this embodiment also satisfies the relational expression: Fno<2.5; wherein, Fno is the aperture value of the optical imaging lens.

In addition, in this embodiment, the light entering the optical imaging lens can be filtered through the optical filter and the anti-reflection and anti-reflection film coated on the surface of the lens, so that the working wavelength of the optical imaging lens can be in any small band between 400nm and 910nm. Optionally, the working wavelength range of the optical imaging lens is 810nm±70nm, which enables the optical imaging lens to better match the special sensor for iris recognition, making the iris image collected by the optical imaging lens clearer and more accurate.

In this embodiment, at least one of the object side and the image side of the first lens 10 is an aspheric surface. Optionally, both the object side and the image side are aspherical; is an aspheric surface, and optionally, its object side and image side are both aspherical. In order to further ensure the imaging quality of the optical imaging lens, any aspheric surface of the first lens 10 and the second lens 30 in any of the above embodiments of the present application satisfies the following relationship:

Wherein, z represents the Z coordinate value of each point on the lens surface, r represents the Y-axis coordinate value of each point on the lens surface, c is the reciprocal of the curvature radius R of the lens surface, k is the cone coefficient, α ₁ , α ₂ , α ₃ , α ₄ , α ₅ , α ₆ , α ₇ , and α ₈ are even-order aspheric coefficients.

In the description of each preferred implementation mode below, this embodiment further discloses the specific parameters of the lens aspheric surface of the optical imaging lens and other parameters.

Implementation Mode 1

In this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, a second lens 30, a filter 40, and an imaging surface 50 arranged sequentially along the same optical axis from the object side to the image side. The structural diagram of the lens is shown in Figure 2, the field curvature and distortion curves are shown in Figure 3, and the spherical aberration curve is shown in Figure 4.

The specific parameters of the first lens 10 , the second lens 30 and the filter 40 refer to Table 1-1, and the specific parameters of the aspheric surfaces of the first lens 10 and the second lens 30 are shown in Table 1-2. Wherein, surface 0 represents the subject, surface 1 represents the object-side surface of the first lens 10, surface 2 represents the image-side surface of the first lens 10, surface 3 represents the diaphragm 20, and surface 4 represents the object-side surface of the second lens 30. , surface 5 represents the image-side surface of the second lens 30 , surface 6 represents the object-side surface of the optical filter 40 , surface 7 represents the image-side surface of the optical filter 40 , and surface 8 represents the imaging surface 50 .

Table 1-1

Table 1-2

Specifically, f/TTL=1.065 in this embodiment satisfies the relational expression of 0.91<f/TTL<1.3;

f1*f2/f=-3.19, satisfying the relationship of -3.2<f1*f2/f<-1.5;

|d3-d2|=0.098, satisfying the relational expression of |d3-d2|<0.2;

(d1+d4)/(d2+d3)=1.144, satisfying the relational expression of 0.8<(d1+d4)/(d2+d3)<2.1;

c12*c21/c11=-0.193, satisfying the relationship of -0.41<c12*c21/c11<-0.15;

(Nd1+Nd2)/Nd2=2.012, satisfying the relational expression of 1.83<(Nd1+Nd2)/Nd2<2.03.

Further, in this embodiment, the effective focal length f of the optical imaging lens is 3.92 mm, the aperture value Fno is 2.0, and the field of view FOV is 35.1°.

Implementation mode two

In this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, a second lens 30, a filter 40, and an imaging surface 50 arranged sequentially along the same optical axis from the object side to the image side. The structural diagram of the lens is shown in Figure 5, the field curvature and distortion curves are shown in Figure 6, and the spherical aberration curve is shown in Figure 7.

The specific parameters of the first lens 10 , the second lens 30 and the filter 40 refer to Table 2-1, and the specific parameters of the aspheric surfaces of the first lens 10 and the second lens 30 are shown in Table 2-2. Wherein, surface 0 represents the subject, surface 1 represents the object-side surface of the first lens 10, surface 2 represents the image-side surface of the first lens 10, surface 3 represents the diaphragm 20, and surface 4 represents the object-side surface of the second lens 30. , surface 5 represents the image-side surface of the second lens 30 , surface 6 represents the object-side surface of the optical filter 40 , surface 7 represents the image-side surface of the optical filter 40 , and surface 8 represents the imaging surface 50 .

table 2-1

Table 2-2

Specifically, f/TTL=1.115 in this embodiment satisfies the relational expression of 0.91<f/TTL<1.3;

f1*f2/f=-2.555, satisfying the relational expression of -3.2<f1*f2/f<-1.5;

|d3-d2|=0.07, satisfying the relation of |d3-d2|<0.2;

(d1+d4)/(d2+d3)=1.156, satisfying the relational formula of 0.8<(d1+d4)/(d2+d3)<2.1;

c12*c21/c11=-0.247, satisfying the relationship of -0.41<c12*c21/c11<-0.15;

(Nd1+Nd2)/Nd2=2.0, satisfying the relational expression of 1.83<(Nd1+Nd2)/Nd2<2.03.

Further, in this embodiment, the effective focal length f of the optical imaging lens is 3.93 mm, the aperture value Fno is 2.35, and the field of view FOV is 35.4°.

Implementation Mode Three

In this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, a second lens 30, a filter 40, and an imaging surface 50 arranged sequentially along the same optical axis from the object side to the image side. The structural diagram of the lens is shown in Figure 8, the field curvature and distortion curves are shown in Figure 9, and the spherical aberration curve is shown in Figure 10.

The specific parameters of the first lens 10 , the second lens 30 and the filter 40 refer to Table 3-1, and the specific parameters of the aspheric surfaces of the first lens 10 and the second lens 30 are shown in Table 3-2. Wherein, surface 0 represents the subject, surface 1 represents the object-side surface of the first lens 10, surface 2 represents the image-side surface of the first lens 10, surface 3 represents the diaphragm 20, and surface 4 represents the object-side surface of the second lens 30. , surface 5 represents the image-side surface of the second lens 30 , surface 6 represents the object-side surface of the optical filter 40 , surface 7 represents the image-side surface of the optical filter 40 , and surface 8 represents the imaging surface 50 .

Table 3-1

Table 3-2

Specifically, f/TTL=1.14 in this embodiment satisfies the relational expression of 0.91<f/TTL<1.3;

f1*f2/f=-2.559, satisfying the relationship of -3.2<f1*f2/f<-1.5;

|d3-d2|=0.127, satisfying the relational expression of |d3-d2|<0.2;

(d1+d4)/(d2+d3)=1.053, satisfying the relational formula of 0.8<(d1+d4)/(d2+d3)<2.1;

c12*c21/c11=-0.216, satisfying the relationship of -0.41<c12*c21/c11<-0.15;

(Nd1+Nd2)/Nd2=1.974, satisfying the relational expression of 1.83<(Nd1+Nd2)/Nd2<2.03.

Further, in this embodiment, the effective focal length f of the optical imaging lens is 4.27 mm, the aperture value Fno is 2.11, and the field of view FOV is 33.2°.

Implementation Mode Four

In this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, a second lens 30, a filter 40, and an imaging surface 50 arranged sequentially along the same optical axis from the object side to the image side. The structural diagram of the lens is shown in Figure 11, the field curvature and distortion curves are shown in Figure 12, and the spherical aberration curve is shown in Figure 13.

The specific parameters of the first lens 10 , the second lens 30 and the filter 40 refer to Table 4-1, and the specific parameters of the aspheric surfaces of the first lens 10 and the second lens 30 are shown in Table 4-2. Wherein, surface 0 represents the subject, surface 1 represents the object-side surface of the first lens 10, surface 2 represents the image-side surface of the first lens 10, surface 3 represents the diaphragm 20, and surface 4 represents the object-side surface of the second lens 30. , surface 5 represents the image-side surface of the second lens 30 , surface 6 represents the object-side surface of the optical filter 40 , surface 7 represents the image-side surface of the optical filter 40 , and surface 8 represents the imaging surface 50 .

Table 4-1

Table 4-2

Specifically, f/TTL=1.190 in this embodiment satisfies the relational expression of 0.91<f/TTL<1.3;

f1*f2/f=-1.83, satisfying the relationship of -3.2<f1*f2/f<-1.5;

|d3-d2|=0.239, satisfying the relational expression of |d3-d2|<0.2;

(d1+d4)/(d2+d3)=1.053, satisfying the relational formula of 0.8<(d1+d4)/(d2+d3)<2.1;

c12*c21/c11=-0.221, satisfying the relationship of -0.41<c12*c21/c11<-0.15;

(Nd1+Nd2)/Nd2=1.982, satisfying the relational expression of 1.83<(Nd1+Nd2)/Nd2<2.03.

Further, in this embodiment, the effective focal length f of the optical imaging lens is 4.46 mm, the aperture value Fno is 1.96, and the field of view FOV is 31.7°.

Implementation Mode Five

In this embodiment, the optical imaging lens includes a first lens 10, a diaphragm 20, a second lens 30, a filter 40, and an imaging surface 50 arranged sequentially along the same optical axis from the object side to the image side. The structure diagram of the lens is shown in Figure 14, the field curvature and distortion curve is shown in Figure 15, and the spherical aberration curve is shown in Figure 16.

The specific parameters of the first lens 10 , the second lens 30 and the filter 40 refer to Table 5-1, and the specific parameters of the aspheric surfaces of the first lens 10 and the second lens 30 are shown in Table 5-2. Wherein, surface 0 represents the subject, surface 1 represents the object-side surface of the first lens 10, surface 2 represents the image-side surface of the first lens 10, surface 3 represents the diaphragm 20, and surface 4 represents the object-side surface of the second lens 30. , surface 5 represents the image-side surface of the second lens 30 , surface 6 represents the object-side surface of the optical filter 40 , surface 7 represents the image-side surface of the optical filter 40 , and surface 8 represents the imaging surface 50 .

Table 5-1

Table 5-2

Specifically, f/TTL=1.064 in this embodiment satisfies the relational expression of 0.91<f/TTL<1.3;

f1*f2/f=-2.611, satisfying the relational expression of -3.2<f1*f2/f<-1.5;

|d3-d2|=0.031, satisfying the relational expression of |d3-d2|<0.2;

(d1+d4)/(d2+d3)=1.12, satisfying the relational formula of 0.8<(d1+d4)/(d2+d3)<2.1;

c12*c21/c11=-0.234, satisfying the relationship of -0.41<c12*c21/c11<-0.15;

(Nd1+Nd2)/Nd2=2.018, satisfying the relational expression of 1.83<(Nd1+Nd2)/Nd2<2.03.

Further, in this embodiment, the effective focal length f of the optical imaging lens is 3.81 mm, the aperture value Fno is 2.2, and the field of view FOV is 36°.

The distortion, curvature of field and spherical aberration of the optical imaging lens disclosed in the above embodiments of the present application are all small, and the distortion of the imaging picture is small, the definition is high, and the layering is rich, so the imaging quality can be significantly improved.

It can be understood that, for the optical imaging lens disclosed in the above-mentioned embodiments of the present application, this application also uses a specific application of the optical imaging lens. Specifically, this application also discloses an application of the optical imaging lens An electronic device, the electronic device may include the optical imaging lens disclosed in any one of the above embodiments of the present application. Wherein, the electronic device may specifically be a mobile phone, a tablet, a notebook computer, a camera, a camcorder, a video monitor, and other electronic product devices that support identity authentication technology.

Finally, it should also be noted that in this text, relational terms such as first and second etc. are only used to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. An optical imaging lens, characterized in that it comprises a first lens, a diaphragm and a second lens which are arranged successively along the same optical axis from the object side to the image side; The first lens has positive refractive power, and its object side is convex; The second lens has negative refractive power, and its image side is convex; The optical imaging lens satisfies the following relationship: 0.91<f/TTL<1.3; -3.2mm<f1*f2/f<-1.5mm; |d3-d2|<0.2mm; 0.8<(d1+d4)/(d2+d3)<2.1; Wherein, TTL is the total length of the optical imaging lens, f is the effective focal length of the optical imaging lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and d2 is the focal length of the first lens The distance from the apex of the mirror image side surface to the central point of the diaphragm, d3 is the distance from the central point of the diaphragm to the apex of the object side surface of the second lens, d1 is the thickness of the first lens on the optical axis, and d4 is the thickness of the first lens on the optical axis. The thickness of the second lens on the optical axis. 2. The optical imaging lens according to claim 1, wherein the optical imaging lens also satisfies the relational expression: -0.41mm ^-1 <c12*c21/c11<-0.15mm ^-1 ; Wherein, c11 is the curvature of the object-side surface of the first lens, c12 is the curvature of the image-side surface of the first lens, and c21 is the curvature of the object-side surface of the second lens. 3. The optical imaging lens according to claim 2, wherein the optical imaging lens also satisfies the relational expression: 1.83<(Nd1+Nd2)/Nd2<2.03; Wherein, Nd1 is the refractive index of the material of the first lens, and Nd2 is the refractive index of the material of the second lens. 4. The optical imaging lens according to any one of claims 1 to 3, wherein the optical imaging lens also satisfies the relational expression: Fno<2.5; Wherein, Fno is the aperture value of the optical imaging lens. 5. The optical imaging lens according to claim 4, wherein the optical imaging lens also satisfies the relational expression: 26°<FOV<36°; Wherein, FOV is the field angle of the optical imaging lens. 6 . The optical imaging lens according to claim 5 , wherein the optical imaging lens further satisfies the relational expression: TTL<3.85mm. 7. The optical imaging lens according to claim 1, further comprising a filter located on the image side of the second lens. 8. An electronic device, characterized in that it comprises an optical imaging lens and an image sensor chip, the optical imaging lens is the optical imaging lens according to any one of claims 1 to 7, and the imaging surface of the image sensor chip is located at The image side of the optical imaging lens.