CN114415334A - Optical imaging lens, photographic system and electronic device - Google Patents

Abstract

The invention relates to an optical imaging lens, a photographing system and an electronic device, wherein the optical imaging lens sequentially comprises from an object side to an image side: the optical imaging lens comprises a first lens, a diaphragm, a second lens, a third lens, a fourth lens and an optical filter, wherein the surfaces of the first lens, the second lens, the third lens and the fourth lens are provided with coatings, the coatings are infrared coatings or visible light antireflection coatings, and the optical imaging lens meets the following relational expression: f2>1, wherein f2 is the second lens focal length. The optical imaging lens adopts a four-piece structure, and the surface of each lens is provided with a coating of an infrared coating film or a visible light antireflection film, so that the optical imaging lens can select different coating films according to different application scenes of products, thereby being suitable for different application requirements, enabling the optical imaging lens to be used day and night without influencing the imaging effect, effectively improving the universality of the optical imaging lens, and enabling the shooting effect of the applied products to be more stable.

Description

Optical imaging lens, photographic system and electronic device

technical field

The present invention relates to the technical field of optical imaging lenses, in particular to an optical imaging lens, a photographing system and an electronic device.

Background technique

In recent years, with the rise of smart homes, general smart home appliances are equipped with cameras, through which a variety of intelligent functions can be realized, such as face recognition, gesture recognition, and portrait tracking. However, the existing traditional cameras can only meet the The shooting requirements required during the day, when the light is dark or at night, the traditional camera has poor shooting effect, and some smart home appliances also need to operate in an environment with poor lighting environment. Simply using traditional cameras will improve the intelligence of smart home appliances. The normal operation of the function has an impact, which affects the consumer experience.

Therefore, in order to make the shooting effect of the intelligent function of the smart home appliance more stable and adapt to the use requirements of different lighting environments, there is an urgent need for an optical imaging lens that can be used both day and night without affecting the imaging effect.

SUMMARY OF THE INVENTION

In order to solve at least one of the above technical problems, the present invention provides an optical imaging lens, a photographing system and an electronic device that can adapt to different lighting environments.

The invention discloses an optical imaging lens, which sequentially comprises:

The first lens with negative refractive power, the object side is convex at the near optical axis, and the image side is concave at the near optical axis;

The second lens with positive refractive power, the image side is convex at the near optical axis;

a third lens having a positive refractive power, the object side is convex at the near optical axis, and the image side is convex at the near optical axis; and

The fourth lens with positive refractive power, the object side is concave at the near optical axis, and the image side is convex at the near optical axis;

The surfaces of the first lens, the second lens, the third lens and the fourth lens are provided with a coating, and the coating is an infrared coating or a visible light antireflection coating;

The optical imaging lens satisfies the relation:

f2>1;

Wherein, f2 is the focal length of the second lens.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

2.5<CT3/T34<5;

Wherein, CT2 is the maximum thickness of the second lens on the optical axis, and T34 is the maximum distance between the third lens and the fourth lens on the optical axis.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

-2<f1/f≤0;

0<f3/f<3;

0<f3/f<2; and

0<f4/f<1.5;

Wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and f is the focal length of the imaging lens group.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

-1<R32/R31<-0.4;

Wherein, R31 is the curvature of the object side of the third lens, and R32 is the curvature of the image side of the third lens.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

0<CT1/TTL<0.2; and

0<CT2/TTL<0.3;

Among them, CT1 is the maximum thickness of the first lens on the optical axis, CT2 is the maximum thickness of the second lens on the optical axis, and TTL is the distance from the object side of the first lens to the image plane at the paraxial position.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

-3<(R41+R42)/(R41-R42)<-1;

Wherein, R41 is the curvature of the object side of the fourth lens, and R42 is the curvature of the image side of the fourth lens.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

0.1<(CT3+CT4)/TTL<1;

Among them, CT3 is the maximum thickness of the third lens on the optical axis, CT4 is the maximum thickness of the fourth lens on the optical axis, and TTL is the distance from the object side of the first lens to the imaging plane at the paraxial position.

According to an embodiment of the present invention, the optical imaging lens satisfies the following relationship:

130<FOV<140;

Among them, FOV is the field of view angle of the lens group.

The invention also discloses a camera system, comprising: the aforementioned optical imaging lens.

The invention also discloses an electronic device, comprising: the aforementioned optical imaging lens.

Compared with the prior art, the beneficial effects of the present invention are: the optical imaging lens of the present invention adopts a four-piece structure, and the overall length of the optical imaging system is short, which effectively adapts to the miniaturized design of the product. The imaging lens has better light-converging ability; the surface of each lens is coated with infrared coating or visible light antireflection coating, so that the optical imaging lens of the present invention can choose different coatings according to different application scenarios of the product to adapt to different application requirements, so that The optical imaging lens can be used both day and night without affecting the imaging effect, which effectively improves the versatility of the optical imaging lens of the present invention, and makes the shooting effect of the applied product more stable.

Description of drawings

FIG. 1 is a schematic structural diagram of an optical imaging lens in Embodiment 1. FIG.

FIG. 2 is a graph of astigmatism and distortion of the optical imaging lens in Example 1. FIG.

FIG. 3 is a spherical aberration curve diagram of the optical imaging lens in Example 1. FIG.

FIG. 4 is a schematic structural diagram of an optical imaging lens in Embodiment 2. FIG.

FIG. 5 is a graph of astigmatism and distortion of the optical imaging lens in Example 2. FIG.

FIG. 6 is a spherical aberration curve diagram of the optical imaging lens in Example 2. FIG.

FIG. 7 is a schematic structural diagram of an optical imaging lens in Embodiment 3. FIG.

FIG. 8 is a graph of astigmatism and distortion of the optical imaging lens in Example 3. FIG.

FIG. 9 is a spherical aberration curve diagram of the optical imaging lens in Example 3. FIG.

FIG. 10 is a schematic structural diagram of an optical imaging lens in Embodiment 4. FIG.

FIG. 11 is a graph of astigmatism and distortion of the optical imaging lens in Example 4. FIG.

FIG. 12 is a spherical aberration curve diagram of the optical imaging lens in Example 4. FIG.

FIG. 13 is a schematic structural diagram of the optical imaging lens in Embodiment 5. FIG.

FIG. 14 is a graph showing astigmatism and distortion of the optical imaging lens in Example 5. FIG.

FIG. 15 is a spherical aberration curve diagram of the optical imaging lens in Example 5. FIG.

Detailed ways

The present invention will be further described below in conjunction with the specific embodiments, wherein, the accompanying drawings are only used for exemplary description, and they are only schematic diagrams, not physical drawings, and should not be construed as restrictions on this patent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some components in the drawings may be omitted, enlarged or reduced, which do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The specific embodiments of the present invention, and all other specific embodiments obtained by those of ordinary skill in the art without creative work, fall within the protection scope of the present invention.

Please refer to Figure 1.

In the description of the present invention, the object side refers to the side of the lens facing the subject, the side of the lens facing the subject is the object side, the image side refers to the side of the lens facing the imaging surface, and the side of the lens facing the imaging surface One side surface is like the side surface.

The object side of the lens described in the present invention is a convex surface, which means that the object side of the lens is cut at any point on the surface, and the surface is always on the right side of the cut surface, and its curvature radius is positive; otherwise, the object side is concave, and its curvature radius is negative; The image side is convex, which means that the image side of the lens passes through any point on the surface to make a cut surface. The surface is always on the left side of the cut surface, and its curvature radius is negative. On the contrary, the image side is concave and its curvature radius is positive. If a section is made at any point on the surface, and the surface has both the left part of the section and the right part of the section, the surface has a curve inflection point, and the judgment of the concave-convex on the object side and the image side at the near optical axis is still applicable to the above.

In addition, the aspheric curve equation of each lens is expressed as follows:

Among them, Z is the distance vector height of the aspheric surface from the origin of the aspheric surface when the height is r along the optical axis direction, and c is the paraxial curvature of the aspheric surface (curvature radius R=1/c, which is the reciprocal of the curvature); k is the conic coefficient; Ai is the i-th order coefficient of the aspheric surface, and the high-order coefficients applied in the present invention are A4, A6, A8, A10, A12, A14, A16, A18, and A20.

Please refer to Figure 1.

The optical imaging lens of the present invention includes, from the object side to the image side, a first lens 1, a diaphragm 2, a second lens 3, a third lens 4, a fourth lens 5 and a filter 6, each lens having a direction of The object side on the object side and the image side on the image side, the optical imaging lens further includes an imaging surface 7 on the image side.

The first lens 1 has negative refractive power, the object side is convex at the near optical axis, and the image side is concave at the near optical axis; the second lens 3 has positive refractive power, and its object side is concave or concave at the near optical axis. Convex, the image side is convex at the near optical axis; the third lens 4 has positive refractive power, the object side is convex at the near optical axis, and the image side is convex at the near optical axis; the fourth lens 5 has positive refractive power , the object side is concave at the near optical axis, and the image side is convex at the near optical axis. For the above four lenses, there is a distance between any adjacent lenses, and the lenses are relatively fixed and cannot move.

In the above structure, the first lens 1 is configured with negative refractive power and the object side is convex at the near optical axis, which can effectively balance low-order aberrations; the second lens 3 has positive refractive power and the image side is convex at the near optical axis. , which is beneficial to eliminate the aberration generated by the first lens 1, and the third lens 4 has a positive refractive power and the image side is convex at the near optical axis, which helps to keep the principal point of the optical imaging system away from the image side end, thereby effectively The overall length of the optical imaging system is shortened, which is beneficial to the miniaturization of the product. The fourth lens 5 has a positive refractive power and the object side surface is convex at the near optical axis, which can effectively correct the paraxial spherical aberration and reduce the surrounding astigmatic field curvature. Thus, the overall imaging quality of the optical imaging system is improved. By utilizing the collocation of the refractive power between the above-mentioned lenses, when certain conditions are met, the entire optics have better light-converging ability.

The surface of each lens is coated with infrared coating or visible light antireflection coating, so that the optical imaging lens of the present invention can choose different coatings according to different application scenarios of the product to adapt to different application requirements, so that the optical imaging lens can be used both day and night without affecting the The imaging effect can effectively improve the versatility of the optical imaging lens of the present invention, so that the shooting effect of the applied product is more stable.

The optical imaging lens satisfies the relational formula: f2>1, where f2 is the focal length of the second lens, and by controlling the value of f2 to satisfy the above relational formula, the optical imaging lens can be effectively guaranteed to have a good imaging level, thereby effectively guaranteeing the The imaging quality of an optical imaging lens.

Further, the optical imaging lens satisfies the following relationship: 2.5<CT3/T34<5, wherein CT2 is the maximum thickness of the second lens 3 on the optical axis, and T34 is the third lens 4 and the fourth lens 5 on the optical axis By controlling the ratio of CT3/T34 to satisfy the above relationship, it can effectively ensure that the thickness and spacing of the third lens 4 and the fourth lens 5 are within a reasonable range, thereby effectively reducing the overall assembly difficulty of the optical imaging lens and improving the assembly efficiency. and assembly effects.

Further, the optical imaging lens satisfies the following relationship: -2<f1/f≤0, 0<f3/f<3, 0<f3/f<2, and 0<f4/f<1.5, where f1 is the first The focal length of a lens 1, f2 is the focal length of the second lens 3, f3 is the focal length of the third lens 4, f4 is the focal length of the fourth lens 5, and f is the focal length of the imaging lens group. , which can effectively prevent the optical power of the first lens 1, the second lens 3, the third lens 4, and the fourth lens 5 from being too large, thereby effectively reducing the low sensitivity of the optical imaging lens and improving the overall imaging quality of the optical imaging system, At the same time, the optical imaging lens has a shorter optical length, which is more suitable for the miniaturized design of the product.

Further, the optical imaging lens satisfies the following relationship: -1<R32/R31<-0.4, where R31 is the curvature of the object side of the third lens 4, R32 is the curvature of the image side of the third lens, and the ratio of R32/R31 is controlled to satisfy the above relationship formula, the imaging chromatic aberration of the third lens 4 is effectively reduced, thereby effectively preventing the imaging of the optical imaging lens from being purplish or reddish, and ensuring the imaging quality.

Further, the optical imaging lens satisfies the following relationship: 0<CT1/TTL<0.2, and 0<CT2/TTL<0.3, where CT1 is the maximum thickness of the first lens 1 on the optical axis, and CT2 is the second lens 3 The maximum thickness on the optical axis, TTL is the distance from the object side of the first lens to the image plane at the paraxial position, and the ratios of CT1/TTL and CT2/TTL are controlled to satisfy the above relationship, which can make the distance distribution between the lenses more Reasonable, thereby effectively reducing the total length of the optical imaging lens, and reducing the assembly difficulty of the optical imaging lens, thereby improving the production efficiency of the enterprise.

Further, the optical imaging lens satisfies the following relationship: -3<(R41+R42)/(R41-R42)<-1, where R41 is the curvature of the object side of the fourth lens, R42 is the curvature of the image side of the fourth lens, and control The ratio of (R41+R42)/(R41-R42) satisfies the above relational formula, which can effectively reduce the stray light generated by the fourth lens and further improve the imaging quality of the optical imaging lens of the present invention.

Further, the optical imaging lens satisfies the following relationship: 0.1<(CT3+CT4)/TTL<1, where CT3 is the maximum thickness of the third lens on the optical axis, and CT4 is the maximum thickness of the fourth lens on the optical axis , TTL is the distance from the object side of the first lens to the imaging plane at the paraxial position, and the ratio of (CT3+CT4)/TTL is controlled to satisfy the above relationship, and the distance between the third lens and the fourth lens is effectively and reasonably allocated, so that the Optical imaging lens has better optical imaging effect.

Still further, the optical imaging lens satisfies the following relational formula: 130<FOV<140, wherein FOV is the field angle of the lens group, and the numerical value of the controlled FOV satisfies the above relational formula, so that the optical imaging lens of the present invention has a good field of view, The wide-angle effect of the optical imaging lens of the present invention is greatly improved during imaging.

The invention also discloses a camera system, comprising: the aforementioned optical imaging lens, wherein the camera system can be applied to various electronic devices or processing equipment.

The invention also discloses an electronic device, comprising: the aforementioned optical imaging lens, the electronic device includes a digital camera, a tablet computer, a smart TV, a network monitoring device, a smart refrigerator, a smart range hood, a driving recorder, and a reversing developing device and wearable devices, etc. The above-mentioned electronic device is only an example to illustrate the practical application of the present invention, and does not limit the application scope of the optical imaging lens of the present application.

When the optical imaging lens of the present invention is imaging, light enters from the object side of the wide-angle imaging lens and passes through the first lens 1 , the diaphragm 2 , the second lens 3 , the third lens 4 , the fourth lens 5 and the filter 6 in sequence. The image is formed on the imaging plane 7 .

In this application, the object side surface and the image side surface of the first lens 1, the second lens 3, the third lens 4 and the fourth lens 5 are all aspherical structures. The overall structure of the invented optical imaging lens is lighter and thinner, and the image is clearer than the spherical structure.

The optical imaging lens of the present invention will be described in detail through the following specific embodiments in conjunction with the accompanying drawings.

Example 1

Please refer to FIGS. 1 to 3 , the optical imaging lens in Example 1 satisfies Table 1-1, Table 1-2 and Table 1-3.

Table 1-1 Basic parameters of the optical imaging lens of this embodiment:

Table 1-2 is the aspheric coefficient of each lens in this embodiment:

Table 1-3 is the value of each conditional expression in this embodiment:

Example 1

Please refer to FIGS. 1 to 3 , the optical imaging lens in Example 1 satisfies Table 1-1, Table 1-2 and Table 1-3.

Table 1-1 Basic parameters of the optical imaging lens of this embodiment:

Table 1-2 is the aspheric coefficient of each lens in this embodiment:

Table 1-3 is the value of each conditional expression in this embodiment:

Example 2

Referring to FIGS. 4 to 6 , the optical imaging lens in Example 2 satisfies Table 2-1, Table 2-2, and Table 2-3.

Table 2-1 Basic parameters of the optical imaging lens of this embodiment:

Table 2-2 Aspheric coefficients of each lens in this embodiment:

Table 2-3 is the value of each conditional expression in this embodiment:

Example 3

Referring to FIGS. 7 to 9 , the optical imaging lens in Example 3 satisfies Table 3-1, Table 3-2, and Table 3-3.

Table 3-1 Basic parameters of the optical imaging lens of this embodiment:

Table 3-2 Aspheric coefficients of each lens in this embodiment:

Table 3-3 is the value of each conditional expression in this embodiment:

Example 4

Please refer to FIGS. 10 to 12 , the optical imaging lens in Example 4 satisfies Table 4-1, Table 4-2 and Table 4-3.

Table 4-1 Basic parameters of the optical imaging lens of this embodiment:

Table 4-2 Aspheric coefficients of each lens in this embodiment:

Table 4-3 is the value of each conditional expression in this embodiment:

Example 5

Please refer to FIGS. 13 to 15 , the optical imaging lens in Example 5 satisfies Table 5-1, Table 5-2 and Table 5-3.

Table 5-1 Basic parameters of the optical imaging lens of this embodiment:

Table 5-2 is the aspheric coefficient of each lens in this embodiment:

Table 5-3 is the value of each conditional expression in this embodiment:

For the convenience of comparing the above-mentioned five embodiments, the following table is a summary of the obtained values of each expression under the corresponding conditions of each embodiment:

To sum up, the optical imaging lens of the present invention adopts a four-piece structure, and the overall length of the optical imaging system is short, which effectively adapts to the miniaturized design of the product. ; The surface of each lens is coated with infrared coating or visible light anti-reflection coating, so that the optical imaging lens of the present invention can choose different coatings according to different application scenarios of the product to adapt to different application requirements, so that the optical imaging lens can be used both day and night without affecting the The imaging effect can effectively improve the versatility of the optical imaging lens of the present invention, so that the shooting effect of the applied product is more stable.

In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top" , "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

Although the present invention is described in conjunction with the above specific embodiments, it will be apparent to those skilled in the art that many substitutions, modifications and changes can be made based on the above. Accordingly, all such substitutions, modifications and variations are intended to be included within the spirit and scope of the present invention.

Claims (10)

1. An optical imaging lens, comprising, in order from an object side to an image side:

a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;

a second lens element with positive refractive power having an image-side surface convex at paraxial region;

a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface; and

a fourth lens element with positive refractive power having a concave object-side surface and a convex image-side surface;

the surfaces of the first lens, the second lens, the third lens and the fourth lens are provided with coatings, and the coatings are infrared coating films or visible light antireflection films;

the optical imaging lens satisfies the relation:

f2>1；

where f2 is the second lens focal length.

2. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: 2.5< CT3/T34< 5;

wherein CT2 is the maximum thickness of the second lens on the optical axis, and T34 is the maximum distance between the third lens and the fourth lens on the optical axis.

3. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: -2< f1/f ≦ 0;

0<f3/f<3；

0< f3/f < 2; and

0<f4/f<1.5；

wherein f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, and f is the focal length of the imaging lens group.

4. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: -1< R32/R31< -0.4;

wherein R31 is the third lens object side curvature and R32 is the fifth lens image side curvature.

5. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: 0< CT1/TTL < 0.2; and

0<CT2/TTL<0.3；

wherein, CT1 is the maximum thickness of the first lens on the optical axis, CT2 is the maximum thickness of the second lens on the optical axis, and TTL is the distance from the object-side surface of the first lens to the image plane at the paraxial position.

6. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: -3< (R41+ R42)/(R41-R42) < -1;

wherein R41 is the fourth lens object side curvature and R42 is the fourth lens image side curvature.

7. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: 0.1< (CT3+ CT4)/TTL < 1;

wherein CT3 is the maximum thickness of the third lens element on the optical axis, CT4 is the maximum thickness of the fourth lens element on the optical axis, and TTL is the distance from the object-side surface of the first lens element to the image plane at the paraxial region.

8. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following relationship: 130< FOV < 140;

wherein, the FOV is the angle of field of the lens group.

9. An image pickup system, comprising: the optical imaging lens of any one of claims 1 to 8.

10. An electronic device, comprising: the optical imaging lens of any one of claims 1 to 8.

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