CN114185150A

CN114185150A - Optical imaging lens

Info

Publication number: CN114185150A
Application number: CN202010965874.6A
Authority: CN
Inventors: 杨益菱; 徐淑娟
Original assignee: Calin Technology Co Ltd
Current assignee: Calin Technology Co Ltd
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2022-03-15

Abstract

An optical imaging lens includes, in order from an object side to an image side along an optical axis: a first lens element with negative refractive power; a second lens element; a third lens element bonded to the second lens element to form a first compound lens element with negative refractive power; a fourth lens element with positive refractive power; a fifth lens element; a sixth lens element cemented with the fifth lens element to form a second compound lens element with positive refractive power; a seventh lens element with positive refractive power. The optical imaging system has the advantages of high imaging quality and low distortion.

Description

Optical imaging lens

Technical Field

The invention relates to the field of application of optical imaging systems; in particular to an optical imaging lens with low distortion and good imaging quality.

Background

In recent years, with the rise of portable electronic products with a photographing function, the demand of an optical system is increasing. The photosensitive elements of a typical optical system are not limited to a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Sensor, and with the refinement of Semiconductor process technology, the pixel size of the photosensitive elements is reduced, and the optical system is gradually developed in the high pixel field. In addition, with the rapid development of unmanned aerial vehicles and unmanned vehicles, Advanced Driver Assistance Systems (ADAS) play an important role, and collect environmental information through various lenses and sensors to ensure the driving safety of drivers. In addition, as the temperature of the external application environment changes, the requirement of the quality of the lens for the vehicle for the temperature is also increased, and thus, the requirement for the imaging quality is also increased.

Good imaging lenses generally have the advantages of low distortion (aberration), high resolution (resolution), and the like. In addition, in practical applications, the problems of small size and cost must be considered, so designing a lens with good imaging quality under various limiting conditions is a big problem for designers.

Disclosure of Invention

Accordingly, the present invention is directed to an optical imaging lens having the advantages of good imaging quality and low distortion.

To achieve the above object, the present invention provides an optical imaging lens, in order from an object side to an image side along an optical axis, comprising: a first lens element with negative refractive power; a second lens element; a third lens element bonded to the second lens element to form a first compound lens element with negative refractive power; a fourth lens element with positive refractive power; a fifth lens element; a sixth lens element cemented with the fifth lens element to form a second compound lens element with positive refractive power; a seventh lens element with positive refractive power.

Another objective of the present invention is to provide an optical imaging lens, in order from an object side to an image side along an optical axis, comprising: a first lens; a second lens element; a third lens element; a fourth lens element; a fifth lens element; a sixth lens element; a seventh lens element; wherein the optical imaging lens satisfies the following conditions: -60 ≤ f23/f ≤ 10, 4.5 ≤ f56/f ≤ 7.5, 2.5 ≤ (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f ≤ 13.5, wherein f is the focal length of the optical imaging lens, f23 is the focal length of the first compound lens, f56 is the focal length of the second compound lens, 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

The present invention provides an optical imaging lens with good imaging quality and low distortion.

Drawings

Fig. 1A is a schematic diagram of an optical imaging lens according to a first embodiment of the invention.

Fig. 1B is a longitudinal spherical aberration diagram of the optical imaging lens according to the first embodiment.

Fig. 1C is a field curvature diagram of the optical imaging lens according to the first embodiment.

Fig. 1D is a distortion diagram of the optical imaging lens according to the first embodiment.

Fig. 2A is a schematic view of an optical imaging lens according to a second embodiment of the invention.

Fig. 2B is a longitudinal spherical aberration diagram of the optical imaging lens according to the second embodiment.

Fig. 2C is a field curvature diagram of the optical imaging lens according to the second embodiment.

Fig. 2D is a distortion diagram of the optical imaging lens according to the second embodiment.

Fig. 3A is a schematic diagram of an optical imaging lens system according to a third embodiment of the invention.

Fig. 3B is a longitudinal spherical aberration diagram of the optical imaging lens according to the third embodiment.

Fig. 3C is a field curvature diagram of the optical imaging lens according to the third embodiment.

Fig. 3D is a distortion diagram of the optical imaging lens according to the third embodiment.

Detailed Description

In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Referring to fig. 1A, an optical imaging lens 100 according to a first embodiment of the present invention includes, in order from an object side to an image side along an optical axis Z: a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

The first lens element L1 with negative refractive power has a convex object-side surface S1 and a concave image-side surface S2.

The second lens element L2 and the third lens element L3 are combined to form a first compound lens element, which can effectively improve the chromatic aberration of the lens system and control the generation of aberration, wherein, in an embodiment, the combined surfaces of the second lens element L2 and the third lens element L3 can be designed to be flat or convex toward the image side. Preferably, in the present embodiment, the first compound lens has negative refractive power. In addition, in the present embodiment, the second lens element L2 with negative refractive power has a concave object-side surface S3 and a convex image-side surface S4, the third lens element L3 with positive refractive power has a concave object-side surface S5 and is cemented with the image-side surface S4 of the second lens element L2, the image-side surface S6 is a convex surface, and the cemented surface of the second lens element L2 and the cemented surface of the third lens element L3 is a convex surface facing the image side. In addition, in an embodiment, the image-side surface S4 of the second lens element L2 and the object-side surface S5 of the third lens element L3 may be designed to be flat, and the bonding surface of the second lens element L2 and the third lens element L3 is flat after they are bonded.

The fourth lens element L4 has positive refractive power, and in this embodiment, the fourth lens element L4 is a biconvex lens element, and both the object-side surface S7 and the image-side surface S8 are convex.

The fifth lens element L5 is cemented with the sixth lens element L6 to form a second compound lens element, which is favorable for improving the chromatic aberration and controlling the aberration generation, and preferably has positive refractive power. The fifth lens element L5 with positive refractive power has a convex object-side surface S9, and in the present embodiment, the fifth lens element L5 is a biconvex lens element with convex object-side surface S9 and convex image-side surface S10. The sixth lens element L6 with negative refractive power has a concave image-side surface S12, and in the present embodiment, the sixth lens element L6 is a biconcave lens element with a concave object-side surface S11 cemented with the image-side surface S10 of the fifth lens element L5, and the cemented surfaces of the fifth lens element L5 and the sixth lens element L6 are convex toward the image side.

The seventh lens element L7 with positive refractive power can be a plano-concave lens element with a concave surface facing the object side, a biconcave lens element or a meniscus lens element, and in the present embodiment, the seventh lens element L7 is a meniscus lens element with a concave object-side surface S13 and a convex image-side surface S14.

In addition, the optical imaging lens 100 may further include an aperture ST, an infrared filter L8, and a protective glass L9. The stop ST is disposed between the fourth lens L4 and the fifth lens L5; the ir filter L8 is disposed between the seventh lens L7 and the protective glass L9, and preferably, the ir filter L8 is made of glass; the protective glass L9 is disposed between the infrared filter L8 and the image plane Im.

In order to maintain the optical imaging lens 100 of the present invention with good optical performance and high imaging quality, the optical imaging lens 100 further satisfies the following conditions:

(1)-60≤f23/f≤-10；

(2)4.5≤f56/f≤7.5；

(3)2.5≤(f1+f2+f3+f4+f5+f6+f7)/f≤13.5；

(4)0.05≤f4/f7≤0.6；

(5)│Vd2-Vd3│≤20；

(6)TTL/(f*tan(FOV/2))≥8；

wherein f is the focal length of the optical imaging lens 100; f1 is the focal length of the first lens L1; f2 is the focal length of the second lens L2; f3 is the focal length of the third lens L3; f4 is the focal length of the fourth lens L4; f5 is the focal length of the fifth lens L5; f6 is the focal length of the sixth lens L6; f7 is the focal length of the seventh lens L7; f23 is the focal length of the first compound lens; f56 is the focal length of the second compound lens; vd2 is the abbe number of the second lens L2; vd3 is the abbe number of the third lens L3; TTL is the optical axis length of the optical imaging lens; the FOV is the full view angle of the optical imaging lens. In addition, it is preferable that a full view angle (FOV) of the optical imaging lens 100 is between 50 degrees and 80 degrees.

The following table is data of the optical imaging lens 100 according to the first embodiment of the present invention, which includes: a focal length f (or called effective focal length) of the optical imaging lens 100, an aperture value Fno, a full view angle FOV, a curvature radius R of each lens, a distance between each surface and a next surface on an optical axis, a refractive index Nd of each lens, and an abbe number Vd of each lens; wherein the unit of focal length, radius of curvature and thickness is mm.

Watch 1

As can be seen from the table one, the focal length f of the optical imaging lens 100 of the first embodiment is 10.200mm, the abbe number Vd2 of the second lens L2 is 32.099206, and the abbe number Vd3 of the third lens L3 is 47.927969. The focal length f1 of the first lens L1 is-18.728 mm, the focal length f2 of the second lens L2 is-14.579 mm, the focal length f3 of the third lens L3 is-20.773 mm, the focal length f4 of the fourth lens L4 is-16.189 mm, the focal length f5 of the fifth lens L5 is-12.268 mm, the focal length f6 of the sixth lens L6 is-12.214 mm, the focal length f7 of the seventh lens L7 is 76.204mm, the focal length f23 of the first compound lens after the second lens L2 and the third lens L3 are cemented is-188.445 mm, and the focal length f56 of the second compound lens after the fifth lens L5 and the sixth lens L6 are cemented is 59.856 mm.

From the above, it can be seen that (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f is about 7.870, f23/f is about-18.48, f56/f is about 5.87, f4/f7 is about 0.21, | Vd2-Vd3 | -15.9, and TTL/(f tan (FOV/2)) is about 8.036, and the conditions set in the above points (1) to (6) are satisfied.

As can be seen from fig. 1B to fig. 1D, with the above design, the optical imaging lens 100 according to the first embodiment of the invention can effectively improve the imaging quality and reduce the distortion.

Referring to fig. 2A, an optical imaging lens 200 according to a second embodiment of the present invention includes, in order from an object side to an image side along an optical axis Z: a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

In addition, the optical imaging lens 200 may further include an aperture ST, an infrared filter L8, and a protective glass L9. The stop ST is disposed between the fourth lens L4 and the fifth lens L5; the ir filter L8 is disposed between the seventh lens L7 and the protective glass L9, and preferably, the ir filter L8 is made of glass; the protective glass L9 is disposed between the infrared filter L8 and the image plane Im.

In order to maintain the optical imaging lens 200 of the present invention with good optical performance and high imaging quality, the optical imaging lens 200 further satisfies the following conditions:

(1)-60≤f23/f≤-10；

(2)4.5≤f56/f≤7.5；

(3)2.5≤(f1+f2+f3+f4+f5+f6+f7)/f≤13.5；

(4)0.05≤f4/f7≤0.6；

(5)│Vd2-Vd3│≤20；

wherein f is the focal length of the optical imaging lens 200; f1 is the focal length of the first lens L1; f2 is the focal length of the second lens L2; f3 is the focal length of the third lens L3; f4 is the focal length of the fourth lens L4; f5 is the focal length of the fifth lens L5; f6 is the focal length of the sixth lens L6; f7 is the focal length of the seventh lens L7; f23 is the focal length of the first compound lens; f56 is the focal length of the second compound lens; vd2 is the abbe number of the second lens L2; vd3 is the abbe number of the third lens L3; TTL is the optical axis length of the optical imaging lens; the FOV is the full view angle of the optical imaging lens. In addition, it is preferable that a full view angle (FOV) of the optical imaging lens 200 is between 50 degrees and 80 degrees.

The following table two is data of the optical imaging lens 200 according to the second embodiment of the present invention, which includes: a focal length f (or called effective focal length) of the optical imaging lens 200, an aperture value Fno, a full view angle FOV, a curvature radius R of each lens, a distance between each surface and a next surface on an optical axis, a refractive index Nd of each lens, and an abbe number Vd of each lens; wherein the unit of focal length, radius of curvature and thickness is mm.

Watch two

As can be seen from the above table two, the focal length f of the optical imaging lens 200 of the second embodiment is 6.743mm, the abbe number Vd2 of the second lens L2 is 45.784277, and the abbe number Vd3 of the third lens L3 is 37.160487. The focal length f1 of the first lens L1 is-18.729 mm, the focal length f2 of the second lens L2 is-19.528 mm, the focal length f3 of the third lens L3 is 27.100mm, the focal length f4 of the fourth lens L4 is 12.440mm, the focal length f5 of the fifth lens L5 is 12.993mm, the focal length f6 of the sixth lens L6 is-17.281 mm, the focal length f7 of the seventh lens L7 is 27.624mm, the focal length f23 of the first compound lens after the second lens L2 and the third lens L3 are cemented is-363.474 mm, and the focal length f56 of the second compound lens after the fifth lens L5 and the sixth lens L6 are cemented is 43.505 mm.

From the above, it can be seen that (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f is about 3.585, f23/f is about-53.91, f56/f is about 6.45, f4/f7 is about 0.45, | Vd2-Vd3 | -8.6, and TTL/(f tan (FOV/2)) is about 6.023, which satisfy the conditions set in the above points (1) to (5).

As can be seen from fig. 2B to fig. 2D, with the above design, the optical imaging lens 200 according to the second embodiment of the present invention can effectively improve the imaging quality and reduce the distortion.

Referring to fig. 3A, an optical imaging lens 300 according to a third embodiment of the present invention includes, in order from an object side to an image side along an optical axis Z: a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5, a sixth lens element L6, and a seventh lens element L7.

In addition, the optical imaging lens 300 may further include an aperture ST, an infrared filter L8, and a protective glass L9. The stop ST is disposed between the fourth lens L4 and the fifth lens L5; the ir filter L8 is disposed between the seventh lens L7 and the protective glass L9, and preferably, the ir filter L8 is made of glass; the protective glass L9 is disposed between the infrared filter L8 and the image plane Im.

In order to maintain the optical imaging lens 300 of the present invention with good optical performance and high imaging quality, the optical imaging lens 300 further satisfies the following conditions:

(1)-60≤f23/f≤-10；

(2)4.5≤f56/f≤7.5；

(3)2.5≤(f1+f2+f3+f4+f5+f6+f7)/f≤13.5；

(4)0.05≤f4/f7≤0.6；

(5)│Vd2-Vd3│≤20；

(6)TTL/(f*tan(FOV/2))≥8；

wherein f is the focal length of the optical imaging lens 300; f1 is the focal length of the first lens L1; f2 is the focal length of the second lens L2; f3 is the focal length of the third lens L3; f4 is the focal length of the fourth lens L4; f5 is the focal length of the fifth lens L5; f6 is the focal length of the sixth lens L6; f7 is the focal length of the seventh lens L7; f23 is the focal length of the first compound lens; f56 is the focal length of the second compound lens; vd2 is the abbe number of the second lens L2; vd3 is the abbe number of the third lens L3; TTL is the optical axis length of the optical imaging lens; the FOV is the full view angle of the optical imaging lens. In addition, it is preferable that a full view angle (FOV) of the optical imaging lens 300 is between 50 degrees and 80 degrees.

The following table three shows data of the optical imaging lens 300 according to the third embodiment of the present invention, which includes: a focal length f (or effective focal length) of the optical imaging lens 300, an aperture value Fno, a full view angle FOV, a curvature radius R of each lens, a distance between each surface and a next surface on an optical axis, a refractive index Nd of each lens, and an abbe number Vd of each lens; wherein the unit of focal length, radius of curvature and thickness is mm.

Watch III

As can be seen from the above table iii, the focal length f of the optical imaging lens 300 of the third embodiment is 8.000mm, the abbe number Vd2 of the second lens L2 is 39.682794, and the abbe number Vd3 of the third lens L3 is 54.822578. The focal length f1 of the first lens L1 is-22.207 mm, the focal length f2 of the second lens L2 is-16.655 mm, the focal length f3 of the third lens L3 is-27.041 mm, the focal length f4 of the fourth lens L4 is-16.390 mm, the focal length f5 of the fifth lens L5 is-11.440 mm, the focal length f6 of the sixth lens L6 is-13.650 mm, the focal length f7 of the seventh lens L7 is 100.243mm, the focal length f23 of the first compound lens after the second lens L2 and the third lens L3 are cemented is-100.000 mm, and the focal length f56 of the second compound lens after the fifth lens L5 and the sixth lens L6 are cemented is-41.341 mm.

From the above, it can be seen that (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f is about 12.862, f23/f is about 12.50, f56/f is about 5.17, f4/f7 is about 0.16, | Vd2-Vd3 |, is about 15.2, and TTL/(f tan (FOV/2)) is about 8.915, which satisfies the conditions set in the above points (1) to (6).

As can be seen from fig. 3B to fig. 3D, with the above design, the optical imaging lens 300 according to the third embodiment of the invention can effectively improve the imaging quality and reduce the distortion.

It should be noted that the data listed in the above table are not intended to limit the present invention, and any person skilled in the art can make appropriate changes to the parameters or settings of the table after referring to the present invention, and the invention shall fall within the scope of the present invention. All equivalent changes made by applying the specification and claims of the present invention are intended to be included within the scope of the present invention.

Description of the reference numerals

[ invention ]

100. 200 and 300: optical imaging lens

L1: first lens

L2: second lens

L3: third lens

L4: fourth lens

L5: fifth lens element

L6: sixth lens element

L7: seventh lens element

L8: infrared filter

L9: cover glass

Im: image plane

ST: aperture

Z: optical axis

S1, S3, S5, S7, S9, S11, S13: side of the object

S2, S4, S6, S8, S10, S12, S14: image side

Claims

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

a first lens element with negative refractive power;

a second lens element having a concave object-side surface and a convex image-side surface;

a third lens element with a concave object-side surface and a convex image-side surface; the object side surface of the third lens element and the image side surface of the second lens element are cemented together to form a first compound lens element with negative refractive power;

a fourth lens element with positive refractive power;

a fifth lens element;

a sixth lens element cemented with the fifth lens element to form a second compound lens element with positive refractive power;

a seventh lens element with positive refractive power.

2. The optical imaging lens according to claim 1, wherein the second lens element has negative refractive power and the third lens element has positive refractive power.

3. The optical imaging lens according to claim 2, wherein the fifth lens element has positive refractive power and the sixth lens element has negative refractive power.

4. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: -60 ≦ f23/f ≦ -10, where f is the focal length of the optical imaging lens and f23 is the focal length of the first compound lens.

5. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: f56/f is not less than 4.5 and not more than 7.5, wherein f is the focal length of the optical imaging lens, and f56 is the focal length of the second compound lens.

6. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: 2.5 ≦ (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f ≦ 13.5, wherein f is a focal length of the optical imaging lens, f1 is a focal length of the first lens, f2 is a focal length of the second lens, f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, f5 is a focal length of the fifth lens, f6 is a focal length of the sixth lens, and f7 is a focal length of the seventh lens.

7. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: f4/f7 is more than or equal to 0.05 and less than or equal to 0.6, wherein f4 is the focal length of the fourth lens, and f7 is the focal length of the seventh lens.

8. The optical imaging lens of claim 1, wherein the object side surface of the seventh lens is concave.

9. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: vd2-Vd3 | -20, wherein Vd2 is the Abbe number of the second lens, and Vd3 is the Abbe number of the third lens.

10. The optical imaging lens of claim 1, wherein the optical imaging lens satisfies the following condition: TTL/(f star tan (FOV/2)) > 8, wherein TTL is the optical axis length of the optical imaging lens, f is the focal length of the optical imaging lens, and FOV is the full visual angle of the optical imaging lens.

11. An optical imaging lens includes, in order from an object side to an image side along an optical axis:

a first lens;

a second lens element;

a third lens element;

a fourth lens element;

a fifth lens element;

a sixth lens element;

a seventh lens element;

wherein the optical imaging lens satisfies the following conditions: -60 ≤ f23/f ≤ 10, 4.5 ≤ f56/f ≤ 7.5, 2.5 ≤ (f1+ f2+ f3+ f4+ f5+ f6+ f7)/f ≤ 13.5, wherein f is the focal length of the optical imaging lens, f23 is the focal length of the first compound lens, f56 is the focal length of the second compound lens, 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, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f7 is the focal length of the seventh lens.

12. The optical imaging lens of claim 11, wherein the second lens is cemented with the third lens and forms a first compound lens.

13. The optical imaging lens of claim 12, wherein the first compound lens has negative refractive power.

14. The optical imaging lens of claim 11, wherein the sixth lens is cemented with the fifth lens to form a second compound lens.

15. The optical imaging lens of claim 14, wherein the second compound lens has positive refractive power.

16. The optical imaging lens of claim 11, wherein the optical imaging lens satisfies at least one of the following conditions:

A. the second lens element with negative refractive power and the third lens element with positive refractive power;

B. the fifth lens element with positive refractive power and the sixth lens element with negative refractive power;

C. the first lens element has negative refractive power;

D. the fourth lens element with positive refractive power;

E. the seventh lens element with positive refractive power.

17. The optical imaging lens of claim 11, wherein the optical imaging lens satisfies the following condition: f4/f7 is more than or equal to 0.05 and less than or equal to 0.6, wherein f4 is the focal length of the fourth lens, and f7 is the focal length of the seventh lens.

18. The optical imaging lens of claim 11, wherein the optical imaging lens satisfies at least one of the following conditions:

A. the image side surface of the second lens is a convex surface;

B. the object side surface of the third lens is a concave surface;

C. the object side surface of the seventh lens is a concave surface.

19. The optical imaging lens of claim 11, wherein the optical imaging lens satisfies the following condition: vd2-Vd3 | -20, wherein Vd2 is the Abbe number of the second lens, and Vd3 is the Abbe number of the third lens.

20. The optical imaging lens of claim 11, wherein the full viewing angle of the optical imaging lens is between 50 degrees and 80 degrees.