CN116249924A

CN116249924A - Imaging lens assembly, camera module, and imaging apparatus that consider distortion correction based on image processing

Info

Publication number: CN116249924A
Application number: CN202080105194.5A
Authority: CN
Inventors: 桂木大午
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-11-24
Filing date: 2020-11-24
Publication date: 2023-06-09
Also published as: WO2022109795A1

Abstract

The imaging lens assembly comprises at least one lens with positive refractive power and at least one lens with negative refractive power, wherein the imaging lens assembly meets the following conditional expression, (ΣD/Ymax) × (FNo+1.8) +.5.4, dist _{1.0_10cm} /Dist _{0.7_10cm} >0.95, wherein ΣD is the total length of the imaging lens assembly, ymax is the maximum image height, FNo is the F number, dist _{1.0_10cm} Is an amount of distortion before performing distortion correction based on image processing, the amount of distortion being obtained at an image height of 100% of a maximum image height when an object distance is 10cm, the object distance being a distance between an object and a lens disposed most on an object side, and Dist _{0.7_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 70% of the maximum image height when the object distance is 10 cm.

Description

Imaging lens assembly, camera module, and imaging apparatus that consider distortion correction based on image processing

Technical Field

The present disclosure relates to an imaging lens assembly, a camera module, and an imaging apparatus that consider image processing-based distortion correction, and more particularly, to an imaging lens assembly, a camera module, and an imaging apparatus that are configured to be compact and achieve good optical performance by considering image processing-based distortion correction.

Background

In recent years, portable imaging devices such as mobile phones and digital cameras have been widely used. With miniaturization of imaging apparatuses, an imaging lens assembly mounted on the imaging apparatus also needs to be miniaturized. Further, imaging elements mounted on imaging devices continue to have a greater number of pixels and larger-sized elements. In order to keep pace with the increase in the number of pixels and the increase in the element size, it is desirable that the imaging lens assembly has high imaging performance in a range from a central angle of view to a peripheral angle of view and the overall length of the imaging lens assembly is reduced.

There is room for improvement because the conventional imaging lens assembly cannot sufficiently reduce its length and ensure high imaging performance.

Disclosure of Invention

The present disclosure is directed to solving at least one of the above-mentioned technical problems. Accordingly, there is a need for providing an imaging lens assembly, a camera module, and an imaging apparatus.

According to the present disclosure, an imaging lens assembly that considers distortion correction based on image processing, includes:

at least one lens having positive refractive power

At least one lens having a negative refractive power, wherein,

the imaging lens assembly satisfies the following conditional expressions,

(ΣD/Ymax)×(Fno+1.8)≤5.4，

Dist _{1.0_10cm} /Dist _{0.7_10cm} >0.95

wherein Σd is the total length of the imaging lens assembly, ymax is the maximum image height, fno is the F number, dist _{1.0_10cm} Is the amount of distortion before performing image processing-based distortion correction when the object distance is 1At 0cm, obtained at an image height of 100% of the maximum image height, the object distance is the distance between the object and the lens arranged closest to the object side, and Dist _{0.7_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 70% of the maximum image height when the object distance is 10 cm.

In one example, the imaging lens assembly may also satisfy the following conditional expression,

1.0<Dist _{1.0_INF} /Dist _{0.7_INF} <2.0

wherein Dist _{1.0_INF} Is an amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 100% of a maximum image height when the object distance is infinity, and Dist _{0.7_INF} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 70% of the maximum image height when the object distance is infinity.

2.0<Dist _{0.7_INF} /Dist _{0.2_INF} <5.0

1.5<Dist _{0.7_10cm} /Dist _{0.2_10cm} <4.5

wherein Dist _{0.7_INF} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 70% of the maximum image height when the object distance is infinity, dist _{0.2_INF} Is an amount of distortion before performing image processing-based distortion correction, which is obtained in an image height of 20% of a maximum image height when an object distance is infinity, and Dist _{0.2_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 20% of the maximum image height when the object distance is 10 cm.

2.5<Dist _{1.0_INF} /Dist _{0.2_INF} <8.0

1.5<Dist _{1.0_10cm} /Dist _{0.2_10cm} <6.0

wherein Dist _{1.0_INF} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 100% of the maximum image height when the object distance is infinity, dist _{0.2_INF} Is an amount of distortion before performing image processing-based distortion correction, which is obtained in an image height of 20% of a maximum image height when an object distance is infinity, and Dist _{0.2_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 20% of the maximum image height when the object distance is 10 cm.

4％≤Dist.≤15％，

wherein dist is an amount of distortion before performing distortion correction based on image processing, the amount of distortion being obtained when the object distance is infinity.

In one example, the surface of the imaging surface side of the lens disposed most on the imaging surface side may have a concave shape in the vicinity of the optical axis, and may have a convex shape at the peripheral portion.

In one example, the lens disposed most on the imaging plane side may have an aspherical shape with an inflection point, and be formed of plastic.

According to the present disclosure, a camera module includes:

an imaging lens; and

an image sensor including an imaging surface.

According to the present disclosure, an imaging apparatus includes the camera module.

Drawings

These and/or other aspects and advantages of the embodiments of the disclosure will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings, wherein:

fig. 1 is a diagram showing distortion correction based on image processing as a brief description of a camera module according to the present disclosure;

FIG. 2 is a diagram illustrating an autofocus operation according to a change in object distance as a brief description of a camera module according to the present disclosure;

fig. 3A and 3B are diagrams showing a distortion curve change according to an object distance change;

fig. 4 is a configuration diagram of a camera module according to a first example of the present disclosure;

fig. 5 is a diagram showing a distortion curve before distortion correction based on image processing in a camera module according to a first example of the present disclosure;

fig. 6 is an aberration diagram of a camera module according to a first example of the present disclosure;

fig. 7 is a configuration diagram of a camera module according to a second example of the present disclosure;

fig. 8 is a diagram showing a distortion curve before distortion correction based on image processing in a camera module according to a second example of the present disclosure;

fig. 9 is an aberration diagram of a camera module according to a second example of the present disclosure;

fig. 10 is a configuration diagram of a camera module according to a third example of the present disclosure;

fig. 11 is a diagram showing a distortion curve before distortion correction based on image processing in a camera module according to a third example of the present disclosure;

fig. 12 is an aberration diagram of a camera module according to a third example of the present disclosure;

fig. 13 is a configuration diagram of a camera module according to a fourth example of the present disclosure;

fig. 14 is a diagram showing a distortion curve before distortion correction based on image processing in a camera module according to a fourth example of the present disclosure; and

fig. 15 is an aberration diagram of a camera module according to a fourth example of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in detail, and examples of the embodiments will be illustrated in the accompanying drawings. Throughout the description, identical or similar elements and elements having identical or similar functions are denoted by identical reference numerals. The embodiments described herein with reference to the drawings are illustrative and are intended to be illustrative of the present disclosure, but should not be construed as limiting the present disclosure.

Summary of the disclosure

First, an overview of the present disclosure will be described. As shown in fig. 1, the camera module 11 to which the present disclosure is applied is configured to focus incident light from an object side (object side) on an imaging surface S of an imaging sensor 23 through an imaging lens assembly 21 to obtain an image of the object.

Further, the camera module 11 to which the present disclosure is applied is configured to perform distortion correction based on image processing in addition to aberration correction based on the optical performance of the imaging lens assembly 21 mounted on the camera module 11. The specific configuration of the distortion correction based on the image processing is not particularly limited. For example, as shown in fig. 1, an image processing unit 24 (e.g., a computer) electrically connected to the imaging sensor 23 may perform distortion correction based on image processing by correcting coordinates of each pixel of an image acquired from the image sensor 23 according to a predetermined correction formula.

As shown in fig. 2, an autofocus mechanism 110 is mounted on the camera module 11, and the autofocus mechanism 110 automatically adjusts the focus of the imaging lens assembly 21 to the subject (i.e., object). The autofocus mechanism 110 includes, for example, a motor such as a voice coil motor. For example, the autofocus mechanism 110 moves the lens barrel 112 and the imaging lens assembly 21 held by the lens barrel 112 in the optical axis direction D in the housing 111 accommodating the lens barrel 112 and the imaging lens assembly 21.

When the object distance OD (i.e., shooting distance), which is the distance between the object and the lens disposed most on the object side, is changed, the auto focus mechanism 110 moves the imaging lens assembly 21 in the optical axis direction D so as to focus the imaging lens assembly 21 on the object. For example, as shown in fig. 2, when the object distance OD is shortened from Infinity (INF) to 10cm, the auto-focus mechanism 110 moves the imaging lens assembly 21 from the imaging surface S side to the object side (i.e., the cover glass 113 side). On the other hand, when the object distance OD is expanded from 10cm to infinity, the auto-focusing mechanism 110 moves the imaging lens assembly 21 from the object side to the imaging surface S side.

According to the autofocus mechanism 110, an object may be automatically focused by following a change in the object distance OD. However, even if focusing is achieved, the optical characteristics of the imaging lens assembly 21 after the object distance OD is changed are different from those of the imaging lens assembly 21 before the object distance OD is changed.

For example, as shown in fig. 3A, when the object distance OD is changed from infinity to 10cm, the shape of the distortion curve is changed so that the amount of distortion per image height is reduced. In fig. 3A, in both cases where the object distance OD is infinity and 10cm, the linearity of the distortion curve is maintained such that the amount of distortion increases substantially monotonously according to the increase in image height. With the distortion curve shown in fig. 3A, by performing distortion correction based on image processing, good image quality can be obtained.

On the other hand, in the case of fig. 3B, although the linearity of the distortion curve is maintained when the object distance OD is infinity, when the object distance OD is 10cm, the distortion curve is shaped so that the amount of distortion decreases when the image height is large. As the object distance OD becomes smaller, the reduction in this amount of distortion becomes more significant. In the case of fig. 3B. When the object distance OD is 10cm, even if distortion correction based on image processing is performed, the distortion correction is insufficient, and the image quality deteriorates.

In order to suppress deterioration of image quality after distortion correction based on image processing caused by a change in the object distance OD, the present disclosure is configured to enhance linearity of a distortion curve regardless of the change in the object distance OD. Hereinafter, this specific configuration of the present disclosure will be given.

The camera module 11 to which the present disclosure is applied is configured as shown in fig. 4, 7, 10, and 13, for example. In the figure, a dash-dot line represents the optical axis of the camera module.

The camera module 11 includes an imaging lens assembly 21, an optical filter 22, and an image sensor 23.

The imaging lens assembly 21 is designed to maintain its good optical performance (i.e., good quality of corrected image) despite small size in consideration of distortion correction based on image processing.

The imaging lens assembly 21 may be configured to perform optical image stabilization by means of an optical image stabilization mechanism that moves the imaging lens assembly 21 in a direction that eliminates camera shake (e.g., a direction orthogonal to the optical axis).

The imaging lens assembly 21 includes at least one lens having positive refractive power and at least one lens having negative refractive power.

The image sensor 23 is, for example, a solid-state image sensor such as CMOS (Complementary Metal Oxide Semiconductor ) or CCD (Charge Coupled Device, charge coupled device). The image sensor 23 has an imaging plane S as an imaging plane of the imaging lens assembly 21. The image sensor 23 receives incident light from an object (object side) via the imaging lens assembly 21 and the filter 22, photoelectrically converts the light, and outputs image data obtained by photoelectrically converting the light to a subsequent stage.

In order to obtain a small-sized camera module having good optical performance, it is preferable to appropriately correct aberrations including distortion of the imaging lens assembly 21 and shorten the back focus of the imaging lens assembly 21.

Therefore, in the camera module 11, the imaging lens assembly 21 includes at least one lens having positive refractive power and at least one lens having negative refractive power, and satisfies the following formulas (1) and (2):

(ΣD / Ymax) × (Fno + 1.8) ≤ 5.4 (1)

Dist _{1.0_10cm} / Dist _{0.7_10cm} > 0.95 (2)

where Σd is the entire length of the imaging lens assembly 21, that is, the distance on the optical axis from the vertex of the object side surface of the lens disposed closest to the object side to the imaging surface S. Ymax is the maximum image height. Fno is the F-number of the imaging lens assembly 21.

Equation (2) shows the range of the variation of the distortion curve in the region with the maximum image height when the object distance OD is small. Specifically, equation (2) defines a lower limit of the ratio of the amount of distortion between 100% of the image height and 70% of the image height when the object distance OD is 10 cm. In equation (2), dist _{1.0_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 100% of the maximum image height when the object distance OD is 10cm (hereinafter, the same applies). Dist (Dist) _{0.7_10cm} Is the amount of distortion before performing the distortion correction based on the image processing, which is obtained at an image height of 70% of the maximum image height when the object distance OD is 10cm (hereinafter, the same applies).

When the ratio shown in formula (1) is reduced, the imaging lens assembly 21 can be miniaturized and its good optical performance can be effectively maintained. When the object distance OD is 10cm, if the ratio of the distortion amount between 100% of the image height and 70% of the image height deviates from the range shown in formula (2), it is difficult to sufficiently reduce the remaining distortion by the distortion correction based on the image processing.

Therefore, the camera module 11 allows miniaturization of the imaging lens assembly 21 while maintaining good optical performance of the imaging lens assembly 21 by satisfying the above formulas (1) and (2).

Further, in the example shown in fig. 4, the lens disposed most on the imaging surface S side has an aspherical shape having an inflection point near the lens edge on the imaging surface S side. Specifically, the surface of the lens disposed closest to the imaging surface S side on the imaging surface S side has a concave shape at the center of the lens (i.e., near the optical axis) and a convex shape at the peripheral portion (i.e., near the peripheral region). Therefore, the back focus can be effectively shortened while maintaining good optical performance.

Further, when the camera module 11 satisfies the following formula (3), the imaging lens assembly 21 can be miniaturized and its good optical performance can be more effectively maintained:

1.0 < Dist _{1.0_INF} / Dist _{0.7_INF} < 2.0 (3)

equation (3) shows the range of the variation of the distortion curve in the region with the maximum image height when the object distance OD is large. Specifically, the formula (3) defines a range of the ratio of the distortion amount between 100% image height and 70% image height when the object distance OD is infinity. In equation (3), dist _{1.0_INF} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 100% of the maximum image height when the object distance OD is infinity (hereinafter, the same applies). Dist (Dist) _{0.7_INF} Is the amount of distortion before performing image processing-based distortion correction,the distortion amount is obtained at an image height of 70% of the maximum image height when the object distance is infinity (hereinafter, the same applies).

If the ratio of the distortion amount between 100% of the image height and 70% of the image height deviates from the range shown in formula (3) when the object distance OD is infinite, the remaining distortion remaining after the distortion correction based on the image processing is large.

Further, when the camera module 11 satisfies the following formulas (4) and (5), the imaging lens assembly 21 can be miniaturized and can maintain its good optical performance more effectively:

2.0 < Dist _{0.7_INF} / Dist _{0.2_INF} < 5.0 (4)

1.5 < Dist _{0.7_10cm} / Dist _{0.2_10cm} <4.5 (5)

equation (4) shows the range of the variation of the distortion curve in the region from small image height to large image height when the object distance OD is large. Specifically, the formula (4) defines a range of the ratio of the distortion amount between 70% image height and 20% image height when the object distance OD is infinity. Equation (5) shows the range of the variation of the distortion curve in the region from small image height to large image height when the object distance OD is small. Specifically, equation (5) defines a range of the ratio of the distortion amount between 70% image height and 20% image height when the object distance OD is 10 cm. In equation (4), dist _{0.2_INF} Is the amount of distortion before performing image processing-based distortion correction, which is obtained in an image height of 20% of the maximum image height when the object distance OD is infinity (the same applies hereinafter). In equation (5), dist _{0.2_10cm} Is the amount of distortion before performing image processing-based distortion correction, which is obtained at an image height of 20% of the maximum image height when the object distance OD is 10cm (the same applies hereinafter).

If the ratio of the distortion amount between 70% of the image height and 20% of the image height deviates from the range shown in formula (4) when the object distance OD is infinite, the remaining distortion remaining after the distortion correction based on the image processing is large. If the ratio of the distortion amount between 70% of the image height and 20% of the image height deviates from the range shown in formula (5) when the object distance OD is 10cm, the remaining distortion remaining after the distortion correction based on the image processing is large.

Further, when the camera module 11 satisfies the following formulas (6) and (7), the imaging lens assembly 21 can be miniaturized and can maintain its good optical performance more effectively:

2.5 < Dist _{1.0_INF} / Dist _{0.2_INF} < 8.0 (6)

1.5 < Dist _{1.0_10cm} / Dist _{0.2_10cm} <6.0 (7)

equation (6) shows the range of the variation of the distortion curve in the region from small image height to large image height when the object distance OD is large. Specifically, the formula (6) defines a range of the ratio of the distortion amount between 100% image height and 20% image height when the object distance OD is infinity. Equation (7) shows the range of the variation of the distortion curve in the region from small image height to large image height when the object distance OD is small. Specifically, equation (7) defines a range of ratios of distortion amounts between 100% image height and 20% image height when the object distance OD is 10 cm.

If the ratio of the distortion amount between 100% of the image height and 20% of the image height deviates from the range shown in formula (6) when the object distance OD is infinite, the remaining distortion remaining after the distortion correction based on the image processing is large. If the ratio of the distortion amount between 100% of the image height and 20% of the image height deviates from the range shown in formula (7) when the object distance OD is 10cm, the remaining distortion remaining after the distortion correction based on the image processing is large.

When the camera module 11 satisfies the following formula (8), the imaging lens assembly 21 can be miniaturized and its good optical performance can be more effectively maintained:

4％ ≤ Dist. ≤ 15％ (8)

in formula (8), dist. is an amount of distortion before distortion correction based on image processing is performed when the object distance OD is infinity.

If the value shown in formula (8) is below the lower limit (4%), it is difficult to miniaturize the imaging lens assembly 21. On the other hand, if the value shown in the formula (8) is higher than the upper limit (15%), it is difficult to sufficiently reduce the residual distortion by the distortion correction based on the image processing.

Further, from the viewpoint of lens formation, the aspherical lens in the imaging lens assembly 21, particularly, the aspherical lens having an aspherical shape with an inflection point is preferably formed of a plastic material (glass material). In addition, among lenses constituting the imaging lens assembly 21, a lens having a size equal to or smaller than a specific size may be a lens formed of a plastic material, and a lens larger than the specific size may be a lens formed of a glass material. This is because it is difficult to form an aspherical lens or a relatively small lens using a material other than a plastic material.

Such a camera module 11 including the imaging lens assembly 21 is suitable for small digital devices (imaging devices) such as mobile phones, wearable cameras, and monitoring cameras.

< configuration example of Camera Module >

Next, a more specific example to which the present disclosure is applied will be described. In the following example, the symbol of "first surface" indicates the surface on the object side of the lens, and the symbol of "second surface" indicates the surface on the imaging surface S side of the lens.

First example

A first example will be described in which specific numerical values are applied to the camera module 11 shown in fig. 4.

In the first example, the imaging lens assembly 21 includes, in order from the object side toward the imaging surface S side: the lens includes a first lens L1 having a positive refractive power and a convex surface facing the object side, a second lens L2 having a negative refractive power and a concave surface facing the imaging surface S side, a third lens L3 having a positive refractive power, a fourth lens L4 having a negative refractive power, a fifth lens L5 having a positive refractive power and a convex surface facing the imaging surface S side, and a sixth lens L6 having a negative refractive power, the sixth lens L6 having a concave surface facing the object side and a concave surface facing the imaging surface S side. The aperture stop 3 is disposed on the imaging surface S side with respect to the vertex of the first surface of the first lens L1, and is disposed on the object side with respect to the second surface of the first lens L1.

Table 1 shows values of formulas (1) to (8) corresponding to the first example. Table 2 shows the focal length of each lens of the imaging lens assembly 21 of the first example.

TABLE 1

(ΣD/Ymax)×(Fno+1.8)≤5.4	4.96
		(Dist1.0_10cm)/(Dist0.7_10cm)>0.95	0.99
1.0＜(Dist1.0_INF)/(Dist0.7_INF)＜2.0	1.19
		2.0＜(Dist0.7_INF)/(Dist0.2_INF)＜5.0	2.48
1.5＜(Dist0.7_10cm)/(Dist0.2_10cm)＜4.5	2.05
		2.5＜(Dist1.0_INF)/(Dist0.2_INF)＜8.0	2.96
1.5＜(Dist1.0_10cm)/(Dist0.2_10cm)＜6.0	2.02
		4％≤Dist.≤15％	8.91

TABLE 2

Lens	Focal length
		L1	5.88
L2	-17.56
		L3	185.18
L4	-48.43
		L5	4.34
L6	-3.83

Table 3 and fig. 5 show the amount of distortion before distortion correction based on image processing is performed in the first example.

In table 3, "IMAGE HEIGHT (image height)" is an image height normalized to 1 or the maximum image height. "IMAGE HEIGHT _a" is the actual image height not normalized to 1. "distortion_inf" is an amount of DISTORTION before performing DISTORTION correction based on image processing, which is obtained when the object distance OD is infinite. "distortion_10cm" is the amount of DISTORTION before performing DISTORTION correction based on image processing, which is obtained when the object distance OD is 10 cm. The meaning of the terms in table 3 applies to all other examples.

TABLE 3 Table 3

IMAGEHEIGHT	IMAGEHEGHT_a	DISTORTION_INF	DISTORTION_10cm
					0	0.00	0.00	0.00
0.05	0.17	1.50	1.52
				0.1	0.33	2.22	2.28
0.15	0.50	2.62	2.69
				0.2	0.66	3.01	3.08
0.25	0.83	3.48	3.53
				0.3	0.99	4.00	4.03
0.35	1.16	4.49	4.49
				0.4	1.32	4.96	4.89
0.45	1.49	5.41	5.24
				0.5	1.65	5.86	5.55
0.55	1.82	6.30	5.82
				0.6	1.98	6.72	6.05
0.65	2.15	7.11	6.22
				0.7	2.31	7.46	6.31
0.75	2.48	7.76	6.33
				0.8	2.64	8.01	6.28
0.85	2.81	8.24	6.19
				0.9	2.97	8.51	6.15
0.95	3.14	8.80	6.20
				1	3.30	8.91	6.23

The aberrations in the first example are shown in fig. 6. Fig. 6 shows spherical aberration, astigmatism (field curvature), and distortion after performing distortion correction based on image processing as examples of aberrations. Each of these aberration diagrams shows aberration with d-line (587.56 nm) as a reference wavelength. In the spherical aberration diagram, aberrations with respect to g-line (435.84 nm) and C-line (656.27 nm) are also shown. In the graph showing astigmatism, "S" indicates an aberration value on the sagittal image surface, and "T" indicates an aberration value on the tangential image surface. In the graph showing astigmatism and distortion, "IMG HT" indicates an actual image height. The same applies to aberration diagrams in other examples.

As is clear from the aberration diagram of fig. 6, the camera module 11 in the first example is capable of satisfactorily correcting various aberrations despite its small size to obtain excellent optical performance.

Second example

Next, a second example will be described in which specific numerical values are applied to the camera module 11 shown in fig. 7.

In the second example, the imaging lens assembly 21 includes, in order from the object side toward the imaging surface S side: the first lens L1 having positive refractive power and the convex surface facing the object side, the second lens L2 having negative refractive power and the concave surface facing the imaging surface S side, the third lens L3 having positive refractive power, the fourth lens L4 having negative refractive power, the fifth lens L5 having positive refractive power and the convex surface facing the imaging surface S side, and the sixth lens L6 having negative refractive power and the concave surface facing the imaging surface S side. The aperture stop 3 is disposed on the imaging surface S side with respect to the vertex of the first surface of the first lens L1, and is disposed on the object side with respect to the second surface of the first lens L1.

Table 4 shows the values of formulas (1) to (8) corresponding to the second example. Table 5 shows the focal length of each lens of the imaging lens assembly 21 of the second example.

TABLE 4 Table 4

(ΣD/Ymax)×(Fno+1.8)≤5.4	4.67
		(Dist1.0_10cm)/(Dist0.7_10cm)>0.95	1.22
1.0＜(Dist1.0_INF)/(Dist0.7_INF)＜2.0	1.34
		2.0＜(Dist0.7_INF)/(Dist0.2_INF)＜5.0	2.53
1.5＜(Dist0.7_10cm)/(Dist0.2_10cm)＜4.5	2.00
		2.5＜(Dist1.0_INF)/(Dist0.2_INF)＜8.0	3.38
1.5＜(Dist1.0_10cm)/(Dist0.2_10cm)＜6.0	2.44
		4％≤Dist.≤15％	10.70

TABLE 5

Table 6 and fig. 8 show the amount of distortion before distortion correction based on image processing is performed in the second example.

TABLE 6

IMAGEHEIGHT	IMAGEHEGHT_a	DISTORTION_INF	DISTORTION_10cm
					0	0.00	0.00	0.00
0.05	0.18	1.63	1.64
				0.1	0.35	2.32	2.38
0.15	0.53	2.74	2.82
				0.2	0.70	3.17	3.23
0.25	0.88	3.70	3.75
				0.3	1.05	4.22	4.23
0.35	1.23	4.72	4.68
				0.4	1.40	5.17	5.03
0.45	1.58	5.65	5.35
				0.5	1.75	6.10	5.62
0.55	1.93	6.58	5.88
				0.6	2.10	7.04	6.09
0.65	2.28	7.53	6.29
				0.7	2.45	8.01	6.46
0.75	2.63	8.52	6.64
				0.8	2.80	9.02	6.84
0.85	2.98	9.62	7.13
				0.9	3.15	10.20	7.50
0.95	3.33	10.62	7.86
				1	3.50	10.70	7.90

The aberrations in the second example are shown in fig. 9. As is apparent from the aberration diagram of fig. 9, the camera module 11 in the second example is capable of satisfactorily correcting various aberrations despite its small size to obtain excellent optical performance.

Third example

Next, a third example will be described in which specific numerical values are applied to the camera module 11 shown in fig. 10.

In the third example, the imaging lens assembly 21 includes, in order from the object side toward the imaging surface S side: a first lens L1 having positive refractive power and a convex surface facing the object side, a second lens L2 having negative refractive power and a concave surface facing the imaging surface S side, a third lens L3 having positive refractive power, a fourth lens L4 having negative refractive power, and a fifth lens L5 having positive refractive power. The aperture stop 3 is disposed on the imaging surface S side with respect to the vertex of the first surface of the first lens L1, and is disposed on the object side with respect to the second surface of the first lens L1.

Table 7 shows values of formulas (1) to (8) corresponding to the third example. Table 8 shows the focal length of each lens of the imaging lens assembly 21 of the third example.

TABLE 7

(ΣD/Ymax)×(Fno+1.8)≤5.4	5.30
		(Dist1.0_10cm)/(Dist0.7_10cm)>0.95	1.06
1.0＜(Dist1.0_INF)/(Dist0.7_INF)＜2.0	1.26
		2.0＜(Dist0.7_INF)/(Dist0.2_INF)＜5.0	4.86
1.5＜(Dist0.7_10cm)/(Dist0.2_10cm)＜4.5	3.88
		2.5＜(Dist1.0_INF)/(Dist0.2_INF)＜8.0	6.11
1.5＜(Dist1.0_10cm)/(Dist0.2_10cm)＜6.0	4.10
		4％≤Dist.≤15％	10.11

TABLE 8

Lens	Focal length
		L1	3.57
L2	-7.42
		L3	17.87
L4	-11.96
		L5	17.15

Table 9 and fig. 11 show the amount of distortion before distortion correction based on image processing is performed in the third example.

TABLE 9

IMAGEHEIGHT	IMAGEHEGHT_a	DISTORTION_INF	DISTORTION_10cm
					0	0.00	0.00	0.00
0.05	0.19	0.55	0.56
				0.1	0.37	0.93	0.96
0.15	0.56	1.27	1.32
				0.2	0.74	1.65	1.70
0.25	0.93	2.21	2.23
				0.3	1.11	2.88	2.88
0.35	1.30	3.68	3.67
				0.4	1.48	4.46	4.43
0.45	1.67	5.21	5.14
				0.5	1.85	5.84	5.64
0.55	2.04	6.46	6.00
				0.6	2.22	7.02	6.24
0.65	2.41	7.57	6.44
				0.7	2.59	8.03	6.60
0.75	2.78	8.44	6.71
				0.8	2.96	8.77	6.76
0.85	3.15	9.10	6.76
				0.9	3.33	9.44	6.77
0.95	3.52	9.82	6.86
				1	3.70	10.11	6.97

The aberrations in the third example are shown in fig. 12. As is apparent from the aberration diagram of fig. 12, the camera module 11 in the third example is capable of satisfactorily correcting various aberrations despite its small size to obtain excellent optical performance.

Fourth example

Next, a fourth example in which specific numerical values are applied to the camera module 11 shown in fig. 13 will be described.

In the fourth example, the imaging lens assembly 21 includes, in order from the object side toward the imaging surface S side: a first lens L1 having positive refractive power and a convex surface facing the object side, a second lens L2 having negative refractive power and a concave surface facing the imaging surface S side, a third lens L3 having positive refractive power, a fourth lens L4 having negative refractive power, a fifth lens L5 having positive refractive power and a convex surface facing the imaging surface S side, and a sixth lens L6 having negative refractive power and a concave surface facing the imaging surface S side. The aperture stop 3 is disposed on the imaging surface S side with respect to the vertex of the first surface of the first lens L1, and is disposed on the object side with respect to the second surface of the first lens L1.

Table 10 shows values of formulas (1) to (8) corresponding to the fourth example. Table 11 shows the focal length of each lens of the imaging lens assembly 21 of the fourth example.

Table 10

(ΣD/Ymax)×(Fno+1.8)≤5.4	4.62
		(Dist1.0_10cm)/(Dist0.7_10cm)>0.95	1.88
1.0＜(Dist1.0_INF)/(Dist0.7_INF)＜2.0	1.68
		2.0＜(Dist0.7_INF)/(Dist0.2_INF)＜5.0	4.40
1.5＜(Dist0.7_10cm)/(Dist0.2_10cm)＜4.5	2.12
		2.5＜(Dist1.0_INF)/(Dist0.2_INF)＜8.0	7.39
1.5＜(Dist1.0_10cm)/(Dist0.2_10cm)＜6.0	3.99
		4％≤Dist.≤15％	7.17

TABLE 11

Lens	Focal length
		L1	6.47
L2	-20.38
		L3	166.07
L4	-54.47
		L5	5.76
L6	-4.24

Table 12 and fig. 14 show the amount of distortion before distortion correction based on image processing is performed in the fourth example.

Table 12

IMAGEHEIGHT	IMAGEHEGHT_a	DISTORTION_INF	DISTORTION_10cm
					0	0.00	0.00	0.00
0.05	0.18	0.49	0.53
				0.1	0.36	0.62	0.67
0.15	0.53	0.74	0.74
				0.2	0.71	0.97	0.91
0.25	0.89	1.28	1.14
				0.3	1.07	1.58	1.34
0.35	1.24	1.84	1.46
				0.4	1.42	2.09	1.51
0.45	1.60	2.34	1.53
				0.5	1.78	2.62	1.53
0.55	1.95	2.93	1.54
				0.6	2.13	3.32	1.61
0.65	2.31	3.77	1.74
				0.7	2.49	4.26	1.93
0.75	2.66	4.73	2.12
				0.8	2.84	5.23	2.33
0.85	3.02	5.80	2.59
				0.9	3.20	6.45	2.96
0.95	3.37	7.01	3.38
				1	3.55	7.17	3.63

The aberration in the fourth example is as shown in fig. 15. As is apparent from the aberration diagram of fig. 15, the camera module 11 in the fourth example is capable of satisfactorily correcting various aberrations despite its small size to obtain excellent optical performance.

In describing embodiments of the present disclosure, it should be understood that terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "back," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "interior," "exterior," "clockwise," and "counterclockwise" should be construed to refer to directions or locations as described or illustrated in the drawings in question. These related terms are only used to simplify the description of the present disclosure and do not indicate or imply that the devices or elements referred to must have a particular orientation or must be constructed or operated in a particular orientation. Accordingly, these terms should not be construed as limiting the present disclosure.

Furthermore, the use of terms such as "first" and "second" herein are used for descriptive purposes and are not intended to indicate or imply relative importance or meaning or number of technical features indicated. Thus, features defined as "first" and "second" may include one or more of the features. In the description of the present disclosure, unless otherwise indicated, "a plurality" means "two or more".

In the description of the embodiments of the present disclosure, unless specified or limited otherwise, the terms "mounted," "connected," "coupled," and the like are used broadly and may be, for example, a fixed connection, a removable connection, or an integral connection; or may be a mechanical or electrical connection; or may be directly or indirectly connected through an intermediate structure; internal communication of two elements as would be understood by one of ordinary skill in the art depending on the particular situation is also possible.

In embodiments of the present disclosure, unless specified or limited otherwise, structures in which a first feature is "on" or "below" a second feature may include embodiments in which the first feature is in direct contact with the second feature, and may also include embodiments in which the first feature and the second feature are not in direct contact with each other, but are contacted by additional features formed therebetween. Furthermore, an embodiment in which a first feature is "on," "above," or "on top of" a second feature may include embodiments in which the first feature is "on," "above," or "on top of" the second feature, either orthogonally or obliquely, or simply meaning that the first feature is at a higher elevation than the second feature; while a first feature "below" or "beneath" a second feature may include embodiments in which the first feature is "below" or "beneath" the second feature, either orthogonally or obliquely, or simply meaning that the first feature is at a lower elevation than the second feature.

Various embodiments and examples are provided in the above description to implement the different structures of the present disclosure. To simplify the present disclosure, certain elements and arrangements are described above. However, these elements and arrangements are merely examples and are not intended to limit the present disclosure. Further, reference numerals (numbers and/or letters) may be repeated in different examples of the disclosure. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations. In addition, examples of different processes and materials are provided in this disclosure. However, those skilled in the art will appreciate that other processes and/or materials may be employed.

Reference throughout this specification to "an embodiment," "some embodiments," "an example embodiment," "an example," "a particular example," or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the above-identified phrases in various places throughout this specification are not necessarily all referring to the same embodiment or example of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Any process or method described in the flow diagrams or otherwise described herein may be understood as comprising one or more modules, segments, or portions of code comprising executable instructions for implementing specific logical functions or steps in the process, and the scope of the preferred embodiments of the present disclosure includes other implementations in which the functions may be implemented in an order different from that shown or discussed, including in substantially the same sequence or in reverse sequence, as would be understood by one of ordinary skill in the art.

The logic and/or steps described elsewhere herein or shown in the flowcharts, for example, a particular sequence of executable instructions for implementing the logic functions, may be embodied in any computer readable medium to be used by or in connection with an instruction execution system, instruction execution apparatus, or instruction execution device (e.g., a computer-based system, processor-containing system, or other system that can fetch instructions from the instruction execution system, instruction execution apparatus, and instruction execution device). For the purposes of this description, a "computer-readable medium" can be any means that can be used in a system, apparatus, or device that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples of the computer-readable medium include, but are not limited to: an electronic connection (electronic device) with one or more wires, a portable computer peripheral (magnetic device), a random access memory (random access memory, RAM), a Read Only Memory (ROM), an erasable programmable read only memory (erasable programmable read-only memory, EPROM or flash memory), a fiber optic device, and a portable compact disc read only memory (portable compact disk read-only memory, CDROM). Furthermore, the computer readable medium may even be paper or other suitable medium upon which the program can be printed, as, for example, when the program is desired to be electronically captured, the paper or other suitable medium can be optically scanned, then compiled, decrypted or otherwise processed in a suitable manner, and then stored in a computer memory.

It should be understood that each portion of the present disclosure may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, in another embodiment as well, the steps or methods may be implemented by one or a combination of the following techniques, which are known in the art: discrete logic circuits with logic gates for implementing logic functions for data signals, application specific integrated circuits with suitable combinational logic gates, programmable gate arrays (programmable gate array, PGA), field programmable gate arrays (field programmable gate array, FPGA), and the like.

Those skilled in the art will appreciate that all or part of the steps in the above-described exemplary methods of the present disclosure may be implemented by commanding the associated hardware with a program. These programs may be stored in a computer readable storage medium and when run on a computer comprise one or a combination of steps in the method embodiments of the present disclosure.

Furthermore, each functional unit of the embodiments of the present disclosure may be integrated in a processing module, or the units may be physically present alone, or two or more units are integrated in one processing module. The integrated modules may be implemented in hardware or in software functional modules. When the integrated module is implemented in the form of a software functional module and sold or used as a stand-alone product, the integrated module may be stored in a computer-readable storage medium.

The storage medium may be a read-only memory, a magnetic disk, a CD, or the like.

Although embodiments of the present disclosure have been shown and described, it will be understood by those skilled in the art that these embodiments are illustrative and not to be construed as limiting the present disclosure, and that changes, modifications, substitutions, and alterations may be made in the embodiments without departing from the scope of the disclosure.

Claims

1. An imaging lens assembly that accounts for image processing based distortion correction, comprising:

at least one lens having positive refractive power

At least one lens having a negative refractive power, wherein,

the imaging lens assembly satisfies the following conditional expression,

(ΣD/Ymax)×(Fno+1.8)≤5.4，

Dist _{1.0_10cm} /Dist _{0.7_10cm} >0.95

wherein Σd is the total length of the imaging lens assembly, ymax is the maximum image height, fno is the F number, dist _{1.0_10cm} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 100% of the maximum image height when an object distance is 10cm, the object distance being a distance between an object and a lens disposed most on an object side, and Dist _{0.7_10cm} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 70% of the maximum image height when the object distance is 10 cm.

2. The imaging lens assembly of claim 1, wherein the imaging lens assembly further satisfies the following conditional expression,

1.0<Dist _{1.0_INF} /Dist _{0.7_INF} <2.0

wherein Dist _{1.0_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 100% of the maximum image height when the object distance is infinity, and Dist _{0.7_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 70% of the maximum image height when the object distance is infinity.

3. The imaging lens assembly of claim 1, wherein the imaging lens assembly further satisfies the following conditional expression,

2.0<Dist _{0.7_INF} /Dist _{0.2_INF} <5.0

1.5<Dist _{0.7_10cm} /Dist _{0.2_10cm} <4.5

wherein Dist _{0.7_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 70% of the maximum image height when the object distance is infinity, dist _{0.2_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 20% of the maximum image height when the object distance is infinity, and Dist _{0.2_10cm} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 20% of the maximum image height when the object distance is 10 cm.

4. The imaging lens assembly of claim 1, wherein the imaging lens assembly further satisfies the following conditional expression,

2.5<Dist _{1.0_INF} /Dist _{0.2_INF} <8.0

1.5<Dist _{1.0_10cm} /Dist _{0.2_10cm} <6.0

wherein Dist _{1.0_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 100% of the maximum image height when the object distance is infinity, dist _{0.2_INF} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 20% of the maximum image height when the object distance is infinity, and Dist _{0.2_10cm} Is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained at an image height of 20% of the maximum image height when the object distance is 10 cm.

5. The imaging lens assembly of claim 1, wherein the imaging lens assembly further satisfies the following conditional expression,

4％≤Dist.≤15％，

wherein dist is a distortion amount before performing distortion correction based on image processing, the distortion amount being obtained when the object distance is infinity.

6. The imaging lens assembly according to claim 1, wherein a surface of an imaging surface side of the lens disposed most on the imaging surface side has a concave shape in the vicinity of the optical axis and a convex shape at the peripheral portion.

7. The imaging lens assembly according to claim 1, wherein the lens disposed most on the imaging plane side has an aspherical shape having an inflection point and is formed of plasticity.

8. A camera module, comprising:

the imaging lens assembly of any of claims 1-7; and

an image sensor including an imaging surface.

9. An imaging device comprising the camera module of claim 8.