CN112285902B

CN112285902B - Image pickup optical lens

Info

Publication number: CN112285902B
Application number: CN202011602659.6A
Authority: CN
Inventors: 山崎郁; 张磊
Original assignee: Changzhou Ruitai Photoelectric Co Ltd
Current assignee: Changzhou Ruitai Photoelectric Co Ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-03-19
Anticipated expiration: 2040-12-30
Also published as: CN112285902A

Abstract

The invention relates to the field of optical lenses, and discloses a camera optical lens, which comprises six lenses in sequence from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power; the focal length of the first lens is f1, the focal length of the sixth lens is f6, the central curvature radius of the object-side surface of the second lens is R3, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the object-side surface of the fourth lens is R7, the central curvature radius of the image-side surface of the fourth lens is R8, and the central curvature radius of the object-side surface of the fifth lens is R9, and the following relational expressions are satisfied: R9/(R7+ R8) is more than or equal to 2.00 and less than or equal to 6.00; f1/f6 is more than or equal to-3.00 and less than or equal to-2.00; R5/R3 is more than or equal to 3.00 and less than or equal to 5.00. The camera optical lens has good optical performance, and also meets the design requirements of large aperture, wide angle and ultra-thinness.

Description

Image pickup optical lens

Technical Field

The present invention relates to the field of optical lenses, and more particularly, to an imaging optical lens suitable for portable terminal devices such as smart phones and digital cameras, and imaging apparatuses such as monitors and PC lenses.

Background

In recent years, with the rise of various smart devices, the demand for miniaturized photographing optical lenses is increasing, and due to the reduction of the pixel size of the photosensitive device and the trend of the electronic products to have a good function and a light, thin and portable appearance, the miniaturized photographing optical lenses with good imaging quality are the mainstream in the market. In order to obtain better imaging quality, a multi-lens structure is often adopted. Moreover, with the development of technology and the increase of diversified demands of users, under the condition that the pixel area of the photosensitive device is continuously reduced and the requirement of the system on the imaging quality is continuously improved, the six-lens structure gradually appears in the design of the lens. There is a strong demand for a wide-angle imaging lens having excellent optical characteristics, a small size, and sufficiently corrected aberrations.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an imaging optical lens that has good optical performance and satisfies design requirements for a large aperture, ultra-thin thickness, and wide angle.

To solve the above-mentioned problems, an embodiment of the present invention provides an imaging optical lens, which includes six lenses, in order from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power; the focal length of the first lens is f1, the focal length of the sixth lens is f6, the central curvature radius of the object-side surface of the second lens is R3, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the object-side surface of the fourth lens is R7, the central curvature radius of the image-side surface of the fourth lens is R8, and the central curvature radius of the object-side surface of the fifth lens is R9, and the following relations are satisfied: R9/(R7+ R8) is more than or equal to 2.00 and less than or equal to 6.00; f1/f6 is more than or equal to-3.00 and less than or equal to-2.00; R5/R3 is more than or equal to 3.00 and less than or equal to 5.00.

Preferably, the object-side surface of the first lens element is convex at the paraxial region, and the image-side surface of the first lens element is concave at the paraxial region; the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, the on-axis thickness of the first lens is d1, and the total optical length of the image pickup optical lens is TTL and satisfies the following relational expression: f1/f is more than or equal to 0.41 and less than or equal to 1.64; -3.57 ≦ (R1+ R2)/(R1-R2) ≦ -0.74; d1/TTL is more than or equal to 0.06 and less than or equal to 0.20.

Preferably, the imaging optical lens satisfies the following relation: f1/f is more than or equal to 0.66 and less than or equal to 1.31; -2.23 ≤ (R1+ R2)/(R1-R2) is ≤ 0.92; d1/TTL is more than or equal to 0.09 and less than or equal to 0.16.

Preferably, the object-side surface of the second lens element is convex at the paraxial region, and the image-side surface of the second lens element is concave at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the second lens is f2, the central curvature radius of the image side surface of the second lens is R4, the on-axis thickness of the second lens is d3, the optical total length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f2/f is not less than 6.45 and not more than-1.33; 1.76-10.27 percent (R3+ R4)/(R3-R4); d3/TTL is more than or equal to 0.03 and less than or equal to 0.08.

Preferably, the imaging optical lens satisfies the following relation: f2/f is not less than 4.03 and not more than-1.66; 2.81-8.22 percent (R3+ R4)/(R3-R4); d3/TTL is more than or equal to 0.04 and less than or equal to 0.07.

Preferably, the object-side surface of the third lens element is convex at the paraxial region, and the image-side surface of the third lens element is convex at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the third lens is f3, the central curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f3/f is more than or equal to 0.88 and less than or equal to 4.15; -0.13 ≤ (R5+ R6)/(R5-R6) 0.56; d5/TTL is more than or equal to 0.06 and less than or equal to 0.21.

Preferably, the imaging optical lens satisfies the following relation: f3/f is more than or equal to 1.42 and less than or equal to 3.32; -0.08 ≤ (R5+ R6)/(R5-R6) 0.45; d5/TTL is more than or equal to 0.09 and less than or equal to 0.17.

Preferably, the object-side surface of the fourth lens element is concave at the paraxial region, and the image-side surface of the fourth lens element is convex at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the fourth lens is f4, the on-axis thickness of the fourth lens is d7, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f4/f is not less than 16.06 and not more than 42847.85; (R7+ R8)/(R7-R8) is not more than 352.48; d7/TTL is more than or equal to 0.03 and less than or equal to 0.10.

Preferably, the imaging optical lens satisfies the following relation: f4/f is more than or equal to 25.69 and less than or equal to 34278.28; (R7+ R8)/(R7-R8) is not more than 281.98; d7/TTL is more than or equal to 0.05 and less than or equal to 0.08.

Preferably, the object-side surface of the fifth lens element is concave at the paraxial region, and the image-side surface of the fifth lens element is convex at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the fifth lens is f5, the central curvature radius of the image side surface of the fifth lens is R10, the on-axis thickness of the fifth lens is d9, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f5/f is more than or equal to 0.33 and less than or equal to 1.06; (R9+ R10)/(R9-R10) is not more than 0.50 and not more than 1.51; d9/TTL is more than or equal to 0.05 and less than or equal to 0.17.

Preferably, the imaging optical lens satisfies the following relation: f5/f is more than or equal to 0.53 and less than or equal to 0.85; (R9+ R10)/(R9-R10) is not more than 0.80 and not more than 1.21; d9/TTL is more than or equal to 0.09 and less than or equal to 0.14.

Preferably, the object-side surface of the sixth lens element is concave at the paraxial region, and the image-side surface of the sixth lens element is concave at the paraxial region; the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the sixth lens element is R11, the central curvature radius of the image side surface of the sixth lens element is R12, the on-axis thickness of the sixth lens element is d11, and the total optical length of the image pickup optical lens is TTL and satisfies the following relational expression: f6/f is more than or equal to-0.82 and less than or equal to-0.24; not more than 0.02 (R11+ R12)/(R11-R12) not more than 0.13; d11/TTL is more than or equal to 0.05 and less than or equal to 0.16.

Preferably, the imaging optical lens satisfies the following relation: f6/f is more than or equal to-0.51 and less than or equal to-0.31; (R11+ R12)/(R11-R12) is not more than 0.04 and not more than 0.11; d11/TTL is more than or equal to 0.09 and less than or equal to 0.13.

Preferably, the aperture value FNO of the imaging optical lens is less than or equal to 2.06.

Preferably, the aperture value FNO of the imaging optical lens is less than or equal to 2.02.

Preferably, the field angle FOV of the image pickup optical lens is greater than or equal to 72.27 °.

Preferably, the field angle FOV of the image pickup optical lens is greater than or equal to 73.00 °.

Preferably, the image height of the image pickup optical lens is IH, the total optical length of the image pickup optical lens is TTL, and the following relation is satisfied: TTL/IH is less than or equal to 1.65.

Preferably, the imaging optical lens satisfies the following relation: TTL/IH is less than or equal to 1.60.

The invention has the beneficial effects that: the imaging optical lens according to the present invention has excellent optical characteristics, and has characteristics of a large aperture, a wide angle of view, and an ultra-thin profile, and is particularly suitable for a mobile phone camera lens module and a WEB camera lens which are constituted by high-pixel imaging elements such as CCDs and CMOSs.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a schematic configuration diagram of an imaging optical lens according to a first embodiment of the present invention;

FIG. 2 is a schematic axial aberration diagram of the imaging optical lens of FIG. 1;

fig. 3 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 1;

FIG. 4 is a schematic view of curvature of field and distortion of the imaging optical lens of FIG. 1;

fig. 5 is a schematic configuration diagram of an imaging optical lens according to a second embodiment of the present invention;

FIG. 6 is a schematic axial aberration diagram of the imaging optical lens of FIG. 5;

fig. 7 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 5;

FIG. 8 is a schematic view of curvature of field and distortion of the imaging optical lens of FIG. 5;

fig. 9 is a schematic configuration diagram of an imaging optical lens according to a third embodiment of the present invention;

fig. 10 is a schematic view of axial aberrations of the image pickup optical lens shown in fig. 9;

fig. 11 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 9;

fig. 12 is a schematic view of curvature of field and distortion of the imaging optical lens shown in fig. 9.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present invention in its various embodiments. However, the technical solution claimed in the present invention can be implemented without these technical details and various changes and modifications based on the following embodiments.

(first embodiment)

Referring to the drawings, the present invention provides an image pickup optical lens 10. Fig. 1 shows an imaging optical lens 10 according to a first embodiment of the present invention, and the imaging optical lens 10 includes six lenses in total. Specifically, the image capturing optical lens system 10, in order from an object side to an image side: the lens comprises a diaphragm S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6. An optical element such as an optical filter (filter) GF may be disposed between the sixth lens L6 and the image plane Si.

In this embodiment, the first lens L1 is made of plastic, the second lens L2 is made of plastic, the third lens L3 is made of plastic, the fourth lens L4 is made of plastic, the fifth lens L5 is made of plastic, and the sixth lens L6 is made of plastic. In other alternative embodiments, each lens may be made of other materials.

In this embodiment, the central curvature radius of the object-side surface of the fourth lens L4 is defined as R7, the central curvature radius of the image-side surface of the fourth lens L4 is defined as R8, and the central curvature radius of the object-side surface of the fifth lens L5 is defined as R9, so that the following relations are satisfied: 2.00 ≦ R9/(R7+ R8) ≦ 6.00, a ratio of a central curvature radius R9 of an object-side surface of the fifth lens L5 to a sum of a central curvature radius R7 of an object-side surface of the fourth lens L4 and a central curvature radius R8 of an image-side surface of the fourth lens L4 is defined, and shapes of the fourth lens L4 and the fifth lens L5 are reasonably controlled, so that the fourth lens L4 and the fifth lens L5 can effectively correct the system spherical aberration.

Defining the focal length of the first lens L1 as f1 and the focal length of the sixth lens L6 as f6, the following relations are satisfied: 3.00 ≦ f1/f6 ≦ -2.00, which specifies the ratio of the focal length f1 of the first lens L1 to the focal length f6 of the sixth lens L6, so that the system has better imaging quality and lower sensitivity through reasonable distribution of focal lengths.

The central curvature radius of the object side surface of the second lens L2 is defined as R3, and the central curvature radius of the object side surface of the third lens L3 is defined as R5, so that the following relational expressions are satisfied: 3.00-R5/R3-5.00, by controlling the ratio of the central curvature radius R5 of the object side of the third lens L3 to the central curvature radius R3 of the object side of the second lens L2, the shape of the third lens L3 can be prevented from being too curved, which is beneficial to improving the manufacturability of the processing and forming of the third lens L3 and is beneficial to reducing the aberration of an optical imaging system.

In this embodiment, the object-side surface of the first lens element L1 is convex at the paraxial region thereof, and the image-side surface thereof is concave at the paraxial region thereof, and the first lens element L1 has positive refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the first lens L1 may be arranged in other concave and convex distribution.

Defining the focal length f of the imaging optical lens 10, satisfying the following relation: f1/f is 0.41-1.64, and the ratio of the focal length f1 to the overall focal length f of the first lens L1 is defined. Within the specified range, the first lens element L1 has a positive refractive power, which is favorable for reducing system aberration and is favorable for the lens to be ultra-thin and wide-angled. Preferably, 0.66. ltoreq. f 1/f. ltoreq.1.31 is satisfied.

The central curvature radius of the object side surface of the first lens L1 is defined as R1, the central curvature radius of the image side surface of the first lens L1 is defined as R2, and the following relational expressions are satisfied: 3.57 ≦ (R1+ R2)/(R1-R2) ≦ -0.74, and the shape of the first lens L1 is controlled appropriately so that the first lens L1 can correct the system spherical aberration effectively. Preferably, it satisfies-2.23 ≦ (R1+ R2)/(R1-R2) ≦ -0.92.

The on-axis thickness of the first lens L1 is d1, the total optical length of the imaging optical lens system 10 is TTL, and the following relations are satisfied: d1/TTL is more than or equal to 0.06 and less than or equal to 0.20, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.09. ltoreq. d 1/TTL. ltoreq.0.16 is satisfied.

In this embodiment, the object-side surface of the second lens element L2 is convex at the paraxial region thereof, the image-side surface thereof is concave at the paraxial region thereof, and the second lens element L2 has negative refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the second lens L2 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f2 of the second lens L2, the following relations are satisfied: 6.45 ≦ f2/f ≦ -1.33, which is advantageous for correcting aberrations of the optical system by controlling the negative power of the second lens L2 in a reasonable range. Preferably, it satisfies-4.03. ltoreq. f 2/f. ltoreq-1.66.

The central curvature radius of the object side surface of the second lens L2 is R3, the central curvature radius of the image side surface of the second lens L2 is R4, and the following relational expression is satisfied: the shape of the second lens L2 is defined to be not less than 1.76 (R3+ R4)/(R3-R4) and not more than 10.27, and the problem of chromatic aberration on the axis can be corrected favorably as the lens is brought to an ultra-thin wide angle within the range. Preferably, 2.81. ltoreq. (R3+ R4)/(R3-R4). ltoreq.8.22 is satisfied.

The on-axis thickness of the second lens L2 is d3, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d3/TTL is more than or equal to 0.03 and less than or equal to 0.08, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.04. ltoreq. d 3/TTL. ltoreq.0.07 is satisfied.

In this embodiment, the object-side surface of the third lens element L3 is convex at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the third lens element L3 has positive refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the third lens L3 may be arranged in other concave and convex distribution.

Defining the focal length of the image pickup optical lens 10 as f, and the focal length of the third lens L3 as f3, the following relations are satisfied: f3/f is more than or equal to 0.88 and less than or equal to 4.15, and the system has better imaging quality and lower sensitivity through reasonable distribution of the focal power. Preferably, 1.42. ltoreq. f 3/f. ltoreq.3.32 is satisfied.

The central curvature radius of the object side surface of the third lens L3 is R5, the central curvature radius of the image side surface of the third lens L3 is R6, and the following relational expressions are satisfied: 0.13-0.56 of (R5+ R6)/(R5-R6), the shape of the third lens L3 is regulated to be beneficial to the forming of the third lens L3, and the deflection degree of light rays passing through the lens can be alleviated within the range regulated by the conditional expression, so that the aberration can be effectively reduced. Preferably, it satisfies-0.08. ltoreq. (R5+ R6)/(R5-R6). ltoreq.0.45.

The on-axis thickness of the third lens L3 is d5, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d5/TTL is more than or equal to 0.06 and less than or equal to 0.21, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.09. ltoreq. d 5/TTL. ltoreq.0.17 is satisfied.

In this embodiment, the object-side surface of the fourth lens element L4 is concave at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the fourth lens element L4 has positive refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the fourth lens L4 may be arranged in other concave and convex distribution situations.

Defining the focal length f of the image pickup optical lens 10 and the focal length f4 of the fourth lens L4, the following relations are satisfied: 16.06 ≦ f4/f ≦ 42847.85, and the system has better imaging quality and lower sensitivity through reasonable distribution of the focal power. Preferably, 25.69. ltoreq. f 4/f. ltoreq. 34278.28 is satisfied.

The central curvature radius of the object side surface of the fourth lens L4 is R7, and the central curvature radius of the image side surface of the fourth lens L4 is R8, and the following relations are satisfied: (R7+ R8)/(R7-R8) is 352.48 or less, and the shape of the fourth lens L4 is defined, so that the problem of aberration of an off-axis picture angle and the like can be favorably corrected along with the development of ultra-thin and wide-angle in the range. Preferably, the (R7+ R8)/(R7-R8) ≦ 281.98.

The on-axis thickness of the fourth lens L4 is d7, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d7/TTL is more than or equal to 0.03 and less than or equal to 0.10, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.05. ltoreq. d 7/TTL. ltoreq.0.08 is satisfied.

In this embodiment, the object-side surface of the fifth lens element L5 is concave at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the fifth lens element L5 has positive refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the fifth lens L5 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f5 of the fifth lens L5, the following relations are satisfied: f5/f is more than or equal to 0.33 and less than or equal to 1.06, and the definition of the fifth lens L5 can effectively make the light ray angle of the shooting optical lens 10 smooth and reduce the tolerance sensitivity. Preferably, 0.53. ltoreq. f 5/f. ltoreq.0.85 is satisfied.

The central curvature radius of the object side surface of the fifth lens L5 is R9, the central curvature radius of the image side surface of the fifth lens L5 is R10, and the following relations are satisfied: the shape of the fifth lens L5 is defined to be not less than 0.50 (R9+ R10)/(R9-R10) and not more than 1.51, and when the shape is within the range, the aberration of the off-axis picture angle is favorably corrected with the development of ultra-thin and wide-angle. Preferably, 0.80. ltoreq. (R9+ R10)/(R9-R10). ltoreq.1.21 is satisfied.

The on-axis thickness of the fifth lens L5 is d9, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d9/TTL is more than or equal to 0.05 and less than or equal to 0.17, and ultra-thinning is facilitated in the condition formula range. Preferably, 0.09. ltoreq. d 9/TTL. ltoreq.0.14 is satisfied.

In this embodiment, the object-side surface of the sixth lens element L6 is concave at the paraxial region, the image-side surface thereof is concave at the paraxial region, and the sixth lens element L6 has negative refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the sixth lens L6 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f6 of the sixth lens L6, the following relations are satisfied: -0.82 ≦ f6/f ≦ -0.24, allowing better imaging quality and lower sensitivity of the system through a reasonable distribution of optical power. Preferably, it satisfies-0.51. ltoreq. f 6/f. ltoreq-0.31.

The center curvature radius of the object side surface of the sixth lens L6 is R11, the center curvature radius of the image side surface of the sixth lens L6 is R12, and the following relations are satisfied: the (R11+ R12)/(R11-R12) is 0.02 or less and 0.13 or less, and the shape of the sixth lens L6 is defined, and when the shape is within the condition range, the problem of aberration of the off-axis picture angle is favorably corrected as the ultra-thin wide-angle is developed. Preferably, 0.04. ltoreq. (R11+ R12)/(R11-R12). ltoreq.0.11 is satisfied.

The on-axis thickness of the sixth lens element L6 is d11, the total optical length of the imaging optical lens system 10 is TTL, and the following relationships are satisfied: d11/TTL is more than or equal to 0.05 and less than or equal to 0.16, and ultra-thinning is facilitated in the condition formula range. Preferably, 0.09. ltoreq. d 11/TTL. ltoreq.0.13 is satisfied.

In this embodiment, the aperture value FNO of the imaging optical lens 10 is less than or equal to 2.06, so that a large aperture is realized and the imaging performance of the imaging optical lens is good. Preferably, the aperture value FNO of the imaging optical lens 10 is less than or equal to 2.02.

In the present embodiment, the field angle FOV of the imaging optical lens 10 is greater than or equal to 72.27 °, thereby achieving a wide angle. Preferably, the field angle FOV of the image pickup optical lens 10 is greater than or equal to 73.00 °.

In the present embodiment, the image height of the image pickup optical lens 10 is IH, the total optical length of the image pickup optical lens 10 is TTL, and the following relational expression is satisfied: TTL/IH is less than or equal to 1.65, thereby being beneficial to realizing ultra-thinning. Preferably, TTL/IH ≦ 1.60 is satisfied.

The imaging optical lens 10 has good optical performance and can meet the design requirements of large aperture, wide angle and ultra-thinness; in accordance with the characteristics of the imaging optical lens 10, the imaging optical lens 10 is particularly suitable for a mobile phone imaging lens module and a WEB imaging lens which are configured by an imaging element such as a high-pixel CCD or a CMOS.

The image pickup optical lens 10 of the present invention will be explained below by way of example. The symbols described in the respective examples are as follows. The unit of focal length, on-axis distance, center curvature radius, on-axis thickness, position of the reverse curvature point and the position of the stagnation point is mm.

TTL: the total optical length (on-axis distance from the object side surface of the first lens L1 to the image plane Si) is in mm;

aperture value FNO: refers to the ratio of the effective focal length and the entrance pupil diameter of the imaging optical lens 10.

Preferably, the object side surface and/or the image side surface of the lens may be further provided with an inflection point and/or a stagnation point to meet the requirement of high-quality imaging.

Tables 1 and 2 show design data of the imaging optical lens 10 according to the first embodiment of the present invention.

[ TABLE 1 ]

Wherein each symbol has the following meaning.

S1: an aperture;

r: a radius of curvature at the center of the optical surface;

r1: the center radius of curvature of the object side of the first lens L1;

r2: the central radius of curvature of the image-side surface of the first lens L1;

r3: the center radius of curvature of the object side of the second lens L2;

r4: the central radius of curvature of the image-side surface of the second lens L2;

r5: the center radius of curvature of the object side of the third lens L3;

r6: the central radius of curvature of the image-side surface of the third lens L3;

r7: the center radius of curvature of the object side of the fourth lens L4;

r8: the central radius of curvature of the image-side surface of the fourth lens L4;

r9: the center radius of curvature of the object side of the fifth lens L5;

r10: the center radius of curvature of the image-side surface of the fifth lens L5;

r11: the center radius of curvature of the object side of the sixth lens L6;

r12: the center radius of curvature of the image-side surface of the sixth lens L6;

r13: the central radius of curvature of the object side of the optical filter GF;

r14: the center radius of curvature of the image side of the optical filter GF;

d: on-axis thickness of the lenses, on-axis distance between the lenses;

d 0: the on-axis distance of the stop S1 to the object-side surface of the first lens L1;

d 1: the on-axis thickness of the first lens L1;

d 2: the on-axis distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2;

d 3: the on-axis thickness of the second lens L2;

d 4: the on-axis distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3;

d 5: the on-axis thickness of the third lens L3;

d 6: the on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4;

d 7: the on-axis thickness of the fourth lens L4;

d 8: an on-axis distance from an image-side surface of the fourth lens L4 to an object-side surface of the fifth lens L5;

d 9: the on-axis thickness of the fifth lens L5;

d 10: an on-axis distance from an image-side surface of the fifth lens L5 to an object-side surface of the sixth lens L6;

d 11: the on-axis thickness of the sixth lens L6;

d 12: the on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the optical filter GF;

d 13: on-axis thickness of the optical filter GF;

d 14: the axial distance from the image side surface of the optical filter GF to the image surface Si;

nd: refractive index of d-line (d-line is green light with wavelength of 550 nm);

nd 1: the refractive index of the d-line of the first lens L1;

nd 2: the refractive index of the d-line of the second lens L2;

nd 3: the refractive index of the d-line of the third lens L3;

nd 4: the refractive index of the d-line of the fourth lens L4;

nd 5: the refractive index of the d-line of the fifth lens L5;

nd 6: the refractive index of the d-line of the sixth lens L6;

ndg: the refractive index of the d-line of the optical filter GF;

vd: an Abbe number;

v 1: abbe number of the first lens L1;

v 2: abbe number of the second lens L2;

v 3: abbe number of the third lens L3;

v 4: abbe number of the fourth lens L4;

v 5: abbe number of the fifth lens L5;

v 6: abbe number of the sixth lens L6;

vg: abbe number of the optical filter GF.

Table 2 shows aspherical surface data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[ TABLE 2 ]

For convenience, an aspherical surface shown in the following formula (1) is used as an aspherical surface of each lens surface. However, the present invention is not limited to the aspherical polynomial form expressed by this formula (1).

z=(cr²)/{1+[1-(k+1)(c²r²)]^1/2}+A4r⁴+A6r⁶+A8r⁸+A10r¹⁰+A12r¹²+A14r¹⁴+A16r¹⁶（1）

Where k is a conic coefficient, a4, a6, A8, a10, a12, a14, a16 are aspheric coefficients, c is the curvature at the center of the optical surface, r is the perpendicular distance between a point on the aspheric curve and the optical axis, and z is the aspheric depth (the perpendicular distance between a point on the aspheric surface at r from the optical axis and a tangent plane tangent to the vertex on the aspheric optical axis).

Tables 3 and 4 show the inflection point and stagnation point design data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention. P1R1 and P1R2 represent the object-side surface and the image-side surface of the first lens L1, P2R1 and P2R2 represent the object-side surface and the image-side surface of the second lens L2, P3R1 and P3R2 represent the object-side surface and the image-side surface of the third lens L3, P4R1 and P4R2 represent the object-side surface and the image-side surface of the fourth lens L4, P5R1 and P5R2 represent the object-side surface and the image-side surface of the fifth lens L5, and P6R1 and P6R2 represent the object-side surface and the image-side surface of the sixth lens L6, respectively. The "inflection point position" field correspondence data is a vertical distance from an inflection point set on each lens surface to the optical axis of the image pickup optical lens 10. The "stagnation point position" field corresponding data is the vertical distance from the stagnation point set on each lens surface to the optical axis of the imaging optical lens 10.

[ TABLE 3 ]

[ TABLE 4 ]

Fig. 2 and 3 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification after light having wavelengths of 656nm, 588nm, and 486nm passes through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 10 according to the first embodiment, where S is curvature of field in the sagittal direction and T is curvature of field in the tangential direction in fig. 4.

Table 13 shown later shows values corresponding to the parameters specified in the conditional expressions for the respective numerical values in the first, second, and third examples.

As shown in table 13, the first embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 2.257mm, a full field image height IH of 3.500mm, and a diagonal field angle FOV of 74.65 °, and the imaging optical lens 10 satisfies the design requirements of a large aperture, a wide angle, and a slimness, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(second embodiment)

The second embodiment is basically the same as the first embodiment, the same reference numerals as in the first embodiment, and only different points will be described below.

Fig. 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.

Tables 5 and 6 show design data of the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 5 ]

Table 6 shows aspherical surface data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 6 ]

Tables 7 and 8 show the inflection point and stagnation point design data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 7 ]

[ TABLE 8 ]

Fig. 6 and 7 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification after light having wavelengths of 656nm, 588nm and 486nm passes through the imaging optical lens 20 according to the second embodiment. Fig. 8 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 20 according to the second embodiment. The field curvature S in fig. 8 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

As shown in table 13, the second embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 2.267mm, a full field image height IH of 3.500mm, and a diagonal field angle FOV of 74.19 °, and the imaging optical lens 20 satisfies the design requirements of a large aperture, a wide angle, and a slimness, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(third embodiment)

The third embodiment is basically the same as the first embodiment, the same reference numerals as in the first embodiment, and only different points will be described below.

Fig. 9 shows an imaging optical lens 30 according to a third embodiment of the present invention.

Tables 9 and 10 show design data of the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 9 ]

Table 10 shows aspherical surface data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 10 ]

Tables 11 and 12 show the inflection points and the stagnation point design data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 11 ]

[ TABLE 12 ]

Fig. 10 and 11 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification after passing through the imaging optical lens 30 according to the third embodiment with the wavelengths of 656nm, 588nm, and 486nm, respectively. Fig. 12 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 30 according to the third embodiment. The field curvature S in fig. 12 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

Table 13 below shows the numerical values corresponding to the respective conditional expressions in the present embodiment, in accordance with the conditional expressions described above. Obviously, the imaging optical lens 30 of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the imaging optical lens 30 has an entrance pupil diameter ENPD of 2.286mm, a full field image height IH of 3.500mm, and a diagonal field angle FOV of 73.74 °, and the imaging optical lens 30 satisfies the design requirements of a large aperture, a wide angle, and a slimness, and has excellent optical characteristics in which the on-axis and off-axis chromatic aberration is sufficiently corrected.

[ TABLE 13 ]

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for practicing the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.

Claims

1. An imaging optical lens, comprising six lens elements in order from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power;

the focal length of the first lens is f1, the focal length of the sixth lens is f6, the central curvature radius of the object-side surface of the second lens is R3, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the object-side surface of the fourth lens is R7, the central curvature radius of the image-side surface of the fourth lens is R8, and the central curvature radius of the object-side surface of the fifth lens is R9, and the following relations are satisfied:

2.00≤R9/(R7+R8)≤6.00；

-3.00≤f1/f6≤-2.00；

3.00≤R5/R3≤5.00；

1.143≤(R7+R8)/(R7-R8)≤352.48。

2. the imaging optical lens of claim 1, wherein the object-side surface of the first lens element is convex at paraxial region and the image-side surface of the first lens element is concave at paraxial region;

the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, the on-axis thickness of the first lens is d1, and the total optical length of the image pickup optical lens is TTL and satisfies the following relational expression:

0.41≤f1/f≤1.64；

-3.57≤(R1+R2)/(R1-R2)≤-0.74；

0.06≤d1/TTL≤0.20。

3. the imaging optical lens according to claim 2, wherein the imaging optical lens satisfies the following relationship:

0.66≤f1/f≤1.31；

-2.23≤(R1+R2)/(R1-R2)≤-0.92；

0.09≤d1/TTL≤0.16。

4. the imaging optical lens of claim 1, wherein the object-side surface of the second lens element is convex at paraxial region and the image-side surface of the second lens element is concave at paraxial region;

the focal length of the image pickup optical lens is f, the focal length of the second lens is f2, the central curvature radius of the image side surface of the second lens is R4, the on-axis thickness of the second lens is d3, the optical total length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

-6.45≤f2/f≤-1.33；

1.76≤(R3+R4)/(R3-R4)≤10.27；

0.03≤d3/TTL≤0.08。

5. the imaging optical lens according to claim 4, wherein the imaging optical lens satisfies the following relation:

-4.03≤f2/f≤-1.66；

2.81≤(R3+R4)/(R3-R4)≤8.22；

0.04≤d3/TTL≤0.07。

6. the imaging optical lens of claim 1, wherein the object-side surface of the third lens element is convex at paraxial region and the image-side surface of the third lens element is convex at paraxial region;

the focal length of the image pickup optical lens is f, the focal length of the third lens is f3, the central curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

0.88≤f3/f≤4.15；

-0.13≤(R5+R6)/(R5-R6)≤0.56；

0.06≤d5/TTL≤0.21。

7. the imaging optical lens according to claim 6, wherein the imaging optical lens satisfies the following relation:

1.42≤f3/f≤3.32；

-0.08≤(R5+R6)/(R5-R6)≤0.45；

0.09≤d5/TTL≤0.17。

8. the imaging optical lens of claim 1, wherein the object-side surface of the fourth lens element is concave at the paraxial region and the image-side surface of the fourth lens element is convex at the paraxial region;

the focal length of the image pickup optical lens is f, the focal length of the fourth lens is f4, the on-axis thickness of the fourth lens is d7, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

16.06≤f4/f≤42847.85；

0.03≤d7/TTL≤0.10。

9. the image-pickup optical lens according to claim 8, wherein the image-pickup optical lens satisfies the following relation:

25.69≤f4/f≤34278.28；

1.143≤(R7+R8)/(R7-R8)≤281.98；

0.05≤d7/TTL≤0.08。

10. the imaging optical lens of claim 1, wherein the object-side surface of the fifth lens element is concave at paraxial region and the image-side surface of the fifth lens element is convex at paraxial region;

the focal length of the image pickup optical lens is f, the focal length of the fifth lens is f5, the central curvature radius of the image side surface of the fifth lens is R10, the on-axis thickness of the fifth lens is d9, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

0.33≤f5/f≤1.06；

0.50≤(R9+R10)/(R9-R10)≤1.51；

0.05≤d9/TTL≤0.17。

11. the image-pickup optical lens according to claim 10, wherein the image-pickup optical lens satisfies the following relation:

0.53≤f5/f≤0.85；

0.80≤(R9+R10)/(R9-R10)≤1.21；

0.09≤d9/TTL≤0.14。

12. the imaging optical lens of claim 1, wherein the object-side surface of the sixth lens element is concave at the paraxial region, and the image-side surface of the sixth lens element is concave at the paraxial region;

the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the sixth lens element is R11, the central curvature radius of the image side surface of the sixth lens element is R12, the on-axis thickness of the sixth lens element is d11, and the total optical length of the image pickup optical lens is TTL and satisfies the following relational expression:

-0.82≤f6/f≤-0.24；

0.02≤(R11+R12)/(R11-R12)≤0.13；

0.05≤d11/TTL≤0.16。

13. the image-pickup optical lens according to claim 12, wherein the image-pickup optical lens satisfies the following relation:

-0.51≤f6/f≤-0.31；

0.04≤(R11+R12)/(R11-R12)≤0.11；

0.09≤d11/TTL≤0.13。

14. the imaging optical lens according to claim 1, wherein an aperture value FNO of the imaging optical lens is less than or equal to 2.06.

15. The imaging optical lens according to claim 14, wherein an aperture value FNO of the imaging optical lens is less than or equal to 2.02.

16. The image-pickup optical lens according to claim 1, wherein a field angle FOV of the image-pickup optical lens is greater than or equal to 72.27 °.

17. The image-pickup optical lens according to claim 16, wherein a field angle FOV of the image-pickup optical lens is greater than or equal to 73.00 °.

18. A camera optical lens according to claim 1, wherein the image height of the camera optical lens is IH, the total optical length of the camera optical lens is TTL, and the following relationship is satisfied: TTL/IH is less than or equal to 1.65.

19. The image-pickup optical lens according to claim 18, wherein the image-pickup optical lens satisfies the following relationship: TTL/IH is less than or equal to 1.60.