CN112285904B

CN112285904B - Image pickup optical lens

Info

Publication number: CN112285904B
Application number: CN202011606368.4A
Authority: CN
Inventors: 新田耕二; 徐丽
Original assignee: Changzhou Ruitai Photoelectric Co Ltd
Current assignee: Changzhou Ruitai Photoelectric Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-03-09
Anticipated expiration: 2040-12-31
Also published as: CN112285904A

Abstract

The invention relates to the field of optical lenses, and discloses a photographic optical lens, which comprises seven lenses, wherein the seven lenses are sequentially 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, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, a sixth lens element with positive refractive power, and a seventh lens element with negative refractive power; the focal length of the imaging optical lens is f, the focal length of the third lens is f3, 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 on-axis thickness of the fourth lens is d7, the on-axis distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is d8, and the following relational expressions are satisfied: -2.00. ltoreq. f 3/f. ltoreq.20.00; d7/d8 is more than or equal to 3.00 and less than or equal to 8.00; R7/R5 is more than or equal to 1.00 and less than or equal to 4.00. 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 smart phones, the demand for miniaturized camera lenses is increasing, and due to the reduction of the pixel size of the photo sensor and the trend of the electronic products toward the appearance with good functions, light weight, small size, etc., the miniaturized camera lenses with good imaging quality are the mainstream in the market at present. 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 seven-piece lens structure gradually appears in the design of the lens. There is a strong demand for a wide-angle imaging optical 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, a wide angle, and an ultra-thin profile.

To solve the above-mentioned problems, an embodiment of the present invention provides an imaging optical lens, which includes seven 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 refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, a sixth lens element with positive refractive power, and a seventh lens element with negative refractive power; the focal length of the imaging optical lens is f, the focal length of the third lens is f3, 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 on-axis thickness of the fourth lens is d7, the on-axis distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is d8, and the following relations are satisfied: -2.00. ltoreq. f 3/f. ltoreq.20.00; d7/d8 is more than or equal to 3.00 and less than or equal to 8.00; R7/R5 is more than or equal to 1.00 and less than or equal to 4.00.

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 first lens is f1, 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, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f1/f is more than or equal to 0.44 and less than or equal to 1.39; -3.28 ≤ (R1+ R2)/(R1-R2) ≤ 1.01; d1/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: f1/f is more than or equal to 0.71 and less than or equal to 1.11; -2.05 ≤ (R1+ R2)/(R1-R2) ≤ 1.27; d1/TTL is more than or equal to 0.08 and less than or equal to 0.13.

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 second lens is f2, the central curvature radius of the object-side surface of the second lens is R3, 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 total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f2/f is more than or equal to minus 5.56 and less than or equal to minus 1.52; 1.02-6.99 of (R3+ R4)/(R3-R4); d3/TTL is more than or equal to 0.02 and less than or equal to 0.09.

Preferably, the imaging optical lens satisfies the following relation: f2/f is not less than-3.48 and not more than-1.90; 1.63-5.59 percent of (R3+ R4)/(R3-R4); d3/TTL is more than or equal to 0.03 and less than or equal to 0.07.

Preferably, a central radius of curvature of an image-side surface of the third lens element is R6, an on-axis thickness of the third lens element is d5, and an optical total length of the imaging optical lens system is TTL and satisfies the following relationship: the ratio of (R5+ R6)/(R5-R6) is not more than 0.64 and not more than 16.42; d5/TTL is more than or equal to 0.04 and less than or equal to 0.13.

Preferably, the imaging optical lens satisfies the following relation: 1.03-13.14 of (R5+ R6)/(R5-R6); d5/TTL is more than or equal to 0.06 and less than or equal to 0.10.

Preferably, the image-side surface of the fourth lens is convex at the paraxial region; the focal length of the fourth lens element is f4, the central curvature radius of the image side surface of the fourth lens element is R8, the total optical length of the image pickup optical lens assembly is TTL, and the following relation is satisfied: f4/f is more than or equal to 1.04 and less than or equal to 45.64; (R7+ R8)/(R7-R8) is not more than 0.33 and not more than 10.37; d7/TTL is more than or equal to 0.02 and less than or equal to 0.07.

Preferably, the imaging optical lens satisfies the following relation: f4/f is more than or equal to 1.67 and less than or equal to 36.51; (R7+ R8)/(R7-R8) is not more than 0.52 and not more than 8.29; d7/TTL is more than or equal to 0.04 and less than or equal to 0.06.

Preferably, the object-side surface of the fifth lens element is convex at the paraxial region, and the image-side surface of the fifth lens element is concave at the paraxial region; the focal length of the fifth lens element is f5, the center curvature radius of the object-side surface of the fifth lens element is R9, the center curvature radius of the image-side surface of the fifth lens element is R10, the on-axis thickness of the fifth lens element is d9, and the total optical length of the imaging optical lens assembly is TTL and satisfies the following relationships: f5/f is more than or equal to 1.81 and less than or equal to 57.00; -161.33 (R9+ R10)/(R9-R10) is less than or equal to-1.61; d9/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: f5/f is more than or equal to 2.89 and less than or equal to 45.60; -100.83 ≤ (R9+ R10)/(R9-R10) ≤ 2.01; d9/TTL is more than or equal to 0.04 and less than or equal to 0.07.

Preferably, an object-side surface of the sixth lens element is convex at a paraxial region, and an image-side surface of the sixth lens element is convex at a paraxial region; the focal length of the sixth lens element is f6, 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, the total optical length of the imaging optical lens assembly is TTL, and the following relations are satisfied: f6/f is more than or equal to 0.71 and less than or equal to 2.59; -1.41 ≤ (R11+ R12)/(R11-R12) ≤ 0.27; d11/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: f6/f is more than or equal to 1.14 and less than or equal to 2.07; -0.88 ≤ (R11+ R12)/(R11-R12) ≤ 0.34; d11/TTL is more than or equal to 0.08 and less than or equal to 0.14.

Preferably, the object side surface of the seventh lens element is concave at the paraxial region, and the image side surface of the seventh lens element is concave at the paraxial region; the focal length of the seventh lens element is f7, the central curvature radius of the object-side surface of the seventh lens element is R13, the central curvature radius of the image-side surface of the seventh lens element is R14, the on-axis thickness of the seventh lens element is d13, the total optical length of the imaging optical lens assembly is TTL, and the following relationships are satisfied: f7/f is not less than 1.45 and not more than-0.47; (R13+ R14)/(R13-R14) is not more than 0.34 and not more than 1.23; d13/TTL is more than or equal to 0.04 and less than or equal to 0.13.

Preferably, the imaging optical lens satisfies the following relation: f7/f is more than or equal to-0.91 and less than or equal to-0.58; (R13+ R14)/(R13-R14) is not more than 0.54 and not more than 0.99; d13/TTL is more than or equal to 0.06 and less than or equal to 0.11.

Preferably, the combined focal length of the first lens and the second lens is f12, and the following relation is satisfied: f12/f is more than or equal to 0.62 and less than or equal to 1.91.

Preferably, the aperture value of the imaging optical lens is FNO, and satisfies the following relationship: FNO is less than or equal to 2.16.

Preferably, the field angle of the imaging optical lens in the diagonal direction is FOV, and satisfies the following relation: the FOV is greater than or equal to 83.85 degrees.

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 1.31.

The invention has the beneficial effects that: the imaging optical lens of the present invention has excellent optical characteristics, and has characteristics of large aperture, wide angle and ultra-thin, and is particularly suitable for a mobile phone camera lens assembly and a WEB camera lens which are composed of high-pixel imaging elements such as a CCD and a CMOS.

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 is a schematic structural diagram of an imaging optical lens 10 according to a first embodiment of the present invention, where the imaging optical lens 10 includes seven lenses. Specifically, the left side is an object side, the right side is an image side, and the imaging optical lens 10, in order from the object side to the image side, includes: a diaphragm S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. An optical element such as an optical filter (filter) GF may be disposed between the seventh lens L7 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, the sixth lens L6 is made of plastic, and the seventh lens L7 is made of plastic. In other embodiments, the lenses may be made of other materials.

In the present embodiment, the focal length of the imaging optical lens 10 is defined as f, and the focal length of the third lens L3 is defined as f3, and the following relational expression is satisfied: 2.00 ≦ f3/f ≦ 20.00, which specifies the ratio of the focal length f3 of the third lens L3 to the focal length f of the image-taking optical lens 10, so that the image-taking optical lens 10 has better image quality and lower sensitivity through reasonable distribution of the focal power.

Defining the on-axis thickness of the fourth lens L4 as d7, and the on-axis distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 as d8, the following relationships are satisfied: d7/d8 is 3.00-8.00, the ratio of the on-axis thickness d7 of the fourth lens L4 to the on-axis distance d8 from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is defined, and the imaging optical lens 10 is beneficial to the wide-angle development within the range of the relational expression.

The central curvature radius of the object side surface of the third lens L3 is defined to be R5, and the central curvature radius of the object side surface of the fourth lens L4 is defined to be R7, so that the following relations are satisfied: the ratio of the central curvature radius R7 of the object side surface of the fourth lens L4 to the central curvature radius R5 of the object side surface of the third lens L3 is defined within a range defined by a conditional expression, wherein R7/R5 is not more than 1.00 and not more than 4.00, and the sensitivity of the imaging optical lens 10 to decentration of the third lens L3 can be effectively reduced within a range defined by the conditional expression.

In this embodiment, the first lens element L1 with positive refractive power has a convex object-side surface and a concave image-side surface at paraxial regions, and the first lens element L1 with convex object-side surface and concave image-side surface at paraxial regions. In other embodiments, the object-side surface and the image-side surface of the first lens element L1 may have other concave and convex distribution at the paraxial region.

The focal length of the image pickup optical lens 10 is f, the focal length of the first lens L1 is defined as f1, and the following relation is satisfied: f1/f is 0.44 ≦ 1.39, and the ratio of the focal length f1 of the first lens L1 to the focal length f of the image-taking optical lens 10 is specified. Within the predetermined range, the first lens element L1 has a proper positive refractive power, which is beneficial to reducing system aberration and to making the lens barrel ultrathin. Preferably, 0.71. ltoreq. f 1/f. ltoreq.1.11 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: -3.28 ≦ (R1+ R2)/(R1-R2) ≦ -1.01, and the shape of the first lens L1 is controlled appropriately so that the first lens L1 can effectively correct the spherical aberration of the imaging optical lens 10. Preferably, it satisfies-2.05 ≦ (R1+ R2)/(R1-R2) ≦ -1.27.

Defining the total optical length of the image pickup optical lens 10 as TTL, and the on-axis thickness of the first lens L1 as d1, which satisfy the following relations: d1/TTL is more than or equal to 0.05 and less than or equal to 0.17, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.08. ltoreq. d 1/TTL. ltoreq.0.13 is satisfied.

In this embodiment, the second lens element L2 with negative refractive power has a convex object-side surface and a concave image-side surface at paraxial regions, and the second lens element L2 has convex object-side surface and concave image-side surface at paraxial regions. In other embodiments, the object-side surface and the image-side surface of the second lens L2 may have other concave and convex distribution at the paraxial region.

The focal length of the image pickup optical lens 10 is f, the focal length of the second lens L2 is defined as f2, and the following relation is satisfied: f2/f is more than or equal to-5.56 and less than or equal to-1.52, and the negative power of the second lens L2 is controlled in a reasonable range, so that the aberration of the shooting optical lens 10 is favorably corrected. Preferably, it satisfies-3.48. ltoreq. f 2/f. ltoreq-1.90.

The central curvature radius of the object side surface of the second lens L2 is defined as R3, the central curvature radius of the image side surface of the second lens L2 is defined as R4, and the following relations are satisfied: the (R3+ R4)/(R3-R4) is 1.02 or more and 6.99 or less, and the shape of the second lens L2 is defined, and when the relationship is within the range of the relational expression, the problem of chromatic aberration on the axis can be corrected favorably as the imaging optical lens 10 becomes thinner and wider. Preferably, 1.63 ≦ (R3+ R4)/(R3-R4) ≦ 5.59.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the second lens L2 is defined as d3, which satisfies the following relation: d3/TTL is more than or equal to 0.02 and less than or equal to 0.09, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.03. ltoreq. d 3/TTL. ltoreq.0.07 is satisfied.

In this embodiment, the third lens element L3 with negative refractive power has a convex object-side surface and a concave image-side surface at paraxial regions, and the third lens element L3 has convex object-side surface and concave image-side surface at paraxial regions. In other embodiments, the third lens element L3 with positive refractive power can have other concave and convex distribution on the paraxial region of the object-side and image-side surfaces of the third lens element L3.

The central curvature radius of the object side surface of the third lens L3 is defined as R5, the central curvature radius of the image side surface of the third lens L3 is defined as R6, and the following relations are satisfied: the shape of the third lens L3 is regulated to be not less than 0.64 and not more than (R5+ R6)/(R5-R6) and not more than 16.42, the molding of the third lens L3 is facilitated, and the deflection degree of light rays passing through the lens can be alleviated within the range specified by the conditional expression, so that the aberration can be effectively reduced. Preferably, 1.03 ≦ (R5+ R6)/(R5-R6) ≦ 13.14.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the third lens L3 is defined as d5, which satisfies the following relation: d5/TTL is more than or equal to 0.04 and less than or equal to 0.13, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.06. ltoreq. d 5/TTL. ltoreq.0.10 is satisfied.

In this embodiment, the fourth lens element L4 with positive refractive power has a convex object-side surface and a convex image-side surface in paraxial regions, and the fourth lens element L4 with positive refractive power has a convex object-side surface and a convex image-side surface in paraxial regions. In other embodiments, the object-side surface and the image-side surface of the fourth lens element L4 may have other concave and convex distribution at the paraxial region.

The focal length of the image pickup optical lens 10 is f, and the focal length of the fourth lens L4 is f4, which satisfies the following relation: f4/f is not less than 1.04 and not more than 45.64, the ratio of the focal length f4 of the fourth lens L4 to the focal length f of the imaging optical lens 10 is regulated, and the ratio is beneficial to improving the performance of the imaging optical lens 10 in the range of the relational expression. Preferably, 1.67. ltoreq. f 4/f. ltoreq. 36.51 is satisfied.

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 following relations are satisfied: the shape of the fourth lens L4 is defined to be not less than 0.33 (R7+ R8)/(R7-R8) and not more than 10.37, and when the shape is within the range, the problem such as aberration of an off-axis angle is favorably corrected with the development of ultra-thinning and wide-angle. Preferably, 0.52. ltoreq. R7+ R8)/(R7-R8. ltoreq.8.29 is satisfied.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the fourth lens element L4 is defined as d7, which satisfies the following relation: d7/TTL is more than or equal to 0.02 and less than or equal to 0.07, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.04. ltoreq. d 7/TTL. ltoreq.0.06 is satisfied.

In this embodiment, the fifth lens element L5 has positive refractive power, and the object-side surface and the image-side surface of the fifth lens element L5 are convex and concave respectively at the paraxial region and the paraxial region. In other embodiments, the object-side surface and the image-side surface of the fifth lens element L5 may have other concave and convex distribution at the paraxial region.

The focal length of the image pickup optical lens 10 is f, the focal length of the fifth lens L5 is f5, and the following relation is satisfied: f5/f is more than or equal to 1.81 and less than or equal to 57.00, 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, 2.89. ltoreq. f 5/f. ltoreq.45.60 is satisfied.

The central curvature radius of the object side surface of the fifth lens L5 is defined as R9, the central curvature radius of the image side surface of the fifth lens L5 is defined as R10, and the following relations are satisfied: the shape of the fifth lens L5 is defined to be not less than 161.33 (R9+ R10)/(R9-R10) and not more than-1.61, and when the shape is within the range, the problem of aberration of an off-axis angle and the like can be favorably corrected with the development of ultra-thinning and wide-angle. Preferably, it satisfies-100.83 ≦ (R9+ R10)/(R9-R10) ≦ -2.01.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the fifth lens L5 is defined as d9, which satisfies the following relation: d9/TTL is more than or equal to 0.03 and less than or equal to 0.08, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.04. ltoreq. d 9/TTL. ltoreq.0.07 is satisfied.

In this embodiment, the sixth lens element L6 with positive refractive power has a convex object-side surface and a convex image-side surface in paraxial regions, and the sixth lens element L6 with positive refractive power has a convex object-side surface and a convex image-side surface in paraxial regions. In other embodiments, the object-side surface and the image-side surface of the sixth lens element L6 may have other concave and convex distribution at the paraxial region.

The focal length of the image pickup optical lens 10 is f, the focal length of the sixth lens L6 is f6, and the following relation is satisfied: f6/f is more than or equal to 0.71 and less than or equal to 2.59, and the shooting optical lens 10 has better imaging quality and lower sensitivity through reasonable distribution of focal power. Preferably, 1.14. ltoreq. f 6/f. ltoreq.2.07 is satisfied.

The central curvature radius of the object side surface of the sixth lens L6 is defined as R11, the central curvature radius of the image side surface of the sixth lens L6 is defined as R12, and the following relations are satisfied: the (R11+ R12)/(R11-R12) is not more than 1.41 and not more than-0.27, the shape of the sixth lens L6 is defined, and when the shape is within the relational expression range, the problem of aberration of off-axis angles and the like is favorably corrected along with the development of ultra-thinning and wide-angle. Preferably, it satisfies-0.88 ≦ (R11+ R12)/(R11-R12). ltoreq.0.34.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the sixth lens element L6 is defined as d11, which satisfies the following relation: d11/TTL is more than or equal to 0.05 and less than or equal to 0.17, and ultra-thinning is facilitated in the relational expression range. Preferably, 0.08. ltoreq. d 11/TTL. ltoreq.0.14 is satisfied.

In this embodiment, the seventh lens element L7 with negative refractive power has a concave object-side surface and a concave image-side surface at the paraxial region of the seventh lens element L7. In other embodiments, the object-side surface and the image-side surface of the seventh lens L7 may have other concave and convex distribution at the paraxial region.

Defining the focal length of the image pickup optical lens 10 as f, and the focal length of the seventh lens L7 as f7, the following relations are satisfied: 1.45 ≦ f7/f ≦ -0.47, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-0.91. ltoreq. f 7/f. ltoreq-0.58.

The central curvature radius of the object side surface of the seventh lens L7 is defined as R13, and the central curvature radius of the image side surface of the seventh lens L7 is defined as R14, which satisfy the following relations: the shape of the seventh lens L7 is defined to be not less than 0.34 (R13+ R14)/(R13-R14) and not more than 1.23, and the problems such as aberration of off-axis view angle and the like are favorably corrected as the thinning and the widening of the angle progress within the condition range. Preferably, 0.54. ltoreq. (R13+ R14)/(R13-R14). ltoreq.0.99 is satisfied.

The on-axis thickness of the seventh lens L7 is d13, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d13/TTL is more than or equal to 0.04 and less than or equal to 0.13, and ultra-thinning is facilitated in the condition formula range. Preferably, 0.06. ltoreq. d 13/TTL. ltoreq.0.11 is satisfied.

In the present embodiment, the focal length of the imaging optical lens 10 is f, and the combined focal length of the first lens L1 and the second lens L2 is f12, and the following relationship is satisfied: f12/f is not less than 0.62 and not more than 1.91, and within the range of the conditional expression, the aberration and distortion of the image pickup optical lens 10 can be eliminated, and the back focal length of the image pickup optical lens 10 can be suppressed, so as to keep the miniaturization of the image lens system. Preferably, 0.99. ltoreq. f 12/f. ltoreq.1.53 is satisfied.

In the present embodiment, the aperture value of the imaging optical lens 10 is defined as FNO, and the following relationship is satisfied: FNO is less than or equal to 2.16, thereby being beneficial to realizing large aperture. Preferably, FNO is less than or equal to 2.12.

In the present embodiment, the focal length of the imaging optical lens 10 is f, the field angle in the diagonal direction of the imaging optical lens 10 is defined as FOV, and the following relational expression is satisfied: the FOV is greater than or equal to 83.85 degrees, thereby being beneficial to realizing wide-angle. Preferably, the FOV is satisfied at 84.71.

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 1.31, thereby being beneficial to realizing ultra-thinning. Preferably, TTL/IH ≦ 1.27 is satisfied.

When the above relationship is satisfied, the imaging optical lens 10 has good optical performance, and can satisfy 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: is the ratio of the effective focal length and the entrance pupil diameter of the imaging optical lens.

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 center radius of curvature of the object side of the seventh lens L7;

r14: the central radius of curvature of the image-side surface of the seventh lens L7;

r15: the central radius of curvature of the object side of the optical filter GF;

r16: 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: an on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the seventh lens L7;

d 13: the on-axis thickness of the seventh lens L7;

d 14: the on-axis distance from the image-side surface of the seventh lens L7 to the object-side surface of the optical filter GF;

d 15: on-axis thickness of the optical filter GF;

d 16: 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;

nd 7: the refractive index of the d-line of the seventh lens L7;

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;

v 7: abbe number of the seventh lens L7;

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+A18r¹⁸+A20r²⁰（1）

Where k is a conic coefficient, a4, a6, A8, a10, a12, a14, a16, a18, a20 are aspheric coefficients, c is a curvature at the center of the optical surface, r is a perpendicular distance from a point on an aspheric curve to the optical axis, and z is an aspheric depth (a perpendicular distance between a point on an aspheric surface at a distance of r from the optical axis and a tangent plane tangent to a 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, P6R1 and P6R2 represent the object-side surface and the image-side surface of the sixth lens L6, and P7R1 and P7R2 represent the object-side surface and the image-side surface of the seventh lens L7, 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 aberration of magnification of light having wavelengths of 650nm, 555nm, and 470nm, respectively, after passing 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 555nm 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 defined in the conditional expressions, for each of the numerical values in the first, second, and third embodiments.

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 3.291mm, a full field image height IH of 6.247mm, and a diagonal field angle FOV of 85.58 °, 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)

Fig. 5 is a schematic structural diagram of an imaging optical lens 20 according to a second embodiment of the present invention, which is basically the same as the first embodiment, and the same reference numerals as the first embodiment, and only differences will be described below.

In this embodiment, the third lens element L3 with positive refractive power has a concave object-side surface at the paraxial region of the third lens element L3, a convex image-side surface at the paraxial region of the third lens element L3, and a concave object-side surface at the paraxial region of the fourth lens element L4.

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 aberration of magnification of light having wavelengths of 650nm, 555nm, and 470nm, respectively, after passing 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 555nm 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 3.130mm, a full field height IH of 6.247mm, and a diagonal field angle FOV of 85.56 °, 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 with on-axis and off-axis chromatic aberration sufficiently corrected.

(third embodiment)

Fig. 9 is a schematic structural diagram of an imaging optical lens 30 according to a third embodiment of the present invention, which is basically the same as the first embodiment, and the same reference numerals as the first embodiment, and only differences will be described below.

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 aberration of magnification of light having wavelengths of 650nm, 555nm, and 470nm, respectively, after passing through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a schematic view showing curvature of field and distortion of light having a wavelength of 555nm 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 3.371mm, a full field height IH of 6.247mm, and a diagonal field angle FOV of 85.57 °, and the imaging optical lens 30 satisfies the design requirements of a large aperture, a wide angle, and a slim size, and has excellent optical characteristics with on-axis and off-axis chromatic aberration 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 seven 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 refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, a sixth lens element with positive refractive power, and a seventh lens element with negative refractive power; the object side surface of the first lens is a convex surface at the paraxial position, and the image side surface of the first lens is a concave surface at the paraxial position; the object side surface of the second lens is convex at the paraxial part, and the image side surface of the second lens is concave at the paraxial part; the image side surface of the fourth lens is convex at the paraxial position; the object side surface of the fifth lens is convex at the paraxial position, and the image side surface of the fifth lens is concave at the paraxial position; the object side surface of the sixth lens element is convex at the paraxial region, and the image side surface of the sixth lens element is convex at the paraxial region; the object side surface of the seventh lens is concave at the paraxial region, and the image side surface of the seventh lens is concave at the paraxial region; the focal length of the imaging optical lens is f, the focal length of the third lens is f3, 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 on-axis thickness of the fourth lens is d7, the on-axis distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is d8, and the following relations are satisfied:

-2.00≤f3/f≤20.00；

3.00≤d7/d8≤8.00；

1.00≤R7/R5≤4.00。

2. the imaging optical lens of claim 1, wherein the focal length of the first lens is f1, the central radius of curvature of the object-side surface of the first lens is R1, the central radius of curvature of the image-side surface of the first lens is R2, the on-axis thickness of the first lens is d1, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied:

0.44≤f1/f≤1.39；

-3.28≤(R1+R2)/(R1-R2)≤-1.01；

0.05≤d1/TTL≤0.17。

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

0.71≤f1/f≤1.11；

-2.05≤(R1+R2)/(R1-R2)≤-1.27；

0.08≤d1/TTL≤0.13。

4. the imaging optical lens of claim 1, wherein the focal length of the second lens is f2, the central radius of curvature of the object-side surface of the second lens is R3, the central radius of curvature of the image-side surface of the second lens is R4, the on-axis thickness of the second lens is d3, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied:

-5.56≤f2/f≤-1.52；

1.02≤(R3+R4)/(R3-R4)≤6.99；

0.02≤d3/TTL≤0.09。

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

-3.48≤f2/f≤-1.90；

1.63≤(R3+R4)/(R3-R4)≤5.59；

0.03≤d3/TTL≤0.07。

6. the imaging optical lens of claim 1, wherein a central radius of curvature of an image-side surface of the third lens is R6, an on-axis thickness of the third lens is d5, an optical total length of the imaging optical lens is TTL, and the following relationship is satisfied:

0.64≤(R5+R6)/(R5-R6)≤16.42；

0.04≤d5/TTL≤0.13。

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

1.03≤(R5+R6)/(R5-R6)≤13.14；

0.06≤d5/TTL≤0.10。

8. the imaging optical lens of claim 1, wherein the focal length of the fourth lens element is f4, the central radius of curvature of the image side surface of the fourth lens element is R8, the total optical length of the imaging optical lens is TTL, and the following relationships are satisfied:

1.04≤f4/f≤45.64；

0.33≤(R7+R8)/(R7-R8)≤10.37；

0.02≤d7/TTL≤0.07。

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

1.67≤f4/f≤36.51；

0.52≤(R7+R8)/(R7-R8)≤8.29；

0.04≤d7/TTL≤0.06。

10. the imaging optical lens of claim 1, wherein the focal length of the fifth lens element is f5, the center radius of curvature of the object-side surface of the fifth lens element is R9, the center radius of curvature of the image-side surface of the fifth lens element is R10, the on-axis thickness of the fifth lens element is d9, the total optical length of the imaging optical lens is TTL, and the following relationships are satisfied:

1.81≤f5/f≤57.00；

-100.83≤(R9+R10)/(R9-R10)≤-1.61；

0.03≤d9/TTL≤0.08。

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

2.89≤f5/f≤45.60；

-100.83≤(R9+R10)/(R9-R10)≤-2.01；

0.04≤d9/TTL≤0.07。

12. the imaging optical lens of claim 1, wherein the focal length of the sixth lens element is f6, the center radius of curvature of the object-side surface of the sixth lens element is R11, the center radius of curvature of the image-side surface of the sixth lens element is R12, the on-axis thickness of the sixth lens element is d11, the total optical length of the imaging optical lens is TTL, and the following relationships are satisfied:

0.71≤f6/f≤2.59；

-1.41≤(R11+R12)/(R11-R12)≤-0.27；

0.05≤d11/TTL≤0.17。

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

1.14≤f6/f≤2.07；

-0.88≤(R11+R12)/(R11-R12)≤-0.34；

0.08≤d11/TTL≤0.14。

14. the imaging optical lens of claim 1, wherein the focal length of the seventh lens is f7, the central radius of curvature of the object-side surface of the seventh lens is R13, the central radius of curvature of the image-side surface of the seventh lens is R14, the on-axis thickness of the seventh lens is d13, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied:

-1.45≤f7/f≤-0.47；

0.34≤(R13+R14)/(R13-R14)≤1.23；

0.04≤d13/TTL≤0.13。

15. the image-pickup optical lens according to claim 14, wherein the image-pickup optical lens satisfies the following relation:

-0.91≤f7/f≤-0.58；

0.54≤(R13+R14)/(R13-R14)≤0.99；

0.06≤d13/TTL≤0.11。

16. the imaging optical lens according to claim 1, wherein a combined focal length of the first lens and the second lens is f12, and the following relationship is satisfied:

0.62≤f12/f≤1.91。

17. the imaging optical lens according to claim 1, wherein an aperture value of the imaging optical lens is FNO, and satisfies the following relationship:

FNO≤2.16。

18. the imaging optical lens according to claim 1, wherein a diagonal field angle of the imaging optical lens is FOV, and the following relationship is satisfied:

FOV≥83.85°。

19. 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≤1.31。