CN108254891B

CN108254891B - Image pickup optical lens

Info

Publication number: CN108254891B
Application number: CN201711475875.7A
Authority: CN
Inventors: 生沼健司; 张磊; 王燕妹; 张丹
Original assignee: AAC Technologies Pte Ltd
Current assignee: AAC Technologies Pte Ltd
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2020-07-17
Anticipated expiration: 2037-12-29
Also published as: CN108254891A

Abstract

The invention relates to the field of optical lenses, and discloses a photographic optical lens which sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side, wherein the second lens has positive refractive power, the third lens has negative refractive power, the following relational expressions of-3-f 1/f-1.7, 1.7-n 1-2.2 and 1.7-n 5-2 are satisfied, and the photographic optical lens can obtain high imaging performance and low TT L.

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 of miniaturized camera lenses is increasing, and the photosensitive devices of general camera lenses are not limited to two types, namely, a Charge Coupled Device (CCD) or a Complementary Metal-oxide semiconductor (CMOS) Sensor, and due to the advanced semiconductor manufacturing process technology, the pixel size of the photosensitive devices is reduced, and in addition, the current electronic products are developed with a good function, a light weight, a small size and a light weight, so that the miniaturized camera lenses with good imaging quality are the mainstream in the current market. In order to obtain better imaging quality, the lens mounted on the mobile phone camera conventionally adopts a three-piece or four-piece lens structure. 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, five-piece, six-piece and seven-piece lens structures gradually appear in the design of the lens. A wide-angle imaging lens having excellent optical characteristics, being ultra-thin and having sufficient chromatic aberration correction is in demand.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an imaging optical lens that can satisfy the requirements of ultra-thinning and wide angle while achieving high imaging performance.

To solve the above-mentioned problems, an embodiment of the present invention provides an imaging optical lens, in order from an object side to an image side, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; the second lens element with positive refractive power and the third lens element with negative refractive power;

the focal length of the image pickup optical lens is f, the focal length of the first lens is f1, the refractive index of the first lens is n1, and the refractive index of the fifth lens is n5, and the following relations are satisfied:

-3≤f1/f≤-1.7；

1.7≤n1≤2.2；

1.7≤n5≤2.2。

compared with the prior art, the embodiment of the invention utilizes the arrangement mode of the lenses and utilizes the common cooperation of the lenses with specific relation on data of focal length, refractive index, total optical length, axial thickness and curvature radius of the shooting optical lens, so that the shooting optical lens can meet the requirements of ultra-thinning and wide angle while obtaining high imaging performance.

Preferably, the imaging optical lens satisfies the following relational expression: f1/f is more than or equal to-2.997 and less than or equal to-1.73; n1 is more than or equal to 1.71 and less than or equal to 2.06; n5 is more than or equal to 1.71 and less than or equal to 2.04.

Preferably, the first lens element with negative refractive power has a convex object-side surface and a concave image-side surface; the radius of curvature of the object-side surface of the first lens is R1, the radius of curvature of the image-side surface of the first lens is R2, and the on-axis thickness of the first lens is d1, and the following relationships are satisfied: 2.81-9.71 of (R1+ R2)/(R1-R2); d1 is more than or equal to 0.12 and less than or equal to 0.36.

Preferably, the imaging optical lens satisfies the following relational expression: 4.5-7.77 of (R1+ R2)/(R1-R2); d1 is more than or equal to 0.19 and less than or equal to 0.29.

Preferably, the object-side surface of the second lens element is convex in the paraxial region, and the image-side surface thereof is convex in the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the second lens is f2, the curvature radius of the object side surface of the second lens is R3, the curvature radius of the image side surface of the second lens is R4, the on-axis thickness of the second lens is d3, and the following relational expression is satisfied: f2/f is more than or equal to 0.3 and less than or equal to 1.09; -1.65 ≤ (R3+ R4)/(R3-R4) ≤ 0.42; d3 is more than or equal to 0.31 and less than or equal to 0.95.

Preferably, the imaging optical lens satisfies the following relational expression: f2/f is more than or equal to 0.48 and less than or equal to 0.87; -1.03 ≤ (R3+ R4)/(R3-R4) ≤ 0.52; d3 is more than or equal to 0.49 and less than or equal to 0.76.

Preferably, the image-side surface of the third lens is concave 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 curvature radius of the object side surface of the third lens is R5, the curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, and the following relations are satisfied: f3/f is not less than 6.52 and not more than-1.05; -0.71 ≤ (R5+ R6)/(R5-R6) 5.5; d5 is more than or equal to 0.11 and less than or equal to 0.71.

Preferably, the imaging optical lens satisfies the following relational expression: f3/f is not less than 4.08 and not more than-1.31; -0.44 ≤ (R5+ R6)/(R5-R6) ≤ 4.4; d5 is more than or equal to 0.17 and less than or equal to 0.57.

Preferably, the fourth lens element with positive refractive power has a concave object-side surface and a convex image-side surface; the focal length of the image pickup optical lens is f, the focal length of the fourth lens is f4, the curvature radius of the object side surface of the fourth lens is R7, the curvature radius of the image side surface of the fourth lens is R8, the on-axis thickness of the fourth lens is d7, and the following relational expression is satisfied: f4/f is more than or equal to 0.69 and less than or equal to 3.34; 2.16-8.09 of (R7+ R8)/(R7-R8); d7 is more than or equal to 0.21 and less than or equal to 0.88.

Preferably, the imaging optical lens satisfies the following relational expression: f4/f is more than or equal to 1.1 and less than or equal to 2.67; 3.45-6.47 of (R7+ R8)/(R7-R8); d7 is more than or equal to 0.34 and less than or equal to 0.7.

Preferably, the fifth lens element with positive refractive power has a convex object-side surface and a convex image-side surface; the focal length of the image pickup optical lens is f, the focal length of the fifth lens is f5, the curvature radius of the object side surface of the fifth lens is R9, the curvature radius of the image side surface of the fifth lens is R10, the on-axis thickness of the fifth lens is d9, and the following relations are satisfied: f5/f is more than or equal to 0.48 and less than or equal to 4.25; -1.85 ≤ (R9+ R10)/(R9-R10) 1; d9 is more than or equal to 0.23 and less than or equal to 0.96.

Preferably, the imaging optical lens satisfies the following relational expression: f5/f is more than or equal to 0.77 and less than or equal to 3.4; -1.16 ≤ (R9+ R10)/(R9-R10) 0.8; d9 is more than or equal to 0.37 and less than or equal to 0.77.

Preferably, the sixth lens element with negative refractive power has a concave object-side surface and a concave image-side surface; the focal length of the imaging optical lens is f, the focal length of the sixth lens is f6, the curvature radius of the object side surface of the sixth lens is R11, the curvature radius of the image side surface of the sixth lens is R12, the on-axis thickness of the sixth lens is d11, and the following relations are satisfied: f6/f is not less than 1.44 and not more than-0.4; -0.99 ≤ (R11+ R12)/(R11-R12) ≤ 0.02; d11 is more than or equal to 0.12 and less than or equal to 0.36.

Preferably, the imaging optical lens satisfies the following relational expression: f6/f is more than or equal to-0.9 and less than or equal to-0.5; -0.62 ≤ (R11+ R12)/(R11-R12) ≤ 0.03; d11 is more than or equal to 0.19 and less than or equal to 0.29.

Preferably, the focal length of the image pickup optical lens is f, 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 0.49 and less than or equal to 1.5.

Preferably, the imaging optical lens satisfies the following relational expression: f12/f is more than or equal to 0.79 and less than or equal to 1.2.

Preferably, the total optical length TT L of the imaging optical lens is less than or equal to 5.7 mm.

Preferably, the total optical length TT L of the imaging optical lens is less than or equal to 5.44 mm.

Preferably, the F-number of the imaging optical lens is 2.16 or less.

Preferably, the F-number of the imaging optical lens is 2.12 or less.

The invention has the advantages that the optical camera lens has excellent optical characteristics, is ultrathin, has wide angle and can fully correct chromatic aberration, and is particularly suitable for mobile phone camera lens components and WEB camera lenses which are composed of high-pixel CCD, CMOS and other camera elements.

Drawings

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, fig. 1 shows an imaging optical lens 10 according to a first embodiment of the present invention, where the imaging optical lens 10 includes six lenses, specifically, the imaging optical lens 10 includes, in order from an object side to an image side, a stop 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, and optical elements such as an optical filter (filter) GF may be disposed between the sixth lens L6 and an image plane Si.

The first lens L1 is made of glass, 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 glass, and the sixth lens L6 is made of plastic.

The second lens element L2 with positive refractive power and the third lens element L3 with negative refractive power;

here, the focal length of the entire imaging optical lens 10 is defined as f, the focal length of the first lens element L1 is defined as f1, -3 ≦ f1/f ≦ -1.7, and the negative refractive power of the first lens element L1 is defined, and when the upper limit value is exceeded, although it is advantageous for the lens to be made thinner, the negative refractive power of the first lens element L1 is too strong to correct aberrations and is disadvantageous for the lens to be made wider, on the other hand, when the lower limit value is exceeded, the negative refractive power of the first lens element becomes too weak to make the lens difficult to be made thinner, and preferably, it is satisfied that-2.997 ≦ f1/f ≦ -1.73.

The refractive index of the first lens L1 is defined as n1, 1.7. ltoreq. n 1. ltoreq.2.2, and the refractive index of the first lens L1 is defined in a range more favorable for the development of ultra-thin lenses and correction of aberration, and preferably 1.71. ltoreq. n 1. ltoreq.2.06 is satisfied.

The refractive index of the fifth lens L5 is defined as n5, 1.7. ltoreq. n 5. ltoreq.2.2, and the refractive index of the fifth lens L5 is defined in such a range that it is more advantageous to make the fifth lens thinner and to correct aberrations, and preferably 1.71. ltoreq. n 5. ltoreq.2.04 is satisfied.

When the focal length of the image pickup optical lens 10, the focal length of each lens, the refractive index of the relevant lens, the optical total length of the image pickup optical lens, the on-axis thickness and the curvature radius satisfy the above relational expressions, the image pickup optical lens 10 can have high performance and satisfy the design requirement of the low TT L.

In this embodiment, the object-side surface of the first lens element L1 is convex at the paraxial region and the image-side surface thereof is concave at the paraxial region, and has negative refractive power.

The curvature radius of the object side surface of the first lens L1 is R1, the curvature radius of the image side surface of the first lens L1 is R2, the following relation is satisfied, the curvature radius of the object side surface of the first lens is 2.81-9.71, the ratio of (R1+ R2)/(R1-R2) is more than or equal to 2.81, the shape of the first lens is reasonably controlled, the spherical aberration of the system can be effectively corrected by the first lens, and the ratio of (R1+ R2)/(R1-R2) is more than or equal to 4.5 and less than or equal to 7.77.

The on-axis thickness of the first lens L1 is d1, and satisfies the following relation that d1 is greater than or equal to 0.12 and less than or equal to 0.36, which is favorable for realizing ultra-thinning, preferably, d1 is greater than or equal to 0.19 and less than or equal to 0.29.

In this embodiment, the object-side surface of the second lens element L2 is convex at the paraxial region, and the image-side surface is convex at the paraxial region.

The focal length of the whole image pickup optical lens 10 is f, the focal length of the second lens L2 is f2, and the following relational expression that f2/f is 0.3 or more and 1.09 or less is satisfied, and the spherical aberration generated by the first lens L1 having negative refractive power and the amount of curvature of field of the system are reasonably and effectively balanced by controlling the positive refractive power of the second lens L2 within a reasonable range, preferably, f2/f is 0.48 or more and 0.87 or less.

The radius of curvature of the object-side surface of the second lens L2 is R3, and the radius of curvature of the image-side surface of the second lens L2 is R4, and satisfies the following relationships of-1.65 ≦ (R3+ R4)/(R3-R4) ≦ -0.42, and the shape of the second lens L2 is defined so that the problem of chromatic aberration on the axis is difficult to correct as the lens is moved to an ultra-thin wide angle when out of the range, and preferably, -1.03 ≦ (R3+ R4)/(R3-R4) ≦ -0.52.

The on-axis thickness of the second lens L2 is d3, and the following relation is satisfied, wherein d3 is more than or equal to 0.31 and less than or equal to 0.95, which is beneficial to realizing ultra-thinning, and preferably, d3 is more than or equal to 0.49 and less than or equal to 0.76.

In this embodiment, the image-side surface of the third lens L3 is concave at the paraxial region;

the focal length of the whole shooting optical lens 10 is f, the focal length of the third lens L3 is f3, and the following relational expression is satisfied, wherein f3/f is more than or equal to-6.52 and less than or equal to-1.05, which is beneficial to the system to obtain good ability of balancing curvature of field so as to effectively improve the image quality, and preferably, f3/f is more than or equal to-4.08 and less than or equal to-1.31.

The curvature radius of the object side surface of the third lens L3 is R5, the curvature radius of the image side surface of the third lens L3 is R6, and the following relations are satisfied, wherein-0.71 ≦ (R5+ R6)/(R5-R6) ≦ 5.5, the shape of the third lens L3 can be effectively controlled, the molding of the third lens L3 is facilitated, and the generation of molding defects and stress caused by the excessive surface curvature of the third lens L3 is avoided, preferably-0.44 ≦ (R5+ R6)/(R5-R6) ≦ 4.4.

The on-axis thickness of the third lens L3 is d5, and the following relation is satisfied, namely, d5 is more than or equal to 0.11 and less than or equal to 0.71, which is beneficial to realizing ultra-thinning, preferably, d5 is more than or equal to 0.17 and less than or equal to 0.57.

In this embodiment, the object-side surface of the fourth lens element L4 is concave in the paraxial region thereof, and the image-side surface thereof is convex in the paraxial region thereof, and has positive refractive power.

The focal length of the whole shooting optical lens 10 is f, the focal length of the fourth lens L4 is f4, the following relational expression is satisfied, wherein f4/f is more than or equal to 0.69 and less than or equal to 3.34, and the system has better imaging quality and lower sensitivity through reasonable distribution of focal power, preferably, f4/f is more than or equal to 1.1 and less than or equal to 2.67.

The radius of curvature R7 of the object-side surface of the fourth lens L4 and the radius of curvature R8 of the image-side surface of the fourth lens L4 satisfy the following relations of 2.16. ltoreq. (R7+ R8)/(R7-R8). ltoreq.8.09, and the shape of the fourth lens L4 is specified, and when out of range, it is difficult to correct the aberration of the off-axis angle with the development of the ultra-thin wide angle, and preferably 3.45. ltoreq. (R7+ R8)/(R7-R8). ltoreq.6.47.

The on-axis thickness of the fourth lens L4 is d7, and the following relation is satisfied, wherein d7 is more than or equal to 0.21 and less than or equal to 0.88, which is beneficial to realizing ultra-thinning, and preferably, d7 is more than or equal to 0.34 and less than or equal to 0.7.

In this embodiment, the fifth lens element L5 has a convex object-side surface and a convex image-side surface.

The focal length of the whole shooting optical lens 10 is f, the focal length of the fifth lens L5 is f5, the following relational expression is satisfied, wherein f5/f is more than or equal to 0.48 and less than or equal to 4.25, the definition of the fifth lens L5 can effectively lead the ray angle of the shooting lens to be flat and reduce the tolerance sensitivity, and preferably, f5/f is more than or equal to 0.77 and less than or equal to 3.4.

The radius of curvature of the object-side surface of the fifth lens L5 is R9, and the radius of curvature of the image-side surface of the fifth lens L5 is R10, and satisfies the following relationships of-1.85 ≦ (R9+ R10)/(R9-R10) ≦ 1, and the shape of the fifth lens L5 is specified, and when the conditions are out of the range, it becomes difficult to correct the off-axis angular aberration with the development of ultra-thin wide-angle, and preferably-1.16 ≦ (R9+ R10)/(R9-R10) ≦ 0.8.

The on-axis thickness of the fifth lens L5 is d9, and satisfies the following relation that d9 is greater than or equal to 0.23 and less than or equal to 0.96, which is favorable for realizing ultra-thinning, preferably, d9 is greater than or equal to 0.37 and less than or equal to 0.77.

In this embodiment, the object-side surface of the sixth lens element L6 is concave in the paraxial region thereof, and the image-side surface thereof is concave in the paraxial region thereof, and has negative refractive power.

The focal length of the whole pick-up optical lens 10 is f, the focal length of the sixth lens L6 is f6, and the following relations that-1.44 ≦ f6/f ≦ -0.4 are satisfied, and the system has better imaging quality and lower sensitivity through reasonable distribution of the focal power, preferably-0.9 ≦ f6/f ≦ -0.5.

The curvature radius of the object side surface of the sixth lens L6 is R11, the curvature radius of the image side surface of the sixth lens L6 is R12, and the following relational expressions of-0.99 ≦ (R11+ R12)/(R11-R12) ≦ -0.02, and the shape of the sixth lens L6 are specified, and when the conditions are out of the range, it is difficult to correct the off-axis angular aberration accompanying the development of an ultra-thin wide angle, and the like, and preferably-0.62 ≦ (R11+ R12)/(R11-R12) ≦ -0.03.

The on-axis thickness of the sixth lens L6 is d11, and satisfies the following relation that d11 is greater than or equal to 0.12 and less than or equal to 0.36, which is favorable for realizing ultra-thinning, preferably, d11 is greater than or equal to 0.19 and less than or equal to 0.29.

In this embodiment, the focal length of the image pickup optical lens is f, the combined focal length of the first lens element and the second lens element is f12, and the following relation is satisfied: f12/f is more than or equal to 0.49 and less than or equal to 1.5. Therefore, the aberration and distortion of the shooting optical lens can be eliminated, the back focal length of the shooting optical lens can be suppressed, and the miniaturization of the image lens system group is maintained. Preferably, 0.79. ltoreq. f 12/f. ltoreq.1.2.

In the present embodiment, the total optical length TT L of the imaging optical lens 10 is less than or equal to 5.7 mm, which is advantageous for achieving ultra-thinning, and preferably, the total optical length TT L of the imaging optical lens 10 is less than or equal to 5.44 mm.

In the present embodiment, the number of apertures F of the imaging optical lens 10 is 2.16 or less. The large aperture is large, and the imaging performance is good. Preferably, the F-number of the imaging optical lens 10 is 2.12 or less.

With such a design, the optical total length TT L of the entire imaging optical lens 10 can be made as short as possible, and the characteristic of miniaturization can be maintained.

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. Distance, radius and center thickness are in mm.

TT L optical length (on-axis distance from the object side of the 1 st lens L1 to the image plane);

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.

The following shows design data of the image pickup optical lens 10 according to the first embodiment of the present invention, the units of focal length, distance, radius, and center thickness being mm.

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, diaphragm;

r is the radius of curvature of the optical surface and the radius of curvature of the center in the case of a lens, R1 is the radius of curvature of the object-side surface of the first lens L1;

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

r3 radius of curvature of object-side surface of second lens L2;

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

r5 radius of curvature of object-side surface of third lens L3;

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

r7 radius of curvature of object-side surface of fourth lens L4;

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

r9 radius of curvature of object-side surface of fifth lens L5;

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

r11 radius of curvature of object-side surface of sixth lens L6;

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

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

r14 radius of curvature of image side of optical filter GF;

d is the on-axis thickness of the lenses and the on-axis distance between the lenses;

d0 on-axis distance of stop S1 to object-side surface of first lens L1;

d1 on-axis thickness of first lens L1;

d2 on-axis distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2;

d3 on-axis thickness of second lens L2;

d4 on-axis distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3;

d5 on-axis thickness of third lens L3;

d6 on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4;

d7 on-axis thickness of fourth lens L4;

d8 on-axis distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5;

d9 on-axis thickness of fifth lens L5;

d10 on-axis distance from the image-side surface of the fifth lens L5 to the object-side surface of the sixth lens L6;

d11 on-axis thickness of sixth lens L6;

d12 axial 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 on-axis distance from the image side surface of the optical filter GF to the image surface;

nd is the refractive index of the d line;

nd1, refractive index of d-line of the first lens L1;

nd2 refractive index of d-line of the second lens L2;

nd3 refractive index of d-line of the third lens L3;

nd4 refractive index of d-line of the fourth lens L4;

nd5 refractive index of d-line of the fifth lens L5;

nd6 denotes a refractive index of the d-line of the sixth lens L6;

ndg, refractive index of d-line of optical filter GF;

vd is Abbe number;

v1 Abbe number of first lens L1;

v2 abbe number of second lens L2;

v3 abbe number of third lens L3;

v4 Abbe number of fourth lens L4;

v5 Abbe number of fifth lens L5;

v6 Abbe number of 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 ]

Wherein k is a conic coefficient, and A4, A6, A8, A10, A12, A14 and A16 are aspheric coefficients.

IH image height

y＝(x²/R)/[1+{1-(k+1)(x²/R²)}^1/2]+A4x⁴+A6x⁶+A8x⁸+A10x¹⁰+A12x¹²+A14x¹⁴+A16x¹⁶(1)

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

Tables 3 and 4 show the inflection points and the stagnation point design data of the respective lenses in the imaging optical lens 10 according to the first embodiment of the present invention, where P1R1 and P1R2 represent the object side surface and the image side surface of the first lens P1, respectively, 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, respectively, 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, respectively, and P6R1 and P6R2 represent the object side surface and the image side surface of the sixth lens L6, respectively, the "inflection point position correspondence data" corresponds to the vertical distance "between the inflection point set for the respective lens surface and the optical axis of the optical lens 10 as the vertical distance between the optical axis of the image-capturing optical lens 10.

[ TABLE 3 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	1	0.645
P1R2	1	0.725
				P2R1	0
P2R2	0
				P3R1	0
P3R2	2	0.235	1.105
				P4R1	1	0.955
P4R2	1	1.095
				P5R1	1	1.135
P5R2	2	1.095	1.605
				P6R1	1	1.555
P6R2	1	0.845

[ TABLE 4 ]

	Number of stagnation points	Location of stagnation 1	Location of stagnation 2
				P1R1	0
P1R2	0
				P2R1	0
P2R2	0
				P3R1	0
P3R2	1	0.405
				P4R1	1	1.365
P4R2	0
				P5R1	1	1.655
P5R2	0
				P6R1	0
P6R2	1	1.605

Fig. 2 and 3 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 470nm, 555nm, and 650nm, 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 of various numerical values in examples 1, 2, and 3 corresponding to the parameters specified in the conditional expressions.

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

In the present embodiment, the imaging optical lens has an entrance pupil diameter of 1.812mm, a full field height of 2.994mm, a diagonal field angle of 76.43 °, a wide angle, and a high profile, and has excellent optical characteristics with on-axis and off-axis chromatic aberration 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.

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 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	1	0.605
P1R2	1	0.645
				P2R1	0
P2R2	0
				P3R1	0
P3R2	2	0.315	1.035
				P4R1	1	1.085
P4R2	1	1.135
				P5R1	1	1.225
P5R2	2	1.115	1.515
				P6R1	1	1.595
P6R2	1	0.775

[ TABLE 8 ]

	Number of stagnation points	Location of stagnation 1	Location of stagnation 2
				P1R1	0
P1R2	0
				P2R1	0
P2R2	0
				P3R1	0
P3R2	2	0.555	1.185
				P4R1	0
P4R2	0
				P5R1	1	1.485
P5R2	0
				P6R1	0
P6R2	1	1.455

Fig. 6 and 7 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 470nm, 555nm, and 650nm, 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.

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

In the present embodiment, the imaging optical lens has an entrance pupil diameter of 1.811mm, a full field image height of 2.994mm, a diagonal field angle of 76.46 °, a wide angle, and a high profile, and has excellent optical characteristics with on-axis and off-axis chromatic aberration 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.

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 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	1	0.645
P1R2	1	0.635
				P2R1	0
P2R2	2	0.695	0.885
				P3R1	1	0.215
P3R2	2	0.325	0.955
				P4R1	1	1.015
P4R2	1	1.035
				P5R1	1	0.525
P5R2	1	1.925
				P6R1	1	1.535
P6R2	1	0.625

[ TABLE 12 ]

Fig. 10 and 11 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 470nm, 555nm, and 650nm, 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.

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 system of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the imaging optical lens has an entrance pupil diameter of 1.811mm, a full field image height of 2.994mm, a diagonal field angle of 76.45 °, a wide angle, and a high profile, 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, in order from an object side to an image side, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; the second lens element with positive refractive power and the third lens element with negative refractive power; the first lens element with negative refractive power, the fourth lens element with positive refractive power, the fifth lens element with positive refractive power, and the sixth lens element with negative refractive power;

the focal length of the image pickup optical lens is f, the focal length of the first lens is f1, the refractive index of the first lens is n1, the refractive index of the fifth lens is n5, the curvature radius of the object-side surface of the second lens is R3, the curvature radius of the image-side surface of the second lens is R4, and the following relations are satisfied:

-3≤f1/f≤-1.7；

1.7≤n1≤2.2；

1.7≤n5≤2.2；

-1.65≤(R3+R4)/(R3-R4)≤-0.42。

2. the imaging optical lens according to claim 1, wherein the imaging optical lens satisfies the following relational expression:

-2.997≤f1/f≤-1.73；

1.71≤n1≤2.06；

1.71≤n5≤2.04。

3. the imaging optical lens assembly of claim 1, wherein the first lens element has a convex object-side surface and a concave image-side surface;

the radius of curvature of the object-side surface of the first lens is R1, the radius of curvature of the image-side surface of the first lens is R2, and the on-axis thickness of the first lens is d1 in millimeters, and the following relationships are satisfied:

2.81≤(R1+R2)/(R1-R2)≤9.71；

0.12≤d1≤0.36。

4. the imaging optical lens according to claim 3, characterized in that the imaging optical lens satisfies the following relation:

4.5≤(R1+R2)/(R1-R2)≤7.77；

0.19≤d1≤0.29。

5. the imaging optical lens assembly of claim 1, wherein the second lens element has a convex object-side surface and a convex image-side surface;

the focal length of the image pickup optical lens is f, the focal length of the second lens is f2, the on-axis thickness of the second lens is d3, the unit is millimeter, and the following relational expression is satisfied:

0.3≤f2/f≤1.09；

0.31≤d3≤0.95。

6. the imaging optical lens according to claim 5, characterized in that the imaging optical lens satisfies the following relation:

0.48≤f2/f≤0.87；

-1.03≤(R3+R4)/(R3-R4)≤-0.52；

0.49≤d3≤0.76。

7. the imaging optical lens of claim 1, wherein the third lens image side surface is concave 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 curvature radius of the object side surface of the third lens is R5, the curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, the unit is millimeter, and the following relational expression is satisfied:

-6.52≤f3/f≤-1.05；

-0.71≤(R5+R6)/(R5-R6)≤5.5；

0.11≤d5≤0.71。

8. the image-pickup optical lens according to claim 7, wherein the image-pickup optical lens satisfies the following relation:

-4.08≤f3/f≤-1.31；

-0.44≤(R5+R6)/(R5-R6)≤4.4；

0.17≤d5≤0.57。

9. the imaging optical lens assembly according to claim 1, wherein the fourth lens element has a concave object-side surface and a convex image-side surface;

the focal length of the image pickup optical lens is f, the focal length of the fourth lens is f4, the curvature radius of the object side surface of the fourth lens is R7, the curvature radius of the image side surface of the fourth lens is R8, the on-axis thickness of the fourth lens is d7, the unit is millimeter, and the following relational expression is satisfied:

0.69≤f4/f≤3.34；

2.16≤(R7+R8)/(R7-R8)≤8.09；

0.21≤d7≤0.88。

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

1.1≤f4/f≤2.67；

3.45≤(R7+R8)/(R7-R8)≤6.47；

0.34≤d7≤0.7。

11. the imaging optical lens assembly according to claim 1, wherein the fifth lens element has a convex object-side surface and a convex image-side surface;

the focal length of the image pickup optical lens is f, the focal length of the fifth lens is f5, the curvature radius of the object side surface of the fifth lens is R9, the curvature radius of the image side surface of the fifth lens is R10, the on-axis thickness of the fifth lens is d9, the unit is millimeter, and the following relational expression is satisfied:

0.48≤f5/f≤4.25；

-1.85≤(R9+R10)/(R9-R10)≤1；

0.23≤d9≤0.96。

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

0.77≤f5/f≤3.4；

-1.16≤(R9+R10)/(R9-R10)≤0.8；

0.37≤d9≤0.77。

13. the imaging optical lens of claim 1, wherein the sixth lens element has a concave object-side surface and a concave image-side surface;

the focal length of the imaging optical lens is f, the focal length of the sixth lens is f6, the curvature radius of the object side surface of the sixth lens is R11, the curvature radius of the image side surface of the sixth lens is R12, the on-axis thickness of the sixth lens is d11, the unit is millimeter, and the following relational expression is satisfied:

-1.44≤f6/f≤-0.4；

-0.99≤(R11+R12)/(R11-R12)≤-0.02；

0.12≤d11≤0.36。

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

-0.9≤f6/f≤-0.5；

-0.62≤(R11+R12)/(R11-R12)≤-0.03；

0.19≤d11≤0.29。

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

0.49≤f12/f≤1.5。

16. an image-pickup optical lens according to claim 15, wherein the image-pickup optical lens satisfies the following relational expression:

0.79≤f12/f≤1.2。

17. a camera optical lens according to claim 1, characterized in that the total optical length TT L of the camera optical lens is less than or equal to 5.7 mm.

18. A camera optical lens according to claim 17, characterized in that the total optical length TT L of the camera optical lens is less than or equal to 5.44 mm.

19. A camera optical lens according to claim 1, characterized in that the F-number of the aperture of the camera optical lens is less than or equal to 2.16.

20. A camera optical lens according to claim 19, characterized in that the F-number of the aperture of the camera optical lens is less than or equal to 2.12.