CN112698482A

CN112698482A - Image pickup optical lens

Info

Publication number: CN112698482A
Application number: CN202011608568.3A
Authority: CN
Inventors: 阪口贵之; 崔元善
Original assignee: AAC Optics Suzhou Co Ltd; AAC Optics Shenzhen Co Ltd
Current assignee: AAC Optics Suzhou Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-04-23

Abstract

The invention provides a photographic optical lens, which comprises the following components in sequence from an object side to an image side: a first lens element with positive refractive power, a second lens element with positive refractive power, a third lens element with negative refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power; the focal length of the first lens is f1, the focal length of the fourth lens is f4, the central curvature radius of the object-side surface of the first lens is R1, 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 first lens is d1, and the following relations are satisfied: f1/f4 is more than or equal to 0.50 and less than or equal to 2.00; r1/d1 is more than or equal to 5.00 and less than or equal to 20.00; 1.00-20.00 (R3+ R4)/(R3-R4). The imaging optical lens has good optical performance and also meets the design requirements of wide angle and ultra-thinness.

Description

Image pickup optical lens

[ technical field ] A method for producing a semiconductor device

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 of the invention ]

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) Device, and due to the refinement of Semiconductor manufacturing 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, thin, short and small shape, 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. However, with the development of technology and the increasing demand of diversification of users, under the condition that the pixel area of the photosensitive device is continuously reduced and the requirement of the system for the imaging quality is continuously improved, the six-piece lens structure gradually appears in the lens design, although the common six-piece lens has good optical performance, the focal power, the lens pitch and the lens shape setting still have certain irrationality, so that the lens structure can not meet the design requirements of wide angle and ultra-thinness while having good optical performance.

Therefore, it is necessary to provide an imaging optical lens having excellent optical performance and satisfying design requirements for a wide angle and a slim profile.

[ summary of the 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 the design requirements of ultra-thinning and wide-angle.

The technical scheme of the invention is as follows: an imaging optical lens comprising, in order from an object side to an image side: a first lens element with positive refractive power, a second lens element with positive refractive power, a third lens element with negative refractive power, a fourth lens element with positive refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power;

the focal length of the first lens is f1, the focal length of the fourth lens is f4, the central curvature radius of the object-side surface of the first lens is R1, 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 first lens is d1, and the following relations are satisfied: f1/f4 is more than or equal to 0.50 and less than or equal to 2.00; r1/d1 is more than or equal to 5.00 and less than or equal to 20.00; 1.00-20.00 (R3+ R4)/(R3-R4).

Preferably, the object side surface of the first lens is convex at the paraxial region; the focal length of the image pickup optical lens is f, the central curvature radius of the image side surface of the first lens is R2, 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 0.69 and less than or equal to 2.85; -3.18 ≤ (R1+ R2)/(R1-R2) ≤ 0.47; d1/TTL is more than or equal to 0.02 and less than or equal to 0.13.

Preferably, the imaging optical lens satisfies the following relation: f1/f is more than or equal to 1.10 and less than or equal to 2.28; -1.99 ≤ (R1+ R2)/(R1-R2) is ≤ 0.59; d1/TTL is more than or equal to 0.04 and less than or equal to 0.10.

Preferably, the object-side surface of the second lens element is concave at the paraxial region, and the image-side surface of the second lens element is convex at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the second lens is f2, the 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 not less than 11.44 and not more than 10571.85; d3/TTL is more than or equal to 0.03 and less than or equal to 0.08.

Preferably, the imaging optical lens satisfies the following relation: f2/f is more than or equal to 18.30 and less than or equal to 8457.48; d3/TTL is more than or equal to 0.04 and less than or equal to 0.06.

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 central curvature radius of the object side surface of the third lens is R5, the central curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f3/f is not less than 3.23 and not more than-0.73; (R5+ R6)/(R5-R6) is not more than 0.16 and not more than 1.55; d5/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: f3/f is not less than-2.02 and not more than-0.91; (R5+ R6)/(R5-R6) is not more than 0.25 and not more than 1.24; d5/TTL is more than or equal to 0.04 and less than or equal to 0.06.

Preferably, the object-side surface of the fourth lens element is convex at the paraxial region, and the image-side surface of the fourth lens element is concave at the paraxial region; the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the fourth lens is R7, the central 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 total optical length of the image pickup optical lens is TTL and satisfies the following relational expression: f4/f is more than or equal to 0.48 and less than or equal to 4.04; -6.50 ≤ (R7+ R8)/(R7-R8) ≤ 0.98; d7/TTL is more than or equal to 0.04 and less than or equal to 0.17.

Preferably, the imaging optical lens satisfies the following relation: f4/f is more than or equal to 0.77 and less than or equal to 3.23; 4.06 is less than or equal to (R7+ R8)/(R7-R8) is less than or equal to-1.23; d7/TTL is more than or equal to 0.07 and less than or equal to 0.13.

Preferably, the object-side surface of the fifth lens element is concave at the paraxial region, and the image-side surface of the fifth lens element is convex at the paraxial region; the focal length of the image pickup optical lens is f, the focal length of the fifth lens is f5, the central curvature radius of the object side surface of the fifth lens is R9, the central curvature radius of the image side surface of the fifth lens is R10, the on-axis thickness of the fifth lens is d9, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f5/f is more than or equal to 0.36 and less than or equal to 1.17; (R9+ R10)/(R9-R10) is not more than 0.64 and not more than 2.07; d9/TTL is more than or equal to 0.06 and less than or equal to 0.20.

Preferably, the imaging optical lens satisfies the following relation: f5/f is more than or equal to 0.57 and less than or equal to 0.94; 1.02-1.65 of (R9+ R10)/(R9-R10); d9/TTL is more than or equal to 0.09 and less than or equal to 0.16.

Preferably, the object-side surface of the sixth lens element is concave at the paraxial region, and the image-side surface of the sixth lens element is concave at the paraxial region; the focal length of the image pickup optical lens is f, the 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 image pickup optical lens is TTL, and the following relational expression is satisfied: f6/f is not less than 1.31 and not more than-0.42; (R11+ R12)/(R11-R12) is not more than 0.39 and not more than 1.28; d11/TTL is more than or equal to 0.03 and less than or equal to 0.10.

Preferably, the imaging optical lens satisfies the following relation: f6/f is more than or equal to-0.82 and less than or equal to-0.52; (R11+ R12)/(R11-R12) is not more than 0.63 and not more than 1.03; d11/TTL is more than or equal to 0.05 and less than or equal to 0.08.

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 0.65 and less than or equal to 2.84.

Preferably, the aperture value of the imaging optical lens is FNO, and satisfies the following relationship: FNO is less than or equal to 2.58.

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 83.34 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 1.57.

The invention has the beneficial effects that:

the imaging optical lens of the present invention has excellent optical characteristics, has a wide angle of view and is made thin, and is particularly suitable for a mobile phone imaging lens unit and a WEB imaging lens which are constituted by high-pixel imaging elements such as CCDs and CMOSs.

[ description of the 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 view of axial aberrations of the image-taking optical lens shown in 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 shown in 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 view of axial aberrations of the image pickup optical lens shown in 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 shown in 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 ] embodiments

The invention is further described with reference to the following figures and embodiments.

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

(first embodiment)

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

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

In this embodiment, the first lens element L1 has positive refractive power, the second lens element L2 has positive refractive power, the third lens element L3 has negative refractive power, the fourth lens element L4 has positive refractive power, the fifth lens element L5 has positive refractive power, and the sixth lens element L6 has negative refractive power.

In this embodiment, the focal length of the first lens L1 is defined as f1, the focal length of the fourth lens L4 is defined as f4, the central radius of curvature of the object-side surface of the first lens L1 is defined as R1, the central radius of curvature of the object-side surface of the second lens L2 is defined as R3, the central radius of curvature of the image-side surface of the second lens L2 is defined as R4, and the on-axis thickness of the first lens L1 is defined as d1, and the following relations are satisfied:

0.50≤f1/f4≤2.00； (1)

5.00≤R1/d1≤20.00； (2)

1.00≤(R3+R4)/(R3-R4)≤20.00。 (3)

the conditional expression (1) specifies the ratio of the focal length f1 of the first lens L1 to the focal length f4 of the fourth lens L4, so that the sensitivity of the optical lens assembly for image pickup can be effectively reduced, and the image quality can be further improved.

Conditional expression (2) is advantageous for correcting aberrations of the optical system by controlling the ratio of the central radius of curvature R1 of the object-side surface of the first lens L1 to the on-axis thickness d1 of the first lens L1 within a reasonable range.

The conditional expression (3) specifies the shape of the second lens L2, and is advantageous for correcting chromatic aberration on the axis as the lens is made to have a very thin and wide angle within the range.

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. In other alternative embodiments, the object-side surface and the image-side surface of the first lens L1 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f1 of the first lens L1, the following relations are satisfied: f1/f is more than or equal to 0.69 and less than or equal to 2.85, the ratio of the focal length f1 of the first lens element L1 to the focal length f of the image pickup optical lens 10 is specified, and when the ratio is within the specified range, the first lens element L1 has proper positive refractive power, which is beneficial to reducing system aberration and is beneficial to the development of the image pickup optical lens towards ultra-thinning and wide-angle. Preferably, 1.10. ltoreq. f 1/f. ltoreq.2.28 is satisfied.

The central curvature radius of the object side surface of the first lens L1 is R1, the central curvature radius of the image side surface of the first lens L1 is R2, and the following relational expression is satisfied: 3.18 ≦ (R1+ R2)/(R1-R2) ≦ -0.47, and the shape of the first lens L1 is controlled appropriately so that the first lens L1 can correct the system spherical aberration effectively. Preferably, it satisfies-1.99 ≦ (R1+ R2)/(R1-R2) ≦ -0.59.

The on-axis thickness of the first lens L1 is d1, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d1/TTL is more than or equal to 0.02 and less than or equal to 0.13, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.04. ltoreq. d 1/TTL. ltoreq.0.10 is satisfied.

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

Defining the focal length of the second lens L2 as f2 and the focal length of the image pickup optical lens 10 as f, the following relations are satisfied: 11.44 ≦ f2/f ≦ 10571.85, and it is advantageous to correct aberrations of the optical system by controlling the positive power of the second lens L2 within a reasonable range. Preferably, 18.30. ltoreq. f 2/f. ltoreq. 8457.48 is satisfied.

Defining the on-axis thickness of the second lens L2 as d3, the total optical length of the image pickup optical lens 10 as TTL, and satisfying the following relation: d3/TTL is more than or equal to 0.03 and less than or equal to 0.08, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.04. ltoreq. d 3/TTL. ltoreq.0.06 is satisfied.

In the present embodiment, the object-side surface of the third lens element L3 is concave in the paraxial region, and the image-side surface is concave in the paraxial region. In other alternative embodiments, the object-side surface and the image-side surface of the third lens L3 may be arranged in other concave and convex distribution.

Defining the focal length of the third lens L3 as f3 and the focal length of the image pickup optical lens 10 as f, the following relations are satisfied: 3.23 ≦ f3/f ≦ -0.73, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-2.02. ltoreq. f 3/f. ltoreq-0.91.

The central curvature radius of the object side surface of the third lens L3 is R5, the central curvature radius of the image side surface of the third lens L3 is R6, and the following relational expressions are satisfied: the shape of the third lens L3 is regulated to be not less than 0.16 (R5+ R6)/(R5-R6) and not more than 1.55, and the deflection degree of light rays passing through the lens can be alleviated within the range regulated by the conditional expression, so that the aberration can be effectively reduced. Preferably, 0.25. ltoreq. (R5+ R6)/(R5-R6). ltoreq.1.24 is satisfied.

The on-axis thickness of the third lens L3 is d5, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d5/TTL is more than or equal to 0.03 and less than or equal to 0.08, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.04. ltoreq. d 5/TTL. ltoreq.0.06 is satisfied.

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

Defining the focal length of the fourth lens L4 as f4, and the focal length of the image pickup optical lens 10 as f, the following relations are satisfied: f4/f is not less than 0.48 and not more than 4.04, and the ratio of the focal length f4 of the fourth lens L4 to the focal length f of the image pickup optical lens 10 is specified, which contributes to the improvement of the optical system performance within the conditional expression range. Preferably, 0.77. ltoreq. f 4/f. ltoreq.3.23 is satisfied.

The central curvature radius of the object side surface of the fourth lens L4 is R7, the central curvature radius of the image side surface of the fourth lens L4 is R8, and the following relations are satisfied: -6.50 ≦ (R7+ R8)/(R7-R8) ≦ -0.98, and defines the shape of the fourth lens L4, which is advantageous for correcting the aberration of the off-axis angle and the like with the development of an ultra-thin wide angle in the range. Preferably, it satisfies-4.06 ≦ (R7+ R8)/(R7-R8) ≦ -1.23.

The on-axis thickness of the fourth lens L4 is d7, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d7/TTL is more than or equal to 0.04 and less than or equal to 0.17, and ultra-thinning is facilitated in the condition formula range. Preferably, 0.07. ltoreq. d 7/TTL. ltoreq.0.13 is satisfied.

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

Defining the focal length of the fifth lens L5 as f5, and the focal length of the image pickup optical lens 10 as f, the following relations are satisfied: f5/f is more than or equal to 0.36 and less than or equal to 1.17, and the definition of the fifth lens L5 can effectively make the light ray angle of the shooting optical lens 10 smooth and reduce the tolerance sensitivity. Preferably, 0.57. ltoreq. f 5/f. ltoreq.0.94 is satisfied.

The central curvature radius of the object side surface of the fifth lens L5 is R9, the central curvature radius of the image side surface of the fifth lens L5 is R10, and the following relations are satisfied: the ratio of (R9+ R10)/(R9-R10) is 0.64 or more and 2.07 or less, and the shape of the fifth lens L5 is defined so that the aberration of the off-axis view angle can be corrected within the range. Preferably, 1.02 ≦ (R9+ R10)/(R9-R10) ≦ 1.65.

The on-axis thickness of the fifth lens L5 is d9, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d9/TTL is more than or equal to 0.06 and less than or equal to 0.20, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.09. ltoreq. d 9/TTL. ltoreq.0.16 is satisfied.

In the present embodiment, the object-side surface of the sixth lens element L6 is concave in the paraxial region, and the image-side surface is concave in the paraxial region. In other alternative embodiments, the object-side surface and the image-side surface of the sixth lens L6 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f6 of the sixth lens L6, the following relations are satisfied: 1.31 ≦ f6/f ≦ -0.42, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-0.82. ltoreq. f 6/f. ltoreq-0.52.

The center curvature radius of the object side surface of the sixth lens L6 is R11, the center curvature radius of the image side surface of the sixth lens L6 is R12, and the following relations are satisfied: the (R11+ R12)/(R11-R12) is 0.39. ltoreq. 1.28, defines the shape of the sixth lens L6, and is advantageous for correcting the aberration of the off-axis picture angle and the like as the ultra-thin wide angle progresses in the conditional expression range. Preferably, 0.63. ltoreq. R11+ R12)/(R11-R12. ltoreq.1.03 is satisfied.

The on-axis thickness of the sixth lens element L6 is d11, the total optical length of the imaging optical lens system 10 is TTL, and the following relationships are satisfied: d11/TTL is more than or equal to 0.03 and less than or equal to 0.10, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.05. ltoreq. d 11/TTL. ltoreq.0.08 is satisfied.

In the present embodiment, the focal length of the imaging optical lens 10 is defined as f, and the combined focal length of the first lens L1 and the second lens L2 is defined as f12, and the following relationship is satisfied: f12/f is not less than 0.65 and not more than 2.84, so that the aberration and distortion of the image pickup optical lens 10 can be eliminated, the back focal length of the image pickup optical lens 10 can be suppressed, and the miniaturization of the image lens system can be maintained. Preferably, 1.04. ltoreq. f 12/f. ltoreq.2.27.

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 2.58, thereby being beneficial to realizing large aperture. Preferably, FNO is less than or equal to 2.53.

In the present embodiment, 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 83.34 degrees, thereby being beneficial to realizing wide-angle. Preferably, the FOV is satisfied at 84.19.

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 1.57, thereby being beneficial to realizing ultra-thinning. Preferably, TTL/IH ≦ 1.53 is satisfied.

When the focal length of the image pickup optical lens 10, the focal length of each lens and the central curvature radius satisfy the above relation, the image pickup optical lens 10 can have good optical performance, and can satisfy the design requirements of 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.

In addition, at least one of the object side surface and/or the image side surface of each lens may be 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 shown in fig. 1.

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

[ TABLE 1 ]

The meanings of the symbols in the above table are as follows.

S1: an aperture;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

vd: an Abbe number;

v 1: abbe number of the first lens L1;

v 2: abbe number of the second lens L2;

v 3: abbe number of the third lens L3;

v 4: abbe number of the fourth lens L4;

v 5: abbe number of the fifth lens L5;

v 6: abbe number of the sixth lens L6;

vg: abbe number of the optical filter GF.

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

[ TABLE 2 ]

In table 2, k is a conic coefficient, and a4, a6, A8, a10, a12, a14, a16, a18, a20 are aspherical coefficients.

y＝(x²/R)/{1+[1-(k+1)(x²/R²)]^1/2}+A4x⁴+A6x⁶+A8x⁸+A10x¹⁰+A12x¹²+A14x¹⁴+A16x¹⁶+A18x¹⁸+A20x²⁰ (4)

Where x is the perpendicular distance between a point on the aspheric curve and the optical axis, and y is the aspheric depth (the perpendicular distance between a point on the aspheric curve that is x from the optical axis and a tangent plane tangent to the vertex on the aspheric optical axis).

For convenience, the aspherical surface of each lens surface uses the aspherical surface shown in the above formula (4). However, the present invention is not limited to the aspherical polynomial form expressed by this formula (4).

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

[ TABLE 3 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2	Position of reverse curvature 3	Position of reverse curve 4
						P1R1	1	1.145	/	/	/
P1R2	3	0.325	1.085	1.255	/
						P2R1	2	1.035	1.305	/	/
P2R2	1	1.295	/	/	/
						P3R1	1	1.355	/	/	/
P3R2	1	0.715	/	/	/
						P4R1	1	1.725	/	/	/
P4R2	4	0.605	1.595	1.795	2.015
						P5R1	1	2.055	/	/	/
P5R2	1	1.905	/	/	/
						P6R1	1	2.845	/	/	/
P6R2	1	1.065	/	/	/

[ TABLE 4 ]

Table 13 below also lists values corresponding to the various parameters in the first, second, and third embodiments and the parameters specified in the conditional expressions.

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

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

In the present embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 2.221mm, a full field image height IH of 5.120mm, and a diagonal field angle FOV of 85.04 °, and the imaging optical lens 10 satisfies the design requirements of a wide angle and a slim size, and has excellent optical characteristics with on-axis and off-axis chromatic aberration sufficiently corrected.

(second embodiment)

Fig. 5 is a schematic structural diagram of the imaging optical lens 20 in the second embodiment, which is basically the same as the first embodiment, and the meanings of symbols in the following list are also the same as those in the first embodiment, so that the same parts are not described herein again, and only different points are listed below.

In the present embodiment, the object-side surface of the third lens element L3 is convex at the paraxial region.

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 inflected point and stagnation point design data of each lens in the imaging optical lens 20.

[ TABLE 7 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	0	/	/
P1R2	1	1.225	/
				P2R1	2	0.465	1.295
P2R2	1	1.345	/
				P3R1	2	0.085	1.435
P3R2	1	0.605	/
				P4R1	1	1.705	/
P4R2	2	0.775	2.085
				P5R1	1	2.175	/
P5R2	1	2.095	/
				P6R1	1	2.825	/
P6R2	1	1.055	/

[ TABLE 8 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	0	/
			P2R1	1	0.595
P2R2	0	/
			P3R1	1	0.135
P3R2	1	1.085
			P4R1	0	/
P4R2	1	1.555
			P5R1	0	/
P5R2	0	/
			P6R1	0	/
P6R2	1	2.655

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

As shown in table 13 below, the imaging optical lens 20 according to the present embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 2.184mm, a full field image height IH of 5.120mm, and a diagonal field angle FOV of 85.97 °, and the imaging optical lens 20 satisfies the design requirements of a wide angle and a slim size, and has excellent optical characteristics with its 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, which is basically the same as the first embodiment, and the meanings of symbols in the following list are also the same as those in the first embodiment, so that the same parts are not described again, and only different points are listed below.

In the present embodiment, the image-side surface of the first lens element L1 is convex at the paraxial region.

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 inflected point and stagnation point design data of each lens in the imaging optical lens 30.

[ TABLE 11 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	1	1.115	/
P1R2	2	0.545	1.225
				P2R1	1	0.535	/
P2R2	1	1.325	/
				P3R1	0	/	/
P3R2	1	0.695	/
				P4R1	2	1.825	2.105
P4R2	2	1.685	2.145
				P5R1	1	2.195	/
P5R2	1	2.095	/
				P6R1	1	2.905	/
P6R2	1	1.055	/

[ TABLE 12 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	1	0.735
			P2R1	1	0.705
P2R2	0	/
			P3R1	0	/
P3R2	1	1.205
			P4R1	0	/
P4R2	1	1.995
			P5R1	0	/
P5R2	0	/
			P6R1	0	/
P6R2	1	2.625

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

As shown in table 13 below, the imaging optical lens 30 according to the present embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 30 has an entrance pupil diameter ENPD of 2.152mm, a full field image height IH of 5.120mm, and a diagonal field angle FOV of 86.82 °, and the imaging optical lens 30 satisfies the design requirements of a wide angle and a slim size, and has excellent optical characteristics with on-axis and off-axis chromatic aberration sufficiently corrected.

[ TABLE 13 ]

Parameter and condition formula	Example 1	Example 2	Example 3
				f1/f4	0.51	1.25	1.98
R1/d1	5.01	12.48	19.90
				(R3+R4)/(R3-R4)	1.01	10.50	19.90
f	5.553	5.460	5.381
				f1	7.637	10.194	10.238
f2	127.012	38480.149	1659.999
				f3	-8.264	-8.820	-5.894
f4	14.942	8.156	5.185
				f5	3.950	4.207	4.212
f6	-3.625	-3.516	-3.358
				f12	7.250	10.192	10.194
FNO	2.50	2.50	2.50
				TTL	7.544	7.661	7.649
FOV	85.04°	85.97°	86.82°
				IH	5.120	5.120	5.120

While the foregoing is directed to embodiments of the present invention, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention.

Claims

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

the focal length of the first lens is f1, the focal length of the fourth lens is f4, the central curvature radius of the object-side surface of the first lens is R1, 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 first lens is d1, and the following relations are satisfied:

0.50≤f1/f4≤2.00；

5.00≤R1/d1≤20.00；

1.00≤(R3+R4)/(R3-R4)≤20.00。

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

the focal length of the image pickup optical lens is f, the central curvature radius of the image side surface of the first lens is R2, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

0.69≤f1/f≤2.85；

-3.18≤(R1+R2)/(R1-R2)≤-0.47；

0.02≤d1/TTL≤0.13。

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

1.10≤f1/f≤2.28；

-1.99≤(R1+R2)/(R1-R2)≤-0.59；

0.04≤d1/TTL≤0.10。

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

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 total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

11.44≤f2/f≤10571.85；

0.03≤d3/TTL≤0.08。

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

18.30≤f2/f≤8457.48；

0.04≤d3/TTL≤0.06。

6. the imaging optical lens according to claim 1, wherein an image side surface of the third lens is concave at a paraxial region;

the focal length of the image pickup optical lens is f, the focal length of the third lens is f3, the central curvature radius of the object side surface of the third lens is R5, the central curvature radius of the image side surface of the third lens is R6, the on-axis thickness of the third lens is d5, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

-3.23≤f3/f≤-0.73；

0.16≤(R5+R6)/(R5-R6)≤1.55；

0.03≤d5/TTL≤0.08。

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

-2.02≤f3/f≤-0.91；

0.25≤(R5+R6)/(R5-R6)≤1.24；

0.04≤d5/TTL≤0.06。

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

the focal length of the image pickup optical lens is f, the central curvature radius of the object side surface of the fourth lens is R7, the central 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 total optical length of the image pickup optical lens is TTL and satisfies the following relational expression:

0.48≤f4/f≤4.04；

-6.50≤(R7+R8)/(R7-R8)≤-0.98；

0.04≤d7/TTL≤0.17。

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

0.77≤f4/f≤3.23；

-4.06≤(R7+R8)/(R7-R8)≤-1.23；

0.07≤d7/TTL≤0.13。

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

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

0.36≤f5/f≤1.17；

0.64≤(R9+R10)/(R9-R10)≤2.07；

0.06≤d9/TTL≤0.20。

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

0.57≤f5/f≤0.94；

1.02≤(R9+R10)/(R9-R10)≤1.65；

0.09≤d9/TTL≤0.16。

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

the focal length of the image pickup optical lens is f, the 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 image pickup optical lens is TTL, and the following relational expression is satisfied:

-1.31≤f6/f≤-0.42；

0.39≤(R11+R12)/(R11-R12)≤1.28；

0.03≤d11/TTL≤0.10。

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

-0.82≤f6/f≤-0.52；

0.63≤(R11+R12)/(R11-R12)≤1.03；

0.05≤d11/TTL≤0.08。

14. 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:

0.65≤f12/f≤2.84。

15. 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≤2.58。

16. 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≥83.34°。

17. 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≤1.57。