CN113759514A

CN113759514A - Image pickup optical lens

Info

Publication number: CN113759514A
Application number: CN202111115142.9A
Authority: CN
Inventors: 杨婷婷
Original assignee: AAC Optics Suzhou Co Ltd
Current assignee: AAC Optics Suzhou Co Ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2021-12-07

Abstract

The invention relates to the field of optical lenses, and discloses an image pickup optical lens, which sequentially comprises 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 negative refractive power, a fourth lens element with positive refractive power, and a fifth lens element with refractive power; the focal length of the image pickup optical lens is f, the total optical length of the image pickup optical lens is TTL, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, the on-axis distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element is d6, the on-axis distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element is d8, and the following relations are satisfied: f is more than or equal to 8.00; f/TTL is more than or equal to 0.90; f1/f is more than or equal to 0.40 and less than or equal to 0.85; f2/f3 is more than or equal to 0.10 and less than or equal to 1.50; d6/d8 is more than or equal to 3.00 and less than or equal to 4.50. The pick-up optical lens has good optical performance and meets the design requirements of large aperture, long focal length and small distortion.

Description

Image pickup optical lens

Technical Field

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

Background

In recent years, with the rise of various smart devices, the demand for miniaturized photographing optical lenses is increasing, and due to the reduction of the pixel size of the photosensitive device and the trend of the electronic products to have a good function and a light, thin and portable appearance, the miniaturized photographing optical lenses with good imaging quality are the mainstream in the market. In order to obtain better imaging quality, a multi-lens structure is often adopted. Moreover, with the development of technology and the increase of diversified demands of users, under the conditions 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 five-piece lens structure appears in the design of the lens. There is a strong demand for a telephoto imaging lens having excellent optical characteristics, small distortion, 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 long focal length, and a small distortion.

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 element with positive refractive power, a second lens element with negative refractive power, a third lens element with negative refractive power, a fourth lens element with positive refractive power, and a fifth lens element with refractive power; the focal length of the image pickup optical lens is f, the total optical length of the image pickup optical lens is TTL, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, the on-axis distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element is d6, the on-axis distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element is d8, and the following relations are satisfied: f is more than or equal to 8.00; f/TTL is more than or equal to 0.90; f1/f is more than or equal to 0.40 and less than or equal to 0.85; f2/f3 is more than or equal to 0.10 and less than or equal to 1.50; d6/d8 is more than or equal to 3.00 and less than or equal to 4.50.

Preferably, the central radius of curvature of the object-side surface of the second lens is R3, the on-axis thickness of the second lens is d3, and the following relation is satisfied: r3/d3 is more than or equal to 8.00 and less than or equal to 25.00.

Preferably, the object side surface of the first lens is convex at the paraxial region; the central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, the on-axis thickness of the first lens is d1, and the following relations are satisfied: -7.67 ≤ (R1+ R2)/(R1-R2) ≤ 0.48; d1/TTL is more than or equal to 0.07 and less than or equal to 0.28.

Preferably, the object-side surface of the second lens element is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region; 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, and the following relations are satisfied: f2/f is not less than-2.11 and not more than-0.34; (R3+ R4)/(R3-R4) is not more than 0.98 and not more than 6.65; d3/TTL is more than or equal to 0.02 and less than or equal to 0.06.

Preferably, the central radius of curvature of the object-side surface of the third lens is R5, the central radius of curvature of the image-side surface of the third lens is R6, the on-axis thickness of the third lens is d5, and the following relationship is satisfied: f3/f is more than or equal to-19.14 and less than or equal to-0.31; -3.74 ≦ (R5+ R6)/(R5-R6) 12.33; d5/TTL is more than or equal to 0.02 and less than or equal to 0.22.

Preferably, the focal length of the fourth lens is f4, the central radius of curvature of the object-side surface of the fourth lens is R7, the central radius of curvature of the image-side surface of the fourth lens is R8, the on-axis thickness of the fourth lens is d7, and the following relationship is satisfied: f4/f is more than or equal to 0.58 and less than or equal to 10.48; -5.85 ≤ (R7+ R8)/(R7-R8) 9.71; d7/TTL is more than or equal to 0.03 and less than or equal to 0.13.

Preferably, the object-side surface of the fifth lens element is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region; 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, and the following relations are satisfied: -3.13. ltoreq. f 5/f. ltoreq.4.65; -21.59 ≤ (R9+ R10)/(R9-R10) 2.32; d9/TTL is more than or equal to 0.02 and less than or equal to 0.11.

Preferably, the image height of the imaging optical lens is IH, and the following relation is satisfied: f/IH is more than or equal to 5.60.

Preferably, one end of the first lens, which is far away from the second lens, is provided with a reflecting surface, and the reflecting surface is used for reflecting and refracting incident light rays.

Preferably, the reflecting surface is formed by a prism.

The invention has the beneficial effects that: the imaging optical lens according to the present invention has excellent optical characteristics, and has characteristics of a large aperture, a long focal length, and a small distortion, and is particularly suitable for a mobile phone imaging lens assembly and a WEB imaging lens which are constituted by imaging elements such as a CCD and a CMOS for high pixel.

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 of FIG. 9;

fig. 13 is a schematic configuration diagram of an imaging optical lens according to a fourth embodiment of the present invention;

fig. 14 is a schematic view of axial aberrations of the image pickup optical lens shown in fig. 13;

fig. 15 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 13;

fig. 16 is a schematic view of curvature of field and distortion of the imaging optical lens shown in fig. 13;

fig. 17 is a schematic configuration diagram of an imaging optical lens according to a fifth embodiment of the present invention;

fig. 18 is a schematic view of axial aberrations of the image pickup optical lens shown in fig. 17;

fig. 19 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 17;

fig. 20 is a schematic view of curvature of field and distortion of the imaging optical lens shown in fig. 17;

fig. 21 is a schematic configuration diagram of an image pickup optical lens of a comparative embodiment;

fig. 22 is a schematic view of axial aberrations of the image pickup optical lens shown in fig. 21;

fig. 23 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 21;

fig. 24 is a schematic view of curvature of field and distortion of the imaging optical lens shown in fig. 21.

Detailed Description

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

(first embodiment)

Referring to the drawings, the present invention provides an image pickup optical lens 10. Fig. 1 shows an imaging optical lens 10 according to a first embodiment of the present invention, and the imaging optical lens 10 includes five lenses. Specifically, the image capturing optical lens system 10, in order from an object side to an image side: a diaphragm S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. An optical element such as an optical filter (filter) GF may be disposed between the fifth lens L5 and the image plane Si. In an alternative embodiment, the end of the first lens L1 away from the second lens L2 may be further provided with a reflecting surface RS for reflecting and deflecting incident light rays to form a periscopic optical system, and the reflecting surface RS may be formed by a prism or a mirror.

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, and the fifth lens L5 is made of plastic. In other alternative embodiments, each lens may be made of other materials.

In the present embodiment, the focal length f of the imaging optical lens 10 is defined to satisfy the following relation: f is not less than 8.00, and the focal length f of the image pickup optical lens 10 is specified, thereby realizing the long focal length effect. Preferably, 8.75. ltoreq. f is satisfied.

The focal length of the image pickup optical lens 10 is f, the total optical length of the image pickup optical lens 10 is defined as TTL, and the following relational expression is satisfied: f/TTL is not less than 0.90, the ratio of the focal length f of the image pickup optical lens 10 to the total optical length TTL of the image pickup optical lens 10 is specified, and the image pickup optical lens 10 has a longer focal length under the condition of the same length. Preferably, 0.95 ≦ f/TTL is satisfied.

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 more than or equal to 0.40 and less than or equal to 0.85, the ratio of the focal length f1 of the first lens L1 to the focal length f of the shooting optical lens 10 is regulated, the curvature of field of the shooting optical lens 10 can be effectively balanced, and the curvature of field offset of the central field of view is smaller than 0.01 mm.

Defining the focal length of the second lens L2 as f2, and the focal length of the third lens L3 as f3, the following relations are satisfied: f2/f3 is more than or equal to 0.10 and less than or equal to 1.50, the ratio of the focal length f2 of the second lens L2 to the focal length f3 of the third lens L3 is specified, and astigmatism and Distortion of the shooting optical lens 10 are favorably corrected through reasonable distribution of the focal lengths, so that the Distortion | is less than or equal to 1.60%, and the possibility of generating a dark angle is reduced.

Defining an on-axis distance d6 from an image-side surface of the third lens L3 to an object-side surface of the fourth lens L4, and an on-axis distance d8 from an image-side surface of the fourth lens L4 to an object-side surface of the fifth lens L5, the following relations are satisfied: 3.00 < d6/d8 < 4.50, and the ratio of the on-axis distance d6 from the image-side surface of the third lens L3 to the object-side surface 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, which contributes to the reduction of the total optical length TTL within the conditional expression range and achieves the effect of making the optical lens thinner.

The central curvature radius of the object side surface of the second lens L2 is defined as R3, the on-axis thickness of the second lens L2 is defined as d3, and the following relational expression is satisfied: r3/d3 is 8.00-25.00, and the ratio of the center radius of curvature R3 of the object-side surface of the second lens L2 to the on-axis thickness d3 of the second lens L2 is defined, whereby chromatic aberration can be corrected well such that the chromatic aberration | LC | is 3.0 μm or less. Preferably, 8.33. ltoreq.R 3/d 3. ltoreq.24.96 is satisfied.

In this embodiment, the first lens element L1 with positive refractive power has a convex object-side surface and a convex image-side surface. 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.

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: 7.67 ≦ (R1+ R2)/(R1-R2) ≦ -0.48, 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-4.79 ≦ (R1+ R2)/(R1-R2) ≦ -0.60.

The total optical length of the imaging optical lens 10 is TTL, the on-axis thickness of the first lens L1 is defined as d1, and the following relational expression is satisfied: d1/TTL is more than or equal to 0.07 and less than or equal to 0.28, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.11. ltoreq. d 1/TTL. ltoreq.0.22 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. 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.

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: 2.11 ≦ f2/f ≦ -0.34, and it is advantageous to correct aberrations of the optical system by controlling the negative power of the second lens L2 in a reasonable range. Preferably, it satisfies-1.32. ltoreq. f 2/f. ltoreq-0.43.

The central curvature radius of the object side surface of the second lens L2 is R3, the central curvature radius of the image side surface of the second lens L2 is defined as R4, and the following relational expression is satisfied: the second lens L2 is defined in a shape of (R3+ R4)/(R3-R4) of 0.98 or more and 6.65 or less, and when the second lens L2 is within the range, the problem of chromatic aberration on the axis is favorably corrected as the lens becomes thinner. Preferably, 1.56 ≦ (R3+ R4)/(R3-R4). ltoreq.5.32 is satisfied.

The on-axis thickness of the second lens L2 is d3, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d3/TTL is more than or equal to 0.02 and less than or equal to 0.06, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.03. ltoreq. d 3/TTL. ltoreq.0.05 is satisfied.

In this embodiment, the third lens element L3 with negative refractive power has a concave object-side surface and a convex image-side surface. 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.

The focal length of the image pickup optical lens 10 is f, the focal length of the third lens L3 is f3, and the following relations are satisfied: 19.14 ≦ f3/f ≦ -0.31, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-11.96 ≦ f3/f ≦ -0.39.

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 relational expressions are satisfied: 3.74 ≦ (R5+ R6)/(R5-R6) ≦ 12.33, defines the shape of the third lens L3, facilitates the formation of the third lens L3, and can alleviate the deflection degree of the light passing through the lens within the range defined by the relation, thereby effectively reducing the aberration. Preferably, it satisfies-2.34 ≦ (R5+ R6)/(R5-R6). ltoreq.9.87.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the third lens L3 is d5, which satisfies the following relation: d5/TTL is more than or equal to 0.02 and less than or equal to 0.22, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.04. ltoreq. d 5/TTL. ltoreq.0.17 is satisfied.

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

The focal length of the image pickup optical lens 10 is f, the focal length of the fourth lens L4 is f4, and the following relations are satisfied: f4/f is more than or equal to 0.58 and less than or equal to 10.48, and the system has better imaging quality and lower sensitivity through reasonable distribution of the focal power. Preferably, 0.92. ltoreq. f 4/f. ltoreq.8.38 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: -5.85 ≦ (R7+ R8)/(R7-R8) ≦ 9.71, and defines the shape of the fourth lens L4, which is advantageous for correcting the aberration of the off-axis view angle and the like with the progress of the ultra-thinning when in the range. Preferably, it satisfies-3.66. ltoreq. (R7+ R8)/(R7-R8. ltoreq.7.77.

The total optical length of the imaging optical lens 10 is TTL, and the on-axis thickness of the fourth lens L4 is d7, which satisfies the following relation: d7/TTL is more than or equal to 0.03 and less than or equal to 0.13, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.05. ltoreq. d 7/TTL. ltoreq.0.11 is satisfied.

In this embodiment, the fifth lens element L5 with negative refractive power has a convex object-side surface and a concave image-side surface. In other alternative embodiments, the object-side surface and the image-side surface of the fifth lens element L5 can have other concave and convex profiles, and the fifth lens element L5 can have positive refractive power.

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 4.65 is more than or equal to 3.13, and the definition of the fifth lens L5 can effectively make the ray angle of the camera optical lens 10 smooth and reduce the tolerance sensitivity. Preferably, it satisfies-1.95. ltoreq. f 5/f. ltoreq.3.72.

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 (R9+ R10)/(R9-R10) to be (2.32) or less at 21.59 or less, and when the shape is within the range, the problem of aberration of an off-axis picture angle and the like can be favorably corrected with the development of ultra-thinning. Preferably, it satisfies-13.49 ≦ (R9+ R10)/(R9-R10). ltoreq.1.85.

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 0.02 and less than or equal to 0.11, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.03. ltoreq. d 9/TTL. ltoreq.0.09 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, which satisfies the following relation: f12/f is not less than 0.32 and not more than 2.71, 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, 0.51. ltoreq. f 12/f. ltoreq.2.17 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 2.50, so that a large aperture is realized, and the imaging performance of the photographic optical lens 10 is good.

In the present embodiment, the focal length of the imaging optical lens 10 is f, the image height of the imaging optical lens 10 is IH, and the following relation is satisfied: f/IH is more than or equal to 5.60, thereby realizing long focal length.

In the present embodiment, the Distortion of the imaging optical lens 10 is defined as | Distortion |, and the following relation is satisfied: the | Distorention | is less than or equal to 1.60 percent, thereby realizing small Distortion.

The photographic optical lens 10 has good optical performance and can meet the design requirements of large aperture, long focal length and small distortion; 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 central radius of curvature of the object side of the optical filter GF;

r12: 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: the on-axis distance from the image-side surface of the fifth lens L5 to the object-side surface of the optical filter GF;

d 11: on-axis thickness of the optical filter GF;

d 12: 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;

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;

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 inflected 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, and P5R1 and P5R2 represent the object-side surface and the image-side surface of the fifth lens L5, 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
				P1R1	0	/	/
P1R2	1	1.735	/
				P2R1	0	/	/
P2R2	0	/	/
				P3R1	1	0.635	/
P3R2	1	0.285	/
				P4R1	0	/	/
P4R2	0	/	/
				P5R1	2	0.295	2.125
P5R2	1	0.685	/

[ TABLE 4 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	1	2.645
			P2R1	0	/
P2R2	0	/
			P3R1	1	1.105
P3R2	1	0.495
			P4R1	0	/
P4R2	0	/
			P5R1	1	0.505
P5R2	1	1.355

Fig. 2 and 3 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm 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 25 shown later shows values corresponding to the parameters specified in the conditional expressions for the respective numerical values in the first, second, third, fourth, and fifth embodiments and the comparative embodiment.

As shown in table 25, the first embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 6.542mm, a full field image height IH of 2.619mm, and a diagonal field angle FOV of 18.36 °, and the imaging optical lens 10 satisfies the design requirements of a large aperture, a long focal length, and a small distortion, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(second embodiment)

Fig. 5 shows 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, except for the differences described below.

In this embodiment, the fifth lens element L5 has positive refractive power; the image-side surface of the first lens L1 is concave at the paraxial region; the object-side surface of the third lens element L3 is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region; the object-side surface of the fourth lens L4 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 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	0	/	/
P1R2	1	2.655	/
				P2R1	0	/	/
P2R2	0	/	/
				P3R1	1	2.395	/
P3R2	0	/	/
				P4R1	2	1.505	2.275
P4R2	1	2.445	/
				P5R1	2	0.755	2.145
P5R2	2	0.845	2.205

[ TABLE 8 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	0	/
			P2R1	0	/
P2R2	0	/
			P3R1	0	/
P3R2	0	/
			P4R1	1	1.965
P4R2	0	/
			P5R1	1	1.425
P5R2	1	1.635

Fig. 6 and 7 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm 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 25, the second embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 6.441mm, a full field image height IH of 2.619mm, and a diagonal field angle FOV of 19.22 °, and the imaging optical lens 20 satisfies the design requirements of a large aperture, a long focal length, and a small distortion, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(third embodiment)

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

In this embodiment, the fifth lens element L5 has positive refractive power; the image-side surface of the first lens L1 is concave at the paraxial region; the object-side surface of the third lens element L3 is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region; 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.

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	Position of reverse curvature 3
					P1R1	0	/	/	/
P1R2
		1	2.445	/	/
P2R1						3	0.625	0.885	2.645
	P2R2	0	/	/	/
P3R1
		1	1.485	/	/
P3R2
		2	1.305	2.255	/
P4R1						1	0.405	/	/
	P4R2
		1	0.165	/	/
	P5R1
		1	0.895	/	/
	P5R2					3	0.945	2.115	2.305

[ TABLE 12 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	0	/
			P2R1	0	/
P2R2	0	/
			P3R1	0	/
P3R2	1	2.045
			P4R1	1	0.835
P4R2	1	0.285
			P5R1	1	1.795
P5R2	1	2.405

Fig. 10 and 11 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm 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 25 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 6.201mm, a full field image height IH of 2.619mm, and a diagonal field angle FOV of 19.94 °, and the imaging optical lens 30 satisfies the design requirements of a large aperture, a long focal length, and a small distortion, has a sufficiently corrected on-axis and off-axis chromatic aberration, and has excellent optical characteristics.

(fourth embodiment)

Fig. 13 shows an imaging optical lens 40 according to a fourth embodiment of the present invention, which is basically the same as the first embodiment, has the same reference numerals as the first embodiment, and only differences will be described below.

In this embodiment, the fifth lens element L5 has positive refractive power; the image-side surface of the third lens L3 is concave at the paraxial region; 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.

Tables 13 and 14 show design data of the imaging optical lens 40 according to the fourth embodiment of the present invention.

[ TABLE 13 ]

Table 14 shows aspherical surface data of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[ TABLE 14 ]

Tables 15 and 16 show the inflection points and the stagnation point design data of each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[ TABLE 15 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2	Position of reverse curvature 3
					P1R1	0	/	/	/
P1R2
		1	1.875	/	/
P2R1
		2	0.635	0.735	/
P2R2						0	/	/	/
	P3R1
		2	0.525	2.085	/
	P3R2					1	2.015	/	/
P4R1
		1	2.335	/	/
P4R2						3	0.405	0.965	2.315
	P5R1	1	2.375	/	/
P5R2						3	0.395	0.645	1.635

[ TABLE 16 ]

Fig. 14 and 15 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm passing through the imaging optical lens 40 according to the fourth embodiment. Fig. 16 is a schematic view showing curvature of field and distortion of light having a wavelength of 555nm after passing through the imaging optical lens 40 according to the fourth embodiment. The field curvature S in fig. 16 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

Table 25 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 40 of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the imaging optical lens 40 has an entrance pupil diameter ENPD of 6.485mm, a full field image height IH of 2.619mm, and a diagonal field angle FOV of 18.26 °, and the imaging optical lens 40 satisfies the design requirements of a large aperture, a long focal length, and a small distortion, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(fifth embodiment)

Fig. 17 shows an imaging optical lens 50 according to a fifth embodiment of the present invention, which is basically the same as the first embodiment, has the same reference numerals as the first embodiment, and only differences will be described below.

In the present embodiment, the image-side surface of the first lens L1 is concave at the paraxial region; the object-side surface of the third lens element L3 is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region.

Tables 17 and 18 show design data of the imaging optical lens 50 according to the fifth embodiment of the present invention.

[ TABLE 17 ]

Table 18 shows aspherical surface data of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[ TABLE 18 ]

Tables 19 and 20 show the inflection points and the stagnation point design data of each lens in the imaging optical lens 50 according to the fifth embodiment of the present invention.

[ TABLE 19 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2
				P1R1	0	/	/
P1R2	0	/	/
				P2R1	0	/	/
P2R2	0	/	/
				P3R1	0	/	/
P3R2	0	/	/
				P4R1	0	/	/
P4R2	0	/	/
				P5R1	2	0.105	1.185
P5R2	1	0.515	/

[ TABLE 20 ]

	Number of stagnation points	Location of stagnation 1
			P1R1	0	/
P1R2	0	/
			P2R1	0	/
P2R2	0	/
			P3R1	0	/
P3R2	0	/
			P4R1	0	/
P4R2	0	/
			P5R1	1	0.175
P5R2	1	1.025

Fig. 18 and 19 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm passing through the imaging optical lens 50 according to the fifth embodiment. Fig. 20 is a schematic view showing curvature of field and distortion of light having a wavelength of 555nm after passing through the imaging optical lens 50 according to the fifth embodiment. The field curvature S in fig. 20 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

Table 25 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 50 of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the imaging optical lens 50 has an entrance pupil diameter ENPD of 3.831mm, a full field image height IH of 1.689mm, and a diagonal field angle FOV of 20.00 °, and the imaging optical lens 50 satisfies the design requirements of a large aperture, a long focal length, and a small distortion, and has excellent optical characteristics with on-axis and off-axis chromatic aberration sufficiently corrected.

(comparative embodiment)

Fig. 21 shows an imaging optical lens 60 according to a comparative embodiment, which is basically the same as the first embodiment, and the same reference numerals as the first embodiment, and only different points will be described below.

In this embodiment, the first lens element L1 is made of glass, and the fifth lens element L5 has positive refractive power; the image-side surface of the first lens L1 is concave at the paraxial region; the object-side surface of the third lens element L3 is convex at the paraxial region, and the image-side surface thereof is concave at the paraxial region; 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.

Tables 21 and 22 show design data of the imaging optical lens 60 according to the comparative embodiment.

[ TABLE 21 ]

Table 22 shows aspheric data of each lens in the imaging optical lens 60 of the comparative embodiment.

[ TABLE 22 ]

Tables 23 and 24 show the inflection point and stagnation point design data of each lens in the imaging optical lens 60 according to the comparative embodiment.

[ TABLE 23 ]

	Number of points of inflection	Position of reverse curvature 1	Position of reverse curvature 2	Position of reverse curvature 3
					P1R1	1	2.655	/	/
P1R2
		1	1.495	/	/
P2R1						3	0.345	0.995	1.545
	P2R2	0	/	/	/
P3R1
		2	0.885	1.565	/
P3R2						2	1.015	2.045	/
	P4R1	0	/	/	/
P4R2
		2	0.275	0.575	/
P5R1						0	/	/	/
	P5R2
		0	/	/	/

[ TABLE 24 ]

	Number of stagnation points	Location of stagnation 1	Location of stagnation 2	Location of stagnation 3
					P1R1	0	/	/	/
P1R2
		1	2.045	/	/
P2R1						3	0.685	1.275	1.725
	P2R2	0	/	/	/
P3R1
		0	/	/	/
P3R2
		0	/	/	/
P4R1
		0	/	/	/
P4R2
		0	/	/	/
P5R1
		0	/	/	/
P5R2
		0	/	/	/

Fig. 22 and 23 are schematic diagrams showing axial aberrations and chromatic aberration of magnification of light having wavelengths of 650nm, 610nm, 555nm, 510nm, 470nm, and 430nm passing through the imaging optical lens 60 according to the comparative embodiment. FIG. 24 is a schematic view showing curvature of field and distortion of light having a wavelength of 555nm after passing through the imaging optical lens 60 according to the comparative embodiment. The field curvature S in fig. 24 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

The following table 25 shows the numerical values corresponding to the respective conditional expressions in the comparative embodiment in accordance with the above conditional expressions. Obviously, the imaging optical lens 60 of the comparative embodiment does not satisfy the conditional expression: f/TTL is more than or equal to 0.90.

In the comparative embodiment, the entrance pupil diameter ENPD of the imaging optical lens 60 is 5.619mm, the full field image height IH is 2.619mm, and the field angle FOV in the diagonal direction is 20.08 °, and the imaging optical lens 60 does not satisfy the design requirements of large aperture, long focal length, and small distortion.

[ TABLE 25 ]

Parameter and condition formula	Example 1	Example 2	Example 3	Example 4	Example 5	Comparative example
							f	15.96	15.46	14.88	16.08	9.50	13.49
f/TTL	1.06	1.04	0.99	1.07	1.06	0.83
							f1/f	0.42	0.59	0.84	0.41	0.44	0.83
f2/f3	0.11	0.75	0.11	1.48	0.13	0.11
							d6/d8	4.46	4.39	3.04	4.45	3.71	3.11
f1	6.704	9.153	12.570	6.594	4.191	11.221
							f2	-8.225	-13.237	-15.667	-11.196	-5.172	-9.885
f3	-74.777	-17.718	-142.415	-7.583	-40.062	-89.454
							f4	18.365	26.741	103.953	22.935	13.225	647.749
f5	-17.949	43.874	20.253	49.858	-14.853	8.317
							f12	13.279	16.601	26.918	10.336	8.468	36.491
FNO	2.44	2.40	2.40	2.48	2.48	2.40
							TTL	14.999	14.874	15.000	15.000	8.924	16.183
IH	2.619	2.619	2.619	2.619	1.689	2.619
							FOV	18.36°	19.22°	19.94°	18.26°	20.00°	20.08°

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 element with positive refractive power, a second lens element with negative refractive power, a third lens element with negative refractive power, a fourth lens element with positive refractive power, and a fifth lens element with refractive power;

the focal length of the image pickup optical lens is f, the total optical length of the image pickup optical lens is TTL, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, the on-axis distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element is d6, the on-axis distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element is d8, and the following relations are satisfied:

8.00≤f；

0.90≤f/TTL；

0.40≤f1/f≤0.85；

0.10≤f2/f3≤1.50；

3.00≤d6/d8≤4.50。

2. the imaging optical lens according to claim 1, wherein a center radius of curvature of an object side surface of the second lens is R3, an on-axis thickness of the second lens is d3, and the following relational expression is satisfied:

8.00≤R3/d3≤25.00。

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

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

-7.67≤(R1+R2)/(R1-R2)≤-0.48；

0.07≤d1/TTL≤0.28。

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

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, and the following relations are satisfied:

-2.11≤f2/f≤-0.34；

0.98≤(R3+R4)/(R3-R4)≤6.65；

0.02≤d3/TTL≤0.06。

5. the imaging optical lens according to claim 1, wherein a central radius of curvature of an object-side surface of the third lens is R5, 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, and the following relationship is satisfied:

-19.14≤f3/f≤-0.31；

-3.74≤(R5+R6)/(R5-R6)≤12.33；

0.02≤d5/TTL≤0.22。

6. the imaging optical lens according to claim 1, wherein the fourth lens has a focal length f4, a central radius of curvature of an object-side surface of the fourth lens is R7, a central radius of curvature of an image-side surface of the fourth lens is R8, an on-axis thickness of the fourth lens is d7, and the following relationship is satisfied:

0.58≤f4/f≤10.48；

-5.85≤(R7+R8)/(R7-R8)≤9.71；

0.03≤d7/TTL≤0.13。

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

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, and the following relations are satisfied:

-3.13≤f5/f≤4.65；

-21.59≤(R9+R10)/(R9-R10)≤2.32；

0.02≤d9/TTL≤0.11。

8. an imaging optical lens according to claim 1, wherein the image height of the imaging optical lens is IH and satisfies the following relation:

f/IH≥5.60。

9. a camera optical lens according to claim 1, wherein a reflective surface is disposed at an end of the first lens element remote from the second lens element, and the reflective surface is configured to reflect and refract incident light.

10. The imaging optical lens according to claim 9, wherein the reflection surface is formed by a prism.