WO2021114083A1 - Camera optical lens - Google Patents

Abstract

A camera optical lens (10), sequentially comprising from an object side to an image side: a first lens (L1) having positive refractive power, a second lens (L2) having positive refractive power, a third lens (L3) having positive refractive power, and a fourth lens (L4). The focal length of the whole optical lens (10) is f, the focal length of the second lens (L2) is f2, the radius of curvature of the object side surface of the fourth lens (L4) is R7, the radius of curvature of the image side surface of the fourth lens (L4) is R8, the axial thickness of the first lens (L1) is d1, the axial thickness of the third lens (L3) is d5, and the axial distance between the image side surface of the third lens (L3) and the object side surface of the fourth lens (L4) is d6, which meet the following relations: 2.50≤f2/f≤5.00; 12.00≤d5/d6≤25.00; 0.20≤d1/f≤0.50; 3.00≤(R7+R8)/(R7-R8)≤15.00. The camera optical lens (10) can satisfy the design requirements of a large aperture and a wide angle while having good optical properties.

Description

Camera optical lens Technical field

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

Background technique

In recent years, with the rise of smart phones, the demand for miniaturized photographic lenses has increased. The photosensitive devices of general photographic lenses are nothing more than photosensitive coupling devices (Charge Coupled Device, CCD) or complementary metal oxide semiconductor devices (Complementary Metal -OxideSemiconductor Sensor, CMOS Sensor), and due to the improvement of semiconductor manufacturing process technology, the pixel size of photosensitive devices has been reduced, and the development trend of current electronic products with good functions, thin and short appearance, therefore, has a good The miniaturized camera lens with image quality has become the mainstream in the current market.

In order to obtain better imaging quality, the lenses traditionally mounted on mobile phone cameras mostly adopt a three-element lens structure. However, with the development of technology and the increase in diversified needs of users, as the pixel area of photosensitive devices continues to shrink and the system's requirements for image quality continue to increase, the four-element lens structure gradually appears in the lens design. Although the four-element lens has good optical performance, its optical power, lens spacing and lens shape settings are still unreasonable, resulting in the lens structure not being able to meet good optical performance while meeting large aperture, Ultra-thin design requirements.

Summary of the invention

In view of the above-mentioned problems, the object of the present invention is to provide an imaging optical lens, which not only has good optical performance, but also satisfies the design requirements of large aperture and ultra-thinness.

In order to solve the above technical problems, an embodiment of the present invention provides an imaging optical lens, from the object side to the image side, including: a first lens with positive refractive power, a second lens with positive refractive power, and positive refractive power. A powerful third lens and a fourth lens; the overall focal length of the imaging optical lens is f, the focal length of the second lens is f2, the radius of curvature of the object side of the fourth lens is R7, and the fourth lens The radius of curvature of the mirror image side is R8, the on-axis thickness of the first lens is d1, the on-axis thickness of the third lens is d5, and the image side of the third lens is to the object side of the fourth lens. The distance on the axis is d6, which satisfies the following relationship: 2.50≤f2/f≤5.00; 12.00≤d5/d6≤25.00; 0.20≤d1/f≤0.50; 3.00≤(R7+R8)/(R7-R8)≤15.00 .

Preferably, the focal length of the third lens is f3, and the following relationship is satisfied: 0.50≤f3/f≤2.00.

Preferably, the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, and the following relationship is satisfied: -10.00≤(R1+R2)/(R1-R2)≤ -3.00.

Preferably, the on-axis thickness of the second lens is d3, and the on-axis distance from the image side surface of the second lens to the object side surface of the third lens is d4, which satisfies the following relationship: 2.50≤d3/d4≤ 5.00.

Preferably, the aperture F number of the imaging optical lens is less than or equal to 1.15.

Preferably, the focal length of the first lens is f1, and the total optical length of the imaging optical lens is TTL, which satisfies the following relationship: 1.16≤f1/f≤4.71; 0.07≤d1/TTL≤0.38.

Preferably, the radius of curvature of the object side surface of the second lens is R3, the radius of curvature of the image side surface of the second lens is R4, the axial thickness of the second lens is d3, and the total optical length of the imaging optical lens is TTL, and satisfies the following relationship: -4.08≤(R3+R4)/(R3-R4)≤-0.42; 0.06≤d3/TTL≤0.19.

Preferably, the radius of curvature of the object side of the third lens is R5, the radius of curvature of the image side of the third lens is R6, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied: 1.29≤(R5 +R6)/(R5-R6)≤7.36; 0.07≤d5/TTL≤0.30.

Preferably, the focal length of the fourth lens is f4, the axial thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied: -9.84≤f4/f≤9.32 ;0.05≤d7/TTL≤0.21.

Preferably, the combined focal length of the first lens and the second lens is f12, which satisfies the following relationship: 1.35≤f12/f≤5.22. .

The beneficial effect of the present invention is that the present invention provides a TOF camera optical lens with good optical performance and meeting the design requirements of wide-angle and large aperture.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of an imaging optical lens in the first embodiment of the present invention;

FIG. 2 is a schematic diagram of field curvature and distortion of the imaging optical lens shown in FIG. 1;

3 is a schematic diagram of the structure of an imaging optical lens according to a second embodiment of the present invention;

4 is a schematic diagram of field curvature and distortion of the imaging optical lens shown in FIG. 3;

5 is a schematic diagram of the structure of an imaging optical lens according to a third embodiment of the present invention;

FIG. 6 is a schematic diagram of field curvature and distortion of the imaging optical lens shown in FIG. 5.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, a person of ordinary skill in the art can understand that, in each embodiment of the present invention, many technical details are proposed for the reader to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed by the present invention can be realized.

(First embodiment)

With reference to the drawings, the present invention provides an imaging optical lens 10. FIG. 1 shows an imaging optical lens 10 according to a first embodiment of the present invention. The imaging optical lens 10 includes four lenses. Specifically, the imaging optical lens 10 includes an aperture S1, a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 in order from the object side to the image side. In this embodiment, preferably, an optical element such as a glass plate GF is arranged between the fourth lens L4 and the image plane Si. The glass plate GF can be a glass cover plate or an optical filter, of course, In other possible embodiments, the glass plate GF can also be arranged in other positions.

In this embodiment, the first lens L1 has positive refractive power; the second lens L2 has positive refractive power; and the third lens L3 has positive refractive power.

Here, the focal length of the entire imaging optical lens is defined as f, the focal length of the second lens L2 is f2, the radius of curvature of the object side of the fourth lens L4 is R7, the radius of curvature of the image side of the fourth lens L4 is R8, and the first lens L1 The on-axis thickness of the third lens L3 is d1, the on-axis thickness of the third lens L3 is d5, the on-axis distance from the image side surface of the third lens L3 to the object side surface of the fourth lens L4 is d6, and the imaging optical lens satisfies the following relationship formula:

2.50≤f2/f≤5.00 (1)

12.00≤d5/d6≤25.00 (2)

0.20≤d1/f≤0.50 (3)

3.00≤(R7+R8)/(R7-R8)≤15.00 (4)

Among them, the conditional formula (1) specifies the ratio of the focal length f2 of the second lens L2 to the total focal length f of the system, which can effectively balance the spherical aberration generated by the first lens L1 and the field curvature of the system. Preferably, 2.55≤f2/f≤4.95.

Conditional expression (2) specifies the ratio of the on-axis thickness d5 of the third lens L3 and the on-axis distance d6 between the image side surface of the third lens L3 and the object side surface of the fourth lens L4, which contributes to the range of the conditional expression Lens processing and lens assembly. Preferably, 13.62≤d5/d6≤24.94.

Conditional formula (3) specifies the ratio of the on-axis thickness d1 of the first lens L1 to the total focal length f of the system. Within this conditional range, it is beneficial to achieve ultra-thinness. Preferably, 0.23≤d1/f≤0.48.

Conditional expression (4) specifies the shape of the fourth lens L4. Within this range, with the development of ultra-thin and wide-angle, it is beneficial to correct the off-axis angle of view aberration and other problems. Preferably, 3.20≤(R7+R8)/(R7-R8)≤14.93.

In this embodiment, through the above-mentioned lens configuration, each lens (L1, L2, L3, L4) with different refractive power is used to make the optical system have good optical performance while satisfying the design of large aperture and wide-angle. Claim.

Specifically, in the embodiment of the present invention, the focal length of the third lens is defined as f3, and the imaging optical lens satisfies the following relationship:

0.50≤f3/f≤2.00 (5)

Conditional formula (5) specifies the ratio of the focal length f3 of the third lens L3 to the total focal length f, and the reasonable distribution of the optical power enables the system to have better imaging quality and lower sensitivity. Preferably, 0.67≤f3/f≤1.95.

Define the curvature radius of the object side surface of the first lens as R1, and the curvature radius of the image side surface of the first lens as R2, and the imaging optical lens satisfies the following relationship:

-10.00≤(R1+R2)/(R1-R2)≤-3.00 (6)

The conditional expression (6) specifies the shape of the first lens L1. When the shape of the first lens L1 is within the range of the conditional expression, the aberration of the optical system can be corrected, thereby improving the imaging quality. Preferably, -9.50≤(R1+R2)/(R1-R2)≤-3.14.

Define the on-axis thickness of the second lens L2 as d3, and the on-axis distance from the image side surface of the second lens L2 to the object side surface of the third lens L3 as d4, and the imaging optical lens satisfies the following relationship:

2.50≤d3/d4≤5.00 (7)

The conditional expression (7) specifies the ratio of the on-axis thickness d3 of the second lens L2 to the on-axis distance d4 from the image side surface of the second lens L2 to the object side surface of the third lens L3, which helps compress optics within the scope of the conditional expression The total length of the system achieves ultra-thin effect. Preferably, 2.52≤d3/d4≤4.56.

Preferably, in this embodiment, the focal length of the first lens L1 is defined as f1, and the imaging optical lens satisfies the following relationship: 1.16≤f1/f≤4.71, which specifies the ratio of the focal length of the first lens L1 to the overall focal length. When within the specified range, the first lens has an appropriate positive refractive power, which is beneficial to reduce system aberrations, and at the same time, is beneficial to the development of ultra-thin and wide-angle lenses. Preferably, 1.86≤f1/f≤3.77.

The axial thickness of the first lens L1 is d1, and the total optical length of the imaging optical lens is TTL. The imaging optical lens satisfies the following relationship: 0.07≤d1/TTL≤0.38, which specifies the axial thickness of the first lens L1 and the imaging The ratio of the total optical length of the optical lens 10 to TTL is conducive to achieving ultra-thinness. Preferably, 0.12≤d1/TTL≤0.31.

The curvature radius of the object side surface of the second lens L2 is R3, and the curvature radius of the image side surface of the second lens L2 is R4, which satisfies the following relationship: -4.08≤(R3+R4)/(R3-R4)≤-0.42. When the shape of the two lens L2 is within the range, as the lens becomes ultra-thin and wide-angle, it is beneficial to correct the problem of axial chromatic aberration. Preferably, -2.55≤(R3+R4)/(R3-R4)≤-0.53.

The on-axis thickness of the second lens L2 is d3, which satisfies the following relationship: 0.06≤d3/TTL≤0.19, which specifies the ratio of the on-axis thickness of the second lens L2 to the total optical length TTL of the imaging optical lens 10, which is conducive to achieving ultra-thin化. Preferably, 0.09≤d3/TTL≤0.15.

The curvature radius of the object side surface of the third lens L3 is R5, and the curvature radius of the image side surface of the third lens L3 is R6, which satisfies the following relationship: 1.29≤(R5+R6)/(R5-R6)≤7.36, which can effectively control the third lens The shape of the lens L3 is conducive to the molding of the third lens L3. Within the specified range of the conditional formula, the degree of deflection of the light passing through the lens can be eased, and aberrations can be effectively reduced. Preferably, 2.06≤(R5+R6)/(R5-R6)≤5.89.

The on-axis thickness of the third lens L3 is d5, which satisfies the following relationship: 0.07≤d5/TTL≤0.30, which specifies the ratio of the on-axis thickness of the third lens L3 to the total optical length TTL of the imaging optical lens 10, which is conducive to achieving ultra-thin化. Preferably, 0.11≤d5/TTL≤0.24.

The focal length of the fourth lens L4 is f4, which satisfies the following relational expression: -9.84≤f4/f≤9.32. The reasonable distribution of optical power enables the system to have better imaging quality and lower sensitivity. Preferably, -6.15≤f4/f≤7.46.

The on-axis thickness of the fourth lens L4 is d7, which satisfies the following relationship: 0.05≤d7/TTL≤0.21, which specifies the ratio of the on-axis thickness of the fourth lens L4 to the total optical length TTL of the imaging optical lens 10, which is conducive to achieving super Thinning. Preferably, 0.07≤d7/TTL≤0.17.

In this embodiment, the combined focal length of the first lens L1 and the second lens L2 is defined as f12, which satisfies the following relational expression: 1.35≤f12/f≤5.22. Within the range of the conditional expression, the imaging optics can be eliminated The aberration and distortion of the lens 10 can suppress the back focal length of the imaging optical lens 10 and maintain the miniaturization of the image lens system group. Preferably, 2.17≤f12/f≤4.18.

In this embodiment, the aperture F number of the imaging optical lens 10 is less than or equal to 1.15. Large aperture, good imaging performance. Preferably, the aperture F number is less than or equal to 1.13.

It is worth mentioning that, since the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 constituting the imaging optical lens 10 of this embodiment have the aforementioned structure and parameter relationship, the imaging The optical lens 10 can reasonably allocate the focal power, surface shape, material, and axial thickness of each lens, etc., and therefore correct various aberrations, and achieve good optical imaging performance while satisfying large aperture, Wide-angle and ultra-thin design requirements.

In addition, the imaging optical lens of this application is a TOF (Time of flight) receiving end lens. The principle of TOF technology is that the transmitting end lens emits an infrared surface light source, which is reflected back on the object, and the receiving end lens receives the reflected infrared light information. This process The 3D recognition process is realized. The working wavelength range of the imaging optical lens of this application is 920nm-960nm.

TTL: Total optical length (the on-axis distance from the object side of the first lens L1 to the imaging surface), in mm.

FIG. 1 is a schematic diagram of the structure of an imaging optical lens 10 in the first embodiment.

The design data of the imaging optical lens 10 in the first embodiment of the present invention is shown below. Table 1 lists the object side and image side curvature radius R of the first lens L1 to the fourth lens L4 constituting the imaging optical lens 10 in the first embodiment of the present invention, the center thickness of the lens, the distance d between the lenses, and the refractive index. nd and Abbe number vd. Table 2 shows the conic coefficient k and the aspherical coefficient of the imaging optical lens 10. It should be noted that, in this embodiment, the unit of distance, radius, and center thickness is millimeter (mm).

【Table 1】

The meaning of each symbol in the above table is as follows.

R: The radius of curvature of the optical surface, and the radius of curvature of the center of the lens;

S1: aperture;

R1: the radius of curvature of the object side surface of the first lens L1;

R2: the radius of curvature of the image side surface of the first lens L1;

R3: the radius of curvature of the object side surface of the second lens L2;

R4: the radius of curvature of the image side surface of the second lens L2;

R5: the radius of curvature of the object side surface of the third lens L3;

R6: the radius of curvature of the image side surface of the third lens L3;

R7: the radius of curvature of the object side of the fourth lens L4;

R8: the radius of curvature of the image side surface of the fourth lens L4;

R9: the curvature radius of the object side surface of the glass plate GF;

R10: the radius of curvature of the image side surface of the glass plate GF;

d: the on-axis thickness of the lens or the on-axis distance between adjacent lenses;

d0: the on-axis distance from the aperture S1 to the object side of the first lens L1;

d1: the on-axis thickness of the first lens L1;

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

d3: the on-axis thickness of the second lens L2;

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

d5: the on-axis thickness of the third lens L3;

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

d7: the on-axis thickness of the fourth lens L4;

d8: the on-axis distance from the image side surface of the fourth lens L4 to the object side surface of the optical filter GF;

d9: the on-axis thickness of the glass plate GF;

d10: the on-axis distance from the image side surface of the glass plate GF to the image surface Si;

nd: refractive index of d-line;

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

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

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

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

ndg: the refractive index of the d-line of the glass plate GF;

vd: Abbe number;

v1: Abbe number of the first lens L1;

v2: Abbe number of the second lens L2;

v3: Abbe number of the third lens L3;

v4: Abbe number of the fourth lens L4;

vg: Abbe number of glass plate GF.

Table 2 shows the aspheric surface data of each lens of the imaging optical lens 10 provided by the first embodiment of the present invention.

【Table 2】

Among them, k is the conic coefficient, and A4, A6, A8, A10, A12, A14, and A16 are the aspheric coefficients.

IH: Image height

y=(x2/R)/{1+[1-(1+k)(x2/R2)] ^1/2 }+A4x ⁴ +A6x ⁶ +A8x ⁸ +A10x ¹⁰ +A12x ¹² +A14x ¹⁴ +A16x ¹⁶ (6)

It should be noted that the aspheric surface of each lens in this embodiment preferably uses the aspheric surface shown in the following conditional expression (6), but the specific form of the following conditional expression (6) is only an example. In fact, It is not limited to the aspheric polynomial form shown in the conditional expression (6).

Table 3 and Table 4 show the design data of the inflection point and stagnation point of each lens in the imaging optical lens 10 of the embodiment of the present invention. Among them, P1R1 and P2R2 represent the object side and image side of the first lens L1 respectively, P2R1 and P2R2 represent the object side and image side of the second lens L2 respectively, and P3R1 and P3R2 represent the object side and image side of the third lens L3 respectively. P4R1 and P4R2 represent the object side surface and the image side surface of the fourth lens L4, respectively. The corresponding data in the “reflection point position” column is the vertical distance from the reflex point set on the surface of each lens to the optical axis of the imaging optical lens 10. The data corresponding to the “stationary point position” column is the vertical distance from the stationary point set on the surface of each lens to the optical axis of the imaging optical lens 10.

【table 3】

To	Number of recurve points	Recurve point position 1	Recurve point position 2
P1R1	1	0.775	To
P1R2	1	0.535	To
P2R1	2	0.325	0.715
P2R2	2	0.265	0.715
P3R1	2	0.555	0.825
P3R2	2	0.635	0.915
P4R1	2	0.395	1.065
P4R2	2	0.435	1.265

【Table 4】

To	Number of stationary points		Stagnation position 1	Stagnation position 2
P1R1	0	To	To
P1R2	1	0.715	To
P2R1	1	0.485	To
P2R2	2	0.375	0.805
P3R1	1	0.755	To
P3R2	0	To	To
P4R1	2	0.835	1.195
P4R2	1	0.975	To

FIG. 2 shows a schematic diagram of field curvature and distortion after light with a wavelength of 940 nm passes through the imaging optical lens 10 of the first embodiment. The curvature of field S in Fig. 2 is the curvature of field in the sagittal direction, and T is the curvature of field in the meridional direction.

The following Table 13 shows the values corresponding to the various values in each of Examples 1, 2, and 3 and the parameters that have been specified in the conditional expressions.

As shown in Table 13, the first embodiment satisfies various conditional expressions.

In this embodiment, the entrance pupil diameter of the imaging optical lens 10 is 1.650mm, the full field of view image height is 1.500mm, the diagonal field angle is 77.80°, the aperture F number is 1.136, the large aperture, Wide-angle, ultra-thin, and has excellent optical characteristics.

(Second embodiment)

3 is a schematic diagram of the structure of the imaging optical lens 20 in the second embodiment. The second embodiment is basically the same as the first embodiment, and the meaning of the symbols is the same as that of the first embodiment, and only the differences are listed below.

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

【table 5】

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

【Table 6】

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

【Table 7】

To	Number of recurve points	Recurve point position 1	Recurve point position 2	Recurve point position 3
P1R1	1	0.695	To	To
P1R2	1	0.455	To	To
P2R1	3	0.185	0.695	0.745
P2R2	1	0.765	To	To
P3R1	2	0.585	0.815	To
P3R2	2	0.765	0.865	To
P4R1	1	0.435	To	To
P4R2	1	0.445	To	To

【Table 8】

To	Number of stationary points		Stagnation position 1
P1R1	0	To
P1R2	1	0.635
P2R1	1	0.305
P2R2	1	0.865
P3R1	0	To
P3R2	0	To
P4R1	1	0.865
P4R2	1	1.105

FIG. 4 shows a schematic diagram of field curvature and distortion of light with a wavelength of 940 nm after passing through the imaging optical lens 20 of the second embodiment. The curvature of field S in Fig. 4 is the curvature of field in the sagittal direction, and T is the curvature of field in the meridional direction.

The following Table 13 shows the values corresponding to the various values in each of Examples 1, 2, and 3 and the parameters that have been specified in the conditional expressions.

As shown in Table 13, the second embodiment satisfies various conditional expressions.

In this embodiment, the entrance pupil diameter of the imaging optical lens 20 is 1.491 mm, the full field of view image height is 1.500 mm, the diagonal field angle is 79.80°, the aperture F number is 1.150, and the large aperture, Wide-angle, ultra-thin, and has excellent optical characteristics.

(Third embodiment)

5 is a schematic diagram of the structure of the imaging optical lens 30 in the third embodiment. The third embodiment is basically the same as the first embodiment, and the meaning of the symbols is the same as that of the first embodiment, and only the differences are listed below.

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

【Table 9】

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

【Table 10】

Table 11 and Table 12 show the design data of the inflection point and stagnation point of each lens in the imaging optical lens 30 of the embodiment of the present invention.

【Table 11】

To	Number of recurve points	Recurve point position 1	Recurve point position 2	Recurve point position 3	Recurve point position 4
P1R1	0	To	To	To	To
P1R2	1	0.625	To	To	To
P2R1	2	0.295	0.755	To	To
P2R2	2	0.165	0.755	To	To
P3R1	4	0.575	0.845	0.885	1.315
P3R2	2	0.665	0.855	To	To
P4R1	2	0.305	1.035	To	To
P4R2	2	0.395	1.265	To	To

【Table 12】

To	Number of stationary points		Stagnation position 1	Stagnation position 2
P1R1	0	To	To
P1R2	0	To	To
P2R1	1	0.445	To
P2R2	2	0.315	0.845
P3R1	2	0.935	1.385
P3R2	0	To	To
P4R1	2	0.775	1.165
P4R2	1	1.085	To

FIG. 6 shows a schematic diagram of field curvature and distortion of light with a wavelength of 940 nm after passing through the imaging optical lens 30 of the third embodiment. The curvature of field S in Fig. 6 is the curvature of field in the sagittal direction, and T is the curvature of field in the meridional direction.

The following Table 13 shows the values corresponding to the various values in each of Examples 1, 2, and 3 and the parameters that have been specified in the conditional expressions.

As shown in Table 13, the third embodiment satisfies various conditional expressions.

In this embodiment, the entrance pupil diameter of the imaging optical lens 30 is 1.650mm, the full field of view image height is 1.500mm, the diagonal field angle is 77.40°, the aperture F number is 0.995, the large aperture, Wide-angle, ultra-thin, and has excellent optical characteristics.

The following Table 13 lists the values of the corresponding conditional expressions in the first embodiment, the second embodiment, and the third embodiment according to the above conditional expressions, as well as the values of other related parameters.

【Table 13】

Parameters and conditions	Example 1	Example 2	Example 3
f2/f	2.600	4.117	4.899
d5/d6	15.233	19.935	24.882
d1/f	0.250	0.266	0.462
(R7+R8)/(R7-R8)	7.452	3.403	14.846
FNO	1.136	1.150	0.995
f	1.875	1.714	1.641
f1	4.922	3.980	5.158
f2	4.875	7.057	8.039
f3	2.934	1.449	3.117
f4	-9.225	-2.404	10.201
f12	2.707	2.764	3.483

A person of ordinary skill in the art can understand that the above-mentioned embodiments are specific embodiments for realizing the present invention, and in practical applications, various changes can be made to them in form and details without departing from the spirit and spirit of the present invention. range.

Claims (10)

1. An imaging optical lens, characterized in that the imaging optical lens, from the object side to the image side, includes: a first lens with positive refractive power, a second lens with positive refractive power, and a first lens with positive refractive power. Three lenses, and a fourth lens;

   The overall focal length of the imaging optical lens is f, the focal length of the second lens is f2, the radius of curvature of the object side of the fourth lens is R7, the radius of curvature of the image side of the fourth lens is R8, and the The axial thickness of a lens is d1, the axial thickness of the third lens is d5, the axial distance from the image side surface of the third lens to the object side surface of the fourth lens is d6, and the following relationship is satisfied :

   2.50≤f2/f≤5.00;

   12.00≤d5/d6≤25.00;

   0.20≤d1/f≤0.50;

   3.00≤(R7+R8)/(R7-R8)≤15.00.
2. The imaging optical lens of claim 1, wherein the focal length of the third lens is f3, and satisfies the following relationship:

   0.50≤f3/f≤2.00.
3. The imaging optical lens of claim 1, wherein the curvature radius of the object side surface of the first lens is R1, and the curvature radius of the image side surface of the first lens is R2, and the following relationship is satisfied:

   -10.00≤(R1+R2)/(R1-R2)≤-3.00.
4. The imaging optical lens of claim 1, wherein the on-axis thickness of the second lens is d3, and the on-axis distance from the image side surface of the second lens to the object side surface of the third lens is d4 , And satisfy the following relationship:

   2.50≤d3/d4≤5.00.
5. The imaging optical lens of claim 1, wherein the aperture F number of the imaging optical lens is less than or equal to 1.15.
6. The imaging optical lens of claim 1, wherein the focal length of the first lens is f1, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied:

   1.16≤f1/f≤4.71;

   0.07≤d1/TTL≤0.38.
7. The imaging optical lens of claim 1, wherein the curvature radius of the object side surface of the second lens is R3, the curvature radius of the image side surface of the second lens is R4, and the on-axis thickness of the second lens Is d3, the total optical length of the camera optical lens is TTL, and satisfies the following relationship:

   -4.08≤(R3+R4)/(R3-R4)≤-0.42;

   0.06≤d3/TTL≤0.19.
8. The imaging optical lens according to claim 1, wherein the curvature radius of the object side surface of the third lens is R5, the curvature radius of the image side surface of the third lens is R6, and the total optical length of the imaging optical lens is TTL, and satisfies the following relationship:

   1.29≤(R5+R6)/(R5-R6)≤7.36;

   0.07≤d5/TTL≤0.30.
9. The imaging optical lens of claim 1, wherein the focal length of the fourth lens is f4, the axial thickness of the fourth lens is d7, and the total optical length of the imaging optical lens is TTL, and satisfies The following relationship:

   -9.84≤f4/f≤9.32;

   0.05≤d7/TTL≤0.21.
10. The imaging optical lens of claim 1, wherein the combined focal length of the first lens and the second lens is f12, which satisfies the following relationship:

    1.35≤f12/f≤5.22.

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