CN114815140B - Image pickup lens - Google Patents

Abstract

The invention provides an imaging lens which can meet the requirements of low back and low F value and has good optical characteristics. The imaging lens includes, in order from an object side toward an image side: a first lens having negative optical power; a second lens having positive optical power; a third lens having negative optical power; a fourth lens having positive optical power; and a fifth lens having negative optical power; the concave surface of the first lens in the paraxial region faces the object side, and the concave surface of the fifth lens in the paraxial region faces the image side, so that a preset conditional expression is met.

Description

Camera lens

Technical Field

The present invention relates to an imaging lens for forming an image of a subject on a solid-state imaging element of a CCD sensor or a C-MOS sensor used in an imaging device.

Background Art

In recent years, camera functions have been widely installed in various products such as home appliances, information terminals, and automobiles. It is expected that the development of products incorporating camera functions will continue in the future.

The imaging lens installed in such equipment needs to be compact and have high resolution performance.

As an imaging lens that aims at improving performance in the related art, for example, an imaging lens disclosed in Patent Document 1 below is known.

Patent document 1 (China Patent Publication No. 110850562) discloses a camera lens, which includes, from the object side, a first lens having a negative refractive index; a second lens having a positive refractive index; a third lens having a negative refractive index; a fourth lens having a positive refractive index; and a fifth lens having a negative refractive index; the relationship between the focal length of the third lens and the focal length of the entire camera lens system,

The relationship between the paraxial curvature radius of the object side of the second lens and the thickness of the second lens on the optical axis,

The relationship between the paraxial curvature radius of the object side surface of the third lens and the paraxial curvature radius of the image side surface of the third lens and the relationship between the optical axis thickness of the first lens and the optical axis distance from the image side surface of the first lens to the object side surface of the second lens satisfy certain conditions.

Summary of the invention

Problem that the invention aims to solve

When attempting to achieve low profile and low F value by using the lens structure described in Patent Document 1, it is very difficult to correct aberrations in the peripheral portion, and good optical performance cannot be obtained.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an imaging lens having a high resolution that satisfies the requirements for low profile and low F-number in a balanced manner and that satisfies various aberrations with good correction.

Furthermore, regarding the terms used in the present invention, the convex surface, concave surface, and plane surface of the lens surface refer to the shape near the optical axis (paraxial). The optical power refers to the optical power near the optical axis (paraxial). The pole refers to the point on the aspheric surface other than the optical axis where the tangent plane intersects the optical axis perpendicularly. The total optical length refers to the distance on the optical axis from the object side of the optical element located closest to the object side to the imaging surface. In addition, the total optical length and the back focal length are distances obtained by converting the thickness of the IR cutoff filter or protective glass disposed between the imaging lens and the imaging surface into air.

Means used to solve problems

The camera lens of the present invention comprises, from the object side toward the image side, a first lens having negative optical focal power; a second lens having positive optical focal power; a third lens having negative optical focal power; a fourth lens having positive optical focal power; and a fifth lens having negative optical focal power; the first lens has a concave surface facing the object side in the paraxial zone, and the fifth lens has a concave surface facing the image side in the paraxial zone.

The first lens has negative power and a concave surface facing the object side in the paraxial region to suppress chromatic aberration, coma, astigmatism and distortion.

The second lens has positive refractive power to achieve low profile, and satisfactorily corrects spherical aberration, astigmatism, field curvature, and distortion.

The third lens has negative power and well corrects chromatic aberration, coma, astigmatism, field curvature and distortion.

The fourth lens has positive refractive power to achieve low profile, and satisfactorily corrects spherical aberration, coma, astigmatism, field curvature, and distortion.

The fifth lens has negative refractive power, and its concave surface faces the image side in the paraxial area, which can well correct chromatic aberration,

Astigmatism, field curvature and distortion. In addition, by facing the image side with the concave surface in the paraxial area, the low profile is maintained and the back focus is ensured.

In the imaging lens having the above configuration, it is preferred that the image-side surface of the first lens be concave toward the image side in the paraxial region.

By making the image-side surface of the first lens concave toward the image side in the paraxial region, coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferred that the object-side surface of the second lens is convex toward the object side in the paraxial region.

By making the object-side surface of the second lens element convex toward the object side in the paraxial region, astigmatism, field curvature and distortion can be corrected well.

In the imaging lens of the above structure, it is preferred that the object-side surface of the fourth lens element is concave toward the object side in the paraxial region.

By making the object-side surface of the fourth lens element concave toward the object side in the paraxial region, coma, astigmatism, field curvature and distortion can be corrected well.

In the imaging lens having the above configuration, it is preferable that the object-side surface of the fourth lens be formed as an aspherical surface having a pole at a position other than on the optical axis.

By forming the object-side surface of the fourth lens as an aspherical surface having a pole at a position other than the optical axis, astigmatism, field curvature and distortion can be corrected favorably.

In the imaging lens having the above configuration, it is preferable that the object-side surface of the fifth lens be formed as an aspherical surface having a pole at a position other than on the optical axis.

By forming the object-side surface of the fifth lens as an aspherical surface having a pole at a position other than the optical axis, astigmatism, field curvature and distortion can be corrected favorably.

In the imaging lens having the above configuration, it is preferable that the image side surface of the fifth lens is formed as an aspherical surface having a pole at a position other than on the optical axis.

By forming the image-side surface of the fifth lens as an aspherical surface having a pole at a position other than the optical axis, astigmatism, field curvature, and distortion can be corrected favorably.

By adopting the above structure, the imaging lens of the present invention can achieve a low profile with an overall aspect ratio (ratio of the optical overall length to the diagonal length of the effective imaging surface of the imaging element) of 0.95 or less, and a low F value of 2.4 or less.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (1) is satisfied:

(1)0.05＜(r10/|r5|)×100＜7.10

in,

r10: paraxial radius of curvature of the image side of the fifth lens,

r5: paraxial radius of curvature of the object side of the third lens.

By satisfying the range of conditional expression (1), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (2) is satisfied:

(2) 2.8＜r9/r8/r10/f5＜10.0

in,

r9: the paraxial radius of curvature of the object side of the fifth lens,

r8: paraxial curvature radius of the image side of the fourth lens,

f5: Focal length of the fifth lens.

By satisfying the range of conditional expression (2), chromatic aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (3) is satisfied:

(3) 0.13＜(r2/T1)/100＜1.15

in,

r2: paraxial radius of curvature of the image side of the first lens,

T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens.

By satisfying the range of conditional expression (3), a low profile can be achieved, and coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (4) is satisfied:

(4) -3.80＜|r5|/r6/r1＜-0.85

in,

r5: the paraxial radius of curvature of the object side of the third lens,

r6: paraxial curvature radius of the image side of the third lens,

r1: paraxial radius of curvature of the object side of the first lens.

By satisfying the range of conditional expression (4), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (5) is satisfied:

(5)-2.5＜r9/f5＜-0.9

in,

r9: the paraxial radius of curvature of the object side of the fifth lens,

f5: Focal length of the fifth lens.

By satisfying the range of conditional expression (5), chromatic aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (6) is satisfied:

(6)1.65＜f3/f5＜4.80

in,

f3: focal length of the third lens,

f5: Focal length of the fifth lens.

By satisfying the range of conditional expression (6), chromatic aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (7) is satisfied:

(7) -4.3＜f5/D5＜-1.0

in,

f5: focal length of the fifth lens,

D5: The thickness of the fifth lens on the optical axis.

By satisfying the range of conditional expression (7), low profile can be achieved, and chromatic aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (8) is satisfied:

(8)-8.75＜(r1×r2/T1)/100＜-0.55

in,

r1: paraxial radius of curvature of the object side of the first lens,

r2: paraxial radius of curvature of the image side of the first lens,

T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens.

By satisfying the range of conditional expression (8), a low profile can be achieved, and coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (9) is satisfied:

(9)2.6＜r2/f＜40.0

in,

r2: paraxial radius of curvature of the image side of the first lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (9), coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (10) is satisfied:

(10)-90.0＜r2/r8＜-9.5

in,

r2: paraxial radius of curvature of the image side of the first lens,

r8: paraxial radius of curvature of the image-side surface of the fourth lens.

By satisfying the range of conditional expression (10), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (11) is satisfied:

(11)2.0＜r2/r3/r10＜30.0

in,

r2: paraxial radius of curvature of the image side of the first lens,

r3: the paraxial radius of curvature of the object side of the second lens,

r10: paraxial curvature radius of the image-side surface of the fifth lens.

By satisfying the range of conditional expression (11), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (12) is satisfied:

(12) -3.5＜r3/r4＜-1.8

in,

r3: the paraxial radius of curvature of the object side of the second lens,

r4: paraxial radius of curvature of the image-side surface of the second lens.

By satisfying the range of conditional expression (12), spherical aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (13) is satisfied:

(13)-1.70＜r3/r7＜-0.15

in,

r3: the paraxial radius of curvature of the object side of the second lens,

r7: paraxial radius of curvature of the object side of the fourth lens.

By satisfying the range of conditional expression (13), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (14) is satisfied:

(14) -29.5＜r4/T2＜-8.0

in,

r4: paraxial curvature radius of the image side of the second lens,

T2: The distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens.

By satisfying the range of conditional expression (14), low profile can be achieved, and spherical aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (15) is satisfied:

(15)0.5＜r6/f＜3.5

in,

r6: paraxial curvature radius of the image side of the third lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (15), coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (16) is satisfied:

(16) 0.03＜r6/r2＜0.65

in,

r6: paraxial curvature radius of the image side of the third lens,

r2: paraxial radius of curvature of the image-side surface of the first lens.

By satisfying the range of conditional expression (16), coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (17) is satisfied:

(17)-180.0＜r7/T2＜-16.5

in,

r7: the paraxial radius of curvature of the object side of the fourth lens,

T2: The distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens.

By satisfying the range of conditional expression (17), a low profile can be achieved, and coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (18) is satisfied:

(18)4.8＜r7/r8＜30.0

in,

r7: the paraxial radius of curvature of the object side of the fourth lens,

r8: paraxial radius of curvature of the image-side surface of the fourth lens.

By satisfying the range of conditional expression (18), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (19) is satisfied:

(19)-0.45＜r8/f＜-0.15

in,

r8: paraxial curvature radius of the image side of the fourth lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (19), coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (20) is satisfied:

(20)-6＜(D1/f1)×100＜-1

in,

D1: The thickness of the first lens on the optical axis,

f1: Focal length of the first lens.

By satisfying the range of conditional expression (20), a low profile can be achieved, and chromatic aberration, coma, astigmatism, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (21) is satisfied:

(21)-8.2＜(D3/f3)×100＜-2.5

in,

D3: The thickness of the third lens on the optical axis,

f3: focal length of the third lens.

By satisfying the range of conditional expression (21), low profile can be achieved, and chromatic aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (22) is satisfied:

(22) 0.10＜f4/f＜0.82

in,

f4: focal length of the fourth lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (22), spherical aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (23) is satisfied:

(23)-1.05＜f5/f＜-0.20

in,

f5: focal length of the fifth lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (23), chromatic aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (24) is satisfied:

(24)-16.00＜f1/f4＜-3.25

in,

f1: focal length of the first lens,

f4: Focal length of the fourth lens.

By satisfying the range of conditional expression (24), chromatic aberration, spherical aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (25) is satisfied:

(25)-3.0＜f2/f5＜-0.8

in,

f2: focal length of the second lens,

f5: Focal length of the fifth lens.

By satisfying the range of conditional expression (25), chromatic aberration, spherical aberration, astigmatism, field curvature, and distortion can be corrected well.

In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (26) is satisfied:

(26)-0.30＜(f4/f)+(f5/f)＜-0.05

in,

f4: focal length of the fourth lens,

f5: focal length of the fifth lens,

f: Focal length of the entire camera lens system.

By satisfying the range of conditional expression (26), chromatic aberration, spherical aberration, coma, astigmatism, field curvature, and distortion can be corrected well.

According to the present invention, it is possible to obtain an imaging lens that satisfies the requirements of low profile and low F value in a balanced manner, corrects various aberrations well, and has high resolution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a schematic configuration of an imaging lens according to Example 1 of the present invention.

FIG. 2 is a diagram showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 1 of the present invention.

FIG. 3 is a diagram showing a schematic configuration of an imaging lens according to Example 2 of the present invention.

FIG. 4 is a diagram showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 2 of the present invention.

FIG. 5 is a diagram showing a schematic configuration of an imaging lens according to Example 3 of the present invention.

FIG. 6 is a diagram showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 3 of the present invention.

FIG. 7 is a diagram showing a schematic configuration of an imaging lens according to Example 4 of the present invention.

FIG. 8 is a diagram showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 4 of the present invention.

FIG. 9 is a diagram showing a schematic configuration of an imaging lens according to Example 5 of the present invention.

FIG. 10 is a diagram showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 5 of the present invention.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 , 3 , 5 , 7 and 9 are schematic diagrams showing the configuration of imaging lenses according to Examples 1 to 5 of the embodiments of the present invention, respectively.

As shown in FIG. 1 , the camera lens of the present invention comprises, from the object side toward the image side, a first lens L1 having negative optical power; a second lens L2 having positive optical power; a third lens L3 having negative optical power; a fourth lens L4 having positive optical power; and a fifth lens L5 having negative optical power; the first lens L1 has a concave surface facing the object side in the paraxial zone, and the fifth lens L5 has a concave surface facing the image side in the paraxial zone.

An infrared cut filter, a protective glass or other filter IR is disposed between the fifth lens L5 and the imaging plane IMG (ie, the imaging plane of the imaging element). The filter IR may be omitted.

The aperture stop ST is disposed between the first lens L1 and the second lens L2, so that distortion correction is easy. In addition, the position of the aperture stop ST is not limited to between the first lens L1 and the second lens L2. It can be appropriately disposed according to the specifications of the imaging element.

The first lens L1 has negative optical power and is biconcave in a paraxial region with a concave surface facing the object side and a concave surface facing the image side. Therefore, chromatic aberration, coma, astigmatism and distortion are suppressed. In addition, a wide field of view is achieved by forming the object side surface of the first lens as an aspheric surface having a pole at a position other than the optical axis.

The second lens L2 has positive refractive power and has a biconvex shape with a convex surface facing the object side and a convex surface facing the image side in the paraxial region, thereby achieving low profile and excellently correcting spherical aberration, astigmatism, field curvature and distortion.

The third lens L3 has negative and positive refractive power and has a meniscus shape with a convex surface facing the object side and a concave surface facing the image side in the paraxial region, so chromatic aberration, coma, astigmatism, field curvature and distortion are well corrected.

The shape of the third lens L3 is not limited to the shape according to Numerical Example 1.

The shape of the third lens L3 may also be a meniscus shape with a concave surface facing the object side and a convex surface facing the image side in the paraxial region. In addition, the shape of the third lens L3 may also be a biconcave shape with a concave surface facing the object side and a concave surface facing the image side in the paraxial region. In this case, the negative optical power of both sides is conducive to the correction of chromatic aberration.

The fourth lens L4 has positive refractive power and is in a meniscus shape with a convex surface facing the object side and a concave surface facing the image side in the paraxial region, so as to achieve low profile and well correct spherical aberration, coma, astigmatism, field curvature and distortion.

In addition, the object-side surface of the fourth lens L4 is formed as an aspherical surface having a pole at a position other than the optical axis, so as to better correct astigmatism, field curvature and distortion.

The fifth lens L5 has negative optical power and is in a meniscus shape with a convex surface facing the object side and a concave surface facing the image side in the paraxial region. Therefore, chromatic aberration, astigmatism, field curvature and distortion are well corrected. In addition, by facing the concave surface in the paraxial region to the image side, the low profile is maintained and the back focus is ensured.

In addition, the object-side surface of the fifth lens L5 is formed as an aspherical surface having a pole at a position other than the optical axis, so as to better correct astigmatism, field curvature and distortion.

In addition, the image-side surface of the fifth lens L5 is formed as an aspherical surface having a pole at a position other than the optical axis, so as to better correct astigmatism, field curvature, and distortion.

In the camera lens of this embodiment, it is preferred that all lenses from the first lens L1 to the fifth lens L5 are composed of respective single lenses. Composed of only single lenses, more aspheric surfaces can be used. In this embodiment, by forming all lens surfaces into appropriate aspheric surfaces, various aberrations can be corrected well. In addition, compared with the case of using a cemented lens, since the man-hours can be reduced, it can be manufactured at a low cost.

Furthermore, the imaging lens of this embodiment uses plastic material for all lenses, so that the manufacturing is easy and mass production is possible at low cost.

In addition, the lens material used is not limited to plastic materials. By adopting glass materials, higher performance can also be expected. In addition, it is preferred that all lens surfaces are formed as aspherical surfaces, but spherical surfaces that are easy to manufacture can also be adopted according to the required performance.

The imaging lens in this embodiment satisfies the following conditional expressions (1) to (26), thereby achieving favorable effects.

(1)0.05＜(r10/|r5|)×100＜7.10

(2) 2.8＜r9/r8/r10/f5＜10.0

(3) 0.13＜(r2/T1)/100＜1.15

(4) -3.80＜|r5|/r6/r1＜-0.85

(5)-2.5＜r9/f5＜-0.9

(6)1.65＜f3/f5＜4.80

(7) -4.3＜f5/D5＜-1.0

(8)-8.75＜(r1×r2/T1)/100＜-0.55

(9)2.6＜r2/f＜40.0

(10)-90.0＜r2/r8＜-9.5

(11)2＜r2/r3/r10＜30

(12) -3.5＜r3/r4＜-1.8

(13)-1.70＜r3/r7＜-0.15

(14) -29.5＜r4/T2＜-8.0

(15)0.5＜r6/f＜3.5

(16) 0.03＜r6/r2＜0.65

(17)-180.0＜r7/T2＜-16.5

(18)4.8＜r7/r8＜30.0

(19)-0.45＜r8/f＜-0.15

(20)-6＜(D1/f1)×100＜-1

(21)-8.2＜(D3/f3)×100＜-2.5

(22) 0.10＜f4/f＜0.82

(23)-1.05＜f5/f＜-0.20

(24)-16.00＜f1/f4＜-3.25

(25)-3.0＜f2/f5＜-0.8

(26)-0.30＜(f4/f)+(f5/f)＜-0.05

in,

D1: thickness of the first lens L1 on the optical axis X,

D3: thickness of the third lens L3 on the optical axis X,

D5: thickness of the fifth lens L5 on the optical axis X,

T1: The distance on the optical axis X from the image side surface of the first lens L1 to the object side surface of the second lens L2,

T2: the distance on the optical axis X from the image side surface of the second lens L2 to the object side surface of the third lens L3,

f: focal length of the entire camera lens system,

f1: focal length of the first lens L1,

f2: focal length of the second lens L2,

f3: focal length of the third lens L3,

f4: focal length of the fourth lens L4,

f5: focal length of the fifth lens L5,

r1: the paraxial radius of curvature of the object side of the first lens L1,

r2: paraxial curvature radius of the image side surface of the first lens L1,

r3: the paraxial radius of curvature of the object side of the second lens L2,

r4: paraxial curvature radius of the image side surface of the second lens L2,

r5: paraxial radius of curvature of the object side of the third lens L3,

r6: paraxial radius of curvature of the image side surface of the third lens L3,

r7: paraxial radius of curvature of the object side of the fourth lens L4,

r8: paraxial curvature radius of the image side surface of the fourth lens L4,

r9: paraxial radius of curvature of the object side of the fifth lens L5,

r10: paraxial curvature radius of the image-side surface of the fifth lens L5.

It is not necessary to satisfy all of the above-mentioned conditional expressions, and by satisfying each conditional expression individually, the effects corresponding to each conditional expression can be obtained.

Furthermore, the imaging lens in this embodiment satisfies the following conditional expressions (1a) to (26a), thereby achieving better effects.

(1a)0.2＜(r10/|r5|)×100＜6.5

(2a) 3.3＜r9/r8/r10/f5＜7.0

(3a) 0.15＜(r2/T1)/100＜0.85

(4a)-3.3＜|r5|/r6/r1＜-1.0

(5a)-1.9＜r9/f5＜-1.1

(6a)1.9＜f3/f5＜4.3

(7a)-4.1＜f5/D5＜-2.5

(8a)-8.0＜(r1×r2/T1)/100＜-0.6

(9a)3.2＜r2/f＜30.0

(10a)-75＜r2/r8＜-11

(11a)2.5＜r2/r3/r10＜23.0

(12a)-3.2＜r3/r4＜-2.3

(13a)-1.4＜r3/r7＜-0.25

(14a)-26.5＜r4/T2＜-10.0

(15a) 0.8＜r6/f＜2.5

(16a) 0.05＜r6/r2＜0.55

(17a) -140＜r7/T2＜-24

(18a)5＜r7/r8＜24

(19a)-0.40＜r8/f＜-0.25

(20a)-5.5＜(D1/f1)×100＜-2.0

(21a)-7.3＜(D3/f3)×100＜-3.3

(22a) 0.40＜f4/f＜0.75

(23a)-0.95＜f5/f＜-0.50

(24a)-13.0＜f1/f4＜-3.7

(25a)-2.40＜f2/f5＜-0.95

(26a)-0.22＜(f4/f)+(f5/f)＜-0.15

The symbols of each conditional expression are the same as those described in the previous paragraph. In addition, the lower limit value or upper limit value of the corresponding conditional expressions (1a) to (26a) can be applied to the lower limit value or upper limit value of the conditional expressions (1) to (26).

In this embodiment, the aspheric shape used on the aspheric surface of the lens surface is expressed by mathematical formula 1 when the axis in the optical axis direction is set to Z, the height in the direction perpendicular to the optical axis is set to H, the near-axis curvature radius is set to R, the cone coefficient is set to k, and the aspheric coefficient is set to A4, A6, A8, A10, A12, A14, A16, A18, and A20.

[Mathematical formula 1]

Next, examples of the imaging lens according to the present embodiment are shown. In each example, f represents the focal length of the entire imaging lens system, Fno represents the F value, and ω represents the half field of view.

, ih represents the maximum image height, TTL represents the total optical length. Moreover, i represents the surface number from the object side, r represents the paraxial curvature radius, d represents the distance between the lens surfaces on the optical axis (surface spacing), Nd represents the refractive index of the d-line (reference wavelength), and νd represents the dispersion coefficient with respect to the d-line. In addition, for aspherical surfaces, an * (asterisk) symbol is added after the surface number i to represent it.

[Example 1]

Basic lens data are shown in Table 1 below.

[Table 1]

Example 1

Unit mm

f＝1.68

Fno＝2.20

ω(°)＝55.8

ih＝2.30

TTL=3.83

Area data

Image plane

Composition lens data

Aspheric surface data

The imaging lens of Example 1 achieves an overall aspect ratio of 0.83 and an F value of 2.20.

As shown in Table 6, conditional expressions (1) to (26) are satisfied.

FIG. 2 shows spherical aberration (mm), astigmatism (mm), and distortion (%) for the camera lens of Example 1. The spherical aberration diagram shows the aberration amount for each wavelength of the F line (486nm), d line (588nm), and C line (656nm). In addition, the astigmatism diagram shows the aberration amount of the d line on the sagittal image plane S (solid line) and the aberration amount of the d line on the meridional image plane T (dashed line) (the same in FIG. 4, FIG. 6, FIG. 8, and FIG. 10). As shown in FIG. 2, it can be seen that each aberration has been well corrected.

[Example 2]

Basic lens data are shown in Table 2 below.

[Table 2]

Example 2

Unit mm

f＝1.68

Fno＝2.20

ω(°)＝54.3

ih＝2.30

TTL=3.82

Area data

Image plane

Composition lens data

Aspheric surface data

The imaging lens of Example 2 achieves an overall aspect ratio of 0.83 and an F value of 2.20.

As shown in Table 6, conditional expressions (1) to (26) are satisfied.

Fig. 4 shows spherical aberration (mm), astigmatism (mm), and distortion (%) for the imaging lens of Example 2. As shown in Fig. 4 , it can be seen that each aberration is well corrected.

[Example 3]

Basic lens data are shown in Table 3 below.

[Table 3]

Example 3

Unit mm

f＝1.68

Fno＝2.20

ω(°)＝55.8

ih＝2.30

TTL=3.83

Area data

Image plane

Composition lens data

Aspheric surface data

The imaging lens of Example 3 achieves an overall aspect ratio of 0.83 and an F value of 2.20.

As shown in Table 6, conditional expressions (1) to (26) are satisfied.

Fig. 6 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens of Example 3. As shown in Fig. 6 , it can be seen that each aberration is well corrected.

[Example 4]

Basic lens data are shown in Table 4 below.

[Table 4]

Example 4

Unit mm

f＝1.68

Fno＝2.20

ω(°)＝55.8

ih＝2.30

TTL=3.83

Area data

Image plane

Composition lens data

Aspheric surface data

The imaging lens of Example 4 achieves an overall aspect ratio of 0.83 and an F value of 2.20.

As shown in Table 6, conditional expressions (1) to (26) are satisfied.

Fig. 8 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens of Example 4. As shown in Fig. 8 , it can be seen that each aberration is well corrected.

[Example 5]

Basic lens data are shown in Table 5 below.

[Table 5]

Example 5

Unit mm

f＝1.68

Fno＝2.20

ω(°)＝55.8

ih＝2.30

TTL=3.83

Area data

Image plane

Composition lens data

Aspheric surface data

The imaging lens of Example 5 achieves an overall aspect ratio of 0.83 and an F value of 2.20.

As shown in Table 6, conditional expressions (1) to (26) are satisfied.

Fig. 10 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens of Example 5. As shown in Fig. 10 , it can be seen that each aberration is well corrected.

Table 6 shows the values of conditional expressions (1) to (26) according to Examples 1 to 5.

[Table 6]

Industrial Applicability

When the imaging lens according to the present invention is applied to a product with a camera function, it can contribute to a lower profile and a lower F value of the camera, and can also achieve higher performance of the camera.

Description of Reference Numerals

ST aperture diaphragm,

L1 first lens,

L2 second lens,

L3 third lens,

L4 fourth lens,

L5 fifth lens,

IR filter,

IMG camera surface.

Claims (5)

1. A camera lens, characterized in that it comprises, from the object side to the image side, the following components: A first lens having negative optical power; A second lens having positive optical power; A third lens having negative optical power; a fourth lens having positive refractive power; and a fifth lens having negative optical power; The first lens has a concave surface facing the object side in the paraxial zone, and an image side surface facing the image side in the paraxial zone, and the fifth lens has a concave surface facing the image side in the paraxial zone, and the predetermined conditional formula is satisfied, and the following conditional formulas (1), (2) and (4) are satisfied: (1)0.05＜(r10/|r5|)×100＜7.10 (2) 2.8＜r9/r8/r10/f5＜10.0 (4) -3.80＜|r5|/r6/r1＜-0.85 in, r10: paraxial curvature radius of the image side surface of the fifth lens L5, r5: paraxial radius of curvature of the object side of the third lens L3, r9: paraxial radius of curvature of the object side of the fifth lens L5, r8: paraxial curvature radius of the image side surface of the fourth lens L4, f5: focal length of the fifth lens L5, r6: paraxial curvature radius of the image side of the third lens, r1: paraxial radius of curvature of the object side of the first lens. 2. The imaging lens according to claim 1, wherein the following condition (3) is satisfied: (3) 0.13＜(r2/T1)/100＜1.15 in, r2: paraxial radius of curvature of the image side of the first lens, T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens. 3. The imaging lens according to claim 1, wherein the following conditional formula (5) is satisfied: (5)-2.5＜r9/f5＜-0.9 in, r9: the paraxial radius of curvature of the object side of the fifth lens, f5: Focal length of the fifth lens. 4. The imaging lens according to claim 1, wherein the following conditional formula (6) is satisfied: (6)1.65＜f3/f5＜4.80 in, f3: focal length of the third lens, f5: Focal length of the fifth lens. 5. The imaging lens according to claim 1, wherein the following conditional formula (7) is satisfied: (7) -4.3＜f5/D5＜-1.0 in, f5: focal length of the fifth lens, D5: The thickness of the fifth lens on the optical axis.