Camera lens

Abstract

The present invention provides a camera lens, which can meet the requirements of low back and low F value and has good optical characteristics. The camera lens includes, from the object side to the image side, a first lens, which is in a meniscus shape with a convex surface in the paraxial area facing the object side and has positive optical power; a second lens, which has positive optical power in the paraxial area; a third lens, which has negative optical power in the paraxial area; a fourth lens, which has positive optical power in the paraxial area; a fifth lens, whose double surfaces are formed as aspherical surfaces; and a sixth lens, which has a concave surface in the paraxial area facing the image side and has negative optical power; and meets a predetermined conditional formula.

Description

Technical Field

[0001] 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

[0002] 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.

[0003] The imaging lens installed in such equipment needs to be compact and have high resolution performance.

[0004] 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.

[0005] Patent document 1 (China Patent Gazette No. 109828355) discloses a camera lens, which includes, from the object side, in sequence: a first lens; a second lens having positive optical focal power; a third lens having positive optical focal power; a fourth lens; a fifth lens; and a sixth lens; the relationship between the paraxial curvature radius of the object side surface of the second lens and the paraxial curvature radius of the image side surface of the second lens satisfies certain conditions. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] 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.

[0008] 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.

[0009] 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.

[0010] Means used to solve problems

[0011] The camera lens of the present invention comprises, in order from the object side to the image side: a first lens having a meniscus shape with a convex surface in a paraxial zone facing the object side and having positive optical power; a second lens having a positive optical power in the paraxial zone; a third lens having a negative optical power in the paraxial zone; a fourth lens having a positive optical power in the paraxial zone; a fifth lens having both surfaces formed as aspherical surfaces; and a sixth lens having a concave surface in the paraxial zone facing the image side and having negative optical power.

[0012] By increasing the optical power, the first lens element can be made low profile. In addition, by making the convex surface of the paraxial region face the object side, spherical aberration and distortion can be suppressed.

[0013] The second lens element achieves low profile and well corrects astigmatism, field curvature, and distortion.

[0014] The third lens well corrects chromatic aberration, coma, astigmatism, and distortion.

[0015] The fourth lens element achieves low profile and satisfactorily corrects astigmatism and distortion.

[0016] The fifth lens well corrects astigmatism, field curvature, and distortion.

[0017] The sixth lens element can well correct chromatic aberration, astigmatism, field curvature and distortion. In addition, the concave surface in the paraxial region faces the image side, thereby maintaining a low profile and ensuring a secure back focus.

[0018] In the imaging lens having the above configuration, it is preferred that the image-side surface of the second lens be convex toward the image side in the paraxial region.

[0019] By making the image-side surface of the second lens element convex toward the image side in the paraxial region, astigmatism, field curvature and distortion can be well corrected.

[0020] In the imaging lens having the above configuration, it is preferred that the image-side surface of the fourth lens be convex toward the image side in the paraxial region.

[0021] Since the image-side surface of the fourth lens element is convex toward the image side in the paraxial region, astigmatism and distortion can be corrected well.

[0022] In addition, in the imaging lens of the above structure, it is preferred that the object-side surface of the sixth lens element has a convex surface facing the object side in the paraxial region.

[0023] By having the object-side surface of the sixth lens element facing the object side in the paraxial region with a convex surface, astigmatism, field curvature and distortion can be well corrected.

[0024] 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.

[0025] 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 and distortion can be corrected favorably.

[0026] 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.

[0027] 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 and distortion can be corrected favorably.

[0028] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (1) is satisfied:

[0029] (1) 0.30<f1 / f4<1.85

[0030] in,

[0031] f1: focal length of the first lens,

[0032] f4: Focal length of the fourth lens.

[0033] Conditional formula (1) specifies the relationship between the focal length of the first lens and the focal length of the fourth lens within an appropriate range. By satisfying the range of conditional formula (1), the focal power of the first lens and the focal power of the fourth lens can be appropriately balanced. As a result, a low profile can be achieved, and spherical aberration, astigmatism and distortion can be well corrected.

[0034] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (2) is satisfied:

[0035] (2)-3.30<r6 / f<-0.70

[0036] in,

[0037] r6: paraxial curvature radius of the image side of the third lens,

[0038] f: Focal length of the entire camera lens system.

[0039] Conditional expression (2) specifies the paraxial curvature radius of the image-side surface of the third lens within an appropriate range. By satisfying the range of conditional expression (2), coma, astigmatism, and distortion can be corrected well.

[0040] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (3) is satisfied:

[0041] (3)15.00<νd6<36.00

[0042] in,

[0043] νd6: The dispersion coefficient of the sixth lens with respect to the d-line.

[0044] The conditional expression (3) defines the Abbe coefficient of the sixth lens with respect to the d-line within an appropriate range. When the conditional expression (3) is satisfied, chromatic aberration can be corrected well.

[0045] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (4) is satisfied:

[0046] (4)1.50<(T2 / f2)×100<5.50

[0047] in,

[0048] T2: The distance on the optical axis from the image side of the second lens to the object side of the third lens.

[0049] f2: Focal length of the second lens.

[0050] Conditional expression (4) specifies the relationship between the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens and the focal length of the second lens within an appropriate range. By satisfying the range of conditional expression (4), low profile can be achieved, the optical power of the second lens becomes an appropriate value, and astigmatism, field curvature and distortion can be well corrected.

[0051] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (5) is satisfied:

[0052] (5) -12.50<r6 / r12<-3.20

[0053] in,

[0054] r6: paraxial curvature radius of the image side of the third lens,

[0055] r12: paraxial radius of curvature of the image-side surface of the sixth lens.

[0056] The conditional expression (5) specifies the relationship between the paraxial curvature radius of the image side surface of the third lens and the paraxial curvature radius of the image side surface of the sixth lens within an appropriate range. By satisfying the range of the conditional expression (5), coma, astigmatism, field curvature and distortion can be corrected well.

[0057] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (6) is satisfied:

[0058] (6)-3.50<r8 / r11<-1.10

[0059] in,

[0060] r8: paraxial curvature radius of the image side of the fourth lens,

[0061] r11: paraxial radius of curvature of the object side surface of the sixth lens.

[0062] The conditional expression (6) specifies the relationship between the paraxial curvature radius of the image side surface of the fourth lens and the paraxial curvature radius of the object side surface of the sixth lens within an appropriate range. By satisfying the range of the conditional expression (6), astigmatism, field curvature and distortion can be corrected well.

[0063] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (7) is satisfied:

[0064] (7) 0.40<r2 / r4 / r6<1.20

[0065] in,

[0066] r2: paraxial radius of curvature of the image side of the first lens,

[0067] r4: paraxial curvature radius of the image side of the second lens,

[0068] r6: paraxial radius of curvature of the image-side surface of the third lens.

[0069] Conditional formula (7) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens, the paraxial curvature radius of the image side surface of the second lens, and the paraxial curvature radius of the image side surface of the third lens within an appropriate range. By satisfying the range of conditional formula (7), coma, astigmatism, field curvature, and distortion can be well corrected.

[0070] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (8) is satisfied:

[0071] (8)3.75<|r3| / f<70.00

[0072] in,

[0073] r3: the paraxial radius of curvature of the object side of the second lens,

[0074] f: Focal length of the entire camera lens system.

[0075] Conditional expression (8) specifies the paraxial curvature radius of the object-side surface of the second lens within an appropriate range. By satisfying the range of conditional expression (8), astigmatism, field curvature, and distortion can be corrected well.

[0076] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (9) is satisfied:

[0077] (9)-2.15<r4 / f<-1.00

[0078] in,

[0079] r4: paraxial curvature radius of the image side of the second lens,

[0080] f: Focal length of the entire camera lens system.

[0081] Conditional expression (9) specifies the paraxial curvature radius of the image-side surface of the second lens within an appropriate range. By satisfying the range of conditional expression (9), astigmatism, field curvature, and distortion can be corrected well.

[0082] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (10) is satisfied:

[0083] (10)4.00<(T1 / f1)×100<11.00

[0084] in,

[0085] T1: The distance on the optical axis from the image side of the first lens to the object side of the second lens.

[0086] f1: focal length of the first lens.

[0087] Conditional expression (10) specifies the relationship between the distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens and the focal length of the first lens within an appropriate range. By satisfying the range of conditional expression (10), low-profile lens can be achieved, and spherical aberration and distortion can be well corrected.

[0088] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (11) is satisfied:

[0089] (11)1.50<T2 / T4<7.25

[0090] in,

[0091] T2: The distance on the optical axis from the image side of the second lens to the object side of the third lens.

[0092] T4: The distance on the optical axis from the image side surface of the fourth lens to the object side surface of the fifth lens.

[0093] Conditional formula (11) specifies the relationship between the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens and the distance on the optical axis from the image side surface of the fourth lens to the object side surface of the fifth lens within an appropriate range. By satisfying the range of conditional formula (11), low-profile lens can be achieved, and coma, astigmatism and distortion can be well corrected.

[0094] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (12) is satisfied:

[0095] (12) 0.70<f1 / f<1.95

[0096] in,

[0097] f1: focal length of the first lens,

[0098] f: Focal length of the entire camera lens system.

[0099] Conditional expression (12) specifies the focal length of the first lens within an appropriate range. When the conditional expression (12) is satisfied, a low profile can be achieved, and spherical aberration and distortion can be corrected well.

[0100] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (13) is satisfied:

[0101] (13) 0.30<f1 / f2<0.95

[0102] in,

[0103] f1: focal length of the first lens,

[0104] f2: Focal length of the second lens.

[0105] Conditional expression (13) specifies the relationship between the focal length of the first lens and the focal length of the second lens within an appropriate range. By satisfying the range of conditional expression (13), the optical power of the first lens and the optical power of the second lens can be appropriately balanced. As a result, low-profile lens can be achieved, and spherical aberration, astigmatism, field curvature and distortion can be well corrected.

[0106] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (14) is satisfied:

[0107] (14) -2.00<f3 / f4<-0.70

[0108] in,

[0109] f3: focal length of the third lens,

[0110] f4: Focal length of the fourth lens.

[0111] Conditional expression (14) specifies the relationship between the focal length of the third lens and the focal length of the fourth lens within an appropriate range. By satisfying the range of conditional expression (14), the focal power of the third lens and the focal power of the fourth lens can be appropriately balanced. As a result, coma, astigmatism and distortion can be well corrected.

[0112] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (15) is satisfied:

[0113] (15)-40.00<f6 / f1<-0.60

[0114] in,

[0115] f6: focal length of the sixth lens,

[0116] f1: focal length of the first lens.

[0117] Conditional expression (15) specifies the relationship between the focal length of the sixth lens and the focal length of the first lens within an appropriate range. By satisfying the range of conditional expression (15), the focal power of the sixth lens and the focal power of the first lens can be appropriately balanced. As a result, low-profile lens can be achieved, and chromatic aberration, spherical aberration, astigmatism, field curvature and distortion can be well corrected.

[0118] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (16) is satisfied:

[0119] (16)-7.50<r2 / r4<-1.55

[0120] in,

[0121] r2: paraxial radius of curvature of the image side of the first lens,

[0122] r4: paraxial radius of curvature of the image-side surface of the second lens.

[0123] Conditional expression (16) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens and the paraxial curvature radius of the image side surface of the second lens within an appropriate range. By satisfying the range of conditional expression (16), astigmatism, field curvature, and distortion can be corrected well.

[0124] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (17) is satisfied:

[0125] (17)20.00<r2 / T2<160.00

[0126] in,

[0127] r2: paraxial radius of curvature of the image side of the first lens,

[0128] 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.

[0129] Conditional expression (17) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens and the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens within an appropriate range. By satisfying the range of conditional expression (17), astigmatism and distortion can be well corrected.

[0130] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (18) is satisfied:

[0131] (18)2.00<|r3| / f2<22.00

[0132] in,

[0133] r3: the paraxial radius of curvature of the object side of the second lens,

[0134] f2: Focal length of the second lens.

[0135] Conditional expression (18) specifies the relationship between the paraxial curvature radius of the object side surface of the second lens and the focal length of the second lens within an appropriate range. By satisfying the range of conditional expression (18), a low profile can be achieved, and astigmatism, field curvature, and distortion can be corrected well.

[0136] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (19) is satisfied:

[0137] (19) 0.30<r4 / r6<2.20

[0138] in,

[0139] r4: paraxial curvature radius of the image side of the second lens,

[0140] r6: paraxial radius of curvature of the image-side surface of the third lens.

[0141] Conditional expression (19) specifies the relationship between the paraxial curvature radius of the image side surface of the second lens and the paraxial curvature radius of the image side surface of the third lens within an appropriate range. By satisfying the range of conditional expression (19), coma, astigmatism, field curvature and distortion can be well corrected.

[0142] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (20) is satisfied:

[0143] (20)3.90<|r7| / f

[0144] in,

[0145] r7: the paraxial radius of curvature of the object side of the fourth lens,

[0146] f: Focal length of the entire camera lens system.

[0147] Conditional expression (20) specifies the paraxial curvature radius of the object-side surface of the fourth lens within an appropriate range. By satisfying the range of conditional expression (20), astigmatism and distortion can be corrected well.

[0148] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (21) is satisfied:

[0149] (21)-1.05<r8 / f<-0.50

[0150] in,

[0151] r8: paraxial curvature radius of the image side of the fourth lens,

[0152] f: Focal length of the entire camera lens system.

[0153] Conditional expression (21) specifies the paraxial curvature radius of the image-side surface of the fourth lens within an appropriate range. By satisfying the range of conditional expression (21), astigmatism and distortion can be corrected well.

[0154] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (22) is satisfied:

[0155] (22) 0.30<r11 / r12<2.00

[0156] in,

[0157] r11: the paraxial curvature radius of the object side of the sixth lens,

[0158] r12: paraxial radius of curvature of the image-side surface of the sixth lens.

[0159] The conditional expression (22) specifies the relationship between the paraxial curvature radius of the object side surface of the sixth lens and the paraxial curvature radius of the image side surface of the sixth lens within an appropriate range. By satisfying the range of the conditional expression (22), astigmatism, field curvature and distortion can be corrected well.

[0160] Effects of the Invention

[0161] 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

[0162] Figure 1 It is a diagram showing a schematic structure of an imaging lens according to Example 1 of the present invention.

[0163] Figure 2 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 1 of the present invention.

[0164] Figure 3 A diagram schematically showing the structure of an imaging lens according to Example 2 of the present invention.

[0165] Figure 4 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 2 of the present invention.

[0166] Figure 5 A diagram schematically showing the structure of an imaging lens according to Example 3 of the present invention.

[0167] Figure 6 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 3 of the present invention.

[0168] Figure 7 A diagram schematically showing the structure of an imaging lens according to Example 4 of the present invention.

[0169] Figure 8 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 4 of the present invention.

[0170] Fig. 9 A diagram schematically showing the structure of an imaging lens according to Example 5 of the present invention.

[0171] Fig.10 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 5 of the present invention.

[0172] Fig.11 A diagram schematically showing the structure of an imaging lens according to Example 6 of the present invention.

[0173] Fig.12 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 6 of the present invention.

[0174] Fig.13 A diagram schematically showing the structure of an imaging lens according to Example 7 of the present invention.

[0175] Fig.14 Graphs showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 7 of the present invention.

[0176] Fig.15 A diagram schematically showing the structure of an imaging lens according to Example 8 of the present invention.

[0177] Fig.16 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 8 of the present invention.

[0178] Fig.17 A diagram schematically showing the structure of an imaging lens according to Example 9 of the present invention.

[0179] Fig.18 Graphs showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 9 of the present invention.

[0180] Fig.19 A diagram schematically showing the structure of an imaging lens according to Example 10 of the present invention.

[0181] Fig. 20 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 10 of the present invention.

[0182] Description of Reference Numerals

[0183] ST: Aperture stop,

[0184] L1: First lens,

[0185] L2: Second lens,

[0186] L3: The third lens,

[0187] L4: The fourth lens,

[0188] L5: The fifth lens,

[0189] L6: The sixth lens,

[0190] ih: maximum image height,

[0191] IR: Filter,

[0192] IMG: Camera side. DETAILED DESCRIPTION

[0193] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0194] Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 The following are schematic structural diagrams of imaging lenses according to Examples 1 to 10 of the embodiments of the present invention.

[0195] The camera lens of this embodiment includes, in order from the object side to the image side: a first lens L1, which is in a meniscus shape with a convex surface in the paraxial zone facing the object side and has positive optical power; a second lens L2, which has positive optical power in the paraxial zone; a third lens L3, which has negative optical power in the paraxial zone; a fourth lens L4, which has positive optical power in the paraxial zone; a fifth lens L5, both surfaces of which are formed as aspherical surfaces; and a sixth lens L6, which has a concave surface in the paraxial zone facing the image side and has negative optical power.

[0196] An infrared cut filter, a protective glass or other filter IR is disposed between the sixth lens L6 and the imaging plane IMG (ie, the imaging plane of the imaging element). The filter IR may be omitted.

[0197] By arranging the aperture stop ST on the object side of the first lens L1, various aberrations can be easily corrected, and the incident angle of light with a high image height onto the imaging element can be easily controlled.

[0198] The first lens L1 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. Therefore, by enhancing the refractive power, low-profile lens is achieved, and astigmatism and distortion are suppressed. In addition, by facing the convex surface to the object side in the paraxial region, spherical aberration and distortion are suppressed.

[0199] The second lens L2 has positive refractive power and is in a meniscus shape with a concave surface facing the object side and a convex surface facing the image side in the paraxial region. Therefore, a low profile is achieved and astigmatism, field curvature and distortion are well corrected. In addition, astigmatism, field curvature and distortion are well corrected by having a convex surface facing the image side in the paraxial region.

[0200] In addition, if Fig.13 , Fig.15 , Fig.17 and Fig.19 As shown in Examples 7, 8, 9 and 10, the second lens L2 may also be in a biconvex shape with a convex surface facing the object side and a convex surface facing the image side in the paraxial region. In this case, both surfaces have positive refractive power, which is beneficial for low-profile.

[0201] The third lens L3 has negative refractive power and has a meniscus shape with a concave surface facing the object side and a convex surface facing the image side in a paraxial region, so chromatic aberration, coma, astigmatism and distortion are well corrected.

[0202] The fourth lens L4 has positive refractive power and is biconvex in shape with the convex surface facing the object side in the paraxial zone and the convex surface facing the image side. Therefore, low profile is achieved and astigmatism and distortion are well corrected. In addition, astigmatism and distortion are well corrected by having the convex surface facing the image side in the paraxial zone.

[0203] In addition, if Fig.19 As shown in Example 10, the shape of the fourth lens L4 can 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 this case, the incident angle of light to the fourth lens L4 can be properly controlled, and astigmatism and distortion can be well corrected.

[0204] The fifth lens L5 is formed into a shape that has substantially no optical power, and is oriented toward the object side and the image side in the paraxial zone plane. Therefore, without affecting the focal length of the entire camera lens system, the double-sided aspherical surface is formed to well correct astigmatism, field curvature and distortion.

[0205] In addition, if Figure 7 and Fig.11 As shown in Example 4 and Example 6, the refractive power of the fifth lens L5 can also be set to a positive value. In this case, it is beneficial to achieve a low profile. Fig. 9 , Fig.13 and Fig.15 As shown in Examples 5, 7 and 8, the refractive power of the fifth lens L5 may be set to a negative value. In this case, it is advantageous to correct chromatic aberration.

[0206] In addition, if Figure 7 and Fig.11As shown in Example 4 and Example 6, the shape of the fifth lens L5 can also be a biconvex shape with the convex surface facing the object side in the paraxial region and the convex surface facing the image side. In this case, the positive optical power on both sides is conducive to low-profile. In addition, Fig. 9 As shown in Example 5, the shape of the fifth lens L5 can also be a biconcave shape with a concave surface facing the object side in the paraxial region and a concave surface facing the image side. In this case, by having negative optical power on both sides, chromatic aberration can be well corrected. In addition, as Fig.13 and Fig.15 As shown in Examples 7 and 8, the fifth lens L5 may also be in a meniscus shape with a convex surface facing the object side and a concave surface facing the image side in the paraxial region. In this case, astigmatism and distortion can be corrected well.

[0207] 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 on the optical axis X. Therefore, astigmatism and distortion are corrected well.

[0208] 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 on the optical axis X. Therefore, astigmatism and distortion are corrected well.

[0209] The sixth lens L6 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 toward the image side, the low profile is maintained and the back focus is ensured.

[0210] In the camera lens of this embodiment, it is preferred that all lenses from the first lens L1 to the sixth lens L6 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.

[0211] 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.

[0212] 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.

[0213] The imaging lens in this embodiment satisfies the following conditional expressions (1) to (22), thereby achieving favorable effects.

[0214] (1) 0.30<f1 / f4<1.85

[0215] (2) - 3.30 < r6 / f < - 0.70

[0216] (3) 15.00 < νd6 < 36.00

[0217] (4) 1.50 < (T2 / f2)×100 < 5.50

[0218] (5) - 12.50 < r6 / r12 < - 3.20

[0219] (6) - 3.50 < r8 / r11 < - 1.10

[0220] (7) 0.40 < r2 / r4 / r6 < 1.20

[0221] (8) 3.75 < |r3| / f < 70.00

[0222] (9) - 2.15 < r4 / f < - 1.00

[0223] (10) 4.00 < (T1 / f1)×100 < 11.00

[0224] (11) 1.50 < T2 / T4 < 7.25

[0225] (12) 0.70 < f1 / f < 1.95

[0226] (13) 0.30 < f1 / f2 < 0.95

[0227] (14) - 2.00 < f3 / f4 < - 0.70

[0228] (15) - 40.00 < f6 / f1 < - 0.60

[0229] (16) - 7.50 < r2 / r4 < - 1.55

[0230] (17) 20.00 < r2 / T2 < 160.00

[0231] (18) 2.00 < |r3| / f2 < 22.00

[0232] (19) 0.30 < r4 / r6 < 2.20

[0233] (20) 3.90 < |r7| / f

[0234] (21) - 1.05 < r8 / f < - 0.50

[0235] (22) 0.30 < r11 / r12 < 2.00

[0236] Among them,

[0237] νd6: dispersion coefficient of the sixth lens L6 with respect to the d-line,

[0238] 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,

[0239] 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,

[0240] T4: the distance on the optical axis X from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5,

[0241] f: focal length of the entire camera lens system,

[0242] f1: focal length of the first lens L1,

[0243] f2: focal length of the second lens L2,

[0244] f3: focal length of the third lens L3,

[0245] f4: focal length of the fourth lens L4,

[0246] f6: focal length of the sixth lens L6,

[0247] r2: paraxial curvature radius of the image side surface of the first lens L1,

[0248] r3: the paraxial radius of curvature of the object side of the second lens L2,

[0249] r4: paraxial curvature radius of the image side surface of the second lens L2,

[0250] r6: paraxial radius of curvature of the image side surface of the third lens L3,

[0251] r7: paraxial radius of curvature of the object side of the fourth lens L4,

[0252] r8: paraxial curvature radius of the image side surface of the fourth lens L4,

[0253] r11: paraxial radius of curvature of the object side surface of the sixth lens L6,

[0254] r12: paraxial curvature radius of the image-side surface of the sixth lens L6.

[0255] It is not necessary to satisfy all of the above-mentioned conditional expressions, and by satisfying each conditional expression individually, an action and effect corresponding to each conditional expression can be obtained.

[0256] Furthermore, the imaging lens in this embodiment satisfies the following conditional expressions (1a) to (22a), thereby achieving better effects.

[0257] <h2 style=";text-align:left;direction:ltr">(1a)0.80<f1 / f4<1.75<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0258] <h2 style=";text-align:left;direction:ltr"> (2a)-2.70<r6 / f<-0.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0259] <h2 style=";text-align:left;direction:ltr"> (3a)20.00<d6<30.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0260] <h2 style=";text-align:left;direction:ltr"> (4a)1.90<(T2 / f2)×100<5.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0261] <h2 style=";text-align:left;direction:ltr"> (5a)-10.50<r6 / r12<-3.60<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0262] <h2 style=";text-align:left;direction:ltr"> (6a)-2.90<r8 / r11<-1.40<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0263] <h2 style=";text-align:left;direction:ltr"> (7a)0.45<r2 / r4 / r6<1.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0264] <h2 style=";text-align:left;direction:ltr"> (8a)4.25 = |r3| / f = 50.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0265] <h2 style=";text-align:left;direction:ltr"> (9a)-1.80 = r4 / f = -1.20<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0266] <h2 style=";text-align:left;direction:ltr"> (10a)5.00<(T1 / f1)×100<9.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0267] <h2 style=";text-align:left;direction:ltr"> (11a)2.50<T2 / T4<6.60<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0268] <h2 style=";text-align:left;direction:ltr"> (12a)1.10<f1 / f<1.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0269] <h2 style=";text-align:left;direction:ltr"> (13a)0.45<f1 / f2<0.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0270] <h2 style=";text-align:left;direction:ltr"> (14a)-1.65<f3 / f4<-0.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0271] <h2 style=";text-align:left;direction:ltr"> (15a)-33.00<f6 / f1<-1.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0272] <h2 style=";text-align:left;direction:ltr"> (16a)-6.00<r2 / r4<-1.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0273] <h2 style=";text-align:left;direction:ltr"> (17a)25.00<r2 / T2<130.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0274] <h2 style=";text-align:left;direction:ltr"> (18a)2.10 = |r3| / f2 = 18.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0275] <h2 style=";text-align:left;direction:ltr"> (19a)0.45<r4 / r6<1.85<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0276] <h2 style=";text-align:left;direction:ltr"> (20a)4.10<|r7| / f<230.00<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0277] <h2 style=";text-align:left;direction:ltr"> (21a)-0.85<r8 / f<-0.55<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0278] (22a)0.80<r11 / r12<1.75

[0279] The symbols of each conditional expression are the same as those described in the previous paragraph.

[0280] 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.

[0281] [Mathematical formula 1]

[0282]

[0283] Next, examples of the imaging lens involved in this embodiment are shown. In each example, f represents the focal length of the entire imaging lens system, Fno represents the F value, ω represents the half field angle, ih represents the maximum image height, and TTL represents the total optical length. In addition, 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 relative to the d-line. In addition, for aspherical surfaces, the symbol * (asterisk) is added after the surface number i to represent it.

[0284] [Example 1]

[0285] Basic lens data are shown in Table 1 below.

[0286] [Table 1]

[0287]

[0288] The imaging lens of Example 1 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0289] Figure 2 The spherical aberration (mm), astigmatism (mm), and distortion (%) are shown for the imaging 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). Figure 4 , Figure 6 , Figure 8 , Fig.10 , Fig.12 , Fig.14 , Fig.16 , Fig.18 and Fig. 20are the same in the examples. Figure 2 As shown, it can be seen that each aberration is well corrected.

[0290] [Example 2]

[0291] Basic lens data are shown in Table 2 below.

[0292] [Table 2]

[0293]

[0294] The imaging lens of Example 2 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0295] Figure 4 For the imaging lens of Example 2, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 4 As shown, it can be seen that each aberration is well corrected.

[0296] [Example 3]

[0297] Basic lens data are shown in Table 3 below.

[0298] [Table 3]

[0299]

[0300] The imaging lens of Example 3 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0301] Figure 6 For the imaging lens of Example 3, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 6 As shown, it can be seen that each aberration is well corrected.

[0302] [Example 4]

[0303] Basic lens data are shown in Table 4 below.

[0304] [Table 4]

[0305]

[0306] The imaging lens of Example 4 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0307] Figure 8 For the imaging lens of Example 4, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 8 As shown, it can be seen that each aberration is well corrected.

[0308] [Example 5]

[0309] Basic lens data are shown in Table 5 below.

[0310] [Table 5]

[0311]

[0312] The imaging lens of Example 5 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0313] Fig.10 For the imaging lens of Example 5, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.10 As shown, it can be seen that each aberration is well corrected.

[0314] [Example 6]

[0315] Basic lens data are shown in Table 6 below.

[0316] [Table 6]

[0317]

[0318] The imaging lens of Example 6 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0319] Fig.12 For the imaging lens of Example 6, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.12 As shown, it can be seen that each aberration is well corrected.

[0320] [Example 7]

[0321] Basic lens data are shown in Table 7 below.

[0322] [Table 7]

[0323]

[0324] The imaging lens of Example 7 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0325] Fig.14 For the imaging lens of Example 7, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.14 As shown, it can be seen that each aberration is well corrected.

[0326] [Example 8]

[0327] Basic lens data are shown in Table 8 below.

[0328] [Table 8]

[0329]

[0330] The imaging lens of Example 8 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0331] Fig.16 For the imaging lens of Example 8, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.16 As shown, it can be seen that each aberration is well corrected.

[0332] [Example 9]

[0333] Basic lens data are shown in Table 9 below.

[0334] [Table 9]

[0335]

[0336] The imaging lens of Example 9 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0337] Fig.18 For the imaging lens of Example 9, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.18 As shown, it can be seen that each aberration is well corrected.

[0338] [Example 10]

[0339] Basic lens data are shown in Table 10 below.

[0340] [Table 10]

[0341]

[0342] The imaging lens of Example 10 satisfies conditional expressions (1) to (22) as shown in Table 11.

[0343] Fig. 20 For the imaging lens of Example 10, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig. 20 As shown, it can be seen that each aberration is well corrected.

[0344] Table 11 shows the values ​​of conditional expressions (1) to (22) according to Examples 1 to 10.

[0345] [Table 11]

[0346]

[0347] Industrial Applicability

[0348] 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.

Claims

1. A camera lens, characterized in that: From the object side to the image side, they include: The first lens is in the shape of a meniscus with a convex surface facing the object side in the paraxial region and has positive optical power; The second lens has positive optical power in the paraxial region; A third lens having negative optical power in a paraxial region; A fourth lens element having positive optical power in a paraxial region; a fifth lens having both surfaces formed as aspherical, wherein the object side surface of the fifth lens is formed as an aspherical surface having a pole at a position other than on the optical axis; and The sixth lens has a concave surface facing the image side in the paraxial region and has negative optical power; and satisfies the following conditional equations (1) and (2): (1) 1.30 ≤ f1 / f4 < 1.85 (2)-3.30＜r6 / f＜-0.70 in, f1: focal length of the first lens, f4: focal length of the fourth lens, r6: paraxial curvature radius of the image side of the third lens, f: Focal length of the entire camera lens system.

2. The imaging lens according to claim 1, wherein: The following condition (3) is satisfied: (3)15.00<νd6<36.00 in, νd6: The dispersion coefficient of the sixth lens with respect to the d-line.

3. The imaging lens according to claim 1, wherein: The following condition (4) is satisfied: (4)1.50<(T2 / f2)×100<5.50 in, T2: The distance on the optical axis from the image side of the second lens to the object side of the third lens. f2: Focal length of the second lens.

4. The imaging lens according to claim 1, wherein: The following condition (5) is satisfied: (5)-12.50＜r6 / r12＜-3.20 in, r6: paraxial curvature radius of the image side of the third lens, r12: paraxial radius of curvature of the image-side surface of the sixth lens.

5. The imaging lens according to claim 1, wherein: The following condition (6) is satisfied: (6)-3.50＜r8 / r11＜-1.10 in, r8: paraxial curvature radius of the image side of the fourth lens, r11: paraxial radius of curvature of the object side surface of the sixth lens.

6. The imaging lens according to claim 1, wherein: The following condition (7) is satisfied: (7)0.40＜r2 / r4 / r6＜1.20 in, r2: paraxial radius of curvature of the image side of the first lens, r4: paraxial curvature radius of the image side of the second lens, r6: paraxial radius of curvature of the image-side surface of the third lens.

7. The imaging lens according to claim 1, wherein: The following condition (8) is satisfied: (8)3.75＜|r3| / f＜70.00 in, r3: paraxial radius of curvature of the object side of the second lens, f: Focal length of the entire camera lens system.

Images