Imaging lens

Abstract

There is provided an imaging lens with high-resolution which satisfies demand of wide field of view, low-profileness and low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises, in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens and a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions are satisfied:
3.00<(T4/f)×100<5.90
0.40<f2/f5<1.45
where
T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens,
f: a focal length of the overall optical system of the imaging lens,
f2: a focal length of the second lens,
f5: a focal length of the fifth lens.

Claims

1. An imaging lens comprising in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens, and a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions (1), (2) and (8) are satisfied:
3.00<(T4/f)×100<5.90 (1)
0.40<f2/f5<1.45 (2)
1.20<D1/D2<3.70 (8) where T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, f: a focal length of the overall optical system of the imaging lens, f2: a focal length of the second lens, f5: a focal length of the fifth lens, D1: a thickness along the optical axis of the first lens, and D2: a thickness along the optical axis of the second lens.

2. The imaging lens according to claim 1, wherein a below conditional expression (7) is satisfied:
1.50<T1/T2<5.30 (7) where T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.

3. The imaging lens according to claim 1, wherein a below conditional expression (11) is satisfied:
−8.50<r6/f<−2.00 (11) where r6: a paraxial curvature radius of the image-side surface of the third lens, and f: a focal length of the overall optical system of the imaging lens.

4. The imaging lens according to claim 1, wherein a below conditional expression (12) is satisfied:
−62<(D1/f1)×100<−29 (12) where D1: a thickness along the optical axis of the first lens, and f1: a focal length of the first lens.

5. An imaging lens comprising in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens, and a fifth lens, wherein said imaging lens is configured with only five lenses, with the lenses configured so that none of the adjacent pairs of the five lenses is cemented, said first lens has negative refractive power near the optical axis, an object-side surface of said second lens has a convex surface facing the object side near the optical axis, an object-side surface of said fifth lens has a concave surface facing the object side near the optical axis, and below conditional expressions (3) and (4) are satisfied:
1.60<T1/f<3.70 (3)
0.10<T2/T3<0.80 (4) where T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, f: a focal length of the overall optical system of the imaging lens, T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, and T3: a distance along the optical axis from the image-side surface of the third lens to the object-side surface of the fourth lens.

6. The imaging lens according to claim 5, wherein an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis.

7. The imaging lens according to claim 5, wherein a below conditional expression (6) is satisfied:
0.30<T2/f<1.00 (6) where T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, and f: a focal length of the overall optical system of the imaging lens.

8. The imaging lens according to claim 5, wherein a below conditional expression (1) is satisfied:
3.00<(T4/f)×100<5.90 (1) where T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, and f: a focal length of the overall optical system of the imaging lens.

9. The imaging lens according to claim 5, wherein a below conditional expression (9) is satisfied:
12<r3/f<40 (9) where r3: a paraxial curvature radius of the object-side surface of the second lens, and f: a focal length of the overall optical system of the imaging lens.

10. The imaging lens according to claim 2, wherein a below conditional expression (10) is satisfied:
6.50<r5/f<42.00 (10) where r5: a paraxial curvature radius of the object-side surface of the third lens, and f: a focal length of the overall optical system of the imaging lens.

11. The imaging lens according to claim 5, wherein a below conditional expression (8) is satisfied:
1.20<D1/D2<3.70 (8) where D1: a thickness along the optical axis of the first lens, and D2: a thickness along the optical axis of the second lens.

12. The imaging lens according to claim 2, wherein a below conditional expression (12) is satisfied:
−62<(D1/f1)×100<−29 (12) where D1: a thickness along the optical axis of the first lens, and f1: a focal length of the first lens.

13. An imaging lens comprising in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens, and a fifth lens, wherein an object-side surface of said second lens has a convex surface facing the object side near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions (1), (3), and (5) are satisfied:
3.00<(T4/f)×100<5.90 (1)
1.60<T1/f<3.70 (3)
−19.5<(D5/f5)×100<−9.00 (5) where T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, f: a focal length of the overall optical system of the imaging lens, T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens D5: a thickness along the optical axis of the fifth lens, and f5: a focal length of the fifth lens.

14. The imaging lens according to claim 13, wherein said first lens has negative refractive power near the optical axis.

15. The imaging lens according to claim 13, wherein a below conditional expression (7) is satisfied:
1.50<T1/T2<5.30 (7) where T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.

16. The imaging lens according to claim 13, wherein a below conditional expression (10) is satisfied:
6.50<r5/f<42.00 (10) where r5: a paraxial curvature radius of the object-side surface of the third lens, and f: a focal length of the overall optical system of the imaging lens.

17. The imaging lens according to claim 13, wherein a below conditional expression (12) is satisfied:
−62<(D1/f1)×100<−29 (12) where D1: a thickness along the optical axis of the first lens, and f1: a focal length of the first lens.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view showing a general configuration of an imaging lens in Example 1 according to the present invention;

(2) FIG. 2 shows spherical aberration, astigmatism, and distortion of the imaging lens in Example 1 according to the present invention;

(3) FIG. 3 is a schematic view showing the general configuration of an imaging lens in Example 2 according to the present invention;

(4) FIG. 4 shows spherical aberration, astigmatism, and distortion of the imaging lens in Example 2 according to the present invention;

(5) FIG. 5 is a schematic view showing the general configuration of an imaging lens in Example 3 according to the present invention;

(6) FIG. 6 shows spherical aberration, astigmatism, and distortion of the imaging lens in Example 3 according to the present invention;

(7) FIG. 7 is a schematic view showing the general configuration of an imaging lens in Example 4 according to the present invention;

(8) FIG. 8 shows spherical aberration, astigmatism, and distortion of the imaging lens in Example 4 according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(9) Hereinafter, the preferred embodiments of the present invention will be described in detail referring to the accompanying drawings.

(10) FIGS. 1, 3, 5 and 7 are schematic views of the imaging lenses in Examples 1 to 4 according to the embodiments of the present invention, respectively.

(11) As shown in FIG. 1, the imaging lens according to the present embodiment comprises, in order from an object side to an image side, a first lens L1, a second lens L2 having negative refractive power near the optical axis X, a third lens L3 having a convex surface facing the image side near the optical axis X, a fourth lens L4, and a fifth lens L5.

(12) A filter IR such as an IR cut filter and a cover glass are arranged between the fifth lens L5 and an image plane IMG (namely, the image plane of an image sensor). The filter IR is omissible.

(13) The first lens L1 achieves wide field of view by strengthening the refractive power. A shape of the first lens L1 is a meniscus shape having a convex surface facing the object side and a concave surface facing the image side near the optical axis X. Thereby, spherical aberration and distortion can be properly corrected.

(14) The second lens L2 has a meniscus shape having a convex surface facing the object side and a concave surface facing the image side near the optical axis X. Thereby, the spherical aberration, coma aberration and field curvature can be properly corrected.

(15) The third lens L3 has positive refractive power, and has a biconvex shape having convex surfaces facing the object side and the image side near the optical axis. Thereby, astigmatism, the field curvature and the distortion can be properly corrected.

(16) An aperture stop ST is arranged between the third lens L3 and the fourth lens L4. By arranging the aperture stop ST between the third lens L3 and the fourth lens L4, downsizing in a radial direction can be achieved.

(17) The fourth lens L4 has positive refractive power, and properly corrects the spherical aberration and chromatic aberration while maintaining low-profileness. A shape of the fourth lens L4 is a biconvex shape having convex surfaces facing the object side and the image side near the optical axis X, and the low-profileness can be achieved by positive refractive power on the object side and the image side. Furthermore, by providing the convex surfaces on both sides, curvature is suppressed from being large, and an effect to reduce sensitivity to manufacturing error is obtained.

(18) The fifth lens L5 has negative refractive power and has a meniscus shape having a concave surface facing the object side and a convex surface facing the image side near the optical axis X. Thereby, the chromatic aberration, the coma aberration, the astigmatism, the field curvature and the distortion can be properly corrected.

(19) An aspheric surface having at least one off-axial pole point is formed on the image side of the fifth lens L5, and the field curvature and the distortion can be properly corrected.

(20) According to the present embodiments, each of the first lens L1 and the third lens L3 is a glass lens having spherical surfaces facing the object side and the image side. Glass material is small in change of optical characteristics with temperature. Therefore, even though the imaging lens according to the present embodiments is used in a wide temperature range from a lower temperature to a higher temperature, high quality of the lens can be maintained. Regarding the lens material and lens surface, various selection can be made in accordance with usage environment or required performance, for example, either the glass material or a resin material, the spherical surface or the aspheric surface, and so on.

(21) Regarding the imaging lens according to the present embodiments, all lenses are single lens. Configuration without a cemented lens can frequently use the aspheric surfaces, and aberrations can be easily corrected. In comparison with the case in which a cemented lens is used, workload is reduced, and manufacturing in low cost becomes available.

(22) The imaging lens according to the present embodiments shows preferable effect by satisfying the below conditional expressions (1) to (17).
3.00<(T4/f)×100<5.90 (1)
0.40<f2/f5<1.45 (2)
1.60<(T1/f)<3.70 (3)
0.10<T2/T3<0.80 (4)
−19.5<(D5/f5)×100<−9.00 (5)
0.30<T2/f<1.00 (6)
1.50<T1/T2<5.30 (7)
1.20<D1/D2<3.70 (8)
12<r3/f<40 (9)
6.50<r5/f<42.00 (10)
−8.50<r6/f<−2.00 (11)
−62<(D1/f1)×100<−29 (12)
8<r3/r4<30 (13)
−3.80<r7/r8<−1.00 (14)
−6.50<f1/f<−1.80 (15)
−4.50<f2/f<−1.00 (16)
−5.50<f5/f<−1.50 (17)
Where
D1: a thickness along the optical axis X of the first lens L1,
D2: a thickness along the optical axis X of the second lens L2,
D5: a thickness along the optical axis X of the fifth lens L5,
T1: a distance along 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: a distance along the optical axis X from the image-side surface of the second lens L2 to the object-side surface of the third lens L3,
T3: a distance along the optical axis X from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4,
T4: a distance along the optical axis X from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5,
f: a focal length of the overall optical system of the imaging lens,
f1: a focal length of the first lens L1,
f2: a focal length of the second lens L2,
f5: a focal length of the fifth lens L5,
r3: a paraxial curvature radius of the object-side surface of the second lens L2,
r4: a paraxial curvature radius of the image-side surface of the second lens L2,
r5: a paraxial curvature radius of the object-side surface of the third lens L3,
r6: a paraxial curvature radius of the image-side surface of the third lens L3,
r7: a paraxial curvature radius of the object-side surface of the fourth lens L4,
r8: a paraxial curvature radius of the image-side surface of the fourth lens L4.

(23) It is not necessary to satisfy the above all conditional expressions, and by satisfying the conditional expression individually, operational advantage corresponding to each conditional expression can be obtained.

(24) The imaging lens according to the present embodiments shows further preferable effect by satisfying the below conditional expressions (1a) to (17a).
3.80<(T4/f)×100<5.60 (1a)
0.60<f2/f5<1.15 (2a)
1.90<(T1/f)<3.00 (3a)
0.30<T2/T3<0.65 (4a)
−15.5<(D5/f5)×100<−10.00 (5a)
0.45<T2/f<0.85 (6a)
2.40<T1/T2<4.40 (7a)
1.60<D1/D2<3.10 (8a)
19<r3/f<33 (9a)
7.70<r5/f<35.00 (10a)
−7.00<r6/f<−3.20 (11a)
−52<(D1/f1)×100<−31 (12a)
13<r3/r4<25 (13a)
−3.10<r7/r8<−1.60 (14a)
−5.20<f1/f<−2.80 (15a)
−3.50<f2/f<−2.00 (16a)
−4.50<f5/f<−2.30 (17a)

(25) The signs in the above conditional expressions have the same meanings as those in the paragraph before the preceding paragraph.

(26) In this embodiment, the aspheric shapes of the surfaces of the aspheric lens are expressed by Equation 1, where Z denotes an axis in the optical axis direction, H denotes a height perpendicular to the optical axis, R denotes a paraxial curvature radius, k denotes a conic constant, and A4, A6, A8, A10, A12, A14 and A16 denote aspheric surface coefficients.

(27) $\begin{matrix} Z = \frac{\frac{H^{2}}{R}}{1 + \sqrt{1 - (k + 1) \frac{H^{2}}{R^{2}}}} + A_{4} H^{4} + A_{6} H^{6} + A_{8} H^{8} + A_{10} H^{10} + A_{12} H^{12} + A_{14} H^{14} + A_{16} H^{16} & Equation 1 \end{matrix}$

(28) Next, examples of the imaging lens according to this embodiment will be explained. In each example, f denotes the focal length of the overall optical system of the imaging lens, Fno denotes an F-number, ω denotes a half field of view, ih denotes a maximum image height, and TTL denotes a total track length. Additionally, i denotes surface number counted from the object side, r denotes a curvature radius, d denotes the distance of lenses along the optical axis (surface distance), Nd denotes a refractive index at d-ray (reference wavelength), and vd denotes an abbe number at d-ray. As for aspheric surfaces, an asterisk (*) is added after surface number i.

Example 1

(29) The basic lens data is shown below in Table 1.

(30) TABLE-US-00001 TABLE 1 Example 1 Unit mm f = 1.08 ih = 1.85 Fno = 2.0 TTL = 12.70 ω (°) = 103.1 Surface Data Surface Curvature Surface Refractive Abbe Number i Radius r Distance d index Nd Number vd (Object) Infinity Infinity 1 10.9473 1.3948 1.773 49.61 (νd1) 2 2.3756 2.5027 3* 28.0000 0.7000 1.535 56.11 (νd2) 4* 1.5666 0.7921 5 30.0000 1.0696 1.921 23.95 (νd3) 6 −4.6300 1.2183 7 (Stop) Infinity 0.5329 8* 2.5433 1.3537 1.535 56.11 (νd4) 9* −1.0271 0.0574 10* −0.8533 0.4000 1.661 20.37 (νd5) 11* −1.5567 0.2000 12 Infinity 0.6100 1.517 64.17 13 Infinity 2.0724 Image Plane Infinity Constituent Lens Data Lens Start Surface Focal Length 1 1 −4.227 2 3 −3.132 3 5 4.420 4 8 1.577 5 10 −3.693 Aspheric Surface Data Third Surface Fourth Surface Eighth Surface Ninth Surface Tenth Surface Eleventh Surface k 0.000000E+00 0.000000E+00 0.000000E+00 −5.000000E−01 −9.450000E−01 −7.536689E−01 A4 −3.184689E−02 −5.726524E−02 −1.579708E−02 1.950291E−01 2.371644E−01 1.052116E−01 A6 7.060004E−03 9.183170E−03 8.343853E−02 −1.188862E−01 −2.059529E−01 −1.573902E−02 A8 −1.015862E−03 −3.780539E−02 −2.701603E−01 1.213196E−01 3.070683E−01 −3.855032E−03 A10 −9.389348E−05 5.539706E−02 3.816636E−01 −5.122357E−02 −2.391139E−01 7.793506E−02 A12 5.556759E−05 −4.483540E−02 −3.037554E−01 1.747603E−03 9.720229E−02 −9.097115E−02 A14 −5.239444E−06 1.755587E−02 1.148534E−01 3.586992E−03 −1.630792E−02 4.515388E−02 A16 0.000000E+00 −2.770964E−03 −1.531802E−02 0.000000E+00 0.000000E+00 −8.611452E−03

(31) The imaging lens in Example 1 satisfies conditional expressions (1) to (17) as shown in Table 5.

(32) FIG. 2 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens in Example 1. The spherical aberration diagram shows the amount of aberration at each wavelength of F-ray (486 nm), d-ray (588 nm), and C-ray (656 nm). The astigmatism diagram shows the amount of aberration at d-ray on a sagittal image surface S (solid line) and on tangential image surface T (broken line), respectively (same as FIGS. 4, 6 and 8). The distortion diagram shows an amount of deviation from an ideal image height fθ where f denotes a focal length of the overall optical system of the imaging lens, and θ denotes a half field of view. As shown in FIG. 2, each aberration is corrected excellently.

Example 2

(33) The basic lens data is shown below in Table 2.

(34) TABLE-US-00002 TABLE 2 Example 2 Unit mm f = 1.08 ih = 1.85 Fno = 2.0 TTL = 12.70 ω (°) = 103.6 Surface Data Surface Curvature Surface Refractive Abbe Number i Radius r Distance d Index Nd Number vd (Object) Infinity Infinity 1 10.3462 1.6207 1.773 49.61 (νd1) 2 2.4061 2.4913 3* 28.0000 0.7000 1.535 56.11 (νd2) 4* 1.4819 0.7262 5 15.0000 1.1366 1.923 20.87 (νd3) 6 −5.9976 0.9787 7 (Stop) Infinity 0.5262 8* 2.2216 1.5420 1.535 56.11 (νd4) 9* −1.0057 0.0500 10* −0.8951 0.4000 1.661 20.37 (νd5) 11* −1.6830 0.2000 12 Infinity 0.6100 1.517 64.17 13 Infinity 1.9215 Image Plane Infinity Constituent Lens Data Lens Start Surface Focal Length 1 1 −4.455 2 3 −2.953 3 5 4.766 4 8 1.553 5 10 −3.626 Aspheric Surface Data Third Surface Fourth Surface Eighth Surface Ninth Surface Tenth Surface Eleventh Surface k 0.000000E+00 0.000000E+00 0.000000E+00 −6.000000E−01 −9.091390E−01 −6.262823E−01 A4 −4.378410E−02 −8.783401E−02 −8.453853E−03 1.606601E−01 1.678151E−01 8.206727E−02 A6 1.628357E−02 6.430488E−02 1.065343E−02 7.718018E−02 4.734845E−02 −8.198620E−03 A8 −5.139827E−03 −1.564028E−01 −3.342274E−02 −2.104236E−01 −1.230240E−01 4.982409E−02 A10 9.986164E−04 2.079809E−01 1.596764E−02 1.962282E−01 1.229087E−01 −5.150573E−02 A12 −9.486833E−05 −1.601155E−01 −2.078143E−03 −8.190882E−02 −5.413078E−02 3.906853E−02 A14 3.155069E−06 6.333459E−02 0.000000E+00 1.337786E−02 8.377920E−03 −1.612314E−02 A16 0.000000E+00 −1.025275E−02 0.000000E+00 0.000000E+00 0.000000E+00 2.368828E−03

(35) The imaging lens in Example 2 satisfies conditional expressions (1) to (17) as shown in Table 5.

(36) FIG. 4 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens in Example 2. As shown in FIG. 4, each aberration is corrected excellently.

Example 3

(37) The basic lens data is shown below in Table 3.

(38) TABLE-US-00003 TABLE 3 Example 3 Unit mm f = 1.09 ih = 1.85 Fno = 2.0 TTL = 12.69 ω (°) = 103.0 Surface Data Surface Curvature Surface Refractive Abbe Number i Radius r Distance d index Nd Number vd (Object) Infinity Infinity 1 10.8693 1.5784 1.773 49.61 (νd1) 2 2.3321 2.4507 3* 28.0000 0.7000 1.535 56.11 (νd2) 4* 1.4945 0.7363 5 15.0000 1.1771 1.921 23.95 (νd3) 6 −5.0429 1.0395 7 (Stop) Infinity 0.5554 8* 2.4566 1.4223 1.535 56.11 (νd4) 9* −0.9795 0.0500 10* −0.8697 0.4000 1.661 20.37 (νd5) 11* −1.6934 0.2000 12 Infinity 0.6100 1.517 64.17 13 Infinity 1.9801 Image Plane Infinity Constituent Lens Data Lens Start Surface Focal Length 1 1 −4.180 2 3 −2.980 3 5 4.216 4 8 1.530 5 10 −3.355 Aspheric Surface Data Third Surface Fourth Surface Eighth Surface Ninth Surface Tenth Surface Eleventh Surface k 0.000000E+00 0.000000E+00 0.000000E+00 −6.000000E−01 −9.240279E−01 −5.971269E−01 A4 −3.911302E−02 −7.765487E−02 2.245820E−03 1.951324E−01 1.980397E−01 8.490239E−02 A6 1.041511E−02 4.429496E−02 −1.320357E−02 −7.969125E−02 −1.003997E−01 −1.517091E−02 A8 −1.415962E−03 −1.132025E−01 −6.849677E−04 6.331840E−02 1.395869E−01 4.481158E−02 A10 −3.014215E−04 1.526696E−01 −1.080274E−02 −2.788741E−02 −9.640108E−02 −2.579547E−02 A12 1.354567E−04 −1.186988E−01 3.832315E−03 5.472374E−03 3.454258E−02 9.553831E−03 A14 −1.321812E−05 4.690625E−02 0.000000E+00 1.159475E−04 −5.345426E−03 −1.952377E−03 A16 0.000000E+00 −7.587189E−03 0.000000E+00 0.000000E+00 0.000000E+00 −6.293644E−05

(39) The imaging lens in Example 3 satisfies conditional expressions (1) to (17) as shown in Table 5.

(40) FIG. 6 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens in Example 3. As shown in FIG. 6, each aberration is corrected excellently.

Example 4

(41) The basic lens data is shown below in Table 4.

(42) TABLE-US-00004 TABLE 4 Example 4 Unit mm f = 1.10 ih = 1.85 Fno = 2.0 TTL = 12.69 ω (°) = 103.5 Surface Data Surface Curvature Surface Refradive Abbe Number i Radius r Distance d Index Nd Number vd (Object) Infinity Infinity 1 10.9939 1.7093 1.773 49.61 (νd1) 2 2.3146 2.4459 3* 28.0000 0.7000 1.535 56.11 (νd2) 4* 1.4639 0.6923 5 10.0000 1.2251 1.921 23.95 (νd3) 6 −5.4746 0.9526 7 (Stop) Infinity 0.5534 8* 2.4526 1.4351 1.535 56.11 (νd4) 9* −0.9719 0.0500 10* −0.8747 0.4000 1.661 20.37 (νd5) 11* −1.7068 0.2000 12 Infinity 0.6100 1.517 64.17 13 Infinity 1.9288 Image Plane Infinity Constituent Lens Data Lens Start Surface Focal Length 1 1 −4.152 2 3 −2.916 3 5 3.992 4 8 1.524 5 10 −3.358 Aspheric Surface Data Third Surface Fourth Surface Eighth Surface Ninth Surface Tenth Surface Eleventh Surface k 0.000000E+00 0.000000E+00 0.000000E+00 −6.138031E−01 −9.152282E−01 −5.327844E−01 A4 −5.082356E−02 −9.627426E−02 2.510352E−03 2.235117E−01 2.075226E−01 7.351707E−02 A6 1.777444E−02 6.549374E−02 −1.483589E−02 −1.521749E−01 −1.600989E−01 −9.952516E−03 A8 −4.110065E−03 −1.563970E−01 5.027399E−03 1.546808E−01 2.329474E−01 3.833259E−02 A10 3.493330E−04 2.167895E−01 −1.533507E−02 −8.976253E−02 −1.664300E−01 −1.123927E−02 A12 4.412087E−05 −1.722172E−01 5.059361E−03 2.687672E−02 6.082811E−02 −5.114294E−03 A14 −7.720963E−06 6.959889E−02 0.000000E+00 −2.893949E−03 −9.278886E−03 4.933013E−03 A16 0.000000E+00 −1.150863E−02 0.000000E+00 0.000000E+00 0.000000E+00 −1.282151E−03

(43) The imaging lens in Example 4 satisfies conditional expressions (1) to (17) as shown in Table 5.

(44) FIG. 8 shows spherical aberration (mm), astigmatism (mm), and distortion (%) of the imaging lens in Example 4. As shown in FIG. 8, each aberration is corrected excellently.

(45) In table 5, values of conditional expressions (1) to (17) related to the Examples 1 to 4 are shown.

(46) TABLE-US-00005 TABLE 5 Conditional expression Example 1 Example 2 Example 3 Example 4 (1) (T4/f) × 100 5.29 4.65 4.60 4.55 (2) f2/f5 0.85 0.81 0.89 0.87 (3) T1/f 2.31 2.31 2.25 2.23 (4) T2/T3 0.45 0.48 0.46 0.46 (5) (D5/f5) × 100 −10.83 −11.03 −11.92 −11.91 (6) T2/f 0.73 0.67 0.68 0.63 (7) T1/T2 3.16 3.43 3.33 3.53 (8) D1/D2 1.99 2.32 2.25 2.44 (9) r3/f 25.84 26.02 25.73 25.49 (10) r5/f 27.69 13.94 13.79 9.10 (11) r6/f −4.27 −5.57 −4.63 −4.98 (12) (D1/f1) × 100 −33.00 −36.38 −37.76 −41.17 (13) r3/r4 17.87 18.90 18.74 19.13 (14) r7/r8 −2.48 −2.21 −2.51 −2.52 (15) f1/f −3.90 −4.14 −3.84 −3.78 (16) f2/f −2.89 −2.74 −2.74 −2.65 (17) f5/f −3.41 −3.37 −3.08 −3.06

(47) When the imaging lens according to the present invention is adopted to a product with the camera function, there is realized contribution to the wide field of view, the low-profileness and the low F-number of the camera, and high performance thereof.

DESCRIPTION OF REFERENCE NUMERALS

(48) ST: aperture stop L1: first lens L2: second lens L3: third lens L4: fourth lens L5: fifth lens ih: maximum image height IR: filter IMG: imaging plane

Imaging lens

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G02B13/06

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G02B9/60

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G02B13/04

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G02B15/145

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G02B15/1455

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G02B15/145513

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G02B13/0045

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G02B15/14

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G02B13/06

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Abstract

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