Imaging lens

Abstract

An imaging lens includes: an aperture stop; a biconvex first lens directing convex surfaces toward an object and an image; a second lens directing a convex surface toward the object near the optical axis and having negative refractive power; a biconvex third lens directing convex surfaces toward the object and the image near the optical axis; a fourth lens directing a concave surface toward the object near the optical axis and having positive refractive power; and a fifth lens directing a convex surface toward the object near the optical axis and having negative refractive power. The aperture stop and the first to fifth lenses are arranged in this order from the object side, and a conditional expression 1 being 0.50<f1/f<0.76 is satisfied, where f1 represents the focal length of the first lens and f represents the focal length of the entire imaging lens.

Claims

.[.1. An imaging lens for use in solid-state image sensors, comprising: an aperture stop; a biconvex first lens directing convex surfaces toward an object side and an image side; a second lens directing a convex surface toward the object side near an optical axis and having negative refractive power; a biconvex third lens directing convex surfaces toward the object side and the image side near the optical axis; a fourth lens directing a concave surface toward the object side near the optical axis and having positive refractive power; and a fifth lens directing a convex surface toward the object side near the optical axis and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and a conditional expression 1 is satisfied, the conditional expression 1 being 0.50<f1/f<0.76 where f1 represents the focal length of the first lens and f represents the focal length of the entire imaging lens..].

.[.2. The imaging lens according to claim 1, wherein a conditional expression 2 is satisfied, the conditional expression 2 being 0.80<(r5+r6)/(r5r6)<0.55 where r5 represents the curvature radius of the object side surface of the third lens and r6 represents the curvature radius of the image side surface thereof..].

.[.3. The imaging lens according to claim 2, wherein a conditional expression 4 is satisfied, the conditional expression 4 being 1.20<f12/f<1.95 where f12 represents the composite focal length of the first and second lenses and f represents the focal length of the entire imaging lens..].

.[.4. The imaging lens according to claim 3, wherein a conditional expression 5 is satisfied, the conditional expression 5 being 1.50<f345/f<9.00 where f345 represents the composite focal length of the third to fifth lenses and f represents the focal length of the entire imaging lens..].

.[.5. The imaging lens according to claim 1, wherein a conditional expression 3 is satisfied, the conditional expression 3 being 8.5<r9/r10<85.0 where r9 represents the curvature radius of the object side surface of the fifth lens and r10 represents the curvature radius of the image side surface thereof..].

.[.6. The imaging lens according to claim 5, wherein a conditional expression 4 is satisfied, the conditional expression 4 being 1.20<f12/f<1.95 where f12 represents the composite focal length of the first and second lenses and f represents the focal length of the entire imaging lens..].

.[.7. The imaging lens according to claim 6, wherein a conditional expression 5 is satisfied, the conditional expression 5 being 1.50<f345/f<9.00 where f345 represents the composite focal length of the third to fifth lenses and f represents the focal length of the entire imaging lens..].

.[.8. The imaging lens according to claim 1, wherein a conditional expression 4 is satisfied, the conditional expression 4 being 1.20<f12/f<1.95 where f12 represents the composite focal length of the first and second lenses and f represents the focal length of the entire imaging lens..].

.[.9. The imaging lens according to claim 8, wherein a conditional expression 5 is satisfied, the conditional expression 5 being 1.50<f345/f<9.00 where f345 represents the composite focal length of the third to fifth lenses and f represents the focal length of the entire imaging lens..].

.[.10. The imaging lens according to claim 1, wherein conditional expressions 6 and 7 are satisfied, the conditional expressions 6 and 7 being 2.10<f3/f1<8.50 and 0.65<f4/f1<1.40 where f1 represents the focal length of the first lens; f3 represents the focal length of the third lens; and f4 represents the focal length of the fourth lens..].

.[.11. The imaging lens according to claim 1, wherein conditional expressions 8 and 9 are satisfied, the conditional expressions 8 and 9 being 3.10<r3/r4<6.80 and 1.40<f2/f<0.70 are satisfied where r3 represents the curvature radius of the object side surface of the second lens; r4 represents the curvature radius of the image side surface thereof; f2 represents the focal length thereof; and f represents the focal length of the entire imaging lens..].

.[.12. The imaging lens according to claim 1, wherein a conditional expression 10 is satisfied, the conditional expression 10 being 2.0f/EPD2.8 where EPD represents the diameter of the aperture stop and f represents the focal length of the entire imaging lens..].

.Iadd.13. An imaging lens for use in solid-state image sensors, comprising: a first lens having a convex surface on an object side and having positive refractive power; a second lens having a convex surface on the object side near an optical axis, and having negative refractive power; a third lens having a convex surface on an image side near the optical axis, and having two aspheric surfaces; a fourth lens having a concave surface on the object side near the optical axis, having two aspheric surfaces, and having positive refractive power; and a meniscus-shaped fifth lens having a convex surface on the object side near the optical axis, having two aspheric surfaces, and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and conditional expressions 1 and 8 are satisfied, the conditional expressions 1 and 8 being 0.50<f1/f<0.76 and 3.10<r3/r4<6.80 where f1 represents the focal length of the first lens, f represents the focal length of the entire imaging lens, r3 represents the curvature radius of the object side surface of the second lens, and r4 represents the curvature radius of the image side surface thereof..Iaddend.

.Iadd.14. The imaging lens according to claim 13, wherein an aperture stop is disposed on the object side of the first lens..Iaddend.

.Iadd.15. The imaging lens according to claim 13, wherein a conditional expression 2 is satisfied, the conditional expression 2 being 0.80<(r5+r6)/(r5r6)<0.55 where r5 represents the curvature radius of the object side surface of the third lens and r6 represents the curvature radius of the image side surface thereof..Iaddend.

.Iadd.16. The imaging lens according to claim 13, wherein a conditional expression 3 is satisfied, the conditional expression 3 being 8.5<r9/r10<85.0 where r9 represents the curvature radius of the object side surface of the fifth lens and r10 represents the curvature radius of the image side surface thereof..Iaddend.

.Iadd.17. The imaging lens according to claim 13, wherein a conditional expression 4 is satisfied, the conditional expression 4 being 1.20<f12/f<1.95 where f12 represents the composite focal length of the first and second lenses and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.18. The imaging lens according to claim 13, wherein a conditional expression 5 is satisfied, the conditional expression 5 being 1.50<f345/f<9.00 where f345 represents the composite focal length of the third to fifth lenses and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.19. The imaging lens according to claim 13, wherein conditional expressions 6 and 7 are satisfied, the conditional expressions 6 and 7 being 2.10<f3/f1<8.50 and 0.65<f4/f1<1.40 where f1 represents the focal length of the first lens; f3 represents the focal length of the third lens; and f4 represents the focal length of the fourth lens..Iaddend.

.Iadd.20. The imaging lens according to claim 13, wherein a conditional expression 9 is satisfied, the conditional expression 9 being 1.40<f2/f<0.70 where f2 represents the focal length of the second lens; and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.21. The imaging lens according to claim 13, wherein a conditional expression 10 is satisfied, the conditional expression 10 being 2.0f/EPD2.8 where EPD represents the diameter of the aperture stop and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.22. An imaging lens for use in solid-state image sensors, comprising: an aperture stop; a first lens having a convex surface on an object side and having positive refractive power; a second lens having negative refractive power; a third lens having a convex surface on an image side near an optical axis, and having two aspheric surfaces; a fourth lens having a convex surface on the image side near the optical axis, having two aspheric surfaces, and having positive refractive power; and a meniscus-shaped fifth lens having a convex surface on the object side near the optical axis, having two aspheric surfaces, and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and conditional expressions 2, 7 and 10a are satisfied, the conditional expressions 2, 7 and 10a being 0.80<(r5+r6)/(r5r6)<0.55, 0.65<f4/f1<1.40, and 2.0f/EPD2.6 where r5 represents the curvature radius of the object side surface of the third lens, r6 represents the curvature radius of the image side surface thereof, f1 represents the focal length of the first lens, f4 represents the focal length of the fourth lens, EPD represents the diameter of the aperture stop, and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.23. The imaging lens according to claim 22, wherein a conditional expression 1 is satisfied, the conditional expression 1 being 0.50<f1/f<0.76 where f1 represents the focal length of the first lens and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.24. The imaging lens according to claim 22, wherein a conditional expression 4 is satisfied, the conditional expression 4 being 1.20<f12/f<1.95 where f12 represents the composite focal length of the first and second lenses and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.25. An imaging lens for use in solid-state image sensors, comprising: an aperture stop; a first lens having a convex surface on an object side and having positive refractive power; a second lens having negative refractive power; a third lens having a convex surface on an image side near an optical axis, and having two aspheric surfaces; a fourth lens having a convex surface on the image side near the optical axis, having two aspheric surfaces, and having positive refractive power; and a meniscus-shaped fifth lens having a convex surface on the object side near the optical axis, having two aspheric surfaces, and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and conditional expressions 3, 7 and 10a are satisfied, the conditional expressions 3, 7 and 10a being 8.5<r9/r10<85.0, 0.65<f4/f1<1.40, and 2.0f/EPD2.6 where r9 represents the curvature radius of the object side surface of the fifth lens, r10 represents the curvature radius of the image side surface thereof, f1 represents the focal length of the first lens, f4 represents the focal length of the fourth lens, EPD represents the diameter of the aperture stop, and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.26. An imaging lens for use in solid-state image sensors, comprising: an aperture stop; a first lens having a convex surface on an object side and having positive refractive power; a second lens having negative refractive power; a third lens having a convex surface on an image side near an optical axis, and having two aspheric surfaces; a fourth lens having a convex surface on the image side near the optical axis, having two aspheric surfaces, and having positive refractive power; and a meniscus-shaped fifth lens having a convex surface on the object side near the optical axis, having two aspheric surfaces, and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and conditional expressions 5, 7 and 10a are satisfied, the conditional expressions 5, 7 and 10a being 1.50<f345/f<9.00, 0.65<f4/f1<1.40, and 2.0f/EPD2.6 where f345 represents the composite focal length of the third to fifth lenses, f1 represents the focal length of the first lens, f4 represents the focal length of the fourth lens, EPD represents the diameter of the aperture stop, and f represents the focal length of the entire imaging lens..Iaddend.

.Iadd.27. An imaging lens for use in solid-state image sensors, comprising: an aperture stop; a first lens having a convex surface on an object side and having positive refractive power; a second lens having negative refractive power; a third lens having a convex surface on an image side near an optical axis, and having two aspheric surfaces; a fourth lens having a convex surface on the image side near the optical axis, having two aspheric surfaces, and having positive refractive power; and a meniscus-shaped fifth lens having a convex surface on the object side near the optical axis, having two aspheric surfaces, and having negative refractive power, wherein the aperture stop and the first to fifth lenses are arranged in this order from the object side of the imaging lens toward an image surface thereof, and conditional expressions 7, 8, 9 and 10a are satisfied, the conditional expressions 7, 8, 9 and 10a being 0.65<f4/f1<1.40, 3.10<r3/r4<6.80, 1.40<f2/f<0.70, and 2.0f/EPD2.6 where f1 represents the focal length of the first lens, f4 represents the focal length of the fourth lens, r3 represents the curvature radius of the object side surface of the second lens, r4 represents the curvature radius of the image side surface of the second lens, f2 represents the focal length of the second lens, EPD represents the diameter of the aperture stop, and f represents the focal length of the entire imaging lens..Iaddend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view of an imaging lens according to Example 1 of an embodiment of the present invention;

(2) FIG. 2 includes graphs showing an aberration of the imaging lens according to Example 1;

(3) FIG. 3 is a sectional view of an imaging lens according to Example 2 of the embodiment of the present invention;

(4) FIG. 4 includes graphs showing an aberration of the imaging lens according to Example 2;

(5) FIG. 5 is a sectional view of an imaging lens according to Example 3 of the embodiment of the present invention;

(6) FIG. 6 includes graphs showing an aberration of the imaging lens according to Example 3;

(7) FIG. 7 is a sectional view of an imaging lens according to Example 4 of the embodiment of the present invention; and

(8) FIG. 8 includes graphs showing an aberration of the imaging lens according to Example 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) Now, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1, 3, 5, and 7 are sectional views of imaging lenses according to Examples 1 to 4 of the embodiment of the present invention. Any Example has the same basic lens configuration, and the configuration of the imaging lens according to this embodiment will be described with reference to the sectional view of the lens according to Example 1.

(10) As shown in FIG. 1, the imaging lens according to this embodiment has therein an aperture stop S, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 arranged in this order from the object side of the imaging lens toward the image surface thereof. Disposed between the fifth lens L5 and the image surface is a cover glass IR. This cover glass may be omitted. In this embodiment, the aperture stop S is disposed between the vertex of the object side surface r1 of the first lens L1 and the end of the effective diameter of the surface r1. However, the position of the aperture stop S is not limited to this position and may be closer to the object than the vertex of the surface r1.

(11) In the imaging lens having the above-mentioned configuration, the first lens L1 is a biconvex lens which directs convex surfaces toward the object side and the image side, and the second lens L2 is a meniscus-shaped lens directing a convex surface toward the object side near the optical axis and having negative refractive power. The third lens L3 is a biconvex lens directing convex surfaces toward the object side and the image side near the optical axis, the fourth lens L4 is a meniscus-shaped lens directing a concave surface toward the object side near the optical axis and having positive refractive power, and the fifth lens 15 is a meniscus-shaped lens directing a loose convex surface toward the object side near the optical axis and having negative refractive power.

(12) Optimum shapes for miniaturization of the imaging lens are selected as the shapes of the lenses according to this embodiment. Among others, the third lens L3 significantly contributes to miniaturization. Both surfaces of the third lens 13 are aspheric surfaces which have few variations in sag amount from their portion near the optical axis to their periphery. This can reduce the volume of the third lens L3 in the optical axis direction, reducing the air space between the second lens 12, located on the object side of the third lens L3, and the fourth lens L4, located on the image side of the third lens L3. Thus, the entire imaging lens can be miniaturized.

(13) The fifth lens L5 is meniscus-shaped and directs a loose convex surface toward the object side near the optical axis. An object side surface r9 of the fifth lens L5 is an aspheric surface, and its periphery more distant from the optical axis is more significantly bent toward the object side. Such a shape can reduce the distance between the fifth lens L5 and the fourth lens L4, realizing further miniaturization.

(14) The imaging lens according to this embodiment is configured so as to meet the conditional expressions 1 to 10 below.
0.50<f1/f<0.76conditional expression 1
0.80<(r5+r6)/(r5r6)<0.55conditional expression 2
8.5<r9/r10<85.0conditional expression 3
1.20<f12/f<1.95conditional expression 4
1.50<f345/f<9.00conditional expression 5
2.10<f3/f1<8.50conditional expression 6
0.65<f4/f1<1.40conditional expression 7
3.10<r3/r4<6.80conditional expression 8
1.40<f2/f<0.70conditional expression 9
2.0f/EPD2.8conditional expression 10
where f represents the focal length of the entire imaging lens; f1 represents the focal length of the first lens L1; f2 represents the focal length of the second lens L2; f3 represents the focal length of the third lens L3; f4 represents the focal length of the fourth lens L4; f12 represents the composite focal length of the first lens L1 and the second lens L2; f345 represents the composite focal length of the third lens L3, the fourth lens L4, and the fifth lens L5; r3 represents the curvature radius of the object side surface of the second lens L2; r4 represents the curvature radius of the image side surface of the second lens L2; r5 represents the curvature radius of the object side surface of the third lens L3; r6 represents the curvature radius of the image side surface of the third lens L3; r9 represents the curvature radius of the object side surface of the fifth lens L5; r10 represents the curvature radius of the image side surface of the fifth lens L5; and EPD represents the diameter of the aperture stop.

(15) In this embodiment, all the lens surfaces are aspheric. The aspheric shapes of these lens surfaces are represented by the formula below.

(16) $\begin{array}{cc}Z=\frac{\frac{H^2}{R}}{1+\sqrt{1-\left(k+1\right)\frac{H^2}{R^2}}}+A_4{H}^4+A_6{H}^6+A_8{H}^8+A_{10}{H}^{10}+A_{12}{H}^{12}+A_{14}{H}^{14}& \mathrm{Formula}1\end{array}$
where Z represents the axis in the optical axis direction; H represents the height in the direction perpendicular to the optical axis; k represents the conic coefficient; and A4, A6, A8, A10, A12, and A14 represent aspheric coefficients.

(17) The imaging lens according to Examples of this embodiment will be described. In each Example, f represents the focal length of the entire imaging lens, Fno represents the f-number, and represents the half angle of view. i represents the surface number counted from the object side, R represents the radius of curvature, d represents the inter-lens surface distance (spacing) along the optical axis, Nd represents the refraction index relative to the d line, and d represents the Abbe's number relative to the d line. Note that the aspheric surfaces are shown with a symbol * (asterisk) attached to the back of their surface number i.

Example 1

(18) Basic data about the imaging lens according to Example 1 is shown in Table 1.

(19) TABLE-US-00001 TABLE 1 f = 4.831 Fno = 2.404 = 30.52 i R d Nd d S (aperture stop) 0.245 1* 1.922 0.6719 1.5346 56.2 2* 5.167 0.023 3* 7.038 0.387 1.6142 25.6 4* 1.620 0.556 5* 8.503 0.469 1.5346 56.2 6* 50.000 0.4395 7* 1.721 0.59 1.5346 56.2 8* 0.973 0.12 9* 11.940 0.5328 1.5346 56.2 10* 1.387 0.5 11 0.3 1.5168 64.2 12 1.004 IMA i k A.sub.4 A.sub.6 A.sub.8 A.sub.10 A.sub.12 A.sub.14 1* 9.000E01 1.430E02 1.080E02 5.887E03 2.142E03 1.326E03 3.454E03 2* 1.047E+02 9.432E03 1.860E02 3.020E02 1.020E02 7.164E03 1.107E03 3* 1.480E+01 2.200E02 6.650E02 5.380E02 1.540E03 8.125E05 5.368E03 4* 5.590E01 1.289E01 1.729E01 1.069E01 3.120E02 3.246E03 3.809E03 5* 3.000E+02 4.320E02 2.420E02 1.130E02 6.194E03 3.310E03 6.472E04 6* 0.000E+00 8.460E02 5.240E02 4.560E02 1.720E02 6.281E04 6.879E04 7* 4.100E01 3.590E02 8.680E02 5.010E02 1.410E02 4.669E04 0.000E+00 8* 2.797E+00 1.370E02 5.428E03 2.020E02 3.985E03 6.448E04 1.466E04 9* 1.4901E+01 7.790E02 6.999E03 3.258E03 6.719E04 1.351E05 2.811E05 10* 1.010E+01 7.840E02 1.900E02 5.454E03 9.781E04 8.262E05 0.000E+00 f1 2.709 f2 3.523 f3 13.631 f12 6.419 f345 16.425 EPD 2.010

(20) The values of the conditional expressions in Example 1 are shown below.
f1/f=0.56
(r5+r6)/(r5r6)=0.71
r9/r10=8.61
f12/f=1.33
f345/f=3.40
f3/f1=5.03
f4/f1=1.21
r3/r4=4.34
f2/f=0.73
f/EPD=2.40

(21) As seen, the imaging lens according to Example 1 satisfies the conditional expressions 1 to 10.

(22) FIG. 2 includes an aberration graph showing the spherical aberration (mm) of the imaging lens according to Example 1, an aberration graph showing the astigmatism (field curvature) (mm) thereof, and an aberration graph showing the distortion (%) thereof. These aberration graphs each show aberration amounts corresponding to wavelengths 587.56 nm, 656.27 nm, and 486.13 nm. The astigmatism graph shows the aberration amount on a sagittal image surface S and the aberration amount on a tangential image surface T (same in FIGS. 4, 6, and 8).

(23) As shown in FIG. 2, the aberrations are favorably corrected in the imaging lens according to Example 1. Further, the air conversion distance TL from the object side surface of the first lens L1 to the image surface is as short as 5.49 mm. Further, TL/2h=0.95 where h represents the maximum image height of the imaging area, suggesting that the image lens is favorably miniaturized.

Example 2

(24) Basic data about the imaging lens according to Example 2 is shown in Table 2.

(25) TABLE-US-00002 TABLE 2 f = 4.30 Fno = 2.80 = 33.72 i R d Nd d S (aperture stop) 0.14 1* 1.914 0.8 1.5346 56.2 2* 4.550 0.0316 3* 13.532 0.341 1.6142 25.6 4* 2.004 0.487 5* 50.000 0.461 1.5346 56.2 6* 15.274 0.231 7* 2.309 0.66 1.5346 56.2 8* 1.155 0.03 9* 70.000 1.06 1.5346 56.2 10* 1.531 0.38 11 0.3 1.5168 64.2 12 0.622 IMA i k A.sub.4 A.sub.6 A.sub.8 A.sub.10 A.sub.12 A.sub.14 1* 1.050E+00 2.815E03 1.440E02 3.030E02 0.000E+00 0.000E+00 0.000E+00 2* 0.000E+00 4.410E02 7.010E02 3.583E03 0.000E+00 0.000E+00 0.000E+00 3* 4.100E+01 2.050E02 5.170E02 7.660E02 3.520E02 0.000E+00 0.000E+00 4* 0.000E+00 9.620E02 1.891E01 1.906E01 1.289E01 3.430E02 0.000E+00 5* 1.470E+02 9.320E02 2.630E02 4.700E02 1.860E02 1.190E02 0.000E+00 6* 0.000E+00 7.150E02 1.610E02 3.810B02 1.320E02 5.080E03 0.000E+00 7* 1.380E+00 6.860E02 1.840E02 3.500E02 9.312E03 2.952E03 0.000E+00 8* 2.700E+00 3.830E02 1.520E02 1.210E02 7.534E03 1.282E03 0.000E+00 9* 0.000E+00 9.020E02 1.266E02 3.429E03 9.405E04 0.000E+00 0.000E+00 10* 7.200E+00 5.290E02 1.555E02 4.154E03 6.797E04 6.219E05 2.232E06 f1 2.634 f2 3.873 f3 21.939 f12 5.355 f345 37.144 EPD 1.535

(26) The values of the conditional expressions in Example 2 are shown below.
f1/f=0.613
(r5+r6)/(r5r6)=0.53
r9/r10=45.732
f12/f=1.25
f345/f=8.64
f3/f1=8.33
f4/f1=1.37
r3/r4=6.75
f2/f=0.90
f/EPD=2.80

(27) As seen, the imaging lens according to Example 2 satisfies the conditional expressions 1 to 10.

(28) FIG. 4 includes an aberration graph showing the spherical aberration (mm) of the imaging lens according to Example 2, an aberration graph showing the astigmatism (field curvature) (mm) thereof, and an aberration graph showing the distortion (%) thereof. As shown in FIG. 4, the aberrations are favorably corrected in the imaging lens according to Example 2. Further, the air conversion distance TL from the object side surface of the first lens L1 to the image surface is as short as 5.31 mm. Further, TL/2h=0.92 where h represents the maximum image height of the imaging area, suggesting that the image lens is favorably miniaturized.

Example 3

(29) Basic data about the imaging lens according to Example 3 is shown in Table 3.

(30) TABLE-US-00003 TABLE 3 f = 3.409 Fno = 2.550 = 39.996 i R d Nd d S (aperture stop) 0.12 1* 1.586 0.518 1.5346 56.2 2* 6.103 0.038 3* 8.851 0.28 1.6142 25.6 4* 1.759 0.3314 5* 8.348 0.3945 1.5346 56.2 6* 66.000 0.336 7* 2.068 0.4367 1.5346 56.2 8* 0.908 0.255 9* 23.673 0.53 1.5346 56.2 10* 1.089 0.38 11 0.3 1.5168 64.2 12 0.391 IMA i k A.sub.4 A.sub.6 A.sub.8 A.sub.10 A.sub.12 A.sub.14 1* 1.000E+00 5.821E03 2.220E02 1.435E01 0.000E+00 0.000E+00 0.000E+00 2* 0.000E+00 7.423E03 1.152E01 2.403E03 0.000E+00 0.000E+00 0.000E+00 3* 1.680E+02 3.130E02 3.670E02 5.950E02 1.349E01 0.000E+00 0.000E+00 4* 0.000E+00 9.610E02 1.910E01 1.769E01 1.600E01 3.130E02 0.000E+00 5* 9.400E+01 9.200E02 6.268E03 4.880E02 3.860E02 2.407E04 0.000E+00 6* 0.000E+00 8.910E02 3.784E03 2.820E02 1.800E02 6.949E03 0.000E+00 7* 1.170E+00 7.550E02 6.515E03 3.460E02 1.210E02 4.966E03 0.000E+00 8* 2.865E+00 2.270E02 2.790E02 1.540E02 8.151E03 6.265E04 0.000E+00 9* 0.000E+00 9.070E02 8.390E03 3.833E03 5.748E04 0.000E+00 0.000E+00 10* 6.930E+00 6.880E02 1.950E02 5.903E03 8.829E04 5.596E05 9.142E07 f1 2.412 f2 3.629 f3 13.888 f12 5.003 f345 14.103 EPD 1.335

(31) The values of the conditional expressions in Example 3 are shown below.
f1/f=0.708
(r5+r6)/(r5r6)=0.78
r9/r10=21.739
f12/f=1.47
f345/f=4.14
f3/f1=5.76
f4/f1=1.11
r3/r4=5.03
f2/f=1.06
f/EPD=2.55

(32) As seen, the imaging lens according to Example 3 satisfies the conditional expressions 1 to 10.

(33) FIG. 6 includes an aberration graph showing the spherical aberration (mm) of the imaging lens according to Example 3, an aberration graph showing the astigmatism (field curvature) (mm) thereof, and an aberration graph showing the distortion (%) thereof. As shown in FIG. 6, the aberrations are favorably corrected in the imaging lens according to Example 3. Further, the air conversion distance TL from the object side surface of the first lens L1 to the image surface is as short as 4.096 mm. Further, TL/2h=0.71 where h represents the maximum image height of the imaging area, suggesting that the image lens is favorably miniaturized.

Example 4

(34) Basic data about the imaging lens according to Example 4 is shown in Table 4.

(35) TABLE-US-00004 TABLE 4 f = 3.775 Fno = 2.00 = 37.269 i R d Nd d S (aperture stop) 0.19 1* 2.023 0.61 1.5346 56.2 2* 5.183 0.0845 3* 4.718 0.29 1.6142 25.6 4* 1.450 0.321 5* 5.009 0.519 1.5346 56.2 6* 34.447 0.4905 7* 2.520 0.5424 1.5346 56.2 8* 0.940 0.03 9* 95.000 0.766 1.5346 56.2 10* 1.140 0.5 11 0.3 1.5168 64.2 12 0.421 IMA i k A.sub.4 A.sub.6 A.sub.8 A.sub.10 A.sub.12 A.sub.14 1* 0.000E+00 1.390E02 1.220E02 2.700E02 0.000E+00 0.000E+00 0.000E+00 2* 0.000E+00 7.270E02 6.140E02 0.000E+00 0.000E+00 0.000E+00 0.000E+00 3* 4.330E+01 3.300E02 1.068E01 1.238E01 3.420E02 1.160E02 0.000E+00 4* 1.451E+00 1.690E01 2.655E01 1.954E01 5.570E02 3.393E03 0.000E+00 5* 1.800E+01 4.730E02 6.790E03 3.630E02 5.400E03 0.000E+00 0.000E+00 6* 0.000E+00 4.970E02 2.030E02 4.440E02 2.460E02 1.251E03 0.000E+00 7* 2.120E+00 1.450E02 5.820E02 3.100E02 4.256E03 2.075E03 0.000E+00 8* 3.130E+00 5.450E02 3.400E02 1.830E02 9.964E03 1.030E03 0.000E+00 9* 0.000E+00 6.440E02 8.226E03 2.074E03 3.618E04 0.000E+00 0.000E+00 10* 7.250E+00 6.090E02 1.880E02 5.456E03 8.217E04 5.400E05 0.000E+00 f1 2.804 f2 3.527 f3 8.217 f12 7.217 f345 6.969 EPD 1.885

(36) The values of the conditional expressions in Example 4 are shown below.
f1/f=0.743
(r5+r6)/(r5r6)=0.75
r9/r10=83.359
f12/f=1.91
f345/f=1.85
f3/f1=2.93
f4/f1=0.89
r3/r4=3.25
f2/f=0.93
f/EPD=2.00

(37) As seen, the imaging lens according to Example 4 satisfies the conditional expressions 1 to 10.

(38) FIG. 8 includes an aberration graph showing the spherical aberration (mm) of the imaging lens according to Example 4, an aberration graph showing the astigmatism (field curvature) (mm) thereof, and an aberration graph showing the distortion (%) thereof. As shown in FIG. 8, the aberrations are favorably corrected in the imaging lens according to Example 4. Further, the air conversion distance TL from the object side surface of the first lens L1 to the image surface is as short as 4.78 mm. Further, TL/2h=0.83 where h represents the maximum image height of the imaging area, suggesting that the image lens is favorably miniaturized.

(39) Accordingly, application of the imaging lens according to this embodiment to imaging optical systems such as cellular phones, digital still cameras, mobile information terminals, security cameras, on-board cameras, and network cameras can achieve both greater functionality and miniaturization of the imaging optical systems.

(40) In the imaging lens according to the aspect of the present invention, both miniaturization and favorable aberration correction are achieved. Thus, it is possible to provide a small, low-cost imaging lens that favorably corrects aberrations.