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.

Description

−0.80<(r5+r6)/(r5−r6)<0.55  conditional expression 2
8.5<r9/r10<85.0  conditional expression 3
1.20<f12/f<1.95  conditional expression 4
1.50<f345/f<9.00  conditional expression 5
2.10<f3/f1<8.50  conditional expression 6
0.65<f4/f1<1.40  conditional expression 7
3.10<r3/r4<6.80  conditional expression 8
−1.40<f2/f<−0.70  conditional expression 9
2.0≤f/EPD≤2.8  conditional 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.

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

$\begin{array}{cc}Z=\frac{\frac{H^2}{R}}{1+\sqrt{1-\left(k+1\right)\frac{H^2}{R^2}}}+A_4{H}^4+A_6{H}^6+A_8{H}^8+A_{10}{H}^{10}+A_{12}{H}^{12}+A_{14}{H}^{14}& \mathrm{Formula}1\end{array}$
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.

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 ω 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 νd 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

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

TABLE 1
f = 4.831 Fno = 2.404 ω = 30.52°
i	R	d	Nd	νd
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	A4	A6	A8	A10	A12	A14
1*	−9.000E−01	1.430E−02	−1.080E−02	5.887E−03	−2.142E−03	−1.326E−03	−3.454E−03
2*	−1.047E+02	9.432E−03	1.860E−02	−3.020E−02	−1.020E−02	7.164E−03	−1.107E−03
3*	1.480E+01	−2.200E−02	6.650E−02	−5.380E−02	1.540E−03	−8.125E−05	5.368E−03
4*	−5.590E−01	−1.289E−01	1.729E−01	−1.069E−01	3.120E−02	−3.246E−03	3.809E−03
5*	−3.000E+02	−4.320E−02	−2.420E−02	1.130E−02	6.194E−03	3.310E−03	−6.472E−04
6*	0.000E+00	−8.460E−02	5.240E−02	−4.560E−02	1.720E−02	−6.281E−04	6.879E−04
7*	4.100E−01	3.590E−02	8.680E−02	−5.010E−02	1.410E−02	−4.669E−04	0.000E+00
8*	−2.797E+00	−1.370E−02	−5.428E−03	2.020E−02	−3.985E−03	−6.448E−04	1.466E−04
9*	1.4901E+01	−7.790E−02	−6.999E−03	3.258E−03	6.719E−04	−1.351E−05	−2.811E−05
10*	−1.010E+01	−7.840E−02	1.900E−02	−5.454E−03	9.781E−04	−8.262E−05	0.000E+00
	f1	2.709
	f2	−3.523
	f3	13.631
	f12	6.419
	f345	16.425
	EPD	2.010

The values of the conditional expressions in Example 1 are shown below.
f1/f=0.56
(r5+r6)/(r5−r6)=−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

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

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).

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

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

TABLE 2
f = 4.30 Fno = 2.80 ω = 33.72°
i	R	d	Nd	νd
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	A4	A6	A8	A10	A12	A14
1*	−1.050E+00	2.815E−03	1.440E−02	−3.030E−02	0.000E+00	0.000E+00	0.000E+00
2*	0.000E+00	4.410E−02	−7.010E−02	3.583E−03	0.000E+00	0.000E+00	0.000E+00
3*	−4.100E+01	−2.050E−02	5.170E−02	−7.660E−02	3.520E−02	0.000E+00	0.000E+00
4*	0.000E+00	−9.620E−02	1.891E−01	−1.906E−01	1.289E−01	−3.430E−02	0.000E+00
5*	1.470E+02	−9.320E−02	−2.630E−02	4.700E−02	−1.860E−02	1.190E−02	0.000E+00
6*	0.000E+00	−7.150E−02	1.610E−02	−3.810B−02	1.320E−02	5.080E−03	0.000E+00
7*	1.380E+00	6.860E−02	1.840E−02	−3.500E−02	9.312E−03	2.952E−03	0.000E+00
8*	−2.700E+00	−3.830E−02	1.520E−02	1.210E−02	−7.534E−03	1.282E−03	0.000E+00
9*	0.000E+00	−9.020E−02	1.266E−02	3.429E−03	−9.405E−04	0.000E+00	0.000E+00
10*	−7.200E+00	−5.290E−02	1.555E−02	−4.154E−03	6.797E−04	−6.219E−05	2.232E−06
	f1	2.634
	f2	−3.873
	f3	21.939
	f12	5.355
	f345	37.144
	EPD	1.535

The values of the conditional expressions in Example 2 are shown below.
f1/f=0.613
(r5+r6)/(r5−r6)=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

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

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

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

TABLE 3
f = 3.409 Fno = 2.550 ω = 39.996°
i	R	d	Nd	νd
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	A4	A6	A8	A10	A12	A14
1*	−1.000E+00	5.821E−03	2.220E−02	−1.435E−01	0.000E+00	0.000E+00	0.000E+00
2*	0.000E+00	7.423E−03	−1.152E−01	−2.403E−03	0.000E+00	0.000E+00	0.000E+00
3*	−1.680E+02	−3.130E−02	3.670E−02	−5.950E−02	1.349E−01	0.000E+00	0.000E+00
4*	0.000E+00	−9.610E−02	1.910E−01	−1.769E−01	1.600E−01	−3.130E−02	0.000E+00
5*	−9.400E+01	−9.200E−02	6.268E−03	4.880E−02	−3.860E−02	2.407E−04	0.000E+00
6*	0.000E+00	−8.910E−02	3.784E−03	−2.820E−02	1.800E−02	6.949E−03	0.000E+00
7*	1.170E+00	7.550E−02	6.515E−03	−3.460E−02	1.210E−02	4.966E−03	0.000E+00
8*	−2.865E+00	−2.270E−02	2.790E−02	1.540E−02	−8.151E−03	6.265E−04	0.000E+00
9*	0.000E+00	−9.070E−02	8.390E−03	3.833E−03	−5.748E−04	0.000E+00	0.000E+00
10*	−6.930E+00	−6.880E−02	1.950E−02	−5.903E−03	8.829E−04	−5.596E−05	−9.142E−07
	f1	2.412
	f2	−3.629
	f3	13.888
	f12	5.003
	f345	14.103
	EPD	1.335

The values of the conditional expressions in Example 3 are shown below.
f1/f=0.708
(r5+r6)/(r5−r6)=−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

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

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

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

TABLE 4
f = 3.775 Fno = 2.00 ω = 37.269°
i	R	d	Nd	νd
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	A4	A6	A8	A10	A12	A14
1*	0.000E+00	−1.390E−02	1.220E−02	−2.700E−02	0.000E+00	0.000E+00	0.000E+00
2*	0.000E+00	7.270E−02	−6.140E−02	0.000E+00	0.000E+00	0.000E+00	0.000E+00
3*	−4.330E+01	−3.300E−02	1.068E−01	−1.238E−01	3.420E−02	1.160E−02	0.000E+00
4*	−1.451E+00	−1.690E−01	2.655E−01	−1.954E−01	5.570E−02	3.393E−03	0.000E+00
5*	−1.800E+01	−4.730E−02	−6.790E−03	3.630E−02	−5.400E−03	0.000E+00	0.000E+00
6*	0.000E+00	−4.970E−02	2.030E−02	−4.440E−02	2.460E−02	1.251E−03	0.000E+00
7*	2.120E+00	1.450E−02	5.820E−02	−3.100E−02	4.256E−03	2.075E−03	0.000E+00
8*	−3.130E+00	−5.450E−02	3.400E−02	1.830E−02	−9.964E−03	1.030E−03	0.000E+00
9*	0.000E+00	−6.440E−02	8.226E−03	2.074E−03	−3.618E−04	0.000E+00	0.000E+00
10*	−7.250E+00	−6.090E−02	1.880E−02	−5.456E−03	8.217E−04	−5.400E−05	0.000E+00
	f1	2.804
	f2	−3.527
	f3	8.217
	f12	7.217
	f345	6.969
	EPD	1.885

The values of the conditional expressions in Example 4 are shown below.
f1/f=0.743
(r5+r6)/(r5−r6)=−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

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

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.

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.

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.

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)/(r5−r6)<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 2.0≤f/EPD≤2.8 where EPD represents the diameter of the aperture stop and f represents the focal length of the entire imaging lens.

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.

14. The imaging lens according to claim 13, wherein

an aperture stop is disposed on the object side of the first lens.

15. The imaging lens according to claim 13, wherein

a conditional expression 2 is satisfied, the conditional expression 2 being −0.80<(r5+r6)/(r5−r6)<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.

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.

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.

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.

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.

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.

21. The imaging lens according to claim 13, wherein

a conditional expression 10 is satisfied, the conditional expression 10 being 2.0≤f/EPD≤2.8 where EPD represents the diameter of the aperture stop and f represents the focal length of the entire imaging lens.

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)/(r5−r6)<0.55, 0.65<f4/f1<1.40, and 2.0≤f/EPD≤2.6 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.

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.

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.

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 2.0≤f/EPD≤2.6 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.

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 2.0≤f/EPD≤2.6 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.

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 2.0≤f/EPD≤2.6 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.