Image pickup lens
An image pickup lens includes a first lens with positive refractive power having a convex object side surface, an aperture stop, a second lens with negative refractive power having a convex image side surface, a third lens with positive refractive power having a concave image side surface, a fourth lens with positive refractive power having a convex image side surface, and a fifth lens with negative refractive power as a double-sided aspheric lens having a concave image side surface near the optical axis; wherein the first lens and the second lens satisfy following conditional expressions (1) and (2); 50<ν1<85 (1) 20<ν2<35 (2) where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens, and where the second lens satisfies a following conditional expression (3); 1.55< Nd 2<1.70 (3) where Nd2 represents a refractive index of d-ray of the second lens.
1. An image pickup lens composed of five lenses for a solid imaging element, comprising, in order from an object side to an image side of the image pickup lens:
a first lens having positive refractive power and a convex surface facing the object side;
a second lens that is a meniscus lens having negative refractive power;
a third lens having positive refractive power and a concave surface facing the image side;
a fourth lens having a concave surface facing the object side; and
a fifth lens having negative refractive power, and both an object-side surface and an image-side surface formed as aspherical surfaces, the object-side surface and image-side surface being concave near an optical axis of the image pickup lens;
wherein a conditional expression (12) below is satisfied:
−0.986≦ f 2/ f<− 0.7 (12)
where f represents an overall focal length of the image pickup lens, and f2 represents a focal length of the second lens.
2. The image pickup lens according to claim 1 , wherein an aperture stop is arranged between the first lens and the second lens.
3. The image pickup lens according to claim 1 , wherein the second lens has a convex surface facing the image side.
4. The image pickup lens according to claim 1 , wherein the fourth lens has positive refractive power.
5. The image pickup lens according to claim 1 , wherein each of the third lens and the fourth lens has a meniscus shape.
6. The image pickup lens according to claim 1 , satisfying the following conditional expressions (1), (2), and (3):
50<ν1<85 (1)
20<ν2<35 (2)
1.55< Nd 2<1.70 (3)
where ν1 represents an Abbe number of the first lens, ν2 represents an Abbe number of the second lens, and Nd2 represents a refractive index of the second lens at d-ray.
7. The image pickup lens according to claim 1 , satisfying the following conditional expressions (5), (6), and (7):
20<ν3<30 (5)
50<ν4<60 (6)
1.5< Nd 3<1.7 (7)
where ν3 represents an Abbe number of the third lens, ν4 represents an Abbe number of the fourth lens, and Nd3 represents a refractive index of the third lens at d-ray.
8. The image pickup lens according to claim 1 , wherein the image-side surface of the fifth lens has a pole-change point separated from the optical axis.
9. The image pickup lens according to claim 1 , satisfying the following conditional expression (9):
1.0<|( r 3+ r 4)/( r 3− r 4)|<1.3 (9)
where r3 represents a curvature radius of an object-side surface of the second lens, and r4 represents a curvature radius of an image-side surface of the second lens.
10. The image pickup lens according to claim 1 , satisfying the following conditional expression (10):
1.7< r 2/ r 3<6.0 (10)
where r2 represents a curvature radius of an image-side surface of the first lens, and r3 represents a curvature radius of an object-side surface of the second lens.
11. The image pickup lens according to claim 1 , satisfying the following conditional expression (11):
0.5< f 1/ f< 0.8 (11)
where f1 represents a focal length of the first lens.
12. The image pickup lens according to claim 1 , satisfying the following conditional expression (13):
0.5< f 4/ f< 0.7 (13)
where f4 represents a focal length of the fourth lens.