Image pickup lens
A wide-angle image pickup lens having small F-value, high resolution, and small distortion is provided. The image pickup lens is configured from, in order from an object side to an image side, a first lens having a positive refractive power with a concave surface facing the object side, an aperture stop, a second lens having a negative refractive power with a concave surface facing the image side, a third lens having a positive refractive power, a fourth lens having a positive refractive power with a concave surface facing the object side, and a fifth lens having a negative refractive power with a concave surface facing the image side.
1. An image pickup lens, comprising, in order from an object side to an image side:
a first lens having a positive refractive power with a concave surface facing the object side;
an aperture stop;
a second lens having a negative refractive power with a concave surface facing the image side;
a third lens having a positive refractive power;
a fourth lens having a positive refractive power with a concave surface facing the object side; and
a fifth lens having a negative refractive power with a concave surface facing the image side.
2. The image pickup lens according to claim 1 , satisfying a following conditional expression:
−70.0 <r 1 /f< 0 (1)
where
r 1 : curvature radius of object side surface of first lens
f: focal length of overall optical system.
3. The image pickup lens according to claim 1 , satisfying following conditional expressions:
−1.20 <r 2 /r 3<−0.40 (2)
1.56< r 3 /r 4<3.0 (3)
where
r 2 : curvature radius of image side surface of first lens
r 3 : curvature radius of object side surface of second lens
r 4 : curvature radius of image side surface of second lens.
4. The image pickup lens according to claim 1 , satisfying a following conditional expression:
−2.0< r 8 /r 10<−0.63 (4)
where
r 8 : curvature radius of image side surface of fourth lens
r 10 : curvature radius of image side surface of fifth lens.
5. The image pickup lens according to claim 1 , satisfying a following conditional expression:
1.0< r 1 /r 2<120. (5)
6. The image pickup lens according to claim 1 , satisfying a following conditional expression:
0.50< r 3 /f< 1.20. (6)
7. The image pickup lens according to claim 2 , satisfying following conditional expressions:
−1.20 <r 2 /r 3<−0.40 (2)
1.56< r 3 /r 4<3.0 (3)
where
r 2 : curvature radius of image side surface of first lens
r 3 : curvature radius of object side surface of second lens
r 4 : curvature radius of image side surface of second lens.
8. The image pickup lens according to claim 2 , satisfying a following conditional expression:
−2.0< r 8 /r 10<−0.63 (4)
where
r 8 : curvature radius of image side surface of fourth lens
r 10 : curvature radius of image side surface of fifth lens.
9. The image pickup lens according to claim 2 , satisfying a following conditional expression:
1.0< r 1 /r 2<120. (5)
10. The image pickup lens according to claim 2 , satisfying a following conditional expression:
0.50< r 3 /f< 1.20. (6)