Image pickup lens
An image pickup lens includes a first lens having a positive refractive power, a second meniscus lens having a negative refractive power, a third lens, a fourth meniscus lens having a negative refractive power, and a fifth lens having both sides formed as aspheric surfaces with a positive refractive power, wherein an F-value is 2.41 or smaller.
1. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
a first lens having a positive refractive power,
a second lens having a meniscus shape and a negative refractive power,
a third lens having a positive refractive power,
a fourth lens having a meniscus shape, a negative refractive power and a concave surface facing the image side near an optical axis, and
a fifth lens having both sides formed as aspheric surfaces and a positive refractive power; wherein
an F-value of the image pickup lens is 2.41 or smaller, and satisfies an expression (8):
−5.0< f 4/ f<− 1.75 (8)
where f represents a focal length of the overall optical system of the image pickup lens, and f4 represents a focal length of the fourth lens.
2. The image pickup lens according to claim 1 , wherein
the first lens has a convex surface facing the object side,
the second lens has a concave surface facing the image side, and
the third lens has a convex surface facing the object side near an optical axis.
3. The image pickup lens according to claim 1 , wherein
the fourth lens has both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a meniscus shape and a concave surface facing the image side near the optical axis, having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.
4. The image pickup lens according to claim 1 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90 (1)
22<ν2<35 (2)
2.0<ν1/ν2<2.6 (3)
where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.
5. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expressions (4) and (5):
0.7< f 1/ f< 0.9 (4)
−1.3< f 2/ f<− 0.9 (5)
where f represents a focal length of the overall optical system of the image pickup lens, f1 represents a focal length of the first lens, and f2 represents a focal length of the second lens.
6. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expression (6):
1.1< TTL/f< 1.3 (6)
where TTL represents a distance on an optical axis from the object side surface of the first lens to the imaging surface with a filter removed, and f represents a focal length of the overall optical system of the image pickup lens.
7. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expression (9):
1.5< f 5/ f< 4.0 (9)
f represents a focal length of the overall optical system of the image pickup lens, and f5 represents a focal length of the fifth lens.
8. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
an aperture stop,
a first lens having a positive refractive power,
a second lens having a meniscus shape, a concave surface facing the image side near the optical axis, and a negative refractive power,
a third lens having a convex surface facing the object side near an optical axis and a positive refractive power,
a fourth lens having a negative refractive power, and
a fifth lens having both sides formed as aspheric surfaces, a meniscus shape and a concave surface facing the image side near the optical axis, and a positive refractive power, wherein
the image pickup lens satisfy expression (9):
1.5< f 5/ f< 4.0 (9)
where f represents a focal length of the overall optical system of the image pickup lens, and f5 represents a focal length of the fifth lens.
9. The image pickup lens according to claim 8 , wherein
the first lens has a convex surface facing the object side.
10. The image pickup lens according to claim 8 , wherein
the fourth lens has a concave surface facing the image side near the optical axis, having both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.
11. The image pickup lens according to claim 8 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90 (1)
22<ν2<35 (2)
2.0<ν1/ν2<2.6 (3)
where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.
12. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expressions (4) and (5):
0.7< f 1/ f< 0.9 (4)
−1.3< f 2/ f 21 −0.9 (5)
where f represents a focal length of the overall optical system of the image pickup lens, f1 represents a focal length of the first lens, and f2 represents a focal length of the second lens.
13. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expression (6):
1.1< TTL/f< 1.3 (6)
where TTL represents a distance on the optical axis from the object side surface of the first lens to the imaging surface with a filter removed, and f represents a focal length of the overall optical system of the image pickup lens.
14. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expression. (8):
−5.0< f 4 /f<− 1.75 (8)
where f4 represents a focal length of the fourth lens, and f represents a focal length of the overall optical system of the image pickup lens.
15. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
an aperture stop,
a first lens having a positive refractive power,
a second lens having a meniscus shape and a concave surface facing the image side near the optical axis, and a negative refractive power,
a third lens having a convex surface facing the object side near an optical axis and a positive refractive power,
a fourth lens having a concave surface facing the image side near the optical axis and a negative refractive power, and
a fifth lens having both sides formed as aspheric surfaces and having positive refractive power, wherein
the image pickup lens satisfy expression (5):
−1.3< f 2/ f<− 0.9 (5)
where f represents a focal length of the overall optical system of the image pickup lens, and f2 represents a focal length of the second lens.
16. The image pickup lens according to claim 15 , wherein
the first lens has a convex surface facing the object side.
17. The image pickup lens according to claim 15 , wherein
the fourth lens has both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a meniscus shape and a concave surface facing the image side near the optical axis, having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.
18. The image pickup lens according to claim 15 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90 (1)
22<ν2<35 (2)
2.0<ν1/ν2<2.6 (3)
where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.
19. The image pickup lens according to claim 15 , wherein the image pickup lens satisfy expression (4):
0.7< f 1 /f< 0.9 (4)
where f represents a focal length of the overall optical system of the image pickup lens, and f1 represents a focal length of the first lens.
20. The image pickup lens according to claim 15 , wherein the image pickup lens satisfy expression (6);
1.1< TTL/f< 1.3 (6)
where TTL represents a distance on the optical axis from the object side surface of the first lens to the imaging surface with a filter removed, and f represents a focal length of the overall optical system of the image pickup lens.