Imaging lens and imaging apparatus
An imaging lens includes, in order from an object side to an image side, a first lens including a negative meniscus lens having a convex shape facing the object, a second lens including a positive meniscus lens having a convex shape facing the image, at least one lens including a third lens, a fourth lens, a fifth lens, and a sixth lens including a positive lens having a convex image side surface, and Expression (1) is satisfied as follows. Further, an imaging apparatus including the imaging lens is provided. 1.2 < D 2 / f ( 1 ) where D 2 is a thickness of the second lens on the optical axis, and f is a focal length of the imaging lens.
1 . An imaging lens comprising: sequentially from an object side to an image side, a first lens including a negative meniscus lens having a convex shape directed to the object side; a second lens consisting of a single positive meniscus lens having a convex shape directed to the image side; at least one lens including a third lens; a fourth lens; a fifth lens; and a sixth lens including a positive lens having a convex surface as an image-side surface, wherein
Expression (1) is satisfied as follows:
1.2
<
D
2
/
f
(
1
)
where
D 2 is a thickness of the second lens on an optical axis, and
f is a focal length of the imaging lens.
2 . The imaging lens according to claim 1 , wherein
Expression (2) is satisfied as follows:
-
10.
<
f
12
/
f
<
0
(
2
)
where
f 12 is a composite focal length of the first lens and the second lens.
3 . The imaging lens according to claim 1 , wherein
Expression (3) is satisfied as follows:
0.05
<
D
1
/
f
<
0.6
(
3
)
where
D 1 is a thickness of the first lens on the optical axis.
4 . The imaging lens according to claim 1 , wherein
Expression (4) is satisfied as follows:
0.1
<
d
1
-
2
/
f
<
2.
(
4
)
where
d 1-2 is an air distance between the first lens and the second lens on the optical axis.
5 . The imaging lens according to claim 1 , wherein the first lens has at least one aspherical face.
6 . The imaging lens according to claim 1 , wherein
Expression (5) is satisfied as follows:
0.5
<
R
11
/
f
<
10.
(
5
)
where
R 11 is a paraxial curvature radius of an object side surface of the first lens.
7 . The imaging lens according to claim 1 , wherein
Expression (6) is satisfied as follows:
0.25
<
D
3
/
f
<
2.
(
6
)
where
D 3 is a thickness of the third lens on the optical axis.
8 . The imaging lens according to claim 1 , wherein
Expression (7) is satisfied as follows:
0
<
d
5
-
6
/
f
<
1.5
(
7
)
where
d 5-6 is an air distance between the fifth lens and the sixth lens on the optical axis.
9 . The imaging lens according to claim 1 , wherein
Expression (8) is satisfied as follows:
2.
<
TTL
/
f
<
10.
(
8
)
where
TTL is a distance from an object side surface of the first lens to an image plane on the optical axis, and a value converted into air is used as a distance from the sixth lens to the image plane on the optical axis.
10 . The imaging lens according to claim 1 , wherein
Expression (9) is satisfied as follows:
0.2
<
BF
/
f
<
2.
(
9
)
where
BF is a distance converted into air from an image side surface of the sixth lens to the image plane on the optical axis.
11 . The imaging lens according to claim 1 , wherein
Expression (10) is satisfied as follows:
90
°
<
FOV
(
10
)
where
FOV is an angle of view of the imaging lens.
12 . The imaging lens according to claim 1 , wherein
Expression (11) is satisfied as follows:
40
<
v
3
(
11
)
where
v 3 is an Abbe number of the third lens with respect to d Line.
13 . The imaging lens according to claim 1 , wherein
Expression (12) is satisfied as follows:
1.
<
f
3
/
f
<
5.
(
12
)
where
f 3 is a focal length of the third lens.
14 . The imaging lens according to claim 1 , wherein
Expression (13) is satisfied as follows:
(
Y
max
-
f
×
tan
θ
)
/
(
f
×
tan
θ
)
<
-
0.3
(
13
)
where
Y max is an image height in an effective image circle, and
θ is a half angle of view in the effective image circle.
15 . The imaging lens according to claim 1 , wherein
the fourth lens includes a positive lens, and the fifth lens includes a negative lens, and wherein
Expression (14) is satisfied as follows:
f
45
/
f
<
-
1.
(
14
)
where
f 45 is a composite focal length of the fourth lens and the fifth lens.
16 . The imaging lens according to claim 1 , wherein all lenses from the first lens to the sixth lens are made of glass.
17 . An imaging apparatus comprising: the imaging lens according to claim 1 ; and an image sensor that converts an optical image formed by the imaging lens into an electrical signal.