Imaging lens
There is provided an imaging lens with high-resolution which satisfies demand of wide field of view, low-profileness and low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises, in order from an object side to an image side, a first lens, a second lens having negative refractive power near the optical axis, a third lens having a convex surface facing the image side near the optical axis, a fourth lens and a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions are satisfied: 3.00<( T 4/ f )×100<5.90 0.40< f 2/ f 5<1.45 where T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, f: a focal length of the overall optical system of the imaging lens, f2: a focal length of the second lens, f5: a focal length of the fifth lens.
1. An imaging lens comprising in order from an object side to an image side,
a first lens,
a second lens having negative refractive power near the optical axis,
a third lens having a convex surface facing the image side near the optical axis,
a fourth lens, and
a fifth lens, wherein said first lens has negative refractive power near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions (1), (2) and (8) are satisfied:
3.00<( T 4/ f )×100<5.90 (1)
0.40< f 2/ f 5<1.45 (2)
1.20< D 1/ D 2<3.70 (8)
where
T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens,
f: a focal length of the overall optical system of the imaging lens,
f2: a focal length of the second lens,
f5: a focal length of the fifth lens,
D1: a thickness along the optical axis of the first lens, and
D2: a thickness along the optical axis of the second lens.
2. The imaging lens according to claim 1 , wherein a below conditional expression (7) is satisfied:
1.50< T 1/ T 2<5.30 (7)
where
T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and
T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.
3. The imaging lens according to claim 1 , wherein a below conditional expression (11) is satisfied:
−8.50< r 6/ f<− 2.00 (11)
where
r6: a paraxial curvature radius of the image-side surface of the third lens, and
f: a focal length of the overall optical system of the imaging lens.
4. The imaging lens according to claim 1 , wherein a below conditional expression (12) is satisfied:
−62<( D 1/ f 1)×100<−29 (12)
where
D1: a thickness along the optical axis of the first lens, and
f1: a focal length of the first lens.
5. An imaging lens comprising in order from an object side to an image side,
a first lens,
a second lens having negative refractive power near the optical axis,
a third lens having a convex surface facing the image side near the optical axis,
a fourth lens, and
a fifth lens, wherein said imaging lens is configured with only five lenses, with the lenses configured so that none of the adjacent pairs of the five lenses is cemented, said first lens has negative refractive power near the optical axis, an object-side surface of said second lens has a convex surface facing the object side near the optical axis, an object-side surface of said fifth lens has a concave surface facing the object side near the optical axis, and below conditional expressions (3) and (4) are satisfied:
1.60< T 1/ f< 3.70 (3)
0.10< T 2/ T 3<0.80 (4)
where
T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens,
f: a focal length of the overall optical system of the imaging lens,
T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, and
T3: a distance along the optical axis from the image-side surface of the third lens to the object-side surface of the fourth lens.
6. The imaging lens according to claim 5 , wherein an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis.
7. The imaging lens according to claim 5 , wherein a below conditional expression (6) is satisfied:
0.30< T 2/ f< 1.00 (6)
where
T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, and
f: a focal length of the overall optical system of the imaging lens.
8. The imaging lens according to claim 5 , wherein a below conditional expression (1) is satisfied:
3.00<( T 4/ f )×100<5.90 (1)
where
T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens, and
f: a focal length of the overall optical system of the imaging lens.
9. The imaging lens according to claim 5 , wherein a below conditional expression (9) is satisfied:
12< r 3/ f< 40 (9)
where
r3: a paraxial curvature radius of the object-side surface of the second lens, and
f: a focal length of the overall optical system of the imaging lens.
10. The imaging lens according to claim 2 , wherein a below conditional expression (10) is satisfied:
6.50< r 5/ f< 42.00 (10)
where
r5: a paraxial curvature radius of the object-side surface of the third lens, and
f: a focal length of the overall optical system of the imaging lens.
11. The imaging lens according to claim 5 , wherein a below conditional expression (8) is satisfied:
1.20< D 1/ D 2<3.70 (8)
where
D1: a thickness along the optical axis of the first lens, and
D2: a thickness along the optical axis of the second lens.
12. The imaging lens according to claim 2 , wherein a below conditional expression (12) is satisfied:
−62<( D 1/ f 1)×100<−29 (12)
where
D1: a thickness along the optical axis of the first lens, and
f1: a focal length of the first lens.
13. An imaging lens comprising in order from an object side to an image side,
a first lens,
a second lens having negative refractive power near the optical axis,
a third lens having a convex surface facing the image side near the optical axis,
a fourth lens, and
a fifth lens, wherein an object-side surface of said second lens has a convex surface facing the object side near the optical axis, an image-side surface of said fifth lens has a convex surface facing the image side near the optical axis, and below conditional expressions (1), (3), and (5) are satisfied:
3.00<( T 4/ f )×100<5.90 (1)
1.60< T 1/ f< 3.70 (3)
−19.5<( D 5/ f 5)×100<−9.00 (5)
where
T4: a distance along the optical axis from the image-side surface of the fourth lens to the object-side surface of the fifth lens,
f: a focal length of the overall optical system of the imaging lens,
T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens
D5: a thickness along the optical axis of the fifth lens, and
f5: a focal length of the fifth lens.
14. The imaging lens according to claim 13 , wherein said first lens has negative refractive power near the optical axis.
15. The imaging lens according to claim 13 , wherein a below conditional expression (7) is satisfied:
1.50< T 1/ T 2<5.30 (7)
where
T1: a distance along the optical axis from the image-side surface of the first lens to the object-side surface of the second lens, and
T2: a distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens.
16. The imaging lens according to claim 13 , wherein a below conditional expression (10) is satisfied:
6.50< r 5/ f< 42.00 (10)
where
r5: a paraxial curvature radius of the object-side surface of the third lens, and
f: a focal length of the overall optical system of the imaging lens.
17. The imaging lens according to claim 13 , wherein a below conditional expression (12) is satisfied:
−62<( D 1/ f 1)×100<−29 (12)
where
D1: a thickness along the optical axis of the first lens, and
f1: a focal length of the first lens.