Imaging lens
An imaging lens includes a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side; a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side; a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side; an aperture diaphragm; a fourth lens having a positive refractive power and a biconvex shape; a fifth lens having a negative refractive power and a biconcave shape and; and a sixth lens having a positive refractive power and a biconvex shape. The imaging lens as a whole is formed with the six lenses in six groups with six independent lenses, the imaging lens has a full angle of view of 150 degrees or more, and the imaging lens satisfies predetermined conditional expressions.
1. An imaging lens comprising, in order from an object side to an image plane side:
a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side;
an aperture diaphragm;
a fourth lens having a positive refractive power and a biconvex shape;
a fifth lens having a negative refractive power and a biconcave shape; and
a sixth lens having a positive refractive power and a biconvex shape,
each of the first, second, third, fourth, fifth, and sixth lenses being independently arranged and being the only lenses within the imaging lens,
the imaging lens having a full angle of view of 150 degrees or more, and satisfying the following conditional expressions (1) and (2):
0<( R 8+ R 9)/( R 8− R 9)<0.4 (1)
2< f 456/ f< 3, (2)
where
R8 is a radius of curvature on an optical axis of an object side surface of the fourth lens,
R9 is a radius of curvature on an optical axis of an image side surface of the fourth lens,
f456 is a composite focal length of the fourth lens, the fifth lens, and the sixth lens, and
f is a focal length of an entire system.
2. The imaging lens according to claim 1 , satisfying the following conditional expression (3):
1.5< D 4/ f< 2.3, (3)
where
D4 is a distance on the optical axis between an image side surface of the second lens and an object side surface of the third lens, and
f is the focal length of the entire system.
3. The imaging lens according to claim 1 , satisfying the following conditional expression (4):
1< D 2/ f< 2, (4)
where
D2 is a distance on the optical axis between an image side surface of the first lens and an object side surface of the second lens, and
f is the focal length of the entire system.
4. The imaging lens according to claim 1 , satisfying the following conditional expression (5):
−8.5< f 1/ f<− 6, (5)
where
f1 is a focal length of the first lens, and
f is the focal length of the entire system.
5. The imaging lens according to claim 1 , satisfying the following conditional expression (6):
5.5< f 3/ f< 8.5, (6)
where
f3 is a focal length of the third lens, and
f is the focal length of the entire system.
6. An imaging lens comprising, in order from an object side to an image plane side:
a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side;
an aperture diaphragm;
a fourth lens having a positive refractive power and a biconvex shape;
a fifth lens having a negative refractive power and a biconcave shape; and
a sixth lens having a positive refractive power and a biconvex shape,
each of the first, second, third, fourth, fifth, and sixth lenses being independently arranged and being the only lenses within the imaging lens,
the imaging lens having a full angle of view of 150 degrees or more, and satisfying the following conditional expressions (1) and (7):
0<( R 8+ R 9)/( R 8− R 9)<0.4 (1)
−4< f 123/ f<− 2.7, (7)
where
R8 is a radius of curvature on an optical axis of an object side surface of the fourth lens,
R9 is a radius of curvature on an optical axis of an image side surface of the fourth lens,
f123 is a composite focal length of the first lens, the second lens, and the third lens, and
f is a focal length of an entire system.
7. The imaging lens according to claim 6 , satisfying the following conditional expression (3):
1.5< D 4/ f< 2.3, (3)
where
D4 is a distance on the optical axis between an image side surface of the second lens and an object side surface of the third lens, and
f is the focal length of the entire system.
8. The imaging lens according to claim 6 , satisfying the following conditional expression (4):
1< D 2/ f< 2, (4)
where
D2 is a distance on the optical axis between an image side surface of the first lens and an object side surface of the second lens, and
f is the focal length of the entire system.
9. The imaging lens according to claim 6 , satisfying the following conditional expression (5):
−8.5< f 1/ f<− 6, (5)
where
f1 is a focal length of the first lens, and
f is the focal length of the entire system.
10. The imaging lens according to claim 6 , satisfying the following conditional expression (6):
5.5< f 3/ f< 8.5, (6)
where
f3 is a focal length of the third lens, and
f is the focal length of the entire system.
11. An imaging lens comprising, in order from an object side to an image plane side:
a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side;
an aperture diaphragm;
a fourth lens having a positive refractive power and a biconvex shape;
a fifth lens having a negative refractive power and a biconcave shape; and
a sixth lens having a positive refractive power and a biconvex shape,
each of the first, second, third, fourth, fifth, and sixth lenses being independently arranged and being the only lenses within the imaging lens,
the imaging lens having a full angle of view of 150 degrees or more, and satisfying the following conditional expressions (1) and (8):
0<( R 8+ R 9)/( R 8− R 9)<0.4 (1)
1.3<( R 1+ R 2)/( R 1− R 2)<1.9, (8)
where
R8 is a radius of curvature on an optical axis of an object side surface of the fourth lens,
R9 is a radius of curvature on an optical axis of an image side surface of the fourth lens,
R1 is a radius of curvature on an optical axis of an object side surface of the first lens, and
R2 is a radius of curvature on an optical axis of an image side surface of the first lens.
12. The imaging lens according to claim 11 , satisfying the following conditional expression (3):
1.5< D 4/ f< 2.3, (3)
where
D4 is a distance on the optical axis between an image side surface of the second lens and an object side surface of the third lens, and
f is a focal length of an entire system.
13. The imaging lens according to claim 11 , satisfying the following conditional expression (4):
1< D 2/ f< 2, (4)
where
D2 is a distance on the optical axis between the image side surface of the first lens and an object side surface of the second lens, and
f is a focal length of an entire system.
14. The imaging lens according to claim 11 , satisfying the following conditional expression (5):
−8.5< f 1/ f<− 6, (5)
where
f1 is a focal length of the first lens, and
f is a focal length of an entire system.
15. The imaging lens according to claim 11 , satisfying the following conditional expression (6):
5.5< f 3/ f< 8.5, (6)
where
f3 is a focal length of the third lens, and
f is a focal length of an entire system.
16. An imaging lens comprising, in order from an object side to an image plane side:
a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side;
an aperture diaphragm;
a fourth lens having a positive refractive power and a biconvex shape;
a fifth lens having a negative refractive power and a biconcave shape; and
a sixth lens having a positive refractive power and a biconvex shape,
each of the first, second, third, fourth, fifth, and sixth lenses being independently arranged and being the only lenses within the imaging lens,
the imaging lens having a full angle of view of 150 degrees or more, and satisfying the following conditional expressions (1) and (9):
0<( R 8+ R 9)/( R 8− R 9)<0.4 (1)
1<( R 3+ R 4)/( R 3− R 4)<1.63, (9)
where
R8 is a radius of curvature on an optical axis of an object side surface of the fourth lens,
R9 is a radius of curvature on an optical axis of an image side surface of the fourth lens,
R3 is a radius of curvature on an optical axis of an object side surface of the second lens, and
R4 is a radius of curvature on an optical axis of an image side surface of the second lens.
17. The imaging lens according to claim 16 , satisfying the following conditional expression (3):
1.5< D 4/ f< 2.3, (3)
where
D4 is a distance on the optical axis between the image side surface of the second lens and an object side surface of the third lens, and
f is a focal length of an entire system.
18. The imaging lens according to claim 16 , satisfying the following conditional expression (4):
1< D 2/ f< 2, (4)
where
D2 is a distance on the optical axis between an image side surface of the first lens and the object side surface of the second lens, and
f is a focal length of an entire system.
19. The imaging lens according to claim 16 , satisfying the following conditional expression (5):
−8.5< f 1/ f<− 6, (5)
where
f1 is a focal length of the first lens, and
f is a focal length of an entire system.
20. The imaging lens according to claim 16 , satisfying the following conditional expression (6):
5.5< f 3/ f< 8.5, (6)
where
f3 is a focal length of the third lens, and
f is a focal length of an entire system.
21. An imaging lens comprising, in order from an object side to an image plane side:
a first lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a second lens having a negative refractive power and a meniscus shape with a convex surface facing an object side;
a third lens having a positive refractive power and a meniscus shape with a convex surface facing an object side;
an aperture diaphragm;
a fourth lens having a positive refractive power and a biconvex shape;
a fifth lens having a negative refractive power and a biconcave shape; and
a sixth lens having a positive refractive power and a biconvex shape,
each of the first, second, third, fourth, fifth, and sixth lenses being independently arranged and being the only lenses within the imaging lens,
the imaging lens having a full angle of view of 150 degrees or more, and satisfying the following conditional expressions (1) and (10):
0<( R 8+ R 9)/( R 8− R 9)<0.4 (1)
2.35< R 5/ f< 5.5, (10)
where
R8 is a radius of curvature on an optical axis of an object side surface of the fourth lens,
R9 is a radius of curvature on an optical axis of an image side surface of the fourth lens,
R5 is a radius of curvature on an optical axis of an object side surface of the third lens, and
f is a focal length of an entire system.
22. The imaging lens according to claim 21 , satisfying the following conditional expression (3):
1.5< D 4/ f< 2.3, (3)
where
D4 is a distance on the optical axis between an image side surface of the second lens and the object side surface of the third lens, and
f is the focal length of the entire system.
23. The imaging lens according to claim 21 , satisfying the following conditional expression (4):
1< D 2/ f< 2, (4)
where
D2 is a distance on the optical axis between an image side surface of the first lens and an object side surface of the second lens, and
f is the focal length of the entire system.
24. The imaging lens according to claim 21 , satisfying the following conditional expression (5):
−8.5< f 1/ f<− 6, (5)
where
f1 is a focal length of the first lens, and
f is the focal length of the entire system.
25. The imaging lens according to claim 21 , satisfying the following conditional expression (6):
5.5< f 3/ f< 8.5, (6)
where
f3 is a focal length of the third lens, and
f is the focal length of the entire system.