IMAGING LENS
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Accused Products
Abstract
There is provided an imaging lens with high resolution which effectively achieves low-profileness while maintaining the wide field of view, and favorably corrects aberrations.
The imaging lens comprising a first lens having negative refractive power, a second lens having positive refractive power, a third lens, a fourth lens having positive refractive power, a fifth lens having negative refractive power as a double-sided aspheric lens, and a sixth lens as a double-sided aspheric lens, wherein the first lens has a concave surface facing the image side, and the aspheric surface on the image side of the sixth lens is formed as a concave surface near the optical axis and has at least one pole point at an off-axial point, and a below conditional expression (1) is satisfied:
ω≥45° (1)
where
- ω: a half field of view.
0 Citations
28 Claims
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1-13. -13. (canceled)
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14. An imaging lens forming an image of an object on a solid-state image sensor, comprising in order from an object side to an image side,
a first lens having negative refractive power, a second lens, a third lens, a fourth lens, a fifth lens having negative refractive power and is a double-sided aspheric lens, and a sixth lens having negative refractive power and is a double-sided aspheric lens, wherein the third lens has a meniscus shape near an optical axis, and the sixth lens has at least one pole point at an off-axial point on the image-side surface, and below conditional expressions (10b) and (12) are satisfied: -
−
2.1<
f6/f<
−
1.2
(10b)
0.2<
t1/f<
0.6
(12)where f6;
a focal length of the sixth lens,f;
a focal length of the overall optical system, andt1;
a distance along the optical axis between the first lens and the second lens.- View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
where ω
;
a half field of view.
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18. The imaging lens according to claim 14,
wherein a conditional expression below is satisfied: -
0.1<
SAG L1R/r2<
0.6
(2)where SAG L1R;
an amount of sag at the peripheral area of the effective diameter of the image-side surface of the first lens,r2;
a curvature radius of the image-side surface of the first lens.
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-
19. The imaging lens according to claim 14,
wherein a conditional expression below is satisfied: -
0.5<
r2/f<
1.5
(3)where r2;
a curvature radius of an image-side surface of the first lens.
-
-
20. The imaging lens according to claim 14,
wherein the second lens has a convex surface facing the object side near the optical axis. -
21. The imaging lens according to claim 14,
wherein the third lens has a concave surface facing the image side near the optical axis. -
22. The imaging lens according to claim 14,
wherein the fourth lens has a convex surface facing the image side near the optical axis. -
23. The imaging lens according to claim 14,
wherein the sixth lens has a convex surface facing the object side near the optical axis and a concave surface facing the image side near the optical axis. -
24. The imaging lens according to claim 14,
wherein a conditional expression below is satisfied: -
f2−
f4>
0
(4)where f2;
a focal length of the second lens, andf4;
a focal length of the fourth lens.
-
-
25. The imaging lens according to claim 14,
wherein conditional expressions below are satisfied: -
−
2.5<
f1/f<
−
1.0
(5)
0.5<
f2/f<
1.5
(6)
−
6.0<
f3/f<
−
1.5
(7)
0.5<
f4/f<
1.5
(8)
−
6.0<
f5/f<
−
1.5
(9)where f1;
a focal length of the first lens,f2;
a focal length of the second lens,f3;
a focal length of the third lens,f4;
a focal length of the fourth lens, andf5;
a focal length of the fifth lens.
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26. The imaging lens according to claim 14,
wherein a conditional expression below is satisfied: -
1.0<
f456/f<
2.5
(11)where f456;
a composite focal length of the fourth lens, the fifth lens and the sixth lens.
-
-
27. The imaging lens according to claim 14,
wherein a conditional expression below is satisfied: -
0.5<
CA1/ih<
2.0
(13)where CA1;
an effective diameter of an object-side surface of the first lens, andIh;
a maximum image height.
-
-
28. The imaging lens according to claim 14,
wherein conditional expressions below are satisfied: -
0.05<
SAG L1F/CA1<
0.50
(14)
0.05<
SAG L1R/CA2<
0.50
(15)where SAG L1F;
an amount of sag at the peripheral area of the effective diameter of the object-side surface of the first lens,SAG L1R;
an amount of sag at the peripheral area of the effective diameter of the image-side surface of the first lens,CA1;
an effective diameter of the object-side surface of the first lens, andCA2;
an effective diameter of the image-side surface of the first lens.
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Specification