Wide-angle imaging lens
View Patent ↗A wide-angle imaging lens is provided and includes: a first lens, a second lens, and a third lens in this order from the object side. The first lens is a negative meniscus and has a convex surface on the object side; the second lens, at least one surface of which is an aspherical surface; and the third lens is a positive lens and has a convex surface on the image side and at least one surface of the third lens is an aspherical surface. The first len is made of a material having an Abbe number of 40 or more and the third lens is made of a material having an Abbe number of 50 or more. An aperture stop is disposed between the second lens and the third lens.
1. A wide-angle imaging lens comprising: in order from an object side of the wide-angle imaging lens,
a first lens of a negative meniscus lens made of a material having an Abbe number of 40 or more, the first lens having a convex surface on the object side thereof
a second lens, at least one surface of which is an aspherical surface, the second lens having a negative power, wherein an object-side surface of the second lens is shaped to be a concave surface on an optical axis of the second lens;
an aperture stop;
a third lens of a positive lens made of a material having an Abbe number of 50 or more, the third lens having a convex surface on an image side thereof and at least one surface of the third lens being an aspherical surface,
the lenses within said wide-angle imaging lens consisting of said first lens, said second lens and said third lens.
2. The wide-angle imaging lens according to claim 1 , wherein both surfaces in each of the second lens and the third lens are aspherical surfaces.
3. The wide-angle imaging lens according to claim 1 , wherein each of the second lens and the third lens is made of plastics.
4. The wide-angle imaging lens according to claim 1 , wherein each of the second lens and the third lens is made of a material having a coefficient of water absorption of 0.3% or less.
5. The wide-angle imaging lens according to claim 1 , wherein the third lens is made of a polyolefin material.
6. The wide-angle imaging lens according to claim 1 , which has a diagonal angle of view of 140° or more.
7. A wide-angle imaging lens comprising: in order from an object side of the wide-angle imaging lens,
a first lens of a negative meniscus lens made of a material having an Abbe number of 40or more, the first lens having a convex surface on the object side thereof
a second lens, at least one surface of which is an aspherical surface, wherein an object-side surface of the second lens is shaped to be a concave surface on an optical axis of the second lens;
an aperture stop;
a third lens of a positive lens made of a material having an Abbe number of 50 or more, the third lens having a convex surface on an image side thereof and at least one surface of the third lens being an aspherical surface,
the lenses within said wide-angle imaging lens consisting of said first lens, said second lens and said third lens, and
wherein an object-side surface of the second lens is shaped in such a manner as to be a concave surface on an optical axis of the second lens and to decrease in negative power of the object-side surface as a position on the object-side surface goes away from the optical axis.
8. The wide-angle imaging lens according to claim 7 , wherein the object-side surface of the second lens is shaped in such a manner as to change from the concave surface to a convex surface in a peripheral portion of the object-side surface as the position on the object-side surface goes away from the optical axis.
9. The wide-angle imaging lens according to claim 7 , wherein an image-side surface of the second lens is shaped in such a manner as to be a concave surface on optical axis and to increase in negative power of the image-side surface as a position on the image-side surface goes away from the optical axis.
10. The wide-angle imaging lens according to claim 7 , wherein an image-side surface of the second lens is shaped in such a manner as to be a convex surface on the optical axis and to decrease in positive power of the image-side surface as a position on the image-side surface goes away from the optical axis.
11. The wide-angle imaging lens according to claim 8 , wherein an image-side surface of the second lens is shaped in such a manner as to be a concave surface on optical axis and to increase in negative power of the image-side surface as a position on the image-side surface goes away from the optical axis.
12. The wide-angle imaging lens according to claim 8 , wherein an image-side surface of the second lens is shaped in such a manner as to be a convex surface on the optical axis and to decrease in positive power of the image-side surface as a position on the image-side surface goes away from the optical axis.
13. The wide-angle imaging lens according to claim 10 , wherein the image-side surface of the second lens is shaped in such a manner as to change from the convex surface to a concave surface in a peripheral portion of the image-side surface as the position on the image-side surface goes away from the optical axis.
14. The wide-angle imaging lens according to claim 1 , which satisfies:
3<L/BF<7
where L is a distance between an object-side surface of the first lens located at the optical axis and an imaging device surface; and BF is a distance between an image-side surface of the third lens located at the optical axis and the imaging device surface.
15. The wide-angle imaging lens according to claim 1 , which satisfies:
2<|fl/f|<11
where f is a focal length of the wide-angle imaging lens; and fl is a focal length of the first lens.
16. The wide-angle imaging lens according to claim 1 , which satisfies:
L/(2ωx)<2.3
where L is a distance between an object-side surface of the first lens located at the optical axis and an imaging device surface; x is a maximum height of an image; and 2ω is a diagonal angle of view in radian.
17. The wide-angle imaging lens according to claim 7 , which satisfies:
3<L/BF<7
where L is a distance between an object-side surface of the first lens located at the optical axis and an imaging device surface; and BF is a distance between an image-side surface of the third lens located at the optical axis and the imaging device surface.
18. The wide-angle imaging lens according to claim 7 , which satisfies:
2<|fl/f|<11
where f is a focal length of the wide-angle imaging lens; and fl is a focal length of the first lens.
19. The wide-angle imaging lens according to claim 7 , which satisfies:
L/(2ωx)<2.3
where L is a distance between an object-side surface of the first lens located at the optical axis and an imaging device surface; x is a maximum height of an image; and 2ω is a diagonal angle of view in radian.