US Patent No. 9,279,965

IMAGE PICKUP APPARATUS


Patent No. 9,279,965
Issue Date March 08, 2016
Title Image Pickup Apparatus
Inventorship Tsuyoshi Wakazono, Utsunomiya (JP)
Shohei Kikuchi, Utsunomiya (JP)
Assignee CANON KABUSHIKI KAISHA, Tokyo (JP)

Claim of US Patent No. 9,279,965

7. An image pickup lens comprising in order from an object side to an image side:
a first lens unit;
a stop; and
a second lens unit having a positive refractive power, the second lens unit comprising a second lens sub-unit composed of
one or more positive lenses,

wherein each of the positive lenses included in the second lens sub-unit is made of material, the material satisfying the
following conditions:

62 N2a<1.63;

0.605?(?2a/1000)
dn2a/dTrelative where N2a represents a refractive index at a d-line, v2a represents an Abbe constant, ?2a represents a partial dispersion
ratio, and dn2a/dTrelative represents an absolute value of a differential of refractive indices against temperature at the
d-line, and
wherein the following conditions are satisfied:
0.20
3.00 where f represents a focal length of the image pickup lens, f2a represents a focal length of the second lens sub-unit, TD
represents an overall length of the image pickup lens, and BF represents a distance from an image-side surface of a lens arranged
closest to an image side in the image pickup lens to an image plane of an image pickup element.