US 11,789,249 B2
Zoom lens and image pickup apparatus
Masao Hori, Tochigi (JP); and Kazuya Shimomura, Saitama (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Jan. 12, 2022, as Appl. No. 17/574,088.
Claims priority of application No. 2021-020779 (JP), filed on Feb. 12, 2021.
Prior Publication US 2022/0269057 A1, Aug. 25, 2022
Int. Cl. G02B 15/163 (2006.01); G02B 13/00 (2006.01); G02B 13/02 (2006.01)
CPC G02B 15/163 (2013.01) [G02B 13/009 (2013.01); G02B 13/02 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A zoom lens comprising, in order from an object side to an image side:
a first lens unit having a positive refractive power; and
a subsequent unit including a plurality of lens units,
wherein the first lens unit is configured not to move for zooming,
wherein a distance between each pair of adjacent lens units changes in zooming,
wherein the subsequent unit includes, in order from the image side to the object side,
a lens unit having a positive refractive power and configured not to move for zooming,
a moving positive lens unit consisting of one or two lenses, having a positive refractive power, and configured to move in zooming, and
a diaphragm configured to move in zooming,
wherein the diaphragm is closer to the object side at the wide-angle end than at the telephoto end, and
wherein the following condition is satisfied:
0.01≤Lwt/Td≤0.25
where Lwt is a distance on an optical axis between a position of the diaphragm at the wide-angle end and a position of the diaphragm at the telephoto end, and Td is a distance on the optical axis from a surface closest to the object side of the zoom lens to an image plane of the zoom lens at the wide-angle end.