Patent ID: 11860348
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 18:
19. A zoom lens comprising, in order from an object side to an image side:
a first lens unit having a positive refractive power;
a second lens unit having a negative power; and
a rear unit having a positive refractive power as a whole and including one or more lens units,
wherein a distance between adjacent lens units changes during zooming,
wherein the first lens unit includes a first subunit having a positive refractive power and a second subunit disposed on the image side of the first subunit,
wherein the first subunit includes a first positive lens,
wherein the second subunit includes a second positive lens and a first negative lens,
wherein the first positive lens is a lens having the smallest absolute value of a focal length among lenses included in the first subunit,
wherein the first negative lens is a lens having the smallest absolute value of a focal length among negative lenses included in the second subunit, and
wherein the following inequalities are satisfied:

0.10<d11/f11<0.50

0.6<f11/f1<2.0

−8.0<f1/f2<−2.5

0.3<d11/T1<1.2, where d11 is a distance on an optical axis from the first subunit to the second subunit, f11 is a focal length of the first subunit, f1 is a focal length of the first lens unit, f2 is a focal length of the second lens unit, and T1 is a distance on an optical axis from a lens surface closest to an object of the first lens unit to a lens surface closest to an image plane of the first lens unit.