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

Claim 17:
18. 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<(D1t−D1w)/|f2|<2.0, 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, D1 t is a distance on an optical axis from the first lens unit to the second lens unit at a telephoto end, and D1w is a distance on the optical axis from the first lens unit to the second lens unit at a wide-angle end.