Zoom lens and image pickup apparatus including the same

An image pickup apparatus comprising:

• a zoom lens;
• and
• a solid-state image pickup element configured to receive light of an image formed by the zoom lens,
• wherein the zoom lens comprises in order from an object side to an image side:
• a first lens unit providing a positive refractive power;
• a second lens unit providing a negative refractive power;
• and
• a rear lens group providing a positive refractive power over an entire zoom range,
• wherein an interval between each pair of adjacent lens units is changed changes during zooming,
• wherein the rear lens group includes:
• a partial lens system LRp1 providing a positive refractive power and disposed closest to the object side in the rear lens group, the partial lens system LRp1 including at least two positive lenses and at least one negative lens;
• an aperture stop disposed on the image side of the partial lens system LRp1;
• and
• at least one lens unit providing a negative refractive power and disposed between the aperture stop and an image plane,
• wherein the first lens unit and the aperture stop are configured to be positioned closer to the object side at a telephoto end than at a wide angle end, and
• wherein the following conditional expressions are satisfied:
• 0.00<fssFw/LssFw<0.75;
• and
• 3.0<f1/fw<20.0,
• where fssFw represents a combined focal length of a front lens system consisting of all lenses disposed on the object side of to the aperture stop at the wide angle end, LssFw represents an absolute value of a distance on an optical axis from a first lens surface closest to the object side in the zoom lens to the aperture stop at the wide angle end, f1 represents a focal length of the first lens unit, and fw represents a focal length of the zoom lens at the wide angle end.

A zoom lens comprising, in order from an object side to an image side:

• a first lens unit providing a positive refractive power;
• a second lens unit providing a negative refractive power;
• and
• a rear lens group providing a positive refractive power over an entire zoom range,
• wherein an interval between each pair of adjacent lens units changes during zooming,
• wherein the rear lens group includes, in order from the object side to the image side:
• a third lens unit providing a positive refractive power;
• an aperture stop;
• a fourth lens unit providing a negative refractive power;
• a fifth lens unit providing a positive refractive power;
• and
• a sixth lens unit providing a negative refractive power,
• wherein the first lens unit and the aperture stop are configured to be positioned closer to the object side at a telephoto end than at a wide angle end, and
• wherein the following conditional expressions are satisfied:
• 0.00<fssFw/LssFw<0.75;
• and
• 3.0<f1/fw<20.0,
• where fssFw represents a combined focal length of a front lens system consisting of all lenses disposed on the object side of the aperture stop at the wide angle end, LssFw represents an absolute value of a distance on an optical axis from a first lens surface closest to the object side in the zoom lens to the aperture stop at the wide angle end, f1 represents a focal length of the first lens unit, and fw represents a focal length of the zoom lens at the wide angle end.

An image pickup apparatus comprising:

• a zoom lens;
• and
• a solid-state image pickup element configured to receive light of an image formed by the zoom lens,
• wherein the zoom lens comprises, in order from an object side to an image side:
• a first lens unit providing a positive refractive power;
• a second lens unit providing a negative refractive power;
• and
• a rear lens group providing a positive refractive power over an entire zoom range,
• wherein an interval between each pair of adjacent lens units changes during zooming,
• wherein the rear lens group includes, in order from the object side to the image side:
• a third lens unit providing a positive refractive power;
• an aperture stop;
• a fourth lens unit providing a negative refractive power;
• a fifth lens unit providing a positive refractive power;
• and
• a sixth lens unit providing a negative refractive power,
• wherein the first lens unit and the aperture stop are configured to be positioned closer to the object side at a telephoto end than at a wide angle end, and
• wherein the following conditional expressions are satisfied:
• 0.00<fssFw/LssFw<0.75;
• and
• 3.0<f1/fw<20.0,
• where fssFw represents a combined focal length of a front lens system consisting of all lenses disposed on the object side of the aperture stop at the wide angle end, LssFw represents an absolute value of a distance on an optical axis from a first lens surface closest to the object side in the zoom lens to the aperture stop at the wide angle end, f1 represents a focal length of the first lens unit, and fw represents a focal length of the zoom lens at the wide angle end.