Zoom lens and optical apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorYoshinori Itoh
Life of this patent
Estimating the term…
Abstract
A zoom lens of the negative lead type includes, in order from the object side, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power consisting of one negative lens, and a fourth lens unit of positive refractive power consisting of one positive lens, wherein, during zooming from the wide-angle end to the telephoto end, all the lens units move along an optical axis in such a manner that the separation between the first lens unit and the second lens unit decreases, the separation between the second lens unit and the third lens unit increases and the separation between the third lens unit and the fourth lens unit decreases.
Claims17
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit of negative refractive power;
- a second lens unit of positive refractive power;
- and
- a third lens unit of positive refractive power, said third lens unit consisting of one positive lens, wherein the positive lens in said third lens unit has an aspheric surface,
- wherein, during zooming from a wide-angle end to a telephoto end, all the lens units move along an optical axis in such a manner that the separation between said first lens unit and said second lens unit decreases and the separation between said second lens unit and said third lens unit decreases.
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit of negative refractive power;
- a second lens unit of positive refractive power, said second lens unit consisting of one positive lens and one negative lens, the positive lens and the negative lens of the second lens unit are respectively a single lens spaced from each other;
- and
- a third lens unit of positive refractive power,
- wherein, during zooming from a wide-angle end to a telephoto end, all the lens units move along an optical axis in such a manner that the separation between said first lens unit and said second lens unit decreases and the separation between said second lens unit and said third lens unit decreases.
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit of negative refractive power, said first lens unit including an aspherical lens;
- a second lens unit of positive refractive power;
- and
- a third lens unit of positive refractive power, said third lens unit including an aspherical lens,
- wherein during zooming from a wide-angle end to a telephoto end, all the lens units move along an optical axis in such a manner that the separation between said first lens unit and said second lens unit decreases and the separation between said second lens unit and said third lens unit decreases.
Dependencies are inferred from the claim text.