Zoom optical system
AssigneeCanon Kabushiki Kaisha
InventorsManabu Hakko, Koshi Hatakeyama
Life of this patent
Estimating the term…
Abstract
A zoom optical system provided, in order from a reduction side toward a magnification side, with: a first lens unit having positive optical power; a second lens unit having positive optical power; a third lens unit having positive optical power; and a fourth lens unit having negative optical power; wherein the interval between adjacent ones of the first, second, third and fourth lens units is varied during zooming, and in an entire zooming range, a magnification side conjugate position relative to a reduction side conjugate position, and the position of the pupil of the zoom optical system relative to the reduction side conjugate position are substantially immovable.
Claims23
A zoom optical system, comprising, in order from a reduction side to a magnification side:
- a first lens unit having positive optical power;
- a second lens unit having positive optical power;
- a third lens unit having positive optical power;
- and
- a fourth lens unit having negative optical power;
- wherein intervals between adjacent ones of said first, second, third and fourth lens units are varied during zooming, and in an entire zooming range, an magnification side conjugate position relative to a reduction side conjugate position, and the position of a pupil of said zoom optical system relative to the reduction side conjugate position are substantially immovable.
Dependencies are inferred from the claim text.