ZOOM LENS AND IMAGE PICKUP APPARATUS INCLUDING THE SAME

摘要

A zoom lens including, in order from an object side: a positive first lens unit that does not move for zooming; a negative second lens unit that moves during the zooming; a negative third lens unit that moves along a locus convex to the object side during the zooming; an aperture stop; and a positive fourth lens unit that does not move for the zooming. The third lens unit includes a cemented lens formed by cementing a single negative lens and a single positive lens and a single negative lens. A focal length (fn1) of the single negative lens included in the cemented lens, a focal length (fp) of the single positive lens included in the cemented lens, and a lateral magnification (β3w) of the third lens unit at a wide angle end are each appropriately set.

主权项

1. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having a positive refractive power that does not move for zooming; a second lens unit having a negative refractive power that moves during the zooming; a third lens unit having a negative refractive power that moves along a locus convex to the object side during the zooming; an aperture stop; and a fourth lens unit having a positive refractive power that does not move for the zooming, the third lens unit comprising:
a cemented lens formed by cementing a single negative lens and a single positive lens; anda single negative lens, wherein the following conditional expressions are satisfied:
0.60<|fn1/fp|<0.97; and0.24<β3w<0.53,where fn1 represents a focal length of the single negative lens included in the cemented lens, fp represents a focal length of the single positive lens included in the cemented lens, and β3w represents a lateral magnification of the third lens unit at a wide angle end.