Zoom lens and image pickup apparatus having the same

摘要

A zoom lens includes a lens unit Ln having negative refractive power including two or less lenses moving during focusing and zooming, a lens unit Lp1 having positive refractive power disposed adjacent to an object side thereof, and a lens unit Lp2 having positive refractive power disposed adjacent to an image side thereof. The lens units Lp1 and Lp2 move during zooming. A distance Tlw between a lens surface nearest to the object side in the entire zoom lens and an image plane at a wide-angle end, a distance Dnw between the lens surface nearest to the image side of the lens unit Ln and the image plane at the wide-angle end, a back focus bfw at the wide-angle end, and a maximum amount of movement Mnz during focusing of the lens unit Ln at a telephoto end are appropriately set.

主权项

1. A zoom lens comprising:
a lens unit Ln having negative refractive power; a lens unit Lp1 having positive refractive power; and a lens unit Lp2 having positive refractive power, wherein the lens unit Ln includes two or less lenses and moves during focusing and zooming, the lens unit Lp1 is disposed adjacent to an object side of the lens unit Ln, the lens unit Lp2 is disposed adjacent to an image side of the lens unit Ln, and the lens unit Lp1 and the lens unit Lp2 move together during zooming, and wherein the zoom lens satisfies the following conditions:
0.2<(Dnw−bfw)/(Tlw−bfw)<0.80.3<−Mnz/Mfnt<1.0 where Tlw denotes a distance between a lens surface of the entire zoom lens nearest to the object side and an image plane at a wide-angle end, Dnw denotes a distance between a lens surface of the lens unit Ln nearest to the image side and the image plane at the wide-angle end, bfw denotes a back focus at the wide-angle end, Mfnt denotes a maximum amount of focusing movement of the lens unit Ln at a telephoto end by assuming movement from the object side to the image side to be positive during focusing from infinite distance to close distance, and Mnz denotes an amount of change in distance between the lens unit Ln and the lens unit Lp1 during zooming from the wide-angle end to the telephoto end by assuming an increase in the distance to be positive.