Patent ID: 7995284

Claim:
A zoom lens, comprising: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a positive refracting power; and a fifth lens group having a positive or negative refracting power; said first, second, third, fourth and fifth lenses being disposed in order from the object side to the image side of said zoom lens; said second lens group and said fourth lens group being moved in the direction of an optical axis upon zooming; said first lens group having a position fixed in the direction of the optical axis upon zooming; said first lens group including a front side lens having a negative refracting power, an optical member for bending an optical path and a rear side lens having a positive refracting power, disposed in order from the object side toward the image side; said third lens group having a position fixed in the direction of the optical axis upon zooming; said zoom lens further comprising an aperture disposed between said second lens group and said third lens group or between said third lens group and said fourth lens group; said zoom lens satisfying the following conditional expressions (1), (2) and (3): 1.8< F 1 /FW< 3.0 (1) 2.0 <D 1 G/FW< 3.3 (2) 2.0 <DIA 11/ DIA 21<3.0 (3) where F1: focal length of said first lens group D1G: thickness of said first lens group on said optical axis FW: focal length of said entire lens system at the wide angle end DIA11: effective diameter of said lens surface on the most object side of said first lens at the wide angle end DIA21: effective diameter of said lens surface on the most object side of said second lens at the wide angle end.