Patent ID: 7719773

Claim:
A zoom lens unit comprising, in order from an object side to an image side: a first lens group having a positive refracting power, which is fixed when changing magnification from a wide-angle end to a telephoto end; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a negative refracting power, which is fixed when changing magnification from the wide-angle end to the telephoto end; a fifth lens group having a positive refracting power; and a sixth lens group having a negative refracting power, an aperture stop being disposed between the second lens group and the third lens group, wherein when changing magnification from the wide-angle end to the telephoto end, at least the second lens group, the third lens group and the fifth lens group are moved, and wherein the first lens group includes a reflecting optical element which is configured to bend a light path in the first lens group to obtain a predetermined light path length.