Patent ID: 8228613

Claim:
A wide-angle projection zoom lens, which is telecentric on a reduction side, comprising, in order from a magnification side: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; a fourth lens group having a positive refractive power; and a fifth lens group having a positive refractive power, wherein during zooming from a wide-angle end to a telephoto end, the first lens group and the fifth lens group remain stationary, and the second lens group, the third lens group, and the fourth lens group are movable in a direction of an optical axis so as to narrow a space between the first lens group and the second lens group and widen a space between the fourth lens group and the fifth lens group, and wherein the first lens group includes five lenses having negative, negative, negative, positive, negative refractive powers in order from the magnification side, and in the first lens group, the negative lens closest to the magnification side and the negative lens closest to the reduction side are formed as aspheric lenses made of plastic.