Patent ID: 8922903
Filing Date: 2014-12-30
Classification: G02B

Abstract:
1. A projection zoom lens, substantially consisting of six lens groups, including: a first lens group having a negative refractive power, which is fixed when changing magnification; second, third, fourth, and fifth lens groups that move when changing magnification; and a sixth lens group having a positive refractive power, which is fixed when changing magnification, provided in this order from a magnification side; the reduction side being telecentric; the second lens group being configured to move toward the magnification side when changing magnification from a wide angle end to a telephoto end; the first and second lenses from a reduction side of the fifth lens group being a positive lens and a negative lens, respectively; the sixth lens group being a single positive lens; and the projection zoom lens satisfying Conditional Formula (1) below: wherein fw is the focal length of the entire system at the wide angle end, and f5 is the focal length of the fifth lens group.