Patent ID: 7684122
Filing Date: 2010-03-23
Classification: G02B

Abstract:
1. A zoom lens comprising, in order from its object side, a first lens group having positive power, a second lens group having negative power, a third lens group having positive power, a fourth lens group having positive power and a fifth lens group having negative power, characterized in that: upon zooming from a wide-angle end to a telephoto end of the zoom lens, said first lens group remains fixed with respect to an image plane, and at least said second lens group and said fourth lens group moves, said first lens group includes a reflecting optical element for bending an optical path and has negative refracting power on an object side with respect to a reflecting surface, said fifth lens group includes at least a cemented lens and a positive lens, and said zoom lens satisfies the following condition (1): where f 5 is a focal length of the fifth lens group, and f w is a focal length of the whole zoom lens system at the wide-angle end.