Patent ID: 6885506
Filing Date: 2005-04-26
Classification: G02B

Abstract:
1. A wide-angle zoom lens system comprising a negative first lens group, a positive second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group, in this order from an object; wherein upon zooming from the short focal length extremity to the long focal length extremity, said negative first lens group first moves toward an image and thereafter moves toward said object, the distance between said negative first lens group and said positive second lens group decreases, the distance between said positive second lens group and said positive third lens group decreases, the distance between said positive third lens group and said negative fourth lens group increases, and the distance between said negative fourth lens group and said positive fifth lens group decreases; wherein said wide-angle zoom lens system satisfies the following conditions: wherein dL dL L fw designates the focal length of said entire wide-angle zoom lens system at the short focal length extremity.