Patent ID: 7369322
Filing Date: 2008-05-06
Classification: G02B

Abstract:
1. An imaging optical system for imaging light from an object side on an image pickup device, comprising in order from the object side: a first lens group with negative power, which is fixed with respect to an image plane during focusing and zooming; a second lens group with positive power; a third lens group with negative power; a fourth lens group with positive power; and a following lens group, wherein at least a moving lens group constituting the following lens group moves during zooming, and a movement distance MGB of the moving lens group from a wide angle end to a telephoto end, an overall focal length fw at the wide angle end, an over all focal length ft at the telephoto end, a distance LB between the most image side surface and the image plane which is minimum over a full zooming range and a diagonal length y of the image pickup device satisfy the following relationships: