Patent ID: 7050241
Filing Date: 2006-05-23
Classification: G02B

Abstract:
1. A zoom lens system for forming an optical image of a subject on a light-receiving surface of an image sensor that converts the optical image into an electrical signal, the zoom lens system comprising, from an object side thereof, at least a first lens unit, a second lens unit, and a third lens unit, the zoom lens system achieving zooming by varying distances between the lens units, the first lens unit having a negative optical power, the second lens unit having a positive optical power, wherein the zoom lens system fulfills the following condition: where Bf represents an axial distance from a last lens surface to an image plane (in a case where a last lens element is movable during zooming, a minimum axial distance from the last lens surface to the image plane throughout a zoom range); and Y′ represents half a diagonal length of an image-sensing area.