Electronic picture taking apparatus having a zoom lens system

Abstract

An electronic picture taking apparatus comprises a zoom lens system and an image pickup device. The zoom lens system has a type of movement suitable for stable, high performance in the range from infinite to near distance and being thoroughly reduced the thickness. The zoom lens system comprises at least four lens units. A foremost first lens unit on the object side of said zoom lens system has a negative refractive power. Each of three consecutive lens units has variable space on the image side thereof between an adjacent lens unit for performing a zooming operation. A rearmost lens unit of the zoom lens system consists of a single positive lens element having an aspherical surface and being fixed during the zooming operation. The zoom lens system includes an aperture stop moving incorporated with the second lens unit which is adjacent to the first lens unit. The electronic picture taking apparatus satisfies the following condition: 1.5<L2/Y<3.5  (1) wherein L2 is an amount of movement of the second lens unit in the direction of optical axis thereof while performing the zooming operation from a wide angle end to a telephoto end, and Y is a length of a diagonal line of an effective image receiving area of the image pickup device.

Dependencies are inferred from the claim text.