Patent ID: 6704149
Filing Date: 2004-03-09
Classification: G02B

Abstract:
A zoom lens apparatus comprising:a zoom lens system which comprises a plurality of lens units and which achieves zooming by varying unit-to-unit distance, the zoom lens system including a cemented lens element formed by cementing at least two constituent lens elements made of different optical materials together, the cemented lens element having a diffractive optical surface formed at a cemented interface between the two constituent lens elements, the two constituent lens elements having at their respective interfaces with air a radius of curvature different from a radius of curvature that they have at the cemented interface; and an image sensor for converting an optical image formed by the zoom lens system into an electrical signal, wherein the following condition is fulfilled by the zoom lens system |Yâ€²max/PZ|<0.4, wherein Yâ€²max represents a maximum image height, and PZ represents a distance from an image plane to an exit pupil.