Patent ID: 7236305
Filing Date: 2007-06-26
Classification: G02B,H04N

Abstract:
1. A zoom lens comprising the following elements arranged in the mentioned order from an object side to an image side: a focusing lens unit; a variator lens unit that moves along an optical axis during zooming; a compensator lens unit that moves along the optical axis to compensate image plane variation during zooming; an aperture stop for regulating light quantity; and a relay lens unit that is kept stationary during zooming, wherein the relay lens unit includes a lens unit L wherein the zoom lens satisfies the following conditions: where e 20 represents a distance from the aperture stop to a position of a front side principal point of the lens unit L 21 , e 21 represents a distance from a position of a rear side principal point of the lens unit L 21 to a position of a front side principal point of the lens unit L 22 , e 22 represents a distance from a position of a rear side principal point of the lens unit L 22 to a position of a front side principal point of the lens unit L 23 , Φ 21 represents a refractive power of the lens unit L 21 , and Φ W represents a refractive power of the entire system of the zoom lens at the wide-angle end.