Patent ID: 6308011
Filing Date: 2001-10-23
Classification: G02B

Abstract:
A zoom lens comprising, in order from an object side to an image side:a first lens unit of negative optical power, said first lens unit having an aspherical lens of negative optical power;a stop;a second lens unit of positive optical power, said second lens unit having an aspherical lens of positive optical power; anda third lens unit of positive optical power,wherein, during a variation in magnification from a wide-angle end to a telephoto end, said second lens unit and said stop move in unison toward the object side, and said first lens unit so moves as to compensate for a shift of an image plane resulting from the variation in magnification,wherein said first lens unit is located closest to the object side among all of the lens units, and said second lens unit consists of two positive lens elements and one negative lens element.