ZOOM LENS AND ELECTRONIC IMAGE PICKUP DEVICE HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a zoom lens eliminating the need of start-up time to a using condition as seen in a collapsible mount type lens barrel, desirable in terms of water- proof and dust-proof effects, easily taking constitution to bend the optical path of an optical system by a catoptric element in order to make a camera extremely thin in the depth direction, having high optical specifications concerning zoom ratio, the angle of view, and F-value, and being little in aberration, and further capable of shortening the length obtained after bonding the optical path, and to provide an electronic image pickup device having the zoom lens. SOLUTION: The zoom lens is provided with a lens group G1 nearest to an object side, which is fixed on an optical axis at the time of varying power and at the time of focusing operation, a lens group G5 nearest to an image side, which is fixed on the optical axis at least at the time of focusing operation, and lens group G2 to G4 positioned between the lens groups G1 and G5 and moving on the optical axis at the time of varying power. The lens group G5 is constituted of a negative lens component L11, the catoptric element R1 having a reflection surface for bending the optical path, and a positive lens component L12in order from the object side, and is provided with at least one aspherical surface. COPYRIGHT: (C)2004,JPO