Patent ID: 6781769
Filing Date: 2004-08-24
Classification: G02B

Abstract:
A three-unit zoom lens comprising: in order from an object side,a first lens unit with positive refracting power; a second lens unit with positive refracting power; and a third lens unit with negative refracting power, said first lens unit, said second lens unit, and said third lens unit being moved toward said object side so that when a magnification of said zoom lens is changed, extending from a wide-angle position to a telephoto position, a space between said first lens unit and said second lens unit, after being increased as said first lens unit and said second lens unit are moved from said wide-angle position toward a proximity of a middle position, is decreased as said first lens unit and said second lens unit are moved toward said telephoto position, and a space between said second lens unit and said third lens unit is also decreased accordingly, wherein said three-unit-zoom lens has a variable magnification ratio of 2 or higher and said first lens unit consists of a single lens element.