Patent ID: RE39899

Claim:
An image pickup system including a finder optical system, a display monitor, and an objective optical system comprising a zoom lens system and an electronic image pickup device located on an image side of said zoom lens system, an object image sensed by said pickup device is displayed as an electronic image on said display monitor, wherein said zoom lens system comprises, in order from the object side of said zoom lens, a first lens group having positive refracting power, a second lens group having negative refracting power and designed to move from the object side to an image plane side of the zoom lens system for zooming from a wide-angle end to a telephoto end of said zoom lens system, a third lens group having positive refracting power and designed to move from the image pane side of the object side for zooming from the wide angle end to the telephoto end, and fourth lens group having positive refracting power and designed to be movable for zooming, wherein said first lens group consists of a positive lens component; wherein said second lens group consists of, in order from the object side, a negative lens element convex toward the object side, a bi-concave negative lens element, and a positive lens element convex toward the object side, wherein said third lens group consists of, in order from the object side, a negative single lens component convex to the object side, and a cemented lens component including a bi-convex lens element and a bi-concave lens element, and wherein said fourth lens group consists of a positive single lens component convex to the object side.