Patent ID: 6714355
Filing Date: 2004-03-30
Classification: G02B

Abstract:
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, andan object image sensed by said image pickup device is displayed as an electronic image on said display monitor, wherein said zoon lens system comprising, 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 powerand designed to be moveable 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 constantly from the image plane side to the other side for zooming from the wide-angle end to the telephoto end, a fourth lens group having positive refracting power and designed to be moveable for zooming, and upon zooming from the wide-angle end to the telephoto end, a spacing between said first lens group and said second lens group becomes wide, a spacing between said second lens group and said third lens group becomes narrow and a spacing between said third lens group and said fourth lens group becomes wide, 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 positive single lens component convex toward the object side, 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 toward the object side.