REDUCING LENS AND IMAGE INPUT DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To realize a superior wide-angle and low-cost lens with high resolution and a large aperture ratio, and to make a small-sized, low-cost image input device having high resolution and fast read performances. SOLUTION: The reducing lens 901 is constituted by arranging 1st to 4th lens groups sequentially from the object side (left side) to the image side (right side). The 1st lens group comprises a cemented lens consisting of a positive meniscus lens which is convex to the object side and a negative meniscus lens which is convex to the object side. The 2nd lens group comprises a negative meniscus lens which is convex to the object side. The 3rd lens group comprises a cemented lens consisting of a negative meniscus lens which is concave to the object side and a positive meniscus lens which is concave to the object side. The 4th lens group comprises a cemented lens consisting of a negative meniscus lens which is concave to the object side and a positive meniscus lens which is concave to the object side. COPYRIGHT: (C)2004,JPO