| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens capable of suppressing occurrence of an undesirable ghost image while maintaining good optical performance. SOLUTION: The imaging lens 1 includes: a stop; and a lens group GP disposed between the stop and an imaging plane and having a positive power as a whole. The lens group GP has an air lens formed by an air gap between lenses adjacent to each other, and the imaging lens satisfies conditional expression (1): -8<L×(1/Ra<SB>2</SB>-1/Ra<SB>1</SB>)<-3, where Ra<SB>1</SB>represents a radius of curvature of an object-side surface of the air lens which has a convex shape and is closest to an image side in the lens group GP, Ra<SB>2</SB>represents a radius of curvature of an image-side surface of the air lens, and L represents a distance on an optical axis from an object-side surface of a lens closest to an object side in the entire system to the imaging plane. COPYRIGHT: (C)2009,JPO&INPIT
|
