| 摘要 |
<P>PROBLEM TO BE SOLVED: To implement a compact, inexpensive, wide-angle, and high-performance image pickup lens and eliminate restrictions on an image pickup element to be used. <P>SOLUTION: An image pickup lens 1 comprises substantially six lenses, in order from an object side: a negative first lens L1; a negative second lens L2; a positive third lens L3; a positive fourth lens L4; a negative fifth lens L5; and a positive sixth lens L6. The surface on the object side of the second lens L2 is a concave surface, the surface on the image side of the third lens L3 is a convex surface, the fourth lens L4 is a biconvex lens, and the fifth lens L5 is a biconcave lens. When R2 represents the radius of curvature of the surface on the image side of the first lens L1, R4 represents the radius of curvature of the surface on the image side of the second lens L2, and f represents the focal length of the entire system, the image pickup lens satisfies the following conditional expressions (11) and (17): (11) 3.40<R2/f, and (17) R4/f<2.6. <P>COPYRIGHT: (C)2013,JPO&INPIT |
