| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact imaging lens that is low-priced and nonetheless attains a photographing angle of view of about 180° at all angles of view and an excellent optical performance.SOLUTION: An imaging lens for a solid state imaging device is provided that comprises, in order from an object side toward an image side, : a first lens which has negative refractive power with a convex surface directed at the object side and whose surface on the image side is aspherical; a second lens which has negative refractive power with a concave surface directed at the image side and whose both surfaces are aspherical; a third lens that has positive refractive power; an aperture stop; and a fourth lens that has positive refractive power. In the imaging lens, the first lens and the second lens are made of a plastic material, and the imaging lens satisfies following expressions (1) and (2). (1)-65.0<f1/f<-17.0, and (2)0.04<f2/f1<0.14 where f denotes a focal length of an entire imaging lens system, f1 denotes a focal length of the first lens, and f2 denotes a focal length of the second lens. |
