| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens, at low cost, which can satisfactorily correct various aberrations while having a small F-number, and can be reduced in thickness as compared with conventional ones while achieving high performance by increasing the number of lenses.SOLUTION: The imaging lens includes, in order from an object side to an image plane side: a first lens with positive refractive power having a convex surface facing the object side near the optical axis; a second lens with positive refractive power having convex surfaces facing the object side and the image plane side near the optical axis; a third lens with negative refractive power having a concave surface facing the image plane side near the optical axis; a fourth lens having at least one aspheric surface; a fifth lens having a meniscus shape and having a concave surface facing the object side near the optical axis; a sixth lens whose both surfaces are aspheric; and a seventh lens with negative refractive power having a concave surface facing the image plane side near the optical axis and whose both surfaces are aspheric. These lenses are arranged without being cemented together. |
