Imaging lens

Abstract

It is to provide a super-wide-angle imaging lens that can be reduced in size and weight, maintain excellent optical performance, and is low in cost. The imaging lens comprises, in order from an object side towards an image surface side, a first lens which is a meniscus lens having a negative power whose convex surface faces the object side, a second lens having a negative power whose concave surface faces the image surface side, a third lens having a positive power whose convex surface faces the object side, a diaphragm, and a fourth lens having a positive power whose convex surface faces the image surface side, wherein conditions expressed by each of following expressions (1) to (4) are to be satisfied: 0≦d2/fl≦2.0, 0≦d4/fl≦2.0, −4.5≦f2/fl≦−1.5, and −4.5≦(r5−r6)/(r5+r6)≦−0.2 (where, fl: focal distance of the entire lens system, f2: focal distance of the second lens, d2: space between the first lens and the second lens on the optical axis, and d4: space between the second lens and the third lens on the optical axis.).

Dependencies are inferred from the claim text.