Patent ID: 7405890

Claim:
An imaging lens, comprising: 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 which is a lens having a negative power whose concave surface faces the image surface side, a third lens which is a lens having a positive power whose convex surface faces the object side, a diaphragm, and a fourth lens which is a 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≦d 2 /fl≦2.0 (1) 0≦d 4 /fl≦2.0 (2) −4.5≦f 2 /fl≦−1.5 (3) −4.5≦(r 5 −r 6 )/(r 5 +r 6 )≦−0.2 (4) where, fl: focal distance of the entire lens system f 2 : focal distance of the second lens d 2 : space between the first lens and the second lens on an optical axis d 4 : space between the second lens and the third lens on the optical axis r 5 : center radius curvature of the object side face of the third lens r 6 : center radius curvature of the imaging surface side face of the third lens.