| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens, composed of five lenses, which is a wide angle lens in which various aberrations are satisfactory corrected despite its size smaller than a conventional type, and which has brightness with an F number of 2.6 or smaller.SOLUTION: An imaging lens comprises, in order from an object side, a first lens L1 of positive refractive power, the convex face of which is oriented on the image side; a second lens L2; a third lens L3, a fourth lens L4 of positive refractive power; and a fifth lens L5 of negative refractive power. At least one of the faces of each of the second lens L2 and third lens L3 is aspheric. At least one face of the fifth lens L5 is aspheric and has an inflection point at a position other than the point at which it intersects the optical axis. The imaging lens 10 satisfies the following conditional formulae (1) to (4): (1) 0.14<(r1+r2)/(r1-r2)<3; (2) 0<f/f45<5; (3) 0.015<d4/L<0.25; and (4) 2ω>76°. |
