Imaging lens

An imaging lens which forms an image of an object on a solid-state image sensor and provides brightness with an F-value of 2.5 or less, in which elements are arranged in order from an object side to an image side, comprising:

• an aperture stop;
• a first lens having positive refractive power and a convex surface on the object side;
• a second lens having negative refractive power and a concave surface on the image side;
• a third lens having positive refractive power, a convex surface on the object side, a concave surface on the image side and at least one aspheric surface;
• a fourth lens as a meniscus double-sided aspheric lens having positive refractive power and a convex surface on the image side;
• and
• a fifth lens as a double-sided aspheric lens having negative refractive power, a concave surface on the object side and a concave surface on the image side,
• wherein the aspheric image-side surface of the fifth lens has a pole-change point off an optical axis,
• and conditional expressions (1) and (10) below are satisfied:
• TTL/2ih0.8 (1)
• 1.98≦r7/r8<3.0 (10)
• where
• TTL:
• total track length
• ih:
• maximum image height
• r7:
• curvature radius of the object-side surface of the fourth lens
• r8:
• curvature radius of the image-side surface of the fourth lens.