Patent ID: 7907353

Claim:
An image pickup lens, comprising: a first lens having a positive refracting power; an aperture stop for adjusting the amount of light; a second lens having a concave face directed to the object side and having a negative refracting power; a third lens having a concave face directed to the object side and having a positive refracting power; and a fourth lens having a negative refracting, power; said first lens, aperture stop, second lens, third lens, and fourth lens being disposed in order from the object side; said image pickup lens satisfying the following conditional expressions (1) and (2), f 2 /f< −1.5 (1) 12<ν 2 <28 (2) where f is the focal length of the entire lens system, f 2 is the focal length of said second lens, and ν 2 is the Abbe number at the d-line, whose wavelength is 587.6 nm, of said second lens.