Patent attributes
An image pickup lens includes, in order from an object side to an image side, an aperture stop, a first lens element having a positive refractive power, a second lens element having a negative refractive power and a biconcave shape, a third lens element having a positive refractive power and a meniscus shape whose concave surface faces the object side, and a fourth lens element having a negative refractive power. In the image pickup lens, the following conditional expressions are satisfied,0.20<f/|f2|<0.9νd1−νd2>25where f denotes the focal length of the entire lens system, f2 denotes the focal length of the second lens element, νd1 denotes the Abbe number of the first lens element, and νd2 denotes the Abbe number of the second lens element.
