| 摘要 |
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|<0.9 &ngr;d1−&ngr;d2>25 where f denotes the focal length of the entire lens system, f2 denotes the focal length of the second lens element, &ngr;d1 denotes the Abbe number of the first lens element, and &ngr;d2 denotes the Abbe number of the second lens element.
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