Image pickup lens

An image pickup lens comprising, in sequence from an object side to an image side:

• an aperture stop;
• a first lens having two convex surfaces and having a positive refractive power;
• a second lens in a meniscus shape whose convex surface faces to the object side having a negative refractive power;
• a third lens in a meniscus shape with the convex surface facing to the image side having a positive refractive power;
• a fourth lens in a meniscus shape with the convex surface facing to the object side having a negative refractive power;
• wherein
• the following conditions (1)˜(5) are satisfied:
• 0.80≦f1/f≦1.05 (1)
• −1.80≦f2/f≦−1.20 (2)
• −0.70≦R1/R2≦−0.17 (3)
• 4.00≦R3/R4≦70.00 (4)
• 0.10≦d4/f≦0.20 (5) where
• f is the focal length of the entire lens;
• f1 is the focal length of the first lens;
• f2 is the focal length of the second lens;
• R1 is the curvature radius of the object side surface of the first lens;
• R2 is the curvature radius of the image side surface of the first lens;
• R3 is the curvature radius of the object side surface of the second lens;
• R4 is the curvature radius of the image side surface of the second lens;
• d4 is the distance along the optical axis between the image side of the second lens and the object side of the third lens.