Imaging lens

An imaging lens, in the order from the object-side to the image-side of the imaging lens, comprising:

• a first lens of positive refraction power, with two convex surfaces along the optical axis of the imaging lens;
• a second lens of negative refraction power, with a convex surface on the object-side and having a meniscus shape;
• a third lens of positive refraction power, with a convex surface on the image-side and having a meniscus shape;
• a fourth lens of negative refraction power, with a convex surface on the object-side and having a meniscus shape;
• wherein the imaging lens satisfies the following conditions:
• 0.50≦f1/f≦0.75;
• 5.20≦f/d1≦8.00;
• 12.00≦f/d6≦45.00;
• −0.35≦R1/R2≦−0.20;
• and 3.00≦R3/R4≦20.00;
• Wherein:
• f is a focal length of the imaging lens;
• f1 is a focal length of the first lens;
• d1 is a center thickness of the first lens on the optical axis of the imaging lens;
• d6 is a distance between the image-side surface of the third lens and the object-side surface of the fourth lens on the optical axis of imaging lens;
• R1 is a radius of curvature of the object-side surface of the first lens;
• R2 is a radius of curvature of the image-side surface of the first lens;
• R3 is a radius of curvature of the object-side surface of the second lens;
• R4 is a radius of curvature of the image-side surface of the second lens.