Imaging lens assembly

1. An imaging lens assembly, comprising in order from an object side to an image side:

an aperture stop;

a first lens having a positive refractive power;

a second lens having a negative refractive power;

a third lens having a positive refractive power;

a fourth lens having a negative refractive power; wherein the imaging lens assembly satisfies the following conditions:

1.08≦ f 1/ f≦ 1.20;

−4.00≦ f 2/ f≦− 2.50;

−1.50≦( R 1+ R 2)/( R 1− R 2)≦−1.25;

1.30≦( R 3+ R 4)/( R 3− R 4)≦5.00;

where:

f is a focal length of the imaging lens assembly;

f 1 is a focal length of the first lens;

f 2 is a focal length of the second lens;

R 1 is a curvature radius of the object side surface of the first lens;

R 2 is a curvature radius of the image side surface of the first lens;

R 3 is a curvature radius of the object side surface of the second lens;

R 4 is a curvature radius of the image side surface of the second lens.

2. The imaging lens assembly of claim 1 further satisfies the following conditions:

0.5 f 3/ f 0.75;

1.40 ( R 5+ R 6)/( R 5− R 6) 2.00;

where:

f 3 is a focal length of the third lens;

R 5 is a curvature radius of the object side surface of the third lens;

R 6 is a curvature radius of the image side surface of the third lens.

3. The imaging lens assembly of claim 1 further satisfies the following conditions:

−0.80 f4/f −0.60;

1.20 (R7+R8)/(R7−R8) 2.50;

where:

f 4 is a focal length of the fourth lens;

R 7 is a curvature radius of the object side surface of the fourth lens;

R 8 is a curvature radius of the image side surface of the fourth lens.