Mobile device and optical imaging lens thereof

1. An optical imaging lens comprising, from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element, each of the first, second, third, fourth and fifth lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the first lens element has a positive refracting power, and the object-side surface of the first lens element has a convex portion in a vicinity of an optical axis and a convex portion near a circumference of the first lens element;

the second lens element has a negative refracting power, and the image-side surface of the second lens element has a concave portion in a vicinity of the optical axis;

the object-side surface of the third lens element has a concave portion near a circumference of the third lens element;

the object-side surface of the fourth lens element has a concave portion near a circumference of the fourth lens element, and the image-side surface of the fourth lens element has a convex portion near the circumference of the fourth lens element;

the object-side surface of the fifth lens element has a convex portion near a circumference of the fifth lens element, and the image-side surface of the fifth lens element has a concave portion in a vicinity of the optical axis and a convex portion near a circumference of the fifth lens element;

the optical imaging lens has only five lens elements having a refracting power; and

the optical imaging lens satisfies the following relation:

1400≦ AG 34/ AG 12≦4.615,

wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis, and AG 34 is a width of an air gap between the third and fourth lens elements along the optical axis.

2. The optical imaging lens of claim 1 , wherein a ratio T 5 /AG 23 is between 0.905 and 1.431, wherein T 5 is a thickness of the fifth lens element along the optical axis, and AG 23 is a width of an air gap between the second and third lens elements along the optical axis.

3. The optical imaging lens of claim 1 , wherein a ratio ALT/AG 23 is between 5.852 and 6.894, wherein ALT is a sum of thicknesses of the first to fifth lens elements, and AG 23 is a width of an air gap between the second and third lens elements along the optical axis.

4. An optical imaging lens comprising, from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element, each of the first, second, third, fourth and fifth lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the first lens element has a positive refracting power, and the object-side surface of the first lens element has a convex portion in a vicinity of an optical axis and a convex portion near a circumference of the first lens element;

the second lens element has a negative refracting power, and the image-side surface of the second lens element has a concave portion in a vicinity of the optical axis;

the object-side surface of the third lens element has a concave portion near a circumference of the third lens element;

the object-side surface of the fourth lens element has a concave portion near a circumference of the fourth lens element, and the image-side surface of the fourth lens element has a convex portion near the circumference of the fourth lens element;

the object-side surface of the fifth lens element has a convex portion near a circumference of the fifth lens element, and the image-side surface of the fifth lens element has a concave portion in a vicinity of the optical axis and a convex portion near a circumference of the fifth lens element;

the optical imaging lens has only five lens elements having a refracting power; and

the optical imaging lens satisfies the following relations:

0.601≦ T 5/ T 4≦0.839; and

2.273≦ AAG/T 3≦3.125,

wherein T 3 is a thickness of the third lens element along the optical axis, T 4 is a thickness of the fourth lens element along the optical axis, T 5 is a thickness of the fifth lens element along the optical axis, and AAG is a sum of widths of air gaps between the first to fifth lens elements.

5. The optical imaging lens of claim 4 , wherein a ratio AG 23 /AG 12 is between 2.812 and 7.177, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis, and AG 23 is a width of an air gap between the second and third lens elements along the optical axis.

6. The optical imaging lens of claim 4 , wherein a ratio AAG/AG 12 is between 7.593 and 18.827, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis.

7. The optical imaging lens of claim 4 , wherein a ratio T 3 /AG 12 is between 2.682 and 6.025, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis.

8. The optical imaging lens of claim 4 , wherein a ratio ALT/AG 12 is between 17.820 and 41.996, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis, and ALT is a sum of thicknesses of the first to fifth lens elements.

9. The optical imaging lens of claim 4 , wherein a ratio ALT/AG 34 is between 6.542 and 13.846, wherein AG 34 is a width of an air gap between the third and fourth lens elements along the optical axis, and ALT is a sum of thicknesses of the first to fifth lens elements.

10. An optical imaging lens comprising, from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element, each of the first, second, third, fourth and fifth lens element having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

the first lens element has a positive refracting power, and the object-side surface of the first lens element has a convex portion in a vicinity of an optical axis and a convex portion near a circumference of the first lens element;

the second lens element has a negative refracting power, and the image-side surface of the second lens element has a concave portion in a vicinity of the optical axis;

the object-side surface of the third lens element has a concave portion near a circumference of the third lens element;

the object-side surface of the fourth lens element has a concave portion near a circumference of the fourth lens element, and the image-side surface of the fourth lens element has a convex portion near the circumference of the fourth lens element;

the object-side surface of the fifth lens element has a convex portion near a circumference of the fifth lens element, and the image-side surface of the fifth lens element has a concave portion in a vicinity of the optical axis and a convex portion near a circumference of the fifth lens element;

the optical imaging lens has only five lens elements having a refracting power; and

the optical imaging lens satisfies the following relations:

2564≦ AAG/T 2≦3.451; and

0.705≦ T 1/ T 3≦1.855,

wherein T 1 is a thickness of the first lens element along the optical axis, T 2 is a thickness of the second lens element along the optical axis, T 3 is a thickness of the third lens element along the optical axis, and AAG is a sum of widths of air gaps between the first to fifth lens elements.

11. The optical imaging lens of claim 10 , wherein a ratio T 1 /AG 12 is between 3.574 and 11.173, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis.

12. The optical imaging lens of claim 10 , wherein a ratio T 4 /AG 12 is between 3.730 and 11.282, wherein AG 12 is a width of an air gap between the first and second lens elements along the optical axis.

13. The optical imaging lens of claim 10 , wherein a ratio T 4 /AG 34 is between 1.638 and 2.664, wherein T 4 is a thickness of the fourth lens element along the optical axis, and AG 34 is a width of an air gap between the third and fourth lens elements along the optical axis.

14. The optical imaging lens of claim 10 , wherein a ratio T 5 /AG 34 is between 1.066 and 1.923, wherein T 5 is a thickness of the fifth lens element along the optical axis, and AG 34 is a width of an air gap between the third and fourth lens elements along the optical axis.