Optical imaging lens

1. An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element sequentially arranged along an optical axis from an object side to an image side, each of the first lens element to the sixth lens element comprising an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through, the six lens elements being the only lens elements having refracting power in the optical imaging lens, wherein

an optical axis region of the image-side surface of the second lens element is convex;

an optical axis region of the object-side surface of the third lens element is concave;

an optical axis region of the object-side surface of the fourth lens element is convex;

the fifth lens element has positive refracting power, and an optical axis region of the object-side surface of the fifth lens element is concave; and

the optical imaging lens satisfies: V3−V6≥20.000 and TTL/(T1+T5)≤4.800, wherein V3 is an Abbe number of the third lens element, V6 is an Abbe number of the sixth lens element, TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, T1 is a thickness of the first lens element along the optical axis, and T5 is a thickness of the fifth lens element along the optical axis.

2. The optical imaging lens as claimed in claim 1 , wherein the optical imaging lens satisfies: (T1+G12)/(G23+G34+G56)≥3.600, wherein G12 is an air gap from the first lens element to the second lens element along the optical axis, G23 is an air gap from the second lens element to the third lens element along the optical axis, G34 is an air gap from the third lens element to the fourth lens element along the optical axis, and G56 is an air gap from the fifth lens element to the sixth lens element along the optical axis.

3. The optical imaging lens as claimed in claim 1 , wherein the optical imaging lens satisfies: EFL/(T3+G56)≥4.600, wherein EFL is an effective focal length of the optical imaging lens, T3 is a thickness of the third lens element along the optical axis, and G56 is an air gap from the fifth lens element to the sixth lens element along the optical axis.

4. The optical imaging lens as claimed in claim 1 , wherein the optical imaging lens satisfies: AAG/T2≤4.000, wherein AAG is a sum of five air gaps from the first lens element to the sixth lens element along the optical axis, and T2 is a thickness of the second lens element along the optical axis.

5. The optical imaging lens as claimed in claim 1 , wherein the optical imaging lens satisfies: TTL/T5≤7.800.

6. The optical imaging lens as claimed in claim 1 , wherein the optical imaging lens satisfies: ALT/(T4+G56)≥3.700, wherein ALT is a sum of thicknesses of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, and the sixth lens element along the optical axis, T4 is the thickness of the fourth lens element along the optical axis, and G56 is an air gap from the fifth lens element to the sixth lens element along the optical axis.

7. An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element sequentially arranged along an optical axis from an object side to an image side, each of the first lens element to the sixth lens element comprising an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through, the six lens elements being the only lens elements having refracting power in the optical imaging lens, wherein

an optical axis region of the image-side surface of the second lens element is convex;

an optical axis region of the object-side surface of the third lens element is concave;

the fifth lens element has positive refracting power, and an optical axis region of the object-side surface of the fifth lens element is concave; and

the optical imaging lens satisfies: V3−V6≥20.000, TTL/(T1+T5)≤4.800 and AAG/T4≤5.000, wherein V3 is an Abbe number of the third lens element, V6 is an Abbe number of the sixth lens element, TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, T1 is a thickness of the first lens element along the optical axis, T5 is a thickness of the fifth lens element along the optical axis, AAG is a sum of five air gaps from the first lens element to the sixth lens element along the optical axis, and T4 is a thickness of the fourth lens element along the optical axis.

8. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: ALT/(G23+G34+G56)≥10.200, wherein ALT is a sum of thicknesses of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, and the sixth lens element along the optical axis, G23 is the air gap from the second lens element to the third lens element along the optical axis, G34 is the air gap from the third lens element to the fourth lens element along the optical axis, and G56 is the air gap from the fifth lens element to the sixth lens element along the optical axis.

9. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: TTL/(T5+T6)≤6.000, wherein T6 is a thickness of the sixth lens element along the optical axis.

10. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: TTL/(T4+G56)≥13.800, wherein G56 is the air gap from the fifth lens element to the sixth lens element along the optical axis.

11. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: AAG/G45≤6.000, wherein G45 is the air gap from the fourth lens element to the fifth lens element along the optical axis.

12. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: EFL/T5≤4.200, wherein EFL is an effective focal length of the optical imaging lens.

13. The optical imaging lens as claimed in claim 7 , wherein the optical imaging lens satisfies: BFL/T3≥3.100, wherein BFL is a distance from the image-side surface of the sixth lens element to an image plane along the optical axis, and T3 is a thickness of the third lens element along the optical axis.

14. An optical imaging lens, comprising a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element sequentially arranged along an optical axis from an object side to an image side, each of the first lens element to the sixth lens element comprising an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through, the six lens elements being the only lens elements having refracting power in the optical imaging lens, wherein

an optical axis region of the image-side surface of the second lens element is convex;

an optical axis region of the object-side surface of the third lens element is concave;

an optical axis region of the object-side surface of the fifth lens element is concave; and

the optical imaging lens satisfies: V3−V6≥20.000, TTL/(T1+T5)≤4.800 and AAG/T5≤1.800, wherein V3 is an Abbe number of the third lens element, V6 is an Abbe number of the sixth lens element, TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, T1 is a thickness of the first lens element along the optical axis, AAG is a sum of five air gaps from the first lens element to the sixth lens element along the optical axis, and T5 is a thickness of the fifth lens element along the optical axis.

15. The optical imaging lens as claimed in claim 14 , wherein the optical imaging lens satisfies: (G12+T5)/(G23+G34+G56)≥4.500, wherein G12 is the air gap from the first lens element to the second lens element along the optical axis, G23 is the air gap from the second lens element to the third lens element along the optical axis, G34 is the air gap from the third lens element to the fourth lens element along the optical axis, and G56 is the air gap from the fifth lens element to the sixth lens element along the optical axis.

16. The optical imaging lens as claimed in claim 14 , wherein the optical imaging lens satisfies: TL/(T1+T5)≤4.100, wherein TL is a distance from the object-side surface of the first lens element to the image-side surface of the sixth lens element along the optical axis.

17. The optical imaging lens as claimed in claim 14 , wherein the optical imaging lens satisfies: ALT/(T3+G56)≥6.200, wherein ALT is a sum of thicknesses of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, and the sixth lens element along the optical axis, T3 is the thickness of the third lens element along the optical axis, and G56 is the air gap from the fifth lens element to the sixth lens element along the optical axis.

18. The optical imaging lens as claimed in claim 14 , wherein the optical imaging lens satisfies: TTL/(T2+T6)≤5.100, wherein T2 is a thickness of the second lens element along the optical axis, and T6 is a thickness of the sixth lens element along the optical axis.

19. The optical imaging lens as claimed in claim 14 , wherein the optical imaging lens satisfies: TL/(T3+T5)≤4.000, wherein TL is a distance from the object-side surface of the first lens element to the image-side surface of the sixth lens element along the optical axis, and T3 is a thickness of the third lens element along the optical axis.