Optical imaging lens

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

the second lens element has negative refracting power;

at least one of the object-side surface and the image-side surface of the third lens element is an aspherical surface;

at least one of the object-side surface and the image-side surface of the fourth lens element is an aspherical surface;

a periphery region of the object-side surface of the fifth lens element is convex, and an optical axis region of the image-side surface of the fifth lens element is convex;

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

the optical imaging lens comprises no other lenses having refracting power beyond the six lens elements, the ratio of a distance from the object-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis to a sum of the thicknesses of the fifth lens element and the sixth lens element along the optical axis is less than or equal to 1.900, and each of less than or equal to three lens elements has an abbe number which is less than 40.000 in the optical imaging lens.

2. The optical imaging lens according to claim 1 , wherein a thickness of the first lens element along the optical axis is represented by T 1 , a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G 12 , a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis is represented by G 45 , and T 1 , G 12 and G 45 satisfy the inequality:

( T 1+ G 12)/ G 45≤5.700.

3. The optical imaging lens according to claim 1 , wherein a thickness of the first lens element along the optical axis is represented by T 1 , a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G 34 , a thickness of the fourth lens element along the optical axis is represented by T 4 , and T 1 , G 34 and T 4 satisfy the inequality:

( T 1+ G 34)/ T 4≤3.300.

4. The optical imaging lens according to claim 1 , wherein a thickness of the first lens element along the optical axis is represented by T 1 , a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G 12 , a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G 34 , a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis is represented by G 23 , and T 1 , G 12 , G 34 and G 23 satisfy the inequality:

( T 1+ G 12+ G 34)/ G 23≤2.100.

5. The optical imaging lens according to claim 1 , wherein an effective focal length of the optical imaging lens is represented by EFL, a distance from the image-side surface of the sixth lens element to an image plane along the optical axis is represented by BFL, a thickness of the fifth lens element along the optical axis is represented by T 5 , and EFL, BFL and T 5 satisfy the inequality:

(EFL+BFL)/ T 5≤3.800.

6. The optical imaging lens according to claim 1 , wherein an effective focal length of the optical imaging lens is represented by EFL, a thickness of the second lens element along the optical axis is represented by T 2 , and EFL and T 2 satisfy the inequality:

EFL/ T 2≤6.000.

7. The optical imaging lens according to claim 1 , wherein a sum of the thicknesses of all six lens elements along the optical axis is represented by ALT, a distance from the image-side surface of the sixth lens element to an image plane along the optical axis is represented by BFL, a thickness of the fifth lens element along the optical axis is represented by T 5 , and ALT, BFL and T 5 satisfy the inequality:

(ALT+BFL)/ T 5≤5.100.

8. The optical imaging lens according to claim 1 , wherein a distance from the object-side surface of the first lens element to an image plane along the optical axis is represented by TTL, a thickness of the first lens element along the optical axis is represented by T 1 , a thickness of the fifth lens element along the optical axis is represented by T 5 , and TTL, T 1 and T 5 satisfy the inequality:

TTL/( T 1+ T 5)≤5.000.

9. The optical imaging lens according to claim 1 , wherein a distance from the object-side surface of the first lens element to an image plane along the optical axis is represented by TTL, a sum of the thicknesses of all six lens elements along the optical axis is represented by ALT, and TTL and ALT satisfy the inequality:

TTL/ALT≤2.000.

10. The optical imaging lens according to claim 1 , wherein a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by AAG, a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G 12 , a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis is represented by G 23 , and AAG, G 12 and G 23 satisfy the inequality:

AAG/( G 12+ G 23)≤2.000.

11. An optical imaging lens, comprising a first element, a second element, a third element, a fourth element, a fifth lens element and a sixth lens element sequentially from an object side to an image side along an optical axis, each of the first, second, third, fourth, fifth and sixth lens elements having an object-side surface facing toward the object side and allowing imaging rays to pass through and an image-side surface facing toward the image side and allowing the imaging rays to pass through, wherein:

the second lens element has negative refracting power;

at least one of the object-side surface and the image-side surface of the third lens element is an aspherical surface;

at least one of the object-side surface and the image-side surface of the fourth lens element is an aspherical surface;

a periphery region of the object-side surface of the fifth lens element is convex, and an optical axis region of the image-side surface of the fifth lens element is convex;

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

the optical imaging lens comprises no other lenses having refracting power beyond the six lens elements, the ratio of a distance from the object-side surface of the first lens element to the object-side surface of the fifth lens element along the optical axis to a sum of the thicknesses of the fifth lens element and the sixth lens element along the optical axis is less than or equal to 1.900, and a thickness of the first lens element along the optical axis is represented by T 1 , a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis is represented by G 12 , a thickness of the second lens element along the optical axis is represented by T 2 , and T 1 , G 12 and T 2 satisfies the inequality:

( T 1+ G 12)/ T 2≤3.600.

12. The optical imaging lens according to claim 11 , wherein a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G 56 , and T 1 , G 12 , G 56 and T 2 satisfy the inequality:

( T 1+ G 12+ G 56)/ T 2≤4.000.

13. The optical imaging lens according to claim 11 , wherein a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G 34 , a thickness of the third lens element along the optical axis is represented by T 3 , and T 1 , G 12 , G 34 and T 3 satisfy the inequality:

( T 1+ G 12+ G 34)/ T 3≤2.500.

14. The optical imaging lens according to claim 11 , wherein a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G 34 , a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by G 56 , a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis is represented by G 23 , and T 1 , G 12 , G 34 , G 56 and G 23 satisfy the inequality:

( T 1+ G 12+ G 34+ G 56)/ G 23≤2.700.

15. The optical imaging lens according to claim 11 , wherein an effective focal length of the optical imaging lens is represented by EFL, a distance from the image-side surface of the sixth lens element to an image plane along the optical axis is represented by BFL, a thickness of the sixth lens element along the optical axis is represented by T 6 , and EFL, BFL and T 6 satisfy the inequality:

(EFL+BFL)/ T 6≤9.000.

16. The optical imaging lens according to claim 11 , wherein an effective focal length of the optical imaging lens is represented by EFL, a thickness of the fourth lens element along the optical axis is represented by T 4 , and EFL and T 4 satisfy the inequality:

EFL/ T 4≤4.500.

17. The optical imaging lens according to claim 11 , wherein a sum of the thicknesses of all six lens elements along the optical axis is represented by ALT, a thickness of the sixth lens element along the optical axis is represented by T 6 , and ALT and T 6 satisfy the inequality:

ALT/ T 6≤7.700.

18. The optical imaging lens according to claim 11 , wherein 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 is represented by TL, a thickness of the sixth lens element along the optical axis is represented by T 6 , and TL, T 1 and T 6 satisfy the inequality:

TL/( T 1+ T 6)≤5.000.

19. The optical imaging lens according to claim 11 , wherein 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 is represented by TL, a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by AAG, and TL and AAG satisfy the inequality:

TL/AAG≤5.400.

20. The optical imaging lens according to claim 11 , wherein a sum of a distance from the image-side surface of the first lens element to the object-side surface of the second lens element along the optical axis, a distance from the image-side surface of the second lens element to the object-side surface of the third lens element along the optical axis, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis, a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis and a distance from the image-side surface of the fifth lens element to the object-side surface of the sixth lens element along the optical axis is represented by AAG, a distance from the image-side surface of the third lens element to the object-side surface of the fourth lens element along the optical axis is represented by G 34 , a distance from the image-side surface of the fourth lens element to the object-side surface of the fifth lens element along the optical axis is represented by G 45 , and AAG, G 34 and G 45 satisfy the inequality:

AAG/( G 34+ G 45)≤3.900.