Optical imaging lens

1. An optical imaging lens, from an object side to an image side in order along an optical axis comprising: a first lens element, a second lens element, a third lens element and a fourth lens element, the first lens element to the fourth lens element each has an object-side surface facing toward the object side to allow imaging rays to pass through as well as an image-side surface facing toward the image side to allow the imaging rays to pass through, wherein:

an optical-axis region of the image-side surface of the first lens element is concave;

a periphery region of the image-side surface of the second lens element is convex;

the third lens has positive refracting power;

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

the lens elements having refracting power included by the optical imaging lens are only the four lens elements described above;

wherein, υ 1 is an Abbe number of the first lens element, υ 2 is an Abbe number of the second lens element, υ 3 is an Abbe number of the third lens element and υ 4 is an Abbe number of the fourth lens element, and the optical imaging lens satisfies the relationship: υ 2 ≤30.000 and υ 1 +υ 3 +υ 4 ≤120.000.

2. The optical imaging lens of claim 1 , wherein BFL is a distance from the image-side surface of the fourth lens element to an image plane along the optical axis and ALT is a sum of thickness of all the four lens elements along the optical axis, and the optical imaging lens satisfies the relationship: ALT/BFL≥1.200.

3. The optical imaging lens of claim 1 , wherein AAG is a sum of three air gaps from the first lens element to the fourth lens element along the optical axis and G 23 is an air gap between the second lens element and the third lens element along the optical axis, and the optical imaging lens satisfies the relationship: AAG/G 23 ≤2.200.

4. The optical imaging lens of claim 1 , wherein EFL is an effective focal length of the optical imaging lens, T 1 is a thickness of the first lens element along the optical axis and T 3 is a thickness of the third lens element along the optical axis, and the optical imaging lens satisfies the relationship: EFL/(T 1 +T 3 )≤3.500.

5. The optical imaging lens of claim 1 , 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 and T 3 is a thickness of the third lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 2 +T 3 )/T 1 ≥1.800.

6. The optical imaging lens of claim 1 , 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, G 23 is an air gap between the second lens element and the third lens element along the optical axis and G 34 is an air gap between the third lens element and the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 3 +T 4 )/(G 23 +G 34 )≤3.500.

7. The optical imaging lens of claim 1 , 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, G 12 is an air gap between the first lens element and the second lens element along the optical axis and G 23 is an air gap between the second lens element and the third lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 1 +T 2 )/(G 12 +G 23 )≤2.800.

8. The optical imaging lens of claim 1 , wherein BFL is a distance from the image-side surface of the fourth lens element to an image plane along the optical axis, T 4 is a thickness of the fourth lens element along the optical axis and G 34 is an air gap between the third lens element and the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: BFL/(G 34 +T 4 )≤3.100.

9. The optical imaging lens of claim 1 , wherein TL is a distance from the object-side surface of the first lens element to the image-side surface of the fourth lens element along the optical axis, T 1 is a thickness of the first lens element along the optical axis and G 12 is an air gap between the first lens element and the second lens element along the optical axis and the optical imaging lens satisfies the relationship: TL/(T 1 +G 12 )≥3.200.

10. The optical imaging lens of claim 1 , wherein EFL is an effective focal length of the optical imaging lens and AAG is a sum of three air gaps from the first lens element to the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: EFL/AAG≤3.900.

11. The optical imaging lens of claim 1 , wherein TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis, T 3 is a thickness of the third lens element along the optical axis and T 4 is a thickness of the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: TTL/(T 3 +T 4 )≥3.800.

12. The optical imaging lens of claim 1 , wherein ALT is a sum of thickness of all the four lens elements along the optical axis and T 2 is a thickness of the second lens element along the optical axis, and the optical imaging lens satisfies the relationship: ALT/T 2 ≤4.800.

13. The optical imaging lens of claim 1 , wherein BFL is a distance from the image-side surface of the fourth lens element to an image plane along the optical axis, T 3 is a thickness of the third lens element along the optical axis and T 4 is a thickness of the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 4 +BFL)/T 3 ≤4.500.

14. The optical imaging lens of claim 1 , wherein T 1 is a thickness of the first lens element along the optical axis and T 2 is a thickness of the second lens element along the optical axis, and the optical imaging lens satisfies the relationship: T 2 /T 1 ≥1.000.

15. The optical imaging lens of claim 1 , wherein ALT is a sum of thickness of all the four lens elements along the optical axis and AAG is a sum of three air gaps from the first lens element to the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: ALT/AAG≤4.500.

16. The optical imaging lens of claim 1 , wherein TL is a distance from the object-side surface of the first lens element to the image-side surface of the fourth lens element along the optical axis and BFL is a distance from the image-side surface of the fourth lens element to an image plane along the optical axis, and the optical imaging lens satisfies the relationship: TL/BFL≥1.800.

17. The optical imaging lens of claim 1 , 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, T 4 is a thickness of the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 2 +T 3 +T 4 )/T 1 ≥2.500.

18. The optical imaging lens of claim 1 , 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, T 4 is a thickness of the fourth lens element along the optical axis, and the optical imaging lens satisfies the relationship: (T 1 +T 3 +T 4 )/T 2 ≤3.500.

19. The optical imaging lens of claim 1 , wherein EFL is an effective focal length of the optical imaging lens, T 2 is a thickness of the second lens element along the optical axis and G 23 is an air gap between the second lens element and the third lens element along the optical axis, and the optical imaging lens satisfies the relationship: EFL/(T 2 +G 23 )≤3.000.

20. The optical imaging lens of claim 1 , wherein ALT is a sum of thickness of all the four lens elements along the optical axis and T 1 is a thickness of the first lens element along the optical axis, and the optical imaging lens satisfies the relationship: ALT/T 1 ≥3.500.