Optical imaging lens

1. An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements having refracting power arranged sequentially in ascending order from an object side to an image side along an optical axis, each of the first, second, third, fourth, and fifth lens elements having an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:

the first lens element has positive refracting power;

the object-side surface of the second lens element comprises a convex portion in a vicinity of a periphery of the second lens element;

the object-side surface of the third lens element comprises a convex portion in a vicinity of a periphery of the third lens element;

the image-side surface of the fourth lens element comprises a concave portion in a vicinity of a periphery of the fourth lens element;

the object-side surface and the image-side surface of the fifth lens element are aspherical surfaces, and an effective radius of each lens element is smaller or equal to 2.5 mm, the effective radius of each lens element is larger than or equal to 1.1 mm, and an focal length of the optical imaging lens is between 8 mm and 13.5 mm.

2. The optical imaging lens according to claim 1 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the second lens element along the optical axis is represented by T2, and the optical imaging lens further satisfies an inequality: AAG/T2≤4.71.

3. The optical imaging lens according to claim 1 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the first lens element along the optical axis is represented by T1, a central thickness of the fifth lens element along the optical axis is represented by T5, and the optical imaging lens further satisfies an inequality: (AAG+T5)/T1≤3.01.

4. The optical imaging lens according to claim 1 , wherein a distance between the object-side surface of the first lens element and an image plane along the optical axis is represented by TTL, a distance from the image-side surface of the fifth lens element to an image plane along the optical axis is represented by BFL, and the optical imaging lens further satisfies an inequality: TTL/BFL≤3.61.

5. The optical imaging lens according to claim 1 , wherein a distance between the object-side surface of the first lens element and an image plane along the optical axis is represented by TTL, a sum of central thicknesses from the first to the fifth lens elements along the optical axis is represented by ALT, and the optical imaging lens further satisfies an inequality: TTL/ALT≤2.21.

6. The optical imaging lens according to claim 1 , wherein a sum of central thicknesses from the first to the fifth lens elements along the optical axis is represented by ALT, a central thickness of the first lens element along the optical axis is represented by T1, a central thickness of the third lens element along the optical axis is represented by T3, a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: ALT/(T1+T3+T4)≤1.8.

7. The optical imaging lens according to claim 1 , wherein a central thickness of the first lens element along the optical axis is represented by T1, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the fifth lens element along the optical axis is represented by T5, an air gap between the second lens element and the third lens element along the optical axis is represented by G23, an air gap between the third lens element and the fourth lens element along the optical axis is represented by G34, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality: (T2+G23+G34+G45+T5)/T1≤3.3.

8. An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements having refracting power arranged sequentially in ascending order from an object side to an image side along an optical axis, each of the first, second, third, fourth, and fifth lens elements having an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:

the first lens element has positive refracting power and the image-side surface of the first lens element comprises a concave portion in a vicinity of the optical axis and a concave portion in a vicinity of a periphery of the first lens element;

the object-side surface of the second lens element comprises a convex portion in a vicinity of a periphery of the second lens element;

the third lens element has positive refracting power and the object-side surface of the third lens element comprises a convex portion in a vicinity of a periphery of the third lens element;

the image-side surface of the fourth lens element comprises a concave portion in a vicinity of a periphery of the fourth lens element;

the object-side surface and the image-side surface of the fifth lens element are aspherical surfaces;

the optical imaging lens further comprises an aperture stop located between the first lens element and the third lens element; and

an effective radius of each lens element is smaller or equal to 2.5 mm, and the effective radius of each lens element is larger than or equal to 1.1 mm.

9. The optical imaging lens according to claim 8 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, an air gap between the second lens element and the third lens element along the optical axis is represented by G23, and the optical imaging lens further satisfies an inequality: AAG/G23≤4.

10. The optical imaging lens according to claim 8 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: (AAG+T2)/T4≤8.51.

11. The optical imaging lens according to claim 8 , wherein an effective focal length of the optical imaging lens is represented by EFL, a distance from the image-side surface of the fifth lens element to an image plane along the optical axis is represented by BFL, and the optical imaging lens further satisfies an inequality: EFL/BFL≤4.2.

12. The optical imaging lens according to claim 8 , wherein a central thickness of the first lens element along the optical axis is represented by T1, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the fifth lens element along the optical axis is represented by T5, an air gap between the first lens element and the second lens element along the optical axis is represented by G12, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality: (G12+T2+G45+T5)/T1≤2.2.

13. The optical imaging lens according to claim 8 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the fifth lens element along the optical axis is represented by T5, an air gap between the second lens element and the third lens element along the optical axis is represented by G23, and the optical imaging lens further satisfies an inequality: (AAG+T5)/(T2+G23)≤4.2.

14. The optical imaging lens according to claim 8 , wherein a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the third lens element along the optical axis is represented by T3, a central thickness of the fifth lens element along the optical axis is represented by T5, an air gap between the second lens element and the third lens element along the optical axis is represented by G23, an air gap between the third lens element and the fourth lens element along the optical axis is represented by G34, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, and the optical imaging lens further satisfies an inequality: (T2+G23+G34+G45+T5)/T3≤6.

15. An optical imaging lens, comprising first, second, third, fourth, and fifth lens elements as five frontmost lens elements having refracting power arranged sequentially in ascending order from an object side to an image side along an optical axis, each of the first, second, third, fourth, and fifth lens elements having an object-side surface facing toward the object side, an image-side surface facing toward the image side, wherein:

the first lens element has positive refracting power and the image-side surface of the first lens element comprises a concave portion in a vicinity of the optical axis and a concave portion in a vicinity of a periphery of the first lens element;

the object-side surface of the second lens element comprises a convex portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the second lens element;

the object-side surface of the third lens element comprises a convex portion in a vicinity of a periphery of the third lens element;

the image-side surface of the fourth lens element comprises a concave portion in a vicinity of a periphery of the fourth lens element;

the object-side surface and the image-side surface of the fifth lens element are aspherical surfaces;

the optical imaging lens further comprises an aperture stop located between the first lens element and the third lens element; and

an effective radius of each lens element is smaller or equal to 2.5 mm, and the effective radius of each lens element is larger than or equal to 1.1 mm.

16. The optical imaging lens according to claim 15 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the fourth lens element along the optical axis is represented by T4, and the optical imaging lens further satisfies an inequality: AAG/T4≤7.2.

17. The optical imaging lens according to claim 15 , wherein a sum of air gaps from the first to the fifth lens elements along the optical axis is represented by AAG, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the fifth lens element along the optical axis is represented by T5, and the optical imaging lens further satisfies an inequality: (AAG+T2)/T5≤4.6.

18. The optical imaging lens according to claim 15 , wherein an effective focal length of the optical imaging lens is represented by EFL, a sum of central thicknesses from the first to the fifth lens elements along the optical axis is represented by ALT, and the optical imaging lens further satisfies an inequality: EFL/ALT≤2.4.

19. The optical imaging lens according to claim 15 , wherein an air gap between the first lens element and the second lens element along the optical axis is represented by G12, an air gap between the fourth lens element and the fifth lens element along the optical axis is represented by G45, a central thickness of the second lens element along the optical axis is represented by T2, a central thickness of the third lens element along the optical axis is represented by T3, a central thickness of the fifth lens element along the optical axis is represented by T5, and the optical imaging lens further satisfies an inequality: (G12+T2+G45+T5)/T3≤4.1.

20. The optical imaging lens according to claim 15 , wherein an abbe number of the fifth lens element is represented by v5, and the optical imaging lens further satisfies an inequality: v5≤35.