Image capturing optical system, image capturing device and electronic device

1. An image capturing optical system comprising in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex;

a second lens element having negative refractive power;

a third lens element having an object-side surface being convex;

a fourth lens element; and

a fifth lens element having an image-side surface being concave;

wherein a total number of lens elements in the image capturing optical system is five, there is an air gap between each of adjacent lens elements of the image capturing optical system, a curvature radius of an object-side surface of the fourth lens element and a curvature radius of an image-side surface of the fourth lens element have the same sign;

wherein an effective radius of the object-side surface of the first lens element is SD11, an effective radius of the image-side surface of the fifth lens element is SD52, half of the maximal field of view of the image capturing optical system is HFOV, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, and the following conditions are satisfied:

1.0< SD 11/ SD 52<1.6;

0<tan (HFOV)<0.45; and

1.0< CT 1/( CT 2+ CT 3).

2. The image capturing optical system of claim 1 , wherein the fourth lens element has positive refractive power.

3. The image capturing optical system of claim 1 , wherein the central thickness of the first lens element is CT1, the central thickness of the second lens element is CT2, the central thickness of the third lens element is CT3, and the following condition is satisfied:

1.28≤ CT 1/( CT 2+ CT 3).

4. The image capturing optical system of claim 1 , wherein a maximum among refractive indexes of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element is Nmax, and the following condition is satisfied:

1.50<Nmax<1.75.

5. The image capturing optical system of claim 1 , wherein the second lens element has an image-side surface being concave and the third lens element has an image-side surface being concave.

6. The image capturing optical system of claim 1 , wherein the half of the maximal field of view of the image capturing optical system is HFOV, and the following condition is satisfied:

0<tan (HFOV)≤0.25.

7. The image capturing optical system of claim 1 , wherein the effective radius of the object-side surface of the first lens element is SD11, the effective radius of the image-side surface of the fifth lens element is SD52, and the following condition is satisfied:

1.09≤ SD 11/ SD 52<1.60.

8. The image capturing optical system of claim 1 , further comprising a prism.

9. The image capturing optical system of claim 1 , wherein a focal length of the second lens element is f2, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a focal length of the y-th lens element is fy, and the following condition is satisfied:

| f 2|<| fy|, y= 3,4,5.

10. The image capturing optical system of claim 1 , wherein the central thickness of the first lens element is a maximum among central thicknesses of the first lens element, the third lens element, the fourth lens element and the fifth lens element.

11. An image capturing device comprising the image capturing optical system of claim 1 and an image sensor disposed on an image surface of the image capturing optical system.

12. An electronic device comprising the image capturing device of claim 11 .

13. An image capturing optical system comprising in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex;

a second lens element having negative refractive power;

a third lens element having an object-side surface being convex;

a fourth lens element having an object-side surface being convex and an image-side surface being concave; and

a fifth lens element having an image-side surface being concave;

wherein a total number of lens elements in the image capturing optical system is five, there is an air gap between each of adjacent lens elements of the image capturing optical system, a central thickness of the first lens element is larger than a central thickness of the second lens element;

wherein an effective radius of the object-side surface of the first lens element is SD11, an effective radius of the image-side surface of the fifth lens element is SD52, half of the maximal field of view of the image capturing optical system is HFOV, a focal length of the second lens element is f2, a focal length of the third lens element is f3, and the following conditions are satisfied:

1.0< SD 11/ SD 52<1.6;

0<tan (HFOV)<0.45; and

| f 2|<| f 3|.

14. The image capturing optical system of claim 13 , wherein the focal length of the second lens element is f2, a focal length of the first lens element is f1, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a focal length of the y-th lens element is fy, and the following condition is satisfied:

| f 2|<| fy|, y= 1,4,5.

15. The image capturing optical system of claim 13 , wherein the half of the maximal field of view of the image capturing optical system is HFOV, and the following condition is satisfied:

0<tan (HFOV)≤0.25.

16. The image capturing optical system of claim 13 , wherein the third lens element has positive refractive power.

17. The image capturing optical system of claim 13 , wherein a maximum among refractive indexes of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element is Nmax, and the following condition is satisfied:

1.50<Nmax<1.75.

18. The image capturing optical system of claim 13 , further comprising a prism.

19. The image capturing optical system of claim 13 , wherein the central thickness of the first lens element is a maximum among central thicknesses of the first lens element, the third lens element, the fourth lens element and the fifth lens element.

20. The image capturing optical system of claim 13 , wherein a focal length of the image capturing optical system is f, a focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a focal length of the x-th lens element is fx, and the following condition is satisfied:

6.0<Σ| f/fx|, x= 1,2,3,4,5.

21. The image capturing optical system of claim 13 , wherein a focal length of the first lens element is f1, the focal length of the second lens element is f2, and the following condition is satisfied:

−0.88< f 2/ f 1<0.

22. An image capturing device comprising the image capturing optical system of claim 13 and an image sensor disposed on an image surface of the image capturing optical system.

23. An electronic device comprising the image capturing device of claim 22 .

24. An image capturing optical system comprising in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex and an image-side surface being convex;

a second lens element having negative refractive power;

a third lens element having an object-side surface being convex;

a fourth lens element having an object-side surface being convex and an image-side surface being concave; and

a fifth lens element having an image-side surface being concave;

wherein a total number of lens elements in the image capturing optical system is five, there is an air gap between each of adjacent lens elements of the image capturing optical system;

wherein an effective radius of the object-side surface of the first lens element is SD11, an effective radius of the image-side surface of the fifth lens element is SD52, half of the maximal field of view of the image capturing optical system is HFOV, a focal length of the second lens element is f2, a focal length of the third lens element is f3, and the following conditions are satisfied:

1.0< SD 11/ SD 52<1.6;

0<tan (HFOV)<0.45; and

| f 2|<| f 3|.

25. The image capturing optical system of claim 24 , wherein a focal length of the first lens element is f1, the focal length of the second lens element is f2, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a focal length of the y-th lens element is fy, and the following condition is satisfied:

| f 2|<| fy|, y= 1,4,5.

26. The image capturing optical system of claim 24 , wherein the half of the maximal field of view of the image capturing optical system is HFOV, and the following condition is satisfied:

0<tan (HFOV)≤0.25.

27. The image capturing optical system of claim 24 , wherein a maximum among refractive indexes of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element is Nmax, and the following condition is satisfied:

1.50<Nmax<1.75.

28. The image capturing optical system of claim 24 , further comprising a prism.

29. The image capturing optical system of claim 24 , wherein a focal length of the image capturing optical system is f, a focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a focal length of the x-th lens element is fx, and the following condition is satisfied:

6.0<Σ| f/fx|, x= 1,2,3,4,5.

30. The image capturing optical system of claim 24 , wherein the effective radius of the object-side surface of the first lens element is SD11, the effective radius of the image-side surface of the fifth lens element is SD52, and the following condition is satisfied:

1.09≤ SD 11/ SD 52<1.6.