Photographing optical lens assembly, image capturing device and electronic device

1. A photographing optical lens assembly comprising six lens elements, the six lens elements being, in order from an object side to an image side:

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;

wherein each of the six lens elements has an object-side surface towards the object side and an image-side surface towards the image side;

wherein each of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element has at least one surface being aspheric;

wherein the first lens element has positive refractive power, the third lens element has negative refractive power, and the sixth lens element has negative refractive power;

wherein a refractive index of the first lens element is N 1 , a refractive index of the second lens element is N 2 , a refractive index of the third lens element is N 3 , a refractive index of the fourth lens element is N 4 , a refractive index of the fifth lens element is N 5 , a refractive index of the sixth lens element is N 6 , a maximum of N 1 , N 2 , N 3 , N 4 , N 5 and N 6 is Nmax, a focal length of the photographing optical lens assembly is f, a maximum image height of the photographing optical lens assembly is ImgH, an Abbe number of the fifth lens element is V 5 , a half of a maximal field of view of the photographing optical lens assembly is HFOV, and the following conditions are satisfied:

N max<1.70;

2.0< f /Img H <5.0;

V 5<30; and

7.5 degrees<HFOV<23.5 degrees.

2. The photographing optical lens assembly of claim 1 , wherein the focal length of the photographing optical lens assembly is f, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

2.35< f /Img H <4.5.

3. The photographing optical lens assembly of claim 1 , wherein the fifth lens element has the object-side surface being concave in a paraxial region thereof and the image-side surface being convex in a paraxial region thereof.

4. The photographing optical lens assembly of claim 1 , wherein each of the fourth lens element, the fifth lens element and the sixth lens element has one surface being concave in a paraxial region thereof and the other surface being convex in a paraxial region thereof.

5. The photographing optical lens assembly of claim 1 , wherein the Abbe number of the fifth lens element is V 5 , and the following condition is satisfied:

V 5≤23.8.

6. The photographing optical lens assembly of claim 1 , wherein the third lens element has the image-side surface being concave in a paraxial region thereof, the six lens elements are made of plastic materials, an axial distance between the object-side surface of the first lens element and an image surface is TL, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

2.0< TL /Img H <3.0.

7. The photographing optical lens assembly of claim 1 , wherein there is no relative displacement among the six lens elements, the focal length of the photographing optical lens assembly is f, an axial distance between the image-side surface of the sixth lens element and an image surface is BL, and the following condition is satisfied:

0< BL/f< 0.25.

8. A photographing optical lens assembly comprising six lens elements, the six lens elements being, in order from an object side to an image side:

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;

wherein each of the six lens elements has an object-side surface towards the object side and an image-side surface towards the image side;

wherein there is an air space between every two lens elements 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 that are adjacent to each other;

wherein each of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element has at least one surface being aspheric;

wherein the first lens element has positive refractive power, the third lens element has negative refractive power, and the sixth lens element has negative refractive power;

wherein a refractive index of the first lens element is N 1 , a refractive index of the second lens element is N 2 , a refractive index of the third lens element is N 3 , a refractive index of the fourth lens element is N 4 , a refractive index of the fifth lens element is N 5 , a refractive index of the sixth lens element is N 6 , a maximum of N 1 , N 2 , N 3 , N 4 , N 5 and N 6 is Nmax, a focal length of the photographing optical lens assembly is f, a maximum image height of the photographing optical lens assembly is ImgH, a curvature radius of the object-side surface of the fourth lens element is R 7 , a curvature radius of the image-side surface of the fourth lens element is R 8 , and the following conditions are satisfied:

N max<1.70;

2.0< f /Img H <5.0; and

−0.3<( R 7− R 8)/( R 7+ R 8)<0.6.

9. The photographing optical lens assembly of claim 8 , wherein the fifth lens element has negative refractive power.

10. The photographing optical lens assembly of claim 8 , wherein the first lens element has the object-side surface being convex in a paraxial region thereof, an entrance pupil diameter of the photographing optical lens assembly is EPD, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

0.8<EPD/Img H <2.0.

11. The photographing optical lens assembly of claim 8 , wherein the focal length of the photographing optical lens assembly is f, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

2.35< f /Img H <4.5.

12. The photographing optical lens assembly of claim 8 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, an axial distance between the image-side surface of the third lens element and the object-side surface of the fifth lens element is Dr 6 r 9 , and the following condition is satisfied:

TD/Dr 6 r 9<3.1.

13. The photographing optical lens assembly of claim 8 , further comprising:

an aperture stop, wherein an axial distance between the aperture stop and the object-side surface of the first lens element is Dsr 1 , an axial distance between the aperture stop and the image-side surface of the first lens element is Dsr 2 , an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, an axial distance between the image-side surface of the third lens element and the object-side surface of the fifth lens element is Dr 6 r 9 , and the following conditions are satisfied:

1.40<| Dsr 1/ Dsr 2|; and

TD/Dr 6 r 9≤2.86.

14. The photographing optical lens assembly of claim 8 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied:

0.30< TD/f< 0.90.

15. The photographing optical lens assembly of claim 8 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied:

0.50< TD/f< 0.85.

16. The photographing optical lens assembly of claim 8 , wherein each of at least two of the first lens element, the second lens element and the third lens element has the object-side surface being convex in a paraxial region thereof and the image-side surface being concave in a paraxial region thereof; each of the fourth lens element, the fifth lens element and the sixth lens element has one surface being concave in a paraxial region thereof and the other one surface being convex in a paraxial region thereof.

17. The photographing optical lens assembly of claim 8 , wherein the object-side surface of the sixth lens element has a surface shape change from concave to convex between a paraxial region and an off-axial region thereof.

18. The photographing optical lens assembly of claim 8 , wherein the image-side surface of the first lens element has a surface shape change from convex to concave between a paraxial region and an off-axial region thereof.

19. A photographing optical lens assembly comprising six lens elements, the six lens elements being, in order from an object side to an image side:

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;

wherein each of the six lens elements has an object-side surface towards the object side and an image-side surface towards the image side;

wherein each of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element has at least one surface being aspheric;

wherein the third lens element with negative refractive power has the image-side surface being concave in a paraxial region thereof, and the fifth lens element has the object-side surface being concave in a paraxial region thereof;

wherein a refractive index of the first lens element is N 1 , a refractive index of the second lens element is N 2 , a refractive index of the third lens element is N 3 , a refractive index of the fourth lens element is N 4 , a refractive index of the fifth lens element is N 5 , a refractive index of the sixth lens element is N 6 , a maximum of N 1 , N 2 , N 3 , N 4 , N 5 and N 6 is Nmax, an entrance pupil diameter of the photographing optical lens assembly is EPD, a maximum image height of the photographing optical lens assembly is ImgH, an Abbe number of the fifth lens element is V 5 , and the following conditions are satisfied:

1.639≤ N max<1.70;

0.8<EPD/Img H <2.0; and

V 5≤23.8.

20. The photographing optical lens assembly of claim 19 , wherein the fourth lens element has the object-side surface being concave in a paraxial region thereof, and the fifth lens element has the image-side surface being convex in a paraxial region thereof.

21. The photographing optical lens assembly of claim 19 , wherein a sum of axial distances between every two lens elements of the six lens elements which are adjacent to each other is ΣAT, an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, and the following condition is satisfied:

0.40<Σ AT/TD.

22. The photographing optical lens assembly of claim 19 , wherein a focal length of the photographing optical lens assembly is f, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

2.35< f /Img H <4.5.

23. The photographing optical lens assembly of claim 19 , wherein the six lens elements are made of plastic materials, an axial distance between the object-side surface of the first lens element and an image surface is TL, the maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied:

2.0< TL /Img H <3.0.

24. The photographing optical lens assembly of claim 19 , wherein the object-side surface of the sixth lens element has a surface shape change from concave to convex between a paraxial region and an off-axial region thereof.

25. The photographing optical lens assembly of claim 19 , wherein the sixth lens element has negative refractive power, there is no relative displacement among the six lens elements, a focal length of the photographing optical lens assembly is f, an axial distance between the image-side surface of the sixth lens element and an image surface is BL, and the following condition is satisfied:

0< BL/f< 0.25.

26. The photographing optical lens assembly of claim 19 , wherein the sixth lens element has one surface being concave in a paraxial region thereof and the other one surface being convex in a paraxial region thereof.

27. The photographing optical lens assembly of claim 19 , wherein the fourth lens element has one surface being concave in a paraxial region thereof and the other surface being convex in a paraxial region thereof, and the photographing optical lens assembly further comprises:

an aperture stop, wherein an axial distance between the aperture stop and the object-side surface of the first lens element is Dsr 1 , an axial distance between the aperture stop and the image-side surface of the first lens element is Dsr 2 , and the following condition is satisfied:

1.40<| Dsr 1/ Dsr 2|

28. An image capturing device, comprising:

the photographing optical lens assembly of claim 19 ; and

a prism disposed on an optical path of the photographing optical lens assembly.

29. An image capturing device, comprising:

the photographing optical lens assembly of claim 19 ; and

an image sensor, wherein the image sensor is disposed on an image surface of the photographing optical lens assembly.

30. An electronic device, comprising:

the image capturing device of claim 29 .