Imaging optical lens assembly, image capturing apparatus and electronic device

1. An imaging optical lens assembly, comprising five lens elements, the five 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 and a fifth lens element; each of the five lens elements comprising an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein the first lens element has negative refractive power and the object-side surface being concave in a paraxial region thereof and having at least one convex surface in an off-axis region thereof, the second lens element has positive refractive power, the third lens element has positive refractive power, the fourth lens element has positive refractive power, the fifth lens element has negative refractive power and the image-side surface being concave in a paraxial region thereof and having at least one convex surface in an off-axis region thereof;

wherein an axial distance between the object-side surface of the first lens element and an image surface is TL, a maximum image height of the imaging optical lens assembly is ImgH, and the following condition is satisfied:

TL /Img H <3.0.

2. The imaging optical lens assembly of claim 1 , wherein the object-side surface of the third lens element is convex in a paraxial region thereof and the image-side surface of the third lens element is concave in a paraxial region thereof.

3. The imaging optical lens assembly of claim 1 , wherein the image-side surface of the second lens element is convex in a paraxial region thereof and the image-side surface of the fourth lens element is convex in a paraxial region thereof.

4. The imaging optical lens assembly of claim 1 , wherein a vertical distance between an off-axial critical point on the object-side surface of the first lens element and an optical axis is Yc11, a vertical distance between an off-axial critical point on the image-side surface of the fifth lens element and the optical axis is Yc52, and the following condition is satisfied:

0.15< Yc 11/ Yc 52<1.20.

5. The imaging optical lens assembly of claim 1 , wherein an axial distance between the image-side surface of the fifth lens element and an image surface is BL, the maximum image height of the imaging optical lens assembly is ImgH, and the following condition is satisfied:

BL /Img H ≤0.55.

6. The imaging optical lens assembly of claim 1 , further comprises an aperture stop disposed between the first lens element and the second lens element, wherein a focal length of the first lens element is f1, 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, and the following conditions are satisfied:

| f 1|>| f 2|, | f 1|>| f 4|, | f 1|>| f 5|; and

| f 3|>| f 2|, | f 3|>| f 4|, | f 3|>| f 5|.

7. An imaging optical lens assembly, comprising five lens elements, the five 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 and a fifth lens element; each of the five lens elements comprising an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein the first lens element has negative refractive power and the object-side surface being concave in a paraxial region thereof, the fifth lens element has negative refractive power, the image-side surface of the fifth lens element is concave in a paraxial region thereof and has at least one convex surface in an off-axis region thereof, an aperture stop is disposed between the first lens element and the second lens element;

wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, and the following condition is satisfied:

f 1/ f 3<2.0.

8. The imaging optical lens assembly of claim 7 , wherein the third lens element has positive refractive power.

9. The imaging optical lens assembly of claim 7 , wherein the object-side surface of the third lens element is convex in a paraxial region thereof and the image-side surface of the third lens element is concave in a paraxial region thereof.

10. The imaging optical lens assembly of claim 7 , wherein the image-side surface of the first lens element is concave in a paraxial region thereof, the second lens element has positive refractive power, the fourth lens element has positive refractive power and the image-side surface being convex in a paraxial region thereof.

11. The imaging optical lens assembly of claim 7 , wherein an Abbe number of the fifth lens element is V5, and the following condition is satisfied:

V 5<30.

12. The imaging optical lens assembly of claim 7 , wherein a vertical distance between a maximum effective diameter position on the image-side surface of the fifth lens element and an optical axis is Y52, a focal length of the imaging optical lens assembly is f, and the following condition is satisfied:

0.85< Y 52/ f.

13. The imaging optical lens assembly of claim 7 , wherein a projected point on an optical axis from an effective radius position of the object-side surface of the first lens element is closer to the image side than an axial vertex of the object-side surface of the first lens element to the image side.

14. An imaging optical lens assembly, comprising five lens elements, the five 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 and a fifth lens element; each of the five lens elements comprising an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein the first lens element has negative refractive power and the object-side surface being concave in a paraxial region thereof, the fourth lens element has positive refractive power, the fifth lens element has the image-side surface being concave in a paraxial region thereof and having at least one convex surface in an off-axis region thereof, an aperture stop is disposed between the first lens element and the second lens element;

wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, a curvature radius of the object-side surface of the first lens element is R1, a focal length of the imaging optical lens assembly is f, and the following conditions are satisfied:

f 1/ f 3<5.0; and

−10.0< R 1/ M< 0.

15. The imaging optical lens assembly of claim 14 , wherein the object-side surface of the first lens element is concave in a paraxial region thereof and has at least one convex surface in an off-axis region thereof, the image-side surface of the first lens element is concave in a paraxial region thereof.

16. The imaging optical lens assembly of claim 14 , wherein the second lens element has positive refractive power and the image-side surface being convex in a paraxial region thereof, and the object-side of the fifth lens element is concave in a paraxial region thereof.

17. The imaging optical lens assembly of claim 14 , wherein the curvature radius of the first lens element is R1, the focal length of the imaging optical lens assembly is f, and the following condition is satisfied:

−3.0< R 1/ f< 0.

18. The imaging optical lens assembly of claim 14 , wherein an axial distance between the image-side surface of the fifth lens element and an image surface is BL, a maximum image height of the imaging optical lens assembly is ImgH, an axial distance between the object-side surface of the first lens element and the image surface is TL, and the following conditions are satisfied:

BL /Img H <0.75; and

TL /Img H <2.40.

19. The imaging optical lens assembly of claim 14 , wherein a vertical distance between an off-axial critical point on the object-side surface of the first lens element and an optical axis is Yc11, a vertical distance between an off-axial critical point on the image-side surface of the fifth lens element and the optical axis is Yc52, and the following condition is satisfied:

0.15< Yc 11/ Yc 52<1.20.

20. The imaging optical lens assembly of claim 14 , wherein a focal length of the first lens element is f1, 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, and the following conditions are satisfied:

| f 1|>| f 2|, | f 1|>| f 4|, | f 1|>| f 5|; and

| f 3|>| f 2|, | f 3|>| f 4|, | f 3|>| f 5|.

21. The imaging optical lens assembly of claim 14 , wherein the focal length of the imaging optical lens assembly is f, a maximum image height of the imaging optical lens assembly is ImgH, and the following condition is satisfied:

1.20<Img H/f< 1.70.

22. An image capturing apparatus, comprising the imaging optical lens assembly of claim 14 and an image sensor disposed on an image surface of the imaging optical lens assembly.

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

24. An imaging optical lens assembly, comprising five lens elements, the five 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 and a fifth lens element; each of the five lens elements comprising an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein the first lens element has the object-side surface being concave in a paraxial region thereof and having at least one convex surface in an off-axis region thereof, the second lens element has the image-side surface being convex in a paraxial region thereof, the third lens element has the image-side surface being concave in a paraxial region thereof, the fifth lens element has negative refractive power and the object-side surface being concave in a paraxial region thereof, the image-side surface of the fifth lens element is concave in a paraxial region thereof and has at least one convex surface in an off-axis region thereof;

wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, and the following condition is satisfied:

f 1/ f 3<2.0.

25. The imaging optical lens assembly of claim 24 , wherein the first lens element has negative refractive power, the fourth lens element has positive refractive power and the image-side surface being convex in a paraxial region thereof.

26. The imaging optical lens assembly of claim 24 , wherein the object-side surface of the third lens element is convex in a paraxial region thereof and the image-side surface of the third lens element is concave in a paraxial region thereof.

27. The imaging optical lens assembly of claim 24 , wherein an axial distance between the image-side surface of the fifth lens element and an image surface is BL, a maximum image height of the imaging optical lens assembly is ImgH, an axial distance between the object-side surface of the first lens element and the image surface is TL, and the following conditions are satisfied:

BL /Img H <0.75; and

TL /Img H <2.22.

28. The imaging optical lens assembly of claim 24 , wherein a vertical distance between an off-axial critical point on the object-side surface of the first lens element and an optical axis is Yc11, a vertical distance between an off-axial critical point on the image-side surface of the fifth lens element and the optical axis is Yc52, and the following condition is satisfied:

0.15< Yc 11/ Yc 52<1.20.

29. The imaging optical lens assembly of claim 24 , further comprising an aperture stop disposed between the first lens element and the second lens element.