Photographing lens assembly, image capturing unit and electronic device

1. A photographing 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 the second lens element has positive refractive power, the third lens element has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, the sixth lens element has an image-side surface being concave in a paraxial region thereof, and the image-side surface of the sixth lens element has at least one inflection point;

wherein the photographing lens assembly further comprises an aperture stop, a focal length of the photographing lens assembly is f, 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, a focal length of the sixth lens element is f6, an axial distance between the aperture stop and the image-side surface of the sixth lens element is SD, an axial distance between an object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, a curvature radius of an image-side surface of the fifth lens element is R10, an axial distance between the object-side surface of the first lens element and an image surface is TL, a central thickness of the first lens element is CT1, an axial distance between the first lens element and the second lens element is T12, and the following conditions are satisfied:

(| f/f 1|+| f/f 3|+| f/f 5|)/(| f/f 2|+| f/f 4|+| f/f 6|)<1.0;

0.72< SD/TD< 1.0;

−0.90< f/R 10<9.0;

1.75< TL/f< 3.0; and

0.10< CT 1/ T 12<3.3.

2. The photographing lens assembly of claim 1 , wherein the sixth lens element has negative refractive power.

3. The photographing lens assembly of claim 1 , wherein the first lens element has negative refractive power, the third lens element has negative refractive power, the 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:

| f 2/ f 1|<0.60.

4. The photographing lens assembly of claim 1 , wherein the focal length of the photographing lens assembly is f, the 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, the focal length of the fourth lens element is f4, the focal length of the fifth lens element is f5, the focal length of the sixth lens element is f6, and the following condition is satisfied:

(| f/f 1|+| f/f 3|+| f/f 5|)/(| f/f 2|+| f/f 4|+| f/f 6|)<0.55.

5. The photographing lens assembly of claim 1 , wherein the central thickness of the first lens element is CT1, the axial distance between the first lens element and the second lens element is T12, the focal length of the photographing lens assembly is f, the curvature radius of the image-side surface of the fifth lens element is R10, and the following conditions are satisfied:

0.20< CT 1/ T 12<1.0; and

−0.60< f/R 10<3.0.

6. The photographing lens assembly of claim 1 , wherein a central thickness of the second lens element is CT2, a central thickness of the fourth lens element is CT4, and the following condition is satisfied:

1.05< CT 4/ CT 2<3.0.

7. The photographing lens assembly of claim 1 , wherein half of a maximum field of view of the photographing lens assembly is HFOV, the axial distance between the object-side surface of the first lens element and the image surface is TL, the focal length of the photographing lens assembly is f, and the following conditions are satisfied:

1.20<tan( HFOV )<2.50; and

1.90< TL/f< 2.60.

8. The photographing lens assembly of claim 1 , wherein an axial distance between the second lens element and the third lens element is T23, an axial distance between the fourth lens element and the fifth lens element is T45, a central thickness of the second lens element is CT2, a central thickness of the fourth lens element is CT4, and the following condition is satisfied:

0<( T 23+ T 45)/( CT 2+ CT 4)<0.20.

9. The photographing lens assembly of claim 1 , wherein an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, a central thickness of the fourth lens element is CT4, and the following condition is satisfied:

( T 45+ T 56)/ CT 4<1.0.

10. The photographing lens assembly of claim 1 , wherein the axial distance between the object-side surface of the first lens element and the image surface is TL, a maximum image height of the photographing lens assembly is ImgH, the focal length of the photographing lens assembly is f, an entrance pupil diameter of the photographing lens assembly is EPD, and the following conditions are satisfied:

1.0< TL/ImgH <2.0; and

1.20< f /EPD<2.10.

11. The photographing lens assembly of claim 1 , wherein an Abbe number of the third lens element is V3, a refractive index of the third lens element is N3, and the following condition is satisfied:

10.0< V 3/ N 3<15.0.

12. The photographing lens assembly of claim 1 , wherein the focal length of the fourth lens element is f4, the focal length of the fifth lens element is f5, the axial distance between the object-side surface of the first lens element and the image surface is TL, a maximum image height of the photographing lens assembly is ImgH, an entrance pupil diameter of the photographing lens assembly is EPD, and the following conditions are satisfied:

| f 4/ f 5|<1.0; and

4.0< TL 2 /( ImgH ×EPD)<8.30.

13. An image capturing unit, comprising:

the photographing lens assembly of claim 1 ; and

an image sensor disposed on the image surface of the photographing lens assembly.

14. An electronic device, comprising:

the image capturing unit of claim 13 .