Photographing optical lens assembly, image capturing unit and electronic device
A photographing optical lens assembly includes, 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. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The sixth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof.
1. A photographing optical lens assembly 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 in a paraxial region thereof;
a second lens element having negative refractive power;
a third lens element having positive refractive power;
a fourth lens element having an image-side surface being concave in a paraxial region thereof;
a fifth lens element with negative refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein both of the object-side surface and the image-side surface of the fifth lens element are aspheric; and
a sixth lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, wherein both of object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point;
wherein the photographing optical lens assembly has a total of six lens elements, the photographing optical lens assembly further comprises an aperture stop located between an imaged object and the third lens element;
wherein a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, a focal length of the fifth lens element is f5, a focal length of the sixth lens element is f6, and the following conditions are satisfied:
0.3< R 8/ f;
0.65< SL/TL< 1.2; and
0< f 5/ f 6.
2. The photographing optical lens assembly of claim 1 , wherein the fourth lens element has an object-side surface being convex in a paraxial region thereof.
3. The photographing optical lens assembly of claim 1 , wherein the third lens element has an image-side surface being convex in a paraxial region thereof.
4. The photographing optical lens assembly of claim 1 , wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element is V1, an Abbe number of the fifth lens element is V5, and the following condition is satisfied:
0< R 8/[ f *( V 1− V 5)]<3.
5. The photographing optical lens assembly of claim 1 , wherein 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:
0.1< f 5/ f 6<10.
6. The photographing optical lens assembly of claim 1 , wherein a curvature radius of an object-side surface of the third lens element is R5, a curvature radius of an image-side surface of the third lens element is R6, the curvature radius of the image-side surface of the fourth lens element is R8, and the following condition is satisfied:
0< R 8/(| R 5|+| R 6|)<2.45.
7. The photographing optical lens assembly of claim 1 , wherein an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, 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, and the following conditions are satisfied:
0<T12<T34<T23<T45; and
0<T12<T56<T23<T45.
8. The photographing optical lens assembly of claim 1 , wherein a vertical distance between non-axial critical point on the image-side surface of the sixth lens element and an optical axis is Yc62, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied:
0.1< Yc 62/ f< 0.7.
9. The photographing optical lens assembly of claim 1 , wherein an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, and the following condition is satisfied:
0.70< V 2/ V 5≦1.0.
10. The photographing optical lens assembly of claim 1 , wherein the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.
11. The photographing optical lens assembly of claim 1 , wherein the image-side surface of the fourth lens element has at least one critical point k, a projection of the critical point k on an optical axis is closer to the image side of the photographing optical lens assembly than an intersection of the image-side surface of the fourth lens element and the optical axis, a vertical distance between the critical point k on the image-side surface of the fourth lens element and the optical axis is Yk42, the focal length of the fifth lens element is f5, and the following condition is satisfied:
−1.0< Yk 42/ f 5<0.
12. An image capturing unit, comprising:
the photographing optical lens assembly of claim 1 ; and
an image sensor, wherein the image sensor is disposed on the image side of the photographing optical lens assembly.
13. An electronic device, comprising:
the image capturing unit of claim 12 .
14. A photographing optical lens assembly comprising, in order from an object side to an image side:
a first lens element with positive refractive power having an image-side surface being concave in a paraxial region thereof;
a second lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof;
a third lens element;
a fourth lens element having an image-side surface being concave in a paraxial region thereof;
a fifth lens element having negative refractive power, wherein both of an object-side surface and an image-side surface of the fifth lens element are aspheric; and
a sixth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point;
wherein the photographing optical lens assembly has a total of six lens elements, the photographing optical lens assembly further comprises an aperture stop located between an imaged object and the second lens element, an air gap in a paraxial region is located between every two 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 a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between an object-side surface of the first lens element and the image surface is TL, an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, and the following conditions are satisfied:
0.3< R 8/ f;
0.85< SL/TL< 1.2; and
0.70< V 2/ V 5≦1.0.
15. The photographing optical lens assembly of claim 14 , wherein the second lens element has an object-side surface being convex in a paraxial region thereof.
16. The photographing optical lens assembly of claim 14 , wherein the fourth lens element has positive refractive power.
17. The photographing optical lens assembly of claim 14 , wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied:
5.0< R 8/ f.
18. The photographing optical lens assembly of claim 14 , 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 optical lens assembly is ImgH, and the following condition is satisfied:
TL/ImgH< 2.0.
19. The photographing optical lens assembly of claim 14 , wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element is V1, the Abbe number of the fifth lens element is V5, and the following condition is satisfied:
0< R 8/[ f *( V 1− V 5)]<3.
20. The photographing optical lens assembly of claim 14 , wherein the curvature radius of the image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, and the following condition is satisfied:
−19< R 8/ R 9<0.
21. The photographing optical lens assembly of claim 14 , wherein 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, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, and the following conditions are satisfied:
CT2, CT4, CT5<CT1, CT3; and
CT1, CT3<CT6.
22. The photographing optical lens assembly of claim 14 , 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:
0.1<| f 1/ f 3|.
23. The photographing optical lens assembly of claim 14 , wherein the object-side surface of the sixth lens element is convex in a paraxial region thereof, the object-side surface of the sixth lens element has at least one concave shape and at least one convex shape in an off-axis region thereof, and the object-side surface of the sixth lens element changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.
24. The photographing optical lens assembly of claim 14 , wherein the image-side surface of the fourth lens element has at least one critical point k, a projection of the critical point k on an optical axis is closer to the image side of the photographing optical lens assembly than an intersection of the image-side surface of the fourth lens element and the optical axis, a vertical distance between the critical point k on the image-side surface of the fourth lens element and the optical axis is Yk42, the focal length of the fifth lens element is f5, and the following condition is satisfied:
−1.0< Yk 42/ f 5<0.