Imaging optical lens system, imaging device and mobile terminal
An imaging optical lens system 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 and a fifth 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 refractive power. The third lens element with positive refractive power 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 fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The imaging optical lens system has a total of five lens elements with refractive power.
1. An imaging optical lens 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 in a paraxial region thereof;
a second lens element having refractive power;
a third lens element with positive 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;
a fourth lens element with refractive power having an image-side surface being concave in a paraxial region thereof; and
a fifth lens element with 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 fifth lens element are aspheric, and at least one of the object-side surface and the image-side surface of the fifth lens element has at least one inflection point;
wherein the imaging optical lens system has a total of five lens elements with refractive power, a focal length of the imaging optical lens system is f, a curvature radius of the image-side surface of the fourth lens element is R8, a central thickness of the fifth lens element is CT5, a central thickness of the fourth lens element is CT4, a focal length of the fourth lens element is f4, an axial distance between the second lens element and the third lens element is T23, a central thickness of the third lens element is CT3, and the following conditions are satisfied:
0< f/R 8<2.0;
1.3< CT 5/ CT 4<3.5;
−0.7<f/f4≦0.15; and
0.2<CT3/T23≦1.00.
2. The imaging optical lens system of claim 1 , wherein the second lens element has negative refractive power, an axial distance between the first lens element and the second lens element is T12, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the third lens element and the fourth lens element is T34, and the following condition is satisfied:
0<(T12+T45)/(T23+T34)<0.40.
3. The imaging optical lens system of claim 2 , wherein the object-side surface of the fifth lens element is convex in a paraxial region thereof.
4. The imaging optical lens system of claim 2 , wherein the first lens element has an image-side surface being concave in a paraxial region thereof.
5. The imaging optical lens system of claim 2 , wherein the fourth lens element has an object-side surface being concave in a paraxial region thereof.
6. The imaging optical lens system of claim 2 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, a vertical distance between a maximum effective radius position on the image-side surface of the fifth lens element and an optical axis is SD52, and the following condition is satisfied:
0.50< TD /(2* SD 52)<0.80.
7. The imaging optical lens system of claim 2 , wherein an axial distance between the object-side surface of the first lens element and the image plane is TL, a maximum image height of the imaging optical lens system is ImgH, and the following condition is satisfied:
TL /Img H <1.7.
8. The imaging optical lens system of claim 1 , wherein a curvature radius of the image-side surface of the fifth lens element is R10, a curvature radius of the image-side surface of the third lens element is R6, and the following condition is satisfied:
0< R 10/ R 6<1.0.
9. The imaging optical lens system of claim 8 , wherein an axial distance between the first lens element and the second lens element is T12, an axial distance between the fourth lens element and the fifth lens element is T45, 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, and the following condition is satisfied:
0<( T 12+ T 45)/( T 23+ T 34)<0.40.
10. The imaging optical lens system of claim 1 , wherein an Abbe number of the second lens element is V2, an Abbe number of the fourth lens element is V4, and the following condition is satisfied:
0.8< V 2/ V 4<1.3.
11. The imaging optical lens system of claim 1 , wherein the central thickness of the fifth lens element is CT5, the central thickness of the fourth lens element is CT4, and the following condition is satisfied:
1.5< CT 5/ CT 4<3.0.
12. The imaging optical lens system of claim 3 , wherein the focal length of the imaging optical lens system is f, a focal length of the third lens element is f3, a focal length of the fifth lens element is f5, and the following condition is satisfied:
0<| f/f 3|+| f/f 5|<0.5.
13. An imaging device, comprising:
the imaging optical lens system of claim 1 ; and
an image sensor.
14. A mobile terminal, comprising:
the imaging device of claim 13 .
15. An imaging optical lens 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 in a paraxial region thereof;
a second lens element having refractive power;
a third lens element with positive 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;
a fourth lens element with 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 fourth lens element are aspheric, and at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point; and
a fifth lens element with 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 the object-side surface and the image-side surface of the fifth lens element are aspheric, and at least one of the object-side surface and the image-side surface of the fifth lens element has at least one inflection point;
wherein the imaging optical lens system has a total of five lens elements with refractive power, a focal length of the imaging optical lens system is f, a curvature radius of the image-side surface of the fourth lens element is R8, a 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, and the following conditions are satisfied:
0.14≦f/R8≦0.85;
| f/f 2|<0.8; and
−3< f 4/ f 5<1.
16. The imaging optical lens system of claim 15 , wherein the second lens element has negative refractive power.
17. The imaging optical lens system of claim 16 , wherein an Abbe number of the second lens element is V2, an Abbe number of the fourth lens element is V4, and the following condition is satisfied:
0.8< V 2/ V 4<1.3.
18. The imaging optical lens system of claim 15 , wherein the focal length of the imaging optical lens system is f, the focal length of the fourth lens element is f4, and the following condition is satisfied:
−0.6< f/f 4<0.
19. The imaging optical lens system of claim 15 , wherein the focal length of the imaging optical lens system is f, a focal length of the third lens element is f3, the focal length of the fifth lens element is f5, and the following condition is satisfied:
0<| f/f 3|+| f/f 5|<0.5.
20. The imaging optical lens system of claim 15 , wherein an axial distance between the first lens element and the second lens element is T12, an axial distance between the fourth lens element and the fifth lens element is T45, 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, and the following condition is satisfied:
0<( T 12+ T 45)/( T 23+ T 34)<0.40.
21. The imaging optical lens system of claim 15 , wherein the object-side surface of the fifth lens element is convex in a paraxial region thereof and changes to a concave shape and then a convex shape from the paraxial region to a peripheral region.
22. The imaging optical lens system of claim 15 , wherein a curvature radius of the image-side surface of the fifth lens element is R10, a curvature radius of the image-side surface of the third lens element is R6, and the following condition is satisfied:
0< R 10/ R 6<0.5.
23. An imaging device, comprising:
the imaging optical lens system of claim 15 ; and
an image sensor.
24. A mobile terminal, comprising:
the imaging device of claim 23 .
25. An imaging optical lens 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 in a paraxial region thereof;
a second lens element having refractive power;
a third lens element with positive 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;
a fourth lens element with 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 an object-side surface and the image-side surface of the fourth lens element are aspheric, and at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point; and
a fifth lens element with 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 the object-side surface and the image-side surface of the fifth lens element are aspheric, and at least one of the object-side surface and the image-side surface of the fifth lens element has at least one inflection point;
wherein the imaging optical lens system has a total of five lens elements with refractive power, a focal length of the imaging optical lens system is f, a curvature radius of the image-side surface of the fourth lens element is R8, a 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, and the following conditions are satisfied:
0<f/R8≦0.85;
|f/f2|<0.8; and
−3<f4/f5< 1 .
26. The imaging optical lens system of claim 25 , wherein the second lens element has negative refractive power.
27. The imaging optical lens system of claim 26 , wherein an Abbe number of the second lens element is V2, an Abbe number of the fourth lens element is V4, and the following condition is satisfied:
0.8<V2/V4<1.3.
28. The imaging optical lens system of claim 25 , wherein the focal length of the imaging optical lens system is f, the focal length of the fourth lens element is f4, and the following condition is satisfied:
−0.6<f/f4<0.
29. The imaging optical lens system of claim 25 , wherein the focal length of the imaging optical lens system is f, a focal length of the third lens element is f3, the focal length of the fifth lens element is f5, and the following condition is satisfied:
0<|f/f3|+|f/f5|<0.5.
30. The imaging optical lens system of claim 25 , wherein an axial distance between the first lens element and the second lens element is T12, an axial distance between the fourth lens element and the fifth lens element is T45, 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, and the following condition is satisfied:
0<(T12+T45)/(T23+T34)<0.40.
31. The imaging optical lens system of claim 25 , wherein the object-side surface of the fifth lens element is convex in a paraxial region thereof, changes to a concave shape from the paraxial region to a peripheral region, and a convex shape in the peripheral region.
32. The imaging optical lens system of claim 25 , wherein a curvature radius of the image-side surface of the fifth lens element is R10, a curvature radius of the image-side surface of the third lens element is R6, and the following condition is satisfied:
0<R10/R6<0.5.
33. An imaging device, comprising:
the imaging optical lens system of claim 25 ; and
an image sensor.
34. A mobile terminal, comprising:
the imaging device of claim 33 .