Optical image capturing system
An optical image capturing 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, a fifth lens element, a sixth lens element and a seventh lens element. The first, the second and the third lens elements all have refractive power. The fourth lens element with refractive power has both surfaces being aspheric. The fifth lens element with refractive power has both surfaces being aspheric. The sixth lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof and both surfaces being aspheric. The seventh lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof, wherein both surfaces being aspheric, and at least one surface has at least one inflection point thereon.
1. An optical image capturing system comprising seven lens elements, the seven 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, a sixth lens element, and a seventh lens element;
wherein each of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element has an object-side surface facing toward the object side, and an image-side surface facing toward the image side;
wherein the fourth lens element has positive refractive power; at least one of the object-side surface and the image-side surface of the sixth lens element is aspheric; the seventh lens element has the image-side surface being concave in a paraxial region thereof, the image-side surface of the seventh lens element is aspheric, and the image-side surface of the seventh lens element has a concave-to-convex shape change from the paraxial region thereof to an off-axis region thereof;
wherein a curvature radius of the object-side surface of the seventh lens element is R13, a curvature radius of the image-side surface of the seventh lens element is R14, a focal length of the optical image capturing system is f, and the following relationships are satisfied:
0.1< R 14/ f< 1.0; and
−5.0< R 14/ R 13<1.0.
2. The optical image capturing system of claim 1 , wherein the image-side surface of the first lens element is concave in a paraxial region thereof; at least one of the object-side surface and the image-side surface of each of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element is aspheric.
3. The optical image capturing system of claim 1 , wherein the object-side surface of the second lens element is convex in a paraxial region thereof and the image-side surface of the second lens element is concave in a paraxial region thereof.
4. The optical image capturing system of claim 1 , wherein the object-side surface of the third lens element is concave in a paraxial region thereof and the image-side surface of the third lens element is convex in a paraxial region thereof.
5. The optical image capturing system of claim 1 , wherein the object-side surface of the fourth 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.
6. The optical image capturing system of claim 1 , wherein the object-side surface of the seventh lens element is convex in a paraxial region thereof.
7. The optical image capturing system of claim 1 , wherein the fifth lens element has negative refractive power; the sixth lens element has positive refractive power; the seventh lens element has negative refractive power.
8. The optical image capturing system of claim 1 , wherein the curvature radius of the object-side surface of the seventh lens element is R13, the curvature radius of the image-side surface of the seventh lens element is R14, and the following relationship is satisfied:
−2.0< R 14/ R 13<0.5.
9. The optical image capturing system of claim 1 , wherein there is an air gap between each of adjacent lens elements of the seven lens elements; the focal length of the optical image capturing system is f, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, and the following relationship is satisfied:
| f/f 3|+| f/f 4|<1.0.
10. The optical image capturing system of claim 1 , wherein the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element are made of plastic material; the focal length of the optical image capturing system is f, a vertical distance from a critical point on the image-side surface of the seventh lens element to an axial vertex on the image-side surface of the seventh lens element is Yc72, and the following relationship is satisfied:
0.1< Yc 72/ f< 0.9.
11. The optical image capturing system of claim 1 , wherein a central thickness of the sixth lens element is greater than a central thickness of the seventh lens element.
12. The optical image capturing system of claim 1 , wherein an absolute value of a curvature radius of the object-side surface of the sixth lens element is greater than an absolute value of the curvature radius of the image-side surface of the seventh lens element.
13. An optical image capturing system comprising seven lens elements, the seven 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, a sixth lens element, and a seventh lens element;
wherein each of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element and the seventh lens element has 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 image-side surface being concave in a paraxial region thereof; at least one of the object-side surface and the image-side surface of the sixth lens element is aspheric; the seventh lens element has the image-side surface being concave in a paraxial region thereof, the image-side surface of the seventh lens element is aspheric, and the image-side surface of the seventh lens element has a concave-to-convex shape change from the paraxial region thereof to an off-axis region thereof;
wherein a curvature radius of the image-side surface of the seventh lens element is R14, a focal length of the optical image capturing system is f, an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, and the following relationships are satisfied:
0.1< R 14/ f< 1.0; and
28< V 1− V 2<42.
14. The optical image capturing system of claim 13 , wherein the object-side surface of the second lens element is convex in a paraxial region thereof and the image-side surface of the second lens element is concave in a paraxial region thereof.
15. The optical image capturing system of claim 13 , wherein the object-side surface of the seventh lens element is convex in a paraxial region thereof.
16. The optical image capturing system of claim 13 , wherein the object-side surface of the sixth lens element has a convex-to-concave shape change from a paraxial region thereof to an off-axis region thereof.
17. The optical image capturing system of claim 13 , wherein the third lens element has positive refractive power; at least one of the object-side surface and the image-side surface of each of the third lens element, the fourth lens element, the fifth lens element and the sixth lens element is aspheric.
18. The optical image capturing system of claim 13 , wherein the sixth lens element has positive refractive power; the seventh lens element has negative refractive power.
19. The optical image capturing system of claim 13 , wherein the Abbe number of the first lens element is V1, the Abbe number of the second lens element is V2, and the following relationship is satisfied:
32.1≤ V 1− V 2<42.
20. The optical image capturing system of claim 13 , wherein a maximal field of view of the optical image capturing system is FOV, and the following relationship is satisfied:
72 degrees<FOV<95 degrees.
21. The optical image capturing system of claim 13 , wherein the fifth lens element, the sixth lens element and the seventh lens element are made of plastic material; the focal length of the optical image capturing system is f, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, and the following relationship is satisfied:
| f/f 3|+| f/f 4|<1.0.
22. The optical image capturing system of claim 13 , wherein a minimum central thickness of a lens element among the seven lens elements of the optical image capturing system is CT min, and the following relationship is satisfied:
0.10 mm<CT min<0.30 mm.
23. The optical image capturing system of claim 13 , wherein there is an air gap between each of adjacent lens elements of the seven lens elements; a central thickness of the sixth lens element is a maximum among central thicknesses of the seven lens elements.
24. The optical image capturing system of claim 13 , wherein an absolute value of a curvature radius of the object-side surface of the sixth lens element is greater than an absolute value of the curvature radius of the image-side surface of the seventh lens element.