Optical image capturing assembly
An optical image capturing assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element with negative refractive power has a concave object-side surface and a convex image-side surface. The third lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface. The fourth lens element with negative refractive power is made of plastic material, and has a convex object-side surface and a concave image-side surface. The object-side surfaces and the image-side surfaces of the third lens element and the fourth lens element are aspheric. The fourth lens element has at least one inflection point formed on at least one surface thereof.
1. An optical image capturing assembly comprising, in order from an object side to an image side:
a first lens element with positive refractive power having a convex object-side surface;
a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface;
a third lens element with positive refractive power which is made of plastic material and has a convex object-side surface and a convex image-side surface, wherein the object-side surface and the image-side surface of the third lens element are aspheric; and
a fourth lens element with negative refractive power which is made of plastic material and has a convex object-side surface and a concave image-side surface, wherein the object-side surface and the image-side surface of the fourth lens element are aspheric, and the fourth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof;
wherein a focal length of the optical image capturing assembly is f, a focal length of the fourth lens element is f4, a curvature radius of the image-side surface of the second lens element is R4, and the following relationships are satisfied:
−2.5 <f/f 4<−0.6; and
−5.0 <R 4 /f<− 0.2.
2. The optical image capturing assembly of claim 1 , wherein a curvature radius of the object-side surface of the fourth lens element is R7, a curvature radius of the image-side surface of the fourth lens element is R8, and the following relationship is satisfied:
1.0<( R 7 +R 8)/( R 7 −R 8)<6.0.
3. The optical image capturing assembly of claim 2 , wherein a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of the image-side surface of the first lens element is R2, and the following to relationship is satisfied:
−2.0<( R 1 +R 2)/( R 1 −R 2)<0.0.
4. The optical image capturing assembly of claim 3 , further comprising:
a stop, located between an object and the second lens element.
5. The optical image capturing assembly of claim 4 , 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:
28 <V 1 −V 2<42.
6. The optical image capturing assembly of claim 4 , wherein an axial distance between the first lens element and the second lens element is T12, the focal length of the optical image capturing assembly is f, and the following relationship is satisfied:
0.13 <T 12 /f <0.27.
7. The optical image capturing assembly of claim 4 , wherein the focal length of the optical image capturing assembly is f, a focal length of the second lens element is f2, and the following relationship is satisfied:
−1.4 <f/f 2<−0.6.
8. The optical image capturing assembly of claim 5 , wherein a central thickness of the first lens element is CT1, the axial distance between the first lens element and the second lens element is T12, and the following relationship is satisfied:
0.2 <CT 1 /T 12<1.3.
9. The optical image capturing assembly of claim 5 , wherein a sum of the central thickness from the first lens element to the fourth lens element is ΣCT, an axial distance between the object-side surface of the first lens element and the image-side surface of the fourth lens element is Td, and the following relationship is satisfied:
0.5 <ΣCT/Td< 0.81.
10. The optical image capturing assembly of claim 2 , wherein both of the second lens element and the third lens element have at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof.
11. The optical image capturing assembly of claim 2 , wherein a maximal field of view of the optical image capturing assembly is FOV, and the following relationship is satisfied:
72 degrees≦FOV<100 degrees.
12. The optical image capturing assembly of claim 3 , wherein the curvature radius of the image-side surface of the second lens element is R4, the focal length of the optical image capturing assembly is f, and the following relationship is satisfied:
−1.8 <R 4 /f<− 0.2.
13. The optical image capturing assembly of claim 3 , wherein the focal length of the optical image capturing assembly is f, a focal length of the third lens element is f3, and the following relationship is satisfied:
1.2 <f/f 3<1.83.
14. The optical image capturing assembly of claim 2 , wherein a maximum image height of the optical image capturing assembly is ImgH, an axial distance between the object-side surface of the first lens element and the image plane is TTL, and the following relationship is satisfied:
TTL /Img H< 1.95.