Image lens assembly system
An image lens assembly 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 lens element with negative refractive power has a convex object-side surface. The second lens element has positive refractive power. The third lens element has refractive power. The fourth lens element has refractive power. The fifth lens element has refractive power. The sixth lens element with refractive power is made of plastic material, wherein at least one surface of the sixth lens element is aspheric. The seventh lens element with refractive power made of plastic material has a concave image-side surface changing from concave in a paraxial region to convex in a peripheral region, and at least one surface thereof is aspheric.
1. An image lens assembly 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 seven lens elements has an object-side surface facing towards the object side and an image-side surface facing towards the image side;
wherein at least one of an object-side surface and an image-side surface of the seventh lens element is aspheric, and the seventh lens element comprises at least one inflection point on at least one of the object-side surface and the image-side surface thereof;
wherein an axial distance between an object-side surface of the first lens element and an image plane is TTL, a maximum image height of the image lens assembly system is ImgH, an axial distance between the object-side surface of the first lens element and the image-side surface of the seventh lens element is Td, and the following relationships are satisfied:
TTL /ImgH<1.85; and
3.2 mm< Td< 7.0 mm.
2. The image lens assembly system of claim 1 , wherein the image-side surface of the seventh lens element is concave in a paraxial region thereof and comprises at least one convex surface in an off-axis region thereof.
3. The image lens assembly system of claim 1 , wherein the seventh lens element has negative refractive power.
4. The image lens assembly system of claim 1 , wherein the second lens element has positive refractive power.
5. The image lens assembly system of claim 1 , wherein the second lens element has an object-side surface being convex in a paraxial region thereof, at least one of an object-side surface and an image-side surface of the fifth lens element is aspheric, and at least one of an object-side surface and an image-side surface of the sixth lens element is aspheric.
6. The image lens assembly system of claim 1 , wherein 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 are made of plastic materials.
7. The image lens assembly system of claim 1 , wherein there is a gap between every two adjacent lens elements 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.
8. The image lens assembly system of claim 1 , 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, and the following relationship is satisfied:
0< R 14/| R 13|<0.5.
9. The image lens assembly system of claim 1 , wherein a focal length of the image lens assembly system 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, and the following relationships are satisfied:
| f/f 2|> f/f 1;
| f/f 2|> f/f 3;
| f/f 2|> f/f 4; and
| f/f 2|> f/f 5.
10. The image lens assembly system of claim 1 , wherein a sum of central thicknesses from the first through seventh lens elements is ΣCT, the axial distance between the object-side surface of the first lens element and the image-side surface of the seventh lens element is Td, and the following relationship is satisfied:
0.60<ΣCT/ Td <0.90.
11. The image lens assembly system of claim 1 , wherein a maximal field of view of the image lens assembly system is FOV, and the following relationship is satisfied:
70 degrees<FOV<100 degrees.
12. The image lens assembly system of claim 1 , wherein the axial distance between the object-side surface of the first lens element and the image plane is TTL, the maximum image height of the image lens assembly system is ImgH, and the following relationship is satisfied:
TTL /ImgH≤1.67.
13. The image lens assembly system of claim 1 , wherein the axial distance between the object-side surface of the first lens element and the image-side surface of the seventh lens element is Td, and the following relationship is satisfied:
3.2 mm< Td≤ 4.892 mm.
14. The image lens assembly system of claim 1 , wherein at least one of the third lens element and the fourth lens element has at least one concave-to-convex or convex-to-concave surface change from a paraxial region thereof to an off-axis region thereof.
15. An image lens assembly 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 seven lens elements has an object-side surface facing towards the object side and an image-side surface facing towards the image side;
wherein the seventh lens element has an object-side surface being convex in a paraxial region thereof, at least one of the object-side surface and an image-side surface of the seventh lens element is aspheric, and the seventh lens element comprises at least one inflection point on at least one of the object-side surface and the image-side surface thereof;
wherein there is a gap between every two adjacent lens elements 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;
wherein an axial distance between an object-side surface of the first lens element and an image plane is TTL, a maximum image height of the image lens assembly system is ImgH, and the following relationship is satisfied:
TTL /ImgH<1.85.
16. The image lens assembly system of claim 15 , wherein the seventh lens element has negative refractive power.
17. The image lens assembly system of claim 15 , wherein the second lens element has positive refractive power.
18. The image lens assembly system of claim 15 , wherein the fourth lens element has positive refractive power.
19. The image lens assembly system of claim 15 , wherein the third lens element has an image-side surface being concave in a paraxial region thereof.
20. The image lens assembly system of claim 15 , wherein an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, and the following relationship is satisfied:
0.25< V 5/ V 6<0.60.
21. The image lens assembly system of claim 15 , wherein the axial distance between the object-side surface of the first lens element and the image plane is TTL, the maximum image height of the image lens assembly system is ImgH, and the following relationship is satisfied:
TTL /ImgH≤1.67.
22. The image lens assembly system of claim 15 , wherein a maximal field of view of the image lens assembly system is FOV, and the following relationship is satisfied:
70 degrees<FOV<100 degrees.
23. The image lens assembly system of claim 15 , 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, and the following relationship is satisfied:
0< R 14/ R 13|<0.5.
24. The image lens assembly system of claim 15 , wherein 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 are made of plastic materials.
25. The image lens assembly system of claim 15 , wherein at least one of the third lens element and the fourth lens element has at least one concave-to-convex or convex-to-concave surface change from a paraxial region thereof to an off-axis region thereof.
26. The image lens assembly system of claim 15 , wherein the image-side surface of the seventh lens element is concave in a paraxial region thereof and comprises at least one convex surface in an off-axis region thereof.
27. The image lens assembly system of claim 15 , wherein the object-side surface of the seventh lens element comprises at least one concave surface in an off-axis region thereof.