Photographing optical lens assembly
A photographing optical lens assembly includes, in order from an object side to an image side: the first lens element with positive refractive power having a convex object-side surface, the second lens element with positive refractive power, the third lens element with positive refractive power, and the fourth lens element with positive refractive power. By such arrangement, the total track length of the photographing optical lens assembly would be suitable for compact electronics.
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 a convex object-side surface;
a second lens element with positive refractive power;
a third lens element with positive refractive power; and
a fourth lens element with positive refractive power;
wherein an axial distance from the object-side surface of the first lens element to an image plane is TTL, a maximum image height of the photographing optical lens assembly is Y, and they satisfy the following relationship:
TTL/Y <2.1.
2. The photographing optical lens assembly of claim 1 , wherein the fourth lens element has a convex object-side surface and a concave image-side surface.
3. The photographing optical lens assembly of claim 2 , wherein a focal length of the photographing optical lens assembly is f, 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, and they satisfy the following relationship:
| f/f 2 |+|f/f 3 |+|f/f 4|<1.15.
4. The photographing optical lens assembly of claim 3 , further comprising:
a stop, wherein an axial distance between the stop and the image plane is SL, an axial distance from the object-side surface of the first lens element to the image plane is TTL, and they satisfy the following relationship:
0.7 <SL/TTL <1.2.
5. The photographing optical lens assembly of claim 3 , wherein the fourth lens element is made of plastic material, 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.
6. The photographing optical lens assembly of claim 3 , wherein the focal length of the photographing optical lens assembly is f, the focal length of the second lens element is f2, the focal length of the third lens element is f3, the focal length of the fourth lens element is f4, and they satisfy the following relationship:
| f/f 2 |+|f/f 3 |+|f/f 4|<0.8.
7. The photographing optical lens assembly of claim 2 , wherein a central thickness of the second lens element is CT2, the focal length of the photographing optical lens assembly is f, and they satisfy the following relationship:
0.02 <CT 2 /f <0.15.
8. The photographing optical lens assembly of claim 2 , wherein a curvature radius of the object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, 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 they satisfy the following relationships:
0.7 <R 5 /R 6<1.2; and
0.8 <R 7 /R 8<1.3.
9. 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 a convex object-side surface;
a second lens element with positive refractive power;
a third lens element with positive refractive power; and
a fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface, and made of plastic material, 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 photographing optical lens assembly is f, 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, and they satisfy the following relationship:
| f/f 2 |+|f/f 3 |+|f/f 4|<1.15.
10. The photographing optical lens assembly of claim 9 , further comprising:
a stop, wherein an axial distance between the stop and an image plane is SL, an axial distance from the object-side surface of the first lens element to the image plane is TTL, and they satisfy the following relationship:
0.7 <SL/TTL <1.2.
11. The photographing optical lens assembly of claim 9 , wherein a central thickness of the second lens element is CT2, the focal length of the photographing optical lens assembly is f, and they satisfy the following relationship:
0.02 <CT 2 /f <0.15.
12. The photographing optical lens assembly of claim 9 , wherein a curvature radius of the object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, 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 they satisfy the following relationships:
0.7 <R 5 /R 6<1.2; and
0.8 <R 7 /R 8<1.3.
13. The photographing optical lens assembly of claim 9 , wherein the third lens element has a concave object-side surface and a convex image-side surface.
14. The photographing optical lens assembly of claim 9 , wherein the third lens element has a convex object-side surface and a concave image-side surface.
15. 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 a convex object-side surface;
a second lens element with positive refractive power being a meniscus;
a third lens element with positive refractive power being a meniscus;
a fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface, and made of plastic material, 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.
16. The photographing optical lens assembly of claim 15 , wherein a focal length of the photographing optical lens assembly is f, 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, and they satisfy the following relationship:
| f/f 2 |+|f/f 3 |+|f/f 4|<0.8.
17. The photographing optical lens assembly of claim 15 , further comprising:
a stop, wherein an axial distance between the stop and an image plane is SL, an axial distance from the object-side surface of the first lens element to the image plane is TTL, and they satisfy the following relationship:
0.7 <SL/TTL <1.2.
18. The photographing optical lens assembly of claim 15 , wherein a central thickness of the second lens element is CT2, the focal length of the photographing optical lens assembly is f, and they satisfy the following relationship:
0.02 <CT 2 /f <0.15.
19. The photographing optical lens assembly of claim 15 , wherein the axial distance from the object-side surface of the first lens element to an image plane is TTL, a maximum image height of the photographing optical lens assembly is Y, and they satisfy the following relationship:
TTL/Y <2.1.
20. The photographing optical lens assembly of claim 15 , wherein a curvature radius of the object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, 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 they satisfy the following relationships:
0.7 <R 5 /R 6<1.2; and
0.8 <R 7 /R 8<1.3.