Wide viewing angle optical lens assembly
A wide viewing angle optical lens assembly comprises, in order from an object side to an image side, a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface, a second lens element with positive refractive power having a convex object-side surface, a third lens element with positive refractive power having a convex image-side surface. By adjusting the relationship among the above-mentioned lens elements, the wide viewing angle optical lens assembly can effectively reduce its size, obtain greater angle of view as well as superior imaging quality.
1. A wide viewing angle optical lens assembly, comprising, in order from an object side to an image side:
a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;
a second lens element with positive refractive power having a convex object-side surface; and
a third lens element with positive refractive power having a convex image-side surface;
wherein the wide viewing angle optical assembly has only three lens elements with refractive power, the first lens element, the second lens element, and the third lens element are non-cemented, near an optical axis, the second lens element has a focal length f 2 , the third lens element has a focal length f 3 , the object-side surface of the first lens element has a curvature radius R 1 , the object-side surface of the third lens element has a curvature radius R 5 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relations are satisfied:
0.8 <f 2 /f 3 <1.2;
0 <R 1 /|R 5 |<1.0; and
0.4<( R 5 +R 6 )/( R 5 −R 6 )<2.0.
2. The wide viewing angle optical lens assembly according to claim 1 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relation is satisfied: −2.5<R 3 /R 6 <−0.7.
3. The wide viewing angle optical lens assembly according to claim 2 , wherein the image-side surface of the first lens element has a curvature radius R 2 , the wide viewing angle optical lens assembly has a focal length f, and the following relation is satisfied: 0<R 2 /f<0.6.
4. The wide viewing angle optical lens assembly according to claim 1 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relation is satisfied: −1.5<R 3 /R 6 <−0.7.
5. The wide viewing angle optical lens assembly according to claim 2 , wherein the first lens element is plastic, there is at least one inflection point on the first lens element and at least one of the object-side and the image-side surfaces of the first lens element is aspheric.
6. The wide viewing angle optical lens assembly according to claim 2 , further comprises a stop and an image plane, an axial distance from the stop to 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 the following relation is satisfied: 0.3<SL/TTL<0.68.
7. The wide viewing angle optical lens assembly according to claim 2 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the second lens element has a curvature radius R 4 , and the following relation is satisfied: −0.5<R 3 /R 4 <0.5.
8. The wide viewing angle optical lens assembly according to claim 2 , wherein a half of a maximal viewing angle in the wide viewing angle optical lens assembly is HFOV, and the following relation is satisfied: HFOV>60.
9. A wide viewing angle optical lens assembly, comprising, in order from an object side to an image side:
a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;
a second lens element with positive refractive power having a convex object-side surface; and
a third lens element with positive refractive power having a convex image-side surface;
wherein the wide viewing angle optical assembly has only three lens elements with refractive power, the first lens element, the second lens element, and the third lens element are non-cemented, the wide viewing angle optical lens assembly further comprises a stop and an image plane, near an optical axis, the wide viewing angle optical lens assembly has a focal length f, the second lens element has a focal length f 2 , the third lens element has a focal length f 3 , the image-side surface of the first lens element has a curvature radius R 2 , an axial distance from the stop to 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 the following relations are satisfied:
0.8 <f 2 /f 3 <1.2;
0 <R 2 /f< 0.56; and
0.3 <SL/TTL< 0.68.
10. The wide viewing angle optical lens assembly according to claim 9 , wherein the object-side surface of the third lens element has a curvature radius R 5 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relation is satisfied: 0.4<(R 5 +R 6 )/(R 5 −R 6 )<2.0.
11. The wide viewing angle optical lens assembly according to claim 10 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relation is satisfied: −1.5<R 3 /R 6 <−0.7.
12. The wide viewing angle optical lens assembly according to claim 10 , wherein the object-side surface of the first lens element has a curvature radius R 1 , the object-side surface of the third lens element has a curvature radius R 5 , and the following relation is satisfied: 0<R 1 /|R 5 |<1.0.
13. The wide viewing angle optical lens assembly according to claim 10 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the second lens element has a curvature radius R 4 , and the following relation is satisfied: −0.5<R 3 /R 4 <0.5.
14. A wide viewing angle optical lens assembly, comprising, in order from an object side to an image side:
a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface, wherein the first lens element is plastic with at least one inflection point and at least one of the object-side and the image-side surfaces being aspheric;
a second lens element with positive refractive power having a convex object-side surface; and
a third lens element with positive refractive power having a convex image-side surface;
wherein the wide viewing angle optical assembly has only three lens elements with refractive power, the first lens element, the second lens element, and the third lens element are non-cemented, the wide viewing angle optical lens assembly further comprises a stop and an image plane, near an optical axis, the wide viewing angle optical lens assembly has a focal length f, the second lens element has a focal length f 2 , the third lens element has a focal length f 3 , the image-side surface of the first lens element has a curvature radius R 2 , the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the third lens element has a curvature radius R 6 , an axial distance from the stop to 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 the following relations are satisfied:
0.8 <f 2 /f 3 <1.2;
0 <R 2 /f< 0.6;
−2.5 <R 3 /R 6 <−0.7; and
0.3 <SL/TTL< 0.68.
15. The wide viewing angle optical lens assembly according to claim 14 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the third lens element has a curvature radius R 6 , and the following relation is satisfied: −1.5<R 3 /R 6 <−0.7.
16. The wide viewing angle optical lens assembly according to claim 14 , wherein the object-side surface of the second lens element has a curvature radius R 3 , the image-side surface of the second lens element has a curvature radius R 4 , and the following relation is satisfied: −0.5<R 3 /R 4 <0.5.
17. The wide viewing angle optical lens assembly according to claim 14 , wherein the object-side surface of the first lens element has a curvature radius R 1 , the object-side surface of the third lens element has a curvature radius R 5 , and the following relation is satisfied: 0<R 1 /|R 5 |<1.0.