Wide angle six-piece lens
A wide angle six-piece lens includes a first lens having a negative refractive power and an image side as a concave surface, a second lens having a positive refractive power and an object side as a convex surface, an aperture, a third lens having a positive refractive power and an image side as a convex surface, a fourth lens having a positive refractive power and an object surface and an image surface as convex surfaces, a fifth lens having a negative refractive power and an object side as a concave surface, and a sixth lens having a positive refractive power and an object side as a convex surface. The overall effective focal length of the wide angle six-piece lens is f, the focal length of the third lens is f3, and an equation 0.29<f/f3<0.36 is satisfied. As such, a wide angle system is formed and aberration is eliminated.
1. A wide angle six-piece lens, from an object side to an image side, sequentially comprising:
a first lens (L 1 ), having a negative refractive power, and including an object side having a radius of curvature greater than a radius of curvature of its image side;
a second lens (L 2 ), having a positive refractive power, and including an object side having a radius of curvature smaller than a radius of curvature of its image side, wherein the radius of curvature of the object side of the second lens is in a positive value;
an aperture (S);
a third lens (L 3 ), having a positive refractive power, and including a concave object side and a convex image side, wherein the radius of curvature of the object side of the third lens is in a negative value;
a fourth lens (L 4 ), having a positive refractive power, and including an object side having a radius of curvature greater than a radius of curvature of its image side, wherein the radius of curvature of the object side of the fourth lens is in a positive value;
a fifth lens (L 5 ), having a negative refractive power, and including an object side having a radius of curvature smaller than a radius of curvature of its image side, wherein the radius of curvature of the object side of the fifth lens is in a negative value; and
a sixth lens (L 6 ), having a positive refractive power, and including an object side having a radius of curvature greater than a radius of curvature of its image side, wherein the radius of curvature of the object side of the sixth lens is in a positive value;
wherein a maximum distortion of an image generated by the wide angle six-piece lens along the image height is smaller than 8.5%;
wherein, an overall effective focal length of the wide angle six-piece lens is f, a focal length of the third lens (L 3 ) is f3, and an equation below is further satisfied:
0.29< f/f 3<0.36.
2. The wide angle six-piece lens of claim 1 , wherein the image side of the first lens is a concave surface; the object side of the second lens is a convex surface; the image side of the third lens is a convex surface; both the object side and the image side of the fourth lens are convex surfaces; the object side of the fifth lens is a concave surface; the object side of the six lens is a convex surface.
3. The wide angle six-piece lens of claim 1 , wherein an image side of the fourth lens (L 4 ) is a convex surface.
4. The wide angle six-piece lens of claim 1 , wherein a system length of the wide angle six-piece lens is TTL, the overall effective focal length of the wide angle six-piece lens is f, and an equation below is further satisfied:
6.11≤ TTL/f≤ 6.64.
5. The wide angle six-piece lens of claim 1 , wherein an object side of the first lens (L 1 ) is a convex surface.
6. The wide angle six-piece lens of claim 1 , wherein an image side of the second lens (L 2 ) is a concave surface.
7. The wide angle six-piece lens of claim 1 , wherein an image side of the fifth lens (L 5 ) is a concave surface.
8. The wide angle six-piece lens of claim 1 , wherein an image side of the sixth lens (L 6 ) is a convex surface.
9. The wide angle six-piece lens of claim 1 , wherein the overall effective focal length of the wide angle six-piece lens is f, a focal length of the fifth lens (L 5 ) is f5, and an equation below is further satisfied:
0.68<| f/f 5|<0.9.
10. The wide angle six-piece lens of claim 1 , wherein a radius of curvature of the image side of the first lens (L 1 ) is R2, a radius of curvature of the object side of the second lens (L 2 ) is R3, and the first lens (L 1 ) and the second lens (L 2 ) further satisfy an equation below:
1.5< R 3/ R 2<4.
11. The wide angle six-piece lens of claim 1 , wherein a distance from an object side of the first lens (L 1 ) to an imaging surface ( 20 ) is D, a focal length of the first lens (L 1 ) is f1, and an equation below is further satisfied:
4.2<| D/f 1|<5.4.
12. The wide angle six-piece lens of claim 1 , wherein a abbe number of the fourth lens (L 4 ) is V4, a abbe number of the fifth lens (L 5 ) is V5, a abbe number of the sixth lens (L 6 ) is V6, and an equation below is further satisfied:
(
V
4
+
V
6
)
2
-
V
5
>
25.
13. The wide angle six-piece lens of claim 1 , wherein an object side and the image side of the first lens (L 1 ) are aspheric.