Optical system
An optical system may include: in order from an object side, a first lens having positive refractive power and an object-side surface convex in the object side direction; a second lens having negative refractive power; a third lens having negative refractive power; a fourth lens having positive refractive power and an image-side surface convex in an image side direction; a fifth lens having negative refractive power and an image-side surface convex in the image side direction; and a sixth lens having negative refractive power and an image-side surface concave in the image side direction, such that bright, high resolution images may be implemented.
1. An optical system comprising:
in order from an object side,
a first lens having positive refractive power and an object-side surface convex in the object side direction;
a second lens having negative refractive power;
a third lens having negative refractive power;
a fourth lens having positive refractive power and an image-side surface convex in an image side direction;
a fifth lens having negative refractive power and an image-side surface convex in the image side direction;
a sixth lens having negative refractive power and an image-side surface concave in the image side direction: and
an aperture stop disposed between the first and second lenses.
2. The optical system of claim 1 , wherein the first lens has a meniscus shape in which it is convex in the object side direction.
3. The optical system of claim 1 , wherein both surfaces of the first lens are convex.
4. The optical system of claim 1 , wherein the second lens has a meniscus shape in which it is convex in the object side direction.
5. The optical system of claim 1 , wherein the third lens has a meniscus shape in which it is convex in the object side direction.
6. The optical system of claim 1 , wherein the fourth lens has a meniscus shape in which it is convex in the image side direction.
7. The optical system of claim 1 , wherein the fourth lens has a meniscus shape in which both surfaces thereof are convex.
8. The optical system of claim 1 , wherein the fifth lens has a meniscus shape in which it is convex in the image side direction.
9. The optical system of claim 1 , wherein the sixth lens has a meniscus shape in which it is convex in the object side direction.
10. The optical system of claim 1 , wherein the optical system satisfies the an Expression of
0.12< Th 6/ f< 0.5
where Th6 is a thickness of the sixth lens in a paraxial region, and f is an overall focal length of the optical system.
11. An optical system comprising:
in order from an object side,
a first lens having positive refractive power and an object-side surface convex in the object side direction;
a second lens having negative refractive power;
a third lens having negative refractive power;
a fourth lens having positive refractive power and an image-side surface convex in an image side direction;
a fifth lens having negative refractive power and an image-side surface convex in the image side direction;
a sixth lens having negative refractive power and an image-side surface concave in the image side direction;
wherein the optical system satisfies an Expression of
20< v 1− v 3<70
where v1 is an abbe number of the first lens, and v3 is an abbe number of the third lens.
12. The optical system of claim 1 , wherein the optical system satisfies an Expression of
| Sag 9/ Th 5|>1.0
where Sag9 is a sag value at an end of an effective aperture of an object-side surface of the fifth lens, and Th5 is a thickness of the fifth lens in a paraxial region.
13. The optical system of claim 1 , wherein the optical system satisfies an Expression of
f 3/ f 2>1.5
where f3 is a focal length of the third lens, and f2 is a focal length of the second lens.
14. The optical system of claim 1 , wherein the optical system satisfies an Expression of
0.5< OAL/f< 2.0
where OAL is a distance from the object-side surface of the first lens to an image surface, and f is an overall focal length of the optical system.
15. The optical system of claim 1 , wherein the optical system satisfies an Expression of
f 5/ f 1<−3.0
where f5 is a focal length of the fifth lens, and f1 is a focal length of the first lens.
16. The optical system of claim 1 , wherein the optical system satisfies an Expression of
1.60< n 5<2.10
where n5 is a refractive index of the fifth lens.
17. An optical system comprising:
in order from an object side,
a first lens having positive refractive power and an object-side surface convex in the object side direction;
a second lens having negative refractive power;
a third lens having refractive power;
a fourth lens having positive refractive power and an image-side surface convex in an image side direction;
a fifth lens having negative refractive power and an image-side surface convex in the image side direction; and
a sixth lens having negative refractive power and an image-side surface concave in the image side direction; and
an aperture stop disposed between the first and second lenses,
wherein the optical system satisfies an Expression of
0.12< Th 6/ f< 0.5
where Th6 is a thickness of the sixth lens in a paraxial region, and f is an overall focal length of the optical system.
18. An optical system comprising:
in order from an object side,
a first lens having positive refractive power and an object-side surface convex in the object side direction;
a second lens having negative refractive power;
a third lens having negative refractive power;
a fourth lens having positive refractive power and an image-side surface convex in an image side direction;
a fifth lens having negative refractive power and an image-side surface convex in the image side direction; and
a sixth lens having negative refractive power and an image-side surface concave in the image side direction,
wherein the optical system satisfies an Expression of
20< v 1− v 3<70
where v1 is an abbe number of the first lens, and v3 is an abbe number of the third lens.
19. The optical system of claim 17 , wherein the optical system satisfies an Expression of
| Sag 9/ Th 5|>1.0
where Sag9 is a sag value at an end of an effective aperture of an object-side surface of the fifth lens, and Th5 is a thickness of the fifth lens in a paraxial region.
20. The optical system of claim 17 , wherein the optical system satisfies an Expression of
f 3/ f 2>1.5
where f3 is a focal length of the third lens, and f2 is a focal length of the second lens.
21. The optical system of claim 17 , wherein the optical system satisfies an Expression of
0.5< OAL/f< 2.0
where OAL is a distance from the object-side surface of the first lens to an image surface, and f is the overall focal length of the optical system.
22. The optical system of claim 17 , wherein the optical system satisfies an Expression of
f 5/ f 1<−3.0
where f5 is a focal length of the fifth lens, and f1 is a focal length of the first lens.
23. The optical system of claim 17 , wherein the optical system satisfies an Expression of
1.60< n 5<2.10
where n5 is a refractive index of the fifth lens.