Lens module
There is provided a lens module including: a first lens having positive refractive power; a second lens having positive refractive power; a third lens having refractive power; a fourth lens having negative refractive power; a fifth lens of which an object-side surface is convex; and a sixth lens having an inflection point formed on an image-side surface or an object-side surface thereof.
1. A lens module comprising, in order from an object side to an image side:
a first lens having positive refractive power;
a second lens having positive refractive power;
a third lens having refractive power;
a fourth lens having negative refractive power;
a fifth lens having negative refractive power and of which an object-side surface is convex; and
a sixth lens having an inflection point formed on an image-side surface or an object-side surface thereof.
2. The lens module of claim 1 , wherein the first to sixth lens are formed of plastic.
3. The lens module of claim 1 , wherein both surfaces of the first lens are convex.
4. The lens module of claim 1 , wherein an image-side surface of the second lens is convex.
5. The lens module of claim 1 , wherein the third lens has negative refractive power.
6. The lens module of claim 1 , wherein an object-side surface of the third lens is concave.
7. The lens module of claim 1 , wherein the fourth lens has a meniscus shape, convex toward the image side.
8. The lens module of claim 1 , wherein the object-side surface of the fifth lens is convex, and an image-side surface thereof is concave.
9. The lens module of claim 1 , wherein the fifth lens has an inflection point formed on the object-side surface or an image-side surface thereof.
10. The lens module of claim 1 , wherein the object-side surface of the sixth lens is convex.
11. The lens module of claim 1 , wherein the image-side surface of the sixth lens is concave.
12. The lens module of claim 1 , wherein the sixth lens has negative refractive power or positive refractive power.
13. The lens module of claim 1 , wherein at least one of object-side surfaces and image-side surfaces of the first to sixth lenses is aspherical.
14. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 1:
0.6<f1/f<1.2 [Conditional Equation 1]
where f is an overall focal length of the optical system, and f1 is a focal length of the first lens.
15. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 2:
| v 2− v 3|>25.0 [Conditional Equation 2]
where v 2 is an abbe number of the second lens, and v3 is an abbe number of the third lens.
16. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 3:
0.8< f 2/ f< 1.4 [Conditional Equation 3]
where f 2 is a focal length of the second lens, and f is an overall focal length of the optical system.
17. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 4:
0.5<| f 3/ f| 21 1.1 [Conditional Equation 4]
where f 3 is a focal length of the third lens, and f is an overall focal length of the optical system.
18. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 5 :
f 4/ f<− 10.0 [Conditional Equation 5]
where f 4 is a focal length of the fourth lens, and f is an overall focal length of the optical system.
19. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 6:
f 5/ f<− 5.0 [Conditional Equation 6]
where f 5 is a focal length of the fifth lens, and f is an overall focal length of the optical system.
20. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 7:
| f 6/ f|> 3.0 [Conditional Equation 7]
where f 6 is a focal length of the sixth lens, and f is an overall focal length of the optical system.
21. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 8:
OAL/ f< 1.4 [Conditional Equation 8]
where OAL is a distance from an object-side surface of the first lens to an image surface, and f is an overall focal length of the optical system.
22. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 9:
0.4< f 1/ f 2<1.1 [Conditional Equation 9]
where f 1 is a focal length of the first lens, and f2 is a focal length of the second lens.
23. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 10:
| f 2/ f 3|<1.5 [Conditional Equation 10]
where f 2 is a focal length of the second lens, and f3 is a focal length of the third lens.
24. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 11:
BFL/ f> 0.25 [Conditional Equation 11]
where BFL is a distance from the image-side surface of the sixth lens to an image surface, and f is an overall focal length of the optical system.
25. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 12:
D 1/ f< 0.5 [Conditional Equation 12]
where D 1 is an air gap between the first and second lenses, and f is an overall focal length of the optical system.
26. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 13:
r 1/ f> 0.5 [Conditional Equation 13]
where r 1 is a radius of curvature of an object-side surface of the first lens, and f is an overall focal length of the optical system.
27. The lens module of claim 1 , wherein an optical system including the first to sixth lens satisfies Conditional Equation 14:
| r 4/ f| <1.0 [Conditional Equation 14]
where r 4 is a radius of curvature of an image-side surface of the second lens, and f is an overall focal length of the optical system.