Lens module
There is provided a lens module including: a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having negative refractive power and having a convex image-side surface; a fifth lens having negative refractive power; and a sixth lens having negative refractive power and having one or more inflection point on an image-side surface thereof.
1. A lens module comprising:
a first lens having positive refractive power;
a second lens having negative refractive power;
a third lens having positive refractive power;
a fourth lens having negative refractive power, wherein an image-side surface of the fourth lens, on an optical axis, is convex;
a fifth lens having negative refractive power; and
a sixth lens having negative refractive power and having one or more inflection point on an image-side surface thereof.
2. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
0.0< f 1/ f< 0.9 [Conditional Expression]
where f1 is a focal length of the first lens, and f is an overall focal length of an optical system including the first to sixth lenses.
3. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
20< V 1− V 2<40 [Conditional Expression]
where V1 is an Abbe number of the first lens, and V2 is an Abbe number of the second lens.
4. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
20< V 1− V 4<40 [Conditional Expression]
where V1 is an Abbe number of the first lens, and V4 is an Abbe number of the fourth lens.
5. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
20< V 1− V 5<40 [Conditional Expression]
where V1 is an Abbe number of the first lens, and V5 is an Abbe number of the fifth lens.
6. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
−2.0< f 2/ f< 0.0 [Conditional Expression]
where f2 is a focal length of the second lens, and f is an overall focal length of an optical system including the first to sixth lenses.
7. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
0.0< f 3/ f< 6.0 [Conditional Expression]
where f3 is a focal length of the third lens, and f is an overall focal length of an optical system including the first to sixth lenses.
8. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
f 4/ f<− 2.0 [Conditional Expression]
where f4 is a focal length of the fourth lens, and f is an overall focal length of an optical system including the first to sixth lenses.
9. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
f 5/ f<− 5.0 [Conditional Expression]
where f5 is a focal length of the fifth lens, and f is an overall focal length of an optical system including the first to sixth lenses.
10. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
OAL/f< 1.5 [Conditional Expression]
where OAL is a distance from an object-side surface of the first lens to an imaging surface, and f is an overall focal length of an optical system including the first to sixth lenses.
11. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
−0.8< f 1/ f 2<0.0 [Conditional Expression]
where f1 is a focal length of the first lens, and f2 is a focal length of the second lens.
12. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
−0.8< f 2/ f 3<0.8 [Conditional Expression]
where f2 is a focal length of the second lens, and f3 is a focal length of the third lens.
13. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
BFL/f< 0.5 [Conditional Expression]
where BFL is a distance from the image-side surface of the sixth lens to an imaging surface, and f is an overall focal length of an optical system including the first to sixth lenses.
14. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
D 12/ f< 0.1 [Conditional Expression]
where D12 is an air interval between the first and second lenses, and f is an overall focal length of an optical system including the first to sixth lenses.
15. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
0.25< r 1/ f [Conditional Expression]
where r1 is a radius of curvature of an object-side surface of the first lens, and f is an overall focal length of an optical system including the first to sixth lenses.
16. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
r 5/ f< 0.7 [Conditional Expression]
where r5 is a radius of curvature of an object-side surface of the third lens, and f is an overall focal length of an optical system including the first to sixth lenses.
17. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
r 8/ f<− 0.6 [Conditional Expression]
where r8 is a radius of curvature of an image-side surface of the fourth lens, and f is an overall focal length of an optical system including the first to sixth lenses.
18. The lens module of claim 1 , wherein the following Conditional Expression is satisfied:
( EPD/ 2)/ f 12<1.0 [Conditional Expression]
where EPD/2 is a radius of an entrance pupil diameter, and f12 is a composite focal length of the first and second lenses.
19. A lens module comprising:
a first lens having positive refractive power, wherein an image-side surface of the first lens, on an optical axis, is concave;
a second lens having negative refractive power, wherein an object-side surface of the second lens, on the optical axis, is convex;
a third lens having positive refractive power, wherein an object-side surface of the third lens, on the optical axis, is convex;
a fourth lens having a convex image-side surface on the optical axis;
a fifth lens having negative refractive power, wherein an image-side surface of the fifth lens, on the optical axis, is concave; and
a sixth lens having refractive power and having one or more inflection point on an image-side surface thereof.
20. The lens module of claim 19 , wherein the first lens has a convex object-side surface.
21. The lens module of claim 19 , wherein the second lens has a concave image-side surface.
22. The lens module of claim 19 , wherein the third lens has a convex image-side surface.
23. The lens module of claim 19 , wherein the fourth lens has a concave object-side surface.
24. The lens module of claim 19 , wherein the fifth lens has a concave object-side surface.
25. The lens module of claim 19 , wherein the sixth lens has a convex object-side surface.
26. The lens module of claim 19 , wherein the image-side surface of the sixth lens is concave.
27. The lens module of claim 19 , wherein the third lens has a concave image-side surface.
28. The lens module of claim 19 , wherein the fifth lens has a convex object-side surface.