Lens module

1. A lens module comprising:

first to seventh lenses each having refractive power and sequentially disposed in numerical order from the first lens to the seventh lens starting from an object side of the lens module,

wherein each of the first and second lenses has a meniscus shape and an image-side surface that is convex,

wherein the fifth lens has an object-side surface that is concave, and

wherein the seventh lens has one or more inflection points on an image-side surface thereof.

2. The lens module of claim 1 , wherein an object-side surface of the first lens is concave.

3. The lens module of claim 1 , wherein an object-side surface of the second lens is concave.

4. The lens module of claim 1 , wherein both surfaces of the third lens are convex.

5. The lens module of claim 1 , wherein the fourth lens has a meniscus shape and an object-side surface that is convex.

6. The lens module of claim 1 , wherein the fifth lens has a meniscus shape and an image-side surface that is convex.

7. The lens module of claim 1 , wherein the sixth lens has a meniscus shape and an image-side surface that is convex.

8. The lens module of claim 1 , wherein the seventh lens has a meniscus shape and an object-side surface that is convex.

9. The lens module of claim 1 , wherein the image-side surface of the seventh lens is concave.

10. The lens module of claim 1 , wherein at least five of the first to seventh lenses are made of plastic.

11. A lens module comprising:

a first lens having positive refractive power, an object-side surface thereof being concave;

a second lens having negative refractive power;

a third lens having positive refractive power;

a fourth lens having negative refractive power;

a fifth lens having refractive power, an object-side surface thereof being concave;

a sixth lens having refractive power; and

a seventh lens having negative refractive power and having one or more inflection points on an image-side surface thereof,

wherein the first to seventh lenses are sequentially disposed in numerical order from the first lens to the seventh lens starting from an object side of the lens module.

12. The lens module of claim 11 , wherein the fifth lens has negative refractive power.

13. The lens module of claim 11 , wherein the sixth lens has positive refractive power.

14. The lens module of claim 11 , further comprising a stop disposed between the third and fourth lenses.

15. The lens module of claim 11 , wherein 80°<FOV is satisfied,

where FOV is a field of view of an optical system comprising the first to seventh lenses.

16. The lens module of claim 11 , wherein d2/d3<0.2 is satisfied,

where d2 is a distance from an image-side surface of the first lens to an object-side surface of the second lens, and

d3 is a thickness of the second lens.

17. A lens module comprising:

first to seventh lenses each having refractive power and sequentially disposed in numerical order from the first lens to the seventh lens starting from an object side of the lens module,

wherein effective radii of surfaces of the first to third lenses strictly decrease in order from an object-side surface of the first lens to an image-side surface of the third lens,

wherein the fifth lens has an object-side surface that is concave, and

wherein effective radii of surfaces of the fourth to seventh lenses strictly increase in order from an object-side surface of the fourth lens to an image-side surface of the seventh lens.

18. The lens module of claim 17 , wherein the first, third, and sixth lens have positive refractive power, and

wherein the second, fourth, fifth, and seventh lenses have negative refractive power.

19. The lens module of claim 17 , wherein the first, second, fourth, fifth, and sixth lenses have a meniscus shape,

wherein the third lens does not have a meniscus shape, and

wherein the seventh lens has one or more inflection points on an image-side surface thereof.

20. The lens module of claim 19 , wherein an image-side surface of each of the first, second, fifth, sixth, and seventh lenses is concave,

wherein both surfaces of the third lens are convex, and

wherein an image-side surface of the fourth lens is convex.