Display apparatus

1. A display apparatus comprising:

a display panel; and

a backlight provided adjacent the display panel, wherein the backlight includes

an optical sheet provided adjacent the display panel,

a reflector provided a prescribed distance from the optical sheet,

at least one light emitting device provided adjacent the reflector, and

a lens provided over a corresponding the light emitting device,

wherein the lens includes

a lower recess formed on a bottom surface of the lens and provided a prescribed distance over the light emitting device, and

an upper recess formed on a top surface of the lens and provided to vertically overlap the bottom recess,

wherein the lower recess has an oval shape and includes

a side surface that extends vertically from the bottom surface, and

a first upper surface that extends from the side surface at a first prescribed angle relative to the side surface, the first upper surface having a convex curvature.

2. The display apparatus of claim 1 , wherein the first upper surface extends from the side surface to form a vertex a prescribed distance above the bottom surface.

3. The display apparatus of claim 2 , wherein the lower recess includes

a second upper surface that extends from the side surface at a second prescribed angle relative to the side surface, and

a third upper surface symmetrical to the second upper surface and extending to the second upper surface from an opposite side of the lower recess.

4. The display apparatus of claim 3 , wherein the second upper surface and the third upper surface have a concave curvature.

5. The display apparatus of claim 4 , wherein the second upper surface and the third upper surface intersect at a prescribed angle relative to each other parallel to a long axis of the lower recess.

6. The display apparatus of claim 5 , wherein the vertex of the first upper surface is adjacent to the first and second upper surfaces where the first and second surfaces intersect.

7. The display apparatus of claim 3 , wherein the first upper surface extends from the side surface at a first prescribed distance from the bottom surface and the second upper surface extends from the side surface at a second prescribed distance from the bottom surface, the second prescribed distance being less than or equal to the first prescribed distance.

8. The display apparatus of claim 4 , wherein the oval shape of the lower recess includes a rectangular portion and round portions provided at short ends of the rectangular portion, and

wherein the first upper surface extends from the side surface at the round portion and the second and third surfaces extend from the side surface at the rectangular portion.

9. The display apparatus of claim 1 , wherein a length of the lower recess is at least twice a width of the lower recess.

10. The display apparatus of claim 1 , wherein the top surface of the lens has a prescribed shape that is convex from an outer circumferential edge to a center of the lens.

11. The display apparatus of claim 10 , wherein the top surface includes a plurality of sections corresponding to circular sectors of the lens, and wherein adjacent sections have different heights relative to each other.

12. The display apparatus according to claim 10 , wherein the curvature of the top surface is such that an angle of incidence of light incident on the top surface of the lens from a corresponding light emitting device is greater than or equal to 42°.

13. A display apparatus comprising:

a display panel; and

a backlight provided adjacent the display panel, wherein the backlight includes

an optical sheet provided adjacent the display panel,

a reflector provided a prescribed distance from the optical sheet,

at least one light emitting device provided adjacent the reflector, and

a lens provided over a corresponding the light emitting device,

wherein the lens includes

a lower recess formed on a bottom surface of the lens and provided a prescribed distance over the light emitting device, and

an upper recess formed on a top surface of the lens and provided to vertically overlap the bottom recess, wherein the upper recess has an oval shape and includes

a side surface that extends vertically from the top surface of the lens,

a first lower surface having a prescribed curvature and extending from the side surface, and

a second lower surface which is symmetrical to the first lower surface and extending toward the first lower surface from an opposite side of the upper recess.

14. The display apparatus of claim 13 , wherein the first lower surface and the second lower surface have concave curvatures.

15. The display apparatus of claim 13 , wherein the first and second lower surfaces intersect at a prescribed angle relative to each other parallel to a long axis of the upper recess.

16. The display apparatus according to claim 15 , wherein a depth of the upper recess is greatest where the first and second lower surfaces intersect.

17. The display apparatus according to claim 13 , wherein a long axis of the lower recess is parallel to a long axis of the upper recess and provided to vertically overlap each other.

18. A display apparatus comprising:

a display panel; and

a backlight provided adjacent the display panel, wherein the backlight includes

an optical sheet provided adjacent the display panel,

a reflector provided a prescribed distance from the optical sheet,

at least one light emitting device provided adjacent the reflector, and

a lens provided over a corresponding the light emitting device,

wherein the lens includes

a lower recess formed on a bottom surface of the lens and provided a prescribed distance over the light emitting device, and

an upper recess formed on a top surface of the lens and provided to vertically overlap the bottom recess, wherein a ratio of a depth of the upper recess to a radius of the lens satisfies a following condition:

0.3≦H/P≦0.5, wherein H is a height from a top of the lens to a lowermost point in the upper recess, and P is the radius of the lens.

19. A display apparatus comprising:

a display panel;

a light emitting device;

a reflector provided adjacent to the light emitting device; and

a lens provided a prescribed distance over the light emitting device and configured to distribute light to illuminate the display panel,

wherein the lens includes a recess having an oval shape provided on a bottom surface of the lens, the recess including

a side surface that extends vertically a prescribed distance from the bottom surface, and

an upper surface that extends from the side surface and having a convex curvature, wherein a width of the upper surface gradually decreases into the recess.