Thin direct-view LED backlights

1. A light-emitting apparatus comprising:

a light-emitting element;

a lens covering the light-emitting element, the lens comprising:

an upper surface having a convex shape; and

a lower surface comprising a cavity to which light emitted from the light-emitting elements is incident; and

a unit cell comprising a film stack, the film stack comprising:

a diffuser; and

at least one brightness enhancement film (BEF) disposed on the diffuser; and

an absorption film,

wherein the cavity comprises an apex facing an upper surface of the light-emitting element and configured to reduce Fresnel reflections emitted vertically,

wherein the light-emitting element is disposed in a hole formed at the central portion of a bottom floor of the unit cell, and

wherein opposing surfaces of the absorption film each comprises an anti-reflective coating.

2. The light-emitting apparatus of claim 1 , wherein the cavity has a pyramidal shape in a cross-sectional view.

3. The light-emitting apparatus of claim 2 , wherein each side of the cavity crosses a side of the light-emitting element in a plan view.

4. The light-emitting apparatus of claim 3 , wherein a height of the cavity is about 0.5 mm.

5. The light-emitting apparatus of claim 1 , wherein:

a diameter of the lens is in a range of 12 mm and 16 mm; and

a thickness of the lens is in a range of 3.5 mm and 4.5 mm.

6. The light-emitting apparatus of claim 1 , wherein the cavity has a conical shape in a cross-sectional view.

7. The light-emitting apparatus of claim 6 , wherein a hypotenuse of the conical shaped cavity has a curvature.

8. The light-emitting apparatus of claim 7 , wherein the hypotenuse of the conical shaped cavity has a concave shape.

9. The light-emitting apparatus of claim 8 , wherein:

the upper surface of the lens comprises a cusp formed in the center portion of the upper surface; and

the apex of the cavity substantially adjoins the cusp in a cross-sectional view.

10. The light-emitting apparatus of claim 1 , wherein:

a bottom surface of the cavity has a polygonal shape; and

a side wall of the cavity forms an acute angle with respect to an axis vertical to the bottom surface of the cavity.

11. A light-emitting apparatus comprising:

a light-emitting element; and

a lens covering the light-emitting element, the lens comprising:

an upper surface having a convex shape; and

a lower surface comprising a cavity to which light emitted from the light-emitting elements is incident; and

a unit cell comprising a film stack, the film stack comprising:

a diffuser; and

at least one brightness enhancement film (BEF) disposed on the diffuser; and

an absorption film,

wherein the cavity comprises an apex facing an upper surface of the light-emitting element and configured to reduce Fresnel reflections emitted vertically,

wherein the light-emitting element is disposed in a hole formed at the central portion of a bottom floor of the unit cell,

wherein the absorption film is disposed on a top surface of the film stack, and

wherein a portion of the absorption film overlapping the light-emitting element has the lowest transmissivity.

12. A backlight unit, comprising:

a plurality of the light-emitting apparatus of claim 1 disposed in a matrix form,

wherein the light-emitting apparatus disposed in each row overlap the light-emitting apparatus disposed in a successive row in a column direction.

13. The backlight unit of claim 12 , wherein a distance between adjacent light-emitting apparatus is 100 mm.

14. A backlight unit, comprising:

a plurality of the light-emitting apparatus of claim 1 disposed in a matrix form,

wherein the light-emitting apparatus disposed in each row do not overlap the light-emitting apparatus disposed in a successive row in a column direction.