Optical member, method of manufacturing the optical member and backlight assembly having the optical member

1. An optical member comprising:

a base body having a first surface and a second surface opposite to the first surface, the second surface receiving light from a plurality of light sources;

a plurality of light-concentrating lenses formed on the first surface at a predetermined pitch; and

a plurality of light-diffusing patterns respectively formed at positions of the second surface respectively corresponding to the light sources to reduce an amount of light reflected by the light-concentrating lenses, each of the light-diffusing patterns including curved surfaces extending in a first direction and having a width which is in a range determined by the following inequality

H ×tan {90°− a −cos −1 (1/ n )}< D<H ×tan {90°−3 a +cos −1 (1/ n )},

in which ‘H’ is a distance between the light sources and the second surface, ‘a’ is an angle between an external surface of one of the light-concentrating lenses and the first surface, ‘n’ is a refractive index of the light-concentrating lenses, and ‘D’ is the width of each light-diffusing pattern.

2. The optical member of claim 1 , wherein the curved surfaces comprise convex surfaces with respect to the second surface or concave surfaces with respect to the second surface.

3. The optical member of claim 2 , wherein a cross-section of each of the curved surfaces comprises one of a substantially semicircular shape, a substantially half-oval shape and a substantially polygonal shape.

4. The optical member of claim 2 , wherein the light-concentrating lenses protrude from the first surface and have a substantially prism shape or a substantially half-cylindrical shape.

5. The optical member of claim 1 , wherein the light-diffusing patterns are separated from one another in a second direction substantially perpendicular to the first direction.

6. A backlight assembly comprising:

a plurality of lamps disposed in parallel and separated from one another; and

an optical member comprising:

a base body disposed on the lamps, the base body having a first surface emitting light and a second surface opposite to the first surface, the second surface receiving the light from the lamps;

a plurality of light-concentrating lenses formed on the first surface at a predetermined pitch; and

a plurality of light-diffusing patterns respectively formed at positions of the second surface which are respectively disposed directly on the lamps, each of the light-diffusing patterns having a width which is in a range determined by the following inequality,

H ×tan {90°− a −cos −1 (1/ n )}< D<H ×tan {90°−3 a +cos −1 (1/ n )},

in which ‘H’ is a distance between the lamps and the second surface, ‘a’ is an angle between an external surface of one of the light-concentrating lenses and the first surface, ‘n’ is a refractive index of the light-concentrating lenses, and ‘D’ is the width of each light-diffusing pattern.

7. The backlight assembly of claim 6 , wherein each of the light-diffusing patterns includes curved surfaces extending in a first direction.

8. The backlight assembly of claim 7 , wherein the curved surfaces comprise convex surfaces with respect to the second surface or concave surfaces with respect to the second surface.

9. The backlight assembly of claim 8 , wherein a cross-section of each of the curved surfaces comprises one of a substantially semicircular shape, a substantially half-oval shape and a substantially polygonal shape.

10. The backlight assembly of claim 9 , wherein the light-concentrating lenses protrude from the first surface and have a substantially prism shape or a substantially half-cylindrical shape.

11. The backlight assembly of claim 10 , further comprising:

a receiving container comprising a bottom plate on which the lamps are disposed and sidewalls supporting the optical member;

a diffusing plate disposed between the lamps and the optical member; and

a brightness enhancement sheet disposed on the optical member.

12. The backlight assembly of claim 7 , wherein the light-diffusing patterns are separated from one another in a second direction substantially perpendicular to the first direction.