Patent ID: 8786802

Claim:
A backlight assembly comprising: a light source that generates light; and a first optical member, wherein the first optical member comprises: a body including an incident surface to which the light is incident and an exit surface facing the incident surface, from which the light exits; and a first diffusion member disposed on the exit surface to diffuse the light, wherein the first diffusion member comprises: a single vertex; four inclined surfaces, wherein the four inclined surfaces meet at the single vertex, each of the four inclined surfaces is inclined with respect to a flat portion of the exit surface, and each of the inclined surfaces has a curved shape; four edges, wherein each of the four edges is disposed between the exit surface and the single vertex and has a curved shape; and wherein the first diffusion member comprising the first and third edges has a cross-section in a first segment that is defined by an elliptical arc of a first ellipse, which includes the first and third edges, and a chord connecting both ends of the elliptical arc of the first ellipse, and the first diffusion member comprising the second and fourth edges has a cross-section in a second segment that is defined by an elliptical arc of a second ellipse, which includes the second and fourth edges, and a chord connecting both ends of the elliptical arc of the second ellipse.