Patent ID: 8780299

Claim:
A backlight unit comprising: a light source configured to generate light; and a plurality of transparent light guide members stacked so that one or more individual surfaces of each transparent light guide member contact a surface of another one of the transparent light guide members, the plurality of light guide members configured to guide the light, wherein each of the light guide members comprises: a light incident surface for receiving incident light from the light source; an opposite surface facing an adjacent one of the light guide members; and a plurality of light path change patterns disposed on the opposite surface; and wherein each light guide member is configured to transmit light from its light incident surface through the light path change patterns of its opposite surface; wherein the light guide members further comprise: a first light guide member comprising a first opposite surface and having a plurality of first light path change patterns disposed on the first opposite surface; a second light guide member comprising a second opposite surface facing the first opposite surface and having a plurality of second light path change patterns disposed on the second opposite surface; and at least one third light guide member disposed between the first light guide member and the second light guide member, wherein each third light guide member comprises: a third opposite surface facing the first opposite surface; a plurality of third light path change patterns disposed on the third opposite surface; a fourth opposite surface facing the second opposite surface; and a plurality of fourth light path change patterns disposed on the fourth opposite surface.