SUPER DIRECTIONAL LIGHT GUIDE FILM AND THIN FILM TYPE BACK LIGHT UNIT FOR FLAT PANEL DISPLAY USING THE SAME

摘要

Provided is a back light unit for a display device that has a light guide film. The light guide film includes, for example, a light entering part at a first side; a light reflecting part disposed at a second side; and a light guiding part between the light entering part and the light reflecting part, wherein the light entering part selectively sends an incident light of an expanded light provided from a light source that satisfies a total reflection condition toward the light guiding part, and wherein the light reflecting part converts the incident light provided from the light guiding part into a collimated light and sends it to the light guiding part.