Backlight using planar hologram for flat display device

摘要

The backlight for a flat display device including a light source, a light guide plate and a surface hologram is provided. The light guide plate is installed at one side of the light source, and light from the light source travels in the light guide plate while being totally reflected. The surface hologram is formed on at least one surface of the light guide plate. The surface hologram has a pattern of a predetermined grating interval and a predetermined grating depth in order to diffract light at a predetermined angle toward the light guide plate.