A backlight unit and method of use are provided having a first light guide plate, a linear light source disposed along at least one side edge of the first light guide plate, a plurality of second light guide plates facing the first light guide plate, and a point light source disposed along at least one side edge of each second light guide plate. Accordingly, the present invention can provide a backlight unit using both a point light source and a linear light source at substantially the same time, and having superior color reproducibility and low power consumption.