The present disclosure is directed to a liquid crystal display device including a display panel having a red pixel, a green pixel, and a blue pixel; and a backlight unit configured to emit light to the display panel. The backlight unit includes a light source which outputs a first color light; a color conversion layer configured to convert the first color light into a second color light such that red light and green light are spatially separated; and an optical sheet which diffuses or condenses the second color light.