A display device including a sub-backlight unit which can prevent the obscure sights caused by light from the light source of the sub-backlight unit arriving on an article or reel of the main display screen and then reflecting in the frontal direction is provided. The sub-backlight unit includes a second light guide panel having an opening part formed therein corresponding to a transparent window, a second light source disposed around the second light guide panel, and a polymer dispersed liquid crystal (PDLC) sheet disposed close to the front side of the opening of the second light guide panel.