The present invention relates to a display device using a separate light source, and the display device includes: a light guide including a plurality of corners and a plurality of edges connecting the corners to each other; a printed circuit board (PCB) disposed at at least one of the plurality of corners of the light guide; at least one light source disposed on the PCB; a display panel overlapping the light guide; and an auxiliary function module disposed proximate to an edge of the light guide connected to the corner where the light source is disposed, wherein the edge of the light guide connected to the corner where the light source is disposed has a depressed portion, and the auxiliary function module is disposed in correspondence with the depressed portion.