The substrate 21′ may extend in a lateral direction, and may be positioned adjacent to the lower side of the light guide plate 23′. The at least one light assembly 21a′ may be mounted on the substrate 21′. Consequently, most of the light emitted from the light assembly 21a′ may be transmitted to the inside of the light guide plate 23′. Here, the light guide plate 23′ may reflect the incident light from the light assembly 21a′ forwards. The diffusion plate 23 (not shown in FIG. 4) may also be provided on the front surface of the light guide plate 23′.

The reflective sheet 22 may be positioned behind the light guide plate 23′. The reflective sheet 22 may reflect the light, which is emitted from the light assembly 21a′ or is reflected by the light guide plate 23′, forwards.

Referring to FIG. 5, a display device 1′ may include a display panel 10′, a middle frame 15′, a frame 30′ and a back cover 40′, unlike the previous embodiments. Here, the display device 1′ may be an OLED panel. The OLED panel is advantageous in that the display device 1′ is capable of being formed extremely slim because there is no need for a backlight unit.