A display device comprising: a reflective sheet; a light guide plate on the reflective sheet, comprising an incident surface; a plurality of optical sheets on the light guide plate; a light emitting diode disposed at lateral side of the light guide plate; a wavelength conversion member adjacent to the LED; and a display panel to which light output from the wavelength conversion member is incident, wherein the wavelength conversion member comprises: a tube; a host in the tube; and a plurality of quantum dots in the host; wherein the tube comprises: an incident surface opposite to the light emitting diode; an exit surface opposite to the incident surface; and wherein the wavelength conversion member is disposed between the light emitting diode and the light guide plate and extends along the lateral side of the light guide plate; characterized in that the wavelength conversion member further comprises an inclined surface (402, 403) extending from the incident surface to the exit surface, wherein the inclined surface (402, 403) includes a first inclined surface and a second inclined surface, wherein the inclined surface (402, 403) is inclined with respect to the incident surface, wherein the display device further comprises a heat transfer part interposed between the LED and the wavelength conversion member, the heat transfer part being disposed on the incident surface of the tube, wherein the heat transfer part covers the first inclined surface and the second inclined surface of the tube, wherein the heat transfer part is transparent. a reflective sheet; a light guide plate on the reflective sheet, comprising an incident surface; a plurality of optical sheets on the light guide plate; a light emitting diode disposed at lateral side of the light guide plate; a wavelength conversion member adjacent to the LED; and a display panel to which light output from the wavelength conversion member is incident, wherein the wavelength conversion member comprises: a tube; a host in the tube; and a plurality of quantum dots in the host; a tube; a host in the tube; and a plurality of quantum dots in the host; wherein the tube comprises: an incident surface opposite to the light emitting diode; an exit surface opposite to the incident surface; and wherein the wavelength conversion member is disposed between the light emitting diode and the light guide plate and extends along the lateral side of the light guide plate; characterized in that the wavelength conversion member further comprises an inclined surface (402, 403) extending from the incident surface to the exit surface, wherein the inclined surface (402, 403) includes a first inclined surface and a second inclined surface, wherein the inclined surface (402, 403) is inclined with respect to the incident surface, wherein the display device further comprises a heat transfer part interposed between the LED and the wavelength conversion member, the heat transfer part being disposed on the incident surface of the tube, wherein the heat transfer part covers the first inclined surface and the second inclined surface of the tube, wherein the heat transfer part is transparent. an incident surface opposite to the light emitting diode; an exit surface opposite to the incident surface; and wherein the wavelength conversion member is disposed between the light emitting diode and the light guide plate and extends along the lateral side of the light guide plate; characterized in that the wavelength conversion member further comprises an inclined surface (402, 403) extending from the incident surface to the exit surface, wherein the inclined surface (402, 403) includes a first inclined surface and a second inclined surface, wherein the inclined surface (402, 403) is inclined with respect to the incident surface, wherein the display device further comprises a heat transfer part interposed between the LED and the wavelength conversion member, the heat transfer part being disposed on the incident surface of the tube, wherein the heat transfer part covers the first inclined surface and the second inclined surface of the tube, wherein the heat transfer part is transparent.