A backlight unit comprising: a light guide member including a first light incident part on a first side surface and a second light incident part on a second side surface opposite to the first side surface; a first light source unit in the first light incident part; a second light source unit in the second light incident part, wherein the first light source unit and the second light source unit have a different luminous intensity, wherein the light guide member comprises a partial light output area defined between the second light incident part and a center portion between the first light incident part and the second light incident part, wherein the second light source unit is configured to irradiate the light onto only the partial light output area, when the backlight unit is partially driven, wherein the light guide member comprises: a base member including the first light incident part and the second light incident part; and a plurality of optical patterns provided on a bottom of the base member, wherein each of the plurality of optical patterns comprises: a first inclined portion including a first inclined surface inclined in a direction from a bottom of the base member to the second light incident part to face the first light incident part; and a second inclined portion including a second inclined surface inclined in a direction from the bottom of the base member to an end of the first inclined portion to face the second light incident part, characterised in that the first inclined portion further includes a first one-side inclined surface inclined in a direction from one side of the first inclined surface to the bottom of the base member, and a first other-side inclined surface (215a2) inclined in a direction from the other side of the first inclined surface to the bottom of the base member, and the second inclined portion further includes a second one-side inclined surface (215b1) inclined in a direction from one side of the second inclined surface to the bottom of the base member, and a second other-side inclined surface (215b2) inclined in a direction from the other side of the second inclined surface to the bottom of the base member. a light guide member including a first light incident part on a first side surface and a second light incident part on a second side surface opposite to the first side surface; a first light source unit in the first light incident part; a second light source unit in the second light incident part, wherein the first light source unit and the second light source unit have a different luminous intensity, wherein the light guide member comprises a partial light output area defined between the second light incident part and a center portion between the first light incident part and the second light incident part, wherein the second light source unit is configured to irradiate the light onto only the partial light output area, when the backlight unit is partially driven, wherein the light guide member comprises: a base member including the first light incident part and the second light incident part; and a plurality of optical patterns provided on a bottom of the base member, a base member including the first light incident part and the second light incident part; and a plurality of optical patterns provided on a bottom of the base member, wherein each of the plurality of optical patterns comprises: a first inclined portion including a first inclined surface inclined in a direction from a bottom of the base member to the second light incident part to face the first light incident part; and a second inclined portion including a second inclined surface inclined in a direction from the bottom of the base member to an end of the first inclined portion to face the second light incident part, characterised in that a first inclined portion including a first inclined surface inclined in a direction from a bottom of the base member to the second light incident part to face the first light incident part; and a second inclined portion including a second inclined surface inclined in a direction from the bottom of the base member to an end of the first inclined portion to face the second light incident part, characterised in that the first inclined portion further includes a first one-side inclined surface inclined in a direction from one side of the first inclined surface to the bottom of the base member, and a first other-side inclined surface (215a2) inclined in a direction from the other side of the first inclined surface to the bottom of the base member, and the second inclined portion further includes a second one-side inclined surface (215b1) inclined in a direction from one side of the second inclined surface to the bottom of the base member, and a second other-side inclined surface (215b2) inclined in a direction from the other side of the second inclined surface to the bottom of the base member.