A display device comprising: an optical member; a display panel disposed above the optical member; and a plurality of light emitting units disposed below the optical member and configured to provide first colour light to the optical member, wherein the optical member comprises: a support substrate (300-G) overlapping the light emitting units; a quantum dot layer (300-Q) disposed on the support substrate and configured to convert the first colour light into second colour light and third colour light; and a filter (300-F) disposed on at least one of an upper surface and a lower surface of the support substrate (300-G), wherein the filter overlaps a portion of the upper surface and the lower surface of the support substrate, wherein the filter has a first transmittance to the first colour light at a first incident angle of o degrees and has a second transmittance greater than the first transmittance to the first colour light at a second incident angle greater than the first incident angle; wherein each of the light emitting units comprises a circuit board (200-P) and a plurality of light emitting elements (200-L) mounted on the circuit board; characterized in that: each circuit board has a substantially elongated shape; the filter comprises a plurality of filter patterns spaced apart from each other; and each of the filter patterns corresponds to a corresponding one of the light emitting elements in a plan view. an optical member; a display panel disposed above the optical member; and a plurality of light emitting units disposed below the optical member and configured to provide first colour light to the optical member, wherein the optical member comprises: a support substrate (300-G) overlapping the light emitting units; a quantum dot layer (300-Q) disposed on the support substrate and configured to convert the first colour light into second colour light and third colour light; and a filter (300-F) disposed on at least one of an upper surface and a lower surface of the support substrate (300-G), wherein the filter overlaps a portion of the upper surface and the lower surface of the support substrate, wherein the filter has a first transmittance to the first colour light at a first incident angle of o degrees and has a second transmittance greater than the first transmittance to the first colour light at a second incident angle greater than the first incident angle; a support substrate (300-G) overlapping the light emitting units; a quantum dot layer (300-Q) disposed on the support substrate and configured to convert the first colour light into second colour light and third colour light; and a filter (300-F) disposed on at least one of an upper surface and a lower surface of the support substrate (300-G), wherein the filter overlaps a portion of the upper surface and the lower surface of the support substrate, wherein the filter has a first transmittance to the first colour light at a first incident angle of o degrees and has a second transmittance greater than the first transmittance to the first colour light at a second incident angle greater than the first incident angle; wherein each of the light emitting units comprises a circuit board (200-P) and a plurality of light emitting elements (200-L) mounted on the circuit board; characterized in that: each circuit board has a substantially elongated shape; the filter comprises a plurality of filter patterns spaced apart from each other; and each of the filter patterns corresponds to a corresponding one of the light emitting elements in a plan view. each circuit board has a substantially elongated shape; the filter comprises a plurality of filter patterns spaced apart from each other; and each of the filter patterns corresponds to a corresponding one of the light emitting elements in a plan view.