A display device comprising: a substrate layer; a light-emitting unit including: a light-emitting element mounted on the substrate layer; and a lens placed on an upper side of the light-emitting element; a reflective layer placed on an upper surface of the substrate layer; an optical sheet placed on an upper side of the reflective layer at a height spaced apart from the light-emitting unit; and a display panel placed on an upper surface of the optical sheet, wherein a center portion of an upper surface of the lens is recessed at a predetermined depth H and extends in a continuous straight line, wherein the upper surface of the lens has an aspheric shape that is curved at a predetermined curvature from the center portion towards its edges which are parallel to the continuous straight line, so as to have an anisotropic distribution of light, wherein the center portion of the upper surface of the lens is recessed lower than the edges of the upper surface, wherein the upper surface of the lens has a parabolic shape, wherein a section cut by a vertical plane perpendicular to the continuous straight line has an open book shape, wherein the shapes of the sections cut by vertical planes at all points defining the center portion of the upper surface are identical to each other, wherein a shape of the lens in a top view is a rectangular shape; wherein the lens further comprises: a bottom center portion formed by a recess on a bottom center of a lower surface portion of the lens, wherein at least a part of the reflective layer is formed to be inclined upwardly towards an edge thereof, wherein the lens is made from polycarbonate and the upper surface of the lens is curved such that an incidence angle of light from the light-emitting unit is 42 degree or more, and wherein the shape of the bottom center portion is a round curved shape. a substrate layer; a light-emitting unit including: a light-emitting element mounted on the substrate layer; and a lens placed on an upper side of the light-emitting element; a light-emitting element mounted on the substrate layer; and a lens placed on an upper side of the light-emitting element; a reflective layer placed on an upper surface of the substrate layer; an optical sheet placed on an upper side of the reflective layer at a height spaced apart from the light-emitting unit; and a display panel placed on an upper surface of the optical sheet, wherein a center portion of an upper surface of the lens is recessed at a predetermined depth H and extends in a continuous straight line, wherein the upper surface of the lens has an aspheric shape that is curved at a predetermined curvature from the center portion towards its edges which are parallel to the continuous straight line, so as to have an anisotropic distribution of light, wherein the center portion of the upper surface of the lens is recessed lower than the edges of the upper surface, wherein the upper surface of the lens has a parabolic shape, wherein a section cut by a vertical plane perpendicular to the continuous straight line has an open book shape, wherein the shapes of the sections cut by vertical planes at all points defining the center portion of the upper surface are identical to each other, wherein a shape of the lens in a top view is a rectangular shape; wherein the lens further comprises: a bottom center portion formed by a recess on a bottom center of a lower surface portion of the lens, wherein at least a part of the reflective layer is formed to be inclined upwardly towards an edge thereof, wherein the lens is made from polycarbonate and the upper surface of the lens is curved such that an incidence angle of light from the light-emitting unit is 42 degree or more, and wherein the shape of the bottom center portion is a round curved shape. a bottom center portion formed by a recess on a bottom center of a lower surface portion of the lens, wherein at least a part of the reflective layer is formed to be inclined upwardly towards an edge thereof, wherein the lens is made from polycarbonate and the upper surface of the lens is curved such that an incidence angle of light from the light-emitting unit is 42 degree or more, and wherein the shape of the bottom center portion is a round curved shape.