A light emitting diode (LED) lamp unit is disclosed for obtain a thin profile display device, to improve uniformity of light, and to simplify a power connection line for operation, which includes an optical lens having a central recess part and an edge, wherein the central recess part is hollowed out inwardly, and the edge is formed in shape of a flat surface or in shape of a convex lens; at least one or more LED chips arranged at fixed intervals in a lower portion of the optical lens; and a lower reflecting sheet positioned on a bottom surface of the LED chip.