A display device comprises a optical member, a plurality of light sources to illuminate the optical member, a representative determining part to determine representative values of image blocks based on image signals applied to the image blocks, wherein the image blocks are arranged in a matrix and correspond to portions of a display panel, a representative integration part to integrate the representative values of the image blocks in one of a row and a column direction of the matrix and determine integrated representative values, and a light control part to control the plurality of light sources based on the integrated representative values.