A backlight, comprising a backplane , a reflective sheet and a plurality of light-emitting elements , wherein an accommodating space is defined on an inner surface of the backplane , the reflective sheet is located on the inner surface of the backplane , wherein the backlight further comprises at least one light-modifying region, the light-modifying region is on the reflective sheet , the light-modifying region comprises at least one light-converting device, the light-converting device being capable of carrying out optical process on light emitted from the light-emitting elements , wherein each of the light-converting devices comprises a quantum dot material; the backplane comprises a bottom plate and first sidewalls , which are longitudinal sidewalls, and second sidewalls , which are lateral sidewalls, provided around edges of the bottom plate , and the light-modifying region being provided on the reflective sheet located on the first and second sidewalls and the bottom plate , and the plurality of light-emitting elements are arranged in a plurality of rows and a plurality of columns on the bottom plate in the accommodating space, characterized in that the light-modifying region comprises a plurality of first light-modifying regions located on the second sidewalls and the first sidewalls , wherein the first light-modifying regions located on the second sidewalls are arranged in the row direction of the light-emitting elements and correspond to the columns of the light-emitting elements , and the first light-modifying regions located on the first sidewalls are arranged in the column direction of the light-emitting elements and correspond to the rows of the light-emitting elements , wherein the row direction of the light-emitting elements is parallel to the second sidewalls , and the column direction of the light-emitting elements is parallel to the first sidewalls . each of the light-converting devices comprises a quantum dot material; the backplane comprises a bottom plate and first sidewalls , which are longitudinal sidewalls, and second sidewalls , which are lateral sidewalls, provided around edges of the bottom plate , and the light-modifying region being provided on the reflective sheet located on the first and second sidewalls and the bottom plate , and the plurality of light-emitting elements are arranged in a plurality of rows and a plurality of columns on the bottom plate in the accommodating space, characterized in that the light-modifying region comprises a plurality of first light-modifying regions located on the second sidewalls and the first sidewalls , wherein the first light-modifying regions located on the second sidewalls are arranged in the row direction of the light-emitting elements and correspond to the columns of the light-emitting elements , and the first light-modifying regions located on the first sidewalls are arranged in the column direction of the light-emitting elements and correspond to the rows of the light-emitting elements , wherein the row direction of the light-emitting elements is parallel to the second sidewalls , and the column direction of the light-emitting elements is parallel to the first sidewalls . <EOS>