A display apparatus comprising: a display panel which selectively displays a 2D image and a 3D image in response to a three-dimensional image enable signal,; and a light source module comprising: a first light-emitting module comprising first to k-th top light source blocks disposed adjacent to a first edge of a light guide plate, wherein k is a natural number; a second light-emitting module comprising first to m-th bottom light source blocks disposed adjacent to a second edge of the light guide plate, wherein m is a natural number, and the second edge is disposed opposite to the first edge; and a light source driving part which generates first to k-th top duty control signals and first to m-th bottom duty control signals based on an image to be displayed, and selectively generates first to k-th top driving signals and first to m-th bottom driving signals using the first to k-th duty control signals and the first to m-th duty control signals, in response to a first enable signal and a second enable signal, respectively, wherein the first to k-th top duty control signals correspond to the first to k-th top light source blocks, and the first to m-th bottom duty control signals correspond to the first to m-th bottom light source blocks, and wherein the first to k-th top driving signals drive the first light-emitting module, and the first to m-th bottom driving signals drive the second light-emitting module, wherein the first and second enable signals have different values during a same period to turn on a corresponding light source block of the first light-emitting module and turn off a corresponding light source block of the second light-emitting module, when a 3D image is displayed in response to a first level of the three-dimensional image enable signal, and wherein the first and second enable signals have a same value during a same period when a 2D image is displayed in response to a second level of the three-dimensional image enable signal. a display panel which selectively displays a 2D image and a 3D image in response to a three-dimensional image enable signal,; and a light source module comprising: a first light-emitting module comprising first to k-th top light source blocks disposed adjacent to a first edge of a light guide plate, wherein k is a natural number; a second light-emitting module comprising first to m-th bottom light source blocks disposed adjacent to a second edge of the light guide plate, wherein m is a natural number, and the second edge is disposed opposite to the first edge; and a light source driving part which generates first to k-th top duty control signals and first to m-th bottom duty control signals based on an image to be displayed, and selectively generates first to k-th top driving signals and first to m-th bottom driving signals using the first to k-th duty control signals and the first to m-th duty control signals, in response to a first enable signal and a second enable signal, respectively, a first light-emitting module comprising first to k-th top light source blocks disposed adjacent to a first edge of a light guide plate, wherein k is a natural number; a second light-emitting module comprising first to m-th bottom light source blocks disposed adjacent to a second edge of the light guide plate, wherein m is a natural number, and the second edge is disposed opposite to the first edge; and a light source driving part which generates first to k-th top duty control signals and first to m-th bottom duty control signals based on an image to be displayed, and selectively generates first to k-th top driving signals and first to m-th bottom driving signals using the first to k-th duty control signals and the first to m-th duty control signals, in response to a first enable signal and a second enable signal, respectively, wherein the first to k-th top duty control signals correspond to the first to k-th top light source blocks, and the first to m-th bottom duty control signals correspond to the first to m-th bottom light source blocks, and wherein the first to k-th top driving signals drive the first light-emitting module, and the first to m-th bottom driving signals drive the second light-emitting module, wherein the first and second enable signals have different values during a same period to turn on a corresponding light source block of the first light-emitting module and turn off a corresponding light source block of the second light-emitting module, when a 3D image is displayed in response to a first level of the three-dimensional image enable signal, and wherein the first and second enable signals have a same value during a same period when a 2D image is displayed in response to a second level of the three-dimensional image enable signal.