A method for driving backlight unit includes generating at least one pulse, after generating the at least one pulse, generating a driving signal having a constant state, supplying a predetermined capacitor voltage to a lamp assembly, wherein the predetermined capacitor voltage corresponds to the at least one pulse, and supplying a second voltage to the lamp assembly supplied with the predetermined capacitor voltage, wherein the second voltage corresponds to the driving signal and wherein the lamp assembly emits light in response to the supplied second voltage.