A liquid crystal driving frequency detection unit that determines a liquid crystal driving frequency based on a vertical synchronization signal is provided in an LED drive circuit. In addition, a look-up table that holds a correspondence relationship between the liquid crystal driving frequency and the lighting frequency of the LEDs is provided in a control unit in the LED drive circuit. The correspondence relationship is held in the look-up table such that, for example, when the liquid crystal driving frequency becomes one-nth of that before change, the lighting frequency of the LEDs becomes n times of that before change. The LED drive circuit determines the lighting frequency of the LEDs by referring to the look-up table when the liquid crystal driving frequency changes.