A liquid crystal display device according to the present disclosure includes a timing controller, a power supply unit, a data supply unit, and a liquid crystal display panel. The timing controller analyzes image data to sense a target pattern, and generates an operating signal in a case where the target pattern is sensed. The power supply unit generates first to fourth gamma voltages in a case where the operating signal is not received. The power supply unit generates first to fourth modulation voltages after a variable time in a case where the operating signal is received. The difference between the first and second modulation voltages is smaller than the difference between the first and second gamma voltages, and the difference between the third and fourth modulation voltages is smaller than the difference between the third and fourth gamma voltages.