Liquid crystal display device and method for driving same

A method for driving a liquid crystal display device including a liquid crystal panel with a built-in touch panel, the liquid crystal display device including a display voltage generation circuit configured to generate a first voltage and a second voltage, a plurality of pixel circuits each including a liquid crystal capacitance constituted by a pixel electrode and a common electrode, a memory circuit configured to store binary data, and a voltage selection circuit configured to supply either the first voltage or the second voltage to the pixel electrode in accordance with a value of the binary data stored in the memory circuit, and a common electrode drive circuit configured to change a voltage value of a voltage applied to the common electrode between a high-level voltage value and a low-level voltage value, and the touch panel using the common electrode as an electrode for touch detection, the method comprising:

• a touch detection step of applying, by the common electrode drive circuit, a continuous pulse voltage for touch detection changing between the high-level voltage value and the low-level voltage value to the common electrode to detect a touched position on the touch panel,
• wherein the display voltage generation circuit changes a voltage value of each of the first voltage and the second voltage between the high-level voltage value and the low-level voltage value inversely with each other in periods other than a period in which the continuous pulse voltage is applied to the common electrode, and
• in the touch detection step, the display voltage generation circuit changes the voltage value of each of the first voltage and the second voltage in synchronization with the continuous pulse voltage to maintain an absolute value of a voltage between the pixel electrode and the common electrode at a constant magnitude in each of the plurality of pixel circuits throughout a period from a point in time immediately before a start of an application of the continuous pulse voltage to the common electrode to a point in time immediately after an end of the application of the continuous pulse voltage to the common electrode.