Patent attributes
A source line through which a video signal is transmitted also serves as a driving electrode of a touch sensor. To perform display, a video signal is transmitted to the source line. To sense the touch, a driving signal is transmitted to the source line. A circuit for transmitting the video signal and the driving signal to the source line has a structure in which a period for transmitting the driving signal is added in the wiring through which the digital video signal is transmitted and the output to the source line is switched by using a switching circuit. Alternatively, the circuit has a structure in which a period for transmitting the driving signal is added in a wiring through which a latch signal is transmitted and the output to the source line is switched.