| abstract |
The object is to provide a semiconductor display device having a touch panel, which can reduce power consumption. The semiconductor display device includes a panel provided with a pixel portion, a driving circuit for controlling input of an image signal to the pixel portion, and a touch panel provided at a position overlapping the panel in the pixel portion. The pixel portion includes a display element configured to perform display in accordance with a voltage of an image signal to be input, and a transistor configured to control the holding of the voltage. The transistor includes an oxide semiconductor in a channel forming region. The driving frequency of the driving circuit, that is, the number of writing operations of the image signal for a constant period is changed in accordance with the operation signal from the touch panel. |