| abstract |
It is an object 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 an 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 maintenance of the voltage. The transistor includes an oxide semiconductor in the channel formation region. The drive frequency of the drive circuit, that is, the number of write operations of the image signal for a certain period of time, is changed in accordance with the operation signal from the touch panel. |