| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor display device with a touch panel which consumes less power.SOLUTION: The display device includes a pixel portion, a panel including a driving circuit that controls the input of image signals to the pixel portion, and a touch panel provided overlapping with the panel in the pixel portion. The pixel portion includes a display element that performs display in accordance with the voltage of the input image signal, and a transistor that controls to maintain the voltage. The transistor includes an oxide semiconductor in a channel formation region thereof. The driving frequency of the driving circuit, i.e., how many times the image signals are written within a certain period is changed based on the operation signals input from the touch panel.SELECTED DRAWING: Figure 1 |
