Patent attributes
A low-power consumption level shifter circuit is provided by preventing a through current which is generated when a level of a signal is changed. In order to prevent a through current which flows when a level of a signal of the input is changed, the p-channel TFTs are controlled so that the p-channel TFTs and the n-channel TFT or the p-channel TFTs and the n-channel TFT are not turned on at once. A high level signal is inputted to the gate of the n-channel TFT, and at the moment when the n-channel TFT is turned on, the p-channel TFT is turned off. Similarly, at the moment when the n-channel TFT is turned on, the p-channel TFT is turned off. The p-channel TFTs and the n-channel TFT, or the p-channel TFTs and the n-channel TFT are not turned on at once, thereby a path in which the through current flows is cut off.