When determining that a level of a deformation detection signal is greater than a threshold, a controller assumes that a touch operation is performed at an initially-detected position and virtually at another position different from the position, and outputs a position detection signal to a processor indicating that the two touch positions and separate from each other based on the touch position. Thus, the controller converts the deformation detection signal into the position detection signal corresponding to a pinch-out operation, and outputs the position detection signal to the processor.