The present disclosure provides a display device including a first display panel, a second display panel, at least one detection device, and a control module. The first display panel includes a first display area having first sub-pixel regions, the second display panel includes a second display area having second sub-pixel regions, and the second display panel is movable to at least partially overlap the first display panel. The detection device is disposed on at least one of the first and second display panels to detect a position of the other one and generate a relative position detection signal correspondingly. The control module is electrically connected to the detection device to receive the relative position detection signal and an image display signal from an image signal source, so as to generate a first display signal and a second display signal to respectively output to the first and second display panels.