A first optical-path changing layer is provided, on a front-face side of a rear-face side transparent substrate including a light source on one side face thereof. There are a first input shaft to be connected to a first clutch and a second input shaft to be connected to a second clutch. The moveable structure has at least a load position and a transport position. Each type of signal corresponds to at least one specific mode of operation of the signal generator associated with said type of signal. Each of the color mode switching options defines a manner in which the printing apparatus and method will switch between the plurality of color modes when printing a document.