DISPLAY DEVICE, THREE-DIMENSIONAL DISPLAY DEVICE, HEAD-UP DISPLAY AND VEHICLE

A display device of the disclosure is a display device to be mounted on a vehicle, and includes a display panel, a first input unit, a second input unit, a third input unit, and a controller. The first input unit is configured so as to acquire an engine rotation speed. The second input unit is configured so as to acquire a vehicle speed. The third input unit is configured so as to acquire a shift position of a transmission of a vehicle. The controller is configured so that a first image representing the engine rotation speed and one or more second images representing the vehicle speed are combined and a combined image is displayed on the display panel. The controller is configured so that switching of the second images is carried out based on the shift position.