Abstract: A display device (500) comprises a micro-display (22) and imaging optics (24) to transmit a light beam (BO), and a diffractive beam expander (10) having an output grating (16). The combination of said micro-display (22) and said imaging optics (24) is together adapted to form a virtual image (710) which is observable through the perimeter (15) of said output grating (16) when said diffractive beam expander (10) is positioned to at least partially intercept said light beam (BO). The combination of said micro-display (22) and said imaging optics (24) may also be adapted to project said light beam (BO) onto an external screen (600) in order to display a real image (610). The display device (500) may comprise a movable optical component (10, 380) to switch the device (500) from a virtual display mode to a projecting mode.