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.

Abstract: A device mount has a base plate to be mounted on a housing or a frame of an optical or display device. The base plate has an opening to accommodate a device holder, which has a frame for holding an optical or display device, for example. The frame is adjustable connected to the base plate through two adjustment plates. In particular, each of the adjustment plates is connected to the base plate by two linking sections, leaving a gap between the adjustment plate and the base plate. The gap is adjustable by a screw so that the height of the optical or display device relative to the base plate can be adjusted.