Patent ID: 8970961
Filing Date: 2015-03-03
Classification: G02B

Abstract:
1. A multifunction optical element for a display device, the display device comprising an image-generating module which generates an image, the multifunction optical element comprising: a coupling-in area and a coupling-out area, the coupling-in area being located separately from the coupling-out area, wherein a structure of the multifunction optical element is such that the image generated by the image-generating module that is coupled into the multifunction optical element via the coupling-in area, is guided in the multifunction optical element along a folded optical path by multiple total internal reflections from the coupling-in area to the coupling-out area and coupled out via the coupling-out area such that a user can perceive a coupled-out image superimposed on surroundings; wherein the coupling-out area comprises a Fresnel structure which receives light from the coupling-in area via the folded optical path and couples the image out of the multifunction optical element; and wherein the coupling-out area has an imaging property because the coupling out area corresponds to an imaginary optically effective surface that is curved.