Patent attributes
A display device includes an optical assembly and a display that includes a front surface and a back surface. The display is configured to output image light from the front surface and transmit ambient light from the back surface to the front surface. The optical assembly includes a substrate that has a substantially uniform thickness, a beam splitter, and a reflector. The optical assembly is configured to receive the image light output from the front surface of the display and to transmit a portion of the image light at a first non-zero optical power via an optical path that includes reflections at the reflector and at the beam splitter. The optical assembly is also configured to transmit a portion of the ambient light through the optical assembly at a second optical power without reflection at the reflector. The second optical power is less than the first optical power.