Patent ID: 8767305

Claim:
An eyepiece for a head mounted display, the eyepiece comprising: an illumination module for providing computer generated image (“CGI”) light along a forward propagation path within the eyepiece; a concave end reflector disposed at an opposite end of the eyepiece from the illumination module to reflect the CGI light back along a reverse propagation path within the eyepiece; a viewing region to be aligned with an eye of a user, the viewing region disposed between the illumination module and the concave end reflector and including an out-coupling polarizing beam splitter (“PBS”), the out-coupling PBS to pass the CGI light traveling along the forward propagation path and to redirect the CGI light traveling along the reverse propagation path out of an eye-ward side of the eyepiece; and a polarization rotator disposed in the forward and reverse propagation paths of the CGI light between the out-coupling PBS and the concave end reflector, wherein the illumination module comprises: an in-coupling PBS; a lamp disposed adjacent to the in-coupling PBS to direct illumination light onto the in-coupling PBS; a display panel disposed opposing and facing the concave end reflector with the in-coupling PBS in between such that the in-coupling PBS redirects the illumination light from the lamp onto the display panel and the display panel reflects the illumination light as the CGI light along the forward propagation path back through the in-coupling PBS; and a diffusion surface disposed opposing and facing the lamp with the in-coupling PBS in between to inhibit unwanted total internal reflections from propagating down the eyepiece from the illumination module to the viewing region.