PROJECTION OPTICAL SYSTEM FOR COUPLING IMAGE LIGHT TO A NEAR-EYE DISPLAY

摘要

Technology is described for a projection optical system which optically couples image light from an image source to a near-eye display (NED) of a wearable near-eye display device. The projection optical system and the image source make up a projection light engine. Light from the image source is directed to a birdbath reflective optical element which is immersed in high index glass. The image light is reflected and collimated by the birdbath element and travels outside a housing of the projection light engine forming an external exit pupil, meaning the exit pupil is external to the projection light engine. A waveguide optically couples the image light of the external exit pupil. An example of a waveguide which can be used is a surface relief grating waveguide.

主权项

1. A projection optical system of a projection light engine for coupling image light from an image source of the projection light engine to a near-eye display comprising:
a support structure of a near-eye display device which may be worn by a user; a high index glass region supported by the support structure; a birdbath optical element having a reflective surface immersed in the high index glass region and positioned by the support structure for optically coupling image light from the image source; and the birdbath optical element collimating and reflecting the image light through the high index glass region to an external exit pupil which is external to the projection light engine.