Patent ID: 9341850
Filing Date: 2016-05-17
CPC Classification: G02B

Claim Text:
1. An optical apparatus for a see-through near-to-eye display, comprising: a diffractive optical combiner having an eye-ward side and an external scene side and including a reflective diffraction grating that is at least partially reflective to image light incident through the eye-ward side of the diffractive optical combiner and at least partially transmissive to external scene light incident through the external scene side of the diffractive optical combiner, wherein the diffractive optical combiner is an off-axis planar diffractive optical combiner; one or more refractive correction lenses disposed in an optical path of the image light prior to being incident upon the eye-ward side of the diffractive optical combiner to aid in pre-correcting aberrations induced in the image light after reflection off of the diffractive optical combiner, wherein the one or more refractive correction lenses offset astigmatism induced by reflection mode diffraction from the off-axis planar diffractive optical combiner; and a diffractive correction element disposed in the optical path of the image light prior to being incident upon the eye-ward side of the diffractive optical combiner to pre-compensate for lateral color aberrations induced in the image light after reflection off of the diffractive optical combiner.