Patent ID: 9632312
Date: 2017-04-25
CPC Classifications: G02B

Claim:
1. An optical apparatus for a head-worn display, the optical apparatus comprising: a first optical element having an eye-ward facing surface and an external world facing surface substantially opposite of the eye-ward facing surface; and a diffractive optical element (“DOE”) adhered to the eye-ward facing surface to substantially follow a curvature of the eye-ward facing surface of the first optical element, wherein the DOE includes a partially reflective diffraction grating configured to direct a portion of image light in an eye-ward direction, the image light incident through an eye facing side of the DOE, and wherein the curvature of the eye-ward facing surface of the first optical element has a reflective optical power configured to collimate the image light within an eyebox sized area, wherein the external world facing surface of the first optical element follows the curvature of the eye-ward facing surface to give the first optical element substantially zero transmissive optical power from a perspective of scene light encountering the first optical element, wherein the scene light is propagating in the eye-ward direction, wherein the DOE is configured to have magnifying optical power to collimate the image light within the eyebox sized area, wherein the magnifying optical power is along a second axis and the reflective optical power of the curvature of the eye-ward facing surface is along a first axis different from the second axis, and wherein the reflective optical power and the magnifying optical power are configured to influence astigmatism.