Patent ID: 11953679
Assignee: META PLATFORMS TECHNOLOGIES, LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 9:
10. A head mounted artificial reality system comprising:
a display for presenting virtual images to an eyebox of the head mounted artificial reality system;
an infrared light source configured to emit infrared illumination light;
an ellipsoidal combiner configured to redirect the infrared illumination light to the eyebox location and configured to pass scene light to the eyebox, the ellipsoidal combiner including a near-eye ellipsoidal lensing structure having a first foci and a second foci, wherein the ellipsoidal combiner is configured to be positioned relative to the eyebox location where the first foci of the near-eye ellipsoidal lensing structure is located at approximately a center of rotation of an eye placed in the eyebox location, and wherein visible display light including the virtual images propagates through the ellipsoidal combiner prior to entering the eyebox;
a beam-steering element configured to selectively direct the infrared illumination light to the ellipsoidal combiner;
a camera configured to capture a tracking image of Purkinje reflections of the infrared illumination light, wherein near-eye ellipsoidal lensing structure is configured to direct the Purkinje reflections of the infrared illumination light to the camera; and
a beam splitter positioned to receive the Purkinje reflections from the near-eye ellipsoidal lensing structure and redirect the Purkinje reflections to the camera, wherein the infrared illumination light propagates through the beam splitter prior to encountering the near-eye ellipsoidal lensing structure.