Patent ID: 9625723
Date: 2017-04-18
CPC Classifications: G02B,G06F

Claim:
1. A see-through head-mounted display system comprising: a freeform prism; a display device configured to emit display light through the freeform prism to an eye of a user; an imaging device having an entrance pupil positioned at a back focal plane of the freeform prism to provide object-space telecentric eye tracking, the imaging device configured to receive gaze-detection light reflected from the eye and directed through the freeform prism; and an illumination prism including a display-facing side, an eye-facing side, a camera-facing side between the display-facing side and the eye-facing side, and an interior beam splitter, wherein the illumination prism is optically intermediate the display device and the freeform prism, optically intermediate the imaging device and the freeform prism, and optically separated from the freeform prism, wherein the illumination prism is positioned to receive, at the display-facing side, the display light from the display device and to transmit the display light through the beam splitter and the eye-facing side to the freeform prism, and wherein the illumination prism is positioned to receive, at the eye-facing side, the gaze-detection light reflected from the eye and through the freeform prism and to reflect the gaze-detection light at the beam splitter through the camera-facing side to the imaging device.