In-field illumination and imaging for eye tracking

Patent metadata

Field	Value
Publication number	US-2019361523-A1
Application number	US-201816033099-A
Country	US
Kind code	A1
Filing date	Jul 11, 2018
Priority date	May 23, 2018
Publication date	Nov 28, 2019
Grant date	—

Abstract

Disclosed herein are techniques for eye tracking in near-eye display devices. In some embodiments, an illuminator for eye tracking is provided. The illuminator includes a light source configured to be positioned within a field of view of an eye of a user; a first reflector configured to shadow the light source from a field of view of a camera; and a second reflector configured to receive light from the light source that is reflected by the eye of the user, and to direct the light toward the camera.

First claim

What is claimed is:

1 . An illuminator for eye tracking comprising:
a light source configured to be positioned within a field of view of an eye of a user; a first reflector configured to shadow the light source from a field of view of a camera; and a second reflector configured to receive light from the light source that is reflected by the eye of the user, and to direct the light toward the camera.

2 . The illuminator of claim 1 , wherein the first reflector is a first coating on a first prism, and the second reflector is a second coating on a second prism.

3 . The illuminator of claim 2 , wherein a first portion of the second prism that is shadowed by the first reflector is uncoated, and a second portion of the second prism that is unshadowed by the first reflector is coated by the first coating.

4 . The illuminator of claim 1 , wherein the light source is configured to emit light that propagates between the first reflector and the second reflector.

5 . The illuminator of claim 1 , further comprising:
a substrate comprising a first surface on which the light source is mounted and a second surface through which light is outcoupled toward the eye of the user; and a beam diverting component configured to direct light from the light source toward the eye of the user, wherein the first reflector and the second reflector are arranged within the substrate between the first surface and the second surface.

6 . The illuminator of claim 5 , wherein the beam diverting component is formed on the second surface of the substrate, is indented toward the first surface of the substrate, and has a shape of a prism, a cone, a diffraction grating, or a lens.

7 . The illuminator of claim 5 , wherein the beam diverting component is formed on the second surface of the substrate, protrudes away from the first surface of the substrate, and has a shape of a prism or a cone.

8 . The illuminator of claim 5 , wherein:
the beam diverting component comprises a third reflector and a fourth reflector, each of which is arranged within the substrate between the first surface and the second surface, the third reflector is configured to reflect light from the light source to the fourth reflector, and the fourth reflector is configured to reflect the light toward the second surface of the substrate.

9 . The illuminator of claim 5 , wherein the beam diverting component is a surface relief grating that is formed at the second surface of the substrate or a volume Bragg grating.

10 . The illuminator of claim 1 , wherein each of the first reflector and the second reflector is configured to reflect infrared light and to transmit visible light.

11 . A system for eye tracking comprising:
a light source configured to be positioned within a field of view of an eye of a user; a camera configured to capture an image of the light source reflected by the eye of the user; a first reflector configured to shadow the light source from a field of view of the camera; and a second reflector configured to receive light from the light source that is reflected by the eye of the user, and to direct the light toward the camera.

12 . The system of claim 11 , wherein the first reflector is a first coating on a first prism, and the second reflector is a second coating on a second prism.

13 . The system of claim 12 , wherein a first portion of the second prism that is shadowed by the first reflector is uncoated, and a second portion of the second prism that is unshadowed by the first reflector is coated by the first coating.

14 . The system of claim 11 , wherein the light source is configured to emit light that propagates between the first reflector and the second reflector.

15 . The system of claim 11 , further comprising:
a substrate comprising a first surface on which the light source is mounted and a second surface through which light is outcoupled toward the eye of the user; and a beam diverting component configured to direct light from the light source toward the eye of the user, wherein the first reflector and the second reflector are arranged within the substrate between the first surface and the second surface.

16 . The system of claim 15 , wherein the beam diverting component is formed on the second surface of the substrate, is indented toward the first surface of the substrate, and has a shape of a prism, a cone, a diffraction grating, or a lens.

17 . The system of claim 15 , wherein the beam diverting component is formed on the second surface of the substrate, protrudes away from the first surface of the substrate, and has a shape of a prism or a cone.

18 . The system of claim 15 , wherein:
the beam diverting component comprises a third reflector and a fourth reflector, each of which is arranged within the substrate between the first surface and the second surface, the third reflector is configured to reflect light from the light source to the fourth reflector, and the fourth reflector is configured to reflect the light toward the second surface of the substrate.

19 . The system of claim 15 , wherein the beam diverting component is a surface relief grating that is formed at the second surface of the substrate or a volume Bragg grating.

20 . The system of claim 11 , wherein each of the first reflector and the second reflector is configured to reflect infrared light and to transmit visible light.

Assignees

• Facebook Tech Llc

Inventors

• Sharma Robin
• Ouderkirk Andrew John
• Zhang Qi

Classifications

• G02B27/0093 Primary

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G02B27/0172

  characterised by optical features · CPC title

• G06F3/013 Primary

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G06F3/011

  Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00) · CPC title

• G06F3/012

  Head tracking input arrangements · CPC title