Visual display with illuminators for gaze tracking

Patent metadata

Field	Value
Publication number	US-9632180-B2
Application number	US-201615005198-A
Country	US
Kind code	B2
Filing date	Jan 25, 2016
Priority date	Apr 1, 2009
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A visual display includes hidden reference illuminators adapted to emit invisible light for generating corneo-scleral reflections on an eye watching a screen surface of the display. The tracking of such reflections and the pupil center provides input to gaze tracking. A method for equipping and an LCD with a reference illuminator are also provided. Also provides are a system and method for determining a gaze point of an eye watching a visual display that includes reference illuminators. The determination of the gaze point may be based on an ellipsoidal cornea model.

First claim

The invention claimed is:

1. A method for determining a gaze point of an eye watching a visual display comprising the steps of:
a) illuminating the eye by light from at least one reference illuminator provided in an object plane;
b) acquiring an image of the eye including at least one corneo-scleral reflection of the at least one reference illuminator;
c) defining, based on at least one location of the at least one corneo-scleral reflection in the image plane, a mapping between a coordinate system in the object plane and a coordinate system in the image plane; and
d) determining, based on the mapping, the eye's gaze point in the object coordinate system, with the mapping comprising an ellipsoidal reflection mapping and a perspective projection.

2. The method of claim 1 , wherein the at least one reference illuminator illuminates the eye by light having a wavelength of at least 700 nm.

3. The method of claim 1 , wherein the at least one reference illuminator illuminates the eye by infrared light or near-infrared light.

4. The method of claim 1 , wherein the at least one reference illuminator is a plurality of reference illuminators.

5. The method of claim 1 , wherein the ellipsoidal reflection mapping comprises a prolate spherical reflection mapping.

6. The method of claim 1 , wherein the at least one reference illuminator is arranged beneath a screen surface, adapted to display graphical information, of the visual display.

7. A system for determining a gaze point of an eye watching a visual display, the visual display comprising at least one reference illuminator adapted to emit light, and a screen surface adapted to display graphical information, the system comprising:
a camera for acquiring an image of the eye including at least one corneo-scleral reflection of the at least one reference illuminator; and
a processor adapted to define, based on at least one location of the at least one cornea-scleral reflection in the image plane, a mapping between a coordinate system in the object plane and a coordinate system in the image plane; and
determine, based on the mapping, the eye's gaze point in the object coordinate system, with the mapping comprising an ellipsoidal reflection mapping and a perspective projection.

8. The system of claim 7 , wherein the at least one reference illuminator is adapted to emit light having a wavelength of at least 700 nm.

9. The system of claim 7 , wherein the at least one reference illuminator is adapted to emit infrared light or near-infrared light.

10. The system of claim 7 , wherein the at least one reference illuminator is a plurality of reference illuminators.

11. The system of claim 7 , wherein the ellipsoidal reflection mapping comprises a prolate spherical reflection mapping.

12. The system of claim 7 , wherein the at least one reference illuminator is arranged beneath the screen surface.

13. The system of claim 7 , wherein the screen surface is adapted to display graphical information based on the at least one reference illuminator.

14. The system of claim 7 , wherein the camera is arranged near a lower edge of the screen surface.

15. A non-transitory computer-readable medium having computer executable instructions for causing a gaze point detection device to perform the following steps:
a) illuminating, by light from at least one reference illuminator provided in an object plane, an eye watching a visual display;
b) acquiring an image of the eye including at least one corneo-scleral reflection of the at least one reference illuminator;
c) defining, based on at least one location of the at least one corneo-scleral reflection in the image plane, a mapping between a coordinate system in the object plane and a coordinate system in the image plane; and
d) determining, based on the mapping, the eye's gaze point in the object coordinate system, with the mapping comprising an ellipsoidal reflection mapping and a perspective projection.

16. The medium of claim 15 , wherein the at least one reference illuminator illuminates the eye by light having a wavelength of at least 700 nm.

17. The medium of claim 15 , wherein the at least one reference illuminator illuminates the eye by infrared light or near-infrared light.

18. The medium of claim 15 , wherein the at least one reference illuminator is a plurality of reference illuminators.

19. The medium of claim 15 , wherein the ellipsoidal reflection mapping comprises a prolate spherical reflection mapping.

20. The medium of claim 15 , wherein the at least one reference illuminator is arranged beneath a screen surface, adapted to display graphical information, of the visual display.

Assignees

• Tobii Ab

Inventors

• Blixt Peter
• Kingback Anders
• Rehnstrom Bengt
• Elvesjö John
• Kuldkepp Mattias

Classifications

• G01S17/46

  Indirect determination of position data · CPC title

• G06F3/01

  Input arrangements or combined input and output arrangements for interaction between user and computer (G06F3/16 takes precedence) · CPC title

• G06F3/013 Primary

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

• A61B3/113

  for determining or recording eye movement · CPC title

• G06K9/00604

  Physics · mapped topic