Eye-gaze tracking

• US 20030156257A1
• Filed: 10/28/2002
• Published: 08/21/2003
• Est. Priority Date: 12/30/1999
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Levola, Tapani
• Granted Patent: US 6,758,563 B2
• Time in Patent Office: Days
• US Class Current: 351/210
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G02B 7/287 including a sight line detecting device
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06V 40/19 Sensors therefor

Abstract

A device and a method for tracking an eye-gaze of an observer. A deep blue or violet light source is used to emit light to eye, particularly to the retina. The deep blue light is partially reflected and partially absorbed by the retina. The absorption is most prominent around the fovea, the area of sharp vision, because of the pigment which protects the fovea from short wavelength radiation. Thus the device and method of tracking eye-gaze according to the invention comprises emitting light having a certain wavelength and transferring the light to the retina of an eye. The wavelength of the light being such as to make the fovea of the eye resolvable. The method further comprises detecting light that is reflected from the eye to form detection information including the resolvable fovea, and mapping the detection information to a predetermined surface, the surface being located at a distance from the eye, the location of the fovea on the surface forming an eye-gaze point.

Claims

1. A method of tracking eye-gaze, the method comprising

emitting light having a certain wavelength;

transferring the light to the retina of an eye;

the wavelength of the light being such as to make the fovea of the eye resolvable;

detecting light that is reflected from said eye to form detection information including the resolvable fovea;

mapping the detection information to a predetermined surface, said surface being located at a distance from said eye, the location of the fovea on said surface forming an eye-gaze point.

2. The method of claim 1, further comprising

using a light having a wavelength in the range of 395 nm to 500 nm.

3. The method of claim 1, further comprising

using a light having a wavelength in the range of 395 nm to 430 nm.

4. The method of claim 1, further comprising

using a light having a wavelength of 405 nm.

5. The method of claim 1, wherein the step of transferring the light comprises transferring the light within optics.

6. The method of claim 1, wherein the method comprises narrow band beam splitting at least one of the emitted and reflected light.

7. The method of claim 1, wherein the method rotating the polarization 90 degrees of at least one of the emitted and reflected light.

8. The method of claim 1, wherein said detecting comprises converting said light reflected from said eye retina to electronic information on a detector.

9. The method of claim 1, wherein said mapping comprises

calculating a blood vessels pattern from said detection information;

comparing said blood vessels pattern to a predetermined pattern;

setting the location of the fovea on said surface based on said comparing.

10. The method of claim 1, and further comprising displaying a mark on said predetermined surface at the eye-gaze point.

11. The method of claim 1, and further comprising performing a control function relating to the particular point of eye-gaze on the surface.

12. An eye-gaze tracking device, comprising:

a light source for emitting light having a certain wavelength;

means for transfering the light to the retina of an eye, the wavelength of the light being such as to make the fovea of the eye resolvable;

a detector for detecting light that is reflected from said eye to form detection information including the resolvable fovea;

a surface located at a distance from said eye; and

means for mapping the detection information to the surface for locating the the fovea on said surface for forming an eye-gaze point by the location of the fovea.

13. The device of claim 12, further comprising display as said surface.

14. The device of claim 12, further comprising a virtual reality display comprising a LCD panel.

15. The device of claim 12, further comprising imaging optics placed between said eye and said surface.

16. The device of claim 12, further comprising a control unit for transferring the detection information from said detector and for converting the detection information to said predetermined surface.

17. The device of claim 12, and comprising a narrow band reflector, a beam splitter and a narrow band mirror for reflecting and filtering the light at a narrow band in the range of said wavelength.

18. The device of claim 12, wherein said detector is a CCD (Charge Coupled Device) detector.

19. The device of claim 12, wherein said light source is for emitting a light having a wavelength in the range of 395 nm to 500 nm.

20. The device of claim 12, wherein said light source is for emitting a light having a wavelength in the range of 395 nm to 430 nm.

21. The device of claim 12, wherein said light source is for emitting a light having a wavelength of 405 nm.