Eye-tracking enabled wearable devices

Patent metadata

Field	Value
Publication number	US-9977960-B2
Application number	US-201615276448-A
Country	US
Kind code	B2
Filing date	Sep 26, 2016
Priority date	Sep 24, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A system for determining a gaze direction of a user is disclosed. The system may include a first illuminator, a first profile sensor, and at least one processor. The first illuminator may be configured to illuminate an eye of a user. The first profile sensor may be configured to detect light reflected by the eye of the user. The processor(s) may be configured to determine a gaze direction of the user based at least in part on light detected by the first profile sensor.

First claim

What is claimed is:

1. A system for determining a gaze direction of a user, wherein the system comprises:
a first illuminator configured to illuminate an eye of a user;
a first profile sensor configured to detect light reflected by the eye of the user;
an area image sensor configured to detect light reflected by the eye of the user, wherein the area image sensor has a sensitive area having a total number of pixels characterized by a total number of rows and a total number of columns;
at least one processor configured to determine a gaze direction of the user based at least in part on light detected by the first profile sensor and based at least in part on light detected by the area image sensor;
wherein determining the gaze direction of the user based at least in part on light detected by the first profile sensor comprises:
determining a location of a glint on the eye caused by light reflected by the eye of the user, based at least in part on a higher magnitude light level detected at one or more pixels of the first profile sensor;
identifying a subset of a total number of pixels of the first profile sensor which include and surround the one or more pixels of the first profile sensor which detected the higher magnitude light level; and
analyzing only the subset of the total number of pixels of the first profile sensor during a subsequent determination of gaze direction; and

wherein determining the gaze direction of the user based at least in part on light detected by the area image sensor comprises:
determining magnitudes of light exposure at a subset of the total number of rows of the sensitive area during one or more illumination periods;
determining magnitudes of light exposure at a subset of the total number of columns of the sensitive area during one or more illumination periods;
identifying a subset of the total number of pixels of the sensitive area based on the magnitudes of light exposure at the subset of the total number of rows and the magnitudes of light exposure at the subset of the total number of columns; and
analyzing only the subset of the total number of pixels of the sensitive area during a subsequent illumination period.

2. The system for determining a gaze direction of a user of claim 1 , wherein the system further comprises:
a second profile sensor configured to detect light reflected by the eye of the user, wherein determining the gaze direction of the user is further based at least in part on light detected by the second profile sensor.

3. The system for determining a gaze direction of a user of claim 2 , wherein the at least one processor is further configured to:
determine a location of a cornea center of the eye based at least in part on light detected by the first profile sensor and light detected by the second profile sensor.

4. The system for determining a gaze direction of a user of claim 1 , wherein the first profile sensor is configured to:
detect light in two dimensions.

5. The system for determining a gaze direction of a user of claim 2 , wherein:
the first profile sensor is configured to detect light in one dimension; and
the second profile sensor is configured to detect light in one dimension.

6. The system for determining a gaze direction of a user of claim 5 , wherein:
the first profile sensor is orientated orthogonally to the second profile sensor.

7. The system for determining a gaze direction of a user of claim 5 , wherein the system further comprises:
a first cylindrical lens between the first profile sensor and the eye; and
a second cylindrical lens between the second profile sensor and the eye.

8. The system for determining a gaze direction of a user of claim 1 , wherein the system further comprises:
a second illuminator configured to illuminate the eye of the user.

9. The system for determining a gaze direction of a user of claim 8 , wherein the at least one processor is further configured to:
modulate activation of the first illuminator and the second illuminator such that only the first illuminator or the second illuminator is activated at a particular point in time.

10. The system for determining a gaze direction of a user of claim 1 , wherein:
the area image sensor operates at between about 0.5 and about 10.0 hertz.

11. A method for determining a gaze direction of a user, wherein the method comprises:
illuminating an eye of a user;
detecting, with an area image sensor, light reflected by the eye of the user, wherein the area image sensor has a sensitive area having a total number of pixels characterized by a total number of rows and a total number of columns;
determining, with at least one processor, a gaze direction of the user based at least in part on light detected by the area image sensor;
wherein determining the gaze direction of the user based at least in part on light detected by the area image sensor comprises:
determining a location of a glint on the eye caused by light reflected by the eye of the user, based at least in part on a higher magnitude light level detected at one or more pixels of the area image sensor;
determining magnitudes of light exposure at a subset of the total number of rows during one or more illumination periods;
determining magnitudes of light exposure at a subset of the total number of columns during one or more illumination periods;
based on the magnitudes of light exposure at the subset of the total number of rows and the magnitudes of light exposure at the subset of the total number of columns, identifying a subset of a total number of pixels of the area image sensor which include and surround the one or more pixels of the area image sensor which detected the higher magnitude light level; and
analyzing only the subset of the total number of pixels of the area image sensor during a subsequent determination of gaze direction during a subsequent illumination period.

12. A non-transitory machine readable medium having instructions stored thereon for determining a gaze direction of a user, wherein the instructions are executable by one or more processors to at least:
cause an illuminator to illuminate an eye of a user;
detect, with an area image sensor, light reflected by the eye of the user, wherein the area image sensor has a sensitive area having a total number of pixels characterized by a total number of rows and a total number of columns;
determine a gaze direction of the user based at least in part on light detected by the an area image sensor;
wherein determining the gaze direction of the user based at least in part on light detected by the an area image sensor comprises:
determining a location of a glint on the eye caused by light reflected by the eye of the user, based at least in part on a higher magnitude light level detected at one or more pixels of the an area image sensor;
determining magnitudes of light exposure at a subset of the total number of rows during one or more illumination periods;
determining magnitudes of light exposure at a subset of the total number of columns during one or more illumination periods;

based on the magnitudes of light exposure at the subset of the total number of rows and the magnitudes of light exposure at the subset of the total number of columns, identifying a subset of a total number of pixels of the an area image sensor which include and surround the one or more pixels of the profile sensor which detected the higher magnitude light level; and
analyzing only the subset of the total number of pixels of the an area image sensor during a subsequent determination of gaze direction during a subsequent illumination period.

13. A system for determining a gaze direction o

Assignees

• Tobii Ab

Inventors

• Gustafsson Simon
• Johansson Tornéus Daniel
• Andersson Jonas
• Kron Johannes
• Skogö Mårten
• Biedert Ralf

Classifications

• G09G2354/00

  Aspects of interface with display user · CPC title

• G09G2340/0464

  Positioning · CPC title

• G06V40/19

  Sensors therefor · CPC title

• G06F2203/0381

  Multimodal input, i.e. interface arrangements enabling the user to issue commands by simultaneous use of input devices of different nature, e.g. voice plus gesture on digitizer · CPC title

• G06F3/04815 Primary

  Interaction with a metaphor-based environment or interaction object displayed as three-dimensional [3D], e.g. changing the user viewpoint with respect to the environment or object · CPC title