Eye tracking using optical coherence methods
AssigneeFacebook Technologies, LLC
InventorsNicholas Daniel Trail, Robert Dale Cavin
Life of this patent
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Abstract
A system tracks eye movement using optical coherence in a head mounted display. The system includes an illumination source configured to project low coherence interference light onto a portion of a user's eye. The system includes a scanning system to select an axial position within the illuminated portion of the user's eye. The system includes a detector configured to collect light reflected from the illuminated portion of the user's eye at the selected axial position, and the reflected light includes measurement data characterizing the illuminated portion of the user's eye. The system includes a controller configured to compare the measurement data with a trained baseline, and determine an eye position based the comparison.
Claims20
An eye tracking device comprising:
- an illumination source configured to project low coherence interference light onto a portion of a user's eye via a scanning system, wherein the portion of the user's eye is a portion of the user's sclera, cornea, or limbus;
- the scanning system configured to scan an illuminated portion of the user's eye with the low coherence interference light from the illumination source at one or more different depths below a surface of the user's eye, wherein the scanning of the one or more different depths is performed along a longitudinal axis that intersects the illuminated portion of the user's eye;
- a detector configured to collect, for each of the one or more different depths, reflected low coherence interference light from the illumination source reflected from the illuminated portion of the user's eye, the reflected low coherence interference light from the illuminated portion of the user's eye at each of the one or more different depths of a plurality of different depths;
- and
- a controller configured to:
- determine, for each of the one or more different depths, measurement data characterizing the illuminated portion of the user's eye based on the reflected low coherence interference light collected for each of the one or more different depths,
- compare the measurement data with a trained baseline, and
- determine an eye position based on the comparison.
A method for eye tracking comprising:
- projecting low coherence interference light onto a portion of a user's eye using one or more coherent light sources of a scanning system comprising a moveable reference mirror, wherein the portion of g user's eye is a portion of the user's sclera, cornea, or limbus;
- capturing, using a detector collecting the projected low coherence interference light reflected from an illuminated portion of the user's eye, measurement data characterizing the illuminated portion of the user's eye at each of one or more different depths of a surface of the user's eye, along a longitudinal axis that intersects the illuminated portion of the user's eye;
- aggregating the measurement data characterizing the illuminated portion of the user's eye at each of the one or more different depths;
- comparing the aggregated measurement data with a trained baseline;
- and
- determining an eye position based the comparison.
An eye tracking device comprising:
- an illumination source configured to project low coherence interference light onto a portion of a user's eye via a scanning system, wherein the portion of the user's eye is a portion of the user's sclera, cornea, or limbus;
- a reference mirror configured to scan an illuminated portion of the user's eye with the low coherence interference light from the illumination source at one or more different depths below a surface of the user's eye via varying a location of the reference mirror, wherein scanning a plurality of one or more different depths are along a longitudinal axis that intersects the illuminated portion of the user's eye;
- a detector configured to collect, for each of the one or more different depths, reflected low coherence interference light reflected from the illuminated portion of the user's eye, the reflected low coherence interference light from the illuminated portion of the user's eye at each of the plurality of one or more different depths;
- and
- a controller configured to:
- determine, for each of the one or more different depths, measurement data characterizing the illuminated portion of the user's eye based on the reflected low coherence interference light collected for each of the one or more different depths;
- compare the measurement data with a trained baseline, and
- determine an eye position based the comparison.
Dependencies are inferred from the claim text.