WAVEGUIDE EYE TRACKING EMPLOYING SWITCHABLE DIFFRACTION GRATINGS
First Claim
1. An apparatus for use in tracking an eye that is illuminated by infrared light having an infrared wavelength, the apparatus comprising:
- a waveguide that is transparent and includes an input-coupler and an output-coupler;
the input-coupler comprising a stack of two or more electronically switchable diffractive gratings arranged parallel to one another;
wherein each of the electronically switchable diffractive gratings has a respective lens power and a respective prismatic power;
wherein the lens power of each of the electronically switchable diffractive gratings differ from one another such that each of the electronically switchable diffractive gratings has a different focal length; and
wherein each of the electronically switchable diffractive gratings, when turned on, is adapted to receive infrared light having the infrared wavelength and couple the received infrared light into the waveguide.
3 Assignments
0 Petitions
Accused Products
Abstract
A transparent waveguide, for use in tracking an eye illuminated by infrared light, includes an input-coupler and an output-coupler. The input-coupler includes a stack of electronically switchable diffractive gratings arranged parallel to one another, each of which has a respective lens power that causes each of the gratings in the stack to have a different focal length. Each grating, when turned on, couples received infrared light into the waveguide. A sensor images an eye in dependence on infrared light beams that exit the waveguide at the output-coupler. Images of an eye, obtained using the sensor, are analyzed to determine which one of the electronically switchable diffractive gratings, when turned on, provides a best focused image of the eye or portion thereof. The one of the electronically switchable diffractive gratings, which provides the best focused image of the eye, is used for imaging the eye during eye tracking.
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Citations
20 Claims
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1. An apparatus for use in tracking an eye that is illuminated by infrared light having an infrared wavelength, the apparatus comprising:
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a waveguide that is transparent and includes an input-coupler and an output-coupler; the input-coupler comprising a stack of two or more electronically switchable diffractive gratings arranged parallel to one another; wherein each of the electronically switchable diffractive gratings has a respective lens power and a respective prismatic power; wherein the lens power of each of the electronically switchable diffractive gratings differ from one another such that each of the electronically switchable diffractive gratings has a different focal length; and wherein each of the electronically switchable diffractive gratings, when turned on, is adapted to receive infrared light having the infrared wavelength and couple the received infrared light into the waveguide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for use in tracking an eye, the method comprising:
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illuminating an eye with infrared light while an input-coupler of a waveguide is generally axially aligned with the eye, the input-coupler comprising a stack of two or more electronically switchable diffractive gratings arranged parallel to one another, each of the electronically switchable diffractive gratings having a respective lens power and a respective prismatic power, the lens power of each of the electronically switchable diffractive gratings differing from one another such that each of the electronically switchable diffractive gratings has a different focal length; selectively causing only one of the electronically switchable diffractive gratings of the input coupler to be turned on at a time, such that each of the electronically switchable diffractive gratings is individually turned on for a separate period of time; separately imaging the eye, in dependence on infrared light beams that exit the waveguide at an output-coupler of the waveguide, while each of the electronically switchable diffractive gratings of the input coupler is separately turned on, to thereby obtain two or more images of the eye; and analyzing the two or more images of the eye to determine which one of the electronically switchable diffractive gratings of the input-coupler, when turned on, provides a best focused image of the eye or portion thereof. - View Dependent Claims (12, 13, 14, 15)
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16. An apparatus for use in tracking an eye that is illuminated by infrared light having an infrared wavelength, the apparatus comprising:
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a waveguide that is transparent and includes an input-coupler and an output-coupler, the input-coupler comprising two or more electronically switchable diffractive gratings arranged relative to one another such that the two or more electronically switchable diffractive gratings have different fields-of-view than one another, and each of the electronically switchable diffractive gratings of the input-coupler, when turned on, adapted to receive infrared light having the infrared wavelength and couple the received infrared light into the waveguide; an input-coupler controller that controls when each of the electronically switchable diffractive gratings is turned on, such that only one of the electronically switchable diffractive gratings is turned on at a time; and a sensor that images an eye in dependence on infrared light beams that exit the waveguide at the output-coupler. - View Dependent Claims (17, 18, 19, 20)
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Specification