Granted Patent B2

US 12,736,817 · App. 18/305,953 · Granted Sep 15, 2026

Inventors: Juan Russo (Denver, CO); Adam Douglas Greengard (Lafayette, CO)

Assignee: Snap Inc.

G02B27/0172G02B6/0016G02B6/0035G02B27/0179G02B6/0065G02B2027/0112G02B2027/0178G02B2027/0187

Abstract

Claims (68)

1 . A waveguide, comprising:

a waveguide body comprising an optically transmissive material having a refractive index different from a surrounding medium and defining an output surface, configured to propagate light by total internal reflection in one or more directions substantially tangential to the output surface;

one or more diffractive optical elements (DOEs), each configured to change its diffraction efficiency in response to a respective stimulus;

a DOE driver configured to provide the respective stimuli to each of the DOEs independently; and

a controller configured to:

receive eye tracking data representative of a location of an eye; and

dynamically control the DOE driver to provide the stimuli based on the eye tracking data to direct the light toward the location of the eye by diffracting the light out of the waveguide body via the output surface.

2 . The waveguide of claim 1 , wherein:

the one or more DOEs comprise:

a first one or more output DOEs configured to diffract light out of the output surface toward the target region; and

a second one or more output DOEs configured to diffract light out of the output surface toward a location outside of the target region; and

the stimuli provided to the DOEs are configured to increase the diffraction efficiency of the first one or more output DOEs relative to the diffraction efficiency of the second one or more output DOEs.

3 . The waveguide of claim 2 , wherein increasing the diffraction efficiency of the first one or more output DOEs relative to the diffraction efficiency of the second one or more output DOEs comprises:

increasing the diffraction efficiency of the first one or more output DOEs.

4 . The waveguide of claim 2 , wherein increasing the diffraction efficiency of the first one or more output DOEs relative to the diffraction efficiency of the second one or more output DOEs comprises:

decreasing the diffraction efficiency of the second one or more output DOEs.

5 . The waveguide of claim 4 , wherein:

the one or more DOEs comprise:

a fold DOE configured to diffract light propagating in a first direction of the one or more directions to propagate in a second direction of the one or more directions;

the light propagating in the second direction is more likely to reach the target region than the light propagating in the first direction; and

the stimuli provided to the DOEs are configured to increase the diffraction efficiency of the fold DOE such that an amount of light diffracted to propagate in the second direction is increased.

6 . The waveguide of claim 1 , wherein:

the stimuli provided to the DOEs are configured to selectively propagate light according to time-varying conditions.

7 . The waveguide of claim 6 , wherein:

the time-varying conditions comprise a temporal sequence of color-specific periods comprising:

a first period in which light of a first color propagates within the waveguide body; and

a second period in which light of a second color propagates within the waveguide body;

the one or more DOEs comprise:

a first one or more DOEs configured to diffract light of the first color; and

a second one or more DOEs configured to diffract light of the second color; and

the stimuli are configured to:

increase the diffraction efficiency of the first one or more DOEs relative to the diffraction efficiency of the second one or more DOEs during the first period; and

increase the diffraction efficiency of the second one or more DOEs relative to the diffraction efficiency of the first one or more DOEs during the second period.

8 . The waveguide of claim 7 , wherein:

the first one or more DOEs comprise a first one or more output DOEs configured to diffract light of the first color out of the output surface;

the second one or more DOEs comprise a second one or more output DOEs configured to diffract light of the second color out of the output surface; and

the first one or more output DOEs and the second one or more output DOEs are arranged in a stacked configuration such that:

during the first period, relatively more light enters the first one or more output DOEs and is diffracted out of the output surface by the first one or more output DOEs; and

during the second period, relatively more light passes through the first one or more output DOEs, enters the second one or more output DOEs, and is diffracted out of the output surface by the second one or more output DOEs.

9 . The waveguide of claim 8 , wherein:

the first one or more DOEs further comprise a first one or more input DOEs configured to diffract light of the first color into the waveguide body at an angle sufficient to achieve the total internal reflection;

the second one or more DOEs further comprise a second one or more input DOEs configured to diffract light of the second color into the waveguide body at an angle sufficient to achieve the total internal reflection; and

the first one or more input DOEs and the second one or more input DOEs are arranged in a stacked configuration such that:

during the first period, relatively more light enters the first one or more input DOEs and is diffracted into the waveguide body by the first one or more input DOEs; and

during the second period, relatively more light passes through the first one or more input DOEs, enters the second one or more input DOEs, and is diffracted into the waveguide body by the second one or more output DOEs.

10 . The waveguide of claim 9 , wherein:

the stacked arrangements do not include air gaps between the first one or more output DOEs and the second one or more output DOEs, or between the first one or more input DOEs and the second one or more input DOEs.

11 . The waveguide of claim 1 , wherein:

the stimuli comprise a physical deformation of at least one DOE.

12 . The waveguide of claim 1 , wherein:

the stimuli comprise a change in temperature of at least one DOE.

13 . The waveguide of claim 1 , wherein:

the stimuli comprise electrical stimulation of at least one DOE.

14 . The waveguide of claim 13 , wherein:

the at least one DOE comprises a liquid crystal material.

15 . The waveguide of claim 1 , wherein:

the optically transmissive material comprises a dielectric material.

16 . The waveguide of claim 1 , wherein:

the optically transmissive material comprises a plastic material.

17 . The waveguide of claim 1 , wherein:

the optically transmissive material comprises a glass material.

18 . A method comprising:

propagating light within a waveguide body in one or more directions substantially tangential to an output surface of the waveguide body;

receiving eye tracking data representative of a location of an eye; and

dynamically providing a respective stimulus to each of one or more diffractive optical elements (DOEs) independently based on the eye tracking data, each DOE being configured to change its diffraction efficiency in response to the respective stimulus, such that at least a portion of the light propagating in the waveguide body is diffracted by the one or more DOEs to direct the light toward the location of the eye by diffracting the light out of the waveguide body via the output surface.

19 . A non-transitory computer-readable storage medium, the computer-readable storage medium including instructions that, when executed by a computer, cause the computer to perform operations including:

receiving eye tracking data representative of a location of an eye; and

dynamically providing a respective stimulus to each of one or more diffractive optical elements (DOEs) independently based on the eye tracking data, each DOE being configured to change its diffraction efficiency in response to the respective stimulus, such that at least a portion of the light propagating in a waveguide body is diffracted by the one or more DOEs to direct the light toward the location of the eye by diffracting the light out of the waveguide body via the output surface.

Assignments (1)

Continuity (2)

References Cited (122)