Polarization mechanism to reduce waveguide reflections in a head-worn display
AssigneeGoogle Inc.
InventorJoseph Daniel Lowney
Life of this patent
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Abstract
A polarization mechanism for a head-mounted device includes a linear polarization film and a waveplate film configured to polarize ambient light before it is guided to the eye of a user by a waveguide. The waveplate film is further configured to receive a reflection of the polarized ambient light off the waveguide and polarize the reflection in a circular direction such that the reflection is polarized in a first linear direction. The linear polarization film then receives the reflection polarized in the first linear direction from the waveplate film and polarizes the reflection in a second linear direction perpendicular to the first linear direction.
Claims20
A method for polarizing light in a wearable display, comprising:
- linearly polarizing ambient light received at a first side of a wearable display in a first linear direction;
- circularly polarizing the ambient light polarized in the first linear direction in a first circular direction;
- circularly polarizing a reflection of the ambient light polarized in the first circular direction reflected off a waveguide of the wearable display such that the reflection of the light is polarized in a second linear direction perpendicular to the first linear direction;
- and
- linearly polarizing ambient light received at a second side of the wearable display in a third linear direction, wherein the second side is different from the first side.
A polarization mechanism for a wearable display, comprising:
- a waveguide;
- a quarter waveplate configured to receive a reflection of ambient light off the waveguide and polarize the reflection of ambient light in a circular direction such that the reflection of ambient light is polarized in a first linear direction;
- and
- a linear polarizer configured to receive the reflection of ambient light polarized in the first linear direction and absorb the reflection of ambient light polarized in the first linear direction, the linear polarizer including an aperture configured to allow display light to pass unattenuated.
An optical combiner, comprising:
- a waveguide;
- a linear polarizer configured to linearly polarize ambient light received at a first side of the optical combiner in a first linear direction;
- a quarter waveplate configured to:
- circularly polarize the ambient light polarized in the first linear direction in a first circular direction;
- and
- circularly polarize a reflection of the ambient light polarized in the first circular direction reflected off the waveguide such that the reflection of the ambient light is polarized in a second linear direction perpendicular to the first linear direction;
- and
- a second linear polarizer configured to linearly polarize ambient light received at a second side of the optical combiner in a third linear direction, wherein the second side is different from the first side.
Dependencies are inferred from the claim text.