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US 2025/0147311 A1Published application
Lateral color alignment correction for diffractive waveguides
AssigneeGoogle Inc.
InventorThomas Hoekman
Life of this patent
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Abstract
One or more diffractive gratings of a waveguide introduce a phase perturbation to offset a lateral color misalignment due to surface deformations such as non-parallelism of the major surfaces of the waveguide. In some embodiments, a pitch and/or angle of the diffractive grating is tuned to change the k-vector of the grating in the direction of a change in total thickness variation (TTV) across the waveguide.
Claims20
A method comprising:
- guiding display light through a waveguide having surface deformations that laterally separate colors of the display light;
- and
- adding a phase perturbation to a diffractive grating of the waveguide to offset the lateral separation of the colors.
A device, comprising:
- a waveguide configured to guide display light, the waveguide comprising:
- a first major surface and a second major surface having deformations that laterally separate colors of the display light;
- and
- a diffractive grating comprising a phase perturbation configured to offset the lateral separation of the colors.
1 more element
An eyewear display device, comprising:
- a waveguide configured to guide display light to an eyebox, comprising:
- non-parallel major surfaces that laterally separate colors of the display light;
- and
- a diffractive grating comprising a phase perturbation configured to modify a k-vector of the diffractive grating by an amount corresponding to a total thickness variation across the waveguide due to the non-parallel major surfaces.
1 more element
Dependencies are inferred from the claim text.