Apple patents waveguide display fix to stop dark color bands
Apple describes a display component that guides light through a thin glass layer using a technique called total internal reflection. It uses a specific patterned surface to bend red, green, and blue light onto slightly different paths, ensuring all colors reach the eye without creating visible dark gaps.
In the filing’s own words
A display may include a waveguide having a grating medium sandwiched between first and second substrates. A cross-coupler can direct light in the waveguide towards an output coupler. The output coupler may include volume holograms in the medium. The output coupler may couple the light out of the waveguide and towards an eye box. The cross-coupler may include a surface relief grating (SRG). The SRG may diffract an entirety of the fields of view of different color channels of light incident upon the SRG from within a total internal reflection (TIR) range of the waveguide onto angles at opposing sides of a TIR transition angle of the waveguide. This may prevent the formation of unsightly dark bands in one or more of the color channels at the eye box.
What exactly they claim (claim 1)
1. An electronic device comprising: a waveguide having a first substrate, a second substrate, and a grating medium sandwiched between the first substrate and the second substrate, wherein the first substrate is configured to propagate at least a first color channel and a second color channel of light via total internal reflection (TIR); a third substrate on the waveguide; a first optical coupler configured to couple the light into the waveguide; a second optical coupler configured to couple the light out of the waveguide, the second optical coupler comprising volume holograms in the grating medium; and a third optical coupler configured to redirect the light from the first optical coupler towards the second optical coupler, wherein the third optical coupler comprises a surface relief grating (SRG) in the third substrate, the SRG is configured to diffract the first color channel of the light onto first angles within a TIR range of the first substrate, and the SRG is configured to diffract the second color channel of the light onto second angles outside the TIR range of the first substrate.
Facts
- Company
- Apple (Apple Inc.)
- Official title
- Waveguide display with total internal reflection band between color channels
- Patent number
- US12730266B1
- Application number
- 18744279
- Filed
- Jun 14, 2024
- Granted
- Sep 8, 2026
- Inventors
- 4
- Claims
- 20
Classified under
G02B 6/34 Physics & computingG02B 27/0172 Physics & computingG02B 2027/0112 Physics & computingG02B 2027/0174 Physics & computingG02B 2027/0178 Physics & computingMore from Apple in AR, VR & displays
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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.