Waveguide structure
AssigneeSnap Inc.
InventorIan Marshall
Life of this patent
Estimating the term…
Abstract
An optical waveguide device for use in a head up display. The waveguide device provides pupil expansion in two dimensions. The waveguide device comprise a primary waveguide and a secondary waveguide, the secondary waveguide being positioned on a face of the primary waveguide. The secondary waveguide has a diffraction grating on a face opposite to the face which contacts the primary waveguide. The diffraction grating diffracts light into more than diffraction order. Rays diffracted into a non-zero order are trapped in the secondary waveguide by total internal reflection.
Claims20
An optical waveguide system, the optical waveguide system comprising:
- a first optical waveguide including a first diffraction grating;
- and
- a second optical waveguide that is arranged parallel to the first optical waveguide, the second optical waveguide including a second diffraction grating,
- the first diffraction grating and the second diffraction grating being arranged in different directions, and the first diffraction grating and the second diffraction grating at least partially overlapping each other such that an input region of the first optical waveguide is arranged such that light projected into the first optical waveguide within an input-angle range substantially strikes the first diffraction grating without passing through the second diffraction grating.
An optical waveguide system to be used in a head-up display, the optical waveguide system comprising:
- a first optical waveguide including a first side and a second side that is spaced apart from the first side;
- a first diffraction grating on the second side of the first optical waveguide;
- a second optical waveguide including a first side and a second side that is spaced apart from the first side, the second side of the second optical waveguide closer to the first side of the first optical waveguide than the second side of the first optical waveguide;
- and
- a second diffraction grating on the first side of the second optical waveguide,
- the first diffraction grating and the second diffraction grating being arranged in different directions, and the first diffraction grating and the second diffraction grating at least partially overlapping each other such that an input region of the first optical waveguide is arranged such that light projected into the first optical waveguide within an input-angle range substantially strikes the first diffraction grating without passing through the second diffraction grating.
Dependencies are inferred from the claim text.