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US 12,638,630 B2Granted
Waveguide
AssigneeBAE SYSTEMS plc
InventorIan Marshall
Life of this patent
Estimating the term…
Abstract
A waveguide for use in a head-up or head-worn display, the waveguide comprising: a prism having an entrance pupil for receiving an image; a plurality of gratings configured to direct illumination through the prism towards first and second semi-reflecting surfaces; wherein the semi-reflecting surfaces each reflect a different amount of illumination towards an exit point to produce an output image.
Claims18
A waveguide for use in display system, the waveguide comprising:
- a one-dimensional prism having an entrance pupil for receiving first order illumination of an image into the one-dimensional prism, the first order illumination received via the entrance pupil being trapped within the one-dimensional prism by total internal reflection (TIR) towards first and second semi-reflecting surfaces;
- and
- a plurality of square wave diffraction gratings applied on opposing external surfaces of the one-dimensional prism, wherein
- a first one of the plurality of square wave diffraction gratings is configured to diffract the first order illumination of the image trapped within the one-dimensional prism by further TIR into second and third orders towards the first and second semi-reflecting surfaces, and
- a second one of the plurality of square wave diffraction gratings is configured to diffract the second and third order illumination back into the first order;
- wherein the first and second semi-reflecting surfaces each reflect the first order illumination towards an eye-box to produce an output image.
3 more elements
A method of transmitting illumination via a waveguide in an optical device, the waveguide comprising:
- a one-dimensional prism having an entrance pupil for receiving first order illumination of an image into the one-dimensional prism, the first order illumination received via the entrance pupil being trapped within the one-dimensional prism by total internal reflection (TIR) towards first and second semi-reflecting surfaces;
- and
- a plurality of square wave diffraction gratings applied on opposing external surfaces of the one-dimensional prism, wherein
- a first one of the plurality of square wave diffraction gratings is configured to diffract the first order illumination of the image trapped within the one-dimensional prism by further TIR into second and third orders towards the first and second semi-reflecting surfaces, and
- a second one of the plurality of square wave diffraction gratings is configured to diffract the second and third order illumination back into the first order;
- wherein the first and second semi-reflecting surfaces each reflect the first order illumination towards an eye-box to produce an output image,
- wherein the method comprises:
- receiving, via the entrance pupil, the image being directed into the one-dimensional prism;
- directing, via the square wave diffraction gratings, the illumination of the image towards the first and second semi-reflecting surfaces formed by two make-up pieces;
- and
- partially reflecting the illumination, via the first and second semi-reflecting surfaces, out of the one-dimensional prism towards the eye-box.
8 more elements
A method of manufacturing a waveguide, the method comprising:
- forming a one-dimensional prism having an entrance pupil for receiving first order illumination of an image into the one-dimensional prism, the first order illumination received via the entrance pupil being trapped within the one-dimensional prism by total internal reflection (TIR) towards first and second semi-reflecting surfaces;
- forming a plurality of square wave diffractive gratings on opposing external surfaces of the one-dimensional prism to enable transmission of illumination entering the one-dimensional prism, wherein a first one of the plurality of square wave diffraction gratings is configured to diffract the first order illumination of the image trapped within the one-dimensional prism by further TIR into second and third orders towards the first and second semi-reflecting surfaces, and a second one of the plurality of square wave diffraction gratings is configured to diffract the second and third order illumination back into the first order;
- forming make-up pieces thereby forming the first and second semi-reflecting surfaces;
- and
- wherein the make-up pieces are positioned to direct the first order illumination to an eye-box to produce an output image.
2 more elements
Dependencies are inferred from the claim text.