Optical systems including light-guide optical elements with two-dimensional expansion
AssigneeLumus Ltd.
InventorsEitan Ronen, Ronen Chriki, Tsion Eisenfeld
Life of this patent
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Abstract
An optical system provides two-stage expansion of an input optical aperture for a display based on a light-guide optical element. A first expansion is achieved using two distinct sets of mutually-parallel partially-reflecting surfaces, each set handing a different part of an overall field-of-view presented to the eye. In some cases, a single image projector provides image illumination to two sets of facets that are integrated into the LOE. In other cases, two separate projectors deliver image illumination corresponding to two different parts of the field-of-view to their respective sets of facets.
Claims13
An optical system for directing image illumination injected into at least one coupling-in region to an eye-motion box for viewing by an eye of a user, the optical system comprising a light-guide optical element (LOE) formed from transparent material, said LOE comprising:
- (a) a first region containing a first set of planar, mutually-parallel, partially-reflecting surfaces having a first orientation;
- (b) said first region further containing a second set of planar, mutually-parallel, partially-reflecting surfaces having a second orientation non-parallel to said first orientation;
- (c) a second region containing a third set of planar, mutually-parallel, partially-reflecting surfaces having a third orientation non-parallel to each of said first orientation and said second orientation;
- (d) a set of mutually-parallel major external surfaces, said major external surfaces extending across said first and second regions such that said first set of partially-reflecting surfaces, said second set of partially-reflecting surfaces and said third set of partially-reflecting surfaces are all located between said major external surfaces,
- wherein said third set of partially-reflecting surfaces are at an oblique angle to said major external surfaces so that a part of the image illumination propagating within said LOE by internal reflection at said major external surfaces from said first region into said second region is coupled out of said LOE towards the eye-motion box, and wherein each of said first and second sets of partially-reflecting surfaces is oriented so that a part of the image illumination propagating within said LOE by internal reflection at said major external surfaces from the at least one coupling-in region is deflected towards said second region,
- and wherein each of said first and second sets of partially-reflecting surfaces includes a deflection surface configured to reflect a majority of the image illumination incident on said deflection surface, said deflection surface being deployed to be the first partially-reflecting surface of each of said first and second sets of partially-reflecting surfaces reached by the image illumination injected into the at least one coupling-in region,
- and wherein each of said first and second sets of partially-reflecting surfaces includes a filler surface adjacent to said deflection surface, said filler surface having a length measured parallel to said major external surfaces that is smaller than a length of said deflection surface and smaller than a length of another partially-reflecting surface adjacent to said filler surface.
Dependencies are inferred from the claim text.