| CPC G02B 27/0103 (2013.01) [G02B 2027/0136 (2013.01)] | 11 Claims |
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1. A method of expanding an eye-box in a viewing window at a viewing plane of a head-up display used by a viewer, the method comprising:
receiving, by a first waveguide pupil expander, first spatially modulated light encoded with a hologram at an input port so that the first waveguide pupil expander replicates the first spatially modulated light encoded with the hologram in order to expand an exit pupil in a first direction of a first dimension;
receiving, by a second waveguide expander, second spatially modulated light encoded with the hologram at an input port so that the second waveguide pupil expander replicates the spatially modulated light encoded with the hologram in order to expand the exit pupil in second direction of the first dimension,
propagating the replicated first spatially modulated light encoded with the hologram from the first waveguide pupil expander to the viewing plane; and
propagating the replicated second spatially modulated light encoded with the hologram from the second waveguide pupil expander to the viewing plane;
wherein the first dimension corresponds to a dimension of the eye-box, and
wherein the first waveguide pupil expander and the second waveguide pupil expander are tilted with respect to the viewing plane of the eye-box in opposite directions,
wherein the first waveguide pupil expander and the second waveguide pupil expander are abutted against one another or together form a single unitary structure, and
wherein replicated first spatially modulated light encoded with the hologram and the replicated second spatially modulated light encoded with the hologram form a continuous viewing window at the viewing plane as a result of the expansion of the exit pupils of the first and second waveguide pupil expanders in the first direction.
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