US Patent 11415794 Low-obliquity pupil relay for near-eye display

A beam scanner for a near-eye display includes a beam-folded pupil relay configured for receiving a light beam reflected from a tiltable reflector and relaying the light beam to an exit pupil while preserving the beam angle of the reflected beam. The beam-folding pupil relay includes a beamsplitter, e.g. a polarization beam splitter configured to redirect the beam to a curved reflector, which sends the beam towards the exit pupil. Polarization of the light beam reflected from the curved reflector may be changed to an orthogonal polarization by a waveplate disposed in an optical path of the light beam between the polarization beam splitter and the curved reflector, enabling the reflected light beam to propagate through the polarization beam splitter towards the exit pupil. A pupil-replicating waveguide may be disposed proximate the exit pupil. A 2D tiltable reflector or a pair of 1D tiltable reflectors may be used.