Switchable display apparatus

Abstract

A display apparatus comprises: an emissive spatial light modulator comprising an array of pixels each arranged to output randomly polarized light; a birefringent lens positioned to receive light from the spatial light modulator arranged in a first mode of operation of the display apparatus to direct light of a first polarization component into a first directional distribution and in a second mode of operation of the display apparatus to direct light of a second polarization component into a second directional distribution different from the first directional distribution; a quarter waveplate; and a linear polarizer. The quarter waveplate is arranged between the spatial light modulator and the birefringent lens and the linear polarizer is arranged on the opposite side of the birefringent lens from the quarter waveplate.

Dependencies are inferred from the claim text.