Patent ID: 8885112

Claim:
A wearable display comprising: a spatial light modulator (SLM); a means for collimating light emitted from each pixel of the SLM; first and second input SBG devices; and first and second output SBG devices wherein each said SBG device is formed in a HPDLC layer sandwiched between first and second transparent plates; wherein each said SBG device is characterised in that it provides a grating in a separate switchable region and is clear elsewhere, wherein said grating has an diffracting state and a non diffracting state, wherein said transparent plates and said HPDLC layers form a laminar structure which functions as a light guide; wherein said first input SBG device in its diffracting state deflects first wavelength collimated light from said SLM incident in a first angular range into first collimated light following a first TIR path inside said light guide, wherein said second input SBG device in its diffracting state deflects first wavelength collimated light from said SLM incident in a second angular range into second collimated light following a second TIR path inside said light guide, wherein said first output SBG device in its diffracting state deflects said first TIR path light out of said lightguide providing a first field of view region, wherein said second output SBG device in its diffracting state deflects said second TIR path light out of said lightguide providing a second field of view region, wherein transparent electrodes are applied to the opposing faces of said first and second transparent plates, wherein at least one of said transparent electrode is patterned into independently switchable transparent electrode elements such that said independently switchable transparent electrodes elements overlap said separately switchable grating regions, wherein said first output SBG device in its diffracting state deflects said first TIR path light out of said lightguide in a first direction and said second output SBG device in its diffracting state deflects said second TIR path light out of said lightguide in a second direction orthogonal to said first direction.