Autostereoscopic display

An autostereoscopic display comprising:

• a light source [200,210,220];
• and
• a spatial light modulator [100,110,120] comprising a two dimensional array of electrically controllable light modulating pixels [112,113,114,121],
• characterised in that there is further provided:
• a first electrically switchable light redirecting grid [2000a, 2010a,2020a,2080a];
• and
• a second electrically switchable light redirecting grid [2000b,2010b,2020b,2080b],
• wherein said spatial light modulator is in optical contact with said light redirecting grids,
• wherein each said light redirecting grid comprises a plurality of elongate parallel switchable diffractive elements extending in a vertical direction,
• wherein said light redirecting grids exhibit a diffracting state and a non-diffracting state,
• wherein said first light redirecting grid is operative to diffract incident light through said spatial light modulator towards the left eye position [30a,32a] of a first viewing position when in said diffracting state,
• wherein said second light redirecting grid is operative to diffract incident light towards the right eye position [30b,32b] of a first viewing position when in said diffracting state.
• wherein said light directing grids are disposed between said source and said spatial light modulator.