Parallax barrier, display, passive polarization modulating optical element and method of making such an element

A display comprising:

• a parallax barrier comprising:
• a polarisation modifying layer having aperture regions, for supplying light of a second polarisation when receiving light of a first polarisation, separated by barrier regions, for supplying light of a third polarisation different from the second polarisation when receiving light of the first polarisation, at least one of the aperture regions and the barrier regions altering the polarisation of light passing therethrough:
• and
• a polariser selectively operable in a first mode to pass and output light of the second polarisation and to block light of the third polarisation and in a second mode to pass and output light of the second polarisation and third polarisation, and
• a spatial light modulator having an input polariser for passing light from the aperture regions.

A display comprising:

• a polarisation modifying layer having aperture regions, for supplying light of a second polarisation when receiving light of a first polarisation, separated by barrier regions, for supplying light of a third polarisation different from the second polarisation when receiving light of the first polarisation;
• a spatial light modulator having an input polariser for passing light of the second polarisation and for blocking light of the third polarisation;
• a light source;
• a mask having polarising regions, for supplying light of the first polarisation from the light source, and non-polarising regions, for transmitting light from the light source;
• and a parallax optic co-operating with the mask to direct light from the polarising regions through the spatial light modulator to a first viewing region and to direct light from the non-polarising regions through the spatial light modulator to a second viewing region.