Abstract: A display is provided for providing a restricted viewing mode, for example a private viewing mode where the display may be viewed from a limited region of space by a single viewer and not by other people outside the viewing region. The display comprises a source of polarised light and an output polariser. Between these are provided a controllable pixellated spatial polarisation modulating layer, for example of the liquid crystal type. Also, a polarisation modifying layer is provided between the polarisers and is spaced from the modulating layer. The modifying later comprises a plurality of sets of regions with the regions of each set having the same polarisation modifying effect and the regions of different sets having different polarisation modifying effects. The light path between the modulating layer and the modifying layer is polariser-free.

Abstract: An optical device comprises an input polariser 4, a patterned retarder 5 and an output polariser 12. The retarder 5 has regions 8 and 9, at least one of which alters the polarisation of light from the input polariser 4. The output polariser 7 has a transmission axis 12 such that light passing through the regions 8 and 9 of the retarder 5 and through the output polariser 7 is matched in amplitude, phase and polarisation. Such a device may be used as a switchable parallax barrier with an LCD 2 to provide a display which is switchable between an autostereoscopic 3D mode and a 2D mode with the 2D mode having more uniform intensity across the display.

Abstract: A method is provided that allows simultaneous control of macroscopic azimuthal and zenithal liquid crystal alignment (?, ?) across a liquid crystal layer by controlling the area ratios between first, second and third different types of alignment region (T1, T2, T3) in a patterned alignment layer, the three different types of alignment region (T1, T2, T3) tending to induce liquid crystal alignment in the liquid crystal layer in three different respective, non-coplanar, principal orientations (z, x, y). In the illustrated example, the first type of alignment region (T1) tends to induce substantially homeotropic alignment (in the z direction) and the second and third types of alignment region (T2, T3) tend to induce substantially planar alignment in different, orthogonal, principal orientations (in the x and y directions).

Abstract: A display is provided for switching between a narrow or private viewing mode and a wide or public viewing mode. The display comprises a display device which is controlled to provide display of a desired image or sequence of images. This is associated with a liquid crystal device having at least one liquid crystal layer whose molecules are switchable between a first state providing a first angular viewing range and a second state providing a second angular viewing range which is within and smaller than the first angular viewing range. With the molecules in the second state, the device at least partially blocks light propagating towards part of the first angular viewing range outside the second angular viewing range. The or each liquid crystal layer is in contact with at least one alignment surface, the or each of which comprises a uniform non-patterned alignment surface.

Abstract: The invention relativ to an electroptical system