Abstract: A lens array structure comprises two birefringent lens arrays arranged in series, both being capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation. The lens arrays are relatively oriented such that incident light of two perpendicular polarisation components are directed into a directional distribution by a respective one of the birefringent lens arrays and not affected by other one of the birefringent lens arrays. Thus control of the polarisation allows switching between the effects of the two lens arrays. To allow switching into a third mode in which neither of the lens arrays has effect, one of the lens arrays may be active. The lens structure may be employed in a display apparatus to provide a switchable directional display.

Abstract: To align a display substrate comprising an array of pixels with a component substrate comprising an array of optical components, the display substrate is divided from a display motherglass formed with an array of panels each comprising an array of pixels sufficient for a single display substrate and with, in respect of each panel, a first alignment feature having a surface relief aligned with the array of pixels. The component substrate is formed with an array of optical components and a second alignment feature aligned with the array of optical components, the second alignment feature having a surface relief shaped to register with the first alignment feature. The display substrates is attached to the component substrate with the first and second alignment features in registration with each other. The alignment of the first alignment feature with the array of pixels may be carried out at the motherglass stage in respect of the entire motherglass.

Abstract: A light direction switching apparatus and method is described. The light direction switching apparatus comprises a passive birefringent lens (138), e.g. a birefringent lenticular screen, and a switchable polariser (146). By switching the polariser (146), different directional distributions of output light are provided. The light direction switching apparatus may be used with or incorporated in a display device, such as a liquid crystal display device, to provide a display device switchable between a two dimensional mode and an autostereoscopic three dimensional mode, or to provide a multi-user display device where different images are displayed to different viewers. The light direction switching apparatus may also be used to provide switchable brightness enhancement of reflective or transflective display devices. The light direction switching apparatus may also be used to provide a fiber-optic switching apparatus. The switchable polariser may be mechanically switchable or electrically switchable.