LC display having public and private viewing modes arranged to display a first image in the public mode and second and third spatially interlaced images in th

摘要

A display is provided having a public viewing mode and a private viewing mode. The display comprises a display device (11), such as an LCD, which always directs image-modulated light towards the whole of a public viewing region. The display device (11) displays a first image in the public mode and second and third spatially interlaced images in the private mode. A controllable liquid crystal device (10) is switchable between the public and private modes. In the public mode, light modulated by the first image has a first polarisation. In the private mode, light modulated by the second and third images is provided with second and third polarisations, respectively. An optical arrangement, comprising an angularly dependent polarisation changer (9) and a polariser (8) permits the passage of light of the first polarisation into substantially the whole of the public region. Light of the second polarisation is substantially restricted to a private viewing region within the public region. Light of the third polarisation is substantially restricted into one or more non-private viewing regions outside the private region and within the public region. The first polarisation may be the same as one of the second and third polarizations; and the second and third polarizations may be orthogonal. The private region may be central in the display and the public regions may be disposed away from the display axis.