A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. Further, display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction and increased frontal reflectivity to ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Retarder stack arrangements are provided to reduce the display visibility to snoopers located in polar viewing regions of the display while achieving minimal reduction of head-on luminance. Further visibility of light reflections from automotive windscreens may be reduced.

A wearable display system includes an eyepiece stack having a world side and a user side opposite the world side. During use, a user positioned on the user side views displayed images delivered by the wearable display system via the eyepiece stack which augment the user's field of view of the user's environment. The system also includes an optical attenuator arranged on the world side of the of the eyepiece stack, the optical attenuator having a layer of a birefringent material having a plurality of domains each having a principal optic axis oriented in a corresponding direction different from the direction of other domains. Each domain of the optical attenuator reduces transmission of visible light incident on the optical attenuator for a corresponding different range of angles of incidence.

A privacy display comprises a spatial light modulator and a compensated switchable liquid crystal retarder arranged between first and second polarisers arranged in series with the spatial light modulator. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction over a wide polar field. In a wide angle mode of operation, the switchable liquid crystal retardance is adjusted so that off-axis luminance is substantially unmodified.

A phase difference compensation element, including: a transparent substrate; a first optical anisotropic layer that includes an inorganic material, and has a C-plate retardance; and a second optical anisotropic layer that includes an inorganic material, and includes an oblique angle vapor deposition film that does not have an O-plate retardance, wherein the phase difference compensation element including the first optical anisotropic layer and the second optical anisotropic layer in combination has a quasi-O-plate retardance.

An improvement in contrast is achieved by suitably offsetting a phase difference produced by oblique light in a liquid-crystal panel.

An optical compensation apparatus includes a negative C-plate and two O-plates, an amount of a composite phase difference between the two O-plates and the negative C-plate in a tilt-direction cross section is substantially same as an amount of a phase difference produced by light having each of incident angles in a predetermined incident-angle range in the liquid-crystal panel, and a sign of the composite phase difference is opposite to a sign of the phase difference, the tilt-direction cross section being a cross section parallel to a tilt direction of the liquid crystal in a vertical-alignment-type liquid-crystal panel.

A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. Further, display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction and increased frontal reflectivity to ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Retarder stack arrangements are provided to reduce the display visibility to snoopers located in polar viewing regions of the display while achieving minimal reduction of head-on luminance. Further visibility of light reflections from automotive windscreens may be reduced.

A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. Further, display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction and increased frontal reflectivity to ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

This application relates to a liquid crystal display which comprises: an upper polarizer; a lower polarizer; and a liquid crystal panel provided between the upper polarizer and the lower polarizer, in which the upper polarizer and the lower polarizer are provided so that absorption axes of the upper and lower polarizers are parallel to each other, a first half wave plate, a positive C plate, and a second half wave plate are sequentially comprised between the upper polarizer and the liquid crystal panel, and the liquid crystal panel is a vertical alignment liquid crystal mode.