Abstract: Reflections from a display device are controlled using retarders arranged on the output side of a display panel which outputs light with a predetermined polarization state. First and second planes of incidence are defined in respect of first and second rays of light output from the device and first and second normals to first and second surfaces of optically transmissive material at first and second points at which the first and second rays of light are reflected. The retarders are selected to cause the polarization state of the first ray to be linearly polarized in a direction that is in the first plane of incidence, and to cause the polarization state of the second ray to be linearly polarized in a direction that is in the second plane of incidence. The reflections from the surfaces are minimized because for both surfaces the polarization direction is in-plane.

Abstract: A switchable privacy display comprises a spatial light modulator with output polariser, a reflective polariser, a polar control liquid crystal retarder and an additional polariser. The electrodes of the polar control liquid crystal retarder are patterned with a mark. In wide angle and narrow angle operational modes, the electrodes of the liquid crystal retarder are driven such that the mark is not visible. In a mark display state, the electrodes are driven to provide visibility of the mark in reflected light to an off-axis observer.

Abstract: A switchable backlight for a switchable privacy display apparatus comprises a collimated waveguide, first and second light sources and an optical turning film comprising elongate prismatic elements with facet orientations that pupillate the output of the waveguide in two orthogonal directions for each of first and second light sources. High luminance uniformity is achieved for a head-on user in privacy and public viewing modes and high uniformity of security factor is achieved for off-axis snoopers, with increased speed of privacy switch-on in privacy mode.

Abstract: An anamorphic directional illumination device may provide a near-eye display apparatus or a vehicle external light device. The anamorphic near-eye display apparatus comprises a spatial light modulator with asymmetric pixels, an input transverse anamorphic lens; and an extraction waveguide that passes input light in a first direction between a polarisation-sensitive reflector and front guide surface to a lateral anamorphic reflector, and to reflect the light back through the extraction waveguide to guide between the rear guide surface and front guide surface. Reflective extraction features are arranged to extract the reflected light towards the pupil of a viewer, maintaining the directionality of the fan of light rays from the spatial light modulator and anamorphic imaging system. A thin, transparent and efficient anamorphic display apparatus for Augmented Reality and Virtual Reality displays and for scene illumination is provided.

Abstract: A directional illumination device for a vehicle external light comprises an array of light sources and an imaging waveguide comprising an input surface and a reflective end. Opposed guide surfaces are arranged to guide input light from the input surface to the reflective end and back along the waveguide after reflection at the reflective end, the waveguide being arranged to extract input light as it is guided back along the waveguide after reflection and to cause the extracted light to exit through the first guide surface. The reflective end has positive optical power in the direction laterally across the waveguide and the waveguide is arranged to direct the extracted light in respective output illumination directions distributed in a lateral direction in dependence on the input positions of the light sources in the direction laterally across the waveguide. A thin, high brightness and high efficiency controllable directional vehicle headlight is provided.

Abstract: A display device comprising a spatial light modulator having a display polariser arranged on one side of the spatial light modulator is provided with an additional polariser arranged on the same side as the display polariser and polar control retarders between the additional polariser and the display polariser. The polar control retarders include a liquid crystal retarder having two surface alignment layers disposed adjacent to a layer of liquid crystal material on opposite sides. The surface alignment layers provide alignment in the adjacent liquid crystal material with an in-plane component, wherein the angle of said in-plane component changes monotonically along a predetermined axis across the display device, providing reduction of luminance in directions that are offset from a viewing axis, increasing uniformity in the reduction of luminance in directions that are offset from a viewing axis.

Abstract: A near-eye display apparatus comprises a spatial light modulator illuminated by a directional backlight and a magnifying lens arranged to provide a magnified wide field of view image to an eye of a user. The directional backlight comprises an array of light sources and a stepped waveguide comprising a curved reflective end. Light propagates along the waveguide without loss and is reflected from the reflective end. The steps of the waveguide are arranged to provide a virtual optical window for each light source. The magnifying lens images the virtual optical window to a real pupil window in an eyebox. The real pupil window may be steered in response to the measured location of the user's pupil. High illumination efficiency is provided to the user in a thin form factor.

Abstract: A dual view display for an automotive vehicle comprises a spatial light modulator and a polar control retarder comprising a switchable liquid crystal retarder arranged between a first pair of polarisers. The switchable liquid crystal retarder comprises a polarisation-switch retarder and a polar control retarder with an average director that is directed towards an off-axis viewing location. In a first temporal phase of operation, the spatial light modulator and polar control retarder are arranged to direct light comprising a first image towards a first direction and in a second temporal phase of operation to direct light comprising a second image towards a second direction.

Abstract: A switchable privacy display comprises a spatial light modulator with output polariser, a reflective polariser, a polar control liquid crystal retarder and an additional polariser. The electrodes of the polar control liquid crystal retarder are patterned with a mark. In wide angle and narrow angle operational modes, the electrodes of the liquid crystal retarder are driven such that the mark is not visible. In a mark display state, the electrodes are driven to provide visibility of the mark in reflected light to an off-axis observer.

Abstract: An illumination apparatus comprises a plurality of LEDs aligned to an array of directional optical elements wherein the LEDs are substantially at the input aperture of respective optical elements. An electrode array is formed on the array of optical elements to provide at least a first electrical connection to the array of LED elements. Advantageously such an arrangement provides low cost and high efficiency from the directional LED array.

Abstract: A switchable privacy display apparatus comprises a polarised output spatial light modulator, and an additional polariser. A reflective polariser, switchable liquid crystal polar control retarder, passive polar control retarders and air gap are arranged between the display output polariser and additional polariser. The passive retarders are arranged to provide no phase difference to polarised light from the spatial light modulator for on-axis light; and simultaneously provide a non-zero phase difference for polarised light in off-axis directions. The polar control retarders are further arranged to achieve low reflectivity for light propagating through the air gap. A switchable privacy display that can be conveniently assembled at low cost can be provided with high contrast images for display users while maintaining high visual security level for off-axis snoopers.

Abstract: A switchable privacy display comprises an emissive SLM, a parallax barrier, a switchable LC retarder, and passive retarders arranged between parallel output polarisers. In privacy mode, on-axis light from the SLM is directed without loss, whereas the parallax barrier and retarder layers cooperate to increase the VSL to off-axis snoopers. The display may be rotated to achieve privacy operation in landscape and portrait orientations. In public mode, the LC retardance is adjusted so that off-axis luminance is increased so that the image visibility is increased for multiple users. The display may also switch between day-time and night-time operation, for example for use in an automotive environment. A low reflectivity emissive display for use in ambient illumination comprises a SLM with emissive pixels, an absorptive parallax barrier and a high spectral leakage optical isolator. Head-on light from the pixels is directed with increased transmission efficiency while ambient light is strongly absorbed.

Abstract: A privacy display comprises a spatial light modulator and a compensated switchable guest-host 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.

Abstract: A colour micro-LED display apparatus comprises an array of reflective optical elements and an array of micro-LED pixels with a uniform emission colour across the array arranged between the army of reflective optical elements and an output substrate. Light from the micro-LEDs is directed into the reflective optical elements and is incident on scattering regions in the apparatus. Colour converted scattered light is transmitted by the output substrate. A thin and efficient display apparatus may be provided with high spatial and angular colour uniformity and long lifetime.

Abstract: An anamorphic near-eye display apparatus comprises a spatial light modulator with asymmetric pixels; an input transverse anamorphic lens; and an extraction waveguide that passes input light in a first direction to a lateral anamorphic reflector arranged to reflect the light back through the waveguide. The transverse and lateral anamorphic components are arranged to achieve desirable aberrations of light cones output from the spatial light modulator. Extraction elements are arranged along the waveguide to extract the reflected light towards the pupil of an observer, maintaining the directionality of the fan of light rays from the spatial light modulator and anamorphic imaging system. A thin, transparent and efficient anamorphic display apparatus for Augmented Reality and Virtual Reality displays is provided.

Abstract: An anamorphic near-eye display apparatus comprises a spatial light modulator with asymmetric pixels; an input transverse anamorphic lens; and an extraction waveguide that passes input light in a first direction to a lateral anamorphic reflector arranged to reflect the light back through the waveguide. Partially reflective extraction elements are arranged between the rear and front guide surfaces of the waveguide to extract the reflected light towards the pupil of an observer, maintaining the directionality of the fan of light rays from the spatial light modulator and anamorphic imaging system. A thin, transparent and efficient anamorphic display apparatus for Augmented Reality and Virtual Reality displays is provided.

Abstract: 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.

Abstract: 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.

Abstract: Forming an array of metallised light input wells and an array of light-deflecting wells in an optical waveguide involves the steps of forming holes through a capped adhesive layer, attaching the adhesive layer to a substrate, metallising the substrate and adhesive layer and removing the capping to expose adhesive and metallised regions. The substrate is aligned to a well layer with an array of light input through-holes and an array of light-deflecting through-holes. The substrate is attached to the well layer with an array of metallised light input wells and an array of metallised light-deflecting wells. The array of light input wells receive light from a respective aligned array of light-emitting diodes. The array of light-deflecting wells reflects guided light in the region around each light-emitting diode. Extracted light from the waveguide is output by refraction and total internal reflection by a light turning optical component.

Abstract: A display device comprising a spatial light modulator having a display polariser arranged on one side is provided with an additional polariser arranged on the same side as the display polariser and a polar control retarder between the additional polariser and the display polariser. The polar control retarder includes a liquid crystal retarder having two surface alignment layers disposed adjacent to a layer of liquid crystal material on opposite sides. The surface alignment layers provide alignment in the adjacent liquid crystal material with a twist. The out-of-plane orientation of the twisted layer of liquid crystal material is modified across at least one region of the display device to provide a transmission function in response to the measured location of an off-axis snooper, achieving increased size of polar region for which desired uniformity of security factor, or reduced distraction across the display to the driver in an automotive application is achieved.