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. In operation, luminance streaks and bright illumination regions may be formed due to undesirable imaging characteristics from the structure of the Fresnel mirror. Fresnel mirror draft facets and reflective facet microstructures are provided that achieve reduction of visibility of light streaks and bright illumination regions.

Abstract: A directional display apparatus including a directional display device that is capable of directing a displayed image into a viewing window of variable width is provided with a privacy control function. A control system detects the presence of one or more secondary viewers in addition to a primary viewer, and decides whether the one or more secondary viewers is permitted to view the displayed image. The control system directs a displayed image into a viewing window which is adjusted, for example by decreasing the width, in dependence on that detection. In addition, the control system detects relative movement between the primary viewer and the display device, and the width of the viewing window is increased in response to detection of said relative movement.

Abstract: A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. A birefringent surface relief diffuser structure is arranged to transmit light from the display with high transparency and provide diffuse reflection of ambient light to head-on display users. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss and with low diffusion, whereas off-axis light has reduced luminance and increased diffusion. Further, overall 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, increased frontal reflectivity and diffusion of ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

Abstract: A directional illumination apparatus comprises a waveguide with a reflective surface comprising reflective pairs of light input facets, reflective light extraction facets and an output transmissive surface. An array of micro-LEDs is arranged to illuminate the reflective surface in a rearwards direction. The pairs of light input facets direct light within the waveguide and reflective light extraction facets cooperate to provide a uniform output illumination across the output aperture of the waveguide with collimated light. A thin and efficient illumination apparatus may be used for high dynamic range display backlighting, privacy display or environmental illumination applications.

Abstract: Generating data to provide an animated visual representation is disclosed. A method comprises receiving input data obtained by a first sensor system measuring information about at least one target person. One data unit is selected from a database comprising a plurality of the data units. Each data unit comprises information about a reference person in a reference state measured at a previous time by the first sensor system or by a second sensor system. The information in each data unit allows generation of an animated visual representation of the reference person in the reference state. The reference state is different for each of the data units. The selected data unit and the input data are used to generate output data usable to provide an animated visual representation corresponding to the target person and synchronized with activity of the target person measured by the first sensor system.

Abstract: 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.

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: 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 backlight includes a directional waveguide and a light source array, for providing large area directed illumination from localized light sources. Interfaces are provided between the directional waveguide and optical components adjacent the directional waveguide such that the coefficient of friction at the waveguide interfaces is greater than the coefficient of friction at least one outer interface on each side of the waveguide in the stack. Damage from compressive forces on the optical stack may be reduced, achieving improved optical performance and lifetime. Privacy display, low stray light display and autostereoscopic display may be provided with high uniformity, long lifetime and reduced cost mechanical components.

Abstract: A switchable directional backlight for a privacy display comprises a waveguide with first and second opposing input ends and a turning film arranged to collect light output from the waveguide for input into a spatial light modulator. The waveguide has an array of light deflecting features arranged on one guiding surface and an opposing planar surface. Light deflecting features are arranged such that light input from the first input end is output with a narrow angular range and light input from the second input end is output with a wide angular range.

Abstract: Disclosed is an imaging directional backlight including an array of light sources, and a control system arranged to provide variable distribution of luminous fluxes, scaled inversely by the width associated with the respective light sources in the lateral direction, across the array of light sources. The luminous intensity distribution of output optical windows may be controlled to provide desirable luminance distributions in the window plane of an autostereoscopic display, a directional display operating in wide angle 2D mode, privacy mode and low power consumption mode. Image quality may be improved and power consumption reduced.

Abstract: 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.

Abstract: A display comprises a polarised output spatial light modulator, switchable liquid crystal retarder, absorbing polariser and touch panel electrodes. The electrodes of the switchable liquid crystal retarder shield the touch panel electrodes from the electrical noise of the spatial light modulator addressing. The touch panel control and sensing may be synchronised with the driving signal of the switchable liquid crystal retarder. The touch panel may be operated independently of the timing of the data addressing of the spatial light modulator.

Abstract: 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.

Abstract: Gaze is corrected by adjusting multi-view images of a head. Image patches containing the left and right eyes of the head are identified and a feature vector is derived from plural local image descriptors of the image patch in at least one image of the multi-view images. A displacement vector field representing a transformation of an image patch is derived, using the derived feature vector to look up reference data comprising reference displacement vector fields associated with possible values of the feature vector produced by machine learning. The multi-view images are adjusted by transforming the image patches containing the left and right eyes of the head in accordance with the derived displacement vector field.

Abstract: Methods and devices for generating reference data for adjusting a digital representation of a head region, and methods and devices for adjusting the digital representation of a head region are disclosed. In some arrangements, training data are received. A first machine learning algorithm generates first reference data using the training data. A second machine learning algorithm generates second reference data using the same training data and the first reference data generated by the first machine learning algorithm.

Abstract: Disclosed is a light guiding valve apparatus including an imaging directional backlight, an illuminator array and an observer tracking system arranged to achieve control of an array of illuminators which may provide a directional display to an observer over a wide lateral and longitudinal viewing range, wherein the number of optical windows presented to the observer as viewing windows is controlled dependent on the lateral and longitudinal position or speed of an observer.

Abstract: An imaging directional backlight apparatus includes a waveguide and light source array for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure in which steps may include extraction features optically hidden to guided light, propagating in a forward direction. Returning light propagating in a backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources and defines the relative positions of system elements and ray paths. Alignment of the waveguide to mechanical and optical components may be provided by surface relief features of the waveguide arranged in regions adjacent the input surface and intermediate the light emitting regions of the light sources.

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: 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. Viewing windows are formed through imaging individual light sources and hence defines the relative positions of system elements and ray paths. Lateral non-uniformities of output image are improved by means of adjustment of input aperture shape and reflective aperture shape. Cross talk in autostereoscopic and privacy displays may further be improved by light blocking layers arranged on the input end of the waveguide.