Abstract: A head-up display for a vehicle comprises an optical component having a reflective surface arranged, during head-up display operation, in a configuration that is conducive to sunlight glare. A light control layer is disposed on the optical component to receive sunlight on an optical path to the reflective surface. The light control layer comprises a sunlight-receiving surface and a core material separating an array of louvres. The sunlight-receiving surface of the light control layer is serrated in coordination with the array of louvres so as to deflect received sunlight away from the eye-box of the head-up display.

Abstract: A waveguide includes a pair of complementary surfaces arranged to provide waveguiding therebetween. A first surface of the pair of complementary surfaces includes a plurality of first layers and a plurality of second layers. Each first layer includes a first dielectric. Each second layer includes a second dielectric. Each first and second layer has a first end and a second end. A percentage change in the thickness of each layer from the first end to the second end of that layer has one of a plurality of discrete allowable values. The total number of first and second layers is greater than the total number of discrete allowable values. A difference in refractive index between the first dielectric and second dielectric is greater than 0.4.

Abstract: A holographic system comprises an image processor, a hologram calculator and a display driver. The image processor is arranged to determine first and second secondary images by sampling the pixel values of a primary image at a regular array of sampling positions. The hologram calculator is arranged to determine a hologram of each secondary image. The display driver is arranged to display each hologram in rapid succession on a display device, first and second times, so as to reconstruct each secondary image from the respective hologram such that respective first and second arrays of image pixels corresponding to the primary image are perceivable. Image pixels of the reconstruction of the second secondary image are interposed between image pixels of the reconstruction of the first secondary image in the first direction.

Abstract: A display device having a viewing window on a viewing plane is described. The display device comprises a picture generating unit, a first waveguide pupil expander and a second waveguide pupil expander. The picture generating unit is arranged to display a picture on a display plane. The picture is a holographic reconstruction formed from a hologram of the picture. The first waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a first exit pupil thereof in a first dimension. The second waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a second exit pupil thereof in the first dimension. The first dimension corresponds to a dimension of the viewing window. A method of expanding a viewing window of a display device is also described.

Abstract: A display device having a viewing window on a viewing plane is described. The display device comprises a picture generating unit, a first waveguide pupil expander and a second waveguide pupil expander. The picture generating unit is arranged to display a picture on a display plane. The picture is a holographic reconstruction formed from a hologram of the picture. The first waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a first exit pupil thereof in a first dimension. The second waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a second exit pupil thereof in the first dimension. The first dimension corresponds to a dimension of the viewing window. A method of expanding a viewing window of a display device is also described.

Abstract: A display device having a viewing window on a viewing plane is described. The display device comprises a picture generating unit, a first waveguide pupil expander and a second waveguide pupil expander. The picture generating unit is arranged to display a picture on a display plane. The picture is a holographic reconstruction formed from a hologram of the picture. The first waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a first exit pupil thereof in a first dimension. The second waveguide pupil expander comprises an input port arranged to receive light of the picture and to expand a second exit pupil thereof in the first dimension. The first dimension corresponds to a dimension of the viewing window. A method of expanding a viewing window of a display device is also described.

Abstract: A head-up display for a vehicle comprises an optical component having a reflective surface arranged, during head-up display operation, in a configuration that is conducive to sunlight glare. A light control layer is disposed on the optical component to receive sunlight on an optical path to the reflective surface. The light control layer comprises a sunlight-receiving surface and a core material separating an array of louvres. The sunlight-receiving surface of the light control layer is serrated in coordination with the array of louvres so as to deflect received sunlight away from the eye-box of the head-up display.

Abstract: A head-up display for a vehicle. The head-up display comprises a projector and processor. The projector is arranged to project image content such that it is visible from an eye-box. The processor is arranged to receive captured images of a scene visible from the eye-box. The processor is arranged, at a first time to: detect a first object in a scene and instruct the image projector to project an icon (e.g. computer graphic) that appears, from the viewing position, to be coincident with the first object. The processor is further arranged to, at a second time later than the first time to: detect a second object in a line of sight from the eye-box position to the first object and instruct the image projector to change the visual appearance of the projected icon in response to the detection of the second object.

Abstract: A method of fabricating an electrically-controlled birefringence cell. The cell has a cell gap no more than 20 micrometers. The cell has an alignment layer arranged to impart a pretilt on liquid crystal in contact with the alignment layer. The method comprises processing the alignment layer to achieve a surface anchoring value between the liquid crystal and alignment layer of less than 1 mJ/m2.

Abstract: A method and system for reducing the effects of glare in a system comprising a picture generating unit, such as a holographic projector. The system may be a head-up display (HUD), which is configured to display a picture to a viewer, without requiring the user to look away from their usual viewpoint. The HUD system may be comprised within a vehicle. The glare in the system may be caused by light being incident on a surface comprising a screen or a window, through which the user looks at their usual viewpoint. The surface may comprise a windshield in a vehicle. The light that causes the glare may be ambient light. The method and system are provided for reducing the effects of glare in a system that comprises a waveguide in conjunction with the picture generating unit. The waveguide may be operable to act as an exit pupil expander.

Abstract: A method and system for reducing the effects of glare in a system comprising a picture generating unit, such as a holographic projector. The system may be a head-up display (HUD), which is configured to display a picture to a viewer, without requiring the user to look away from their usual viewpoint. The HUD system may be comprised within a vehicle. The glare in the system may be caused by light being incident on a surface comprising a screen or a window, through which the user looks at their usual viewpoint. The surface may comprise a windshield in a vehicle. The light that causes the glare may be ambient light. The method and system are provided for reducing the effects of glare in a system that comprises a waveguide in conjunction with the picture generating unit. The waveguide may be operable to act as an exit pupil expander.

Abstract: There is disclosed herein a waveguide comprising an optical slab and an optical wedge. The optical slab has a first refractive index, n1>1. The optical slab comprises: a pair of opposing surfaces and an input port. The pair of opposing surfaces are arranged in a parallel configuration. The input port is arranged to receive light into the optical slab at an angle such that the light is guided between the first and second opposing surfaces by a series of internal reflections. The optical wedge has a second refractive index, n2, wherein 1<n2<n1. The optical wedge comprises a pair of opposing surfaces arranged in a wedge configuration. A first surface of the optical wedge abuts the second surface of the optical slab to form an interface that allows partial transmission of light guided by the optical slab into the optical wedge at a plurality of points along the interface such that the light is divided a plurality of times.

Abstract: A method and system for improving the control of a holographic projection system in order to meet, or to attempt to meet, one or more targets or aims for a holographically reconstructed image that is produced by the holographic projection system. The target, or aim, may concern the luminance of part or all of the holographically reconstructed image.

Abstract: A head-up display for a vehicle comprises an optical component having a reflective surface arranged, during head-up display operation, in a configuration that is conducive to sunlight glare. A light control layer is disposed on the optical component to receive sunlight on an optical path to the reflective surface. The light control layer comprises a sunlight-receiving surface and a core material separating an array of louvres. The sunlight-receiving surface of the light control layer is serrated in coordination with the array of louvres so as to deflect received sunlight away from the eye-box of the head-up display.

Abstract: There is provided a head-up display having an eye-box comprising a driver monitoring system, picture generating unit and optical system. The driver monitoring system is arranged to illuminate and monitor a driver. The driver monitoring system comprises a first display channel. The picture generating unit is arranged to display a picture on a replay plane. The picture generating unit comprises a second display channel. Each display channel comprises a light source, spatial light modulator and controller. Each light source is arranged to emit light. Each spatial light modulator is arranged to receive light from the respective light source and output spatially-modulated light in accordance with a computer-generated hologram displayed on the spatial light modulator to form a respective light pattern on the replay plane. Each controller is arranged to output the computer-generated hologram to the spatial light modulator. The optical system is arranged to relay each light pattern from the replay plane.

Abstract: A holographic system comprises a display device and a waveguide pupil expander. The display device is arranged to display a hologram and to output spatially modulated light in accordance with the hologram. The waveguide pupil expander is configured to receive spatially modulated light from the display device at the input port thereof and to expand the viewing window of the system. The waveguide pupil expander comprises first and second substantially planar reflective surfaces arranged in parallel having an optically transparent material therebetween. The first reflective surface is fully reflective and the second reflective surface is partially reflective such that light is guided from the input port to an output port at the second reflective surface by a series of internal reflections. The optically transparent material is formed by a layered glass structure arranged to maintain the integrity of the waveguide in the event of breakage of glass.

Abstract: Display system and methods including a display device arranged to display a hologram and spatially modulate light and a hologram engine arranged to receive contribution information identifying contributory and non-contributory areas of the display device based on the location of an entrance pupil. The contributory areas of the display device propagate light passing through the entrance pupil at the determined location. The non-contributory areas of the display device propagate light stopped by the entrance pupil at the determined location. The contribution information identifies (i) at least one primary contributory area of the display device that contributes to a primary image and (ii) at least one secondary contributory area of the display device that contributes to a secondary image. The hologram engine is arranged to determine a hologram based on the at least one primary contributory area of the display device identified by the processing engine.

Abstract: A holographic projector comprising a spatial light modulator arranged to display a hologram of a light pattern for projection and to spatially-modulate light, in accordance with display, to form a holographic reconstruction, wherein the holographic reconstruction is spatially-separated from the spatial light modulator. If the holographic projection is operating properly, the formed holographic reconstruction should correspond to the light pattern. The holographic projector also comprises a detector array comprising a plurality of light detection elements arranged to detect light corresponding to a respective plurality of positions of the holographic reconstruction and to provide a respective plurality of output signals related to light detection, and a fault detection circuit arranged to compare one or more of the plurality of output signals from the respective plurality of light detection elements with one or more of a plurality of expected signals based on the light distribution of the light pattern.

Abstract: A projection system arranged to receive an image for projection. The image is a colour image comprising a first colour component and a second colour component. The system is arranged to calculate a first hologram of the first colour component and a second hologram of the second colour component. The system is further arranged to add content of the second colour component to the first colour component before calculating the first hologram. The first hologram contains information of the first colour component and information of at least a portion of the second colour component. The system is further arranged to form a first holographic reconstruction by illuminating the first hologram with first colour light and to form a second holographic reconstruction by illuminating the second hologram with second colour light. The first holographic reconstruction changes the chromaticity of the at least a portion of the second colour component.

Abstract: There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).