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.

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: 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: A fuel tank contains a swirl pot into which a fuel return pipe from the engine is directed and which induces fuel flow from the tank into the pot so that the fuel level in the pot is kept high. Fuel flow into the pot is induced by directing a flow of fuel from the return pipe over a ramp past an opening into the tank so as to create a low pressure area at the opening.