A voltage-controlled optical wedge is formed by creating an adjustable voltage gradient along the length of a relatively large-sized LC cell. A pair of bias voltages (AC voltages) are applied at the opposing side terminations of the LC cell, their RMS values selected to create a continuous phase variation along the length of the cell, where a defined phase variation is associated with a specific beam steering angle. Adjustments in the applied bias voltages (specifically, changes in the RMS values of the bias voltages) result in changing the beam steering angle, providing for active, controllable beam steering as a function of time. The LC cell may be configured to provide either a linear or nonlinear continuous phase variation, as preferred for different beam steering applications.

An optical device useful for spatial light modulation. The device comprises: a semiconductor layer having a first surface and a second surface, the semiconductor having an electric field-dependent resonance wavelength; a first electrode electrically connected to the semiconductor layer; a first insulating layer adjacent to the first surface of the semiconductor layer, and a second insulating layer adjacent to the second surface of the semiconducting layer, the first and the second insulating layers each being optically transparent at the resonance wavelength; a first group of at least one gate electrodes disposed adjacent to the first insulating layer, and a second group of at least one gate electrodes disposed adjacent to the second insulating layer, each gate electrode being at least 80% optically transparent at the resonance wavelength; wherein the first and the second groups of gate electrodes, taken together, form at least two regions in the semiconductor layer, an electrostatic field in each of the at least two regions being independently controllable by application of voltage to the first and the second groups of gate electrodes, the at least two regions abutting each other along at least one boundary.

A display or light blocking screen includes a liquid crystal (LC) array layer having a plurality of LC pixels, and a transparent LED layer having a plurality of LED pixels. A controller is operatively connected to the LC array layer and the transparent LED layer. The controller is configured to selectively trigger emission of light from a selection of the LED pixels, and to selectively darken a selection of the LC pixels that correspond directly to the selection of LED pixels. Therefore, the emitting LED pixels and the darkened LC pixels match and light is emitted from the LED pixels in substantially the opposite direction of the LC array layer. The display screen, or different aspects thereof, may be operatively incorporated into one or more windows of a vehicle, may be a standalone unit, or may be incorporated into a building.

The invention concerns a liquid crystal spatial light modulator (101) comprising: a liquid crystal layer (7); and on at least one side of the liquid crystal layer (7), at least one photovoltaic cell (456), each photovoltaic cell (456) comprising a photosensitive layer (5) comprising electron-donating (D) molecules and electron accepting (A) molecules, each photovoltaic cell (456) being arranged for spontaneous photovoltage under illumination. Electron-donating molecules and electron accepting molecules are preferably blended and form preferably an organic bulk heterojunction layer. The photosensitive layer (5) of each photovoltaic cell (456) is preferably comprised between: —an electron conducting layer (4) arranged for a transfer of an electron from its contacting photosensitive layer (5) easier than a transfer of an electron hole from its contacting photosensitive layer (5), and —an electron hole conducting layer (6) arranged for a transfer of an electron hole from its contacting photosensitive layer (5) easier than a transfer of an electron from its contacting photosensitive layer (5).

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. The directional backlight may be arranged to switch between at least a first wide angular luminance profile mode and a second narrow angular luminance profile mode. The directional backlight is arranged to illuminate an LCD with a bias electrode arranged to switch liquid crystal directors in black state pixels between a first wide angular contrast profile mode and a second narrow angular contrast profile mode. Performance of privacy operation for off-axis snoopers is enhanced in comparison to displays with only directional backlights or switchable contrast properties.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

A display device includes a display panel and an optical modulator. The display panel includes a plurality of pixels. The optical modulator is disposed over the display panel and includes a plurality of optical modulation units. The optical modulator modulates light emitted from the display panel to corresponding directions. A slant angle of the optical modulator is between 45° and 90°.

A direct-retina holographic projection system includes first and second spatial light modulators (SLMs) and a control module. The first SLM receives a beam of light and dithers the beam of light at a predetermined frequency to provide multiple instances of the beam of light. The second SLM receives the instances of the beam of light, displays an encoded phase hologram of a graphic image to be projected, and diffracts the instances of the beam of light to provide instances of the encoded phase hologram with the same graphic image but multiplied with dithered wavefronts. The control module: iteratively adjusts a parameter of the first SLM to generate the instances of the beam of light; and controls operation of the second SLM to, based on the instances of the beam of light, display multiple instances of the graphic image on a retina of an eye of a viewer.

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.

The phase modulation device includes an image data generator, a gradation data generator, an adjustment voltage controller, and a reflective liquid crystal element. The image data generator generates image data corresponding to a distribution of phase change amount or a distribution of phase velocity. The gradation data generator generates gradation data corresponding to each pixel. The reflective liquid crystal element includes a pixel region having a plurality of pixel blocks, and an adjustment electrode. The adjustment voltage controller applies an adjustment voltage having a same voltage value as a driving voltage applied to a pixel electrode of the pixel block adjacent to the adjustment electrode.