Envisics Ltd

Timothy Smeeton

Yiren Xia

Jamieson Christmas

Neil Collings

Ruisheng Lin

Daniel Burnham

Alexander Cole

Rakesh Maharjan

Celedonia Krawczyk

Máté Karner

Abdullah Asmari

Gavin Fowler

Edward Boardman

Disclosed embodiments include a display system comprising an eye-box from which virtual images formed by the display system are visible. In some embodiments, the display system includes an image projector arranged to project a virtual image at a virtual image distance from the eye-box, and a user-tracking system arranged to determine an eye-box position of a user within the eye-box and a confidence value associated with the determined eye-box position. In some embodiments, the image projector is arranged to (i) project the virtual image at a finite virtual image distance after determining that the confidence value is above a threshold value and (ii) project the virtual image at an infinite virtual image distance after determining that the confidence value is below the threshold value.

Head-up display

A method of manufacturing a light control film includes providing a plurality of alternating layers of transparent material and light absorbing material. Each layer of light absorbing material is interspersed between respective layers of transparent material. The plurality of alternating layers are stacked in a stacking direction perpendicular to the plane of a surface of at least one of the plurality of alternating layers. The method includes cutting the plurality of alternating layers in a first and second cutting plane resulting in an intermediate film including a first cut surface parallel to the first cutting plane and a second cut surface parallel to the second cutting plane. Each of the first and second cutting planes is orientated at an angle less than or equal to 90° to the stacking direction. The method includes hot embossing the repeating prismatic structure on the first cut surface of the intermediate film resulting in a serrated/corrugated first surface.

Light control film

A light shuttering device comprises a plurality of liquid crystal cells, wherein each liquid crystal cell is operable in a first optical state or a second optical state in response to a respective first or second drive signal. A drive circuit comprises a plurality of switches and a drive controller. Each switch is arranged to output the respective first or second drive signal to a respective liquid crystal cell. The drive controller is arranged to sequentially update the output of each switch during an update cycle. The drive circuit is arranged to determine the order in which the switches are sequentially updated during an update cycle based on any changes to the respective drive signals that will be made during the update.

Light shuttering for waveguide pupil expansion

A method for light detection and ranging that includes forming a first light pattern within a region of a scene by holographic projection. The first light pattern includes n light spots arranged in a regular array. A light return signal is received from each light detection element of an array of light detection elements directed at the region of the scene. The intensity of the light return signals is assessed. If the light return signals do not meet at least one signal validation criterion, a second light pattern is formed within the region of the scene by holographic projection. The second light pattern includes m light spots arranged in a regular array, wherein m≠n. A time-of-flight in association with each light spot of the second light pattern is then determined.

Light detection and ranging

Systems and method disclosed herein include, among other features, receiving an image for display within a display area of a display system, determining a first image component of the image, calculating a hologram of the image, displaying the hologram on a display device and spatially modulating light in accordance with the displayed hologram, and propagating the spatially modulated light through a pupil expander arranged to provide a plurality of different light propagation paths for the spatially modulated light from the display device to the viewing area, wherein each light propagation path corresponds to a respective continuous region of the image owing to the angular distribution of light from the hologram.

Hologram calculation

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.

Display system and light control film therefor

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.

Waveguide with four gradient coating

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.

Display system and method

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.

Image projection

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.

Pupil expander integrity

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.

Holographic projector having a fault detection circuit and method of using same

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.

Colour optimisation for direct view

A waveguide arranged as a pupil expander for a display system is disclosed. The waveguide comprises a pair of opposing surfaces arranged to guide a light field therebetween by internal reflection. An input port is arranged to receive light from the display system. A reflective element is arranged to internally reflect the light field. The input port and reflective element are formed on a second surface of the pair of opposing surfaces. An output port is formed on a first surface of the pair of opposing surfaces by a transmissive-reflective element configured to divide the light field at each internal reflection therefrom such that a plurality of replicas of the light field are transmitted out of the waveguide through the output port.

Growing community of inventors

Milton Keynes, United Kingdom

Timothy Smeeton