Sharp Kabushiki Kaisha Corporation

Cambridge Display Technology Limited

Paul May

Gillian Margaret Davis

Graham John Woodgate

David Ezra

Michael G Robinson

Kathryn Walsh

Jonathan Harrold

Craig Tombling

Edward P Raynes

Nick Harrison

Karl Pichler

Robert George Watling Brown

Nir Tessler

A multi-color electroluminescent display has a plurality of discrete, laterally spaced areas of light emitting material formed over respective groups of first and second electrode regions. The light emissive material over each group is capable of emitting radiation of a different color. The multi-colored device is formed by a sequence of steps where each emitting layer is deposited as. a precursor which is susceptible to patterning and which is then converted into its polymer which is not susceptible to subsequent patterning steps. This allows a second color to be deposited on top of a first color, the second color being patterned while avoiding damage to the first color below it.

Organic light emitting diode color display

An electrically controllable grating is provided by forming regions and of different refractive index within an electro-optic material. Electrodes are provided so that a readily controllable electric field may be applied to the index grating formed by the alternating regions such that the refractive index of the regions may be varied electrically to form a controllable grating. The grating may be used as an electrically controllable distributed Bragg reflector to allow variable wavelength feedback within a laser cavity. The grating may be used to perform wavelength division multiplexing and/or frequency modulation.

Electrically controllable grating, and optical elements having an electrically controllable grating

The contrast of an electroluminescent display using an organic EL layer is improved by using a circular polariser in front of the surface. The polariser causes ambient light to be absorbed, while allowing transmission of emitted light and therefore improves the contrast of the display.

High contrast electroluminescent displays

An electroluminescent device is described which utilizes a &ldquo;memory effect&rdquo; which allows a device to be turned on by a turn on voltage and then for the voltage to be reduced without a reduction in the light output. The present electroluminescent device incorporates a semiconductive conjugated polymer layer together with a light dependent voltage regulating layer the conductivity of which varies with light incident thereon from the semiconductive conjugated polymer layer. An electroluminescent device using a semiconductive conjugated polymer layer is relatively simple to manufacture as compared with earlier devices.

Electroluminescent device

Display with a light modulator and a light source

A photoemission apparatus includes a spatial light modulator (2) and an integral photoemitter (5). A lens array (1) focuses light through the spatial light modulator (2) onto the photoemitter. Electrons emitted by the photoemitter (5) are deflected electrostatically by electrodes (10) and are accelerated through a screening mesh (8) onto a phosphor screen (6). Light emitted by the screen (6) passes through a further lens array (7).

Photoemission apparatus with spatial light modulator

An organic electroluminescent device, particularly for use as a display, is disclosed which is driven according to a pulsed mode of operation which allows much higher current densities to be injected into the device. This is achieved by selection of particular pulse durations and duty cycles, and by an improved geometry for the electroluminescent device in which the resistance of anode lines is reduced.

Organic EL devices and operation thereof

An illumination system includes a polarization selective holographic element, which includes at least one optically anisotropic material, arranged to separate light of a first polarization type from light of a second polarization type, and converting section for converting light of at least one of the first and second polarization types to light of a common polarization type. Where the polarization selective holographic element separates two orthogonal components of plane polarized light from one another, the converting section can include a polarization rotator, for example a half wave plate, or alternatively a quarter wave plate and a reflector arranged to reflect light back through the quarter wave plate. Where the polarization selective holographic element separates opposite handed components of circularly polarized light, the converting section can include a reflector.

Illumination system and display device

A film of photosensitive material is illuminated from first and second sides with coherent polarized light so as to form an interference pattern within the film. Regions of cyclicly varying refractive index are provided in the film in accordance with the intensity of the interference patten, thereby forming an polarization sensitive refractive index grating. The refractive index grating may be used as a polarization and wavelength dependent mirror, patterned polarizer, beamsplitter or filter.

Polarization sensitive devices and methods of manufacture thereof

A birefringent element is patterned such that for light of a first polarisation the element acts as a first refractive optical element and for light of a second polarisation the optical response of the element changes. The element can be used in conjunction with a polarisation selecting means, such as a liquid crystal device, to provide an electrically controllable optical element that can be used in light beam manipulation applications.

Polarisation dependent refractive device exhibiting independtly varying

An optical apparatus of this invention comprises a first spatial light modulator, an array of imaging elements, and a plurality of light sources, and an image surface. Each of the imaging elements of the array is arranged to form an image of the plurality of light sources via the spatial light modulator at a respective position on the image surface.

Optical apparatus

An electro-optic material has first and second regions formed therein. The optic axes of the first and second regions are antiparallel and define a domain inversion pattern. The difference in refractive index between the first and second regions is a function of an electric field applied thereto. The difference in refractive index enables spatial light phase modulators and refractive optical devices having electrical control to be formed.

A three dimensional imaging apparatus may be used as a microscope or camera. The apparatus includes an array of lenses, each of which is aligned with a respective photodetector element. A liquid crystal spatial light modulator has several pixels between each photodetector element and lens. A control circuit controls the modulator so that the pixels in front of each photodetector element act as a moving shutter. The outputs of the photodetector elements are processed and stored to form a three dimensional image.

Three dimensional imaging apparatus, camera, and microscope using

A display device comprises a liquid crystal spatial light modulator (1) associated with diffractive means, such as a diffraction grating comprising grating elements (5). The diffraction grating is illuminated by a light source (6, 7) and each element is chirped and blazed so as to separate the primary colors of the illuminating light and direct them to individual light-modulating elements (R, G, B) of the modulator (1). By dispensing with conventional color filters, the efficiency of the display device is improved. Further, the focusing action of the grating elements (5) directs light to the elements of the modulator (1) so as to prevent light wastage caused by blocking of light by opaque regions of the display.

Color display device with chirped diffraction gratings

An optical transmission system comprises a plurality of mode-locked diode lasers each providing an output pulse at a different respective sub-carrier frequency. Means are provided for modulating each sub-carrier in response to respective input signals for providing a plurality of optical signals for transmission. A reference sub-carrier having a frequency such that the intervals between the reference sub-carrier frequency of each of the respective signal carrying sub-carrier channel frequencies is distinguishable from the intervals between respective signal carrying sub-carrier channels.

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Cambridge, United Kingdom

Paul May