Patents by Inventor William A Crossland

William A Crossland has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20140355985
    Abstract: This invention relates to methods and apparatus for routing light beams in telecommunications devices using holographic techniques, in particular by displaying kinoforms on LCOS (Liquid Crystal on Silicon) devices.
    Type: Application
    Filed: March 7, 2012
    Publication date: December 4, 2014
    Inventors: Daping Chu, Neil Collings, William Crossland, Maura Michelle Redmond, Brian Robertson
  • Patent number: 8878759
    Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.
    Type: Grant
    Filed: January 7, 2014
    Date of Patent: November 4, 2014
    Assignee: Cambridge Enterprise Limited
    Inventors: William Crossland, Neil Collings, Edward Buckley, Adrian Cable, Nicholas Lawrence, Peter Mash, Timothy Wilkinson
  • Publication number: 20140118806
    Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.
    Type: Application
    Filed: January 7, 2014
    Publication date: May 1, 2014
    Applicant: Cambridge Enterprise Limited
    Inventors: William Crossland, Neil Collings, Edward Buckley, Adrian Cable, Nicholas Lawrence, Peter Mash, Timothy Wilkinson
  • Patent number: 8654048
    Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: February 18, 2014
    Assignee: Cambridge Enterprise Limited
    Inventors: Neil Collings, Timothy Wilkinson, William Crossland, Edward Buckley, Adrian Cable, Nicholas Lawrence, Peter Mash
  • Publication number: 20110280573
    Abstract: This invention generally relates to an optical beam steering apparatus and a method of manufacturing an optical beam steering apparatus, and more particularly to an optical add drop multiplexer (OADM) such as a reconfigurable OADM (ROADM) comprising the optical beam steering apparatus. In one embodiment, the apparatus comprises a slab and a plurality of optical elements in or on a first surface of said slab, the plurality of optical elements including at least one liquid crystal on silicon element, the apparatus being arranged such that at least one optical beam can propagate freely in the slab from one of said plurality of optical elements to another one of said plurality of optical elements via a reflection from a second surface of the optical beam steering apparatus.
    Type: Application
    Filed: November 13, 2009
    Publication date: November 17, 2011
    Applicant: CAMBRIDGE ENTERPRISE LIMITED
    Inventors: Neil Collings, William Crossland, Maura Michelle Redmond, David Nugent, Brian Robertson
  • Publication number: 20110273657
    Abstract: The invention relates to optical beam steering. There is described an optical beam steering apparatus, comprising: a splitter arranged to split an optical beam into at least a first part having a first polarisation and a second part having a second polarisation, said first and second polarisations being substantially mutually orthogonal; a first liquid crystal device region arranged to receive said first part and to have director orientation substantially aligned to said first polarisation; and a second liquid crystal device region arranged to receive said second part and to have director orientation substantially aligned to said second polarisation.
    Type: Application
    Filed: November 13, 2009
    Publication date: November 10, 2011
    Applicant: CAMBRIDGE ENTERPRISE LIMITED
    Inventors: Neil Collings, William Crossland, Maura Michelle Redmond, John Richard Moore, David Nugent, Brian Robertson
  • Publication number: 20070206143
    Abstract: A liquid crystal device including a layer of liquid crystal material, and provided on one side of the liquid crystal material layer an array of conductors for generating electric fields therebetween to change the molecular orientation of pixel portions of the layer of liquid crystal material, wherein each pixel portion of the liquid crystal material layer is associated with a respective group of conductors distributed over the respective pixel area for the application of voltages across distances smaller than the pixel dimensions, wherein the conductors and the spacing therebetween within each group are sufficiently small with respect to the thickness of the liquid crystal material layer that each group can be used to generate an electric field that induces through at least a portion of the thickness of the liquid crystal material layer a different molecular orientation pattern that is substantially uniform across the whole area of the respective pixel portion.
    Type: Application
    Filed: June 2, 2004
    Publication date: September 6, 2007
    Inventors: William Crossland, Anthony Davey
  • Patent number: 7257007
    Abstract: In an active semiconductor backplane for a liquid crystal spatial light modulator, spacers (25) which are distributed over the backplane extend above an array of electrical and/or electronic elements and comprise at least two layers essentially of the same material and occuring in the same order as is found in at least one of the electrical or electronic elements, such as an NMOS transistor (52). The latter is formed from a stack of layers on a silicon substrate (51) comprising polysilicon (56), continuous silicon oxide (57) modified to include gate oxide GOX (55), metallic gate electrode (59), continuous silicon oxide (58) and a metallic drain electrode (60) which is coupled to a spaced mirror electrode over the layer (58). Likewise, spacer (25) comprises the layers (57 and 58) with metallic (67, 68) deposited simultaneously with electrodes (59, 60). The foot of layer (57) is differently modified to include field oxide layer (69) and polysilicon layers thin oxide (71).
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: August 14, 2007
    Assignee: Qinetiq Limited
    Inventors: Timothy D Wilkinson, William A Crossland, Tat C B Yu
  • Publication number: 20070131904
    Abstract: The present invention provides a liquid crystal cell that is bistable in operation and comprises a ferroelectric compound having a smectic C phase, arranged between alignment layers of polyamide or polyester. Said compound has the general formula wherein R represents an alkyl group having from 1 to 10 carbon atoms or the group each R? represents an alkyl group having from 1 to 4 carbon atoms, T is X represents an alkyl or halogen-substituted alkyl group having at least one chiral centre, Y represents a fluorine atom, m has a value of 0, 1 or 2, p has a value of 2, 3 or 4 and n has a value of 10, 11 or 12.
    Type: Application
    Filed: August 16, 2004
    Publication date: June 14, 2007
    Inventor: William Crossland
  • Publication number: 20070076163
    Abstract: An optical switch uses a polarisation insensitive spatial light modulator operating by a double pass through a liquid crystal cell. The switch includes two such modulators in a cross bar arrangement. Different embodiments employing techniques for reducing cross talk are described.
    Type: Application
    Filed: November 30, 2006
    Publication date: April 5, 2007
    Inventors: William Crossland, Melanie Holmes, Ilias Manolis, Timothy Wilkinson, Maura Redmond, Brian Robertson
  • Publication number: 20070024999
    Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforns allowing reproduction of the image using a suitable illumination beam.
    Type: Application
    Filed: June 14, 2006
    Publication date: February 1, 2007
    Inventors: William Crossland, Neil Collings, Timothy Wilkinson
  • Publication number: 20060165070
    Abstract: A packet switch having plural input sectors and output sectors, each input sector being arranged to hold at least one queue per output sector, each output sector having plural output ports and being arranged to hold at least one queue per output port wherein the input sectors are connected to the output sectors via links configured to afford speed-up of data transfer, wherein the links comprise a set of links, and wherein the switch has means for cyclically connecting different subsets of the set of links between the input sectors and the output sectors, and means responsive to statistical variations in traffic applied to input ports of said input sectors to vary the set of links.
    Type: Application
    Filed: April 16, 2003
    Publication date: July 27, 2006
    Inventors: Trevor Hall, William Crossland
  • Patent number: 7071907
    Abstract: A display (50) with enhanced image contrast contains an image-producing component (60) and a set of shutter strips (80). The image-producing component, typically a flat-panel device, has multiple imaging lines that provide light to produce an image. Each shutter strip is situated in front of one or more associated imaging lines. By appropriately switching the shutter strips between light-absorptive and light-transmissive states, the image contrast is enhanced. The shutter strips are typically implemented with a liquid-crystal display structure. The switching of the shutter strips is typically performed with a control component (52/76) which utilizes light to control the shutter switching and which is synchronized to signals (90 or/and 100) that control the imaging lines.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: July 4, 2006
    Assignees: Candescent Technologies Corporation, Candescent Intellectual Property Services, Inc.
    Inventors: Robert M. Duboc, Jr., Christopher J. Curtin, William A. Crossland, Anthony B. Davey, Theodore S. Fahlen
  • Patent number: 7061463
    Abstract: An active semiconductor backplane for a matrix liquid crystal display comprises a plurality of mutually exclusive sets of electrically-addressable elements defining a pixel array. Scanning circuitry addresses the sets one at a time. Set selection circuitry addresses more than one of the plurality of sets simultaneously. Preferably, the sets are simultaneously addressable rows for fast blanking. Single pass and two-pass schemes for writing and re-writing the array are described.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: June 13, 2006
    Assignee: QinetiQ Limited
    Inventors: William A Crossland, Tat CB Yu
  • Publication number: 20060104281
    Abstract: A packet router has an input stage (1), an output stage (15) and a coupling stage (10) for coupling the input and output stages. The input stage has plural input devices, the output stage has plural output devices and the coupling stage provides paths for signals between output elements of the input devices and input elements of the output devices. Each input device has circuitry arranged to respond to packet destination data of a packet received by its input device for adding, to the packet data of the packet, information indicative of a router output node at which the packet is to be output. The router has a controller (20) connected to the input stage and to the coupling stage for causing packets to be output to said coupling stage in dependence on this information. Each output device has circuitry for removing the information prior to output of packets.
    Type: Application
    Filed: June 30, 2003
    Publication date: May 18, 2006
    Inventors: Robert Scarr, William Crossland
  • Patent number: 6975786
    Abstract: An optical switch uses two ferroelectric liquid crystal spatial light modulators (10, 11) with an interconnect region in between. The switch uses bulk lenses (2, 8) to focus light from an input fibre array (1) to a first spatial light modulator (10), and from the second spatial light modulator (11) to an output array (9). Each spatial light modulator displays a respective hologram selected from a previously calculated set, to cause a desired switching of light from the input fibre array to the output array.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: December 13, 2005
    Assignee: Thomas Swan & Co. Ltd.
    Inventors: Steven Warr, Kim Leong Tan, William Crossland, Ilias Manolis, Maura Redmond, Timothy Wilkinson, Melanie Holmes, Brian Robertson
  • Patent number: 6954252
    Abstract: An optical switch uses a polarization insensitive spatial light modulator operating by a double pass through a liquid crystal cell. The switch includes two such modulators in a cross bar arrangement. Different embodiments employing techniques for reducing cross talk are described.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: October 11, 2005
    Assignee: Thomas Swan & Co. LTD
    Inventors: William Crossland, Melanie Holmes, Ilias Manolis, Timothy Wilkinson, Maura Redmond, Brian Robertson
  • Publication number: 20050219457
    Abstract: An optical switch uses a polarisation insensitive spatial light modulator operation by a double pass through a liquid crystal cell. The switch includes two such modulators in a cross bar arrangement. Different embodiments employing techniques for reducing cross talk are described.
    Type: Application
    Filed: June 2, 2005
    Publication date: October 6, 2005
    Inventors: William Crossland, Melanie Holmes, Ilias Manolis, Timothy Wilkinson, Maura Redmond, Brian Robertson
  • Patent number: 6930692
    Abstract: In a method of multi-level spatial light modulation, using a weighted bit plane technique where an n-digit binary number represents the intended grey level of each pixel location in an array of binary pixels, representative binary numbers are altered to closely adjacent values such as to reduce the inequality of 1s and 0s therein. The method may be applied to a single frame so modifying the gray scale somewhat, or a multi-frame method may be used in which at least some binary numbers are altered to different values in different frames for reducing the inequality of 1s and 0s over the set of frames, while maintaining or approximating the gray scale value as a time average. The methods are particularly useful for maintaining or approximating pixel-wise dc balance in liquid crystal spatial array modulators.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: August 16, 2005
    Assignee: QinetiQ Limited
    Inventors: Timothy M Coker, William A Crossland
  • Patent number: 6930693
    Abstract: In a method of signal processing for greyscale imaging in which weighted bitplanes corresponding to a greyscale image are stored as binary strings in sequential locations in a memory, in decreasing order of intended duration (weighting), a number of read passes equal to the number of weighted bitplanes are made from the set of stored bitplanes, each pass commencing with the highest order bitplanes and continuing along the stored bitplanes in sequence, the lengths of the sequences being varied and selected such that at the end of the said number of read passes each bit plane has been read out a plurality of times proportional to or equal to its duration (weighting). The method has utility in driving high speed liquid crystal matrix arrays particularly where each bitplane needs to be refreshed. A small ac potential may be applied to the array between writing steps.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: August 16, 2005
    Assignee: QinetiQ Limited
    Inventors: Timothy M Coker, William A Crossland