Patents Assigned to Cambridge Display Technology
  • Patent number: 7474288
    Abstract: Display driver circuits are described for driving organic light-emitting diode displays, particularly passive matrix displays, with greater efficiency. Display driver circuitry includes a frame memory interface for reading data from a frame memory for presentation on a passive matrix OLED display. A blank line identifier identifies one or more substantially blank rows of pixels defined by the data in the frame memory and the control circuitry skips past these rows when the passive matrix display is addressed. When blank lines are skipped the apparent brightness of the remaining lines increases and thus preferably the control circuitry includes a power-controller for reducing a power supply to the display in proportion to the number of skipped lines. The disclosed circuitry is particularly suited to a display driver providing a controlled current drive.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: January 6, 2009
    Assignee: Cambridge Display Technology Limited
    Inventors: Euan C. Smith, Paul R. Routley, William Goodchild
  • Publication number: 20080315757
    Abstract: An electronic device containing a hole transporting semiconductive polymer comprising a first repeat unit comprising a first nitrogen of a triarylamine in the polymer backbone and a second nitrogen of an arylamine pendant from the polymer backbone, characterised in that said semiconductive polymer performs the function of transporting holes to or from a semiconductive material in said device.
    Type: Application
    Filed: December 18, 2006
    Publication date: December 25, 2008
    Applicants: Cambridge Display Technology Limited, CDT Oxford Limited
    Inventors: Mary McKiernan, Natasha Conway, Richard Wilson
  • Publication number: 20080309229
    Abstract: A semiconductive polymer comprising a first repeat unit in the polymer backbone comprising general formula 1: where a=1 or 2; b=0 or 1; and c=0, 1 or 2, provided that when c=0 then b=0; Ar1, Ar2, Ar3, Ar4, Ar5, and Ar6 each independently represent an aryl or heteroaryl ring or a fused derivative thereof; characterised in that at least one of Ar1, Ar2, Ar4, and Ar5 is non-conjugating; and provided that (a) when a=1, Ar1 is not linked to Ar2 by a direct bond, (b) when b=1 and c=1, Ar4 is not linked to Ar5 by a direct bond, (c) when b=0 and c=1, Ar2 is not linked to Ar5 by a direct bond, (d) when a=2, the Ar1 groups are not linked by a single bond, and (e) when c=2, the Ar5 groups are not linked by a single bond.
    Type: Application
    Filed: December 18, 2006
    Publication date: December 18, 2008
    Applicants: Cambridge Display Technology Limited, CDT Oxford Limited
    Inventors: Annette Steudel, Nalinkumar Lallubhai Patel, Jonathan Pillow, Mary McKiernan, Sophie Heidenhain, Natasha Conway
  • Publication number: 20080303756
    Abstract: This invention generally relates to methods and apparatus for driving passive matrix displays, in particular OLED (Organic Light Emitting Diode) displays. A method of driving a passive matrix electroluminescent display, the display having a plurality of rows and columns of emissive elements addressed by respective row and column electrodes, the method comprising: addressing said row electrodes, one at a time; and driving a set of said column electrodes whilst addressing each said row electrode; wherein said column electrode driving comprises driving said column electrodes to determine ratios of column drive signals to one another for said set of column electrodes; and wherein the method further comprises controlling an overall drive for said set of column electrodes to control a drive to said emissive elements in each said addressed row.
    Type: Application
    Filed: December 15, 2006
    Publication date: December 11, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventor: Euan Smith
  • Publication number: 20080305245
    Abstract: Disclosed are compositions, useful in ink jet printing methods, that prevent clogging during dispensing, achieve stable dispensing, prevent precipitating of content matter during dispensing, and prevent phase separation during film formation. Also disclosed are uniform, homogenous, functional films formed using the compositions and manufacturing methods therefor, as well as organic EL devices and other such display devices and manufacturing methods therefor. The compositions contain a functional material and a solvent comprising at least one benzene derivative having one or more substituents, whereby the substituents have at least three carbon atoms in total.
    Type: Application
    Filed: August 4, 2008
    Publication date: December 11, 2008
    Applicants: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED, SEIKO EPSON CORPORATION
    Inventors: Sadao Kanbe, Shunichi Seki
  • Publication number: 20080297039
    Abstract: A display device comprising: a light switching unit comprising an array of pixels each operable to vary the transmission of light therethrough; and a backlight comprising a first series of regions of organic light-emissive material having a first emission colour and a second series of regions of organic light-emissive material having a second emission colour, each region of organic material being located so as to lie behind a plurality of pixels of the array in the viewing direction for backlighting those pixels; and at least one of the regions of organic light-emissive material being formed by a process of ink-jet deposition.
    Type: Application
    Filed: May 27, 2008
    Publication date: December 4, 2008
    Applicant: Cambridge Display Technology Ltd.
    Inventors: Stephen Karl Heeks, Julian Charles Carter
  • Patent number: 7456812
    Abstract: Display driver circuitry for electro-optic displays, in particular active matrix displays using organic light emitting diodes. The circuitry includes a driver to drive an electro-optic element in accordance with a drive voltage, a photosensitive device optically coupled to the electro-optic display element to pass a current dependent upon illumination reaching the photosensitive device, a first control device coupled between the photosensitive device and a data line and responsive to a first control signal on a first control line to couple the photosensitive device to the data line, and a second control device coupled between the photosensitive device and the driver and responsive to a second control signal on a second control line to couple the photosensitive device to the driver. The circuit can be operated in a number of different modes and provides flexible control of an electro-display element such as an organic LED pixel.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: November 25, 2008
    Assignee: Cambridge Display Technology Limited
    Inventors: Euan C. Smith, Paul R. Routley
  • Publication number: 20080278071
    Abstract: An organic light-emitting device, comprising: a substrate; a first conductive layer formed over the substrate; at least one layer of a light-emissive organic material formed over the first conductive layer; a barrier layer formed over the at least one organic layer which acts to protect the at least one layer of organic material; and a second conductive layer, preferably a patterned sputtered layer, formed over the barrier layer.
    Type: Application
    Filed: May 23, 2008
    Publication date: November 13, 2008
    Applicant: Cambridge Display Technology Limited
    Inventor: Karl Pichler
  • Patent number: 7449714
    Abstract: An electroluminescent device comprising: a first charge carrier injecting layer for injecting positive charge carriers; a second charge carrier injecting layer for injecting negative charge carriers; and a light-emissive layer located between the charge carrier injecting layers and comprising a mixture of: a first component for accepting positive charge carriers from the first charge carrier injecting layer; a second component for accepting negative charge carriers from the second charge carrier injecting layer; and a third, organic light-emissive component for generating light as a result of combination of charge carriers from the first and second components; at least one of the first, second and third components forming a type II semiconductor interface with another of the first, second and third components.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: November 11, 2008
    Assignee: Cambridge Display Technology Ltd.
    Inventors: Jeremy Henley Burroughes, Richard Henry Friend, Christopher John Bright, David John Lacey, Peter Devine
  • Publication number: 20080265751
    Abstract: An organic light emissive device comprising: a first electrode; a second electrode; and an organic light emissive region between the first and second electrodes comprising an organic light emissive material which has a peak emission wavelength, wherein at least one of the electrodes is transparent and comprises a composite of a charge injecting metal and another material which is codepositable with the charge injecting metal, the other material having a different refractive index to that of the charge injecting metal and wherein the other material has a lower degree of quenching at the peak emission wavelength than the charge injecting metal whereby quenching of excitons by the at least one electrode is reduced, the charge injecting metal comprising either a low work function metal having a work function of no more than 3.5 eV or a high work function metal having a work function of no less than 4.5 eV.
    Type: Application
    Filed: August 10, 2005
    Publication date: October 30, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventors: Euan C. Smith, Matthew Roberts, William Young, Clare Louise Foden
  • Publication number: 20080265756
    Abstract: A conductive composition for use in an organic light-emitting device comprising: a polycation having a conjugated backbone; a polyanion to balance the charge on the polycation; and a semiconductive hole transport polymer containing side groups pendant from the polymer backbone, each side group comprising one or more groups XY, where XY represents a group with a high dissociation constant such that it is ionized completely.
    Type: Application
    Filed: July 14, 2006
    Publication date: October 30, 2008
    Applicants: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED, CDT OXFORD LIMITED
    Inventors: Mary J. McKiernan, Jeremy Burroughes, Annette Steudel
  • Publication number: 20080258606
    Abstract: A light-emitting device comprising: an anode; a cathode; and a light emitting region situated between the anode and the cathode, the light emitting region comprising an exciton generating layer and a phosphorescent layer, the exciton generating layer comprising an organic material, wherein the organic material of the exciton generating layer generates singlet and triplet excitons and emits light by fluorescent emission from the singlet excitons and the phosphorescent layer accepts the triplet excitons from the exciton generating layer and emits light by phosphorescent emission from the triplet excitons.
    Type: Application
    Filed: October 7, 2005
    Publication date: October 23, 2008
    Applicant: Cambridge Display Technology Limited
    Inventors: Timothy Butler, Nalinkumar Patel, Matthew Roberts, Nicholas Baynes
  • Publication number: 20080259987
    Abstract: A device comprising an organic light emitting diode coupled to a cavity, said cavity containing an emitting species, said device being arranged such that light emitted from said organic light emitting diode is at least partially absorbed by the emitting species and re-emitted from the emitting species. The device may be arranged such that the emitting species acts as the gain media of a laser, and the organic light emitting diode may be arranged to pump the emitting species. Also provided is method of generating light, said method comprising: coupling an organic light emitting diode to a cavity, said cavity containing an emitting species, said organic light emitting diode and said cavity being arranged such that light emitted from said organic light emitting diode is at least partially absorbed by the emitting species; operating said organic light emitting diode to emit light which is at least partially absorbed by the emitting species; and re-emitting light from the emitting species.
    Type: Application
    Filed: August 17, 2005
    Publication date: October 23, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventor: Euan C. Smith
  • Publication number: 20080246606
    Abstract: A consumer electronic device (CED) having a display and including at least one light sensor for recalibrating said display at intervals, wherein said display and said at least one light sensor are mounted within different parts of a unitary housing such that when said CED is not in use said light sensor is able to monitor light from said display. Preferably the different parts of the unitary housing comprise two hinged parts, one mounting the display, the other at least a light sensing portion of the sensor.
    Type: Application
    Filed: October 6, 2006
    Publication date: October 9, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventors: Euan Smith, Jeremy Burroughes
  • Publication number: 20080246703
    Abstract: A method of driving a passive matrix multicolor electroluminescent display, the display comprising a plurality of pixels arranged in rows and columns, each said pixel comprising at least first and second sub-pixels having different respective first and second colors, the method comprising: driving groups of said pixels in turn to display a multicolor image frame, said driving of a group of pixels comprising driving first and second sub-groups of sub-pixels of respective said first and second colors; and wherein said driving further comprises driving a said group of pixels for a duration dependent upon a maximum drive level of a sub-pixel of a said sub-group.
    Type: Application
    Filed: August 9, 2006
    Publication date: October 9, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventor: Euan C. Smith
  • Publication number: 20080197768
    Abstract: An organic light emissive device, which comprises: an anode; a cathode; and an organic light emissive region between the anode and the cathode, which region comprises: a layer of blue light electroluminescent organic material which emits light having first CIE co-ordinates by exciton radiative decay; and a layer of longer wavelength electroluminescent organic material which intrinsically emits light having second CIE co-ordinates by exciton radiative decay; wherein the layers of blue light and longer wavelength materials are selected so that the organic light emissive region emits white light falling within a region having a CIE X coordinate equivalent to that emitted by a black body at 3000-9000K and CIE ? co-ordinate of said light emitted by a black body.
    Type: Application
    Filed: December 23, 2005
    Publication date: August 21, 2008
    Applicants: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED, CDT OXFORD LIMITED
    Inventors: Natasha M. Conway, Nalinkumar Patel, Richard Wilson, Ilaria Grizzi
  • Publication number: 20080176104
    Abstract: An electroluminescent device comprising:—a first electrode for injection of positive charge carriers;—a second electrode for injection of negative charge carriers; and—an electroluminescent layer located between the first and second electrodes comprising a host material and a metal complex, wherein the host material comprises a polymer having a first repeat unit of formula (I): wherein each Ar is the same or different and independently represents an optionally substituted aryl or heteroaryl and any two Ar groups may be directly linked by a single bond.
    Type: Application
    Filed: August 2, 2004
    Publication date: July 24, 2008
    Applicants: CDT Oxford Limited, Cambridge Display Technology Limited
    Inventors: Carl Towns, Ilaria Grizzi, Stephen O'Connor, Annette Steudel, Jonathan Pillow, Michael Frampton
  • Patent number: 7402091
    Abstract: A display device comprising: a light switching unit comprising an array of pixels each operable to vary the transmission of light therethrough; and a backlight comprising a first series of regions of organic light-emissive material having a first emission color and a second series of regions of organic light-emissive material having a second emission color, each region of organic material being located so as to lie behind a plurality of pixels of the array in the viewing direction for backlighting those pixels; and at least one of the regions of organic light-emissive material being formed by a process of ink-jet deposition.
    Type: Grant
    Filed: May 15, 2006
    Date of Patent: July 22, 2008
    Assignee: Cambridge Display Technology Ltd.
    Inventors: Stephen Karl Heeks, Julian Charles Carter
  • Patent number: 7400090
    Abstract: A light-emissive device including: a light-emissive region (12); a first electrode (10) located on a viewing side of the light-emissive region for injecting charge carriers of a first type; and a second-electrode (11) located on a non-viewing side of the light-emissive region for injecting charge carriers of a second type; and wherein there is a reflectivity-influencing structure (13) located on the non-viewing side of the light-emissive region and having a light absorbent layer including graphite and/or a fluoride or oxide of a low work function metal.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: July 15, 2008
    Assignee: Cambridge Display Technology Ltd.
    Inventors: Paul Berger, Jeremy Henley Burroughes, Julian Charles Carter, Stephen Karl Heeks
  • Publication number: 20080164461
    Abstract: An organic transistor comprising source and drain electrodes; a gate electrode; an organic insulating layer between the gate electrode and the source and drain electrodes; and an organic semiconductive region between the insulating layer and the source and drain electrodes; wherein the organic semiconductive region comprises (a) a high mobility layer of an organic semiconductor and (b) a blocking layer of organic material positioned between the high mobility layer and the source and drain electrodes, in which the ionization potential of the organic material of the blocking layer exceeds the workfunction of the source and drain electrodes so as to inhibit charge injection from the source electrode into the blocking layer in the off-state.
    Type: Application
    Filed: October 12, 2005
    Publication date: July 10, 2008
    Applicant: CAMBRIDGE DISPLAY TECHNOLOGY LIMITED
    Inventor: Richard Wilson