Patents by Inventor Johannes Hofstraat

Johannes Hofstraat 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: 20080043329
    Abstract: A display device comprising at least one substrate, a first and a second electrode, a display medium and an optically active layer, wherein said optically active layer comprises a polarizer and is arranged between said substrate and said display medium, and wherein said substrate is made of a birefringent material.
    Type: Application
    Filed: August 25, 2005
    Publication date: February 21, 2008
    Applicant: Koninklijke Philips Electronics, N.V.
    Inventors: Henri Jagt, Bianca Van Der Zande, Emiel Peeters, Peter Cirkel, Johannes Hofstraat
  • Publication number: 20070235727
    Abstract: An electronic device comprising a heterojunction, wherein the heterojunction comprises a blend comprising an electron donor and an electron acceptor; and wherein the blend is treated so as to form one or more linkages between the electron donor and/or electron acceptor in the treated blend.
    Type: Application
    Filed: June 7, 2005
    Publication date: October 11, 2007
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS, N.V.
    Inventors: Sepas Setayesh, Johannes Hofstraat
  • Publication number: 20070077594
    Abstract: The invention relates to a matrix of electroluminescent organic material having quantum dots embedded therein. Electrodes provide electrons and holes to the matrix forming excitons to be transferred to the quantum dots. The invention provides transfer molecules on the quantum dots facilitating the transfer of excitons from the electroluminescent organic material to the quantum dots, by first transferring them to the transfer molecules. The transfer molecules are chosen to make a transfer rate of excitons from the organic material to the transfer molecules larger than a decay rate of excitons in the organic material. More specifically, the organic matrix forms a light emitting layer in a light emitting device (LED). Also, the electroluminescent organic material is preferably an electroluminescent polymer.
    Type: Application
    Filed: November 23, 2004
    Publication date: April 5, 2007
    Inventors: Rafat Hikmet, Johannes Hofstraat
  • Publication number: 20070072286
    Abstract: The invention provides a method and a device for label-free detection of biomolecules or analytes in a sample liquid. The method comprises the steps of allowing an analyte to bind to one of at least two conductive surfaces. An alternating electrical field between at least two conductive surfaces. Amplitude and phase of alternating current, flowing between the at least two conductive surfaces, are compared with amplitude and phase of reference signal. From the difference between both currents it is possible to determine whether an analyte is present at the conductive surface.
    Type: Application
    Filed: September 20, 2004
    Publication date: March 29, 2007
    Applicant: Koninkljke Philips Electronics N.V.
    Inventors: Joukje Orsel, Johannes Hofstraat, Hendrik Stapert
  • Publication number: 20060127637
    Abstract: The invention relates to a system for use in an electric or optical device comprising at least two organic or metallo-organic energy and/or charge variable moieties having conjugated unsaturated bonds, wherein at least one moiety has an energy state different from another of said moieties, characterized in that the system is a H-donor-Hacceptor system comprising at least one H-donor molecule having at least two hydrogen bonding clusters, each cluster comprising at least two groups having formed a hydrogen bond, and at least two H-acceptor molecules, each having at least one hydrogen bonding cluster, each cluster comprising at least two groups having formed a hydrogen bond with the groups of the H-donor molecule, at least one of the H-donor and H-acceptor molecules 10 further comprising one or more of the organic or metallo-organic energy and/or charge variable moieties.
    Type: Application
    Filed: June 4, 2004
    Publication date: June 15, 2006
    Applicant: Koninklijke Philips Electronics N.V.
    Inventors: Johannes Hofstraat, Egbert Meijer, Albertus Petrus Hendrikus Schenning, Freek Hoeben
  • Publication number: 20060073357
    Abstract: A carbazole compound, polymeric or of low molecular weight, comprises a carbazole multimer unit of formula (I), wherein each carbazole unit may be unsubstituted or substituted with one or more substituents and n is larger than or equal to 2 for use in organic electroluminescent devices. The carbazole compounds provide facile hole-injection from a hole-injecting electrode and have a relatively triplet level enabling highly efficient electroluminescent devices to be obtained if combined with triplet emitter compounds.
    Type: Application
    Filed: January 23, 2004
    Publication date: April 6, 2006
    Inventors: Klemens Brunner, Margaretha De Kok-Van Breemen, Bea Langeveld, Nicole Kiggen, Jolanda Bastiaansen, Johannes Hofstraat, Herbert Boerner, Hermannus Schoo
  • Publication number: 20050221118
    Abstract: An electroluminescent device includes a first electrode, a second electrode and, dispersed therebetween, an electroluminescent layer comprising a first and a second electroluminescent compound capable of emitting light of a first and a second color respectively, the first color being different form the second color. The electroluminescent device is capable of reversibly emitting light having predominantly the first color when biased at a low voltage in a first direction and light having predominantly the second color when biased at a low voltage in a second direction opposite to the first direction. The first electroluminescent compound may be an electroluminescent polymer or low-molecular weight conjugated electroluminescent compound. The second electroluminescent compound is a metal-ion complex, typically mono-kernel or bi-kernel, having one or more ligands. At least one of said one or more ligands is substituted with a conjugated moiety, such as an oligo-phenylenevinylene or an oligo-phenylene derivative.
    Type: Application
    Filed: May 28, 2003
    Publication date: October 6, 2005
    Applicant: Koinklijke Philips Electronics N.V.
    Inventors: Klemens Brunner, Johannes Hofstraat, Luisa De Cola, Steve Welter, Edward Plummer