Patents by Inventor Daniel B. Roitman

Daniel B. Roitman 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).

  • Patent number: 6087771
    Abstract: In the method of the present invention, a bottom electrode having a planar sheet of conducting material is first deposited on a substrate. A mask is then deposited on the bottom electrode to define wells. For at least first and second ones of the wells defined by the mask, an electroluminescent material is dispensed into the wells. The electroluminescent material dispensed into the first well emits a different spectrum of light from the electroluminescent material dispensed into the second well. In one embodiment of the invention, an isolation layer is deposited over the electroluminescent material after the electroluminescent material has dried. A top electrode is then deposited over the isolation layer. In a display according to the present invention, a plurality of pixels are deposited on a bottom electrode and then a top electrode is provided for energizing the pixels.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: July 11, 2000
    Assignee: Agilent Technologies, Inc.
    Inventor: Daniel B. Roitman
  • Patent number: 5972419
    Abstract: A method for constructing an electroluminescent display and a novel display constructed thereby. In the method of the present invention, a bottom electrode having a planar sheet of conducting material is first deposited on a substrate. A mask is then deposited on the bottom electrode to define wells. For at least first and second ones of the wells defined by the mask, an electroluminescent material is dispensed into the wells. The electroluminescent material dispensed into the first well emits a different spectrum of light from the electroluminescent material dispensed into the second well. In one embodiment of the invention, an isolation layer is deposited over the electroluminescent material after the electroluminescent material has dried. A top electrode is then deposited over the isolation layer. In a display according to the present invention, a plurality of pixels are deposited on a bottom electrode and then a top electrode is provided for energizing the pixels.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: October 26, 1999
    Assignee: Hewlett-Packard Company
    Inventor: Daniel B. Roitman
  • Patent number: 5965280
    Abstract: A PPV based electroluminescent device and method for constructing the same. The electroluminescent device is constructed on a substrate by depositing a layer of material having a PPV precursor and photoacid generator on the substrate. The substrate typically includes the anode for the device. The PPV precursor is converted to PPV in the presence of an acid. The photoacid generator produces an acid when exposed to electromagnetic radiation. Those portions of the layer that are not to contain electroluminescent elements are masked. The unmasked portion is then illuminated with electromagnetic radiation; and any unreacted PPV precursor is removed to provide a plurality of isolated PPV regions on the substrate. An electron transport layer is then deposited over the PPV regions and the cathode is deposited on top of the electron transport layer.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: October 12, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Daniel B. Roitman, James R. Sheats, Guillermo Bazan, Michelle Lee Renak
  • Patent number: 5948552
    Abstract: An organic electroluminescent device that comprises a substrate, a first conductive layer on the substrate, an electron-transporting and light-emitting layer, a second conductive layer adjacent the electron-transporting and light-emitting layer and remote from the first conductive layer, and a hole-conducting layer sandwiched between the first conductive layer and the electron-transporting and light-emitting layer. The hole-conducting layer comprises a poly(arylamine) including at least one compound of formula (I): ##STR1## In this: R is independently in each occurrence a C.sub.1-24 hydrocarbyl, hydrocarboxyl, hydrothiocarboxy, hydroarylcarboxy, or hydrothioarylcarboxy; Ar.sub.1 and Ar.sub.2 are independently in each occurrence a C.sub.6-18 aryl moiety optionally substituted with one or more C.sub.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: September 7, 1999
    Assignees: Hewlett-Packard Company, The Dow Chemical Company
    Inventors: Homer Antoniadis, Daniel B. Roitman, William R. Shiang, Edmund P. Woo, Weishi Wu
  • Patent number: 5777433
    Abstract: A high refractive index package material is described that encapsulates a semiconductor light emitting chip. The high refractive index package material is transparent to the light emitted from the chip and includes a host material and a plurality of nanoparticles held in the host material. The host material has a refractive index lower than that of the chip and is transparent to the light emitted from the chip. The nanoparticles are (1) formed from a material having a refractive index higher than that of the host material, (2) substantially smaller in size than the wavelength of the light emitted from the chip, (3) included in the host material at such a density that the effective refractive index of the high refractive index package material is higher than that of the host material without decreasing the transparency of the high refractive index package material.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: July 7, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Steven D. Lester, Jeffrey N. Miller, Daniel B. Roitman
  • Patent number: 5719467
    Abstract: An organic electroluminescent device with a conducting polymer layer beneath the hole transport layer. A conducting polymer layer of doped polyaniline (PANI) is spin-cast onto an indium-tin oxide (ITO) anode coating on a glass substrate. Then a hole transport layer, for example TPD or another aromatic tertiary amine, is vapor-deposited onto the conducting polymer layer, followed by an electron transport layer and a cathode. Polyester may be blended into the PANI before spin-casting and then removed by a selective solvent after the spincasting, leaving a microporous layer of PANI on the anode. The conducting polymer layer may instead be made of a .pi.-conjugated oxidized polymer or of TPD dispersed in a polymer binder that is doped with an electron-withdrawing compound. An additional layer of copper-phthalocyanine, or of TPD in a polymer binder, may be disposed between the conducting polymer layer and the hole transport layer.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: February 17, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Homer Antoniadis, Daniel B. Roitman, Jeffrey N. Miller
  • Patent number: 5629389
    Abstract: An improved electroluminescent device which includes a hole injection electrode, an electron injection electrode, and an electroluminescent layer located between the hole and electron injection electrodes. The electroluminescent layer includes an organic polymer and a hindered phenolic additive in a concentration greater than 4% by weight. The preferred organic polymer is a derivative of PPV. The preferred hindered phenolic additives are and 2,4,6 tri-tert-butyl phenol 2,6 di-tert-butyl-methylphenol. The device has higher efficiency and a slower rate of degradation than devices lacking the hindered phenolic additive.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: May 13, 1997
    Assignee: Hewlett-Packard Company
    Inventors: Daniel B. Roitman, James R. Sheats, Mark R. Hueschen
  • Patent number: 5552221
    Abstract: Described is a method for preparing a polybenzazole filament which comprises extruding a polybenzazole dope filament, drawing the filament across an air gap, coagulating and washing the filament, and drying the filament, characterized in that a solution of a compound selected from the group consisting of ferrocenes, ruthocene, iodide-, cobalt-, and copper-containing compounds, dyes, and mixtures thereof is contacted with a filament subsequent to the washing step and prior to the drying step. This method provides a means to improve the tensile strength retention of damaged polybenzazole filaments following exposure to sunlight.
    Type: Grant
    Filed: December 29, 1994
    Date of Patent: September 3, 1996
    Assignee: The Dow Chemical Company
    Inventors: Ying H. So, Steven J. Martin, Chieh-Chun Chau, Ritchie A. Wessling, Ashish Sen, Katsuhiko Kato, Daniel B. Roitman, Willie E. Rochefort