Patents by Inventor Damodar M. Pai

Damodar M. Pai 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: 5401615
    Abstract: An electrophotographic imaging member fabricated by forming on a charge generating layer a first coating including charge transporting molecules dispersed in a solution of a first polymer binder dissolved in a first solvent, drying the coating to remove the solvent to form a substantially dry charge transport layer, forming on the charge transport layer a second coating including charge transporting molecules and a chemical stabilizer additive selected from the group consisting of a nitrone, isobenzofuran, hydroxyaromatic compound and mixtures thereof molecularly dispersed in an electrically inactive second polymer binder in a solution of a second polymer binder dissolved in a second solvent, the first polymer binder being insoluble in the second solvent, and drying the second coating to remove the second solvent to form a substantially dry overcoat layer. This electrophotographic imaging member may be utilized in an electrophotographic imaging process.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: March 28, 1995
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Paul J. DeFeo, Kathleen M. Carmichael, Dale S. Renfer
  • Patent number: 5391447
    Abstract: An electrophotographic imaging member including a substrate, a charge generating layer, a charge transport layer including charge transporting molecules dispersed in a first polymer binder, and an overcoat layer including a triphenyl methane molecule dispersed in a second polymer binder, the second polymer binder being soluble in a solvent in which the first polymer binder is insoluble and the charge transport layer being substantialy free of any triphenyl methane molecules. The overcoat layer may also contain a charge transport molecule. The device may also include any suitable optional charge blocking, adhesive and other sub layers.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: February 21, 1995
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Paul J. DeFeo, Kathleen M. Carmichael
  • Patent number: 5386277
    Abstract: An apparatus for developing a latent image that contains a housing with a supply of a developer of carrier and toner and a coated toner donor member, which member is spaced from the surface on which a latent image Is being recorded. The apparatus also includes a means for advancing the developer material in the chamber of the housing and this means cooperates with the donor means and both means define a region wherein a substantially constant quantity of toner is deposited on the donor member. The apparatus further includes an electrode means positioned near the surface of a dielectric core roll and these electrodes are biased to detach toner from the donor member and to form a donor cloud for developing the latent image. The coated toner transport means can be comprised of a core with a coating of an oxidized polyether carbonate.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: January 31, 1995
    Assignee: Xerox Corporation
    Inventors: Dah A. Hays, Joseph Mammino, Damodar M. Pai, Donald S. Sypula, William H. Wayman, John F. Yanus, Paul J. DeFeo
  • Patent number: 5368967
    Abstract: An electrophotographic imaging member comprising a substrate, a charge generating layer, a charge transport layer, and an overcoat layer comprising a small molecule hole transporting arylamine having at least two hydroxy functional groups, a hydroxy or multihydroxy triphenyl methane and a polyamide film forming binder capable of forming hydrogen bonds with the hydroxy functional groups the hydroxy arylamine and hydroxy or multihydroxy triphenyl methane. This overcoat layer may be fabricated using an alcohol solvent. This electrophotographic imaging member may be utilized in an electrophotographic imaging process.
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: November 29, 1994
    Assignee: Xerox Corporation
    Inventors: Richard L. Schank, Damodar M. Pai, John F. Yanus, Dale S. Renfer, Paul J. DeFeo, William W. Limburg
  • Patent number: 5350654
    Abstract: A layered photoreceptor is composed of a substrate, an extrinsic pigment layer that has been sensitized disposed over the substrate, and a charge transport polymer in contact with the pigment layer. A method for producing a photoreceptor comprises depositing a layer of sensitizing electron donor material in a polymer binder on a substrate. An extrinsic pigment layer is deposited on the layer of sensitizing electron donor material. A charge transport layer is deposited on the pigment layer.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: September 27, 1994
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Andrew R. Melnyk, Donald J. Teney
  • Patent number: 5342719
    Abstract: An electrophotographic imaging member including a charge generating layer, a charge transport layer with charge transport molecules and as sensitizing additive or dopant a hydroxy derivative of the transport molecule.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: August 30, 1994
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, John F. Yanus, Paul J. DeFeo, Alan E. J. Toth, Walter Mychajlowskij, Zoran Popovic
  • Patent number: 5336577
    Abstract: A thick organic ambipolar layer on a photoresponsive device is simultaneously capable of charge generation and charge transport. In particular, the organic photoresponsive layer contains an electron transport material such as a fluorenylidene malonitrile derivative and a hole transport material such as a dihydroxy tetraphenyl benzadine containing polymer. These may be complexed to provide photoresponsivity, and/or a photoresponsive pigment or dye may also be included.
    Type: Grant
    Filed: June 2, 1993
    Date of Patent: August 9, 1994
    Assignee: Xerox Corporation
    Inventors: John W. Spiewak, John F. Yanus, Damodar M. Pai, Joseph Mammino, Dennis A. Abramsohn, William W. Limburg, Dale S. Renfer, Chei-Jen Chen, Paul DeFeo, Steven J. Grammatica, J. Michael Ishler, Merlin E. Scharfe, Donald S. Sypula
  • Patent number: 5316880
    Abstract: An electrophotographic imaging member including a charge generating layer and a charge transport layer, the charge transport layer including a charge transporting small molecule dissolved or molecularly dispersed in a film forming charge transporting polymer comprising charge transporting moieties in the backbone of the film forming charge transporting polymer, the charge transporting moieties having a structure substantially identical to the structure of the charge transporting small molecule, the charge transporting small molecule having an ionization potential substantially identical to the ionization potential of the polymer, and the charge transport layer being substantially free of electrically inactive film forming binder. This imaging member may be employed in an electrophotographic imaging process.
    Type: Grant
    Filed: August 26, 1991
    Date of Patent: May 31, 1994
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, John F. Yanus, William W. Limburg, Dale S. Renfer
  • Patent number: 5310613
    Abstract: An electrophotographic imaging member including a charge generating layer containing a dispersed oxytitanium phthalocyanine polymorph and a charge transport layer containing a film forming charge transporting polymer including charge transporting moieties in the backbone of the film forming charge transporting polymer, for example, polysilylenes and polyarylamine derivative. The charge transporting polymers may optionally be used as a binder in the charge generating layer. The imaging member may be employed in an electrophotographic imaging process, particularly in high sensitivity infrared photoreceptors which are compatible with liquid ink development processes.
    Type: Grant
    Filed: December 16, 1991
    Date of Patent: May 10, 1994
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Santokh S. Badesha, John F. Yanus, Michael J. Rice
  • Patent number: 5306586
    Abstract: An electrophotographic imaging member including a charge generating layer and a heterogeneous charge transport layer, the charge transport layer having regions of charge transport and inactive regions and the charge transporting regions are in contact with each other. This imaging member has characteristics that enable high quality and high contrast imaging.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: April 26, 1994
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Andrew R. Melnyk, Milan Stolka
  • Patent number: 5300339
    Abstract: A coated toner transport roll containing a core with a coating thereover of transporting molecules dispersed in a binder and an oxidizing agent selected from the group consisting of ferric chloride and trifluoroacetic acid. These oxidizing agents can be selected in an amount of from about 1 to about 50 weight percent. Also, the coating possesses a relaxation time of from about 0.0099 millisecond to about 3.5 milliseconds, and a residual voltage of from about 1 to about 10 volts.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: April 5, 1994
    Assignee: Xerox Corporation
    Inventors: Dan A. Hays, Joseph Mammino, Damodar M. Pai, Donald S. Sypula, William H. Wayman, John F. Yanus, Paul J. DeFeo
  • Patent number: 5283143
    Abstract: An electrophotographic imaging member including a charge generation layer and a hole transport layer, at least the charge generation layer or charge transport layer comprising a polyarylamine polymer represented by the following formula: ##STR1## wherein: n is between about 5 and about 5,000p is between about 5 and about 5,000X' and X" are independently selected from a group having bifunctional linkages, andQ is a divalent group derived from certain hydroxy terminated arylamine reactants.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: February 1, 1994
    Assignee: Xerox Corporation
    Inventors: John F. Yanus, William W. Limburg, Dale S. Renfer, Damodar M. Pai
  • Patent number: 5230974
    Abstract: An electrophotographic imaging member includes two charge generator layers and a charge transport layer. The first charge generator layer is fabricated in the form of a dot or line pattern and is sensitive to a wavelength region to which the second continuous generator layer is both transparent and insensitive. This imaging member may be employed in an electrophotographic imaging process to produce textual or pictorial reproduction on demand.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: July 27, 1993
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Andrew R. Melnyk
  • Patent number: 5215844
    Abstract: A photoconductive imaging member comprised of a photogenerating layer comprised of a photogenerating pigment or pigments dispersed in a linear phenoxy resin with a weight average molecular weight of from about 50,000 to about 150,000, and a transport layer comprised of transport molecules dispersed in a resinous binder.
    Type: Grant
    Filed: September 3, 1991
    Date of Patent: June 1, 1993
    Assignee: Xerox Corporation
    Inventors: Santokh S. Badesha, Damodar M. Pai
  • Patent number: 5202408
    Abstract: A polyarylamine polymer represented by the following formula: ##STR1## wherein: n is between about 5 and about 5,000p is between about 5 and about 5,000X' and X" are independently selected from a group having bifunctional linkages, andQ is a divalent group derived from certain hydroxy terminated arylamine reactants.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: April 13, 1993
    Assignee: Xerox Corporation
    Inventors: John F. Yanus, William W. Limburg, Dale S. Renfer, Damodar M. Pai
  • Patent number: 5166016
    Abstract: A photoconductive imaging member comprised of a supporting substrate and thereover a charge transfer complex comprised of a polysilylene donor polymer and an electron acceptor.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: November 24, 1992
    Assignee: Xerox Corporation
    Inventors: Santokh S. Badesha, Michael M. Shahin, Damodar M. Pai
  • Patent number: 5132627
    Abstract: A process is disclosed for ascertaining electrical discharge properties of an electrophotographic imaging member including the steps of (a) providing at least one electrophotographic imaging member comprising an electrically conductive layer and at least one photoconductive layer, (b) contacting the surface of the electrophotographic imaging member with a substantially transparent electrode and applying an electric potential or an electric current to form an electric field across the photoconductive layer, (c) terminating the applying of the electric potential or the electric current, (d) exposing the photoconductive layer to activating radiation to discharge the electrophotographic imaging member, (e) repeating steps (b), (c) and (d), and (f) measuring the potential across the photoconductive layer during steps (b), (c) and (d) as a function of time by means of an electrostatic meter coupled to the electrode.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: July 21, 1992
    Assignee: Xerox Corporation
    Inventors: Zoran D. Popovic, Damodar M. Pai, Merlin E. Scharfe, Satchidanand Mishra, Edward A. Domm
  • Patent number: 5030536
    Abstract: A process for restoring imaging members, which comprises (1) providing, subsequent to its utilization and removal from an electrophotographic imaging device, an amorphous silicon photoconductive imaging member with a protective overcoating; (2) contacting this member with a fluorine containing composition for an effective time period enabling the removal of the protective layer; (3) washing and drying the surface of the resulting imaging member; and (4) subsequently depositing a protective layer thereover.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: July 9, 1991
    Assignee: Xerox Corporation
    Inventors: Damodar M. Pai, Santokh S. Badesha
  • Patent number: 5028502
    Abstract: An electrophotographic imaging process including providing an electrophotographic imaging member containing a change generating layer and a charge transport layer, the charge transport layer containing polystyrene film forming binder and certain specified aromatic diamine or certain specified hydrazone charge transport molecules, depositing a uniform electrostatic charge on the imaging member with a corona charging device, exposing the imaging member to activating radiation in image configuration to form an electrostatic latent image on the imaging member, developing the electrostatic latent image with electrostatically attractable marking particles to form a toner image, transferring the toner image to a receiving member and repeating the depositing, exposing, developing and transferring steps, the time elapsed between the exposing and the developing steps being between about 0.5 millisecond and about 500 milliseconds.
    Type: Grant
    Filed: January 29, 1990
    Date of Patent: July 2, 1991
    Assignee: Xerox Corporation
    Inventors: Huoy-Jen Yuh, Damodar M. Pai, John F. Yanus
  • Patent number: 5004663
    Abstract: A photoconductive imaging member comprised of a photogenerating layer and a hole transport layer, including aryl amines dispersed in resin binders containing a polyphosphazene, such as poly[bis(p-tolylamino)]polyphosphazene, poly[bis(naphthoxy)]polyphosphazene, or mixtures thereof.
    Type: Grant
    Filed: July 28, 1989
    Date of Patent: April 2, 1991
    Assignee: Xerox Corporation
    Inventors: Santokh S. Badesha, Milan Stolka, Damodar M. Pai, Martin A. Abkowitz