Patents by Inventor James R. Larson

James R. Larson 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: 5525450
    Abstract: A liquid developer comprised of a nonpolar liquid, thermoplastic resin particles, a charge adjuvant, pigment, and a charge director selected from the group consisting of the triblock polymers BAA', BA'A, and ABA' wherein A, A' and B represent polymer segments or blocks, the polar A block repeat units contain an alkylated or protonated ammonium charged site and the polar A' block repeat units contain an acid group of a pKa equal to or less than about 7.0, and wherein the nonpolar B block repeat units contain aliphatic hydrocarbon solubilizing groups; and wherein the A and A' block number average molecular weights range from about 200 to 120,000, and the B block number average molecular weights range from about 2,000 to 190,000; and the total number average molecular weight of said charge director is from about 2,400 to about 300,000, and the ratio of M.sub.w to M.sub.n for said charge director is 1 to 5.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: June 11, 1996
    Assignee: Xerox Corporation
    Inventors: John W. Spiewak, James R. Larson, Scott D. Chamberlain
  • Patent number: 5512978
    Abstract: An apparatus for measuring concentrations of a first vapor pressure carrier fluid component and a second vapor, pressure carrier fluid component in a carrier fluid mixture, including a supply vessel for holding the carrier fluid mixture. A light source is provided for transmitting an infrared light source to the carrier fluid mixture. Detector is provided for detecting infrared light intensity transmitted through the carrier fluid mixture, and, in response thereto, determining infrared absorption of carbon hydrogen stretching frequencies of the carrier fluid mixture. And means are provided for calculating concentrations of the first carrier fluid component and the second carrier fluid component in the mixture based on the infrared absorption of carbon hydrogen stretching frequencies of the carrier fluid mixture. This method can also be extended to a mixture of more than two fluids. A means for maintaining a predetermined ratio of the carrier fluids.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 30, 1996
    Assignee: Xerox Corporation
    Inventors: Ralph A. Mosher, Rasin Moser, James R. Larson, John S. Berkes
  • Patent number: 5484679
    Abstract: A negatively charged liquid developer comprised of a nonpolar liquid, thermoplastic resin particles, a charge adjuvant, pigment, and an ABA polymer charge director wherein A and B represent the polymer segments.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: January 16, 1996
    Assignee: Xerox Corporation
    Inventors: John W. Spiewak, James R. Larson
  • Patent number: 5478688
    Abstract: A positively charged liquid developer comprised of liquid, thermoplastic resin particles, optional pigment, a charge director, and an insoluble charge adjuvant comprised of a copolymer of an alkyl acrylamidoglycolate alkyl ether and an alkenylester, and wherein the charge adjuvant is associated with or combined with said resin and said optional pigment, and which charge adjuvant is of the formula ##STR1## wherein R.sup.1 is hydrogen or alkyl of 1 to 20 carbons; R.sup.2 is H, alkyl of 1 to 20, aryl of 6 to 20 carbons, and aryl alkyl of 7 to 35 carbons; m is from 0 to about 10; and wherein the alkyl and aryl groups optionally contain heteroatoms of F, Cl, O, S, N, Si, and P; R.sup.3 and R.sup.4 are alkyl; and x and y represent the number of segments.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: December 26, 1995
    Assignee: Xerox Corporation
    Inventors: John W. Spiewak, James R. Larson, Frank J. Bonsignore
  • Patent number: 5476743
    Abstract: A liquid developer comprised of a nonpolar liquid, thermoplastic resin particles, polar organic additives with a dielectric constant in the range of about 20 to about 150, and soluble in the nonpolar liquid; and charge director.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: December 19, 1995
    Assignee: Xerox Corporation
    Inventors: John W. Spiewak, James R. Larson
  • Patent number: 5471287
    Abstract: System for replenishing liquid developer in equipment, such as a printer, whereby the percent of toner solids is maintained at about 0.5 to 4% by weight based on the total weight of liquid developer, the system comprising at least one liquid toner concentrate vessel containing aggregates of thermoplastic resin particles, median particle size (volume weighted) greater than 15 .mu.m, and with 90% of the particles (volume weighted) not less than 30 .mu.m, composed of 50 to 100% by weight of particles and 0 to 50% by weight carrier liquid; a liquid vessel containing carrier liquid, means communicating each of said vessels with a dispersing vessel containing high shearing or high impact means wherein contents of the liquid toner concentrate vessel and the liquid vessel are supplied thereto and the resin particles are dispersed in the carrier liquid to form particles having a median particle size (volume weighted) of less than 15 .mu.m, and with 90% of the particles (volume weighted) less than 30 .mu.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: November 28, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: David E. Blair, William A. Houle, Gregg A. Lane, James R. Larson, Kathryn A. Pearlstine
  • Patent number: 5459007
    Abstract: A liquid developer comprised of a liquid, thermoplastic resin particles, a nonpolar liquid soluble charge director comprised of an ionic or zwitterionic quaternary ammonium block copolymer ammonium block copolymer, and wherein the number average molecular weight thereof of said charge director is from about 70,000 to about 200,000.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: October 17, 1995
    Assignee: Xerox Corporation
    Inventors: James R. Larson, John W. Spiewak, Joseph Mort, Inan Chen, Martin A. Abkowitz, Homer Antoniadis
  • Patent number: 5451483
    Abstract: A liquid developer comprised of a nonpolar liquid, thermoplastic resin particles comprised of a polyalkylene or polyalkylene with pendant acid or ammonium groups thereon, optional pigment, optional charge adjuvant and charge director.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: September 19, 1995
    Assignee: Xerox Corporation
    Inventors: Timothy J. Fuller, Ralph A. Mosher, John S. Berkes, John S. Chambers, James R. Larson
  • Patent number: 5441841
    Abstract: A liquid developer comprised of a liquid, thermoplastic resin particles, optional pigment, a nonpolar liquid soluble charge director comprised of an ionic or zwitterionic quaternary ammonium block copolymer, and wherein said charge director possesses a molecular weight distribution that is bimodal comprising a first AB diblock copolymer component with a number average molecular weight of from about 70,000 to about 200,000, and a second AB diblock copolymer component with a number average molecular weight of from about 2,200 to about 60,000.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: August 15, 1995
    Assignee: Xerox Corporation
    Inventors: James R. Larson, John W. Spiewak, George A. Gibson
  • Patent number: 5411834
    Abstract: A negatively charged liquid developer comprised of thermoplastic resin particles, optional pigment, a charge director, and an insoluble charge adjuvant comprised of a copolymer of an alkene and an unsaturated acid derivative, and wherein the acid derivative contains pendant fluoroalkyl or pendant fluoroaryl groups, and wherein the charge adjuvant is associated with or combined with said resin and said optional pigment.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: May 2, 1995
    Assignee: Xerox Corporation
    Inventors: Timothy J. Fuller, James R. Larson, John W. Spiewak, David H. Pan, Ralph A. Mosher, Frank J. Bonsignore
  • Patent number: 5409796
    Abstract: A positively charged liquid developer comprised of thermoplastic resin particles, optional pigment, a charge director, and a charge adjuvant comprised of a polymer of an alkene and unsaturated acid derivative; and wherein the acid derivative contains pendant ammonium groups, and wherein the charge adjuvant is associated with or combined with said resin and said optional pigment.An example of a charge adjuvent copolymer compound containing alkylene and an unsaturated acid derivative such as acrylic acid and methacrylic acid containing pendent ammonium groups is represented, for example, by the following general formula ##STR1## wherein Z is oxygen or substituted nitrogen; Y is alkyl; R is hydrogen, alkyl or aryl; and X is an anion.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: April 25, 1995
    Assignee: Xerox Corporation
    Inventors: Timothy J. Fuller, James R. Larson, John W. Spiewak, David H. Pan, Ralph A. Mosher, Frank J. Bonsignore
  • Patent number: 5407775
    Abstract: A liquid developer comprised of a liquid, thermoplastic resin particles, a nonpolar liquid soluble charge director comprised of a zwitterionic quaternary ammonium block copolymer wherein both cationic and anionic sites contained therein are covalently bonded within the same polar repeat unit in the quaternary ammonium block copolymer.
    Type: Grant
    Filed: January 24, 1994
    Date of Patent: April 18, 1995
    Assignee: Xerox Corporation
    Inventors: James R. Larson, John W. Spiewak
  • Patent number: 5397672
    Abstract: A liquid developer comprised of a liquid, thermoplastic resin particles, a nonpolar liquid soluble charge director, comprised of a quaternary ammonium block copolymer with hydroxide as the anion.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: March 14, 1995
    Assignee: Xerox Corporation
    Inventors: James R. Larson, John W. Spiewak
  • Patent number: 5387489
    Abstract: Disclosed is a process for preparing a liquid or dry electrophotographic developer comprising: (a) forming a melt mixture comprised of a polymer resin or resins, a colorant, a charge director, and a nonaqueous solvent to obtain a first suspension of colored polymeric particles with a volume average diameter of from about 5 to about 100 microns; and (b) homogenizing with a dairy piston homogenizer said first suspension under pressure of from about 100 to about 500 Bars to obtain a second suspension containing colored polymeric particles with a volume average diameter of from about 0.1 to about 5 microns.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: February 7, 1995
    Assignee: Xerox Corporation
    Inventors: Timothy J. Fuller, James R. Larson, Frank J. Bonsignore
  • Patent number: 5366840
    Abstract: A liquid developer comprised of thermoplastic resin particles, an optional charge director, and a charge additive or adjuvant comprised of a component of the formulas ##STR1## wherein R.sub.1 is selected from the group consisting of hydrogen and alkyl, and n is 0 (zero), 1,2,3, or 4.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: November 22, 1994
    Assignee: Xerox Corporation
    Inventors: James R. Larson, Frank J. Bonsignore, Roger N. Ciccarelli, Thomas R. Pickering, Denise R. Bayley, Jacques C. Bertrand
  • Patent number: 5308731
    Abstract: A liquid developer comprised of a liquid, thermoplastic resin particles, a nonpolar liquid soluble charge director, and a charge adjuvant comprised of a metal hydroxycarboxylic acid.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: May 3, 1994
    Assignee: Xerox Corporation
    Inventors: James R. Larson, Bing R. Hsieh
  • Patent number: 5306591
    Abstract: A liquid developer comprised of thermoplastic resin particles, a charge director, and a charge adjuvant comprised of an imine bisquinone.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: April 26, 1994
    Assignee: Xerox Corporation
    Inventors: James R. Larson, Bing R. Hsieh
  • Patent number: 5155530
    Abstract: A method for controlling toner developed mass per unit area in an electrostatic or electrophotographic device includes the steps of: forming a toner image on a printing sheet; measuring a toner density of the toner image on the printing sheet; measuring a gloss of the toner image on the printing sheet; determining a toner developed mass per unit area for the measured gloss and measured toner density; and adjusting a voltage of a developement field in the electrostatic device in accordance with the determined toner developed mass per unit area.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: October 13, 1992
    Assignee: Xerox Corporation
    Inventors: James R. Larson, Jon R. Swanson
  • Patent number: 5077171
    Abstract: An electrostatic liquid developer having positive charging characteristics consisting essentially of:(A) a non-polar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) thermoplastic resin particles having an average by area particle size of less than 10 .mu.m,(C) a nonpolar liquid soluble ionic or zwitterionic charge director compound, and(D) a carbohydrate product of photosynthesis comprised of at least one saccharose present in (A) and/or dispersed in (B).The liquid developer is useful in copying, color proofing, digital color proofing, making lithographic printing plates, and resists.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: December 31, 1991
    Assignee: DX Imaging
    Inventors: James R. Larson, Arnold R. Lee
  • Patent number: H1483
    Abstract: A liquid developer comprised of thermoplastic resin particles, and a charge director comprised of an ammonium AB diblock copolymer of the formula ##STR1## wherein X.sup.- is a conjugate base or anion of a strong acid, R is hydrogen or alkyl, R' is alkyl, R" is an alkyl group containing from about 6 to about 20 carbon atoms, and y and x represent the number average degree of polymerization (DP) wherein the ratio of y to x is in the range of from about 10 to 2 to about 100 to 20.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: September 5, 1995
    Inventors: James R. Larson, John W. Spiewak, Anthony M. Wallace