Patents by Inventor Benjamin T. Chen

Benjamin T. Chen 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: 6422736
    Abstract: A mixer for preparing silver halide grains for photographic use has upper and lower impellers housed in a draft tube. The bottom impeller has flat blades for micromixing silver and halide reactants introduced into the bottom of the draft tube. The upper impeller has pitched blades for macromixing the bulk fluid. The impellers are spaced apart at least the distance of their diameters so that the upper and lower impellers operate independently of one another so that micromixing is independent of macromixing. A flow disrupter structurally associated with the draft tube and positioned above the top impeller prevents vortexing of the fluid during mixing. Baffles may be provided in the draft tube to discourage vortexing.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: July 23, 2002
    Assignee: Eastman Kodak Company
    Inventors: Michael G. Antoniades, Harold G. Judd, Katrin I. Parsiegla, Benjamin T. Chen, Douglas E. Singer, Donald R. Irwin, Sucheta Tandon, Jess B. Hendricks, III, Heinz E. Stapelfeldt
  • Patent number: 6350567
    Abstract: A silver halide photographic element comprising a silver halide emulsion which is greater than 50 mole-% silver chloride, said emulsion containing an isothiazolone compound represented by the formula wherein R1 is a substituent; and Z contains the carbon atoms necessary to form a substituted or unsubstituted non-aromatic ring, wherein the isothiazolone compound was added before or during precipitation of the emulsion.
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: February 26, 2002
    Assignee: Eastman Kodak Company
    Inventors: Benjamin T. Chen, Roger L. Klaus, Jeri L. Mount
  • Patent number: 6033842
    Abstract: The invention relates to a method of forming a silver halide emulsion comprising adding triiodide during grain formation or sensitization.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: March 7, 2000
    Assignee: Eastman Kodak Company
    Inventors: Roger Lok, Benjamin T. Chen, Weimar W. White
  • Patent number: 5547827
    Abstract: The invention relates to a radiation sensitive emulsion comprised of a dispersing medium and silver iodochloride grainsWherein the silver iodochloride grainsare partially bounded by {100} crystal faces satisfying the relative orientation and spacing of cubic grains andcontain from 0.05 to 1 mole percent iodide, based on total silver, with maximum iodide concentrations located nearer the surface of the grains than their centerand wherein said emulsion further comprises a quinone comprising ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be independently substituted or non-substituted alkyl, aryl, alkylaryl, or halogen, carboxy, amido, cyano, methoxy; together R.sub.1 and R.sub.2, R.sub.3 and R.sub.4 may form carbocyclic, heterocyclic, aromatic, or heteroaromatic rings.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: August 20, 1996
    Assignee: Eastman Kodak Company
    Inventors: Benjamin T. Chen, Roger Lok
  • Patent number: 5512103
    Abstract: The invention provides a cyan color producing silver halide emulsion layer or a magenta color producing silver halide emulsion layer wherein said at least one layer has an exposure range of at least 0.6 log E from the point where the instantaneous contrast is 1.0 and wherein the instantaneous contrast of said layer increases as a function of increasing exposure over at least 70 percent of said exposure range.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: April 30, 1996
    Assignee: Eastman Kodak Company
    Inventors: James L. Edwards, Eric L. Bell, Benjamin T. Chen, Richard L. Parton
  • Patent number: 5418118
    Abstract: The invention provides a cyan color producing silver halide emulsion layer or a magenta color producing silver halide emulsion layer wherein said at least one layer has an exposure range of at least 0.6 log E from the point where the instantaneous contrast is 1.0 and wherein the instantaneous contrast of said layer increases as a function of increasing exposure over at least 70 percent of said exposure range.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: May 23, 1995
    Assignee: Eastman Kodak Company
    Inventors: James L. Edwards, Eric L. Bell, Benjamin T. Chen, Richard L. Parton
  • Patent number: 5380629
    Abstract: This invention provides a process for preparing a bleach accelerator silver salt dispersion by precipitating a salt of a bleach accelerating compound and a silver salt wherein the vAg is maintained at a predetermined level during the precipitation. This invention further provides a photographic element containing a dispersion of grains of a bleach accelerator silver salt wherein the grains are isomorphic or derived from needle or platelet isomorphic crystals.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: January 10, 1995
    Assignee: Eastman Kodak Company
    Inventor: Benjamin T. Chen