Patents by Inventor Alberto Vacca

Alberto Vacca 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: 5882846
    Abstract: Infrared sensitive photographic elements comprise an opaque film support, an infrared sensitized silver halide emulsion layer and a hydrophilic colloid protective layer on one side of the film support, said protective layer comprising colloidal silica having an average particle size lower than 15 nanometers.The elements have an increased exposure latitude upon exposure to infrared laser diodes, and higher maximum density upon photographic processing.
    Type: Grant
    Filed: January 8, 1993
    Date of Patent: March 16, 1999
    Assignee: Imation Corp.
    Inventors: Alberto Vacca, Marino Rossi
  • Patent number: 5486451
    Abstract: A method is disclosed of preparing washed silver halide photographic emulsions wherein silver halide grain formation is effected in the presence of an acid-coagulable gelatin derivative or a mixture of gelatin and an acid-coagulable gelatin derivative and coagulation of the emulsion occurs in the presence of ionic copolymers of styrene sulfonic acid and maleic acid.
    Type: Grant
    Filed: August 4, 1994
    Date of Patent: January 23, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Alberto Vacca, Paolo Barletta
  • Patent number: 5316901
    Abstract: UV-sensitive negative acting silver halide photographic elements for contact processes which can be safely handled under white light and have increased UV exposure latitude, said elements comprising a support base, a hydrophilic colloidal silver halide emulsion layer comprising UV sensitive negative acting silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion is reactively associated with a water-removable UV-absorbing compound having at least 80% of the absorption in the range from 350 to 400 micronmeter.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: May 31, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Alberto Vacca, Aldo Sgarbi
  • Patent number: 5169750
    Abstract: An improved process for preparing silver halide emulsions by precipitation of silver halide grains in a single reaction vessel comprising a dispersing medium is disclosed. The process comprises forming a silver halide emulsion by adding silver salt and halide salt solutions in a dispersing medium contained in a reaction vessel to form silver halide nuclei and allowing said silver halide nuclei to grow in said reaction vessel. The improvement comprises, during a pause of addition of silver salt and halide salt solutions, reducing the volume of silver halide emulsion by continuously delivering the silver halide emulsion to a cleaning stage for the partial removal of dispersing medium and any salt soluble therein and returning the silver halide emulsion to the reaction vessel.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: December 8, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Alberto Vacca
  • Patent number: 4849326
    Abstract: UV-sensitive direct positive silver halide photographic elements for duplicating processes which can be safely handled under white light, said elements comprising a support base, a hydrophilic colloidal silver halide emulsion layer comprising fogged silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion is reactively associated with a water-removable UV-absorbing compound having at least 80% of the absorption in the range from 350 to 400 .mu.m.
    Type: Grant
    Filed: July 8, 1988
    Date of Patent: July 18, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Mauro Besio, Alberto Vacca, Angelo Vallarino
  • Patent number: 4659647
    Abstract: A photosensitive silver halide material for obtaining black and white half-tone dot or line images comprises a fine grain and high-chloride silver halide emulsion reactively associated with an aqueous latex of a hydrophobic vinyl addition polymer in combination with a stabilizer selected from the group consisting of 4-hydroxy-1,3,3a,7-tetrazaindenes, benzotriazoles and benzimidazoles. The silver halide emulsion has an average grain size lower than or equal to 0.20 micron with at least 60% of its molar halide content consisting of chloride ions.The material allows high-contrast and high resolving power images to be obtained.The material has a good developability in photographic processings and this reduces the development times and increases productivity.
    Type: Grant
    Filed: December 10, 1985
    Date of Patent: April 21, 1987
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Alberto Vacca, Angelo Vallarino