Patents by Inventor James Harkin

James Harkin 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: 3954657
    Abstract: This disclosure depicts a process for reclaiming from contaminated color cathode ray tube screening waste rare earth oxysulfide phosphors, especially the red-emitting phosphor yttrium oxysulfide. The screening waste from which the phosphor material is to be reclaimed may contain, in addition to the phosphor material contaminants such as hardened photoresist material, blue-emitting and green-emitting zinc sulfide type phosphor materials and graphite. The novel phosphor reclaim process disclosed is characterized by having steps including subjecting the partially purified oxysulfide phosphor material to a wash in dilute nitric, acetic, hydrochloric or citric acid, preferably citric acid, in order to enhance the adherability of the reclaimed phosphor material during subsequent rescreening thereof. The phosphor material is subjected to a wash with sodium tri-polyphosphate to minimize during rescreening of the phosphor material cross-contamination of underlying blue-emitting or green-emitting phosphor materials.
    Type: Grant
    Filed: November 21, 1974
    Date of Patent: May 4, 1976
    Assignee: Zenith Radio Corporation
    Inventors: Harvey Forest, James Harkin