Granted Patent
Utility
US 6,060,428 · App. 09/073,796
Heat-sensitive chromogenic system
Inventors:
John C. H. Chang, Donald J. Hoffmann, Ronald R. Garrison, Derrick Kraus
Patented Case
View Patent ↗
Granted: May 9, 2000
Filed: May 7, 1998
Inventors
John C. H. Chang
Donald J. Hoffmann
Ronald R. Garrison
Derrick Kraus
Assignee (at issue)
Wallace Computer Services, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.