Granted Patent
Utility
US 5,484,169 · App. 08/390,568
Hidden entry system and image-developing device therefor
Inventors:
John C. H. Chang, Donald J. Hoffmann
Patented Case
View Patent ↗
Granted: Jan 16, 1996
Filed: Feb 17, 1995
Inventors
John C. H. Chang
Donald J. Hoffmann
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.