Granted Patent
Utility
US 4,890,471 · App. 07/297,283
Punch press forming CRT shadow masks
Inventor:
Hideya Ito
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Jan 17, 1989
Inventor
Hideya Ito
Assignee (at issue)
MITSUBISHI ELECTRIC CORPORATION
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.