Granted Patent
Utility
US 5,239,558 · App. 07/751,534
Pulse code modulation circuit
Inventor:
Shin Shimizu
Patented Case
View Patent ↗
Granted: Aug 24, 1993
Filed: Aug 29, 1991
Inventor
Shin Shimizu
Assignee (at issue)
NIPPON STEEL 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.