Granted Patent
Utility
US 6,513,161 · App. 09/859,764
Monitoring system for recording device
Inventors:
Henry B. Wheeler, Daozheng Lu
Patented Case
View Patent ↗
Granted: Jan 28, 2003
Filed: May 17, 2001
Inventors
Henry B. Wheeler
Daozheng Lu
Assignee (at issue)
Nielsen Media Research, 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.