Granted Patent
Utility
US 6,798,893 · App. 09/642,476
Digital watermarking technique
Inventor:
Nobuyuki Tanaka
Patented Case
View Patent ↗
Granted: Sep 28, 2004
Filed: Aug 18, 2000
Inventor
Nobuyuki Tanaka
Assignee (at issue)
NEC 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.