Granted Patent
Utility
US 6,636,617 · App. 09/584,081
Method and apparatus for inserting and extracting watermark into and from contents information
Inventors:
Takayuki Sugahara, Joji Naito
Patented Case
View Patent ↗
Granted: Oct 21, 2003
Filed: Jun 1, 2000
Inventors
Takayuki Sugahara
Joji Naito
Assignee (at issue)
Victor Company of Japan, Ltd.
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.