Granted Patent
Utility
US 6,434,092 · App. 09/466,537
Optical head for land and groove recording
Inventor:
Ryuichi Katayama
Patented Case
View Patent ↗
Granted: Aug 13, 2002
Filed: Dec 17, 1999
Inventor
Ryuichi Katayama
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.