Granted Patent
Utility
US 5,859,721 · App. 08/630,488
Optical device using a point light source
Inventor:
Junichi Oka
Patented Case
View Patent ↗
Granted: Jan 12, 1999
Filed: Apr 10, 1996
Inventor
Junichi Oka
Assignee (at issue)
DAINIPPON SCREEN MFG. CO., 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.