Granted Patent
Utility
US 4,452,174 · App. 06/525,259
Toner concentration sensor assembly for electro-photographic apparatus
Inventor:
Richard C. Fedder
Patented Case
View Patent ↗
Granted: Jun 5, 1984
Filed: Aug 22, 1983
Inventor
Richard C. Fedder
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.