Granted Patent
Utility
US 4,963,456 · App. 07/320,301
Electrophotographic toner
Inventors:
Masaaki Shin, Nobuhiro Hirayama, Keiichi Ishikawa, Akira Misawa
Patented Case
View Patent ↗
Granted: Oct 16, 1990
Filed: Feb 22, 1989
Inventors
Masaaki Shin
Nobuhiro Hirayama
Keiichi Ishikawa
Akira Misawa
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
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.