Granted Patent
Utility
US 6,638,675 · App. 10/141,959
Black magnetic toner
Inventors:
Kazuyuki Hayashi, Hiroko Morii, Yasuyuki Tanaka, Seiji Ishitani
Patented Case
View Patent ↗
Granted: Oct 28, 2003
Filed: May 10, 2002
Inventors
Kazuyuki Hayashi
Hiroko Morii
Yasuyuki Tanaka
Seiji Ishitani
Assignee (at issue)
TODA KOGYO CORP.
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.