Granted Patent
Utility
US 4,731,292 · App. 06/930,777
Magnetic recording medium
Inventors:
Kunitsuna Sasaki, Yoshitaka Yasufuku, Toshiaki Shibue, Kazumasa Matsumoto
Patented Case
View Patent ↗
Granted: Mar 15, 1988
Filed: Nov 14, 1986
Inventors
Kunitsuna Sasaki
Yoshitaka Yasufuku
Toshiaki Shibue
Kazumasa Matsumoto
Assignee (at issue)
Konishiroku Photo Industry 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.