Granted Patent
Utility
US 5,863,631 · App. 08/813,017
Perpendicular magnetic recording medium and magnetic recording device using the same
Inventors:
Yoshiaki Sonobe, Yoshihiro Ikeda, Hiroshi Uchida, Takashi Toyooka, Yoshiuki Tagashira
Patented Case
View Patent ↗
Granted: Jan 26, 1999
Filed: Mar 6, 1997
Inventors
Yoshiaki Sonobe
Yoshihiro Ikeda
Hiroshi Uchida
Takashi Toyooka
Yoshiuki Tagashira
Assignee (at issue)
International Business Machines Corporation
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.