Granted Patent
Utility
US 4,618,901 · App. 06/515,135
High density magnetic head
Inventors:
Iwao Hatakeyama, Yasushi Maeda, Osamu Ishii, Shizuka Yoshii
Patented Case
View Patent ↗
Granted: Oct 21, 1986
Filed: Jul 19, 1983
Inventors
Iwao Hatakeyama
Yasushi Maeda
Osamu Ishii
Shizuka Yoshii
Assignee (at issue)
Nippon Telegraph and Telephone Public 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.