Granted Patent
Utility
US 4,415,939 · App. 06/257,608
Head positioning servo for disk drive
Inventor:
Douglas F. Ballard
Patented Case
View Patent ↗
Granted: Nov 15, 1983
Filed: Apr 27, 1981
Inventor
Douglas F. Ballard
Assignee (at issue)
IO-Mega Holding 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.