Granted Patent
Utility
US 6,690,137 · App. 10/053,694
Sensorless control system for synchronous motor
Inventors:
Yoshitaka Iwaji, Tsunehiro Endo, Kiyoshi Sakamoto, Yuhachi Takakura
Patented Case
View Patent ↗
Granted: Feb 10, 2004
Filed: Jan 24, 2002
Inventors
Yoshitaka Iwaji
Tsunehiro Endo
Kiyoshi Sakamoto
Yuhachi Takakura
Assignee (at issue)
HITACHI, 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.