Granted Patent
Utility
US 4,213,692 · App. 06/001,055
Bias voltage switching circuit for controlling concentration of image in copying apparatus
Inventors:
Mistuo Akiyama, Shunichi Abe
Patented Case
View Patent ↗
Granted: Jul 22, 1980
Filed: Jan 5, 1979
Inventors
Mistuo Akiyama
Shunichi Abe
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.