Granted Patent
Utility
US 4,422,670 · App. 06/343,840
Color developing sheet for pressure-sensitive recording sheet
Inventors:
Akira Hasegawa, Ippei Shimizu
Patented Case
View Patent ↗
Granted: Dec 27, 1983
Filed: Jan 29, 1982
Inventors
Akira Hasegawa
Ippei Shimizu
Assignee (at issue)
Jujo Paper 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.