Granted Patent
Utility
US 4,835,134 · App. 07/131,556
Color-developing sheet for pressure-sensitive sheets
Inventors:
Hiroaki Umeda, Mamoru Suzuki, Akira Hasegawa, Kunio Hata
Patented Case
View Patent ↗
Granted: May 30, 1989
Filed: Dec 11, 1987
Inventors
Hiroaki Umeda
Mamoru Suzuki
Akira Hasegawa
Kunio Hata
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.