Granted Patent
Utility
US 5,202,450 · App. 07/589,372
Phthalic acid derivative metal salt and shading and light-responsive plate containing the metal salt
Inventors:
Toshimi Satake, Tomoaki Nagai, Hiroshi Fukui, Miyuki Yokoyama, Akio Sekine
Patented Case
View Patent ↗
Granted: Apr 13, 1993
Filed: Sep 27, 1990
Inventors
Toshimi Satake
Tomoaki Nagai
Hiroshi Fukui
Miyuki Yokoyama
Akio Sekine
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.