Granted Patent
Utility
US 4,497,878 · App. 06/405,724
Photomask material
Inventors:
Takashi Hatano, Akira Maruyama
Patented Case
View Patent ↗
Granted: Feb 5, 1985
Filed: Aug 6, 1982
Inventors
Takashi Hatano
Akira Maruyama
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.