Granted Patent
Utility
US 4,166,148 · App. 05/824,447
Photomask blanks and photomasks prepared therefrom
Inventor:
Kunio Sakurai
Patented Case
View Patent ↗
Granted: Aug 28, 1979
Filed: Aug 15, 1977
Inventor
Kunio Sakurai
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.