Granted Patent
Utility
US 5,844,657 · App. 08/517,438
Progressive power lens and mold for producing same
Inventor:
Moriyasu Shirayanagi
Patented Case
View Patent ↗
Granted: Dec 1, 1998
Filed: Aug 21, 1995
Inventor
Moriyasu Shirayanagi
Assignee (at issue)
Asahi Kogaku Kogyo Kabushiki Kaisha
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.