Granted Patent
Utility
US 6,220,704 · App. 09/485,573
Progressive power lens
Inventors:
Hiroyuki Mukaiyama, Akira Komatsu
Patented Case
View Patent ↗
Granted: Apr 24, 2001
Filed: Feb 14, 2000
Inventors
Hiroyuki Mukaiyama
Akira Komatsu
Assignee (at issue)
SEIKO EPSON CORPORATION
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.