Granted Patent
Utility
US 5,804,128 · App. 08/818,914
Cylindrical filter and process for producing the same
Inventors:
Satoshi Ogata, Yoshimi Tsujiyama
Patented Case
View Patent ↗
Granted: Sep 8, 1998
Filed: Mar 17, 1997
Inventors
Satoshi Ogata
Yoshimi Tsujiyama
Assignee (at issue)
Chisso 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.