Granted Patent
Utility
US 5,835,871 · App. 08/785,098
Method and system for diagnosing and reporting failure of a vehicle emission test
Inventors:
Mary Virginia SMITH, Mark Frost
Patented Case
View Patent ↗
Granted: Nov 10, 1998
Filed: Jan 21, 1997
Inventors
Mary Virginia SMITH
Mark Frost
Assignee (at issue)
Envirotest Systems Holdings Corp.
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.