Granted Patent
Utility
US 4,734,574 · App. 06/942,819
Light-projecting and-receiving unit for use in a human body detecting apparatus for automatic doors
Inventor:
Tamotsu Tanaka
Patented Case
View Patent ↗
Granted: Mar 29, 1988
Filed: Dec 17, 1986
Inventor
Tamotsu Tanaka
Assignee (at issue)
Yoshida Kogyo K.K.
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.