Granted Patent
Utility
US 4,707,689 · App. 06/715,278
Adaptive thresholding scheme for optically-based touch screens
Inventors:
Philip Silvano DiPiazza, Dale E. Lynn, Donald J. Weber
Patented Case
View Patent ↗
Granted: Nov 17, 1987
Filed: Mar 25, 1985
Inventors
Philip Silvano DiPiazza
Dale E. Lynn
Donald J. Weber
Assignee (at issue)
AT&T Information Systems American Telephone and Telegraph Company
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.