US and International Patents:

US 7,062,337 Artificial ambiance processing system.

US 4,963,703 Coordinate determining device using spatial filters.

US 4,694,471 Digital data communicating.

US 4,694,124 Digitizing tablet system including a tablet having a grid structure made of two orthogonal sets of parallel uniformly sized and spaced U shaped loops of conductive material.

US 4,644,102 Digitizing tablet system.

US 4,638,119 Position indicating apparatus for use in a digitizing tablet system.

US 4,582,955 Digitizing tablet system including a tablet having a grid structure made of two orthogonal sets of parallel uniformly sized and spaced U shaped loops of conductive material.

US 4,577,057 Digitizing tablet system having stylus tilt correction.

US 4,375,081 Multistage digital filtering utilizing several criteria.

US 4,181,820 Electric reverberation apparatus.

DE 2,719,276 C2 Elektronisches Nachhallgeraet.

CA 1,269,186 A Digital Data Communicating.

DE 2,842,324 A1 Verfahren Zum Unterdruecken Von Stoerenden Seitenbaendern Bei Der Aussendung Von Frequenzmodulierten Signalen Sowie Ein Sendebegrenzer Fuer Einen Frequenzmodulierten Sender Zur Durchfuehrung Dieses Verfahrens.

EP 220,331 A1 Digitizing tablet comprising "U"-shaped loops of conductive material.

EP 218,745 A1 Digitizing tablet system having stylus tilt correction.

EP 196,361 A1 Digitizing tablet system.

EP 182,144 A 2 Position indicating apparatus for use in a digitizing tablet system.