IP Library › Granted Patent US 4,922,528
Granted Patent Utility
US 4,922,528 · App. 07/173,510

Circuitry for recognizing two-tone compound signals in telephone installations

Inventors: Christian Hubert, Rainer Janssen
Patented Case View Patent ↗
Granted: May 1, 1990 Filed: Mar 25, 1988
Inventors
Christian Hubert
Rainer Janssen
Assignee (at issue)
Nixdorf Computer AG

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Quick Facts
Patent No.
US 4,922,528
App. No.
07/173,510
Filed
1988-03-25
Granted
1990-05-01
Kind
A