The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 23, 1982
Filed:
Oct. 16, 1980
Gerhard Kunde, Munich, DE;
Siegfried Schoen, Starnberg, DE;
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
A multifrequency signaling method is provided between a cordless hand set and a base set which normally operates with audio frequency/pulse phase modulation and pulse phase modulation/audio frequency conversion. The cordless hand set is provided with a dialing device and a frequency generator for providing frequency combinations corresponding to dialed digits or special characters. In the base set a monitoring circuit monitors the existence of optical transmission channels between the hand set and the base set and causes disconnection after a loss of such channels for a predetermined interval. The base set also includes a converter for converting the multifrequency signals to dial pulse signals and a special character evaluation circuit for providing corresponding signals to control various functions such as signaling a secretary, through connection of a call and disconnection of a call.