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:
May. 18, 1982
Filed:
May. 05, 1980
Radamis Botros, Nepean, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A telephone group listening system is one in which one member of an assembled group has a telephone for communication with a remote party while the other members may only listen to the communication through the agency of a loudspeaker. The system is subject to the Larsen effect on call answering or clear down if the telephone handset is normally sited close to the loudspeaker. This effect is overcome by including a proximity switch in the loudspeaker circuit, the switch being triggered by a change in the level of coupling of a capacitively or inductively coupled circuit, the coupling being dependent on the closeness of the speaker's body to the switch or on the separation of the handset and the loudspeaker.