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:
Dec. 04, 1990
Filed:
Jun. 15, 1989
Jeff M Wimsatt, Aptos, CA (US);
Frederick P DeKalb, Ben Lomond, CA (US);
Gary L Sanders, Saratoga, CA (US);
Robert J Bernardi, Scotts Valley, CA (US);
Plantronics, Inc., Santa Cruz, CA (US);
Abstract
An electronic telephone set for use with a telephone headset receiver/transmitter apparatus is disclosed. The telephone set is line-powered, and is capable of transmit muting, last number re-dial, and memory dialing. The volume of the received voice signal is controllable by a user, and a visual indication of the volume setting is provided. The receiver and transmitter amplifiers includes circuitry for compensating for the frequency response characteristics of two or more headsets, the compensation circuitry being selectively and automatically engaged by means of a programmable connecting jack. The design of the telephone is such that it consumes very little power, especially during 'on-hook' operation. Moreover, an electrical storage device is employed to provide continuous operational power to the dialer circuitry and electronic hook-switch control circuitry, so that the telephone set retains its dialing memory when not in use. Bell tap suppression circuitry is included to prevent the ringer from responding to sporadic voltage transients on the transmission lines, allowing the telephone can be installed in parallel with other phones.