Electronic headset telephone
US4975949A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Jun 15, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.