Loudspeaker telephone
US4493950A · kind A · utility
3Cited by
2References
1Claims
0Family size
Inventor
Key dates
| Filing date | Dec 17, 1982 |
| Grant date | Jan 15, 1985 |
| Priority date | — |
| Expiry date | Dec 17, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A line powered loudspeaker telephone is provided with a lightweight headset and microphone as well as a loudspeaker and second microphone. A first switch is employed to go from the loudspeaker to the headphone and their respective microphones while a second switch is used as a listen-talk switch, preventing acoustical feedback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.