Telephone voice frequency response system for message recording
US4122307A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 10, 1977 |
| Grant date | Oct 24, 1978 |
| Priority date | — |
| Expiry date | Aug 10, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A voice frequency response system consisting of a central voice frequency response device and a thermal unit, the central voice frequency response device including means for confirming a specific code allotted to the thermal unit, a PB signal receiver, a message drum and a trunk, and the terminal unit including a recorder recording message information transmitted from the central voice frequency response device, a PB signal oscillator, and a push button dial generating the specific code applied to the central voice frequency response device. In the system, a signal consisting of the combination of three frequencies in the voice frequency band is recorded on a portion of the message drum to be selectively applied to the terminal unit prior to transmission of important message information. The terminal unit includes a filter which detects this three-frequency signal so that the recorder is actuated by the output signal of the filter. In the terminal unit, a signal is generated in response to the normal operation of the recorder for actuating the PB signal oscillator. This PB signal is received by the PB signal receiver in the central voice frequency response device, and the central v…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.