Voice mail system on magnetic tape
US4747126A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1986 |
| Grant date | May 24, 1988 |
| Priority date | — |
| Expiry date | Feb 27, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a magnetic tape-based "voice mail" multi-user message system. The system transmits audio prompts to callers to help guide them through the various procedures. The callers respond with Touch-Tone commands. A novel circuit is provided to detect these tone commands without significant interference from the audio prompt signals. This circuit is highly insensitive to deviations in the impedance of the incoming telephone line from its expected value. A circuit is also provided to prevent Touch-Tone commands which are recorded on tape from being re-executed when they are played back from the tape. A single L.E.D. indicator on each recipient's telephone set indicates the status of the system: idle with new message waiting; idle without new message waiting; busy with new message waiting; or busy without new message waiting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.