Telecommunications device for the hearing impared
US4608457A · kind A · utility
27Cited by
6References
1Claims
0Family size
Inventors
Key dates
| Filing date | Apr 11, 1984 |
| Grant date | Aug 26, 1986 |
| Priority date | — |
| Expiry date | Apr 11, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S379/906
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
This apparatus having means responsive to a dual multifrequency telephone output to provide an electrical signal to an automatic gain control so as to provide preconditioning to a signal for amplification so as to provide an amplified signal to a comparator with visual light source responsive thereto to indicate activity at the other end of the phone line and a tone decoder also receiving the amplified signal to a digital binary code corresponding to the dual tone multifrequency signal received.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.