Data base accessing system
US4700378A · kind A · utility
Inventor
Key dates
| Filing date | Aug 8, 1985 |
| Grant date | Oct 13, 1987 |
| Priority date | — |
| Expiry date | Aug 8, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/085
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Inexpensive communication is provided between a data base and a plurality of subscribers each equipped with only a telephone and a TV set by using only tone signals to communicate from the subscribers to the data base, and data signals at least partially to communicate from the data base to the subscribers. For this purpose, each subscriber location needs to be provided with only the demodulator portion of a modem, and the base location needs to be provided only with the modulator portion of a modem and a tone decoder. A microprocessor-controlled security device is disclosed for remotely disabling a subscriber's module in case of misuse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.