Portable keyboard operated telecommunications system
US4471165A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1980 |
| Grant date | Sep 11, 1984 |
| Priority date | — |
| Expiry date | Oct 28, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/066
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A portable handheld battery operated telecommunications terminal (10) is acoustically coupled to a telephone hand set for the transmission and reception of alphanumeric information over ordinary telephone lines. A standard typewriter ASCII keyboard (34) enables the encoding of messages for transmission on a character by character basis (Baudot code) or the entire message to a second communications terminal (10) with the same transmission protocol. A visual display (32) provides a display of data for editing the encoded message prior to transmission and for display of a message received from a second communications terminal (10). A microprocessor (50) is programmed by processor instructions stored in EPROMs (66) and (68) for controlling operation of the communications terminal (10) from entries from the keyboard (34). A transmit audio transducer (76) and receive audio transducer (84) transmit and receive audio tones over ordinary telephone lines in the frequency shift key transmission mode in response to pulses from the programmed microprocessor (50). Random access memories (62) and (64) enable the user to store an entire message for editing prior to transmission, to enter blocks of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.