| 摘要 |
The proposed system makes possible the covering of communication needs for people at locations where receiving messages by usual means (television, radio, etc.) are difficult. The system is comprised of a Central Station (11) from which information messages are transmitted and channelled to the system by computer (12). Message transmission to Isolated Units is accomplished with hertzian electromagnetic waves and is encoded. At the Isolated Units (13) of the system, reception and demodulation of the signal is followed by decoding and processing. Every remote unit can have a special key code so that activation only occurs upon its receipt (multi-channel transmission). The final message appears in a lighted matrix (15, 31) where any type of characters and figures can be displayed, while for long messages, the shift technique is used. |
