| 摘要 |
<p>The invention relates to a television system in which a telephone network (1) is used for transmitting to a television receiver (2) from a computer (3) messages in the form of packets of information represented visually as pages. The television receiver is provided with control means (5) for transmitting responses via the telephone network and for selecting a page, and the packets of information are stored by the computer in the form of information blocks each comprising a first information packet (7) representing the message of a corresponding page and a second information packet (8) representing data relating to the same page. According to the invention, the information blocks comprise a third information packet (9) arranged to be received by the computer from a remote terminal (10) via the telephone network and to instruct the computer to make such a transmittal that said data are represented visually at the television receiver as information added to said messages in a chosen subfield of said page. In a preferred embodiment, the computer is provided with a physical security monitoring system (11) and arranged to make said transmittal dependent on local events detected by this system.</p> |
