| 摘要 |
<p>A television transmitter transmits addditional information in the form of Web pages along with the television signal. The transmission further includes triggers (71) for selectively invoking said Web pages in synchronism with the program. The triggers include (or refer to) a perceptible signal, e.g. a pictogram or an audible beep. In response to receiving a trigger, a receiver reproduces said perceptible signal without substantially disturbing the television screen. The user is thus timely alerted about additional information related to the television program when viewing it. Then, he may or may not invoke the relevant Web page at his own discretion. To inform the public in advance of the triggers that will be broadcast and to provide easy access to the Web pages at an earlier or later stage, the transmission further includes a table of contents (80) identifying the triggers that are being transmitted during the program. The table of contents itself may be invoked by a trigger (70).</p> |
