Teletext decoder comprising a decoding circuit (45) and a memory medium (46) in which a reception indication is stored for the transmitted pages so as to indicate whether a requested page is present or not present in a transmitted cycle. The teletext decoder is adapted to determine the duration of the...http://www.google.com.tw/patents/US5038212?utm_source=gb-gplus-share專利 US5038212 - Teletext decoder and receiver for television signals for receiving cyclically transmitted teletext pages
