FERNSEHEMPFAENGER MIT BILDSCHIRMTEXTEMPFANGSFUNKTION UND VERFAHREN ZUM UEBERLAGERN EINES BILDSCHIRMTEXTBILDS ZU EINEM FERNSEHBILD

摘要

Teletext data stored in a video RAM is developed in a work RAM. A CPU selectively deletes picture elements from the developed teletext data, to thereby compress the teletext data into data adapted for display in an auxiliary screen which is e.g., 1/4 of the display screen of a CRT. The compressed teletext data is written into the video RAM. A display controller supplies the compressed teletext data stored in the video RAM to a synthesizing circuit, together with an appropriate display switching signal representing a timing for switching between the compressed teletext data and a TV broadcast video signal. In accordance with the display switching signal, the synthesizing circuit selectively supplies the TV broadcast video signal and the compressed teletext data to a video output circuit. Accordingly, the teletext picture compressed to a 1/4 size is displayed on the display screen of the CRT as an auxiliary screen image, while being superimposed on the TV picture.