Test pattern generator for video recorders with microprocessor and built-in teletext decoder

摘要

To be able to operate a video recorder on a television set, the user must tune the tuner frequency of the television receiver and the frequency of the RF modulator of the video recorder to each other. For this purpose, however, the RF modulator must be modulated with an RF carrier. The invention proposes in the case of microprocessor-controlled video recorders which are already equipped with a teletext decoder using the micro-controller of the video recorder also for making the teletext processor generate a colour test pattern.