Screen automatic expanding display apparatus for wide screen television

摘要

An improved screen automatic expanding display apparatus for a wide screen television capable of detecting a wide screen signal and a character signal from a broadcasting station, moving the character signal to an active video region, and automatically expanding and displaying a reflection, which includes a trapping circuit (206) for removing a carrier component of a color signal from an externally applied combined picture signal so as to extract a brightness signal; a clamping circuit (207) for outputting a brightness signal having a predetermined level outputted from the trapping circuit; a level comparison circuit (208) for comparing the brightness signal outputted from the clamping circuit with a reference voltage; and a signal judging circuit (209) for judging a wide screen signal type contained in the combined picture signal outputted in accordance with a signal outputted from the level comparison circuit, for transmitting a control signal corresponding to the judgement to a deflection controller (202), and for varying horizontal and vertical synchronous signals, so that a watcher of the television can enjoy quality resolution by improving the resolution of the screen.