METHOD OF PICTURE INFORMATION TRANSMISSION, AS WELL AS AN INFORMATION CARRIER, A PICTURE INFORMATION RECEIVING AND A PICTURE INFORMATION TRANSMITTING DEVICE

摘要

PICTURE INFORMATION INTENDED FOR BEING DISPLAYED ON A PICTURE SCREEN (1) CONTAINS NOT ONLY THE MAIN INFORMATION SUCH AS FILM PICTURES (2), BUT ALSO OVERLAY INFORMATION SUCH AS GRAPHIC INFORMATION (3) OR SUBTITLES (4). THIS IS TRANSMITTED SEPARATELY, ENCODED IN PACKETS OF DIGITAL SYMBOLS IN WHICH A PAGE OF OVERLAY INFORMATION IS REPRESENTED BY A GROUP OF PACKETS. IN THE DISCLOSED METHOD, ALL THE PACKETS RECEIVE IDENTIFICATION INFORMATION (25, 26, 27) CONCERNING THE RELATION OF A PACKET TO THE GROUP. THIS MAKES IT POSSIBLE TO ASCERTAIN WHETHER A PAGE OF OVERLAY INFORMATION HAS BEEN RECEIVED COMPLETELY. THIS AVOIDS INCOMPLETE PAGES OR COMBINATIONS OF PARTS OF PAGES BEING DISPLAYED ON THE PICTURE SCREEN. THIS IS ADVANTAGEOUS IN THE CASE OF INTERRUPTIONS OF PICTURE SIGNAL RECEPTION, SUCH AS A DISTURBED TV SIGNAL, OR WHEN A VIDEO DISC OR TAPE IS USED IN TRICK MODES SUCH AS FAST FORWARD.(FIG. 1C)