Television transmission system including encoder and decoder compatible with current television standards having a 4:3 aspect ratio

A system for processing a television signal containing wide aspect ratio information compatible with a standard television signal containing image information having an aspect ratio less than that of said compatible television signal, said system comprising:

• means for providing a widescreen television signal having an image aspect ratio greater than said standard aspect ratio, said widescreen television signal (a) occupying a frequency spectrum including a first carrier modulated with first image information defining a first modulation band, and (b) containing vacated spatial areas along upper and lower edges of an image defined by lines remaining after lines are separated from groups of a prescribed number of successive lines within an image scanning interval, said separated lines being inserted into said vacated spatial areas;
• means for temporally expanding active image portions of said separated lines;
• means for modulating a second carrier with said time expanded portions of said separated lines to produce a second modulation band disposed in an upper portion of said frequency spectrum, said second modulation band subject to being suppressed in a standard television receiver for processing a standard aspect ratio television signal;
• means for modulating said first carrier with nonactive portions of said separated lines and with said remaining lines so that said first modulation band is within a passband of said standard receiver for processing by said standard receiver as said standard television signal;
• means for modulating a third carrier with audio information;
• and
• means for combining said modulated first, second and third carriers for transmission.