Compatibility of widescreen and non-widescreen television transmissions

A method of displaying a transmitted widescreen television signal at both a widescreen receiver and a non-widescreen receiver wherein the transmitted signal comprises separate luminance and chrominance signal components, the method comprising the steps of:

• writing the luminance signal components into a first memory device at a first clock rate;
• writing the chrominance signal components into a second memory device at a second clock rate;
• reading the luminance signal components stored in the first memory device at either a third clock rate corresponding to the clock rate for displaying television signals on the non-widescreen receiver or a fourth clock rate corresponding to the product of the third clock rate and the ratio of the aspect ratio of the widescreen receiver to that of the non-widescreen receiver;
• reading the chrominance signal components stored in the second memory device at either a fifth clock rate corresponding to the clock rate for displaying television signals on the non-widescreen receiver or a sixth clock rate corresponding to the product of the fifth clock rate and the ratio of the aspect ratio of the widescreen receiver to that of the non-widescreen receiver;
• and,
• selectively displaying the signals read from the first and second memory devices at the respective receivers.

A method of transmitting a widescreen television signal so as to display a portion of the widescreen television signal without geometric distortion on a non-widescreen television, the method comprising the steps of:

• selecting the portion of the widescreen television signal;
• developing a selection signal representative of the selected portion;
• and
• transmitting the entire widescreen television signal together with the selection signal.

A method of displaying a line of a widescreen line-and-field scanned television signal so as to display the entire line on a widescreen receiver's display and a portion of the entire line on a non-widescreen receiver's display, the method comprising the steps of:

• selecting the portion of the line;
• developing a selection signal representative of the selected portion;
• transmitting the entire line;
• transmitting the selection signal;
• receiving the entire line at the widescreen receiver;
• displaying the entire line on the widescreen receiver's display;
• receiving the entire line and the selection signal at the non-widescreen receiver;
• and
• displaying the portion of the line on the non-widescreen receiver's display according to the selection signal.

A method of transmitting and receiving a composite color television signal having a first aspect ratio for display on both a display screen having the first aspect ratio and a display screen having a second aspect ratio, the method comprising the steps of:

• transmitting the composite color signal at a subcarrier substantially corresponding to the product of the ratio of the first aspect ratio to the second aspect ratio and the horizontal scanning frequency;
• receiving the transmitted composite color signal and demodulating the transmitted signal to baseband;
• selectively displaying the baseband color signal by either
• (a) decoding the baseband color signal for display on the display screen having the first aspect ratio;
• or
• (b)
• (i) time decompressing the baseband color signal by an amount proportional to the ratio of the second aspect ratio to the first aspect ratio;
• and
• (ii) decoding the time decompressed signal for display on the display screen having the second aspect ratio.

A method of displaying a portion of a transmitted line-and-field scanned television signal having a first aspect ratio for display on a television receiver having a second aspect ratio, the method comprising the steps of:

• sampling the transmitted signal at a first clock rate;
• separating the sampled signal into chrominance components and luminance components;
• writing the chrominance components into a first memory means at the first clock rate;
• writing the luminance components into a second memory means at the first clock rate;
• reading the chrominance components from the first memory means at a second clock rate;
• reading the luminance components from the second memory means at a third clock rate;
• developing a display enable signal for enabling a contiguous portion of the chrominance components and a correspondingly contiguous portion of the luminance components to be displayed;
• displaying the contiguous portion of the chrominance and luminance components on the display having the second aspect ratio according to the display enable signal.

A method of converting a composite line-and-field scanned video signal into a signal for display on a widescreen display wherein the signal displayed has a non-widescreen aspect ratio, the steps of the method comprising:

• sampling the composite video signal at a first clock rate, producing digital samples therefrom;
• separating the digital samples into chrominance and luminance components;
• writing the digital chrominance components representing one line into a first memory means at the first clock rate;
• writing the digital luminance components representing one line into a second memory means at the first clock rate;
• alternately reading the chrominance and luminance components from the first and second memory means, respectively, at a second clock rate after a predetermined delay;
• converting the chrominance and luminance components into analog components;
• and
• matrixing the analog components to produce signals representative of color signals for display on a wide-screen display.

A method of converting a composite line-and-field scanned video signal into a signal for display on a widescreen display wherein the picture displayed has a non-widescreen aspect ratio, the steps of the method comprising:

• sampling the composite video signal at a first clock rate, producing digital samples therefrom;
• separating the digital samples into chrominance and luminance components;
• writing the digital chrominance components representing one line into a first memory means at the first clock rate;
• writing the digital luminance components representing one line into a second memory means at the first clock rate;
• alternately reading the chrominance and luminance components at a second clock rate so as to time-compress the components;
• delaying the alternative reading of the components so as to create null components;
• converting the chrominance, luminance and null components into analog components;
• and
• matrixing the analog chrominance and luminance components to produce signals representative of color signals for display on a widescreen display as picture elements and matrixing the null components to produce signals representative of a border for bordering the picture elements.

A method of transmitting and receiving first aspect ratio television signals for display at both a first aspect ratio television receiver and a second aspect ratio television receiver, wherein the transmitted signals comprise separate luminance and chrominance signal components, the method comprising the steps of:

• transmitting the television signals at a sampling frequency proportional to the ratio of the first aspect ratio to the second aspect ratio;
• receiving the luminance and chrominance signal components and writing the luminance signal components into one memory device at a first clock rate;
• writing the chrominance signal components into another memory device at a second clock rate;
• reading the luminance signal components stored in the one memory device at either a third clock rate which represents the clock rate for displaying television signals on said first aspect ratio television receiver or a fourth clock rate corresponding to the product of the third clock rate and the ratio of the second aspect ratio to the first aspect ratio;
• reading the chrominance signal components stored in the other memory device at either a fifth clock rate which represents the clock rate for displaying television signals on said first aspect ratio television receiver or a sixth clock rate corresponding to the product of the fifth clock rate and the ratio of the second aspect ratio to the first aspect ratio;
• and
• selectively displaying at the respective receivers the signals read from said one and said other memory devices.

An apparatus for receiving a widescreen television signal containing luminance and chrominance components occurring at a first frequency and outputting the luminance and chrominance components at a second and a third frequency, respectively, said apparatus comprising:

• a first storage device for storing a line of the luminance components at the first frequency;
• a second storage device for storing a line of luminance components at the first frequency;
• first input switch means for receiving the luminance components and directing the luminance components for storage to said first and second storage devices;
• a third storage device for storing a line of the chrominance components at the first frequency;
• a fourth storage device for storing a line of the chrominance components at the first frequency;
• second input switch means for receiving the chrominance components and alternately directing the chrominance components for storage to said third and fourth storage devices;
• first output switch means for alternately retrieving and outputting the luminance components at the second frequency from said first and second storage devices;
• and
• second output switch means for alternately retrieving and outputting the chrominance components at the third frequency from said third and fourth storage devices.

An apparatus for converting a non-widescreen composite color television signal into a signal for display on a widescreen display, said apparatus comprising:

• A/D converting means for sampling the non-widescreen signal at a first frequency and producing digital samples therefrom;
• filter means for separating the digital video samples into chrominance and luminance component samples;
• storage means for storing the chrominance and luminance component samples at the first frequency;
• selective readout means for selectively reading out a block of chrominance and luminance component samples from said storage means at a second frequency higher than the first frequency;
• delay means for delaying the output of the block of component samples from said storage means for a predetermined time;
• D/A converting means for receiving the chrominance and luminance component samples from said storage means and producing analog signals therefrom;
• and
• matrix means for converting the analog luminance and chrominance signals to a form appropriate for display on the widescreen display.

An apparatus for displaying a transmitted television signal having a first aspect ratio at both a television receiver having a first aspect ratio and a television receiver having a second aspect ratio, wherein the transmitted signal comprises luminance signal components, said apparatus comprising:

• writing means for writing the luminance signal components into a first memory device at a first clock rate;
• reading means for reading the luminance signal components at either a second clock rate which represents the clock rate for displaying the television signals on the television receiver having the second aspect ratio or a third clock rate corresponding to the product of the second clock rate and the ratio of the first aspect ratio to the second aspect ratio;
• and,
• display means for selectively displaying at the respective receivers the signal components read from the first memory device.

An apparatus for transmitting a widescreen television signal so as to display a portion of the widescreen television signal without geometric distortion on a non-widescreen television, said apparatus comprising:

• selection means for selecting the portion of the widescreen television signal;
• signal generating means for developing a selection signal representative of the selected portion;
• and
• transmitter means for transmitting the entire widescreen television signal together with the selection signal.