Monochrome-compatible color slow scan television system

Claim 3

A system according to Claim 1, further comprising means for storing a line of the luminance information signal and for retrieving the stored line of the luminance information signal over an interval corresponding to a slow scan video visible line interval to provide the luminance information signal that is sequentially combined with the chrominance information signal; means for alternately storing either a line of the Eirst color difference signal or a line of the second color difference signal simultaneously with the storage of each line of the luminance information signal and for alternately retrieving the stored lines of the first and second color difference signals during the interval between successive intervals of retrieval of the stored lines of the luminance information signal to provide the first and second color difference signals that are time-division-multiplexed.

Claim 4

A system according to Claim 2, further comprising means for providing line sync pulses at the slow scan video line rate; and means for providing chrominance sync pulses at the slow scan video line rate and delayed from the line sync pulses by the duration of the slow scan video visible line interval; wherein the means for combining the luminance information signal and the chrominance information signal are responsive to the sync pulses for providing the luminance information signal in the slow scan video visible iline interval following the line sync pulse and for providing the chrominance information signal in the interval following the chrominance sync pulse prior to the next line sync pulse.

Claim 5

A system according to Claim 3, further comprising means for providing a chrominance ID signal to indicate whether the first or second color difference signal is being retrieved; and means for frequency modulating the composite slow scan video signal to include a chrominance ID component at either a first or second frequency during the chrominance sync pulse in accordance with the indication of the chrominance ID signal.

Claim 8

A system according to Claim 5, wherein the segregating means include means for storing an odd-numbered line of the luminance information signal from every other line of the composite slow scan video signal beginning with the first line in each frame of the composite slow scan video signal and for retrieving the stored odd-numbered line of the luminance information signal during the next even-numbered visible line interval of the composite slow scan video signal; means for storing an even-numbered line of the luminance information signal from every other line of the composite slow scan video signal beginning with the second line in each frame of the composite slow scan video signal and for retrieving the stored even-numbered line of the luminance information signal during the next odd-numbered visible line interval of the composite slow scan video signal; and means for storing the color difference signal from every line of the composite slow scan video signal and for retrieving the stored color difference signal during the next visible line interval of the composite slow scan video signal.

Claim 9

A system according to Claim 6, further comprising means for delaying the retrieved color difference signal by the duration of one slow scan video signal line to provide a one-line-delayed color difference signal; means for further delaying the one-line-delayed color difference signal by the duration of an additional slow scan video signal line to provide a two-line-delayed color difference signal; means for averaging the retrieved color difference signal with the two-line-delayed color difference signal to provide an averaged first or second color difference signal during the same interval that a one-line-delayed second or first color difference signal is provided respectively.

Claim 10

8 . A system according to Claim 7, wherein the composite slow scan video signal includes a chrominance ID component at either a first or second frequency to indicate whether the first or second color difference signal is being retrieved, the system further comprising means for demodulating the composite slow scan video signal to provide a chrominance ID signal indicating whether the first or second color difference signal is being retrieved; means for multiplexing the averaged color difference signal and the one-line-delayed color difference signal in accordance with the chrominance ID signal to provide the averaged color difference signal to the recombining means when the first color difference signal is being retrieved and to provide the one-line-delayed color difference signal to the recombining means when the second color difference signal is being retrieved; and means for multiplexing the averaged color difference signal and the one-line-delayed color difference signal in accordance with the chrominance ID signal to provide the averaged color difference signal to the recombining means when the second color difference signal is being retrieved and to provide the one-line-delayed color difference signal to the recombining means when the first color difference signal is being retrieved.

Claim 11

A system according to Claim 8, further comprising means for delaying the retrieved luminance information signals by the duration of one slow scan video signal line and to provide the delayed luminance information signals to the recombining means.

Claim 12

A system according to Claim 7, further comprising means for delaying the retrieved luminance information signals by the duration of one slow scan video signal line and to provide the delayed luminance information signals to the recombining means.

Claim 15

A method according to Claim 11, further comprising the steps of (f) storing a line of the luminance information signal and for retrieving the stored line of the luminance information signal over an interval corresponding to a slow scan video visible line interval to provide the luminance information signal that is sequentially combined with the chrominance information signal in step (e); (g) alternately storing either a line of the first color difference signal or a line of the second color difference signal simultaneously with the storage of each line of the luminance information signal and for alternately retrieving the stored lines of the first and second color difference signals during the interval between successive intervals of retrieval of the stored lines of the luminance information signal to provide the first and second color difference signals that are time-division-multiplexed in step (d).

Claim 16

A method according to Claim 12, further comprising the steps of (h) providing line sync pulses at the slow scan video line rate; and (i) providing chrominance sync pulses at the slow scan video line rate and delayed from the line sync pulses by the duration of the slow scan video visible line interval; wherein in step (e) the luminance information signal and the chrominance information signal are responsive to the sync pulses for providing the luminance information signal in the slow scan video visible line interval following the line sync pulse and for providing the chrominance information signal in the interval following the chrominance sync pulse prior to the next line sync pulse.

Claim 17

A method according to Claim 13, further comprising the steps of (j) providing a chrominance ID signal to indicate whether the first or second color difference signal is being retrieved; and (k) frequency modulating the composite slow scan video signal to include a chrominance ID component at either a first or second frequency during the chrominance sync pulse in accordance with the indication of the chrominance ID signal.

Claim 20

A method according to Claim 15, wherein step (a) includes the steps of (c) storing an odd-numbered line of the luminance information signal from every other line of the composite slow scan video signal beginning with the first line in each frame of the composite slow scan video signal and for retrieving the stored odd-numbered line of the luminance information signal during the next even-numbered visible line interval of the composite slow scan video signal; (d) storing an even-numbered line of the luminance inrormation signal from every other line of the composite slow scan video signal beginning with the second line in each frame of the composite slow scan video signal and for retrieving the stored even-numbered line of the luminance intormation signal during the next odd-numbered visible line interval of the composite slow scan video signal; and (e) storing the color difference signal from every line of the composite slow scan video signal and for retrieving the stored color difference signal during the next visible line interval of the composite slow scan video signal.

Claim 21

A method according to Claim 16, further comprising the steps of (f) delaying the retrieved color difference signal by the duration of one slow scan video signal line to provide a one-line-delayed color difference signal; (g) further delaying the one-line-delayed color difference signal by the duration of an additional slow scan video signal line to provide a two-line-delayed color difference signal; (h) averaging the retrieved color difference signal with the two-line-delayed color difference signal to provide an averaged first or second color difference signal during the same interval that a one-line-delayed second or first color difference signal is provided respectively.

Claim 22

A method according to Claim 17, wherein the composite slow scan video signal includes a chrominance ID component at either a first or second frequency to indicate whether the first or second color difference signal is being retrieved, the system further comprising the steps of (i) demodulating the composite slow scan video signal to provide a chrominance ID signal indicating whether the first or second color difference signal is being retrieved; (j) multiplexing the averaged color difference signal and the one-line-delayed color difference signal in accordance with the chrominance ID signal to provide the averaged color difference signal for recombination pursuant to step (b) when the first color difference signal is being retrieved and to provide the one-line-delayed color difference signal for recombination pursuant to step •{b) when the second color difference signal is being retrieved; and (k) multiplexing the averaged color difference signal and the one-line-delayed color difference signal in accordance with the chrominance ID signal to provide the averaged color difference signal for recombination pursuant to step (b) when the second color difference signal is being retrieved and to provide the one-line-delayed color difference signal for recombination pursuant to step (b) when the first color difference signal is being retrieved.

Claim 23

A method according to Claim 18, further comprising the steps of (1) delaying the retrieved luminance information signals by the duration of one slow scan video signal line and providing the delayed luminance information signals for recombination pursuant to step (b).

Claim 24

A method according to Claim 17, further comprising the. steps of (1) delaying the retrieved luminance information signals by the duration of one slow scan video signal line and providing the delayed luminance information signals for recombination pursuant to step (b).