Television signal transmission system
First Claim
Patent Images
1. Method for generating a color television signal comprising:
- (a) a first step of providing a luminance signal and a color signal of a video signal;
(b) a second step of modulating a first subcarrier by said color signal in order to obtain a modulated color signal;
(c) a third step of modulating a second subcarrier by one part of said luminance signal to obtain a modulated luminance signal; and
(d) a fourth step of multiplexing another part of said luminance signal, said modulated color signal and said modulated luminance signal;
wherein the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just over said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said second subcarrier on a scanning line just over said current scanning line and delayed by about one field period.
1 Assignment
0 Petitions
Accused Products
Abstract
A television signal transmission system is improved to be able to transmit a video signal having a frequency band wider than existing transmission frequency bands while maintaining compatibility with existing television systems. On the sending side, a wide-band luminance signal is frequency-shifted and inserted into a vacant frequency spectrum of a television signal in the existing television systems before transmission.
43 Citations
23 Claims
-
1. Method for generating a color television signal comprising:
-
(a) a first step of providing a luminance signal and a color signal of a video signal; (b) a second step of modulating a first subcarrier by said color signal in order to obtain a modulated color signal; (c) a third step of modulating a second subcarrier by one part of said luminance signal to obtain a modulated luminance signal; and (d) a fourth step of multiplexing another part of said luminance signal, said modulated color signal and said modulated luminance signal; wherein the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just over said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said second subcarrier on a scanning line just over said current scanning line and delayed by about one field period. - View Dependent Claims (2, 12)
-
-
3. A color television signal generating apparatus comprising:
-
(a) first means for obtaining a luminance signal and a color signal of a video signal; (b) first modulating means for modulating a first subcarrier by said color signal in order to obtain a modulated color signal; (c) second modulating means for modulating a second subcarrier by one part of said luminance signal to obtain a modulated luminance signal; and (d) multiplexing means for multiplexing another part of said luminance signal, said modulated color signal and said modulated luminance signal; wherein the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just over said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said second subcarrier on a scanning line just over said current scanning line and delayed by about one field period. - View Dependent Claims (4, 5, 6, 7)
-
-
8. A television signal transmission system comprising:
-
(a) sending means including means for modulating a first subcarrier by a color signal in order to obtain a modulated color signal and means for modulating a second subcarrier by one part of a luminance signal having a frequency higher than a predetermined frequency to convert the one part of said luminance signal into a television signal having a frequency lower than said predetermined frequency; (b) transmission means for transmitting at least said signal having a frequency lower than said predetermined frequency; and (c) receiving means for demodulating the luminance signal having a frequency higher than the predetermined frequency through processing reverse to the modulation carried out in the sending means; wherein the means for modulating said second subcarrier by said one part of said luminance signal and the means for modulating said first subcarrier by said color signal enable modulation so that the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just over said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said second subcarrier on a scanning line just over said current scanning line and delayed about one field period. - View Dependent Claims (9, 10, 11, 20)
-
-
13. Method for reproducing a luminance signal and a color signal from a color television signal, comprising the steps of:
-
(a) providing said color television signal including a modulated color signal obtained by modulating a first subcarrier, a modulated information signal obtained by modulating a second subcarrier and a luminance signal; and (b) demodulating to obtain one part of said luminance signal and a color signal; wherein the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just cover said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said second subcarrier on a scanning line just over said current scanning line and delayed by about one field period. - View Dependent Claims (14, 15)
-
-
16. A color television receiver comprising:
-
(a) signal receiving means for receiving a received color television signal including a modulated color signal having a first subcarrier, a modulated luminance signal having a second subcarrier, and a first luminance signal having a horizontal frequency lower than a predetermined horizontal frequency; (b) means for separating said modulated luminance signal from said color television signal; (c) demodulating means for demodulating said modulated luminance signal to obtain a second luminance signal; and (d) means for separating and demodulating said modulated color signal from said color television signal to obtain a color signal; wherein the phase of at least said first subcarrier changes by substantially 180°
every scanning line of said television signal, the phase of said first subcarrier on a current scanning line being substantially equal to that of said first subcarrier on a scanning line located just over said current scanning line and delayed by about one field period from said current scanning line, the phase of said second subcarrier on said current scanning line being substantially 180°
out of phase to that of said subcarrier on a scanning line just over said current scanning line and delayed by about one field period. - View Dependent Claims (17, 18, 19, 21, 22, 23)
-
Specification