Line voltage compensating circuitry for rgb color drive system

Claim 2

In a color television receiver having an RGB color drive system and employing a color cathode ray tube having cathode and control grid electrodes with the control grid electrodes coupled to a substantially constant bias potential, varying line voltage compensating circuitry comprising: an unregulated potential source; video signal source means; color difference signal source means; a plurality of color amplifier stages each AC coupled to said color difference signal source means and DC coupled to said unregulated potential source, said video signal source means, and to a cathode electrode of said color cathode ray tube; and feedback means in the form of an impedance DC coupling a potential from said unregulated potential source to said video signal source means to effect alterations in the DC gain thereof in accordance with the variations in potential of said unregulated potential source whereby said DC gain variations substantially cancel said unregulated potential source variations to effect application of a substantially constant DC potential to said cathode electrode of said color cathode ray tube.

Claim 3

The line voltage compensating circuitry of claim 1 wherein said video signal source includes an amplifier stage having an output electrode coupled to said color amplifier stages and an input electrode coupled by said feedback means to said unregulated potential source.

Claim 4

The line voltage compensating circuitry of claim 1 wherein said color amplifier stages are each in the form of an electron device having a first input circuit coupled to said color difference signal source means, a second input circuit coupled to said video signal source means, and an output circuit coupled to said unregulated potential source, said video signal source means and said cathode electrode of said color cathode ray tube.

Claim 5

The line voltage compensating circuitry of claim 1 wherein said impedance of said feedback means is in the form of a resistor.

Claim 6

Varying line voltage compensating circuitry for a color television receiver utilizing an RGB color drive system having a color cathode ray tube with a plurality of cathode electrodes and control grid electrodes wherein the control grid electrodes are coupled to a substantially constant bias potential source comprising: an unregulated potential source; means for providing video signals; means for providing signals representative of color difference information; a plurality of color amplifier means each coupled to said unregulated potential source, said means for providing video signals, said means for providing signals representative of color difference information, and to a cathode electrode of said color cathode ray tube; and potential feedback means DC coupling said unregulated potential source to said means for providing video signals to effect alterations in DC gain thereof in accordance with alterations in said unregulated potential source whereby potential variations at the cathode electrodes of the color cathode ray tube due to line voltage variations are essentially cancelled by increased DC voltage gain potentials of said video signal source in response to potentials from said potential feedback means.

Claim 7

Varying line voltage compensating circuitry for a color television receiver utilizing an RGB color drive system having a color cathode ray tube with a plurality of cathode electrodes and control grid electrodes wherein the control grid electrodes are coupled to a substantially constant bias potential source comprising: an unregulated potential source; means for providing video signals; means for providing signals representative of color difference information; a plurality of color amplifier means each coupled to said unregulated potential source, said means for providing video signals, said means for providing signals representative of color difference information, and to a cathode electrode of said color cathode ray tube; and potential feedback means DC coupling said unregulated potential source to said means for providing video signals to effect alterations in DC gain thereof in accordance with alterations in said unregulated potential source whereby potential variations at the cathode electrodes of the color cathode ray tube due to line voltage variations are essentially cancelled by increased DC voltage gain potentials of said video signal source in response to potentials from said potential feedback means.

Claim 8

The line voltage compensating circuitry of claim 5 wherein said potential feedback means includes a resistor coupling said unregulated potential source to said means for providing video signals.

Claim 9

The line voltage compensating circuitry of claim 5 wherein each of said plurality of color amplifier means is in the form of an electron device having a first input electrode coupled to said means for providing signals representative of color difference information; a second input electrode coupled to said means for providing video signals; and an output electrode coupled to an electrode of said color cathode ray tube and to said unregulated potential source.