US 4,059,838 A · Chroma-preference control for VIR automatic operation

Abstract

Viewer preference adjustment of saturation is realized in a VIR controlled color television receiver by provision of a closed loop control circuit exclusive of the RGB matrix. During the presence of the VIR signal a control signal is generated within the closed loop that controls the chrominance to luminance ratio of the chrominance and luminance signals applied to the RGB matrix and to the blue matrix contained within the closed loop. Adjustment of the level of either the luminance signal or the chrominance signal applied to the blue matrix affects the control signal which in turn adjusts said chrominance to luminance ratio to compensate and thereby brings about a shift in the levels of the red, green and blue signals outputted by the RGB matrix to change the saturation of the color picture.

Claims7

Dependent claims

In a color television receiver, an automatic saturation control circuit responsive to a VIR signal comprising:

means for providing a luminance signal,
means for providing a color difference signal from a chrominance signal,
control means responsive to both said luminance signal and said color difference signal during receipt of said VIR signal for governing the chrominance to luminance matrix ratio of said receiver, and
means to enable a viewer to preferentially control the level of at least one of said luminance and said color difference signals to vary said chrominance to luminance matrix ratio.

1 more element

In a color television receiver responsive to a VIR signal, an automatic chroma control circuit comprising:

means for providing a luminance signal,
means for providing color difference signals from a chrominance signal,
matrix means responsive to said color difference signals and to said luminance signal to provide color signals for the color picture of said television receiver,
means for providing a sample of said luminance signal,
a closed loop video control circuit responsive to said sample luminance signal and to a selected one of said color difference signals during the presence of said VIR signal to provide a control signal,
said closed loop video control circuit including means responsive to said control signal to adjust the ratio of said chrominance signal to said luminance signal, such that the ratio of said selected color difference signal to said sample luminance signal remains in accordance with said VIR signal,
preference means within said closed loop video control circuit for adjusting the level of at least one of said sample luminance and selected color difference signals such that said control signals shifts the ratio of said chrominance signal to said luminance signal to maintain the ratio of said selected color difference signal to said sample luminance signal thereby causing a saturation shift in said color signals.

4 more elements

Dependencies are inferred from the claim text.

Chroma-preference control for VIR automatic operation

Life of this patent

Chroma-preference control for VIR automatic operation

Life of this patent

Abstract

Claims7