Automatic tint control circuit

Claim 2

An automatic tint control circuit for a color television receiver adapted to receive a composite color television signal containing a chrominance signal, the phase of which represents hue and the amplitude of which represents color saturation, said circuit comprising: A. Means supplied with the chrominance signal for producing a phase correcting signal when the phase of said chrominance signal is positioned in a predetermined phase range; B. Detecting means for detecting the level of the chrominance signal; C. Means for controlling said phase correcting signal producing means in accordance with a level-detected input of said detecting means so that said phase correcting signal is produced only when the detected level of the chrominance signal is below the maximum level corresponding to the color saturation for flesh tones; and D. Means for adding said phase correcting signal to the chrominance signal to provide the chrominance signal with a predetermined phase corresponding to the hue of flesh tones only when the chrominance signal has its phase positiOned in said predetermined phase qrea and its level below said maximum level.

Claim 3

An automatic tint control circuit in accordance with claim 1, in which said maximum level substantially corresponds to about 30 percent color saturation.

Claim 4

An automatic tint control circuit in accordance with claim 1, in which said phase correcting signal producing means comprises: A. Means for producing a reference signal having a phase corresponding to a predetermined hue; B. Means for reforming the waveform of the chrominance signal; C. Means for phase-detecting the reformed chrominance signal with said reference signal; and D. Means for producing, from the output of said phase-detecting means, a signal of a phase bearing a fixed relation to the phase of said reference signal.

Claim 5

An automatic tint control circuit in accordance with claim 3, in which said predetermined phase range includes the phase of said reference signals and signals within approximately 10* thereof.

Claim 6

An automatic tint control circuit in accordance with claim 4, in which said signal produced from the output of said phase-detecting means is provided with a phase perpendicular to the phase axis of said reference signal.

Claim 7

An automatic flesh tone control circuit for a color television receiver adapted to receive a composite color television signal containing a chrominance signal the phase of which represents hue and the amplitude of which represents color saturation, said circuit comprising: A. Means for producing a reference signal having a phase corresponding to a hue of flesh tone; B. Means for reforming the waveform of the chrominance signal; C. Means for phase-detecting the reformed chrominance signal with said reference signal; D. Means for producing a phase correcting signal from the output of said phase-detecting means when the phase of the chrominance signal is adjacent to the reference signal; E. Means for detecting the level of the chrominance signal; F. Means for controlling said phase-detecting means in accordance with the output of said level detecting means so as to deactivate said phase-detecting means and thereby avoid production of said phase correcting signal when the level of the chrominance signal exceeds thn level corresponding to maximum color saturation for flesh tones; and G. Means for adding said phase correcting signal to the chrominance signal, thereby to provide the chrominance signal with the phase representing proper flesh tone only when the chrominance signal has a phase adjacent to the phase of flesh tone and a level less than said level corresponding to the maximum color saturation for flesh tones.

Claim 8

An automatic flesh tone control circuit for a color television receiver adapted to receive a composite color television signal containing a chrominance signal the phase of which represents hue and the amplitude of which represents color saturation, said circuit comprising: A. Means for producing a reference signal having a phase corresponding to a hue of flesh tone; B. Means for reforming the waveform of the chrominance signal; C. Means for phase-detecting the reformed chrominance signal with said reference signal; D. Means for producing a phase correcting signal from the output of said phase-detecting means when the phase of the chrominance signal is adjacent to the reference signal; E. Means for detecting the level of the chrominance signal; F. Means for controlling said phase-detecting means in accordance with the output of said level detecting means so as to deactivate said phase-detecting means and thereby avoid production of said phase correcting signal when the level of the chrominance signal exceeds thn level corresponding to maximum color saturation for flesh tones; and G. Means for adding said phase correcting signal to the chrominance signal, thereby to provide the chrominance signal with the phase representing proper flesh tone only when the chrominance signal has a phase adjacent to the phase of flesh tone and a level less than said level corresponding to the maximum color saturation for flesh tones.