Color television receiver

Claim 2

A color television receiver, comprising: amplifying means for amplifying a carrier chrominance signal; subcarrier generating means for generating a continuous subcarrier to demodulate said carrier chrominance signal; gate circuit means having a first signal corresponding to said carrier chrominance signal as a first input signal and a second signal corresponding to said subcarrier as a second input signal, the output of said gate circuit means increasing as the phase difference between said first and second input signalS decreases and decreasing as the phase difference between said first and second input signals increases, the phase of said output increasing in correspondence with the increasing phase difference between said first and second input signals; phase shifting means for shifting the phase of said subcarrier to maintain a predetermined phase relation between said carrier chrominance signal and said subcarrier for a specific hue signal before being applied to said gate circuit means; adding means for adding the output of said gate circuit means to the output of said subcarrier generating means; and demodulating means for demodulating said carrier chrominance signal by the output of said adding means, said carrier chrominance signal being applied to said demodulating means without any change of phase.

Claim 3

A color television receiver according to claim 1, in which an amplitude limiter is inserted between said amplifying means and said gate circuit means.

Claim 4

A color television receiver according to claim 1, wherein said phase shifting means is connected between said amplifying means and said gate circuit means to correspond the phase of a signal corresponding to said specific hue signal to the phase of said subcarrier.

Claim 5

A color television receiver according to claim 1, wherein said gate circuit means comprises: a transistor having base, emitter and collector electrodes, the carrier chrominance signal from the output of said amplifying means being applied to said base electrode as an input signal, an output signal appearing at said collector electrode; a bridge rectifier comprising four diodes, said emitter electrode being connected to the anode-cathode junction of one pair of said diodes, the anodecathode junction of a second pair of said diodes being connected to ground; and further comprising means for applying the phase shifted subcarrier from the output of said phase shifting means across the anode-cathode junctions of third and fourth pairs of said diodes.

Claim 6

A color television receiver according to claim 4, in which said subcarrier is applied to said rectifier through a parallel circuit comprising a resistor and a capacitor.

Claim 7

A color television receiver according to claim 4, further comprising means for applying a constant bias to said base electrode for maintaining said transistor in a conductive state when said carrier chrominance signal is applied to said transistor when said bridge rectifier is in a conductive state and for maintaining said transistor in a non-conductive state when said carrier chrominance signal is absent from said transistor in the conductive state of said bridge rectifier.

Claim 8

A color television receiver according to claim 1, wherein the phase of said specific hue signal is the phase of said carrier chrominance signal corresponding to flesh tint.

Claim 9

A color television receiver, comprising: amplifying means for amplifying a carrier chrominance signal; subcarrier generating means for generating a continuous subcarrier to demodulate said carrier chrominance signal; gate circuit means having a first signal corresponding to said carrier chrominance signal as a first input signal and a second signal corresponding to said subcarrier as a second input signal, the output of said gate circuit means increasing as the phase difference between said first and second input signals decreases and decreasing as the phase difference between said first and second input signals increases, the phase of said output increasing in correspondence with the increasing phase difference between said first and second input signals; first phase shifting means connected between said subcarrier generating means and said gate circuit means for shifting the phase of said subcarrier to maintain a predetermined phase relation between said carrier chrominance signal and said subcarrier for a specific hue signal before being applied to said gate circuit means; second phase shifting means for shifting the phase of the output oF said gate circuit means so that the phase of a maximum output of said gate circuit means corresponding to the phase said specific hue signal corresponds with the phase of said subcarrier; adding means for adding the output of said second phase shifting means to the output of said subcarrier generating means; and demodulating means for demodulating said carrier chrominance signal by the output of said adding means.

Claim 10

A color television receiver, comprising: amplifying means for amplifying a carrier chrominance signal; subcarrier generating means for generating a continuous subcarrier to demodulate said carrier chrominance signal; gate circuit means having a first signal corresponding to said carrier chrominance signal as a first input signal and a second signal corresponding to said subcarrier as a second input signal, the output of said gate circuit means increasing as the phase difference between said first and second input signals decreases and decreasing as the phase difference between said first and second input signals increases, the phase of said output increasing in correspondence with the increasing phase difference between said first and second input signals; first phase shifting means connected between said subcarrier generating means and said gate circuit means for shifting the phase of said subcarrier to maintain a predetermined phase relation between said carrier chrominance signal and said subcarrier for a specific hue signal before being applied to said gate circuit means; second phase shifting means for shifting the phase of the output oF said gate circuit means so that the phase of a maximum output of said gate circuit means corresponding to the phase said specific hue signal corresponds with the phase of said subcarrier; adding means for adding the output of said second phase shifting means to the output of said subcarrier generating means; and demodulating means for demodulating said carrier chrominance signal by the output of said adding means.