MULTI-SYSTEM VIDEO SIGNAL DEMODULATING APPARATUS

A MULTI-SYSTEM VIDEO SIGNAL DEMODULATING APPARATUS INCLUDES AT LEAST A COLOR SIGNAL PROCESSING UNIT AND A COLOR DISCRIMINATING FUNCTION FOR DEMODULATING A COMPONENT VIDEO SIGNAL FROM VIDEO SIGNALS OF TWO DIFFERENT SYSTEMS OR GREATER. THE MULTI-SYSTEM VIDEO SIGNAL DEMODULATING APPARATUS INCLUDES DETECTING MEANS FOR DETECTING CONTINUITY BETWEEN VERTICAL SYNCHRONIZING SIGNALS OF THE INPUT VIDEO SIGNALS. THE COLOR DISCRIMINATING FUNCTION IS EXECUTED WHEN THE DETECTING MEANS DETECTS A DISCONTINUITY BETWEEN THE VERTICAL SYNCHRONIZING SIGNALS. THE CONTINUITY BETWEEN THE VERTICAL SYNCRONIZING SIGNALS OF THE INPUT VIDEO SIGNALS IS DETECTED. THE COLOR DISCRIMINATING FUNCTION IS EXECUTED WHEN A DISCONTINUITY BETWEEN THE VERTICAL SYNCHRONIZING SIGNAL IS DETECTED UPON CONTINUITY DETECTION. A SYNCHRONIZING SIGNAL OF AN INPUT VIDEO SIGNAL IS DISCRIMINATED. A FREQUENCY OF A COLOR BURST SIGNAL IS DISCRIMINATED BASED ON A RESULT OF THE SYNCHRONIZING SIGNAL DISCRIMINATION. THE COLOR BURST DISCRIMINATION IS EXECUTED OR STOPPED BASED ON A RESULT OF THE COLOR BURST DISCRIMINATION. AN AMPLITUDE OF THE COLOR BURST IS DISCRIINATED BASED ON A RESULT OF THE SYNCHRONIZING SIGNAL DISCRIMINATION. A PHASE OF THE COLOR BURST IS DISCRIMINATED BASED ON A RESULT OF THE AMPLITUDE DETECTION. A TELEVISION SYSTEM OF THE VIDEO SIGNAL IS DISCRIMINATED BASED ON A RESULT OF THE PHASE DETECTION. AN OSCILLATION FREQUENCY OF THE CRYSTAL OSCILLATOR IS DISCRIMINATED BASED ON A DISCRIMINATED RESULT OF THE TELEVISION SYSTEM DISCRIMINATION.FIGURE 1