| 摘要 |
PROBLEM TO BE SOLVED: To enhance the continuity of displayed video image by correcting amplitude of a deflection current so as to suppress an amplitude change caused accompanying circuit temperature drift or the like. SOLUTION: Current transformers 11a, 11b as a detection means 11 detect an amplitude change of a deflection current given to a deflection yoke 2 a current-voltage conversion circuit 12 integrates the detected current to obtain a sawtooth deflection voltage waveform equivalent to that of a deflection current. A comparator circuit 13 compares the sawtooth deflection voltage waveform from the current-voltage conversion circuit 12 with a prescribed voltage waveform that is an optional reference value to generate a correction signal in response to the amplitude change in the deflection current and to give it to horizontal and vertical deflection circuits 6, 7. The horizontal and vertical deflection circuits 6, 7 correct the amplitude of the deflection current based on the correction signal supplied by using, e.g. an amplitude control element. Thus, even when an amplitude change in the deflection current takes place due to temperature drift the amplitude change is suppressed to cause stabilization and the continuity of a displayed video image on a large sized screen consisting of pluralities of CRTs is ensured. |
