| 摘要 |
PURPOSE:To obtain a monitor device having simple constitution in which picture quality can be improved by switching the polarity of a modulation magnetic field according to a back-and-forth path to modulate a speed according to bidirectional deflection. CONSTITUTION:This device is equipped with a modulating coil 10 which forms the modulation magnetic field for accelerating and decelerating the scanning speed of the beam of a cathode ray tube 2, and speed modulating means 11, 12, and 21-26 which obtain a differentiated signal S1 by differentiating a video signal SV1, generate a driving signal by using the differentiated signal S1 as a reference, and drive the modulating coil 10 by impressing the driving signal to the modulating coil 10. Then, the polarity of the driving signal to be impressed to the modulating coil 10 is switched by the speed modulating means 11, 12, and 21-26 according to the scanning of the back-and-forth path. Thus, the polarity of the driving signal to be impressed to the modulating coil 10 is switched according to the scanning of the back-and-forth path, so that even when the scanning direction is switched on the back-and-forth path, the scanning speed of the beam of the cathode ray tube 2 can be accelerated and decelerated corresponding to the switching of the scanning direction. |
