| 摘要 |
PROBLEM TO BE SOLVED: To realize a vertical output circuit with a low cost which is operated by class D amplification without using a carrier removing low-pass filter. SOLUTION: A ramp wave generating circuit 10 generates a ramp wave where an output level is linearly changed during the generation period of a horizontal fly-back pulse. An error amplifier circuit 12 inputs vertical saw tooth wave and a smoothing signal (g) outputted from an integrator 3 and outputs the difference value of them as an error signal. A comparator 11 compares levels of the ramp wave and the error signal and gives a positive polar pulse and a negative polar pulse to a drive circuit 2. First and second switch elements 4 and 5 are energized by the output pulse of the drive circuit 2 and a switching operation is executed only within a horizontal fly-back period. Thus, the low-pass filter for removing carrier is not required with respect to a vertical deflection coil 6 so that the vertical output circuit where power consumption is saved is realized. |
