Patent ID: 7166972
Filing Date: 2007-01-23
Classification: H04N

Abstract:
1. A vertical deflection apparatus supplying a vertical deflection current to a vertical deflection coil to deflect an electron beam in the vertical direction of a screen, comprising: a vertical deflection current output circuit that outputs a vertical deflection current to said vertical deflection coil; a correction circuit that outputs a correction signal periodically changing in a parabolic shape in a horizontal scanning period to correct a north-south pincushion distortion; a modulation circuit that modulates the phase of the correction signal output from said correction circuit in a vertical scanning period; and a superimposition device that superimposes a correction current based on an output signal of said modulation circuit on the vertical deflection current, wherein said correction circuit comprises a folded waveform generator that generates a folded waveform changing in a sawtooth shape in the horizontal scanning period and having a bending point at a level which is half the amplitude thereof, a turn-up waveform generator that generates a turn-up waveform obtained by turning up a portion below the level which is half the amplitude thereof in the folded waveform generated by said folded waveform generator at said bending point, and a correction signal generator that generates said correction signal having a peak corresponding to a turn-up point of said turn-up waveform generated by said turn-up waveform generator.