DYNAMIC S-CORRECTION

摘要

A simple and cheap dynamic S-correction circuit compensates the higher order errors like the so-called moustache effect and the inner linearity distortion. This is achieved in a known way by connecting an additional proper tuned S-capacitor in parallel with the original one during the start and end of the scan interval. Duty cycle modulation of the on/off times as a function of the frame compensates the inner-pin distortion (also called inner-linearity or modulated S-correction). In accordance with the invention, the duty cycle or the switch on and off instants required to compensate the horizontal distortion or moustache effect is derived by comparing the AC parabolic waveform generated on the S-capacitors with a DC-voltage. Duty-cycle modulation required for compensation of the inner-pin distortion is, in this way, atomically obtained.