Parabolic-wave shaping circuit for focus-correction

摘要

A focus correcting circuit for a CRT including a parabolic wave outputting circuit for outputting a combined signal of a vertical parabolic wave and a horizontal parabolic wave as an output wave, and a parabolic wave shaping circuit for clipping the output wave making it possible to lower the power supply voltage necessary for outputting the parabolic waveforms. The parabolic wave shaping circuit includes one or more holding circuits for receiving a blanking pulse used to clip a portion of the output wave corresponding to a flyback period of the CRT.