Method of adjusting white balance of CRT display, apparatus for same, and television receiver

An apparatus for adjusting a white balance of a CRT display system, comprising:

• level adjustment means receiving a color video signal for adjusting a ratio of a tip level of a synchronous signal and a pedestal level of the video signal in accordance with the application of an adjustment mode signal so that the level of the synchronous signal is minimized and outputting a R, G or B color video signal;
• drive adjustment means for changing an amplitude of the respective R, G or B color video signal from the level adjustment means;
• background voltage adjustment means connected to the drive adjustment means, for clamping the ratio of the tip level of the synchronous signal and the pedestal level of the video signal at an adjusted reference level;
• and
• signal connecting means for connecting an adjusted signal from the background voltage adjustment means to a cathode electrode of a CRT in the CRT display system.

A television receiver which has a white balance adjustment circuit for a color CRT display system comprising:

• first circuit means for minimizing a ratio of a level of a synchronous tip of a synchronizing portion of an input video signal and a level of a video portion of the input video signal;
• second circuit means for varying a magnitude of a signal output from the first circuit means;
• signal output amplification means for amplifying a signal output from the second circuit means;
• third circuit means for supplying an output of the amplification means as a control voltage of a color CRT display unit of the display system through a coupling capacitor;
• fourth circuit means connected to the signal output amplification means through the coupling capacitor for clamping to a predetermined value the ratio of the level of the synchronous tip and the video portion and for outputting the clamped ratio to a cathode electrode of the CRT display unit.