Moire control of a color display device

A video circuit for a color cathode ray tube which has an inner surface and a plurality of phosphors dots thereon and on which an electric beam is selectively impinged for generating image, responsive to a video signal, against a raster, the video circuit being coupled to a horizontal deflection circuit, comprising:

• a divide-by-2N circuit for generating an activation signal, responsive to a horizontal synchronization signal, N being an integer;
• a horizontal position control circuit having an input terminal adapted to receive a horizontal position control signal for controlling horizontal position of said image relative to the raster, said horizontal position control circuit having a terminal coupled to the horizontal deflection circuit for sinking current therefrom and for changing timing of the horizontal synchronization signal relative to the video signal;
• a horizontal position modulation circuit coupled to said horizontal position control circuit at said current-sinking terminal for micro-adjusting horizontal impingement position of electric beam of a predetermined horizontal scan lines relative to the phosphors dots, responsive to am H-MOIRE control signal and the activation signal, wherein the horizontal position modulation circuit comprises a transistor having an emitter connected in a DC path to ground via a resistor, a base of said transistor is adapted to receive the H-MOIRE control signal, a collector of said transistor is connected to said current-sinking terminal, the horizontal position modulation circuit further includes a switch transistor having a collector connected to the base of said transistor, an emitter connected to ground, and a base, the base of the switch transistor is adapted to receive the activation signal.