Color cathode-ray tube

A color cathode-ray tube having a tube axis, a horizontal axis and a vertical axis, these being perpendicular to one another, comprising:

• a face plate having an inner surface;
• a phosphor screen formed on the inner surface of the face plate and including a plurality of groups of red, green and blue phosphor stripes, said phosphor stripes extending across the horizontal axis and being spaced apart therealong;
• means for emitting electron beams toward the phosphor screen, said emitting means including electron guns arranged along the horizontal axis;
• and
• a shadow mask including a curved plate portion facing the inner surface of the face plate and having a plurality of slit apertures allowing passage of electron beams therethrough, the center-to-center interval Px between adjacent slit apertures along the horizontal axis being increased as a first function along the horizontal axis from the center of the shadow mask to the periphery thereof, the center-to-center interval Sx between adjacent slit apertures in peripheral regions remotest from the horizontal axis being increased as a second function different from the first function along the horizontal axis from the center of the shadow mask to the periphery of the shadow mask, the first and second functions being determined such that said phosphor screen has a substantially rectangular shape.