Patent ID: 6998765

Claim:
A color cathode ray tube comprising: a panel installed at a front surface of the cathode ray tube; a shadow mask for selecting a color of an electron beam emitted from an inside of the panel; a funnel engaged to a rear surface of the panel for maintaining a vacuum state inside the cathode ray tube; a deflection yoke surrounding an outer side of the funnel for deflecting the electron beam; and an electron gun formed behind the funnel, wherein a curvature coefficient (a/b) of the shadow mask is in a range of about 70,000–200,000, where a curvature formula of the shadow mask is defined as a polynomial of Z(X,Y)=aX 2 +bX 4 +cY 2 +dY 4 +eX 2 Y 2 +fX 4 Y 2 +gX 2 Y 4 , and where X and Y are defined as arbitrary coordinate points of a horizontal axis (long axis) and a vertical axis (short axis).