Patent ID: 6650071
Filing Date: 2003-11-18
Classification: H01J

Abstract:
A color display tube (1) comprising an electron gun (10), a display window (3) with a screen (6), and a color selection electrode (12) having a shadow mask (13) positioned between the electron gun (10) and the screen (6), said shadow mask (13), having a center point, a horizontal axis and a vertical axis intersecting at the center point, is provided with a hexagonal pattern of round apertures (20) which are arranged on substantially horizontal (21) and vertical lines (22), characterized in that the apertures (20) on a horizontal line (21) follow a curved trajectory which is a polynomial of order 2n that satisfies equation: y=y0&CenterDot;&Sum;k=0n&it;a2&it;k&CenterDot;x2&it;kin which x is a horizontal coordinate and y is a vertical coordinate measured with respect to the center point, y0 is an intercept of the horizontal line (21) with the vertical axis, a0=1 and a2k are constants for 1&lE;k&lE;n at least one of which is unequal to zero.