Abstract: Cathode ray tube for which the front face is flat and/or for which the deflection angle is greater than 110°. The tube comprises a front panel supporting a luminescent screen surrounded by a flange perpendicular to the panel, the said panel being defined by: a thickness t at the corner of the screen, a distance t1 between the corner of the screen and the free edge of the flange, a rear part in the form of a funnel, whose tapered free edge is arranged at the distance t2 from the reference line of the tube. The tube is characterized by values of t, t1, t2 chosen in such a manner that the ratio A=(t1+/t)/t2 is between the range of values [0.0061?m?7.8 10?6(?m)2±0.05]. for which ?m is expressed in degrees. Hence, the quantity of glass reduced while providing the mechanical strength necessary for resisting the application of a vacuum to the tube.

Abstract: Self-converging cathode ray tube with a deflection angle that is greater than 110°. The tube comprises a front panel supporting a luminescent screen surrounded by a flange perpendicular to the panel, the internal surface of the said panel being defined by radii of curvature Rdi along the diagonal, Rxi along the major axis and Ryi along the minor axis such that: 4?Rdi/d?2 0.8?Ryi/Rdi?0.4 1?Rxi/Rdi?0.7 Hence, the geometric distortion of the picture engendered by the self-converging deflection device is minimized, while enabling the shadow mask equipping such a tube to be less sensitive to thermal interferences.

Abstract: The invention concerns cathode ray tubes with substantially planar front surface, whereof the colour selecting mask is produced by swaging. The mask comprises an active surface enclosed by a solid peripheral edge terminated by a skirt substantially perpendicular to the active surface. In order to rigidify the active surface in a direction parallel to the main axis, the mean radius of curvature of said active surface is greater than the mean radius of curvature of the peripheral edge.

Abstract: Color cathode-ray tube comprising a color selection mask tensioned in at least one direction, the mask having, on its peripheral area, mask-vibration damper means in the form of a coupled oscillator of the type comprising a metal strip whose ends are welded to the surface of the mask and whose central region comes into contact with the surface of the mask by a spring effect.

Abstract: Color cathode-ray tube comprising a color selection mask tensioned in at least one direction, the mask having, on its peripheral area, mask-vibration damper means in the form of a coupled oscillator of the type comprising a metal strip whose ends are welded to the surface of the mask and whose central region comes into contact with the surface of the mask by a spring effect.