Abstract: A cathode ray tube comprising a curved substantially rectangular display window, the outside surface and/or inside surface of the display window being given by:z=f(X, Y)where each point situated off the x-axis and the y-axis complies with the formula-.sqroot.(z.sub.xx z.sub.yy)<z.sub.xy /signXY<0.wherez.sub.xx =.differential..sup.2 z/.differential.X.sup.2,z.sub.yy =.differential..sup.2 z/.differential.Y.sup.2 andz.sub.xy =.differential..sup.2 z/(.differential.X.differential.Y)signXY=+1 for X*Y>0, andsignXY=-1 for X*Y<0.An improved reflection image of linear light sources is obtained.

Abstract: A method of manufacturing a display tube comprising an envelope having an envelope portion and a display window. The quantity of X-rays released from the envelope portion is determined, after which discrete X-ray absorbing means are provided in those places of the envelope where the quantity of X-rays released exceeds a limiting value. In a display tube manufactured according to such a method and comprising, in particular, a substantially rectangular display screen and a cylindrical neck portion having an electron gun the diagonals of the envelope of which are provided with discrete X-ray absorbing means, the desirable quantity of X-rays is absorbed in a simple and cost-effective manner.

Abstract: In a method of manufacturing a colour television display tube, a reference system is used for adjusting the various components of the tube relative to each other. The system fixes the deflection centre and the electron-optical axis of a deflection device, provided afterwards on the tube, in an early stage of the manufacturing process of the tube. The adjustment of the components is carried out while being referred to the fixed deflection centre or the fixed electron-optical axis. The method simplifies the subsequent positioning of the deflection device on the tube.

Abstract: A color display tube comprising an envelope consisting of a neck, a cone, and a flat or slightly curved display window having a skirt which is substantially parallel to the axis of the envelope. The inner surface of the display window is joined to the inner surface of the skirt via a sharply curved surface. The display window has on its inside a substantially rectangular display screen comprising a material luminescing in at least one color and over which an aluminum film is provided. Means is provided in the neck to generate at least one electron beam. By making the outer periphery of the display window extend substantially parallel to the boundary of the luminescent material of the display window, and by making the camber a'/b' of the sides of the boundary outwards smaller than 0.

Abstract: A color display tube comprising a display window which changes into a skirt which is substantially parallel to the axis of the tube via a strongly curved part. The inner surface of the window changes into the inner surface of the skirt via a strongly curved surface having a radius of curvature r. The outer surface of the window changes into the outer surface of the skirt via a strongly curved surface. The display window comprises on its inside a substantially rectangular display screen and a shadow mask at a short distance in front of the display screen, which mask is supported in the corners of the display window by suspension means fixed in the skirt. In the proximity of the strongly curved transition the skirt has a thickness d. In a plane perpendicular to the tube axis the distance D between the boundary of the luminescent material of the display screen and the outer surface of the skirt throughout the circumference of the window is substantially equally large and for r.ltoreq.

Abstract: A color display tube comprising a faceplate including a display window connected to a skirt which is substantially parallel to the axis of the envelope via a sharply curved transition portion. The set of points defining where the inner surface of the window meets the inner surface of the transition part is formed by a closed line l. The set of points defining where the outer surface of the window meets the outer surface of the transition portion is formed by a closed line m. A display screen of luminescent material provided on the inner surface of the display window has a substantially rectangular boundary which coincides substantially with the line l. A large viewing angle .alpha. is obtained within which no distortion of the picture edge occurs when, from any point Q in the line m, the shortest connection line to the line l encloses with a normal line h (normal to the outer surface of the window) an angle .gamma., for which the relationship holds that:n sin .gamma.=sin (.alpha.-.beta.

Abstract: A display tube comprising an envelope consisting of a neck, a cone, and a faceplate including a flat or slightly curved, substantially rectangular display window and a skirt which is substantially parallel to the axis of the envelope. The skirt and the display window meet at a sharply-curved transition portion of the faceplate. The display window has on its inside a substantially rectangular display screen. The display window and the skirt near the sharply curved portion and over the whole circumference of the display window have a thickness d which to an approximation satisfies the following relationship:d=C D.sup.0.8 R.sup.0.2whereinC is a constant between 0.015 and 0.025,D is the diagonal of the inner surface of the display window, andR is the radius of the curvature of the inner surface of the display window.The tube is implosion-safe and the faceplate has a narrow dark edge which is equally wide substantially everywhere around the display screen.

Abstract: In a method of manufacturing a color television display tube, marks for the positioning of the display window are provided on the funnel part of the tube. Upon providing the marks the funnel part is fixed in a centering device which locates in the funnel part a reference point to which the provision of the marks is referenced. The reference point is situated in or substantially in the deflection center of a deflection device provided afterwards on the funnel part.

Abstract: A cathode ray tube of the shadow mask type for displaying coloured pictures. Colour defects are reduced to a considerable extent by minimizing the influencing as a result of temperature influences of the shape of the shadow mask by the frame in which said shadow mask is mounted by means of supporting means which are resilient in the radial direction.