Abstract: An electron beam device such as a cathode ray tube having an electron gun (15) comprising a profiled tubular body (22) of a vitreous material. At least some of the electrodes (30, 32, 34, 36) of the electron gun comprising cup-shaped drawn metal members which are push fitted against respective engaging surfaces formed in the tubular body (22). Electrical connections to one or more of these cup-shaped members are point contacts made with lead-out wires (38, 40) held captive in the wall of the tubular body (22). In order to ensure a good point contact, at least the area of the wall in the vicinity of the terminal portion of the or each lead-out wire is flat. In consequence thereof a skirted portion of the or each cup-shaped electrode is flattened slightly against the surface of the wall.

Abstract: The invention relates to a cathode ray tube having an envelope 1 comprising a screen 2 and an electron gun 3 which is situated inside the envelope 1 opposite to the screen and which has three electrodes 4, 5 and 6, which electrodes are provided coaxially on the inner wall of a glass tube 7 in adjoining places having diameters differing for each electrode. In order to obtain, for example, smaller dimensions and a better alignment of the electron gun and a higher resolution, a focusing lens associated with the electron gun 3 is a high-ohmic resistance layer 8 having a spiral shape 9.

Abstract: An electron gun for an electron beam device comprises a vitreous elongate tubular body (22) having a plurality of electrodes (24, 27 to 31 and 33 to 37) provided therein. Electrical connections (50, 52, 54) to at least some of these electrodes comprise respective conductors extending within the thickness of the wall of the tubular body (22). The tubular body is made by uniting inner and outer cylindrical members under the influence of heat while drawing them under sub-atmospheric pressure onto a profiled mandril, the electrical connections (50, 52 and 54) having been prepositioned on the inner cylindrical member.

Abstract: An electron beam device such as a cathode ray tube in which spherical aberration is reduced by optimising the axial potential distribution in the focusing lens of the electron gun. In one embodiment of the invention the electron gun comprises a beam forming part and a segmented focusing lens (25). The focusing lens (25) comprises a preformed glass tube (22) having a high-ohmic resistive layer (23) on the interior wall thereof, the resistive layer (23) comprises helical segments (33 to 37) alternated with intermediate segments (42 to 47). A focusing voltage is applied to the intermediate section (42) closest to the beam forming part and a higher voltage is applied to the end segment (47). The lengths of the helical segments (33 to 37) increase in a direction from the point of application of the focusing voltage whereas the lengths of the intermediate segments (42 to 46) decrease. The lengths of the helical segments (33 37) are such as to produce the desired axial potential distribution.

Abstract: An electron tube comprising a window having a radiation-sensitive layer. The window is laid on a bearing surface of an envelope, normal to the tube axis. There is no sealing material in the seam between the bearing surface and the window. The seam is sealed hermetically by a mass of indium or an indium alloy in which a metal wire is embedded along the circumference or the seam. The wire can be soldered with indium or an indium alloy. The seal is made by locally melting the indium or the indium alloy by a heated ultrasonically vibrating heat transfer member. The heat transfer member traverses the circumference of the seam.

Abstract: The invention relates to a method of manufacturing a device in which a homogeneous electrical resistance layer of a resistive material having 10 ohm.cm is formed on an insulating substrate. According to the invention a stable binder-free suspension containing ruthenium hydroxide and glass particles is provided on the insulating substrate from which a ruthenium oxide-containing electrical resistance layer is formed by heating. The method according to the invention may be used successfully, for example, in the manufacture of cathode ray tubes.

Abstract: An electron tube comprising a window having a radiation-sensitive layer. The window is laid on a bearing surface of an envelope normal to the tube axis. There is no sealing material in the seam between the bearing surface and the window. The seam is sealed hermetically by a mass of indium or an indium alloy in which a metal wire is embedded along the circumference of the seam. The wire can be soldered with indium or an indium alloy. The seal is made by locally melting the indium or the indium alloy by a heated ultrasonically vibrating heat transfer member. The heat transfer member traverses the circumference of the seam.

Abstract: A television camera tube comprising in an evacuated envelope, an electron gun for generating at least one electron beam. The electron beam is focused onto a target, and is deflected over the target. A grid electrode having hexagonal apertures is provided in front of the target.The apertures in the grid electrode are arranged in a honeycomb structure. Each aperture has the form of an equilateral hexagon having angles of 120.degree.. As a result, the susceptibility to Moire effects is reduced, the microphonic properties are improved, and the mesh obtained has a high transmissivity while it can more readily be tensioned and is easier to handle.

Abstract: A method of manufacturing a cathode-ray tube is provided by drawing a glass tube section softened by heating onto a mandrel whose transverse dimensions increase near one end of the tube section in the direction of the end at least twice in a generally stepwise manner, so that in the direction of the end, upon drawing, at least a first and a second wall portion of the inner wall of the tube section become located in planes substantially perpendicular to the tube axis. The first wall portion may serve as an engaging surface for an electrode and the second wall portion may serve as an engaging surface for the window. A third drawn wall portion may serve as a reference face of the tube in a device.

Abstract: An electric discharge tube is provided with a hermetically sealed leadthrough which electrically connects electrodes on the inner and outer walls of the envelope. The leadthrough consists of an aperture in the envelope having a conductive layer provided on the wall of the aperture. The aperture is hermetically sealed by means of a plug of thermally devitrified glass which is provided in the form of a suspension of a devitrified glass powder in an organic binder. To manufacture the leadthrough, the envelope of the tube is subjected to temperature treatments in which at a first temperature range the binder is fired from the suspension in an oxygen-containing atmosphere, and at a second temperature range the devitrifiable glass is devitrified in a non-oxidizing atmosphere. A hermetically sealed leadthrough results, without excessive oxidation of the electrodes, while the deformation of the glass envelope at the area of the leadthrough is avoided.

Abstract: In a cathode-ray tube, in particular a camera tube, the inner wall of the glass envelope is coated with an electrically conductive material interrupted in the proximity of electrodes extending transversely to the wall coating and supported by transversely extending supporting surfaces. At the area of each of the interruptions the envelope has a stepwise decrease of the inside diameter in two steps. In the direction of decreasing diameter the first of these steps constitutes the supporting surface for the transverse electrode and the interruption in the wall coating is provided on a wall portion of the second of these steps. The interruptions provided in this manner do not exert any disturbing influence on the electron beam in the tube.

Abstract: Disclosed is a bayonet catch for directly securing an electrode in a glass envelope which comprises projections extending inwardly from the envelope and radially extending portions on the electrode which are clamped between the projections upon rotation of the electrode. The material of the envelope and the electrode have substantially equal coefficients of expansion to minimize relative movement between the envelope and the electrode with changes in temperature.