Abstract: A display tube comprising in an evacuated envelope (1) an electron gun system (6) for generating and focusing by means of a focusing lens at least two electron beams (28 to 35) on a display screen (5), which electron beams are deflected by deflection means and describe a frame on the display screen. The electron gun system (6) comprises at least two electron sources (20 to 26), the electrons in each electron beam being accelerated immediately after leaving the electron source by means of an electric field having a field strength exceeding 600 V/mm. The central axes (36) of the electron beam extend substantially parallel to each other, and all beams are converged by the focusing lens in the immediate proximity of the focus of the focusing lens, after which each separate beam is focused on the display screen by the focusing lens to form a spot.

Abstract: An electron gun for a camera tube includes an anode and a cathode. The cathode is assembled in a cathode support which can very readily be adjusted relative to the anode in the non-connected condition. In particular, the cathode support and the anode are movable radially with respect to each other and with respect to an axis. An emissive cathode surface and a part of the anode extending perpendicular to the axis remain accurately parallel to each other during the radial movement. As a result of this it is possible to cause the central path of the generated electron beam and the gun axis to coincide so that extra correction coils for aligning the electron beam may be omitted.

Abstract: An electron gun for a camera tube includes an anode and a cathode. The cathode is assembled in a cathode support which can very readily be adjusted relative to the anode in the nonconnected condition. In particular, the cathode support and the anode are movable radially with respect to each other and with respect to an axis. An emissive cathode surface and a part of the anode extending perpendicular to the axis remain accurately parallel to each other during the radial movement. As a result of this it is possible to cause the central path of the generated electron beam and the gun axis to coincide so that extra correction coils for aligning the electron beam may be omitted.

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: 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: A cathode-ray tube having an electron gun to generate an electron beam and a focusing lens to focus the electron beam on a target. The anode of the electron gun forms part of the focusing lens and has a very small aperture to limit the electron beam. In order to prevent positive ions formed in the tube from poisoning the cathode the potential of the anode is at most 75 volts relative to the cathode potential and the distance from the center of the focusing lens to the aperture in the anode is at least equal to 1.5 times the largest dimension of the anode taken in a cross-section at right angles to the axis.

Abstract: A device having a camera tube of the vidicon type. During flybacks of the deflection, the beam current and the cathode potential is increased so as to achieve the so-called anti-comet tail effect. In order to ensure that the beam lands on the radiation sensitive layer perpendicularly everywhere during flybacks, as well as during scanning of the target, the electron beam is focused at the deflection point of the deflection coils during the flyback.

Abstract: A deflection device for the electron beam, in, for example, an image pick-up tube, comprising an annular yoke of a magnetic material, having at least two pairs of diametrically arranged, inwards directed cores which are enveloped by deflection coils. On the inner end of each core there is provided a poleshoe in the form of a ring segment, said poleshoes enclosing a deflection space. In order to ensure that the shape of the generated deflection fields can be accurately and reproducibly defined, each coil is situated, viewed from the deflection space, completely behind the associated poleshoe, the spaces between the poleshoes being bridged by intermediate pieces of a non-magnetic material.