Abstract: A color cathode ray tube comprises an electron gun and a deflection unit, the electron gun being arranged in a neck portion of an envelope, and the deflection unit being arranged around the envelope. The neck portion of the envelope includes a first part in which the electron gun is arranged. Behind this first part, the neck portion narrows (the outside diameter decreases). The deflection unit is at least partly provided around this narrowed part.

Abstract: The invention relates to a deflection unit (10) for cathode ray tubes in which the external magnetic stray fields are further reduced and the sensitivity of the line deflection coils (17) is increased. This is done by applying a (preferably plastic deformable) magnetic material (56) in the first void spaces (52) between the wire strands (50) of the field deflection coils (18) and/or the second void spaces (54) between the field deflection coils (18) and the yoke ring (22). The plastic deformable magnetic material (56) can be additionally used for adhering the yoke ring (22) to the field deflection coils (18).

Abstract: The invention relates to a cathode-ray tube 1 having an electron gun 3 positioned in a neck portion 2. The electron gun 3 is provided with a focusing structure 10 which includes a hollow tube 12 of electrically insulating material. A layer 14 of a material having a high resistance is applied to the inner surface of the hollow tube. The resistance layer 14 is shielded from a getter arrangement 44 positioned in the cathode ray tube 1.

Abstract: A monochrome cathode ray tube including a magnetic focusing device provided with means for generating a static magnetic focusing field. These means surround the neck of the cathode ray tube without contacting this neck, and a system of correction coils for generating an additional focusing field and 2-, 4- and/or 6-pole fields is provided coaxially between these means and the neck of the tube.

Abstract: Picture display device comprising a display tube having an electron gun with an electrostatic focusing lens for generating a focusing lens field, which tube further comprises deflection means for generating a deflection field. The focusing lens field partly overlaps the deflection field. The focusing lens comprises a tubular structure having an inner surface on which a helical resistance structure of a material having a high electrical resistance is provided, which tubular structure has a coaxial input portion and a coaxial output portion, the output portion having dimensions which prevent the deflected electron beam from impinging upon the glass of the inner wall. Correction means may be provided for correcting errors caused by the advanced position of the focusing lens.

Abstract: A display tube comprising an electron gun having a beam-shaping part and a focusing structure. The focusing structure comprises an elongate hollow structure with a high-ohmic resistive layer provided on the inner and/or outer surface and comprises means for forming a non-rotationally symmetrical lens element in the area of the focusing structure. This may be a structure generating an electric multipole (for example, dipole or quadrupole) which may be incorporated particularly in the high-ohmic resistive layer.

Abstract: Projection television display tubes having an evacuated envelope (1) with a display window (4) which on its inside comprises a display screen (5) and in front of which a light permeable second window (6) is provided on its outside, a cooling liquid (16) flowing through the space (7) between the display window (4) and the second window (6) from at least one inlet aperture to at least one outlet aperture (17) namely by temperature differences in said cooling liquid. When in such a projection television display tube at the area of the windows (4, 6) and around the said space (7) a cooling jacket (8) is provided which comprises at least one duct (9) which transports the cooling liquid (6) from the outlet aperture(s) to the inlet aperture(s) of the said space, an effective cooling is obtained at a power between 12 and 25-30 W without external pipes or a heat exchanger.

Abstract: An efficiently cooled display tube is obtained by pumping a low viscosity liquid having a high heat capacity through a cooling space less than 1 mm. thick on the outside of the display window. A chamber is smoothly connected to the inlet aperture of the cooling space to assure a laminar flow, eliminating swirls which could give rise to refractive patterns in the display picture.

Abstract: A channel plate electron multiplier is mounted parallel to, but spaced from, the screen. The electron multiplier comprises a stack of juxtaposed substantially planar apertured dynodes with the apertures therein aligned to form channels. An apertured extractor electrode is mounted on the output side of the electron multiplier. Preferably two or more foraminous deflector electrodes are mounted on the extractor electrode. The apertures in the foraminous deflector electrodes have the same pitch as the channels of the electron multiplier but are offset laterally relative to each other and to the axes of the channels by amounts which allow the emergent electron beam from each channel to pass through to the screen without impinging upon the deflector electrodes. By applying a potential difference between the deflector electrodes an electron beam emerging from its respective channel is deflected laterally onto a respective one of its associated group of phosphor stripes.

Abstract: A method of de-burring and cleaning an electrode system, a printed circuit board, or the like comprising at least two conductors positioned at a predetermined distance from each other by means of insulation material. The electrode system is immersed in a dielectric liquid and an electric potential difference is then applied between the conductors which is sufficiently large to generate an electric flash-over between the conductors. As a result of the small free path length in the dielectric liquid metal sputtered from the conductors can not deposit on the insulating parts of the electrode system.