Abstract: An electrostatic-shutter image tube (10) has a shutter electrode (17) disposed between an electron source (12) and a focusing and accelerating electrode (13). An electron flow is propagated through a network of equipotential lines to form an image on a target (14). The shutter electrode (17) is annular and conforms with an equipotential line. Deflection electrodes (20a,20b) and an image sequencer (21) make it possible to influence the position of a sequence of small images on the target (14) where they are temporarily stored.

Abstract: A method and apparatus for depositing emitter material (3) on a wire cathode by means of electrodeposition. An amount (13) of a suspension comprising an alkaline-earth compound is transferred by a drop holder (11) which is positioned around the wire (2), by movement in a direction transverse to a longitudinal axis of the wire (2), whereafter an electric voltage is applied to the drop holder (11) and the wire (2) to deposit the emitter material (3) on the wire (2), after which the drop holder (11) is withdrawn from the wire (2) again. During the electrodeposition process the drop holder (11) and the wire (2) can be moved with respect to each other along sections of the wire (2) where the emitter material (3) has to be deposited.

Abstract: Flat-panel type picture display device having a luminescent screen and a large number of electron propagation ducts operating by means of electron wall interaction. Electrons are withdrawn from the ducts by means of an addressing system, whereafter these electrons are directed towards desired locations on the luminescent screen. An apertured spacer plate of electrically insulating material for passing electrons is arranged between the addressing system and the screen. To enable large voltage differences to be applied across the dimension of thickness of the spacer plate, the spacer plate is provided with a high-ohmic layer, or with a pattern of a low-ohmic material, or with an equalization layer at one side and with a low-ohmic layer at the other side, and at least the walls of the apertures are preferably coated with a material having a low secondary emission.

Abstract: A color display tube having an in-line electron gun. The in-line electron gun has two elongated supporting elements and is secured to the electrical leadthroughs in the neck by two pairs of supports. The distance between the supports is at least 3 mm. By virtue thereof, one or more supports can be connected to a high-voltage leadthrough without the risk of flashover between the supports.

Abstract: A light source for projecting rectangular color light bands includes a white-light source, a color separation device for separating the white light into red, green and blue components, and separate optics for forming images of rectangular red, green and blue light bands at predetermined positions. The light source is particularly useful in projection television apparatus having single panel light valves.

Abstract: A matrix display device comprising a row and column array of display elements (14), e.g. LC display elements, each of which is connected in series with a two terminal non-linear device (15), such as a MIM, between associated row and column address conductors (16,17) and drive means (20,22,25) for applying drive voltages to the picture elements comprising a scanning signal circuit (20) and a data signal circuit (22) for applying selection signals and data signals respectively to the sets of address conductors, in which a sensing circuit (40) provides a control signal (V.sub.1) indicative of current flowing in one, or more, address conductor (16) of one set during the application of selection signals to that conductor which determines the drive voltages applied to the picture elements, preferably by adjustment of the selection signal level, so as to compensate for changes over time in the threshold characteristics of the non-linear devices. Four or five level scanning signal drive schemes may be used.

Abstract: A method of manufacturing a dispenser cathode, in which method a powder of a refractory metal and a scandium-containing powder are mixed with each other and pressed to form a cathode body. According to the invention at least both these powders and a suitable binder are mixed with each other to form a homogeneous suspension prior to the pressing operation and the whole mixture is subsequently cured and ground to granules having a larger average size and hence a greater fluidity than the grains of the starting powders. Subsequently the granules thus obtained are pressed to form a cathode body (2). The invention leads to a better processibility and greater convenience of handling of the starting powders so that notably very fine staring powders can be used, which results in cathodes (1) having a better recovery after ion bombardment as compared with cathodes manufactured in conventional manners which are necessarily based on relatively coarse powders.

Abstract: A magnetoelastic layer is provided on a shaft for sensing torque carried by the shaft around a longitudinal axis. The layer includes first and second adjacent annular parts of a magnetically anisotropic material with circumferential easy axes. The parts are magnetically polarized in opposite circumferential directions when in a quiescent state, but produce helical magnetic fields with respective axial components when torque is carried by the shaft. First and second magnetic-field-guiding structures combine to provide shielding of the magnetoelastic layer from ambient external magnetic fields and to maximize coupling of the axial components from the magnetoelastic layer to one or more magnetic field detectors.

Abstract: The invention relates to a method of providing tracks, for example conductive tracks, in a flat display device (such as a plasma display or PALC display) by means of a stencil-printing method. In particular, paste is formed through multilayer stencils enabling the quantity of printing paste passed to be varied locally.

Abstract: A semiconductor cathode (11) in a semiconductor structure, in which the sturdiness of the cathode is increased by covering the emitting surface (4) with a layer of a semiconductor material (7) having a larger bandgap than the semiconductor material of the semiconductor cathode. Various measures for increasing the electron-emission efficiency are indicated.

Abstract: A rigid ferrite-containing ring and plastic holder are described for mounting on the neck of a color cathode ray tube (CRT) which ring is to be custom magnetized in order to provide correction of static convergence, color purity and/or frame errors in the CRT. The holder is provided with depressible tabs which releasably secure the ring to the holder. The holder is mounted on the neck of the CRT in the vicinity of the main focusing gap of the electron gun of the CRT, using an adhesive.

Abstract: An electric discharge tube or discharge lamp, in particular a flat-panel display screen, includes one or more low-temperature cathodes having a holder, which, optionally, is provided with a heating or cooling element, a conductive bottom layer which is applied to the holder, optionally a substrate with dispenser material, and a top coating of ultrafine particles having a nanostructure. The top coating has a surface layer consisting of an emitter complex formed from an emission material comprising several components. The cathodes have a high reliability and a long service life under a normal working load. The emission is stable, which contributes to a constant picture quality throughout the life of the discharge lamp or discharge tube. The discharge tubes or discharge lamps in accordance with the invention have short switching times and the advantage that their construction has been simplified and that their energy consumption is low.

Abstract: A multiplexer for use in conjunction with a cell-based network, which includes a plurality of access terminals each of which receives respective cells, each of the cells having one of a plurality of different classifications, a plurality of FIFO buffers each of which is coupled to a respective one of the access terminals for queuing the cells received at the respective access terminals, a plurality of decoding elements each of which is coupled to a respective one of the FIFO buffers, and, an allocation circuit which generates a coded selection signal that is applied to each of the decoding elements, wherein the decoding elements each decode the coded selection signal for selectively reading the cells out of the FIFO buffers in a manner whereby the cells are read out of the FIFO buffers in an order which is dependent upon their classification.

Abstract: Electron-optical device having two elongate emitting regions arranged symmetrically with respect to a longitudinal axis for producing two electron beams having an elongate cross-section. By means of electron grids, the two beams are focused at the same point of an electron target arranged transversely to the longitudinal axis and having a short central axis and a long central axis. The elongate emitting regions have their smallest cross-section parallel to the scanning direction of a device, cooperating with the electron-optical device, for scanning a target arranged transversely to the longitudinal axis.

Abstract: A picture display device having a vacuum envelope which is provided with a transparent face plate and a display screen having a pattern of luminescent pixels, and with a rear wall, comprising electron-producing means, an addressing system arranged between said means and the face plate so as to address desired pixels, and, adjacent to the display screen, a plate of electrically insulating material provided with apertures for passing electrons, in operation a voltage difference being applied across said plate, characterized in that the surface at the electron entrance side of the apertured plate is coated with a coating of a material selected from the group comprising nonstoichiometric nitrides, borides and carbides of Al and/or Si, and amorphous Si.

Abstract: A color cathode ray tube includes an in-line electron gun. The electron gun includes at least a tubular part which is composed of two (or more) folded portions which are secured to each other.

Abstract: The servosystem includes adjusting means (1) for changing the position of mechanical element (3), a first transducer (5) for forming an adjusting voltage which is a measure of a desired position of the element, a second transducer (15) for forming a response voltage which is a measure of the actual position of the element, and detection means (13) for forming an error signal (If) which is a measure of a difference between the response voltage and the adjusting voltage. The detection means (13) have a first and a second input (11, 21) which are connected to the first transducer and the second transducer, respectively, and an output (23) which is connected to an input (27) of control means (29) for generating, in dependence on the value of the error signal, a control signal (Vc1, Vc2), for controlling the adjusting means. A compensation resistor (31) is inserted in the connection lead (9) between, for example the first transducer (5) and the input (11) of the detection means (13) connected thereto.

Abstract: A scanning-light-band display apparatus includes a light-valve panel and an optical system. The optical system includes a multicolor light source and a faceted, rotatable light-transmissive polygonal prism. The light source projects illumination rays for forming images of red, green and blue light bands through the prism along different respective paths. A combination of optical components is arranged for intercepting the illumination rays and forming the images on the panel.

Abstract: Flat-panel type picture display device having a luminescent screen and a large number of electron propagation ducts operating by means of electron wall interaction. Electrons are withdrawn from the ducts by means of an addressing system, whereafter these electrons are directed towards desired locations on the luminescent screen. An apertured spacer plate of electrically insulating material for passing electrons is arranged between the addressing system and the screen. To enable large voltage differences to be applied across the dimension of thickness of the spacer plate, the spacer plate is provided with a high-ohmic layer, or with a pattern of a low-ohmic material, or with an equalization layer at one side and with a low-ohmic layer at the other side, and at least the walls of the apertures are preferably coated with a material having a low secondary emission.

Abstract: A vacuum tube is provided with a line-shaped getter, which includes a holder (2) with a longitudinal axis, which holder (2) contains a getter material (3) over at least a part of its length, said getter being provided with clamping means to clamp the holder (2). The vacuum tube includes aligning means for exerting a torque about the longitudinal axis of the holder (2), said torque being as small as possible for a preferred orientation of the holder (2) relative to the clamping means. The clamping means preferably includes two leaf springs (7, 7'), which are bent so as to be S-shaped and which are provided with apertures (9, 9', 9") at locations where the leaf springs (7, 7') intersect, for passing the holder (2), and a member (6; 19) is provided on the holder (2) in a clamping manner and the clamping means are provided with an orientation surface (17, 17'; 18, 18'), which extends radially relative to the longitudinal axis of the holder (2).