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 Electrons are withdrawn from the ducts by means of an addressing system, whereafter these electrons are directed towards desired locations on the luminescent screen.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: In, for example a field emission display, the invention provides the possibility of combining a plurality of sub-substrates that are attached to a larger rear wall, because notably different modes of multiplexing provide a wider positioning tolerance of a sub-substrate with respect to the front plate. Moreover, the different multiplexing techniques lead to a smaller number of connections, even if no use is made of a rear wall supporting sub-substrates. A plurality of multiplexing techniques provides the possibility of activating a substantially equally large number of pixels of different colors during parts of an image period, so that there is substantially no color flicker.

Abstract: The thin-type display device (1) with a vacuum envelope has a transparent front wall (3), which is provided with a display screen, and at least an electron source (5) and a duct structure, which cooperates with the electron source (5) and which extends substantially parallel to the front wall (3). Ducts (6, 6', 6") of the duct structure serve as electron-propagation means and are provided with walls (11, 11', 11") of an electrically insulating material having a secondary emission coefficient which is suitable for electron propagation. In the display device (1) 1.ltoreq.s/w.ltoreq.5 and s.multidot.w.gtoreq.5 mm.sup.2, where s is the depth of the ducts (6, 6', 6") and w is the width of the ducts (6, 6', 6"). Preferably, the width w.gtoreq.1.5 mm and the depth 3.5.ltoreq.s.ltoreq.15 mm. The voltage difference over the length of the ducts (6, 6', 6"), measured parallel to the front wall (3), is less than 75 V/cm, preferably less than 40 V/cm.

Abstract: A display device including a vacuum envelope having an electroluminescent screen, an electron source and a branched network of electron-transport ducts having at least one entrance for electrons and at least two exits at end portions of the network. An electron current flows from the entrance to a desired one of the exits via nodes in the network. The network exits corresponding to one entrance form a two or three dimensional array of exits. Preferably, the distance, via the network, between an entrance and its corresponding exits is equal.

Abstract: A flat display device is provided with a wire cathode or wire cathodes and with apertures which allow passage of electrons emitted by the wire cathode. The wire cathode is stretched in a wire-cathode support having positioning grooves for the wire cathode. This support engages the element in which the passages are made. The support and the element are provided with corresponding contacting surfaces.

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: 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: Flat-panel type picture display device having a face plate with a luminescent screen at the inner side and, arranged at a short distance therefrom, a rear plate adjoined by a large number of electron transport ducts operating by means of wall interaction of electrons. An active selection structure for directing electrons from transport ducts towards pixels on the luminescent screen comprises an apertured preselection plate and an apertured fine-selection plate, each preselection aperture being associated with at least two fine-selection apertures. Special auxiliary (or dummy) electrodes between the preselection plate and the selection plate, and/or a special geometry of the preselection apertures ensure that colour purity and contrast are maximal.

Abstract: A flat-panel type picture display device having a face plate with a luminescent screen at the inner side and, arranged at a short distance therefrom, a rear wall adjoined by a large number of electron transport ducts operating by means of wall interaction of electrons. A selection structure for withdrawing electrons from transport ducts and for directing them towards pixels on the luminescent screen comprises a preselection structure provided with preselection locations and a fine-selection plate provided with fine-selection apertures, each preselection location being associated with at least two fine-selection apertures. To improve contrast and/or color purity, an apertured obstruction plate forming chicanes in the electron paths is arranged between the preselection plate and the fine-selection plate.

Abstract: A display device comprising electron-transport ducts having entrance apertures for electrons and means for generating electrons and injecting electrons into the transport ducts via the entrance apertures. Measures have been taken to improve the picture quality. For example, the location of the entrance aperture is not the same for each transport duct, but instead shows a variation. This enables an improved control of the electron flow in the transport ducts to be achieved; in particular crosstalk between the transport ducts can be reduced.

Abstract: A display device comprising electron-transport ducts having entrance apertures for electrons and means for generating electrons and injecting electrons into the transport ducts via the entrance apertures. Measures have been taken to improve the picture quality. For example, the location of the entrance aperture is not the same for each transport duct, but instead shows a variation. This enables an improved control of the electron flow in the transport ducts to be achieved; in particular crosstalk between the transport ducts can be reduced.

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. At a given resolution, hexagonal phosphor dot patterns in which dots are horizontally staggered generally produce fewer artefacts than in a 90.degree. tilted orientation. An addressing system for withdrawing electrons from the propagation ducts and for directing them towards the luminescent screen is preferably formed as a multistepped structure with a preselection structure of rows of preselection electrodes and a fine-selection structure of rows of fine-selection electrodes. To interconnect the fine-selection electrodes in parallel in a minimal number of groups, it is advantageous when the fine-selection electrodes are arranged parallel to the preselection electrodes.

Abstract: Picture display device includes a display unit having a vacuum envelope which is provided with a transparent face plate with a luminescent screen and a rear plate. The display unit includes a plurality of juxtaposed sources for emitting electrons, a plurality of electron transport ducts cooperating with the sources and extending substantially parallel to the face plate for transporting the electrons in the form of electron currents, and an active selection structure for withdrawing each electron current at predetermined locations from its transport duct and for directing the current towards desired pixels of the luminescent screen.The picture display device further includes a video signal processing circuit for receiving an incoming video signal having a given line number, for processing the video signal to a video signal which is suitable for the luminescent screen, and for applying the processed video signal to a video drive circuit coupled to the sources.

Abstract: A picture display device having a vacuum envelope whose inner wall is provided with a luminescent screen. The device is a plurality has a of juxtaposed sources for producing electrons, local transport ducts having walls of electrically substantially insulating material having a secondary emission coefficient which is suitable for transporting, through a vacuum, electron beams, preselection means for withdrawing electrons from the transport ducts at predetermined extraction locations and for directing them towards the luminescent screen for producing a picture composed of pixels. A structure of distribution ducts having selection apertures is positioned between the transport ducts and the luminescent screen for fine selection of electrons withdrawn from the transport ducts.

Abstract: Flat-panel type picture display device having a face plate with a luminescent screen at the inner side and, arranged at a short distance therefrom, a rear plate adjoined by a large number of electron transport ducts operating by means of wall interaction of electrons. An active selection structure for directing electrons from transport ducts towards pixels on the luminescent screen comprises an apertured preselection plate and an apertured fine-selection plate, each preselection aperture being associated with at least two fine-selection apertures. Special auxiliary (or dummy) electrodes between the preselection plate and the selection plate, and/or a special geometry of the preselection apertures, ensure that color purity and contrast are maximal.

Abstract: A flat, thin picture display device has a transparent face plate and a rear plate and a large number of electron sources and local electron transport ducts cooperating therewith. A selection plate arranged between the face plate and the rear plate has an arrangement of apertures which defines locations for withdrawing electrons from the electron transport ducts and, aligned therewith, a row of apertures defining locations for the electron sources.