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.

Abstract: A planar electron-optical lens is obtained on a semiconductor cathode surface by providing an extra electrode (16) around the gate electrode (14). Dependent on the applied voltage, this configuration operates, for example, as a positive lens which supplies parallel beams without dispersion, suitable for thin, flat display devices. A large positioning tolerance is obtained due to the inherent magnification of the beam diameter in the semiconductor device, while a grid can be dispensed with.