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: Picture display device having a vacuum envelope with a front wall supporting a luminescent screen at its inner side and a rear wall at a short distance therefrom, connected by side walls. The envelope accommodates a plurality of adjacent electron sources and juxtaposed, local electron ducts cooperating with these sources and having walls of substantially electrically insulating material having a secondary emission coefficient which is suitable for transporting, through vacuum, produced electrons in the form of electron currents. Means are provided to make each electron current substantially travel along a particular wall of its electron duct, as well as means for withdrawing each electron current at predetermined locations from its duct and directing it towards the luminescent screen for producing a picture composed of pixels.