Abstract: A projection screen providing an improved contrast between projected light and ambient light, which projection screen comprises a light-absorbing layer and an active layer located in front of said light-absorbing layer. The active layer is transparent to light having a first direction of polarization and reflective to light having a second direction of polarization. The reflecting polarizing layer may be provided between the active layer and the light-absorbing layer.

Abstract: A scrolling scan optical band scanner is provided having a scrolling scan optic with a scan function that inherently deviates from an ideal imaging function over wide apertures. Compensation optics are provided to correct the scrolling scan optic performance to provide accurate imaging over a wide aperture. The compensation optics and the scrolling scan optic together accurately scroll the input pattern to an output pattern according to the formula: xo(t)/X=(t/T+xi/X) modulo 1, with X being the total height of input and output beam, xi being the ray height in the input beam, xo being the corresponding ray height in the output beam as a function of time, T being the frame period, and t being the time, and said scroll patterns remains telecentric even where X is large with respect to a physical size of the scanning optic system.

Abstract: Picture display device having a vacuum envelope with a face plate whose inner side is provided with a luminescent screen having a repetitive pattern of triplets of red, green and blue-luminescing phosphor elements, a rear plate at a short distance therefrom and in the space therebetween a plurality of electron emitters and juxtaposed, electron ducts cooperating therewith and having walls of substantially electrically insulating material having a secondary emission coefficient suitable for electron transport for transporting, through vacuum, produced electrons in the form of electron currents. Means are provided for withdrawing each electron current at predetermined locations from its duct and for directing this current towards a desired location on the luminescent screen for producing a picture composed of pixels.

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 Electrons are withdrawn from the ducts by means of an addressing system, whereafter these electrons are directed towards desired locations on the luminescent screen.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 picture display device has a vacuum envelope and is provided with a face plate whose inner side supports a luminescent screen, a rear wall situated at a short distance therefrom, and the space in-between accommodating a plurality of electron sources, which cooperate with a plurality of electron transport duct including dielectric walls fro transporting, through vacuum, the produced electrons towards positions at a small distance from the luminescent screen. The display device further includes means for reducing the effects of undesired charge transfer of the duct walls, which are provided to improve the start-up and/or steady state electron transport conditions. Specifically, the outer sides of the duct rear walls are provided with a conductor to which an initiation potential is applied, which is equal to or higher than the potential applied for producing the electron transport field.

Abstract: A picture display device having a flat vacuum envelope which is provided with a transparent face plate with a luminescent screen and with a rear wall, which display device has an electron supply section with an electron source for emitting electron currents in a direction parallel to the face plate, and an active selection electrode section with first, preselection, electrodes and second, fine-selection, electrodes, located closer to the screen, for directing each electron current towards desired pixels on the luminescent screen. The fine-selection electrodes are divided into groups and corresponding fine-selection electrodes of at least two groups are interconnected in a series or parallel arrangement in such a way that the technology of providing these electrodes is as simple as possible and/or the possible fine-selection electrode patterns are such that the number of required selection drivers can be reduced considerably.

Abstract: A picture display device has a vacuum envelope and is provided with a face plate whose inner side supports a luminescent screen, a rear wall situated at a short distance therefrom, and the space in-between accommodating a plurality of electron sources, which cooperate with a plurality of electron transport ducts including dielectric walls for transporting, through vacuum, the produced electrons towards positions at a small distance from the luminescent screen. The display device further includes means for reducing the effects of undesired charge transfer of the duct walls, which are provided to improve the start-up and/or steady state electron transport conditions. Specifically, the outer sides of the duct rear walls are provided with a conductor to which an initiation potential is applied, which is equal to or higher than the potential applied for producing the electron transport field.

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: Color display device including a plurality of electron transport ducts for transporting electrons in the form of electron currents, and selection electrodes for extracting each electron current from its transport duct at predetermined locations and for directing them to different color pixels of a luminescent screen. The color selection time fractions during which the color pixels are activated are different for different color pixels in such a way that the color selection time fraction for the color pixel which requires the largest quantity of electrons for displaying maximum white is longer than the color selection time fraction of the color pixel which requires the smallest quantity of electrons for this purpose.

Abstract: Picture display device with one or more resonant selection pulse drivers for generating selection pulses for selecting rows of pixels. The resonant selection pulse driver has two driver output electrodes to which selection electrode(s) are connected for simultaneously generating a pulse trailing edge at one driver output electrode and generating a pulse leading edge at the other driver output electrode.

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: Picture display device comprising a plurality of electron transport ducts or transporting electrons in the form of electron currents, and selection electrodes for withdrawing each electron current at predetermined locations from its transport duct and for directing said current towards a luminescent screen. The selection electrodes are driven by a selection driver comprising integrated driver circuits having outputs which are DC-coupled to the selection electrodes and are cascaded as regards their power supply voltages in such a way that they apply both selection pulses and transport (bias) voltage to the selection electrodes.

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: A picture display device (W) includes a display unit (1) having a vacuum envelope which is provided with a transparent face plate (3), having a luminescent screen, and a rear plate (4). The display unit has a plurality of juxtaposed sources (5) for emitting electrons, a plurality of electron transport ducts (6, 6', 6") cooperating with the sources for transporting the electrons in the form of electron currents, and selection means (611) for withdrawing each electron current at predetermined locations from its transport duct and for directing the withdrawn current toward desired pixels of the luminescent screen. In order to direct the correct quantity of electrons into the electron transport ducts for relevant video information, the voltages applied to the grids are modulated with a video signal and a uniformity correction signal. One of these signals controls a pulse-duration and the other signal controls a pulse-height of the drive signals.

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.