Abstract: A flat display screen anode, including phosphor elements intended for being excited by an electron bombarding, these elements being deposited on at least one biasing electrode including, at least under the phosphor elements, a resistive layer deposited on a conductive layer for biasing the phosphor element.

Abstract: A cathode plate of a flat display screen of the type including a set of electron emission cathode conductors, organized in columns, a set of electron extraction grid conductors, organized in rows, and a peripheral protection area, surrounding an active area taking part in the display, to prevent propagation of secondary electrons out of the perimeter of the protection area.

Abstract: A cathode-grid plate of a field-effect flat display screen of the type including a first set of row conductors, a second set of column conductors and, for each screen pixel, defined by the intersection of a column and of a line, an element for temporarily storing the luminance control signal of the considered pixel.

Abstract: A tool and a method for positioning spacers on a first plate intended for being maintained at a distance from a second plate by said spacers, said tool including openings for receiving said spacers, and said openings being of variable size between a first position of introduction of the spacers and a second position of mechanical blocking of the spacers.

Abstract: A flat display screen including a.cathode provided with field effect electron emission means, a cathodoluminescent anode placed opposite to the cathode, an extraction grid associated with the cathode, and at least one filtering grid, permeable to electron bombardment and biased to forbid parasitic ions, generated on one side of this filtering grid, to reach the cathode or the anode located on the other side.

Abstract: An arrangement of spacer posts in a flat panel display. The spacer posts maintain a fixed separation between a back plate and a face plate. The back plate includes one or more electron emission sources. Phosphors or other electro-optic material are distributed among a plurality of pixel areas on the face plate. The pixel areas are arranged in distinct groups, where each group contains N adjacent pixel areas. Each pixel area includes an area free of phosphor material. Within each group of N pixel areas, the respective phosphor-free areas of the N pixel areas are contiguous so as to form a combined phosphor-free area equal to or greater than the transverse cross-section of one end of a spacer. Consequently, a spacer can be attached to the face plate at each combined phosphor-free area without disrupting the uniformity of the distribution of phosphors on the face plate.

Abstract: A push-pull switch including a first N-channel MOS transistor, the drain-source path of which is connected between a high voltage terminal and an output terminal, a first resistor connected between the gate of the first transistor and the high voltage, a diode having its anode connected to the output terminal and its cathode connected to the gate of the first transistor, a second N-channel MOS transistor having its drain connected to the cathode of the diode, its source connected to a reference potential, and its gate connected to a control terminal, and a second resistor connected between the gate of the second transistor and the output terminal.

Abstract: The present invention relates to an electric connection between the internal space of a flat screen and the outside by means of a conductive line of small thickness underlying a substantially thicker peripheral seal, and including an open-worked structure making its expansion easier, said open-worked structure being such that the electric connection has no rectilinear conductive section.

Abstract: The present invention relates to a flat display screen including a light-emitting source organized in a first array of strips generally parallel in a first direction, and at least one second opaque array, interposed between the light-emitting source and a display surface, and organized in a second direction generally non-perpendicular to the first direction, at least one of the arrays exhibiting, along an axis parallel to the general direction of the first array and whatever the position of this axis in a perpendicular direction, a constant proportion of transparent surface for an elementary pattern.

Abstract: The present invention relates to a flat display screen, comprising a cathode with electron emission microtips associated with a grid for extracting electrons from the microtips, the cathode/grid comprising conductive grid or cathode lines adapted to being sequentially addressed, and cathode or grid columns perpendicular to the lines and adapted to being addressed individually and simultaneously during the addressing of a line, and the screen comprising a return electrode adapted to being biased to a return potential corresponding to a no electron emission potential, each grid or cathode line being connected, via at least one resistive element, to the return electrode.

Abstract: The present invention relates to a method of assembly, in a furnace in vacuum conditions or under a neutral atmosphere, of two parallel plates leaving a closed internal space, consisting, in a first step, of performing a peripheral sealing by means of a first seal fusible at a first temperature, while maintaining open at least one opening of communication with the internal space and, in a second step, of closing the opening by means of a closing element with the interposition of a second seal fusible at a second temperature lower than the first temperature.

Abstract: The present invention relates to a flat display screen cathode of the type including, on a substrate, columns of cathode conductors which can be biased individually and associated with a resistive layer on which are deposited electron emission microtips, and including means for canceling a possible lateral electric field between two neighboring columns brought to different potentials.

Abstract: The present invention relates to a flat color display screen including a cathode associated with an electron extraction grid, an anode provided with at least two types of phosphor elements, all polarized to a same potential, and at least two additional superposed grids, positioned on the extraction grid, and each provided with holes defining sub-pixels associated with each of the colors. Each additional grid is associated with a color and some of the holes thereof are of smaller diameter than the coaxially corresponding holes of the other additional grids, for activating the sub-pixels of the corresponding color.

Abstract: A flat microtip display screen including a cathode provided with active areas of electron emission microtips; a cathodoluminescent anode provided, at least in front of the active microtip areas, with active areas of phosphor elements; a main grid of extraction of electrons emitted by the active microtips towards the phosphor elements; and on the cathode side, at least one sacrificial area of microtips adapted to being addressed, outside screen operation periods and independently from the active areas.

Abstract: The present invention relates to a flat display screen anode of the type including at least two sets of parallel alternate strips of anode conductors coated with phosphor elements and separated from one another by insulating strips, and focusing conductive strips, aligned and substantially centered with the insulating strips, the focusing conductive strips having lower widths than the insulating strips.

Abstract: The present invention relates to a method for regenerating microtips of a flat display screen including a cathode with electronic emission microtips associated with a grid for extracting electrons emitted by the microtips, wherein the microtips are made to emit under a current density which is substantially higher than a nominal operating current density and for a duration which is substantially higher than a nominal operating addressing duration.

Abstract: A flat display screen comprises a microtip cathode for electronically bombarding an anode including at least two groups of alternate conductive strips with phosphor strips and a control circuit adapted to sequentially address each group. The control circuit includes means for applying, at least temporarily, to each group of conductive strips a voltage lower than the minimum biasing voltage of the cathode's microtips.

Abstract: A device for controlling an electrode of a flat display screen includes a first electrode constituting a microtip cathode, a second electrode constituting an anode provided with phosphor elements and a gate that is arranged in rows. At least one of the electrodes is arranged in columns. The device includes circuitry for individually addressing each column and for interrupting the biasing of a column as soon as its charge reaches a threshold voltage corresponding to a desired luminescence value.

Abstract: The present invention relates to a flat display screen including a cathode associated with a grid for extracting electrons emitted by at least one region of the cathode, and an anode provided with phosphor elements placed facing the cathode/grid, the cathode having no emissive region in the areas located above the phosphor elements, these areas including a conductive layer which can be biased independently from the emissive regions.

Abstract: The present invention relates to a method and device for assembling two elements spaced apart by means of a peripheral seal, consisting of adding a seal on a surface of a first element facing a surface to be assembled of a second element, bringing the assembly thus constituted, in vacuum conditions, to a temperature enabling the melting of the seal while temporarily maintaining, by means of spacers having a thickness higher than the thickness of the seal and distributed outside the seal, the surface of the second element distant from the seal, and enabling the elements to come closer to each other to assemble them, sealably, by means of the melting seal.