Abstract: A display panel provided with at least two arrays of coplanar electrodes Y, Y? and a network of address electrodes X is described. The network of address electrodes X is formed between the plates bearing these electrodes and has a two-dimensional set of elementary discharge regions. Each elementary discharge region is subdivided into two matrix discharge regions, each located at the intersection of one Y of the coplanar electrodes and of the address electrode X and one coplanar discharge region between the coplanar electrodes Y, Y?. Each matrix discharge region is located closer to the external edge than the internal edge of the coplanar electrode Y with which the matrix discharge region is associated.

Abstract: Display panel comprising two plates, separated by a gas-filled space partitioned by separating elements forming an array of barrier ribs, and arrays of coplanar sustain electrodes and address electrodes; with each cell subdivided into a trigger zone at each of the intersections of an address electrode with a sustain electrode and into at least one coplanar discharge expansion zone that extends between the trigger zones, the array of barrier ribs is designed so that, in each cell, each coplanar expansion zone has a width that is less than the width of all the trigger zones. By applying a method of driving the sustain discharges in the display panel by matrix triggering, the luminous efficiency is very substantially improved.

Abstract: The invention concerns a faceplate comprising, for each discharge zone, at least two electrode elements having an axis of symmetry Ox and which are adapted such that the surface potential V(x) measured at the dielectric layer surface covering said elements increases, away from the edge of the discharge elements, continuously or discontinuously, without decreasing portion, when a constant potential difference is applied between the two electrodes serving said discharge zone, thereby substantially enhancing the panel luminous efficacy.

Abstract: Panel comprising an array of barrier ribs each having a base resting on a plate and a top in contact with another plate that includes at least two arrays of coplanar electrodes each preferably having a constant width. According to the invention, these barrier ribs have, at their top, a low-permittivity region of thickness greater than 3 ?m and less than or equal to one fifth of their total height, which has a mean dielectric permittivity at least three times smaller than the dielectric permittivity of these barrier ribs measured at their base. Thanks to the invention, the confinement of the plasma discharges far from the barrier ribs is substantially improved.

Abstract: Display panel comprising two plates, separated by a gas-filled space partitioned by separating elements forming an array of barrier ribs, and arrays of coplanar sustain electrodes and address electrodes; with each cell subdivided into a trigger zone at each of the intersections of an address electrode with a sustain electrode and into at least one coplanar discharge expansion zone that extends between the trigger zones the array of barrier ribs is designed so that, in each cell, each coplanar expansion zone has a width that is less than the width of all the trigger zones. By applying a method of driving the sustain discharges in the display panel by matrix triggering, the luminous efficiency is very substantially improved.

Abstract: A method for driving a plasma display having discharge regions each crossed by a pair of sustain electrodes (YS, YAS) and at least one trigger electrode (XA) is disclosed. The method includes a succession of image frames or subframes which each have a discharge region sustain phase including the application of voltage pulses VS between the electrodes of each pair of sustain electrodes serving these regions, and the application of a trigger pulse VM, of duration ?M less than 1 ?S, between the trigger electrode (XA) and one and/or the other of the electrodes of each pair serving these regions. The intensity and luminous efficiency of plasma displays can thus be significantly improved.

Abstract: The invention concerns a plasma panel display wherein the coplanar faceplate of the display panel comprising electrode triads including each two opposite side electrodes and a central electrode, and wherein during sustain operations by application of a series of sustain voltage pulses between the electrode triads, the central electrode always acts as anode. Such an arrangement, and preferably at an adapted width of the central electrode, enables to enhance substantially the luminous efficacy of the display panel.

Abstract: Panel comprising an array of barrier ribs each having a base resting on a plate and a top in contact with another plate that includes at least two arrays of coplanar electrodes each preferably having a constant width. According to the invention, these barrier ribs have, at their top, a low-permittivity region of thickness greater than 3 ?m and less than or equal to one fifth of their total height, which has a mean dielectric permittivity at least three times smaller than the dielectric permittivity of these barrier ribs measured at their base. Thanks to the invention, the confinement of the plasma discharges far from the barrier ribs is substantially improved.

Abstract: A display panel provided with at least two arrays of coplanar electrodes Y, Y? and a network of address electrodes X is described. The network of address electrodes X is formed between the plates bearing these electrodes and has a two-dimensional set of elementary discharge regions. Each elementary discharge region is subdivided into two matrix discharge regions, each located at the intersection of one Y of the coplanar electrodes and of the address electrode X and one coplanar discharge region between the coplanar electrodes Y, Y?. Each matrix discharge region is located closer to the external edge than the internal edge of the coplanar electrode Y with which the matrix discharge region is associated.

Abstract: The invention concerns a faceplate comprising, for each discharge zone, at least two electrode elements having an axis of symmetry Ox and which are adapted such that the surface potential V(x) measured at the dielectric layer surface covering said elements increases, away from the edge of the discharge elements, continuously or discontinuously, without decreasing portion, when a constant potential difference is applied between the two electrodes serving said discharge zone, thereby substantially enhancing the panel luminous efficacy.

Abstract: The invention concerns a display panel comprising a front faceplate and a rear faceplate providing between them a two-dimensional matrix of zones filled with discharge gas, addressing means for selectively activating pre-selected discharge zones by depositing therein electric charges, and a device for generating microwave electromagnetic radiation adapted to apply through the rear faceplate to the assembly of the display panel discharge zones, a microwave radiation of sufficient intensity to generate plasma discharges solely in the activated discharge zones. Thus, an easy-to-monitor panel with high luminous efficacy is obtained wherein the addressing and maintenance functions are separate.

Abstract: Each sustain electrode of a pair includes a continuous ignition conductor, a bus without any overlap and without any direct contact with the latter, electrical connection between the ignition conductor and the bus, and a connector for spreading the discharge. This arrangement allows the luminous efficiency of sustained discharges to be increased.

Abstract: A method for driving a plasma display having discharge regions each crossed by a pair of sustain electrodes (YS, YAS) and at least one trigger electrode (XA) is disclosed. The method includes a succession of image frames or subframes which each have a discharge region sustain phase including the application of voltage pulses VS between the electrodes of each pair of sustain electrodes serving these regions, and the application of a trigger pulse VM, of duration &tgr;M less than 1 &mgr;S, between the trigger electrode (XA) and one and/or the other of the electrodes of each pair serving these regions. The intensity and luminous efficiency of plasma displays can thus be significantly improved.

Abstract: According to this method, before a high-frequency pulse train is applied between the two electrodes of a pair carried by one plate, at least one sustain pulse is applied between an electrode of this pair and an electrode of another plate of the panel. As the sustain discharges are not generated between the same electrodes as the stabilized discharges, the electrodes may be moved further apart so as to lower the stabilization frequency without thereby having to increase the sustain voltages.

Abstract: Since the coplanar tile of the panel comprises triads of electrodes, each comprising two opposed lateral electrodes 13, 14 and one central electrode 20, during sustain applications by applying a series of sustain voltage pulses between the electrodes of the triads, the central electrode 20 always acts as anode.

Abstract: According to this structure, each sustain electrode (1, 1′) of a pair comprises: a continuous ignition conductor (2); a bus (3) without any overlap and without any direct contact with the latter, means (6) for electrically connecting the ignition conductor (2) to the bus (3); and means (42, 43) for spreading the discharge, these means being independent of the electrical connection means (6). This arrangement allows the luminous efficiency of sustained discharges to be increased.

Abstract: According to this method, before a high-frequency pulse train (TSY) is applied between the two electrodes of a pair X, Y carried by one plate, at least one sustain pulse SHX, SHA is applied between an electrode X of this pair and an electrode A of another plate of the panel.

Abstract: The aliphatic carboxylic acids, e.g., acetic acid, are selectively prepared, even on an industrial scale, by controlledly oxidizing the corresponding alkanes, e.g., ethane, with a source of oxygen, in the presence of a catalytically effective amount of an advantageously supported heteropolyacid catalyst having the formula (I):[A.sub.a B.sub.b ].sub.f [C.sub.c D.sub.d E.sub.e O.sub.x ].sup.f-(I)in which A is at least one monovalent cation selected from among hydrogen, an alkali metal, or the ammonium ion; B is VO.sup.2 +, VO.sup.3 +, an alkaline earth metal ion, or an ion of a metal of Groups VII A, VIII, I B, IV B and V B of the Periodic Table; C is Mo and/or W; D is phosphorus, arsenic, antimony, silicon, germanium and/or boron; E is vanadium, optionally in combination with at least one metal of Groups V A, VII A and VIII of the Periodic Table or chromium; f=a+.alpha.b wherein .alpha.