Abstract: A low-pressure gas discharge lamp comprising a gas discharge vessel with a gas filling containing mercury, and comprising electrodes, means for igniting and maintaining a gas discharge, and a phosphor coating containing at least one phosphor layer and a UV-C phosphor and a phosphor that can be excited by UV-C radiation.

Abstract: The invention relates to a gas discharge lamp for dielectrically impeded discharges, which gas discharge lamp comprises a discharge vessel filled with a gas filling, which discharge vessel comprises at least one wall of a dielectric material and at least one wall having a surface which is at least partly transparent to visible radiation, and a phosphor layer containing a blue phosphor with a host lattice and Nd3+ as the activator, electrodes for a dielectrically impeded discharge and means for igniting and maintaining the discharge.

Abstract: The invention relates to a gas discharge lamp for dielectrically impeded discharges, which gas discharge lamp is provided with a discharge vessel filled with a gas filling, which discharge vessel comprises at least a wall of a dielectric material and at least a wall having a surface which is at least partly transparent to visible radiation and coated with a phosphor layer, which phosphor layer comprises a phosphor having a host lattice, Eu2+ as the activator and a doping D selected from the group formed by Ce3+, Pr3+ and Tb3+, and provided with an electrode structure for a dielectrically impeded discharge and means for igniting and maintaining the discharge. The invention also relates to a phosphor comprising a host lattice, Eu2+ as the activator and a doping D selected from the group formed by Ce3+, Pr3+ and Tb3+.

Abstract: A plasma display with a carrier plate, a transparent front plate, a ribbed structure which subdivides the space between the carrier plate and the front plate into plasma cells, which cells are filled with a gas, with one or several electrode arrays for generating corona discharges in the plasma cells, and with a phosphor layer which comprises a phosphor chosen from the group of doped europium(II)-activated barium-magnesium aluminates with the general formula

Abstract: The invention relates to a plasma picture screen provided with a phosphor layer (9) which comprises an intrinsically pigmented phosphor. The plasma picture screen has an improved value for the luminance contrast performance without the efficiency of the phosphors being detracted from.

Abstract: Willemite (Zn2SiO4:Mn) is doped with one or more ions selected from the group formed by Gd3+, Eu2+, Co2+, Ce3+, Pr3+, Nd3+, Sm3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+ and Yb3+. This results in a increase in absorption and quantum yield and a decrease of the decay time.

Abstract: The invention describes a light-emitting device (1) which comprises a light-emitting diode and a phosphor layer. To prolong the useful life of the light-emitting device (1), a phosphor (4) in the phosphor layer (2) has a water-resistant coating. FIG.

Abstract: A luminescent material is dispersed in a watery solution of sodium polyphosphate, a watery solution of a nitrate of the metal M is added, after which the luminescent material is separated, dried and fired. The metal is chosen from the group consisting of Ca, Sr, and Ba, whereby a protective layer of metal polyphosphate is formed on the luminescent material.

Abstract: The invention describes a plasma picture screen, in particular an AC plasma picture screen with a coplanar arrangement which has an enhanced luminance. A UV light emitting layer (8) is provided on the front plate (1), which comprises a glass plate (3) on which a dielectric layer (4) and a protective layer (5) are provided, or on the carrier plate (2) with the phosphor (10). Said layer (8) comprises a VUV phosphor which converts the VUV light of the plasma discharge into UV light with a wavelength between 200 and 350 nm and emits this in the direction of the phosphor layer (10).

Abstract: A plasma picture screen fitted with a phosphor layer comprising a red phosphor activated by Eu3+shows an improved red color point (x≧0.64 and y≦0.35) and shorter decay times &tgr;1/10 as compared with the standard phosphor (Y,Gd)BO3. The phosphor according to the invention has a lattice in which the activator Eu3+occupies a location which has no inversion symmetry.

Abstract: A plasma display device with a phosphor screen, comprising a phosphor composition of an UV-phosphor furnished with a coating which includes one or more catena-polyphosphates of metals of the group formed by the alkaline earth metals, zinc, cadmium and manganese, can effectively be used to counteract degradation of the phosphor by UV-excitation.

Abstract: The invention relates to a method of coating luminescent powders with a coating which comprises silicon dioxide, which method is characterized in that in a first step luminescent particles are dispersed in a solution containing one or more metallo-organic compounds of silicon and, optionally, metallo-organic compounds of further elements in a hydrous solvent mixture having a pH-value of 1<pH 5, whereafter the metallo-organic compounds are hydrolysed by adding ammonia. A further aspect of the invention relates to a luminescent powder having a coating composed of silicon oxide and at least one oxide of a further element selected from the group formed by aluminum, barium, lead, boron, magnesium, titanium, zinc, zirconium, cobalt, copper and iron.

Abstract: The invention relates to a display screen comprising a phosphor composition of a sulphide and/or selenide-containing phosphor which is provided with a coating which comprises one or more catena-polyphosphates of one or more alkaline earth metals, zinc, cadmium and/or manganese. In such a display screen, in particular a low-energy cathode ray display screen, the advantages of the efficient sulphide or selenide-containing phosphors can be used and said display screen remains bright and rich in contrast for a long period of time because the coating acts as a stabilizing protective coating which limits the corrosion processes in sulphide and/or selenide-containing phosphors induced by low-energy radiation.

Abstract: A method describing the manufacture and use of aqueous suspensions comprising fine-powdered ceramic solid particles, dispersing agents and, if necessary, binders, in which method the manufacture of the suspensions includes the following process steps which are carried out separately or in combination:washing the solid particles in water before preparing the suspension;adding anionic compounds, in the form of sulphates, carbonates, iodates, chromates, oxalates, citrates and/or tartrates;manufacturing the suspensions and/or storing the finished suspensions in a CO.sub.2 -free gaseous atmosphere;manufacturing the suspensions and storing the finished suspensions at a temperature below 20.degree. C., preferably below 15.degree. C.;adding additional dispersing agents to the suspension at a time when reagglomeration of the solid particles in the suspension has not yet started or just started.

Abstract: A nozzle of a dyestuff applicator has a cylindrical valve housing formed with an orifice obstructable by the tip of an electromagnetically displaceable needle which controls the outflow of dyestuff from a chamber in that housing. The chamber is sealed by a rubber diaphragm which is penetrated by the needle whose shaft is engaged by a pair of parallel membranes of spring steel peripherally clamped in an extension of the housing. Each membrane comprises a narrow outer ring with an inwardly projecting tongue split into two diverging branches which are interconnected at their free ends, near the diametrically opposite side of the outer ring, by a re-entrant web extending radially between these branches and terminating in an inner, needle-supporting ring concentric with the outer ring.