Abstract: The object of the present invention is to provide a gas discharge display device having improved luminous efficiency by effectively using ultraviolet ray, which is absorbed in a partition wall or a protective film and the like without contributing to excitation of a fluorescent material. By adding gadolinium to the materials excluding the fluorescent material among structures surrounding the discharge cell, ultraviolet ray having a wavelength of 315 nm is generated, which can excite the fluorescent material. The ultraviolet ray excites the fluorescent material to generate visible light, and then, electric-light conversion efficiency is improved.

Abstract: A cathode for an electron tube provided with a base containing at least one kind of reducing agent, a metal layer whose main component is tungsten formed on the base, and an electron emission material layer whose main component is an alkaline-earth metal oxide including barium formed thereon, deformation of the base in operation is controlled by composing the metal layer with a porous metal layer and limiting the thickness and the porosity of the metal layer. As a result, it is possible to achieve a cathode for an electron tube applicable to a cathode-ray tube for a display in which the cutoff voltage is liable to change.

Abstract: A cathode for an electron tube provided with a base containing at least one kind of reducing agent, a metal layer whose main component is tungsten formed on the base, and an electron emission material layer whose main component is an alkaline-earth metal oxide including barium formed thereon, deformation of the base in operation is controlled by composing the metal layer with a porous metal layer and limiting the thickness and the porosity of the metal layer. As a result, it is possible to achieve a cathode for an electron tube applicable to a cathode-ray tube for a display in which the cutoff voltage is liable to change.

Abstract: The object of the present invention is to provide a gas discharge display device having improved luminous efficiency by effectively using ultraviolet ray, which is absorbed in a partition wall or a protective film and the like without contributing to excitation of a fluorescent material. By adding gadolinium to the materials excluding the fluorescent material among structures surrounding the discharge cell, ultraviolet ray having a wavelength of 315 nm is generated, which can excite the fluorescent material. The ultraviolet ray excites the fluorescent material to generate visisble light, and then, electric-light conversion efficiency is improved.

Abstract: A control electrode portion for passing electrons through a given electron-passing hole selected from a plurality of electron-passing holes provided on an insulating substrate is formed by coating the insulating substrate with a conductive film and dividing the into a plurality of conductive films as control electrodes. This structure obviates the mesh structure of electrons which are necessary in the case of arranging control electrodes on the insulating substrate, thereby realizing high-definition display devices with improved luminance.

Abstract: Planar display devices which have a small thickness and used as a display unit of a television set, a monitor or the like. A control electrode portion for passing electrons through a given electron-passing hole selected from a plurality of electron-passing holes provided on an insulating substrate is formed by coating the insulating substrate with a conductive film and dividing them into a plurality of conductive films as control electrodes. This structure obviates the mesh structure of electrons which are necessary in the case of arranging control electrodes on the insulating substrate, thereby realizing high-definition display devices with improved luminance.

Abstract: A flat display apparatus is disclosed which includes a grid interposed between and spaced apart from control electrodes and an electron source. The grid which includes holes has a higher potential applied than the one applied to a cathode so as to enable electrons to pass through the holes. An additional grid may be interposed between and spaced apart from the grid and the control electrodes. Alternatively, a rear electrode is located between adjacent porous cover electrodes to connect them, and a second rear electrode is located near the rear electrode and has a lower potential applied than the one applied to the cover electrodes.

Abstract: A cathode for use in electron tubes which comprises a base metal made of nickel as a principal component and having a surface on which a porous electron emissive layer is formed. The porous electron emissive layer is of a composition comprising 0.1 to 20 wt % (relative to the total weight of the porous electron emissive layer) of scandium oxide having a layered crystalline structure dispersed in an oxide of alkaline earth metal including at least barium. This cathode can be made by preparing a solution in which nitrocellulose is dissolved with the use of an organic solvent, mixing both of barium carbonate and scandium oxide having a layered crystalline structure into the solution to provide an suspension, pulverizing solid components of the suspension for the adjustment of particle size, and depositing the suspension on a surface of the base metal to form the electron emissive layer.

Abstract: A metal layer of not more than 2.0 .mu.m thick is formed on a base, containing nickel as the main ingredient and a reducing agent such as silicon and magnesium, by depositing tungsten by an electron beam under heating in a vacuum. The base is heat treated in a hydrogen atmosphere at 800.degree. to 1,100.degree. C. An emissive material layer, containing an alkali earth metal oxide and 0.01 to 25 wt % of a rare earth metal oxide, the alkali earth metal oxide containing at least barium oxide, is formed on the metal layer. Thus, life characteristics of the cathode, especially during the operation at a high current density such as not less than 2A/cm.sub.2, are greatly enhanced.

Abstract: An electrode for discharge light source which is suitable for discharge display on account of its high reliability and outstanding discharge characteristics attributable to the metal conductor which is formed 1-5 .mu.m thick in the discharge container and also to the film of the material for secondary emission which is formed on the metal conductor from a compound composed of LaB.sub.6 and Ba in an amount of 0.01-20 mol % of LaB.sub.6 or a compound composed of LaB.sub.6, Ba in an amount of 0.01-20 mol % of LaB.sub.6, and Ca in an amount of 0.01-5 mol % of Ba, and is 0.5-2 .mu.m thick so that it is free of pin-holes.

Abstract: A cathode for an electron tube in accordance with the present invention comprises: a base (2) containing not only nickel as a major element but also a reducing agent; a layer (3) of an electron-emissive substance which is applied to the base (2) and contains not only an alkaline earth metal oxide as a principal component but also a scandium oxide; and a heater for heating the layer (3).

Abstract: An oxide-coated cathode for an electron tube comprises a layer (2) of an electron-emissive substance. This layer (2) contains: an alkaline earth metal oxide as a principal component containing at least Ba; an oxide of Sc; and at least one heat-resisting oxide selected from the group consisting of oxides of Al, Si, Ta, V, Cr, Fe, Zr, Nb, Hf, Ta, Mo and W.

Abstract: A hot cathode in a wire form is useful in a vacuum tube, a CRT or a fluorescent display tube is disclosed. The cathode is composed of a heat-resistant metal in a wire form that holds on it an electron-emitting metal material that is made of 0.2-20 wt % of a rear earth metal oxide in admixture with an alkaline earth metal oxide the balance of which contains at least barium oxide. The reduction of oxide barium to barium as a result of reaction with the cathode wire is so much retarded that an increased emission current will be produced from the cathode not only in its initial operation but also through out its operation.

Abstract: A cathode for an electron tube in accordance with the present invention comprises: a base containing not only nickel as a major element but also a reducing agent; a layer of an electron-emissive substance which is applied to the base and contains not only an alkaline earth metal oxide as a principal component but also a scandium oxide; and a heater for heating the layer.

Abstract: This invention is a cathode of an indirect heated type having improved electron emission characteristics.A cathode for an electron tube in accordance with the present invention comprises: a base containing Ni as a major element; and a layer of an electron-emissive substance formed on the base, this layer comprising not only alkaline earth metal oxide as a principal component containing at least Ba, but also rare earth metal oxide of 0.1 to 20 wt. % or rare earth metal of 0.05 to 15 wt. %.

Abstract: A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.

Abstract: An electrode for a discharge lamp such as high pressure metal vapor lamps and fluorescent lamps is improved by using an electron emission material comprising lanthanum oxide and yttrium oxide. The electron emission material can be a combination of lanthanum oxide and yttrium oxide with barium.strontium.calcium tungstate or an alkaline earth metal oxide including at least barium oxide.When the electrode is used in a high pressure metal vapor discharge lamp, luminous flux maintenance percent in an initial lightening period is highly improved without forming a black deposition at an end of an arc tube.When the electrode is used in a fluorescent lamp, a formation of a black deposition is prevented and a starting voltage is lowered.

Abstract: An electrode of a high pressure metal-vapor lamp such as a high pressure mercury-vapor lamp including mercury and rare-gas and a high pressure sodium-vapor lamp including mercury, rare-gas and sodium, is disclosed.The electrode has an improved electron emission material containing beryllium oxide and yttrium oxide coated on the substrate of the electrode whereby the electron emission material is uniformly coated to form an electron emission material layer which is firmly bonded and the starting characteristic is excellent and the lumen maintenance is excellent.