Abstract: A cathode for an electron tube and a method of preparing the same are provided. The cathode includes a base metal and an electron emissive material layer attached to the base metal. A surface roughness, which is measured from the distance between a highest point and a lowest point of the surface of the electron emissive material layer, is controlled to be no greater than 8 ?m. By controlling the sizes of particles and pores constituting the electron emissive material layer to be uniform and controlling the density and porosity of the electron emissive material layer, the cathode is improved in compactness and surface evenness compared to a cathode prepared according to a spraying method. Accordingly, shrinking of the cathode during operation can be prevented, and the distance between the cathode and a G1 (first grid) electrode can be maintained uniform, so that the life of the cathode can be greatly extended, and a stable electron emission characteristic can be realized.

Abstract: A screen for a cathode ray tube and a method for manufacturing the screen are provided. The screen for a cathode ray tube includes: a phosphor film formed on the inner front surface of a panel where at least one stud pin is mounted, the phosphor film including phosphor layers; a metal layer formed on the phosphor film, which reflects light emitted from the phosphor layers toward the front side of the panel; and a gas exhaust member extended from the metal layer, which provides a path for gas to exhaust, the gas being generated as a filming layer interposed between the phosphor film and the metal layer to make the thickness of the phosphor film uniform is decomposed. To manufacture this screen, a guide block having a mask pattern, which corresponds to a pattern of a metal layer and gas exhaust member to be formed as a single body inside the panel on which the phosphor film and a filming layer have been formed, is fitted into the panel.

Abstract: A monochrome cathode ray tube, and method of manufacture, including a face panel having a screen portion on which a single color phosphor screen is formed, and the phosphor screen being formed corresponding to an effective viewing area of an outer surface of the face panel. The cathode ray tube may further include a funnel including a neck and connected to the face panel, an electron gun mounted within the neck and emitting an electron beam, and a deflection yoke mounted on the funnel.

Abstract: A screen for a cathode ray tube and a method for manufacturing the screen are provided. The screen for a cathode ray tube includes: a phosphor film formed on the inner front surface of a panel where at least one stud pin is mounted, the phosphor film including phosphor layers; a metal layer formed on the phosphor film, which reflects light emitted from the phosphor layers toward the front side of the panel; and a gas exhaust member extended from the metal layer, which provides a path for gas to exhaust, the gas being generated as a filming layer interposed between the phosphor film and the metal layer to make the thickness of the phosphor film uniform is decomposed. To manufacture this screen, a guide block having a mask pattern, which corresponds to a pattern of a metal layer and gas exhaust member to be formed as a single body inside the panel on which the phosphor film and a filming layer have been formed, is fitted into the panel.

Abstract: A cathode for an electron tube, including a metal base and an electron-emitting material layer coated on the metal base, where the electron-emitting material layer contains a needle-shaped conductive material and the surface roughness corresponding to a distance between the highest point and the lowest point on the surface of the electron-emitting material layer is controlled to be under 10 microns. A needle-shaped conductive material is contained in an electron-emitting material layer to effectively form a conductive path, thereby minimizing the generation of Joule heat due to self-heating of the electron-emitting material layer. Also, grain and pore sizes of the electron-emitting material layer are uniformly controlled and the density and porosity of the electron-emitting material layer are also controlled, thereby improving the density and surface planarity of the cathode compared to the conventional cathode manufactured by a spraying method.

Abstract: A cathode for an electron tube and a method of preparing the same are provided. The cathode includes a base metal and an electron emissive material layer attached to the base metal. A surface roughness, which is measured from the distance between a highest point and a lowest point of the surface of the electron emissive material layer, is controlled to be no greater than 8 &mgr;m. By controlling the sizes of particles and pores constituting the electron emissive material layer to be uniform and controlling the density and porosity of the electron emissive material layer, the cathode is improved in compactness and surface evenness compared to a cathode prepared according to a spraying method. Accordingly, shrinking of the cathode during operation can be prevented, and the distance between the cathode and a G1 (first grid) electrode can be maintained uniform, so that the life of the cathode can be greatly extended, and a stable electron emission characteristic can be realized.

Abstract: An anti-doming composition including a mixture of electron reflecting material such as bismuth oxide, and a zeolite, and a shadow-mask coated with the composition restrict temperature increase by preventing heat transfer, an anti-doming composition including lead and a ZnO, B2O3, Bi2O3 or a mixture thereof, and a shadow-mask coated with the composition protect mechanical expansion of a shadow-mask, and an anti-doming composition including ferroelectrics such as PZT, PT, PZ or PLZT, and a shadow-mask coated with the composition restrict temperature increase by changing the energy of electron beams into non-thermal energy. The shadow-mask of the present invention reduces about 30 to 50% of the anti-doming ratio and has a low production cost and easiness during processes.

Abstract: An anti-doming composition including a mixture of electron reflecting material such as bismuth oxide, and a zeolite, and a shadow-mask coated with the composition restrict temperature increase by preventing heat transfer, an anti-doming composition including lead and a ZnO, B.sub.2 O.sub.3, Bi.sub.2 O.sub.3 or a mixture thereof, and a shadow-mask coated with the composition protect mechanical expansion of a shadow-mask, and an anti-doming composition including ferroelectrics such as PZT, PT, PZ or PLZT, and a shadow-mask coated with the composition restrict temperature increase by changing the energy of electron beams into non-thermal energy. The shadow-mask of the present invention reduces about 30 to 50% of the anti-doming ratio and has a low production cost and easiness during processes.

Abstract: A paste composition for screen printing a cathode ray tube (CRT) shadow mask, the composition including 12-32 wt % of a vehicle, 34-87 wt % of an electron reflecting material, and 0.7-44 wt % of a frit, and a screen printing method using the paste composition. A CRT shadow mask to which the paste composition has been applied, the vehicle driven off, and the frit glassified exhibits decreased doming due to reduced thermal expansion of the shadow mask.

Abstract: A color cathode ray tube in which the structure of a shadowmask frame assembly is improved. The color cathode ray tube includes a panel, a funnel sealingly coupled to the panel, an electron gun installed in a neck portion of the funnel, a deflection yoke installed around a conical portion of the funnel, a shadowmask frame assembly including a shadowmask in which a multiplicity of electron beam passing holes are formed and a frame installed at an inner edge of the panel for supporting the shadowmask, and a heater for thermally expanding the frame in the same direction as the thermal expansion direction of the shadowmask. According to the color cathode ray tube, it is possible to stabilize an initial screen.

Abstract: A shadow mask for color picture tubes made of AK steel has an Ni layer on its surface so that an Fe-Ni alloy layer is obtained in a hydrogen heating furnace to induce substance diffusion of both the Ni layer and the AK steel shadow mask. A method for making shadow mask for color picture tubes including the steps of making a main flat shadow mask body with AK steel, coating its surface with Ni, forming an Fe-Ni alloy layer on the main flat shadow mask, and pressing the main flat shadow mask body to form a certain shape.

Abstract: A method for manufacturing a shadow mask including an electron reflection layer on the surface of the shadow mask on which electrons impact. The electron refection layer is formed by spray coating a composition including an inorganic binder and a bismuth ammonium citrate solution containing 10-50 wt % of bismuth, and heat treating the coated shadow mask. The method is simple in application and greatly reduces hole-blocking and thermal deformation of the shadow mask, improving color purity of a reproduced image and enhancing the quality of the image.

Abstract: Disclosed is a method for making a shadow mask for a color picture tube, including the steps of: forming a pattern, corresponding to apertures of the shadow mask, on a screen mesh fixed to a frame; applying metal paste on the screen mesh having the pattern; disposing a flat AK steel shadow mask under the screen mesh; printing a metal layer on a face of the flat AK steel shadow mask by squeezing the metal paste on the screen mesh with a constant pressure along a direction; and pressing the flat shadow mask to form a skirt portion and a bead portion of the shadow mask.

Abstract: A method of exposing a photosensitive layer or a fluorescent slurry layer deposited on the inner surface of a panel in which a shadow mask frame assembly is installed and apparatus therefor, are provided. A shadow mask installed inside the panel is induction-heated to a predetermined temperature using an induction-heating coil to be sufficiently expanded, and then the photosensitive layer or the fluorescent slurry layer deposited inside the panel is exposed via electron beam passing holes formed in the shadow mask. Therefore, the initial stabilization time for the CRT can be shortened.

Abstract: A method for manufacturing a screen having high luminance is provided including the steps of forming a phosphor layer on a black matrix adhered to a panel, forming a filming layer by coating and drying a filming composition containing a decomposable organic polymer and a reducing agent on the phosphor layer, forming a metal layer on the filming layer, and heating the phosphor layer, filming layer and metal layer to a temperature sufficient to decompose the filming layer.

Abstract: A dispenser cathode includes a tungsten matrix which is impregnated with an active cathode material and coated with a refractory thin film layer metal material along the surfaces thereto, but not including the electron emissive surface of the matrix, thereby improving a heat transfer efficiency from a heater to the electron emissive surface.