Abstract: A color toner is provided which has a dielectric strength equal to or lower than that of a black toner containing carbon black, and which has an improved charging rate and charge stability against changes in the environment.

Abstract: A method for producing a master pattern used for manufacture of a color picture tube phosphor screen is disclosed. An image of an interchangeable shadow mask is formed on the internal surface of the face glass and transferred onto a photosensitive plate, thereby producing a master pattern with a very high accuracy. In the case of a very thin photosensitive plate, the master pattern is produced directly from the interchangeable shadow mask. The method for producing a color picture tube by use of a master pattern involves equipment much lower in cost and easier in manufacturing processes than the conventional methods due to the facts that exposure by flood light is possible and that the shadow mask and the face glass need not be handled as a couple.

Abstract: A method for forming flat display panel phosphor dots is disclosed wherein a conventional printing method or procedure is used in combination with an optical method.The paste film containing the phosphor, photoresist and powdered glass is coated on the surface of the dielectric layer, e.g. lead glass layer by means of the printing method. The paste layer is irradiated by a ultraviolet light through a mask, and after the development of the paste layer has been completed, the remaining hardened portions of the paste layer are subjected to a heat treatment. In this way, phosphor dots having a desired shape can be formed very firmly and very exactly at certain predetermined portions on said dielectric layer.