| 摘要 |
PURPOSE:To perfectly prevent the mixing of colors due to extrusion of a fluorescent substance by minimizing a decrease in the strength of exposure through the selection of an optimum diameter of a light source. CONSTITUTION:In the case where a fluorescent screen 13 consisting of a mosaic structure is formed on the inner surface of a face panel by a photographic printing process which uses a light source 10 and a shadow mask 11, when the distance between the light source 10 and the shadow mask 11 is expressed as L, the distance from the shadow mask 11 to the inner surface of the face panel as Q, the opening width of the shadow mask 11 as D, the opening width of the shadow mask 11 on the fluorescent screen 13 as d, and the width of the light emitting portion of the light source 10 as a, the fluorescent screen 13 is exposed to light by using the light source which is expressed by a<=(D-d)XL/Q. In this way, there will be no extrusion of a fluorescent substance and no bad mixing of colors. |
