| 摘要 |
PURPOSE:To prevent phosphor from its damage in such a way that a metal back on the fulorescent screen which produces duplication of scanning lines of radial scanning system or the like forms thicker at the thcikness of the part which is high in scanning line density than the other part. CONSTITUTION:A cathode-ray tube fulorescent screen which is used in the radial scanning system provides a fluorscent membrane 3 to excite on the side of an electron gun of a glass face plate by electron rays and a long persistence fluorescent membrane 2 which is excited thereby, and provides a metal back 5 that is the thickest in the thickness at the part C of the central point on the rear side and varies continuously thinner in the thickness toward the rim parts E of the fluorscent screen. In consequence, this facilitates to prevent the phosphor from the damage at its part due to the incrase in energy loss of the electronic beams at the central point of the fulorescent screen which produces duplication of the scanning lines and in its propinquity. |
