PURPOSE: To provide an image tube which is highly sensitive, has low afterimage characteristics and does not cause any deterioration of time response characteristics even during low intensity of illumination, by providing a specified phosphor on a fluorescent output screen.
CONSTITUTION: A glass plate 11 provided with a photoelectric surface 12 and a fiber optics face plate 13 having a fluorescent screen 14 coated with a phosphor having an average particle size of 0.5W3.5μ and the formula of Ln2O2S:xEu (wherein 5×10-4≤x≤4×10-2g atom and Ln is at least one element selected from among La, Gd, Y) are arranged in such a manner that the photoelectric surfasce 12 and the fluorescent screen 14 are opposed to each other and hermetically sealed through holding fitments 15, 16 and an insulating ring 17. The inside thereof is kept under high vacuum to form an image tube 10.
TAKAHARA TAKESHI
YANAGISAWA TAKUJI
