X-RAY IMAGE INTENSIFER

PURPOSE:To improve a diagnosis property and shorten time while largely extending an area possible to offer information at the time of diagnosis by making a domain of a visual field in the operation of the second visual field to be included in the flat part of brightness at the time of normal visual field operation. CONSTITUTION:The operation in the normal visual field (a) of a multistage type X-ray image intensifier (II) and a brightness distribution property in the case of a signal visual field type II are falttened from the central part to the middle part of an output image. At the same time, brightness distribution in the operation of an expanded visual field (c) beyond the second visual field (b) of the maultistage visual field type II is formed so as to be excellent in brightness uniformity having bringhtness on a flat and equal level all over the output image. Accordingly, film thickness distribution of a phosphor layer II of an input surface for II to be used forms the largest film thickness part between the central part of the input surface 7 and the peripheral part while forming film thickness of the central part at that time of 230-8 350mum. Thereby, bringtness drop near 90 % of th periphery is extremely minimized so as to enable to catch information from the whole image thus improving a diagnosis property.