X-ray conversion screens
AssigneeTokyo Shibaura Electric Co., Ltd.
InventorsMinoru Watanabe, Ryoichi Kubo, Toshio Nishimura, Kazuto Yokota
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Abstract
An X-ray conversion screen having reduced afterglow without any appreciable loss in the brightness under X-ray excitation comprises a substrate and at least one fluorescent layer applied thereto, the fluorescent layer containing a fluorescent substance which comprises terbium-activated lanthanum or gadolinium oxyhalide having yttrium or lutetium and, as desired, ytterbium added thereto as impurities.
Claims8
An X-ray conversion screen comprising a substrate and at least one fluorescent layer applied thereto, said fluorescent layer containing at least one fluorescent substance which comprises a rare earth oxyhalide having the general formula:
- M.sub.1-v-w-z OX:
- Tb.sub.v Yb.sub.w L.sub.z
- wherein M is an element selected from the group consisting of lanthanum and gadolinium;
- X is an element selected from the group consisting of chlorine and bromine;
- L is an element selected from the group consisting of yttrium and lutetium;
- v is from 0.00005 to 0.05 mole per mole of the selected oxyhalide;
- w is not more than 0.005 mole per mole of the selected oxyhalide;
- and z is from 0.000001 to 0.05 mole per mole of the selected oxyhalide.
Dependencies are inferred from the claim text.