The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1993
Filed:
May. 08, 1992
Shigeharu Nakajima, Anan, JP;
Genichi Shinomiya, Anan, JP;
Mizuho Takeda, Anan, JP;
Satoru Chikutei, Anan, JP;
Nichia Kagaku Kogyo K.K., Tokushima, JP;
Abstract
The phosphor and the X-rays intensifing screen according to the present inventin emit light by the excitation of X-ray, and they are used for medical and industrial radiography. In addition to the conventional contents of rare earth tantalate and/or rare earth niobate, the phosphor according to the present invention contains a determined quantity of divalent metal. This divalent metal content can make the improvement of the afterglow characteristic and the light emission characteristic of the phosphor. The phosphor according to the present invention is represented by the general formula (I) MyLn.sub.1 -x-(2/3)yDO.sub.4 : xR.sup.3+ (I). In the general formula above, M is at least one divalent metal selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn and Cd, Ln being at least one selected from the group consisting of Y, Gd, La, and Lu, D being either or both of Ta and Nb, R being at least one selected from the group consisting of Tm, Pr, Sm, Eu, Tb, Dy and Yb or the base substance is self-activating, and y is a value in the range 1.times.10.sup.-5 .ltoreq.y.ltoreq.1, and x is a value in the range 0.ltoreq.y.ltoreq.0.05.