GB772572A - Improvements in or relating to x-ray image transformers - Google Patents

Abstract

772,572. Electroluminescence. WESTING- HOUSE ELECTRIC INTERNATIONAL CO. May 23, 1955 [May 28, 1954], No. 14781/55. Class 39(1). An X-ray image transformer comprises an electroluminescent cell irradiated by the X-rays to give an enhanced brightness of the luminescent screen. An electroluminescent layer 20 of ZnS, Cd S activated by manganese with or without sulphur, is superimposed in Fig. 3 on a layer of dielectric material 22, both being enclosed between transparent conductive layers 24, 26, and the whole enclosed between a viewing plate 28 and an insulating layer 30. An alternating potential is applied across the conductive layers. The ratio of ZnS and CdS in the electroluminescent material may be from 9 : 1 to 3 : 7, the manganese in a mol. proportion of 0À3 x 10<-2> to 1À1 x 10<-2>, and the silver from a mere trace to 1À0 x 10<-2> mols per mol of manganese. Specific examples of materials are described and graphs are given showing the brightness and sensitivities of the devices. The electroluminescent material may be dispersed in the dielectric material.