GB799141A - Electroluminescent lamp - Google Patents

Abstract

799,141. Electroluminescence. SYLVANIA ELECTRIC PRODUCTS, Inc. Aug. 17, 1954, [Aug. 17, 1953], No. 23958/54. Class 39(1). One of the electrodes of an electroluminescent lamp has a resistivity of at least 10<SP>4</SP> ohms per unit square. A glass plate 1 carries a transparent conductive coating .2, an electroluminescent layer 3 which may incorporate dielectric material, and a backing coating 4 of high resistance material, e.g., carbon, a high resistivity metal or a semi-conductor. The surface of layer 3 may be rough or wavy, the high resistance layer conforming thereto and contacting also a low resistance layer 8. Clamping rims 9, 10 hold the parts together, and the device may be enclosed in an evacuated hermetically-sealed envelope. If the layer 3 is of an electroluminescent layer, alone, it is applied as a suspension in ethyl cellulose, and the latter subsequently burnt off. The high resistance coating may be a conductive glass, e.g., as made by burning glass and semi-conductive spinels or glass or resin and graphite mixed and fused on porcelain. The electroluminescent material may be a tincontaining zinc manganese silicate, a manganeseactivated zinc fluoride, a zinc or cadmium sulphide or selenide activated by copper or copper and manganese and containing a little lead.