GB717171A - Improvements in or relating to electroluminescent devices - Google Patents

Abstract

717,171. Electro-luminescence. GENERAL ELECTRIC CO., Ltd., and JENKINS, H. G. Dec. 10, 1952 [Dec. 19, 1951], No. 29758/51. Class 39(1) An electro-luminescent lamp comprises a blown glass bulb 1 the inner surface of which carries in the order named a first conducting coating 2, an insulating coating 3 consisting of or containing the luminescent material and a second conductive coating 5, the first coating being at least partly transparent. A layer 4 of transparent insulating material e.g. an alkyd resin, is applied between the luminescent layer 3 and the conducting layer 5. Leaf springs 9, 10 contact with the conductive layers and with stout wires 7, 8 which pass through the pinch 6 to terminal wires 11, 12, and the bayonet cap 15. The bulb 1 may be filled with nitrogen, carbon dioxide or inert gas. The leaf spring 10 may be replaced by a helical spring contacting a curved contact plate abutting resiliently against coating 5. Coating 2 is of stannic chloride with the region adjoining the leaf spring 9, coated with silver paint. The layer 3 is zinc sulphide activated by copper, of grain size 5-30Á. suspended in a nitrocellulose synthetic resin or other binder and flushed on to the conducting layer. Layer 5 is applied by evaporation of aluminium, a short piece 18 thereof being held between leads 7, 8 and which after evacuation of the tube, is heated by passage of current through the wires. An insulating baffle 19 prevents deposition on to ends of the layers which would cause short circuiting. The aluminium may be applied by a separate evaporator which is withdrawn before closure of the pinch. Specification 717,169 is referred to.