GB448887A - Improvements in luminous electric discharge devices - Google Patents

Abstract

448,887. Discharge lamps. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London.-(Patent - Treuhand - Ges., f³r Elektrische Gl³hlampen; 11, Ehrenbergstrasse, Berlin) Jan. 3, 1935, No. 225. Addition to 445,187. Drawings to Specification. [Class 39 (i)] An improvement in or modification of the means for illumination described and claimed in the parent Specification comprises a transparent or translucent jacket surrounding both the envelope enclosing the discharge and the primary luminescent substance A, which jacket contains the secondary luminescent material B. If the substance B is solid it may be placed on the outer surface of the discharge envelope or on the inner surface of the jacket or on surfaces disposed between the two. The jacket may then be exhausted or filled with indifferent gas. Alternatively, the substance B may comprise liquids, such as solutions of eosin, fluorescine or fuchsin, or gases, such as iodine vapour. The cross-section of the jacket may be made different from that of the discharge envelope, when the ratio of light from the discharge and substance A to that from substance B will vary with the direction of view. Inlet and outlet tubes may provide a continuous flow of luminescent liquid or gas through the outer envelope, and allow changes in concentration or composition of the material. The envelope may be of coloured glass or coated with a coloured transparent layer. The substances A and B may be zinc silicate, fluorescing yellow, and rhodamine respectively, the discharge being in a mixture of neon and mercury vapour. If the substances will withstand the requisite temperature a high pressure discharge may be employed. Thermionic or sheet metal electrodes may be employed.