GB424895A - Improvements in and relating to metallic vapour and gaseous electric discharge devices - Google Patents

Abstract

424,895. Discharge devices. FREEDMAN, P., 6, Hillside Gardens, Highgate, London. Sept. 7, 1933, No. 24857. [Class 39 (i)] A vapour or gas discharge device, such as a lamp for television purposes, has one main electrode 6 located within a vitreous capsule 7, which is provided with an extension 8 in the form of a flattened cylinder. The electrode 6 consists of a cylinder which may be conically tapered at one or both ends, a spiral or a wire brush, and the other main electrode 9, which is supported on the insulated wire 10, consists of a pointed rod or block, a bundle of wires or a block provided with sharp edges. One or both of the electrodes may be coated with, or be formed of an alloy incorporating barium or strontium. The filling may consist of one or more of the gases or vapours neon, helium, argon, mercury, sodium, cadmium and hydrogen and the colour of the light may be modified by the introduction into the vessel of titanium chloride and thallium chloride, and by the use of anuranium glass or a yellow glass which is preferably fluorescent. When auxiliary electrodes are provided, they may consist of plates or strips or filaments, which are coated with or contain the oxides of barium and strontium, and are located on the exterior of, or are wholly or partly embedded in, the flattened faces of the extension. A plate-shaped auxiliary electrode 11 partly surrounds the extension 8 and is enclosed by a vitreous member 12 in the form of a flattened cylinder which at one end is joined to the extension 8 and at the other end is bell-shaped. An auxiliary electrode may be connected within the device directly or through a resistance to a main electrode or it may be connected to an external contact.