| 摘要 |
525,000. Cathode-ray tubes. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. (Radio Corporation of America). Feb. 10, 1939, No. 4437. Drawings to Specification. [Class 39 (i)] Electrostatic deflecting electrodes for a cathode-ray tube are formed by four plates of high-resistance material fitted together to form a square or rectangular tube, the deflecting potentials being applied along the joined edges. For this purpose the edges of the plates may be bevelled and joined together by a conducting cement to which the leads are attached. A suitable cement consists of fifteen parts of finely powdered silver, 10 parts of Burgundy pitch, and one part of bismuth subnitrate, made into a paste by means of oil of rosemary. The plates, which may be of sintered alumina, are joined by this cement and the whole fired at 500‹C and soaked in a suspension of colloidal graphite in boiling water to render the plates conducting. The end of the tube may be oblique to prevent " Keystone " distortion. Specification 462,275 is referred to. |
