| 摘要 |
PURPOSE:To increase the vapor pressure of metal halides including a sodium halide charged in the emission tube so as to improve the characteristics of an electric discharge lamp coating the outer surface of the end of the emission tube surrounding an electrode with a shield layer made of black titanium. CONSTITUTION:A quartz emission tube is charged with mercury, sodium iodide, scandium iodide and cesium iodide as well as argon. A liquid suspension prepared by mixing a black titania powder called Titaminum Black (commercial name) with butyl acetate, nitrocellulose and a low-melting glass powder is applied to the outer surface of the end of the emission tube surrounding one of the electrodes before drying and baking are performed to form a shield layer, thereby constituting an electric discharge lamp. By the means mentioned above, the shield layer can be very easily formed which has excellent heat-retaining effect and adhesive property. As a result, it is possible to improve the restarting characteristics and the color rendering of the lamp by maintaining the temperature of the tube wall during lighting. |
