| 摘要 |
PURPOSE:To elevate the minimum cooling temperature of a luminous tube and thereby to enhance the lamp efficiency, by forming a luminous tube having small inside volume in such manner so that the intersectional angle of the electrode core and the internal end of the luminous tube sealing part of an electrode conductor is smaller than the specified angle. CONSTITUTION:A metal such as mercury which, when evaporates, becomes a buffer gas, and sodium are charged into a luminous tube made of alumina having an inside volume of less than 2cm<3>, futher both ends of the luminous tube are charged with two niobium tubes and hermetically sealed with ceramic cement, and electrode coils 4 and 5 are fixed at the top of the niobium tubes 2 and 3, using electrodes cores 6 and 7. Also, the intersectional angle (theta) of the electrode core axis X and the inside ends of the sealing part of the niobium tubes is made to be less than 120 degree, and heat protective films 9 and 10 are installed on the outer part of the tubes. Thus, the minimum cooling temperature of the luminous tube, can be elevated, thereby the difficulties of luminous emission removed, thus a small-type, high color rendering, ligh luminous lamp can be obtained, by selecting the optimum angle (theta). |
