| 摘要 |
PURPOSE:To provide increased luminous flux and enhanced efficiency without degrading color rendering properties, by providing at least on layer, which is disposed toward the high-pressure discharge tube, of layers of phosphor coatings spread over the interior of the external bulb by an electrostatic coating method. CONSTITUTION:At least one layer 8 disposed toward the high-pressure discharge tube 4 of more than two layers of phosphor coatings 7, 8 spread over the interior of the external bulb 1 is applied by electrostatic coating method, whereby neither interface mixture between the first phosphor coating layer 7 disposed toward the internal wall of the external bulb 1 and the second phosphor coating layer 8 disposed toward the high-pressure illuminating tube 4 noe peeling of the phosphor coating of the first layer 7 occurs, both layers therefore being operative to serve as individual phosphor screens. By the visible rays emitted by the high-pressure illuminating tube 4 as well as by the visible rays produced by conversion of the ultraviolet rays radiated by the tube 4 through the phosphor coating layers 7, 8, the lamp functions as a high-pressure discharge lamp providing good efficiency and color rendering qualities. |
