| 摘要 |
PURPOSE:To easily remove impurity gases in an exhausting process, which are absorbed in a luminescent layer in a manufacturing process, by specifying means particle size of rare earth phosphors constituting a luminescent layer. CONSTITUTION:In a fluorescent lamp in which a mixed gas containing Kr is sealed, a luminescent layer which is in contact with a discharge space is formed with a plurality of rare earth phosphors having emission peaks in three wave length zones of near 450, 540, and 610nm. Mean particle size of rare earth phosphorous is set to a range of 5-10mum. Even if particle size is decreased to 2mum, rare earth phosphor shows good emission efficiency, but when mean particle size is decreased less than 5mum, removal of impurity gases in an exhausting process is made difficult. When mean particle size exceeds 10mum, forming of luminescent layer is made difficult and appearance of the layer is made bad. Mean particle size of 5-10mum is preferable. Thereby, removal of impurity gases in an exhausting process is made easy and starting characteristic of the lamp is improved. |
