| 摘要 |
PURPOSE:To improve luminous flux characteristics in a fluorescent lamp without lowering phosphor layer film strength, by mixing alumina, which is proper in particle diameter, in a phosphor layer within the range decided by the particle diameter. CONSTITUTION:Alumina particles 4, which have mean particle diameters of 0.5mu or more, are mixed in a phosphor layer I, in a ratio of 5weight% or more of phosphor 3, and a mixture amount y(%) is made to be in the range of y<=80logD+30 where D(mu) is the mean particle diameter of the alumina particles 4. Because the alumina particles 4 are mixed into the phosphor layer I by dispersion, the amount of mixture is allowed to become larger than that used for a usual protective film, resulting in improvement of the phosphor layer film strength and luminous flux decay characteristics in accordance with an increase in this mixture amount.
|
