| 摘要 |
PURPOSE:To encomize the phosphor material coated on the discharge side without sacrificing lamp characteristics, by appropriately determining the average grain- diameters of both a phosphor material coated on the glass side, and a phosphor material coated on the discharge side. CONSTITUTION:A phosphor material 2 made of phosphor material with grains of a large-diameter is formed on the glass-bulb surface of a fluorescent-lamp glass bulb 1. A phosphor material layer 3 made of phosphor material with grains of a small-diameter is formed on the layer 2, on the discharge side. Filaments 4 and 4 are fused to the ends of the bulb 1. The layer 2 is made of, for example, a calcium- halophosphate phosphor or 4,200 deg.K. The layer 3 is made of a 4,200 deg.K mixture- phoshoric which consists of, for example, 14wt% of strontium-calcium phosphoric chloride activated with europium, 66wt% of yttrium silicate activated with cerium- terbium, and 20wt% of yttrium oxide activated with europium. |
