| 摘要 |
PURPOSE:To increase the amount of a phoshor fixed to the inner surface of the bulb without changing its dimensions so as to increase the luminous intensity of a fluorescent lamp by fixing the phosphor to the inner surface after it is provided with concaves and convexes sufficiently larger than the particle diameter of the phosphor and smaller than the diameter of the bulb. CONSTITUTION:A straight or U-shaped fluorescent lamp is constituted of a glass bulb 1, a phophor film 2, a pair of filaments 5, bases 6 and other members. The outer surface of the glass bulb 1 is smooth and its inner surface has an irregular surface 11 having concaves and convexes sufficiently larger than the diameter of phosphor particles 21 and smaller than the diameter of the bulb 1. After that, phosphor particles 21 are fixed to the irregular surface 11 to form a fluorescent surface 2. As a result, the area to which the phosphor is fixed can be widely increased as compared to a conventional smooth inner surface, thereby increasing the optical output without changing the shape and the dimensions of the bulb 1. |
