| 摘要 |
PURPOSE:To obtain a rapid start type circular fluorescent lamp which has low starting voltage, low fluctuation and good starting characteristics by apply ing a permanent water repellent processing to the outer surface of a glass bulb, and specifying the angle which is made by the center axis of at least one of tungsten coil filament of electrodes sealed at both ends of the glass bulb and a plane containing the center axis of the glass bulb. CONSTITUTION:Silicone etc. is coated on the outer surface of a glass bulb 2 to apply a permanent water repellent processing, and a phosphor film 3 is coated in the inner surface of the glass bulb 2, and an electrode of the tungsten coil filament 4 is sealed at both end portions of the glass bulb 2. Further, the angle theta which is made by the center axis A of the tungsten coil filament 4 and a plane containing the center axis B of the glass bulb 2 is formed to have the angle 60 deg.-120 deg.. Whereby, the fluctuation or the rising of starting voltage due to temperature, humidity and dirt of a lamp surface etc. in a rapid start type circular fluorescent lamp is not generated at all, and the starting character istic is always excellent, and the deviation of the starting voltage is also low. |
