摘要 |
A fluorescent lamp including a curved glass bulb that has a layer including a phosphor layer on an inner surface, mercury and a rare gas enclosed inside, and a pair of electrodes at both ends, and when a tube inner diameter (mm) of the glass bulb is plotted on a horizontal axis of an orthogonal coordinate system and a total amount of CO2 and CO (mol %) contained in gas present inside the glass bulb is plotted on a vertical axis of the orthogonal coordinate system, the tube inner diameter and the total amount of CO2 and CO are in a predetermined area or on a boundary thereof, the predetermined area being bounded by line segments AB, BC, CD, and DA that connect a point A (1.5 mm, 0.008 mol %), a point B (4.0 mm, 0.0005 mol %), a point C (4.0 mm, 0 mol %), and a point D (1.5 mm, 0 mol %) in the stated order. As a result, a fluorescent lamp that has no illumination failure caused by snaking can be obtained even though the fluorescent lamp is in a curved shape.
|