| 摘要 |
A luminous tube, a fluorescent lamp, and a luminous tube production method in which a larger quantity of light is emitted downward in actual use of the fluorescent lamp are provided. The luminous tube includes a glass tube including a folded structure where the glass tube is a spiral from at least one of the ends to a middle part and a fluorescent film on the inner surface thereof, wherein the fluorescent film on the inner surface is thicker on the side closer to the middle part than on the side closer to the ends in a cross-section along the axis of the spiral at any point of the glass tube.
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