| 摘要 |
PURPOSE:To obtain easily a uniform phosphor film which does not crack, by spreading phosphor suspension on the internal surface of a bulb after a straight bulb is bent into a desired configuration, and forming the desired bulb by drying the resulted film, and burning it. CONSTITUTION:A straight bulb is bent nearly into a U-shape to form 1st bent part 1, and further said bulb is bent toward the direction which intersects orthogonally with the plane containing the both bulb ends 2, 2 and 1st bent part 1 in a U-shape respectively, then 2nd bent part 3, 3 is formed in order to obtain a saddle-type bulb. In this bulb, the phosphor suspension is caused to flow to attach the phosphor film hermetically onto the internal surface of said bulb. The bulb is heated by the hot blast fed into the bulb while it is rotated after the residual suspension is discharged outward. The saddle-type bulb is burned to remove organic matter such as binder or the like after a drying process. Consequently, an uniform phosphor film which does not crack can be easily formed. |
