| 摘要 |
PURPOSE:To obtain a low-cost and uniform phosphor film, by mixing 2 kinds of organic solvents with different evaporating speeds to prepare the mixed solvent with desired evaporating speeds, and spreading the phosphor suspension into which the phosphor is added on the internal wall surface of said bulb. CONSTITUTION:Mixture of two kinds of organic solvents with different evaporating speed, for instance, a mixture of butyl acetate and acetone is used as solvent, phosphor is mixed in it, and nitrocellulose or the like as a binder is added into said mixture to prepare the phosphor suspension. This suspension is caused to flow into a bulb, any excessive solution is discharged and the phosphor film is attached hermetically. Thereafter, hot blast is fed into the bulb and the solvent is made vacuum-vaporized on the film, which is dried and then burnt to remove the nitrocellulose acting as a binder. In this way, the evaporating speed of the solvent becomes optimum, and the uniform phosphor film can be produced. |
