摘要 |
<p>A low-pressure mercury vapor discharge lamp having a phosphor film formed in the inner surface of a glass tube, wherein the phosphor film contains a phosphor, a pyrophosphate with a mean particle diameter of 3.0 νm or less, preferably 1.0 νm or less, at least either on alkaline earth metal salt or a nitrate, and a boric acid compound. The lamp is improved in the adhesion of the phosphor film and the total luminous flux, enhanced in the human maintenance factor, and reduced in the blackening.</p> |