| 摘要 |
<p>48,628 "FLUORESCENT LAMP" Conventionally, the inside surfaces of fluorescent lamps are known to be coated with two layers of fluorescent material. The manufacture of such lamps, however, requires two coating operations, and the red-emitting fluorescent material of the first layer has a low luminous efficiency, and the light emitted by the second layer is partially absorbed by the first layer. In order to overcome these problems, a fluorescent lamp is provided which comprises a discharge tube on an inner surface of which there is a single layer comprising an alkaline earth metal boron phosphate containing a divalent europium compound as an activator together with a second fluorescent material which has an emission peak in a wavelength range of 620 to 640 nm and a band width (50%) of 120 to 160 nm.</p> |
