| 摘要 |
PURPOSE:To enable the optical color of a luminous tube to be freely varied by preparing a phosphor from a blue phosphor and an yellow phosphor with different excitation energies. CONSTITUTION:A thermion-emissive cathode 3 is installed in an inner area corresponding to the rivet of a glass tube 1 which has a fan-like cross section and forms a vacuum space 2. An anode 4 consisting of a transparent conductive film is formed on the inner surface of the spherical section of the glass tube 1. And, a phosphor 5 is applied to the above transparent conductive film. The phosphor 5 consists of a mixture of blue phoshor and an yellow phosphor having different excitation energies. The ratio of the yellow phosphor to the blue phosphor is adjusted so that the optical color of the phosphor 5 becomes white for the rated electric potential applied. By the means mentioned above, the optical color (color temperature) can be freely changed from tones of the cold color system to those of the warm color system. |
