| 摘要 |
PURPOSE:To enhance the luminous efficiency of a low-pressure mercury vapor electric- discharge lamp by providing a transparent conductive film on the outer surface of a glass tube, and electrically connecting said film in such a manner that it has a more negative electric potential than the cathode side so as to increase the chances of mercury atoms colliding with other and to effectively utilizing the collisions for the emission of the lamp. CONSTITUTION:When a conductive film 10 is made to have an electric potential more negative than that of the cathode side through a terminal, positive-column plasmas become positive and the film 10 becomes negative during discharge, and an electric field directed from the positive-column plasmas toward the film 10 develops. Due to such dielectric polarization, the inner wall of the glass tube 2 of a fluorescent lamp comes to have a negative electric potential. Then, electrons which tend to diffuse toward the wall of the tube 2 are confined within the tube 2 since electric repulsive force develops between the wall of the tube having a negative electric potential. Therefore, high-speed electrons having an energy of over 4.89eV which is useful for the emission of the fluorescent lamp, can be confined inside the tube 2. As a result, the loss which might be caused due to high-speed electrons being lost on the wall of the tube 2 and becoming uncontributable to the emission of the lamp, can be prevented. |
