| 摘要 |
PURPOSE:To decrease the potential difference between terminals of an induction coil and between the induction coil and the ground and suppress the nonuniformity of the lamp electric field by providing a feeding point at an adequate position of the induction coil and providing an electrostatic shield body nearly half-circling a lamp centering the feeding point. CONSTITUTION:An induction coil 2 is wound around the outer periphery of a lamp 1, a feeding point is provided at the center of one side in the longitudinal direction of the lamp 1, and a high-frequency power source 3 is connected to the feeding point. An electrostatic shield body 5 nearly half-circling the lamp 1 centering the feeding point is applied between the lamp 1 and the coil 2, and the shield body 5 is grounded at its middle point. When the high-frequency potential is plotted at A, B, C...H, the points A, H are in the opposite phases and have the same magnitude. This shield body 5 is electrostatically shielded, but the electromotive force by electromagnetic induction is generated on it, and its potential gradient is in parallel with the potential gradient on the coil 2. The potential difference between terminals of the coil 2 and between the coil 2 and the ground can be thereby decreased, and the nonuniformity of the electric field on the lamp 1 can be suppressed. |
