| 摘要 |
PURPOSE:To continuously vary visible area and vary power consumption by slidably mounting a pair of conductors on the outside of a nonelectrode discharge lamp in the direction of tube axis, and applying a high-frequency electromagnetic field between both conductors. CONSTITUTION:A pair of conductors 6a, 6b are slidably mounted on the outside of a nonelectrode discharge lamp 5 in the direction of tube axis, and connected to a radio frequency oscillator 8. When the oscillator 8 is operated, a high-frequency electromagnetic field is generated between conductors 6a, 6b, and metal vapor inside the discharge lamp is ionized, and visible light is emitted from the discharge lamp 5. Since metal vapor is rarely ionized in the space between the each tube end and conductors 6a, 6b, light is not emitted. By sliding conductors 6a, 6b toward the tube axis direction, emission area is freely varied. When the distance between the conductors 6a and 6b is shortened, emission brightness is increased even if a constant power is supplied. This means that constant brightness is obtained by decreased power. |
