| 摘要 |
PURPOSE:To reduce activating energy to avoid damage to an electric discharge lamp by detecting the state of power supply to the electric discharge lamp, and reducing the height of activating pulses applied to the lamp with the lapse of time after power supply is started. CONSTITUTION:A first control means 5 which detects the state of power supply to an electric discharge lamp and reduces the height of activating pulses applied to an electric discharge lamp 9 with the lapse of time is provided to ensure that a little amount of activating energy causes the lamp to light up. In addition, a second control means which detects the internal state of a luminous tube after being put out as a difference from its state during stable lighting and increases the height of activating pulses if the difference becomes large is provided to ensure that a little amount of activating energy causes the lamp to be activated if the lamp is to be restarted after being out for a short time. Moreover, a detection means 7 which detects, when the lamp is to be reactivated, the deviation of the state of filler gas in the luminous tube during lights-out from its state during stable lighting-up is provided and connected to the front stage of the means 6 to ensure that the height of pulses is increased as the deviation becomes larger and a little amount of energy causes the lamp to be activated even when the lamp is frequently reactivated. |
