To provide a discharge lamp lighting device, equipped with a function to sense. The On-period of AC voltage phase controlled, even under the condition that a fluorescent lamp be light out, whereby it is possible to light out and restart the fluorescent lamp according to the sensed On-period and to prevent malfunction in the operation to put on and off the fluorescent lamp.
The arrangement of this discharge lamp lighting device is equipped with fluorescent lamp 3, an AC/DC conversion part 6 for turning the phase-controlled AC voltage into a DC voltage, a dimming control part 7 for calculating dimming control signals from the AC voltage phase-controlled, and a DC/AC conversion part 9 for turning the DC voltage from the AC/DC conversion part 6 into a high-frequency AC voltage, impress the result on the fluorescent lamp 3, and light it off in dimmed lighting according to the dimming control signal. The DC/AC conversion part operates in two operating modes: a first mode for holding the lamp lit and perform dimmed lighting and a second mode for impressing a voltage lower than the lamp start voltage under the condition that the lamp be lit off.
TAKAHASHI KENICHIRO
NARIAMA MASAYOSHI
MIYAZAKI MITSUHARU
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