| 摘要 |
PROBLEM TO BE SOLVED: To provide a power feeding device for a discharge lamp capable of perfectly preventing the emission failure of the lamp in a high-pressure mercury vapor discharge lamp having a large mercury filling quantity. SOLUTION: In this power feeding device for a discharge lamp for lighting a high-pressure mercury vapor discharge lamp having a large mercury filling quantity, a dummy arc discharge resistor 59 having a resistance nearly equal to the arc discharge resistance of the high-pressure mercury vapor discharge lamp is formed at the output end of the power feeding device 2 for a discharge lamp in a manner capable of changing over its connected state to the combination of dummy glow discharge resistors 59, 60 having a resistance of around 1/7 as much as glow discharge resistance. The device has such a characteristic that a continuation period in which a dummy glow discharge current in a transient state in changing over to the dummy glow discharge resistors from the state that the dummy arc discharge current is flowing by connecting the dummy arc discharge resistor to the power feeding device for the discharge lamp is equal to or less than 30% of the dummy arc discharge current is 10μs or less, and a period until it returns to at least 70% of the dummy arc discharge current is 100μs or less. |
