| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp driving device capable of improving a service life of a discharge lamp.SOLUTION: In one aspect of a discharge lamp driving device of the present invention, a control unit can execute first discharge lamp driving and second discharge lamp driving. The first discharge lamp driving executes first control when a voltage between electrodes is not higher than a first threshold voltage, and executes second control when the voltage between electrodes is higher than the first threshold voltage. The second discharge lamp driving executes third control when the voltage between the electrodes is not higher than a second threshold voltage higher than the first threshold voltage, and executes fourth control when the voltage between the electrodes is higher than the second threshold voltage. The ratio of DC current in the second control is larger than the ratio of DC current in the first control, and the ratio of DC current in the fourth control is larger than the ratio of DC current in the third control and the ratio of DC current in the second control. When the voltage between the electrodes is higher than a first transition voltage and consecutive execution time of the second control is longer than the first transition time, the control unit switches from the first discharge lamp driving to the second discharge lamp driving.SELECTED DRAWING: Figure 8 |
