| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for prolonging the life of a high voltage discharge lamp lighting device of DC lighting system by minimizing decrease in the screen illuminance in the initial stage of life possibly caused by wear of a negative electrode.SOLUTION: In a projector 10, a power supply circuit 21 has a function for superposing a boot pulse current, and a function for controlling the pulse output timing by turning the pulse superposition on/off. As the pulse superposition condition, the pulse superposition period is a period of 1/3 of one revolution of a color wheel 12 for a pulse peak value of 150%. More specifically, there are two types of (1) a pattern where pulse superposition is performed at a timing of continuous red and blue color filters having a pulse peak value of 150%, a pulse width of 2.222 ms, and a pulse period of 6.667 ms, and (2) a pattern where pulse superposition is performed at a timing of a red color filter having a pulse peak value of 150%, a pulse width of 1.111 ms, and a pulse period of 3.333 ms. |
