HIGH-PRESSURE DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp lighting device capable of preventing the damage of a high-pressure discharge lamp caused by the rise of lamp voltage at the end of life. SOLUTION: When the output signal of a life end detecting circuit 9 becomes an H-level during lighting of a lamp La which is the high-pressure discharge lamp, a second control circuit 8 serving as a control means stores the life end state of the lamp La in a storage part. If an AC power supply Vs is closed after cutting off the AC power supply Vs to put out the lamp La, since the life end state of the lamp La is stored in the storage part, the second control circuit 8 performs the on-off control of a switching element Q2 so that the output voltage V1 of a step-down chopper circuit 3 becomes voltage lower than that at the normal starting time. Since an igniter 6 generates high-voltage pulse using the output voltage V1 of the step-down chopper circuit, the wave height value of the high-voltage pulse becomes lower than that at the normal starting time when the output voltage V1 of the step-down chopper circuit 3 becomes low.