| 摘要 |
PROBLEM TO BE SOLVED: To allow the detection time of a discharge lamp on-off state not to depend on the turned off time of the on-off time, and constitute such a circuit as no significant cost rise accompanying the same. SOLUTION: A discharge lamp lighting circuit 1 is provided with a detection means 5 detecting the on-off state of a discharge lamp 3, and an abnormal judge means 6 judging discharge lamp 3 abnormality in response to a detection signal from the detection means 5, and displaying the matter or stopping power supply to the discharge lamp 3. When such states as the off time of the discharge lamp 3 is more than a first setting time and the on time of the discharge lamp 3 is less than a second setting time are repeated more than a predetermined time or a predetermined number or times based on the detection signals from the detection means 5, the abnormal judge means 6 judges the situation as the lighting abnormality of the discharge lamp 3. |
