| 摘要 |
PROBLEM TO BE SOLVED: To prevent the excessive stress applied to an element, even if the half-wave discharge occurs, at starting of a discharge lamp. SOLUTION: This discharge lamp lighting device is provided with a direct current power source circuit 1, load circuit 2, polarity-reversing circuit 3, an ignitor circuit 4, a control circuit 5 and a correcting circuit. The control circuit 5 performs control of turning a FETQ2 off and turning a FETQ2 on /off at several tens of kHz of high frequency for a period of T1, and continuously, performs the control for turning the FETQ1 and for turning the FETQ2 on/off at several tens of kHz of high frequency for a period T2, and repeatedly performs this series of control at a low frequency (normally, from tens to one hundred Hz) in a period in a total time of the sum of T1 and T2. The correcting circuit 6 corrects each voltage of capacitors Cs1 and Cs2, to a prescribed value E/2 for the prescribed period of time, immediately after lighting a discharge lamp 1a. The correcting circuit 6 is formed of a FETQ6, resistors R61 and R62 and a control circuit 61 for turning the FETQ5 on for the prescribed time, immediately after lighting the discharge lamp 1a by utilizing the result of the detection by an I1a detecting circuit 51. |
