| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device achieving detection circuits for detecting an abnormality of a lighting circuit by a simple and inexpensive structure and enabling secure operation of a protection circuit. SOLUTION: In this discharge lamp lighting device 10, common lines e1, e2 to which a plurality of output ends in low-voltage sides of step-up transformers T1 to Tn having a plurality of discharge lamps La1 to La2n connected thereto are connected are provided, and the output ends in the low-voltage sides connected to the common lines e1, e2 include the same number of two different types of output ends in which phases of lamp current vary with each other at 180°. The discharge lamp lighting device 10 is provided with abnormality detection circuits CM1, CM1' which include detection resistances Rb1, Rb1' detecting lamp current converged in the common lines e1, e2, and comparators CP1, CP1' for comparing the detection voltage with a predetermined reference voltage Vth3 and output abnormality detection signals when the detection voltage exceeds the predetermined reference voltage Vth3; and with a protection circuit 25 stopping drive of bridge circuits BR1 to BRn based on the abnormality detection signals. COPYRIGHT: (C)2008,JPO&INPIT |
