Patent ID: 7282867

Claim:
A lighting device for a discharge lamp, comprising: a DC power source; a power conversion circuit, on the basis of an on-off operation of a first switching element, for increasing to an increased voltage a voltage of said DC power source supplied to a primary side according to a turn ratio of a transformer, outputting said increased voltage to a secondary side, and rectifying said increased voltage; a smoothing capacitor for smoothing output of said power conversion circuit; an inverter circuit having said first switching element and a second switching element arranged for output of said power conversion circuit for converting DC power supplied from said smoothing capacitor to AC power by alternately turning on and off by said first and second switching elements; and a load circuit for lighting a lamp resonating with output of said inverter circuit, wherein the transformer includes a primary coil electrically coupled to the primary side and in a first direction and a secondary coil electrically coupled to the secondary side and wound in an opposing second direction.