| 摘要 |
PROBLEM TO BE SOLVED: To prevent a lighting failure at dead time of a full bridge inverter circuit and to prevent the occurrence of a phenomenon in which the emitted light becomes instantaneously dark, by shortening the delay of rise time and fall time of the output rectangular wave of the inverter circuit. SOLUTION: An AC rectangular wave current outputted by the full bridge inverter circuit 2 is supplied and the discharge lamp 3 is lighted. At the drive of the full bridge inverter circuit 2, a period (dead time Td) in which the switching elements Q2-5 are all turned off is provided, and in order to prevent the lighting failure of the discharge lamp 3 caused by this, an inductance L2 is provided at the rear stage of the full bridge inverter circuit 2. Then, by making the value LL of the inductance L2 as LL≥VL / IL×Td (lighting voltage of the discharge lamp as VL, current as IL, and dead time as Td), and by the energy stored in the inductance, a current is made to flow to the discharge lamp 3 during the dead time. COPYRIGHT: (C)2004,JPO |
