Patent ID: 7772785

Claim:
A parallel lighting system for discharge lamps for a surface light source having a surface light source system, step-up transformers (T 1 , T 2 ) and a shunt transformer (CT 1 ), the surface light source system comprising: multiple discharge lamps (DT), and a current shunt circuit module (CD) which lights said discharge lamps (DT) in parallel, wherein: the surface light source system are driven by the step-up transformers (T 1 , T 2 ) each including two resonance circuits which generate voltage waveforms different in phase by 180 degrees from each other (−VH, +VH), one input terminal and another input terminal of the surface light source system are driven by the voltage waveforms different in phase by 180 degrees from each other (−VH, +VH), and ground side terminals of the step-up transformers (T 1 , T 2 ) are connected to a ground via the shunt transformer (CT 1 ) in such a way that magnetic fluxes which are generated in windings of the shunt transformer are opposed to each other so that the currents respectively flowing in the windings cancel out the generated magnetic fluxes.