Patent ID: 8552657

Claim:
A method of driving a gas-discharge lamp and stabilizing the light flux of the lamp under constant flux requirements, wherein, at any one time, the lamp is driven according to one of a plurality of different driving schemes (DS 1 , DS 2 ) and the lamp power is controlled according to one of a plurality of different power control strategies (PC s , PC f ), wherein the lamp is driven according to a first driving scheme (DS 1 ) prior to a trigger event (t sw )and, upon occurrence of the trigger event (t sw ), a driving scheme switchover is effected so that the lamp is subsequently driven according to a second driving scheme (DS 2 ), wherein, in temporal dependence on the trigger event (t sw ), a power control strategy switchover is effected from a first power control strategy (PC s ) to a second power control strategy (PC f ) such that the lamp power is subsequently controlled according to the second power control strategy (PC f ) for a time interval (t m , t f ), and wherein at least one of the power control strategies (PC s , PC f ) comprises a direct power control strategy (PC f ) and at least one of the power control strategies (PC s , PC f , is an indirect power control strategy (PC s ) and, when the lamp power is being controlled according to a direct power control strategy.