A method for driving an electroluminescent lamp to emit light at a
brightness set level includes providing a variable bias voltage to the
electroluminescent lamp. The variable bias voltage is increased with the
duration of the on-time of the electroluminescent lamp. To stabilize the
electroluminescent lamp at the brightness set level against aging, a
closed loop control of the brightness of the electroluminescent lamp is
applied, which is subject to said duration of the on-time the
electroluminescent lamp.