Patent ID: 7081720
Filing Date: 2006-07-25
Classification: H05B,Y02B

Abstract:
1. An electroluminescent driver circuit for driving an electroluminescent lamp to emit light at a brightness set level, comprising: a closed control loop including an electroluminescent lamp brightness detector arranged to detect a brightness of the electroluminescent lamp and generate a lamp brightness signal in response to the detected brightness, and a controllable power supply arranged to generate a variable bias voltage for driving the electroluminescent lamp at the brightness set level in response to said lamp brightness signal; an on-time detector arranged to detect the total on-time of the electroluminescent lamp and generate therefrom an on-time signal; and a signal combining circuit arranged to generate an output signal combining the lamp brightness signal and the on-time signal, said controllable power supply increasing the variable bias in response to the on-time signal and receiving said output signal of said signal combining circuit for stabilization of the light intensity of the electroluminescent lamp at the brightness set level during aging of the electroluminescent lamp.