Patent ID: 8044604

Claim:
A control circuit for an inverter which drives an external electrode fluorescent lamp connected to a secondary line of a transformer, the control circuit comprising: a soft start circuit structured to generate a soft start voltage which changes over time when the external electrode fluorescent lamp is ignited; a pulse modulator structured to receive a feedback voltage that corresponds to the output voltage of the inverter and the soft start voltage, and structured to adjust the duty ratio of a pulse signal such that the feedback voltage matches the soft start voltage; a driver structured to control the switching of the voltage at a primary coil of the transformer according to the pulse signal output from the pulse modulator; and a striking control circuit structured to monitor an error signal which is asserted when an abnormal state occurs, and structured to reset and restart the soft start circuit when the error signal has been asserted at a detection timing after the soft start voltage has reached a threshold voltage.