Patent ID: 7282871

Claim:
A backlight inverter for inductively detecting a current, comprising: a drive unit for generating a first voltage controlled in a Pulse Width Modulation (PWM) mode; a main transformer including first and second coils, the main transformer converting the first voltage from the drive unit into a second voltage according to a turn ratio between the first and second coils, and outputting the second voltage in the form of an AC driving current to both ends of a lamp, the both ends of the lamp connected to both ends of the second coil; an auxiliary transformer including a first auxiliary coil formed on a current line connecting between the second coil of the main transformer and the lamp and a second auxiliary coil inductively coupled with the first auxiliary coil, the auxiliary transformer detecting the current flowing to the lamp according to the turn ratio between the first and second auxiliary coils; a full-wave rectifier for rectifying the current detected by the auxiliary transformer; and a drive controller for controlling the PWM duty of the first voltage based on a voltage from the full-wave rectifier.