Patent ID: 8072151

Claim:
A backlight module comprising: a plurality of light sources; and an inverter circuit disposed on a single layer circuit driving the light sources, the inverter circuit comprising: at least one group of transformers, comprising two primary windings and two secondary windings each comprising a high voltage terminal and a low voltage terminal, wherein a polarity of one of the high voltage terminals is opposite to a polarity of the other high voltage terminal; at least two first copper foils electrically connected between the light sources and the high voltage terminals of the transformer respectively; a power stage circuit electrically connected to the primary winding of the transformer, for converting a received a signal to an alternating current (AC) signal; at least one detection circuit detecting voltages output from the high voltage terminals of the transformer, the at least one detection circuit comprising: at least one second copper foil positioned between the first copper foils, two equivalent capacitors formed between the at least one second copper foil and the first copper foils detecting voltages output from the high voltage terminals of the transformer; and an impedance electrically connected between the at least one second copper foil and ground, dividing voltages detected by the equivalent capacitors; a protection circuit electrically connected to a node formed between the impedance and the at least one second copper foil, for comparing the voltage divided by the impedance to a reference voltage and outputting a protection signal; and a pulse width modulation (PWM) controller electrically connected between the protection circuit and the power stage circuit, for controlling output of the power stage circuit according to the protection signal.