There is provided a backlight unit that determines whether a lamp performs
an abnormal operation by detecting a voltage that is induced in a power
conversion transformer without using a complicated and expensive
detection circuit. A backlight unit having a protection circuit using
induced voltage detection according to an aspect of the invention
includes an inverter part including a primary coil receiving power and at
least one secondary coil converting the power from the primary coil to AC
power set beforehand, a lamp part including at least one lamp receiving
the AC power from the inverter part to emit light, a detection part
including conductors detecting voltages electromagnetically induced in
the secondary coil, and an abnormality determining part comparing
detection voltages from the detection part with a reference voltage set
beforehand.