Lamp driving apparatus for liquid crystal display device having high contrast ratio

1. A lamp driving apparatus for an LCD device, comprising:

a control unit configured to output control signals and video data to control a driving of a gate driving unit and a data driving unit, and brightness control signals;

the gate driving unit configured to supply scan signals to gate lines on a liquid crystal panel by controlling the control unit and the data driving unit for supplying a data voltage to data lines;

the liquid crystal panel comprising:

liquid crystal cells arranged in a matrix type; and

thin film transistors formed at each intersection between the data lines and the gate lines; and

a backlight driving unit configured to:

control an optical amount by controlling a tube current supplied to a plurality of lamps on a backlight unit; and

selectively turn off some lamps of the plurality of lamps in response to the brightness control signals being inputted,

wherein the backlight unit is configured to implement a lower brightness backlight output in a dark image area by irradiating a backlight comprising a brightness corresponding to light from the lamps emitted by the backlight driving unit toward the liquid crystal panel, and turning off some of the lamps,

wherein the backlight driving unit includes:

a pulse width modulation integrated circuit outputting switching control signals for switching a switching device inside of an inverter integrated circuit, the inverter integrated circuit converting a power source voltage supplied from a power source into an alternating voltage by using the switching device switched by the switching control signals to supply the alternating voltage to a transformer, the transformer outputting the alternating voltage outputted from the inverter integrated circuit by converting into a high alternating voltage corresponding to a winding ratio, and

a turn-off lamp selection unit configured to:

selectively transfer the high alternating voltage outputted from the transformer to the lamps on the backlight unit, and

pass through the outputted high alternating voltage from the transformer to selected lamps, in response to the brightness control signals being inputted, such that the selected lamps can be turned on, and

wherein the turn-off lamp selection unit comprises a plurality of switching devices such that all of the lamps are turned on in response to the brightness control signals comprising a non-specific value is inputted and some of the lamps are selectively turned on when the brightness control signals comprising a specific value is inputted.

2. The lamp driving apparatus of claim 1 , wherein the turn-off lamp selection unit is provided with a plurality of switching devices to selectively transfer the high alternating voltage.

3. The lamp driving apparatus of claim 1 , wherein the backlight driving unit is further configured to turn off the lamps by selecting some lamps per unit number.

4. The lamp driving apparatus of claim 1 , wherein the backlight driving unit is further configured to turn off the lamps in a selected area by dividing all the lamps into some areas.

5. The lamp driving apparatus of claim 1 , wherein the backlight driving unit is further configured to control a tube current supplied to lamps in an analog dimming method or a burst dimming method.

6. The lamp driving apparatus of claim 1 , wherein the backlight driving unit is further configured to drive the lamps in a scanning method or a non-scanning method.