KR20070040973A - Apparatus for driving of back light unit - Google Patents

Abstract

The present invention relates to a drive unit of a backlight unit, which enables the common use of the control circuit of the backlight according to the model of the backlight unit.

The driving apparatus of the backlight unit according to the present invention includes a circuit board having a plurality of lamps including first and second electrodes, a driving voltage generation circuit for supplying a lamp driving voltage to the plurality of lamps, and the driving unit. And a control board on which a control circuit for controlling the voltage generation circuit is mounted, and a connection portion for electrically connecting the control board and the circuit board.

According to this configuration, the present invention dualizes a circuit board on which a driving voltage generation circuit for generating a lamp driving voltage is mounted, and a control board on which a control circuit for controlling a driving voltage generation circuit is mounted, and connecting the circuit board and the control board. The board size can be reduced by interconnecting them. Furthermore, the present invention can reduce the cost by replacing only the control board or circuit board on which the defective circuit is mounted when the driving voltage generating circuit or the control circuit is defective. In addition, the control board can be used in common in the model using this type of lamp, thereby improving component efficiency.

Description

Driving device for backlight unit {APPARATUS FOR DRIVING OF BACK LIGHT UNIT}

1 is a cross-sectional view schematically showing a liquid crystal display module having a conventional direct backlight unit.

Figure 2 is a schematic view showing an inverter for a conventional external electrode lamp.

Figure 3 is a schematic view showing an inverter for a conventional tube electrode lamp.

4 is a block diagram schematically showing a driving apparatus of a backlight unit according to a first embodiment of the present invention;

5 is a block diagram schematically illustrating a driving device of a backlight unit according to a second embodiment of the present invention;

<Description of the symbols for the main parts of the drawings>

12, 112, 212, 412: lamp

50: printed circuit board

60, 160, 260, 460: Voltage Regulator

70, 170, 270, 470: control unit

80, 180, 380, 480: switching part

82, 182, 282, 582: protection circuit

90, 190, 390, 590: Transformer

150, 450: control board

300, 500: circuit board

310, 510: connection

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a driving apparatus of a backlight unit, which enables to use a backlight control circuit in common according to a model of a backlight unit.

In general, a liquid crystal display module includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix between two glass substrates, and a back light unit for irradiating light to the liquid crystal panel. Will be. In addition, optical sheets are arranged in the liquid crystal display module to vertically generate the light traveling from the backlight unit toward the liquid crystal panel.

The backlight unit may be divided into an edge type and a direct type. The edge type arrange | positions a lamp to the side surface of a light guide plate, and the light from a lamp is irradiated to a liquid crystal panel through a light guide plate. The direct type is provided with a plurality of lamps in the lower portion of the liquid crystal panel, the light from each lamp is irradiated to the liquid crystal panel through the diffusion plate.

1 is a schematic cross-sectional view of a liquid crystal display module having a conventional direct type backlight unit.

Referring to FIG. 1, a conventional liquid crystal display module includes a liquid crystal panel 20 for displaying an image and a direct type backlight unit 2 for irradiating uniform light onto the liquid crystal panel 20.

In the liquid crystal panel 20, liquid crystal cells are arranged in an active matrix form between the upper and lower substrates 22 and 24, and pixel electrodes and a common electrode for applying an electric field to each of the liquid crystal cells are provided. Will be prepared. In general, the pixel electrode is formed for each liquid crystal cell on the lower substrate 24, that is, the thin film transistor substrate, while the common electrode is integrally formed on the entire surface of the upper substrate 22. Each of the pixel electrodes is connected to a thin film transistor used as a switching element. The pixel electrode drives the liquid crystal cell along with the common electrode according to the data signal supplied through the thin film transistor to display an image corresponding to the video signal.

The backlight unit 2 includes a plurality of lamps 12 for generating light, a bottom cover 10 for accommodating the plurality of lamps 12, and a reflective sheet attached to sidewalls and bottom surfaces of the bottom cover 10. 11, a diffusion plate 14 covering the entire surface of the bottom cover 10, and a plurality of optical sheets 16 stacked on the diffusion plate 14 are provided.

Each of the plurality of lamps 12 includes a glass tube, inert gases inside the glass tube, and first and second electrodes provided at both ends of the glass tube. Inert gas is filled in the glass tube, and phosphor is coated on the inner wall of the glass tube.

Each of the plurality of lamps 12, when an alternating voltage from an inverter (not shown) is applied to the first electrode and the second electrode, electrons are emitted from any one of the first electrode and the second electrode to inert gas in the glass tube. The collision with the field increases the amount of electrons exponentially. As the current flows inside the glass tube by the increased electrons, ultraviolet rays are emitted as the inert gas is excited by the electrons. The ultraviolet rays collide with the luminescent phosphor applied to the inner wall of the glass tube to emit visible light.

The bottom cover 10 supports and accommodates the plurality of lamps 12 to prevent light leakage of visible light emitted from each of the plurality of lamps 12.

The reflective sheet 11 is attached to the side walls and the bottom surface of the bottom cover 10 facing the plurality of lamps 12 by a double-sided tape, and diffuses visible light propagating to the side and back surfaces of the plurality of lamps 12. Reflecting toward 14 improves the efficiency of the light generated in the lamps 12.

The diffuser plate 14 propagates the light emitted from the plurality of lamps 12 toward the liquid crystal panel 20 and diffuses the light from the plurality of lamps 12 so as to be incident at a wide range of angles. The diffusion plate 14 is a material in which a light diffusion member is mixed with a transparent polymer and has a flat plate shape having a predetermined thickness.

The plurality of optical sheets 16 increases the efficiency and luminance of light incident from the diffuser plate 14 and irradiates the liquid crystal panel 20. To this end, the plurality of optical sheets 16 includes at least one prism sheet that collects light from the diffusion plate 14 and irradiates the liquid crystal panel 20. In this case, the plurality of optical sheets 16 may further include at least one diffusion sheet.

On the other hand, the inverter for driving the plurality of lamps 12 depends on the type of the lamp (12). That is, the first and second electrodes of the lamp 12 are divided into an external electrode lamp inverter formed outside the glass tube, and the first and second electrodes of the lamp 12 are formed into an inner tube lamp inverter formed inside the glass tube.

2 is a view schematically showing a conventional inverter for external electrode lamps.

Referring to FIG. 2, a conventional external electrode lamp inverter includes a first connector 52, a voltage regulator 60, a control unit 70, a switching unit 80, and a transformer (mounted on a printed circuit board 50). 90), a protection circuit 82, and a second connector 54.

First, a first electrode of each of the plurality of lamps 12 is commonly connected to the first common electrode 56, and a second electrode is commonly connected to the second common electrode 58.

The first connector 52 is electrically connected to an external power source to supply an input power source to the voltage regulator 60.

The voltage regulator 60 converts an input power input through the first connector 52 into a DC voltage and supplies it to the controller 70.

The controller 70 generates a switching control signal to control the switching unit 80. In addition, the controller 70 controls the switching unit 80 according to the feedback signal supplied from the protection circuit 82 or shuts down the inverter by cutting off the DC voltage applied to the switching unit 80.

The switching unit 80 converts the DC voltage supplied via the control unit 70 into an AC voltage in response to the switching control signal from the control unit 70 and supplies the converted voltage to the transformer 90.

The transformer 90 boosts the lamp driving voltage for driving the lamp 12 to supply the AC voltage supplied from the switching unit 80 to the second connector 54. At this time, the transformer 90 supplies the lamp driving voltage of the first phase to supply the first electrode of the lamp 12 and the second electrode of the lamp 12 by using the AC voltage supplied from the switching unit 80. A lamp driving voltage having a second phase opposite to the first phase is generated and supplied to the second connector 54.

The protection circuit 82 detects a lamp driving voltage supplied from the transformer 90 to the second connector 54 to maintain a constant tube current flowing through the lamp 12 or to shut down the inverter to the controller 70. Supply.

The second connector 54 is electrically connected to the first common electrode through the first voltage line to supply the lamp driving voltage of the first phase supplied from the transformer 90 to the first common electrode 56. The lamp driving voltage of the second phase, which is electrically connected to the second common electrode through the voltage line and supplied from the transformer 90, is supplied to the second common electrode 58.

In the conventional external electrode lamp inverter, one or two large-capacity transformers 90 are used to apply first and second lamp driving voltages having reverse phases to the first and second electrodes of the plurality of lamps 12. The supply causes the plurality of lamps 12 to be driven.

However, such a conventional inverter for external electrode lamps includes a first connector 52, a voltage regulator 60, a controller 70, a switching unit 80, a transformer 90 and a protection circuit 82, a second. By mounting the driving circuit including the connector 54 on one printed circuit board 50, the size of the printed circuit board 50 is increased. In addition, the conventional external electrode lamp inverter has a problem that the printed circuit board 50 must be replaced when any one of the driving circuits is defective.

3 is a view schematically showing a conventional inverter for a tube lamp.

Referring to FIG. 3, a conventional inverter for an internal electrode lamp may include a first connector 152, a voltage regulator 160, a controller 170, a switching unit 180, and a plurality of inverters mounted on a printed circuit board 150. The transformer 190, the protection circuit 182, and the second connector 154 are included.

The first connector 152 is electrically connected to an external power source to supply input power to the voltage regulator 160.

The voltage regulator 160 converts an input power input through the first connector 152 into a DC voltage and supplies it to the controller 170.

The controller 170 generates a switching control signal to control the switching unit 180. In addition, the controller 170 controls the switching unit 180 according to the feedback signal supplied from the protection circuit 182 or shuts down the inverter by cutting off the DC voltage applied to the switching unit 180.

The switching unit 180 converts the DC voltage supplied via the control unit 170 into an AC voltage in response to the switching control signal from the control unit 170 and supplies the converted voltage to the plurality of transformers 190.

Each of the plurality of transformers 190 boosts the lamp driving voltage for driving the lamp 112 to supply the AC voltage supplied from the switching unit 180 to the second connector 154.

The protection circuit 182 detects a lamp driving voltage supplied from each transformer 190 to the second connector 154 to control a feedback signal for maintaining a constant tube current flowing through the lamp 112 or shutting down the inverter. To feed.

The second connector 154 is electrically connected to the first electrode of each of the plurality of lamps 112 through the plurality of first voltage lines 156. Accordingly, the second connector 154 supplies a lamp driving voltage supplied from each of the plurality of transformers 190 to each first electrode of each of the plurality of lamps 112 through each of the plurality of first voltage lines 156. . At this time, the second electrode of each of the plurality of lamps 112 is commonly connected to the second voltage line 158 and electrically connected to the base voltage source.

The conventional inverter for luminescent electrode lamps drive the plurality of lamps 112 by supplying a lamp driving voltage to the first electrodes of the plurality of lamps 112 using the plurality of small-capacity transformers 190.

However, the conventional inverter for the luminescent electrode lamp includes a first connector 152, a voltage regulator 160, a controller 170, a switching unit 180, a plurality of transformers 190, a protection circuit 182, and a second. The size of the printed circuit board 150 is increased by mounting the driving circuit including the connector 154 on one printed circuit board 150. In addition, the conventional inverter for a tube lamp has a problem that the printed circuit board 150 must be replaced when any one of the driving circuits is defective.

Accordingly, it is an object of the present invention to provide a driving apparatus of a backlight unit, which enables the control circuit of the backlight to be used in common according to the model of the backlight unit.

In order to achieve the above object, a driving apparatus of a backlight unit according to an embodiment of the present invention includes a plurality of lamps including first and second electrodes and a driving voltage for supplying a lamp driving voltage to the plurality of lamps. And a circuit board on which a circuit is mounted, a control board on which a control circuit for controlling the driving voltage generation circuit is mounted, and a connection part for electrically connecting the control board and the circuit board.

The connection part is characterized in that the cable or flexible printed circuit (FPC).

Each of the plurality of lamps may include a glass tube having an inner wall coated with a phosphor and filled with a discharge gas, and the first and second electrodes formed at both ends of the glass tube.

The control board includes a voltage regulator for converting the input power into a DC voltage, and a control unit for controlling the driving voltage generation circuit.

The circuit board may include a switching unit for converting the DC voltage into an AC voltage according to a switching control signal from the controller, and a transformer for converting the AC voltage into the lamp driving voltage.

The transformer generates a lamp driving voltage having a first phase commonly supplied to the first electrode and a lamp driving voltage having a second phase opposite to the first phase commonly supplied to the second electrode. do.

One of the control board and the circuit board further comprises a protection circuit for generating a feedback signal corresponding to the lamp driving voltage supplied to the lamp and supplying it to the controller.

Each of the plurality of lamps may include a glass tube having an inner wall coated with a phosphor and filled with a discharge gas, and the first and second electrodes formed at both ends of the glass tube.

The control board includes a voltage regulator for converting the input power into a DC voltage, a controller for generating a switching control signal, and a switching unit for converting the DC voltage into an AC voltage according to the switching control signal.

The circuit board may include a plurality of transformers configured to convert an AC voltage supplied from the switching unit into the lamp driving voltage and supply it to any one of the first and second electrodes of each of the plurality of lamps.

One of the control board and the circuit board further comprises a protection circuit for generating a feedback signal corresponding to the lamp driving voltage supplied to the lamp and supplying it to the controller.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 and 5.

4 is a block diagram schematically illustrating an apparatus for driving a backlight unit according to a first embodiment of the present invention.

Referring to FIG. 4, the driving apparatus of the backlight unit according to the first embodiment of the present invention has a plurality of lamps 212 having first and second electrodes and different phases on the first and second electrodes. A control circuit in which a circuit board 300 mounted with a driving voltage generation circuit for supplying the first and second lamp driving voltages and a control circuit for supplying input power to the driving voltage generation circuit and controlling the driving voltage generation circuit are mounted. The board 250 and the connection part 310 for electrically connecting the control board 250 and the circuit board 300 are provided.

Each of the plurality of lamps 212 includes a glass tube, inert gases inside the glass tube, and first and second electrodes installed outside both ends of the glass tube. Inert gas is filled in the glass tube, and phosphor is coated on the inner wall of the glass tube.

The first electrode of each of the plurality of lamps 212 is commonly connected to the first common electrode 256 to receive a first lamp driving voltage having a first phase from the circuit board 300. In addition, a second electrode of each of the plurality of lamps 212 is commonly connected to the second common electrode 258 to receive a second lamp driving voltage having a second phase opposite to the first phase from the circuit board 300. .

Each of the plurality of lamps 212 may have electrons from any one of the first and second electrodes when the first and second lamp driving voltages from the circuit board 300 are applied to the first and second electrodes, respectively. Is released and collides with the inert gases in the glass tube, and the amount of electrons increases exponentially. As the current flows inside the glass tube by the increased electrons, ultraviolet rays are emitted as the inert gas is excited by the electrons. The ultraviolet rays collide with the luminescent phosphor applied to the inner wall of the glass tube to emit visible light.

The control board 250 includes a control circuit including a first connector 252, a voltage regulator 260, a controller 270, a protection circuit 282, and a second connector 254.

The first connector 252 is electrically connected to an external power source to supply input power to the voltage regulator 260.

The voltage regulator 260 converts an input power input through the first connector 252 into a DC voltage and supplies it to the controller 270.

The controller 270 generates a switching control signal and supplies it to the second connector 254. In this case, the controller 270 varies the switching control signal such that the first and second lamp driving voltages supplied to the lamps 212 are constant according to the feedback signal supplied from the protection circuit 282. The controller 270 shuts down the inverter by cutting off the DC voltage applied to the circuit board 300 according to the feedback signal supplied from the protection circuit 282.

The protection circuit 282 uses a lamp driving voltage supplied from the circuit board 300 to the lamp 212 through the connection part 310 to feed back a constant tube current to the lamp 212 or to shut down the inverter. It is supplied to the control unit 270. Here, the protection circuit 282 may be mounted on the circuit board 300.

The second connector 254 outputs a switching control signal from the controller 270, a DC voltage, and the like to the connection unit 310 via the controller 270.

The circuit board 300 includes a driving voltage generation circuit including a third connector 302, a switching unit 380, a transformer 390, and a fourth connector 304.

The third connector 302 supplies a DC voltage supplied from the second connector 254 to the switching unit 380 through the connection unit 310.

The switching unit 380 converts the DC voltage supplied via the control unit 270 into an AC voltage in response to a switching control signal supplied from the control unit 270 mounted on the control board 250 via the connection unit 310. To the transformer 190.

The transformer 390 boosts the lamp driving voltage for driving the lamp 212 to supply the AC voltage supplied from the switching unit 380 to the fourth connector 304. At this time, the transformer 390 supplies the lamp driving voltage of the first phase for supplying the first electrode of the lamp 212 and the second electrode of the lamp 212 using the AC voltage supplied from the switching unit 380. A lamp driving voltage having a second phase opposite to the first phase is generated and supplied to the fourth connector 254.

The fourth connector 304 is electrically connected to the first common electrode 256 through the first voltage line to supply the lamp driving voltage of the first phase supplied from the transformer 390 to the first common electrode 256. The lamp driving voltage of the second phase which is electrically connected to the second common electrode 258 through the second voltage line and supplied from the transformer 390 is supplied to the second common electrode 258.

On the other hand, the circuit board 300 is folded along the connection portion 310 is located on the back of the control board 250.

The connection part 310 is electrically connected between the second connector 254 of the control board 250 and the third connector 302 of the circuit board 300 to transmit a signal between the control board 250 and the circuit board 300. do. In this case, the connection unit 310 may be a cable or a flexible printed circuit (FPC).

As described above, the driving apparatus of the backlight unit according to the first embodiment of the present invention controls the circuit board 300 mounted with the driving voltage generation circuit for generating the first and second lamp driving voltages, and the driving voltage generation circuit. The size of the board can be reduced by including a control board 250 having a control circuit mounted thereon and a connection part 310 electrically connecting the circuit board 300 and the control board 250. Furthermore, the driving device of the backlight unit according to the first embodiment of the present invention replaces only the control board 250 or the circuit board 300 on which the defective circuit is mounted when the driving voltage generating circuit or the control circuit is defective. This can reduce costs.

In addition, the driving apparatus of the backlight unit according to the first embodiment of the present invention may improve component efficiency since the control board 250 may be used in common according to the type of the backlight unit. That is, the control circuit mounted on the control board 250 may be used because the driving method is determined according to the type of the lamp 212 because there is almost no difference depending on the model.

5 is a block diagram schematically illustrating a driving device of a backlight unit according to a second embodiment of the present invention.

Referring to FIG. 5, a driving apparatus of a backlight unit according to a second embodiment of the present invention includes a plurality of lamps 412 having first and second electrodes, and a drive for supplying a lamp driving voltage to the first electrodes. A circuit board 500 mounted with a voltage generation circuit, a control board 450 mounted with a control circuit for supplying input power to the driving voltage generation circuit and controlling the driving voltage generation circuit, and a control board 450 and a circuit The connection part 510 for electrically connecting the board 500 is provided.

Each of the lamps 412 includes a glass tube, inert gases inside the glass tube, and first and second electrodes installed in both ends of the glass tube. Inert gas is filled in the glass tube, and phosphor is coated on the inner wall of the glass tube.

The first electrode of each of the plurality of lamps 412 is electrically connected to the circuit board 500 through each of the plurality of first voltage lines 456. The lamp driving voltage is supplied to the first electrode of each of the plurality of lamps 412 from the circuit board 500 through each of the plurality of first voltage lines 456. The second electrode of each of the plurality of lamps 412 is commonly connected to the second voltage line 458 and electrically connected to the base voltage source.

When the lamp driving voltage from the circuit board 500 is applied to the first electrode, each of the plurality of lamps 412 emits electrons from any one of the first electrode and the second electrode, and the inert gases inside the glass tube. Collision increases the amount of electrons exponentially. As the current flows inside the glass tube by the increased electrons, ultraviolet rays are emitted as the inert gas is excited by the electrons. The ultraviolet rays collide with the luminescent phosphor applied to the inner wall of the glass tube to emit visible light.

The control board 450 includes a control circuit including a first connector 452, a voltage regulator 460, a controller 470, a switching unit 480, and a second connector 454.

The first connector 452 is electrically connected to an external power source to supply an input power source to the voltage regulator 460.

The voltage regulator 460 converts an input power input through the first connector 452 into a DC voltage and supplies it to the controller 470.

The controller 470 generates a switching control signal and supplies it to the switching unit 480. At this time, the control unit 470 varies the switching control signal so that the lamp driving voltage supplied to each lamp 412 is constant according to the feedback signal supplied from the circuit board 500. In addition, the controller 470 shuts down the inverter by cutting off the DC voltage applied to the circuit board 500 according to a feedback signal supplied from the circuit board 500.

The switching unit 480 converts the DC voltage supplied through the control unit 470 into an AC voltage in response to the switching control signal supplied from the control unit 470 and supplies the converted voltage to the second connector 454.

The second connector 454 outputs an AC voltage supplied from the switching unit 480 to the connection unit 510. In addition, the second connector 454 supplies a feedback signal from the circuit board 500 to the controller 470.

The circuit board 500 includes a driving voltage generation circuit including a third connector 502, a plurality of transformers 590, a protection circuit 582, and a fourth connector 504.

The third connector 502 supplies an AC voltage supplied from the second connector 454 to each of the plurality of transformers 590 through the connection portion 510. The third connector 502 supplies a feedback signal from the protection circuit 582 to the second connector 454.

Each of the transformers 590 boosts a lamp driving voltage for driving the lamp 112 and supplies the alternating voltage supplied from the switching unit 480 through the third connector 502 to the fourth connector 504. .

The protection circuit 582 is configured to generate a feedback signal for maintaining a constant tube current flowing through the lamp 412 or shutting down the inverter using a lamp driving voltage supplied from the plurality of transformers 590 to the fourth connector 504. Supply to the control unit 470 through the second connector (502, 454). Here, the protection circuit 582 may be mounted on the control board 450.

The fourth connector 504 supplies a lamp driving voltage supplied from each of the plurality of transformers 590 through the plurality of first voltage lines 456 to the first electrode of each of the plurality of lamps 412.

On the other hand, the circuit board 300 may be folded along the connection portion 310 may be located on the back of the control board 250.

The connection part 510 is electrically connected between the second connector 454 of the control board 450 and the third connector 502 of the circuit board 500 to transmit a signal between the control board 450 and the circuit board 500. do. In this case, the connection unit 510 may be a cable or a flexible printed circuit (FPC).

As described above, the driving unit of the backlight unit according to the second embodiment of the present invention includes a circuit board 500 in which a driving voltage generation circuit for generating a lamp driving voltage is mounted, and a control circuit for controlling the driving voltage generation circuit. The control board 450 and the circuit board 500 and the connection portion 510 for electrically connecting the control board 450 may be provided to reduce the size of the board. Furthermore, the driving device of the backlight unit according to the second embodiment of the present invention replaces only the control board 450 or the circuit board 500 in which the defective circuit is mounted when the driving voltage generating circuit or the control circuit is defective. This can reduce costs.

In addition, the driving device of the backlight unit according to the second embodiment of the present invention may improve the efficiency of the component since the control board 450 may be used in common according to the type of the backlight unit. That is, the control circuit mounted on the control board 450 may be shared since the driving method is determined according to the type of the lamp 412 because there is almost no difference depending on the model.

As described above, the driving apparatus of the backlight unit according to the embodiment of the present invention is a circuit board mounted with a driving voltage generation circuit for generating a lamp driving voltage, and a control board mounted with a control circuit for controlling the driving voltage generation circuit. The size of the board can be reduced by dualizing the circuit board and interconnecting the circuit board with the control board. Furthermore, the present invention can reduce the cost by replacing only the control board or circuit board on which the defective circuit is mounted when the driving voltage generating circuit or the control circuit is defective.

In addition, the present invention is a control circuit mounted on the control board because the driving method is determined according to the type of lamp, so that the control board can be used in common in the model using the lamp of the same type can improve the efficiency of the component.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (11)

A plurality of lamps including first and second electrodes, A circuit board mounted with a driving voltage generation circuit for supplying a lamp driving voltage to the plurality of lamps; A control board mounted with a control circuit for controlling the driving voltage generation circuit; And a connecting portion for electrically connecting the control board and the circuit board. According to claim 1, The connecting unit is a drive device of a backlight unit, characterized in that the cable or flexible printed circuit (FPC). According to claim 1, Each of the plurality of lamps, The inner wall is coated with a phosphor and filled with a discharge gas, And a first electrode and a second electrode formed outside both ends of the glass tube. The method of claim 3, wherein The control board, A voltage regulator for converting the input power into a DC voltage; And a control unit for controlling the driving voltage generation circuit. The method of claim 4, wherein The circuit board, A switching unit converting the DC voltage into an AC voltage according to a switching control signal from the controller; And a transformer for converting the AC voltage into the lamp driving voltage. The method of claim 5, The transformer generates a lamp driving voltage having a first phase commonly supplied to the first electrode and a lamp driving voltage having a second phase opposite to the first phase commonly supplied to the second electrode. Driving device of the backlight unit. The method of claim 5, Any one of the control board and the circuit board further comprises a protection circuit for generating a feedback signal corresponding to the lamp driving voltage supplied to the lamp to supply to the control unit. According to claim 1, Each of the plurality of lamps, The inner wall is coated with a phosphor and filled with a discharge gas, And a first electrode and a second electrode formed in both ends of the glass tube. The method of claim 8, The control board, A voltage regulator for converting the input power into a DC voltage; A control unit for generating a switching control signal; And a switching unit for converting the DC voltage into an AC voltage according to the switching control signal. The method of claim 9, The circuit board includes a plurality of transformers for converting an AC voltage supplied from the switching unit into the lamp driving voltage and supplying it to one of the first and second electrodes of each of the plurality of lamps. Drive of the unit. The method of claim 10, Any one of the control board and the circuit board further comprises a protection circuit for generating a feedback signal corresponding to the lamp driving voltage supplied to the lamp to supply to the control unit.

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