KR101362152B1 - Backlight unit and liquid crystal display device using the same - Google Patents

Abstract

The present invention relates to a backlight unit and a liquid crystal display device using the same. The backlight unit of the present invention is connected in common with a plurality of lamps having first and second electrodes and first electrodes of odd-numbered lamps, and has a first drive. A first common electrode pattern for supplying a voltage, a second common electrode pattern for common connection with the first electrodes of even-numbered lamps, and a second common electrode pattern for supplying a second driving voltage in a phase opposite to the first driving voltage; A third common electrode pattern commonly connected to the second electrodes of the lamps, the third common electrode pattern supplying a third driving voltage opposite to the first driving voltage, and commonly connected to the second electrodes of the even-numbered lamps; A fourth common electrode pattern supplying a fourth driving voltage having a phase opposite to that of the third driving voltage, a first substrate on which the first and second common electrode patterns are formed, and the third and fourth common electrode patterns A second socket formed on the first substrate, the first socket on which the odd first electrodes are fixed and integrally formed with the first common electrode pattern on the first substrate, and formed on the first substrate. A second socket formed integrally with an electrode pattern to which the even-numbered first electrodes are fixed, and formed on the second substrate, and integrally formed with the third common electrode pattern to fix the odd-numbered second electrodes. And a fourth socket formed on the third socket and the second substrate and integrally formed with the fourth common electrode pattern to which the even second electrodes are fixed.

Backlight, socket

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME}

1 is an exploded perspective view illustrating a liquid crystal display including a backlight unit according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of a liquid crystal display device taken along the line II ′ of FIG. 1.

3 is a cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention.

4 is an exploded perspective view showing first and second connections of a backlight unit according to a second embodiment of the present invention;

5 is a configuration diagram showing a part of a backlight unit according to a third embodiment of the present invention;

Description of the Related Art [0002]

10 bottom case 20 first substrate

22 socket 30 second substrate

40: lamp 50, 60: side frame

300, 400: inverter substrate 310, 410: transformer

330, 430: wire connector 340, 440: wire

350, 510, 450, 610: pin connector 530, 630: hook

The present invention relates to a liquid crystal display, and more particularly, to a backlight unit capable of preventing noise and a liquid crystal display using the same.

In general, the liquid crystal display device displays a desired image by adjusting the amount of light transmitted from the back light unit.

The backlight unit is divided into an edge type backlight unit and a direct type backlight unit according to the position of the lamp. The edge type backlight unit is mainly used for small liquid crystal display devices such as notebooks, and the direct type backlight unit is mainly used for medium and large liquid crystal display devices such as televisions.

The conventional direct type backlight unit includes a plurality of lamps connected in parallel through the first and second common electrodes. The first common electrode is commonly connected to the first electrodes positioned on one side of the plurality of lamps, and the second common electrode is commonly connected to the second electrodes positioned on the other side of the plurality of lamps. The positive voltage is applied to the first electrodes through the first common electrode of the plurality of lamps, and the negative voltage is applied to the second electrodes through the second common electrode. In other words, a positive voltage of the same phase is applied to the first electrodes and a negative voltage of the same phase is applied to the second electrodes.

As a result, a double amplified positive electric field is formed between the first electrodes to which the positive voltage of the same phase is supplied, and a double amplified even between the second electrodes to which the negative positive pressure of the same phase is supplied. Electric field is formed. Such positive and negative electric fields affect the liquid crystal panel, and wave noise is generated. In particular, the wave noise is peaked at the point where the frequency of the horizontal synchronization signal of the liquid crystal panel and the frequency of the lamp driving voltage are the same.

Accordingly, an object of the present invention is to provide a backlight unit capable of preventing noise and a liquid crystal display using the same.

In order to achieve the above object, a backlight unit according to an aspect of the present invention is connected in common with a plurality of lamps having a first and a second electrode, and the first electrodes of the odd-numbered lamps, and supplies a first driving voltage. A second common electrode pattern commonly connected with a first common electrode pattern, first electrodes of even-numbered lamps, and supplying a second driving voltage having a phase opposite to that of the first driving voltage, and second of the odd-numbered lamps A third common electrode pattern commonly connected to the electrodes, the third common electrode pattern supplying a third driving voltage opposite to the first driving voltage, and commonly connected to the second electrodes of the even-numbered lamps; A fourth common electrode pattern supplying a fourth driving voltage having opposite phases, a first substrate on which the first and second common electrode patterns are formed, and a second substrate on which the third and fourth common electrode patterns are formed; And that is characterized.

According to another aspect of the present invention, a liquid crystal display device includes a liquid crystal panel, a backlight unit according to any one of claims 1 to 6 for supplying light to the liquid crystal panel, and a first common electrode pattern of the backlight unit. A first inverter unit supplying a first driving voltage, a second inverter unit supplying a second driving voltage having a phase opposite to the first driving voltage to a second common electrode pattern of the backlight unit, and a second unit of the backlight unit; A third inverter unit for supplying a third driving voltage having a phase opposite to the first driving voltage to the third common electrode pattern; and a fourth driving voltage having a phase opposite to the third driving voltage to the fourth common electrode pattern of the backlight unit; And a fourth inverter unit for supplying.

Hereinafter, a backlight unit and a liquid crystal display using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view schematically illustrating a liquid crystal display device including a backlight unit according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the liquid crystal display device taken along line II ′ of FIG. 1.

1 and 2 illustrate a liquid crystal panel 100 that displays an image, a backlight unit 2 that provides light to the liquid crystal panel 100, a liquid crystal panel 100, and a backlight unit 2. It is configured to include a front case 130 and the bottom case 10 to accommodate.

The front case 130 is bent to surround the non-display area of the liquid crystal panel 100 and the side surface of the bottom case 10. At this time, the front case 130 is fastened and fixed to the panel guide 90 surrounding the side of the bottom case 10.

The inner surface of the bottom case 10 is attached with a reflective sheet 12 for reflecting light from each lamp 40 toward the liquid crystal panel 100, or coated with a reflective material. Here, the reflective sheet 12 may not be attached to portions of both bottom edges of the bottom case 10, that is, portions corresponding to the sizes of the first and second connecting portions 28 and 38.

The liquid crystal panel 100 is mounted on the panel guide 90 to adjust the transmittance of light from the backlight unit 2 in accordance with an image signal to display an image. The liquid crystal panel 100 includes a liquid crystal layer (not shown) formed between the lower substrate 102 and the upper substrate 104, and a spacer for maintaining a constant gap between the lower substrate 102 and the upper substrate 104. Not).

The upper substrate 104 includes a color filter, a black matrix, a common electrode, and the like.

The lower substrate 102 includes a thin film transistor and a pixel electrode connected to the thin film transistor. Here, the common electrode formed on the upper substrate 104 may be formed on the lower substrate 102 depending on the mode of the liquid crystal.

In addition, a data pad region connected to each of the data lines (not shown) and a gate pad region connected to each of the gate lines (not shown) are formed in the non-display area of the lower substrate 102. In the data pad area, a plurality of data circuit films 110 mounted with a data integrated circuit 112 for supplying image signals to the data lines are attached. In the gate pad region, a plurality of gate circuit films 120 mounted with gate integrated circuits 122 for supplying gate scan signals to the gate lines are attached.

In contrast, the data integrated circuit 112 and the gate integrated circuit 122 may be directly mounted on the lower substrate 102 by a chip on glass (COG) method, or the gate integrated circuit 122 may be mounted on the lower substrate 102. It may be formed together with a thin film transistor.

The panel guide 90 is mounted on the seating portion of the bottom case 10 so as to wrap the edges and sides of the diffuser plate 70 and the plurality of optical sheets 80 and to cover the side surface of the bottom case 10. The panel guide 90 prevents the flow of the backlight unit 2 and absorbs external shock applied to the backlight unit 2.

The backlight unit 2 includes a plurality of lamps 40 including first and second electrodes 42 and 44, a diffusion plate 70 disposed below the panel guide so as to face the plurality of lamps 40, and a diffusion plate. At least one optical sheet 80 disposed on the 70, a first connecting portion 28 electrically connected to the first electrodes 42 of each lamp 40, and one side of the bottom case 10. A first side frame 50 which surrounds the first connection 28 and one edge of each lamp 40, and a second connection 38 electrically connected to the second electrodes 44 of each lamp 40. The second side frame 60 is disposed at the other side of the bottom case 10 and surrounds the second connection portion 38 and the other edge of each lamp 40.

The diffusion plate 70 diffuses the light emitted from the plurality of lamps 40 to the entire area of the liquid crystal panel 100.

The plurality of optical sheets 80 allow the light diffused by the diffuser plate 70 to be irradiated perpendicularly to the liquid crystal panel 100. To this end, the plurality of optical sheets 80 may be at least one prism sheet 82 or 84 for condensing the light diffused by the diffusion plate 70.

The first side frame 50 is installed at one edge of the bottom case 10 and surrounds one side edge of the lamp 40 mounted to the first connector 28. To this end, the first side frame 50 includes an inclined surface that reflects light emitted from the lamp 40 and a lamp hole that is formed on the inclined surface and penetrates the lamp 40. The first side frame 50 is installed at one edge of the bottom case 10 by a screw.

The second side frame 60 is installed at the other edge of the bottom case 10 to surround the other edge of the lamp 40 mounted to the second connector 38. To this end, the second side frame 60 has an inclined surface that reflects light emitted from the lamp 40 and a lamp hole which is formed on the inclined surface and penetrates the lamp 40. The second side frame 60 is installed at the other edge of the bottom case 10 by a screw.

Each of the plurality of lamps 40 is detachably mounted to the first and second connectors 28 and 38 to face the liquid crystal panel 100, and is driven through the first and second connectors 28 and 38. It is turned on by the voltage and irradiates light to the liquid crystal panel 100. The lamp 40 uses an external electrode fluorescent lamp (EEFL). The external electrode fluorescent lamp includes a lamp tube in which the phosphor emits light by gas discharge, and first and second electrodes 42 and 44 formed on outer surfaces of both ends of the lamp tube.

Although not shown in the drawings, a hot cathode fluorescent lamp (HCFL) or a cold cathode fluorescent lamp (CCFL) connected to electrodes at both ends of the lamp may be used, and the structure of the socket may vary. have.

The first connecting portion 28 is attached to be alternately connected to the first substrate 20 and the first and second common electrode patterns 25 and 27 on which the first and second common electrode patterns 25 and 27 are formed. A plurality of first and second sockets 22a and 22b are provided. The first and second common electrode patterns 25 and 27 are formed on the first substrate 20 so as to face each other and to be spaced apart from each other. The first common electrode pattern 25 includes a first common line 25a and a plurality of first protrusions 25b protruding from the first common line 25a. The second common electrode pattern 27 may include a plurality of second protrusions protruding from the second common line 27a to cross the second common line 27a and the first protrusion 25b that are parallel to the first common line 25a. (27b) is provided.

The first socket 22a is connected to each of the first protrusions 25b of the first common electrode pattern 25 by a soldering method, and the second socket 22b is connected to the second protrusions of the second common electrode pattern 27. 27b) are connected with each other by a soldering method. The first electrode 42 of the odd numbered lamp is connected to the first socket 22a, and the first electrode 42 of the even numbered lamp is connected to the second socket 22b.

The second connecting portion 38 is attached to be alternately connected to the second substrate 30 and the third and fourth common electrode patterns 34 and 36 on which the third and fourth common electrode patterns 34 and 36 are formed. A plurality of third and fourth sockets 32a and 32b are provided. The third and fourth common electrode patterns 34 and 36 are formed on the second substrate 30 to face each other and to be spaced apart from each other. The third common electrode pattern 34 includes a third common line 34a and a plurality of third protrusions 34b protruding from the third common line 34a. The fourth common electrode pattern 36 may include a plurality of fourth protrusions protruding from the fourth common line 27a to intersect the fourth common line 36a and the third protrusion 34b that are parallel to the third common line 34a. 36b is provided.

The third socket 32a is connected to each of the third protrusions 34b of the third common electrode pattern 34 by soldering, and the fourth socket 32b is connected to the fourth protrusions of the fourth common electrode pattern 36. 36b) is connected with each other by a soldering method. The second electrode 44 of the odd numbered lamp is connected to the third socket 32a, and the second electrode 44 of the even numbered lamp is connected to the fourth socket 32b.

The first and second substrates 20 and 30 use a printed circuit board (PCB), and the sockets attached to the printed circuit board have a clip-type socket structure.

The driving voltages of opposite phases are supplied to the first and second common electrode patterns 25 and 27 of the first substrate 20. For example, the first common electrode pattern 25 supplies the positive driving voltage to the first electrode 42 of the odd-numbered lamp 40 through the first socket 22a and the second common electrode pattern 27. ) Supplies the negative driving voltage to the first electrode 42 of the even-numbered lamp 40 through the second socket 22b. Accordingly, the odd-numbered first electrode 42 and the even-numbered first electrode 42 are supplied with driving voltages in phases opposite to each other, so that the electric field is canceled.

The third and fourth common electrode patterns 34 and 36 of the second substrate 30 are supplied with driving voltages having opposite phases. For example, the third common electrode pattern 34 supplies the negative driving voltage to the second electrode 44 of the odd-numbered lamp 40 through the third socket 32a, and the fourth common electrode pattern 36. ) Supplies the positive driving voltage to the second electrode 44 of the even-numbered lamp 40 through the fourth socket 32b. Accordingly, the odd-numbered second electrode 44 and the even-numbered second electrode 44 are supplied with driving voltages in phases opposite to each other, so that the electric field is canceled.

In addition, the first and second sockets 22a and 22b of the first substrate 20 and the third and fourth sockets 32a and 32b of the second substrate 30 are supplied with driving voltages opposite to each other. do. For example, when the positive driving voltage is supplied to the first sockets 22a of the first substrate 20, the negative driving voltage is supplied to the third sockets 32a of the second substrate 30. Accordingly, the odd first electrode 20 and the odd second electrode 30 are supplied with driving voltages in phases opposite to each other.

As such, since the odd-numbered and even-numbered electrodes on the same substrate are supplied with driving voltages in opposite phases, the electric field is canceled to reduce the wave noise.

Referring to FIG. 2, the backlight unit includes first and second inverter units generating lamp driving voltages, first wires 340 and first lamps supplying lamp driving voltages from the first inverter unit to the first connection unit 28. And a second wire (not shown), a third wire 440 and a fourth wire (not shown) for supplying the lamp driving voltage from the second inverter portion to the second connection portion 38.

The first inverter unit 300 is disposed on one side of the bottom case 10, the first inverter substrate 300, the first inverter integrated circuit 320 and the second inverter integrated circuit (not shown), which are converted into AC power, and AC power. The first transformer 310 for boosting the voltage to the lamp driving voltage and the first wire connector 330 for outputting the lamp driving voltage to the first connection portion 28 are provided.

The first transformer 310 boosts the AC power supplied from the first inverter integrated circuit 320 to the first driving voltage and supplies it to the first wire 340, and supplies it from the second inverter integrated circuit (not shown). The AC power is boosted to the second driving voltage and supplied to the second wire (not shown).

The first wire 340 penetrates one side of the first side frame 50 and is located in the first or second radix socket 330 and the first substrate 20 of the first connector 28. The electrode pattern 25 is electrically connected. In detail, the first wire 340 supplies the first driving voltage supplied from the first transformer 310 to the first wire connector 330 to the first common electrode pattern 25 formed on the first substrate 20. do.

The second wire (not shown) penetrates one side of the first side frame 50 to form a first socket or first socket disposed on the first substrate 20 of the first wire connector 330 and the first connector 28. The common electrode pattern 27 is electrically connected.

Here, the first common electrode pattern 25 and the second common electrode pattern 47 have opposite voltage phases.

The second inverter unit includes a second inverter substrate 400 disposed on the other side of the bottom of the bottom case 10, a third inverter integrated circuit 420 and a fourth inverter integrated circuit (not shown), and an AC power source. The second transformer 410 boosts the power to the lamp driving voltage and the second wire connector 430 outputs the lamp driving voltage to the second connection part 38.

The second transformer 410 boosts the AC power supplied from the third inverter integrated circuit 420 to a third driving voltage and supplies it to the third wire 440, and supplies it from the fourth inverter integrated circuit (not shown). The AC power is boosted to the fourth driving voltage and supplied to the fourth wire (not shown).

The third wire 440 penetrates one side of the second side frame 60 to be disposed on the second substrate 30 of the second wire connector 430 and the second connecting portion 38 or the third common socket. The electrode pattern 34 is electrically connected. In detail, the third wire 440 supplies the third driving voltage supplied to the second wire connector 430 from the second transformer 410 to the third common electrode pattern 34.

A fourth wire (not shown) passes through one side of the second side frame 60 and is an odd-numbered socket or first socket disposed on the second substrate 30 of the second wire connector 430 and the second connecting portion 38. The common electrode pattern 36 is electrically connected. Here, the third common electrode pattern 34 and the fourth common electrode pattern 36 have opposite voltage phases.

In addition, the first sockets 22 of the first connector 28 and the second sockets 32 of the second connector 38 have different voltage phases.

The backlight unit 2 may use a pin connection method as shown in FIG. 3 instead of a wire connection method.

Referring to FIG. 3, except for the connection structure between the inverter unit and the first and second connection units 28 and 38, the same configuration as that of FIG. 2 is omitted.

The backlight unit 2 is disposed in the first inverter unit and is connected to the first pin connector 350 through the first pin connector 350 and the bottom case 10 of the bottom case 10 to output the lamp driving voltage. A pin connector 510, a third pin connector 450 disposed in the second inverter unit and outputting a lamp driving voltage, and a third pin connector 450 penetrating the bottom surface of the bottom case 10 and connected to the third pin connector 450; And a four pin connector 610.

The first pin connector 350 is installed on the rear surface of the first inverter substrate 300 to face the bottom case 10. The first pin connector 350 includes a plurality of first and second lower pins 360a and 360b for outputting a lamp driving voltage to the second pin connector 510. The first pin connector 350 controls the lamp driving voltage supplied from the first transformer 310 to the first and second lower pins 360a and 360b through the through hole formed in the first inverter substrate 300. It is supplied to the 2-pin connector 510.

The first transformer 310 boosts the AC power supplied from the first inverter integrated circuit 320 to the first driving voltage to supply it to the first lower pin 360a and from the second inverter integrated circuit (not shown). The AC power supplied is boosted to the second driving voltage and supplied to the second lower pin 360b.

The second pin connector 510 is installed on the first substrate 20 of the first connecting portion 28 to penetrate the bottom case 10. The second pin connector 510 protrudes from the first insertion groove 522 and the first insertion groove 522 into which the first pin connector 350 is inserted, and thus the first lower pins of the first pin connector 350. The first upper pin 520a electrically connected to the 360360a, the second upper pin 520b electrically connected to the second lower pins 360b, and the first substrate 20 of the first connector 28 A plurality of first hooks 530 for fixing to the bottom case 10 is provided.

A first pin connector 350 is formed in the first insertion groove 522 to be inserted and fixed.

The first and second upper pins 520a and 520b protrude from the first insertion groove 522 of the second pin connector 510 at a predetermined distance, and the first and second upper pins 520a and 520b are formed in the first insertion groove 522. The first pin connector 350 having the second upper pins 520a and 520b is inserted and fixed thereto. In other words, the first upper pin 520a is inserted between the first lower pins 360a to supply a lamp driving voltage to the first common electrode pattern 25 of the first substrate 20. In addition, the second upper pin 520b is inserted between the second lower pins 360b to supply a lamp driving voltage to the second common electrode pattern 27 of the first substrate 20. Here, the first common electrode pattern 25 and the second common electrode pattern 27 have opposite voltage phases.

The plurality of first hooks 530 pass through the bottom case 10 and are fastened to the rear surface of the bottom case 10 so that the first substrate 20 is mounted on the bottom case 10.

The third pin connector 450 is installed on the rear surface of the second inverter substrate 400 so as to face the bottom case 10. The third pin connector 450 includes a plurality of third and fourth lower pins 460a and 460b for outputting the lamp driving voltage to the fourth pin connector 610. The third pin connector 450 controls the lamp driving voltage supplied from the second transformer 410 to the third and fourth lower pins 460a and 460b through the through hole formed in the second inverter substrate 400. Supply to 4 pin connector 610.

The second transformer 410 boosts the AC power supplied from the third inverter integrated circuit 420 to the third driving voltage to supply it to the third lower pin 460a and from the fourth inverter integrated circuit (not shown). The supplied AC power is boosted to the fourth driving voltage and supplied to the fourth lower pin 460b.

The fourth pin connector 610 is installed on the second substrate 30 of the second connecting portion 38 to penetrate the bottom case 10. The fourth pin connector 610 protrudes from the second insertion groove 622 into which the third pin connector 450 is inserted and the second insertion groove 622 to form a third lower portion of the third pin connector 450. The third upper pin 620a electrically connected to the pins 460a, the fourth upper pin 620b electrically connected to the fourth lower pins 460b, and the second substrate 30 of the second connection portion 38. A plurality of second hooks 630 for fixing the bottom case 10 to the bottom case 10.

A third pin connector 450 is formed in the second insertion groove 622 to be inserted and fixed.

The third and fourth upper pins 620a and 620b protrude from the second insertion groove 622 at a predetermined distance, and the third pin connector 450 is inserted into and fixed to the second insertion groove 622. . In other words, the third upper pin 620a is inserted between the third lower pins 460a to supply the lamp driving voltage to the third common electrode pattern 34 of the second substrate 30. In addition, the fourth upper pin 620b is inserted between the fourth lower pins 460b to supply the lamp driving voltage to the fourth common electrode pattern 36 of the second substrate 30. Here, the third common electrode pattern 34 and the fourth common electrode pattern 36 have opposite voltage phases.

The plurality of second hooks 630 are fastened to the bottom of the bottom case 10 by penetrating the bottom case 10 so that the second substrate 30 is mounted on the bottom case 10.

In this way, the connection structure of the inverter unit and the connection unit may be simplified by electrically connecting the inverter unit and the connection unit using the pin connection method, and the leakage current may be minimized by minimizing the transmission distance of the lamp driving voltage.

4 is an exploded perspective view showing another embodiment of the first and second connecting portions 28, 38 of FIG.

Referring to FIG. 4, the first connection part 28 is integrated with the first and second common electrode patterns 25 and 27 and the first and second common electrode patterns 25 and 27 which face each other and are spaced apart from each other. The first and second sockets 22a and 22b formed thereon and the first substrate 20 to which the sockets 22a and 22b integrated with the common electrode patterns 25 and 27 are attached. The first and second sockets 22a and 22b are alternately connected to the first and second common electrode patterns 25 and 27 to be connected to the first electrodes 42 of the lamp 40.

The second connecting portion 38 is formed to be integrally formed with the third and fourth common electrode patterns 34 and 36 facing and spaced apart from each other, and the third and fourth common electrode patterns 34 and 36. The sockets 32a and 32b and the second substrate 30 to which the sockets integrated with the common electrode patterns are attached. The third and fourth sockets 32a and 32b are alternately connected to the third and fourth common electrode patterns 34 and 36 to be connected to the second electrodes 44 of the lamp 40.

FIG. 5 is a diagram illustrating a part of the backlight unit of FIG. 1 according to still another embodiment of the present invention. FIG.

Except for the first and second connectors 28 and 38 and the lamp 40 of FIG. 5, the rest of the structure is the same as that of the LCD shown in FIG. 1.

Referring to FIG. 5, the first connector 28 alternates with the first substrate 20 and the first and second common electrode patterns 25 and 27 on which the first and second common electrode patterns 25 and 27 are formed. A plurality of first and second sockets 22a and 22b are attached to each other so as to be electrically connected. The first and second common electrode patterns 25 and 27 are formed on the first substrate 20 so as to face each other and to be spaced apart from each other. The first common electrode pattern 25 includes a first common line 25a and a plurality of first protrusions 25b protruding from the first common line 25a. The second common electrode pattern 27 may include a plurality of second protrusions protruding from the second common line 27a to cross the second common line 27a and the first protrusion 25b that are parallel to the first common line 25a. (27b) is provided.

The first socket 47a is connected to each of the first protrusions 25b of the first common electrode pattern 25, and the second socket 47b is each of the second protrusions 27b of the second common electrode pattern 27. Connected with. The first electrode 42 of the radix lamp 40 is connected to the first socket 47a, and the first electrode 42 of the even lamp is connected to the second socket 47b.

The second connecting portion 38 is attached to be alternately connected to the second substrate 30 and the third and fourth common electrode patterns 34 and 36 on which the third and fourth common electrode patterns 34 and 36 are formed. A plurality of third and fourth sockets 49a and 49b are provided. The third and fourth common electrode patterns 34 and 36 are formed on the second substrate 30 to face each other and to be spaced apart from each other. The third common electrode pattern 34 includes a third common line 34a and a plurality of third protrusions 34b protruding from the third common line 34a. The fourth common electrode pattern 36 may include a plurality of fourth protrusions protruding from the fourth common line 27a to intersect the fourth common line 36a and the third protrusion 34b that are parallel to the third common line 34a. 36b is provided.

The third socket 49a is connected to each of the third protrusions 34b of the third common electrode pattern 34, and the fourth socket 49b is each of the fourth protrusions 36b of the fourth common electrode pattern 36. Connected with. The second electrode 44 of the odd numbered lamp is connected to the third socket 49a, and the second electrode 44 of the even numbered lamp is connected to the fourth socket 49b.

Each of the first to fourth protrusions 25b, 27b, 34b, 36b is formed in a "B" shape.

The first and second substrates 20 and 30 use a printed circuit board (PCB), and the sockets attached to the printed circuit board may be formed in a box-like structure integrated or separated from the common electrode pattern. The lamp 40 uses a Hot Cathode Fluorescent Lamp (HCFL) or a Cold Cathode Fluorescent Lamp (CCFL) in which electrodes are connected to both ends of the lamp. Hot cathode fluorescent lamps and cold cathode fluorescent lamps include a lamp tube emitting ultraviolet rays by gas discharge such as argon gas and mercury gas in the lamp, first and second internal electrodes connected to both ends of the inside of the lamp tube, and first and second electrodes. And a lead wire connected to the internal electrode and protruding out of the lamp tube.

The driving voltages of opposite phases are supplied to the first and second common electrode patterns 25 and 27 of the first substrate 20. For example, the first common electrode pattern 25 supplies the positive driving voltage to the first electrode 42 of the odd-numbered lamp 40 through the first socket 22a and the second common electrode pattern 27. ) Supplies the negative driving voltage to the first electrode 42 of the even-numbered lamp 40 through the second socket 22b. Accordingly, the odd-numbered first electrode 42 and the even-numbered first electrode 42 are supplied with driving voltages in phases opposite to each other, so that the electric field is canceled.

The third and fourth common electrode patterns 34 and 36 of the second substrate 30 are supplied with driving voltages having opposite phases. For example, the third common electrode pattern 34 supplies the negative driving voltage to the second electrode 44 of the odd-numbered lamp 40 through the third socket 32a, and the fourth common electrode pattern 36. ) Supplies the positive driving voltage to the second electrode 44 of the even-numbered lamp 40 through the fourth socket 32b. Accordingly, the odd-numbered second electrode 44 and the even-numbered second electrode 44 are supplied with driving voltages in phases opposite to each other, so that the electric field is canceled.

In addition, the first and second sockets 22a and 22b of the first substrate 20 and the third and fourth sockets 32a and 32b of the second substrate 30 are supplied with driving voltages opposite to each other. do. For example, when the positive driving voltage is supplied to the first sockets 22a of the first substrate 20, the negative driving voltage is supplied to the third sockets 32a of the second substrate 30. Accordingly, the odd first electrode 42 and the odd second electrode 44 are supplied with driving voltages in phases opposite to each other.

As such, since the odd-numbered and even-numbered electrodes on the same substrate are supplied with driving voltages in opposite phases, the electric field is canceled to reduce the wave noise.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be clear to those who have knowledge.

In the backlight unit and the liquid crystal display using the same according to the present invention as described above, since the odd and even electrodes are supplied with driving voltages in opposite phases, the electric field is canceled to reduce wave noise, thereby improving image quality. You can.

Claims (7)

A plurality of lamps having first and second electrodes, A first common electrode pattern connected in common with the first electrodes of the odd-numbered lamps and supplying a first driving voltage; A second common electrode pattern connected in common with first electrodes of even-numbered lamps and supplying a second driving voltage having a phase opposite to that of the first driving voltage; A third common electrode pattern connected in common with second electrodes of the odd-numbered lamps and supplying a third driving voltage having a phase opposite to that of the first driving voltage; A fourth common electrode pattern connected to the second electrodes of the even-numbered lamps and supplying a fourth driving voltage having a phase opposite to that of the third driving voltage; A first substrate having the first and second common electrode patterns formed thereon; A second substrate on which the third and fourth common electrode patterns are formed; A first socket formed integrally with the first common electrode pattern on the first substrate to fix the odd first electrodes; A second socket formed on the first substrate and integrally formed with the second common electrode pattern to which the even first electrodes are fixed; A third socket formed on the second substrate and integrally formed with the third common electrode pattern to which the odd second electrodes are fixed; And a fourth socket formed on the second substrate and integrally formed with the fourth common electrode pattern to which the even second electrodes are fixed. The method of claim 1, Each of the first to fourth common electrode patterns includes a common line and a protrusion which protrudes from the common line and is connected to an electrode of a corresponding lamp. The method of claim 2, The common line of the first common electrode pattern and the common line of the second common electrode pattern are disposed parallel to each other, The common line of the third common electrode pattern and the common line of the fourth common electrode pattern are disposed parallel to each other, The protrusions of the first common electrode pattern and the protrusions of the second common electrode pattern are disposed to alternate with each other. And a protrusion of the third common electrode pattern and a protrusion of the fourth common electrode pattern are disposed to be alternated with each other. delete delete The method of claim 1, The lamp unit comprises any one of an external electrode fluorescent lamp, a hot cathode fluorescent lamp and a cold cathode fluorescent lamp. A liquid crystal panel, A backlight unit according to any one of claims 1 to 3 and 6 for supplying light to the liquid crystal panel; A first inverter supplying a first driving voltage to the first common electrode pattern of the backlight unit; A second inverter supplying a second driving voltage having a phase opposite to that of the first driving voltage to a second common electrode pattern of the backlight unit; A third inverter configured to supply a third driving voltage having a phase opposite to the first driving voltage to a third common electrode pattern of the backlight unit; And a fourth inverter for supplying a fourth driving voltage having a phase opposite to that of the third driving voltage to the fourth common electrode pattern of the backlight unit.

Images