KR20080054556A - Lcd module including backlight unit - Google Patents

Abstract

An LCD(Liquid Crystal Display) module having a backlight unit is provided to minimize electrical influence and thermal influence on fluorescent lamps and capacitors. A backlight unit includes a plurality of fluorescent lamps(124), balance PCBs(Printed Circuit Boards)(134), optical sheets, a reflector(122), and a cover bottom(150). Lamp sockets into which the fluorescent lamps are inserted(132) and capacitors(139) for electrically connecting the lamp sockets in parallel are mounted on the balance PCBs. The optical sheets are arranged on the fluorescent lamps and the reflector is located under the fluorescent lamps. The balance PCBs are respectively mounted on both sides of the cover bottom.

Description

Liquid crystal display module including a backlight unit {LCD module including Backlight unit}

1 is an exploded perspective view schematically illustrating a liquid crystal display module including a conventional direct type backlight unit.

FIG. 2 is a view schematically illustrating a rear structure of the liquid crystal display module of FIG. 1.

3 is an exploded perspective view schematically showing a liquid crystal display module including a backlight unit according to an exemplary embodiment of the present invention.

FIG. 4 is a diagram illustrating a balance PCB and a fluorescent lamp mounted inside a cover bottom of a liquid crystal display module according to an exemplary embodiment of the present invention.

5 is an enlarged view of a portion of the balance PCB of the liquid crystal display module according to the embodiment of the present invention.

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

110: liquid crystal panel 115: gate, data printed circuit board

120: backlight unit 130: support main

150: cover bottom 170: inverter unit

180: cover shield

The present invention relates to a liquid crystal display device, and more particularly, to a direct type liquid crystal display device including a plurality of backlight lamps, the backlight unit including a plurality of fluorescent lamps and a capacitor connecting the plurality of fluorescent lamps in parallel. It relates to a liquid crystal display module comprising a.

Recently, a liquid crystal display device is advantageous for thinning and reducing weight and has advantages of low power consumption and low operating voltage. Therefore, many studies have been conducted.

The image realization principle of the liquid crystal display device uses the optical anisotropy and polarization property of the liquid crystal material. The liquid crystal has a thin and long molecular structure and when placed in an anisotropy and an electric field having an orientation in the array, the direction of the molecular array changes according to its size. It is polarized. The liquid crystal display device is a liquid crystal panel composed of a pair of transparent insulating substrates, each having a liquid crystal layer interposed therebetween and having a field generating electrode, as an essential component. The arrangement direction of the molecules is artificially adjusted, and various images are displayed by using the light transmittance which is changed at this time.

Since the liquid crystal panel does not have a light emitting element, and thus requires a separate light source, the liquid crystal panel receives light through a backlight unit provided on the rear surface of the liquid crystal panel, thereby realizing an image of identifiable luminance. According to the arrangement method of the fluorescent lamp included in the backlight unit, a side light type or a liquid crystal panel which refracts the light of the fluorescent lamp disposed at one side edge of the liquid crystal panel with the light guide plate and enters the front of the liquid crystal panel. By arranging a plurality of fluorescent lamps on the back side can be divided into a direct type (direct type) for supplying light directly over the entire liquid crystal panel.

The light metering type has a structure in which one or a pair of lamps is disposed on one side of the light guide plate, and two or two pairs of lamps are disposed on both sides of the light guide plate, and the direct type has several lamps disposed below the light guide plate. With the structure, the photometric type has the advantage of being easy to manufacture, while the direct type has a relatively advantageous advantage for a large liquid crystal display in terms of high uniformity of light.

Here, the backlight unit of the direct type liquid crystal display device does not need a light guide plate because light is directly irradiated to the front surface of the substrate, and a plurality of backlight lamps are available, so that the light utilization rate is high, the handling is simple, and the size of the display surface. Since there is no limitation in this, it is used for the large screen liquid crystal display device of 20 inches or more.

1 is an exploded perspective view schematically illustrating a liquid crystal display module including a conventional direct type backlight unit.

As illustrated, the liquid crystal panel 10, the backlight unit 20, the support main 30, the top case 40, the cover bottom 50, the inverter unit 70, and the cover shield ( 80).

The liquid crystal panel 10 is configured to include a liquid crystal layer spaced apart a predetermined distance, and injected between the upper and lower substrates facing each other. Although not shown, a thin film transistor, which is a switching element, is positioned on the lower substrate, and the gray level of the image is displayed by the turn-on / off driving of the thin film transistor. In addition, a color filter is positioned on the upper substrate to combine R, G, and B primary colors, thereby displaying an image close to a natural color.

 In addition, the liquid crystal panel 10 includes a gate and a data printed circuit board 15 for supplying a scan signal and an image signal to the lower substrate of the liquid crystal panel 10.

The backlight unit 20 positioned at the rear of the liquid crystal panel 10 to supply light is a direct type in which a plurality of fluorescent lamps 24 are used, and a reflective sheet 22 is positioned below the fluorescent lamp 24. At both ends, the support side 33 supports the fluorescent lamp 24, and a plurality of optical sheets 26 are stacked on the upper side.

More specifically, both side ends of the fluorescent lamp 24 is fitted to the lamp holder 32, the lamp holder 32 is inserted into the opening of the support side 33, the support side 33 is the cover bottom 50 Is coupled to both side ends, and supports / fixes the fluorescent lamp 24.

In addition, the fluorescent lamp 24 is connected to a wire connected to an external power source at one end, the wire is extended to the back of the cover bottom 50, is connected to the connector 38 of the inverter unit 70.

The liquid crystal panel 10 and the backlight unit 20 are seated on the support main 30, and the support main 30 prevents and supports the flow of the liquid crystal panel 10 and the backlight unit 20.

The top case 40 covers the upper edge of the liquid crystal panel 10 and the side surface of the support main 30 to support and protect the edge of the liquid crystal panel 10 and the side surface of the support main 30.

The cover bottom 50 covers the lower portion of the support main 30 to protect the lower portion of the liquid crystal display module component described above. The cover bottom 50 is fastened through the support main 30, the top case 40, and a fastening means (not shown) to be modularized.

In addition, an inverter unit 70 for supplying power to the fluorescent lamp 24 is located under the cover bottom 50. The inverter unit 70 includes a plurality of inverters 60, a connector 38 which is a connecting means of the fluorescent lamp 24, and an inverter PCB 35 mounting the same.

In addition, the inverter unit 70 is covered by the cover shield 80. Accordingly, the cover bottom 50 and the cover shield 80 surrounds the inverter unit 70 to protect the inverter unit 70 from external shock, and additionally, the cover bottom 50 and the cover shield 80 ) Is made of a metal material to function to shield the electromagnetic waves generated from the inverter unit 70.

As described above, the inverter unit 70 includes an inverter 60, which generally needs to be equal to or greater than the number of lamps of the fluorescent lamp 24. The inverter 60 is mounted on the inverter PCB 35 in the direction of the cover shield 80 (that is, on the rear side), and the inverter PCB 35 is coupled to the cover shield 80 by the same fastening means.

The inverter unit 70 converts the low voltage of the DC waveform supplied from the external power supply unit into the high voltage of the AC waveform and applies it to the lamp 24.

FIG. 2 is a view schematically illustrating a rear structure of the liquid crystal display module of FIG. 1.

As shown, a plurality of fluorescent lamps (24 of FIG. 1) are supplied with the AC waveform power through a wire 36 connected to an electrode configured at one end, and emit light. In the drawing, the fluorescent lamps (FIG. 1) An example of a high-high system in which an inverter unit is configured at both ends of 24) is shown.

In this high-high scheme, at least two fluorescent lamps (24 of FIG. 1) are provided in pairs and electrically connected to the inverter 60 through wires 36, one end of which is connected to the socket connector 38a. Connected.

As described above, since the high voltage of the AC waveform is required to drive the fluorescent lamp (24 of FIG. 1), an inverter 60 for converting a DC voltage into an AC of high voltage must be provided. ) Generates a lot of heat, so it is placed where it is easy to dissipate as much heat as possible.

Accordingly, a separate inverter PCB 35 is mounted on the outer side of the modular liquid crystal display device, generally, the bottom of the cover bottom 50, and the socket connector 38a is mounted on the inverter PCB 35. And a plug connector 38b to be connected, and the two are electrically connected to the fluorescent lamp 24 of FIG. 1 through a connection.

Here, the fluorescent lamp (24 of FIG. 1) may be used as a CCFL (Cold Cathode Fluorescent Lamp), EEFL (External Electrode Fluorescent Lamp), etc., a direct backlight unit using a CCFL is a plurality of CCFLs using one inverter In the case of parallel driving, only a part of the plurality of lamps are driven by the discharge characteristic of the CCFL.

More specifically, the CCFL has an infinite resistance value before being discharged, whereas the CCFL has a small resistance value due to the plasma of the conductor generated inside the glass tube after discharge. Accordingly, there is a characteristic that the amount of tube current increases by decreasing the resistance value from the initial stage.

For this reason, when driving a plurality of CCFLs in parallel, after the initial discharge, a current flows toward the lamp having a small resistance value, and the remaining lamps are not driven.

Accordingly, the direct backlight unit to which the CCFL is applied should have the inverter 60 as many as the number of lamps, or should have separate parallel driving means, and as shown, the inverter 60 and the plug connector 38b. Capacitors 39, which are parallel driving means, are to be provided between them.

As a result, the number of elements mounted on the inverter PCB 35 increases, and the area occupied by the inverter unit 70 in FIG. 1 increases on the rear surface of the liquid crystal display module.

The present invention has been made to solve the above-described problem, when a plurality of fluorescent lamps are CCFL, to provide a balance PCB (balance PCB) in which the lamp socket to which the fluorescent lamp is fitted, and the capacitors connected in parallel are soldered Let it be a 1st objective.

It is also a second object of the present invention to provide a structure of a balance PCB which minimizes the electrical influence between the fluorescent lamp and the capacitor and the influence of heat emitted.

In order to achieve the above object, the backlight unit according to an embodiment of the present invention, a plurality of fluorescent lamps; A lamp socket into which the fluorescent lamp is fitted, and a balance PCB mounted on the opposite end to which the fluorescent lamp is inserted, a capacitor connecting the lamp sockets in parallel in electrical connection; An optical sheet and a reflecting sheet provided above and below the fluorescent lamp; The balance PCB is characterized in that it comprises a cover bottom mounted on both ends.

In the balance PCB, an opening having a predetermined size, which is an electrical separation space and a heat dissipation space of both electrodes, is formed in a portion where the capacitor is mounted.

Coupled to both ends of the cover bottom, characterized in that it further comprises a support side covering the balance PCB completely.

The balance PCB is characterized in that the PCB wiring for electrically connecting the lamp socket and the capacitor is formed.

The backlight unit may further include an inverter unit for supplying driving power of the fluorescent lamp.

The inverter unit includes a connector connected to the wire; An inverter generating the drive power; It characterized in that it comprises an inverter PCB mounted with the connector and the inverter.

In the liquid crystal display module comprising the backlight unit described above,

A liquid crystal panel mounted on the backlight unit; A support main surrounding the liquid crystal panel and the backlight unit; A top cover surrounding an edge of the liquid crystal panel; It characterized in that it comprises a cover shield provided on the back of the cover bottom.

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

3 is an exploded perspective view schematically illustrating a liquid crystal display module including a backlight lamp according to a first embodiment of the present invention.

As illustrated, the liquid crystal panel 110, the backlight unit 120, the support main 130, the top case 140, the cover bottom 150, the inverter unit 170, and the cover shield ( 180).

Although not shown, a thin film transistor, which is a switching element, is positioned on the lower substrate, and the gray level of the image is displayed by the turn-on / off driving of the thin film transistor. In addition, a color filter is positioned on the upper substrate to combine R, G, and B primary colors, thereby displaying an image close to a natural color. In addition, the liquid crystal panel 110 is connected to a gate and a data printed circuit board 115 for supplying a scan signal and an image signal to the liquid crystal panel 110.

The backlight unit 120 positioned at the rear of the liquid crystal panel 110 to supply light uses a direct type. A plurality of fluorescent lamps 124 are arranged in parallel as a light source, and a lower portion of the fluorescent lamp 124 is provided. The reflective sheet 122 is positioned, and both side ends of the support sheet 133 cover both ends of the fluorescent lamp 124. In addition, a plurality of optical sheets 126 are stacked and positioned on an upper portion of the fluorescent lamp 124.

Both side ends of the fluorescent lamp 124 are fitted to the plurality of lamp sockets 132, the lamp socket 132 is soldered to the balance PCB (134).

The liquid crystal panel 110 and the backlight unit 120 are seated on the support main 130, and the support main 130 prevents and supports the flow of the liquid crystal panel 110 and the backlight unit 120.

The top case 140 covers the edges of the liquid crystal panel 110 and the side surfaces of the support main 130 to support and protect the edges of the liquid crystal panel 110 and the side surfaces of the support main 130.

The cover bottom 150 covers the lower portion of the support main 140 to protect the lower portion of the liquid crystal display device described above. The cover bottom 150 is fastened through the support main 130, the top case 140, and a fastening means (not shown) to be modularized.

In addition, an inverter unit 170 for supplying power to the fluorescent lamp 124 is located under the cover bottom 150, and the inverter unit 170 is a plurality of inverters 160 and a connection means of the fluorescent lamp 124. The in connector 138 and the inverter PCB 135 mounting the same.

The inverter unit 170 is covered by the cover shield 180. Accordingly, the cover bottom 150 and the cover shield 180 surrounds the inverter unit 170 to protect the inverter unit 170 from external shock, and additionally, the cover bottom 150 and the cover shield 180 ) Is made of a metal material to function to shield the electromagnetic waves generated from the inverter unit 170.

The inverter 160 is mounted on the inverter PCB 135 in the direction of the cover shield 180 (ie, rear), and the inverter PCB 135 is coupled to the cover shield 180 by the same fastening means.

The inverter unit 170 converts power supplied from an external power supply unit and supplies the converted power to the fluorescent lamp 124.

Accordingly, when the fluorescent lamp 124 is CCFL is applied, the capacitor 139 mounted on the balance PCB 134 supplies the driving power to be supplied to the plurality of fluorescent lamps in parallel at the same level, thereby providing a high- In the case of a high-high system, a plurality of fluorescent lamps can be driven by only two inverters.

As described above, the inverter unit 170 includes an inverter 160, in general, the number of the inverter 160 is equal to or greater than the number of fluorescent lamps 124, in the embodiment of the present invention The balance PCB 134 is provided with a smaller number of inverters 160 than the lamps 124 and a capacitor 139 which distributes the current flowing in the fluorescent lamp 124 by dividing the driving power supplied in parallel. It is mounted inside the cover bottom.

The balance PCB 134 is mounted on the side end of the cover bottom 150 outside the reflective sheet 122, and the support side 133 covers the lamp socket 132 and the balance PCB 134 completely. Combined with 150. At this time, the fluorescent lamp 124 exits through the opening of the support side 133.

The structure of the balance PCB 134 will be described in more detail. In the balance PCB 134, the lamp socket 132 into which the fluorescent lamp 124 is fitted is soldered side by side in the longitudinal direction of the balance PCB 134, and the cover bottom is covered. It is mounted on both side ends of the to support the fluorescent lamp 124.

In addition, the balance PCB 134 is supplied with the AC waveform power supplied from the inverter unit 170, through which the capacitor 139 for adjusting the amount of current flowing through the plurality of fluorescent lamps is soldered.

At this time, the capacitor 139 is soldered to the side end of the balance PCB 134, that is, the position to secure the maximum distance to the fluorescent lamp 124 in the opposite direction that the fluorescent lamp 124 is fitted to the lamp socket 132 do.

Therefore, the fluorescent lamp 124 and the capacitor 139 have a structure in which the influence of the electrical and the heat emitted from each other is minimized.

FIG. 4 is a diagram showing the form of a balance PCB and a fluorescent lamp mounted inside the cover bottom of the liquid crystal display module according to the embodiment of the present invention. As shown, the balance PCB 134 is a cover bottom ( A lamp socket 132 mounted inside both ends of the 150 and mounted side by side in the longitudinal direction of the balance PCB 134, and a plurality of fluorescent lamps 124 whose ends are fitted into the lamp socket 132; The PCB 134 electrically connecting the capacitor 139 mounted side by side in the longitudinal direction of the balance PCB 134 on the opposite side end on which the lamp socket 132 is mounted in the PCB 134 and one electrode of the capacitor 139 ( 334).

Although not shown, the PCB wiring 334 is electrically connected through a wire (not shown) and a plug connector (138b of FIG. 3) of the inverter unit (170 of FIG. 3) provided as a rear surface of the cover bottom 150. Although it may be connected to each of a plurality of wires, by forming a hole in one end of the balance PCB 134, by connecting one or two wires through the hole, configured to be electrically connected to the inverter unit (170 of FIG. 3) It is preferable.

FIG. 5 is an enlarged view of a portion of the balance PCB of the liquid crystal display module according to the exemplary embodiment of the present invention. As shown in the figure, the balance PCB 134 includes the fluorescent lamp 124 inserted into the lamp socket 132. The capacitor 139 is soldered to one side end of the opposite direction, and a predetermined size opening 338 is formed between both electrodes of the capacitor 139 to minimize electrical influence and to generate heat. Both electrodes of the capacitor 139 are connected to the lamp socket 132 and the PCB wiring 334, respectively. Accordingly, the capacitor 139 functions to equally regulate the tube current flowing in the fluorescent lamp 124.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

Therefore, the liquid crystal display module including the backlight unit according to an embodiment of the present invention, one or two through a lamp socket to which a plurality of fluorescent lamps are fitted, and a balance PCB (solar PCB) soldered capacitors connected in parallel thereto; The CCFL can be driven in parallel using an inverter of, thereby reducing the cost.

In addition, the fluorescent lamp and the capacitor minimize the influence of the electrical and heat emitted from each other.

Claims (7)

A plurality of fluorescent lamps; A lamp socket into which the fluorescent lamp is fitted, and a balance PCB mounted on the opposite end to which the fluorescent lamp is inserted, a capacitor connecting the lamp sockets in parallel in electrical connection; An optical sheet and a reflecting sheet provided above and below the fluorescent lamp; A cover bottom on which the balance PCB is mounted at both ends; Backlight unit comprising a. The method of claim 1, The balance PCB may include an opening having a predetermined size, which is an electrical separation space and a heat dissipation space between both electrodes, in a portion where the capacitor is mounted. The method of claim 1, And a support side coupled to both ends of the cover bottom and completely covering the balance PCB. The method of claim 1, The balance PCB is a backlight unit, characterized in that the PCB wiring for electrically connecting the lamp socket and the capacitor is formed. The method of claim 1, The backlight unit further comprises a inverter unit for supplying the driving power of the fluorescent lamp. The method of claim 5, wherein The inverter unit includes a connector connected to the wire; An inverter generating the drive power; An inverter PCB on which the connector and the inverter are mounted; Backlight unit comprising a. A liquid crystal display module comprising the backlight unit of claim 1, A liquid crystal panel mounted on the backlight unit; A support main surrounding the liquid crystal panel and the backlight unit; A top cover surrounding an edge of the liquid crystal panel; A cover shield provided on a rear surface of the cover bottom; Liquid crystal display module comprising a.

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