KR101341789B1 - Backlight unit of liquid crystal display device - Google Patents

Abstract

The present invention relates to a backlight unit of a liquid crystal display device which can simplify the manufacturing process and structure.

The backlight unit of the liquid crystal display device includes: a backlight unit of a liquid crystal display device for irradiating light to the liquid crystal display panel, the backlight unit comprising: a plurality of lamps disposed under the liquid crystal display panel and including a high voltage electrode and a low pressure electrode; An inverter for supplying a driving voltage to the lamps; A bottom cover of a metal material having an upper side opened to place the lamps in an inner space and grounded to the inverter; A plurality of first lamp holders formed of conductive silicon and disposed on the low pressure electrodes of the lamps, the plurality of first lamp holders having holes or grooves to insert the low pressure electrode portions of the lamps to fix the lamps; A plurality of second lamp holders disposed on the high voltage electrodes of the lamps to fix the lamps and formed of a non-conductive material; And a side supporter coupled to the bottom cover to fix the first and second lamp holders together with the bottom cover, wherein the first lamp holder is connected to the bottom cover to ground the low voltage electrode to the inverter. .

Description

BACKLIGHT UNIT OF LIQUID CRYSTAL DISPLAY DEVICE}

1 is a view showing a direct backlight unit of a conventional liquid crystal display device.

2 illustrates a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a view showing the first lamp holder shown in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

8, 58: lamps 10, 60, 61: lamp holder

11: ground PCB 12, 62: bottom cover

52 liquid crystal display panel 54 optical sheet

55 optical member 56 diffuser plate

64: side supporter 66: panel guide

68: top case 70: inverter

72: wire

The present invention relates to a backlight unit of a liquid crystal display device, and more particularly to a backlight unit of a liquid crystal display device that can simplify the manufacturing process and structure.

2. Description of the Related Art Generally, a liquid crystal display device is in a trend of widening its application range due to features such as light weight, thinness, and low power consumption driving. In accordance with this trend, liquid crystal display devices are used in office automation equipment, audio / video equipment, and the like. In such a liquid crystal display, a transmission amount of a light beam is adjusted according to a signal applied to a plurality of control switches arranged in a matrix to display a desired image on a screen.

Since the liquid crystal display is not a self-luminous display, a separate backlight is required.

The light source includes a direct type method and an edge type method according to its position. The backlight unit using the edge type light source is provided with a light source at one edge of the liquid crystal display device, and irradiates the liquid crystal display panel with light incident from the light source through the light guide plate and the plurality of optical sheets. In the backlight unit using the direct light source, a plurality of light sources are disposed directly under the liquid crystal display panel, and the light incident from the light sources is irradiated onto the liquid crystal display panel through the diffusion plate and the plurality of optical sheets.

Recently, the direct type backlight having higher luminance, light uniformity and color purity than the edge type has been used more mainly in LCD TVs.

1 is a view illustrating a direct type backlight unit of a conventional liquid crystal display device.

Referring to FIG. 1, a backlight unit of a conventional liquid crystal display device includes a plurality of lamps 8, a plurality of lamp holders 10, a printed circuit board 11, and a bottom cover 12. do.

First, the bottom cover 12 is made of a container structure in which the lamps 8 are accommodated in the inner space, and reflecting plates are formed on the bottom and side surfaces of the inner space.

The lamps 8 emit light by an AC high voltage from an inverter. In FIG. 1, a cold cathode fluorescent lamp (CCFL) is illustrated as an example, but an external electrode fluorescent lamp (EEFL) may be used. Do. The low pressure electrode 8a is formed at one side of the lamp 8 shown in FIG. 1, and the high pressure electrode is formed at the other side. The low voltage electrode 8a of the lamp 8 is grounded to the inverter, and the high voltage electrode is connected to the inverter formed on the bottom of the bottom cover 12 via a wire or the like to receive an AC high voltage.

The lamp holder 10 serves to fix the lamp 8 by a predetermined number, and a plurality of lamp holders 10 are formed according to the number of the lamps 8. The lamp holder 10 is fixed on the bottom cover 12 through a bottom cover 12 and a side supporter fastened to the bottom cover 12.

The ground PCB 11 is attached to the side of the lamp holder 10 formed on the low voltage electrode 8a side of the lamp 8 by soldering to connect the low voltage electrodes 8a of the lamps 8 to each other. The ground PCB 11 is formed with a wire connected to the low voltage electrodes 8a of the lamps 8, and the wire is connected to the inverter through an outlet, such as a hole formed in the bottom cover 12, so that the low voltage electrode 8a is connected to the inverter. To ground.

The backlight unit of the conventional liquid crystal display device has such a structure, and has a separate wire connected to the electrodes to be connected to the inverter. In order to take out the wire from the bottom cover 12 to the inverter formed on the rear surface outside the bottom cover 12, a hole is provided in the bottom cover 12. This hole reduces light efficiency by leaking light generated from the lamp 8 of the backlight unit. In addition, in the backlight unit of the conventional liquid crystal display device, the manufacturing process is complicated by attaching a wire to the bottom cover 12 using a tape or the like for wiring arrangement. In particular, in the case of the low voltage electrode 8a, since the ground PCB 11 connecting the low voltage electrode 8a should be soldered, this causes a problem in that the backlight unit of the conventional liquid crystal display device becomes more complicated in its manufacturing process and structure. have.

Accordingly, an object of the present invention is to provide a backlight unit of a liquid crystal display device which can simplify the manufacturing process and structure.

In order to achieve the above object, a backlight unit of a liquid crystal display device according to an embodiment of the present invention is a backlight unit of a liquid crystal display device for irradiating light to the liquid crystal display panel, disposed below the liquid crystal display panel, the high pressure electrode and low pressure A plurality of lamps comprising electrodes; An inverter for supplying a driving voltage to the lamps; A bottom cover of a metal material having an upper side opened to place the lamps in an inner space and grounded to the inverter; A plurality of first lamp holders disposed on the low voltage electrodes of the lamps to fix the lamps, and formed of a conductive material and connected to the low voltage electrodes; A plurality of second lamp holders disposed on the high voltage electrodes of the lamps to fix the lamps and formed of a non-conductive material; And a side supporter coupled to the bottom cover to fix the first and second lamp holders together with the bottom cover, wherein the first lamp holder is connected to the bottom cover to ground the low voltage electrode to the inverter. .

The first lamp holder has a hole or a groove into which the low voltage electrode portion of the lamp is inserted and to which the low voltage electrode is connected.

The second lamp holder has a hole into which the high voltage electrode portion of the lamp is inserted and the high voltage electrode is taken out.

Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 and 3.

2 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

2, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal display panel 52, a panel guide 66, a top case 68, and a backlight unit. The backlight unit includes an optical member 55, a lamp 58, a lamp holder 60, a bottom cover 62, and a side supporter 64.

The liquid crystal display panel 52 includes an upper substrate 52a on which a color filter array is formed and a lower substrate 52b on which a thin film transistor array is formed. The upper substrate 52a and the lower substrate 52b are bonded together with the liquid crystal layer interposed therebetween.

Data lines and gate lines perpendicular to each other are formed on the lower substrate 52b of the liquid crystal display panel 52. The thin film transistor is connected to the intersection of the data lines and the gate lines. The thin film transistor supplies a data voltage supplied through the data line to the pixel electrode of the liquid crystal cell in response to the scan pulse of the gate line.

The liquid crystal mode of the liquid crystal display panel 52 includes a liquid crystal mode of a horizontal electric field driving method such as an in plane switching (IPS) mode, a fringe field switching (FFS) mode, a twisted nematic (TN) mode, a vertical alignment (VA) mode, and the like. It is roughly classified into the liquid crystal mode of the same vertical electric field driving method.

When the liquid crystal display panel 52 is a horizontal electric field driving method, a common electrode is further formed on the lower substrate 52b, and a black matrix, a color filter, and the like are formed on the upper substrate 52a. A liquid crystal capacitor is formed in the liquid crystal layer between the pixel electrode and the common electrode, and a liquid crystal having dielectric anisotropy is driven through a horizontal electric field due to a potential difference between the data voltage supplied to the pixel electrode and the common voltage supplied to the common electrode to drive the video data. The light transmittance is adjusted according to the data voltage of.

When the liquid crystal display panel 52 is a vertical electric field driving method, a black matrix, a color filter, a common electrode, and the like are formed on the upper substrate 52a. A liquid crystal capacitor is formed in the liquid crystal layer between the pixel electrode and the common electrode, and the dielectric anisotropy is obtained through a vertical electric field due to a potential difference between the data voltage supplied to the pixel electrode and the common voltage supplied to the common electrode positioned on the upper substrate 52a. The liquid crystal having a light is driven to adjust the light transmittance according to the data voltage of the video data.

A polarizing plate having an optical axis orthogonal to each other is attached to the lower substrate 52b and the upper substrate 52a of the liquid crystal display panel 52, and an alignment layer for determining the pretilt angle of the liquid crystal is formed on the inner surface of the liquid crystal display panel 52. In addition, a storage capacitor is formed on the lower substrate 52b of each liquid crystal cell. The storage capacitor is formed between the pixel electrode supplied with the data voltage and the storage electrode supplied with the storage voltage to keep the data voltage charged in the liquid crystal cell constant.

The bottom cover 62 is made of a container structure in which the upper side is opened and the lamps 58 are disposed in the inner space, and reflecting plates are formed on the bottom and side surfaces of the inner space. The bottom cover 62 is formed of a metal material and grounded to the inverter 70 positioned on the rear surface thereof.

The lamp 58 emits light by the AC high voltage from the inverter 70. In FIG. 2, the cold cathode fluorescent lamp CCFL is illustrated as an example, but an external electrode fluorescent lamp EEFL may be used. On one side of the lamp 58 shown in Figure 2 is formed a low voltage electrode (58a), the other side is formed a high voltage electrode (58b). The low voltage electrode of the lamp 58 is grounded to the inverter 70, and the high voltage electrode 58b is connected to the inverter 70 formed on the rear surface of the bottom cover 62 via the wire 72 to receive an AC high voltage.

The first lamp holder 60 is disposed on the low voltage electrode 58a side of the lamp 58, and the second lamp holder 61 is disposed on the high voltage electrode 58b side. The first and second lamp holders 60 and 61 serve to fix a predetermined number of lamps, and a plurality of first and second lamp holders 60 and 61 are formed according to the number of lamps 58. The first and second lamp holders 60 and 61 are fixed on the bottom cover 62 by the pressure of the bottom cover 62 and the side supporter 64 fastened to the bottom cover 62.

The first lamp holder 60 is made of a conductive material such as conductive silicon, and is connected to the low voltage electrode 58a of the lamp 58, and is connected to the bottom cover 62 to connect the low voltage electrode 58a to the inverter 70. Ground it. The first lamp holder 60 has a hole 60a or a groove so that a portion of the low voltage electrode 58a of the lamp 58 is inserted, and the low voltage electrode 58a can be connected.

The second lamp holder 61 has a hole 61a so that the high voltage electrode 58b portion of the lamp 58 can be inserted and the high voltage electrode 58b can protrude so as to connect with the wire 72. It is formed of a substance.

As described above, the first lamp holder 60 illustrated in FIGS. 2 and 3 may be made of a conductive material so that the first lamp holder 60 may be grounded to the inverter without using a separate grounding medium such as a ground PCB or a wire. Accordingly, the backlight unit of the liquid crystal display according to the exemplary embodiment of the present invention removes not only components such as a ground PCB and a wire, but also additional components such as a tape attached to the wire, thereby reducing manufacturing costs and simplifying the manufacturing process. In addition, the backlight unit of the liquid crystal display according to the exemplary embodiment does not need to form a hole such as a wire outlet in the bottom cover 62 of the low pressure electrode 58a, thereby reducing light leakage.

The optical member 55 includes the optical sheets 54 and the diffusion plate 56.

The diffuser plate 56 includes a plurality of beads and scatters the light incident through the lamps 58 using the beads, thereby displacing the lamps 58 on the display surface of the liquid crystal display panel 52. The luminance difference does not occur at the position of and the position between the lamps 58.

The optical sheets 54 include one or more diffusion sheets and one or more prism sheets to uniformly irradiate the light incident from the diffusion plate 56 onto the entire liquid crystal display panel 52 and to be perpendicular to the display surface. It breaks the path of light and condenses the light to the front of the display surface.

The panel guide 66 is a mold positioned on the edge of the bottom cover 62. The sidewall surface of the panel guide 66 is formed into a stepped stepped surface so that the liquid crystal display panel 52 and the optical member 55 are formed on the stepped surface. Is mounted.

The top case 68 is manufactured in the form of a square strip having a flat portion and a side portion bent at right angles. The top case 68 is formed to surround the edge of the liquid crystal display panel 52, the top and side surfaces of the panel guide 66, and a part of the side surface of the bottom cover 14.

As described above, the backlight unit of the liquid crystal display according to the exemplary embodiment of the present invention forms a lamp holder disposed on the low voltage electrode side of the lamp holders for fixing the lamps, and connects the lamp holder to the low voltage electrode, using the inverter. The low voltage electrode of the lamp can be grounded to the inverter while simplifying the manufacturing process and structure by connecting to a bottom cover grounded at the.

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. 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 (3)

In the backlight unit of the liquid crystal display device for irradiating light to the liquid crystal display panel, A plurality of lamps disposed under the liquid crystal display panel and including a high voltage electrode and a low voltage electrode; An inverter for supplying a driving voltage to the lamps; A bottom cover of a metal material having an upper side opened to place the lamps in an inner space and grounded to the inverter; A plurality of first lamp holders formed of conductive silicon and disposed on the low pressure electrodes of the lamps, the plurality of first lamp holders having holes or grooves to insert the low pressure electrode portions of the lamps to fix the lamps; A plurality of second lamp holders disposed on the high voltage electrodes of the lamps to fix the lamps and formed of a non-conductive material; And A side supporter coupled to the bottom cover to fix the first and second lamp holders together with the bottom cover; And the first lamp holder is connected to the bottom cover to ground the low voltage electrode to the inverter. delete The method of claim 1, And the second lamp holder includes a hole into which the high voltage electrode portion of the lamp is inserted and through which the high voltage electrode is taken out.

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