KR20050066661A - Liquid crystal display - Google Patents

Abstract

The present invention relates to a liquid crystal display device, wherein the liquid crystal display device of the present invention includes a lamp for emitting light, a lamp housing having the lamp therein, a cover for supporting the lamp housing, and light supplied from the lamp. A liquid crystal panel configured to display an image by adjusting light transmittance of the light source; an inverter provided on the rear surface of the cover to supply driving power to the lamp; and a heat radiating unit provided on the cover to radiate heat generated from the inverter. do.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device that separates heat distribution areas of a lamp and an inverter, absorbs heat through a heat dissipation unit, and improves image quality degradation due to heat.

In general, a liquid crystal display device is a flat panel display device that can display a desired image by separately supplying data signals according to image information to pixels arranged in a matrix form, and adjusting light transmittance of the pixels. to be.

Accordingly, the LCD device includes a liquid crystal panel in which pixels are arranged in a matrix; A driving unit for driving the pixels is provided.

The liquid crystal panel has a thin film transistor array substrate and a color filter substrate bonded to each other to maintain a uniform cell gap therebetween, and the liquid crystal panel is disposed at a spaced interval between the color filter substrate and the thin film transistor array substrate. It consists of the formed liquid crystal layer.

Since the liquid crystal display does not emit light by itself and has a characteristic of displaying an image by adjusting light transmittance, a separate device for irradiating light to the liquid crystal panel, that is, a backlight unit, is required.

The backlight unit includes a lamp disposed on a rear surface of the liquid crystal panel so that light is transmitted directly to the front surface of the liquid crystal panel, and a lamp is disposed on one side or both sides of the liquid crystal panel so that the light is disposed on the light guide plate, the reflecting plate and the optical sheets. By reflecting, diffusing and condensing through, it is divided into an edge (edge) method to be transmitted to the front of the liquid crystal panel.

As described above, the liquid crystal display includes a liquid crystal panel, a driver, and a backlight unit, and various types of components are used to support and couple the liquid crystal panel, the driver, and the backlight unit.

The liquid crystal display as described above will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view of a liquid crystal display device.

Referring to FIG. 1, a liquid crystal display device includes a liquid crystal panel 10 in which pixels are arranged in a matrix form; A gate driver 20 and a data driver 30 connected to side surfaces of the liquid crystal panel 10, respectively; The backlight unit 40 is disposed on the rear surface of the liquid crystal panel 10.

The liquid crystal panel 10 includes a thin film transistor array substrate and a color filter substrate which are bonded to face each other to maintain a uniform cell-gap, and a liquid crystal layer formed at a spaced interval between the color filter substrate and the thin film transistor array substrate.

A common electrode and a pixel electrode are formed in the liquid crystal panel where the thin film transistor array substrate and the color filter substrate are bonded to apply an electric field to the liquid crystal layer.

Therefore, when the voltage of the data signal applied to the pixel electrode is controlled while the voltage is applied to the common electrode, the liquid crystal of the liquid crystal layer rotates by dielectric anisotropy according to the electric field between the common electrode and the pixel electrode. For example, characters or images are displayed by transmitting or blocking light for each pixel.

In addition, switching elements such as thin film transistors are individually provided in the pixels in order to control the voltage of the data signal applied to the pixel electrode for each pixel.

The gate driver 20 and the data driver 30 are combined with the liquid crystal panel 10 in various forms to supply scan signals and image information to gate lines and data lines formed in the liquid crystal panel 10, thereby providing liquid crystals. The pixels of the panel 10 are driven.

The backlight unit 40 may include a light guide plate 41 disposed on a rear surface of the liquid crystal panel 10; Lamps 42 disposed on both sides of the light guide plate 41; A lamp housing 43 which protects the lamp 42 and reflects the light of the lamp 42, and a reflecting plate 44 disposed on a rear surface of the light guide plate 41, and the liquid crystal panel 10. And the optical sheet 45 between the light guide plate 41.

The light generated by the lamp 42 is incident on the side surface of the light guide plate 41 formed of a transparent material.

The reflector plate 44 disposed on the rear surface of the light guide plate 41 reflects the light transmitted to the rear surface of the light guide plate 41 to the upper surface of the light guide plate 41 to reduce the loss of light and is transmitted to the upper surface of the light guide plate 41. Improves light uniformity

The light guide plate 41 transmits the light generated by the lamp 42 together with the reflecting plate 44 to the upper surface.

In the optical sheet 45 disposed between the liquid crystal panel 10 and the light guide plate 41, a diffusion sheet and a prism sheet may be applied, and a protective sheet may be added.

The diffusion sheet disperses the light incident from the light guide plate 41 to prevent the light from being partially concentrated to cause staining in the image displayed on the liquid crystal panel 10, and the prism sheet is incident from the diffusion sheet. By refracting the angle of light vertically to focus the light, the light is uniformly distributed on the front surface of the liquid crystal panel 10.

The protective sheet protects the optical sheet 45 which is sensitive to dust and scratches, prevents the flow of the optical sheet 45 when the backlight unit 40 is transported, and diffuses light incident from the prism sheet. It can have a function to make the light more uniformly distributed.

On the other hand, the backlight unit 40 has an edge method provided with lamps 42 on both sides of the light guide plate 41, but an edge method provided with a lamp may be applied only to one side of the light guide plate 41, or The direct method in which the lamp is disposed to correspond to the entire rear surface of the liquid crystal panel 10 may be applied.

The liquid crystal panel 10 and the backlight unit 40 are stacked on the main support 50, and the side surfaces of the stacked liquid crystal panel 10 and the backlight unit 40 are supported by the main support 50.

The upper edge of the liquid crystal panel 10 is compressed by the upper case 51, and the upper case 51 is coupled to the main support 50.

The liquid crystal panel 10 and the backlight unit 40 are supported by a lower cover 52 disposed on the rear surface of the backlight unit 40, and the lower cover 52 is coupled to the upper case 51.

The data driver 30 includes a printed circuit board 31, and the printed circuit board 31 includes integrated circuit chips for generating various electrical signals for driving pixels of the liquid crystal panel 10, and the electrical circuit board 31. Since wires for transmitting signals are mounted, a constant area is required.

Accordingly, the printed circuit board 31 is disposed on the rear surface of the lower cover 52 and rides from the side of the liquid crystal panel 10 to the bottom of the lower cover 52 from the side of the main support 50. It is connected to the liquid crystal panel 10 through the flexible conductive film 32 that is bent.

The printed circuit board 31 disposed on the bottom surface of the lower cover 52 is protected by the first cover shield 53 coupled to the lower cover 52 by a screw.

In addition, in order to drive the backlight unit, a driving voltage must be supplied to a lamp. An inverter plays such a role. The inverter receives a driving voltage of direct current from the printed circuit board, converts the current into an alternating current, and then boosts the lamp to a voltage that can sufficiently drive the lamp to supply the lamp. Since the inverter must include a circuit for converting direct current to alternating current and a circuit for boosting voltage converted to alternating current, a constant area is required. Therefore, it is provided on the rear surface of the lower cover and protected by the second cover shield 58.

The structure of the back of the liquid crystal display device as described above is as follows.

FIG. 2A is a diagram schematically illustrating a rear surface of the liquid crystal display. FIG.

In the drawing, the second cover shield covering the inverter 160 is omitted in order to accurately represent the inverter 160.

Referring to FIG. 2A, a liquid crystal display device includes a printed circuit board (not shown) positioned on a rear surface of a lower cover, a first cover shield 153 protecting the printed circuit board, and a rear surface of the lower cover. , An inverter 162 for supplying driving power to a lamp (not shown), and a supply line 165 for supplying power to the inverter 160.

The inverter 160 is provided on the bottom of the lower cover due to the limited space inside the liquid crystal display, and covers the second cover shield to prevent an accident caused by the high voltage generated in the inverter 160.

The inverter 160 receives a DC driving voltage from the printed circuit board, converts the AC voltage into an AC voltage, and boosts the converted AC voltage to a voltage level sufficient to drive the lamp. The inverter 160 is provided with a number of components that generate heat, such as a transformer (trans) for boosting the voltage as described above, so that a lot of heat is emitted from the inverter 160.

Further, heat is emitted from the lamp when the lamp is driven regardless of an edge type system in which a lamp is provided on one side or both sides of the liquid crystal display and a direct type system in which a plurality of lamps are arranged on the rear surface of the light guide plate. Usually, the liquid crystal display device is used in a stand-up manner in which the liquid crystal display device is used vertically, and since the inside of the liquid crystal display device is an enclosed space, heat emitted from the lamp is accumulated from the upper region of the liquid crystal display device by convection. do. As such, the distribution of heat generated in the lamp and the inverter is shown in FIG. 2B.

2B is a diagram showing a heat distribution of heat generated in a liquid crystal display.

Referring to the drawings, the heat distribution of the liquid crystal display device includes a first region 181 due to heat emitted from an inverter, a second region 182 due to heat emitted from a lamp inside the liquid crystal display, and the first region 181. ) And the second region 182 are overlapped with each other.

The first region 181 is distributed by heat emitted from the inverter, and heat generated in the heat generating unit is condensed inside the inverter and accumulated from the upper region. In addition, since the inverter is protected inside the second cover shield, heat emitted from the inverter is accumulated from the upper region of the second cover shield which is sealed. Therefore, as a whole, more heat accumulates toward the upper region. Higher heat is distributed toward the darker portion of the first region 181.

In addition, the second region 182 shows that heat emitted from the lamp is accumulated from the upper region in the liquid crystal display. As such, the heat emitted from the inverter and accumulated from the upper region and the heat generated from the lamp overlap from the upper region in the upper region of the liquid crystal display so that a considerably high heat is distributed in the region. (183).

Due to the high heat distributed in the third region 183, the liquid crystal molecules of the liquid crystal display device deteriorate, so that an accurate light transmittance cannot be obtained, and the driving circuit malfunctions, thereby degrading the image quality in the liquid crystal display device.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to reposition the inverter or to form a heat dissipation unit to prevent the heat distribution of the heat emitted from the lamp and the inverter to overlap. To provide a device.

According to an aspect of the present invention, a liquid crystal display device includes a lamp for emitting light, a lamp housing having the lamp therein, a cover for supporting the lamp housing, and a light supplied from the lamp. A liquid crystal panel that displays an image by adjusting light transmittance, an inverter provided on the back of the cover to supply driving power to the lamp, and a heat dissipation unit provided on the cover to radiate heat generated from the inverter. .

FIG. 3A illustrates a liquid crystal display according to a first embodiment of the present invention, and FIG. 3B illustrates heat distribution of heat emitted from the liquid crystal display of FIG. 3A.

Referring to the drawings, a liquid crystal display device includes a lamp for emitting light, a lamp housing including the lamp therein, a lower cover supporting the lamp housing from below, and a light transmittance of light supplied from the lamp. And an inverter provided on the rear surface of the lower cover to supply driving power to the lamp, and a heat radiating portion provided on the lower cover to dissipate heat generated from the inverter.

In the conventional liquid crystal display device, the inverter is generally formed vertically. That is, since the liquid crystal panel is formed parallel to the short side, when heat is generated in the inverter, the heat distribution is also represented by a vertical distribution. When the inverters are formed vertically so that the heat distribution appears vertically, there is a high possibility that overlapping regions with heat distributions emitted from the lamps and accumulated in the upper region of the liquid crystal display are generated.

Therefore, the inverter 260 is formed in a horizontal direction parallel to the long side of the liquid crystal panel, so that the heat distribution appears horizontally when heat is generated in the inverter 260, thereby overlapping an area overlapping the distribution region of heat emitted from the lamp. Can be removed.

Meanwhile, hereinafter, the distribution region of heat emitted from the inverter 260 will be referred to as the first region 281, and the distribution region of heat emitted from the lamp will be referred to as the second region 282.

In general, the liquid crystal display is used in a state where it is erected at a predetermined angle with the ground, so that the inverter 260 is connected to the inverter 260 so that there is no overlapping area in the second region 282 and the first region 281. It is preferable to form in parallel with the lower side of the liquid crystal display in a standing state.

As such, by separating the first region 281 and the second region 282, the overlapping region of the first region 281 and the second region 282 can be prevented.

However, when the inverter 260 is formed parallel to the lower side of the liquid crystal panel so that the heat distribution region appears horizontally, when the high heat is generated in the inverter 260 to expand the heat distribution region, the second region 282 and the first region 281 may overlap. Thus, as shown, the heat radiating portion 270 is formed adjacent to the inverter 260.

Since the heat dissipation unit 270 absorbs heat emitted from the inverter 260 and releases it to the outside, the heat emitted from the inverter 260 prevents diffusion and thus the first region 281 and the second region. Prevent overlap of 282. The heat dissipation unit 270 is made of a metal having good thermal conductivity, for example, aluminum is used a lot.

The heat dissipation unit 270 may improve a heat dissipation effect by forming a plurality of corrugated structures and widening an area to absorb heat.

In addition, the heat dissipation unit 270 may be separately manufactured and attached to the lower cover, or the lower cover may be manufactured to have a heat dissipation unit shape.

Meanwhile, the heat dissipation rate of the heat dissipation unit 270 may be improved by changing the structure of the inverter 260, which will be described with reference to the accompanying drawings.

FIG. 4A illustrates a liquid crystal display according to a second exemplary embodiment of the present invention, and FIG. 4B illustrates heat distribution of heat emitted from the lamp and the inverter of FIG. 4A.

Since the second embodiment has a feature in the structure of the inverter compared to the first embodiment, the inverter will be described in detail, and descriptions overlapping with the first embodiment will be omitted.

Referring to the drawings, a liquid crystal display includes a lamp for emitting light, a lamp housing including the lamp therein, a lower cover 352 for supporting the lamp housing from below, and light supplied from the lamp. A liquid crystal panel that displays an image by adjusting transmittance, a first inverter 360 and a second inverter 361 provided on a rear surface of the lower cover 352 to supply driving power to the lamp, and the lower cover 352. It is configured to include a heat dissipation unit 370 provided to the heat dissipation heat generated from the inverter.

The inverters 360 and 361 are formed by dividing the first inverter 360 and the second inverter 361. In this case, the first inverter 360 is formed in one direction, and the second inverter 361 is formed perpendicular to the first inverter 361.

As described above, the circuits inside the inverters 360 and 361 are separated into two parts, and the heat generating regions of the first and second inverters 360 and 361 are separated from each other, as shown in FIG. 4B. It is reversed.

In addition, by forming the first inverter 360 and the second inverter 361 perpendicular to each other, the heat radiating portion 370 provided adjacent to the inverter (360,361) to form a shorter length than the first embodiment Can be. Therefore, the manufacturing cost of the heat dissipation unit 370 can be reduced.

The biggest feature of the second embodiment is to form the inverter (360,361) divided into the first inverter 360 and the second inverter 361, the heat dissipation unit 370 is the first inverter 360 and the second It is possible to intensively absorb the heat emitted from any one of the inverters 361, thereby improving the heat radiation effect. That is, since any one of the first inverter 360 and the second inverter 361 is spaced apart from the heat dissipation unit 370, except for the heat emitted by natural convection, the heat dissipation unit 370 is actually The heat to absorb is reduced. That is, the heat of heat emitted from the first inverter 360 and the heat of heat emitted from the second inverter 361 are different from each other.

FIG. 5A is a diagram showing an example of another inverter arrangement in the second embodiment of the present invention, and FIG. 5B is a diagram showing the heat distribution of heat emitted from the lamp and the inverter in FIG. 5A.

FIG. 5A illustrates another example of FIG. 4A in which the first inverter 460 and the second inverter 461 are disposed opposite to FIG. 4A. That is, the first inverter 460 is formed in one direction, and the second inverter 461 is formed perpendicular to the first inverter 460. Therefore, heat emitted from the first inverter 460 is absorbed intensively by the heat dissipation unit 470, and heat emitted from the second inverter 461 is convection in a space separated from the heat dissipation unit 470. Due to the heat dissipated by the heat sink, less heat is absorbed by the heat dissipation unit 470 than the one inverter 460.

As described above, the liquid crystal display device of the present invention overlaps the heat distribution area of the lamp and the heat distribution area of the inverter by separating the heat distribution area of the lamp from the heat distribution area of the inverter and absorbing heat emitted from the inverter through the heat radiating part. Since the heat distribution area is removed, the image quality deterioration of the liquid crystal display device due to heat can be improved.

1 is an exploded perspective view of a liquid crystal display device;

FIG. 2A is a schematic view showing the back of the liquid crystal display; FIG.

2B is a diagram showing a heat distribution of heat generated in a liquid crystal display device.

3A is a diagram showing a liquid crystal display device according to a first embodiment of the present invention.

FIG. 3B illustrates a heat distribution of heat emitted from the liquid crystal display of FIG. 3A. FIG.

4A shows a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4B shows a heat distribution of heat emitted from the lamp and inverter of FIG. 4A;

Fig. 5A shows an example of another inverter arrangement in the second embodiment of the present invention.

FIG. 5B shows the heat distribution of heat emitted from the lamp and inverter in FIG. 5A;

** Description of the symbols for the main parts of the drawings **

252: lower cover 260: inverter

270: heat dissipation unit

Claims (12)

Lamps emitting light; A lamp housing having the lamp therein; A cover for supporting the lamp housing; A liquid crystal panel which displays an image by adjusting a light transmittance of light supplied from the lamp; An inverter provided at a rear surface of the cover to supply driving power to the lamp; And And a heat dissipation unit provided on the cover to dissipate heat generated from the inverter. The liquid crystal display of claim 1, wherein the inverter is formed to be substantially parallel to one side of the liquid crystal panel. The liquid crystal display of claim 1, wherein the heat dissipation unit is formed to be substantially parallel to the inverter. The liquid crystal display of claim 1, wherein the heat distribution of heat emitted from the inverter is displayed horizontally. The liquid crystal display of claim 1, wherein the heat dissipation part is made of a material having thermal conductivity. The liquid crystal display device according to claim 5, wherein the heat dissipation part is made of aluminum. The liquid crystal display of claim 1, wherein the heat dissipation unit has a plurality of corrugation structures. The liquid crystal display device according to claim 1, wherein the heat dissipation part is a part of the cover. The liquid crystal display of claim 1, wherein the heat dissipation unit is separately attached to the cover. Lamps emitting light; A lamp housing having the lamp therein; A cover for supporting the lamp housing; A liquid crystal panel which displays an image by adjusting a light transmittance of light supplied from the lamp; A first inverter provided on a rear surface of the cover to supply driving power to the lamp and formed in one direction; A second inverter formed in a direction perpendicular to the first inverter; And And a heat dissipation unit provided on the cover to dissipate heat generated from the inverter. The liquid crystal display of claim 10, wherein the heat dissipation unit is formed in parallel to one of the first inverter and the second inverter. The liquid crystal display device according to claim 10, wherein the emission heat of the first inverter and the second inverter absorbed by the heat dissipation unit are different from each other.