KR20090073451A - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display device is provided to reduce a distance between a light source and an optical sheet unit by a light source module composed of a sub light guide plate and an LED array, thereby reducing thickness. A bottom cover(200) has a mounted light source module(300) and an LCD(Liquid Crystal Display) panel(500). A reflecting member installed at the inside of the bottom cover reflects light. An optical sheet unit(350) is arranged between the light source module and the LCD panel. The light source module is composed of a sub light guide plate(111) and an LED(Light Emitting Diode) array(120). The LED array installed at a side part of the sub light guide plate emits light to the sub light guide plate.

Description

Liquid crystal display device

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 for implementing split driving and thinning using an LED array.

Recently, with the development of the information society, the demand for display devices for outputting image information is increasing in various forms. Accordingly, liquid crystal displays (LCDs), plasma display panels (PDPs), and electro luminescent (ELD) devices are increasing. Various flat panel display devices such as a display (VFD) and a vacuum fluorescent display (VFD) have been researched and developed.

Here, due to the advantages of excellent image quality, light weight, thinness, and low power consumption, it is widely used as a mobile flat panel display device. In particular, a liquid crystal display device which is widely used as a laptop, a computer monitor, a TV, a monitor, and the like is the most representative flat panel display device. Could be.

However, the liquid crystal display does not emit light by itself and requires a separate external light source to realize a high quality image.

Therefore, the structure of the liquid crystal display device further includes a backlight unit as a light source of the liquid crystal display panel in addition to the liquid crystal display panel, so that the backlight unit uniformly supplies a high brightness light source to the liquid crystal display panel, thereby realizing high quality images. do.

In general, a backlight unit of a liquid crystal display is a cylindrical light source such as a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an external electrode fluorescent lamp (EEFL), or a light emitting diode (LED). Diode devices and EL (Electro Luminescence) devices are mainly used, and are classified into edge-lighting and direct-lighting backlights according to the way light sources are arranged.

As shown in FIG. 1, the edge type backlight 10 has a light guide plate 11 that scatters and homogenizes light on the side of the fluorescent lamp 12, which is a light source of the backlight, and the fluorescent lamp 12 includes a lamp housing 13. It has a structure wrapped in). For reference, the same reference numerals refer to the same components below.

Light emitted from the fluorescent lamp 12 is directly or reflected by the lamp housing 13 is incident to the light guide plate (11).

The reflective member 14 is positioned below the light guide plate 11, and various optical sheet portions 15 such as a diffusion sheet, a prism sheet, and a protective sheet are positioned above the light guide plate 11.

In the edge type backlight of this structure, the light emitted from the fluorescent lamp 12 is incident on the light guide plate 11, and the light guide plate 11 converts the light of the fluorescent lamp incident to the line light source into a surface light source by scattering and uniformizing the light. The reflective member 14 of the reflector to the upper side of the light guide plate (11).

The optical sheet unit 15, such as a diffusion sheet or a prism sheet, located on the upper side of the light guide plate 11, condenses and diffuses light again to improve optical characteristics such as brightness and uniformity, and is positioned on the upper side. ), It acts as a backlight.

This type of edge type disperses light to the entire surface by using a light guide plate after installing a fluorescent lamp on the outer side of the flat panel, and has a lower luminance than a direct type backlight and is difficult to use in a large screen liquid crystal display device.

On the other hand, as shown in FIG. 2, the direct type backlight 20 has various optical elements such as a diffusion sheet, a prism sheet, and a protective sheet on the diffusion plate 21 to which a diffusion agent is added to diffuse and uniformize light from a light source. The sheet part 25 is stacked, and a fluorescent lamp 22 and a reflecting member 24 are positioned at a lower side of the diffusion plate 21 to be included in the cover bottom 23 of the backlight device.

The structure of the direct type backlight device is that the fluorescent lamp is disposed in the plane below the diffuser plate, and the light is directly radiated by the fluorescent lamp to improve the light efficiency compared to the edge type backlight device and to be easily applied to the large screen. The shape of the fluorescent lamp may be displayed on the liquid crystal display panel.

In order to prevent this, the space between the fluorescent lamp and the diffuser plate must be sufficiently secured and maintained, and the diffuser must be added to the diffuser plate for uniform light distribution. Therefore, the overall thickness of the backlight device is thick, which limits the thinning. There is a problem.

That is, since a predetermined distance must be secured between the light source and the optical sheet unit for uniform light distribution, there is a limit in implementing thinness.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a liquid crystal display device for implementing split driving and thinning using an LED array.

In order to achieve the above object, the liquid crystal display device according to an embodiment of the present invention,

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel,

The backlight unit includes a plurality of light source modules for emitting light to the liquid crystal display panel, a bottom cover for mounting the light source module and the liquid crystal display panel, a reflection member provided inside the bottom cover to reflect light, An optical sheet unit disposed between the light source module and the liquid crystal display panel;

The light source module may include a sub light guide plate and an LED array provided at a side portion of the sub light guide plate to emit light to the sub light guide plate.

Such a liquid crystal display device according to the present invention includes a light source module composed of a sub light guide plate and an LED array provided on the side portion of each sub light guide plate, thereby reducing the distance between the light source and the optical sheet part more easily. Can be implemented,

In addition, by dividing the inside of the bottom cover into a plurality of areas, and having a light source module in each area, it has a side that is advantageous for the divided driving. As described above, when the divided driving is enabled, it is advantageous to improve display quality and reduce power consumption.

In addition, it provides an effect that can further improve the brightness by increasing the light utilization efficiency.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail.

In the liquid crystal display according to the embodiment of the present invention,

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel,

The backlight unit includes a plurality of light source modules for emitting light to the liquid crystal display panel, a bottom cover for mounting the light source module and the liquid crystal display panel, a reflection member provided inside the bottom cover to reflect light, An optical sheet unit disposed between the light source module and the liquid crystal display panel;

The light source module may include a sub light guide plate and an LED array provided at a side portion of the sub light guide plate to emit light to the sub light guide plate.

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

3 is an exploded perspective view showing the configuration of a liquid crystal display according to a first embodiment of the present invention.

As shown in FIG. 3, the liquid crystal display according to the first exemplary embodiment of the present invention is provided.

In the liquid crystal display device comprising a liquid crystal display panel 500 for displaying an image and a backlight unit 400 for supplying light to the liquid crystal display panel 500,

The backlight unit 400 includes a plurality of light source modules 300 for emitting light to the liquid crystal display panel, a bottom cover 200 for mounting the light source module and the liquid crystal display panel, and an inside of the bottom cover. A reflection member (not shown) for reflecting light, and an optical sheet unit 350 disposed between the light source module and the liquid crystal display panel,

The light source module 300 may include a sub light guide plate 111 and an LED array 120 provided at a side portion of the sub light guide plate to emit light to the sub light guide plate.

In FIG. 3, the inner side of the bottom cover 200 is divided into four regions A, B, C, and D, and a light source module is provided in each region.

The liquid crystal display panel 500 includes two substrates bonded to each other by facing the liquid crystal layer, and although not illustrated, a polarizing film may be attached to an outer surface of each substrate.

The two substrates include, for example, an array substrate in which pixel regions defined by crossing gate lines and data lines are arranged in a matrix form, a color filter formed corresponding to the pixel regions, and a black matrix formed between the color filters. It may be composed of a color filter substrate.

The liquid crystal molecules constituting the liquid crystal layer have optical anisotropy and dielectric anisotropy, and thus rotate images according to an electric field to change an optical transmittance.

The optical sheet unit 350 uniformly diffuses the light emitted from the light source module and emits the light to the liquid crystal display panel, and the light diffused by the diffusion sheet is refracted to enter the liquid crystal display panel, thereby providing luminance. It may be composed of a prism sheet for improving, a protective sheet for protecting other sheets, and the like, but is not limited thereto.

The bottom cover 200 mounts the liquid crystal display panel, the optical sheet unit, and a light source module to be described later.

The light source module is disposed under the optical sheet unit and is provided in each of a plurality of regions that divide the bottom cover.

The light source module may include an LED array including a plurality of LED packages electrically connected to each other on a substrate, and a sub light guide plate configured to convert light emitted from the LED package incident from the side to the liquid crystal display panel and output the light. It consists of.

Although not shown, a reflecting member is provided inside the bottom cover to provide the effect of increasing the light utilization efficiency by re-reflecting the light emitted from the light source module again.

4 is a perspective view showing a detailed configuration of the light source module.

In FIG. 4, the sub light guide plate 111 has a quadrangular shape, and the LED array 120 is provided in a neighboring first side part and a second side part in the rectangular sub light guide plate.

The LED array 120 is provided on the neighboring first side portion and the second side portion of the sub light guide plate, wherein the LED array provided on the first side portion and the LED array provided on the second side portion are integrated. It may be formed as, or may be formed separately and then electrically connected.

The LED array 120 is composed of a plurality of LED packages 125 mounted on the substrate 122, the light irradiated from the LED package is incident to the side of the sub light guide plate.

In this case, it is preferable that the LED package is a side view type of LED.

Although not shown, the substrate may be provided with a heat radiating member for generating heat generated from the LED package. The heat dissipation member may be provided on the rear surface of the LED array, that is, on the opposite side on which the LED package is mounted, but is not limited thereto.

In addition, as shown in FIG. 5A, the light source module includes an LED array 120a provided in a first side portion and a second side portion of the sub light guide plate 111a in an arbitrary light source module in a neighboring light source module. The LED arrays 120b and 120c may not be directly adjacent to the LED arrays 120b and 120c.

In addition, as shown in FIG. 5B, one of the LED arrays 120a provided in the first and second side portions of the sub light guide plate 111a may be adjacent to the light source module. The LED array 120b and 120c may be disposed to be directly adjacent to each other.

In addition, as shown in FIG. 5C, the light source module is provided in a neighboring light source module in all of the LED arrays 120a provided in the first side portion and the second side portion of the sub light guide plate 111a in an arbitrary light source module. It may also be arranged to be directly adjacent to the LED array (120b, 120c).

As described above, each of the plurality of light source modules may include an LED package mounted on the LED array 120 provided in the neighboring first and second side portions of each sub light guide plate 111. At 125, light is emitted to the sub light guide plate 111 provided in each light source module.

Light incident into the sub light guide plate is uniformly incident on the entire surface of the liquid crystal display panel.

As described above, the liquid crystal display according to the first exemplary embodiment of the present invention includes a light source module including a sub light guide plate and an LED array provided at side portions of each sub light guide plate, thereby reducing the distance between the light source and the optical sheet unit. As a result, the thickness can be more easily implemented.

In addition, by dividing the inside of the bottom cover into a plurality of areas, and having a light source module in each area, it has a side that is advantageous for the divided driving. As described above, when the divided driving is enabled, it is advantageous to improve display quality and reduce power consumption.

Next, a liquid crystal display according to a second embodiment of the present invention will be described.

In the liquid crystal display device according to the second embodiment of the present invention,

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel,

The backlight unit may include a light source for supplying light radiated to the liquid crystal display panel, a bottom cover for mounting the light source and the liquid crystal display panel, a reflection member provided inside the bottom cover to reflect light emitted from the light source; A light guide plate disposed on the reflective member and configured to supply light emitted from a light source toward a liquid crystal display panel, and an optical sheet unit disposed on the light guide plate,

The light guide plate is formed on a surface facing the bottom cover and includes a first trench and a second trench formed to divide the light guide plate into a plurality of sub-regions, and the light source is disposed in the first trench and the second trench. Characterized in that consists of.

7A is a perspective view illustrating an example of a light guide plate in the liquid crystal display according to the second exemplary embodiment of the present invention. FIG. 7A illustrates a top surface of the light guide plate that faces the bottom cover.

In FIG. 7A, a first trench 130a and a second trench 130b formed to cross each other on a surface of the light guide plate opposite to the bottom cover are formed to cross each other, and the first trench 130a and the second trench are formed. The case where the light guide plate is divided into four sub-regions A, B, C, and D by 130b is illustrated.

On the other hand, the first trench and the second trench may be formed to cross in the form of x, in addition to the cross shape.

LED arrays are provided in the first trench 130a and the second trench 130b to supply light.

In this case, one LED array is provided in each trench, and each LED array includes a plurality of LED packages mounted on a substrate.

In this case, as shown in FIG. 7B, a plurality of LED packages may be arranged in two rows and each column may be provided to emit light in opposite directions. In this case, light may be simultaneously supplied to each sub-region of the light guide plate.

In addition, the LED array is provided in a pair so as to correspond to each of the inner portion of each trench, each of which may be able to emit light in the opposite direction to each other.

FIG. 7C is a diagram illustrating a case where an LED array is provided to correspond to each of inner portions of each trench.

That is, the light guide plate is divided into four sub-regions A, B, C, and D by the first trench 130a and the second trench 130b, and the first trench corresponding to each of the inner parts of the first trench 130a and the second trench 130b. The LED array 120a and the second LED array 120b are provided, and the third LED array 120c and the fourth LED array 120d corresponding to the respective inner portions are provided in the second trench.

At this time, the first LED array 120a and the second LED array 120b emit light in opposite directions, that is, in the direction of the subregion of the light guide plate, and the third LED array 120c and the fourth LED array 120d. ) Also emit light in opposite directions.

As such, since the LED array is provided to correspond to each of the inner portions of the trenches, it may be possible to divide and drive each sub-region.

As described above, in the liquid crystal display according to the second exemplary embodiment of the present invention, the LED array is provided in the trench formed in the light guide plate, thereby reducing the distance between the light source and the optical sheet part, thereby making it easier to reduce the thickness of the liquid crystal display. ,

In addition, the light guide plate is divided into a plurality of sub-regions, and a pair of LED arrays are provided to correspond to each of the inner portions of the trenches, so that the light guide plate is advantageously divided. As described above, when the divided driving is enabled, it is advantageous to improve display quality and reduce power consumption.

Next, a liquid crystal display according to a third exemplary embodiment of the present invention will be described.

In the liquid crystal display according to the third embodiment of the present invention,

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel,

The backlight unit includes a plurality of light source modules for emitting light to the liquid crystal display panel, a bottom cover for mounting the light source module and the liquid crystal display panel, a reflection member provided inside the bottom cover to reflect light, An optical sheet unit disposed between the light source module and the liquid crystal display panel;

Each of the light source modules includes a sub light guide plate, a side portion of the sub light guide plate to emit light to the sub light guide plate, a plurality of LED packages mounted on a substrate, and the light to emit to the sub light guide plate. It is configured to include a housing formed to surround the LED package with an open one side for.

The housing may be formed to have a curved surface so that light incident from the rear surface of the housing is reflected from the outer surface of the housing to be emitted toward the liquid crystal display panel.

FIG. 8 is a view for explaining a configuration of a light source module in the liquid crystal display according to the third exemplary embodiment of the present invention. FIG. 8 illustrates a case where two light source modules are disposed.

As shown in FIG. 8, the light source module includes a sub light guide plate 111 and an LED array 120 provided at a side portion of the sub light guide plate.

The LED array has a housing formed to surround the LED package 125 with a plurality of LED packages 125 mounted on a substrate 122 and an open side for emitting light to the sub light guide plate 111. 127).

The housing 127 may be formed to have a curved surface so that light incident from the rear surface of the housing 127 is reflected from the outer surface of the housing to travel toward the liquid crystal display panel.

Referring to FIG. 8, the light irradiated from the LED array on the right side is incident on the sub light guide plate on the right side, and at this time, some light is emitted in the rear direction of the LED array on the left side.

At this time, since the housing 127 has a curved shape, the light emitted from the rear surface is reflected from the outer surface of the housing and emitted to the liquid crystal display panel.

In addition, the light emitted from the LED package is reflected inside the housing and is incident to the side surface of the sub light guide plate.

In addition, the housing may be formed of an insulating material and form a first reflective layer on the inner side of the insulating material, or only one of the second reflective layers on the outer side of the insulating material, or both the first reflective layer and the second reflective layer. It will be possible.

In addition, the housing may be formed of a metal having a high reflectance to have a heat dissipation effect in addition to the above-described effects.

In addition to the effects of the liquid crystal display according to the first embodiment of the present invention described above, the liquid crystal display device according to the third embodiment of the present invention provides an effect of further improving luminance by increasing light utilization efficiency. .

As described above, in the liquid crystal display according to the third exemplary embodiment of the present invention, a top view type LED package may be used as shown in FIG. 8, and as shown in FIG. 9, a side view type is shown. It would be possible to use LED packages.

Other configurations in the liquid crystal display according to the third embodiment of the present invention are the same as those described in the first embodiment of the present invention, and thus the description thereof will be replaced with the above description.

Next, a liquid crystal display according to a fourth exemplary embodiment of the present invention will be described with reference to FIG. 10.

In the liquid crystal display according to the fourth embodiment of the present invention,

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel,

The backlight unit includes a plurality of light source modules for emitting light to the liquid crystal display panel, a bottom cover for mounting the light source module and the liquid crystal display panel, a reflection member provided inside the bottom cover to reflect light, An optical sheet unit disposed between the light source module and the liquid crystal display panel;

Each of the light source modules has a first region (I) having a first thickness d1 and a second region (II) having a second thickness d2 smaller than the first thickness and positioned at one end of the first region. Sub light guide plate 111 consisting of,

A plurality of LED packages 125 mounted below the second region of the sub light guide plate to emit light to the sub light guide plate and mounted on the substrate 122 and an open side for emitting light to the sub light guide plate And a housing 127 formed to surround the LED package.

The housing may be formed to have a curved surface so that light incident from the rear surface of the housing is reflected from the outer surface of the housing to be emitted toward the liquid crystal display panel.

As described above, the liquid crystal display according to the fourth exemplary embodiment of the present invention has a predetermined region of the sub light guide plate on the LED array in addition to the effects of the liquid crystal display according to the first exemplary embodiment of the present invention. It provides an effect that makes it possible to emit more light.

In the liquid crystal display according to the fourth exemplary embodiment of the present invention, the other configuration is the same as that described in the third exemplary embodiment of the present invention.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art.

1 is a cross-sectional view of a conventional edge type liquid crystal display device.

2 is a cross-sectional view of a conventional direct type liquid crystal display device.

3 is an exploded perspective view showing an example of a liquid crystal display device according to a first embodiment of the present invention;

4 is a perspective view showing an example of a light source module in the first embodiment of the present invention;

5A to 5C are plan views showing an example of the liquid crystal display device according to the first embodiment of the present invention.

Fig. 6 is a view for explaining light irradiation of the LED array in the first embodiment of the present invention.

FIG. 7A illustrates a light guide plate of a liquid crystal display according to a second exemplary embodiment of the present invention. FIG.

7B and 7C are plan views illustrating an example of the second embodiment of the present invention.

FIG. 8 is a view showing a case in which a top view type LED package is used in a liquid crystal display according to a third exemplary embodiment of the present invention. FIG.

FIG. 9 is a diagram illustrating a case in which a side view type LED package is used in a liquid crystal display according to a third exemplary embodiment of the present invention. FIG.

10 is a diagram showing an example of a liquid crystal display according to a fourth embodiment of the present invention.

Claims (14)

In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel, The backlight unit may include a plurality of light source modules emitting light to the liquid crystal display panel; A bottom cover to mount the light source module and the liquid crystal display panel; A reflection member provided inside the bottom cover to reflect light; An optical sheet unit disposed between the light source module and the liquid crystal display panel; The light source module may include a sub light guide plate and an LED array provided at a side portion of the sub light guide plate to emit light to the sub light guide plate. The method of claim 1, The sub light guide plate may have a quadrangular shape, and the LED array may be provided in adjacent first side parts and second side parts of the sub light guide plate. The method of claim 2, The light source module may include an LED array provided in a first side part and a second side part of a sub light guide plate in an arbitrary light source module, and an LED provided in the first side part and the second side part of a sub light guide plate in a neighboring light source module. And a liquid crystal display device disposed so as not to be directly adjacent to the array. The method of claim 2, The light source module includes only one LED array among the LED arrays provided in the first and second side parts of the sub light guide plate in any light source module, and the first side part and the second side of the sub light guide plate in the neighboring light source module. And a liquid crystal display device disposed adjacent to the LED array provided in the side part. The method of claim 2, The light source module may include an LED array provided in a first side portion and a second side portion of a sub light guide plate in an arbitrary light source module, and in the neighboring light source module. And a liquid crystal display device disposed adjacent to the array. In the liquid crystal display device which consists of a liquid crystal display panel which displays an image, and the backlight unit which supplies light to the said liquid crystal display panel, The backlight unit may include a light source for supplying light emitted to the liquid crystal display panel; A bottom cover to mount the light source and the liquid crystal display panel; A reflection member provided inside the bottom cover to reflect light emitted from a light source; A light guide plate disposed on the reflective member and configured to supply light emitted from a light source toward a liquid crystal display panel; And An optical sheet unit disposed on the light guide plate, The light guide plate is formed on a surface facing the bottom cover and includes a first trench and a second trench formed to divide the light guide plate into a plurality of sub-regions, and the light source is disposed in the first trench and the second trench. The liquid crystal display device characterized by the above-mentioned. The method of claim 6, And the first trench and the second trench cross each other in a cross or X shape. The method of claim 6, And one LED array is provided in each trench, and each LED array is mounted in two rows to emit light in opposite directions on the substrate. The method of claim 6, The LED array is provided in a pair so as to correspond to each of the inner portion of each trench, each liquid crystal display device characterized in that a plurality of LED packages are mounted on the substrate to emit light in the opposite direction. The method of claim 1, The LED array includes a plurality of LED packages mounted on a substrate; And And a housing having one side open to surround the LED package so that light may be emitted to the sub light guide plate. The method of claim 10, And the housing is formed in a curved surface. The method of claim 10, And the housing has at least one of a first reflective layer provided inside and a second reflective layer provided outside. The method of claim 10, And a heat dissipation member provided on the substrate for dissipating heat generated from the LED package. The method of claim 1, The sub light guide plate has a first region having a first thickness, a second region having a second thickness smaller than the first thickness, and corresponding to the first side portion and the second side portion, And a LED array in the second region.

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