KR20150069823A - liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device, and more specifically, to a liquid crystal display device which can prevent circulation of a light guide plate, and can prevent degradation of image quality. As a pad is located on one side edge of anti-incident light surfaces of the light guide plate, the position of the light guide plate is fixed in the modularized liquid crystal display device, and circulation is defended. Also, the pad is made of a translucent material, and a guide unit of a reflection plate covers the outside of the pad so that image darkness in which an area where the pad is located is seen darker than other areas can be prevented. Accordingly, a problem that image quality is degraded since optical properties are changed can be prevented.

Description

[0001] The present invention relates to a 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 capable of preventing a flow of a light guide plate and preventing a deterioration in image quality of a liquid crystal display device.

A liquid crystal display device (LCD), which is advantageous for moving picture display and has a large contrast ratio and is actively used in TVs and monitors, exhibits optical anisotropy and polarization properties of a liquid crystal, And the like.

Such a liquid crystal display device has a liquid crystal panel in which a liquid crystal panel is interposed between two adjacent substrates through a liquid crystal layer as an essential component and changes the alignment direction of the liquid crystal molecules in an electric field in the liquid crystal panel to realize a difference in transmittance do.

However, since the liquid crystal panel does not have its own light emitting element, a separate light source is required to display the difference in transmittance as an image. To this end, a backlight having a light source is disposed on the back surface of the liquid crystal panel.

1 is a cross-sectional view of a general liquid crystal display device.

As shown in the figure, a typical liquid crystal display device includes a liquid crystal panel 10, a backlight unit 20, a guide panel 30, a cover bottom 50, and a top cover 40.

The liquid crystal panel 10 is constituted by first and second substrates 12 and 14 which are in contact with each other with a liquid crystal layer interposed therebetween, which plays a key role in image display.

A backlight unit 20 is provided behind the liquid crystal panel 10.

The backlight unit 20 includes an LED assembly 29 arranged along one longitudinal edge of the guide panel 30, a white or silver reflective plate 25 seated on the cover bottom 50, ) And a plurality of optical sheets 21 interposed therebetween.

The LED assembly 29 is formed on one side of the light guide plate 23. The LED assembly 29 includes a plurality of LEDs 29a and an LED PCB 29b on which a plurality of LEDs 29a are mounted. .

The liquid crystal panel 10 and the backlight unit 20 are covered with a top cover 40 covering the top edge of the liquid crystal panel 10 with the edges thereof being surrounded by a rectangular guide panel 30, The cover bottoms 50 are integrally joined to each other through the guide panel 30.

And reference numerals 19a and 19b denote polarizing plates attached to the front and back surfaces of the liquid crystal panel 10 to control the polarization direction of light, respectively.

On the other hand, it is important to fix the LED assembly 29, the light guide plate 23, and the optical sheet 21 of the backlight unit 20 so that they do not flow.

Particularly, when the light guide plate 23 flows due to an external shock or vibration, the LED 29a of the LED assembly 29 is damaged or the optical characteristics of the liquid crystal display device are changed, It is possible to cause.

This causes a problem that the quality of a liquid crystal display device such as brightness and image quality deteriorates.

SUMMARY OF THE INVENTION It is a first object of the present invention to solve the above problems and to prevent the flow of a light guide plate.

A second object of the present invention is to improve the brightness and image quality of a liquid crystal display device.

In order to achieve the above object, according to the present invention, there is provided a light guiding plate comprising: a light guide plate having guide grooves formed at one side edge of a light-incident surface; A pad inserted into the guide groove and made of translucent material; And a guide portion disposed at a lower portion of the light guide plate and surrounding an outer side surface of the pad; An LED assembly attached along an incident surface of the light guide plate; An optical sheet that is seated on the light guide plate; And a liquid crystal panel that is seated on top of the optical sheet.

At this time, the size of the pad is 1.1 to 1.2 times larger than the size of the guide groove, and the pad is formed in a bar shape such that the lower surface of the pad facing the reflection plate has a narrower width than the upper surface facing the liquid crystal panel .

The guide portion is formed to be perpendicularly bent from one end of the reflection plate to correspond to the width and the height of the pad, and a stopper is provided on the light-incoming surface of the light guide plate to maintain an interval between the LED assembly and the light- .

And a cover bottom having a horizontal plane and an edge portion perpendicular to the horizontal plane, the side face connecting the receiving light plane and the light incidence plane perpendicular to the carrying light plane and the light receiving plane, And a gap is formed.

As described above, by positioning the pad on one side edge of the light-incident side of the light guide plate according to the present invention, the position of the light guide plate is fixed in the modularized liquid crystal display device, thereby preventing the flow.

In addition, by forming the pad with a semi-transparent material and surrounding the outside of the side surface of the pad with the guide portion of the reflection plate, it is possible to prevent darkness of the image where the pad is located to be dark compared with other regions.

Therefore, it is possible to prevent the problem that the optical characteristics of the liquid crystal display device are changed and the image quality is lowered.

1 is a sectional view of a general liquid crystal display device.
2 is a perspective view schematically showing a liquid crystal display device according to an embodiment of the present invention.
FIG. 3 is a perspective view schematically showing a state where a pad is inserted into a guide groove of the light guide plate of FIG. 2; FIG.
4A is a photograph showing a state in which darkness of an image is observed in an area where a pad is located.
4B is a photograph showing a state in which darkness of an image is not observed in a region where a pad of the liquid crystal display device according to the embodiment of the present invention is located.
Figure 5 is a cross-sectional view schematically illustrating the modularized Figure 2;

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

2 is a perspective view schematically showing a liquid crystal display device according to an embodiment of the present invention.

A liquid crystal display device according to an embodiment of the present invention includes a liquid crystal panel 110, a backlight unit 120, a guide panel 130, a top cover 140, and a cover bottom 150 .

For the sake of convenience, the backlight unit 120 is disposed behind the liquid crystal panel 110 under the assumption that the display surface of the liquid crystal panel 110 faces forward, The top cover 140 is positioned in front of the liquid crystal panel 110 and the cover bottom 150 is positioned on the back surface of the backlight unit 120 in a state in which the guide- And are integrated.

Let's take a closer look at each of these.

First, the liquid crystal panel 110 plays a key role in image display of a liquid crystal display device. The liquid crystal panel 110 includes a first substrate 112 and a second substrate 114 which are bonded to each other and a liquid crystal layer (Not shown).

Although not shown in the drawings, a plurality of gate lines and data lines cross each other on a first substrate 112 called a lower substrate or an array substrate, pixels are defined, and a thin film transistor film transistors (TFT) are connected in one-to-one correspondence with the transparent pixel electrodes formed in each pixel.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, color filters of red (R), green (G), and blue (B) And a black matrix for covering the gate lines, the data lines, and the thin film transistors.

In addition, color filters of red (R), green (G), and blue (B) colors and transparent common electrodes covering the black matrix are provided.

At this time, an upper and a lower alignment film (not shown) for determining the initial alignment direction of the liquid crystal are interposed at the boundary between the two substrates 112 and 114 and the liquid crystal layer (not shown) A seal pattern (not shown) is formed along edges of both substrates 112 and 114 to prevent leakage of a liquid crystal layer (not shown) filled between the first and second substrates 112 and 114 .

Polarizing plates 119a and 119b (see FIG. 5) for selectively transmitting only specific light are attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A printed circuit board 117 is connected to the liquid crystal panel 110 via a connection member 116 such as a flexible circuit board or a tape carrier package (TCP) along one edge of the liquid crystal panel 110, And is properly brought into close contact with the side surface of the panel 130 or the back surface of the cover bottom 150.

Accordingly, when the selected thin film transistor for each gate line is turned on by the on / off signal of the thin film transistor which is transferred to the gate line, the liquid crystal panel 110 supplies the image signal of the data line And the alignment direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode which is generated thereby, and the difference in transmittance is shown.

In the liquid crystal display device according to the present invention, a backlight unit 120 is provided for supplying light from the rear surface of the liquid crystal display panel 110 so that the difference in transmittance of the liquid crystal panel 110 is externally expressed.

The backlight unit 120 includes an LED assembly 129 arranged along at least one longitudinal edge of the cover bottom 150, a reflection plate 125, a light guide plate 123 mounted on the reflection plate 125, And an optical sheet 121 positioned above the light guide plate.

The LED assembly 129 is a light source of the backlight unit 120 and is disposed at one side of the light guide plate 123 to face the light incident surface of the light guide plate 123. The LED assembly 129 includes a plurality of LEDs 129a, And a PCB 129b on which a plurality of LEDs 129a are mounted with a predetermined spacing.

The plurality of LEDs 129a emit light having colors of red (R), green (G), and blue (B) toward the front of the light guide plate 123, and the plurality of RGB LEDs 129a ) Can be turned on at once to realize white light by color mixing.

In particular, in recent years, a blue LED 129a including a blue LED chip having excellent luminous efficiency and brightness has been used for improving the luminous efficiency and brightness, and a phosphor such as yttrium aluminum garnet (YAG: Ce) doped with cerium, A blue LED 129a made of a yellow phosphor is used.

The blue light emitted from the LED 129a is mixed with the yellow light transmitted through the phosphor and emitted by the fluorescent material, thereby realizing white light.

The light guiding plate 123 through which the light emitted from the plurality of LEDs 129a is incident is formed such that the light incident from the LED 129a travels in the light guiding plate 123 by total reflection several times, And provides a surface light source to the liquid crystal panel 110.

The light guide plate 123 includes a light incident surface 123a corresponding to the LED assembly 129a and a light incident surface 123b corresponding to the light incident surface 123a and a light incident surface 123a and a light incident surface 123b, A lower surface 123d facing the surface 123c and the reflective plate 125 and two opposite surfaces 123e and 123f facing each other.

The light guide plate 123 may include a pattern of a specific shape on the lower surface to supply a uniform surface light source. The pattern may be formed in various shapes such as an elliptical pattern, a polygon pattern, a hologram pattern, and the like in order to guide light incident into the light guide plate 123. The pattern is formed on the lower surface of the light guide plate 220 by a printing method or an injection method.

The liquid crystal display device according to the embodiment of the present invention includes a light guide plate 123 and a light guide plate 123. The light guide plate 123 is disposed along the longitudinal direction of the light incidence surface 123a on the light incidence surface 123a of the light guide plate 123 corresponding to one edge of the LED assembly 129, And a stopper 123g for maintaining an optical separation distance between the light incidence surface 123a of the LED assembly 129 and the LED assembly 129.

That is, the interval between the LED assembly 129 and the light-incoming surface 123a of the light guide plate 123 is determined by the width of an optical gap or an air gap in the backlight unit 120 The liquid crystal panel 110 is provided with a high-quality surface light source.

Therefore, by providing the stopper 123g on the light incidence surface 123a of the light guide plate 123, the interval between the light incidence surface 123a of the light guide plate 123 and the LED assembly 129 can be kept constant, The light source may be provided to the liquid crystal panel 110.

A guide groove 123h is formed at one side edge of the light-receiving optical surface 123b opposite to the light incidence surface 123a provided with the stopper 123g and the guide groove 123h is provided with a light- A pad 160 made of a translucent material is positioned.

The position of the light guide plate 123 according to the embodiment of the present invention is fixed in the modularized liquid crystal display device through the pad 160 inserted into the guide groove 123h, The light guide plate 123 is prevented from being horizontally or vertically moved due to external shock or vibration in a state of being housed in the light guide plate 150.

Accordingly, it is possible to prevent the plurality of LEDs 129a from being damaged by the flow of the light guide plate 123.

Here, the pads 160 are formed to have a larger size than the guide grooves 123h.

At this time, the pad 160 is formed such that the lower surface 163 facing the reflection plate 125 has a narrower width than the upper surface 161. To this end, the pad 160 has a lower surface 163 and a side surface 165, The inclined surfaces 167 are inclined at an equal angle to each other.

This is because the pads 160 formed to have a larger size than the guide grooves 123h are inserted into the guide grooves 123h of the light guide plate 123 to more easily insert the pads 160 into the guide grooves 123h of the light guide plate 123, (123h).

The reflection plate 125 is disposed on the back surface of the light guide plate 123 and reflects light passing through the back surface of the light guide plate 123 toward the liquid crystal panel 110 to improve the brightness of light.

The reflective plate 125 may further include a guide portion 125a surrounding the outer side surface of the pad 160. The reflective plate 125 may have a guide groove 123h formed in the guide groove 123h.

Accordingly, the light guide plate 123 according to the embodiment of the present invention is fixed in its position in the modularized liquid crystal display device and prevented from flowing, and at the same time, It is possible to prevent darkness from being observed.

Therefore, it is possible to prevent the problem that the optical characteristics of the liquid crystal display device are changed to deteriorate the image quality. Let's take a closer look at this later.

The optical sheet 121 on the light guide plate 123 includes a diffusion sheet and at least one light condensing sheet and diffuses or condenses the light passing through the light guide plate 123 to provide a more uniform surface light source to the liquid crystal panel 110 Let it enter.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the guide panel 130 and the cover bottom 150. The top cover 140 is disposed on the top edge of the liquid crystal panel 110, So as to cover the side surface.

Here, the top cover 140 has a rectangular frame shape bent in a "? &Quot; shape so as to cover the top and side edges of the liquid crystal panel 110, As shown in Fig.

The guide panel 130 has a rectangular shape for supporting the edges of the liquid crystal panel 110 and covering the edge of the backlight unit 120 and includes a vertical part 131 and a vertical part 131 surrounding the side surface of the backlight unit 120 And a horizontal portion 133 for separating the position of the liquid crystal panel 110 and the backlight unit 120 from each other.

The liquid crystal panel 110 is attached and fixed on the horizontal portion 133 through a bonding pad 170 (see Fig. 5) such as a double-sided tape.

The guide panel 130 is mounted on the cover bottom 150. The cover bottom 150 includes a horizontal surface 151 and an edge portion 153 having a vertically bent edge.

The guide panel 130, the cover bottom 150 and the top cover 140 are formed by laminating the top edges of the liquid crystal panel 110 and the backlight unit 20 in a state where the edges of the liquid crystal panel 10 and the backlight unit 20 are covered with the guide panel 130 A cover top 140 covering the rear surface of the backlight unit 120 and a cover bottom 150 covering the back surface of the backlight unit 120 are combined at the front and rear sides to be modularly integrated through the guide panel 130. [

Here, the top cover 140 may be referred to as a case top or a top case, and the guide panel 130 may be referred to as a support main or main support or a mold frame. The cover bottom 150 may be referred to as a bottom cover or a bottom cover I will.

At this time, the liquid crystal display of the above-described structure can eliminate the top cover 140 and the cover bottom 150 in order to realize a lightweight and thin liquid crystal display device which is recently required. The liquid crystal display device can be made light and thin by eliminating the top cover 140 and the cover bottom 150, and the process can be simplified.

In addition, the elimination of the cover cover 140 and the cover valve 150, which are made of a metal material, may reduce the process cost.

The liquid crystal display according to the embodiment of the present invention may have a guide groove 123h formed at one side edge of the light receiving surface 123b of the light guide plate 123 and prevent the light guide plate 123 from flowing to the guide groove 123h. The flow of the light guide plate 123 can be prevented.

Accordingly, it is possible to prevent the plurality of LEDs 129a from being damaged by the flow of the light guide plate 123.

A guide part 125a which surrounds the side surface of the pad 160 is formed at the corner of the reflection plate 125 corresponding to one corner where the guide groove 123h of the light guide plate 123 is formed, It is possible to prevent darkness in the vicinity of the edge where the pad 160 is located from being observed darker than in other regions.

Therefore, it is possible to prevent the problem that the optical characteristics of the liquid crystal display device are changed to deteriorate the image quality.

FIG. 3 is a perspective view schematically showing a state where a pad is inserted into a guide groove of the light guide plate of FIG. 2;

2) and the light guide plate 123 are sequentially seated on a horizontal plane (151 in FIG. 2) of the cover bottom (150 in FIG. 2). At this time, A guide groove 123h is formed in the guide groove 123h and a pad 160 made of a translucent material is inserted into the guide groove 123h.

The pad 160 is made of a translucent material and is formed to have a bar shape having a predetermined thickness and the guide groove 123h is formed to have the same shape as the pad 160.

At this time, since the size of the pad 160 is larger than that of the guide groove 123h, due to the overlap of the pad 160 and the guide groove 123h, In the diagonal direction.

Accordingly, the light guide plate 123 of the present invention is fixed in its position in the modular liquid crystal display device.

Particularly, since the light guide plate 123 is pushed in the diagonal direction of the pad 160 by the pad 160, the light guide plate 123 is guided along the vertical light guide surface 123b, The side surface 123f forms a gap A with the edge portion 153 of the cover bottom (150 in FIG. 2). The light incident surface 123b and the side surface 123f of the light guide plate 123, The gap A formed between the edge portions 153 of the light guide plate 150 (FIG. 2) serves to prevent the flow due to the expansion of the light guide plate 123 due to the high temperature heat generated when driving the liquid crystal display device.

Here, it is preferable that the pad 160 is formed to be about 1.1 to 1.2 times larger than the guide groove 123h.

When the size of the pad 160 is greater than 1.2 times the size of the guide groove 123h, it may be difficult to insert the pad 160 into the guide groove 123h, When the light guide plate 123 has the same size as the groove 123h, the light guide plate 123 can not be pushed diagonally from one corner where the pad 160 is positioned by the pad 160, so that the flow of the light guide plate 123 can not be completely blocked.

2) of the reflection plate 125 (see FIG. 2) is further formed on the reflection plate 125 (see FIG. 2) And is vertically bent from one end to cover the outer side surface of the pad 160.

The guide portion 125a is formed to have a width and a height corresponding to the length and height of the pad 160. The outer surface of the guide portion 125a is vertically bent from the reflection plate 125 The inner surface of the guide portion 125a is in close contact with the outer side of the side surface of the pad 160 and is wrapped.

Accordingly, in the liquid crystal display device of the present invention, the pad 160 is made of a semi-transparent material and the guide portion 125a of the reflection plate 125 is closely adhered to the outside of the side surface of the pad 160, Can be prevented from being observed in the vicinity of the corner where darkness appears in comparison with other regions.

Recently, a liquid crystal display device having a lightweight, thin and narrow bezel has been demanded, and a guide panel (130 in FIG. 2) for modulating a liquid crystal panel (110 in FIG. 2) and a backlight unit The width of the cover cover (150 in FIG. 2), the top cover (140 in FIG. 2), and the like are also reduced. When the width of the pad 160 is reduced and the pad 160 is not formed of a translucent material and the guide portion 125a of the reflector 125 is not formed, ) Is exposed to the negative part, darkness is observed in the image.

This is because a part of light incident into the light guide plate 123 can be emitted to the pad 160 through the guide groove 123h of the light guide plate 123. Since a pad not made of a translucent material absorbs light In the region where the pad is located, darkness appears darker than in other regions.

The liquid crystal display of the present invention is formed of a translucent material so that the pad 160 can partially reflect the light while having elasticity and the guide part 125a of the reflection plate 125 The light emitted through the guide groove 123h is partially reflected and partially transmitted by the pad 160 and the light transmitted through the pad 160 is reflected by the guide portion 125a It is possible to prevent light darkness that is darker than the other regions by increasing the light transmission efficiency.

Therefore, it is possible to prevent the problem that the optical characteristics of the liquid crystal display device are changed to deteriorate the image quality.

FIG. 4A is a photograph showing the darkness of the image observed in the region where the pad is located. As the pad absorbs light, darkness appears darker than other regions in the region where the pad is located.

In contrast, according to the embodiment of the present invention, the pad 160 is made of a translucent material and the guide portion 125a of the reflection plate 125 (FIG. 2) is wrapped around the lateral side of the pad 160, As shown in the figure, it can be confirmed that the darkness of the image is not observed in the region where the pad 160 is located.

This is because the pad 160 is made of a translucent material and the guide portion 125a of the reflection plate 125 is wrapped around the side surface of the pad 160 so that the light transmittance efficiency The area where the pad 160 is located can be prevented from being darker than the other areas.

Figure 5 is a cross-sectional view schematically illustrating the modularized Figure 2;

As shown in the figure, an LED assembly (see FIG. 2) including a reflection plate 125, a light guide plate 123, and a PCB (129b in FIG. 2) on which an LED (129a in FIG. 2) The optical sheets 121 are stacked on the light guide plate 129 and the light guide plate 123 to form a backlight unit (120 of FIG. 2).

A liquid crystal panel 110 in which a liquid crystal layer (not shown) is interposed between the first and second substrates 112 and 114 and the first and second substrates 112 and 114 is disposed on the backlight unit 120 On the outer surfaces of the substrates 112 and 114, polarizers 119a and 119b selectively transmitting only specific light are attached.

The liquid crystal panel 110 surrounded by the backlight unit 120 of FIG. 2 and the guide panel 130 is seated on the horizontal surface 151 of the cover bottom 150 so that the edge of the cover bottom 150 The outer surface of the guide portion 153 is positioned in close contact with the inner surface of the vertical portion 131 of the guide panel 130.

At this time, the liquid crystal panel 110 is attached and supported on the horizontal portion 133 of the guide panel 130 through the bonding pad 170.

The top cover 140 covers the top edge of the liquid crystal panel 110 and is assembled with the guide panel 130 so that the side surfaces thereof cover the outer surface of the vertical portion 131 of the guide panel 130.

A pad 160 made of translucent material is placed in the guide groove 123h formed at one corner of the light receiving surface 123b of the light guide plate 123 and the outer side of the pad 160 is connected to the guide So that the portion 125a is enclosed.

Therefore, in the process of the light generated from the LED assembly (129 in FIG. 2) entering into the light guide plate 123 and spreading in the light guide plate 123 while spreading through the light guide plate 123 by multiple total reflection, The pad 160 is made of a translucent material so that some of the light is reflected to enter the light guide plate 123 again and a part of the light is reflected by the light guide plate 123. In this case, (Not shown).

The light transmitted through the pad 160 is reflected by the guide portion 125a of the reflection plate 125 and is incident again into the light guide plate 123. [

This improves the light transmission efficiency in one corner area of the light guide plate 123 where the pad 160 is located, thereby preventing darkness of the area where the pad 160 is located from being dark compared with other areas can do.

Therefore, it is possible to prevent the problem that the optical characteristics of the liquid crystal display device are changed to deteriorate the image quality.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

123: light guide plate 123b (incoming light surface, 123f: side surface, 123h: guide groove)
125a: guide portion
153:
160: Pad

Claims (6)

A light guide plate having guide grooves formed at one side edge of the light-receiving surface;
A pad inserted into the guide groove and made of translucent material;
And a guide portion disposed at a lower portion of the light guide plate and surrounding an outer side surface of the pad;
An LED assembly attached along an incident surface of the light guide plate;
An optical sheet that is seated on the light guide plate;
And a liquid crystal panel
And the liquid crystal display device.
The method according to claim 1,
Wherein the size of the pad is 1.1 to 1.2 times larger than the size of the guide groove.
The method according to claim 1,
Wherein the pad is formed in a bar shape such that a lower surface of the pad facing the reflection plate has a narrower width than an upper surface of the pad facing the liquid crystal panel. The method according to claim 1,
And the guide portion is formed by being bent perpendicularly from one end of the reflection plate corresponding to the width and height of the pad.
The method according to claim 1,
And a stopper for maintaining a distance between the LED assembly and the light incidence surface is provided on the light incidence surface of the light guide plate.
The method according to claim 1,
And a cover bottom having a horizontal plane and an edge portion perpendicular to the horizontal plane. The side surface connecting the light-incident surface and the light-incident surface is perpendicular to the light-incident surface and the light- Thereby forming a gap.

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