KR20140082557A - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device, more particularly, to a liquid crystal display device realizing a narrow bezel while improving brightness and image quality. The feature of the present invention is to form a side wall of a guide panel as a dual structure, and to provide a stopper having elasticity on a part of the side wall. Thus, a narrow bezel can be realized and movement of the guide panel can be prevented. Also, an optical gap between a light guide plate and an LED assembly can be constantly maintained. Therefore, movement of the light guide plate can be prevented from occurring from the movement of the guide panel, and brightness and image quality can be improved. In addition, light leaking from a guide groove can be prevented since separate guide grooves are not required to be provided on four edges of the light guide plate. Furthermore, problems of damage to a plurality of LEDs of the LED assembly can be prevented, or degradation of image quality caused by variation in optical characteristics of the liquid crystal display device can be prevented.

Description

[0001] Liquid crystal display device [0002]

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 realizes a narrow bezel and at the same time has improved luminance and image quality.

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.

The backlight unit uses a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) as a light source.

In particular, LEDs are widely used as light sources for displays, having characteristics such as small size, low power consumption, and high reliability.

Meanwhile, the general backlight unit is divided into a direct type and an edge type depending on the arrangement of the lamps. In the edge type, one or a pair of light sources is divided into one side of the light guide plate and two or two pairs The light source has a structure in which the light sources are disposed on both side portions of the light guide plate, and the direct light type structure has a structure in which several light sources are disposed under the liquid crystal panel.

Here, the direct type type is mainly used in a liquid crystal display device in which brightness is more important than thickness in view of thinness, and an edge type in which a light weight and thin type can be compared with a direct type type is used for a notebook PC or a monitor PC And is mainly used in a liquid crystal display device in which thickness is important.

1 is a cross-sectional view of a liquid crystal display including a backlight unit of a general edge type using an LED as a light source.

As shown in the figure, a liquid crystal display device including a backlight unit 20 of a general edge type includes a liquid crystal panel 10, a backlight unit 20, a guide panel 30, a cover bottom 50, 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.

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

The backlight unit 20 includes an LED assembly 29 arranged along the longitudinal direction of at least one edge of the guide panel 30 and composed of a PCB 29b on which a plurality of LEDs 29a and LEDs 29a are mounted, A reflector 25 of white or silver color resting on the bottoms 50 and a light guide plate 23 resting on the reflector 25 and an optical sheet 21 located thereon.

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 polarizers attached to the front and back surfaces of the liquid crystal panel 10 to control the polarization direction of light, respectively.

In order to supply a high-quality surface light source, which is the most important role of the backlight unit 20, to the liquid crystal panel 10, various optical designs are considered in the backlight unit 20 of the liquid crystal display device constructed as described above, 23) and the LED assembly 29 is an important factor.

However, in the process of realizing a lightweight, thin and narrow bezel liquid crystal display device as recently required, a separate component for preventing the flow of the light guide plate 23 is located close to the active area It is difficult to maintain the optical gap A between the light guide plate 23 and the LED assembly 29 due to the flow of the light guide plate 23 when a separate component is removed in order to prevent this phenomenon .

Therefore, it is very difficult to supply a high-quality surface light source to the liquid crystal panel 10. Especially, light leakage phenomenon occurs between the light guide plate 23 and the LED assembly 29, Failure of the assembly 29 may also occur. This causes a problem that the quality of the liquid crystal display device such as luminance and image quality deteriorates.

SUMMARY OF THE INVENTION It is a first object of the present invention to prevent flow of a light guide plate and prevent a light leakage phenomenon from occurring.

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

A third object of the present invention is to provide a liquid crystal display device having a light weight, a thin shape and a narrow bezel.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a liquid crystal panel; A backlight unit disposed on a rear surface of the liquid crystal panel, the backlight unit including an LED assembly, a light incident surface facing the LED assembly, and a light incident surface on the opposite side; A cover bottom having a horizontal surface on which the backlight unit is seated and a side surface perpendicular to the horizontal surface; And a guide panel including a side wall including a first vertical portion surrounding an outer side surface of the side surface of the cover bottom, and a horizontal portion vertically bent from the first vertical portion to support the liquid crystal panel, And a side wall having a stopper having an elastic force to be brought into close contact with the light receiving surface of the light guide plate.

In this case, a portion of the side wall may include a second vertical portion spaced apart from the first vertical portion by a predetermined distance to cover the edge of the backlight unit, and the stopper having the elastic force may be disposed below the horizontal portion, And is inclined at a predetermined angle from the normal to the opposite side of the first vertical portion.

The stopper having the elastic force may have a hole at a connection portion with the horizontal portion, and the stopper having the elastic force may include a stepped portion protruding toward the light receiving surface.

At least two of the stoppers are provided along the longitudinal direction of the side wall of the guide panel. The side walls of the guide panel, which are perpendicular to the side wall of the guide panel, And a stopper for maintaining an optical gap between the light incidence surface of the light guide plate and the LED assembly.

At this time, a guide groove in which the stopper is inserted is formed at a longitudinal edge of the light incidence surface of the light guide plate.

As described above, according to the present invention, since the side wall of the guide panel is formed in a double structure and a stopper having an elastic force is formed on a part of the side wall, the flow of the light guide plate can be prevented Thereby, the optical gap between the light guide plate and the LED assembly can be maintained constant.

In addition, it is unnecessary to form a separate component at the edge of the light guide plate, thereby preventing the light leakage phenomenon caused by the separately provided components, the damage of the LEDs of the LED assembly, There is an effect that it is possible to prevent a problem that the image quality is deteriorated due to a change in optical characteristics.

1 is a cross-sectional view of a liquid crystal display including a backlight unit of a general edge type using an LED as a light source.
2 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.
FIG. 3A is a perspective view schematically showing a guide panel according to an embodiment of the present invention. FIG.
Figs. 3B to 3D are enlarged views of a part of Fig. 3A. Fig.
4A is a plan view schematically showing a guide panel and a light guide plate according to an embodiment of the present invention.
FIG. 4B is a cross-sectional view schematically showing a section cut along the line IV-IV 'of FIG. 4A of FIG. 5A-5B are cross-sectional views schematically illustrating a cross-section taken along line V-V 'of FIG. 4A of FIG. 2 modularized.
6A to 6B are simulation results of measurement of deformation amount of a stopper having an elastic force according to an embodiment of the present invention.
6C is a simulation result of measuring the tensile strength of a stopper having an elastic force.
7A to 7D are simulation results of measuring the light leakage phenomenon when the liquid crystal display according to the embodiment of the present invention is operated in different temperature environments.

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

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

As shown in the figure, the liquid crystal display according to the present invention includes a liquid crystal panel 110 and a backlight unit 120 which are stacked on top and bottom, and a guide panel 130 and a cover bottom 150 as mechanical elements for integrating the liquid crystal panel 110 and the backlight unit 120, Respectively.

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, A cover bottom 150 which is in close contact with the back surface of the backlight unit 120 in a state where the guide panel 130 of a rectangular shape is wiped is combined at the front and rear sides to be 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 drawing, a plurality of gate lines and data lines intersect each other on the inner surface of a first substrate 112 called a lower substrate or an array substrate, pixels are defined, and thin- and a thin film transistor (TFT), which are connected in a one-to-one correspondence with the transparent pixel electrodes formed in the respective pixels.

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.

A polarizing plate (not shown) for selectively transmitting only specific light is 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.

When the thin film transistor selected for each gate line is turned on by the on / off signal of the gate driving circuit, the liquid crystal panel 110 transmits the signal voltage of the data driving circuit to the corresponding pixel electrode through the data line. The alignment direction of the liquid crystal molecules in the liquid crystal layer is changed by the electric field between the pixel electrode and the common electrode to show a difference in transmittance.

And a backlight unit 120 for supplying light to the back surface of the liquid crystal panel 110 so that the difference in transmittance of the liquid crystal panel 110 is externally expressed.

The backlight unit 120 includes a white or silver reflective plate 125, an LED assembly 129 arranged along one longitudinal edge of the reflective plate 125, a light guide plate 123 mounted on the reflective plate 125, And an optical sheet 121 which is seated on the optical sheet 121.

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 so as to face the light incident surface 123a 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 at a predetermined interval.

At this time, the plurality of LEDs 129a emit light having red (R), green (G), and blue (B) colors toward the light incoming surface 123a of the light guide plate 123, White light by color mixing can be realized by lighting the LED 129a all at once.

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 is excellent in transparency, weatherability, and colorability, and induces light diffusion when light is transmitted.

The light guide plate 123 is made of one selected from a plastic material such as polymethylmethacrylate (PMMA) or polycarbonate (PC), which is an acrylic transparent resin, which is one of transparent materials capable of transmitting light PMMA is widely used because it has excellent transparency, weatherability and colorability and induces light diffusion when light is transmitted.

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 123 by a printing method or an injection method.

Particularly, guide grooves 123c are formed on both sides of the light incidence surface 123a of the light guide plate 123 of the present invention in the form of a part of the corners being separated.

The light guide surface 123a of the light guide plate 123 and the LED assembly 129 can maintain the optical gap A (see FIG. 4A) constant by the guide groove 123c. Let's take a closer look at this later.

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 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 guide panel 130 and the cover bottom 150. The cover bottom 150 is formed by mounting the backlight unit 120 including the liquid crystal panel 110 The horizontal plane 151 serves as a lower frame that supports the entire liquid crystal display and minimizes the occurrence of light loss. The edge of the horizontal plane 151 is vertically bent to form a side surface 153.

A rectangular guide panel 130 mounted on the cover bottom 150 and covering the edge of the backlight unit 120 is coupled with the cover bottom 150.

The guide panel 130 includes a side wall 131 that encloses a side surface of the backlight unit 120 and a horizontal portion 133 that separates the liquid crystal panel 110 and the backlight unit 120 from each other, So that the liquid crystal panel 110 is attached and fixed on the horizontal portion 133 through a bonding pad 118 (see Fig. 5A) such as a double-sided tape.

Accordingly, the liquid crystal panel 110 and the backlight unit 120 are integrally modularized.

The liquid crystal display of the present invention realizes a light bead and a thin shape, and also realizes a narrow bezel in which a display area is wide and a bezel area which is a non-display area other than the display area is formed as small as possible .

At this time, the side wall 131 of the guide panel 130 of the present invention has a double structure, and a part of the side wall 131 having a double structure is provided with elasticity for preventing the flow of the light guide plate 123 A stopper 135 is formed.

The liquid crystal display device of the present invention can prevent the flow of the light guide plate 123 in a double manner and prevent the guide panel 130 from sagging due to the liquid crystal panel 110 being seated on the horizontal portion 133 of the guide panel 130 Can be prevented.

The optical gap A between the light guide plate 123 and the LED assembly 129 for supplying a high-quality surface light source to the liquid crystal panel 110, which is the most important role of the backlight unit 120, 4a) can be maintained, and the luminance and image quality of the liquid crystal display device can be improved.

In addition, the liquid crystal display of the present invention does not need to include a separate component for preventing the flow of the light guide plate 123, thereby preventing the light leakage phenomenon caused by the component located close to the active area have.

In addition, it is also possible to prevent the flow of the light guide plate 123, which may cause breakage of the LED 129a of the LED assembly 129, or deterioration of image quality due to various optical characteristics of the liquid crystal display device Can be prevented.

Here, the guide panel 130 may be referred to as a support main or main support, or a mold frame, and the cover bottom 150 may be referred to as a bottom cover or a bottom cover.

The liquid crystal display according to the embodiment of the present invention has a structure in which the top cover (40 in FIG. 1) is removed, and a lightweight, thin and narrow bezel is possible through the elimination of the top cover And has the effect of simplifying the process.

Further, the elimination of the top cover (40 in Fig. 1) made of a metal material can reduce the process cost.

The liquid crystal display device according to the embodiment of the present invention can realize the structure in which the side wall 131 of the guide panel 130 is formed in a double structure to prevent the flow of the double light guide plate 123, The optical gap A (see Fig. 4A) of the LED assembly 129 can be kept constant.

Accordingly, it is possible to prevent the brightness and the image quality of the liquid crystal display from being lowered due to the flow of the light guide plate 123, and to prevent the damage of the LED 129a of the LED assembly 129 can do. In addition, it is possible to prevent the light leakage phenomenon from occurring due to the components provided to prevent the light guide plate 123 from flowing.

FIG. 3A is a perspective view schematically showing a guide panel according to an embodiment of the present invention, and FIGS. 3B to 3C are enlarged views of part of FIG. 3A.

2, the guide panel 130 covering the edge of the backlight unit 120 (see FIG. 2) is made of a molding material made of a synthetic resin such as polycarbonate, and covers the edge of the backlight unit 120 And a horizontal portion 133 protruding inwardly from the side wall 131 and the side wall 131 in a vertical direction and on which the liquid crystal panel 110 is mounted.

At this time, the guide panel 130 of the present invention has a double structure in which the side wall 131 has a double structure and an elastic force is applied to one edge of the light guide plate 123 of the backlight unit 120 A stopper 135 is formed.

The guide panel 130 includes a first edge portion 130a on which the LED assembly (129 in FIG. 2) is arranged, and a second edge portion 130b on which the LED assembly And third and fourth edge portions 130c and 130d connecting the second edge portion 130b on the opposite side of the first edge portion 130a and the first and second edge portions 130a and 130b The first to fourth edge portions 130a, 130b, 130c and 130d are formed by a side wall 131 covering the edge of the backlight unit (120 in FIG. 2) and a backlight unit And a horizontal portion 133 for separating the position of the liquid crystal panel (110 of FIG. 2).

At this time, the liquid crystal panel (110 of FIG. 2) is seated and supported on the horizontal portion 133.

A part of the side wall 131 includes a first vertical part 131a vertically bent from the end of the horizontal part 133 and a second vertical part 131 perpendicular to the horizontal part 133 below the horizontal part 133, And a second vertical part 131b which is spaced apart from the second vertical part 131a by a predetermined distance.

Therefore, the guide panel 130 is formed in a rectangular frame shape in which a part of the guide panel 130 is bent in the shape of "∩" by the first and second vertical portions 131a, 131b and the horizontal portion 133.

At this time, the first and second vertical portions 131a and 131b are spaced apart from each other by a predetermined distance, and a side face (153 in FIG. 2) of the cover bottom (150 in FIG. 2) of the liquid crystal panel (110 of FIG. 2) is positioned above the horizontal portion 133, and a part of the back edge of the liquid crystal panel (110 of FIG. 2) is seated on the horizontal portion 133 to be fixed in position .

Here, since the side wall 131 of the guide panel 130 has a dual structure of the first and second vertical portions 131a and 131b, the rigidity of the guide panel 130 is improved, It is possible to prevent the guide panel 130 from being sagged by the weight of the liquid crystal panel 110 in the process of seating the liquid crystal panel 110 on the horizontal portion 133.

At this time, the side edge of the second edge portion 130b on the opposite side of the first edge portion 130a where the LED assembly (129 in FIG. 2) of the guide panel 130 is located is provided with the second edge portion 130b A stopper 135 having at least two elastic forces is provided along the longitudinal direction.

That is, a portion of the side wall 131 of the second edge portion 130b where the second vertical portion 131b is not formed is present in the region of the second edge portion 130b, and as shown in FIGS. 3B and 3C, (135).

Here, the stopper 135 having elasticity is extended from the horizontal portion 133 to a lower side of the horizontal portion 133 so as to be inclined at a predetermined angle from the normal line perpendicular to the horizontal portion 133 toward the opposite side of the first vertical portion 131a Respectively. A hole 135a is formed in the stopper 135 having elasticity near the connection part with the horizontal part 133 and a convex step 135b is formed in the lower part of the hole 135a to the opposite side of the first vertical part 131a. Respectively.

The stopper 135 having such an elastic force is formed on the second edge portion 130b of the guide panel 130 so as to face the receiving light surface 123b of the light guide plate 123, The stopper 135 having an elastic force formed on the edge portion 130b is formed to be inclined at a predetermined angle from the normal line perpendicular to the horizontal portion 133 toward the opposite side of the first vertical portion 131a, The light guide plate 135 is brought into close contact with the light receiving surface 123b of the light guide plate 123 as shown in FIG.

2), which is the interval between the LED assembly (129 in FIG. 2) and the light incidence plane (123a in FIG. 2) of the light guide plate 123, by the stopper 135 having elasticity, ) Can be kept constant.

In addition, the stopper 135 having elasticity has an elastic restoring force like a kind of spring in the X-axis direction defined in the drawing.

Therefore, even if the light guide plate 123 is caused to flow due to external vibration or impact from the modularized liquid crystal display device, the light guide plate 123 is returned to the original position by the elastic restoring force of the stopper 135 having elasticity, The optical gap A (see Fig. 4A), which is the interval between the light incident surface (129 in Fig. 2) and the light incident surface (123a in Fig. 2) of the light guide plate 123, can be kept constant.

In addition, when the light guide plate 123 is exposed for a long time at a high temperature by driving the backlight unit (120 of FIG. 2) and driving the liquid crystal panel (110 of FIG. 2), thermal expansion occurs due to the material characteristics of the light guide plate 123 At this time, since the stopper 135 having an elastic force applies a constant force to the light guide plate 123, the amount of expansion of the light guide plate 123 can be reduced.

The expansion of the light guide plate 123 is absorbed by the resilient restoring force of the stopper 135 having elasticity even when the light guide plate 123 is expanded, thereby preventing the light guide plate 123 from flowing.

Since the stopper 135 having an elastic force has fluidity within a certain range due to the elastic restoring force of the stopper 135 having elasticity, vibration and shock are absorbed by the fluidity, It is possible to prevent breakage from occurring.

2) and the light guide plate 123 by applying a constant force to the light guide plate 123 through the stopper 135 having an elastic force even if the light guide plate 123 is contracted due to the material properties thereof. The optical gap A (see Fig. 4A) between the light incidence surface (123a in Fig. 2) can be kept constant.

It is also possible to prevent the flow of the light guide plate 123 from occurring by applying a constant force of the light guide plate 123 through the stopper 135 having the elastic force provided on the guide panel 130, It is possible to prevent the light leakage phenomenon caused by the components provided separately from being generated.

As a result, the quality of the liquid crystal display device is improved by improving the brightness and image quality.

In the guide panel 130 of the present invention, since a part of the side wall 131 is formed by the double structure of the first and second vertical parts 131a and 131b, the elasticity of the elasticity restoring force of the stopper 135, It is possible to disperse the force applied to the stopper 135 having elastic force through the second vertical portion 131b when the expansion amount of the light guide plate 123 is generated and to prevent the flow and damage of the light guide plate 123 more stably And the optical gap A (see Fig. 4A), which is the interval between the light incident surface (123a in Fig. 2) of the light guide plate 123, can be kept constant.

At this time, the stopper 135 having an elastic force forms a hole 135a in the vicinity of the connection portion with the horizontal portion 133, thereby improving the fluidity of the stopper 135 having an elastic force, ) Is increased.

Here, when the hole 135a is not formed in the stopper 135 having the elastic force, if the stopper 135 having the elastic force exerts an impact from the outside, the elastic restoring force of the stopper 135 having elastic force is small, The impact is not applied to only the stopper 135 provided with the guide panel 130, and the entire guide panel 130 is impacted.

Therefore, the flow of the guide panel 130 is caused, and the flow of the light guide plate 123 due to the flow of the guide panel 130 may also occur. As a result, a large number of LEDs (129a in FIG. 2) of the LED assembly (129 in FIG. 2) are damaged or optical characteristics of the liquid crystal display device are changed.

Further, the stopper 135 having the elastic force of the present invention is formed to have the convex stepped portion 135b at the lower portion of the hole 135a, so that a greater force can be applied to the light guide plate 123. [

Therefore, even if the elastic restoring force of the stopper 135 having elasticity is small due to material properties, the force applied to the light guide plate 123 by the stepped portion 135b formed on one surface of the stopper 135 having elasticity is large The flow of the light guide plate 123 can be prevented more stably and the optical gap A between the LED assembly (129 in Fig. 2) and the light incident surface (123a in Fig. 2) of the light guide plate 123 ) Can be kept constant.

FIG. 4A is a plan view schematically showing a guide panel and a light guide plate according to an embodiment of the present invention, and FIG. 4B is a cross-sectional view schematically showing a cross section taken along line IV-IV 'of FIG.

2, the guide panel 130 includes a side wall 131 surrounding the side surface of the backlight unit 120 (see FIG. 2) and a horizontal portion 133 vertically protruding from the side wall 131 .

A part of the side wall 131 is formed by a double structure of the first and second vertical parts 131a and 131b and a part of the side wall 131 is surrounded by the side surface of the light guide plate 123 of the backlight unit 120 And a stopper 135 having an elastic force is formed at an edge thereof.

The light guide plate 123 is positioned inside the guide panel 130 and the LED assembly 129 is arranged along one edge of the guide panel 130 corresponding to the light incident surface 123a of the light guide plate 123. [

At this time, guide grooves 123c are formed on both sides of the light incidence surface 123a of the light guide plate 123 in the form of a part of the corners thereof being separated from each other. In correspondence with the guide grooves 123c, A stopper 137 is formed on one of the two edges.

Accordingly, the light guide plate 123 of the present invention prevents the light guide plate 123 from flowing by the stopper 135 having an elastic force in the -X-axis direction defined in the drawing, and the stopper 137 The light guide plate 123 can keep the optical gap A between the light guide plate 123 and the LED assembly 129 constant.

By the elastic restoring force of the elastic stopper 135 having elasticity, vibration and impact are externally applied to the modularized liquid crystal display device so that even when the light guide plate 123 generates a flow, the light guide plate 123 is restored immediately, The optical gap A, which is the interval between the assembly 129 and the light incidence surface 123a of the light guide plate 123, can be kept constant.

Since the stopper 135 having an elastic force exerts a constant force on the light guide plate 123, the amount of expansion of the light guide plate 123 can be reduced and even if the light guide plate 123 is expanded, It is possible to prevent the flow of the light guide plate 123 by absorbing the elastic force of the stopper 135 with the elastic restoring force of the elastic stopper 135. [

In addition, vibration and shock can be absorbed through the stopper 135 having an elastic force, and damage to the light guide plate 123 can be prevented. By applying a constant force to the light guide plate 123, The optical gap A between the LED assembly 129 and the light incidence surface 123a of the light guide plate 123 can be maintained constant even if shrinkage occurs due to material properties of the light guide plate 123. [

5A to 5B are cross-sectional views schematically showing cross sections taken along line V-V 'of FIG. 4A of FIG.

An LED assembly 129 including a reflection plate 125, a light guide plate 123, a PCB 129b on which the LED 129a and the LED 129a are mounted, and a light guide plate 123 on the light guide plate 123, 121 are stacked to form a backlight unit 120. [

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 are disposed on the backlight unit 120, And 114 are attached with polarizing plates 119a and 119b selectively transmitting only specific light.

Here, the backlight unit 120 is surrounded by the guide panel 130, and the cover bottom 150 is coupled to the backside thereof.

The guide panel 130 includes a side wall 131 and side walls 131 that cover the side surface of the backlight unit 120 and protrude inward from the side wall 131 to cover the upper portion of the LED assembly 129 and the upper edge of the light guide plate 123, (133).

A portion of the side wall 131 of the guide panel 130 has a double structure and includes a first vertical portion 131a bent vertically from an end of the horizontal portion 133 and a second vertical portion 131b extending downward from the horizontal portion 133, And a second vertical part 131b perpendicular to the first vertical part 133 and spaced apart from the first vertical part 131a by a predetermined distance.

Therefore, a part of the guide panel 130 is formed into a rectangular frame whose cross section is bent in the form of "∩" by the first and second vertical parts 131a, 131b and the horizontal part 133, The side face 153 of the cover bottom 150 is inserted between the two vertical portions 131a and 131b.

An adhesive pad 118 is formed between the liquid crystal panel 110 and the horizontal portion 133 to support the edge of the liquid crystal panel 110.

The adhesive pad 118 is made of an adhesive material such as a double-sided tape to fix the liquid crystal panel 110 on the horizontal portion 133.

At this time, a stopper 135 having an elastic force is provided on the guide panel 130 facing the light receiving surface 123b opposite to the light incident surface 123a of the light guide plate 123, and the stopper 135 having elasticity And extends from the horizontal portion 133 to a lower side of the horizontal portion 133 so as to be inclined at a predetermined angle from a normal line perpendicular to the horizontal portion 133 toward the opposite side of the first vertical portion 131a.

At this time, the stopper having elastic force is provided with a hole 135a near the connection part with the horizontal part 133, and the stopper 135 having elastic force is protruded toward the light-incoming optical surface 123b of the light guide plate 123 A stepped portion 135b is formed.

The stopper 135 having such an elastic force is brought into close contact with the receiving light surface 123b of the light guide plate 123 and applies a constant force to the light guide plate 123 toward the LED assembly 129 as shown in FIG.

Therefore, the liquid crystal display of the present invention is an interval between the light guide plate 123 and the LED assembly 129, which is one of the conditions for providing a high-quality surface light source to the liquid crystal panel 110, which is an important role of the backlight unit 120 The optical gap A can be kept constant.

In this case, when an external impact is applied to the modularized liquid crystal display device, the elastic restoring force of the stopper 135 having the elastic force causes the stopper 135 having elasticity as shown in FIG. 5B to have a fluidity It is possible to prevent the light guide plate 123 from being damaged because vibration and impact are absorbed by the fluidity.

Even if the flow of the light guide plate 123 occurs due to the elastic restoring force of the stopper 135 having the elastic force, the light guide plate 123 can be positioned immediately after the LED assembly 129 and the light incident surface 123a of the light guide plate 123 It is possible to keep the optical gap A, which is the interval between the light source and the light source, constant.

Even when the light guide plate 123 is contracted due to the material properties, a certain force is applied to the light guide plate 123 through the stopper 135 having an elastic force, so that the LED assembly 129 and the light guide plate 123 123a can be kept constant.

In addition, even if the light guide plate 123 is expanded, the expansion amount of the light guide plate 123 is absorbed by the elastic restoring force of the stopper 135 having the elastic force, thereby preventing the guide panel 130 from flowing .

For example, when the linear expansion coefficient of the light guide plate 123 is 6.5E-5 / ° C, the light guide plate 123 expands by about 0.7 mm in an environment of 60 degrees. In order to realize the narrow bezel, When the total gap of the panel 130 is 0.2 mm, an overlap of 0.5 mm is generated.

When the overlap occurs, the flow of the guide panel 130 is generated.

When the total gap of the light guide plate 123 and the guide panel 130 is 0.7 mm or more by calculating the overlap caused by the expansion of the light guide plate 123 in order to prevent the flow of the guide panel 130, Which is difficult to implement.

However, according to the present invention, even when expansion of the light guide plate 123 occurs, the amount of expansion of the light guide plate 123 is absorbed by the elastic restoring force of the stopper 135 having elasticity, .

Accordingly, it is unnecessary to determine the total gap between the light guide plate 123 and the guide panel 130 by calculating the overlap caused by the expansion of the light guide plate 123 to prevent the guide panel 130 from flowing, thereby realizing a narrow bezel It is.

Particularly, the guide panel 130 according to the embodiment of the present invention has the hole 135a formed in the stopper 135 having the elastic force to further improve the fluidity of the stopper 135 having the elastic force, The elastic restoring force of one stopper 135 can be further increased.

Here, when the hole 135a is not formed in the stopper 135 having the elastic force, if the stopper 135 having the elastic force exerts an impact from the outside, the elastic restoring force of the stopper 135 having elastic force is small, The impact is not applied to only the stopper 135 provided with the guide panel 130, and the entire guide panel 130 is impacted.

6A to 6B are simulation results of measurement of the deformation amount of the guide panel according to the presence or absence of holes of a stopper having an elastic force according to an embodiment of the present invention.

6C is a simulation result of measuring the tensile strength of a stopper having an elastic force.

6A, the guide panel 130 according to the embodiment of the present invention includes a stopper (not shown) having an elastic force, 135, the fluidity due to the elastic restoring force is improved to 0.7 to 0.8 mm.

Therefore, even if the light guide plate (123 in Fig. 5B) having a linear expansion coefficient of 6.5E-5 / 占 폚 expands about 0.7 mm in an environment of 60 degrees, the expansion of the light guide plate (123 in Fig. The total thickness of the light guide plate (123 in FIG. 5B) and the guide panel 130 can be 0.2 mm, thereby realizing a narrow bezel. In addition, It is possible to prevent the flow of the guide panel 130 from occurring.

6C is a simulation result of measuring the tensile strength of the stopper having the elastic force when the light guide plate slowly pushes the guide panel. As shown in the figure, the stopper 135 having elasticity according to the embodiment of the present invention is elastic The maximum tensile strength applied to the stopper 135 having the elastic force by the flow of the light guide plate (123 in Fig. 5B) is 26.6 MPa, which is the tensile strength of the guide panel 130, which is 65 MPa So that breakage of the stopper 135 having elastic force does not occur.

7A to 7D are graphs illustrating the results of a simulation of light leakage phenomenon when the liquid crystal display according to the embodiment of the present invention is operated in different temperature environments. FIGS. 7C to 7D are simulation results of measuring the light leakage phenomenon when the liquid crystal display according to the embodiment of the present invention is operated at a low temperature of 0 ° C. FIG.

7A to 7D, the liquid crystal display of the present invention does not have a separate component in the light guide plate 123 (FIG. 5B) while implementing a narrow bezel, so that light leakage does not occur even when the light guide plate operates at a high temperature or a low temperature .

As described above, in the liquid crystal display of the present invention, a part of the side wall (131 in FIG. 5B) of the guide panel 130 is formed in a double structure to improve the rigidity of the guide panel 130, (A in FIG. 5B) of the light guide plate (123 in FIG. 5B) and the LED assembly (129 in FIG. 5B) can be kept constant by constituting the light guide plate have.

Accordingly, it is possible to prevent the flow of the light guide plate (123 in FIG. 5B) due to the flow of the guide panel 130, and to improve the brightness and image quality of the liquid crystal display device.

Further, since it is not necessary to form a separate component in the light guide plate (123 in FIG. 5B), it is possible to prevent the light leakage phenomenon caused by the separately provided components.

Also, it is possible to prevent a problem that a large number of LEDs (129a in FIG. 5B) of the LED assembly (129 in FIG. 5B) are damaged or the optical characteristics of the liquid crystal display device are changed, thereby deteriorating 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.

110: liquid crystal panel (112: first substrate, 114: second substrate)
118: Adhesive pad
119a and 119b: first and second polarizing plates
The present invention relates to a light emitting diode (LED), and more particularly,
The guide panel 131 includes first and second vertical portions 133 and 133, a horizontal portion 135, and a stopper 135a having an elastic force.
150: cover bottom (151: horizontal plane, 153: side)

Claims (8)

A liquid crystal panel;
A backlight unit disposed on a rear surface of the liquid crystal panel, the backlight unit including an LED assembly, a light incident surface facing the LED assembly, and a light incident surface on the opposite side;
A cover bottom having a horizontal surface on which the backlight unit is seated and a side surface perpendicular to the horizontal surface;
A side wall including a first vertical portion surrounding an outer side surface of the side face of the cover bottom, and a horizontal portion vertically bent from the first vertical portion to support the liquid crystal panel,
And a stopper having an elastic force that is in close contact with a light-incoming surface of the light guide plate is formed on the side wall of the guide panel.
The method according to claim 1,
Wherein a part of the side wall is spaced apart from the first vertical part by a predetermined distance and includes a second vertical part covering an edge of the backlight unit.
The method according to claim 1,
Wherein the stopper having the elastic force is formed at a lower side of the horizontal portion and is inclined at a predetermined angle from a normal line perpendicular to the horizontal portion toward the opposite side of the first vertical portion.
The method of claim 3,
Wherein a hole is formed in a connection portion of the stopper having the elastic force with the horizontal portion.
The method of claim 3,
And the stopper having the elastic force includes a stepped portion protruding toward the light receiving surface.
The method according to claim 1,
And the stopper having the elastic force is constituted by at least two along the longitudinal direction of the side wall of the guide panel.
The method according to claim 1,
Wherein a stopper for maintaining an optical gap between the light incidence surface of the light guide plate and the LED assembly is provided on a sidewall of both side edges of the guide panel perpendicular to the sidewall, the stopper comprising the elastic force.
8. The method of claim 7,
Wherein a guide groove is formed in an edge of the light guide plate in the lengthwise direction of the light incidence surface, into which the stopper is inserted.

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