KR102078026B1 - Liquid crystal display device - Google Patents

Abstract

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 implements a narrow bezel and improves brightness and image quality.
A feature of the present invention is to form a sidewall of the guide panel in a double structure, and to configure a stopper having elastic force on a part of the sidewall.
Through this, it is possible to implement a narrow bezel, it is possible to prevent the flow of the guide panel. In addition, the optical gap between the light guide plate and the LED assembly can be kept constant. Therefore, the flow of the light guide plate due to the flow of the guide panel can be prevented, and the brightness and the image quality of the liquid crystal display can be improved.
In addition, it is not necessary to form the guide grooves separate from the four edges of the light guide plate, thereby preventing occurrence of light leakage by the guide grooves.
In addition, it is possible to prevent the occurrence of a breakdown of a plurality of LEDs of the LED assembly, or a problem of deterioration of the image quality due to the optical characteristics of the liquid crystal display device is changed.

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 that implements a narrow bezel and improves brightness and image quality.

Liquid crystal display devices (LCDs), which are used for TVs and monitors due to their high contrast ratio and are advantageous for displaying moving images, are characterized by optical anisotropy and polarization of liquid crystals. The principle of image implementation by

Such a liquid crystal display is an essential component of a liquid crystal panel, which is bonded between two substrates in parallel with a liquid crystal layer, and realizes a difference in transmittance by changing an arrangement direction of liquid crystal molecules with an electric field in the liquid crystal panel. 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, and for this purpose, a backlight having a light source embedded therein is disposed on the back 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.

Among them, LEDs are particularly widely used as light sources for displays having features such as small size, low power consumption, and high reliability.

Meanwhile, a general backlight unit is classified into a direct type method and an edge type method according to an arrangement of lamps. In the edge type method, one or a pair of light sources is provided with one or two or two pairs of light guide plates. The light source has a structure in which both sides of the light guide plate are disposed, and the direct type has a structure in which several light sources are disposed below the liquid crystal panel.

Here, the direct type has a limitation in thinning, and is mainly used in a liquid crystal display device in which brightness is more important than the thickness of the screen, and the edge type which is lighter and thinner than the direct type is such as a notebook PC or a monitor PC. It is mainly used in liquid crystal displays where thickness is important.

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

As illustrated, the LCD including the backlight unit 20 of the general edge type has a liquid crystal panel 10 and a backlight unit 20, and a guide panel 30, a cover bottom 50, and a top cover ( 40).

The liquid crystal panel 10 is a part that plays a key role in image expression and is composed of first and second substrates 12 and 14 bonded to each other with a liquid crystal layer interposed therebetween.

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

The backlight unit 20 is arranged along at least one side edge length direction of the guide panel 30, and includes a plurality of LEDs 29a and a PCB 29b on which the LEDs 29a are mounted. A white or silver reflector 25 mounted on the bottom 50, a light guide plate 23 seated on the reflector 25, and an optical sheet 21 positioned thereon.

The liquid crystal panel 10 and the backlight unit 20 have a top cover 40 covering the top edge of the liquid crystal panel 10 and the back of the backlight unit 20 with the edges surrounded by the rectangular guide panel 30. Cover cover 50 to cover each is coupled in front and rear are integrated through the guide panel 30.

In addition, reference numerals 19a and 19b denote polarizers attached to the front and rear surfaces of the liquid crystal panel 10 to control the polarization direction of light, respectively.

In the backlight unit 20 of the liquid crystal display device configured as described above, various optical designs are considered 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, and one of them is a light guide plate ( The maintenance of the optical gap A, which is the distance between the 23 and the LED assembly 29, is an important factor.

However, in the process of implementing a recently required lightweight, thin, and narrow bezel liquid crystal display device, a separate component for preventing the light guide plate 23 from flowing is located close to the active region. Light leakage may occur, and in order to prevent this, 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. .

Therefore, it is very difficult to supply high-quality surface light source to the liquid crystal panel 10, and in particular, light leakage occurs between the light guide plate 23 and the LED assembly 29, or LEDs are caused by the flow of the light guide plate 23. Breakage of assembly 29 may also occur. This causes a problem that the quality of the liquid crystal display device, such as brightness and image quality deterioration.

The present invention has been made to solve the above problems, and a first object of the present invention is to prevent the flow of the light guide plate and to prevent the occurrence of light leakage.

For this reason, the second object is to improve the brightness and the image quality of the liquid crystal display device.

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

In order to achieve the above object, the present invention is a liquid crystal panel; A backlight unit disposed on a rear surface of the liquid crystal panel, the backlight unit including a light guide plate comprising an LED assembly, a light incident surface facing the LED assembly, and an incoming light incident surface on the opposite side; A cover bottom comprising a horizontal surface on which the backlight unit is mounted and a side surface perpendicular to the horizontal surface; And a guide panel including a sidewall including a first vertical portion surrounding an outer surface of the side surface of the cover bottom, and a horizontal portion bent vertically from the first vertical portion to support the liquid crystal panel. A liquid crystal display device having a first stopper having an elastic force in close contact with the light incident plate surface of the light guide plate is provided on the side wall.
In this case, a part of the side wall may include a second vertical part surrounding the edge of the backlight unit at a predetermined distance from the first vertical part, and the first stopper having the elastic force may be disposed under the horizontal part, It is formed to be inclined at an angle from the normal to the opposite side of the first vertical portion.
In addition, a hole is formed in the first stopper having the elastic force at a connection portion with the horizontal portion, and the first stopper having the elastic force includes a step portion protruding convex toward the incoming light incident surface.
In addition, at least two first stoppers having the elastic force are formed along the longitudinal direction of the side wall of the guide panel, and both side edges perpendicular to the sidewalls of the guide panel having the first stopper having the elastic force are configured. Sidewalls of the second stopper are provided to maintain an optical gap between the light incident surface of the light guide plate and the LED assembly.
In this case, a guide groove into which the second stopper is inserted is formed at a corner in the longitudinal direction of the light incident surface of the light guide plate.

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As described above, by forming a sidewall of the guide panel in a double structure according to the present invention, and by forming a first stopper having an elastic force on a portion of the sidewall, thereby preventing the flow of the light guide plate even when implementing a narrow bezel In this case, the optical gap between the light guide plate and the LED assembly may be kept constant.
In addition, since it is not necessary to form a separate component at the edge of the light guide plate, it is possible to prevent the light leakage phenomenon caused by the components provided separately, to cause the breakage of a plurality of LEDs of the LED assembly, or to There is an effect that can prevent the problem of deterioration of the image quality due to the optical properties are changed.

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1 is a cross-sectional view of a liquid crystal display including a backlight unit of a general edge type method using an LED as a light source.
2 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.
Figure 3a is a perspective view schematically showing a guide panel according to an embodiment of the present invention.
3B-3D are enlarged views of a portion of FIG. 3A.
Figure 4a is a plan view schematically showing a guide panel and a light guide plate according to an embodiment of the present invention.
4B is a schematic cross-sectional view taken along the line IV-IV 'of FIG. 4A of FIG. 5A-5B are schematic cross-sectional views taken along the line VV ′ of FIG. 4A of FIG.
6a to 6b are simulation results of measuring the deformation amount of the first stopper with elastic force according to the embodiment of the present invention.
Figure 6c is a simulation result of measuring the tensile strength of the first stopper having an elastic force.
7A to 7D are simulation results of measuring light leakage when the liquid crystal display according to the exemplary embodiment of the present invention is operated in different temperature environments.

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

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

As shown, the liquid crystal display according to the present invention includes a liquid crystal panel 110 and a backlight unit 120 stacked up and down, and as a mechanical element for integrating them, a guide panel 130 and a cover bottom 150. Is provided.

In this case, for convenience of description, the direction on the drawing is defined, and the backlight unit 120 is disposed behind the liquid crystal panel 110 under the premise that the display surface of the liquid crystal panel 110 faces the front, The cover bottom 150, which is in close contact with the back surface of the backlight unit 120 in a state in which the rectangular frame-shaped guide panel 130 is worn, is integrated by being integrated in front and rear.

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

First, the liquid crystal panel 110 plays a key role in the image expression of the liquid crystal display device. The liquid crystal layer interposed therebetween with the first and second substrates 112 and 114 bonded to each other. (Not shown).

Here, although not shown in the drawings, a plurality of gate lines and data lines intersect each other on the inner surface of the first substrate 112, which is commonly referred to as a lower substrate or an array substrate, and a pixel is defined at each intersection. (thin film transistor: TFT) is provided and is connected one-to-one with the transparent pixel electrode formed in each pixel.

In addition, an inner surface of the second substrate 114 called an upper substrate or a color filter substrate may correspond to each pixel, for example, a color filter of red (R), green (G), and blue (B) color, and these. A black matrix is provided covering each of the gate lines, the data lines, and the thin film transistors.

In addition, a transparent common electrode covering the red (R), green (G), and blue (B) colors and the black matrix is provided.

Polarizers (not shown) for selectively transmitting only specific light are attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

Along the edge of the liquid crystal panel 110, the printed circuit board 117 is connected through a connecting member 116 such as a flexible printed circuit board or a tape carrier package (TCP) to guide the module in the modularization process. The side surface of the panel 130 or the cover bottom 150 may be properly folded to be in close contact with each other.

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

In addition, the backlight unit 120 is provided to supply light to the rear surface of the liquid crystal panel 110 so that the difference in transmittance indicated by the liquid crystal panel 110 is expressed to the outside.

The backlight unit 120 includes a white or silver reflecting plate 125, a LED assembly 129 arranged along one longitudinal edge thereof, a light guide plate 123 mounted on the reflecting plate 125, and an upper portion of the light guide plate 123. It consists of an optical sheet 121 seated on.

The LED assembly 129 is a light source of the backlight unit 120, and is located at one side of the light guide plate 123 to face the light incident surface 123a of the light guide plate 123, and the LED assembly 129 is provided with a plurality of LEDs 129a. And a plurality of LEDs 129a are mounted at predetermined intervals.

In this case, the plurality of LEDs 129a emit light having red (R), green (G), and blue (B) colors toward the light incident surface 123a of the light guide plate 123, respectively. By lighting the LEDs 129a at once, white light by color mixing can be realized.

In particular, recently, in order to improve luminous efficiency and luminance, a blue LED 129a including a blue LED chip having excellent luminous efficiency and luminance is used, and as a phosphor, a yttrium aluminum garnet (YAG: Ce) doped with cerium, In other words, a blue LED 129a made of yellow phosphor is used.

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

The light guide plate 123 to which light emitted from the plurality of LEDs 129a is incident is uniformly spread over a wide area of the light guide plate 123 while the light incident from the LED 129a propagates through the light guide plate 123 by several total reflections. Spread provides a surface light source to the liquid crystal panel (110).

The light guide plate 123 has excellent transparency, weather resistance, and colorability to induce light diffusion when light is transmitted.

The light guide plate 123 is one selected from a plastic material such as polymethylmethacrylate (PMMA), which is one of transparent materials that can transmit light, or a polycarbonate (PC) series. It can be manufactured, PMMA which is excellent in transparency, weather resistance, colorability to induce the diffusion of light when light is transmitted is the most widely used.

The light guide plate 123 may include a pattern of a specific shape on the lower surface to supply a uniform surface light source. Here, the pattern may be configured in various ways such as an elliptical pattern, a polygon pattern, a hologram pattern, and the like to guide the 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, the guide grooves 123c having a part of a corner thereof are formed on both sides of the light incident surface 123a of the light guide plate 123 of the present invention.

The light guide surface 123a and the LED assembly 129 of the light guide plate 123 may maintain the optical gap A (see FIG. 4A) by the guide groove 123c. We will discuss this in more detail later.

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

The optical sheet 121 on the light guide plate 123 includes a diffusion sheet and at least one light collecting sheet, and diffuses or collects light passing through the light guide plate 123 to provide a more uniform surface light source to the liquid crystal panel 110. Make it incident.

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 includes the backlight unit 120 including the liquid crystal panel 110 mounted thereon. It provides a horizontal plane 151 to support the entire liquid crystal display and at the same time serves as a lower frame to minimize the loss of light, the edge of the horizontal plane 151 is vertically bent to form a side 153.

In addition, a rectangular frame-shaped guide panel 130 seated on the cover bottom 150 and surrounding the edge of the backlight unit 120 is coupled to the cover bottom 150.

Here, the guide panel 130 has a side wall 131 surrounding the side surface of the backlight unit 120 and a horizontal portion 133 for distinguishing the positions of the liquid crystal panel 110 and the backlight unit 120 into the side wall 131. The liquid crystal panel 110 is attached and fixed on the horizontal portion 133 through an adhesive pad 118 (see FIG. 5A) such as a double-sided tape.

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

The liquid crystal display device of the present invention implements a narrow bezel, which realizes light weight and thinness, and has a wide display area and a bezel area that is a non-display area other than the display area 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 an elastic force (elastic) to prevent the flow of the light guide plate 123. The first stopper 135 is configured.

Accordingly, the liquid crystal display device of the present invention prevents the flow of the light guide plate 123 in a double manner and sags the guide panel 130 by the liquid crystal panel 110 seated on the horizontal portion 133 of the guide panel 130. This can be prevented from occurring.

Through this, an optical gap, A, which is a gap between the light guide plate 123 and the LED assembly 129 for supplying a high quality surface light source, which is the most important role of the backlight unit 120, to the liquid crystal panel 110. 4a), the brightness 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 form a separate component for preventing the flow of the light guide plate 123, thereby preventing the light leakage phenomenon generated when the separately provided component is located close to the active region. have.

In addition, the flow of the light guide plate 123 may also be prevented, which may cause breakage of the plurality of LEDs 129a of the LED assembly 129 or deterioration in image quality due to changes in optical characteristics of the liquid crystal display. Can be prevented.

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

The liquid crystal display according to the exemplary embodiment of the present invention has a structure in which the top cover (40 of FIG. 1) is deleted, and thus, the light weight, thinness, and narrow bezel of the liquid crystal display can be achieved by removing the top cover (40 of FIG. 1). It has an effect that can simplify the process.

In addition, due to the deletion of the top cover 40 of FIG. 1, the process cost may be reduced.

In the liquid crystal display according to the exemplary embodiment of the present invention, the sidewalls 131 of the guide panel 130 may be formed in a double structure to implement a double light guide plate 123 to prevent flow of the light guide plate 123. The optical gap A (see FIG. 4A) of the LED assembly 129 may be kept constant.

Therefore, it is also possible to prevent the problem that the brightness and image quality of the liquid crystal display device is degraded due to the flow of the light guide plate 123, and the damage of the plurality of LEDs 129a of the LED assembly 129 is prevented from occurring. can do. In addition, light leakage may be prevented from occurring by the components provided to prevent the light guide plate 123 from flowing.

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

As shown, the guide panel 130 covering the edge of the backlight unit (120 of Figure 2) is made of a synthetic resin mold material, such as polycarbonate, and the edge of the backlight unit (120 of Figure 2) A horizontal portion 133 protrudes vertically inward from the sidewall 131 and the sidewall 131 to which the liquid crystal panel 110 (see FIG. 2) is seated.

At this time, the guide panel 130 of the present invention has a side wall 131 has a double structure, and has an elastic force at one edge surrounding the light incident plate 123b side of the light guide plate 123 of the backlight unit (120 of FIG. 2). One first stopper 135 is configured.

Looking at this in more detail, the guide panel 130 is configured by injection molding method through a synthetic resin in a rectangular frame shape, the guide panel 130 is the first edge portion 130a is arranged LED assembly (129 of FIG. 2) ), A second edge portion 130b on the opposite side of the first edge portion 130a, and third and fourth edge portions 130c and 130d connecting the first and second edge portions 130a and 130b. The first to fourth edge portions 130a, 130b, 130c, and 130d may be perpendicular to the sidewall 131 and the sidewall 131 that surround the edge of the backlight unit 120 (FIG. 2). ) And a horizontal portion 133 for distinguishing positions of the liquid crystal panel (110 of FIG. 2).

In this case, the liquid crystal panel 110 (see FIG. 2) is seated and supported on the horizontal portion 133.

Here, a part of the side wall 131 is perpendicular to the horizontal portion 133 under the first vertical portion 131a and the horizontal portion 133 which are bent vertically from the end of the horizontal portion 133 and the first vertical portion ( It consists of a second vertical portion (131b) formed facing each other at a predetermined interval spaced 131a.

Accordingly, the guide panel 130 has a rectangular frame shape, a part of which is bent in a "∩" shape by the first and second vertical parts 131a and 131b and the horizontal part 133.

In this case, the first and second vertical parts 131a and 131b are spaced apart by a predetermined interval, and the side surface (153 of FIG. 2) of the cover bottom (150 of FIG. 2) is inserted into an intervening region. In addition, the upper portion of the horizontal portion 133 is a liquid crystal panel (110 of FIG. 2) is located, the rear part of the four edges of the liquid crystal panel (110 of FIG. 2) is seated on the horizontal portion 133 is supported by the position is fixed .

Here, as a part of the side wall 131 of the guide panel 130 is formed of a double structure of the first and second vertical portions 131a and 131b, the rigidity of the guide panel 130 is improved to improve the rigidity of the guide panel 130. In the process of mounting the liquid crystal panel 110 on the horizontal portion 133, the sagging of the guide panel 130 may be prevented by the weight of the liquid crystal panel 110.

At this time, the second edge portion 130b may be formed on the sidewall 131 of the second edge portion 130b on the opposite side of the first edge portion 130a where the LED assembly (129 of FIG. 2) of the guide panel 130 is located. A first stopper 135 having at least two elastic forces along the longitudinal direction is provided.

That is, a partial region in which the second vertical portion 131b is not formed exists on the sidewall 131 of the second edge portion 130b, and the region having the elastic force as shown in FIGS. 3B and 3C in the region thereof. 1 stopper 135 is provided.

Here, the first stopper 135 having the elastic force is inclined at a predetermined angle toward the opposite side of the first vertical portion 131a from a normal perpendicular to the horizontal portion 133 below the horizontal portion 133. Is formed extending from). A hole 135a is formed in the first stopper 135 having the elastic force near the horizontal portion 133 and the connection portion, and a stepped portion convex toward the opposite side of the first vertical portion 131a in the lower portion of the hole 135a. 135b).

As the first stopper 135 having such elastic force is formed at the second edge portion 130b of the guide panel 130, the first stopper 135 faces the incoming light incident surface 123b of the light guide plate 123, As the first stopper 135 having the elastic force formed on the second edge portion 130b is inclined at an angle toward the opposite side of the first vertical portion 131a from a normal perpendicular to the horizontal portion 133, the elastic force As shown in FIG. 3D, the first stopper 135 including the first contactor 135 is in close contact with the carry-in light receiving surface 123b of the light guide plate 123 to apply a constant force to the light guide plate 123.

Therefore, the light guide plate 123 is an optical gap A, which is an interval between the LED assembly (129 of FIG. 2) and the light receiving plate 123 (123a of FIG. 2) by the first stopper 135 having elastic force. 4a) can be kept constant.

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

Therefore, even when a vibration and an impact are applied to the modular liquid crystal display from outside, the light guide plate 123 is immediately returned by the elastic restoring force of the first stopper 135 having the elastic force even when the flow of the light guide plate 123 occurs. The optical gap A (see FIG. 4A), which is the distance between the LED assembly (129 of FIG. 2) and the light guide plate 123 (123a of FIG. 2), 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 material properties of the light guide plate 123. In this case, since the first stopper 135 having the elastic force exerts a constant force on the light guide plate 123, the amount of expansion of the light guide plate 123 may be reduced.

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

In addition, since the first stopper 135 having elastic force has fluidity within a predetermined range by the elastic restoring force of the first stopper 135 having elastic force, the light guide plate absorbs vibration and impact due to fluidity. The breakage of 123 can be prevented.

In addition, even when shrinkage occurs due to material properties of the light guide plate 123, the LED assembly (129 of FIG. 2) and the light guide plate (FIG. 2) are applied by applying a constant force to the light guide plate 123 through the first stopper 135 having elastic force. 123) The optical gap A (refer to FIG. 4A) between the light incident surfaces (123a in FIG. 2) can be kept constant.

In addition, by applying a constant force of the light guide plate 123 through the first stopper 135 having the elastic force provided in the guide panel 130, the flow of the light guide plate 123 may be prevented from occurring. Since it is not necessary to form a separate component for preventing the flow of the light guide plate 123, it is possible to prevent the light leakage phenomenon by the component provided separately.

As a result, the quality of the LCD may be improved by improving luminance and image quality.

On the other hand, the guide panel 130 of the present invention, as a part of the side wall 131 is formed in a double structure of the first and second vertical parts (131a, 131b), the elastic restoring force of the first stopper 135 having an elastic force When the amount of expansion of the light guide plate 123 occurs, the force applied to the first stopper 135 having elastic force can be dispersed through the second vertical portion 131b, so that the light guide plate 123 flows and breaks more stably. The optical gap A (see FIG. 4A), which is an interval between the light guide plate 123 and the light incident surface (123a of FIG. 2), can be kept constant.

At this time, the first stopper 135 having elastic force has elasticity by forming a hole 135a near the horizontal portion 133 and the connection portion, thereby improving the fluidity of the first stopper 135 having elastic force. The elastic restoring force of the first stopper 135 is increased.

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

Therefore, the fluidity of the guide panel 130 is caused, and the light guide plate 123 may also be generated by the flow of the guide panel 130. As a result, breakage of a plurality of LEDs (129a of FIG. 2) of the LED assembly (129 of FIG. 2) may occur, or optical characteristics of the liquid crystal display may be changed, resulting in a problem of deterioration of image quality.

In addition, the first stopper 135 having the elastic force of the present invention may be formed to have a convex stepped portion 135b in the lower portion of the hole 135a, so that a greater force may be applied to the light guide plate 123.

Therefore, even if the elastic restoring force of the first stopper 135 having elastic force is small due to the material property, the light guide plate 123 is formed by the stepped part 135b formed on one surface of the first stopper 135 having elastic force. By increasing the applied force, it is possible to more stably prevent the flow of the light guide plate 123, so that the optical gap that is the interval between the LED assembly (129 of FIG. 2) and the light entering surface (123a of FIG. A, see FIG. 4A) can be kept constant.

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

As shown in the drawing, the guide panel 130 has a rectangular frame shape, and includes a sidewall 131 surrounding the side surface of the backlight unit 120 of FIG. 2 and a horizontal portion 133 vertically protruding from the sidewall 131. Is done.

In this case, a part of the sidewall 131 is formed in a double structure of the first and second vertical portions 131a and 131b, and surrounds the side of the light incident plate 123b of the light guide plate 123 of the backlight unit 120 of FIG. 2. The first stopper 135 having an elastic force is formed at the edge.

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.

In this case, guide grooves 123c having a part of a corner thereof are formed on both sides of the light incident surface 123a of the light guide plate 123, and are vertical to one edge of the guide panel 130 in correspondence with the guide grooves 123c. Second stoppers 137 are formed at both edges.

Accordingly, the light guide plate 123 of the present invention prevents the light guide plate 123 from flowing by the first stopper 135 having elastic force in the -X axis direction defined in the drawing, and in the + X axis direction. 2, the light guide plate 123 is prevented by the stopper 137, so that the light guide plate 123 may maintain an optical gap A, which is an interval between the light guide plate 123 and the LED assembly 129. .

By the elastic restoring force of the first stopper 135 having the elastic force, the light guide plate 123 is immediately returned to the modular liquid crystal display device even when vibration and impact are applied from the outside to cause the light guide plate 123 to flow. The optical gap A, which is an interval between the LED assembly 129 and the light guide plate 123, the light incident surface 123a, may be kept constant.

In addition, since the first 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 may be reduced, and the light guide plate 123 may be expanded even when the light guide plate 123 is expanded. The amount of expansion can be absorbed by the elastic restoring force of the first stopper 135 having the elastic force, thereby preventing the light guide plate 123 from flowing.

In addition, vibration and shock can be absorbed through the first stopper 135 having elastic force, thereby preventing breakage of the light guide plate 123 and applying a constant force to the light guide plate 123, thereby providing a light guide plate. Even when shrinkage occurs due to the material property of the material 123, the optical gap A between the LED assembly 129 and the light guide plate 123 incident surface 123a may be kept constant.

5A through 5B are cross-sectional views schematically illustrating a cross section taken along line VV ′ of FIG. 4A of FIG.

As shown, the LED assembly 129 and the light guide plate 123 formed of a reflector plate 125, a light guide plate 123, a PCB 129b on which the LEDs 129a and 129a are mounted. 121 are stacked to form the backlight unit 120.

In addition, the liquid crystal panel 110 having a liquid crystal layer (not shown) is disposed between the first and second substrates 112 and 114 and the backlight unit 120, and the first second substrate 112. Are attached to the outer surfaces of each of the 114 and polarizing plates 119a and 119b for selectively transmitting only specific light.

Here, the edge of the backlight unit 120 is surrounded by the guide panel 130, the cover bottom 150 is coupled to the back thereof.

Here, the guide panel 130 has a sidewall 131 covering the side surface of the backlight unit 120 and a horizontal portion protruding inward from the sidewall 131 to cover the top of the LED assembly 129 and the top edge of the light guide plate 123. It consists of 133.

At this time, a part of the side wall 131 of the guide panel 130 has a double structure, the horizontal portion below the first vertical portion 131a and the horizontal portion 133 which is bent vertically from the end of the horizontal portion 133 It consists of a second vertical portion 131b perpendicular to 133 and formed to face the first vertical portion 131a at a predetermined interval.

Therefore, a part of the guide panel 130 is formed in a rectangular frame having a cross section bent in a "∩" shape by the first and second vertical parts 131a and 131b and the horizontal part 133. 2 The side surface 153 of the cover bottom 150 is inserted between the vertical portions 131a and 131b.

The liquid crystal panel 110 is fixed to the upper portion of the horizontal portion 133 so that the edge thereof is supported. An adhesive pad 118 is formed between the liquid crystal panel 110 and the horizontal portion 133.

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

In this case, the guide panel 130 facing the light incident surface 123b opposite to the light incident surface 123a of the light guide plate 123 is provided with a first stopper 135 having elastic force and a first stopper having elastic force. The 135 is extended from the horizontal portion 133 so as to be inclined at a predetermined angle toward the opposite side of the first vertical portion 131a from a normal perpendicular to the horizontal portion 133 below the horizontal portion 133.

In this case, the stopper having elastic force is formed with a hole 135a near the horizontal portion 133 and the connection portion, and the first stopper 135 having elastic force is directed toward the light-receiving surface 123b of the light guide plate 123. A protruding step portion 135b is formed.

The first stopper 135 having such elastic force is in close contact with the light incident 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. 5A. .

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

At this time, when an impact is applied to the modular liquid crystal display from the outside, the elasticity of the first stopper 135 having elastic force causes the first stopper 135 having elastic force to have a predetermined range as shown in FIG. 5B. Since the fluidity within the fluid absorbs vibrations and impacts due to fluidity, breakage of the light guide plate 123 may be prevented.

In addition, even when the light guide plate 123 flows due to the elastic restoring force of the first stopper 135 having elastic force, the light guide plate 123 is immediately returned to the LED assembly 129 and the light guide plate 123 by the light receiving surface 123a. It becomes possible to keep the optical gap A which is the space | interval between () constant.

In addition, even when shrinkage occurs due to material properties of the light guide plate 123, the LED assembly 129 and the light guide plate 123 may be formed by applying a constant force to the light guide plate 123 through the first stopper 135 having elastic force. The optical gap A between the optical surfaces 123a can be kept constant.

In addition, even when 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 first stopper 135 having the elastic force, so that the flow of the guide panel 130 occurs. It can prevent.

For example, when the linear expansion coefficient of the light guide plate 123 is 6.5E-5 / ° C., the light guide plate 123 expands about 0.7 mm in an environment of 60 degrees. In this case, the light guide plate 123 and the guide are implemented to implement a narrow bezel. When the total gap of the panel 130 is 0.2 mm, an overlap of 0.5 mm occurs.

As such, when the overlap occurs, the flow of the guide panel 130 is generated.

Alternatively, in order to prevent the flow of the guide panel 130, when the overlap due to the expansion of the light guide plate 123 is calculated to form the total gap between the light guide plate 123 and the guide panel 130 to 0.7 mm or more, the narrow bezel It has a disadvantage that is difficult to implement.

However, according to the present invention, the expansion of the light guide plate 123 is absorbed by the elastic restoring force of the first stopper 135 having the elastic force even when the light guide plate 123 is expanded, thereby preventing the flow of the guide panel 130. It can be prevented from occurring.

Accordingly, the narrow bezel may be implemented by not calculating the overlap between the light guide plate 123 and the guide panel 130 by calculating an overlap due to the expansion of the light guide plate 123 to prevent the flow of the guide panel 130. It is.

In particular, the guide panel 130 according to the embodiment of the present invention by forming a hole (135a) in the first stopper 135 having an elastic force, thereby improving the flowability of the first stopper 135 having an elastic force In addition, the elastic restoring force of the first stopper 135 having the elastic force may be further increased.

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

6a to 6b are simulation results of measuring the amount of deformation of the guide panel according to the presence or absence of the hole of the stopper with elastic force according to an embodiment of the present invention.

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

As shown in FIG. 6A, the amount of deformation of the guide panel without holes is 0.02 mm. On the other hand, as shown in FIG. 6B, the guide panel 130 according to the embodiment of the present invention has a first elastic force. By forming the hole 135a in the stopper 135, it can be seen that the fluidity due to the elastic restoring force is improved to 0.7 to 0.8 mm.

Therefore, even when the light guide plate (123 of FIG. 5B) having a linear expansion coefficient of 6.5E-5 / ° C expands about 0.7 mm in an environment of 60 degrees, the expansion of the light guide plate (123 of FIG. 5B) is performed by the first stopper 135 having elastic force. ), So that the total gap between the light guide plate 123 of FIG. 5B and the guide panel 130 may be 0.2 mm, thereby implementing a narrow bezel, and the light guide plate 123 of FIG. 5B. The expansion of the guide panel 130 can be prevented from occurring.

6C is a simulation result of measuring the tensile strength of the stopper having elastic force when the light guide plate slowly pushes the guide panel. As shown in FIG. 6C, the first stopper 135 having the elastic force according to the exemplary embodiment of the present invention is illustrated. Although the fluidity caused by the elastic restoring force is 0.7 to 0.8 mm, the maximum tensile strength applied to the first stopper 135 having elastic force by the flow of the light guide plate (123 in FIG. 5B) is 26.6 MPa. Lower than 65 MPa, which is the tensile strength, breakage of the first stopper 135 with elastic force does not occur.

7A to 7D are simulation results of measuring light leakage when the liquid crystal display according to the exemplary embodiment of the present invention is operated in different temperature environments. The liquid crystal display according to the exemplary embodiment of the present invention is operated at a high temperature of 60 ° C. When the light leakage phenomenon is measured, and FIGS. 7C to 7D are simulation results of measuring the light leakage phenomenon when the liquid crystal display according to the exemplary embodiment of the present invention is operated at a low temperature of 0 ° C.

7A to 7D, the liquid crystal display of the present invention implements a narrow bezel but does not form a separate component on the light guide plate 123 of FIG. 5B, so that light leakage does not occur even when operating at high or low temperatures. You can see that it does not.

As described above, in the liquid crystal display of the present invention, a part of the sidewall of the guide panel 130 (131 of FIG. 5B) is formed in a double structure to improve the rigidity of the guide panel 130 and the sidewall of the guide panel 130. (131 in FIG. 5B) A part of the first stopper 135 having elastic force makes the optical gap (A in FIG. 5B) of the light guide plate (123 in FIG. 5B) and the LED assembly (129 in FIG. 5B) constant. I can keep it.

Through this, the flow of the light guide plate 123 of FIG. 5B due to the flow of the guide panel 130 may be prevented, and the brightness and the image quality of the liquid crystal display may be improved.

In addition, since it is not necessary to form a separate component on the light guide plate 123 of FIG. 5B, it is possible to prevent the light leakage phenomenon caused by the separately provided component.

In addition, damage to a plurality of LEDs (129a of FIG. 5B) of the LED assembly (129 of FIG. 5B) may occur, or optical characteristics of the liquid crystal display may be changed to prevent a problem of deterioration of image quality.

The present invention is not limited to the above embodiments, and various modifications can 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
120: backlight unit (121: optical sheet, 123: light guide plate, 125: reflector, 129: LED assembly (129a: LED, 129b: PCB))
130: guide panel (131a, 131b: first and second vertical portion, 133: horizontal portion, 135: first stopper with elastic force (135a: hole, 135b: stepped portion))
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 a light guide plate comprising an LED assembly, a light incident surface facing the LED assembly, and an incoming light incident surface on the opposite side;
A cover bottom comprising a horizontal surface on which the backlight unit is mounted and a side surface perpendicular to the horizontal surface;
A sidewall including a first vertical portion surrounding the outer surface of the side surface of the cover bottom, a second vertical portion surrounding the edge of the backlight unit at a predetermined distance from the first vertical portion, and a vertical portion from the first vertical portion Guide panel including a horizontal portion that is bent to support the liquid crystal panel
And a first stopper having an elastic force in close contact with the incoming light incident surface of the light guide plate on the sidewall of the guide panel.
And the LED assembly is positioned inward of the second vertical portion to face the light incident surface.
The method of claim 1,
And the second vertical portion spaced apart from each other with a first stopper having the elastic force along the length direction.
The method of claim 1,
The first stopper having the elastic force is formed below the horizontal portion and is inclined at an angle toward the opposite side of the first vertical portion from a normal line perpendicular to the horizontal portion.
The method of claim 3, wherein
And a hole formed in the first stopper having the elastic force at a connection portion with the horizontal portion.
The method of claim 3, wherein
The first stopper having the elastic force includes a stepped portion protruding convexly toward the light incident surface.
The method of claim 1,
And at least two first stoppers having the elastic force along the longitudinal direction of the sidewalls of the guide panel.
The method of claim 1,
And a second stopper on the guide panel to maintain an optical gap between the light incident surface of the light guide plate and the LED assembly between the LED assembly and the light incident surface of the light guide plate.
The method of claim 7, wherein
A guide groove is provided at a corner in the longitudinal direction of the light incident surface of the light guide plate, and the second stopper is inserted into the guide groove.

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