KR101854697B1 - Backlight unit and lcd module inculding the same - Google Patents

Abstract

The present invention discloses a backlight unit. More particularly, the present invention relates to a backlight unit for improving the quality of images by improving the phenomenon of light generated by the coupling structure of the LED array and the optical sheet constituting the backlight unit in the photometric type liquid crystal display, And a liquid crystal display device module.
A backlight unit according to a preferred embodiment of the present invention includes a light guide plate for guiding light incident on at least one side surface to an upper surface of the light guide plate and a light guide plate disposed on the upper and lower surfaces of the light guide plate for diffusing and condensing incident light, And an LED array including an LED FPCB to which a plurality of LEDs PKG are bonded and which are arranged to be spaced apart from the optical sheet and in which a support portion abutting at least one side surface of the optical sheet is formed.
According to this structure, the optical sheet is supported by protruding a part of the LED array in the direction of the optical sheet, thereby removing the irregularities formed on the optical sheet and the guide panel, thereby improving the light- There is an effect that can be implemented.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL UNIT AND LCD MODULE INCULDING THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and, more particularly, to a backlight unit which improves the quality of an image by improving the light-scattering phenomenon caused by a coupling structure of an LED array and an optical sheet constituting a backlight unit in a metering type liquid- To a liquid crystal display device module.

The liquid crystal display device uses a passive transmissive display element and displays the desired image gradation on the screen by adjusting the amount of light transmitted through the liquid crystal layer by the refractive index anisotropy of the liquid crystal molecules. Accordingly, in a liquid crystal display device, a backlight unit for providing light to the liquid crystal layer for displaying an image is provided, and the liquid crystal display device is combined with various mechanical structures and modularized.

In the above-described liquid crystal display device, the backlight unit is generally divided into two types according to the structure of the light source.

One is a direct type method in which a light source, the LED PKG, is located on the backside of the liquid crystal panel and direct light is irradiated from the bottom to the panel front. The other is an edge type LED PKG The liquid crystal panel is positioned on the side of the liquid crystal panel, and the direction of light is switched to the panel direction through an optical sheet or the like.

The above-mentioned direct-type type is mainly applied to manufacture a liquid crystal panel for a large-screen TV because the light emitted from the LED PKG is directly supplied to the liquid crystal panel, and thus can be applied to a large-

On the other hand, the photometric method is provided on the side of the liquid crystal panel and supplies light to the liquid crystal panel through the reflection plate and the light guide plate as the optical sheet. Therefore, it is difficult to apply the liquid crystal panel to a large- Light is supplied, and it becomes difficult to obtain a high luminance. However, since the backlight unit is disposed on the side surface, the thickness of the LCD module can be reduced.

1 is an exploded perspective view showing a part of a conventional metering type liquid crystal display device module.

As shown in the figure, a conventional photometric light modulating type liquid crystal display device module 1 includes an LED array 20 in which a plurality of LEDs PKG are arranged in a line on one side and provided on at least one side of a liquid crystal display device, A guide panel 40 on which an optical sheet is mounted on the inner side on which the array 20 is mounted on one side and an optical sheet 35 disposed on an upper side of the optical sheet 35, And a light-shielding tape 50 for fixing the light-shielding tape 50 to a liquid crystal panel (not shown).

In the liquid crystal display module 1 having such a structure, the plurality of optical sheets 35 optically convert light incident from a lower light guide plate (not shown) into an upper liquid crystal panel, They must be fixed and aligned with each other. Therefore, a predetermined concave portion is formed at a portion in contact with the optical sheet 35 in the inside direction of the guide panel 40, and a portion of the side surface of the optical sheet 35 corresponding to the concave portion is protruded The optical sheets 35 are aligned and stably fixed.

2A is an enlarged view of part A of FIG. 2A. As shown in FIG. 2A, the guide panel 40 includes a LED array 20 And the optical sheet 35 is mounted inside to surround each side surface. In this structure, the LED array 20 is spaced apart from the optical sheet 35 by a predetermined distance, and the light emitting surface of the LED PKG (not shown) bonded to the rear surface of the LED array 20 (Not shown) provided on the back surface.

The other side surfaces of the optical sheet 35 except the side adjacent to the LED array 20 are framed by the guide panel 40 and a plurality of convex portions 35a to 35d are protruded on opposite sides of the optical sheet 35 . Further, the guide panel 40 has a concave portion formed on the inner side surface, and the optical sheet is stably fixed in a state in which the convex portions 35a to 35d are inserted.

However, in the liquid crystal display device module having such a structure, light reflection phenomenon occurs due to the recesses and convex portions of the optical sheet and the guide panel. When light emitted from the LED array 20 passes through a light guide plate (not shown) and travels inside the optical sheet, incident light L1 passes through the convex portions 35a and the bent portions 40a of the concave portions 40a. (L2), and the light L2 is scattered, and the brightness of the corresponding region in the image is different from that of the other regions.

The above-mentioned phenomenon of light incidence occurs particularly in the recesses and convex portions of the region adjacent to the light source, which causes the quality of the image to deteriorate.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-described problems, and it is an object of the present invention to provide a backlight unit which removes at least one concave / convex portion formed in an optical sheet and a guide panel in a metering type backlight unit, And the like.

In order to achieve the above object, a backlight unit according to a preferred embodiment of the present invention includes: a light guide plate that guides light incident on at least one side surface to an upper surface; At least one optical sheet arranged on an upper surface of the light guide plate and diffusing and condensing the incident light and outputting the light to the upper surface; A reflection plate disposed on a lower surface of the light guide plate; And an LED array including LED FPCB to which a plurality of LEDs PKG are bonded and arranged so as to be spaced apart from the optical sheet and in which a support portion abutting at least one side surface of the optical sheet is formed.

The support portion is characterized by extending from both ends of the FPCB toward the optical sheet.

The optical sheet is characterized in that the side surface is flat in a region adjacent to the LED array.

The supporting portion is characterized in that its thickness is the same as that of the optical sheet.

In order to achieve the above object, a liquid crystal display module including a backlight unit according to a preferred embodiment of the present invention includes: a liquid crystal panel; A backlight unit for providing light to the liquid crystal panel; And a guide panel for mounting the liquid crystal panel and the backlight unit, wherein the backlight unit includes: a light guide plate for guiding light incident on at least one side surface to the liquid crystal panel; At least one optical sheet arranged on an upper surface of the light guide plate and diffusing and condensing the incident light and outputting the light to the upper surface; A reflection plate disposed on a lower surface of the light guide plate; And an LED array including LED FPCB to which a plurality of LEDs PKG are bonded and arranged so as to be spaced apart from the optical sheet and in which a support portion abutting at least one side surface of the optical sheet is formed.

The support portion is characterized by extending from both ends of the FPCB toward the optical sheet.

The optical sheet is characterized in that the side surface is flat in a region adjacent to the LED array.

The optical sheet is characterized in that at least one convex portion for supporting and fixing is formed on the side surface.

The guide panel may have at least one concave portion corresponding to the convex portion.

And the FPCB is attached to the liquid crystal panel together with the guide panel by a light shielding tape.

The backlight unit and the liquid crystal display module according to the embodiments of the present invention can support the optical sheet by projecting a part of the LED array in the direction of the optical sheet to thereby remove the irregularities formed on the optical sheet and the guide panel, So that it is possible to realize a high-quality image.

1 is an exploded perspective view showing a part of a conventional metering type liquid crystal display device module.
2A is a plan view showing a part of the assembled liquid crystal display device module, and FIG. 2B is an enlarged view of a portion `A` in FIG. 2A.
3 is an exploded perspective view showing a structure of a liquid crystal display module including a backlight unit according to an embodiment of the present invention.
FIG. 4A is a plan view of a backlight unit according to an embodiment of the present invention, and FIG. 4B is an enlarged view of an LED array included in a backlight unit.
5A and 5B are cross-sectional views of a liquid crystal display module according to an exemplary embodiment of the present invention.

Hereinafter, a backlight unit according to a preferred embodiment of the present invention and a liquid crystal display module including the same will be described with reference to the drawings.

3 is an exploded perspective view showing a structure of a liquid crystal display module including a backlight unit according to an embodiment of the present invention.

As shown, the liquid crystal display device module including the backlight unit of the present invention includes a liquid crystal panel 100 for displaying an image, a backlight unit 200 for providing light, a guide panel 300 for modulating the light, Lt; / RTI >

The liquid crystal panel 100 includes a liquid crystal layer interposed between the first substrate and the second substrate with a predetermined distance therebetween. In addition, a driver IC 150 is provided on the first substrate to implement an image as the control and image signals are applied.

On the first substrate constituting the liquid crystal panel 100, a thin film transistor as a switching element and various wirings and pixel electrodes are formed. The second substrate is a color filter substrate for displaying RGB colors, and a color filter layer and a black matrix (BM) are formed. The driver IC 150 may include a gate driver for providing a scan signal for driving the thin film transistor described above and a data driver for providing a data signal to the pixel electrode and may be connected to an external system via a flexible cable And a power supply unit.

A plurality of scanning wirings and data wirings are formed on the first substrate to define a plurality of pixel regions arranged in one direction. In each pixel region, a thin film transistor Respectively. The thin film transistor includes a gate electrode connected to a gate line, a semiconductor layer formed by stacking amorphous silicon or the like on the gate electrode, a source electrode formed on the semiconductor layer and electrically connected to the data line and the pixel electrode, And serves as a switching element.

The second substrate includes a color filter composed of a plurality of sub-color filters implementing the colors of red, green and blue, a color filter for separating each sub-color filter and blocking light transmitted through the liquid crystal layer, And a matrix (BM).

The first and second substrates are arranged to face each other with a sealant formed on the outer periphery of the image display area and are spaced apart from each other by a predetermined distance to constitute the liquid crystal panel 100. A polarizing plate is attached to the outer side surfaces of the first and second substrates, which are bonded together, to linearly polarize incident and output light.

The backlight unit 200 includes an LED array 210, a light guide plate 220, an optical sheet 230, and a reflector 240.

The LED array 210 includes an LED PKG 211 as a plurality of light sources disposed on one side of the lower side of the liquid crystal panel 100 to emit light and an LED FPCB 215).

Here, the LED PKG 211 as a light source may be an R, G, or B LED element that emits monochromatic light of each of R (Red), G (Green), and B .

When the LEDs PKG emitting the monochromatic light are arranged, monochromatic LEDs PKG of R, G, and B are alternately arranged at regular intervals, monochromatic light emitted therefrom is mixed into white light, and then supplied to the liquid crystal panel 100, When the LEDs PKG emitting white light are disposed, the plurality of LEDs PKG are arranged at regular intervals to provide white light to the liquid crystal panel 100. [

In addition, the LED PKG 211 constituting the LED array 210 is bonded to the LED FPCB 215 of a flexible material. The LED FPCB 215 electrically connects a plurality of LED PKGs 211 through electrodes formed on one surface of the LED FPCB 215. Each electrode is connected to a liquid crystal display module module 210 through a connection portion 217 extending from one side of the LED FPCB 215, And is electrically connected to an external power supply or the like provided on the back surface of the battery.

In addition, one or more supporting portions 219 are formed at two corners of the other side of the LED FPCB 215, that is, the inside direction of the liquid crystal display device. The supporting portion 219 is extended from the upper surface of the light guide plate 220 to be described later by extending the edge of the LED FPCB 215 to have a predetermined width, Partially in contact with the side.

According to such a structure, the support portion 219 supports one surface of the plurality of optical sheets 230, and when the optical sheet 230 expands due to the flow or heat of the liquid crystal display module, Thereby preventing any one of them from being separated.

The LED array 210 is disposed such that the light emitting surface of the LED PKG 211 faces at least one side surface of the light guide plate 220 along one side of the light guide plate 220. Accordingly, the light emitted from the LED array 210 is incident on the side surface of the light guide plate 220.

The light guide plate 220 is disposed to correspond to the lower portion of the liquid crystal panel 100 and serves to guide the light emitted from the LED array 210 to the liquid crystal panel 100 without any loss. The light incident on the light guide plate 220 is refracted and reflected repeatedly by the diffuser added to the inner side, proceeds to the other side, and then is emitted to the upper portion of the light guide plate 220.

The optical sheet 230 includes a diffusion sheet for diffusing light emitted from the light guide plate 220 and a plurality of light sources for collecting light diffused by the diffusion sheet and supplying uniform light to the entire area of the liquid crystal panel 100 And a prism sheet.

The prism sheet includes a first prism sheet and a second prism sheet that are perpendicular to each other in the x- and y-axis directions and refract light in the x- and y-axis directions, And is configured to improve the straightness.

The optical sheet 230 should be aligned such that the sides thereof do not deviate from each other. Thus, one side is supported by the support 219 of the LED array 210 as described above, and at least one of the remaining other side surfaces can be formed with the same convex portion as the conventional optical sheet (35 in Fig. 2A). When the convex portion is formed on the optical sheet 230, the concave portion is also formed in the guide panel described later.

A reflective sheet 240 is disposed on the back surface of the light guide plate 220 so as to reflect the light emitted to the lower side and then travel toward the upper direction of the light guide plate 220, that is, toward the liquid crystal panel 300, And is attached to the lower portion of the panel 300 to enhance light efficiency and support the back surface of the LCD module.

The guide panel 300 has a rectangular frame shape and has a plurality of protrusions on one side thereof on which the LED array 210 is mounted. The liquid crystal panel 100 is attached to the upper portion of the guide panel 300 by the light- A light guide plate 220 and a plurality of optical sheets 230 are laminated. And a reflective sheet 240 is attached to the lower portion. The guide panel 300 may be formed of a synthetic resin formed by dual injection molding.

The light shielding tape 250 not only attaches and fixes the liquid crystal panel 100 and the guide panel 300 but also blocks the light emitted from the optical sheet 230 from leaking to the outside do. The light shielding tape 250 extends inward from the rim of the guide panel 300 and is configured to cover a part of the optical sheet 230.

According to this structure, the liquid crystal display module including the backlight unit of the present invention is configured such that a portion adjacent to the light source is removed from among a plurality of uneven portions formed on the optical sheet and the guide panel, and the optical sheet is supported It can improve the light phenomenon by doing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a backlight unit according to an embodiment of the present invention; FIG.

FIG. 4A is a plan view of a backlight unit according to an embodiment of the present invention, and FIG. 4B is an enlarged view of an LED array included in a backlight unit.

The backlight unit of the present invention includes a stacked optical sheet 135 and an LED array 210 supporting one side of the optical sheet 135. The backlight unit is mounted on the guide panel 300 Lt; / RTI >

In this structure, the LED array 210 is spaced apart from the optical sheet 135 by a predetermined distance, and protrudes from both sides toward the optical sheet 135 to come in contact with a part of the edge of the optical sheet. And an LED PKG (not shown) is bonded to the rear surface, and is disposed to face a side surface of a light guide plate (not shown) provided on the back surface of the optical sheet 135.

The LED array 210 is made up of a flexible FPCB 215 made of a flexible material to which a plurality of LEDs PKG (not shown) and an LED PKG are bonded to the rear surface of the LED array 210. The LED FPCB 215 includes electrodes And each electrode is electrically connected to an external power source and a driver (not shown) or the like through a connection portion 217 extending from one side of the LED FPCB 215. Typically, the external power source is disposed on the back surface of the LCD module, and the central area 216 of the connection part 217 may be formed of a material that can be flexed more flexibly.

Particularly, the LED FPCB 215 has support portions 219 protruding at predetermined lengths at both ends thereof. The support portion 219 is extended corresponding to the distance between the LED FPCB 215 and the optical sheet 135 And comes into contact with the edge portion of the optical sheet 135 (B). The support portion 219 may be formed so that its thickness is the same as that of the optical sheet 135.

In addition, the optical sheet 135 is surrounded by the guide panel 400 except for the side facing the LED array 210. In contrast to the conventional structure, the convex portions (35a to 35d in FIG. 2) ) Is removed and becomes flat. The flat regions 135a and 135b where the convex portions are removed are adjacent to the LED array 210 at a distance.

The remaining portions of the convex portions 135e and 135f are remote from the LED array 210 and fix the remaining side surfaces in addition to the surface supported by the LED array 210 in the optical sheet 135. [ Since the convex portions 135e and 135f are distant from the light source, even if light traveling in the optical sheet 135 is reflected at the bent portion, the convex portions 135e and 135f do not have brightness enough to cause light shining, It is possible to implement a video without a video.

Hereinafter, a coupling structure of the LED array and the optical sheet will be described with reference to cross sections of the liquid crystal display module of the present invention with reference to the drawings.

5A and 5B are cross-sectional views of a liquid crystal display module according to an exemplary embodiment of the present invention.

As shown in the figure, the liquid crystal display module of the present invention comprises a liquid crystal panel 100, a backlight unit 200 arranged on the rear surface of the liquid crystal panel, and a guide panel 300 for mounting the backlight unit 200.

In the liquid crystal panel 100, first and second substrates, on which various switching elements and wirings are formed, are opposite to each other with a predetermined distance therebetween, and a liquid crystal layer is interposed between the two substrates. In addition, a polarizing plate (not shown) is attached to the outer side surfaces of the first and second substrates that are bonded together to linearly polarize incident and output light. In the liquid crystal panel 100 having such a structure, the optical characteristics of the liquid crystal layer are converted according to the electric field control between the two substrates to display the gray level of the image.

The backlight unit 200 is provided on the back surface of the liquid crystal panel 100. The LED array 210 is disposed on at least one side portion of the backlight unit 200 and the light guide plate 220 and the optical sheet 230 are disposed on the liquid crystal panel 100, So as to provide light.

Particularly, the LED array 210 is mounted on the guide panel 300 such that a plurality of LED PKGs 211 are bonded to one side of the FPCB 215 side by side in a row and a bonding surface of the LED PKG 211 faces downward . And the connection portion 217 extending from the FPCB 215 is pulled out in the outer direction of the LCD module.

Further, on the side surface of the LED array 210, an optical member disposed under the liquid crystal panel 100 and for guiding, diffusing, and condensing light emitted from the LED PKG 211 is provided. The optical member includes a light guide plate 220 for supplying incident light over the entire area of the liquid crystal panel 100 and a light guide plate 220 interposed between the liquid crystal panel 100 and the light guide plate 220 to diffuse the light guided from the light guide plate 220 And a reflector 240 disposed on the back surface of the light guide plate 220 and reflecting the light output in the downward direction toward the light guide plate 220. [

The liquid crystal panel 100 and the backlight unit 200 described above are mounted on the guide panel 300, which is an opaque synthetic resin mechanism structure in the form of a rectangular frame. The liquid crystal panel 100 is mounted on the upper surface of the guide panel 300 and the backlight unit 200 is mounted on the inner space of the guide panel 300. The backlight unit 200 is mounted on the back surface of the guide panel 300, (240) is attached.

The liquid crystal panel 100 is attached to the guide panel 300 by the light shielding tape 250. The light shielding tape 250 is attached to the surface of the FPCB 215 on which the LED PKG 211 is not bonded, Thereby fixing the array 210.

The FPCB 215 of the LED array 210 is opposed to the optical sheet 230 so as to form a space 280 spaced apart from the optical sheet 230 by a predetermined distance. At least one supporting portion 219 is formed to extend to abut the edge portion of the optical sheet 230 made of a plurality of sheets (C).

According to the above-described structure, when the internal temperature of the LCD module rises, the optical sheet 230 expands toward the LED array 210, but the support portion 219 catches both sides of the optical sheet 230 And its expansion is suppressed. In addition, the alignment state between the plurality of optical sheets 230 is continuously maintained.

Therefore, the backlight unit and the liquid crystal display module including the backlight unit of the present invention are provided with a support for supporting and fixing the optical sheet on the LED array, thereby removing the irregularities formed on each side of the optical sheet.

While a great many are described in the foregoing description, it should be construed as an example of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

100: liquid crystal panel 150: driver IC
200: backlight unit 210: LED array
211: LED PKG 215: LED FPCB
217: connecting portion 219:
220: light guide plate 230: optical sheet
250: Shading tape 300: Guide panel

Claims (10)

A light guide plate guiding light incident on at least one side surface to an upper surface;
At least one optical sheet arranged on an upper surface of the light guide plate and diffusing and condensing the incident light and outputting the light to the upper surface;
A reflection plate disposed on a lower surface of the light guide plate; And
An LED array including a plurality of LEDs PKG bonded and arranged to be spaced apart from the optical sheet, the LED FPCB being formed with a support portion abutting at least one side surface of the optical sheet,
Wherein the support portion is formed to have the same thickness as that of the optical sheet stacked in a plurality of layers so as to partially protrude from both ends of the FPCB in the direction of the optical sheet. delete The method according to claim 1,
Wherein the optical sheet has a side surface in a flat shape in a region adjacent to the LED array. delete A liquid crystal panel;
A backlight unit for providing light to the liquid crystal panel;
And a guide panel for mounting the liquid crystal panel and the backlight unit,
The backlight unit includes: a light guide plate that guides light incident on at least one side surface to the liquid crystal panel;
At least one optical sheet arranged on an upper surface of the light guide plate and diffusing and condensing the incident light and outputting the light to the upper surface;
A reflection plate disposed on a lower surface of the light guide plate; And
An LED array including a plurality of LEDs PKG bonded and arranged to be spaced apart from the optical sheet, the LED FPCB being formed with a support portion abutting at least one side surface of the optical sheet,
Wherein the support portion is extended at both ends of the FPCB so as to protrude partially toward the optical sheet, and has the same thickness as the optical sheet laminated with the plurality of layers. delete 6. The method of claim 5,
Wherein the optical sheet has a side surface in a flat shape in a region adjacent to the LED array. 8. The method of claim 7,
Wherein the optical sheet has at least one convex portion for supporting and fixing the side surface thereof. 9. The method of claim 8,
Wherein the guide panel has at least one concave portion corresponding to the convex portion. 6. The method of claim 5,
Wherein the FPCB is attached to the liquid crystal panel together with the guide panel by a light shielding tape.

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