KR20160059005A - Blacklight Unit and Liquid Crystal Display Device having the same - Google Patents

Abstract

Disclosed are a backlight unit and a liquid crystal display device having the same. According to the present invention, the liquid crystal display device comprises: a liquid crystal display panel; and a backlight unit which includes a light source supplying a surface light source to the liquid crystal display panel, a light guide plate converting light input from the light source into the surface light source, an optical sheet disposed on the light guide plate, and a reflective plate accommodating the light guide plate, the optical sheet and the light sources. The liquid crystal display device further comprises side surfaces arranged along four sides of the reflective plate, and a first and a second supports bent from the side surfaces in parallel to a lower surface of the reflective plate to surround the light source, the light guide plate and the optical sheet. The backlight unit according to the present invention and the liquid crystal display device having the same remove a support main and a lower cover used in the liquid crystal display device, so as to provide an effect of realizing a flexible element and a narrow bezel area.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD), and more particularly, to a backlight unit capable of realizing a narrow bezel region and a flexible device by removing a support main and a bottom cover used in a liquid crystal display And a liquid crystal display device.

Recently, liquid crystal display devices have been attracting attention as next generation advanced display devices with low power consumption, good portability, and high value-added.

Of these liquid crystal display devices, an active matrix type liquid crystal display device having a thin film transistor, which is a switching device capable of controlling voltage on and off for each pixel, .

In general, a liquid crystal display device forms an array substrate and a color filter substrate through an array substrate manufacturing process for forming thin film transistors and pixel electrodes, and a color filter substrate manufacturing process for forming color filters and common electrodes, And a liquid crystal interposed therebetween.

However, since the liquid crystal display device 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 unit having a light source is disposed on the back surface of the liquid crystal display panel do.

The backlight unit is divided into a direct type and an edge type according to the position of the light source. The backlight unit of the direct-type type arranges the light source below the liquid crystal display panel, The backlight unit of the side-type type has a structure in which a light guide plate is disposed under the liquid crystal display panel and a light source is disposed on at least one side surface of the light guide plate to emit light from the light source by using refraction and reflection in the light guide plate And the light is indirectly supplied to the liquid crystal display panel.

As a light source of the backlight unit, a fluorescent lamp such as a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL) has been widely used. Recently, however, Light-emitting diodes (LEDs), which have advantages in terms of power consumption, weight, and brightness, have been replacing fluorescent lamps with lightweight trends.

In general, a liquid crystal display device includes a backlight unit including a light source, a light guide plate, optical sheets, and a reflection plate inside a lower cover. The liquid crystal display panel is fixed to a support main body on the backlight unit, And is assembled in the form of a single liquid crystal display module while being fastened to the main and lower covers.

The support main is formed in a rectangular frame shape made of a plastic material, and the lower cover is formed of a metal sUS (SUS) or an aluminum (Al) die.

Since the support main and the lower cover are made of a rigid material, it is difficult to implement a flexible backlight unit or a flexible display device.

Since the support main plays a role of supporting the liquid crystal display panel, it is required to have a certain thickness and width, and there is a limit in reducing the bezel area.

Further, since the support main and lower covers are used to assemble the liquid crystal display panel and the backlight unit, it is difficult to reduce the thickness of the liquid crystal display device.

In addition, since the support main and lower cover are manufactured by injection molding or metal mold using plastic material and metal, the manufacturing cost is high and the assembling process is complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight unit and a liquid crystal display device having the backlight unit, which can realize a flexible element and a narrow bezel region by removing a support main and a lower cover used in a liquid crystal display device.

It is another object of the present invention to provide a backlight unit and a liquid crystal display device having the backlight unit, which reduces light weight and shortening manufacturing cost by using a reflector used in a liquid crystal display device as a backlight unit storage and liquid crystal display panel fixing means .

According to an aspect of the present invention, there is provided a backlight unit including a light source, a light guide plate for converting light incident from the light source into a surface light source, and an optical sheet disposed on the light guide plate And a reflecting plate on which the light guide plate, the optical sheet, and the light sources are housed, the side surfaces disposed along the four sides of the reflection plate, and the light guide plate bent from the side surfaces in parallel with the lower surface of the reflection plate, By including the first and second support portions surrounding the sheet, the support main and lower covers used in the liquid crystal display device can be removed to realize a flexible element and a narrow bezel region.

According to another aspect of the present invention, there is provided a liquid crystal display device including a liquid crystal display panel, including a light source for supplying a surface light source to the liquid crystal display panel, a light guide plate for converting light incident from the light source into a surface light source, And a backlight unit including a reflection plate on which the light guide plate, the optical sheet, and the light sources are housed, wherein the backlight unit includes: side surfaces disposed along a circumference of the reflection plate; The support main and lower covers used in the liquid crystal display device are removed by including the first and second support portions which are folded and wrapped around the light source, the light guide plate, and the optical sheet, thereby realizing a flexible device and a narrow bezel region It is effective.

INDUSTRIAL APPLICABILITY The backlight unit and the liquid crystal display device having the same according to the present invention have the effect of realizing a flexible element and a narrow bezel region by removing the support main and lower cover used in the liquid crystal display device.

Further, the backlight unit and the liquid crystal display device having the same according to the present invention have the effect of reducing light weight shortening and manufacturing cost by using a reflector used in a liquid crystal display device as a backlight unit storing and liquid crystal display panel fixing means.

1 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.
2A and 2B are cross-sectional views taken along lines I-I 'and II-II' of FIG. 1, respectively.
3 is a view showing the structure of a reflection plate used in the liquid crystal display device of the present invention.
4A is a view illustrating a structure of a reflection plate according to another embodiment of the present invention.
4B is a cross-sectional view taken along line III-III 'of FIG. 4A.
FIG. 5A is a view schematically showing an assembling process of the liquid crystal display device of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can be added unless '~ only' is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if a temporal posterior relationship is described by 'after', 'after', 'after', 'before', etc., 'May not be contiguous unless it is used.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

FIG. 1 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views taken along lines I-I 'and II-II' of FIG.

Referring to FIGS. 1 and 2B, the liquid crystal display 100 of the present invention includes a liquid crystal display panel 110, a backlight unit 120, and a top cover 140.

The liquid crystal display panel 110 and the backlight unit 120 are modularized by the reflector 150 of the top cover 140 and the backlight unit 120.

The liquid crystal display panel 110 and the backlight unit 120 are modularized through a top cover 140 and a reflective plate 150. The top cover 140 is disposed on the liquid crystal display panel 110, The top cover 140 is opened so that an image to be displayed on the liquid crystal display panel 110 is displayed on the top cover 140 in a rectangular shape having a cross section bent in a "? &Quot; shape to cover the top and side edges.

The reflective plate 150 on which the liquid crystal display panel 110 and the backlight unit 120 are mounted so as to be the basis for assembling the entire structure of the liquid crystal display device has a horizontal surface 151 (bottom surface) closely contacting the back surface of the backlight unit 120, And a first and a second support portions 152 and 154 bent inwardly in parallel with the horizontal surface 151 from the side surface 153. The first and second support portions 152 and 154 are bent upward.

The first support part 152 is opposed to the first support part 152 with the horizontal surface 151 interposed therebetween at the upper side of the two opposing side surfaces of the four side surfaces 153. The second support part 154 is opposed to the first support part 152, And is opposed to each other with the horizontal plane 151 therebetween.

That is, the first supporting part 152 and the second supporting part 154 are arranged in a direction perpendicular to each other, the liquid crystal display panel 110 is mounted on the first and second supporting parts 152 and 154, A backlight unit 120 is housed in a horizontal plane 151 of the display unit 150 and inside the first and second support units 152 and 154.

The top cover 140 may be coupled along the periphery of the reflector 150, which may be referred to as a case top or a top case. The top cover 140 may have a rectangular frame shape and may be formed of a plastic material or a film.

However, in some cases, the top cover 140 may be removed.

The liquid crystal display panel 110 is a part that plays a key role in image display and includes an array substrate 112 and a color filter substrate 114 which are bonded to each other with a liquid crystal layer interposed therebetween.

At this time, a plurality of gate lines and data lines intersect to define the pixels on the inner surface of the array substrate 112, which is usually referred to as a lower substrate or a thin film transistor substrate, though not shown in the drawing, A thin film transistor (TFT) is provided at each of the intersections and is connected in one-to-one correspondence with the transparent pixel electrodes formed in each pixel.

On the inner surface of the color filter substrate 114 called an upper substrate, a color filter of red (R), green (G), and blue (B) colors corresponding to each pixel and a color filter A black matrix for covering gate lines, data lines and thin film transistors is provided. In addition, color filters of red (R), green (G), and blue (B) colors and transparent common electrodes covering the black matrix are provided.

However, in the case of the IPS (In-Plane Switching) mode or the FFS (Fringe Field Switching) mode liquid crystal display, the pixel electrode and the common electrode may be disposed in the array substrate 112.

A polarizing plate (not shown) selectively transmitting only specific light is attached to the outer surfaces of the array substrate and the color filter substrates 112 and 114, respectively.

A printed circuit board 117 is connected to at least one edge of the liquid crystal display panel 110 via a connection member 116 such as a flexible circuit board or a tape carrier package (TCP) A hole may be formed in the side surface 153 of the reflection plate 150 or may be appropriately flipped over the side surface 153 to the rear surface of the reflection plate 150.

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

In addition, the liquid crystal display device according to the present invention includes a backlight unit 120 for supplying light from the backside of the liquid crystal display panel 110 so that the difference in transmittance represented by the liquid crystal display panel 110 is externally expressed.

The backlight unit 120 includes an LED assembly 129, a white or silver reflective plate 150, a light guide plate 123 mounted on the horizontal surface 151 of the reflective plate 150, and an optical sheet 210). The optical sheet 210 may include a quantum dot light conversion sheet.

The LED assembly 129 is located at one side of the light guide plate 123 so as to face the light incident surface of the light guide plate 123. The LED assembly 129 includes a plurality of LEDs 129a, And a PCB 129b mounted spaced apart.

The LED assembly 129 is of a top view type in which light emitted from the plurality of LEDs 129a is perpendicular to the PCB 129b.

The LED 129a may include a blue LED or a red (R), green (G), and blue (B) LED for emitting blue light having a wavelength of about 430 to 450 nm for improving luminous efficiency and luminance .

Also, the LED 129a may be a white (W) LED.

The optical sheet 210 disposed on the light guide plate 123 includes a diffusion sheet and at least one light collecting sheet and a light conversion sheet and diffuses or condenses the light passing through the light guide plate 123, So that a more uniform surface light source is incident.

Referring to FIGS. 2A and 2B, an assembly sectional view taken along line I-I 'and line II-II' in FIG. 1 will be described in detail.

The light guide plate 123, the optical sheet 210 and the LED assemblies 129 of the backlight unit 120 of the present invention are housed inside the reflector 150. [ The side surface 153 and the first and second support portions 152 and 154 of the reflective plate 150 are assembled by surrounding the light guide plate 123, the optical sheet 210, and the LED assembly 129.

The first support part 152 of the reflection plate 150 is disposed on the light incident area of the light guide plate 123 and the LED assembly 129, And is disposed parallel to the upper surface of the light guide plate 123.

A reflective film 160 is disposed on the lower surface of the first supporting portion 152 corresponding to the light incident portion of the light guide plate 123. The first supporting portion 152, And is fixed to the upper surface of the light entrance area of the light guide plate 123 by the adhesive film T2.

The liquid crystal display panel 110 is fixed to the upper surface of the first supporting part 152 of the reflector 150 by the first adhesive film T1.

In a region II-II 'where the LED assembly 129 is not disposed, the light guide plate 123 and the optical sheet 210 are assembled so as to surround the side surface 9153 of the reflection plate 150 and the second support portion 154 do. Third and fourth adhesive films T3 and T4 are attached to the lower surface and the upper surface of the second support portion 154 of the reflection plate 150, respectively.

The second supporting part 154 of the reflection plate 150 is fixed to the optical sheet 210 by the fourth adhesive film T4 and the liquid crystal display panel 110 is fixed to the third adhesive film T3 And is fixed to the second support portion 154 by the second support portion 154.

Although not shown in the drawings, the first and second pads 141 and 142 are not illustrated.

As described above, the backlight unit and the liquid crystal display device having the backlight unit of the present invention can realize a flexible backlight unit by removing the support main and lower covers used in the conventional liquid crystal display device and accommodating the backlight unit by changing the structure of the reflector There is an effect that can be.

Further, by fixing the liquid crystal display panel on the support portion of the reflection plate and fixing it, a narrow bezel area can be realized, and a flexible liquid crystal display device can be realized.

In addition, in the present invention, by removing the support main and lower cover used in the conventional liquid crystal display, it is possible to reduce the size and weight of the liquid crystal display device and reduce the manufacturing cost.

4A is a view illustrating a structure of a reflection plate according to another embodiment of the present invention. FIG. 4B is a cross-sectional view taken along the line III- Sectional view taken along line III 'of FIG.

3 to 4B, the reflector 150 of the present invention includes a horizontal surface 151 (lower surface) on which the components of the backlight unit are stacked, a side surface 153 And first and second support portions 152 and 154 that are bent in the horizontal direction with respect to the horizontal surface 151 at each of the side surfaces 153.

3, when the first and second support portions 152 and 154 are folded in parallel with the horizontal plane 151 of the reflection plate 150, the reflection areas of the four corner areas of the reflection plate 150 And the heights of the first and second support portions 152 and 154 are changed.

When a step is formed between the four corners of the reflection plate 150 and the first and second support portions 152 and 154 as described above, the liquid crystal display panel may be separated from the first and second support portions 152 and 154 A problem that is not supported in the entire area occurs.

In order to solve this problem, in the present invention, only the width X of the first support part 152 is removed, and the edge area of the second support part 154 is removed. Therefore, even though the first and second supporting portions 152 and 154 of the reflection plate 150 are folded in parallel to the horizontal plane 151, the height of the edge of the reflection plate 150 maintains the same height.

3, the edges of the second support part 154 are removed, but both side edge areas of the first support part 152 are removed by the width X of the second support part 154, The first and second support portions 152 and 154 can be prevented from overlapping each other in the four corner regions of the first and second corner portions.

Therefore, if the thickness D1 of the first support 152 and the thickness D2 of the second support 154 of the reflector 150 are equal to each other, And the second supporting portions 152 and 154 are flush with each other at the same height.

If the height of the edge region of the reflective plate 150 is the same, the liquid crystal display panel can be in contact with and support all the regions of the first and second support portions 152 and 154 The liquid crystal display panel can be assembled at a uniform height.

4A and 4B, the reflection plate 250 according to another embodiment of the present invention includes a horizontal surface 251 (lower surface) where the components of the backlight unit are stacked, And first and second support portions 252 and 254 that are bent in the horizontal direction with the horizontal surface 251 in each of the side surfaces 253.

The side portion 252a of the first support portion 252 and the side portion 254a of the second support portion 254 are overlapped with each other at four corners of the reflection plate 250. [

The thickness D3 of the side portion 252a of the first support portion 252 and the thickness D3 of the side portion 254a of the second support portion 254 are set so as not to generate a step in the four corners of the reflection plate 250, ) Were made equal to each other.

However, the thickness D4 of the first and second support portions 252 and 254 disposed in the region other than the four corners of the reflection plate 250 (the region excluding the side portions) is smaller than the thickness D4 of the first support portion 252 The height of the first and second support portions 252 and 254 around the edge of the reflection plate 250 is made equal to twice the thickness D3.

The first and second support portions 252 and 254 of the reflection plate 250 are bent in a direction parallel to the horizontal plane 251 and the four sides of the reflection plate 250 are bent in a direction parallel to the horizontal plane 251, The side surfaces 252a and 254a of the first and second support portions 252 and 253 overlap with each other while the upper surface around the edge of the reflection plate 250 maintains the same height.

Accordingly, the liquid crystal display panel of the present invention is in contact with the first and second support portions 252 and 254 of the reflection plate 250, so that the entire area of the liquid crystal display panel can be fixedly arranged at the same height.

FIG. 5A is a view schematically showing an assembling process of the liquid crystal display device of the present invention.

5A to 5D, the light guide plate and the optical sheet are assembled by the second support part 154 of the reflection plate 150 in FIGS. 1 and 3. However, as shown in FIG. 2, And the other side of the light guide plate are assembled in the same manner.

5A to 5D, a second support portion 154 is extended from the side surface 153 of the reflection plate 150 of the present invention. On the lower surface and the upper surface of the second support portion 154, The fourth adhesive films T3 and T4 are attached.

5B, when the light guide plate 123 and the optical sheet 210 are laminated on the lower surface (the horizontal plane) of the reflection plate 150, the second support portion 154 of the reflection plate 150 is fixed to the reflection plate 150, In the horizontal direction. At this time, the second supporting portion 154 is fixed to the optical sheet 210 by the fourth adhesive film T4 attached to the lower surface of the second supporting portion 154.

5D, the liquid crystal display panel 110 is mounted on the second support part 154 of the reflector 150. The liquid crystal display panel 110 is mounted on the second support part 154, And the liquid crystal display panel 110 is fixed by the third adhesive film T3 attached on the upper surface.

3, the first and second support portions 152 and 154 formed on the reflection plate 150 are bent in parallel with the lower surface 151 of the reflection plate 150 And the height of the upper surfaces of the first and second support portions 152 and 154 disposed around the edge of the reflection plate 150 are equal to each other.

Therefore, the liquid crystal display panel 110 mounted on the reflection plate 150 may be fixed on the reflection plate 150 at the same height.

As described above, the backlight unit of the present invention and the liquid crystal display device having the same have the effect of realizing the flexible element and the narrow bezel region by removing the support main and lower cover used in the liquid crystal display device.

Further, the reflector used in the liquid crystal display of the present invention is used as a backlight unit storage and a liquid crystal display panel fixing unit, thereby reducing light weight shortening and manufacturing cost.

100: liquid crystal display device 110: liquid crystal display panel
112: first substrate 114: second substrate
117: printed circuit board 120: backlight unit
210: optical sheet 123: light guide plate
150: reflector 153: side
152: first support portion 154: second support portion

Claims (11)

Light source;
A light guide plate for converting light incident from the light source into a surface light source;
An optical sheet disposed on the light guide plate; And
An optical sheet, and a reflector for receiving the light sources,
And first and second support portions that are bent in parallel with the lower surface of the reflection plate from the side surfaces and surround the light source, the light guide plate, and the optical sheet.
The backlight unit according to claim 1, wherein the first and second support portions are fixed to the optical sheet disposed inside the reflection plate along an edge of the reflection plate.
The backlight unit according to claim 1, wherein at least one of the first and second support portions is partially removed at four corners of the reflection plate.
The backlight unit according to claim 1, wherein the height of the first and second supports disposed along the edge of the reflector is equal to each other.
2. The liquid crystal display device according to claim 1, wherein the first and second supporting portions overlap each other in the four corners of the reflection plate, and the first and second supporting portions overlap with each other without overlapping the thicknesses of the first and second supporting portions And the thicknesses in the regions are different from each other.
A liquid crystal display panel; And
A light guide plate for converting light incident from the light source into a planar light source; an optical sheet disposed on the light guide plate; and a reflection plate for receiving the light guide plate, the optical sheet, And a backlight unit,
And first and second supporting portions that are bent in parallel with the lower surface of the reflection plate from the side surfaces and surround the light source, the light guide plate, and the optical sheet.
The liquid crystal display device according to claim 6, wherein the liquid crystal display panel is fixed on the first and second supporting portions.
The liquid crystal display of claim 6, wherein the first and second supporting portions are fixed to the optical sheet disposed inside the reflection plate along the edge of the reflection plate.
7. The liquid crystal display of claim 6, wherein at least one of the first and second supporting portions is partially removed at four corners of the reflection plate.
The liquid crystal display of claim 6, wherein the height of the first and second supporting portions disposed along the edge of the reflection plate are equal to each other.
7. The backlight unit according to claim 6, wherein the first and second support portions overlap each other in the four corner regions of the reflector, and the first and second support portions overlap with each other without overlapping the thicknesses of the first and second support portions And the thicknesses of the regions are different from each other.

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