KR20180047618A - Back Light Unit and Liquid Crystal Display Device using the same - Google Patents

Abstract

The present invention provides a liquid crystal display device which comprises: a liquid crystal panel displaying an image; and a backlight unit providing light to the liquid crystal panel. The backlight unit includes: a light guide plate; a light source providing the light to the light guide plate; a reflection plate having a lower surface facing a lower surface of the light guide plate and a side surface vertically folded from the lower surface of the reflection plate so as to surround the periphery of a side surface of the light guide plate; and a cover bottom storing the light guide plate, the light source and the reflection plate. The reflection plate has a cutting line formed by being cut so as to have the side surface vertically folded from the lower surface. A side surface reflection member installed on a side surface to compensate optical loss is deleted, thereby reducing a manufacturing cost and simplifying a process.

Description

BACKLIT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME

The present invention relates to a backlight unit and a liquid crystal display using the same.

As the information technology is developed, the market of display devices, which is a connection medium between users and information, is getting larger. Accordingly, a flat panel display (FPD) such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display and a plasma liquid crystal display (PDP) ) Have been increasing. Among them, liquid crystal display devices capable of realizing high resolution and capable of not only miniaturization but also enlargement are widely used.

A liquid crystal display device includes a liquid crystal panel and a backlight unit. The liquid crystal panel includes a transistor substrate on which a thin film transistor, a storage capacitor, a pixel electrode, and the like are formed, and a liquid crystal layer disposed between the color filter substrate and the color filter substrate on which the color filter and the black matrix are formed.

The backlight unit includes a light-emitting diode (hereinafter, LED) that provides light to the liquid crystal panel, an LED substrate on which an LED driver for driving the LED is formed, a light guide plate that converts light emitted from the LED into a planar light source, Optical sheets for condensing and diffusing the light emitted from the light guide plate, and the like.

The liquid crystal display device displays an image on the display panel based on the light provided from the backlight unit. Therefore, the luminance and the display quality of the display panel are improved as the light emitted from the backlight unit is supplied without loss as much as possible. Therefore, there is a demand for a method for improving the light-emitting ability of the light emitted from the backlight unit.

The present invention for solving the problems of the background art minimizes the influence on light guide plates and optical sheets (improvement of wrinkles of optical sheets) due to shrinkage / relaxation due to high temperature and high humidity while minimizing loss of light, And simplify the process.

According to an aspect of the present invention, there is provided a liquid crystal display including a liquid crystal panel for displaying an image and a backlight unit for providing light to the liquid crystal panel. The backlight unit includes a light guide plate, a light source for providing light to the light guide plate, a lower surface facing the lower surface of the light guide plate, a reflection plate having a vertically folded side from the lower surface of the reflection plate to surround the side surface of the light guide plate, And a cover bottom for accommodating the light source and the reflection plate. The reflector has a cutting line formed so as to have a vertically folded side from the lower surface.

The cutting line may include cutting areas that are cut to separate the bottom and side surfaces of the reflector and bent areas that are bent to vertically fold the sides of the reflector and disposed between the cut areas.

The cutting line draws a straight line and can have a dotted line form or a long straight line form.

The cutting line may include a densely arranged portion cut in a dotted line drawn along a straight line extending along the longitudinal direction of both sides of the reflector and a portion closely arranged in a dotted line drawn along a short axis direction of one side of the reflector .

The cutting line may include a portion that is long in a linear shape along both major axis directions of the reflection plate and a portion that is long in a linear shape along one minor axis direction of the reflection plate.

The light guide plate includes a first pattern portion disposed corresponding to an area where the banding regions are disposed, and the first pattern portion may have a stepped portion removed so that the edge of the light guide plate is inwardly inward.

The light guide plate may include a second pattern portion disposed corresponding to an area in which the banding regions are disposed and the second pattern portion may be removed so that the major axis surface of the light guide plate is directed inward to have a step.

In another aspect, the present invention provides a backlight unit having a light guide plate, a light source, a reflector, and a cover bottom. The light source provides light to the light guide plate. The reflector has a lower surface facing the lower surface of the light guide plate and a side vertically folded from the lower surface of the reflector so as to surround the periphery of the side surface of the light guide plate. The cover bottom houses a light guide plate, a light source, and a reflector. The reflector has a cutting line formed so as to have a vertically folded side from the lower surface.

The cutting line may include cutting areas that are cut to separate the bottom and side surfaces of the reflector and bent areas that are bent to vertically fold the sides of the reflector and disposed between the cut areas.

The cutting line draws a straight line and can have a dotted line form or a long straight line form.

The present invention provides a reflector capable of minimizing the influence of a light guide plate or optical sheets (wrinkles of optical sheets) due to shrinkage / relaxation due to high temperature and high humidity while minimizing loss of light. In addition, the present invention has the effect of reducing the material cost and simplifying the process by eliminating the side reflecting member that is provided on the side for compensation of optical loss. Further, the present invention has an effect of providing a reflector and a light guide plate capable of reducing the influence of thermal expansion / contraction characteristics (including shrinkage / relaxation due to high temperature and high humidity).

1 is a block diagram schematically showing a liquid crystal display device.
Fig. 2 is a circuit diagram schematically showing the subpixel shown in Fig. 1. Fig.
3 is an exploded perspective view of a liquid crystal panel module according to a first embodiment of the present invention;
4 is a plan view showing a reflection plate and a light guide plate according to the first embodiment.
5 is a sectional view of a liquid crystal panel module according to the first embodiment.
6 is a state diagram of a reflector after a thermal shock test.
7 is a plan view showing a reflection plate and a light guide plate according to the second embodiment.
8 is a sectional view of a liquid crystal panel module according to the second embodiment.
9 is a state view of a reflector after a thermal shock test.
10 is a structural view of a reflection plate and a light guide plate according to the third embodiment.
11 is an enlarged view showing a partial area of Fig.
12 is a structural view of a reflector and a light guide plate according to the fourth embodiment.
13 is an enlarged view showing a partial area of Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The liquid crystal display device described below may be applied to a liquid crystal display device such as a TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In Plane Switching) mode, FFS And can be implemented in an ECB (Electrically Controlled Birefringence) mode.

The backlight unit and the liquid crystal display using the backlight unit described below can be used in various fields such as a portable computer such as a notebook PC, office automation equipment, audio / video equipment, indoor and outdoor advertisement display, and vehicle display.

≪ Embodiment 1 >

FIG. 1 is a block diagram schematically showing a liquid crystal display device, and FIG. 2 is a circuit diagram schematically showing a subpixel shown in FIG.

1 and 2, the liquid crystal display device includes an image supply unit 110, a timing control unit 130, a gate driving unit 140, a data driving unit 150, a liquid crystal panel 160, a power supply unit 180, Backlight unit 170 is included.

The image supply unit 110 processes the data signal and outputs the image signal together with a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a clock signal, and the like. The image supplying unit 110 supplies a vertical synchronizing signal, a horizontal synchronizing signal, a data enable signal, a clock signal, and a data signal to the timing controller 130 through a Low Voltage Differential Signaling (LVDS) interface or a TMDS (Transition Minimized Differential Signaling) .

The timing controller 130 outputs a gate timing control signal GDC for controlling the operation timing of the gate driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 150. [ The timing controller 130 supplies the data driver 150 with the data signal DATA supplied from the image processor 110 together with the data timing control signal DDC.

The gate driver 140 outputs a gate signal in response to the gate timing control signal GDC supplied from the timing controller 130. The gate driver 140 supplies gate signals to the sub-pixels SP included in the liquid crystal panel 160 through the gate lines GL. The gate driver 140 is formed in the form of an integrated circuit (IC) or a gate in panel (LCD) panel.

The data driver 150 samples and latches the digital data signal DATA in response to the data timing control signal DDC supplied from the timing controller 130 and converts the sampled data signal into a gamma reference voltage, do. The data driver 150 inverts the polarity of the data voltage in one frame period. The data driver 150 supplies a data voltage (or a data signal) to the sub-pixels SP included in the liquid crystal panel 160 through the data lines SL. The data driver 150 is formed in the form of an IC (Integrated Circuit).

The power supply unit 180 generates and outputs a high potential voltage VCC, a low potential voltage GND, and a common voltage VCOM. The high potential voltage VCC and the low potential voltage GND are supplied to at least one of the timing controller 130, the gate driver 140 and the data driver 150. The common voltage VCOM is supplied to the liquid crystal panel 160. The common voltage VCOM is supplied to the subpixels SP through the common voltage line Vcom of the liquid crystal panel 160. [

The liquid crystal panel 160 displays an image corresponding to the gate signal supplied from the gate driver 140 and the data voltage supplied from the data driver 150. The liquid crystal panel 160 includes subpixels SP for controlling light provided through the backlight unit 170. [

One sub-pixel includes a switching transistor SW, a storage capacitor Cst, and a liquid crystal layer Clc. The gate electrode of the switching transistor SW is connected to the gate line GL1 and the source electrode thereof is connected to the data line SL1. One end of the storage capacitor Cst is connected to the drain electrode of the switching transistor SW and the other end is connected to the common voltage line Vcom. The liquid crystal layer Clc is formed between the pixel electrode 1 connected to the drain electrode of the switching transistor SW and the common electrode 2 connected to the common voltage line Vcom.

The backlight unit 170 provides light to the liquid crystal panel 160 using a light source or the like that emits light. The backlight unit 170 includes a light emitting diode (LED), an LED driver for driving the LED, an LED substrate on which the LED is mounted, a light guide plate for converting the light emitted from the LED into a surface light source, Optical sheets for condensing and diffusing light emitted from the light guide plate, and the like. The backlight unit 170 may be turned on and off according to a pulse width modulation signal output from the LED driver.

The liquid crystal display device described above has been developed and released as a method of adding white subpixels in addition to red subpixels, green subpixels, and blue subpixels (hereinafter, RGBW type liquid crystal display device). The RGBW type liquid crystal display device can increase the brightness of the liquid crystal panel using the white subpixel, thereby reducing the brightness of the backlight unit 170 and reducing power consumption.

A part of the liquid crystal display device described above is attached to the liquid crystal panel and is implemented as a liquid crystal panel module.

4 is a plan view showing a reflection plate and a light guide plate according to a first embodiment, FIG. 5 is a cross-sectional view of a liquid crystal panel module according to a first embodiment of the present invention, And FIG. 6 is a state diagram of the reflector after the thermal shock test.

3, the liquid crystal panel modules 160, 165 and 170 include a cover bottom 171 located at a lower portion of the backlight unit 170 and a cover top 165 positioned at an upper portion of the liquid crystal panel 160, As shown in Fig.

The cover bottom 171 and the guide panel 177 accommodate an LED 174, a reflector (or reflective sheet) 172, a light guide plate 175, and a plurality of optical sheets 176. The cover top 165 and the guide panel 177 accommodate the liquid crystal panel 160 and the like. Hereinafter, the configuration and the functions of the cover bottom 171 and the cover top 165 will be described.

The reflector 172 is seated inside the cover bottom 171. The reflection plate 172 serves to reflect light at the lower portion of the light guide plate. The reflection plate 172 includes a lower surface 172a facing the lower surface (or the back surface) of the light guide plate 175 and a side surface (or a bending surface) 172b surrounding the periphery of at least one side surface of the light guide plate 175 . Its description is discussed in more detail below.

The side surface 172b of the reflector 172 is a vertically folded portion (the folded portion is the outer edge of the reflector) from the lower surface 172a so as to surround the portion except the portion where the LED 174 is disposed (light incoming surface). The reflection plate 172 is folded in at least two areas or folded in three areas with respect to the side surface of the light guide plate 175. Therefore, the side surface 172b of the reflector 172 may be two or three depending on the portion where the LED 174 is disposed. However, in the following description, it is assumed that there are three sides 172b of the reflector 172. [

The light guide plate 175 is seated on the reflector 172. The light guide plate 175 serves to convert the light emitted from the LED 174 into a surface light source. An LED substrate 173 on which the LED 174 is mounted is provided on the light incoming surface (light incoming portion or side surface) of the light guide plate 175.

A plurality of optical sheets 176 are seated on the light guide plate 175. The plurality of optical sheets 176 serve to condense and diffuse the light emitted from the light guide plate 175. The plurality of optical sheets 176 are composed of sheets having one or more different structures and functions.

The guide panel 177 is seated on the cover bottom 171. The guide panel 177 supports the liquid crystal panel 160 and fixes the plurality of optical sheets 176 and the like so as to be safely contained in the cover bottom 171. The guide panel 177 has a frame shape capable of passing light emitted through a plurality of optical sheets 176.

The liquid crystal panel 160 is seated on the guide panel 177. The liquid crystal panel 160 serves to display an image. The liquid crystal panel 160 includes a lower substrate 160a on which switching transistors and the like are formed, an upper substrate 160b on which color filters are formed, and a liquid crystal layer formed therebetween. The liquid crystal panel 160 is accommodated by a cover top 165 and a guide panel 177. The cover top 165 has a frame shape that can expose a display area of the liquid crystal panel 160.

3 and 4, the lower surface 172a and the side surface 172b of the reflector 172 are separated by a cutting line CL. The cutting line CL includes cutting areas (CA, cutting area) and banding areas (BA, Bending area).

The cutting line CL is located on three sides of the reflector 172. [ The cutting line CL is formed by cutting a dotted line (or a dotted line) in a straight line along three planes of the reflector 172. The cutting line CL includes a portion arranged in the longitudinal direction of both sides of the reflection plate 172 and a portion arranged in the direction of the one short axis of the reflection plate 172. [ The cutting line CL is formed in a dashed line (or dot-shaped) shape to the vicinity of the corner where the portion arranged in both the major axis direction of the reflection plate 172 and the portion arranged in the one minor axis direction of the reflection plate 172 meet.

The cutting areas CA are disposed with the banding areas BA interposed therebetween as the cut areas to separate the lower surface 172a and the side surface 172b of the reflector 172. [ The banding areas BA are arranged closely to the cutting areas CA as areas bent to vertically fold the side surfaces 172b of the reflector 172. [

The lower surface 172a of the reflection plate 172 supports the lower surface of the light guide plate 175 and the side surface 172b of the reflection plate 172 is fixed to the light guide plate 175 by the cutting line CL formed on the reflection plate 172. [ As shown in FIG.

(Before test entry)

As shown in FIG. 5A, the reflection plate 172 surrounds the periphery of at least one side surface of the light guide plate 175, and has a shape of a letter N in cross-section. And the side surface 172b of the reflector 172 is brought into contact with the side wall of the cover bottom 171. [ 5 is a cross-sectional view taken along the line A1-A2 in FIG.

The reflector 172 is constructed and arranged so as to face the lower surface (or the back surface) of the light guide plate 175 in the related art. However, since the conventional structure reflects light emitted from the LED driving unit only at the bottom, the loss of the light emitted from the LED driving unit is not enough to be minimized.

However, the first embodiment constitutes and disposes the reflector 172 so as to have the lower surface 172a facing the lower surface (or the back surface) of the light guide plate 175 and the side surface 172b surrounding the side surface of the light guide plate 175 . The first embodiment reflects the light emitted from the LED driving unit on both sides as well as on the side, so that the loss of light emitted from the LED driving unit can be minimized.

In addition, the structure of the first embodiment can reduce the material cost and simplify the manufacturing process because it can eliminate the side reflection member installed on the side for optical loss compensation as in the conventionally proposed method.

(After the test input)

However, as shown in FIG. 5 (b), the first embodiment has an advantage of minimizing the loss of light emitted from the LED driving unit, but a problem caused by the contraction of the reflector 172 after the thermal shock test It can be done.

The shrinkage problem of the reflector 172 mainly occurs near the cutting line. The light guide plate 175 is lifted while the side surface 172b of the reflection plate 172 is lifted (away from the bottom) due to the contraction of the reflection plate 172, and the optical sheets 176 on the light guide plate 175 are lifted, (Guide panel). As a result, the problem that the optical sheets 176 on the light guide plate 175 are wrinkled can also be caused.

On the other hand, the liquid crystal panel 160 includes a lower polarizer 161 and an upper polarizer 162. The cover top 165 includes a side wall portion 165a fitted to the side wall of the cover bottom 171 and a support portion 165b supporting the non-display region of the liquid crystal panel 160. [ The supporting member 165b of the cover 165 may be provided with a substrate 180 for supporting and fixing the liquid crystal panel 160 and preventing the liquid crystal panel 160 from being impacted.

As shown in FIGS. 4 and 6, the cutting areas CA and the banding areas BA are formed at the reflection plate 172 with close spacing. The width of the cutting areas CA is larger than the width of the banding areas BA.

According to the results of the experiment, the above-described problem is solved by the structure of the banding area BA and the cutting area CA included in the cutting line of the reflector 172, (CA1) is separated (Sep1) and the banding area (BA) is crying. In FIG. 6 (a), it is before the heat shock test, and (b) is after the heat shock test.

Therefore, the following proposes structures for solving the problem that may be caused in the first embodiment of the present invention.

≪ Embodiment 2 >

FIG. 7 is a plan view showing a reflection plate and a light guide plate according to a second embodiment, FIG. 8 is a sectional view of a liquid crystal panel module according to a second embodiment, and FIG. 9 is a state diagram of a reflection plate after a thermal shock test.

3 and 7, the lower surface 172a and the side surface 172b of the reflector 172 are separated by a cutting line CL. The cutting line CL includes cutting areas (CA, cutting area) and banding areas (BA, Bending area).

The cutting line CL is located on three sides of the reflector 172. [ The cutting line CL is formed by cutting along a long straight line along three planes of the reflection plate 172. [ The cutting line CL includes a long portion disposed along the major axis direction of both sides of the reflector 172 and a long portion disposed along the minor axis direction of one side of the reflector 172. [ The cutting line CL is formed in a straight line up to the vicinity of the corner where the portion disposed in both the major axis direction of the reflection plate 172 and the portion disposed in the one minor axis direction of the reflection plate 172 meet. The banding areas BA are formed at the edges of the reflector 172 where the cutting line CL is omitted.

The cutting areas CA are arranged in a straight line on three sides of the reflection plate 172 as areas cut to separate the lower surface 172a and the side surface 172b of the reflection plate 172. [ The banding areas BA are disposed at both corner portions between the cutting areas CA, that is, in the minor axis direction of the reflector 172, as areas bent to vertically fold the side surface 172b of the reflector 172. [

The lower surface 172a of the reflection plate 172 supports the lower surface of the light guide plate 175 and the side surface 172b of the reflection plate 172 is fixed to the light guide plate 175 by the cutting line CL formed on the reflection plate 172. [ As shown in FIG.

(Before and after the test input)

The reflector 172 surrounds the periphery of at least one side of the light guide plate 175, as shown in Figs. 8A and 8B (before and after the test entry and after the test entry) ) Shape. And the side surface 172b of the reflector 172 is brought into contact with the side wall of the cover bottom 171. [

Although the first embodiment has an advantage that loss of light emitted from the LED driving unit can be minimized, it has been shown that a problem may occur due to contraction of the reflector 172 after the thermal shock test.

However, in the second embodiment, the side surface 172b (bending side) of the reflector 172 is heard due to the shrinkage problem of the reflector 172, as shown in (a) The problem that the light guide plate 175 is lifted (apart from the bottom) and the problem that wrinkles occur in the optical sheets 176 are not caused.

On the other hand, the liquid crystal panel 160 includes a lower polarizer 161 and an upper polarizer 162. The cover top 165 includes a side wall portion 165a fitted to the side wall of the cover bottom 171 and a support portion 165b supporting the non-display region of the liquid crystal panel 160. [ The supporting member 165b of the cover 165 may be provided with a substrate 180 for supporting and fixing the liquid crystal panel 160 and preventing the liquid crystal panel 160 from being impacted.

7 and 9, the cutting areas CA are elongated along the major axis or the minor axis direction of the reflector 172, and the banding areas BA are formed at the corner portions where the cutting areas CA end . In FIG. 9 (a), it is before the heat shock test and (b) is after the heat shock test.

The second embodiment differs from the first embodiment in that the thermal expansion / contraction characteristics (depending on the high temperature and high humidity) are controlled by the banding area BA and the cutting area CA structure (solid line shape instead of the dotted line) included in the cutting line of the reflector 172 Shrinkage / relaxation), it was found that the cutting area (CA2) was not significantly separated (Sep2) after the thermal shock test.

Therefore, according to the second embodiment of the present invention, it is possible to solve the problem that can be caused in the first embodiment while minimizing the loss of light. In addition, the structure of the second embodiment can reduce the material cost and simplify the process since it can eliminate the side reflecting member provided on the side for optical loss compensation like the conventionally proposed method.

Hereinafter, a structure of a reflector and a light guide plate capable of reducing the influence of thermal expansion / contraction characteristics (including shrinkage / relaxation due to high temperature and high humidity) is proposed.

≪ Third Embodiment >

FIG. 10 is a structural view of a reflector and a light guide plate according to a third embodiment, and FIG. 11 is an enlarged view showing a partial area of FIG.

As shown in Fig. 10, the lower surface 172a and the side surface 172b of the reflector 172 are separated by a cutting line CL. The cutting line CL includes cutting areas (CA, cutting area) and banding areas (BA, Bending area).

The cutting line CL is located on three sides of the reflector 172. [ The cutting line CL is formed in a straight line shape along three planes of the reflector 172. The cutting line CL includes a portion arranged in the longitudinal direction of both sides of the reflection plate 172 and a portion arranged in the direction of the one short axis of the reflection plate 172. [ The cutting line CL is formed in a straight line up to the vicinity of the corner where the portion disposed in both the major axis direction of the reflection plate 172 and the portion disposed in the one minor axis direction of the reflection plate 172 meet. The banding areas BA are formed at the edges of the reflector 172 where the cutting line CL is omitted.

The cutting areas CA are arranged in a straight line on three sides of the reflection plate 172 as areas cut to separate the lower surface 172a and the side surface 172b of the reflection plate 172. [ The banding areas BA are disposed at both corner portions between the cutting areas CA, that is, in the minor axis direction of the reflector 172, as areas bent to vertically fold the side surface 172b of the reflector 172. [

A first pattern unit CC is formed at the corner of the light guide plate 175 to minimize a problem caused by a shrinkage effect that may occur at the corner of the reflection plate 172. [ The first pattern portion CC is removed so that the edge of the light guide plate 175 is inwardly and has a step difference with respect to the other surface.

11, the first pattern portion CC is opened after the thermal impact test of the reflector 172 by the contraction of the cutting line CL so that the cutting line CL is separated from the edge portion of the light guide plate 175 Which is a problem of dispersing and preventing the problem of pushing or lifting.

<Fourth Embodiment>

12 is a structural view of a reflector and a light guide plate according to a fourth embodiment, and Fig. 13 is an enlarged view showing a part of Fig.

As shown in Fig. 12, the lower surface 172a and the side surface 172b of the reflector 172 are separated by a cutting line CL. The cutting line CL includes cutting areas (CA, cutting area) and banding areas (BA, Bending area).

The cutting lines CL are located on at least two sides of the three sides of the reflector 172. The cutting line CL is formed in a straight line shape along three planes of the reflector 172. The cutting line CL includes a portion arranged in the longitudinal direction of both sides of the reflection plate 172 and a portion arranged in the direction of the one short axis of the reflection plate 172. [ The cutting line CL is formed in a straight line shape with at least two spaced apart from each other in the vicinity of the corner where the portion disposed in both the major axis direction of the reflection plate 172 and the portion disposed in the one minor axis direction of the reflection plate 172 meet.

The cutting areas CA are cut areas for separating the lower surface 172a and the side surface 172b of the reflector 172 and are arranged at least two in a straight line on three sides of the reflector 172 . The banding areas BA are bent areas for vertically folding the side surface 172b of the reflector 172 so as to be located between the cutting areas CA, that is, both corner parts in the minor axis direction of the reflector 172, As shown in Fig.

Two banding areas BA are arranged in the longitudinal direction of both sides of the reflector 172 and one in the minor axis direction. However, the number of the cutting areas CA and the bending areas BA is not limited thereto. However, it is better that the cutting areas CA and the banding areas BA are arranged in a small number.

A second pattern portion DD is formed on both sides of the reflector 172 in order to minimize a problem caused by shrinkage that may occur in the corner portion of the reflector 172. The second pattern portion DD is removed so that the long axis face of the light guide plate 175 is inwardly inward and has a step difference with respect to the other face.

As shown in FIG. 13, the second pattern portion DD is located corresponding to the region where the banding regions BA are disposed. The cutting line CL is opened due to the contraction after the thermal shock test of the reflector 172 in the second pattern unit DD as in the first pattern unit of the third embodiment, so that the cutting line CL is separated from the light guide plate 175 And serves to disperse and prevent the problem of pushing or lifting the corner portion.

On the other hand, the light guide plate 175 may have both the first pattern portion and the second pattern portion. In addition, one or more of the structures of the third and fourth embodiments may be applied to the structure of the first embodiment to solve the problems that may occur after the thermal shock test. The cutting line structure may also be provided by suitably combining the first and second embodiments.

As described above, the present invention has the effect of providing a reflector capable of minimizing the influence on light guide plates and optical sheets (wrinkles of optical sheets) due to shrinkage / relaxation due to high temperature and high humidity while minimizing light loss. In addition, the present invention has the effect of reducing the material cost and simplifying the process by eliminating the side reflecting member that is provided on the side for compensation of optical loss. Further, the present invention has an effect of providing a reflector and a light guide plate capable of reducing the influence of thermal expansion / contraction characteristics (including shrinkage / relaxation due to high temperature and high humidity).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the appended claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

160: liquid crystal panel 170: backlight unit
171: Cover bottom 177: Guide panel
176: Clear sheet 172: Reflector
CL: Cutting line CA: Cutting areas
BA: Bending areas 175: Light guide plate
CC: first pattern portion DD: second pattern portion

Claims (10)

A liquid crystal panel for displaying an image; And
And a backlight unit for providing light to the liquid crystal panel,
The backlight unit
A light guide plate,
A light source for providing light to the light guide plate,
A reflecting plate having a lower surface facing the lower surface of the light guide plate and a vertically folded side surface from the lower surface of the reflector so as to surround the periphery of the side surface of the light guide plate,
And a cover bottom for accommodating the light guide plate, the light source, and the reflection plate,
Wherein the reflection plate has a cutting line formed so as to have a vertically folded side from the lower surface. The method according to claim 1,
The cutting line
Cutting areas cut to separate the lower surface and the side surface of the reflector,
And bending regions bent to vertically fold the side surface of the reflection plate and disposed between the cut regions. 3. The method of claim 2,
The cutting line
A liquid crystal display device having a straight line and a dotted line shape or a long straight line shape. 3. The method of claim 2,
The cutting line
And a liquid crystal display device including a portion of the reflector which is cut in a dashed line and forms a straight line along both longitudinal axes of the reflector, and a portion of the reflector, which is cut in a dotted line shape, . 3. The method of claim 2,
The cutting line
Wherein the reflection plate includes a portion that is long in a linear shape along both longitudinal axes of the reflection plate and a portion that is long in a linear shape along one short axis direction of the reflection plate. 3. The method of claim 2,
The light-
And a first pattern portion disposed corresponding to a region where the banding regions are arranged,
Wherein the first pattern portion has a stepped portion removed so that a corner of the light guide plate is inwardly inward. 3. The method of claim 2,
The light-
And a second pattern portion disposed corresponding to a region where the banding regions are arranged,
And the second pattern portion is removed so that the major axis surface of the light guide plate is directed inward to have a step. A light guide plate;
A light source for providing light to the light guide plate;
A reflecting plate having a lower surface facing the lower surface of the light guide plate and a vertically folded side surface from the lower surface of the reflector so as to surround the periphery of the side surface of the light guide plate; And
And a cover bottom for accommodating the light guide plate, the light source, and the reflection plate,
Wherein the reflection plate has a cutting line formed so as to have a vertically folded side from the lower surface. 9. The method of claim 8,
The cutting line
Cutting areas cut to separate the lower surface and the side surface of the reflector,
And bending regions bent to vertically fold the sides of the reflector and disposed between the cut regions. 9. The method of claim 8,
The cutting line
A backlight unit that draws a straight line and has a dotted line shape or a long straight line shape.

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