KR20170133101A - Display Device - Google Patents

Abstract

The present invention relates to a display device. The edge part of an optical sheet constituting a backlight unit is attached and fixed to the bottom surface of a guide panel. The height of the attachment surface of the guide panel and the optical sheet is set to be lower than the reference surface of the optical sheet. So, the optical sheet is fixed in a state in which a downward tension is applied to the optical sheet. The optical sheet and its subcomponents can be firmly supported. Deformation of the optical sheet due to heat or humidity can be prevented. Moisture penetration from the outside can be prevented.

Description

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a display device having a structure capable of firmly fixing an optical sheet included in a backlight unit for a display device.

2. Description of the Related Art [0002] As an information-oriented society develops, there have been various demands for display devices for displaying images. Recently, liquid crystal displays (LCDs), plasma display panels (PDPs) Various display devices such as an OLED (Organic Light Emitting Diode Display Device) have been utilized.

Among these display devices, a liquid crystal display (LCD) has an array substrate including a thin film transistor, which is a switching element for controlling on / off each pixel region, and an array substrate including a color filter and / or a black matrix A display panel including a top substrate, a liquid crystal material layer formed therebetween, a driving unit for controlling the thin film transistor, a backlight unit (BLU) for providing light to the display panel, and the like , A pixel (PXL) electrode provided in a pixel region, and a common voltage (Vcom) electrode, and the transmittance of light is adjusted accordingly, thereby displaying an image.

In the case of such a liquid crystal display device, there is a backlight unit for providing light from the outside. Such a backlight unit may include a light source, a light guide plate, a reflection plate, an upper sheet, and the like. One or more frames or a chassis as a structure.

Such a frame or chassis includes a cover bottom which is a plate-shaped member for supporting a side surface and a rear surface of the backlight unit, a guide panel provided in relation to the cover bottom and supporting the backlight unit and the display panel, Or a guide sheet or the like is used.

On the other hand, a plurality of optical sheets for diffusing or condensing light from the light guide plate are used for the backlight unit. Such an optical sheet is disposed on the upper side of the light guide plate, but may not be adhered to the light guide plate, It needs to be supported and fixed to a part of the display support structure.

Although various schemes have been developed for fixing the optical sheet constituting the backlight unit as described above, there has been a problem in that the structure is complicated or the supporting force is not provided in a certain direction.

In addition, in the conventional structure for fixing the optical sheet to the display device in accordance with the tendency of thinning of the thickness of the display device in recent years and the narrow bezel tendency for reducing the width of the bezel portion of the display device, .

The present invention is based on this point, and proposes a structure capable of firmly supporting the optical sheet of the backlight unit even when the thickness of the display apparatus and the bezel width are small.

 In view of the foregoing, it is an object of the present invention to provide a display device including a supporting structure for firmly fixing an optical sheet of a backlight unit.

Another object of the present invention is to provide a backlight unit in which the edge portion of the optical sheet is fixed by being attached to the bottom surface of the guide panel so that the height of the attachment surface of the optical sheet and the guide panel is lower than the reference surface of the optical sheet, The present invention provides a display device capable of preventing moisture from penetrating from the outside and preventing the optical sheet from being deformed due to heat or humidity by firmly fixing the optical sheet.

It is a further object of the present invention to provide a method of manufacturing a display device in which a guide panel for supporting a display panel is formed in a vertically split manner and an edge portion of the optical sheet is fixed by an engaging portion of an upper and lower guide panel, To thereby provide a display device capable of firmly fixing the optical sheet.

Another object of the present invention is to fix the edge of the uppermost optical sheet among the plurality of optical sheets disposed on the upper side of the light guide plate of the backlight unit by attaching the edge of the uppermost optical sheet to the bottom surface of the guide panel, It is an object of the present invention to provide a display device capable of preventing defective display due to expansion of an optical sheet due to heat or moisture while maintaining firm fixation of the optical sheet.

According to an embodiment of the present invention, there is provided a display device including a display panel, a guide panel, and a backlight unit, wherein edge portions of the optical sheet included in the backlight oil are fixed to the bottom surface of the guide panel, And the optical sheet edge portion and the attachment surface of the guide panel are disposed lower than the reference surface of the optical sheet central region.

At this time, the guide panel may be configured to be separated from the upper guide panel and the lower guide panel, and the optical sheet may be attached and fixed to the engagement surface of the upper guide panel and the lower guide panel.

Further, the upper guide panel may include a protruding portion and / or a hook portion for coupling the detachable guide panel and the optical sheet, and the lower guide panel may include a receiving groove and / or a hook groove corresponding thereto, May be inserted into the mounting slot.

The optical sheet includes one or more lower optical sheets and an uppermost optical sheet disposed on the lower optical sheet, wherein only the edges of the uppermost optical sheet can be attached and fixed to the bottom surface of the guide panel, And may be made of a material having a lower coefficient of thermal expansion than that of the lower optical sheet material or having low moisture absorption properties.

According to the embodiment of the present invention, there is an effect that the optical sheet of the backlight unit can be firmly fixed to the supporting structure of the display device.

The edge of the optical sheet constituting the backlight unit is attached and fixed to the bottom surface of the guide panel so that the height of the attachment surface of the optical sheet and the guide panel is lower than the reference surface of the optical sheet, The optical sheet and its subcomponents can be firmly supported, deformation of the optical sheet due to heat or humidity is prevented, and moisture penetration from the outside can be prevented.

By forming the guide panel for supporting the display panel in a vertically and horizontally split manner and fixing the edge portions of the optical sheet with the engaging portions of the up and down guide panels while the positions of the attaching surfaces of the up and down guide panels are made lower than the reference surface of the optical sheet, The optical sheet can be firmly fixed to the supporting structure of the display device in a state where the tension is applied.

Further, the edge portion of the uppermost optical sheet among the plurality of optical sheets disposed on the upper side of the light guide plate of the backlight unit is attached and fixed to the bottom surface of the guide panel. By constituting the uppermost optical sheet with a low expansion material or a low moisture absorbing material, There is an effect that it is possible to prevent defective display due to expansion of the optical sheet due to heat or moisture while maintaining firm fixation of the optical sheet.

1 is a cross-sectional view of a general form of a liquid crystal display device to which the present invention can be applied.
Fig. 2 shows an embodiment of the structure for fixing the optical sheet.
FIG. 3A is a side sectional view of the display device using the optical sheet fixing method according to FIG. 2, and FIG. 3B is a partial plan view.
FIG. 4 is a cross-sectional view of a display device using an optical sheet fixing method according to an embodiment. FIG. 4A shows a state before the optical sheet is fixed, and FIG. 4B shows a state after the optical sheet is fixed.
FIG. 5A is a plan view of a top optical sheet having a mounting slot formed therein according to one embodiment, and FIG. 5B shows an upper guide panel having protrusions inserted into mounting slots of the top optical sheet.
6 is a plan view of the uppermost optical sheet according to another embodiment, showing a structure in which mounting slots are formed intermittently along one side of the uppermost optical sheet.
7 shows a coupling structure of a hook type which is an example of a coupling structure of the upper guide panel and the lower guide panel.
8 is a diagram illustrating various effects when the optical sheet fixing system according to the present embodiment is applied.
Fig. 9 shows an optical sheet fixing method according to another embodiment of the present invention. Fig. 9A shows a state before the optical sheet is fixed, and Fig. 9B shows a state after the optical sheet is fixed.
Fig. 10 shows an optical sheet fixing method according to another embodiment of the present invention. Fig. 10a shows a state before the optical sheet is fixed, and Fig. 10b shows a state after the optical sheet is fixed.
Fig. 11 is a detailed configuration diagram of an optical sheet used in this embodiment, and shows one example of a lower optical sheet and an uppermost optical sheet disposed thereon.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

1 shows a side sectional view of a liquid crystal display device having a general structure to which the present invention can be applied.

1, the display device to which the present invention can be applied includes a display panel 140 such as a liquid crystal display panel and a backlight unit 120 disposed below the display panel 140 to irradiate light to the display panel. The backlight unit 120 And a cover bottom or plate bottom 110 of a metal or plastic material that extends across the entire rear surface of the display device.

In addition, a guide panel 140 of a plastic material, which is fixed to the plate bottom 110 and connects the backlight unit 120 and the display panel 140, may be additionally provided. A double-sided tape (not shown) is attached to a part of the upper surface of the horizontally extending portion of the guide panel 130, and the display panel 140 is disposed on the double-sided tape.

The display device may further include a case top 150 that covers the side surface of the plate bottom 110 disposed at the outermost portion and extends to a part of the front surface of the display panel to protect the front edge of the display panel .

The case top 150 may be disposed on the rear side of the plate bottom 110 to cover the side surface of the plate bottom 110 to extend to a front part of the front side of the display panel 140, On-film (COF) circuit unit, which is a connection circuit for connecting a printed circuit board (not shown) to a display panel.

In the case of a liquid crystal display panel, the display panel 140 includes a plurality of gate lines, a data line, a pixel defined in the intersecting region, and a thin film transistor serving as a switching element for adjusting light transmittance in each pixel An upper substrate provided with a color filter and / or a black matrix, and a liquid crystal material layer formed therebetween.

The display panel to which the present invention can be applied is not limited to such a liquid crystal display panel but may be a display panel such as a plasma display or the like, . ≪ / RTI >

Meanwhile, a backlight unit 120 used in a liquid crystal display device to which an embodiment of the present invention can be applied includes a light source module (not shown) including a light source such as an LED, a holder for fixing a light source, A light guide plate 122 or a diffusion plate for diffusing light to the entire panel area, a reflection plate 124 for reflecting light in the direction of the display panel, and an LED flexible And a sub-unit such as one or more optical sheets 126 disposed on the upper side of the light guide plate and arranged for improving brightness, diffusing and protecting light, and the like.

The optical sheet 126 of the backlight unit 120 may be disposed on the light guide plate 122 and may not be bonded to the light guide plate 122.

Even if the optical sheet 126 is adhered to the upper surface of the light guide plate 122, an external impact may be applied in a process of transporting or testing for mounting the display device on a set device, which is a final electronic product such as a notebook computer or a TV. The position of the seat 126 can be changed.

Since the optical sheet 126 functions to condense and diffuse the light from the light guide plate as will be described later, when the position of the optical sheet is changed, the display image may be deteriorated.

Therefore, it is necessary to prevent the change of the position of the optical sheet by fixing the optical sheet to the remaining fixed support structure of the display device, in addition to simply placing the optical sheet on top of the light guide plate.

Various types of optical sheet structures have been proposed for this purpose, and FIG. 2 shows an example of the optical sheet structure.

Fig. 2 shows an embodiment of a structure for fixing an optical sheet, Fig. 3a is a side sectional view of a display device using an optical sheet fixing method according to Fig. 2, and Fig. 3b is a partial plan view.

2 and 3, the optical sheet 226 has a rectangular protruding portion 227 protruding outward at a portion of an edge thereof, and the rectangular protrusion 227 of the optical sheet is provided on the guide panel 230, A seating groove 232 is formed for receiving the seating groove.

According to this structure, the rectangular projecting portion 227 of the optical sheet 226 is placed in the seating groove 232 of the guide panel 232, and a foam pad 272, which is a kind of one-sided adhesive tape, Thereby fixing the sheet to the guide panel.

At this time, as shown in Fig. 2B, the fixation of the optical sheet is performed at two or three positions on one side of the panel.

2 and 3, the upper surface of the rectangular projecting portion 227 of the optical sheet is adhered to the bonding surface of the lower surface of the foam pad 270, which has the following disadvantages.

The first disadvantage arises in the process of transporting or testing the display device, even though the oblong protrusion 227 of the optical sheet is adhered to the lower surface of the foam pad 270, The adhesion to the foam pad may be deteriorated, and the optical sheet in which the contact with the foam pad is released may flow in the X direction in FIG.

The second disadvantage arises from the use of the display device. When the display device is used, the light from the light source of the backlight unit is transmitted to the light guide plate, the optical sheet, and the like, whereby the light guide plate and the optical sheet are repeatedly expanded and contracted by heat . However, in the structure shown in Figs. 2 and 3, since the optical sheet is adhered and fixed to the foam pad and the guide panel, when thermal deformation in the X direction occurs during the use of the display device, such thermal deformation can not be accommodated, There is a possibility that the optical sheet may be distorted due to the optical sheet.

A third disadvantage is a problem with the thin and narrow bezel tendencies of the display device.

The size of the edge region of the display device has been reduced in accordance with the thinning tendency in which the thickness T of the display device has recently become thin and the narrow bezel tendency in order to reduce the width of the bezel portion of the display device.

Therefore, in the conventional structure for fixing the optical sheet to the display device as shown in FIGS. 2 and 3, when the width Wb of the bezel, which is the edge area of the panel, is reduced, it is difficult to design the protrusion of the optical sheet, And as a result, the fixing force of the optical sheet decreases.

Therefore, there is a possibility that the optical sheet and the lower part thereof may flow due to the external impact. In this process, there is a high possibility that defects such as wrinkles and shattering of the optical sheet occur due to friction between the parts.

In addition, the fixation force of the optical sheet is weakened due to the reduction of the fixed area, and the possibility of deformation of the optical sheet due to heat and humidity becomes larger.

As shown in FIG. 3B, a gap g is formed between the protrusion 227 of the optical sheet and the seating groove 232 of the guide panel 230 in terms of design, and moisture or foreign matter There is a possibility that the light may leak into the display device, and light leakage may occur due to light leakage through the gap.

The present invention has been proposed in order to solve the drawbacks of the optical sheet fixing method according to Figs. 2 and 3, wherein the edge of the uppermost optical sheet of the optical sheet is directly attached to the guide panel, The attachment surface of the sheet and the guide panel is made lower than the reference surface of the uppermost optical sheet.

Hereinafter, a display device including an optical sheet fixing structure according to various embodiments of the present invention will be described with reference to FIGS. 4 to 11. FIG.

FIG. 4 is a cross-sectional view of a display device using an optical sheet fixing method according to an embodiment. FIG. 4A shows a state before the optical sheet is fixed, and FIG. 4B shows a state after the optical sheet is fixed.

The display device according to the present embodiment includes a display panel 440, a guide panel 430 for supporting the bottom edge of the display panel, a backlight unit including the optical sheets 426 and 426 ' Wherein the edge of the uppermost optical sheet 426 'of the optical sheet is attached and fixed to the bottom surface of the guide panel, and the edge of the uppermost optical sheet 426' And the height H2 is lower than the height H1 of the reference plane S1 which is the remaining surface of the uppermost optical sheet.

Thus, as shown in FIG. 4B, the uppermost optical sheet 426 'can be fixed with the tension Ft, which is the force directed to the lower portion of the display device, thereby enabling firm fixing or support of the optical sheet and its lower parts .

Further, since the edge portion of the optical sheet is entirely fixed to the guide panel, the fixation force of the optical sheet is improved as compared with a method in which only a partial region is fixed as shown in Figs. 2 and 3, and furthermore, the optical sheet can be firmly fixed even in a low- It becomes.

The backlight unit includes a light source (not shown), a light guide plate 422 for transmitting light from the light source, and a reflection plate 424 disposed under the light guide plate. The optical sheet is provided on the light guide plate 422 with two Or more.

At this time, the two or more optical sheets may include one or more lower optical sheets disposed on the light guide plate and the uppermost optical sheet disposed on the upper optical sheet.

In this embodiment, at least two optical sheets may be fixed to the guide panel with the above structure, but only the edge portions of the uppermost optical sheet may be attached and fixed to the bottom surface of the guide panel with the structure described above.

4 shows a first embodiment of the present invention in which a guide panel 430 is divided into an upper guide panel 432 and a lower guide panel 434, And is attached and fixed to the coupling surface of the panel.

4, the upper guide panel 432 is provided with a protrusion 433 arranged in the longitudinal direction and the lower guide panel 434 is provided with a receiving groove 435 in which the protrusion is received and engaged And a mounting slot 427 into which the protrusion 433 of the upper guide panel is inserted is formed at the edge of the uppermost optical sheet 426 '.

Further, the height h of the upper surface of the lower guide panel is formed to be lower than the height h 'of the upper surface of the lower optical sheet 426.

4A, a part of the backlight unit constituted by the reflection plate 424, the light guide plate 422 and the lower optical sheet 426 is disposed on the inner surface of the cover bottom 410 and the mounting slot 427 'of the uppermost optical sheet 426' The protruding portion 433 of the upper guide panel 432 is press-fitted into the receiving groove 435 of the lower guide panel 434. As a result, the protruding portion 433 of the upper guide panel 432 is inserted into the receiving groove 435 of the lower guide panel 434.

Therefore, the edge portion of the uppermost optical sheet 426 'is fixed at the engagement surface of the upper guide panel 432 and the lower guide panel 434, and the height H2 of the edge portion of the uppermost optical sheet and the attachment surface of the guide panel Is fixed to be lower than the height H1 of the reference plane S1 which is the center area surface of the uppermost optical sheet 426 '.

As a result, as shown in FIG. 4B, the edge portion of the uppermost optical sheet 426 'is fixed in a state in which the downward force Ft is applied.

In addition, according to the embodiment of FIG. 4, the edge portion of the uppermost optical sheet 426 'is firmly fixed to the guide panel as a whole.

Thus, even if the width of the bezel is reduced, not only the optical sheet constituting the backlight unit can be firmly fixed, but also the uppermost optical sheet is fixed in a state in which the lower tension is applied so that the flow of the lower component including the light guide plate and the lower optical sheet is also prevented .

FIG. 5A is a plan view of a top optical sheet having a mounting slot formed therein according to one embodiment, and FIG. 5B shows a top guide panel having protrusions inserted into mounting slots of the top optical sheet.

FIG. 6 is a plan view of the uppermost optical sheet according to another embodiment, in which the mounting slots are formed intermittently along one side of the uppermost optical sheet, and FIG. 7 is an example of a combined structure of the upper guide panel and the lower guide panel Hook type coupling structure.

5A, mounting slots 427 may be formed on all three sides of the four sides constituting the edges of the uppermost optical sheet 426 ', except for the side where the light source portion of the backlight unit is disposed.

5B, the protruding portions 433 of the upper guide panel 432 are also disposed to protrude in the longitudinal direction on three sides of the upper guide panel to correspond to the positions where the mounting slots are formed as shown in FIG. 5A.

Of course, as shown in FIG. 6, the mounting slots 427 and 427 'may not be formed on one side of the uppermost optical sheet 426', but may be intermittently provided on one side of the uppermost optical sheet 426 ' . In this case, at least two projections of the upper guide panel should be formed on one side.

Further, as shown in Fig. 7, The protruding portion 433 of the upper guide panel includes a hook portion 433 'and the receiving groove 435 of the lower guide panel 434 may have a hook groove 435' into which the hook portion is inserted.

As described above, by joining the upper guide panel and the lower guide panel in a hook structure, the coupling force of the guide panel can be increased, and convenience in assembly can be provided.

It is easy to fix the edge portion of the uppermost optical sheet to the guide panel by forming a mounting slot in the edge portion of the uppermost optical sheet, There is an effect that the assembling process is simplified.

11, the optical sheet includes at least one lower optical sheet and an uppermost optical sheet disposed on the lower optical sheet, wherein only the edge portions of the uppermost optical sheet are attached to the bottom surface of the guide panel Thus, there is an advantage that it is sufficient to change only the structure of the uppermost optical sheet without changing the structure of the lower optical sheet among the plurality of optical sheets.

Further, the lower optical sheet is protected to some extent from the influence of heat or external moisture by the uppermost optical sheet, thereby making it possible to widen the material selection of the lower optical sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed configuration of components constituting a display device according to an embodiment of the present invention will be described below.

The light source unit of the backlight unit may include a light source device and a light source holder having a long plate-like structure that supports the light source device and includes an LED driving circuit for driving the light source, and the light source device of the light source module includes a light emitting diode A light emitting diode (LED) or a light emitting diode strip may be used, but the present invention is not limited thereto, and any type of light source may be used as long as it can provide light necessary for a display panel.

The light guide plate (LGP) 422 can be generally formed of a rectangular clear plastic sheet die-cut, extruded or injection-molded from a plastic sheet, and light from a light source such as a light- And is diffused across the back surface of the display panel while being totally reflected inside the light guide plate. Light emitted through the flat upper surface of the light guide plate functions as a backlight of the display panel.

As the material of the light guide plate 422, a material such as polymethyl methacrylate (PMMA), MS (methystyrene) resin, polystyrene (PS), polypropylene (PP), polyethylene terephthalate : PET) and polycarbonate (PC), but the present invention is not limited thereto

The reflection plate 424 is positioned on the back surface of the light guide plate 422 and reflects light passing through the back surface of the light guide plate toward the display panel 440 to improve the brightness of light.

The optical sheets 426 and 426 'disposed on the upper side of the light guide plate 422 include a light collecting sheet or a prism sheet PS having a light collecting function, a diffusing sheet DS for diffusing light, and a reflection type polarizing film for brightness enhancement called dual brightness enhancement film, and it is possible to diffuse or condense light passing through the light guide plate to obtain a more uniform surface light source So that they can join.

At this time, the edge portion of the uppermost optical sheet 426 'of the optical sheets used in the embodiment of the present invention is attached to the bottom surface of the guide panel. In particular, in the embodiment of FIG. 4, A mounting slot 427 may be formed.

In general, among the functional individual sheets constituting the optical sheets 426 and 426 ', the light converging sheet PS includes a light-converging pattern or the like on the sheet in the form of a transparent film, so that a light converging function for collecting the incident light in a certain direction do.

On the other hand, a diffusing sheet (DS) for diffusing light is an optical sheet that functions to diffuse incident light in various directions. The diffusing sheet DS may include a transparent diffusion sheet, have.

In addition, the reflection type polarizing film is an optical film that transmits only light that vibrates in one direction among natural incident lights while vibrating in various directions, and reflects light that vibrates in the other direction, and has a luminance enhancement called DBEF (dual brightness enhancement film Film.

The cover bottom 410 constitutes the rear and side view and support portions of the display device according to the present embodiment, and is a metal or plastic frame structure that is bent in a L-shaped form as a whole.

A lower surface of the lower guide panel 434 is seated on the inner surface of the cover bottom 410, and a double-sided tape or the like is disposed therebetween to join the guide panel and the cover bottom.

The guide panel 430 according to the present embodiment is a plastic or metal frame structure and is coupled to the inner surface of the side wall of the cover bottom 410. An edge of the display panel 440 is seated on the upper surface of the guide panel, do.

The guide panel 430 may be a detachable structure including two upper guide panels 432 and a lower guide panel 434 coupled to the projecting portion in a receiving groove or a hook structure as in the embodiment of FIG. 4, It is not.

For example, as shown in FIG. 9, the guide panel may be a detachable structure in which the bottom surface of the upper guide panel 532 and the upper surface of the lower guide panel 534 are coupled by an adhesive pad or the like without protrusions or receiving grooves, But may be a single non-removable guide panel 630 as shown in FIG.

In the present specification, the cover bottom 410 is not limited to the term, but may be a plate bottom, a base frame, a metal frame, a metal chassis, a chassis base Chassis base, m-chassis, etc., and it should be understood as a concept including all frame or plate-like structures disposed at the base of the display device as a support for fixing at least one of the display panel and the backlight unit something to do.

In addition, the guide panel 430 in this specification may be replaced with other representations such as a plastic chassis, a p-chassis, a support main, a main support, a mold frame, and a rectangular frame- As well as any type of plastic member that is connected to the cover bottom 410 to be used to support the optical sheet, display panel, etc. of the backlight unit.

The guide panel 600 may be made of a synthetic resin material such as polycarbonate, and may be manufactured through an injection molding method, but is not limited thereto.

In addition, although not shown, a case top may be further formed to extend from the side of the cover bottom to a part of the front surface of the display panel to protect a part of the front surface of the display panel.

In the case where the display panel 440 used in the display device according to the present embodiment is a liquid crystal display panel, a pixel defined in a plurality of gate lines, a data line and a crossing region thereof, and a light- An upper substrate provided with a color filter and / or a black matrix, and a liquid crystal material layer formed therebetween.

The term "display device" is used herein to refer to a display device such as a liquid crystal module (LCM) including a display panel and a driver for driving the display panel, as well as a notebook computer , A set of electronic devices or set devices such as a television, a computer monitor, a mobile electronic device such as a smart phone or an electronic pad, and the like.

That is, the display device in this specification is used to mean not only a conferring display device such as LCM but also a set device which is an application including the display device.

Figure 8 Are diagrams illustrating various effects when the optical sheet fixing system according to the present embodiment is applied.

8, according to the present embodiment, the edge portion of the uppermost optical sheet 426 'of the optical sheets constituting the backlight unit is attached and fixed to the bottom surface of the guide panel, and the edge portions of the uppermost optical sheet 426' The height of the surface is made lower than the height of the reference surface of the central region of the uppermost optical sheet, so that the uppermost optical sheet is fixedly coupled with the lower tension applied.

As a result, the optical sheet and the lower part thereof can be firmly fixed or supported, and the components such as the light guide plate and the lower optical sheet disposed under the uppermost optical sheet are prevented from flowing.

Further, since the edge portion of the optical sheet is entirely fixed to the guide panel, the fixation force of the optical sheet is improved as compared with a method in which only a partial region is fixed as shown in Figs. 2 and 3, and furthermore, the optical sheet can be firmly fixed even in a low- It becomes.

Further, since the edge portion of the uppermost optical sheet is entirely assembled in the guide panel without gaps, moisture or foreign matter penetration through a gap between the protruding portion (ear portion) of the optical sheet and the guide panel, It is also possible to prevent defects caused by the gap or light leakage through the gap.

 Fig. 9 shows an optical sheet fixing method according to another embodiment of the present invention. Fig. 9A shows a state before the optical sheet is fixed, and Fig. 9B shows a state after the optical sheet is fixed.

In the above-described embodiment, the case where the guide panel for fixing the edge portion of the uppermost optical sheet is composed of the upper guide panel and the lower guide panel which are coupled with the press-in or hook structure is exemplified.

9, the bottom surface of the upper guide panel 532 and the upper surface of the lower guide panel 534 may be coupled by an adhesive pad or the like without protrusions or receiving grooves.

9, the guide panel is constituted by an upper guide panel 532 of a frame structure having a flat bottom surface and a lower guide panel 534 having a flat upper surface, and the lower guide panel 534 of the uppermost optical sheet 526 ' No mounting slot is formed in the edge portion, and the edge portion can be attached between the mating surfaces of the upper and lower guide panels by double-sided tape or adhesive.

9A, a first adhesive member 550 such as a double-sided tape is attached to the bottom surface of the upper guide panel 532 and the edge portion of the uppermost optical sheet 526 'is bonded to the other surface of the adhesive member.

Meanwhile, a bottom surface and a side surface of the lower guide panel 534 are fixed to the inner surface of the cover bottom, and a second adhesive member 550 'such as a double-sided tape is attached to the upper surface of the lower guide panel 534.

Of course, the height of the upper surface of the lower guide panel 534 is set lower than the height of the backlight unit to the lower optical sheet. That is, the height of S2, which is the joining face of the upper guide panel 532 and the lower guide panel 534 and the attachment face of the edge portion of the uppermost optical sheet and the guide panel, is lower than the height of the reference face S2 of the central region of the uppermost optical sheet.

In this state, when the upper guide panel 532 and the lower guide panel 534 are adhered to each other, the edge portion of the uppermost optical sheet is already fixed to the bottom surface of the upper guide panel by the first adhesive member, Since the height of the mounting surface S2 of the guide panel is lower than the height of the reference surface S2 of the central area of the uppermost optical sheet, the uppermost optical sheet 526 'is fixed while receiving the downward tension as shown in FIG.

Therefore, it is possible to obtain the same effect as the first embodiment described with reference to FIG.

Fig. 10 shows an optical sheet fixing method according to another embodiment of the present invention. Fig. 10a shows a state before the optical sheet is fixed, and Fig. 10b shows a state after the optical sheet is fixed.

Unlike the previous embodiment, in the embodiment of FIG. 10, a single non-detachable guide panel 630 is used instead of the detachable guide panel.

That is, a first adhesive member 550 such as a double-sided tape is attached to the bottom surface of the single non-detachable guide panel 630 and the edge portion of the uppermost optical sheet 626 'is bonded to the other surface of the adhesive member.

On the other hand, a second bonding member 550 'such as a double-sided tape is also attached to the inner surface of the cover bottom 410.

When the non-detachable guide panel 630 is engaged with the cover bottom in this state, the edge portion of the uppermost optical sheet is already fixed to the bottom surface of the non-detachable guide panel 630 by the first adhesive member, And the mounting surface S2 of the non-detachable guide panel 630 substantially coincide with the upper surface of the cover bottom, the uppermost optical sheet 626 'is fixed while receiving the downward tension as shown in FIG. 10B.

Therefore, it is possible to obtain the same effect as the first embodiment described with reference to FIG.

Fig. 11 is a detailed configuration diagram of an optical sheet used in this embodiment, and shows one example of a lower optical sheet and an uppermost optical sheet disposed thereon.

As shown in Fig. 11, the optical sheet used in this embodiment may be a multiple optical sheet combination including at least one lower optical sheet disposed on the light guide plate and a top optical sheet disposed on the lower optical sheet.

11 shows an example of an optical sheet combination according to the present embodiment, in which a diffusion sheet DS, a light condensing sheet PS, a reflection type polarizing film (DBEF) for improving brightness or a light condensing sheet PS are arranged on a light guide plate Fig.

At this time, the reflective polarizing film DBEF or the light collecting sheet PS disposed at the uppermost position becomes the uppermost optical sheet 426 ', and the diffusing sheet DS and the light collecting sheet PS disposed at the lower portion thereof become the lower And can be expressed as an optical sheet 426.

In this case, only the edge portion of the uppermost optical sheet 426 'is attached and fixed to the guide panel, and the lower optical sheet 426 may not be attached to the guide panel.

Of course, the edges of all of the two or more optical sheets including the topmost optical sheet may be fixedly attached to the guide panel.

As described above, if only the edge portion of the uppermost optical sheet 426 'is attached and fixed to the guide panel, it is sufficient to change only the structure of the uppermost optical sheet without changing the structure of the lower optical sheet among the plurality of optical sheets There is also an advantage that the lower optical sheet is partially protected from the influence of heat or external moisture by the uppermost optical sheet, thereby widening the material selection of the lower optical sheet.

In addition, it is preferable that only the edge portion of the uppermost optical sheet 426 'is attached and fixed to the guide panel, and the material constituting the uppermost optical sheet has a lower thermal expansion coefficient than that of the material constituting the lower optical sheet, The constituent material can have a lower moisture absorption characteristic than that of the material constituting the lower optical sheet.

Examples of the material of the optical sheet include polymethyl methacrylate (PMMA), MS (methystyrene) resin, polystyrene (PS), polypropylene (PP), polyethylene terephthalate (PET) and polycarbonate (PC) can be used. Among these materials, the uppermost optical sheet 426 'is made of a material having a low thermal expansion property or hygroscopic expansion property (hygroscopic property) And the remaining lower optical sheet can be produced from a material having a hygroscopic expansion characteristic (hygroscopic property).

 Since only the uppermost optical sheet 426 'is exposed to the outside of the backlight unit and covers and protects the components disposed therebelow, the uppermost optical sheet has lower thermal expansion characteristics or hygroscopic expansion characteristics (moisture absorption characteristics) It is possible to minimize the deformation of the uppermost optical sheet due to wrinkles, swelling, shattering, etc., even if humidity and heat are applied from the outside, and it is possible to protect the parts arranged below from the external environment.

As described above, according to the embodiment of the present invention, the edge portion of the optical sheet constituting the backlight unit is attached and fixed to the bottom surface of the guide panel, and the height of the attachment surface of the optical sheet and the guide panel is lower than the reference surface of the optical sheet The optical sheet and its subcomponents can be firmly supported, the deformation of the optical sheet due to heat or humidity can be prevented, and the moisture penetration from the outside can be prevented There is an effect that can be prevented.

By forming the guide panel for supporting the display panel in a vertically and horizontally split manner and fixing the edge portions of the optical sheet with the engaging portions of the up and down guide panels while the positions of the attaching surfaces of the up and down guide panels are made lower than the reference surface of the optical sheet, The optical sheet can be firmly fixed to the supporting structure of the display device in a state where the tension is applied.

Further, the edge portion of the uppermost optical sheet among the plurality of optical sheets disposed on the upper side of the light guide plate of the backlight unit is attached and fixed to the bottom surface of the guide panel. By constituting the uppermost optical sheet with a low expansion material or a low moisture absorbing material, There is an effect that it is possible to prevent defective display due to expansion of the optical sheet due to heat or moisture while maintaining firm fixation of the optical sheet.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

410: cover bottom 430, 630: guide panel
432, 532: upper guide panel 434, 534: lower guide panel
422: light guide plate 424: reflector
433: protrusion 435: receiving groove
440: Display panel
426 ', 526', 626 ': (uppermost) optical sheet
550, 550 ': first half bonding member

Claims (7)

Display panel;
A guide panel for supporting the display panel;
A backlight unit comprising: a light source; a light guide plate for transmitting light from the light source; and at least one optical sheet disposed on the light guide plate, wherein an edge of the optical sheet is attached and fixed to a bottom surface of the guide panel, And a mounting surface of the guide panel is disposed lower than a reference plane of the optical sheet central region;
A cover bottom supporting the guide panel and the backlight unit;
. The method according to claim 1,
Wherein the guide panel includes an upper guide panel and a lower guide panel, and the optical sheet is attached and fixed to a mating surface of the upper guide panel and the lower guide panel. 3. The method of claim 2,
The upper guide panel is provided with protrusions arranged in the longitudinal direction, and the lower guide panel is provided with receiving recesses in which the protrusions are received and engaged,
Wherein a mounting slot in which a protrusion of the upper guide panel is inserted is provided at an edge of the optical sheet. The method of claim 3,
Wherein a projecting portion of the upper guide panel includes a hook portion and a hook groove into which the hook portion is inserted is disposed in a receiving groove of the lower guide panel. The method according to claim 1,
Wherein the optical sheet includes at least one lower optical sheet and an uppermost optical sheet disposed on the lower optical sheet,
Only the edge portion of the uppermost optical sheet is attached and fixed to the bottom surface of the guide panel. 6. The method of claim 5,
Wherein the material constituting the uppermost optical sheet is lower in thermal expansion coefficient than the material constituting the lower optical sheet. 6. The method of claim 5,
Wherein the material constituting the uppermost optical sheet has lower moisture absorption characteristics than the material constituting the lower optical sheet.

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