KR20180016684A - Display Device - Google Patents

Abstract

The present invention relates to a display device, capable of minimizing a ratio of light toward a display region of a display panel among light leaked to a lateral side of a light guide plate by forming a downward inclined reflection part in a part facing the lateral side of the light guide plate among the regions of a guide panel which is a support structure supporting a lateral side of a backlight unit and arranging a light absorption member on a lower side thereof, and consequently suppressing a display failure due to a light leakage phenomenon on the edge of the display device.

Description

[0001]

The present invention relates to a display device, and more particularly to a display device including a support structure capable of preventing light leakage from 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.

In a display device using such a backlight unit, light is leaked through a space between the backlight unit and the guide panel, which is a supporting structure for supporting the side surface of the backlight unit. As a result, There is a possibility of occurrence.

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.

Particularly, according to 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 display area of the display device (active area) As the area expands, the possibility of such light leakage is increasing.

Accordingly, the present invention is directed to this point, and proposes a method of changing the structure of the guide panel, which is the support structure of the display device, in order to suppress the edge light leakage phenomenon of the display device.

 In view of the foregoing, it is an object of the present invention to provide a display device capable of preventing edge light leakage phenomenon of a display device.

It is another object of the present invention to provide a display device in which a downward inclined surface is formed in a side supporting structure and a reflective layer is disposed on the inclined surface to reflect light emitted to the side of the light guide plate toward the rear of the display device, And to provide a display device capable of performing the display.

Another object of the present invention is to provide a light guiding plate which is formed by forming a downward inclined reflecting portion in a portion of a guide panel which is a supporting structure for supporting a side surface of a backlight unit and facing a side surface of a light guide plate, And a display device capable of suppressing light leakage phenomenon.

According to an embodiment of the present invention, there is provided a display device including a display panel, a guide panel, a cover bottom, and a backlight unit, wherein the guide panel includes a horizontal extension portion for supporting the rear edge of the display panel, And a downwardly inclined reflector on the inner surface of the vertical extension portion facing the side surface of the light guide plate, the vertically extending portion supporting the side surface of the backlight unit.

At this time, the downwardly inclined reflecting portion includes a vertically extending portion inclined surface disposed so as to have a first inclination angle &thetas; with the thickness direction of the display device and a reflective layer disposed on the inclined surface.

The first inclination angle? Of the downward inclination reflector may be determined based on the total reflection critical angle? 1 of the light guide plate. For example, the first inclination angle of the vertically extending surface may be inversely proportional to the total reflection critical angle of the light guide plate.

In addition, a light absorbing member having light absorbing characteristics may be disposed in a projection area on the inner surface of the cover bottom where the downwardly inclined reflecting part is projected.

At this time, an adhesive member for fixing the guide panel to the cover bottom is disposed between the bottom surface of the vertically extending portion of the guide panel and the cover bottom, and the adhesive member can be extended to the projection area on the cover bottom to constitute the light absorbing member .

More specifically, the downwardly inclined reflector may include a vertically extending portion inclined surface disposed between the upper horizontal extending portion and the lower horizontal extending portion so as to have a first inclination angle with the thickness direction of the display device, and a reflective layer disposed on the inclined surface A vertical extending portion inner surface extending in the thickness direction of the display device between the upper horizontal extending portion and the lower horizontal extending portion, and a separate reflecting member contacting the inner surface of the vertically extending portion and having a downward inclined reflecting surface .

In addition, at least one or more optical seat fixing recesses may be disposed in the vertical extension portion of the guide panel.

According to an embodiment of the present invention, a downward inclined surface is formed in the side support structure of the display device, a reflective layer is disposed on the inclined surface, and light reflected toward the side of the light guide plate is reflected to the back of the display device, The phenomenon can be prevented.

In addition, by forming a downward inclined reflector in a portion of the guide panel, which is a supporting structure for supporting the side surface of the backlight unit, facing the side surface of the light guide plate, light reflected toward the side of the light guide plate is reflected in a direction opposite to the display panel, .

FIG. 1 is a cross-sectional view of a liquid crystal display device of a general type to which the present invention can be applied. FIG. 1 (a) is a cross-sectional view of a light-incoming portion where a light source is disposed, and FIG.
Fig. 2 shows an embodiment of a structure for fixing the optical sheet to the guide panel in the display device as shown in Fig.
FIG. 3 shows the principle of light leakage occurring in the edge region of the display device as shown in FIG.
4 shows a cross section of a display device according to an embodiment of the present invention.
5A is a perspective view of a guide panel used in an embodiment of the present invention, and Figs. 5B and 5C are sectional views.
6 is a view for explaining an optical path on the side of the light guide plate and a light leakage preventing effect when the guide panel according to the present embodiment is used.
FIGS. 7A and 7B are views illustrating the relationship between the position of the downwardly inclined reflector and the magnitude of the first inclination angle of the guide panel according to the present embodiment.
8A to 8D show the shape of a guide panel according to another embodiment of the present invention.
FIGS. 9A and 9B show test results of measuring the amount of light shielding in a display device according to an embodiment of the present invention and a general display device as shown in FIG.

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.

FIG. 1 is a cross-sectional view of a liquid crystal display device of a general type to which the present invention can be applied. FIG. 1 (a) is a cross-sectional view of a light-incoming portion where a light source is disposed, and FIG.

1, a display device to which an embodiment of 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, And a cover bottom 110 made of a metal or plastic material that extends over the entire rear surface of the display device.

The liquid crystal display device further includes a guide panel 130 for supporting the light source housing 127 constituting the backlight unit at the side while supporting the display panel 140 at an upper portion thereof, A case top 150 which is enclosed and extends to a part of the front surface of the display panel, and the like.

In such a liquid crystal display device, a backlight unit for providing light to the display panel is included, and the backlight unit is classified into an edge-type or a direct-type according to the arrangement of light sources and the transmission mode of light .

1A, the edge type backlight unit 120 includes a light source module 127 including a light source 128 such as an LED, a holder or a housing for fixing the light source, and a light source driving circuit, A light guide plate 122 (light guide plate) for diffusing light to the entire panel area, a reflection plate 124 for reflecting light in the direction of the display panel, and a reflection plate 124 disposed above the light guide plate to improve brightness, And one or more optical sheets 126 arranged for use such as protection and the like

In this edge type backlight unit, light from the light source is incident on the light guide plate entrance portion, and is totally reflected by the light guide plate and spreads toward the display panel in the direction of the display panel.

1B, a guide panel 140 made of a plastic material, which is fixed to the cover bottom 110 and connects the backlight unit 120 and the display panel 140, is additionally provided on the non- As shown in FIG. 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 the structure for fixing the optical sheet.

2, the optical sheet 226 has a rectangular protruding portion 227 protruding outward at a portion of an edge of the optical sheet 226, and a rectangular protrusion 227 of the optical sheet is accommodated in the guide panel 230 A seating groove 232 is formed.

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 230, 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.

As described above, in a general display device, light is totally reflected and propagated inside the light guide plate 122 constituting the backlight unit, and light travels outside the side surface of the light guide plate.

1, the side surface of the guide panel 130 is disposed immediately outside the side surface of the light guide plate 122. Generally, the guide panel 130 is formed of plastic or metal, Light traveling outside the side surface of the light guide plate may be reflected by the side surface of the guide panel and some of the light may travel toward the display area of the display panel 140. Light leakage may occur at the edge of the display device due to such light.

FIG. 3A shows a principle of generating a light leakage phenomenon in an edge region of the display device as shown in FIG. 1, and FIG. 3B shows a light leakage enhancement problem in a narrow bezel structure.

3A, in the case of a general display device, the guide panel 230 includes a vertical extension portion 234 extending along the thickness direction of the display device, and a vertical extension portion 234 extending from the vertical extension portion 234 in the horizontal direction And includes a horizontally extending portion 236 extending therefrom.

An outer surface of the vertical extension portion 234 of the guide panel is in contact with the cover bottom 110 and a seating groove for fixing the optical sheet 126 of the backlight unit is formed in a part of the horizontal extension portion 236 And the display panel 140 is seated on the horizontal extending portion 236.

Since the guide panel 230 is formed of a metal or a reinforced plastic material, the vertical extension inner surface 234 'of the vertical extension portion 234 of the guide panel facing the side surface 122' of the light guide plate 122 It is forced to have a reflection characteristic of a certain degree or more.

Therefore, in this general display apparatus, the light L totally reflected by the light guide plate 122 and traveling to the outside through the side surface 122 'of the light guide plate is partially reflected by the inner surface of the vertical extending portion 234 of the guide panel 230, L ', which is a part of the emitted light, proceeds to the display area A / A of the display panel 140.

As described above, a part of the light traveling to the outside of the light guide plate 122 is cut by the guide panel, and the light is leaked to the outside of the display panel by proceeding to the display area A / A of the display panel. A display failure occurs in which the edge portion of the display region of the apparatus is lighter than the other regions.

Particularly, there is a growing need for a narrow bezel that minimizes the size of a bezel, which is a non-display area of a display device.

3B, the bezel area of the display device is generally defined as the sum of the width Wb of the support structure of the guide panel and the cover bottom, and the non-display area N / A formed at the edge of the display panel, as shown in FIG. 3B .

Therefore, in order to minimize the bezel area, the width of the guide panel must be minimized. In this case, the size of the horizontal extension of the guide panel must also be reduced.

In addition to the use for supporting the display panel and the optical sheet, the horizontally extending portion of the guide panel also has a function of blocking reflected light or leakage light directed toward the display area as described with reference to Fig. 3A. If the size of the extension is reduced, the above-mentioned light leakage phenomenon may occur more frequently.

In particular, as described in Fig. 2, a structure for fixing the optical sheet (seating groove; 232 or the like) must be provided in a part of the guide panel, and light leaked through the optical sheet fixing structure can be further increased .

In order to prevent light leakage at the edge of the display device, a method of forming a guide panel with a black material having light absorption characteristics is considered. However, in this case, the light leakage phenomenon is reduced to some extent, Is generated.

In order to solve the problem of light leakage, a method of printing a black or gray light diffusion pattern on a part of the inner surface of the guide panel may be considered. However, in this case, an additional black light may be generated, A problem arises.

Therefore, in the embodiment of the present invention, the downward inclined reflector is formed on the inner surface of the vertically extending portion of the guide panel opposite to the side surface of the light guide plate, and the light advancing to the outside of the side surface of the light guide plate is reflected Thereby minimizing light leakage at the edge of the display device.

4 shows a cross-sectional view of a display device according to an embodiment of the present invention.

A display device according to an embodiment of the present invention includes a display panel 440 for displaying an image, a backlight unit (not shown) for providing light to the display panel, including a light source portion, an optical sheet portion disposed above the light guide plate, 420, a guide panel 430 including a downwardly inclined reflector 435 facing the side of the light guide plate, and a cover bottom 410 coupled to the guide panel to cover the rear surface of the display device .

The guide panel 430 includes a horizontal extension portion 436 for supporting the rear edge of the display panel and a vertical extension portion 436 for supporting the side surface of the backlight unit, The portion 435 is formed on the inner surface of the vertical extension portion facing the side surface of the light guide plate 422. [

The guide panel 430 may be formed in a frame shape that covers all four sides of the display device, and the downward inclined reflector 435 may be formed along three sides except for four light-incident portions of the guide panel And may be formed along all four sides of the guide panel including the light-entering portion.

The downwardly inclined reflector 435 of the guide panel is disposed on the vertical extension slope 435 'and the vertical extension slope 435' arranged to have a first inclination angle and a thickness direction of the display device Reflective layer 435 ".

At this time, the reflective layer 435 '' may be formed by directly applying or vapor-depositing a material having a reflective property on the vertically extending portion inclined surface 435 ', or by forming a reflective tape or the like, (435 ').

The first inclination angle? Of the downward inclination reflector 435 can be determined according to the total reflection critical angle? 1 of the light guide plate 422. For example, the first inclination angle? May be in inverse proportion to the total reflection critical angle [theta] 1 of the light guide plate 422. [

The first inclination angle? Of the downwardly inclined reflector 435 and the position of the downwardly inclined reflector will be described in detail below with reference to FIG.

The downward inclined reflector 435 of the guide panel reflects light emitted to the outside of the light guide plate through the side surface of the light guide plate in a direction opposite to the display panel to minimize light traveling to the display area of the display panel, And minimizes the phenomenon.

According to the present embodiment, a part of the inner surface of the cover bottom 410 may further include a light absorbing member 460 for absorbing light reflected by the downwardly inclined reflecting portion.

4, a light absorbing member 460 having a light absorbing characteristic may be disposed in the projection area on the inner surface of the cover bottom 410 where the downward inclined reflecting portion 435 is projected.

On the other hand, an adhesive member such as a double-sided tape or the like for fixing the guide panel to the cover bottom may be disposed between the bottom of the vertically extended portion of the guide panel and the cover bottom, So that the light absorbing member 460 can be constructed.

The light absorbing member 460 serving also as the bonding member functions not only to fix the guide panel to the cover bottom but also to reduce the light directed toward the display panel by absorbing the light reflected by the downward inclined reflecting portion .

Of course, such a light absorbing member may be composed of a double-sided tape having black or gray having an adhesive function, but the present invention is not limited thereto, and may be constituted by a separate member from the adhesive member.

For example, the light absorbing member 460 may include black paint or the like on the inner surface of the cover bottom corresponding to the projection area of the downward inclined reflecting surface, in addition to the adhesive member disposed between the bottom surface of the vertically extending portion of the guide panel and the inner surface of the cover bottom. Or may be a separate member formed by printing or coating.

5A is a perspective view of a guide panel used in an embodiment of the present invention, and Figs. 5B and 5C are sectional views.

5A, the guide panel 430 according to the present embodiment is a rectangular frame-shaped member disposed along four sides of the display device, and includes a horizontal extension portion 436 on which the edge of the display panel is seated, The outer surface of which is coupled with the cover bottom and the inner surface includes a vertical extension 434 that faces the outer surface of the backlight unit.

As shown in FIG. 5, the vertical extension may extend to the upper portion of the horizontal extension, but may be formed only under the horizontal extension, as shown in FIG. 8 and the like.

More specifically, the inner surface of the vertically extending portion 433, more specifically, the inner surface of the backlight unit facing the side surface of the light guide plate is formed with a downwardly reflecting inclined portion 435 inclined toward the outer periphery of the display device and having reflection characteristics.

5B and FIG. 5C, the guide panel 430 according to the present embodiment is formed so as to be parallel to the side surface of the light guide plate, Is formed with an inclined surface 435 'that is inclined outwardly with the inner surface of the vertically extending portion facing the side surface of the light guide plate and the side surface direction of the light guide plate (i.e., the thickness direction of the display device) A reflection layer 435 "having a reflection characteristic is formed.

The reflective layer 435 "may be formed to have a thickness of about 1 to 20 um by depositing a reflective material selected from Al, Au, and Ag on the inclined surface 435 'by a method such as sputtering, This direct deposition method may be applied to a case where the guide panel is made of a metal material.

Further, as shown in FIG. 5C, a separate reflection film or a tape having a reflection characteristic may be adhered to the inclined surface 435 'of the guide panel.

Such a separate film or tape attaching method can be applied to a case where the guide panel is made of a non-metallic material such as reinforced plastic or the like. An ESR film (Enhanced Spectral Reflector Film) or the like can be used as the reflective film or reflective tape used at this time But the present invention is not limited thereto.

At least one optical seat fixing groove 432 may be formed on the horizontal extension portion 436 of the guide panel of the present embodiment. One or more optical groove fixing grooves 432 may be formed on one side of the guide panel .

A projection (not shown) formed on the optical sheet 426 is seated in the seating groove 432 and an adhesive foam pad is attached to the seating groove 432 to fix the optical sheet to the guide panel.

The guide panel 430 is a concept including all kinds of members used to support the backlight unit and the side surface of the display panel. The guide panel 430 is not necessarily limited to the guide panel, and may be a plastic chassis, a p- , A main support, a mold frame, and the like.

In other words, the guide panel 430 in this embodiment is a rectangular frame-like structure having a cross-sectional shape with at least one bent portion, and is connected to the cover bottom 410 to be used for supporting the optical sheet and the display panel of the backlight unit But it should be understood that it includes all types of plastic members.

The guide panel 430 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.

Hereinafter, the remaining components of the display apparatus according to the present embodiment will be described in detail.

The backlight unit constituting the display device according to the embodiment of the present invention may include a light source unit (not shown), a light guide plate 422, a reflection plate 424, an optical sheet unit 426, and the like.

Among the components constituting the backlight unit, the light source unit may include a light source device and a light source holder having a long plate-like structure including an LED driving circuit for supporting the light source device and driving the light source device. The light source device of the light source module includes a light emitting diode ) 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 necessary light to the 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, and glass or the like may be used.

The reflection plate 424 is disposed on the back surface (rear surface) of the light guide plate 422 and functions to improve the brightness of light by reflecting light passing through the back surface of the light guide plate toward the display panel 440.

The optical sheet portion 426 disposed on the light guide plate 422 includes a light collecting sheet or a prism sheet PS having a light collecting function, a diffusing sheet DS for diffusing light, a dual brightness a reflection type polarizing film for enhancing brightness called enhancement film, or a combination of two or more sheets of various functional sheets. The light may be diffused or condensed through a light guide plate so that a more uniform surface light source is incident on the display panel. .

Among the individual functional sheets constituting the optical sheet portion 426, the light converging sheet PS includes a light-converging pattern or the like on a sheet in the form of a transparent film, thereby functioning to converge the incident light in a certain direction.

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.

On the inner surface of the cover bottom 410, a bottom surface (437 in FIG. 7A) of the vertically extended portion of the guide panel is seated, and a double-sided tape or the like is disposed therebetween to join the guide panel and the cover bottom.

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

In addition, the display device may further include a case top 450 extending from a side of the cover bottom to a front portion of the display panel to protect a part of the front surface of the display panel.

In the case of a liquid crystal display panel, a display panel 440 used in the display device according to the present embodiment includes a plurality of gate lines and data lines, pixels defined in the intersecting areas, An array substrate including a thin film transistor serving as a switching element for adjusting light transmittance in a pixel, an upper substrate provided with a color filter and / or a black matrix, and a liquid crystal material layer formed therebetween have.

Of course, the display panel according to the present embodiment is not limited to the liquid crystal display panel, and may include any type of display panel that displays light by receiving light by a backlight unit including a light guide plate.

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.

6 is a view for explaining an optical path on the side of the light guide plate and a light leakage preventing effect when the guide panel according to the present embodiment is used.

6, when the guide panel 430 having the downward inclination reflecting surface 435 according to the present embodiment is used, the light is totally reflected along the inside of the light guide plate 422 of the backlight unit, The light L1 and L2 that are emitted to the backward inclined reflecting portion 435 are reflected in the direction opposite to the display panel, that is, the cover bottom direction. (L1 ', L2 "in Fig. 6)

3, the ratio of the light reflected by the guide panel and traveling to the display area of the display panel out of the light emitted to the outside of the light guide plate through the side surface of the light guide plate sharply decreases, and as a result, the light leakage phenomenon at the edge of the display device described above is minimized do.

This effect is also caused by the inclined downward inclination of the inner surface of the guide panel facing the side of the light guide plate. However, by arranging the reflective layer on the inclined surface, the outgoing light from the light guide plate can be totally reflected in the downward direction.

In other words, in FIG. 3, due to irregular reflection on the side of the guide panel, light leakage occurs. In the present embodiment, all the outgoing light is reflected downward and absorbed by the light absorbing member disposed below the downward inclined reflection surface, The reflected light can be minimized.

FIGS. 7A and 7B are views illustrating the relationship between the position of the downwardly inclined reflector and the magnitude of the first inclination angle of the guide panel according to the present embodiment.

7A, the guide panel 430 according to the present embodiment includes a vertical extending portion 434 and a horizontal extending portion 436. The guide panel 430 includes an inner surface A downward inclined reflecting portion 435 is formed.

At this time, assuming that the entire width of the vertical extension portion, that is, the maximum width of the vertical extension portion is W1 and the width of the bottom surface 437 of the vertical extension portion is W2, the downward inclination reflector 435 and the thickness direction A of the display device, Can be defined as a first inclination angle [theta].

In addition, the height at which the downward inclined reflecting portion 435 is formed can be denoted by H1.

At this time, the height H1 of the downward inclination reflecting portion 435 may be equal to or larger than the thickness T of the light guide plate 422. [

In general, since the light emitted from the side surface of the light guide plate can be directed to a position higher than the height of the light guide plate by totally reflecting the inside of the light guide plate, the height of the downward inclined reflector 435 It may be advantageous that H1 is larger than the thickness T of the light guide plate 422. [

The larger the first inclination angle? Of the downward inclination reflector 435 is, the more the reflected light can be directed downward. However, under the condition that the entire width W1 of the vertically extended portion is constant, 437 is reduced.

When the width W2 of the bottom surface 437 of the vertically extending portion is reduced, the contact area between the guide panel and the cover bottom is reduced, so that the fixing force of the guide panel can be reduced.

Therefore, the first inclination angle? Of the downward inclination reflector 435 should be appropriately selected, and more specifically, the first inclination angle? Of the downward inclination reflector 435 should be determined by the total reflection critical angle? 1 of the light guide plate. Can be determined.

The light guide plate is formed of a material having a refractive index of about 1.5 or more. In terms of optical characteristics, light incident on the critical plane of the light guide plate and the air layer at a critical angle or less is totally reflected inside the light guide plate .

7A, the total reflection critical angle? 1 of the light guide plate 422 can be defined as a minimum incident angle at which the refraction angle of refraction light is 90 degrees, and the total reflection critical angle? 1 is determined according to the refraction index of the light guide plate .

Therefore, light having an incident angle larger than the total reflection critical angle is totally reflected within the light guide plate at the same refraction angle.

7B shows a light guide plate having a relatively large total reflection critical angle? 1 ', and a total reflection critical angle? 1' is relatively small in the lower portion.

When the total reflection critical angle? 1 'is large as shown in the upper part of FIG. 7B, the refraction angle of the total refracted light also becomes larger than a certain level, so that the light advances obliquely to the light guide plate. As a result, .

Therefore, in this case, even if the first inclination angle? Of the downwardly inclined reflector is small, since the incident angle of the incident light incident on the downwardly inclined reflector (i.e., the angle formed by the incident light direction with the normal line of the downwardly inclined reflector) It can effectively reflect in the direction opposite to the display panel.

On the other hand, when the total reflection critical angle? 1 'is small as shown in the lower portion of FIG. 7B, the refraction angle of some of the total refracted light beams may be less than a certain angle.

Therefore, in this case, there is a possibility that light emitted to the outside of the side surface of the light guide plate is obliquely incident on the downward inclined reflecting portion.

Therefore, in this case, since the angle of incidence of the incident light incident on the downwardly inclined reflector (i.e., the angle formed between the incident light direction and the normal line of the downwardly inclined reflector) is relatively small, the first inclined angle & It can effectively reflect in the direction opposite to the display panel.

As a result, the first inclination angle [theta] of the downward inclination reflector can be in inverse proportion to the total reflection critical angle [theta] 1 of the light guide plate.

In other words, when the total reflection critical angle [theta] 1 of the light guide plate 422 is small, the first inclination angle [theta] of the downward inclined reflector must be large and when the total reflection critical angle [theta] 1 of the light guide plate 422 is relatively large, The first inclination angle? Can be formed to be relatively smaller.

As described above, the first inclination angle [theta] of the downward inclination reflector has a relationship in inverse proportion to the total reflection critical angle [theta] 1 of the light guide plate, so that reflected light directed to the display panel can be minimized, It is possible to optimize the first inclination angle which is the inclination angle of the reflecting portion.

 8A to 8D show the shape of a guide panel according to another embodiment of the present invention.

8 illustrates a guide panel in which a vertical extension 834 having a downwardly inclined reflector 835 is formed only in a lower region of the horizontal extension 836. FIG.

8A, a horizontal extension portion 836 extending horizontally and having a display panel 440 mounted thereon, a vertical extension portion 836 formed only on the lower portion of the horizontal extension portion and having a downwardly inclined reflection portion 835 on the inner side, (834).

In FIG. 8B, the wedge-shaped guide panel 930 is shown without a clear distinction between the vertical extension and the horizontal extension.

The embodiment of FIG. 8B includes a wedge-shaped guide panel having an upper width larger than the lower width, a display panel is mounted on the upper portion, and a downward inclined reflector 935 is formed on an inclined surface inclined downward from the upper portion .

8C and 8D illustrate an upper horizontal extension portion 1036, 1136 for seating the display panel in the upper portion, a lower horizontal extension portion (not shown) in contact with the cover bottom at the lower portion and extending beyond a certain width in parallel with the upper horizontal extension portion 1036, 1036 ').

In other words, the upper and lower horizontal extension parts 1036 and 1136 and the lower horizontal extension parts 1036 'and 1136' are formed with vertical extension parts 1034 and 1134 therebetween. As a result, Shaped cross-section.

In this case, the downward inclination reflector may be disposed in a space between the horizontal extension and the lower horizontal extension. Specifically, the downward inclination reflector may be realized in two forms.

8D illustrates the inner surface of the vertical extension 1134 where the downwardly inclined reflector 1135 is disposed between the upper horizontal extension 1136 and the lower horizontal extension 1136 ' And the reflective layer may be disposed on the inclined surface of the vertically extending portion of the vertically extending portion.

8C, a downwardly inclined reflector 1035 is disposed between the upper horizontal extending portion 1036 and the lower horizontal extending portion 1036 'in the thickness direction of the display device, 'And a separate reflecting member 1038 which is in contact with the inner surface of the vertically extending portion and has a downward inclined reflecting surface.

8D, a separate reflecting member 1038 having a downward inclined surface is disposed in a 'C' space defined by an upper horizontal extending portion 1036 and a lower horizontal extending portion 1036 '.

At this time, the separate reflective member 1038 may be a long bar-shaped member having a right triangular cross section, and at least one of the two orthogonal surfaces may be formed on the inner surface of the vertical extension portion and / And the remaining one surface constitutes the lower inclined surface, and the lower inclined surface forms the reflective layer.

8C and 8D, the portion contacting the guide panel is a bottom surface of the lower horizontal extension portions 1036 and 1036 '. In comparison with the structure of FIG. 7 and the like, the lower horizontal extension portions 1036, The width of the bottom surface of the guide panel 1036 'is increased, so that the fixing force of the guide panel and the cover bottom can be improved.

4 to 8B, the width of the bottom surface of the downwardly inclined reflector which is in contact with the cover bottom 410 is relatively small, so that the coupling force between the guide panel and the cover bottom can be reduced. On the other hand, The fixing force of the guide panel can be improved by bonding the wide bottom surface of the lower horizontal extension portion to the cover bottom by the adhesive member 1060. [

Of course, although not shown, in the case of the embodiment of Figs. 8C and 8D, a light absorbing member capable of absorbing the reflected light reflected by the downwardly inclined reflector may be disposed on the upper surface of the lower horizontal extension portion.

FIGS. 9A and 9B show test results of measuring the amount of light shielding in a display device according to an embodiment of the present invention and a general display device as shown in FIG.

FIG. 9A is a simulation result of a general display device as shown in FIGS. 1 and 3. FIG. 9A shows a result that part of the light emitted to the outside of the light guide plate side is reflected by the guide panel and travels toward the display area side of the display panel.

On the other hand, FIG. 9B shows the result of simulation in the case where the present embodiment is applied. In the light emitted from the side of the light guide plate, there is almost no light traveling to the display region of the display panel, .

As described above, according to the embodiment of the present invention, the downward inclined surface is formed in the side support structure of the display device, the reflective layer is disposed on the inclined surface, and the light emitted to the side surface of the light guide plate is reflected to the back of the display device, There is an effect of preventing the light leakage phenomenon in the light source.

More specifically, a downward inclined reflector is formed at a portion of the guide panel opposite to the side surface of the light guide plate, which is a supporting structure for supporting the side surface of the backlight unit, and a light absorbing member is disposed at a lower portion thereof. It is possible to minimize the ratio of the light directed to the display area of the middle display panel and consequently to suppress the display failure due to the light leakage phenomenon at the edge of the display device.

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 420: Backlight Unit
430, 830, 930, 1030, 1130: guide panel
422: light guide plate 424: reflector
426: Optical sheet part 435: Downward slant reflection part
460: light absorbing member 434:
436: horizontal extension part 432:

Claims (10)

Display panel;
A backlight unit for providing light to the display panel, the backlight unit including a light source part, a light guide plate and an optical sheet part disposed above the light guide plate;
A guide panel including a horizontal extension portion for supporting a rear edge of the display panel and a vertical extension portion for supporting a side surface of the backlight unit and including a downward inclined reflector on the inner surface of the vertical extension portion facing the side surface of the light guide plate;
A cover bottom coupled to the guide panel to cover a rear surface of the display device;
. The method according to claim 1,
Wherein the downwardly inclined reflecting portion includes a vertically extending portion inclined surface disposed so as to have a first inclination angle with the thickness direction of the display device and a reflective layer disposed on the inclined surface. 3. The method of claim 2,
And a light absorbing member having a light absorbing property is disposed in a projection region on the inner surface of the cover bottom where the downwardly inclined reflecting portion is projected. The method of claim 3,
An adhesive member for fixing the guide panel to the cover bottom is disposed between a bottom surface of the vertically extended portion of the guide panel and the cover bottom, and the adhesive member is extended to a projection region on the cover bottom, Display device. 3. The method of claim 2,
Wherein the first inclination angle of the vertical extending surface is determined based on a total reflection critical angle of the light guide plate. 6. The method of claim 5,
Wherein the first inclination angle of the vertical extending surface is inversely proportional to the total reflection critical angle of the light guide plate. The method according to claim 1,
Wherein the guide panel further comprises a lower horizontal extension portion that contacts the inner surface of the cover bottom, and the downward slant reflector is disposed in a space between the horizontal extension portion and the lower horizontal extension portion. 8. The method of claim 7,
Wherein the downwardly inclined reflector includes a vertically extending portion inclined surface disposed between the horizontal extending portion and the lower horizontal extending portion so as to have a first inclination angle and a thickness direction of the display device, and a reflective layer disposed on the inclined surface. 8. The method of claim 7,
Wherein the downwardly inclined reflector includes a vertically extending portion inner surface extending between the horizontal extending portion and the lower horizontal extending portion in the thickness direction of the display device and a reflective member having a downwardly inclined reflective surface in contact with the inner surface of the vertical extending portion / RTI > The method according to claim 1,
Wherein at least one optical seat fixing recess for each of the at least one optical sheet fixing groove is disposed in a vertically extending portion of the guide panel.

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