KR20170035059A - Optical sheet and liquid crystal display device having the same - Google Patents

Abstract

The present invention relates to an optical sheet and a liquid crystal display including the same.
A backlight unit for providing a planar light source, wherein the backlight unit includes a light guide plate, at least one optical sheet on the light guide plate, and a support main body for fixing the optical sheet, wherein the optical sheet includes at least one The ear portion may include at least one hole, and the hole of the ear portion may provide a backlight unit corresponding to the spaced space between the light guide plate and the support main.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical sheet and a liquid crystal display including the optical sheet.

The present invention relates to an optical sheet and a liquid crystal display including the same.

BACKGROUND ART In general, a liquid crystal display (LCD) displays a desired image by adjusting the light transmittance of liquid crystal cells arranged in a matrix according to image signal information. Thereby forming an image on the panel. The liquid crystal display device using such a principle has been gradually widened due to features such as light weight, thinness, and low power consumption driving. In accordance with this trend, the liquid crystal display device is used in office automation equipment, audio / video equipment, and the like.

In such a liquid crystal display device, a light transmission amount is adjusted according to a signal applied to a plurality of control switches arranged in a matrix form to display a desired image on a screen.

In recent years, liquid crystal display devices have been widely applied not only to computer monitors, televisions, display devices for navigation systems for vehicles, and portable display devices such as notebook computers and cellular phones.

In general liquid crystal display devices, a voltage is applied to a specific molecular array of a liquid crystal to convert it into another molecular array, and changes in optical properties such as birefringence, spinelability, dichroism and light scattering characteristics of a liquid crystal cell emitting light by such molecular arrangement And is a light-receiving type display device for displaying information by using modulation of light by a liquid crystal cell. Since such a liquid crystal display device is a light receiving type device, it includes a backlight unit for providing light to express an image, and the backlight unit is divided into a direct type and an edge type according to the arrangement of the light sources .

The direct-type backlight unit is a system in which a plurality of light sources are arranged directly under the liquid crystal display panel at regular intervals and directly irradiated directly under the liquid crystal display panel. The edge-type backlight unit includes a light guide plate for converting light emitted from the light source into surface light Thereby emitting light to the liquid crystal display panel. BACKGROUND ART A backlight unit of a liquid crystal display device includes optical sheets composed of a diffusion plate, a diffusion sheet and a prism sheet in order to improve optical characteristics of light emitted from a light source, for example, luminance uniformity and front luminance.

Referring to FIG. 1, a conventional liquid crystal display includes a support main body 20 and at least one optical sheet 10. The optical sheet 10 includes an ear portion 11 for fixing to the support main 20. The support main body 20 includes a coupling portion 21 to which the ear portion 11 of the optical sheet 10 is coupled.

In the conventional liquid crystal display device, there is a spacing space between the optical sheet 10 and the support main 20, and light leakage occurs. There is a problem in that the shape of the ear portion 11 of the optical sheet is visually recognized as indicated by the dotted line 30 in the view angle of the liquid crystal display device. That is, there is a light leakage at a place where the ear 11 of the optical sheet is not arranged, but a place where the ear 11 of the optical sheet is disposed is dark.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and in particular, it is intended to remove the visual appearance of the optical sheet at the viewing angle of the liquid crystal display device.

The backlight unit may include a light guide plate and at least one optical sheet on the light guide plate and a support main body for fixing the optical sheet, The ear portion may include at least one hole, and the hole of the ear portion may provide a backlight unit corresponding to a spaced space between the light guide plate and the support main.

In the backlight unit according to another preferred embodiment of the present invention, the width of the hole may be larger than the separation distance between the support main and the light guide plate.

In the backlight unit according to still another preferred embodiment of the present invention, the hole of the ear portion may be a plurality of holes.

In the backlight unit according to still another preferred embodiment of the present invention, the hole of the ear portion is one and the long axis of the hole may be parallel to the edge of the optical sheet.

In addition, the present invention provides, as means for solving the above-mentioned problems, a liquid crystal display panel; At least one optical sheet disposed between the light guide plate and the liquid crystal display panel, and a support main body fixing the liquid crystal display panel and the optical sheet, wherein the optical sheet And the at least one ear portion disposed in the support main, wherein the ear portion includes at least one hole, and the hole of the ear portion corresponds to the spaced space between the light guide plate and the support main body .

In the liquid crystal display device according to another preferred embodiment of the present invention, the width of the hole may be larger than the separation distance between the support main and the light guide plate.

In the liquid crystal display device according to another preferred embodiment of the present invention, the hole of the ear portion may be a plurality of holes.

In the liquid crystal display device according to still another preferred embodiment of the present invention, the hole of the ear portion is one and the long axis of the hole may be parallel to the edge of the optical sheet.

The ear portion of the optical sheet is not visually recognized at the viewing angle of the liquid crystal display device.

The ear portion of the optical sheet is not visually observed, and as a result, the brightness of the light-shielding portion becomes uniform, so that no separate process is required for the light guide plate or the diffusion plate for uniformizing the brightness.

1 is a view showing a part of a conventional liquid crystal display device.
2 is a view showing a light leakage phenomenon of a conventional liquid crystal display device.
3 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.
4 is a plan view of an optical sheet and a support main according to the first embodiment of the present invention.
5 is a cross-sectional view taken along the line A-A 'in FIG.
6 is a cross-sectional view taken along the line B-B 'in FIG.
7 is a plan view of an optical sheet according to a second embodiment of the present invention.
8 is a plan view of an optical sheet according to a third embodiment of the present invention.
9 is a plan view of an optical sheet according to a fourth embodiment of the present invention.
10 is a plan view of an optical sheet according to a fifth embodiment of the present invention.

Hereinafter, an optical sheet according to an embodiment of the present invention and a liquid crystal display device including the optical sheet will be described in detail with reference to the drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of the layers and regions in the figures may be exaggerated for clarity of illustration.

It will be understood that when an element or layer is referred to as being another element or "on" or "on ", it includes both intervening layers or other elements in the middle, do. On the other hand, when a device is referred to as "directly on" or "directly above ", it does not intervene another device or layer in the middle.

The terms spatially relative, "below," "lower," "above," "upper," and the like, And may be used to easily describe the correlation with other elements or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprise "and / or" comprising ", as used in the specification, means that the presence of stated elements, Or additions.

3 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention.

3, the liquid crystal display 100 includes a liquid crystal panel 110, a backlight unit 120, a support main 130, a bottom cover 150, and a top cover 140.

The liquid crystal panel 110 includes a color filter array substrate 112 and a TFT array substrate 114 and a liquid crystal layer (not shown) interposed therebetween. The color filter array substrate 112 and the TFT array substrate And a polarizing plate (not shown) is attached to the outer surface of the light guide plate 114

In this liquid crystal panel 110, liquid crystal cells constituting pixel units are arranged in a matrix form, and liquid crystal cells adjust image transmittance according to image signal information transmitted from a driver driving circuit to form an image.

Specifically, on the inner surface of the TFT array substrate 114, a plurality of gate lines and data lines intersect to define pixels, and thin film transistors (TFTs) are provided at each of the intersections, One-to-one correspondence with the transparent pixel electrodes.

The inner surface of the color filter array substrate 112 is provided with color filters of red (R), green (G), and blue (B) A data line, and a black matrix covering a non-display element such as a thin film transistor. In addition, a transparent common electrode covering these elements is provided.

A gate and a data printed circuit board 117 are connected to each other via a connection member 116 such as a flexible printed circuit board along at least one edge of the liquid crystal panel 110 to support the side of the support main 130, (150).

The driving signal of the liquid crystal panel 110 provided from the gate and the data printed circuit board 117 on one side of the liquid crystal panel 110 is supplied to a plurality of gate lines and a plurality of data lines of the liquid crystal panel 110 And the liquid crystal panel 110 is driven. When the liquid crystal panel 110 controls the voltage of the data signal applied to the pixel electrode in the state where the voltage is applied to the common electrode, the liquid crystal layer rotates by dielectric anisotropy according to the electric field between the common electrode and the pixel electrode, An image is displayed by transmitting or blocking light for each pixel region.

In addition, when the liquid crystal panel 110 is a GIP (Gate In Pannel) type, the gate printed circuit board 117 and a part of the connection member 116 connected thereto can be removed.

Although not clearly shown in the drawing, an alignment film for determining the initial alignment direction of the liquid crystal is interposed at the boundary between the color filter array substrate 112 and the TFT array substrate 114 and the liquid crystal layer of the liquid crystal panel 110 A seal pattern is formed along the edges of the color filter array substrate 112 and the TFT array substrate 114 to prevent leakage of the liquid crystal layer filled therebetween.

A backlight unit 120 for supplying light is provided on a back surface of the liquid crystal panel 110 so that a difference in transmittance represented by the liquid crystal panel 110 is externally expressed.

The backlight unit 120 includes an LED assembly 200 arranged along the longitudinal direction of at least one edge of the support main body 130, a white or silver reflective plate 125, and a light guide plate 123 And an optical sheet 300 interposed therebetween.

The LED assembly 200 is a light source of the backlight unit 120 and is disposed at one side of the light guide plate 123 so as to face the light incident surface of the light guide plate 123. The LED assembly 200 includes a plurality of LEDs 210, And a PCB 220 on which a plurality of LEDs 210 are mounted at a predetermined interval.

Light emitted from the plurality of LEDs 210 is provided to the liquid crystal panel 110 via the light guide plate 123.

As the material of the light guide plate 123, PMMA (Polymethylmethacrylate), which has high strength and is not easily deformed or broken and has a high transmittance, may be used. Here, the light guide plate 123 may be a wedge having a lower surface inclined and a flat upper surface, or a plate type having a lower surface and an upper surface all in parallel. In addition, the thickness of the light guide plate 123 may be relatively larger.

The light guide plate 123 may include a condensing pattern (not shown) on its upper surface.

The outgoing angle of light emitted to the upper surface of the light guide plate 123 can be adjusted according to the density of the light condensing pattern.

The optical sheet 300 may be composed of one optical sheet or a plurality of optical sheets. The optical sheet 300 may be formed by bonding a plurality of optical sheets together. The optical sheet 300 may include a diffusion sheet, a prism sheet, and a protective sheet. In some cases, it may be provided with two diffusion sheets and two prism sheets. At this time, the diffusion sheet may include a base plate and a bead coating layer formed on the base plate. The optical sheet 300 may include an ear portion 310 which can be fixed to the coupling portion 131 of the support main body 130.

The diffusion sheet 300 diffuses light from the light guide plate 123 and supplies the light to the liquid crystal panel 110. Two or three sheets of the diffusion sheet may be used in a superimposed manner. In addition, the prism sheet may have a triangular columnar prism with a predetermined arrangement on the upper surface. The prism sheet may function to condense light diffused in the diffusion sheet in a direction perpendicular to the plane of the upper liquid crystal panel 110. Two prism sheets may be used, and the micro prisms formed on each prism sheet form a predetermined angle. Accordingly, the light passing through the prism sheet proceeds almost vertically and provides a uniform luminance distribution. The topmost protective sheet protects the prism sheet, which is susceptible to scratches.

The reflection plate 125 is disposed on the back surface of the light guide plate 123 and reflects light passing through the back surface of the light guide plate 123 toward the liquid crystal panel 110 to improve the brightness of light.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130 and the bottom cover 150. The top cover 140 is disposed on the top edge of the liquid crystal panel 110, So as to cover the side surface.

Further, one side of the corner of the support main 130 can be removed like the support main 130 of Fig.

Here, the top cover 140 has a rectangular frame shape bent in a "?" Shape so as to cover the top and side edges of the liquid crystal panel 110, As shown in Fig.

In addition, the bottom cover 150, on which the liquid crystal panel 110 and the backlight unit 120 are mounted and is a basis for assembling the entire structure of the liquid crystal display device, includes a bottom portion and side walls whose edges are vertically bent.

In this case, the top cover 140 may be referred to as a case top or a top case, and the support main 130 may be referred to as a guide panel, a main support, or a mold frame, and the bottom cover 150 may be referred to as a bottom cover.

4 is a plan view of the optical sheet 300 and the support main body 130 according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the line A-A 'in FIG. 4, and FIG. 6 is a cross-sectional view taken along line B-B' in FIG.

4, the optical sheet 300 may include at least one ear 310 disposed in the support main 130, and the ear 310 may include at least one hole 311 have. 4, at least one hole 311 may be formed in the ear portion 310, that is, a hole 311 may be provided.

More specifically, the ear portion 310 may be disposed on the engaging portion 131 of the support main body 130. The hole 311 may have a suitable size or a suitable number so that the ear 310 may be engaged with or fixed to the joint 131 of the support main 130. That is, if the hole 311 is too large, the connection area between the optical sheet 300 and the tab 310 is small, so that the fixing force to fix the optical sheet 300 to the support main 130 is weakened by the tab 310 If the hole 311 is too small, it is possible to determine the size or the number of the holes 311 in consideration of the problem that appropriate light leakage is not induced.

Referring to FIG. 5, the cut portion A-A 'is a portion where the ear portion 310 of the optical sheet 300 is not disposed. When light is emitted to the side of the light guide plate 123, light may not be condensed on the optical sheet 300. In this case, the outgoing light may escape into the spacing space between the support main 130 and the optical sheet 300, and light leakage may occur.

Referring to FIG. 6, the cut-away portion of B-B 'is where the ear portion 310 of the optical sheet 300 is disposed. When light is emitted to the side of the light guide plate 123, light may not be condensed on the optical sheet 300. In this case, the outgoing light may escape through the spacing space between the support main 130 and the optical sheet 300 and through the holes 311 of the ear 310 to generate light leakage.

The hole 311 of the tab 310 may correspond to the spaced space between the light guide plate 123 and the support main 130. The hole 311 of the tab 310 may be formed in contact with one end of the light guide plate 123 and outside the light guide plate 123. The formation of the hole 311, that is, the provision of the hole 311, can effectively cause light leakage, and the light leakage boundary with the region where the ear portion 310 is not disposed is similar.

Further, since the nose portion of the optical sheet is not visually observed, and as a result, the brightness of the light-shielding portion becomes uniform, a separate process is not required for the light guide plate or the diffusion plate for uniformizing the brightness.

5, the width of the hole 311 is set to be equal to or larger than the width of the support main body 130 and the width of the cut- May be larger than the separation distance between the light guide plate 123. The hole 311 is provided so as to be similar to the light leakage level with respect to a region where the ear portion 310 is not disposed. Also, a plurality of holes 311 of the ear portion 310 may be provided. It is possible to maintain the level of the light leakage from the region where the nail portion 310 is not disposed and to secure the connection region between the optical sheet 300 and the nail portion 310, It is possible to secure a fixing force that can be fixed to the support main body 130.

In addition, the shape of the hole 311 may be a square, a circle, a triangle, a rhombus, or a star.

In the case of the first embodiment, the number of the holes 311 of the ear portion 310 may be plural and circular.

FIG. 7 is a plan view of an optical sheet according to a second embodiment of the present invention, FIG. 8 is a plan view of an optical sheet according to a third embodiment of the present invention, FIG. 9 is a cross- 10 is a plan view of an optical sheet according to a fifth embodiment of the present invention.

Referring to FIG. 7, a plurality of holes 311 of the ear 310 of the second embodiment may be square.

Referring to FIG. 8, a plurality of holes 311 of the ear 310 of the third embodiment may have an elliptical shape.

Referring to FIG. 9, a plurality of holes 311 of the ear 310 of the fourth embodiment may be triangular in shape.

That is, the second, third, and fourth embodiments are modified only in the shape of the hole 311 in the first embodiment.

Referring to FIG. 10, the hole 311 of the ear 310 of the fifth embodiment may have a single long shape.

That is, in the fifth embodiment, only the shape of the hole 311 is modified in the first embodiment, the hole 311 of the ear 310 is one, and the long axis of the hole 311 is the optical sheet 300 ). ≪ / RTI > And one hole 311 is provided. The connecting area between the optical sheet 300 and the ears 310 is reduced so that the fixing force for fixing the optical sheet 300 to the support main 130 can be weakened as compared with the case where a plurality of holes 311 are provided However, the level of light leakage from the region where the ear portion 310 is not disposed is most similar.

Therefore, according to the present invention, the nose portion of the optical sheet is not visually recognized at the viewing angle of the liquid crystal display device. Further, since the nose portion of the optical sheet is not visually observed, and as a result, the brightness of the light-shielding portion becomes uniform, a separate process is not required for the light guide plate or the diffusion plate for uniformizing the brightness.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

100 liquid crystal display
110 liquid crystal panel
112 color filter array substrate
114 TFT array substrate
116 connecting member
117 printed circuit board
120 Backlight Unit
123 light guide plate
125 reflector
130 Support Main
131 coupling portion
140 Top cover
150 bottom cover
200 LED assembly
210 light source
220 PCB
300 optical sheet
310 ear
311 hole

Claims (8)

A backlight unit for providing a planar light source,
The backlight unit includes:
A light guide plate;
At least one optical sheet on the light guide plate; And
And a support main which fixes the optical sheet,
Wherein the optical sheet includes at least one ear portion disposed in the support main portion,
Wherein the ear portion includes at least one hole, and the hole of the ear portion corresponds to a spaced space between the light guide plate and the support main. The method according to claim 1,
Wherein a width of the hole is larger than a separation distance between the support main and the light guide plate. The method according to claim 1,
And a plurality of holes in said ear portion. The method according to claim 1,
And the long axis of the hole is parallel to the edge of the optical sheet. A liquid crystal display panel;
A light guide plate for providing a surface light source to the liquid crystal display panel;
At least one optical sheet disposed between the light guide plate and the liquid crystal display panel; And
And a support main which fixes the liquid crystal display panel and the optical sheet,
Wherein the optical sheet includes at least one ear portion disposed in the support main portion,
Wherein the ear portion includes at least one hole, and the hole of the ear portion corresponds to a spaced space between the light guide plate and the support main body. 6. The method of claim 5,
Wherein a width of the hole is larger than a separation distance between the support main and the light guide plate. 6. The method of claim 5,
And a plurality of holes in said ear portion. 6. The method of claim 5,
Wherein one hole is formed in the ear portion, and a long axis of the hole is parallel to an edge of the optical sheet.

Images