KR20090033731A - Prism sheet, method for manufacturing the prism sheet, backlight unit comprising the prism sheet and liquid crystal display comprising the prism sheet - Google Patents

Abstract

A prism sheet, a manufacturing method thereof, a BLU(Back Light Unit) having the same and a liquid crystal display having the same for improving durability are provided to improve display quality by improving instrument durability of the prism sheet. A material(132) transmits the light which is income from outside. A prism pattern(130) comprises a protrusion(134a) formed on material. The protrusion of the prism pattern is formed around the floor of the prism pattern. The width of the protrusion of the prism pattern is irregular. The prism sheet is mutually detached at the protrusion of the prism pattern.

Description

PRISM SHEET, METHOD FOR MANUFACTURING THE PRISM SHEET, BACKLIGHT UNIT COMPRISING THE PRISM SHEET AND LIQUID CRYSTAL DISPLAY COMPRISING THE PRISM SHEET}

The present invention relates to a prism sheet, a manufacturing method thereof, a backlight unit having the same, and a liquid crystal display including the same.

A liquid crystal display (LCD), which is classified as a light receiving display device, includes a backlight unit mounted below a liquid crystal panel displaying an image.

The backlight unit according to the background art may include not only a light source for emitting light but also a prism sheet for improving optical characteristics of the backlight unit, for example, brightness.

The prism sheet generally includes a substrate and a prism pattern formed on the substrate. Due to the shape and material of the prism pattern, the prism sheet is vulnerable to external force introduced from the outside. That is, the prism pattern may be damaged by an external force, which may cause a problem that the mechanical durability of the prism sheet is degraded.

Furthermore, since the problem is transferred to each of the backlight unit and the liquid crystal display including the prism sheet, the display quality of the backlight unit and the liquid crystal display may be degraded.

Accordingly, an object of the present invention is to provide a prism sheet capable of improving mechanical durability, a manufacturing method thereof, a backlight unit having the same, and a liquid crystal display having the same.

Another object of the present invention is to provide a prism sheet capable of improving display quality, a method of manufacturing the same, a backlight unit having the same, and a liquid crystal display having the same.

Further objects to be solved by the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description. Could be.

Prism sheet according to an embodiment of the present invention for achieving the problem to be solved is a substrate for transmitting the light incident from the outside; And a prism pattern formed on the substrate and having a protrusion.

On the other hand, the method of manufacturing a prism sheet according to an embodiment of the present invention for achieving the problem to be solved comprises the steps of preparing a substrate; And forming a prism pattern having protrusions on the substrate.

On the other hand, the backlight unit according to an embodiment of the present invention for achieving the problem to be solved is a light source for emitting light; And a prism sheet for collecting light incident from the light source, the prism sheet comprising: a substrate transmitting light incident from the light source; And a prism pattern formed on the substrate and having a protrusion.

On the other hand, the liquid crystal display device according to an embodiment of the present invention for achieving the problem to be solved is a light source for emitting light; A prism sheet for collecting light incident from the light source; And a liquid crystal panel displaying an image using light emitted from the light source, wherein the prism sheet comprises: a substrate transmitting light incident from the light source; And a prism pattern formed on the substrate and having a protrusion.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings.

According to the present invention, the mechanical durability of the prism sheet can be improved, and thereby the display quality of each of the backlight unit and the liquid crystal display device having the prism sheet can be improved.

Hereinafter, a prism sheet, a manufacturing method thereof, a backlight unit having the same, and a liquid crystal display having the same will be described in detail with reference to the accompanying drawings.

Like reference numerals refer to like elements throughout. In addition, when describing the arrangement relationship between the components throughout the specification, when it is disposed on the top, this includes not only the case in which it is arranged in the upper direction in the vertical direction, but also the case in which it is arranged in the oblique direction. Similarly, when describing the arrangement relationship between the components throughout the specification, when disposed below, this includes not only the case disposed below the vertical direction but also the case disposed below the oblique direction.

1 is a perspective view illustrating a prism sheet according to an embodiment of the present invention. 2 is a cross-sectional view illustrating a prism sheet according to an embodiment of the present invention.

1 and 2, the prism sheet 130 according to an embodiment of the present invention may be provided in the backlight unit of the liquid crystal display.

The prism sheet 130 may collect light incident from an external light source, and may include a substrate 132 and a prism pattern 134 formed on the substrate 132.

Since the substrate 132 must be able to transmit light incident from an external light source, the light transmissive material, for example, any one selected from the group consisting of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, and polyepoxy It may be formed to include a material, but is not limited thereto.

The prism pattern 134 may collect light incident from an external light source.

The prism pattern 134 may have an optical cross section, that is, an optical cross section on a YZ plane, approximately, in a triangular shape. In addition, the prism pattern 134 may be linearly formed along the X-axis direction, which is the longitudinal direction of the prism pattern 134, but may be formed in a triangular prism bar shape in appearance, but is not limited thereto. That is, since the prism pattern 134 only needs to condense the light incident from the external light source, the shape thereof is not particularly limited.

The prism pattern 134 may have a protrusion 134a protruding relatively to the prism pattern 134. Here, the prism pattern 134 and the protrusion 134a may be formed in an integrated form of the same material, but are not limited thereto.

The protrusion 134a formed on the prism pattern 134 may be formed approximately and symmetrically about the floor of the prism pattern 134. Specifically, the protrusion 134a may be formed in a wedge shape by being formed along the valley direction of the prism pattern 134 around the floor of the prism pattern 134, but is not limited thereto.

The width W of the protrusion 134a may be irregular. Here, the meaning that the width W of the protrusion 134a is irregular means that the width W may be irregular within one protrusion 134a and the width W between the protrusions 134a is different. It includes. However, the width W of the protrusion 134a may be regular.

The protrusions 134a may be spaced apart from each other, and the distance D between the protrusions 134a may be irregular, but is not limited thereto.

The above-described prism pattern 134 and the protrusion 134a formed in the prism pattern 134 are shown in more detail in FIG. 3. 3 is a photograph of a portion of a prism sheet according to an embodiment of the present invention by using a scanning electron microscope.

As described above, since the protrusion 134a protrudes relative to the prism pattern 134, for example, when the external force flows from the top of the prism pattern 134 to the bottom of the prism pattern 134, the external force may be a protrusion. Primary dispersion by 134a. Accordingly, since the external force flowing directly into the prism pattern 134 may be alleviated, mechanical durability of the prism pattern 134 may be improved.

As a result, display quality of the backlight unit and the liquid crystal display including the prism sheet 130 according to the exemplary embodiment of the present invention may be improved.

The prism pattern 134 may be manufactured by preparing a substrate 132 and then forming a prism pattern 134 having a protrusion 134a on the substrate 132. This will be described in more detail with reference to FIG. 4.

4 is a process flowchart schematically illustrating a method of manufacturing a prism sheet according to an embodiment of the present invention. On the other hand, the manufacturing method of the prism sheet according to an embodiment of the present invention is not limited to that shown in FIG.

2 and 4, in order to manufacture the prism sheet 130 according to an embodiment of the present invention, first, a substrate 132 is prepared (S100).

Next, a polymer resin solution is coated on the substrate 132 (S110). Here, any one method of knife coating, roll coating, and gravure coating may be used for the application of the polymer resin solution, but is not limited thereto.

Next, the polymer resin solution is cured (S120). At this time, for curing the polymer resin solution, for example, ultraviolet rays may be used. The prism pattern 134 may be formed through the curing process, but the protrusion 134a may not be formed. That is, the protrusion 134a may be formed by the process described below.

Next, the prism pattern 134 is pressed (S130). Thus, the prism sheet 130 according to the embodiment of the present invention can be manufactured. In this case, the reason for pressing the prism pattern 134 is to form the protrusion 134a on the prism pattern 134 through the pressing process since the protrusion 134a is not formed through the above-described curing process.

Here, various methods may be used to compress the prism pattern 134 to form the protrusion 134a. For example, the prism pattern 134 may be formed by pressing the prism pattern 134 using a mold in which a reverse phase of the protrusion 134a is formed, or the prism pattern 134 may be formed using a sheet on which the reverse phase of the protrusion 134a is formed. By pressing, the protrusion 134a can be formed.

On the other hand, unlike the above, the prism pattern 134 and the protrusion 134a may be formed at the same time.

5 is an exploded perspective view for describing the configuration of a backlight unit according to an embodiment of the present invention. FIG. 6 is a cross-sectional view taken along the line VI-VI ′ of FIG. 5. In FIG. 5, an edge type backlight unit is illustrated as the backlight unit, but the present invention is not limited thereto. In addition, since the prism sheet shown in FIG. 5 is the same as the prism sheet shown in FIG. 1, the overlapping description is abbreviate | omitted and only the characteristic is demonstrated.

5 and 6, the backlight unit 210 according to an exemplary embodiment of the present invention may be provided in the liquid crystal display, and may provide light to the liquid crystal panel provided in the liquid crystal display.

The backlight unit 210 may include a light source 220 and a prism sheet 130. In addition, the backlight unit 210 may further include a light guide plate 240, a reflective plate 250, a bottom cover 260, and a mold frame 270.

The light source 220 may generate light by using driving power applied from the outside, and may emit the generated light.

For example, at least one light source 220 may be formed on one side of the light guide plate 240 along the X axis direction, which is the long axis direction of the light guide plate 240, or both sides of the light guide plate 240 along the X axis direction. At least one or more may be formed in each. Here, the light emitted from the light source 220 is incident directly into the light guide plate 240, or the light source housing 222 formed to surround a portion of the light source 220, for example, about 3/4 of the outer peripheral surface of the light source 220 After the light is reflected, the light guide plate 240 may be incident into the light guide plate 240.

Specifically, the light source 220 is a cold cathode fluorescent lamp (Cold Cathode Fluorescent)

Lamp: CCFL, Hot Cathode Fluorescent Lamp (HCFL), External Electrode Fluorescent Lamp (EEFL), and Light Emitting Diode (LED) may be any one of, but not limited to, It doesn't work.

The prism sheet 130 may be disposed on the light guide plate 240. In this case, the prism sheet 130 may be stacked in one or two sheets, for example, and when two sheets are stacked, the prism patterns 134 of the prism sheet 130 may be stacked to cross each other. It is not limited to this.

The prism sheet 130 may collect light incident from the light source 220, and may include a substrate 132 and a prism pattern 134 formed on the substrate 132. Here, the protrusion 134a may be provided on the prism pattern 134.

When an external force flows from the upper portion of the prism pattern 134 to the lower portion of the prism pattern 134, the external force may be primarily dispersed by the protrusion 134a. Accordingly, since the external force flowing directly into the prism pattern 134 may be alleviated, mechanical durability of the prism pattern 134 may be improved.

As a result, the display quality of the backlight unit 210 according to the exemplary embodiment of the present invention may be improved.

The light guide plate 240 may be disposed to face the light source 220, and may guide the light so that the light incident from the light source 220 is emitted upward.

The reflector 250 may be disposed under the light guide plate 240, and may reflect light emitted downward through the light guide plate 240 among the light emitted from the light source 220.

The bottom cover 260 may include a bottom part 262 and a side part 264 formed to extend from the bottom part 262 to form an accommodation space, and the light source 220 and the prism sheet 130 may be formed in the accommodation space. ), The light guide plate 240 and the reflective plate 250 may be accommodated.

The mold frame 270 may be formed in a substantially rectangular frame shape and may be fastened with the bottom cover 260 from the top of the bottom cover 260 in a top down manner.

On the other hand, Figure 7 is an exploded perspective view for explaining the configuration of the backlight unit according to an embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line VII-VII 'of FIG. 7. In FIG. 7, the direct type backlight unit is illustrated as the backlight unit, but the present invention is not limited thereto. Meanwhile, the backlight unit illustrated in FIG. 7 is substantially the same as the backlight unit illustrated in FIG. 5 except for disposing a light source and changing a component thereof, and thus, redundant descriptions thereof will be omitted and only the characteristics thereof will be omitted. Explain.

7 and 8, the backlight unit 310 according to an embodiment of the present invention may be provided in the liquid crystal display, and may provide light to the liquid crystal panel provided in the liquid crystal display.

The backlight unit 310 may include a light source 320 and a prism sheet 130. In addition, the backlight unit 310 may further include a reflecting plate 350, a bottom cover 360, a mold frame 370, and a diffusion plate 380.

At least one light source 320 may be disposed under the diffuser plate 380. For this reason, the light emitted from the light source 320 may be incident directly to the diffuser plate 380.

The prism sheet 130 may be disposed on the diffuser plate 380. In this case, the prism sheet 130 is stacked in two pieces, but the prism patterns of the prism sheet 130 may be stacked to cross each other, but is not limited thereto.

The prism sheet 130 may collect light incident from the light source 320 and may include a substrate 132 and a prism pattern 134 formed on the substrate 132. Here, the protrusion 134a may be provided on the prism pattern 134.

When an external force flows from the upper portion of the prism pattern 134 to the lower portion of the prism pattern 134, the external force may be primarily dispersed by the protrusion 134a. Accordingly, since the external force flowing directly into the prism pattern 134 may be alleviated, mechanical durability of the prism pattern 134 may be improved.

As a result, the display quality of the backlight unit 310 according to the exemplary embodiment of the present invention may be improved.

The diffusion plate 380 may be disposed between the light source 320 and the prism sheet 130, and may diffuse light incident from the light source 320 upward. This is to prevent the shape of the light source 320 from being visible through the backlight unit 310 and to further diffuse the light.

FIG. 9 is an exploded perspective view illustrating the configuration of a liquid crystal display according to an exemplary embodiment of the present invention. FIG. 10 is a cross-sectional view taken along the line VII-VII 'of FIG. 9. In FIG. 9, the backlight unit illustrated in FIG. 5 is illustrated as the backlight unit, but the present invention is not limited thereto, and the backlight unit illustrated in FIG. 7 may be employed as the backlight unit. Meanwhile, since the backlight unit illustrated in FIG. 9 is the same as described above, overlapping descriptions are omitted and only the features thereof will be described.

9 and 10, the liquid crystal display device 400 according to an exemplary embodiment may display an image by using the electro-optical characteristics of the liquid crystal.

The liquid crystal display device 400 may include a backlight unit 210 and a liquid crystal panel 410.

The backlight unit 210 may be mounted under the liquid crystal panel 410 and may provide light to the liquid crystal panel 410.

The backlight unit 210 may include a light source 220 and a prism sheet 130. In addition, the backlight unit 210 may further include a light guide plate 240, a reflective plate 250, a bottom cover 260, and a mold frame 270.

The liquid crystal panel 410 is seated on the mold frame 270 and may be fixed by the top cover 420 fastened to the bottom cover 260 in a top-down manner.

The liquid crystal panel 410 may display an image using light provided from the backlight unit 210, specifically, light emitted from the light source 220.

The liquid crystal panel 410 may include a color filter substrate 412 and a thin film transistor substrate 414 facing each other with the liquid crystal interposed therebetween.

The color filter substrate 412 may implement colors of an image displayed through the liquid crystal panel 410.

The color filter substrate 412 may include a color filter array formed of a thin film on a transparent substrate such as glass or plastic, for example, a red / green / blue color filter. Here, an upper polarizer may be disposed on the color filter substrate 412.

The thin film transistor substrate 414 is electrically connected to the printed circuit board 418 on which a plurality of circuit components are mounted through the driving film 416. The thin film transistor substrate 414 may apply a driving voltage provided from the printed circuit board 418 to the liquid crystal in response to a driving signal provided from the printed circuit board 418.

The thin film transistor substrate 414 may include a thin film transistor and a pixel electrode formed of a thin film on another substrate of a transparent material such as glass or plastic. Here, a lower polarizer may be attached to the lower portion of the thin film transistor substrate 414.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can realize that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. I can understand that.

Therefore, since the embodiments described above are provided to completely inform the scope of the invention to those skilled in the art, it should be understood that they are exemplary in all respects and not limited. The invention is only defined by the scope of the claims.

1 is a perspective view illustrating a prism sheet according to an embodiment of the present invention.

2 is a cross-sectional view illustrating a prism sheet according to an embodiment of the present invention.

3 is a photograph of a portion of a prism sheet according to an embodiment of the present invention by using a scanning electron microscope.

4 is a process flowchart schematically illustrating a method of manufacturing a prism sheet according to an embodiment of the present invention.

5 is an exploded perspective view for describing the configuration of a backlight unit according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along the line VI-VI ′ of FIG. 5.

7 is an exploded perspective view for explaining the configuration of a backlight unit according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along the line VII-VII 'of FIG. 7.

9 is an exploded perspective view illustrating a configuration of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 10 is a cross-sectional view taken along the line VII-VII 'of FIG. 9.

{Description of symbols for main parts of the drawing}

130: prism sheet 132: base material

134: prism pattern 134a: protrusion

210, 310: backlight unit 220, 320: light source

400: liquid crystal display 410: liquid crystal panel

Claims (13)

A substrate for transmitting light incident from the outside; And A prism pattern formed on the substrate and having a protrusion Prism sheet comprising a. The method of claim 1, The prism sheet of the prism pattern, characterized in that formed around the floor of the prism pattern. The method of claim 1, The prism sheet, characterized in that the width of the protrusion of the prism pattern is irregular. The method of claim 1, The prism sheet of the prism pattern, characterized in that spaced apart from each other. Preparing a substrate; And Forming a prism pattern having protrusions on the substrate; Method for producing a prism sheet comprising a. The method of claim 5, wherein the forming of the prism pattern comprises: Applying a polymer resin solution onto the substrate; Curing the polymer resin solution to form an unformed prism pattern; And Pressing the prism pattern to form the protrusion on the prism pattern in which the protrusion is not formed. Method for producing a prism sheet comprising a. The method of claim 6, In the pressing of the prism pattern, a method of manufacturing a prism sheet, characterized by using a mold having a reverse phase of the protruding portion. The method of claim 6, In the pressing of the prism pattern, a method of manufacturing a prism sheet, characterized in that a sheet in which a reverse phase of the protrusion is formed is used. A light source for emitting light; And Prism sheet for collecting light incident from the light source Including; The prism sheet, A substrate that transmits light incident from the light source; And A prism pattern formed on the substrate and having a protrusion Backlight unit comprising a. The method of claim 9, The projection unit of the prism pattern of the prism sheet, characterized in that formed around the floor of the prism pattern. The method of claim 9, And a width of a protrusion of the prism pattern of the prism sheet is irregular. The method of claim 9, The projection unit of the prism pattern of the prism sheet, characterized in that spaced apart from each other. A light source for emitting light; A prism sheet for collecting light incident from the light source; And Liquid crystal panel for displaying an image using the light emitted from the light source Including; The prism sheet, A substrate that transmits light incident from the light source; And A prism pattern formed on the substrate and having a protrusion Liquid crystal display comprising a.

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