KR101380056B1 - Liquid crystal display - Google Patents

Abstract

An optical sheet, a backlight unit having the same, and a liquid crystal display including the same are disclosed. The optical sheet includes a substrate having a microlens formed on one surface thereof and a prism pattern formed on one surface of the substrate.

Optical sheet, base material, microlens, prism pattern, luminance

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY}

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

2 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 1.

3 is a perspective view illustrating an optical sheet according to an embodiment of the present invention.

4 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 3.

5 is a perspective view illustrating an optical sheet according to an embodiment of the present invention.

6 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 5.

7 is a perspective view illustrating an optical sheet according to an embodiment of the present invention.

8 is a cross-sectional view for describing in detail the optical sheet illustrated in FIG. 7.

9 is an exploded perspective view illustrating the configuration of a backlight unit according to an embodiment of the present invention.

FIG. 10 is a cross-sectional view taken along the line II ′ of FIG. 9.

11 is an exploded perspective view illustrating the configuration of a backlight unit according to an exemplary embodiment of the present invention.

FIG. 12 is a cross-sectional view taken along the line II-II ′ of FIG. 11.

FIG. 13 is an exploded perspective view illustrating a configuration of a liquid crystal display according to an exemplary embodiment of the present invention.

14 is a cross-sectional view taken along line III-III ′ of FIG. 13.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS FIG.

130: optical sheet 132: base material

134: lenticular lens 136: prism pattern

210: backlight unit 220: light source

300: liquid crystal display 310: liquid crystal panel

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

A liquid crystal display classified into a light receiving display device includes a backlight unit mounted below a liquid crystal panel displaying an image.

The conventional backlight unit may include not only a light source for emitting light but also an optical sheet for improving optical characteristics of the backlight unit, for example, brightness. For example, the backlight unit may include an optical sheet having a prism pattern formed on one surface of a substrate having a flat shape.

Since the optical sheets are generally provided in the backlight unit in a plurality of stacked forms, the optical sheets may contact each other. In this case, when the contact range between the optical sheets is large, optical defects of the optical sheets, for example, a wet-out phenomenon may occur.

The infiltration phenomenon may appear as a moire pattern in an image displayed through a liquid crystal display.

Accordingly, an aspect of the present invention is to provide an optical sheet capable of reducing optical defects in a display device, a backlight unit having the same, and a liquid crystal display device having the same.

Further technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above are clearly understood by those skilled in the art from the following description. It can be understood.

Optical sheet according to an embodiment of the present invention for achieving the above technical problem is a substrate formed with a micro lens on one surface; And a prism pattern formed on one surface of the substrate.

On the other hand, the backlight unit according to an embodiment of the present invention for achieving the above technical problem is a light source for emitting light; And an optical sheet including a substrate having a microlens formed on one surface and a prism pattern formed on one surface of the substrate, and condensing light emitted from the light source.

According to another aspect of the present invention, there is provided a liquid crystal display comprising: a light source for emitting light; An optical sheet having a substrate having a microlens formed on one surface thereof and a prism pattern formed on one surface of the substrate, and condensing light emitted from the light source; And a liquid crystal panel which displays an image using light emitted from the light source.

The details of other embodiments are included in the detailed description and drawings. 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. Like reference numerals refer to like elements throughout the specification.

When describing the arrangement relationship between each component throughout the specification, when it is disposed on the upper side, this includes not only the case disposed on the upper side in the vertical direction, but also the case disposed on the upper side in the oblique direction. Likewise, when describing the arrangement relationship among the respective components throughout the specification, the term "disposed at the bottom" includes not only the case of being disposed at the lower side in the vertical direction but also the case of being disposed at the lower side in the oblique direction.

Meanwhile, in an embodiment of the present invention, a case in which a lenticular lens, which is a type of micro lens, is formed on one surface of the substrate of the optical sheet is described as an example, but the present invention is not limited thereto. That is, a micro lens of another type may be formed on one surface of the substrate instead of the lenticular lens.

Hereinafter, an optical sheet, a backlight unit having the same, and a liquid crystal display including the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view illustrating an optical sheet according to an embodiment of the present invention. 2 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 1.

1 and 2, an optical sheet 130 according to an embodiment of the present invention may be provided in a backlight unit of a liquid crystal display. In this case, the optical sheet 130 may improve the optical characteristics of the backlight unit, for example, brightness.

The optical sheet 130 may include a substrate 132 and a prism pattern 136.

The substrate 132 may transmit light incident from an external light source, and may partially condense the light.

The substrate 132 is a light transmissive material that can smoothly transmit light in the visible region, for example, any one material selected from the group consisting of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, and polyepoxy It can be formed as.

A lenticular lens 134, which is a kind of micro lens, is formed on one surface of the substrate 132. Here, the lenticular lens 134 may be formed in an integrated form with the substrate 132, but is not limited thereto. For example, after the substrate 132 and the lenticular lens 134 are respectively formed, the lenticular lens 134 may be stacked on one surface of the substrate 132.

The lenticular lens 134 may be formed in a semi-cylindrical shape or a semi-elliptic cylinder shape. That is, the lenticular lens 134 has a semi-circle or semi-ellipse shape on the XZ plane and is linearly formed along the Y-axis direction, thereby forming a semi-cylindrical shape or a semi-elliptic cylinder shape. Due to the shape of the lenticular lens 134, the base material 132 can condense part of the light incident from the external light source as described above.

The lenticular lens 134 may be formed to be spaced apart from each other, but is not limited thereto. In addition, the pitch P1 of the lenticular lens 134 may be constant, but this may vary depending on the specification of the optical sheet 130, but is not limited thereto.

The prism pattern 136 is formed on one surface of the substrate 132 on which the lenticular lens 134 is formed, and may collect light incident on the substrate 132 from an external light source and transmitted through the substrate 132. . In this case, the light collected by the prism pattern 136 may be emitted upward.

The prism pattern 136 may be formed in a triangular prism bar shape by having a triangular shape on the XZ plane and being linearly formed along the Y-axis direction. In this case, since the prism pattern 136 is formed to be parallel to the Y-axis direction, which is the longitudinal direction of the lenticular lens 134, the prism pattern 136 is 0 degrees (or 180) with respect to the longitudinal direction of the lenticular lens 134. Degree of intersection). In addition, the height H1 of the prism pattern 136 may be constant not only on the XZ plane but along the Y-axis direction, which is the longitudinal direction of the prism pattern 136. In this case, the top end of the prism pattern 136 is formed in a straight line along the Y-axis direction.

Meanwhile, although the height H1 of the prism pattern 136 is constant, since the prism pattern 136 is also formed between the lenticular lens 134 and the lenticular lens 134, the prism pattern 136 is apparently between the prism patterns 136. Elevation will occur.

This is possible because the width W1 of the prism pattern 136 is smaller than the width W2 of the lenticular lens 134. That is, when the width W1 of the prism pattern 136 is larger than the width W2 of the lenticular lens 134, the prism pattern 136 may be formed to accommodate the lenticular lens 134, in which case Apparently the height between the prism patterns 136 may not occur. Therefore, by making the width W1 of the prism pattern 136 smaller than the width W2 of the lenticular lens 134, the height may be generated between the prism patterns 136 in appearance.

As such, since the height is generated between the prism patterns 136 in appearance, the contact range between the optical sheets 130 is significantly reduced even if the optical sheets 130 are stacked to be in contact with each other. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

3 is a perspective view illustrating an optical sheet according to an embodiment of the present invention. 4 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 3. The optical sheets shown in FIGS. 3 and 4 are the same as the optical sheets shown in FIGS. 1 and 2 except that the pitch of the lenticular lens is variable, and thus descriptions thereof will not be repeated, and only the features thereof will be described. .

3 and 4, an optical sheet 130 according to an embodiment of the present invention may be provided in a backlight unit of a liquid crystal display. In this case, the optical sheet 130 may improve the optical characteristics of the backlight unit, for example, brightness.

The optical sheet 130 may include a substrate 132 and a prism pattern 136, and a lenticular lens 134, which is a type of micro lens, is formed on one surface of the substrate 132.

The lenticular lens 134 may be formed to be spaced apart from each other, but is not limited thereto. In addition, the pitch P1 of the lenticular lens 134 may vary. For example, the pitch P1 of the lenticular lens 134 may become smaller or randomly vary from the center of the substrate 132 to the edge of the substrate 132. Here, the degree to which the pitch P1 of the lenticular lens 134 varies may be appropriately selected according to the specification of the optical sheet 130 and the arrangement of the external light source.

Although the prism pattern 136 is formed to have a predetermined height H1 on one surface of the substrate 132 on which the lenticular lens 134 is formed, the prism pattern 136 is formed on the lenticular lens 134 and the lenticular lens. Since it is also formed between the 134, the height is generated between the prism pattern 136 in appearance.

For this reason, even if the optical sheets 130 are in contact with each other by being stacked, the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

5 is a perspective view illustrating an optical sheet according to an embodiment of the present invention. 6 is a cross-sectional view for describing in detail the optical sheet shown in FIG. 5. 5 and 6 are the same as the optical sheets shown in FIGS. 1 and 2 except that the height of the prism pattern varies along the longitudinal direction of the prism pattern. Only its features will be described.

5 and 6, the optical sheet 130 according to an embodiment of the present invention may be provided in the backlight unit of the liquid crystal display. In this case, the optical sheet 130 may improve the optical characteristics of the backlight unit, for example, brightness.

The optical sheet 130 may include a substrate 132 and a prism pattern 136, and a lenticular lens 134, which is a type of micro lens, is formed on one surface of the substrate 132.

The prism pattern 136 is formed on one surface of the substrate 132 on which the lenticular lens 134 is formed.

The height H1 of the prism pattern 136 may vary not only on the XZ plane but also along the Y-axis direction, which is the longitudinal direction of the prism pattern 136. For example, the height H1 of the prism pattern 136 may vary along the Y-axis direction such that the uppermost portion of the prism pattern 136 has a wave shape. In addition, the height H1 of the prism pattern 136 may vary in a random form along the Y-axis direction.

Accordingly, the height is more and more generated between the prism patterns 136 in appearance.

For this reason, even if the optical sheets 130 are contacted by stacking the optical sheets 130, the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

7 is a perspective view illustrating an optical sheet according to an embodiment of the present invention. 8 is a cross-sectional view for describing in detail the optical sheet illustrated in FIG. 7. The optical sheet shown in FIGS. 7 and 8 is the same as the optical sheet shown in FIGS. 1 and 2 except that the prism pattern is formed to be perpendicular to the longitudinal direction of the lenticular lens, and thus redundant description is omitted. Only its features will be described.

7 and 8, the optical sheet 130 according to an embodiment of the present invention may be provided in the backlight unit of the liquid crystal display. In this case, the optical sheet 130 may improve the optical characteristics of the backlight unit, for example, brightness.

The optical sheet 130 may include a substrate 132 and a prism pattern 136, and a lenticular lens 134, which is a type of micro lens, is formed on one surface of the substrate 132.

The prism pattern 136 is formed on one surface of the substrate 132 on which the lenticular lens 134 is formed.

The prism pattern 136 has a triangular shape on the XZ plane and is linearly formed along the Y-axis direction, thereby forming a triangular prism bar shape. In this case, since the prism pattern 136 may be formed to be perpendicular to the Y-axis direction, which is the longitudinal direction of the lenticular lens 134, the prism pattern 136 has a cross angle of 90 degrees with respect to the longitudinal direction of the lenticular lens 134. Will have This is to further improve the brightness and viewing angle characteristics of the backlight unit by changing the condensing direction between the lenticular lens 134 and the prism pattern 136.

Although the prism pattern 136 is formed to have a predetermined height H1 on one surface of the substrate 132 on which the lenticular lens 134 is formed, the region where the prism pattern 136 overlaps the lenticular lens 134 and The height of the prism pattern 136 is apparent between the lenticular lens 134 and the non-overlapped region. That is, the prism pattern 136 may be formed in a curved shape by the shape of the lenticular lens 134.

For this reason, even if the optical sheets 130 are in contact with each other by being stacked, the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

Meanwhile, in the optical sheet 130 according to an embodiment of the present invention, when the prism pattern 136 is formed to have an intersection angle of 0 degrees (or 180 degrees) or 90 degrees with respect to the longitudinal direction of the lenticular lens 134. Although described as an example, the present invention is not limited thereto, and the crossing angle may have a range of 0 degrees to 180 degrees.

9 is an exploded perspective view illustrating the configuration of a backlight unit according to an embodiment of the present invention. FIG. 10 is a cross-sectional view taken along the line II ′ of FIG. 9. In FIG. 9, an edge type backlight unit is illustrated as the backlight unit, but the present invention is not limited thereto. In addition, although the optical sheet shown in FIG. 1 is shown in FIG. 9 as an optical sheet, this invention is not limited to this, The optical sheet shown in FIGS. 3, 5, and 7 may be employ | adopted as the said optical sheet. . On the other hand, the overlapping description of the optical sheet will be omitted, and only its features will be described.

9 and 10, the backlight unit 210 according to an embodiment of the present invention may be provided in the liquid crystal display. In this case, the backlight unit 210 may provide light to the liquid crystal panel of the liquid crystal display device.

The backlight unit 210 may include a light source 220 and an optical sheet 130. The backlight unit 210 may further include a light guide plate 240, a reflection plate 250, a bottom cover 260, and a mold frame 270.

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

The light source 220 may be formed on at least one side of the light guide plate 240 along the X axis direction that is the long axis direction of the light guide plate 240 or may be formed on both sides of the light guide plate 240 along the X axis direction At least one or more of them may be formed. The light emitted from the light source 220 may be directly incident into the light guide plate 240 or may be incident on the light source housing 222 formed to surround a part of the light source 220, for example, about 3/4 of the outer peripheral surface of the light source 220 And then may be incident into the light guide plate 240.

Specifically, the light source 220 may include a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an External Electrode Fluorescent Lamp (EEFL), and a Light Emitting Diode. It may be one of (Light Emitting Diode: LED), but is not limited thereto.

The optical sheet 130 is disposed on the light guide plate 240, and condenses the light emitted from the light source 220 to improve optical characteristics of the backlight unit 210, for example, brightness. Here, the optical sheet 130 may be stacked in two layers of the optical sheet 130 shown in FIG. 1, and the prism patterns 136 of the optical sheet 130 may cross each other.

As such, even when the optical sheets 130 are in contact with each other by stacking the optical sheets 130, heights are generated between the prism patterns 136 in appearance, so that the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

According to the specification of the backlight unit 210, at least one or more of an optical sheet, for example, a protective sheet, a diffusion sheet, and a reflective polarizing film, which are not shown in addition to the optical sheet 130, may be additionally provided.

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

The reflector 250 is disposed below the light guide plate 240, and may reflect light emitted downward from the light source 220 through the light guide plate 240 upward.

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. The light source 220 and the optical sheet 130 may be formed in the accommodation space. I can store it. In addition, the bottom cover 260 may accommodate the reflective plate 250 and the light guide plate 240 in the storage space.

The mold frame 270 may be formed in a substantially rectangular frame shape and disposed at the outermost portion of the backlight unit 210 to surround the edge of the optical sheet 130. The mold frame 270 may be fastened to the bottom cover 260 in a top down manner from an upper side of the bottom cover 260.

11 is an exploded perspective view illustrating the configuration of a backlight unit according to an exemplary embodiment of the present invention. FIG. 12 is a cross-sectional view taken along the line II-II ′ of FIG. 11. In FIG. 11, the direct type backlight unit is illustrated as the backlight unit, but the present invention is not limited thereto. In addition, although the optical sheet shown in FIG. 1 is shown in FIG. 11 as an optical sheet, this invention is not limited to this, The optical sheet shown in FIGS. 3, 5, and 7 may be employ | adopted as the said optical sheet. . On the other hand, the backlight unit shown in FIG. 11 is substantially the same as the backlight unit shown in FIG. 9 except that the arrangement of the light sources is different. Therefore, the overlapping description is omitted and only the features thereof will be described. Similarly, the description which overlaps with an optical sheet is abbreviate | omitted and only the characteristic is demonstrated.

11 and 12, the backlight unit 210 according to an embodiment of the present invention may be provided in the liquid crystal display. In this case, the backlight unit 210 may provide light to the liquid crystal panel of the liquid crystal display device.

The backlight unit 210 may include a light source 220 and an optical sheet 130. In addition, the backlight unit 210 may further include a reflection plate 250, a bottom cover 260, a mold frame 270, and a diffusion plate 280.

The light source 220 may be driven by receiving power from the outside to generate light, and may emit the generated light. Here, at least one light source 220 may be disposed below the diffusion plate 280. For this reason, the light emitted from the light source 220 may be incident directly to the diffuser plate 280.

The optical sheet 130 may be disposed on the diffuser plate 280 to improve optical characteristics of the backlight unit 210, for example, brightness by condensing the light emitted from the light source 220. Here, the optical sheet 130 may be stacked in two layers of the optical sheet 130 shown in FIG. 1, and the prism patterns 136 of the optical sheet 130 may cross each other.

As such, even when the optical sheets 130 are in contact with each other by stacking the optical sheets 130, heights are generated between the prism patterns 136 in appearance, so that the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur.

The diffusion plate 280 may be disposed between the light source 220 and the optical sheet 130, and may diffuse light incident from the light source 220 upward. This is to prevent the shape of the light source 220 from being visible through the backlight unit 210 and to further diffuse the light.

FIG. 13 is an exploded perspective view illustrating a configuration of a liquid crystal display according to an exemplary embodiment of the present invention. 14 is a cross-sectional view taken along line III-III ′ of FIG. 13. In FIG. 13, the backlight unit illustrated in FIG. 9 is illustrated as the backlight unit. However, the present invention is not limited thereto, and the backlight unit illustrated in FIG. 11 may be employed as the backlight unit. Meanwhile, since the backlight unit illustrated in FIG. 13 is the same as described above, overlapping descriptions are omitted and only the features thereof will be described.

Referring to FIGS. 13 and 14, the liquid crystal display 300 according to the exemplary embodiment displays an image using the electro-optical characteristics of the liquid crystal.

The liquid crystal display 300 according to the exemplary embodiment of the present invention may include a backlight unit 210 and a liquid crystal panel 310.

The backlight unit 210 may be mounted under the liquid crystal panel 310 and may provide light to the liquid crystal panel 310.

The backlight unit 210 may include a light source 220 and an optical sheet 130. The backlight unit 210 may further include a light guide plate 240, a reflection plate 250, a bottom cover 260, and a mold frame 270.

The optical sheets 130 may be stacked to contact the optical sheets 130. However, as described above, since the height is generated between the prism patterns 136 in appearance, the contact range between the optical sheets 130 is significantly reduced. As a result, optical defects, for example, infiltration of the optical sheet 130 do not occur. As a result, since the moire pattern may not appear in the liquid crystal display 300, the image quality of the liquid crystal display 300 may be improved.

The liquid crystal panel 310 may be seated on the mold frame 270 and may be fixed by the top cover 320 fastened to the bottom cover 260 in a top-down manner.

The liquid crystal panel 310 may display an image using light provided from the backlight unit 210, specifically, light emitted from the light source 220.

The liquid crystal panel 310 may include a color filter substrate 312 and a thin film transistor substrate 314 facing each other with the liquid crystal interposed therebetween.

The color filter substrate 312 may implement colors of the image displayed through the liquid crystal panel 310.

The color filter substrate 312 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, the upper polarizer may be disposed on the color filter substrate 312.

The thin film transistor substrate 314 is electrically connected to the printed circuit board 318 on which a plurality of circuit components are mounted through the driving film 316. The thin film transistor substrate 314 applies the driving voltage provided from the printed circuit board 318 to the liquid crystal in response to the driving signal provided from the printed circuit board 318.

The thin film transistor substrate 314 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 314.

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, You will understand.

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.

According to the present invention, it is possible to reduce the occurrence of optical defects of the optical sheet, for example, infiltration phenomenon. Through this, it is possible to prevent the deterioration of the image quality of the liquid crystal display.

Claims (19)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A light source for emitting light; An optical sheet having a substrate having a microlens formed on one surface thereof and a prism pattern formed on one surface of the substrate, and condensing light emitted from the light source; And It includes a liquid crystal panel for displaying an image using the light emitted from the light source, The micro lens is formed in a semi-cylindrical shape or semi-elliptic cylinder shape, The micro lenses are formed to be spaced apart from each other, The width of the prism pattern is smaller than the width of the micro lens, The prism pattern has a crossing angle of 0 degrees or more and 180 degrees or less with respect to the length direction of the micro lens, And at least two optical sheets stacked on the optical sheets so that the prism patterns cross each other.

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