KR20140073012A - Prism sheet, back light unit and display device comprising the same - Google Patents

Abstract

The present invention relates to a prism sheet a back light unit and a display device including the same. The prism sheet includes: first and second base layers disposed in parallel; a plurality of first prism mountains formed on one surface of the first base layer, arrayed along a first axis direction, and extended in a second axis direction which is perpendicular to the first axis direction; a first opaque layer disposed on another surface of the first base layer; a plurality of second prism mountains formed on one surface of the second base layer, arrayed along the second axis direction, and extended in the first axis direction; and a second opaque layer disposed on another surface of the second base layer, wherein the first opaque layer includes a plurality of optical grooves scattering a light and the optical grooves are formed on a surface facing the second prism mountains on the first opaque layer. In addition, the second opaque layer includes a plurality of optical bumps scattering a light and the optical bumps are formed to protrude in a direction facing the second opaque layer in the second prism mountains. According to the present invention, image quality displayed on a display panel can be improved by preventing or minimizing an effect due to a light interference phenomenon occurring in the prism sheet by the first opaque layer including the optical grooves and the second opaque layer including the optical bumps.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a prism sheet, a backlight unit including the prism sheet,

The present invention relates to a prism sheet for improving brightness of light supplied to a display panel, a backlight unit including the prism sheet, and a display device.

In recent years, flat panel display devices replacing a cathode ray tube (CRT) display device have been developed to attain thinning, tilting, and low power consumption.

As a flat panel display device, a liquid crystal display device, a plasma display panel, a field emission display device, and a light emitting display device have been actively studied , Mass production technology, ease of driving means, and realization of high image quality.

A liquid crystal display device displays an image using a thin film transistor (Thin Film Transistor) as a switching element. The liquid crystal display device is used not only in a television or a monitor, but also in a notebook computer, a tablet computer, a navigation system, or various portable information devices.

Since a liquid crystal display panel used in such a liquid crystal display device is not a self-luminous device, a light source is provided and an image is displayed using light emitted from a light source.

A plurality of optical sheets are disposed between the light source and the liquid crystal display panel. Such an optical sheet diffuses light emitted from a light source to uniformize or refract and condense light to control the light path. As the number of the optical sheets increases, the thickness of the display device becomes thicker. Therefore, research on reducing the number of such optical sheets has been conducted in recent years. As a result of this research, a prism sheet having two sheets of prism sheets joined together to form a single sheet was developed.

1 is a perspective view schematically showing a prism sheet according to the prior art. 2 is a cross-sectional view illustrating a problem of a prism sheet according to the related art.

Referring to FIG. 1, a prism sheet 1 according to the prior art is composed of a first sheet 10 and a second sheet 20. In the prism sheet 1 according to the related art, the first sheet 10 and the second sheet 20 are integrally joined together.

The first sheet 10 includes a first base layer 11 and a plurality of first prism mountains 12 formed on the upper surface of the first base layer 11.

The second sheet 20 is attached to the lower surface of the first sheet 10. The second sheet 20 includes a second base layer 21 and a plurality of second prism mountains 22 formed on the upper surface of the second base layer 21. The plurality of second prism mountains 22 are formed between the first base layer 11 and the second base layer 21.

As a result, when the first sheet 10 and the second sheet 20 are joined together, the first base layer 11 of the first sheet 10 and the second prism 20 of the second sheet 20, The acid 22 is bonded.

Referring to FIG. 2, the diffusion sheet 30 is attached to the lower surface of the prism sheet 1 according to the related art. That is, the diffusion sheet 30 is bonded to the second base layer 21 of the prism sheet 1.

The following problems occur in the prism sheet 1 according to the related art as described above.

First, the prism sheet 1 according to the related art is formed by integrally joining the first sheet 10 and the second sheet 20 together. As a result, the prism sheet 1 according to the prior art is formed by joining two sheets. In the case where two thin sheets are adhered to each other, impurities such as foreign matter or air are introduced between the sheets, and the sheet continues to be positioned between the two sheets. The impurity layer due to the impurities affects the light passing through the prism sheet 1 according to the prior art, causing a light interference phenomenon such as a wet-out phenomenon or a Newton's ring phenomenon. As a result, light passing through the prism sheet 1 according to the prior art is scattered by such an impurity layer, and the quality of the image displayed on the display device is deteriorated by such light.

Secondly, the prism sheet 1 according to the prior art is bonded to the diffusion sheet 30. Even when the prism sheet 1 according to the related art is bonded to the diffusion sheet 30, optical interference phenomena such as wet-out phenomenon or Newton's ring phenomenon may also occur due to impurities. This causes a problem that the quality of the image displayed on the display device is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a prism sheet capable of preventing or minimizing optical interference phenomenon, a backlight unit including the prism sheet, and a display device.

In order to solve the above-described problems, the present invention can include the following configuration.

A prism sheet according to the present invention includes a first base layer and a second base layer arranged in parallel with each other; A plurality of first prism mountains formed on one surface of the first base layer and extending along a first axis direction and extending in a second axis direction perpendicular to the first axis direction; A first opaque layer disposed on the other surface of the first base layer; A plurality of second prism mountains formed on one surface of the second base layer, the second prism mountains being arranged along the second axis direction and extending in the first axis direction; And a second opaque layer disposed on the other side of the second base layer, wherein the first opaque layer includes a plurality of optical grooves for scattering light, wherein the optical grooves are formed in the first opaque layer, Is formed on the surface facing the prism mountain; The second opaque layer may include a plurality of optical protrusions for scattering light, and may be formed to protrude from the second prism mountain toward the second opaque layer.

A display device according to the present invention includes: a display panel for displaying an image; A plurality of light emitting diodes for emitting light to be supplied to the display panel; A light guide plate for transmitting light emitted from the plurality of light emitting diodes to the display panel; A diffusion sheet disposed in front of the light guide plate; And a prism sheet disposed in front of the diffusion sheet.

According to the present invention, there are the following effects.

The first opaque layer including the optical grooves and the second opaque layer including the optical protrusions can prevent or minimize the influence of the optical interference phenomenon occurring in the prism sheet to improve the quality of the image displayed on the display panel .

Specifically, the optical quality of the image can be prevented or minimized by the optical interference phenomenon occurring between the first sheet and the second sheet due to the plurality of optical grooves formed in the first opaque layer of the first sheet.

In addition, the plurality of optical protrusions formed on the second opaque layer of the second sheet can prevent or minimize deterioration of image quality due to a light interference phenomenon occurring between the prism sheet and the diffusion sheet.

1 is a perspective view schematically showing a prism sheet according to the related art.
2 is a cross-sectional view illustrating a problem of a prism sheet according to the related art.
3 is a perspective view schematically showing a backlight unit including a prism sheet according to an embodiment of the present invention.
4A is a cross-sectional view showing the backlight unit seen from the line AA in Fig.
FIG. 4B is a cross-sectional view showing the backlight unit viewed from the line BB in FIG. 3; FIG.
5 is a cross-sectional view schematically showing a prism sheet according to an embodiment of the present invention.
6 is a cross-sectional view showing a prism sheet viewed from an AA line to explain a prism sheet according to another embodiment of the present invention.
7 is a cross-sectional view showing a prism sheet viewed from a BB line to explain a prism sheet according to another embodiment of the present invention.
8 is a perspective view schematically showing a backlight unit according to the present invention.
9 is a perspective view schematically showing a display device according to the present invention.

Hereinafter, preferred embodiments of the prism sheet according to the present invention will be described in detail with reference to the accompanying drawings.

3 to 5, a prism sheet 1 according to the present invention includes a first sheet 10 and a second sheet 20. [ The first sheet 10 includes a first base layer 11, a plurality of first prism mountains 12 formed on one surface of the first base layer 11, And a first opaque layer 13 formed on the other surface. The second sheet 20 includes a second base layer 21 arranged in parallel with the first base layer 11 and a plurality of second prism mountains 21 formed on one surface of the second base layer 21, 22 and a second opaque layer 23 formed on the other surface of the second base layer 21. The first sheet 10 and the second sheet 20 are integrally joined together to constitute a prism sheet 1 according to the present invention.

The first prism mountains 12 are arranged along the first axis direction (X axis direction). The first prism mountains 12 are formed to extend in a second axis direction (Y axis direction) perpendicular to the first axis direction (X axis direction).

The first opaque layer (13) is formed on the other surface of the first base layer (11). The first opaque layer (13) includes a plurality of optical grooves (14). The optical grooves 14 scatter light passing through the first opacifying layer 13 to make the first opacifying layer 13 opaque.

The second prism mountains 22 are arranged along the second axis direction (Y axis direction). The second prism mountain 22 is formed to extend in the first axis direction (X axis direction).

The second opaque layer 23 is formed on the other surface of the second base layer 21. The second opaque layer (23) includes a plurality of optical protrusions (24). The optical protrusions 24 scatter light passing through the second opacifying layer 23 to make the second opacifying layer 23 opaque.

The prism sheet 1 according to the present invention as described above exerts the following operational effects.

First, the prism sheet 1 according to the present invention is characterized in that the first sheet 10 and the second sheet 20 are bonded together by the first opaque layer 13 including the plurality of optical grooves 14, It is possible to minimize the influence of the optical interference phenomenon occurring in the case where the light interference occurs. The first opaque layer 13 is formed opaque by the plurality of optical grooves 14 that scatter light. Therefore, even if an optical interference phenomenon occurs between the first sheet 10 and the second sheet 20, this phenomenon can not be visually confirmed. Since the optical interference phenomenon is obscured by the first opaque layer 13 so that it can not be visually confirmed, the optical interference phenomenon does not affect the image displayed on the display panel. Accordingly, the prism sheet 1 according to the present invention can improve the quality of the image displayed on the display panel.

The prism sheet 1 according to the present invention is characterized in that when the prism sheet 1 and the diffusion sheet 30 are bonded by the second opaque layer 23 including the plurality of optical protrusions 24 The influence of the optical interference phenomenon occurring can be minimized. The second opacifying layer 23 is formed opaquely by the plurality of optical protrusions 24 that scatter light. Therefore, even if an optical interference phenomenon occurs in the prism sheet 1 and the diffusion sheet 30, this phenomenon can not be visually confirmed. That is, since the second opaque layer 23 does not affect the image displayed on the display panel, the quality of the image displayed on the display panel can be improved.

Hereinafter, the first base layer 11, the first prism mountain 12, the first sheet 10 including the first opaque layer 13 and the second base layer 21, 2 prism mountain 22, and the second sheet 20 including the second opacifying layer 23 will be described in detail with reference to the accompanying drawings.

3 to 5, the first base layer 11 is formed of a transparent material. The first base layer 11 may be formed of polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), or the like. The plurality of first prism mountains 12 are formed on one surface of the first base layer 11 and the first opaque layer 13 is formed on the other surface.

3 to 5, the plurality of first prism mountains 12 are formed on one surface of the first base layer 11. The plurality of first prism mountains 12 are formed on the front surface of the first base layer 11. The plurality of first prism mountains 12 are arranged along the first axis direction (X-axis direction) on the front surface of the first base layer 11. The plurality of first prism mountains 12 extend along the second axis direction (Y axis direction).

The prism sheet 1 according to the present invention is bonded to the display panel 40. The display panel 40 includes a lower substrate 42 and a lower polarizer 43 attached to the lower substrate 42. When the prism sheet 1 according to the present invention is adhered to the display panel 40, the plurality of first prism mountains 12 of the prism sheet 1 and the lower polarizer plate 43 are bonded.

3 to 5, each of the plurality of first prism mountains 12 is composed of a first surface 121 and a second surface 122. That is, the first surface 121, the second surface 122, and the upper surface of the first base layer 11 are formed. An angle formed between the first base layer 11 and the first surface 121 and the second surface 122 is defined as a bottom angle? 1. An angle at which the first surface 121 of the first prism mountain 12 and the second surface 122 meet is defined as a prism angle? 2. The prism angle [theta] 2 is formed by two surfaces protruding from the first base layer 11.

The first prism mountains 12 are formed such that the first surface 121 and the second surface 122 have the same length. That is, the cross section of the first prism mountain 12 is formed in an isosceles triangle. Whereby the two bottom angles? 1 are formed to be the same.

The prism angle [theta] 2 of the first prism mountain 12 is formed to be larger than 88 degrees and smaller than 93 degrees. When the prism angle [theta] 2 of the first prism mountains 12 is within the above range, the brightness of light passing through the first prism mountains 12 can be improved.

Referring to FIG. 6, the height of each of the plurality of first prism mountains 12 is irregularly formed. That is, the height of one of the first prism mountains 12 is different from the height of the other first prism mountain 12. That is, the height of each of the first prism mountains 12 may be all different, or some of them may be formed identically. Here, the height of the plurality of first prism mountains 12 refers to the length of each of the first prism mountains 12 protruding from the first base layer 11.

When the plurality of first prism mountains 12 are formed to have the same height, the plurality of first prism mountains 12 are entirely in contact with the lower polarizer plate 43. In this case, impurities such as foreign matter and air may flow into the gap between the lower polarizer 43 and the first prism mountains 12 to cause a light interference phenomenon such as a wet-out phenomenon or a Newton's ring phenomenon.

When the height of each of the plurality of first prism mountains 12 is irregularly formed as in the present embodiment, portions where the lower polarizer plate 43 and the first prism mountains 12 are in contact with each other also become irregular. That is, a part of the first prism mountain 12 is in contact with the lower polarizer 43, while the other part is not in contact with the lower polarizer 43. Therefore, a predetermined empty space may be formed between the first prism mountain 12 and the lower polarizer plate 43. Impurities such as foreign matter or air can move through this space. The optical interference phenomenon can be minimized while the impurities move, and the impurity can be discharged to the outside between the first prism mount 12 and the lower polarizer 43 in the process of moving the impurities. This can minimize or prevent optical interference phenomena such as wet-out phenomenon or Newton's ring phenomenon.

When the height of each of the plurality of first prism mountains 12 is irregularly formed, the height of the plurality of first prism mountains 12 is made equal to that of the prism sheet 1 according to the present invention, The brightness of the light passing through the light guide plate is improved.

6, when the height of each of the plurality of first prism mountains 12 is irregularly formed, the maximum prism mountain having the maximum height H1 and the minimum height H1 of the plurality of first prism mountains 12 H2. ≪ / RTI >

The height difference between the height H1 of the maximum prism mountain and the height H2 of the minimum prism mountain is greater than 2 um and less than 10 um. That is, the difference in height between any one of the first prism mountains 12 and the other one of the first prism mountains 12 is greater than 2 um and smaller than 10 um.

When the height difference between the maximum prism mountain and the minimum prism mountain is smaller than 2 um, the difference in height between the maximum prism mountain and the minimum prism mountain is not large, and a space formed between the plurality of first prism mountains 12 and the lower polarizer plate 43 It may not be enough. In this case, the optical interference phenomenon such as the wet-out phenomenon or the Newton's ring phenomenon can not be sufficiently solved.

If the height difference between the maximum prism mountains and the minimum prism mountains is 10 m or more, the minimum prism mountains become too small, and the minimum prism mountains can not perform the function of refracting or condensing the light. On the other hand, the size of the maximum prism mountains becomes too large, which causes a problem that the thickness of the entire prism sheet 1 becomes thick.

Referring to FIGS. 3 to 5, the first opaque layer 13 is formed on the first base layer 11. The first opaque layer 13 is formed on the surface of the first base layer 11 opposite to the surface on which the plurality of first prism mountains 12 are formed. The first opaque layer 13 is formed to be opaque by scattering light. When the first sheet 10 and the second sheet 20 are adhered to each other, the first opaque layer 13 scatters the interfered light even if the optical interference phenomenon occurs, and the optical interference phenomenon is visually confirmed It does not function. That is, the first opaque layer 13 functions to mask the optical interference phenomenon.

The first opaque layer 13 has a haze characteristic of more than 5% and less than 15%. The haze characteristic refers to a characteristic in which, when light passes through a transparent film, light diffuses depending on the type of the film, depending on the intrinsic properties of the material other than reflection or absorption, and thus an opaque blurred appearance appears. This haze characteristic can be quantified in accordance with the following [Equation 1].

[Formula 1]

If the haze characteristic of the first opaque layer 13 is less than 5%, optical interference phenomena such as wet-out phenomenon or Newton's ring phenomenon can not be sufficiently solved. When the haze characteristic of the first opacifying layer 13 is greater than 15%, the brightness of the light passing through the prism sheet 1 according to the present invention is so low that the quality of the image displayed on the display panel 40 Can be degraded.

Referring to FIGS. 3 to 5, the first opaque layer 13 includes a plurality of optical grooves 14. The plurality of optical grooves 14 are arranged along the second axial direction (Y-axis direction). The plurality of optical grooves 14 are formed to extend in the first axial direction (X-axis direction). As a result, the plurality of first prism mountains 12 and the plurality of optical grooves 14 are formed to be orthogonal to each other.

The optical groove 14 makes the first opaque layer 13 opaque. The optical groove 14 allows the first opaque layer 13 to have the haze characteristic described above. The haze characteristics of the first opaque layer 13 can be controlled by adjusting the size and the number of the optical grooves 14. [ The optical groove 14 scatters light passing through the first opacifying layer 13 to impart the haze characteristic to the first opacifying layer 13.

3 to 5, the second base layer 21 is formed of a transparent material. The second base layer 21 may be formed of polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), or the like. The plurality of second prism mountains 22 are formed on one surface of the second base layer 21 and the second opaque layer 23 is formed on the other surface.

Referring to FIGS. 3 to 5, the second prism mountain 22 is formed on one surface of the second base layer 21. The plurality of second prism mountains (22) are formed on the front surface of the second base layer (21). That is, the second prism mountain 22 is formed so as to protrude from the second base layer 21 toward the first base layer 11. The plurality of second prism mountains 22 are arranged along the second axis direction (Y axis direction) on the front surface of the second base layer 21. [ The plurality of second prism mountains 22 are formed extending along the first axis direction (X axis direction). As a result, the first prism mountains 12 and the second prism mountains 22 are formed to be orthogonal to each other.

Since the second prism mountains 22 are formed to extend in the first axial direction (X-axis direction) like the optical grooves 14, the second prism mountains 22 and the optical grooves 14 are arranged in parallel with each other. However, the second prism mountains 22 are not inserted between the optical grooves 14. That is, the second prism mountains 22 are formed to adhere to the portion of the first opaque layer 13 where the optical grooves 14 are not formed. When the second prism mountain 22 is inserted and adhered to the optical grooves 14, a predetermined space is not formed between the second prism mountain 22 and the first opaque layer 13 to be.

Referring to FIGS. 3 to 5, the second opaque layer 23 is formed on the second base layer 21. The second opaque layer 23 is formed on a surface of the second base layer 21 opposite to the surface on which the plurality of second prism mountains 22 are formed. The second opaque layer 23 is formed to appear to be opaque by scattering light. When the prism sheet 1 and the diffusion sheet 30 are adhered to each other, the second opaque layer 23 scatters the interference-generated light even if an optical interference phenomenon occurs, and thus the optical interference phenomenon can not be visually confirmed . That is, the second opaque layer 23 functions to mask the optical interference phenomenon.

The second opacifying layer 23 has a haze characteristic of more than 5% and less than 15%. If the haze characteristic of the second opaque layer 23 is less than 5%, optical interference phenomena such as wet-out phenomenon or Newton's ring phenomenon can not be sufficiently solved. When the haze characteristic of the second opacifying layer 23 is greater than 15%, the brightness of the light passing through the prism sheet 1 according to the present invention is so low that the quality of the image displayed on the display panel 40 Can be degraded.

3 to 5, the second opacifying layer 23 includes a plurality of optical protrusions 24. In the drawing, the plurality of optical protrusions 24 are arranged along the second axis direction (Y-axis direction), but the present invention is not limited thereto.

The optical protrusion 24 makes the second opaque layer 23 opaque. That is, the optical protrusion 24 allows the second opaque layer 23 to have the haze characteristic described above. The haze characteristic of the second opacifying layer 23 can be controlled by controlling the size and the number of the optical protrusions 24. [ The optical protrusion 24 scatters light passing through the second opacifying layer 23 and imparts a haze characteristic to the second opacifying layer 23.

Referring to FIG. 7, the height of each of the optical protrusions 24 may be irregularly formed. That is, the height of one of the plurality of optical protrusions 24 may be different from the height of the other optical protrusion 24. As a result, the height of each of the plurality of optical protrusions 24 may be all different, and the height of some of the optical protrusions 24 may be the same. Here, the height of the plurality of optical protrusions 24 refers to the length of the optical protrusions 24 protruded.

When the plurality of optical protrusions 24 are all formed to have the same height, the entire second sheet 20 comes into contact with the diffusion sheet 30. In this case, impurities such as foreign substances and air may flow into the gap between the diffusion sheet 30 and the plurality of optical protrusions 24 to cause a light interference phenomenon such as a wet-out phenomenon or a Newton's ring phenomenon.

As shown in FIG. 7, when the height of each of the plurality of optical protrusions 24 is irregularly formed, the portion where the diffusion sheet 30 and the optical protrusions 24 contact with each other becomes irregular. That is, a part of the optical protrusion 24 is in contact with the diffusion sheet 30, but the other part is not in contact with the diffusion sheet 30. Therefore, a predetermined void space may be formed between the optical protrusion 24 and the diffusion sheet 30. [ Impurities such as foreign matter or air can move through this space. The optical interference phenomenon can be minimized while the impurities move and can be discharged to the outside between the optical protrusions 24 and the diffusion sheet 30 in the process of moving the impurities. This can minimize or prevent optical interference phenomena such as wet-out phenomenon or Newton's ring phenomenon.

Hereinafter, preferred embodiments of a backlight unit according to the present invention will be described in detail with reference to the accompanying drawings.

8, the backlight unit 100 according to the present invention includes the prism sheet 1, a diffusion sheet 30 disposed behind the prism sheet 1, And a light source unit 60 that emits light toward the light guide plate 50. The light guide plate 50 includes a light guide plate 50,

Since the above-described prism sheet 1 according to the present invention can be used for the prism sheet 1, a detailed description thereof will be omitted.

The description of the diffusion sheet 30 will be replaced with the one described above.

Referring to FIG. 8, the light guide plate 50 transmits light emitted from the light source unit 60 toward the display panel 40. The light guide plate 50 may include a pattern capable of refracting light emitted from the light source unit 60 toward the display panel 40.

8, the light source unit 60 includes a plurality of light emitting diodes 61 for emitting light and a printed circuit board 62 on which the plurality of light emitting diodes 61 are mounted. The plurality of light emitting diodes (61) emits light toward one side of the light guide plate (50). The printed circuit board 62 is disposed adjacent to the light guide plate 50 so that the plurality of light emitting diodes 61 can emit light toward the light guide plate 50.

Referring to FIG. 8, the backlight unit 100 according to the present invention may further include a reflection plate 55 disposed behind the light guide plate 50. The reflection plate 55 is disposed in parallel with the back surface of the light guide plate 50. The reflection plate 55 reflects the light that is emitted from the light source unit 60 and directed to the back surface of the light guide plate 50 toward the front surface of the light guide plate 50 from the light incident on the light guide plate 50. That is, the light emitted from the light source unit 60 and incident on the light guide plate 50 reflects light not directed to the display panel 40, and directs the light toward the display panel 40. The reflection plate 55 may have a size and a shape substantially coinciding with the light guide plate 50. The reflection plate 55 may have a rectangular plate shape.

Hereinafter, preferred embodiments of the display device according to the present invention will be described in detail with reference to the accompanying drawings.

9, the display device 200 according to the present invention includes the backlight unit 100, a display panel 40 disposed in front of the backlight unit 100, And a lower cover 80 for receiving the backlight unit 100 and the display panel 40. The guide frame 70 includes a lower cover 80,

Since the backlight unit 100 according to the present invention described above can be used, a detailed description thereof will be omitted.

Referring to FIG. 9, the display panel 40 is positioned in front of the backlight unit 100. The display panel 40 displays an image using light transmitted from the backlight unit 100.

The display panel 40 includes an upper substrate 41, a lower substrate 42, an upper polarizer 44 and a lower polarizer 43. A liquid crystal side (not shown) is formed between the upper substrate 41 and the lower substrate 42. The specific configuration of the upper substrate 41 and the lower substrate 42 may be a driving mode of the display panel 40, for example, a TN (Twisted Nematic) mode, a VA (Vertical Alignment) Mode, a fringe field switching (FFS) mode, and the like.

The upper polarizer 44 is attached to the front side of the upper substrate 41 and the lower polarizer 43 is attached to the lower side of the lower substrate 42. The combination of the upper polarizer 44 and the lower polarizer 43 can adjust the transmittance of light to realize a color of black or white.

Referring to FIG. 9, the lower cover 80 supports and protects the backlight unit 100 and the display panel 40. That is, the backlight unit 100 and the display panel 40 are stacked and supported on the lower cover 80.

Referring to FIG. 9, the guide frame 70 guides the position of the backlight unit 100 supported by the lower cover 80. In particular, since the light guide plate 50 of the backlight unit 100 is weak in impact and weak in impact, the guide frame 70 is disposed around the light guide plate 50 to protect the light guide plate 50. Since the prism sheet 1 and the diffusion sheet 30 are formed of a flexible material, the prism sheet 1 and the diffusion sheet 30 are fixed.

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 invention. It will be clear to those who have knowledge.

1: prism sheet
10: first sheet 11: first base layer
12: first prism acid 13: first opaque layer
14: Optical groove
20: second sheet 21: second base layer
22: second prism acid 23: second opaque layer
24: Optical projection
30: diffusion sheet 40: display panel
100: backlight unit 200: display device

Claims (10)

A first base layer and a second base layer disposed side by side;
A plurality of first prism mountains formed on one surface of the first base layer and extending along a first axis direction and extending in a second axis direction perpendicular to the first axis direction;
A first opaque layer disposed on the other surface of the first base layer;
A plurality of second prism mountains formed on one surface of the second base layer, the second prism mountains being arranged along the second axis direction and extending in the first axis direction; And
And a second opaque layer disposed on the other surface of the second base layer.
Wherein the first opaque layer includes a plurality of optical grooves for scattering light, wherein the optical grooves are formed on a surface of the first opaque layer facing the second prism mountain;
Wherein the second opaque layer includes a plurality of optical protrusions for scattering light, and is formed to protrude from the second prism mountain toward the second opaque layer. The method according to claim 1,
Wherein the optical grooves are arranged along the second axis direction and extend in the first axis direction. The method according to claim 1,
Wherein the first opaque layer has a haze greater than 5% and less than 15%. The method according to claim 1,
Wherein the second opacifying layer has a haze greater than 5% and less than 15%. The method according to claim 1,
Wherein the height of one of the first prism mountains is different from the height of one of the other first prism mountains. The method according to claim 1,
Wherein a height difference between any one of the first prism mountains and the other one of the first prism mountains is greater than 2 um and less than 10 um. The method according to claim 1,
Wherein the first prism mountains each include a prism angle formed by two surfaces protruding from the first base layer, the prism angle being greater than 88 degrees and smaller than 93 degrees. The method according to claim 1,
Wherein a height of one of the optical protrusions is different from a height of the other one of the optical protrusions. A plurality of light emitting diodes for emitting light to be supplied to the display panel;
A light guide plate for transmitting light emitted from the plurality of light emitting diodes to the display panel;
A diffusion sheet disposed in front of the light guide plate; And
A backlight unit comprising a prism sheet according to any one of claims 1 to 8 arranged in front of the diffusion sheet. A display panel for displaying an image;
A plurality of light emitting diodes for emitting light to be supplied to the display panel;
A light guide plate for transmitting light emitted from the plurality of light emitting diodes to the display panel;
A diffusion sheet disposed in front of the light guide plate; And
A display device comprising a prism sheet according to any one of claims 1 to 8 arranged in front of the diffusion sheet.

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