KR102176263B1 - Light guide plate having engraved pattern and back light unit using the same - Google Patents

Abstract

The present invention relates to a light guide plate having an engraved pattern and an embossed pattern, a backlight unit using the same, and a display device including the same. The present invention includes a light guide plate member which emits light of a light source introduced from one side surface to an upper surface and has a plurality of engraved patterns and a plurality of embossed patterns spaced apart on the lower surface, and improves total internal reflection efficiency, increases the amount of emitted light, improves the use efficiency of the light, and increases the luminance of the backlight unit.

Description

A light guide plate having an intaglio pattern and a relief pattern, and a backlight unit using the same, and a display device including the same. {LIGHT GUIDE PLATE HAVING ENGRAVED PATTERN AND BACK LIGHT UNIT USING THE SAME}

The present invention relates to a light guide plate having an intaglio pattern and a relief pattern, a backlight unit using the same, and a display device including the same, and includes an intaglio pattern and a relief pattern that can increase the use efficiency of light and maximize total internal reflection efficiency. The present invention relates to a light guide plate and a backlight unit using the same.

In general, a liquid crystal display device is one of the flat panel display devices that display images using liquid crystals, and has the advantage of being thinner and lighter than other display devices, and having a low driving voltage and low power consumption, so it is widely used in the general industry. .

Since the liquid crystal display device is a non-light-emitting device in which a display panel displaying an image does not emit light by itself, a separate backlight unit is required to supply light to the display panel.

The backlight unit includes a light source that generates light, a light guide plate that receives light from the light source and emits light to the upper side, a diffusion sheet that diffuses light emitted through the light guide plate to the front of the panel, and a prism sheet positioned on the upper side of the diffusion sheet. .

The backlight unit passes light generated from an LED light source through a light guide plate, a diffusion sheet, and a prism sheet to adjust the amount of light emitted and the angle of light to be emitted to the front of the panel.

The backlight unit sequentially increases the light emission angle of the light source while passing the light generated from the LED light source through the light guide plate, the diffusion sheet, and the prism sheet so that the main path is maintained at 90° when the light is emitted.

However, the conventional backlight unit is designed to maintain the main path of light at 90° when the final light is emitted, but due to total reflection of 2 to 3%, there is a problem of low luminance because it cannot prevent the intrinsic loss of returning the emitted light.

In addition, in the conventional backlight unit, the LED light source is located on one side of the light guide plate because the LED light source is positioned so as to be spaced apart in a row, and the light generated from each LED light source is displayed in a spaced line on the light incident surface side of the light guide plate. The light stiffness phenomenon is occurring.

In addition, the conventional backlight unit has a problem in that the use efficiency of light is low and the total internal reflection efficiency is low because only the embossed pattern is provided on the lower surface thereof.

As a prior patent related to the present invention, there is Korean Patent Application Publication No. 2004-0014890,'High luminance light guide plate of embossed pattern for non-printing in LCD display backlight device' (published on February 18, 2004).

Korean Patent Laid-Open Publication No. 2004-0014890'High luminance light guide plate with embossed pattern for non-printing in LCD display backlight device' (published on Feb. 18, 2004) forms a cone-shaped protrusion having a certain arrangement horizontally and vertically on the light guide plate. , Adjusting the height of each protrusion, or adjusting the density of protrusions of a certain size to make the luminance on the surface of the light guide plate uniform.

However, Korean Patent Laid-Open Publication No. 2004-0014890'high luminance light guide plate of a non-printing embossed pattern in an LCD display backlight device' has a problem of low light use efficiency and low total internal reflection efficiency due to a relief cone-shaped projection.

Korean Patent Laid-Open Patent No. 2004-0014890'High luminance light guide plate with embossed pattern for non-printing in LCD display backlight device' (published on February 18, 2004)

An object of the present invention is a light guide plate having an intaglio pattern and a relief pattern for increasing the amount of light emitted by maximizing the total internal reflection efficiency with an intaglio pattern and a relief pattern simultaneously applied to the lower surface, and a backlight unit using the same, and a display including the same To provide the device.

In order to achieve the above object, an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention emits light from a light source introduced from one side to the upper surface, and includes a plurality of intaglio patterns and a plurality of And a light guide plate member on which the embossed pattern is positioned, wherein the plurality of embossed patterns are arranged regularly spaced apart, and the plurality of engraved patterns are arranged irregularly spaced apart on the lower surface of the light guide plate member.

In the present invention, at least one of the plurality of intaglio patterns may be partially positioned to partially overlap the relief pattern.

In the present invention, it may be manufactured by regularly forming the embossed pattern on the lower surface of the light guide plate member and then forming the embossed pattern irregularly.

In the present invention, the plurality of embossed patterns are arranged to have a plurality of rows in which the first row and the second row are repeated, and the embossed pattern of the first row may have a regular arrangement such that the embossed pattern of the second row is positioned between the embossed patterns of the second row.

In the present invention, the depth of the intaglio pattern may be 4 μm or more and 12 μm or less.

In the present invention, the height of the embossed pattern may be 1 μm or more and 4 μm or less.

In the present invention, the depth of the embossed pattern may be within 1.6 to 7 times the height of the embossed pattern.

In the present invention, the intaglio pattern is formed in a circular arc shape with a curvature of the incident surface facing the light source on a plane, the shape of the longitudinal section on a straight line passing through the center of the incident surface has a triangular shape, and the embossed pattern has a hemispherical dot shape Can be

In the present invention, the incident surface may be formed as an inclined curved surface.

In the present invention, the pattern lower surface, which is the lower surface of the intaglio pattern, is a plane coincident with the lower surface of the light guide plate, and the angle of the incident surface based on the pattern lower surface may be 30° to 90°.

In the present invention, the angle of the top vertex of the intaglio pattern may be 70° to 125°.

In the present invention, the incidence surface has an arc-shaped upper curve having a curvature on a plane at the upper end side, and an arc-shaped lower curve having a curvature smaller than the upper curve on the plane at the lower end side, the lower curve is 30 It may have a radius of curvature of ㎛ ~ 150㎛.

In the present invention, the depth of the intaglio pattern may be 4 μm to 12 μm.

In the present invention, the incident surface is formed as an inclined curved surface, the pattern lower surface, which is the lower surface of the intaglio pattern, is a plane coincident with the lower surface of the light guide plate, and the angle of the incident surface based on the pattern lower surface is 30° ~ 90°, the angle of the top vertex of the intaglio pattern is 70° ~ 125°, and the incidence surface has an arc-shaped upper curve having a curvature on a plane at the upper end side, and smaller than the upper curve on the plane at the lower end side. An arc-shaped lower curve having a curvature is located, and the lower curve has a radius of curvature of 30 μm to 150 μm, and the depth of the intaglio pattern may be 4 μm to 12 μm.

In the present invention, the intaglio pattern is a conical pattern in which a portion of the basic conical shape is cut to form an inclined surface on one side, and the conical pattern may be cut obliquely to include a portion including a vertex and a portion of the lower surface in the basic conical shape.

In order to achieve the above object, an embodiment of the backlight unit according to the present invention includes a light source that emits light, a light guide plate that emits light from the light source that is located on the side and emits light from the side to the upper surface, and the light guide plate. And a diffusion sheet positioned on the upper side of and diffusing light, and a prism sheet disposed on the diffusion sheet and capable of refracting and condensing light, wherein the light guide plate has an intaglio pattern and a relief pattern according to the present invention It is characterized by being.

In order to achieve the above object, a display device according to the present invention includes a liquid crystal display panel, an image processing unit for processing an image to be displayed on the liquid crystal display panel, and a backlight unit providing light to the liquid crystal display panel, The backlight unit is characterized in that it is a backlight unit according to the present invention.

The present invention has an effect of improving total internal reflection efficiency by simultaneously forming an intaglio pattern and an embossed pattern on a lower surface, improving light use efficiency by increasing the amount of light emitted, and increasing brightness of a backlight unit.

In addition, the present invention has the effect of increasing the light efficiency by increasing the amount of light emitted by maximizing the total internal reflection efficiency by forming the intaglio pattern in an arc shape with the incident surface on the plane and forming the longitudinal cross-sectional shape passing through the center in a triangular shape. .

1 is a bottom view showing an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention.
2 is a longitudinal sectional view showing an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention.
3 is a perspective view showing an embodiment of an intaglio pattern in an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention.
4 is a plan view showing a point at which luminance is measured on a backlight unit in a luminance measurement test of a backlight unit according to Comparative Examples and Examples of the present invention.
5 is a cross-sectional view showing an embodiment of a backlight unit according to the present invention.
6 is a perspective view showing another embodiment of an intaglio pattern in an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention.
Fig. 6 is an enlarged plan view of part A of Fig. 6(b).

The present invention will be described in more detail.

The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to the detailed description of the present invention, terms or words used in the present specification and claims described below should not be construed as being limited to their conventional or dictionary meanings. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention, and thus various It should be understood that there may be equivalents and variations.

1 is a bottom view showing an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention, and FIG. 2 is a view showing an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention. It is a longitudinal sectional view, and FIG. 3 is a perspective view showing the intaglio pattern 110 in an embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention.

An embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention will be described in detail below with reference to FIGS. 1 to 3.

The light guide plate having an intaglio pattern and a relief pattern according to the present invention emits light of a light source introduced from one side to the upper surface, and a plurality of intaglio patterns 110 and a plurality of relief patterns 120 are located on the lower surface. It includes a light guide plate member 100.

In order to achieve the above object, the light guide plate having an intaglio pattern and a relief pattern according to the present invention emits light of a light source introduced from one side to the upper surface, and a plurality of intaglio patterns 110 and a plurality of It characterized in that it comprises a light guide plate member 100 on which the embossed pattern 120 is positioned.

Another embodiment of the light guide plate having an intaglio pattern and an embossed pattern according to the present invention reveals that the light guide plate member 100 emits light from a light source introduced from the side surface to the upper surface.

That is, the light guide plate member 100 is a PMMA (Polymethyl Methacrylate) or PC (Polycarbonate) that changes the path of light from a line or point light source composed of a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) light source to a surface light source. ), MS (Methyl Methacrylate-co-styrene), and other transparent synthetic resins.

The light guide plate member 100 has one side as a light-incident surface to which light from a light source is received, and an upper surface positioned in a vertical direction with one side, that is, a light-exiting surface from which light received from the light-incident surface is emitted. Take an example.

The intaglio pattern 110 is formed in an arc shape in which the incident surface 101 facing the light source on a plane, that is, the incident surface 101 facing the light source has a curvature.

That is, the incident surface 101 is formed as a curved surface inclined in the vertical direction.

In addition, the intaglio pattern 110 has a triangular shape in a longitudinal section on a straight line passing through the center of the incident surface 101.

The intaglio pattern 110 minimizes luminance loss by varying only the path of light according to the shape of the pattern, and the refraction of light can be maximized by varying the light receiving angles in the x, y, and z axis directions.

The embossed pattern 120 is an example of a dot-shaped protrusion, and is formed as a hemispherical protrusion to improve the refraction shape of light and to minimize luminance loss.

In addition, the plurality of embossed patterns 120 are regularly arranged on the lower surface of the light guide plate member 100, that is, regularly spaced apart at a predetermined interval, and the plurality of engraved patterns 110 are formed under the light guide plate member 100. Arranged irregularly spaced on the surface.

The plurality of embossed patterns 120 are arranged to have a plurality of rows, and a first row in which the embossed patterns 120 are spaced apart from each other at a predetermined interval and a second row in which the embossed patterns 120 are located are repeatedly It is positioned, but as an example, the embossed pattern 120 of the first row is positioned between the embossed pattern 120 of the second row.

The plurality of embossed patterns 120 are arranged to have a plurality of rows in which the first row and the second row are repeated, and the embossed pattern 120 of the first row is regularly positioned between the embossed patterns 120 of the second row. Have an array

That is, the light guide plate having the intaglio pattern and the relief pattern according to the present invention is manufactured by regularly forming the relief pattern 120 on the lower surface of the light guide plate member 100 and then irregularly forming the intaglio pattern 110.

In addition, at least one of the plurality of intaglio patterns 110 is positioned so that a part of it overlaps the plurality of intaglio patterns 120.

The light guide plate having an intaglio pattern and an embossed pattern according to the present invention includes a regularly positioned embossed pattern 120 and an irregularly positioned embossed pattern to improve total internal reflection efficiency and increase the amount of light emitted to increase light use efficiency. Can be further improved.

On the other hand, in the present invention, the intaglio pattern is formed in an arc shape in which the incident surface 101 facing the light source on a plane has a curvature, and the longitudinal section has a triangular shape on a straight line passing through the center of the incident surface 101. Luminance loss by changing only the path of light by limiting the angle of incidence (θ ₁ ), the angle of the top vertex (θ ₂ ), and the curvature of the incident surface 101 on the plane based on the plane of the light guide plate member 100, which is a plane in a triangle. Minimizes and maximizes the refraction of light by varying the angles of light received in the x, y, and z-axis directions.

The incidence surface 101 is located obliquely so that an upper curve 101b of an arc shape having a curvature on a plane is located at the upper end side, and a lower curve of an arc shape having a curvature smaller than the upper curve 101b on the plane at the lower end side ( 101a) is located.

Since the intaglio pattern 110 has a triangular shape on a straight line that passes through the center of the incidence surface 101 and coincides with the incidence direction of the light source, the incidence surface 101 forms a straight inclined surface in the longitudinal section.

In addition, the intaglio pattern 110 has an intaglio shape, that is, a groove open to the lower side from the lower surface of the light guide plate member 100, and it is shown in a three-dimensional shape with the intaglio pattern and the relief pattern according to the present invention in FIG. It turns out that it is a perspective view showing the intaglio pattern 110 in one embodiment of the light guide plate.

In addition, the intaglio pattern 110 has a semicircular shape on a plane including an open lower surface and an inclined surface of a plane that is connected to the incident surface of the inclined curved surface, and the longitudinal section passing through the center is formed to form a triangular shape.

The lower surface of the intaglio pattern 110, that is, the lower side of the triangle in the longitudinal section is a plane coincident with the lower surface of the light guide plate, and that is, the light guide plate member (which is a plane) based on the pattern lower surface 103 of the intaglio pattern 110 An example is that the incident surface angle θ ₁ based on the lower surface of 100) is 30° to 90°.

In addition, the upper vertex angle (θ ₂ ) of the intaglio pattern 110 is 70° to 125°, and the lower curve 101a on the plane located at the lower end of the incident surface 101 has a radius of curvature of 30 μm to 150 μm. Take as an example to have.

The cathode pattern 110 has an incident surface angle (θ ₁ ) of 30° to 90°, a vertex angle (θ ₂ ) of 70° to 125°, and an incident surface angle (θ ₁ ) of an opposite angle, that is, an intaglio pattern 110 An example is that the angle is greater than the angle between the lower surface of) and the inclined surface of the plane.

In addition, the depth, that is, the height of the intaglio pattern 110 may be 4 μm to 12 μm.

As an example, the upper vertex angle θ ₂ of the intaglio pattern 110 is an angle between the incident surface 101 and the incident surface 101 and the pattern inclined surface 102 meeting at the upper vertex.

Table 1 below is a test result for confirming an embodiment of the intaglio pattern 110 in a light guide plate having an intaglio pattern and an intaglio pattern, and this is seen to demonstrate the characteristics of the shape of the intaglio pattern 110 of the present invention. It turns out that the intaglio pattern 110 of the present invention is a test result of the example in which only the dot-shaped protrusions protrude from the lower surface of the light guide plate and the example in which the conduit pattern 110 is located on the lower surface of the conduit plate.

When the incident surface angle (θ ₁ ) for the intaglio pattern applied to the light guide plate having the intaglio pattern and the intaglio pattern according to the present invention is 30°, 40°, 50°, 60°, the amount of light emitted from Comparative Example 1 was compared. Show the test results.

In Table 1 below, the amount of light in the vertical direction is the amount of light that is measured within the range of 0° to 43° of the light-out angle based on the light-exit surface of the light guide plate member 100, that is, the direction from the upper surface toward the light source. It should be noted that the directional outgoing light amount is an outgoing light amount measured within a range of 25° to 75° of an outgoing light angle based on a direction perpendicular to the direction from the top surface toward the light source, that is, the light exit surface of the light guide plate member 100.

In addition, the following Comparative Example 1 is a conventional light guide plate having a plurality of hemispherical embossed patterns 120, and the amount of light emitted in the vertical direction of the conventional light guide plate, that is, the light exit surface of the light guide plate member 100, that is, from the upper surface toward the light source. The outgoing light amount measured within the range of the outgoing light angle from 0° to 43° based on the direction, and the outgoing light amount in the horizontal direction is the direction from the light exit surface of the conventional light guide plate, that is, the top surface toward the light source, that is, the direction perpendicular to the incident direction. It should be noted that the amount of light emitted is measured within the range of 25° to 75° of the light emission angle based on.

Comparative Example 1 Incident plane angle 30° Incident plane angle 40° Incident plane angle 50° Incident plane angle 60° Light output in the vertical direction (cd) 498 94 594 580 793 Light output in the horizontal direction (cd) 212 70 297 258 190

As shown in Table 1, when the incident surface angle (θ ₁ ) is 30°, it is difficult to obtain a sufficient amount of outgoing light, so it is preferable that the incident surface angle (θ ₁ ) is 35° or more, and the larger the incident surface angle (θ ₁ ) The amount of light emitted in the vertical direction increases, but when the angle of the incident surface 101 is 60° or more, the amount of light emitted in the horizontal direction, that is, the amount of light emitted based on the direction perpendicular to the direction of incidence, decreases rapidly, causing a problem in the uniformity of light. do.

Accordingly, the angle of incidence (θ ₁ ) is 30° to 90° as an example.

In addition, Table 2 below is a comparative example when the angle of incidence (θ ₁ ) is fixed at 40° and the top vertex angle (θ ₂ ) of the intaglio pattern 110 is 80°, 90°, 100°, 110° The test result comparing 1 and the amount of light emitted is shown.

Comparative Example 1 60° vertex angle 90° vertex angle 100° vertex angle Angle of vertex 110° Light output in the vertical direction (cd) 498 526 580 691 899 Light output in the horizontal direction (cd) 212 276 286 297 271

As can be seen in Table 2, it can be seen that the amount of light is significantly higher compared to Comparative Example 1 in the range of 90° to 110° in the upper vertex angle (θ ₂ ) of the intaglio pattern 110, and the upper vertex angle (θ ₂ ) is 110 When it exceeds °, the amount of light emitted in the horizontal direction, that is, the amount of light emitted based on a direction perpendicular to the incident direction, decreases rapidly, causing a problem in the uniformity of light.

Accordingly, as an example, the range of the upper vertex angle θ ₂ of the intaglio pattern 110 is 70° to 125°.

In addition, in Table 3 below, the incident surface angle (θ ₁ ) is fixed at 40°, and the upper vertex angle (θ ₂ ) of the intaglio pattern 110 is fixed at 100°. When the lower curve 101a on the positioned plane has a radius of curvature of 50 µm, 75 µm, and 100 µm, a test result comparing the amount of light emitted from Comparative Example 1 is shown.

It should be noted that the total amount of light in Table 3 below means the total amount of light emitted from the upper surface of the light guide plate member 100, that is, the light exit surface of the light guide plate member 100.

Radius of curvature 50㎛ 75㎛ radius of curvature 100㎛ radius of curvature Total light intensity (cd) 9418 10621 12312

As can be seen in Table 3, it can be seen that as the radius of curvature of the lower curve 101a on the plane positioned at the lower end of the incident surface increases, the amount of light emitted from the light exit surface of the light guide plate member 100 increases. However, intaglio When the radius of curvature of the pattern 110 exceeds 150 μm, there is a problem that the intaglio pattern 110 can be visually recognized on the screen of the backlight unit.

The visibility of the intaglio pattern 110 may be determined according to the structure of the backlight unit, the matching structure, and the characteristics of individual products, but when the radius of curvature of the intaglio pattern 110 exceeds 150㎛, the intaglio pattern 110 on the screen of the backlight unit This can be recognized, and since the upper curve 101b of the intaglio pattern 110 has a larger radius of curvature than the lower curve 101a, the lower curve 101a of the intaglio pattern 110 has a curvature of 30 μm to 150 μm or less. It is preferable to have.

In the following, a test for analyzing the luminance of Comparative Examples 2 to 4 and Comparative Example 1 of the present invention was performed, and the results are shown in Table 4 below.

In Comparative Examples 2 to 4, only the embodiment of the intaglio pattern 110 applied to the light guide plate having the intaglio pattern and the relief pattern according to the present invention is applied, that is, the intaglio pattern 110 which is an embodiment of the present invention on the lower surface of the light guide plate. ) Is applied.

The tests in Table 4 below show the results of a test of measuring luminance in the backlight unit including the light guide plate of Comparative Example 1 and the backlight unit including the light guide plate of Comparative Example 4.

In addition, it is revealed that the backlight unit for the luminance measurement test of Comparative Example 1 and Comparative Examples 2 to 4 identified in Table 4 below has the same configuration of a light source, a diffusion sheet, a prism sheet, and a reflector.

4 is a plan view showing a point at which the brightness is measured on the backlight unit in the brightness measurement test of the backlight unit in Table 4, and it is found that the brightness measurement points, that is, points 1 to 25, can be confirmed in Table 4 below. Put.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 1-point luminance value 6176 6075 6080 5609 2-point luminance value 6172 7348 7165 7357 3-point luminance value 6384 7220 7517 7430 4-point luminance value 6492 6942 7245 7420 5-point luminance value 5948 5508 5766 5753 6-point luminance value 5247 8310 8265 8376 7-point luminance value 7126 8789 8820 8991 8-point luminance value 7344 8383 8422 8510 9-point luminance value 7459 8831 8541 8706 10-point luminance value 5977 7993 8029 8115 11-point luminance value 5141 8494 8440 8595 12-point luminance value 7066 8973 8725 8395 13-point luminance value 7359 8623 8425 8279 14-point luminance value 7434 8781 8301 8541 15-point luminance value 6071 8546 8173 8122 16-point luminance value 5462 7516 7527 7418 17-point luminance value 6413 7355 7200 7363 18-point luminance value 6674 8052 7768 7766 19-point luminance value 7014 7535 7556 7252 20-point luminance value 5530 7247 6902 6762 21-point luminance value 5092 6534 6810 6489 22-point luminance value 5698 6495 6648 6510 23-point luminance value 5780 5895 5991 5862 24-point luminance value 6062 5815 6074 6209 25-point luminance value 5878 6221 6002 5858 Average luminance value at points 1 to 25 6456 7443
Point 1 ~ Point 25
Uniformity 65% 61%

As can be seen in Table 4, it can be seen that the light guide plates of Comparative Examples 2 to 3 to which only the intaglio pattern of the present invention is applied increase the amount of light of the backlight unit by 13% when compared to the light guide plate of Comparative Example 1.

That is, the intaglio pattern 110, which is an embodiment of the present invention, has an incidence surface in an arc shape on a plane, and a longitudinal cross-sectional shape passing through the center in a triangular shape, thereby maximizing the internal total reflection efficiency and increasing the amount of light emitted to increase the light use efficiency. It has the effect of improving and increasing the brightness of the backlight unit.

On the other hand, Table 5 below is a test for measuring luminance in a backlight unit including an example of a light guide plate having an intaglio pattern and an embossed pattern according to the present invention and a backlight unit including the light guide plate of Comparative Examples 2 to 4. The results are shown.

In addition, it turns out that the configurations of the light source, the diffusion sheet, the prism sheet, and the reflector are applied in the same manner as the backlight unit for the test of Examples and Comparative Examples 2 to 4 shown in Table 5 below.

FIG. 4 is a plan view showing points at which luminance is measured on the backlight unit in the luminance measurement test of the backlight unit identified in Table 5 below, and the luminance measurement points, that is, points 1 to 25, can be identified in Table 5 below. Make it clear.

Example Comparative Example 2 Comparative Example 3 Comparative Example 4 1-point luminance value 6024 6075 6080 5609 2-point luminance value 7342 7348 7165 7357 3-point luminance value 7225 7220 7517 7430 4-point luminance value 6947 6942 7245 7420 5-point luminance value 5511 5508 5766 5753 6-point luminance value 8316 8310 8265 8376 7-point luminance value 8796 8789 8820 8991 8-point luminance value 8389 8383 8422 8510 9-point luminance value 8838 8831 8541 8706 10-point luminance value 7998 7993 8029 8115 11-point luminance value 8500 8494 8440 8595 12-point luminance value 8979 8973 8725 8395 13-point luminance value 8629 8623 8425 8279 14-point luminance value 8788 8781 8301 8541 15-point luminance value 8553 8546 8173 8122 16-point luminance value 7521 7516 7527 7418 17-point luminance value 7360 7355 7200 7363 18-point luminance value 8058 8052 7768 7766 19-point luminance value 7541 7535 7556 7252 20-point luminance value 7252 7247 6902 6762 21-point luminance value 6539 6534 6810 6489 22-point luminance value 6500 6495 6648 6510 23-point luminance value 6205 5895 5991 5862 24-point luminance value 5819 5815 6074 6209 25-point luminance value 6214 6221 6002 5858 Average luminance value at points 1 to 25 7514 7443

As can be seen in Table 5, the embodiment of the light guide plate having the intaglio pattern and the relief pattern according to the present invention increases the amount of light of the backlight unit by 4% compared to Comparative Examples 2 to 4 in which only the intaglio pattern is applied, and It can be seen that the amount of light of the backlight unit increased by 17% compared to Comparative Example 1.

It is revealed that the luminance measurement test of the backlight unit in Table 4 and the luminance measurement test of the backlight unit in Table 5 are tests using a backlight unit in which other conditions except for the light guide plate are the same.

In other words, the light guide plate having an intaglio pattern and an embossed pattern according to the embodiment of the present invention simultaneously forms the intaglio pattern 110 and the embossed pattern 120 on the lower surface, thereby improving total internal reflection efficiency and increasing the amount of emitted light. It can be seen that the use efficiency is improved and the brightness of the backlight unit is increased.

On the other hand, Table 6 is a result of the luminance measurement test of the backlight unit according to the depth of the intaglio pattern 110 in the light guide plate having the intaglio pattern and the relief pattern according to the present invention, and the intaglio pattern and the relief pattern according to the present invention are provided. The results of a test of measuring luminance in the backlight unit including the light guide plate of Examples 2 to 5 and the backlight unit including the light guide plate of Comparative Example 5 are shown.

In addition, the backlight unit for the luminance measurement test of Examples 2 to 5 and Comparative Example 5 identified in Table 6 below has the same configuration as a light source, a diffusion sheet, a prism sheet, and a reflector.

FIG. 4 is a plan view showing points at which luminance is measured on the backlight unit in the luminance measurement test of the backlight unit identified in Table 6 below, and luminance measurement points, that is, points 1 to 25, can be identified in Table 6 below. Make it clear.

Examples 2 to 5 identified in Table 6 below are examples in which the depth of the intaglio pattern 110 is 7㎛, 6㎛, 5㎛, 4㎛, Comparative Example 5 is the depth of the intaglio pattern 110 is 3 There is a difference of μm.

In Examples 2 to 5 and Comparative Example 5 of Table 6 below, it is confirmed that the height of the embossed pattern 120 is 2.5 μm, and the light guide plate member 100 has the same embossed pattern and only the depth of the engraved pattern 110 is different. .

Example 2
(7㎛) Example 3
(6㎛) Example 4
(5㎛) Example 5
(4㎛) Comparative Example 5
(3㎛) 1-point luminance value 4155 4377 4333 4193 4070 2-point luminance value 5224 5158 5106 4941 4796 3-point luminance value 5429 5412 5357 5184 5033 4-point luminance value 5159 5216 5153 4996 5850 5-point luminance value 4389 4151 4109 3976 3860 6-point luminance value 5789 5950 5890 5700 5533 7-point luminance value 6154 6350 6286 6083 5905 8-point luminance value 6055 6063 6002 5808 5638 9-point luminance value 6361 6149 6075 5890 5718 10-point luminance value 5984 5780 5712 5537 5375 11-point luminance value 5897 6076 6015 5820 5650 12-point luminance value 6289 6282 6219 6018 5842 13-point luminance value 6075 6066 6005 5811 5641 14-point luminance value 6154 5976 5916 5725 5557 15-point luminance value 5786 5884 5825 5636 5472 16-point luminance value 5425 5419 5354 5191 5039 17-point luminance value 5194 5184 5132 4966 4821 18-point luminance value 5597 5592 5536 5357 5200 19-point luminance value 5442 5440 5385 5211 5059 20-point luminance value 4978 4969 4919 4760 4621 21-point luminance value 4914 4903 4853 4697 4559 22-point luminance value 4795 4786 4738 4584 4450 23-point luminance value 4302 4313 4259 4131 4011 24-point luminance value 4399 4373 4329 4189 4066 25-point luminance value 4335 4321 4267 4139 4018 Average luminance value at points 1 to 25 5371.24
(100%) 5367.6
(99.9%) 5311
(98.9%) 5141.72
(95.8%) 4991.36
(93.0%)

Referring to Table 6, it can be seen that the depth of the intaglio pattern 110 in the light guide plate having the intaglio pattern and the relief pattern is preferably 4 μm or more and 12 μm or less.

On the other hand, Table 7 is the result of the luminance measurement test of the backlight unit according to the height of the embossed pattern 120 in the light guide plate having the embossed pattern and the embossed pattern according to the present invention. The results of a test of measuring luminance in a backlight unit including Examples 6 to 8 of a light guide plate and a backlight unit including the light guide plate of Comparative Example 6 are shown.

In addition, it is revealed that the backlight units for the luminance measurement test of Examples 6 to 8 and Comparative Example 6 identified in Table 7 below have the same configurations of a light source, a diffusion sheet, a prism sheet, and a reflector.

FIG. 4 is a plan view showing points at which luminance is measured on the backlight unit in the luminance measurement test of the backlight unit identified in Table 7 below, and luminance measurement points, that is, points 1 to 25, can be identified in Table 7 below Make it clear.

Examples 6 to 8 identified in Table 7 below are examples in which the height of the embossed pattern 120 is 1 μm, 2 μm, and 2.5 μm, respectively, and Comparative Example 6 is that the height of the embossed pattern 120 is 3 μm. There is a difference.

In Examples 6 to 8 and Comparative Example 6 of Table 6 below, it is confirmed that the intaglio pattern 110 has the same depth of 5.5 μm, and the light guide plate member 100 differs only in the height of the relief pattern 120.

Example 6
(1㎛) Example 7
(2㎛) Example 8
(2.5㎛) Comparative Example 6
(3㎛) 1-point luminance value 4335 4469 4100 3654 2-point luminance value 5087 5245 4751 4189 3-point luminance value 5112 5270 4811 4350 4-point luminance value 5324 5489 4860 4399 5-point luminance value 4914 5066 4483 4419 6-point luminance value 5473 5643 5236 5278 7-point luminance value 6141 6331 5877 5924 8-point luminance value 6156 6346 5827 5873 9-point luminance value 6230 6423 5820 5866 10-point luminance value 5568 5740 5083 5123 11-point luminance value 6171 6362 6221 6270 12-point luminance value 6881 7093 6748 6802 13-point luminance value 6994 7211 6886 6941 14-point luminance value 6852 7064 6645 6698 15-point luminance value 6217 6410 5933 5981 16-point luminance value 6271 6465 6837 6892 17-point luminance value 6393 6590 7007 7063 18-point luminance value 6252 6446 7104 7161 19-point luminance value 6297 6491 7040 7096 20-point luminance value 5980 6165 6346 6396 21-point luminance value 5719 5896 6915 7225 22-point luminance value 5567 5739 7039 7396 23-point luminance value 5626 5800 7300 7858 24-point luminance value 5556 5728 7130 7487 25-point luminance value 5501 5671 6506 7158 Average luminance value at points 1 to 25 5865 6046 6100 6140 Point 1 ~ Point 25
Uniformity 62% 62% 56% 46%

Referring to Table 7 above, when the height of the embossed pattern 120 is 3 μm or more in the light guide plate having the embossed pattern and the embossed pattern according to the present invention, the uniformity of the luminance is lowered, and thus uniform light cannot be provided as a whole. It can be seen that it is preferable that the height of the embossed pattern 120 is 1 μm or more and 4 μm or less in the light guide plate having the embossed pattern and the embossed pattern according to the present invention.

Accordingly, in the light guide plate having the intaglio pattern and the relief pattern according to the present invention, the depth ratio of the intaglio pattern 110 and the height of the intaglio pattern 120 may be within 1.6 to 7.

That is, it is revealed that the depth of the intaglio pattern 110 is formed to be 1.6 to 7 times the height of the embossed pattern 120.

Meanwhile, FIG. 5 is a cross-sectional view showing an embodiment of a backlight unit according to the present invention, and referring to FIG. 5, in an embodiment of the backlight unit according to the present invention, a light source emitting light and a light source are positioned on the side. The light guide plate member 100 that emits light from the light source from the side to the upper surface, the diffusion sheet 200 that is located on the upper side of the light guide plate member 100 and diffuses the light, and is located on the diffusion sheet 200 It includes a prism sheet 300 capable of refracting and condensing light.

A reflective plate member 100a may be positioned on the lower surface of the light guide plate member 100.

A plurality of engraved patterns 110 spaced apart from each other are positioned on the lower surface of the light guide plate member 100, and the engraved pattern 110 is formed in an arc shape in which an incident surface facing the light source on a plane has a curvature.

In addition, the intaglio pattern 110 has a triangular shape in a longitudinal section on a straight line passing through the center of the incident surface.

The light guide plate member 100 is positioned so that the curved incident surface faces the light source, so that the curved incident surface is positioned at one side of the light guide plate facing the light source, that is, perpendicular to the light incident surface.

It should be noted that the embodiment of the intaglio pattern 110 overlaps with the embodiment of the other embodiment of the light guide plate having the intaglio pattern and the relief pattern according to the present invention and is omitted.

In addition, the light source is a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED, Light Emitting Diode) light source as an example, and it should be noted that it can be variously modified and implemented as a light source used in a known backlight unit.

In addition, the prism sheet 300 may include a first prism sheet part 310 and a second prism sheet part 320 positioned on an upper side of the first prism sheet part 310.

The first prism sheet portion 310 may be positioned with a plurality of first prism portions protruding to be spaced apart from the upper surface of the substrate, and the second prism sheet portion 320 is disposed on the upper surface of the substrate in a different direction from the first prism portion. A plurality of second prism portions protruding spaced apart from each other may protrude.

As an example, the first prism portion is positioned to be spaced apart in the X-axis direction, and the second prism portion is positioned to be spaced apart in the Y-axis direction.

It should be noted that the prism sheet 300 may be variously modified into a known prism sheet structure and implemented.

The diffusion sheet 200 is positioned between the light guide plate 100 and the prism sheet 300 and is stacked on the lower diffusion sheet 210 and the prism sheet 300 for diffusing light, and the upper diffusion sheet 220 for diffusing light. It may include.

Although not shown, the display device according to the present invention includes the backlight unit according to the present invention.

The display device includes a liquid crystal display panel, an image processing unit for processing an image to be displayed on the liquid crystal display panel; And a backlight unit providing light to the liquid crystal display panel, wherein the backlight unit includes the embodiment of the backlight unit according to the present invention.

Meanwhile, FIG. 6 is a perspective view showing another embodiment of an intaglio pattern 110 in another embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention, and FIG. 7 is a portion A in FIG. 6B. This is an enlarged plan view.

Another embodiment of a light guide plate having an intaglio pattern and a relief pattern according to the present invention will be described in detail below with reference to FIGS. 6 and 7.

In another embodiment of the light guide plate having an intaglio pattern and a relief pattern according to the present invention, a part of the intaglio pattern 110 located on the lower surface of the light guide plate member 100 is cut from the basic conical shape 10 to be inclined surface 110b on one side. ) May be formed in a conical pattern.

The intaglio pattern 110 is developed as a conical pattern in which a portion of the basic conical shape 10 is cut to have an inclined surface 110b formed on one side thereof to prevent light stiffness.

The light stiffness phenomenon is a phenomenon in which light generated from each LED light source has a string shape at a part of the light incident surface side of the light guide plate where a plurality of LED light sources are located.

The basic conical shape (10) has a horn-shaped shape with a pointed vertex, a circular lower surface and a curved side, and the inner angle of the vertex is 95° to 115° (α), and the diameter of the lower surface is 85 μm to 105 μm ( D ₁ ) as an example.

In addition, in the basic conical shape 10, the inclination inner angle of the side surface, that is, the inclination angle of the side surface relative to the lower surface is 32° to 42.5° (β) as an example.

In addition, the conical pattern is a conical shape in which a part including a vertex is cut obliquely in the basic conical shape 10 and has a flat inclined surface 110b on one side thereof.

As an example, the conical protrusion is cut inclined to include a part including a vertex and a part of a lower surface in the basic conical shape 10, and a part having a planar inclined surface 110b on one side thereof is a cut conical shape.

Figure 6 (a) is a view showing a basic cone 10, Figure 6 (b) is a three-dimensional conical pattern in the present invention cut the hatched portion in Figure 6 (a) basic cone 10 It is a figure shown in figure.

In addition, as an example, the height difference H ₁ between the vertex of the conical pattern and the basic conical shape 10 is 17 μm to 23 μm.

In addition, as an example, the vertex portion of the conical pattern is formed as an arc having a curvature R ₁ of 22 μm to 30 μm.

In addition, the inner angle of the vertex of the conical pattern may be 75° to 115°.

In addition, as an example, the inclined surface 110b of the conical pattern is formed such that a straight line passing through the center crosses the straight line passing through the center of the lower surface.

In the basic conical shape 10, the inclination angle of the side surface, that is, the inclination angle of the side surface relative to the lower surface, that is, the angle β of the light incident surface in the conical pattern is 35° to 60°. In addition, the conical pattern is an example. As an example, when a circle is drawn by following the arc of the lower surface, the corresponding diameter is 40 µm to 130 µm.

In addition, the conical pattern is located in a direction in which the curved surface 110a faces the light-incident surface and the inclined surface 110b faces the light-incident surface, that is, the opposite side of the light-incident surface.

When the inclined surface 110b is located toward the light-incident surface, it has been confirmed that the luminance increase effect and the light stiffness on the light-incident surface cannot be improved compared to the conventional dot-shaped pattern, which will be described in more detail below.

Another embodiment of the light guide plate having an intaglio pattern and an embossed pattern according to the present invention is an example in which a cut conical protrusion corresponding to the conical pattern is roll stamped by a protruding electric pole stamp.

The conical protrusion is not shown separately, but an example is formed in the same shape as in FIG. 6(b) illustrating a conical pattern as a three-dimensional figure.

That is, as an example, the conical protrusion is a conical shape in which a part including a vertex is cut obliquely in the basic conical shape 10 and has a flat inclined surface 110b on one side thereof.

The basic conical shape (10) is a horn-shaped shape with a pointed vertex, a circular lower surface and a curved side, and an inner angle of the vertex is 95° to 115°, and the diameter of the lower surface is 40 μm to 130 μm. do.

In addition, in the basic conical shape 10, the inclination inner angle of the side surface, that is, the inclination angle of the side surface relative to the lower surface, that is, the angle β of the light incident surface in the conical pattern is 35° to 60°.

In addition, the conical protrusion is cut inclined to include a portion including a vertex and a portion of a lower surface in the basic conical shape 10, and a portion having an inclined surface 110b on one side is cut conical shape.

In addition, as an example, the height difference between the vertex of the conical protrusion and the basic conical shape 10 is 17 μm to 23 μm.

In addition, as an example, the vertex portion of the conical protrusion is formed as an arc having a curvature of 22 μm to 30 μm.

In addition, the inner angle of the vertex of the conical projection may be 70 to 115°.

In addition, as an example, the inclined surface 110b of the conical protrusion is formed such that a straight line passing through the center crosses the straight line passing through the center of the lower surface to form an intersection.

In addition, the conical protrusion is a circle shape having a corresponding diameter of 40 μm to 130 μm when a circle is drawn following the arc of the lower surface, that is, the curvature of the curved portion of the lower surface is 40 μm to 130 μm.

The electric pole stamp with a plurality of conical protrusions is wound on a stamping roll, and the light guide plate member 100 according to the present invention is a transparent synthetic resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), and methyl methacrylate-co-styrene (MS). As an example, it is manufactured by roll stamping in which a plurality of conical patterns are formed on the optical panel body by pressing with an electric pole stamp while rotating the stamping roll while transporting the optical panel body manufactured with a transfer conveyor.

It should be noted that the electric pole stamp can be variously manufactured through a process of manufacturing a well-known embossed stamp that a plurality of conical patterns are manufactured in a protruding shape after designing a conical pattern.

That is, by roll stamping using a stamping roll in which the electric pole stamp from which the conical protrusion of the conical protrusion is protruded, an intaglio conical pattern corresponding to the conical protrusion of the relief is formed on the lower surface of the light guide plate member 100.

The present invention improves the total internal reflection efficiency by simultaneously forming the concave pattern 110 and the relief pattern 120 on the lower surface, increases the amount of emitted light, improves light use efficiency, and increases the brightness of the backlight unit.

In addition, the present invention maximizes the total internal reflection efficiency by forming the intaglio pattern 110 in an arc shape on the plane of the incidence surface in an arc shape and forming a triangle shape in the longitudinal section passing through the center, thereby increasing the amount of light emitted to further improve the light efficiency. .

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, which is included in the configuration of the present invention.

10: basic cone 100: light guide plate
100a: reflector member 101: incident surface
101a: lower curve 101b: upper curve
102: pattern slope 103: pattern lower surface
110: engraved pattern 120: embossed pattern
110a: curved surface 110b: inclined surface
200: diffusion sheet 210: lower diffusion sheet
220: upper diffusion sheet 300: prism sheet
310: first prism sheet part 320: second prism sheet part

Claims (17)

It emits light of a light source introduced from one side to the upper surface, and includes a plurality of intaglio patterns spaced apart from the lower surface and a light guide plate member in which a plurality of relief patterns are located, and the plurality of relief patterns are arranged regularly spaced apart from each other, and a plurality of The intaglio patterns are arranged irregularly spaced apart on the lower surface of the light guide plate member,
The plurality of embossed patterns are arranged to have a plurality of rows in which the first row and the second row are repeated, and the embossed pattern has a regular arrangement so that the embossed pattern of the first row is positioned between the embossed patterns of the second row. Light guide plate with pattern and embossed pattern.
The method according to claim 1,
A light guide plate having an intaglio pattern and a relief pattern, characterized in that at least one of the plurality of intaglio patterns is partially overlapped with the relief pattern.
The method according to claim 1,
A light guide plate having an intaglio pattern and a relief pattern, characterized in that it is manufactured by regularly forming the relief pattern on a lower surface of the light guide plate member and then irregularly forming the intaglio pattern.
delete The method according to claim 1,
The light guide plate having an intaglio pattern and a relief pattern, characterized in that the depth of the intaglio pattern is 4㎛ or more and 12㎛ or less.
The method according to claim 1,
The light guide plate having an intaglio pattern and a relief pattern, characterized in that the height of the relief pattern is 1㎛ or more and 4㎛ or less.
The method according to claim 1,
A light guide plate having an intaglio pattern and a relief pattern, characterized in that the depth of the intaglio pattern is within 1.6 to 7 times the height of the relief pattern.
It emits light of a light source introduced from one side to the upper surface, and includes a plurality of intaglio patterns spaced apart from the lower surface and a light guide plate member in which a plurality of relief patterns are located, and the plurality of relief patterns are arranged regularly spaced apart from each other, and a plurality of The intaglio patterns are arranged irregularly spaced apart on the lower surface of the light guide plate member,
The intaglio pattern is formed in an arc shape with a curvature of the incident surface toward the light source on a plane, and the shape of the longitudinal section has a triangular shape on a straight line passing through the center of the incident surface.
The light guide plate having an intaglio pattern and a relief pattern, wherein the relief pattern has a hemispherical dot shape.
The method of claim 8,
The incident surface is a light guide plate having an intaglio pattern and a relief pattern, characterized in that the inclined curved surface.
The method of claim 8,
The pattern lower surface, which is the lower surface of the intaglio pattern, is a plane coincident with the lower surface of the light guide plate, and the angle of the incident surface relative to the lower surface of the pattern is 30° to 90°. Equipped light guide plate.
The method of claim 8,
The light guide plate having an intaglio pattern and a relief pattern, wherein the angle of the top vertex of the intaglio pattern is 70° to 125°.
The method of claim 8,
The incidence surface has an arc-shaped upper curve having a curvature on a plane at the upper end side, and an arc-shaped lower curve having a curvature smaller than the upper curve on the plane at the lower end side,
The lower curve has a radius of curvature of 30 µm to 150 µm, wherein the light guide plate has an intaglio pattern and a relief pattern.
The method of claim 8,
A light guide plate having an intaglio pattern and a relief pattern, wherein the intaglio pattern has a depth of 4 μm to 12 μm.
The method of claim 8,
The incident surface is formed as an inclined curved surface,
The pattern lower surface, which is the lower surface of the intaglio pattern, is a plane coincident with the lower surface of the light guide plate, and the angle of the incident surface based on the pattern lower surface is 30° to 90°,
The angle of the top vertex of the intaglio pattern is 70° to 125°,
The incidence surface has an arc-shaped upper curve having a curvature on a plane at the upper end side, and an arc-shaped lower curve having a curvature smaller than the upper curve on the plane at the lower end side,
The lower curve has a radius of curvature of 30 µm to 150 µm, and a depth of the intaglio pattern is 4 µm to 12 µm.
The method of claim 8,
The intaglio pattern is a conical pattern having an inclined surface formed on one side by cutting a part from the basic conical shape,
The conical pattern is a light guide plate having an intaglio pattern and a relief pattern, characterized in that the conical pattern is cut obliquely to include a portion including a vertex and a portion of a lower surface in the basic cone shape.

A light source that emits light;
A light guide plate in which the light source is positioned on a side surface and emits light of the light source introduced from the side surface to an upper surface;
A diffusion sheet positioned on the upper side of the light guide plate to diffuse light; And
It is located on the diffusion sheet and includes a prism sheet capable of refracting and condensing light,
The backlight unit, wherein the light guide plate is the light guide plate of any one of claims 1 to 3 and 5 to 15.
Liquid crystal display panel;
An image processing unit for processing an image to be displayed on the liquid crystal display panel; And
And a backlight unit providing light to the liquid crystal display panel,
The backlight unit is a display device, characterized in that the backlight unit of claim 16.

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