WO2012064013A2

WO2012064013A2 - Optical member, method for manufacturing same, backlight unit using the optical member, and method for manufacturing the backlight unit

Info

Publication number: WO2012064013A2
Application number: PCT/KR2011/006404
Authority: WO
Inventors: 김준형
Original assignee: 주식회사 엘지화학
Priority date: 2010-11-10
Filing date: 2011-08-30
Publication date: 2012-05-18
Also published as: WO2012064013A3

Abstract

The present invention relates to an optical member, comprising: a light incidence surface; and a light-emitting surface which comprises a patterned portion intended for adjusting the intensity of light and formed at an area corresponding to a light source, and an adhesive portion disposed in an area other than the patterned portion. When the optical member of the present invention is applied to a backlight unit, the patterned portion, which diffuses the light from the light source, is formed in the area corresponding to the light source so as to effectively diffuse the light from the light source into the peripheral area. Also, the optical member and a diffusion plate are stacked via an air layer in the area corresponding to the light source (the area in which the patterned portion is disposed), and the optical member and the diffusion plate closely contact each other without an air layer in the remaining area, such that the intensity of the light transmitted between a light source portion and the peripheral portion may be adjusted with an improvement in the balance of brightness and uniformity.

Description

【Specification】

[Name of invention]

Optical member, manufacturing method thereof, and back light unit using the optical member, and manufacturing method thereof

Technical Field

The present invention relates to an optical member and to an optical member for use in a backlight unit.

Background Art

A backlight unit used in a display device such as an LCD refers to a component that is positioned on the back of a display panel without a self-light emitting function and uniformly illuminates the display panel. The backlight unit can be classified into a direct type and an edge type according to the position of the light source that actually emits light. The direct type is a backlight unit in which the light source is located at the bottom of the display panel. The edge type is preferably a backlight unit in which the light source is positioned at the edge of the display panel, which is advantageous for thinning the thickness of the backlight unit.

1 is a cross-sectional view showing the configuration of a conventional direct type backlight unit.

As shown in FIG. 1, the conventional direct type backlight unit includes a plurality of light sources 120, a reflecting plate 110, a light guide plate 130, a plurality of diffusion films 140 and 150, a light collecting film 160, and a protective film ( 170).

On the other hand, in the case of the direct type backlight, there is a problem that luminance luminance is generated because the luminance between the light source and the light source and the light source is not uniform. In the related art, as shown in FIG. 1, a plurality of diffusion films 140 and 150 are used to purge the light of a light source to the entire surface so as to prevent the luminance block from occurring. However, the use of multiple diffusion films increases the manufacturing cost and the thickness of the backlight unit has a problem.

In addition, the conventional direct-type backlight has a problem that the light transmittance is lowered due to the reflection of light occurs at the interface between the film and the airworm because a plurality of optical pillows are laminated with an air layer therebetween. [Detailed Description of the Invention]

[Technical problem]

The present invention has been made to solve the problem between the above, in one aspect, advantageous in the diffusion of light in the region where the light source is located, and in other areas to reduce the luminance decrease by reflection of light at the interface An optical member and a manufacturing method of the optical member are provided.

In another aspect, the present invention provides a backlight unit and a method of manufacturing the backlight unit that advantageously diffuse the light in the region where the light source is located, and prevents the lowering of the luminance due to the reflection of light at the interface in other regions. do.

In another aspect, the present invention provides a display device including a backlight unit.

Technical Solution

The present invention is a light incident surface; And a light emitting surface including a pattern portion for adjusting the intensity of light formed in a region corresponding to the light source and an adhesive portion formed in a region other than the pattern portion.

It provides an optical member roll containing. In addition, the present invention is a light source; The optical member; And at least one optical film stacked on the optical member. In addition, the present invention (a) forming an adhesive portion on the light exit surface of the optical member: and (b) a non-adhesive pattern portion for adjusting the intensity of light in the area of the light exit surface of the optical member against the light source It provides a method of manufacturing an optical member comprising the step of forming. In addition, the present invention provides a method of manufacturing a backlight unit comprising the step of laminating an optical film of the diffusion function on top of the optical member.

Advantageous Effects

When the optical member according to the present invention is applied to the backlight unit, a pattern portion for diffusing the light of the light source is formed in the area facing the light source so that the light of the light source can be effectively diffused to the periphery, and also the area (the pattern part facing the light source) The formed region is spaced between the air bubble and the optical member and the diffusing optical film are stacked, while the rest of the area allows the optical member and the optical filler of the diffusing function to be in close contact with each other without air blow, thereby transmitting between the light source and the peripheral part. It is possible to improve the uniformity of luminance by controlling the intensity of the light to be balanced.

[Brief Description of Drawings]

1 is a cross-sectional view showing the structure of a conventional backlight unit.

2 is a view showing the configuration of an optical member according to an embodiment of the present invention. 3 is a view schematically showing an example of a pattern formed on the optical member according to the present invention.

4 is a view showing the configuration of an optical member according to another embodiment of the present invention. 5 is a view showing a structure roll in which an optical film is laminated on an optical member according to an embodiment of the present invention.

6 is an optical film is stacked on the optical member according to another embodiment of the present invention Figure showing the structure.

7 is a photograph taken from the backlight unit according to an embodiment of the present invention, showing the uniformity of the brightness of the backlight unit according to the embodiment.

8 is a photograph taken on the backlight unit according to the comparative example of the present invention, showing the uniformity of the brightness of the backlight unit according to Comparative Example 1.

9 is a photograph taken on the backlight unit according to Comparative Example 2, and shows the uniformity of the luminance of the backlight unit according to Comparative Example 2.

[Description of the code]

110 reflector

120 light source

130 light guide plate

140 diffuser plate

150 Micro Lens Diffusion Film

160 Prism Sheet

170 protective film

200 optical elements

212 light incident

214 light exit

220 pattern parts

230 adhesive

240 spacer

300 airworms

400 upper optical film

Area where A reflection pattern is formed

[Best form for implementation of the invention]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention may be variously modified and may have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to the specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, the same reference numerals are used for the same components. 2 is a view showing the configuration of an optical member according to an embodiment of the present invention. The optical member 200 shown in FIG. 2 includes a light incident surface 212, a light emitting surface 214, a pattern portion 220, and an adhesive portion 230. The light incident surface 212 is a surface of the optical member 200 that faces the light source 120, and is the surface on which the light of the light source 120 is incident, and the light exit surface 214 receives the light of the light source 120. It is a surface facing a top film as a surface which exits to a top film. The optical member 200 serves as a light guide plate that transmits the light of the light source 120 to diffuse to the front surface, and thus is formed of a film or a sheet that can pass the light. For example, the polymethylmethacrylate (P MA) acrylic resin, thir-acetyl cel lulose, polyester resin (Polyethylene Terephthalate) and the like, but is not particularly limited. In addition, the optical member 200 of the present invention may use a resin having an adhesive function in order to effectively form the adhesive portion 230. For example, an acrylic resin, a urethane resin, a vinyl resin, a silicone resin, and the like, but is not particularly limited. The pattern portion 220 is formed in a region corresponding to the light source 120. This is to form a pattern portion in a predetermined area corresponding to the light source, to block the light of the light source transmitted directly above the light source, and to effectively diffuse to the peripheral portion.

Specifically, the pattern portion 220 is formed in a predetermined region of the light exit surface 214 of the optical member to the center of the light source 120 in the center, the size of the region according to the arrangement or size of the light source Is determined. Specifically, the pattern portion 220 effectively blocks the light. In order to diffuse, it is preferable to form an elliptical contour with a long axis of about 6 mm to 60 m and a short axis of about 5 mm to -45 mm around the light source 120. More preferably, the light source may be formed in an elliptical contour having a long axis of about 10-30 ram and a short axis of about 7-20 ram. However, when a plurality of LEDs are used and the distance between the LEDs is smaller than the above dimensions, the diffusion pattern portions of the LEDs may be largely overlapped with each other. In addition, the pattern portion 220 is preferably formed by an inkjet method. This is because the inkjet method can form a pattern in a non-contact manner, which is advantageous in forming a pattern on the light exit surface of the optical member provided with the adhesion function. In addition, the ink used to form the pattern portion 220 is preferably a non-adhesive ink. This is to ensure that the pattern portion 220 does not have adhesiveness and has adhesiveness only in other areas. Also. The printing thickness of the pattern portion 220 depends on the amount of pigment components in the ink, and when printing with inkjet, a pattern of about 0.2 to 15 is generally formed. In addition, when printing with an inkjet it can be adjusted to the desired degree of light diffusion by adjusting the dosage of the pigment in the ink within the above-described range. In addition, the pattern unit 220 may adjust the intensity of light passing through the optical member 200 by the pattern by forming a pattern that enables blocking and diffusion of light. In detail, the pattern unit 220 may include at least one of diffusion patterns for diffusing light of the reflective pattern light source to reduce the amount of light transmitted by reflecting the light of the light source. Here, the reflective pattern is aluminum, creme, It may be formed using an ink containing one selected from the group consisting of silver, mercury, platinum and molybdenum. Where aluminum chromium and silver. Mercury platinum and molybdenum serve to reflect light. In addition, the diffusion pattern is selected from the group consisting of titanium dioxide, teflon, polystyrene and silica

It can be formed using the ink containing 1 type. Titanium dioxide here. Teflon, polystyrene and silica play a role in diffusing light. 3 is a view schematically showing an example of a pattern formed in the pattern portion 220 of the optical member 200 according to the present invention. In detail, FIG. 3 is a view illustrating a pattern form in the case of forming both a reflection pattern and a diffusion pattern. Referring to FIG. 3, when both the reflection pattern and the diffusion pattern are formed in the pattern part 220, a diffusion pattern is formed in the entire area of the pattern part 220, and the reflection pattern is added to A, the upper center part. The pattern portion can be formed.

The adhesive part 230 is formed in an area other than the pattern part 220. This is because the air bubble is formed between the region 220 where the pattern portion is formed, that is, the portion that supports the light source, and the film laminated thereon, whereas the optical member and the upper portion thereof are provided by giving an adhesion function to the regions other than the pattern portion. This is to ensure that the film, which is filled in the air, adheres without air blow (see FIG. 5). That is, in the region where the light source exists in the lower portion, the air layer is formed between the optical member 200 and the optical film 400 in the upper portion so that the light is scattered, thereby reducing the intensity of the light. By adhering the optical member 200 and the optical film 400 on the top without air blow, the reflection of light at the interface is minimized to minimize the loss of transmitted light, thereby improving the uniformity of luminance. The light source 120 may be a light source generally used for a backlight unit without limitation. For example, there are a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), and the like. Meanwhile, although the light source 120 is illustrated as being positioned below the optical member 200 in FIG. 2, the light source 120 is not limited thereto. For example, the light source may be embedded in the optical member 200. In addition, the adhesive portion 230 may be formed by patterning a predetermined area with a non-adhesive ink on the light exit surface 214 of the optical member having an adhesive function, and the light exit surface of the optical member having no adhesive function. It may be formed by coating a pressure-sensitive adhesive on (214) and then patterning a constant area ratio with a non-adhesive ink. 4 is a view showing the configuration of an optical member according to another embodiment of the present invention. As shown in FIG. 4, the optical member 200 of the present invention may further include a spacer 240 in the pattern portion 220. The spacer 240 is at the top It is to maintain a constant interval with the optical film 400 to be laminated. The spacer 240 is formed by a method of overlapping ink and patterning, and can be formed into a structure of a lamp shape by this method. In order to form the spacer 240φ, the ink may be patterned by using ultraviolet curing ink or phase change ink, which minimizes the phenomenon of spreading on the surface of the substrate, and may be patterned using ultraviolet curing ink or phase change ink. In this case, the height of the pattern can reach several tens of 卿. 5 is a view showing a structure in which an optical film is stacked on the optical member according to an embodiment of the present invention. When the optical film 400 is stacked on the optical member 200 of the present invention, as shown in FIG. 5, an air blower may be formed between the pattern portion 220 and the optical film 400 stacked on the upper portion. 300 is formed, the optical film 400 is laminated on the adhesive portion 230 and the top

The air layer is not formed between them and is in close contact with each other. Since the pattern part 220 is non-adhesive, the air film 300 is formed between the pattern part 220 and the optical film 400 deposited on the upper portion, and the adhesive part 230 has an adhesive function. This is because the adhesive portion 230 and the optical film 400 stacked on the upper portion are in close contact with each other without an air layer. In addition, as shown in FIG. 5, the air layer 300 is formed only in an area facing the light source. This is because the pattern part 220, which is an area where the air blower 300 is formed, is formed in an area that supports the light source 120. That is, when the optical film 400 is laminated on the optical member 200 of the present invention, the region where the light source 120 is present in the lower part of the optical member is provided with the optical pillar 400 therebetween with an air gap therebetween. The region 230 which is stacked and the light source 120 does not exist in the lower portion has a structure in which the optical film 400 is in close contact with the upper portion without the air blower. In this case, the optical film 400 is preferably an optical film to perform a diffusion function. According to this structure, in the region 220 where the light source 120 is present in the lower portion and the amount of light transmitted is large, reflection of light occurs at the interface between the air layer and the upper film, thereby reducing the amount of transmitted light. Since there is no air layer in the region 230 where 120 does not exist, the reflection of light does not occur at the interface, thereby minimizing the loss of transmitted light, thereby contributing to the uniform distribution of the transmitted light throughout the surface. 6 is a view showing a structure in which an optical film is stacked on the optical member according to another embodiment of the present invention. Referring to FIG. 6, since the pattern part 220 of the optical member 200 of the present invention includes a spacer 240, the upper optical pillow 400 has an air gap in a predetermined region by the spacer 240. It may be stacked on the pattern portion 220 while securing (300). In addition, the optical member 200 and the upper portion by adjusting the height of the spacer 240 Since the distance between the optical films 400 can be adjusted, the most suitable structure can be selected to effectively diffuse the light of the light source in the area of the light source and to uniform the brightness of the entire surface. Although the optical member according to the embodiment of the present invention described above is preferably applied to the direct type backlight unit, it may be used to increase the uniformity of luminance by applying to the interface between the light source and the optical member in the edge type backlight unit. Method for producing an optical member according to the present invention comprises the steps of (a) forming an adhesive on the light exit surface of the optical member; And (b) forming a pattern portion in a predetermined region of the light exit surface of the optical member. Here, the pattern portion of step (b) is a region corresponding to the light source. This is because the optical pattern is formed in a certain area of the light source to direct light from the light source to the periphery.

To effectively block and spread. In addition, the pattern portion of step (b) is preferably non-adhesive. This is to make the pattern portion non-adhesive so that the light of the light source is effectively diffused to the periphery by tapping the area with the air film only between the areas facing the light source. That is, by forming an adhesive part on the light exit surface of the optical member, and then further forming a non-adhesive pattern part in the area facing the light exit surface light source, the adhesive part is in close contact with the film and the air layer that is deposited on the upper part, and the pattern part is on the upper part. It is characterized by being laminated with the film to be laminated and the airworm therebetween. In addition, the step (b) is preferably formed by the inkjet method. This is because the inkjet method can form a pattern in a non-contact manner, which is advantageous in forming a patternol on the light exit surface of the optical member provided with an adhesive function. In addition, the step (b) is preferably formed of a non-tacky ink. In addition, the pattern unit of step (b) may include at least one of a reflection pattern for reflecting the light of the light source and a diffusion pattern for diffusing the light of the light source to the peripheral portion. The reflection pattern reflects the light of the light source and reduces the amount of light transmitted from the upper portion of the light source, while the diffusion pattern diffuses the light of the light source to the periphery so as to have a uniform distribution of light throughout the surface. Do it. The reflective pattern may be formed of an ink including at least one selected from the group consisting of aluminum, chromium, silver, mercury, platinum, and molybdenum. Where aluminum. Cream, silver, mercury, platinum, and molybdenum serve to reflect light. In addition, the diffusion pattern may be formed of an ink including at least one selected from the group consisting of titanium dioxide, teflon, polystyrene, and silica. . Here, titanium dioxide, teflon, polystyrene and silica play a role in diffusing light Perform. In addition, the manufacturing method of the optical member according to the present invention may further include the step of forming a spacer to maintain a predetermined distance from the film laminated on the upper portion of the pattern portion of the (b) step (b). Here, the spacer is formed by a method of patterning by overlapping the ink, it can be formed in a structure of a lamp shape by this method. In order to form the spacer, the ink is preferably patterned using ultraviolet curing ink or phase change ink, which minimizes the phenomenon of spreading on the surface of the substrate. The manufacturing method of the backlight unit using the optical member manufactured by the above-mentioned manufacturing method includes laminating an optical film of a diffusion function on the upper part of the optical member manufactured by the above-mentioned method. That is, the optical film having a diffusion function is laminated on the optical member by using a press or the like. As a result, the pattern portion in which the adhesive remains on the surface

In other areas, the diffusion film is in close contact with the air blower, and the pattern portion has a structure in which the diffusion film is not in close contact with the air blower and interposed therebetween. Since the pattern is formed only in a certain area that serves the light source, the diffusion film is laminated on the area of the optical member that serves only the light source, with the air layer interposed therebetween, and the remaining areas are in close contact with each other without air blow. Due to this structure, the area where the light source exists in the lower part is reflected by light at the interface between the air layer and the diffusion film, and the amount of light transmitted is reduced. Since reflection does not occur, loss of transmitted light can be minimized, and as a result, luminance uniformity can be improved. [form for implementation of the invention]

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention.

EXAMPLE

1. Manufacture of optical member

A sheet formed of acrylic adhesive resin is attached to the surface of the optical member by using the sheet formed of polymethylmethacrylate (PMMA) acrylic resin as an optical member.

The pattern part is formed by the inkjet method in the fixed area which opposes a light source among the light exit surfaces of the optical member with an adhesive resin sheet.

The pattern portion has an elliptical contour having a long axis of about 20 mm and a short axis of about 15 mm around the light source, and the inside of the pattern part has a fine optical pattern that adjusts the density of the ink chamber hit by the inkjet. Specifically, the optical pattern is a reflective pattern formed using a non-tacky ink containing silver nanoparticles, and a diffusion pattern formed using a non-tacky white ultraviolet curing ink containing titanium dioxide.

A portion of the formed pattern is overlaid with the white UV curable ink to have a height of about

50 _/ an, a spacer having a structure of about 100 in diameter is formed. Hundreds of spacers are formed at intervals of about 0.2 mm apart. After that, the pattern is cured by ultraviolet irradiation. 2. Manufacturing of Backlight Unit

The diffusion film is laminated on the optical member manufactured as described above using a roll press. As a result, in the regions other than the pattern portion where the pressure-sensitive adhesive remains on the surface, the diffusion film is in close contact with the air layer without the air layer, and the pattern portion has a structure in which the diffusion film is not adhered by the spacer and is filled with the air gap therebetween. In the backlight unit including the structure, the light source is concealed by reducing the difference between the brightness of the light and the other areas of the light source, and the light is uniformly distributed in all areas.

Comparative Example 1

1. Manufacturing of optical member

Polymethylmethacrylate (PMMA) A sheet formed of acrylic resin is used as an optical member. It is the same as an Example except that an adhesive resin does not adhere to the surface of an optical member and a light-diffusion pattern is not formed.

2. Manufacturing of Backlight Unit

The diffusion film is laminated on the optical member manufactured as described above using a press. As a result, the diffusion film is laminated on the optical member between the air layers.

Comparative Example 2

1. Manufacturing of optical member

A sheet formed of a polymethylmethacrylate (PMMA) acrylic resin is used as an optical member, and the pattern portion is formed in a predetermined region of the light exit surface of the optical member by the light source. That is, it is the same as that of an Example except that a sticky ^" resin is not attached to the surface of an optical member.

2. Manufacturing of Backlight Unit

The diffusion film is laminated on the optical member manufactured as described above using a roll press. As a result, it has a structure in which a diffusion film is stacked on the optical sub-system with an air gap therebetween. 7 is a photograph taken from above of the backlight unit according to an embodiment of the present invention, FIG. 8 is a photograph taken from above of the backlight unit according to Comparative Example 1 of the present invention, and FIG. 9 shows a backlight unit according to Comparative Example 2. The above picture is taken to show the uniformity of the luminance of the backlight unit. 7 to 9, when the luminance uniformity of the backlight unit according to the embodiment is compared with the backlight unit according to the comparative example, the backlight unit according to the embodiment is compared to the backlight unit according to Comparative Examples 1 and 2 and the entire back light area. It was confirmed that the light is uniformly distributed over, the degree of concealment of the light source is large, and the uniformity of luminance is large.

Claims

[Range of request]

[Claim 1]

Light incident surface; And

An optical member comprising a light emitting surface comprising a pattern portion for adjusting the intensity of the light formed in the area facing the light source and a pressure-sensitive adhesive roll formed in a region other than the pattern portion.

[Claim 2]

The optical member of claim 1, wherein the pattern part is formed of a non-tacky ink.

[Claim 3]

The optical member of claim 1, wherein the pattern portion is formed by an inkjet method.

[Claim 4]

The optical member of claim 1, wherein the pattern unit comprises at least one of a reflection pattern reflecting light of a light source and a diffusion pattern diffusing light of the light source to a peripheral portion. [Claim 5]

The optical member according to claim 4, wherein the reflective pattern is formed of an ink containing at least one selected from the group consisting of aluminum, crotom, silver, mercury, platinum, and molybdenum.

[Claim 6]

The optical member of claim 4, wherein the diffusion pattern is formed of an ink including at least one selected from the group consisting of titanium dioxide, teflon, polystyrene, and silica. [Claim 7]

The optical member of claim 1, wherein the pattern part further comprises a spacer to maintain a predetermined distance from the film deposited on the upper portion.

[Claim 8]

The optical member of claim 7, wherein the spacers are formed by patterning the ink rolls.

[Claim 91]

The optical member of claim 8, wherein the spacer is formed of ultraviolet curing ink or phase change ink.

[Claim 10] Light source;

The optical member of any one of claims 1 to 9; And

And a optical film laminated on the light exit surface of the optical member. [Claim 111]

The method of claim 10,

An air layer is formed between the pattern portion of the optical member and the optical film, and the adhesive unit and the optical film of the optical member is to close contact without the air blow to the backlight unit.

[Claim 12]

Display device comprising the backlight unit of claim 11.

[Claim 13]

( _a ) forming an adhesive part on the light exit surface of the optical member; And

(b) forming a non-adhesive pattern portion for adjusting the light intensity roll in a region of the light exit surface of the optical member facing the light source.

[Claim 14]

The method of claim 13,

Cc) an optical member manufacturing method further comprising forming a spacer on a portion of the pattern portion of the step (b) to maintain a predetermined gap with the film deposited thereon. [Claim 15]

15. A method of manufacturing a backlight unit comprising the step of laminating an optical film having a diffusion function on top of an optical member manufactured by the method of claim 13 or 14.