KR20170047157A - Multilayer Optical Sheet Assembly - Google Patents

Abstract

Disclosed is an optical sheet assembly. According to an embodiment of the present invention, the optical sheet assembly includes: a first base film having a first pattern layer; a second base film formed on one side of the first base film, wherein a second pattern layer coming into contact with and supported on the bottom of the first base film is formed in the second base film; and a third base film formed on one side of the second base film, wherein a bead diffusing light is mixed with the third base film and a groove is formed on the surface attached to the second base film. The second pattern layer is formed in a same direction as that of the first pattern layer, and the groove includes the diameter larger than that of an inlet. The first pattern layer and the second pattern layer comprise: multiple protrusions; and the groove formed between the multiple protrusions. The second pattern layer comprises: a first protrusion coming into contact with the first base film and supported on the first base film; a second protrusion lower than the first protrusion; and the groove formed between the first protrusion and the second protrusion. According to the present invention, the each pattern layer is processed in an uneven shape in the upper part of the first and second base films which is a duplex structure. Therefore, even if there is no light diffusion layer containing an additional light diffusion agent, the optical sheet assembly can obtain diffusion effect of the light. So, the number of components of the optical sheet assembly is reduced, and the thickness of an optical lamination film can be thin. As the groove including the diameter larger than that of the inlet is formed in the third base film, a sparkling phenomenon is improved.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical sheet assembly,

The present invention relates to an optical sheet assembly, and more particularly, to an optical sheet assembly that allows a prism having a uniform pitch, a prism having a variable pitch, and a diffusing unit to be stacked in multiple layers to improve the light- .

BACKGROUND ART Generally, a liquid crystal display (LCD) is provided on the rear side thereof to produce image information by white light supplied by a backlight unit (BLU) that shines light.

Such a backlight unit is composed of a light source, a light guide plate, a reflection plate, and an optical sheet.

The optical sheet is formed by sequentially laminating a base layer, a prism sheet, and a protective sheet.

The substrate layer serves to scatter light incident on a display portion (not shown) emitted from the light guide plate to uniformize the luminance distribution of light.

A prism sheet having a triangular prism shape is repeatedly formed on the upper surface of the prism sheet, and light diffused by the base layer is condensed in a direction perpendicular to the plane of the display unit to increase the brightness.

Accordingly, the light passing through the prism sheet proceeds almost perpendicular to the plane of the display portion (not shown) and has a uniform luminance distribution.

On the other hand, Korean Patent Application No. 10-2007-0168974 entitled " Composite Optical Sheet, Method for Producing the Same, and Light Source Assembly Including Composite Optical Sheet "

The above prior art patents generally disclose a light-shielding layer formed on a substrate, a light-shielding layer formed on the bottom surface of the substrate and including organic particles and inorganic particles dispersed in a binder and a binder, And a second optical pattern layer disposed on the first optical pattern layer and penetrating or fusing the convex portion of the first optical pattern layer through the bottom surface, And a low refractive index region having a refractive index lower than that of the first optical pattern layer and the second optical pattern layer between the concave portions of one optical pattern layer.

However, in the related art, there is a need to further improve the luminance by insufficient optical modulation characteristics because the thickness of the optical sheet is thick, the manufacturing process is complicated, and the manufacturing cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art described above, and it is an object of the present invention to provide a prism sheet having a multi-layer structure for improving light diffusing function and light modulation property, And an object of the present invention is to provide an optical sheet assembly.

In addition, since the pattern layers are formed on the first and second base films of the multilayer structure in a concavo-convex form, the light diffusion effect can be obtained even without a light diffusion layer containing a separate light diffusion agent, Another object of the present invention is to provide an optical sheet assembly in which the thickness can be thinned and grooves including a diameter larger than the diameter of the inlet are formed in the third base film to thereby improve the sparkling phenomenon.

The above object of the present invention can be achieved by a method of manufacturing a light emitting device, comprising: a first base film on which a first pattern layer is formed; A second base film formed on one side of the first base film and having a second pattern layer supported on the bottom surface of the first base film on an upper surface thereof; And a third base film formed on one side of the second base film and containing a bead for dispersing light and having a groove formed on a surface bonded to the second base film, Wherein the first pattern layer and the second pattern layer include a plurality of protrusions and grooves formed between the plurality of protrusions and the protrusions, the protrusions being formed in the same direction as the first pattern layer, the grooves having a diameter larger than the diameter of the inlet, Wherein the second pattern layer comprises a first projection which is held in contact with the first base film, a second projection which is lower in height than the first projection, and a groove which is formed between the first projection and the second projection. Can be achieved by an optical sheet assembly.

And the second protrusion of the second pattern layer is formed such that an upper end thereof is spaced apart from a lower portion of the first base film.

The third base film is characterized in that a diffusion layer for diffusing light before the light is introduced into the second base film is formed on one surface.

And the diffusion layer includes a binder resin and a bead contained in the binder resin.

The third base film is characterized in that a bead coating layer is formed on the other surface.

According to the embodiment of the present invention, since the pattern layers are formed on the first and second base films of the multilayer structure in a concavo-convex pattern, a light diffusion effect can be obtained even without a light diffusion layer containing a separate light diffusion agent, And the thickness of the optical laminated film can be reduced.

In addition, the third base film is formed with a groove having a diameter larger than the diameter of the inlet, thereby improving the sparkling phenomenon.

1 is a perspective view showing an optical sheet assembly according to an embodiment of the present invention,
2 is a cross-sectional view of an optical sheet assembly according to an embodiment of the present invention,
FIGS. 3 and 4 are cross-sectional views illustrating embodiments of a 'first pattern layer' in an optical sheet assembly according to an embodiment of the present invention,
5 and 6 are sectional views showing an embodiment of a 'second pattern layer' in an optical sheet assembly according to an embodiment of the present invention,
7 is an enlarged cross-sectional view showing another embodiment of a 'second pattern layer' in an optical sheet assembly according to an embodiment of the present invention,
8 is a cross-sectional photograph showing an optical sheet according to a contrast example,
9 is a tomographic photograph of an optical sheet assembly according to an embodiment of the present invention.
10 is a photograph showing the sparkling phenomenon caused by the UV adhesive in the process of manufacturing the optical sheet assembly.
11 is a photograph showing a sparkling phenomenon taken by a scanning electron microscope (SEM) on the optical sheet assembly of Example 1 and Comparative Example 1 of the present invention.

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

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. It does not mean anything.

In addition, the sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation, and the terms defined specifically in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user, operator It should be noted that the definitions of these terms should be made on the basis of the contents throughout this specification.

1 is a perspective view showing an optical sheet assembly according to an embodiment of the present invention, FIG. 2 is a sectional view showing an optical sheet assembly according to an embodiment of the present invention, and FIGS. 3 and 4 are cross- 5 and 6 illustrate an embodiment of a 'second patterned layer' in an optical sheet assembly according to an embodiment of the present invention. 7 is an enlarged cross-sectional view showing another embodiment of the 'second pattern layer' in the optical sheet assembly according to the embodiment of the present invention, FIG. 8 is a cross-sectional photograph showing the optical sheet according to the comparative example, 9 is a tomographic photograph of an optical sheet assembly according to an embodiment of the present invention.

1 to 7, an optical sheet assembly according to an embodiment of the present invention includes a first base film 100 on which a first pattern layer 110 is formed; A second pattern layer 220 formed on one side of the first base film 100 and supported on the upper surface of the first base film 100 in the same direction as the first pattern layer 110, A second base film 200 formed; A third base film 300 formed on one side of the second base film 200 and having beads for dispersing light and grooves 310 formed on a surface bonded to the second base film 200, The second pattern layer 220 is formed in the same direction as the first pattern layer 110, and the groove 310 includes a diameter larger than the diameter of the inlet.

The first base film 100 and the second base film 200 are transparent films through which light can be transmitted and are generally made of polyethersulphone (PES), polyacrylate (PAR), polyether imide polyetherimide (PEI), polyethylenenaphthalate (PEN), polyethyeleneterephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, poly (PET), cellulose triacetate (TAC), and cellulose acetate propinonate (CAP), and it is particularly preferable that it is made of polyethylene terephthalate (PET).

The first base film 100 should have good adhesion with the first pattern layer 110, transmittance of light incident from the rear surface should be 90% or more, and uniformity of the surface should be uniform so that the brightness does not vary.

The thickness of the first base film 100 is preferably 24 to 26 mu m. If the thickness of the first base film 100 is less than 24 占 퐉, the handleability in the manufacturing process is lowered. If the thickness of the first base film 100 is more than 26 占 퐉, the structure is contrary to the trend of thinning of the LCD module in recent years.

A UV adhesive 140 is applied to the lower surface of the first base film 100. The thickness of the UV adhesive 140 is preferably 2 to 4 mu m.

The thickness of the second base film 200 is preferably 48 to 52 탆. If the thickness of the first base film 100 is less than 48 mu m, the handling property of the first base film 100 is lowered. If the thickness of the first base film 100 is more than 52 mu m,

Meanwhile, the first pattern layer 110 and the second pattern layer 220 are formed on the first base film 100 and the second base film 200, respectively, and the first base film 100 and the second pattern layer 220 And serves to enhance the brightness of light by condensing the light passing through the base film 200.

Further, refraction, scattering or diffused reflection of light incident from a light guide plate (not shown) may occur, and light may be diffused.

The first pattern layer 110 and the second pattern layer 220 also prevent scratches. The first pattern layer 110 and the second pattern layer 220 may be formed by a method such as sandblasting or photolithography.

The first pattern layer 110 and the second pattern layer 220 are processed into a plurality of protrusions and grooves formed between the protrusions and the protrusions.

Light may be emitted in a direction perpendicular to the LCD screen by the first pattern layer 110 and the second pattern layer 220.

The height of the protrusion 111 of the first pattern layer 110 is preferably 14 to 16 μm. At this time, if the height of the protrusion 111 is less than 14 mu m, the first pattern layer 110 has poor handleability in the manufacturing process. If the height exceeds 16 mu m, the structure of the first pattern layer 110 is contrary to the trend of thinning of the LCD module in recent years.

The protrusions 11 of the first pattern layer 110 may have a semi-circular shape 110-2 or a trapezoidal shape 110-3 as shown in FIGS. 3 and 4, in addition to the triangular shape in section.

The second pattern layer 220 includes a first protrusion 221 that is in contact with the first base film 100 and a second protrusion 222 that is lower in height than the first protrusion 221, And a groove 223 formed between the first protrusion 221 and the second protrusion 222.

Accordingly, as shown in FIG. 2, the second pattern layer 220 includes a first protrusion 221 having a long height and a second protrusion 222 having a low height. This is called 'variable pitch shape'.

The first protrusion 221 contacts the lower portion of the first base film 100 and is bonded to the UV adhesive 240 applied to the lower surface of the first base film 100. Whereas the second protrusion 222 is separated from the lower surface of the first base film 100.

When a space is formed between the second protrusions 222 and the lower surface of the first base film 100 and the first base film 100 and the second base film 200 are laminated and bonded together, 221 are inserted into the UV adhesive 140 applied to the lower surface of the first base film 100 and the lower surface of the first base film 100 is pressed by the pressure load, So that the thickness of the optical sheet assembly according to the embodiment of the present invention can be reduced.

As will be described later, the comparative example has a thickness of 185 mu m, while the multilayered mattress sheet assembly according to the embodiment of the present invention can be made slimmer with a thickness of 175 mu m.

The first protrusions 221 and the second protrusions 222 of the second pattern layer 220 may have a triangular shape, a semicircular shape, or a trapezoidal shape in cross section.

As shown in FIGS. 5 and 6, the first protrusions and the second protrusions of the second pattern layer 220 may be formed of a semicircular pattern 200-2 and a trapezoid pattern 200-3.

Alternatively, the first and second protrusions 200-2 and 200-3 may be formed to have different heights to have a height.

As shown in FIG. 7, the first protrusion 221 of the second pattern layer 220 may have a planar flat portion 225 formed at the upper end thereof, thereby enlarging the bonding area.

Further, by forming a plurality of fine protrusions 227 in the flat surface portion 225, the adhesive force can be doubled.

Also, since the second pattern layer 220 is formed, an anti-blocking property is imparted. Blocking refers to a phenomenon in which the inner surfaces of the films tend to adhere to each other. Due to the second pattern layer 220 laminated on the upper surface of the second base film 200, blocking that sticks to the first base film 100 Can be prevented.

Blocking is not only an obstacle to work but also causes interference patterns.

Therefore, light can be diffused by the second pattern layer 220, and blocking can be prevented.

The third base film 300 is a transparent film through which light can be transmitted. The third base film 300 includes a diffusion layer 320 made of polyethylene terephthalate (PET) and diffusing light before the light is introduced into the second base film 200, As shown in Fig.

The diffusion layer 320 formed on one side of the second base film 200 is mixed with beads for dispersing the light and the diffusion layer 320 is formed on a surface to be bonded to the second base film 200 1 and 2, grooves 310 are formed in the diffusion layer 320. The grooves 310 include a diameter larger than the diameter of the inlet, and the diffusion layer 320 is formed in the diffusion layer 320. In this case, 3 plays a role of improving the sparkling phenomenon caused by the adhesive component that bonds the base film 300 and the second base film 200. The sparkling phenomenon caused by the adhesive component is shown in Fig.

The diffusion layer 320 includes a binder resin and a bead contained in the binder resin. Preferably, the diffusion layer 320 is formed by mixing 10 to 50 parts by weight of beads with 100 parts by weight of the binder resin.

The binder resin is preferably made of any one of a UV curable epoxy binder and a UV curable binder including silicon. The binder resin is preferably composed of tris (2-acryloxyethyl) isocyanurate- 2-propenoic acid, (1-methylethylidene) bis (4,1-phenyleneoxy-2,1-ethane dioxy- More preferably a ternary copolymer of 1-phenyleneoxy-2,1-ethanediyloxy-2,1-ethanediyl ester and 1-hydroxy-cyclohexyl-phenyl ketone. The terpolymer may be a block copolymer or a random copolymer and has a glass transition temperature (Tg) of about 52 ° C and a number average molecular weight of about 4,500.

The beads have a particle size of 1.5 to 5 micrometers. The beads are formed as a layer having a predetermined thickness on the upper surface of the diffusion layer 320 and contact the lower surface of the second base film 200, Is used to minimize the adhesive area of the UV adhesive used in the process of bonding the third base film and the second base film to prevent optical loss and to reduce the sparkling phenomenon caused by the adhesive refraction.

At this time, the beads are preferably made of polymethylmethacrylate (PMMA) or poly-n-buthyl-methylacrylate (PBMA).

If the content of the beads is less than 10 parts by weight, the efficiency of the light diffusion layer of the diffusion layer 320 decreases. If the content of the beads exceeds 50 parts by weight, the light diffusion effect of the diffusion layer 320 is not greatly improved, Is too high, the mechanical properties of the diffusion layer may be deteriorated.

The third base film 300 is formed on the lower surface of the bead coating layer 340.

The bead coating layer 340 is composed of a binder resin and granular beads contained in the binder resin.

The binder resin is preferably made of any one of a UV curable epoxy binder and a UV curable binder including silicon. The binder resin is preferably composed of tris (2-acryloxyethyl) isocyanurate- 2-propenoic acid, (1-methylethylidene) bis (4,1-phenyleneoxy-2,1-ethane dioxy- More preferably a ternary copolymer of 1-phenyleneoxy-2,1-ethanediyloxy-2,1-ethanediyl ester and 1-hydroxy-cyclohexyl-phenyl ketone. The terpolymer may be a block copolymer or a random copolymer and has a glass transition temperature (Tg) of about 52 ° C and a number average molecular weight of about 4,500.

Preferably, the bead coating layer 340 is formed to a thickness of 2 to 4 탆. If the thickness of the bead coating layer 340 is less than 2 占 퐉, the handling property of the bead coating layer 340 is lowered. If the thickness of the bead coating layer 340 is more than 4 占 퐉,

A process of transmitting light through the optical sheet assembly according to an embodiment of the present invention will now be described.

First, light emitted from a light source (not shown) and guided by a light guide plate (not shown) is incident on the third base film 300, and is diffused primarily by the bead coating layer 340 and the diffusion layer 320 do.

Further, light is rediffused by the beads contained in the bead coating layer 340 and the diffusion layer 320, and is incident on the second base film 200 with a uniform distribution.

Thereafter, the light passes through the second base film 200, is condensed on the second pattern layer 220, and is incident on the first base film 100 in a state where the brightness is increased.

Then, the light passes through the first base film 100, is condensed on the first pattern layer 110, and is emitted upward in a state where the brightness is increased.

The emitted light is incident on the LCD screen to illuminate the screen.

Experimental examples of the characteristics of the optical sheet assembly according to an embodiment of the present invention are shown in FIGS. 8 and 9. FIG.

8 is a cross-sectional view and a cross-sectional photograph showing an embodiment in contrast to the present invention. The comparative example is a product of a third party, and the product name is 'XLAS200JM7', which is formed by laminating two layers of base films, and each layer has a pattern layer formed thereon.

It has a thickness of 185 탆 and a luminous intensity of 100.00%.

9 is a tomographic photograph showing an embodiment of the present invention.

The second pattern layer 220 is seen in the middle, and the multilayer optical sheet assembly according to an embodiment of the present invention has a thickness of 175 μm and a luminous intensity of 101.00%.

Therefore, it was found that the thickness was thinner than that of the comparative example, but the brightness was increased.

Hereinafter, the physical properties of the optical sheet assembly according to the present invention will be described with reference to examples.

≪ Example 1 >

A first pattern layer having a height of 15 탆 is formed, and a first base film is formed of polyethylene terephthalate having a thickness of 25 탆 and formed on one side of the first base film with a UV adhesive, A second base film having a thickness of 25 탆 and having a second pattern layer (14 to 16 탆 in height) formed in contact with the bottom of the film was formed. The second base film was formed on one side of the second base film with a UV adhesive (100 parts by weight of tris (2-acryloxyethyl) isocyanurate-2-propenoic acid and 30 parts by weight of PMMA beads) in which the beads are introduced, Wherein the second pattern layer is formed in the same direction as the first pattern layer and the groove is formed to have a diameter larger than the diameter of the inlet, The optical sheet assembly It was.

≪ Comparative Example 1 &

A conventional optical sheet assembly (product name: XLAS200JM7) shown in Fig.

The sparkling phenomenon of the optical sheet assembly of Example 1 and Comparative Example 1 was photographed by a scanning electron microscope (SEM) and is shown in FIG. 11 below.

As shown in FIG. 11, the optical sheet assembly manufactured through Example 1 of the present invention is superior to the optical sheet assembly of Comparative Example 1 in that the sparkling phenomenon is remarkably improved.

The brightness of the optical sheet assembly of Example 1 and Comparative Example 1 was measured three times and the average value thereof was calculated and shown in Table 1 below.

(However, the luminance of the optical sheet assembly was measured using a luminance meter).

<Table 1>

As shown in Table 1 above, it can be seen that the optical sheet assembly manufactured through Example 1 of the present invention has much improved brightness compared to the optical sheet assembly manufactured through Comparative Example 1.

Therefore, in the optical sheet assembly according to the present invention, the pattern layer is formed in a concavo-convex pattern on the first and second base films having a multilayer structure, so that a light diffusion effect can be obtained even without a light diffusion layer containing a separate light diffusion agent The number of parts can be reduced, the thickness of the optical laminated film can be thinned, and a groove including a diameter larger than the diameter of the inlet is formed in the third base film, thereby improving the sparkling phenomenon.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention, It is obvious that the claims fall within the scope of the claims.

100: a first base film 110; The first pattern layer
111: projection 112: groove
140; UV adhesive
200: second base film 220: second pattern layer
221: first projection 222: second projection
223: groove 240; UV adhesive
300: third base film 310; home
320: diffusion layer 340: bead coating layer

Claims (18)

A first base film on which a first pattern layer is formed;
A second base film formed on one side of the first base film and having a second pattern layer supported on the bottom surface of the first base film on an upper surface thereof;
And a third base film formed on one side of the second base film, wherein a bead for dispersing light is mixed, and a groove is formed on a surface to be bonded to the second base film,
The second pattern layer is formed in the same direction as the first pattern layer,
Wherein the groove comprises a diameter greater than the diameter of the entrance. The method according to claim 1,
Wherein the first pattern layer comprises a plurality of protrusions and grooves formed between the plurality of protrusions and the protrusions. The method according to claim 1,
Wherein the second pattern layer comprises a first projection which is held in contact with the first base film, a second projection which is lower in height than the first projection, and a groove which is formed between the first projection and the second projection. . 3. The method of claim 2,
The first pattern layer
And the height of the protrusion is 14 to 16 占 퐉. The method according to claim 1,
Wherein the first base film is a polyethylene phthalate material. The method according to claim 1,
Wherein the thickness of the first base film is 24 to 26 占 퐉. The method according to claim 1,
Wherein a UV adhesive is applied to a lower surface of the first base film. 8. The method of claim 7,
Wherein the UV adhesive has a thickness of 2 to 4 占 퐉. 5. The method of claim 4,
Wherein the projection has a triangular, semicircular or trapezoidal cross-sectional shape. The method according to claim 1,
Wherein the first protrusions and the second protrusions of the second pattern layer have a triangular, semi-circular or trapezoidal cross-sectional shape. 11. The method of claim 10,
And the second projection of the second pattern layer is formed such that an upper end thereof is spaced apart from a lower portion of the first base film. 11. The method of claim 10,
Wherein the first protrusion of the second pattern layer is formed with a flat flat portion at an upper end thereof so that the adhesive area can be enlarged. 13. The method of claim 12,
Wherein a plurality of fine protrusions are formed on the flat portion to improve the adhesive force. The method according to claim 1,
Wherein the second base film is made of polyethylene phthalate and has a thickness of 48 to 52 占 퐉. The method according to claim 1,
Wherein a UV adhesive is applied to a bottom surface of the second base film, and a thickness of the UV adhesive is 2 to 4 占 퐉. The method according to claim 1,
The third base film
Wherein a diffusion layer for diffusing light before the light is introduced into the second base film is formed on one surface. 17. The method of claim 16,
Wherein the diffusion layer comprises a binder resin and a bead contained in the binder resin. 18. The method of claim 17,
Wherein the beads are formed as a layer having a predetermined thickness on the upper surface of the diffusion layer and contact the lower surface of the second base film.

Images