JP5741161B2 - Method for producing optical sheet having adhesive layer in contact with microlouver layer - Google Patents

Description

  The present invention relates to a method for producing an optical sheet having a microlouver layer that is disposed on the viewer side of a display panel and performs contrast enhancement and viewing angle regulation. In particular, the present invention relates to a method for manufacturing an optical sheet having an adhesive layer adjacent to a microlouver layer.

  Currently, various display panels such as plasma display panels, liquid crystal panels, and EL (electroluminescent) panels are widely used, and various image display devices such as televisions, electronic signboards, and monitor displays using these display panels are put into practical use. Has been. When the image of the image display device is observed in a bright room environment where external light such as fluorescent light or sunlight enters the display panel, the external light is mixed with the image light from the display panel and the image contrast in the bright room That is, the bright room contrast decreases. Therefore, in order to prevent a decrease in contrast under the bright room, it is known to dispose a contrast enhancement filter on the front surface on the viewer side of the image on the display panel. As a contrast enhancement filter, a filter having a microlouver layer having a microlouver structure disclosed in Patent Document 1, Patent Document 2, and the like is representative. In addition, the microlouver layer has a function of regulating the viewing angle, and is also known as a peep prevention filter.

  The micro louver layer used as a contrast enhancement filter or a peep prevention filter includes a transparent resin layer 2 formed on a transparent substrate 1, like the optical sheet 10 illustrated in the perspective view of FIG. This is a structure composed of linear dark colored stripes 3 formed so as to be supported by the transparent resin layer 2 and arranged in parallel in the plane direction of the optical sheet.

The optical sheet 10 having the microlouver layer 4 is generally manufactured using a so-called wiping method. That is,
(A) First, on the transparent base material 1, the transparent resin layer 2 in which groove-like recesses whose extending directions are parallel to each other is formed on the surface.
(B) Next, dark ink is applied to the entire surface including the inside and outside of the groove-shaped recess on the surface where the groove-shaped recess is formed.
(C) Next, the coated surface on which the dark ink is applied is scraped off with a doctor blade or the like to remove the dark ink outside the groove-shaped recess, and only the inside of the groove-shaped recess is filled with the dark ink so that the dark line Forming part 3;
It is a method.

Japanese Patent Laid-Open No. 2-97904 JP 2008-46644 A

By the way, the optical sheet disposed on the front surface of the display panel is provided with various functions such as an antireflection function and an antifouling function as required, in addition to the contrast enhancement function and the peeping prevention function. For this reason, even in an optical sheet having a microlouver layer, a functional layer that realizes a function other than the function of the microlouver layer is usually laminated via an adhesive layer. However, when the functional layer is laminated via the pressure-sensitive adhesive layer, if the laminated surface is the surface of the microlouver layer, air may remain between the laminated surface and the pressure-sensitive adhesive layer during the lamination, resulting in residual bubbles. there were.
As shown in the cross-sectional view of FIG. 4B, this is because the dark colored stripes 3 filled in the groove-like depressions are generally formed by the manufacturing method (wiping method) of the dark colored stripes 3. This is because a concave portion r of about 1 to 5 μm is inevitably generated on the surface exposed surface e. This is because when the liquid dark ink is solidified by a curing reaction or the like, a volume reduction due to curing shrinkage or the like occurs. Therefore, like the conventional optical sheet 20 with the pressure-sensitive adhesive layer shown in the cross-sectional view of FIG. 5, the surface of the microlouver layer 4 with the anti-reflection sheet or the like as the functional layer 6 and the pressure-sensitive adhesive layer 5 therebetween. When sticking together, air remains in the recessed part r, and residual bubbles G are easily generated. When the residual bubbles G are generated, the image light is scattered there, so that the screen is whitened and the image quality is deteriorated.

  That is, the subject of this invention is providing the manufacturing method which can suppress the generation | occurrence | production of the residual bubble at the time of lamination | stacking an adhesive layer about the optical sheet which has an adhesive layer in contact with a microlouver layer.

Accordingly, in the present invention, a manufacturing method having the following configuration is adopted.
(A) A micro louver layer comprising a plurality of linear dark color stripes arranged in the plane direction parallel to each other in the plane direction and a transparent resin layer supporting the dark color stripes from at least the side surface is a transparent substrate. An optical sheet preparing step for preparing an optical sheet formed on the exposed surface of the dark line portion and having a recessed portion on its exposed surface;
(B) When the pressure-sensitive adhesive is applied to the surface of the optical louver layer of the optical sheet on the side where the dark colored stripes have the concave portions, the pressure-sensitive adhesive layer is previously formed on the substrate. By using the method of transferring the pressure-sensitive adhesive layer from the pressure-sensitive adhesive film, the smaller angle formed between the extending direction of the dark color stripe and the coating direction is in the range of 0 ° to 20 °. adhesive coating step of coating, the
(C) a functional layer laminating step of laminating a functional layer via an adhesive layer,
The manufacturing method of the optical sheet which has an adhesive layer in contact with a microlouver layer which performs each of these processes in this order.

  According to the present invention, even if the pressure-sensitive adhesive layer is laminated on the surface of the micro louver layer on the side having the concave portion of the dark colored strip portion, it is possible to avoid the generation of residual bubbles in the concave portion. For this reason, whitening of the image due to residual bubbles can be prevented.

The perspective view and top view explaining the manufacturing method of the optical sheet by this invention. Sectional drawing which illustrates the various shapes of the main cut surface shape of a dark color strip. Sectional drawing which illustrates one form of the optical sheet obtained by this invention. The perspective view (a) explaining an example of the optical sheet which has a microlouver layer by a prior art, and sectional drawing (b) explaining the recessed part of a dark colored strip part. Sectional drawing explaining the residual bubble which generate | occur | produces in a recessed part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relationships, aspect ratios, and the like of components may be exaggerated.

A. Definition:
In this specification, the meanings of the following terms are as follows.
The “main cut surface shape” is a cross section including a normal line N (corresponding to the Z-axis direction in FIG. 1) standing on the plane of the light incident surface or light output surface of the optical sheet 10 or 100. "A main cutting plane" defined as a cross section (ZX plane in FIG. 1) orthogonal to the extending direction (Y-axis direction in FIG. 1) in which the dark colored stripe 3 extends. This means a cross-sectional shape.
The “surface direction” is a specific direction parallel to the plane of the light incident surface or light output surface of the optical sheets 10 and 100, and is also a direction parallel to the front and back surfaces of the optical sheets 10 and 100. In FIG. 1, it is a specific direction (Y-axis direction in FIG. 1) in a plane parallel to the XY plane.

B. Method for producing optical sheet having adhesive layer in contact with microlouver layer:
The method for producing an optical sheet having an adhesive layer in contact with a microlouver layer according to the present invention comprises at least (A) an optical sheet preparation step, (B) an adhesive coating step, and (C) a functional layer lamination step. It is the manufacturing method implemented in order.

<< Optical sheet preparation process >>
(A) In the optical sheet preparation step, as shown in FIGS. 1 (a), 1 (b), and 4, linear dark colors in which a large number of extending directions are arranged in parallel to each other in the surface direction of the optical sheet 10 are arranged. A micro louver layer 4 having a micro louver structure comprising a linear portion 3 and a transparent resin layer 2 that supports the dark colored linear portion 3 from at least a side surface is formed on the transparent substrate 1, and the dark colored linear portion 3 is formed. An optical sheet 10 having a recess r on the exposed surface e is prepared.
As the optical sheet 10 having the concave portion r on the exposed surface e of the dark color stripe portion 3, a conventionally known one can be appropriately used. Here, each layer constituting such an optical sheet 10 will be described in the order of the transparent base material 1, the transparent resin layer 2, and the dark colored stripe portion 3.

(Transparent substrate)
As the transparent substrate 1, a transparent substrate made of glass, resin or the like can be used. The resin of the transparent substrate 1 is, for example, a polyester resin such as polyethylene terephthalate, a polyolefin resin such as a cycloolefin polymer, a cellulose resin such as triacetyl cellulose, an acrylic resin, or a polycarbonate resin. These resins are used in the form of films, sheets, and plates. Note that “film”, “sheet”, and “plate” are generally roughly distinguished by thickness, but in the present invention, they are merely different in name and there is no particular distinction in meaning. In addition, the thickness of the transparent base material 1 is 20-500 micrometers in the case of a resin sheet, for example.
Among these, since the resin-made transparent base material 1 used as a resin sheet or a resin film can give flexibility, it is preferable at the point of the manufacture aptitude in a roll-to-roll system. The roll-to-roll method means a production method in which the transparent substrate 1 is unwound from a roll (winding) as a continuous belt-like sheet, subjected to predetermined processing, and then wound on a roll. .

[Transparent resin layer]
The transparent resin layer 2 constitutes a micro louver layer 4 together with the dark colored strip portion 3. The transparent resin layer 2 serves as a light transmission part that transmits the image light incident on the optical sheet 10 and emits the image light to the viewer side.
The transparent resin layer 2 is made of a transparent resin material, and the resin material may be a thermoplastic resin such as an acrylic resin, a polycarbonate resin, or a styrene resin, but is preferably curable in terms of rapid solidification. It is desirable to use a resin, which is also an ionizing radiation curable resin that is cured by ultraviolet rays or electron beams. Examples of the ionizing radiation curable resin include acrylate-based, epoxy-based, and polyester-based resins.
The thickness of the transparent resin layer 2 is, for example, about 100 to 300 μm. The thickness of the transparent resin layer 2 is equal to or greater than the thickness of the dark color filament 3.

[Dark colored stripes]
The dark colored strip portion 3 constitutes a microlouver layer 4 together with the transparent resin layer 2. The dark-colored line portion 3 serves as a light absorbing portion that absorbs external light to improve contrast, or regulates the viewing angle by regulating the traveling direction of image light.
The dark color strip 3 is maintained in spatial position by being supported by the transparent resin layer 2 at least on both side surfaces in the plane direction. Further, normally, as shown in FIGS. 1 (a), 1 (b), and 4, the dark colored stripe 3 is in the direction of the normal N perpendicular to the surface direction, and the transparent substrate 1 side is also transparent resin layer 2 side. Is supported by. Therefore, the exposed surface e of the dark color stripe portion 3 exists in a direction far from the transparent base material 1 in the direction of the normal line N, and this exposed surface e is not a flat surface but a recessed surface, r is formed. The depth of the recess r is about 1 to 5 μm.

The main cut surface shape of the dark colored strip 3 is a shape when assuming that the exposed surface e is a flat surface without the concave portion r, and in the shape illustrated in FIG. Although the shape is a wedge shape, other shapes may be used. For example, if it is shown in the shape when it is assumed that the exposed surface e does not have a concave portion r and is a flat surface, the slope as shown in FIG. ) (Including isosceles triangles), a pentagonal shape as shown in FIG. 2 (3), a hexagonal shape, or the like. Further, as shown in FIG. 2 (4), both the trapezoidal shape, the triangular shape, etc., or one of the hypotenuses is a bent or curved modulated shape (a convex shape or a concave shape toward the outside of the dark colored stripe 3). ), Etc. (in the figure, the triangle is a modulated shape).
As for the dimension of the dark color stripe part 3, the width | variety which is the dimension in the arrangement direction is 5-50 micrometers, height is 50-300 micrometers, and the inclination angle with respect to the normal line N of a side surface is about 0-30 degree. The arrangement period of the dark color stripe part 3 is about 50-200 micrometers.

  The dark color stripe 3 extends linearly in the plane (XY plane in FIGS. 1 and 4) (extends in the Y-axis direction in FIG. 1), but this “linear” is literally In addition to the straight line, the extending dark colored line portion 3 generally extends linearly when viewed from the direction of the normal line N of the optical sheet 10, and when viewed locally, a broken line or Also includes a shape extending in a wave shape. The reason why the line is not a straight line but is a polygonal line or a corrugated shape is to eliminate moire as described in the adhesive layer coating process. The direction extending when viewed globally as a whole is the extending direction d, and when the direction extending when viewed locally is the local extending direction da (not shown), the local extending direction da and the general direction The general extending direction d is preferably in a substantially parallel relationship in that any part can be in a parallel or substantially parallel relationship with the coating direction. Here, “substantially parallel” means a smaller angle (subordinate angle) formed by the global extending direction d and the local extending direction da of the dark colored strip portion 3 and means 20 ° or less.

The dark color strip 3 can be formed of a light-absorbing dark material. The dark material may be either an organic material or an inorganic material. For example, a resin composition such as paint (or ink) in which a light-absorbing color material such as carbon black or aniline black is contained in a resin binder is used. Note that the dark representative color is black, but may have chromatic colors such as low brightness brownish brown, amber, rosin, and dark green as long as the image display color is not adversely affected.
The resin of the resin binder may be a thermoplastic resin such as an acrylic resin, a polyester resin, or a vinyl chloride-vinyl acetate copolymer, but is preferably a curable resin or an ultraviolet ray in terms of rapid solidification. It is desirable to use an ionizing radiation curable resin that can be cured with an electron beam. Examples of the ionizing radiation curable resin include acrylate-based, epoxy-based, and polyester-based resins.

[Method of forming micro louver layer]
The method for forming the micro louver layer 4 having the micro louver structure composed of the transparent resin layer 2 and the dark colored strip portion 3 is not particularly limited (if the concave portion r is generated). Here, a formation method using a typical wiping method will be described.

(A) First, the transparent resin layer 2 is formed on the transparent substrate 1 in which a groove-like concave portion having a concave and convex shape opposite to the dark colored stripe portion 3 is formed. In order to form the transparent resin layer 2 in which the groove-shaped concave portion opposite to the dark color stripe portion 3 is formed, a known molding method, for example, a hot press that presses a heated molding die against the thermoplastic resin layer. A casting method in which a thermoplastic resin composition is injected into a mold and solidified, an injection molding method, and a 2P method in which an ionizing radiation curable resin composition is injected into the mold (inside) and cured with ionizing radiation ( Photopolymer method) can be used. Among these molding methods, the 2P method is more preferable in terms of excellent productivity. In the 2P method, using a cylindrical (cylindrical) mold, a large number of convex strips having the same shape as the dark colored strips 3 are arranged in the circumferential direction of the cylinder, and the extending directions thereof are parallel to each other. On a forming die formed at a predetermined interval, it can be continuously formed while supplying a band-shaped transparent substrate sheet or the like. If the transparent base material 1 is used as the belt-like sheet, the transparent resin layer 2 laminated on the transparent base material 1 and the dark colored stripes 3 on the surface thereof have a reverse uneven shape, and the length of the belt-like transparent base material sheet is long. A groove-like recess extending in the direction is formed.

(B) Next, on the surface where the groove-shaped recess is formed, dark ink for forming the dark color strip portion 3 is applied to the entire surface including the inside and the outside of the groove-shaped recess. A dark color material such as an ionizing radiation curable resin composition can be used for the dark color ink.
(C) Next, the coated surface on which the dark ink is applied is scraped off with a doctor blade or the like to remove the dark ink outside the groove-shaped recess, and only the inside of the groove-shaped recess is filled with the dark ink and solidified. As a result, the dark colored strip portion 3 is formed.
A concave portion r is formed on the exposed surface of the dark color stripe 3 due to curing shrinkage when the dark ink is solidified or volume shrinkage due to solvent drying.
At this time, the scraping direction of the dark ink (the traveling direction relative to the transparent resin layer 2 such as a doctor blade) is any of the extending direction of the groove-shaped recess, the parallel direction, the orthogonal direction, or the oblique direction. Is also possible. However, the scraping direction in which the dark ink is filled into the groove-shaped concave portion and the dark ink other than the groove-shaped concave portion is optimally scraped is parallel to the extending direction of the groove-shaped concave portion.

The processes (b) and (c) above correspond to the wiping method.
As a result, the optical sheet 10 in which the micro louver layer 4 composed of the transparent resin layer 2 and the dark colored strip portion 3 is formed on the transparent substrate 1 is obtained.

《Adhesive coating process》
(B) In the adhesive coating step, as shown in FIGS. 1 (a) and 1 (b), for the optical sheet 10 prepared as described above, the dark colored stripes of the microlouver layer 4 are prepared. An adhesive layer is formed by applying the adhesive 5C on the surface of the side 3 having the recessed part r in a direction parallel or substantially parallel to the extending direction d of the dark colored stripe 3. 5 is formed. The coating direction dc is a direction in which the portion where the adhesive 5C comes into contact with the coated surface for the first time moves with time.
By making the coating direction dc of the pressure-sensitive adhesive parallel to the extending direction d of the dark color stripe 3, even if there is a recess r on the exposed surface e of the dark color stripe 3, the coating direction In terms of dc, the coated surface is free from surface irregularities based on the concave portion r. For this reason, the escape route of air is always ensured, and it can be avoided that the residual bubbles G are generated without the air being completely escaped. In addition, even when the coating direction dc of the adhesive 5C is substantially parallel to the extending direction d of the dark colored strip portion 3, there is no abrupt surface unevenness that prevents air from escaping. Therefore, it is possible to avoid the occurrence of residual bubbles G without air being escaped.

  By the way, the extending direction d of the dark colored strip 3 is usually parallel to any of the four sides in the optical sheet 100 having a rectangular shape such as a rectangle. However, when the optical sheet 100 is applied to the display panel, in order to prevent the moire from occurring due to interference between the arrangement period of the array pixels of the display panel and the arrangement period of the dark color stripes 3, May be slightly inclined. In consideration of such a situation, when coating the optical sheet 100 in the case where the coating direction dc is finally made a quadrangular shape so as to be parallel to any one of the four sides, The coating direction dc and the extending direction d of the dark colored strip 3 are applied under non-parallel conditions. However, even at this time, it is preferable that the coating is performed under the condition that the coating direction dc and the extending direction d of the dark colored stripe 3 are substantially parallel. Here, “substantially parallel” is an inclination angle of the smaller angle (subordinate angle) formed by the extending direction d of the dark colored strip 3 and the coating direction dm, and is 20 ° or less. If this inclination angle exceeds 20 °, residual bubbles are likely to be generated even if the coating speed is slowed down.

There is no restriction | limiting in particular in the coating method of the adhesive 5C, What is necessary is just to employ | adopt a well-known method suitably. For example, there are coating methods such as transfer coating in addition to roll coating, knife coating, bar coating and curtain flow coating. The transfer coating is a method of transferring the pressure-sensitive adhesive layer 5 from a pressure-sensitive adhesive film previously formed as a pressure-sensitive adhesive layer 5 on a substrate such as a resin film. In the case of transfer coating, the pressure-sensitive adhesive film is sequentially transferred by applying pressure to the surface to be coated with a laminating roller or the like. In the transfer coating, the release film for the pressure-sensitive adhesive layer 5 may be transferred at the same time.
As a peeling film, the well-known thing which carried out mold release processing, such as silicone processing, can be used for polyester resins, such as a polyethylene terephthalate, and olefin resins, such as a polypropylene, for example.

The pressure-sensitive adhesive 5C used for forming the pressure-sensitive adhesive layer 5 is not particularly limited as long as it is transparent, and a known pressure-sensitive adhesive may be appropriately used. For example, an acrylic adhesive, a silicone adhesive, a polyester adhesive, a rubber adhesive, and the like. The thickness of the pressure-sensitive adhesive layer is usually about 15 to 50 μm.
The pressure-sensitive adhesive layer 5 can also be used as a specific light selection layer by containing a dye or an ultraviolet absorber used in the specific light selection layer such as a near infrared absorption layer described in the functional layer. Alternatively, when the thickness of the pressure-sensitive adhesive layer 5 is 200 μm or more (1000 μm or less), more preferably 500 μm or more (800 μm or less), the pressure-sensitive adhesive layer 5 can also be used as an impact resistant layer.

《Functional layer lamination process》
(C) In the functional layer lamination step, as shown in FIG. 1 (c), the functional layer 6 is laminated on the surface of the pressure-sensitive adhesive layer 5 formed in the pressure-sensitive adhesive layer coating step to form a microlouver layer. An optical sheet 100 having a pressure-sensitive adhesive layer in contact therewith is obtained.
The functional layer 6 may be a rigid plate, but a film or sheet is preferable in terms of easy lamination. The functional layers 6 are stacked by sequentially pressing the pressure-sensitive adhesive layer surface with a laminating roller or the like.

As the functional layer 6, various functional layers in a conventional optical sheet for display panels can be appropriately employed. Such a functional layer 6 can be broadly classified into an optical functional layer responsible for optical functions and a non-optical functional layer responsible for functions other than optical functions.
Examples of optical functional layers include a near infrared absorbing layer that absorbs near infrared rays, an ultraviolet absorbing layer that absorbs ultraviolet rays, or neon light absorption that absorbs neon light from a plasma display panel that provides a visual effect. Layer, a specific light selection layer that suppresses transmission of light of a specific wavelength and transmits the remaining light, such as a color correction layer that corrects the display image to a desired color tone, and an antireflection layer (anti-glare, reflection) that is usually provided on the outermost layer Prevention, anti-glare and anti-reflection).
The optical functional layer may be the microlouver layer 4. In this case, an optical sheet 100 having two or more microlouver layers 4 is obtained.
Examples of non-optical functional layers include electromagnetic wave shielding layers that shield electromagnetic waves from display panels, surface protective layers and hard coat layers that protect surfaces, antistatic layers, antifouling layers, impact resistant layers, and materials between two layers There is a barrier layer that prevents movement.

  Each layer of the optical functional layer and the non-optical functional layer may be a single layer that also functions, or may be shared between the optical functional layer and the non-optical functional layer.

The functional layer 6 may be formed by laminating a transparent support, such as when the mechanical layer alone is insufficient. For the transparent support, the materials listed for the transparent substrate 1 can be used. For example, in terms of a hard coat layer, it is a hard coat layer composed of a transparent support and a hard coating film formed as a function realizing layer on the transparent support.
The thickness of the functional layer 6 is, for example, 20 to 1000 μm.

Specifically, the functional layer 6 is an optical functional layer, for example, a specific light selection layer such as a near infrared absorbing layer, an ultraviolet absorbing layer, a neon light absorbing layer, or a color correction layer, and a near infrared absorbing layer is a near infrared absorbing dye. The ultraviolet absorbing layer is formed by a coating method or the like as a function realizing layer in which an ultraviolet absorber is dispersed and a neon light absorbing layer is dispersed in a binder resin.
As the antireflection layer, for example, a layer formed of a low refractive index material layer containing a fluorine compound or a composition layer containing low refractive particles such as hollow silica and a resin binder is used.

In the non-optical functional layer of the functional layer 6, in the case of the electromagnetic wave shielding layer, for example, a conductor pattern layer is formed as a function realizing layer on one surface of a transparent support such as a polyethylene terephthalate sheet. For the conductive pattern layer, for example, a conductive composition layer containing conductive particles and a resin binder, which is formed by printing a conductive composition (for example, silver paste) on a transparent support surface in a mesh shape, is used. The plan view shape of the conductor pattern layer is typically a square lattice mesh shape.
For the surface protective layer and the hard coat layer, for example, a thermosetting urethane resin or an ionizing radiation curable resin made of an acrylic resin or the like is used as the curable resin. As the surface protective layer, the transparent support itself can perform its function.

<< Other processes >>
The production method according to the present invention may include other steps other than the steps described above as long as they do not depart from the gist of the present invention. For example, the functional layer 6 is laminated on the surface of the micro louver layer 4 composed of the transparent resin layer 2 and the dark colored stripe 3 via the pressure-sensitive adhesive layer 5, but the functional layer 6 is also disposed on the surface of the transparent substrate 1. May be laminated. Or the process of laminating | stacking the peeling film which protects the surface of the adhesive layer for adhering to another layer or a to-be-adhered body on the surface of the transparent base material 1, or this adhesive layer temporarily until it uses it. Etc.

C. Application The optical sheet 100 having an adhesive layer in contact with the microlouver layer according to the present invention is suitably used for applications arranged on the viewer side of various display panels in an image display device. The display panel is, for example, a plasma display panel, a liquid crystal panel, an EL (electroluminescence) panel, or the like. An image display device equipped with such an optical sheet on the viewer side such as a display panel is a television receiver, measuring device or instrument, office device, medical device, computer device, telephone, electronic signboard, amusement device, It is suitable as an image display device such as a digital photo frame.
In addition, it can also be used for a window of a building such as a house, a school, a hospital, an office, a store, a vehicle, an aircraft, a ship or the like, or a direct sunlight shading sheet.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Transparent resin layer 3 Dark color stripe part 4 Microlouver layer 5 Adhesive layer 5C Adhesive 6 Functional layer 10 Optical sheet 20 Conventional optical sheet 100 Optical sheet which has an adhesive layer in contact with a microlouver layer d Dark line strip direction (overall) dc coating direction e Dark line strip exposed surface N Normal r Recess

Claims (1)

(A) A micro louver layer comprising a plurality of linear dark color stripes arranged in the plane direction parallel to each other in the plane direction and a transparent resin layer supporting the dark color stripes from at least the side surface is a transparent substrate. An optical sheet preparing step for preparing an optical sheet formed on the exposed surface of the dark line portion and having a recessed portion on its exposed surface;
(B) When the pressure-sensitive adhesive is applied to the surface of the optical louver layer of the optical sheet on the side where the dark colored stripes have the concave portions, the pressure-sensitive adhesive layer is previously formed on the substrate. By using the method of transferring the pressure-sensitive adhesive layer from the pressure-sensitive adhesive film, the smaller angle formed between the extending direction of the dark color stripe and the coating direction is in the range of 0 ° to 20 °. adhesive coating step of coating, the
(C) a functional layer laminating step of laminating a functional layer via an adhesive layer,
The manufacturing method of the optical sheet which has an adhesive layer in contact with a microlouver layer which performs each of these processes in this order.

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